|
Records |
Links |
|
Author |
Madan, I.; Kusar, P.; Baranov, V.V.; Lu-Dac, M.; Kabanov, V.V.; Mertelj, T.; Mihailovic, D. |
|
|
Title |
Real-time measurement of the emergence of superconducting order in a high-temperature superconductor |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
93 |
Issue |
22 |
Pages |
224520 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Systems which rapidly evolve through symmetry-breaking transitions on timescales comparable to the fluctuation timescale of the single-particle excitations may behave very differently than under controlled near-ergodic conditions. A real-time investigation with high temporal resolution may reveal insights into the ordering through the transition that are not available in static experiments. We present an investigation of the system trajectory through a normal-to-superconductor transition in a prototype high-temperature superconducting cuprate in which such a situation occurs. Using a multiple pulse femtosecond spectroscopy technique we measure the system trajectory and time evolution of the single-particle excitations through the transition in La1.9Sr0.1CuO4 and compare the data to a simulation based on the time-dependent Ginzburg-Landau theory, using the laser excitation fluence as an adjustable parameter controlling the quench conditions in both experiment and theory. The comparison reveals the presence of significant superconducting fluctuations which precede the transition on short timescales. By including superconducting fluctuations as a seed for the growth of the superconducting order we can obtain a satisfactory agreement of the theory with the experiment. Remarkably, the pseudogap excitations apparently play no role in this process. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
|
|
Language |
|
Wos |
000378815800003 |
Publication Date |
2016-07-01 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
5 |
Open Access |
|
|
|
Notes |
; We wish to acknowledge the useful discussion with T. W. Kibble regarding the importance of a variable quench rate in the experiment. The funding was provided by European Research Council advanced grant TRAJECTORY. ; |
Approved |
Most recent IF: 3.836 |
|
|
Call Number |
UA @ lucian @ c:irua:144701 |
Serial |
4683 |
|
Permanent link to this record |
|
|
|
|
Author |
Stosic, D.; Ludermir, T.B.; Milošević, M.V. |
|
|
Title |
Pinning of magnetic skyrmions in a monolayer Co film on Pt(111) : Theoretical characterization and exemplified utilization |
Type |
A1 Journal article |
|
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
96 |
Issue |
21 |
Pages |
214403 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
<script type='text/javascript'>document.write(unpmarked('Magnetic skyrmions are nanoscale windings of the spin structure that can be observed in chiral magnets and hold promise for potential applications in storing or processing information. Pinning due to ever-present material imperfections crucially affects the mobility of skyrmions. Therefore, a proper understanding of how magnetic skyrmions pin to defects is necessary for the development and performance of spintronic devices. Here we present a fundamental analysis on the interactions of single skyrmions with atomic defects of distinctly different origins, in a Co monolayer on Pt, based on minimum-energy paths considerations and atomic-spin simulations. We first report the preferred pinning loci of the skyrmion as a function of its nominal size and the type of defect being considered, to further reveal the manipulation and \u0022breathing\u0022 of skyrmion core in the vicinity of a defect. We also show the behavior of skyrmions in the presence of an extended defect of particular geometry, that can lead to ratcheted skyrmion motion or a facilitated guidance on a defect \u0022trail.\u0022 We close the study with reflections on the expected thermal stability of the skyrmion against collapse on itself for a given nature of the defect, and discuss the applications where control of skyrmions by defects is of particular interest.')); |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
|
|
Language |
|
Wos |
000416846900002 |
Publication Date |
2017-12-01 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
52 |
Open Access |
|
|
|
Notes |
; This work was supported by the Research Foundation, Flanders (FWO-Vlaanderen) and Brazilian agency CNPq (Grants No. 442668/2014-7 and No. 140840/2016-8). ; |
Approved |
Most recent IF: 3.836 |
|
|
Call Number |
UA @ lucian @ c:irua:147684 |
Serial |
4890 |
|
Permanent link to this record |
|
|
|
|
Author |
Plumadore, R.; Baskurt, M.; Boddison-Chouinard, J.; Lopinski, G.; Modarresi, M.; Potasz, P.; Hawrylak, P.; Sahin, H.; Peeters, F.M.; Luican-Mayer, A. |
|
|
Title |
Prevalence of oxygen defects in an in-plane anisotropic transition metal dichalcogenide |
Type |
A1 Journal article |
|
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
102 |
Issue |
20 |
Pages |
205408 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Atomic scale defects in semiconductors enable their technological applications and realization of different quantum states. Using scanning tunneling microscopy and spectroscopy complemented by ab initio calculations we determine the nature of defects in the anisotropic van der Waals layered semiconductor ReS2. We demonstrate the in-plane anisotropy of the lattice by directly visualizing chains of rhenium atoms forming diamond-shaped clusters. Using scanning tunneling spectroscopy we measure the semiconducting gap in the density of states. We reveal the presence of lattice defects and by comparison of their topographic and spectroscopic signatures with ab initio calculations we determine their origin as oxygen atoms absorbed at lattice point defect sites. These results provide an atomic-scale view into the semiconducting transition metal dichalcogenides, paving the way toward understanding and engineering their properties. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000587595800007 |
Publication Date |
2020-11-09 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.7 |
Times cited |
9 |
Open Access |
|
|
|
Notes |
; The authors acknowledge funding from National Sciences and Engineering Research Council (NSERC) Discovery Grant No. RGPIN-2016-06717. We also acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC) through QC2DM Strategic Project No. STPGP 521420. P.H. thanks uOttawa Research Chair in Quantum Theory of Materials for support. P.P. acknowledges partial financial support from National Science Center (NCN), Poland, Grant Maestro No. 2014/14/A/ST3/00654, and calculations were performed in theWroclaw Center for Networking and Supercomputing. H.S. acknowledges financial support from TUBITAK under Project No. 117F095 and from Turkish Academy of Sciences under the GEBIP program. Our computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid eInfrastructure). ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
|
|
Call Number |
UA @ admin @ c:irua:173525 |
Serial |
6584 |
|
Permanent link to this record |
|
|
|
|
Author |
Benito Llorens, J.; Embon, L.; Correa, A.; Gonzalez, J.D.; Herrera, E.; Guillamon, I.; Luccas, R.F.; Azpeitia, J.; Mompean, F.J.; Garcia-Hernandez, M.; Munuera, C.; Aragon Sanchez, J.; Fasano, Y.; Milošević, M.V.; Suderow, H.; Anahory, Y. |
|
|
Title |
Observation of a gel of quantum vortices in a superconductor at very low magnetic fields |
Type |
A1 Journal article |
|
Year |
2020 |
Publication |
Physical review research |
Abbreviated Journal |
|
|
|
Volume |
2 |
Issue |
1 |
Pages |
013329 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
A gel consists of a network of particles or molecules formed for example using the sol-gel process, by which a solution transforms into a porous solid. Particles or molecules in a gel are mainly organized on a scaffold that makes up a porous system. Quantized vortices in type-II superconductors mostly form spatially homogeneous ordered or amorphous solids. Here we present high-resolution imaging of the vortex lattice displaying dense vortex clusters separated by sparse or entirely vortex-free regions in beta-Bi2Pd superconductor. We find that the intervortex distance diverges upon decreasing the magnetic field and that vortex lattice images follow a multifractal behavior. These properties, characteristic of gels, establish the presence of a novel vortex distribution, distinctly different from the well-studied disordered and glassy phases observed in high-temperature and conventional superconductors. The observed behavior is caused by a scaffold of one-dimensional structural defects with enhanced stress close to the defects. The vortex gel might often occur in type-II superconductors at low magnetic fields. Such vortex distributions should allow to considerably simplify control over vortex positions and manipulation of quantum vortex states. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000602698100008 |
Publication Date |
2020-03-18 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
|
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
|
Times cited |
14 |
Open Access |
|
|
|
Notes |
; We acknowledge support, discussions and critical reading of the manuscript from Eli Zeldov, who also devised and setup the SOT system. We also acknowledge critical reading and suggestions of Vladimir Kogan and Alexander Buzdin. Work performed in Spain was supported by the MINECO (FIS2017-84330-R, MAT2017-87134-C2-2-R, RYC-2014-16626 and RYC-2014-15093) and by the Region of Madrid through programs NANOFRONTMAG-CM (S2013/MIT-2850) and MAD2D-CM (S2013/ MIT-3007). The SEGAINVEX at UAM is also acknowledged as well as PEOPLE, Graphene Flagship, NMP programs of EU (Grant Agreements FP7-PEOPLE-2013-CIG 618321, 604391 and AMPHIBIAN H2020-NMBP-03-2016 NMP3-SL 2012-310516). Work in Israel was supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (Grant No. 802952). Y.F. acknowledges the support of grant PICT 2017-2182 from the ANPCyT. R.F.L. acknowledges the support of grant PICT 2017-2898 from the ANPCyT. E.H. acknowledges support of Departamento Administrativo de Ciencia, Tecnologia e Innovacion, COLCIENCIAS (Colombia) Programa de estancias Postdoctorales convocatoria 784-2017 and the Cluster de investigacin en ciencias y tecnologas convergentes de la Universidad Central (Colombia). I.G. was supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (Grant No. 679080). M.V.M. acknowledges support from Research FoundationFlanders (FWO). The international collaboration on this work was fostered by the EU-COST Action CA16218 Nanoscale Coherent Hybrid Devices for Superconducting Quantum Technologies (NANOCOHYBRI). J.D.G. and M.V.M. gratefully acknowledge support from the Research Fund (FONCIENCIAS) of Universidad del Magdalena. ; |
Approved |
Most recent IF: NA |
|
|
Call Number |
UA @ admin @ c:irua:175138 |
Serial |
6694 |
|
Permanent link to this record |
|
|
|
|
Author |
Demirkol, Ö.; Sevik, C.; Demiroğlu, I. |
|
|
Title |
First principles assessment of the phase stability and transition mechanisms of designated crystal structures of pristine and Janus transition metal dichalcogenides |
Type |
A1 Journal article |
|
Year |
2022 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
|
Volume |
24 |
Issue |
12 |
Pages |
7430-7441 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Two-dimensional Transition Metal Dichalcogenides (TMDs) possessing extraordinary physical properties at reduced dimensionality have attracted interest due to their promise in electronic and optical device applications. However, TMD monolayers can show a broad range of different properties depending on their crystal phase; for example, H phases are usually semiconductors, while the T phases are metallic. Thus, controlling phase transitions has become critical for device applications. In this study, the energetically low-lying crystal structures of pristine and Janus TMDs are investigated by using ab initio Nudged Elastic Band and molecular dynamics simulations to provide a general explanation for their phase stability and transition properties. Across all materials investigated, the T phase is found to be the least stable and the H phase is the most stable except for WTe2, while the T' and T '' phases change places according to the TMD material. The transition energy barriers are found to be large enough to hint that even the higher energy phases are unlikely to undergo a phase transition to a more stable phase if they can be achieved except for the least stable T phase, which has zero barrier towards the T ' phase. Indeed, in molecular dynamics simulations the thermodynamically least stable T phase transformed into the T ' phase spontaneously while in general no other phase transition was observed up to 2100 K for the other three phases. Thus, the examined T ', T '' and H phases were shown to be mostly stable and do not readily transform into another phase. Furthermore, so-called mixed phase calculations considered in our study explain the experimentally observed lateral hybrid structures and point out that the coexistence of different phases is strongly stable against phase transitions. Indeed, stable complex structures such as metal-semiconductor-metal architectures, which have immense potential to be used in future device applications, are also possible based on our investigation. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000766791000001 |
Publication Date |
2022-02-23 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1463-9076; 1463-9084 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.3 |
Times cited |
|
Open Access |
OpenAccess |
|
|
Notes |
|
Approved |
Most recent IF: 3.3 |
|
|
Call Number |
UA @ admin @ c:irua:187184 |
Serial |
7164 |
|
Permanent link to this record |
|
|
|
|
Author |
Gurel, T.; Altunay, Y.A.; Bulut, P.; Yildirim, S.; Sevik, C. |
|
|
Title |
Comprehensive investigation of the extremely low lattice thermal conductivity and thermoelectric properties of BaIn₂Te₄ |
Type |
A1 Journal article |
|
Year |
2022 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
106 |
Issue |
19 |
Pages |
195204-195210 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Recently, an extremely low lattice thermal conductivity value has been reported for the alkali-based telluride material BaIn2Te4. The value is comparable with low-thermal conductivity metal chalcogenides, and the glass limit is highly intriguing. Therefore, to shed light on this issue, we performed first-principles phonon thermal transport calculations. We predicted highly anisotropic lattice thermal conductivity along different directions via the solution of the linearized phonon Boltzmann transport equation. More importantly, we determined several different factors as the main sources of the predicted ultralow lattice thermal conductivity of this crystal, such as the strong interactions between low-frequency optical phonons and acoustic phonons, small phonon group velocities, and lattice anharmonicity indicated by large negative mode Gruneisen parameters. Along with thermal transport calculations, we also investigated the electronic transport properties by accurately calculating the scattering mechanisms, namely the acoustic deformation potential, ionized impurity, and polar optical scatterings. The inclusion of spin-orbit coupling (SOC) for electronic structure is found to strongly affect the p-type Seebeck coefficients. Finally, we calculated the thermoelectric properties accurately, and the optimal ZT value of p-type doping, which originated from high Seebeck coefficients, was predicted to exceed unity after 700 K and have a direction averaged value of 1.63 (1.76 in the y-direction) at 1000 K around 2 x 1020 cm-3 hole concentration. For n-type doping, a ZT around 3.2 x 1019 cm-3 concentration was predicted to be a direction-averaged value of 1.40 (1.76 in the z-direction) at 1000 K, mostly originating from its high electron mobility. With the experimental evidence of high thermal stability, we showed that the BaIn2Te4 compound has the potential to be a promising mid- to high-temperature thermoelectric material for both p-type and n-type systems with appropriate doping. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000918954800001 |
Publication Date |
2022-11-21 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.7 |
Times cited |
|
Open Access |
OpenAccess |
|
|
Notes |
|
Approved |
Most recent IF: 3.7 |
|
|
Call Number |
UA @ admin @ c:irua:194384 |
Serial |
7290 |
|
Permanent link to this record |
|
|
|
|
Author |
Duden, E.I.; Savaci, U.; Turan, S.; Sevik, C.; Demiroglu, I. |
|
|
Title |
Intercalation of argon in honeycomb structures towards promising strategy for rechargeable Li-ion batteries |
Type |
A1 Journal article |
|
Year |
2023 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
|
|
|
Volume |
35 |
Issue |
8 |
Pages |
085301-85311 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
High-performance rechargeable batteries are becoming very important for high-end technologies with their ever increasing application areas. Hence, improving the performance of such batteries has become the main bottleneck to transferring high-end technologies to end users. In this study, we propose an argon intercalation strategy to enhance battery performance via engineering the interlayer spacing of honeycomb structures such as graphite, a common electrode material in lithium-ion batteries (LIBs). Herein, we systematically investigated the LIB performance of graphite and hexagonal boron nitride (h-BN) when argon atoms were sent into between their layers by using first-principles density-functional-theory calculations. Our results showed enhanced lithium binding for graphite and h-BN structures when argon atoms were intercalated. The increased interlayer space doubles the gravimetric lithium capacity for graphite, while the volumetric capacity also increased by around 20% even though the volume was also increased. The ab initio molecular dynamics simulations indicate the thermal stability of such graphite structures against any structural transformation and Li release. The nudged-elastic-band calculations showed that the migration energy barriers were drastically lowered, which promises fast charging capability for batteries containing graphite electrodes. Although a similar level of battery promise was not achieved for h-BN material, its enhanced battery capabilities by argon intercalation also support that the argon intercalation strategy can be a viable route to enhance such honeycomb battery electrodes. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000899825400001 |
Publication Date |
2022-12-05 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
|
Impact Factor |
2.7 |
Times cited |
|
Open Access |
OpenAccess |
|
|
Notes |
|
Approved |
Most recent IF: 2.7; 2023 IF: 2.649 |
|
|
Call Number |
UA @ admin @ c:irua:193399 |
Serial |
7313 |
|
Permanent link to this record |
|
|
|
|
Author |
Karaaslan, Y.; Yapicioglu, H.; Sevik, C. |
|
|
Title |
Assessment of Thermal Transport Properties of Group-III Nitrides: A Classical Molecular Dynamics Study with Transferable Tersoff-Type Interatomic Potentials |
Type |
A1 Journal article |
|
Year |
2020 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
|
|
Volume |
13 |
Issue |
3 |
Pages |
034027 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
In this study, by means of classical molecular dynamics simulations, we investigate the thermal-transport properties of hexagonal single-layer, zinc-blend, and wurtzite phases of BN, AlN, and GaN crystals, which are very promising for the application and design of high-quality electronic devices. With this in mind, we generate fully transferable Tersoff-type empirical interatomic potential parameter sets by utilizing an optimization procedure based on particle-swarm optimization. The predicted thermal properties as well as the structural, mechanical, and vibrational properties of all materials are in very good agreement with existing experimental and first-principles data. The impact of isotopes on thermal transport is also investigated and between approximately 10 and 50% reduction in phonon thermal transport with random isotope distribution is observed in BN and GaN crystals. Our investigation distinctly shows that the generated parameter sets are fully transferable and very useful in exploring the thermal properties of systems containing these nitrides. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000518820200003 |
Publication Date |
2020-03-10 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
4.6 |
Times cited |
|
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 4.6; 2020 IF: 4.808 |
|
|
Call Number |
UA @ admin @ c:irua:193766 |
Serial |
7508 |
|
Permanent link to this record |
|
|
|
|
Author |
Demiroglu, I.; Sevik, C. |
|
|
Title |
Extraordinary negative thermal expansion of two-dimensional nitrides : a comparative ab initio study of quasiharmonic approximation and molecular dynamics simulations |
Type |
A1 Journal article |
|
Year |
2021 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
103 |
Issue |
8 |
Pages |
085430 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Thermal expansion behavior of two-dimensional (2D) nitrides and graphene were studied by ab initio molecular dynamics (MD) simulations as well as quasiharmonic approximation (QHA). Anharmonicity of the acoustic phonon modes are related to the unusual negative thermal expansion (NTE) behavior of the nitrides. Our results also hint that direct ab initio MD simulations are a more elaborate method to investigate thermal expansion behavior of 2D materials than the QHA. Nevertheless, giant NTE coefficients are found for h-GaN and h-AlN within the covered temperature range 100-600 K regardless of the chosen computational method. This unusual NTE of 2D nitrides is reasoned with the out-of-plane oscillations related to the rippling behavior of the monolayers. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000620346100007 |
Publication Date |
2021-02-22 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
|
Open Access |
OpenAccess |
|
|
Notes |
|
Approved |
Most recent IF: 3.836 |
|
|
Call Number |
UA @ admin @ c:irua:176671 |
Serial |
7956 |
|
Permanent link to this record |
|
|
|
|
Author |
Karaaslan, Y.; Haskins, J.B.; Yapicioglu, H.; Sevik, C. |
|
|
Title |
Influence of randomly distributed vacancy defects on thermal transport in two-dimensional group-III nitrides |
Type |
A1 Journal article |
|
Year |
2021 |
Publication |
Journal Of Applied Physics |
Abbreviated Journal |
J Appl Phys |
|
|
Volume |
129 |
Issue |
22 |
Pages |
224304 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Efficient thermal transport control is a fundamental issue for electronic device applications such as information, communication, and energy storage technologies in modern electronics in order to achieve desired thermal conditions. Structural defects in materials provide a mechanism to adjust the thermal transport properties of these materials on demand. In this context, the effect of structural defects on lattice thermal conductivities of two-dimensional hexagonal binary group-III nitride (XN, X = B, Al, and Ga) semiconductors is systematically investigated by means of classical molecular dynamics simulations performed with recently developed transferable inter-atomic potentials accurately describing defect energies. Here, two different Green-Kubo based approaches and another approach based on non-equilibrium molecular dynamics are compared in order to get an overall understanding. Our investigation clearly shows that defect concentrations of 3% decrease the thermal conductivity of systems containing these nitrites up to 95%. Results hint that structural defects can be used as effective adjustment parameters in controlling thermal transport properties in device applications associated with these materials. Published under an exclusive license by AIP Publishing. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000692024300001 |
Publication Date |
2021-06-09 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0021-8979; 1089-7550 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
2.068 |
Times cited |
|
Open Access |
Not_Open_Access |
|
|
Notes |
|
Approved |
Most recent IF: 2.068 |
|
|
Call Number |
UA @ admin @ c:irua:181618 |
Serial |
8096 |
|
Permanent link to this record |
|
|
|
|
Author |
Sar, H.; Ozden, A.; Demiroglu, I.; Sevik, C.; Perkgoz, N.K.; Ay, F. |
|
|
Title |
Long-Term Stability Control of CVD-Grown Monolayer MoS2 |
Type |
A1 Journal article |
|
Year |
2019 |
Publication |
Physica status solidi: rapid research letters |
Abbreviated Journal |
|
|
|
Volume |
13 |
Issue |
7 |
Pages |
1800687 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
The structural stability of 2D transition metal dichalcogenide (TMD) formations is of particular importance for their reliable device performance in nano-electronics and opto-electronics. Recent observations show that the CVD-grown TMD monolayers are likely to encounter stability problems such as cracking or fracturing when they are kept under ambient conditions. Here, two different growth configurations are investigated and a favorable growth geometry is proposed, which also sheds light onto the growth mechanism and provides a solution for the stability and fracture formation issues for TMDs specifically for MoS2 monolayers. It is shown that 18 months naturally and thermally aged MoS2 monolayer flakes grown using specifically developed conditions, retain their stability. To understand the mechanism of the structural deterioration, two possible effective mechanisms, S vacancy defects and growth-induced tensile stress, are assessed by the first principle calculations where the role of S vacancy defects in obtaining oxidation resistant MoS2 monolayer flakes is revealed to be rather more critical. Hence, these simulations, time-dependent observations and thermal aging experiments show that durability and stability of 2D MoS2 flakes can be controlled by CVD growth configuration. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000477671800009 |
Publication Date |
2019-03-18 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1862-6254 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
|
Times cited |
|
Open Access |
|
|
|
Notes |
|
Approved |
no |
|
|
Call Number |
UA @ admin @ c:irua:193784 |
Serial |
8184 |
|
Permanent link to this record |
|
|
|
|
Author |
Bulut, P.; Beceren, B.; Yildirim, S.; Sevik, C.; Gurel, T. |
|
|
Title |
Promising room temperature thermoelectric conversion efficiency of zinc-blende AgI from first principles |
Type |
A1 Journal article |
|
Year |
2021 |
Publication |
Journal Of Physics-Condensed Matter |
Abbreviated Journal |
J Phys-Condens Mat |
|
|
Volume |
33 |
Issue |
1 |
Pages |
015501 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
The theoretical investigation on structural, vibrational, and electronic properties of zinc-blende (ZB) AgI were carried out employing first principles density functional theory calculations. Thermoelectric properties then were predicted through semi-classical Boltzmann transport equations within the constant relaxation time approximation. Equilibrium lattice parameter, bulk modulus, elastic constants, and vibrational properties were calculated by using generalized gradient approximation. Calculated properties are in good agreement with available experimental values. Electronic and thermoelectric properties were investigated both with and without considering spin-orbit coupling (SOC) effect which is found to have a strong influence on p-type Seebeck coefficient as well as the power factor of the ZB-AgI. By inclusion of SOC, a reduction of the band-gap and p-type Seebeck coefficients as well as the power factor was found which is the indication of that spin-orbit interaction cannot be ignored for p-type thermoelectric properties of the ZB-AgI. By using deformation potential theory for electronic relaxation time and experimentally predicted lattice thermal conductivity, we obtained aZTvalue 1.69 (0.89) at 400 K for n-type (p-type) carrier concentration of 1.5 x 10(18)(4.6 x10(19)) cm(-3)that makes ZB-AgI as a promising room temperature thermoelectric material. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000577217600001 |
Publication Date |
2020-09-14 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
|
Impact Factor |
2.649 |
Times cited |
|
Open Access |
Not_Open_Access |
|
|
Notes |
|
Approved |
Most recent IF: 2.649 |
|
|
Call Number |
UA @ admin @ c:irua:193762 |
Serial |
8425 |
|
Permanent link to this record |
|
|
|
|
Author |
Mobaraki, A.; Sevik, C.; Yapicioglu, H.; Cakir, D.; Gulseren, O. |
|
|
Title |
Temperature-dependent phonon spectrum of transition metal dichalcogenides calculated from the spectral energy density: Lattice thermal conductivity as an application |
Type |
A1 Journal article |
|
Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
|
|
|
Volume |
100 |
Issue |
3 |
Pages |
035402 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Predicting the mechanical and thermal properties of quasi-two-dimensional (2D) transition metal dichalco-genides (TMDs) is an essential task necessary for their implementation in device applications. Although rigorous density-functional-theory-based calculations are able to predict mechanical and electronic properties, mostly they are limited to zero temperature. Classical molecular dynamics facilitates the investigation of temperature-dependent properties, but its performance highly depends on the potential used for defining interactions between the atoms. In this study, we calculated temperature-dependent phonon properties of single-layer TMDs, namely, MoS2, MoSe2, WS2, and WSe2, by utilizing Stillinger-Weber-type potentials with optimized sets of parameters with respect to the first-principles results. The phonon lifetimes and contribution of each phonon mode in thermal conductivities in these monolayer crystals are systematically investigated by means of the spectralenergy-density method based on molecular dynamics simulations. The obtained results from this approach are in good agreement with previously available results from the Green-Kubo method. Moreover, detailed analysis of lattice thermal conductivity, including temperature-dependent mode decomposition through the entire Brillouin zone, shed more light on the thermal properties of these 2D crystals. The LA and TA acoustic branches contribute most to the lattice thermal conductivity, while ZA mode contribution is less because of the quadratic dispersion around the Brillouin zone center, particularly in MoSe2 due to the phonon anharmonicity, evident from the redshift, especially in optical modes, by increasing temperature. For all the considered 2D crystals, the phonon lifetime values are compelled by transition metal atoms, whereas the group velocity spectrum is dictated by chalcogen atoms. Overall, the lattice thermal conductivity is linearly proportional with inverse temperature. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000473536400003 |
Publication Date |
2019-07-02 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
|
Times cited |
|
Open Access |
|
|
|
Notes |
|
Approved |
no |
|
|
Call Number |
UA @ admin @ c:irua:193764 |
Serial |
8645 |
|
Permanent link to this record |
|
|
|
|
Author |
Mobaraki, A.; Kandemir, A.; Yapicioglu, H.; Gulseren, O.; Sevik, C. |
|
|
Title |
Validation of inter-atomic potential for WS2 and WSe2 crystals through assessment of thermal transport properties |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Computational materials science |
Abbreviated Journal |
|
|
|
Volume |
144 |
Issue |
|
Pages |
92-98 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
In recent years, transition metal dichalcogenides (TMDs) displaying astonishing properties are emerged as a new class of two-dimensional layered materials. The understanding and characterization of thermal transport in these materials are crucial for efficient engineering of 2D TMD materials for applications such as thermoelectric devices or overcoming general overheating issues. In this work, we obtain accurate Stillinger-Weber type empirical potential parameter sets for single-layer WS2 and WSe2 crystals by utilizing particle swarm optimization, a stochastic search algorithm. For both systems, our results are quite consistent with first-principles calculations in terms of bond distances, lattice parameters, elastic constants and vibrational properties. Using the generated potentials, we investigate the effect of temperature on phonon energies and phonon linewidth by employing spectral energy density analysis. We compare the calculated frequency shift with respect to temperature with corresponding experimental data, clearly demonstrating the accuracy of the generated inter-atomic potentials in this study. Also, we evaluate the lattice thermal conductivities of these materials by means of classical molecular dynamics simulations. The predicted thermal properties are in very good agreement with the ones calculated from first-principles. (C) 2017 Elsevier B.V. All rights reserved. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000424902300013 |
Publication Date |
2017-12-16 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0927-0256 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
|
Times cited |
|
Open Access |
|
|
|
Notes |
|
Approved |
no |
|
|
Call Number |
UA @ admin @ c:irua:193774 |
Serial |
8729 |
|
Permanent link to this record |
|
|
|
|
Author |
Li, L.L.; Gillen, R.; Palummo, M.; Milošević, M.V.; Peeters, F.M. |
|
|
Title |
Strain tunable interlayer and intralayer excitons in vertically stacked MoSe₂/WSe₂ heterobilayers |
Type |
A1 Journal article |
|
Year |
2023 |
Publication |
Applied physics letters |
Abbreviated Journal |
|
|
|
Volume |
123 |
Issue |
3 |
Pages |
033102-33106 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Recently, interlayer and intralayer excitons in transition metal dichalcogenide heterobilayers have been studied both experimentally and theoretically. In spite of a growing interest, these layer-resolved excitons in the presence of external stimuli, such as strain, remain not fully understood. Here, using density-functional theory calculations with many-body effects, we explore the excitonic properties of vertically stacked MoSe2/WSe2 heterobilayer in the presence of in-plane biaxial strain of up to 5%. We calculate the strain dependence of exciton absorption spectrum, oscillator strength, wave function, and binding energy by solving the Bethe-Salpeter equation on top of the standard GW approach. We identify the interlayer and intralayer excitons by analyzing their electron-hole weights and spatial wave functions. We show that with the increase in strain magnitude, the absorption spectrum of the interlayer and intralayer excitons is red-shifted and re-ordered, and the binding energies of these layer-resolved excitons decrease monotonically and almost linearly. We derive the sensitivity of exciton binding energy to the applied strain and find that the intralayer excitons are more sensitive to strain than the interlayer excitons. For instance, a sensitivity of -7.9 meV/% is derived for the intra-MoSe2-layer excitons, which is followed by -7.4 meV/% for the intra-WSe2-layer excitons, and by -4.2 meV/% for the interlayer excitons. Our results indicate that interlayer and intralayer excitons in vertically stacked MoSe2/WSe2 heterobilayer are efficiently tunable by in-plane biaxial strain. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
001033604700003 |
Publication Date |
2023-07-20 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0003-6951; 1077-3118 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
4 |
Times cited |
2 |
Open Access |
OpenAccess |
|
|
Notes |
|
Approved |
Most recent IF: 4; 2023 IF: 3.411 |
|
|
Call Number |
UA @ admin @ c:irua:198382 |
Serial |
8823 |
|
Permanent link to this record |
|
|
|
|
Author |
Blundo, E.; Faria, P.E., Jr.; Surrente, A.; Pettinari, G.; Prosnikov, M.A.; Olkowska-Pucko, K.; Zollner, K.; Wozniak, T.; Chaves, A.; Kazimierczuk, T.; Felici, M.; Babinski, A.; Molas, M.R.; Christianen, P.C.M.; Fabian, J.; Polimeni, A. |
|
|
Title |
Strain-Induced Exciton Hybridization in WS2 Monolayers Unveiled by Zeeman-Splitting Measurements |
Type |
A1 Journal article |
|
Year |
2022 |
Publication |
Physical review letters |
Abbreviated Journal |
|
|
|
Volume |
129 |
Issue |
6 |
Pages |
067402 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Mechanical deformations and ensuing strain are routinely exploited to tune the band gap energy and to enhance the functionalities of two-dimensional crystals. In this Letter, we show that strain leads also to a strong modification of the exciton magnetic moment in WS2 monolayers. Zeeman-splitting measurements under magnetic fields up to 28.5 T were performed on single, one-layer-thick WS2 microbubbles. The strain of the bubbles causes a hybridization of k-space direct and indirect excitons resulting in a sizable decrease in the modulus of they factor of the ground-state exciton. These findings indicate that strain may have major effects on the way the valley number of excitons can be used to process binary information in two-dimensional crystals. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000842367600007 |
Publication Date |
2022-08-04 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0031-9007; 1079-7114 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
|
Times cited |
|
Open Access |
OpenAccess |
|
|
Notes |
|
Approved |
no |
|
|
Call Number |
UA @ admin @ c:irua:198538 |
Serial |
8936 |
|
Permanent link to this record |
|
|
|
|
Author |
Zuniga-Puelles, E.; Levytskyi, V.; Özden, A.; Guerel, T.; Bulut, N.; Himcinschi, C.; Sevik, C.; Kortus, J.; Gumeniuk, R. |
|
|
Title |
Thermoelectric properties and scattering mechanisms in natural PbS |
Type |
A1 Journal article |
|
Year |
2023 |
Publication |
Physical review B |
Abbreviated Journal |
|
|
|
Volume |
107 |
Issue |
19 |
Pages |
195203-195215 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
X-ray diffraction and energy dispersive x-ray spectroscopic analyses showed a natural galena (PbS) crystal from Freiberg in Saxony (Germany) to be a single phase specimen [rock salt (NaCl) structure type, space group Fm3m, a = 5.932(1) angstrom] with stoichiometric composition and an enhanced dislocation density (8 approximate to 1011 cm-2). The latter parameter leads to an increase of the electrical resistivity in the high-temperature regime, as well as to the appearance of phonon resonance with a characteristic frequency coPR = 3.8(1) THz. Being in the same range (i.e., 3-5.5 THz) with the sulfur optical modes of highest group velocities, it results in a drastic reduction (by similar to 75%) of thermal conductivity (K) at lower temperatures (i.e., < 100 K), as well as in the appearance of a characteristic minimum in K at T approximate to 30 K. Furthermore, the studied galena is characterized by phonon-drag behavior and by temperature dependent switch of the charge carrier scattering mechanism regime (i.e., scattering on dislocations for T < 100 K, on acoustic phonons for 100 K < T < 170 K and on both acoustic and optical phonons for 170 K < T < 300 K). The combined theoretical calculation and optical spectroscopic study confirm this mineral to be a direct gap degenerate semiconductor. The possible origins of the second-order Raman spectrum are discussed. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
001009980400008 |
Publication Date |
2023-05-30 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.7 |
Times cited |
|
Open Access |
Not_Open_Access |
|
|
Notes |
|
Approved |
Most recent IF: 3.7; 2023 IF: 3.836 |
|
|
Call Number |
UA @ admin @ c:irua:197808 |
Serial |
8943 |
|
Permanent link to this record |
|
|
|
|
Author |
Luo, Y.; He, Y.; Ding, Y.; Zuo, L.; Zhong, C.; Ma, Y.; Sun, M. |
|
|
Title |
Defective biphenylene as high-efficiency hydrogen evolution catalysts |
Type |
A1 Journal article |
|
Year |
2023 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
|
|
|
Volume |
63 |
Issue |
2 |
Pages |
1136-1141 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Electrocatalysts play a pivotal role in advancing the application of water splitting for hydrogen production. This research unveils the potential of defective biphenylenes as high-efficiency catalysts for the hydrogen evolution reaction. Using first-principles simulations, we systematically investigated the structure, stability, and catalytic performance of defective biphenylenes. Our findings unveil that defect engineering significantly enhances the electrocatalytic activity for hydrogen evolution. Specifically, biphenylene with a double-vacancy defect exhibits an outstanding Gibbs free energy of -0.08 eV, surpassing that of Pt, accompanied by a remarkable exchange current density of -3.08 A cm(-2), also surpassing that of Pt. Furthermore, we find the preference for the Volmer-Heyrovsky mechanism in the hydrogen evolution reaction, with a low energy barrier of 0.80 eV. This research provides a promising avenue for developing novel metal-free electrocatalysts for water splitting with earth-abundant carbon elements, making a significant step toward sustainable hydrogen production. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
001143581300001 |
Publication Date |
2023-12-31 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0020-1669 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
|
Impact Factor |
4.6 |
Times cited |
|
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 4.6; 2023 IF: 4.857 |
|
|
Call Number |
UA @ admin @ c:irua:202780 |
Serial |
9018 |
|
Permanent link to this record |
|
|
|
|
Author |
Rakesh Roshan, S.C.; Yedukondalu, N.; Pandey, T.; Kunduru, L.; Muthaiah, R.; Rajaboina, R.K.; Ehm, L.; Parise, J.B. |
|
|
Title |
Effect of atomic mass contrast on lattice thermal conductivity : a case study for alkali halides and alkaline-earth chalcogenides |
Type |
A1 Journal article |
|
Year |
2023 |
Publication |
ACS applied electronic materials |
Abbreviated Journal |
|
|
|
Volume |
5 |
Issue |
11 |
Pages |
5852-5863 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Lattice thermal conductivity (kappa(L)) is of great scientific interest for the development of efficient energy conversion technologies. Therefore, microscopic understanding of phonon transport is critically important for designing functional materials. In our previous study (Roshan et al., ACS Applied Energy Mater. 2021, 5, 882-896), anomalous kappa(L) trends were predicted for rocksalt alkaline-earth chalcogenides (AECs). In the present work, we extended it to alkali halides (AHs) and conducted a thorough investigation to explore the role of atomic mass contrast on lattice dynamics and phonon transport properties of 36 binary compounds (20 AHs + 16 AECs). The calculated spectral and cumulative kappa(L) reveal that low-lying optical phonon modes significantly boost kappa(L) alongside acoustic phonons in materials where the atomic mass ratio approaches unity and cophonocity nears zero. Phonon scattering rates are relatively low for materials with a mass ratio close to one, and the corresponding phonon lifetimes are higher, which enhances kappa(L). Phonon lifetimes play a critical role, outweighing phonon group velocities, in determining the anomalous trends in kappa(L) for both AHs and AECs. To further explore the role of atomic mass contrast in kappa(L), the effect of tensile lattice strain on phonon transport has also been investigated. Under tensile strain, both group velocities and phonon lifetimes decrease in the low frequency range, leading to a decrease in kappa(L). This work provides insights on how atomic mass contrast can tune the contribution of optical phonons to kappa(L) and its implications on scattering rates by either enhancing or suppressing kappa(L). These insights would aid in the selection of elements for designing new functional materials with and without atomic mass contrast to achieve relatively high and low kappa(L) values, respectively. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
001096792500001 |
Publication Date |
2023-10-26 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2637-6113 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
|
Impact Factor |
|
Times cited |
|
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: NA |
|
|
Call Number |
UA @ admin @ c:irua:201198 |
Serial |
9026 |
|
Permanent link to this record |
|
|
|
|
Author |
Zhang, C.; Ren, K.; Wang, S.; Luo, Y.; Tang, W.; Sun, M. |
|
|
Title |
Recent progress on two-dimensional van der Waals heterostructures for photocatalytic water splitting : a selective review |
Type |
A1 Journal article |
|
Year |
2023 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
|
|
|
Volume |
56 |
Issue |
48 |
Pages |
483001-483024 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
Hydrogen production through photocatalytic water splitting is being developed swiftly to address the ongoing energy crisis. Over the past decade, with the rise of graphene and other two-dimensional (2D) materials, an increasing number of computational and experimental studies have focused on relevant van der Waals (vdW) semiconductor heterostructures for photocatalytic water splitting. In this review, the fundamental mechanism and distinctive performance of type-II and Z-scheme vdW heterostructure photocatalysts are presented. Accordingly, we have conducted a systematic review of recent studies focusing on candidates for photocatalysts, specifically vdW heterostructures involving 2D transition metal disulfides (TMDs), 2D Janus TMDs, and phosphorenes. The photocatalytic performance of these heterostructures and their suitability in theoretical scenarios are discussed based on their electronic and optoelectronic properties, particularly in terms of band structures, photoexcited carrier dynamics, and light absorption. In addition, various approaches for tuning the performance of these potential photocatalysts are illustrated. This strategic framework for constructing and modulating 2D heterostructure photocatalysts is expected to provide inspiration for addressing possible challenges in future studies. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
001076327300001 |
Publication Date |
2023-08-30 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0022-3727 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.4 |
Times cited |
|
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 3.4; 2023 IF: 2.588 |
|
|
Call Number |
UA @ admin @ c:irua:200353 |
Serial |
9081 |
|
Permanent link to this record |
|
|
|
|
Author |
Zamani, M.; Yapicioglu, H.; Kara, A.; Sevik, C. |
|
|
Title |
Statistical analysis of porcelain tiles' technical properties : full factorial design investigation on oxide ratios and temperature |
Type |
A1 Journal article |
|
Year |
2023 |
Publication |
Physica scripta |
Abbreviated Journal |
|
|
|
Volume |
98 |
Issue |
12 |
Pages |
125953-18 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
|
Abstract |
This study focuses on optimizing the composition and firing temperature of porcelain tiles using statistical analysis techniques. A full factorial design, including model adequacy checking, analysis of variance, Pareto charts, interaction plots, regression model, and response optimizer is employed. The key factors were the Seger ratios of SiO2/Al2O3, Na2O/K2O, MgO/CaO, and firing temperature. The response variables investigated were bulk density, water absorption, linear shrinkage, coefficient of thermal expansion (at 500 degrees C), and strength. The statistical analysis revealed highly significant results, which were further validated, confirming their reliability for practical use in the production of porcelain tiles. The study demonstrated the effectiveness of utilizing Seger formulas and properties of typical raw materials to accurately predict the final properties of ceramic tiles. By employing SiO2/Al2O3 = 5.2, Na2O/K2O = 1.50, MgO/CaO = 3.0, and firing temperature of 1180 degrees C, optimized properties, such as maximum strength, maximum bulk density, and minimum water absorption, was achieved with a composite desirability of 0.9821. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
001105879800001 |
Publication Date |
2023-11-08 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0031-8949; 1402-4896 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
|
Impact Factor |
2.9 |
Times cited |
|
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 2.9; 2023 IF: 1.28 |
|
|
Call Number |
UA @ admin @ c:irua:202033 |
Serial |
9097 |
|
Permanent link to this record |
|
|
|
|
Author |
Dabral, A.; Pourtois, G.; Sankaran, K.; Magnus, W.; Yu, H.; de de Meux, A.J.; Lu, A.K.A.; Clima, S.; Stokbro, K.; Schaekers, M.; Collaert, N.; Horiguchi, N.; Houssa, M. |
|
|
Title |
Study of the intrinsic limitations of the contact resistance of metal/semiconductor interfaces through atomistic simulations |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
ECS journal of solid state science and technology |
Abbreviated Journal |
Ecs J Solid State Sc |
|
|
Volume |
7 |
Issue |
6 |
Pages |
N73-N80 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
|
Abstract |
In this contribution, we report a fundamental study of the factors that set the contact resistivity between metals and highly doped n-type 2D and 3D semiconductors. We investigate the case of n-type doped Si contacted with amorphous TiSi combining first principles calculations with Non-Equilibrium Green functions transport simulations. The evolution of the intrinsic contact resistivity with the doping concentration is found to saturate at similar to 2 x 10(-10) Omega.cm(2) for the case of TiSi and imposes an intrinsic limit to the ultimate contact resistance achievable for n-doped Silamorphous-TiSi (aTiSi). The limit arises from the intrinsic properties of the semiconductors and of the metals such as their electron effective masses and Fermi energies. We illustrate that, in this regime, contacting heavy electron effective mass metals with semiconductor helps reducing the interface intrinsic contact resistivity. This observation seems to hold true regardless of the 3D character of the semiconductor, as illustrated for the case of three 2D semiconducting materials, namely MoS2, ZrS2 and HfS2. (C) The Author(s) 2018. Published by ECS. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
Electrochemical society |
Place of Publication |
Pennington (N.J.) |
Editor |
|
|
|
Language |
|
Wos |
000440836000004 |
Publication Date |
2018-05-25 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2162-8769; 2162-8777 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
1.787 |
Times cited |
2 |
Open Access |
Not_Open_Access |
|
|
Notes |
; The authors thank the imec core CMOS program members, the European Commission, its TAKEMI5 ECSEL research project and the local authorities for their support. ; |
Approved |
Most recent IF: 1.787 |
|
|
Call Number |
UA @ lucian @ c:irua:153205UA @ admin @ c:irua:153205 |
Serial |
5130 |
|
Permanent link to this record |
|
|
|
|
Author |
Hu, L.; Amini, M.N.; Wu, Y.; Jin, Z.; Yuan, J.; Lin, R.; Wu, J.; Dai, Y.; He, H.; Lu, Y.; Lu, J.; Ye, Z.; Han, S.-T.; Ye, J.; Partoens, B.; Zeng, Y.-J.; Ruan, S. |
|
|
Title |
Charge transfer doping modulated raman scattering and enhanced stability of black phosphorus quantum dots on a ZnO nanorod |
Type |
A1 Journal article |
|
Year |
2018 |
Publication |
Advanced Optical Materials |
Abbreviated Journal |
Adv Opt Mater |
|
|
Volume |
6 |
Issue |
15 |
Pages |
1800440 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
|
Abstract |
Black phosphorus (BP) has recently triggered an unprecedented interest in the 2D community. However, many of its unique properties are not exploited and the well-known environmental vulnerability is not conquered. Herein, a type-I mixed-dimensional (0D-1D) van der Waals heterojunction is developed, where three-atomic-layer BP quantum dots (QDs) are assembled on a single ZnO nanorod (NR). By adjusting the indium (In) content in ZnO NRs, the degree and even the direction of surface charge transfer doping within the heterojunction can be tuned, which result in selective Raman scattering enhancements between ZnO and BP. The maximal enhancement factor is determined as 4340 for BP QDs with sub-ppm level. Furthermore, an unexpected long-term ambient stability (more than six months) of BP QDs is revealed, which is ascribed to the electron doping from ZnO:In NRs. The first demonstration of selective Raman enhancements between two inorganic semiconductors as well as the improved stability of BP shed light on this emerging 2D material. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000440815200023 |
Publication Date |
2018-05-18 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2195-1071 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
6.875 |
Times cited |
37 |
Open Access |
Not_Open_Access |
|
|
Notes |
; L. Hu and M. N. Amini contributed equally to this work. This work was supported by the National Natural Science Foundation of China under Grant Nos. 51502178, 81571763 and 81622026, the Shenzhen Science and Technology Project under Grant Nos. JCYJ20150324141711644, JCYJ20170412105400428, KQJSCX20170727101208249 and JCYJ20170302153853962. Parts of the computational calculations were carried out using the HPC infrastructure at University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center VSC, supported financially by the FWO-Vlaanderen and the Flemish Government (EWI Department). L. H. acknowledges the PhD Start-up Fund of Natural Science Foundation of Guangdong Province under Grand No. 2017A030310072. J. Y. acknowledges the funding of Shanghai Jiao Tong University (Nos. YG2016MS51 and YG2017MS54). ; |
Approved |
Most recent IF: 6.875 |
|
|
Call Number |
UA @ lucian @ c:irua:153112UA @ admin @ c:irua:153112 |
Serial |
5082 |
|
Permanent link to this record |
|
|
|
|
Author |
Nicholas, R.J.; Sasaki, S.; Miura, N.; Peeters, F.M.; Shi, J.M.; Hai, G.Q.; Devreese, J.T.; Lawless, M.J.; Ashenford, D.E.; Lunn, B. |
|
|
Title |
Interband magnetooptical studies of resonant polaron coupling in CdTe/Cd1-xMnxTe quantum-wells |
Type |
A1 Journal article |
|
Year |
1994 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
50 |
Issue |
11 |
Pages |
7596-7601 |
|
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
|
|
Abstract |
Magnetoreflectivity measurements of the 1s and 2s exciton energies in a CdTe/Cd1-xMnxTe superlattice have been made in magnetic fields up to 45 T, showing the resonant polaron coupling of electrons to LO phonons. Strong reflectivity features are seen for both the 1s and 2s excitons, which show a strong field-dependent spin splitting due to the dilute magnetic barriers. At B-z=0, the 2s exciton feature is observed lying 18 meV above the Is state, and is shifted upward in energy by the magnetic fields. No resonant behavior occurs when the 2s state passes through the LO-phonon energy of 21 meV, but at higher fields of around 20 T, the resonances for both spin states (sigma(+/-)) of the 2s exciton broaden and show a strong anticrossing behavior. These experiments are shown to be in excellent agreement with a theoretical treatment which includes the resonant polaron coupling of the electrons alone. Both experiment and theory demonstrate an extremely strong resonant splitting of the 2s exciton states of approximately 11 meV, which is over 50% of the LO-phonon energy. The dominance of single-particle polaron coupling is attributed to the relative sizes of the polaron (35 Angstrom A) and the exciton (50 Angstrom A) radius. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
|
|
Language |
|
Wos |
A1994PJ43700045 |
Publication Date |
2002-07-27 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.736 |
Times cited |
10 |
Open Access |
|
|
|
Notes |
|
Approved |
no |
|
|
Call Number |
UA @ lucian @ c:irua:99837 |
Serial |
1687 |
|
Permanent link to this record |
|
|
|
|
Author |
Maes, D.; Van Dael, M.; Vanheusden, B.; Goovaerts, L.; Reumerman, P.; Luzardo, N.M.; Van Passel, S. |
|
|
Title |
Assessment of the sustainability guidelines of EU Renewable Energy Directive : the case of biorefineries |
Type |
A1 Journal article |
|
Year |
2015 |
Publication |
Journal Of Cleaner Production |
Abbreviated Journal |
J Clean Prod |
|
|
Volume |
88 |
Issue |
|
Pages |
61-70 |
|
|
Keywords |
A1 Journal article; Economics; Engineering Management (ENM) |
|
|
Abstract |
Sustainability guidelines can help to safeguard the sustainable use of biological materials. When these guidelines are legally prescribed, their influence on the economic viability of bioenergy, biofuel and bioliquid projects is increased substantially, through their impact on national subsidy regimes and international trade. One of the key examples is the European directive 2009/28/EC, or the Renewable Energy Directive (RED), and the related COM/2010/11 that integrate guidelines for calculating greenhouse gas impact for various bioenergy pathways. This paper looks further into the sustainability results when influenced by principal decisions that are legally open for debate. Therefore, a concise review is conducted of the legal state-of-the-art on whether a product is waste or not. The review pinpoints uncertainty, leading to four potential legal scenarios. The sustainability of a complex biorefinery is analysed for each scenario. The results show (i) a high sensitivity to the principal decisions on the nature of waste materials in the scenarios, and (ii) to the definition of boundaries between the processes. More detailed rules for the application of the RED guidelines are needed, and should be complemented with methods specifically targeting all relevant sustainability aspects, thereby enhancing the overall understanding of the sustainability of the process. (C) 2014 Elsevier Ltd. All rights reserved. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000347771100007 |
Publication Date |
2014-04-30 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0959-6526 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
5.715 |
Times cited |
25 |
Open Access |
|
|
|
Notes |
; We would like to thank the editor and the anonymous referees for their helpful suggestions and insightful comments that have significantly improved the paper. The 'Energy Conversion Parks' (ECP) project is funded as Project nr IVA-VLANED-2.39 by the Interreg IVa-Flanders-Netherlands program from the European Fund for Regional Development that stimulates cross border projects. Also the Dutch Ministry of Economic Affairs, the Flemish Government, the Provinces of Noord-Brabant (NL), Zeeland (NL), Limburg (BE) and the partners (VITO, Avans University of Applied Sciences, Wageningen University and Research, Hasselt University, and Zeeland University of Applied Sciences) themselves are co-financing the project. Finally, we would like to express our gratitude towards the organization of the eighth Conference on Sustainable Development of Energy, Water and Environment systems in Dubrovnik (Croatia) for giving us the opportunity to present and thereby fine-tune our work. ; |
Approved |
Most recent IF: 5.715; 2015 IF: 3.844 |
|
|
Call Number |
UA @ admin @ c:irua:127538 |
Serial |
6157 |
|
Permanent link to this record |
|
|
|
|
Author |
Vávra, O.; Gaži, S.; Golubović, D.S.; Vávra, I.; Dérer, J.; Verbeeck, J.; Van Tendeloo, G.; Moshchalkov, V.V. |
|
|
Title |
0 and π phase Josephson coupling through an insulating barrier with magnetic impurities |
Type |
A1 Journal article |
|
Year |
2006 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
74 |
Issue |
2 |
Pages |
020502 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
We have studied the temperature and field dependencies of the critical current I(C) in the Nb-Fe(0.1)Si(0.9)-Nb Josephson junction with a tunneling barrier formed by a paramagnetic insulator. We demonstrate that in these junctions coexistence of both the 0 and the pi states within one tunnel junction occurs, and leads to the appearance of a sharp cusp in the temperature dependence I(C)(T), similar to the I(C)(T) cusp found for the 0-pi transition in metallic pi junctions. This cusp is not related to the 0-pi temperature-induced transition itself, but is caused by the different temperature dependencies of the opposing 0 and pi supercurrents through the barrier. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
|
|
Language |
|
Wos |
000239426600010 |
Publication Date |
2006-07-15 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
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 |
27 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 3.836; 2006 IF: 3.107 |
|
|
Call Number |
UA @ lucian @ c:irua:60087 c:irua:60087 c:irua:60087 c:irua:60087UA @ admin @ c:irua:60087 |
Serial |
1 |
|
Permanent link to this record |
|
|
|
|
Author |
Turner, S.; Shenderova, O.; da Pieve, F.; Lu, Y.-G.; Yücelen, E.; Verbeeck, J.; Lamoen, D.; Van Tendeloo, G. |
|
|
Title |
Aberration-corrected microscopy and spectroscopy analysis of pristine, nitrogen containing detonation nanodiamond |
Type |
A1 Journal article |
|
Year |
2013 |
Publication |
Physica status solidi : A : applications and materials science |
Abbreviated Journal |
Phys Status Solidi A |
|
|
Volume |
210 |
Issue |
10 |
Pages |
1976-1984 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Aberration-corrected transmission electron microscopy, electron energy-loss spectroscopy, and density functional theory (DFT) calculations are used to solve several key questions about the surface structure, the particle morphology, and the distribution and nature of nitrogen impurities in detonation nanodiamond (DND) cleaned by a recently developed ozone treatment. All microscopy and spectroscopy measurements are performed at a lowered acceleration voltage (80/120kV), allowing prolonged and detailed experiments to be carried out while minimizing the risk of knock-on damage or surface graphitization of the nanodiamond. High-resolution TEM (HRTEM) demonstrates the stability of even the smallest nanodiamonds under electron illumination at low voltage and is used to image the surface structure of pristine DND. High resolution electron energy-loss spectroscopy (EELS) measurements on the fine structure of the carbon K-edge of nanodiamond demonstrate that the typical * pre-peak in fact consists of three sub-peaks that arise from the presence of, amongst others, minimal fullerene-like reconstructions at the nanoparticle surfaces and deviations from perfect sp(3) coordination at defects in the nanodiamonds. Spatially resolved EELS experiments evidence the presence of nitrogen within the core of DND particles. The nitrogen is present throughout the whole diamond core, and can be enriched at defect regions. By comparing the fine structure of the experimental nitrogen K-edge with calculated energy-loss near-edge structure (ELNES) spectra from DFT, the embedded nitrogen is most likely related to small amounts of single substitutional and/or A-center nitrogen, combined with larger nitrogen clusters. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000329299700025 |
Publication Date |
2013-10-18 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1862-6300; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
1.775 |
Times cited |
37 |
Open Access |
|
|
|
Notes |
262348 ESMI; 246791 COUNTATOMS; FWO; Hercules; GOA XANES meets ELNES |
Approved |
Most recent IF: 1.775; 2013 IF: 1.525 |
|
|
Call Number |
UA @ lucian @ c:irua:110821UA @ admin @ c:irua:110821 |
Serial |
41 |
|
Permanent link to this record |
|
|
|
|
Author |
Lu, Y.-G.; Verbeeck, J.; Turner, S.; Hardy, A.; Janssens, S.D.; De Dobbelaere, C.; Wagner, P.; Van Bael, M.K.; Van Tendeloo, G. |
|
|
Title |
Analytical TEM study of CVD diamond growth on TiO2 sol-gel layers |
Type |
A1 Journal article |
|
Year |
2012 |
Publication |
Diamond and related materials |
Abbreviated Journal |
Diam Relat Mater |
|
|
Volume |
23 |
Issue |
|
Pages |
93-99 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
The early growth stages of chemical vapor deposition (CVD) diamond on a solgel TiO2 film with buried ultra dispersed diamond seeds (UDD) have been studied. In order to investigate the diamond growth mechanism and understand the role of the TiO2 layer in the growth process, high resolution transmission electron microscopy (HRTEM), energy-filtered TEM and electron energy loss spectroscopy (EELS) techniques were applied to cross sectional diamond film samples. We find evidence for the formation of TiC crystallites inside the TiO2 layer at different diamond growth stages. However, there is no evidence that diamond nucleation starts from these crystallites. Carbon diffusion into the TiO2 layer and the chemical bonding state of carbon (sp2/sp3) were both extensively investigated. We provide evidence that carbon diffuses through the TiO2 layer and that the diamond seeds partially convert to amorphous carbon during growth. This carbon diffusion and diamond to amorphous carbon conversion make the seed areas below the TiO2 layer grow and bend the TiO2 layer upwards to form the nucleation center of the diamond film. In some of the protuberances a core of diamond seed remains, covered by amorphous carbon. It is however unlikely that the remaining seeds are still active during the growth process. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
|
|
Language |
|
Wos |
000302887600017 |
Publication Date |
2012-01-26 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0925-9635; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
2.561 |
Times cited |
16 |
Open Access |
|
|
|
Notes |
Iap; Esteem 026019; Fwo |
Approved |
Most recent IF: 2.561; 2012 IF: 1.709 |
|
|
Call Number |
UA @ lucian @ c:irua:95037UA @ admin @ c:irua:95037 |
Serial |
111 |
|
Permanent link to this record |
|
|
|
|
Author |
Lu, Y.-G.; Turner, S.; Ekimov, E.A.; Verbeeck, J.; Van Tendeloo, G. |
|
|
Title |
Boron-rich inclusions and boron distribution in HPHT polycrystalline superconducting diamond |
Type |
A1 Journal article |
|
Year |
2015 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
|
|
Volume |
86 |
Issue |
86 |
Pages |
156-162 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Polycrystalline boron-doped superconducting diamond, synthesized at high pressure and high temperature (HPHT) via a reaction of a single piece of crystalline boron with monolithic graphite, has been investigated by analytical transmission electron microscopy. The local boron distribution and boron environment have been studied by a combination of (scanning) transmission electron microscopy ((S)TEM) and spatially resolved electron energy-loss spectroscopy (EELS). High resolution TEM imaging and EELS elemental mapping have established, for the first time, the presence of largely crystalline diamond-diamond grain boundaries within the material and have evidenced the presence of substitutional boron dopants within individual diamond grains. Confirmation of the presence of substitutional B dopants has been obtained through comparison of acquired boron K-edge EELS fine structures with known references. This confirmation is important to understand the origin of superconductivity in polycrystalline B-doped diamond. In addition to the substitutional boron doping, boron-rich inclusions and triple-points, both amorphous and crystalline, with chemical compositions close to boron carbide B4C, are evidenced. (C) 2015 Elsevier Ltd. All rights reserved. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Oxford |
Editor |
|
|
|
Language |
|
Wos |
000352922700019 |
Publication Date |
2015-01-22 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0008-6223; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
6.337 |
Times cited |
20 |
Open Access |
|
|
|
Notes |
FWO; 246791 COUNTATOMS; 278510 VORTEX; Hercules ECASJO_; |
Approved |
Most recent IF: 6.337; 2015 IF: 6.196 |
|
|
Call Number |
c:irua:125994UA @ admin @ c:irua:125994 |
Serial |
250 |
|
Permanent link to this record |
|
|
|
|
Author |
Colomer, J.-F.; Henrard, L.; Launois, P.; Van Tendeloo, G.; Lucas, A.A.; Lambin, P. |
|
|
Title |
Bundles of identical double-walled carbon nanotubes |
Type |
A1 Journal article |
|
Year |
2004 |
Publication |
Chemical communications |
Abbreviated Journal |
Chem Commun |
|
|
Volume |
|
Issue |
22 |
Pages |
2592-2593 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
|
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000225375100035 |
Publication Date |
2004-09-30 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1359-7345;1364-548X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
6.319 |
Times cited |
13 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 6.319; 2004 IF: 3.997 |
|
|
Call Number |
UA @ lucian @ c:irua:54875 |
Serial |
263 |
|
Permanent link to this record |