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Author |
Siriwardane, E.M.D.; Demiroglu, I.; Sevik, C.; Peeters, F.M.; Çakir, D. |
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Title |
Assessment of sulfur-functionalized MXenes for li-ion battery applications |
Type |
A1 Journal article |
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Year  |
2020 |
Publication |
Journal Of Physical Chemistry C |
Abbreviated Journal |
J Phys Chem C |
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Volume |
124 |
Issue |
39 |
Pages |
21293-21304 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
The surface termination of MXenes greatly determines the electrochemical properties and ion kinetics on their surfaces. So far, hydroxyl-, oxygen-, and fluorine-terminated MXenes have been widely studied for energy storage applications. Recently, sulfur-functionalized MXene structures, which possess low diffusion barriers, have been proposed as candidate materials to enhance battery performance. We performed first-principles calculations on the structural, stability, electrochemical, and ion dynamic properties of Li-adsorbed sulfur-functionalized groups 3B, 4B, 5B, and 6B transition-metal (M)-based MXenes (i.e., M2CS2 with M = Sc, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W). We performed phonon calculations, which indicated that all of the above M2CS2 MXenes, except for Sc, are dynamically stable at T = 0 K. The ground-state structure of each M2CS2 monolayer depends on the type of M atom. For instance, while sulfur prefers to sit at the FCC site on Ti2CS2, it occupies the HCP site of Cr-based MXene. We determined the Li adsorption configurations at different concentrations using the cluster expansion method. The highest maximum open-circuit voltages were computed for the group 4B element (i.e., Ti, Zr, and Hf)-based M2CS2, which are larger than 2.1 V, while their average voltages are approximately 1 V. The maximum voltage for the group 6B element (i.e., Cr, Mo, W)-based M2CS2 is less than 1 V, and the average voltage is less than 0.71 V. We found that S functionalization is helpful for capacity improvements over the O-terminated MXenes. In this respect, the computed storage gravimetric capacity may reach up to 417.4 mAh/g for Ti2CS2 and 404.5 mAh/g for V2CS2. Ta-, Cr-, Mo-, and W-based M2CS2 MXenes show very low capacities, which are less than 100 mAh/g. The Li surface diffusion energy barriers for all of the considered MXenes are less than 0.22 eV, which is favorable for high charging and discharging rates. Finally, ab initio molecular dynamic simulations performed at 400 K and bond-length analysis with respect to Li concentration verify that selected promising systems are robust against thermally induced perturbations that may induce structural transformations or distortions and undesirable Li release. |
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Place of Publication |
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Wos |
000577151900008 |
Publication Date |
2020-09-01 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1932-7447; 1932-7455 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.7 |
Times cited |
15 |
Open Access |
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Notes |
; Computational resources were provided by the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules Foundation. This work was supported, in part, by The Scientific and Technological Research Council of Turkey (TUBITAK) under contract no. 118F512 and the Air Force Office of Scientific Research under award no. FA9550-19-1-7048. This work was performed in part at the Center for Nanoscale Materials, a U.S. Department of Energy Office of Science User. Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract no. DE-AC02-06CH11357. This work was supported, in part, by The Scientific and Technological Research Council of Turkey (TUBITAK) under contract no. 118C026. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 4.536 |
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Call Number |
UA @ admin @ c:irua:172693 |
Serial |
6452 |
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Author |
Sevik, C.; Çakir, D. |
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Title |
Tailoring Storage Capacity and Ion Kinetics in Ti2CO2/Graphene Heterostructures by Functionalization of Graphene |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Physical review applied |
Abbreviated Journal |
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Volume |
12 |
Issue |
1 |
Pages |
014001 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using first-principles calculations, we evaluate the electrochemical performance of heterostructures made up of Ti2CO2 and chemically modified graphene for Li batteries. We find that heteroatom doping and molecule intercalation have a significant impact on the storage capacity and Li migration barrier energies. While N and S doping do not improve the storage capacity, B doping together with molecule interaction make it possible to intercalate two layers of Li, which stick separately to the surface of Ti2CO2 and B-doped graphene. The calculated diffusion-barrier energies (E-diff), which are between 0.3 and 0.4 eV depending on Li concentration, are quite promising for fast charge and discharge rates. Besides, the predicted E-diff as much as 2 eV for the diffusion of the Li atom from the Ti2CO2 surface to the B-doped graphene surface significantly suppresses the interlayer Li migration, which diminishes the charge and discharge rates. The calculated volume and lattice parameter changes indicate that Ti2CO2/graphene hybrid structures exhibit cyclic stability against Li loading and unloading. Consequently, first-principles calculations we perform evidently highlight the favorable effect of molecular intercalation on the capacity improvement of ion batteries. |
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Wos |
000473312000001 |
Publication Date |
2019-07-01 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2331-7019 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:193755 |
Serial |
8640 |
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Author |
Aierken, Y.; Sevik, C.; Gulseren, O.; Peeters, F.M.; Çakir, D. |
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Title |
In pursuit of barrierless transition metal dichalcogenides lateral heterojunctions |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
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Volume |
29 |
Issue |
29 |
Pages |
295202 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
There is an increasing need to understand interfaces between two-dimensional materials to realize an energy efficient boundary with low contact resistance and small heat dissipation. In this respect, we investigated the impact of charge and substitutional atom doping on the electronic transport properties of the hybrid metallic-semiconducting lateral junctions, formed between metallic (1T and 1T(d)) and semiconducting (1H) phases of MoS2 by means of first-principles and non-equilibrium Green function formalism based calculations. Our results clearly revealed the strong influence of the type of interface and crystallographic orientation of the metallic phase on the transport properties of these systems. The Schottky barrier height, which is the dominant mechanism for contact resistance, was found to be as large as 0.63 eV and 1.19 eV for holes and electrons, respectively. We found that armchair interfaces are more conductive as compared to zigzag termination due to the presence of the metallic Mo zigzag chains that are directed along the transport direction. In order to manipulate these barrier heights we investigated the influence of electron doping of the metallic part (i.e. 1T(d) -MoS2). We observed that the Fermi level of the hybrid system moves towards the conduction band of semiconducting 1H-MoS2 due to filling of 4d-orbital of metallic MoS2, and thus the Schottky barrier for electrons decreases considerably. Besides electron doping, we also investigated the effect of substitutional doping of metallic MoS2 by replacing Mo atoms with either Re or Ta. Due to its valency, Re (Ta) behaves as a donor (acceptor) and reduces the Schottky barrier for electrons (holes). Since Re and Ta based transition metal dichalcogenides crystallize in either the 1T(d) or 1T phase, substitutional doping with these atom favors the stabilization of the 1T(d) phase of MoS2. Co-doping of hybrid structure results in an electronic structure, which facilities easy dissociation of excitons created in the 1H part. |
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Place of Publication |
Bristol |
Editor |
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Wos |
000432823800002 |
Publication Date |
2018-05-01 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0957-4484 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.44 |
Times cited |
4 |
Open Access |
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Notes |
; This work was supported by the bilateral project between the The Scientific and Technological Research Council of Turkey (TUBITAK) and FWO-Flanders, Flemish Science Foundation (FWO-VI) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRGrid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. We acknowledge the support from TUBITAK (Grant No. 115F024). ; |
Approved |
Most recent IF: 3.44 |
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Call Number |
UA @ lucian @ c:irua:151451UA @ admin @ c:irua:151451 |
Serial |
5029 |
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Author |
Sarikurt, S.; Çakir, D.; Keceli, M.; Sevik, C. |
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Title |
The influence of surface functionalization on thermal transport and thermoelectric properties of MXene monolayers |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Nanoscale |
Abbreviated Journal |
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Volume |
10 |
Issue |
18 |
Pages |
8859-8868 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
The newest members of a two-dimensional material family, involving transition metal carbides and nitrides (called MXenes), have garnered increasing attention due to their tunable electronic and thermal properties depending on the chemical composition and functionalization. This flexibility can be exploited to fabricate efficient electrochemical energy storage (batteries) and energy conversion (thermoelectric) devices. In this study, we calculated the Seebeck coefficients and lattice thermal conductivity values of oxygen terminated M2CO2 (where M = Ti, Zr, Hf, Sc) monolayer MXene crystals in two different functionalization configurations (model-II (MD-II) and model-III (MD-III)), using density functional theory and Boltzmann transport theory. We estimated the thermoelectric figure-of-merit, zT, of these materials by two different approaches, as well. First of all, we found that the structural model (i.e. adsorption site of oxygen atom on the surface of MXene) has a paramount impact on the electronic and thermoelectric properties of MXene crystals, which can be exploited to engineer the thermoelectric properties of these materials. The lattice thermal conductivity kappa(l), Seebeck coefficient and zT values may vary by 40% depending on the structural model. The MD-III configuration always has the larger band gap, Seebeck coefficient and zT, and smaller kappa(l) as compared to the MD-II structure due to a larger band gap, highly flat valence band and reduced crystal symmetry in the former. The MD-III configuration of Ti2CO2 and Zr2CO2 has the lowest kappa(l) as compared to the same configuration of Hf2CO2 and Sc2CO2. Among all the considered structures, the MD-II configuration of Hf2CO2 has the highest kappa(l), and Ti2CO2 and Zr2CO2 in the MD-III configuration have the lowest kappa(l). For instance, while the band gap of the MD-II configuration of Ti2CO2 is 0.26 eV, it becomes 0.69 eV in MD-III. The zT(max) value may reach up to 1.1 depending on the structural model of MXene. |
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Wos |
000432096400055 |
Publication Date |
2018-04-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2040-3364; 2040-3372 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:193788 |
Serial |
8654 |
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Author |
Aierken, Y.; Sevik, C.; Gulseren, O.; Peeters, F.M.; Çakir, D. |
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Title |
MXenes/graphene heterostructures for Li battery applications : a first principles study |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Journal of materials chemistry A : materials for energy and sustainability |
Abbreviated Journal |
J Mater Chem A |
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Volume |
6 |
Issue |
5 |
Pages |
2337-2345 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
MXenes are the newest class of two-dimensional (2D) materials, and they offer great potential in a wide range of applications including electronic devices, sensors, and thermoelectric and energy storage materials. In this work, we combined the outstanding electrical conductivity, that is essential for battery applications, of graphene with MXene monolayers (M2CX2 where M = Sc, Ti, V and X = OH, O) to explore its potential in Li battery applications. Through first principles calculations, we determined the stable stacking configurations of M2CX2/graphene bilayer heterostructures and their Li atom intercalation by calculating the Li binding energy, diffusion barrier and voltage. We found that: (1) for the ground state stacking, the interlayer binding is strong, yet the interlayer friction is small; (2) Li binds more strongly to the O-terminated monolayer, bilayer and heterostructure MXene systems when compared with the OHterminated MXenes due to the H+ induced repulsion to the Li atoms. The binding energy of Li decreases as the Li concentration increases due to enhanced repulsive interaction between the positively charged Li ions; (3) Ti2CO2/graphene and V2CO2/graphene heterostructures exhibit large Li atom binding energies making them the most promising candidates for battery applications. When fully loaded with Li atoms, the binding energy is -1.43 eV per Li atom and -1.78 eV per Li atom for Ti2CO2/graphene and V2CO2/graphene, respectively. These two heterostructures exhibit a nice compromise between storage capacity and kinetics. For example, the diffusion barrier of Li in Ti2CO2/graphene is around 0.3 eV which is comparable to that of graphite. Additionally, the calculated average voltages are 1.49 V and 1.93 V for Ti2CO2/graphene and V2CO2/graphene structures, respectively; (4) a small change in the in-plane lattice parameters (<1%), interatomic bond lengths and interlayer distances (<0.5 angstrom) proves the stability of the heterostructures against Li intercalation, and the impending phase separation into constituent layers and capacity fading during charge-discharge cycles in real battery applications; (5) as compared to bare M2CX2 bilayers, M2CX2/graphene heterostructures have lower molecular mass, offering high storage capacity; (6) the presence of graphene ensures good electrical conductivity that is essential for battery applications. Given these advantages, Ti2CO2/graphene and V2CO2/graphene heterostructures are predicted to be promising for lithium-ion battery applications. |
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Place of Publication |
Cambridge |
Editor |
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Language |
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Wos |
000423981200049 |
Publication Date |
2018-01-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2050-7488; 2050-7496 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
8.867 |
Times cited |
131 |
Open Access |
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Notes |
; This work was supported by the bilateral project between the Scientific and Technological Research Council of Turkey (TUBITAK) and FWO-Flanders, Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by the TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRGrid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. We acknowledge the support from the TUBITAK (Grant No. 115F024 and 116F080). Part of this work was supported by the BAGEP Award of the Science Academy. ; |
Approved |
Most recent IF: 8.867 |
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Call Number |
UA @ lucian @ c:irua:149265UA @ admin @ c:irua:149265 |
Serial |
4945 |
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Author |
Sevik, C.; Wallbank, J.R.; Gulseren, O.; Peeters, F.M.; Çakir, D. |
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Title |
Gate induced monolayer behavior in twisted bilayer black phosphorus |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
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Volume |
4 |
Issue |
3 |
Pages |
035025 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Optical and electronic properties of black phosphorus strongly depend on the number of layers and type of stacking. Using first-principles calculations within the framework of density functional theory, we investigate the electronic properties of bilayer black phosphorus with an interlayer twist angle of 90 degrees. These calculations are complemented with a simple (k) over right arrow . (p) over right arrow model which is able to capture most of the low energy features and is valid for arbitrary twist angles. The electronic spectrum of 90 degrees twisted bilayer black phosphorus is found to be x-y isotropic in contrast to the monolayer. However x-y anisotropy, and a partial return to monolayer-like behavior, particularly in the valence band, can be induced by an external out-of-plane electric field. Moreover, the preferred hole effective mass can be rotated by 90 degrees simply by changing the direction of the applied electric field. In particular, a +0.4 (-0.4) V angstrom(1) out-of-plane electric field results in a similar to 60% increase in the hole effective mass along the y (x) axis and enhances the m(y)*/m(x)* (m(x)*/m(y)*) ratio as much as by a factor of 40. Our DFT and (k) over right arrow . (p) over right arrow simulations clearly indicate that the twist angle in combination with an appropriate gate voltage is a novel way to tune the electronic and optical properties of bilayer phosphorus and it gives us a new degree of freedom to engineer the properties of black phosphorus based devices. |
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Publisher |
IOP Publishing |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000406926600001 |
Publication Date |
2017-08-03 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2053-1583 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.937 |
Times cited |
13 |
Open Access |
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Notes |
; This work was supported by the bilateral project between the The Scientific and Technological Research Council of Turkey (TUBITAK) and FWO-Flanders, Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRGrid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. We acknowledge the support from TUBITAK (Grant No. 115F024), ERC Synergy grant Hetero2D and the EU Graphene Flagship Project. We also thank Vladimir Fal'ko for helpful discussions. ; |
Approved |
Most recent IF: 6.937 |
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Call Number |
UA @ lucian @ c:irua:145151 |
Serial |
4717 |
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Author |
Michel, K.H.; Çakir, D.; Sevik, C.; Peeters, F.M. |
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Title |
Piezoelectricity in two-dimensional materials : comparative study between lattice dynamics and ab initio calculations |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
95 |
Issue |
95 |
Pages |
125415 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The elastic constant C-11 and piezoelectric stress constant e(1),(11) of two-dimensional (2D) dielectric materials comprising h-BN, 2H-MoS2, and other transition-metal dichalcogenides and dioxides are calculated using lattice dynamical theory. The results are compared with corresponding quantities obtained with ab initio calculations. We identify the difference between clamped-ion and relaxed-ion contributions with the dependence on inner strains which are due to the relative displacements of the ions in the unit cell. Lattice dynamics allows us to express the inner-strain contributions in terms of microscopic quantities such as effective ionic charges and optoacoustical couplings, which allows us to clarify differences in the piezoelectric behavior between h-BN and MoS2. Trends in the different microscopic quantities as functions of atomic composition are discussed. |
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Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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Language |
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Wos |
000396013400005 |
Publication Date |
2017-03-11 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
29 |
Open Access |
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Notes |
; The authors acknowledge useful discussions with L. Wirtz and A. Molina-Sanchez. This work was supported by the Methusalem program and the Fonds voor Wetenschappelijk Onderzoek-Vlaanderen. Computational resources were provided by HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. ; |
Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ lucian @ c:irua:142444 |
Serial |
4603 |
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Author |
Fatima; Oguz, I.C.; Çakir, D.; Hossain, S.; Mohottige, R.; Gulseren, O.; Oncel, N. |
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Title |
On the structural and electronic properties of Ir-silicide nanowires on Si(001) surface |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
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Volume |
120 |
Issue |
120 |
Pages |
095303 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Iridium (Ir) modified Silicon (Si) (001) surface is studied with Scanning Tunneling Microscopy/Spectroscopy (STM/STS) and Density Functional Theory (DFT). A model for Ir-silicide nanowires based on STM images and ab-initio calculations is proposed. According to our model, the Ir adatom is on the top of the substrate dimer row and directly binds to the dimer atoms. I-V curves measured at 77K shows that the nanowires are metallic. DFT calculations confirm strong metallic nature of the nanowires. Published by AIP Publishing. |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000383978100030 |
Publication Date |
2016-09-01 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0021-8979; 1089-7550 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.068 |
Times cited |
7 |
Open Access |
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Notes |
; We gratefully acknowledge the NSF (Grant No. DMR-1306101) for financial support. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. ; |
Approved |
Most recent IF: 2.068 |
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Call Number |
UA @ lucian @ c:irua:137132 |
Serial |
4359 |
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Author |
Sevik, C.; Çakir, D.; Gulseren, O.; Peeters, F.M. |
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Title |
Peculiar piezoelectric properties of soft two-dimensional materials |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
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| |
Volume |
120 |
Issue |
120 |
Pages |
13948-13953 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
Group II-VI semiconductor honeycomb monolayers have a noncentrosymmetric crystal structure and therefore are expected to be important for nano piezoelectric device applications. This motivated us to perform first principles calculations based on density functional theory to unveil the piezoelectric properties (i.e., piezoelectric stress (e(11)) and piezoelectric strain (d(11)) coefficients) of these monolayer materials with chemical formula MX (where M = Be, Mg, Ca, Sr, Ba, Zr, Cd and X = S, Se, Te). We found that these two-dimensional materials have peculiar piezoelectric properties with d(11) coefficients 1 order of magnitude larger than those of commercially utilized bulk materials. A clear trend in their piezoelectric properties emerges, which |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000379457000010 |
Publication Date |
2016-06-09 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1932-7447; 1932-7455 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.536 |
Times cited |
39 |
Open Access |
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| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the Methusalem foundation of the Flemish government and the Bilateral program FWO-TUBITAK between Flanders and Turkey. We acknowledge the support from the Scientific and Technological Research Council of Turkey (TUBITAK-115F024). Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (Cal-cUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. C.S. acknowledges the support from the Scientific and Technological Research Council of Turkey (TUBITAK-113F333) and the support from Anadolu University (BAP-1407F335, -1505F200), and the Turkish Academy of Sciences (TUBA-GEBIP). ; |
Approved |
Most recent IF: 4.536 |
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| |
Call Number |
UA @ lucian @ c:irua:134948 |
Serial |
4222 |
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| Permanent link to this record |
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Author |
Aierken, Y.; Çakir, D.; Peeters, F.M. |
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| |
Title |
Strain enhancement of acoustic phonon limited mobility in monolayer TiS3 |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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| |
Volume |
18 |
Issue |
18 |
Pages |
14434-14441 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Strain engineering is an effective way to tune the intrinsic properties of a material. Here, we show by using first-principles calculations that both uniaxial and biaxial tensile strain applied to monolayer TiS3 are able to significantly modify its intrinsic mobility. From the elastic modulus and the phonon dispersion relation we determine the tensile strain range where structure dynamical stability of the monolayer is guaranteed. Within this region, we find more than one order of enhancement of the acoustic phonon limited mobility at 300 K (100 K), i.e. from 1.71 x 10(4) (5.13 x 10(4)) cm(2) V-1 s(-1) to 5.53 x 10(6) (1.66 x 10(6)) cm(2) V-1 s(-1). The degree of anisotropy in both mobility and effective mass can be tuned by using tensile strain. Furthermore, we can either increase or decrease the band gap of TiS3 monolayer by applying strain along different crystal directions. This property allows us to use TiS3 not only in electronic but also in optical applications. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge |
Editor |
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Language |
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Wos |
000378102700036 |
Publication Date |
2016-05-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
|
| |
ISSN |
1463-9076 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.123 |
Times cited |
24 |
Open Access |
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Notes |
; This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-V1). Computational resources were provided by HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation and the Flemish Government-department EWI. ; |
Approved |
Most recent IF: 4.123 |
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| |
Call Number |
UA @ lucian @ c:irua:134628 |
Serial |
4250 |
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| Permanent link to this record |
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Author |
Çakir, D.; Sevik, C.; Gulseren, O.; Peeters, F.M. |
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| |
Title |
Mo2C as a high capacity anode material: a first-principles study |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Journal of materials chemistry A : materials for energy and sustainability |
Abbreviated Journal |
J Mater Chem A |
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| |
Volume |
4 |
Issue |
16 |
Pages |
6029-6035 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
The adsorption and diffusion of Li, Na, K and Ca atoms on a Mo2C monolayer are systematically investigated by using first principles methods. We found that the considered metal atoms are strongly bound to the Mo2C monolayer. However, the adsorption energies of these alkali and earth alkali elements decrease as the coverage increases due to the enhanced repulsion between the metal ions. We predict a significant charge transfer from the ad-atoms to the Mo2C monolayer, which indicates clearly the cationic state of the metal atoms. The metallic character of both pristine and doped Mo2C ensures a good electronic conduction that is essential for an optimal anode material. Low migration energy barriers are predicted as small as 43 meV for Li, 19 meV for Na and 15 meV for K, which result in the very fast diffusion of these atoms on Mo2C. For Mo2C, we found a storage capacity larger than 400 mA h g(-1) by the inclusion of multilayer adsorption. Mo2C expands slightly upon deposition of Li and Na even at high concentrations, which ensures the good cyclic stability of the atomic layer. The calculated average voltage of 0.68 V for Li and 0.30 V for Na ions makes Mo2C attractive for low charging voltage applications. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge |
Editor |
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Language |
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Wos |
000374790700033 |
Publication Date |
2016-03-18 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2050-7488; 2050-7496 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
8.867 |
Times cited |
202 |
Open Access |
|
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| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. C. S. acknowledges the support from Turkish Academy of Sciences (TUBA-GEBIP). C. S acknowledges the support from Anadolu University (Grant No. 1407F335). We acknowledge the support from TUBITAK, The Scientific and Technological Research Council of Turkey (Grant No. 115F024). ; |
Approved |
Most recent IF: 8.867 |
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| |
Call Number |
UA @ lucian @ c:irua:144763 |
Serial |
4669 |
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| Permanent link to this record |
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Author |
Çakir, D.; Sevik, C.; Peeters, F.M. |
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Title |
Significant effect of stacking on the electronic and optical properties of few-layer black phosphorus |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
92 |
Issue |
92 |
Pages |
165406 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The effect of the number of stacking layers and the type of stacking on the electronic and optical properties of bilayer and trilayer black phosphorus are investigated by using first-principles calculations within the framework of density functional theory. We find that inclusion of many-body effects (i.e., electron-electron and electron-hole interactions) modifies strongly both the electronic and optical properties of black phosphorus. While trilayer black phosphorus with a particular stacking type is found to be a metal by using semilocal functionals, it is predicted to have an electronic band gap of 0.82 eV when many-body effects are taken into account within the G(0)W(0) scheme. Though different stacking types result in similar energetics, the size of the band gap and the optical response of bilayer and trilayer phosphorene are very sensitive to the number of layers and the stacking type. Regardless of the number of layers and the type of stacking, bilayer and trilayer black phosphorus are direct band gap semiconductors whose band gaps vary within a range of 0.3 eV. Stacking arrangements that are different from the ground state structure in both bilayer and trilayer black phosphorus exhibit significant modified valence bands along the zigzag direction and result in larger hole effective masses. The optical gap of bilayer (trilayer) black phosphorus varies by 0.4 (0.6) eV when changing the stacking type. The calculated binding energy of the bound exciton hardly changes with the type of stacking and is found to be 0.44 (0.30) eV for bilayer (trilayer) phosphorous. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000362435300005 |
Publication Date |
2015-10-08 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121; 1550-235x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
127 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. C.S. acknowledges support from Turkish Academy of Sciences (TUBA-GEBIP). ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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| |
Call Number |
UA @ lucian @ c:irua:128320 |
Serial |
4242 |
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| Permanent link to this record |
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Author |
Çakir, D.; Peeters, F.M. |
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Title |
Fluorographane : a promising material for bipolar doping of MoS2 |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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Volume |
17 |
Issue |
17 |
Pages |
27636-27641 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using first principles calculations we investigate the structural and electronic properties of interfaces between fluorographane and MoS2. Unsymmetrical functionalization of graphene with H and F results in an intrinsic dipole moment perpendicular to the plane of the buckled graphene skeleton. Depending on the orientation of this dipole moment, the electronic properties of a physically absorbed MoS2 monolayer can be switched from n-to p-type or vice versa. We show that one can realize vanishing n-type/p-type Schottky barrier heights when contacting MoS2 to fluorographane. By applying a perpendicular electric field, the size of the Schottky barrier and the degree of doping can be tuned. Our calculations indicate that a fluorographane monolayer is a promising candidate for bipolar doping of MoS2, which is vital in the design of novel technological applications based on two-dimensional materials. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge |
Editor |
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Language |
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Wos |
000363193800043 |
Publication Date |
2015-09-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1463-9076 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.123 |
Times cited |
7 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRGrid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. ; |
Approved |
Most recent IF: 4.123; 2015 IF: 4.493 |
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Call Number |
UA @ lucian @ c:irua:129477 |
Serial |
4182 |
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| Permanent link to this record |
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Author |
Chaves, A.; Low, T.; Avouris, P.; Çakir, D.; Peeters, F.M. |
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Title |
Anisotropic exciton Stark shift in black phosphorus |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
91 |
Issue |
91 |
Pages |
155311 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We calculate the excitonic spectrum of few-layer black phosphorus by direct diagonalization of the effective mass Hamiltonian in the presence of an applied in-plane electric field. The strong attractive interaction between electrons and holes in this system allows one to investigate the Stark effect up to very high ionizing fields, including also the excited states. Our results show that the band anisotropy in black phosphorus becomes evident in the direction-dependent field-induced polarizability of the exciton. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000353459200005 |
Publication Date |
2015-04-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121; 1550-235x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
88 |
Open Access |
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Notes |
; Discussions with J. M. Pereira Jr. and J. S. de Souza are gratefully acknowledged. This work was supported by the Brazilian Council for Research (CNPq) through the PQ and Science Without Borders programs, the Flemish Science Foundation (FWO-Vl), the Methusalem programme of the Flemish government, and the Bilateral program (CNPq-FWO) between Flanders and Brazil. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:132506 |
Serial |
4141 |
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Author |
Çakir, D.; Kecik, D.; Sahin, H.; Durgun, E.; Peeters, F.M. |
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Title |
Realization of a p-n junction in a single layer boron-phosphide |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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Volume |
17 |
Issue |
17 |
Pages |
13013-13020 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Two-dimensional (2D) materials have attracted growing interest due to their potential use in the next generation of nanoelectronic and optoelectronic applications. On the basis of first-principles calculations based on density functional theory, we first investigate the electronic and mechanical properties of single layer boron phosphide (h-BP). Our calculations show that h-BP is a mechanically stable 2D material with a direct band gap of 0.9 eV at the K-point, promising for both electronic and optoelectronic applications. We next investigate the electron transport properties of a p-n junction constructed from single layer boron phosphide (h-BP) using the non-equilibrium Green's function formalism. The n-and p-type doping of BP are achieved by substitutional doping of B with C and P with Si, respectively. C(Si) substitutional doping creates donor (acceptor) states close to the conduction (valence) band edge of BP, which are essential to construct an efficient p-n junction. By modifying the structure and doping concentration, it is possible to tune the electronic and transport properties of the p-n junction which exhibits not only diode characteristics with a large current rectification but also negative differential resistance (NDR). The degree of NDR can be easily tuned via device engineering. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge |
Editor |
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Language |
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Wos |
000354195300065 |
Publication Date |
2015-04-16 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1463-9076;1463-9084; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.123 |
Times cited |
104 |
Open Access |
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| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the Methusalem foundation of the Flemish government and the Bilateral program FWO-TUBITAK (under the Project No. 113T050) between Flanders and Turkey. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. D.C. is supported by a FWO Pegasus-short Marie Curie Fellowship. H.S. is supported by a FWO Pegasus Marie Curie-long Fellowship. E.D. acknowledges support from Bilim Akademisi – The Science Academy, Turkey under the BAGEP program. ; |
Approved |
Most recent IF: 4.123; 2015 IF: 4.493 |
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Call Number |
c:irua:126394 |
Serial |
2835 |
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Author |
Nicholls, D.; Li, R.R.; Ware, B.; Pansegrau, C.; Çakir, D.; Hoffmann, M.R.; Oncel, N. |
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Title |
Scanning tunneling microscopy and density functional theory study on zinc(II)-phthalocyanine tetrasulfonic acid on bilayer epitaxial graphene on silicon carbide(0001) |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
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Volume |
119 |
Issue |
119 |
Pages |
9845-9850 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Zinc(II)-phthalocyanine tetrasulfonic acid (Zn-PcS) molecules physisorbed on bilayer epitaxial graphene on silicon carbide (SiC(0001)) were studied by using scanning tunneling microscopy/spectroscopy (STM/STS) and density functional theory (DFT). Two different methods were used to deposit Zn-PcS molecules and regardless of the method being used, the surface coverage stayed very low indicating the weakness of surface-molecule interaction. STS measurements revealed that derivative of tunneling current with respect to voltage (dI/dV) measured on Zn-PcS molecules did not exhibit the characteristic dip observed on dI/dV curves of pristine bilayer epitaxial graphene. DFT calculations show that the energy of the lowest unoccupied molecular orbital (LUMO) of the Zn-PcS molecule is below the Dirac point of graphene which enhances local density of states (LDOS). We attribute the disappearance of the dip in the dI/dV curves measured on the Zn-PcS/bilayer system to the LUMO of Zn-PcS. Charge density calculations along Zn-PcS/graphene interface reveal that there is a small charge transfer from graphene to the molecule. Calculated adsorption energy (3.13 eV) of the molecule is notably low and is consistent with the observed low surface coverage at room temperature. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000354339000020 |
Publication Date |
2015-04-15 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1932-7447;1932-7455; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.536 |
Times cited |
3 |
Open Access |
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| |
Notes |
; We gratefully acknowledge the NSF (Grant Nos.: DMR-1306101, EPS-814442, and EPS-1354366) for financial support. ; |
Approved |
Most recent IF: 4.536; 2015 IF: 4.772 |
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| |
Call Number |
c:irua:126370 |
Serial |
2947 |
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| Permanent link to this record |
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Author |
Çakir, D.; Otalvaro, D.M.; Brocks, G. |
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Title |
Magnetoresistance in multilayer fullerene spin valves: A first-principles study |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
24 |
Pages |
245404 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Carbon-based molecular semiconductors are explored for application in spintronics because their small spinorbit coupling promises long spin lifetimes. We calculate the electronic transport from first principles through spin valves comprising bi-and tri-layers of the fullerene molecules C-60 and C-70, sandwiched between two Fe electrodes. The spin polarization of the current, and the magnetoresistance depend sensitively on the interactions at the interfaces between the molecules and the metal surfaces. They are much less affected by the thickness of the molecular layers. A high current polarization (CP > 90%) and magnetoresistance (MR > 100%) at small bias can be attained using C-70 layers. In contrast, the current polarization and the magnetoresistance at small bias are vanishingly small for C-60 layers. Exploiting a generalized Julliere model we can trace the differences in spin-dependent transport between C-60 and C-70 layers to differences between the molecule-metal interface states. These states also allow one to interpret the current polarization and the magnetoresistance as a function of the applied bias voltage. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000345875200005 |
Publication Date |
2014-12-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
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| |
Notes |
; ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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| |
Call Number |
UA @ lucian @ c:irua:122177 |
Serial |
1928 |
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| Permanent link to this record |
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Author |
Çakir, D.; Sahin, H.; Peeters, F.M. |
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Title |
Tuning of the electronic and optical properties of single-layer black phosphorus by strain |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
90 |
Issue |
20 |
Pages |
205421 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Using first principles calculations we showed that the electronic and optical properties of single-layer black phosphorus (BP) depend strongly on the applied strain. Due to the strong anisotropic atomic structure of BP, its electronic conductivity and optical response are sensitive to the magnitude and the orientation of the applied strain. We found that the inclusion of many body effects is essential for the correct description of the electronic properties of monolayer BP; for example, while the electronic gap of strainless BP is found to be 0.90 eV by using semilocal functionals, it becomes 2.31 eV when many-body effects are taken into account within the G(0)W(0) scheme. Applied tensile strain was shown to significantly enhance electron transport along zigzag direction of BP. Furthermore, biaxial strain is able to tune the optical band gap of monolayer BP from 0.38 eV (at -8% strain) to 2.07 eV (at 5.5%). The exciton binding energy is also sensitive to the magnitude of the applied strain. It is found to be 0.40 eV for compressive biaxial strain of -8%, and it becomes 0.83 eV for tensile strain of 4%. Our calculations demonstrate that the optical response of BP can be significantly tuned using strain engineering which appears as a promising way to design novel photovoltaic devices that capture a broad range of solar spectrum. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
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Wos |
000345642000015 |
Publication Date |
2014-11-17 |
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| |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
219 |
Open Access |
|
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. H.S. is supported by a FWO Pegasus Marie Curie-long Fellowship. D.C. is supported by a FWO Pegasus-short Marie Curie Fellowship. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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| |
Call Number |
UA @ lucian @ c:irua:122203 |
Serial |
3752 |
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| Permanent link to this record |
| |
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| |
|
Author |
Çakir, D.; Sevik, C.; Peeters, F.M. |
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| |
Title |
Engineering electronic properties of metal-MoSe2 interfaces using self-assembled monolayers |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Journal of materials chemistry C : materials for optical and electronic devices |
Abbreviated Journal |
J Mater Chem C |
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| |
Volume |
2 |
Issue |
46 |
Pages |
9842-9849 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Metallic contacts are critical components of electronic devices and the presence of a large Schottky barrier is detrimental for an optimal device operation. Here, we show by using first-principles calculations that a self-assembled monolayer (SAM) of polar molecules between the metal electrode and MoSe2 monolayer is able to convert the Schottky contact into an almost Ohmic contact. We choose -CH3 and -CF3 terminated short-chain alkylthiolate (i.e. SCH3 and fluorinated alkylthiolates (SCF3)) based SAMs to test our approach. We consider both high (Au) and low (Sc) work function metals in order to thoroughly elucidate the role of the metal work function. In the case of Sc, the Fermi level even moves into the conduction band of the MoSe2 monolayer upon SAM insertion between the metal surface and the MoSe2 monolayer, and hence possibly switches the contact type from Schottky to Ohmic. The usual Fermi level pinning at the metal-transition metal dichalcogenide (TMD) contact is shown to be completely removed upon the deposition of a SAM. Systematic analysis indicates that the work function of the metal surface and the energy level alignment between the metal electrode and the TMD monolayer can be tuned significantly by using SAMs as a buffer layer. These results clearly indicate the vast potential of the proposed interface engineering to modify the physical and chemical properties of MoSe2. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000344998700007 |
Publication Date |
2014-10-16 |
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| |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
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| |
ISSN |
2050-7526;2050-7534; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
5.256 |
Times cited |
22 |
Open Access |
|
|
| |
Notes |
; Part of this work is supported by the Flemish Science Foundation (FWO-VI) and the Methusalem foundation of the Flemish Government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). D. C. is supported by a FWO Pegasus-short Marie Curie Fellowship. C. S. acknowledges the support from Scientific and Technological Research Council of Turkey (TUBITAK 113F096), Anadolu University (BAP-1306F281, -1404F158) and Turkish Academy of Science (TUBA). ; |
Approved |
Most recent IF: 5.256; 2014 IF: 4.696 |
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| |
Call Number |
UA @ lucian @ c:irua:122157 |
Serial |
1046 |
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| Permanent link to this record |
| |
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| |
|
Author |
Çakir, D.; Sahin, H.; Peeters, F.M. |
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| |
Title |
Doping of rhenium disulfide monolayers : a systematic first principles study |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
| |
Volume |
16 |
Issue |
31 |
Pages |
16771-16779 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
The absence of a direct-to-indirect band gap transition in ReS2 when going from the monolayer to bulk makes it special among the other semiconducting transition metal dichalcogenides. The functionalization of this promising layered material emerges as a necessity for the next generation technological applications. Here, the structural, electronic, and magnetic properties of substitutionally doped ReS2 monolayers at either the S or Re site were systematically studied by using first principles density functional calculations. We found that substitutional doping of ReS2 depends sensitively on the growth conditions of ReS2. Among the large number of non-metallic atoms, namely H, B, C, Se, Te, F, Br, Cl, As, P. and N, we identified the most promising candidates for n-type and p-type doping of ReS2. While Cl is an ideal candidate for n-type doping, P appears to be the most promising candidate for p-type doping of the ReS2 monolayer. We also investigated the doping of ReS2 with metal atoms, namely Mo, W, Ti, V. Cr, Co, Fe, Mn, Ni, Cu, Nb, Zn, Ru, Os and Pt. Mo, Nb, Ti, and V atoms are found to be easily incorporated in a single layer of ReS2 as substitutional impurities at the Re site for all growth conditions considered in this work. Tuning chemical potentials of dopant atoms energetically makes it possible to dope ReS2 with Fe, Co, Cr, Mn, W, Ru, and Os at the Re site. We observe a robust trend for the magnetic moments when substituting a Re atom with metal atoms such that depending on the electronic configuration of dopant atoms, the net magnetic moment of the doped ReS2 becomes either 0 or 1 mu(B). Among the metallic dopants, Mo is the best candidate for p-type doping of ReS2 owing to its favorable energetics and promising electronic properties. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge |
Editor |
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| |
Language |
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Wos |
000340075700048 |
Publication Date |
2014-07-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1463-9076;1463-9084; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.123 |
Times cited |
58 |
Open Access |
|
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| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-VI) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. H.S. is supported by a FWO Pegasus-long Marie Curie Fellowship. D.C. is supported by a FWO Pegasus-short Marie Curie Fellowship. ; |
Approved |
Most recent IF: 4.123; 2014 IF: 4.493 |
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| |
Call Number |
UA @ lucian @ c:irua:118742 |
Serial |
752 |
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| Permanent link to this record |
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Author |
Oncel, N.; Çakir, D.; Dil, J.H.; Slomski, B.; Landolt, G. |
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| |
Title |
Angle-resolved synchrotron photoemission and density functional theory on the iridium modified Si(111) surface |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
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| |
Volume |
26 |
Issue |
28 |
Pages |
285501 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The physical and electronic properties of the Ir modified Si(1 1 1) surface have been investigated with the help of angle resolved photoemission spectroscopy and density functional theory. The surface consists of Ir-ring clusters that form a root 7 x root 7 -R19.1 degrees reconstruction. A comparison between the measured and calculated band structure of the system reveals that the dispersions of the projected bulk states and the states originating from '1x1' domains are heavily modified due to Umklapp scattering from the surface Brillouin zone. Density of states calculations show that Ir-ring clusters contribute to the states in the vicinity of the Fermi level. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000338830300019 |
Publication Date |
2014-06-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0953-8984;1361-648X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.649 |
Times cited |
4 |
Open Access |
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| |
Notes |
; This work was partially supported by the National Science Foundation (DMR-1306101), North Dakota EPSCoR office (NSF grant #EPS-814442), the University of North Dakota and the Swiss National Science Foundation. Computer resources used in this work partially provided by Computational Research Center (HPC-Linux cluster) at UND and TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). ; |
Approved |
Most recent IF: 2.649; 2014 IF: 2.346 |
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| |
Call Number |
UA @ lucian @ c:irua:118636 |
Serial |
114 |
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| Permanent link to this record |
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Author |
Çakir, D.; Peeters, F.M. |
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| |
Title |
Dependence of the electronic and transport properties of metal-MoSe2 interfaces on contact structures |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
89 |
Issue |
24 |
Pages |
245403 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Transition metal dichalcogenides (TMDs) are considered as promising candidates for next generation of electronic and optoelectronic devices. To make use of these materials, for instance in field effect transistor applications, it is mandatory to know the detailed properties of contacts of such TMDs with metal electrodes. Here, we investigate the role of the contact structure on the electronic and transport properties of metal-MoSe2 interfaces. Two different contact types, namely face and edge contacts, are studied. We consider both low (Sc) and high (Au) work function metals in order to thoroughly elucidate the role of the metal work function and the type of metal. First principles plane wave calculations and transport calculations based on nonequilibrium Green's function formalism reveal that the contact type has a large impact on the electronic and transport properties of metal-MoSe2 interfaces. For the Sc electrode, the Schottky barrier heights are around 0.25 eV for face contact and bigger than 0.6 eV for edge contact. For the Au case, we calculate very similar barrier heights for both contact types with an average value of 0.5 eV. Furthermore, while the face contact is found to be highly advantageous as compared to the edge contact for the Sc electrode, the latter contact becomes a better choice for the Au electrode. Our findings provide guidelines for the fabrication of TMD-based devices. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000336917700004 |
Publication Date |
2014-06-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
39 |
Open Access |
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| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. D. C. is supported by a FWO Pegasus-short Marie Curie Fellowship. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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| |
Call Number |
UA @ lucian @ c:irua:117750 |
Serial |
644 |
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| Permanent link to this record |
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Author |
Çakir, D.; Peeters, F.M.; Sevik, C. |
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Title |
Mechanical and thermal properties of h-MX2 (M = Cr, Mo, W; X = O, S, Se, Te) monolayers : a comparative study |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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| |
Volume |
104 |
Issue |
20 |
Pages |
203110 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using density functional theory, we obtain the mechanical and thermal properties of MX2 monolayers (where M = Cr, Mo, W and X = O, S, Se, Te). The C-centered phonon frequencies (i.e., A(1), A(2)'', E ', and E ''), relative frequency values of A(1), and E ' modes, and mechanical properties (i.e., elastic constants, Young modulus, and Poisson's ratio) display a strong dependence on the type of metal and chalcogenide atoms. In each chalcogenide (metal) group, transition-metal dichalcogenides (TMDCs) with W (O) atom are found to be much stiffer. Consistent with their stability, the thermal expansion of lattice constants for TMDCs with O (Te) is much slower (faster). Furthermore, in a heterostructure of these materials, the difference of the thermal expansion of lattice constants between the individual components becomes quite tiny over the whole temperature range. The calculated mechanical and thermal properties show that TMDCs are promising materials for heterostructures. (C) 2014 AIP Publishing LLC. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000337140800063 |
Publication Date |
2014-05-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0003-6951;1077-3118; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.411 |
Times cited |
130 |
Open Access |
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| |
Notes |
; Cem Sevik acknowledges the support from Scientific and Technological Research Council of Turkey (TUBITAK-113F096) and Anadolu University (BAP-1306F261 and -1306F281) to this project. We would also like to thank the ULAKBIM High Performance and Grid Computing Center for a generous time allocation for our projects. D. C. was supported by a FWO Pegasus-short Marie Curie Fellowship. Part of this work was supported by the Methusalem foundation of the Flemish Government. ; |
Approved |
Most recent IF: 3.411; 2014 IF: 3.302 |
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| |
Call Number |
UA @ lucian @ c:irua:118379 |
Serial |
1974 |
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| Permanent link to this record |
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Author |
Horzum, S.; Çakir, D.; Suh, J.; Tongay, S.; Huang, Y.-S.; Ho, C.-H.; Wu, J.; Sahin, H.; Peeters, F.M. |
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| |
Title |
Formation and stability of point defects in monolayer rhenium disulfide |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
89 |
Issue |
15 |
Pages |
155433 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Recently, rhenium disulfide (ReS2) monolayers were experimentally extracted by conventional mechanical exfoliation technique from as-grown ReS2 crystals. Unlike the well-known members of transition metal dichalcogenides (TMDs), ReS2 crystallizes in a stable distorted-1T structure and lacks an indirect to direct gap crossover. Here we present an experimental and theoretical study of the formation, energetics, and stability of the most prominent lattice defects in monolayer ReS2. Experimentally, irradiation with 3-MeV He+2 ions was used to break the strong covalent bonds in ReS2 flakes. Photoluminescence measurements showed that the luminescence from monolayers is mostly unchanged after highly energetic a particle irradiation. In order to understand the energetics of possible vacancies in ReS2 we performed systematic first-principles calculations. Our calculations revealed that the formation of a single sulfur vacancy has the lowest formation energy in both Re and S rich conditions and a random distribution of such defects are energetically more preferable. Sulfur point defects do not result in any spin polarization whereas the creation of Re-containing point defects induce magnetization with a net magnetic moment of 1-3 mu B. Experimentally observed easy formation of sulfur vacancies is in good agreement with first-principles calculations. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000337301200009 |
Publication Date |
2014-04-28 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
130 |
Open Access |
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| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the bilateral project FWO-TUBITAK, and the Methusalem Foundation of the Flemish government. Computational resources were provided by TUBITAK ULAK-BIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H. S. was supported by a FWO Pegasus Long Marie Curie Fellowship. D. C. was supported by a FWO Pegasus-short Marie Curie Fellowship. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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| |
Call Number |
UA @ lucian @ c:irua:118410 |
Serial |
1250 |
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| Permanent link to this record |
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Author |
Çakir, D.; Otalvaro, D.M.; Brocks, G. |
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Title |
From spin-polarized interfaces to giant magnetoresistance in organic spin valves |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
89 |
Issue |
11 |
Pages |
115407 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We calculate the spin-polarized electronic transport through a molecular bilayer spin valve from first principles, and establish the link between the magnetoresistance and the spin-dependent interactions at the metal-molecule interfaces. The magnetoresistance of a Fe vertical bar bilayer-C-70 vertical bar Fe spin valve attains a high value of 70% in the linearresponse regime, but it drops sharply as a function of the applied bias. The current polarization has a value of 80% in linear response and also decreases as a function of bias. Both these trends can be modeled in terms of prominent spin-dependent Fe vertical bar C-70 interface states close to the Fermi level, unfolding the potential of spinterface science to control and optimize spin currents. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000332504900007 |
Publication Date |
2014-03-10 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1098-0121; 1550-235x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
14 |
Open Access |
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| |
Notes |
; ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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| |
Call Number |
UA @ lucian @ c:irua:128321 |
Serial |
4596 |
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| Permanent link to this record |
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Author |
Lawson, N.C.; Janyavula, S.; Çakir, D.; Burgess, J.O. |
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Title |
An analysis of the physiologic parameters of intraoral wear: a review |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
Journal Of Physics D-Applied Physics |
Abbreviated Journal |
J Phys D Appl Phys |
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Volume |
46 |
Issue |
40 |
Pages |
Unsp 404007 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
This paper reviews the conditions of in vivo mastication and describes a novel method of measuring in vitro wear. Methods: parameters of intraoral wear are reviewed in this analysis, including chewing force, tooth sliding distance, food abrasivity, saliva lubrication, and antagonist properties. Results: clinical measurement of mastication forces indicates a range of normal forces between 20 and 140 N for a single molar. During the sliding phase of mastication, horizontal movement has been measured between 0.9 and 2.86 mm. In vivo wear occurs by three-body abrasion when food particles are interposed between teeth and by two-body abrasion after food clearance. Analysis of food particles used in wear testing reveals that food particles are softer than enamel and large enough to separate enamel and restoration surfaces and act as a solid lubricant. In two-body wear, saliva acts as a boundary lubricant with a viscosity of 3 cP. Enamel is the most relevant antagonist material for wear testing. The shape of a palatal cusp has been estimated as a 0.6 mm diameter ball and the hardest region of a tooth is its enamel surface. pH values and temperatures have been shown to range between 2-7 and 5-55 degrees C in intraoral fluids, respectively. These intraoral parameters have been used to modify the Alabama wear testing method. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
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Publication Date |
2013-09-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0022-3727 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.588 |
Times cited |
|
Open Access |
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| |
Notes |
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Approved |
Most recent IF: 2.588; 2013 IF: 2.521 |
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| |
Call Number |
UA @ lucian @ c:irua:128322 |
Serial |
4585 |
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| Permanent link to this record |
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Author |
Lindell, L.; Çakir, D.; Brocks, G.; Fahlman, M.; Braun, S. |
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| |
Title |
Role of intrinsic molecular dipole in energy level alignment at organic interfaces |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
Applied Physics Letters |
Abbreviated Journal |
Appl Phys Lett |
|
| |
Volume |
102 |
Issue |
22 |
Pages |
223301 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The energy level alignment in metal-organic and organic-organic junctions of the widely used materials tris-(8-hydroxyquinoline) aluminum (Alq(3)) and 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) is investigated. The measured alignment schemes for single and bilayer films of Alq(3) and NTCDA are interpreted with the integer charge transfer (ICT) model. Single layer films of Alq(3) feature a constant vacuum level shift of similar to 0.2-0.4 eV in the absence of charge transfer across the interface. This finding is attributed to the intrinsic dipole of the Alq(3) molecule and (partial) ordering of the molecules at the interfaces. The vacuum level shift changes the onset of Fermi level pinning, as it changes the energy needed for equilibrium charge transfer across the interface. (C) 2013 AIP Publishing LLC. |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000320621600081 |
Publication Date |
2013-06-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-6951; 1077-3118 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.411 |
Times cited |
22 |
Open Access |
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Notes |
; We acknowledge funding from the European Community's Framework Programme under Grant No. FP7-NMP-228424 of the MINOTOR project as well as a project grant from the Swedish Energy Agency, STEM. ; |
Approved |
Most recent IF: 3.411; 2013 IF: 3.515 |
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Call Number |
UA @ lucian @ c:irua:128323 |
Serial |
4605 |
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Author |
Celebi, S.; Sezgin, M.E.; Çakir, D.; Baytan, B.; Demirkaya, M.; Sevinir, B.; Bozdemir, S.E.; Gunes, A.M.; Hacimustafaoglu, M. |
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Title |
Catheter-associated bloodstream infections in pediatric hematology-oncology patients |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Pediatric Hematology And Oncology |
Abbreviated Journal |
Pediatr Hemat Oncol |
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Volume |
30 |
Issue |
3 |
Pages |
187-194 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Catheter-associated bloodstream infections (CABSIs) are common complications encountered with cancer treatment. The aims of this study were to analyze the factors associated with recurrent infection and catheter removal in pediatric hematology-oncology patients. All cases of CABSIs in patients attending the Department of Pediatric Hematology-Oncology between January 2008 and December 2010 were reviewed. A total of 44 episodes of CABSIs, including multiple episodes involving the same catheter, were identified in 31 children with cancer. The overall CABSIs rate was 7.4 infections per 1000 central venous catheter (CVC) days. The most frequent organism isolated was coagulase-negative Staphylococcus (CONS). The CVC was removed in nine (20.4%) episodes. We found that hypotension, persistent bacteremia, Candida infection, exit-side infection, neutropenia, and prolonged duration of neutropenia were the factors for catheter removal. There were 23 (52.2%) episodes of recurrence or reinfection. Mortality rate was found to be 9.6% in children with CABSIs. In this study, we found that CABSIs rate was 7.4 infections per 1000 catheter-days. CABSIs rates in our hematology-oncology patients are comparable to prior reports. Because CONS is the most common isolated microorganism in CABSIs, vancomycin can be considered part of the initial empirical regimen. |
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Publisher |
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Place of Publication |
New York |
Editor |
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Language |
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Wos |
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Publication Date |
2013-04-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0888-0018 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.12 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 1.12; 2013 IF: 0.963 |
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Call Number |
UA @ lucian @ c:irua:128324 |
Serial |
4589 |
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Author |
Janyavula, S.; Lawson, N.; Çakir, D.; Beck, P.; Ramp, L.C.; Burgess, J.O. |
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Title |
The wear of polished and glazed zirconia against enamel |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Journal Of Prosthetic Dentistry |
Abbreviated Journal |
J Prosthet Dent |
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Volume |
109 |
Issue |
1 |
Pages |
22-29 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Statement of problem. The wear of tooth structure opposing anatomically contoured zirconia crowns requires further investigation. Purpose. The purpose of this in vitro study was to measure the roughness and wear of polished, glazed, and polished then reglazed zirconia against human enamel antagonists and compare the measurements to those of veneering porcelain and natural enamel. Material and methods. Zirconia specimens were divided into polished, glazed, and polished then reglazed groups (n=8). A veneering porcelain (Ceramco3) and enamel were used as controls. The surface roughness of all pretest specimens was measured. Wear testing was performed in the newly designed Alabama wear testing device. The mesiobuccal cusps of extracted molars were standardized and used as antagonists. Three-dimensional (3D) scans of the specimens and antagonists were obtained at baseline and after 200 000 and 400 000 cycles with a profilometer. The baseline scans were superimposed on the posttesting scans to determine volumetric wear. Data were analyzed with a 1-way ANOVA and Tukey Honestly Significant Difference (HSD) post hoc tests (alpha=.05) Results. Surface roughness ranked in order of least rough to roughest was: polished zirconia, glazed zirconia, polished then reglazed zirconia, veneering porcelain, and enamel. For ceramic, there was no measureable loss on polished zirconia, moderate loss on the surface of enamel, and significant loss on glazed and polished then reglazed zirconia. The highest ceramic wear was exhibited by the veneering ceramic. For enamel antagonists, polished zirconia caused the least wear, and enamel caused moderate wear. Glazed and polished then reglazed zirconia showed significant opposing enamel wear, and veneering porcelain demonstrated the most. Conclusions. Within the limitations of the study, polished zirconia is wear-friendly to the opposing tooth. Glazed zirconia causes more material and antagonist wear than polished zirconia. The surface roughness of the zirconia aided in predicting the wear of the opposing dentition. (J Prosthet Dent 2013;109:22-29) |
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Publisher |
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Place of Publication |
St. Louis, Mo. |
Editor |
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Language |
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Wos |
000313934900004 |
Publication Date |
2013-01-15 |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0022-3913 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.095 |
Times cited |
89 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 2.095; 2013 IF: 1.419 |
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Call Number |
UA @ lucian @ c:irua:128327 |
Serial |
4612 |
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Author |
Tran, T.L.A.; Çakir, D.; Wong, P.K.J.; Preobrajenski, A.B.; Brocks, G.; van der Wiel, W.G.; de Jong, M.P. |
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Title |
Magnetic properties of bcc-Fe(001)/C-60 interfaces for organic spintronics |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Acs Applied Materials & Interfaces |
Abbreviated Journal |
Acs Appl Mater Inter |
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Volume |
5 |
Issue |
3 |
Pages |
837-841 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The magnetic structure of the interfaces between organic semiconductors and ferromagnetic contacts plays a key role in the spin injection and extraction processes in organic spintronic devices. We present a combined computational (density functional theory) and experimental (X-ray magnetic circular dichroism) study on the magnetic properties of interfaces between bcc-Fe(001) and C-60 molecules. C-60 is an interesting candidate for application in organic spintronics due to the absence of hydrogen atoms and the associated hyperfine fields. Adsorption of C-60 on Fe(001) reduces the magnetic moments on the top Fe layers by similar to 6%, while inducing an antiparrallel magnetic moment of similar to-0.2 mu(B) on C-60. Adsorption of C-60 on a model ferromagnetic substrate consisting of three Fe monolayers on W(001) leads to a different structure but to very similar interface magnetic properties. |
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Thesis |
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Publisher |
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Place of Publication |
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Language |
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Wos |
000315079700050 |
Publication Date |
2013-01-10 |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1944-8244 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.504 |
Times cited |
28 |
Open Access |
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Notes |
; The authors acknowledge support from the European project MINOTOR (Grant No. FP7-NMP-228424), the European Research Council (ERC Starting Grant No. 280020), and the NWO VIDI program (Grant No. 10246). The use of supercomputer facilities was sponsored by the “Stichting Nationale Computerfaciliteiten (NCF)”, financially supported by the “Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)”. ; |
Approved |
Most recent IF: 7.504; 2013 IF: 5.900 |
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Call Number |
UA @ lucian @ c:irua:128326 |
Serial |
4599 |
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