Home | << 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 >> |
![]() |
Records | |||||
---|---|---|---|---|---|
Author | Mescia, L.; Bia, P.; Caratelli, D.; Chiapperino, M.A.; Stukach, O.; Gielis, J. | ||||
Title | Electromagnetic mathematical modeling of 3D supershaped dielectric lens antennas | Type | A1 Journal article | ||
Year | 2016 | Publication | Mathematical problems in engineering: theory, methods, and applications | Abbreviated Journal | |
Volume | Issue | Pages ![]() |
8130160-10 | ||
Keywords | A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) | ||||
Abstract | The electromagnetic analysis of a special class of 3D dielectric lens antennas is described in detail. This new class of lens antennas has a geometrical shape defined by the three-dimensional extension of Gielis formula. The analytical description of the lens shape allows the development of a dedicated semianalytical hybrid modeling approach based on geometrical tube tracing and physical optic. In order to increase the accuracy of the model, the multiple reflections occurring within the lens are also taken into account. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000372246600001 | Publication Date | 2016-02-29 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1024-123x; 1563-5147 | 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:131516 | Serial | 7866 | ||
Permanent link to this record | |||||
Author | Barreca, D.; Carraro, G.; Gasparotto, A.; Maccato, C.; Warwick, M.E.A.; Toniato, E.; Gombac, V.; Sada, C.; Turner, S.; Van Tendeloo, G.; Fornasiero, P.; | ||||
Title | Iron-titanium oxide nanocomposites functionalized with gold particles : from design to solar hydrogen production | Type | A1 Journal article | ||
Year | 2016 | Publication | Advanced Materials Interfaces | Abbreviated Journal | Adv Mater Interfaces |
Volume | 3 | Issue | 3 | Pages ![]() |
1600348 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Hematite-titania nanocomposites, eventually functionalized with gold nanoparticles (NPs), are designed and developed by a plasma-assisted strategy, consisting in: (i) the plasma enhanced-chemical vapor deposition of -Fe2O3 on fluorine-doped tin oxide substrates; the radio frequency-sputtering of (ii) TiO2, and (iii) Au in controlled amounts. A detailed chemicophysical characterization, carried out through a multitechnique approach, reveals that the target materials are composed by interwoven -Fe2O3 dendritic structures, possessing a high porosity and active area. TiO2 introduction results in the formation of an ultrathin titania layer uniformly covering Fe2O3, whereas Au sputtering yields a homogeneous dispersion of low-sized gold NPs. Due to the intimate and tailored interaction between the single constituents and their optical properties, the resulting composite materials are successfully exploited for solar-driven applications. In particular, promising photocatalytic performances in H-2 production by reforming of water-ethanol solutions under simulated solar illumination are obtained. The related insights, presented and discussed in this work, can yield useful guidelines to boost the performances of nanostructured photocatalysts for energy-related applications. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000383783200021 | Publication Date | 2016-07-20 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2196-7350; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.279 | Times cited | 15 | Open Access | |
Notes | Approved | Most recent IF: 4.279 | |||
Call Number | UA @ lucian @ c:irua:137154 | Serial | 4389 | ||
Permanent link to this record | |||||
Author | Dubrovinskaia, N.; Dubrovinsky, L.; Solopova, N.A.; Abakumov, A.; Turner, S.; Hanfland, M.; Bykova, E.; Bykov, M.; Prescher, C.; Prakapenka, V.B.; Petitgirard, S.; Chuvashova, I.; Gasharova, B.; Mathis, Y.-L.; Ershov, P.; Snigireva, I.; Snigirev, A. | ||||
Title | Terapascal static pressure generation with ultrahigh yield strength nanodiamond | Type | A1 Journal article | ||
Year | 2016 | Publication | Science Advances | Abbreviated Journal | |
Volume | 2 | Issue | 7 | Pages ![]() |
e1600341-12 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Studies of materials' properties at high and ultrahigh pressures lead to discoveries of unique physical and chemical phenomena and a deeper understanding of matter. In high-pressure research, an achievable static pressure limit is imposed by the strength of available strong materials and design of high-pressure devices. Using a high-pressure and high-temperature technique, we synthesized optically transparent microballs of bulk nanocrystalline diamond, which were found to have an exceptional yield strength (similar to 460 GPa at a confining pressure of similar to 70 GPa) due to the unique microstructure of bulk nanocrystalline diamond. We used the nanodiamond balls in a double-stage diamond anvil cell high-pressure device that allowed us to generate static pressures beyond 1 TPa, as demonstrated by synchrotron x-ray diffraction. Outstanding mechanical properties (strain-dependent elasticity, very high hardness, and unprecedented yield strength) make the nanodiamond balls a unique device for ultrahigh static pressure generation. Structurally isotropic, homogeneous, and made of a low-Z material, they are promising in the field of x-ray optical applications. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000381805300029 | Publication Date | 2016-07-21 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2375-2548 | 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:190527 | Serial | 8647 | ||
Permanent link to this record | |||||
Author | Ben Dkhil, S.; Pfannmöller, M.; Bals, S.; Koganezawa, T.; Yoshimoto, N.; Hannani, D.; Gaceur, M.; Videlot-Ackermann, C.; Margeat, O.; Ackermann, J. | ||||
Title | Square-centimeter-sized high-efficiency polymer solar cells : how the processing atmosphere and film quality influence performance at large scale | Type | A1 Journal article | ||
Year | 2016 | Publication | Laser physics review | Abbreviated Journal | Adv Energy Mater |
Volume | 6 | Issue | 6 | Pages ![]() |
1600290 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Organic solar cells based on two benzodithiophene-based polymers (PTB7 and PTB7-Th) processed at square centimeter-size under inert atmosphere and ambient air, respectively, are investigated. It is demonstrated that the performance of solar cells processed under inert atmosphere is not limited by the upscaling of photoactive layer and the interfacial layers. Thorough morphological and electrical characterizations of optimized layers and corresponding devices reveal that performance losses due to area enlargement are only caused by the sheet resistance of the transparent electrode reducing the effi ciency from 9.3% of 7.8% for PTB7-Th in the condition that both photoactive layer and the interfacial layers are of high layer quality. Air processing of photoactive layer and the interfacial layers into centimeter-sized solar cells lead to additional, but only slight, losses (< 10%) in all photovoltaic parameters, which can be addressed to changes in the electronic properties of both active layer and ZnO layers rather than changes in layer morphology. The demonstrated compatibility of polymer solar cells using solution-processed photoactive layer and interfacial layers with large area indicates that the introduction of a standard active area of 1 cm(2) for measuring effi ciency of organic record solar cells is feasible. However electric standards for indium tin oxides (ITO) or alternative transparent electrodes need to be developed so that performance of new photovoltaic materials can be compared at square centimeter-size. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Place of publication unknown | Editor | ||
Language | Wos | 000379314700010 | Publication Date | 2016-05-04 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1614-6832 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 16.721 | Times cited | 6 | Open Access | Not_Open_Access |
Notes | ; The authors acknowledge financial support by the French Fond Unique Intermisteriel (FUI) under the project “SFUMATO” (Grant number: F1110019V/ 201308815) as well as by the European Commission under the Project “SUNFLOWER” (FP7-ICT-2011-7-contract no. 287594). Generalitat Valenciana (ISIC/2012/008 Institute of Nanotechnologies for Clean Energies) is also acknowledged for providing financial support. The synchrotron radiation experiments were performed at BL46XU and BL19B2 in SPring-8 with the approval of Japan Synchrotron Radiation Research Institute (JASRI) (Proposal Nos. 2014B1916 and 2015A1984). The authors further acknowledge financial support from the European Research Council (ERC Starting Grant #335078-COLOURATOMS). ; | Approved | Most recent IF: 16.721 | ||
Call Number | UA @ lucian @ c:irua:134951 | Serial | 4249 | ||
Permanent link to this record | |||||
Author | De Keukeleere, K.; Cayado, P.; Meledin, A.; Vallès, F.; De Roo, J.; Rijckaert, H.; Pollefeyt, G.; Bruneel, E.; Palau, A.; Coll, M.; Ricart, S.; Van Tendeloo, G.; Puig, T.; Obradors, X.; Van Driessche, I. | ||||
Title | Superconducting YBa2Cu3O7-δNanocomposites Using Preformed ZrO2Nanocrystals: Growth Mechanisms and Vortex Pinning Properties | Type | A1 Journal article | ||
Year | 2016 | Publication | Advanced Electronic Materials | Abbreviated Journal | |
Volume | 2 | Issue | 2 | Pages ![]() |
1600161 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Although high temperature superconductors are promising for power applications, the production of low-cost coated conductors with high current densities—at high magnetic fields—remains challenging. A superior superconducting YBa2Cu3O7–δ nanocomposite is fabricated via chemical solution deposition (CSD) using preformed nanocrystals (NCs). Preformed, colloidally stable ZrO2 NCs are added to the trifluoroacetic acid based precursor solution and the NCs' stability is confirmed up to 50 mol% for at least 2.5 months. These NCs tend to disrupt the epitaxial growth of YBa2Cu3O7–δ, unless a thin seed layer is applied. A 10 mol% ZrO2 NC addition proved to be optimal, yielding a critical current density JC of 5 MA cm−2 at 77 K in self-field. Importantly, this new approach results in a smaller magnetic field decay of JC(H//c) for the nanocomposite compared to a pristine film. Furthermore, microstructural analysis of the YBa2Cu3O7–δ nanocomposite films reveals that different strain generation mechanisms may occur compared to the spontaneous segregation approach. Yet, the generated nanostrain in the YBa2Cu3O7–δ nanocomposite results in an improvement of the superconducting properties similar to the spontaneous segregation approach. This new approach, using preformed NCs in CSD coatings, can be of great potential for high magnetic field applications. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000386624100003 | Publication Date | 2016-09-05 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2199160X | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | 26 | Open Access | ||
Notes | This work was financially supported by a BOF research fund of Ghent University (BOF11/DOC/286), FWO Flanders (F08512), and Eurotapes, a collaborative project funded by the European Community’s Seven Framework Program (EU-FP7 NMP-LA-2012-280432). We also acknowledge MINECO and FEDER funds for MAT2014-51778-C2-1-R and the Center of Excellence award Severo Ochoa SEV-2015-0496, and SGR753 from the Generalitat of Catalunya. MC acknowledges RyC contract 2013-12448 | Approved | Most recent IF: NA | ||
Call Number | EMAT @ emat @ c:irua:135171 | Serial | 4118 | ||
Permanent link to this record | |||||
Author | Yang, S.; Kang, J.; Yue, Q.; Coey, J.M.D.; Jiang, C. | ||||
Title | Defect-modulated transistors and gas-enhanced photodetectors on ReS2 nanosheets | Type | A1 Journal article | ||
Year | 2016 | Publication | Advanced Materials Interfaces | Abbreviated Journal | Adv Mater Interfaces |
Volume | 3 | Issue | 3 | Pages ![]() |
1500707 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | |||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000373149400011 | Publication Date | 2016-01-18 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2196-7350; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.279 | Times cited | 22 | Open Access | |
Notes | ; This work was supported by the National Natural Science Foundations of China (NSFC) under Grant No.51331001. The authors thank S. Tongay for giving them the ReS<INF>2</INF> crystals. ; | Approved | Most recent IF: 4.279 | ||
Call Number | UA @ lucian @ c:irua:133232 | Serial | 4159 | ||
Permanent link to this record | |||||
Author | Kiymaz, D.; Yagmurcukardes, M.; Tomak, A.; Sahin, H.; Senger, R.T.; Peeters, F.M.; Zareie, H.M.; Zafer, C. | ||||
Title | Controlled growth mechanism of poly (3-hexylthiophene) nanowires | Type | A1 Journal article | ||
Year | 2016 | Publication | Nanotechnology | Abbreviated Journal | Nanotechnology |
Volume | 27 | Issue | 27 | Pages ![]() |
455604 |
Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
Abstract | Synthesis of 1D-polymer nanowires by a self-assembly method using marginal solvents is an attractive technique. While the formation mechanism is poorly understood, this method is essential in order to control the growth of nanowires. Here we visualized the time-dependent assembly of poly (3-hexyl-thiophene-2,5-diyl) (P3HT) nanowires by atomic force microscopy and scanning tunneling microscopy. The assembly of P3HT nanowires was carried out at room temperature by mixing cyclohexanone (CHN), as a poor solvent, with polymer solution in 1,2-dichlorobenzene (DCB). Both pi-pi stacking and planarization, obtained at the mix volume ratio of P3HT (in DCB):CHN (10:7), were considered during the investigation. We find that the length of nanowires was determined by the ordering of polymers in the polymer repetition direction. Additionally, our density functional theory calculations revealed that the presence of DCB and CHN molecules that stabilize the structural distortions due to tail group of polymers was essential for the core-wire formation. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Bristol | Editor | ||
Language | Wos | 000386132600003 | Publication Date | 2016-10-11 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0957-4484 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.44 | Times cited | 24 | 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, the High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules Foundation. HS is supported by a FWO Pegasus-Long Marie Curie Fellowship. HS and RTS acknowledge support from TUBITAK through Project No. 114F397. Also, DA is supported by the Scientific Research Project Fund of Ege University (Project Nr: 12GEE011). ; | Approved | Most recent IF: 3.44 | ||
Call Number | UA @ lucian @ c:irua:138159 | Serial | 4350 | ||
Permanent link to this record | |||||
Author | Spadaro, M.C.; Luches, P.; Bertoni, G.; Grillo, V.; Turner, S.; Van Tendeloo, G.; Valeri, S.; D'Addato, S. | ||||
Title | Influence of defect distribution on the reducibility of CeO2-x nanoparticles | Type | A1 Journal article | ||
Year | 2016 | Publication | Nanotechnology | Abbreviated Journal | Nanotechnology |
Volume | 27 | Issue | 27 | Pages ![]() |
425705 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Ceria nanoparticles (NPs) are fundamental in heterogeneous catalysis because of their ability to store or release oxygen depending on the ambient conditions. Their oxygen storage capacity is strictly related to the exposed planes, crystallinity, density and distribution of defects. In this work a study of ceria NPs produced with a ligand-free, physical synthesis method is presented. The NP films were grown by a magnetron sputtering based gas aggregation source and studied by high resolution- and scanning-transmission electron microscopy and x-ray photoelectron spectroscopy. In particular, the influence of the oxidation procedure on the NP reducibility has been investigated. The different reducibility has been correlated to the exposed planes, crystallinity and density and distribution of structural defects. The results obtained in this work represent a basis to obtain cerium oxide NP with desired oxygen transport properties. | ||||
Address | Dipartimento FIM, Universita di Modena e Reggio Emilia, via G. Campi 213/a, I-41125 Modena, Italy. CNR-NANO, via G. Campi 213/a, I-41125 Modena, Italy | ||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | English | Wos | 000385483900004 | Publication Date | 2016-09-15 |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0957-4484 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.44 | Times cited | 11 | Open Access | |
Notes | The authors gratefully acknowledge financial support by the Italian MIUR under grant FIRB RBAP115AYN (Oxides at the nanoscale: multifunctionality and applications). The activity is performed within the COST Action CM1104 'Reducible oxide chemistry, structure and functions'. The research leading to these results has received funding also from the European Union Seventh Framework Programme under Grant Agreement 312483—ESTEEM2 (Integrated Infrastructure Initiative–I3).; esteem2_ta | Approved | Most recent IF: 3.44 | ||
Call Number | EMAT @ emat @ c:irua:135424 | Serial | 4130 | ||
Permanent link to this record | |||||
Author | Tinck, S.; Tillocher, T.; Dussart, R.; Neyts, E.C.; Bogaerts, A. | ||||
Title | Elucidating the effects of gas flow rate on an SF6inductively coupled plasma and on the silicon etch rate, by a combined experimental and theoretical investigation | Type | A1 Journal article | ||
Year | 2016 | Publication | Journal of physics: D: applied physics | Abbreviated Journal | J Phys D Appl Phys |
Volume | 49 | Issue | 49 | Pages ![]() |
385201 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Experiments show that the etch rate of Si with SF6 inductively coupled plasma (ICP) is significantly influenced by the absolute gas flow rate in the range of 50–600 sccm, with a maximum at around 200 sccm. Therefore, we numerically investigate the effects of the gas flow rate on the bulk plasma properties and on the etch rate, to obtain more insight in the underlying reasons of this effect. A hybrid Monte Carlo—fluid model is applied to simulate an SF6 ICP. It is found that the etch rate is influenced by two simultaneous effects: (i) the residence time of the gas and (ii) the temperature profile of the plasma in the ICP volume, resulting indeed in a maximum etch rate at 200 sccm. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000384095900011 | Publication Date | 2016-08-24 | |
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 | 2.588 | Times cited | 1 | Open Access | |
Notes | We are very grateful to Mark Kushner for providing the computational model. The Fund for Scientific Research Flanders (FWO; grant no. 0880.212.840) is acknowledged for financial support of this work. The work was carried out in part using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the University of Antwerp. | Approved | Most recent IF: 2.588 | ||
Call Number | c:irua:134867 | Serial | 4108 | ||
Permanent link to this record | |||||
Author | Moors, K.; Sorée, B.; Magnus, W. | ||||
Title | Validity criteria for Fermi's golden rule scattering rates applied to metallic nanowires | Type | A1 Journal article | ||
Year | 2016 | Publication | Journal of physics : condensed matter | Abbreviated Journal | J Phys-Condens Mat |
Volume | 28 | Issue | 28 | Pages ![]() |
365302 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Fermi's golden rule underpins the investigation of mobile carriers propagating through various solids, being a standard tool to calculate their scattering rates. As such, it provides a perturbative estimate under the implicit assumption that the effect of the interaction Hamiltonian which causes the scattering events is sufficiently small. To check the validity of this assumption, we present a general framework to derive simple validity criteria in order to assess whether the scattering rates can be trusted for the system under consideration, given its statistical properties such as average size, electron density, impurity density et cetera. We derive concrete validity criteria for metallic nanowires with conduction electrons populating a single parabolic band subjected to different elastic scattering mechanisms: impurities, grain boundaries and surface roughness. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | London | Editor | ||
Language | Wos | 000380754400013 | Publication Date | 2016-07-12 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0953-8984 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.649 | Times cited | 2 | Open Access | |
Notes | ; ; | Approved | Most recent IF: 2.649 | ||
Call Number | UA @ lucian @ c:irua:135011 | Serial | 4274 | ||
Permanent link to this record | |||||
Author | Tomak, A.; Bacaksiz, C.; Mendirek, G.; Sahin, H.; Hur, D.; Gorgun, K.; Senger, R.T.; Birer, O.; Peeters, F.M.; Zareie, H.M. | ||||
Title | Structural changes in a Schiff base molecular assembly initiated by scanning tunneling microscopy tip | Type | A1 Journal article | ||
Year | 2016 | Publication | Nanotechnology | Abbreviated Journal | Nanotechnology |
Volume | 27 | Issue | 27 | Pages ![]() |
335601 |
Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
Abstract | We report the controlled self-organization and switching of newly designed Schiff base (E)-4-((4-(phenylethynyl) benzylidene) amino) benzenethiol (EPBB) molecules on a Au (111) surface at room temperature. Scanning tunneling microscopy and spectroscopy (STM/STS) were used to image and analyze the conformational changes of the EPBB molecules. The conformational change of the molecules was induced by using the STM tip while increasing the tunneling current. The switching of a domain or island of molecules was shown to be induced by the STM tip during scanning. Unambiguous fingerprints of the switching mechanism were observed via STM/STS measurements. Surface-enhanced Raman scattering was employed, to control and identify quantitatively the switching mechanism of molecules in a monolayer. Density functional theory calculations were also performed in order to understand the microscopic details of the switching mechanism. These calculations revealed that the molecular switching behavior stemmed from the strong interaction of the EPBB molecules with the STM tip. Our approach to controlling intermolecular mechanics provides a path towards the bottom-up assembly of more sophisticated molecular machines. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Bristol | Editor | ||
Language | Wos | 000383780500012 | Publication Date | 2016-07-05 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0957-4484 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.44 | Times cited | 2 | Open Access | |
Notes | ; The authors acknowledge financial support from TUBITAK (PROJECT NO: 112T507). This work was also supported by the Flemish Science Foundation (FWO-Vl). Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid-Infrastructure). HS is supported by an FWO Pegasus Long Marie Curie Fellowship. ; | Approved | Most recent IF: 3.44 | ||
Call Number | UA @ lucian @ c:irua:137155 | Serial | 4363 | ||
Permanent link to this record | |||||
Author | Van der Donck, M.; Peeters, F.M.; Van Duppen, B. | ||||
Title | Comment on “Creating in-plane pseudomagnetic fields in excess of 1000 T by misoriented stacking in a graphene bilayer” | Type | Editorial | ||
Year | 2016 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 93 | Issue | 93 | Pages ![]() |
247401 |
Keywords | Editorial; Condensed Matter Theory (CMT) | ||||
Abstract | In a recent paper [Phys. Rev. B 89, 125418 (2014)], the authors argue that it is possible to map the electronic properties of twisted bilayer graphene to those of bilayer graphene in an in-plane magnetic field. However, their description of the low-energy dynamics of twisted bilayer graphene is restricted to the extended zone scheme and therefore neglects the effects of the superperiodic structure. If the energy spectrum is studied in the supercell Brillouin zone, we find that the comparison with an in-plane magnetic field fails because (i) the energy spectra of the two situations exhibit different symmetries and (ii) the low-energy spectra are very different. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Amer physical soc | Place of Publication | College pk | Editor | |
Language | Wos | 000377802200009 | Publication Date | 2016-06-14 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9950;2469-9969; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 6 | Open Access | |
Notes | ; ; | Approved | Most recent IF: 3.836 | ||
Call Number | UA @ lucian @ c:irua:134601 | Serial | 4151 | ||
Permanent link to this record | |||||
Author | van den Bos, K.H. W.; De Backer, A.; Martinez, G.T.; Winckelmans, N.; Bals, S.; Nellist, P.D.; Van Aert, S. | ||||
Title | Unscrambling Mixed Elements using High Angle Annular Dark Field Scanning Transmission Electron Microscopy | Type | A1 Journal article | ||
Year | 2016 | Publication | Physical review letters | Abbreviated Journal | Phys Rev Lett |
Volume | 116 | Issue | 116 | Pages ![]() |
246101 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The development of new nanocrystals with outstanding physicochemical properties requires a full threedimensional (3D) characterization at the atomic scale. For homogeneous nanocrystals, counting the number of atoms in each atomic column from high angle annular dark field scanning transmission electron microscopy images has been shown to be a successful technique to get access to this 3D information. However, technologically important nanostructures often consist of more than one chemical element. In order to extend atom counting to heterogeneous materials, a new atomic lensing model is presented. This model takes dynamical electron diffraction into account and opens up new possibilities for unraveling the 3D composition at the atomic scale. Here, the method is applied to determine the 3D structure of Au@Ag core-shell nanorods, but it is applicable to a wide range of heterogeneous complex nanostructures. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000378059500010 | Publication Date | 2016-06-17 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0031-9007 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.462 | Times cited | 46 | Open Access | OpenAccess |
Notes | The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through Projects No. G.0374.13N, No. G.0368.15N, and No. G.0369.15N, and by grants to K. H.W. van den Bos and A. De Backer. S. Bals and N. Winckelmans acknowledge funding from the European Research Council (Starting Grant No. COLOURATOMS 335078). The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant No. 312483—ESTEEM2. The authors are grateful to A. Rosenauer for providing the STEMsim program.; esteem2jra2; ECASSara; (ROMEO:green; preprint:; postprint:can ; pdfversion:can); | Approved | Most recent IF: 8.462 | ||
Call Number | c:irua:133954 c:irua:133954 | Serial | 4084 | ||
Permanent link to this record | |||||
Author | Mohammed, M.; Verhulst, A.S.; Verreck, D.; Van de Put, M.; Simoen, E.; Sorée, B.; Kaczer, B.; Degraeve, R.; Mocuta, A.; Collaert, N.; Thean, A.; Groeseneken, G. | ||||
Title | Electric-field induced quantum broadening of the characteristic energy level of traps in semiconductors and oxides | Type | A1 Journal article | ||
Year | 2016 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 120 | Issue | 120 | Pages ![]() |
245704 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The trap-assisted tunneling (TAT) current in tunnel field-effect transistors (TFETs) is one of the crucial factors degrading the sub-60 mV/dec sub-threshold swing. To correctly predict the TAT currents, an accurate description of the trap is required. Since electric fields in TFETs typically reach beyond 10(6) V/cm, there is a need to quantify the impact of such high field on the traps. We use a quantum mechanical implementation based on the modified transfer matrix method to obtain the trap energy level. We present the qualitative impact of electric field on different trap configurations, locations, and host materials, including both semiconductors and oxides. We determine that there is an electric-field related trap level shift and level broadening. We find that these electric-field induced quantum effects can enhance the trap emission rates. Published by AIP Publishing. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000392174000028 | Publication Date | 2016-12-26 | |
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 | 6 | Open Access | |
Notes | ; This work was supported by imec's Industrial Affiliation Program. D. Verreck acknowledges the support of a PhD stipend from IWT-Vlaanderen. ; | Approved | Most recent IF: 2.068 | ||
Call Number | UA @ lucian @ c:irua:141481 | Serial | 4593 | ||
Permanent link to this record | |||||
Author | Grujić, M.M.; Ezawa, M.; Tadic, M.Z.; Peeters, F.M. | ||||
Title | Tunable skewed edges in puckered structures | Type | A1 Journal article | ||
Year | 2016 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 93 | Issue | 93 | Pages ![]() |
245413 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We propose a type of edges arising due to the anisotropy inherent in the puckered structure of a honeycomb system such as in phosphorene. Skewed-zigzag and skewed-armchair nanoribbons are semiconducting and metallic, respectively, in contrast to their normal edge counterparts. Their band structures are tunable, and a metal-insulator transition is induced by an electric field. We predict a field-effect transistor based on the edge states in skewed-armchair nanoribbons, where the edge state is gapped by applying arbitrary small electric field E-z. A topological argument is presented, revealing the condition for the emergence of such edge states. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000377802700010 | Publication Date | 2016-06-16 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9950;2469-9969; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 29 | Open Access | |
Notes | ; This work was supported by the Serbian Ministry of Education, Science and Technological Development, and the Flemish Science Foundation (FWO-Vl). M.E. is thankful for the support by the Grants-in-Aid for Scientific Research from MEXT KAKENHI (Grants No. 25400317 and No. 15H05854). ; | Approved | Most recent IF: 3.836 | ||
Call Number | UA @ lucian @ c:irua:134599 | Serial | 4268 | ||
Permanent link to this record | |||||
Author | Yagmurcukardes, M.; Senger, R.T.; Peeters, F.M.; Sahin, H. | ||||
Title | Mechanical properties of monolayer GaS and GaSe crystals | Type | A1 Journal article | ||
Year | 2016 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 94 | Issue | 94 | Pages ![]() |
245407 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The mechanical properties of monolayer GaS and GaSe crystals are investigated in terms of their elastic constants: in-plane stiffness (C), Poisson ratio (nu), and ultimate strength (sigma(U)) by means of first-principles calculations. The calculated elastic constants are compared with those of graphene and monolayer MoS2. Our results indicate that monolayer GaS is a stiffer material than monolayer GaSe crystals due to the more ionic character of the Ga-S bonds than the Ga-Se bonds. Although their Poisson ratio values are very close to each other, 0.26 and 0.25 for GaS and GaSe, respectively, monolayer GaS is a stronger material than monolayer GaSe due to its slightly higher sU value. However, GaS and GaSe crystals are found to be more ductile and flexible materials than graphene and MoS2. We have also analyzed the band-gap response of GaS and GaSe monolayers to biaxial tensile strain and predicted a semiconductor-metal crossover after 17% and 14% applied strain, respectively, for monolayer GaS and GaSe. In addition, we investigated how the mechanical properties are affected by charging. We found that the flexibility of single layer GaS and GaSe displays a sharp increase under 0.1e/cell charging due to the repulsive interactions between extra charges located on chalcogen atoms. These charging-controllable mechanical properties of single layers of GaS and GaSe can be of potential use for electromechanical applications. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000389503400008 | Publication Date | 2016-12-05 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9950;2469-9969; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 108 | Open Access | |
Notes | ; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. acknowledges support from Bilim Akademisi-The Science Academy, Turkey under the BAGEP program. R.T.S. acknowledges the support from TUBITAK through project 114F397. ; | Approved | Most recent IF: 3.836 | ||
Call Number | UA @ lucian @ c:irua:139229 | Serial | 4356 | ||
Permanent link to this record | |||||
Author | Tinck, S.; Bogaerts, A. | ||||
Title | Role of vibrationally excited HBr in a HBr/He inductively coupled plasma used for etching of silicon | Type | A1 Journal article | ||
Year | 2016 | Publication | Journal of physics: D: applied physics | Abbreviated Journal | J Phys D Appl Phys |
Volume | 49 | Issue | 49 | Pages ![]() |
245204 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | In this work, the role of vibrationally excited HBr (HBr(vib)) is computationally investigated for a HBr/He inductively coupled plasma applied for Si etching. It is found that at least 50% of all dissociations of HBr occur through HBr(vib). This additional dissociation pathway through HBr(vib) makes the plasma significantly more atomic. It also results in a slightly higher electron temperature (i.e. about 0.2 eV higher compared to simulation results where HBr(vib) is not included), as well as a higher gas temperature (i.e. about 50 K higher than without including HBr(vib)), due to the enhanced Franck–Condon heating through HBr(vib) dissociation, at the conditions investigated. Most importantly, the calculated etch rate with HBr(vib) included in the model is a factor 3 higher than in the case without HBr(vib), due to the higher fluxes of etching species (i.e. H and Br), while the chemical composition of the wafer surface shows no significant difference. Our calculations clearly show the importance of including HBr(vib) for accurate modeling of HBr-containing plasmas. |
||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000377427100020 | Publication Date | 2016-05-17 | |
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 | 2.588 | Times cited | Open Access | ||
Notes | The Fund for Scientific Research Flanders (FWO) is acknowledged for financial support of this work (Grant no. 0880.212.840). This work was carried out in part using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the University of Antwerp. Prof. Mark Kushner is also gratefully acknowledged for the useful discussions and for providing the HPEM code. | Approved | Most recent IF: 2.588 | ||
Call Number | c:irua:133457 | Serial | 4072 | ||
Permanent link to this record | |||||
Author | Heshmati-Moulai, A.; Simchi, H.; Esmaeilzadeh, M.; Peeters, F.M. | ||||
Title | Phase transition and spin-resolved transport in MoS2 nanoribbons | Type | A1 Journal article | ||
Year | 2016 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 94 | Issue | 94 | Pages ![]() |
235424 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The electronic structure and transport properties of monolayer MoS2 are studied using a tight-binding approach coupled with the nonequilibrium Green's function method. A zigzag nanoribbon of MoS2 is conducting due to the intersection of the edge states with the Fermi level that is located within the bulk gap. We show that applying a transverse electric field results in the disappearance of this intersection and turns the material into a semiconductor. By increasing the electric field the band gap undergoes a two stage linear increase after which it decreases and ultimately closes. It is shown that in the presence of a uniform exchange field, this electric field tuning of the gap can be exploited to open low energy domains where only one of the spin states contributes to the electronic conductance. This introduces possibilities in designing spin filters for spintronic applications. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000394546100005 | Publication Date | 2016-12-20 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9950;2469-9969; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 7 | Open Access | |
Notes | ; ; | Approved | Most recent IF: 3.836 | ||
Call Number | UA @ lucian @ c:irua:141978 | Serial | 4557 | ||
Permanent link to this record | |||||
Author | Petrovic, M.D.; Peeters, F.M. | ||||
Title | Quantum transport in graphene Hall bars: Effects of vacancy disorder | Type | A1 Journal article | ||
Year | 2016 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 94 | Issue | 94 | Pages ![]() |
235413 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Using the tight-binding model, we investigate the influence of vacancy disorder on electrical transport in graphene Hall bars in the presence of quantizing magnetic fields. Disorder, induced by a random distribution of monovacancies, breaks the graphene sublattice symmetry and creates states localized on the vacancies. These states are observable in the bend resistance, as well as in the total DOS. Their energy is proportional to the square root of the magnetic field, while their localization length is proportional to the cyclotron radius. At the energies of these localized states, the electron current flows around the monovacancies and, as we show, it can follow unexpected paths depending on the particular arrangement of vacancies. We study how these localized states change with the vacancy concentration, and what are the effects of including the next-nearest-neighbor hopping term. Our results are also compared with the situation when double vacancies are present in the system. Double vacancies also induce localized states, but their energy and magnetic field dependencies are different. Their localization energy scales linearly with the magnetic field, and their localization length appears not to depend on the field strength. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000389574200005 | Publication Date | 2016-12-14 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9950;2469-9969; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 14 | Open Access | |
Notes | ; This work was supported by the Methusalem program of the Flemish government. ; | Approved | Most recent IF: 3.836 | ||
Call Number | UA @ lucian @ c:irua:140237 | Serial | 4459 | ||
Permanent link to this record | |||||
Author | Berdiyorov, G.R.; Mortazavi, B.; Ahzi, S.; Peeters, F.M.; Khraisheh, M.K. | ||||
Title | Effect of straining graphene on nanopore creation using Si cluster bombardment: A reactive atomistic investigation | Type | A1 Journal article | ||
Year | 2016 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 120 | Issue | 120 | Pages ![]() |
225108 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Graphene nanosheets have recently received a revival of interest as a new class of ultrathin, high-flux, and energy-efficient sieving membranes because of their unique two-dimensional and atomically thin structure, good flexibility, and outstanding mechanical properties. However, for practical applications of graphene for advanced water purification and desalination technologies, the creation of well controlled, high-density, and subnanometer diameter pores becomes a key factor. Here, we conduct reactive force-field molecular dynamics simulations to study the effect of external strain on nanopore creation in the suspended graphene by bombardment with Si clusters. Depending on the size and energy of the clusters, different kinds of topography were observed in the graphene sheet. In all the considered conditions, tensile strain results in the creation of nanopores with regular shape and smooth edges. On the contrary, compressive strain increases the elastic response of graphene to irradiation that leads to the formation of net-like defective structures with predominantly carbon atom chains. Our findings show the possibility of creating controlled nanopores in strained graphene by bombardment with Si clusters. Published by AIP Publishing. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000391535900022 | Publication Date | 2016-12-15 | |
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 | 10 | Open Access | |
Notes | ; ; | Approved | Most recent IF: 2.068 | ||
Call Number | UA @ lucian @ c:irua:141451 | Serial | 4554 | ||
Permanent link to this record | |||||
Author | Clima, S.; Chen, Y.Y.; Chen, C.Y.; Goux, L.; Govoreanu, B.; Degraeve, R.; Fantini, A.; Jurczak, M.; Pourtois, G. | ||||
Title | First-principles thermodynamics and defect kinetics guidelines for engineering a tailored RRAM device | Type | A1 Journal article | ||
Year | 2016 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 119 | Issue | 119 | Pages ![]() |
225107 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Resistive Random Access Memories are among the most promising candidates for the next generation of non-volatile memory. Transition metal oxides such as HfOx and TaOx attracted a lot of attention due to their CMOS compatibility. Furthermore, these materials do not require the inclusion of extrinsic conducting defects since their operation is based on intrinsic ones (oxygen vacancies). Using Density Functional Theory, we evaluated the thermodynamics of the defects formation and the kinetics of diffusion of the conducting species active in transition metal oxide RRAM materials. The gained insights based on the thermodynamics in the Top Electrode, Insulating Matrix and Bottom Electrode and at the interfaces are used to design a proper defect reservoir, which is needed for a low-energy reliable switching device. The defect reservoir has also a direct impact on the retention of the Low Resistance State due to the resulting thermodynamic driving forces. The kinetics of the diffusing conducting defects in the Insulating Matrix determine the switching dynamics and resistance retention. The interface at the Bottom Electrode has a significant impact on the low-current operation and long endurance of the memory cell. Our first-principles findings are confirmed by experimental measurements on fabricated RRAM devices. Published by AIP Publishing. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000378925400035 | Publication Date | 2016-06-10 | |
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 | 17 | Open Access | |
Notes | Approved | Most recent IF: 2.068 | |||
Call Number | UA @ lucian @ c:irua:134651 | Serial | 4181 | ||
Permanent link to this record | |||||
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 | Mulkers, J.; Milošević, M.V.; Van Waeyenberge, B. | ||||
Title | Cycloidal versus skyrmionic states in mesoscopic chiral magnets | Type | A1 Journal article | ||
Year | 2016 | Publication | Physical review : B : condensed matter and materials physics | Abbreviated Journal | Phys Rev B |
Volume | 93 | Issue | 93 | Pages ![]() |
214405 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | When subjected to the interfacially induced Dzyaloshinskii-Moriya interaction, the ground state in thin ferromagnetic films with high perpendicular anisotropy is cycloidal. The period of this cycloidal state depends on the strength of the Dzyaloshinskii-Moriya interaction. In this work, we have studied the effect of confinement on the magnetic ground state and excited states, and we determined the phase diagram of thin strips and thin square platelets by means of micromagnetic calculations. We show that multiple cycloidal states with different periods can be stable in laterally confined films, where the period of the cycloids does not depend solely on the Dzyaloshinskii-Moriya interaction strength but also on the dimensions of the film. The more complex states comprising skyrmions are also found to be stable, though with higher energy. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000377298600006 | Publication Date | 2016-06-06 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 28 | Open Access | |
Notes | ; ; | Approved | Most recent IF: 3.836 | ||
Call Number | c:irua:133919 | Serial | 4081 | ||
Permanent link to this record | |||||
Author | Van de Put, M.L.; Vandenberghe, W.G.; Sorée, B.; Magnus, W.; Fischetti, M.V. | ||||
Title | Inter-ribbon tunneling in graphene: An atomistic Bardeen approach | Type | A1 Journal article | ||
Year | 2016 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 119 | Issue | 119 | Pages ![]() |
214306 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | A weakly coupled system of two crossed graphene nanoribbons exhibits direct tunneling due to the overlap of the wavefunctions of both ribbons. We apply the Bardeen transfer Hamiltonian formalism, using atomistic band structure calculations to account for the effect of the atomic structure on the tunneling process. The strong quantum-size confinement of the nanoribbons is mirrored by the one-dimensional character of the electronic structure, resulting in properties that differ significantly from the case of inter-layer tunneling, where tunneling occurs between bulk two-dimensional graphene sheets. The current-voltage characteristics of the inter-ribbon tunneling structures exhibit resonance, as well as stepwise increases in current. Both features are caused by the energetic alignment of one-dimensional peaks in the density-of-states of the ribbons. Resonant tunneling occurs if the sign of the curvature of the coupled energy bands is equal, whereas a step-like increase in the current occurs if the signs are opposite. Changing the doping modulates the onset-voltage of the effects as well as their magnitude. Doping through electrostatic gating makes these structures promising for application towards steep slope switching devices. Using the atomistic empirical pseudopotentials based Bardeen transfer Hamiltonian method, inter-ribbon tunneling can be studied for the whole range of two-dimensional materials, such as transition metal dichalcogenides. The effects of resonance and of step-like increases in the current we observe in graphene ribbons are also expected in ribbons made from these alternative two-dimensional materials, because these effects are manifestations of the one-dimensional character of the density-of-states. Published by AIP Publishing. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000378923100022 | Publication Date | 2016-06-07 | |
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 | 6 | Open Access | |
Notes | ; ; | Approved | Most recent IF: 2.068 | ||
Call Number | UA @ lucian @ c:irua:134652 | Serial | 4198 | ||
Permanent link to this record | |||||
Author | Milovanović, S.P.; Peeters, F.M. | ||||
Title | Strain controlled valley filtering in multi-terminal graphene structures | Type | A1 Journal article | ||
Year | 2016 | Publication | Applied physics letters | Abbreviated Journal | Appl Phys Lett |
Volume | 109 | Issue | 109 | Pages ![]() |
203108 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Valley-polarized currents can be generated by local straining of multi-terminal graphene devices. The pseudo-magnetic field created by the deformation allows electrons from only one valley to transmit, and a current of electrons from a single valley is generated at the opposite side of the locally strained region. We show that valley filtering is most effective with bumps of a certain height and width. Despite the fact that the highest contribution to the polarized current comes from electrons from the lowest sub-band, contributions of other sub-bands are not negligible and can significantly enhance the output current. Published by AIP Publishing. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000388000000049 | Publication Date | 2016-11-16 | |
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 | 3.411 | Times cited | 50 | Open Access | |
Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN. ; | Approved | Most recent IF: 3.411 | ||
Call Number | UA @ lucian @ c:irua:139165 | Serial | 4463 | ||
Permanent link to this record | |||||
Author | Yagmurcukardes, M.; Torun, E.; Senger, R.T.; Peeters, F.M.; Sahin, H. | ||||
Title | Mg(OH)2-WS2 van der Waals heterobilayer : electric field tunable band-gap crossover | Type | A1 Journal article | ||
Year | 2016 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 94 | Issue | 94 | Pages ![]() |
195403 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Magnesium hydroxide [Mg(OH)(2)] has a layered brucitelike structure in its bulk form and was recently isolated as a new member of two-dimensional monolayer materials. We investigated the electronic and optical properties of monolayer crystals of Mg(OH)(2) and WS2 and their possible heterobilayer structure by means of first-principles calculations. It was found that both monolayers of Mg(OH)(2) and WS2 are direct-gap semiconductors and these two monolayers form a typical van der Waals heterostructure with a weak interlayer interaction and a type-II band alignment with a staggered gap that spatially separates electrons and holes. We also showed that an out-of-plane electric field induces a transition from a staggered to a straddling-type heterojunction. Moreover, by solving the Bethe-Salpeter equation on top of single-shot G(0)W(0) calculations, we show that the low-energy spectrum of the heterobilayer is dominated by the intralyer excitons of the WS2 monolayer. Because of the staggered interfacial gap and the field-tunable energy-band structure, the Mg(OH)(2)-WS2 heterobilayer can become an important candidate for various optoelectronic device applications in nanoscale. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000386769400007 | Publication Date | 2016-11-03 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9950;2469-9969; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 38 | 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). H.S. is supported by a FWOPegasus Long Marie Curie Fellowship. H.S. and R.T.S. acknowledge support from TUBITAK through Project No. 114F397. H.S. acknowledges support from Bilim Akademisi – The Science Academy, Turkey, under the BAGEP program. ; | Approved | Most recent IF: 3.836 | ||
Call Number | UA @ lucian @ c:irua:138205 | Serial | 4364 | ||
Permanent link to this record | |||||
Author | Cukaric, N.A.; Partoens, B.; Tadic, M.Z.; Arsoski, V.V.; Peeters, F.M. | ||||
Title | The 30-band k . p theory of valley splitting in silicon thin layers | Type | A1 Journal article | ||
Year | 2016 | Publication | Journal of physics : condensed matter | Abbreviated Journal | J Phys-Condens Mat |
Volume | 28 | Issue | 28 | Pages ![]() |
195303 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The valley splitting of the conduction-band states in a thin silicon-on-insulator layer is investigated using the 30-band k . p theory. The system composed of a few nm thick Si layer embedded within thick SiO2 layers is analyzed. The valley split states are found to cross periodically with increasing quantum well width, and therefore the energy splitting is an oscillatory function of the quantum well width, with period determined by the wave vector K-0 of the conduction band minimum. Because the valley split states are classified by parity, the optical transition between the ground hole state and one of those valley split conduction band states is forbidden. The oscillations in the valley splitting energy decrease with electric field and with smoothing of the composition profile between the well and the barrier by diffusion of oxygen from the SiO2 layers to the Si quantum well. Such a smoothing also leads to a decrease of the interband transition matrix elements. The obtained results are well parametrized by the effective two-valley model, but are found to disagree from previous 30-band calculations. This discrepancy could be traced back to the fact that the basis for the numerical solution of the eigenproblem must be restricted to the first Brillouin zone in order to obtain quantitatively correct results for the valley splitting. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | London | Editor | ||
Language | Wos | 000374394700009 | Publication Date | 2016-04-19 | |
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 | ||
Notes | ; This work was supported by the Ministry of Education, Science, and Technological Development of Serbia, the Flemish fund for Scientific Research (FWO-Vl), and the Methusalem programme of the Flemish government. ; | Approved | Most recent IF: 2.649 | ||
Call Number | UA @ lucian @ c:irua:133610 | Serial | 4261 | ||
Permanent link to this record | |||||
Author | Sivek, J.; Sahin, H.; Partoens, B.; Peeters, F.M. | ||||
Title | Giant magnetic anisotropy in doped single layer molybdenum disulfide and fluorographene | Type | A1 Journal article | ||
Year | 2016 | Publication | Journal of physics : condensed matter | Abbreviated Journal | J Phys-Condens Mat |
Volume | 28 | Issue | 28 | Pages ![]() |
195301 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Stable monolayer materials based on existing, well known and stable two-dimensional crystal fluorographene and molybdenum disulfide are predicted to exhibit a huge magnetocrystalline anisotropy when functionalized with adsorbed transition metal atoms at vacant sides. Ab initio calculations within the density-functional theory formalism were performed to investigate the adsorption of the transitional metals in a single S (or F) vacancy of monolayer molybdenum disulfide (or fluorographene). We found strong bonding of the transitional metal atoms to the vacant sites with binding energies ranging from 2.5 to 5.2 eV. Our calculations revealed that these systems with adsorbed metal atoms exhibit a magnetic anisotropy, specifically the structures including Os and Ir show a giant magnetocrystalline anisotropy energy of 31-101 meV. Our results demonstrate the possibility of obtaining stable monolayer materials with huge magnetocrystalline anisotropy based on preexisting, well known and stable two-dimensional crystals: fluorographene and molybdenum disulfide. We believe that the results obtained here are useful not only for deeper understanding of the origin of magnetocrystalline anisotropy but also for the design of monolayer optoelectronic devices with novel functionalities. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | London | Editor | ||
Language | Wos | 000374394700007 | Publication Date | 2016-04-13 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0953-8984 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.649 | Times cited | 7 | Open Access | |
Notes | Approved | Most recent IF: 2.649 | |||
Call Number | UA @ lucian @ c:irua:133611 | Serial | 4185 | ||
Permanent link to this record | |||||
Author | Tinck, S.; Bogaerts, A. | ||||
Title | Computational study of the CF4 /CHF3 / H2 /Cl2 /O2 /HBr gas phase plasma chemistry | Type | A1 Journal article | ||
Year | 2016 | Publication | Journal of physics: D: applied physics | Abbreviated Journal | J Phys D Appl Phys |
Volume | 49 | Issue | 49 | Pages ![]() |
195203 |
Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | A modelling study is performed of high-density low-pressure inductively coupled CF4/CHF3/H2/Cl2/O2/HBr plasmas under different gas mixing ratios. A reaction set describing the complete plasma chemistry is presented and discussed. The gas fraction of each component in this mixture is varied to investigate the sensitivity of the plasma properties, like electron density, plasma potential and species densities, towards the gas mixing ratios. This research is of great interest for microelectronics applications because these gases are often combined in two (or more)-component mixtures, and mixing gases or changing the fraction of a gas can sometimes yield unwanted reaction products or unexpected changes in the overall plasma properties due to the increased chemical complexity of the system. Increasing the CF4 fraction produces more F atoms for chemical etching as expected, but also more prominently lowers the density of Cl atoms, resulting in an actual drop in the etch rate under certain conditions. Furthermore, CF4 decreases the free electron density when mixed with Cl2. However, depending on the other gas components, CF4 gas can also sometimes enhance free electron density. This is the case when HBr is added to the mixture. The addition of H2 to the gas mixture will lower the sputtering process, not only due to the lower overall positive ion density at higher H2 fractions, but also because more H+, H2 + and H3 + are present and they have very low sputter yields. In contrast, a larger Cl2 fraction results in more chemical etching but also in less physical sputtering due to a smaller abundance of positive ions. Increasing the O2 fraction in the plasma will always lower the etch rate due to more oxidation of the wafer surface and due to a lower plasma density. However, it is also observed that the density of F atoms can actually increase with rising O2 gas fraction. This is relevant to note because the exact balance between fluorination and oxidation is important for fine-tuning the overall etch rate and for control of the sidewall profile. Finally, HBr is often used as a chemical etcher, but when mixed with F- or Cl-containing gases, HBr creates the same diluting effects as Ar or He, because a higher fraction results in less chemical etching but more (physical) sputtering. |
||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000375255500017 | Publication Date | 2016-04-13 | |
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 | 2.588 | Times cited | 5 | Open Access | |
Notes | We acknowledge the Fund for Scientific Research Flanders (FWO) for financial support of this work. This work was carried out in part using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the University of Antwerp. | Approved | Most recent IF: 2.588 | ||
Call Number | c:irua:132890 | Serial | 4062 | ||
Permanent link to this record | |||||
Author | Andrikopoulos, D.; Sorée, B.; De Boeck, J. | ||||
Title | Skyrmion-induced bound states on the surface of three-dimensional topological insulators | Type | A1 Journal article | ||
Year | 2016 | Publication | Journal of applied physics | Abbreviated Journal | J Appl Phys |
Volume | 119 | Issue | 119 | Pages ![]() |
193903 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The interaction between the surface of a 3D topological insulator and a skyrmion/anti-skyrmion structure is studied in order to investigate the possibility of electron confinement due to the skyrmion presence. Both hedgehog (Neel) and vortex (Bloch) skyrmions are considered. For the hedgehog skyrmion, the in-plane components cannot be disregarded and their interaction with the surface state of the topological insulator (TI) has to be taken into account. A semi-classical description of the skyrmion chiral angle is obtained using the variational principle. It is shown that both the hedgehog and the vortex skyrmion can induce bound states on the surface of the TI. However, the number and the properties of these states depend strongly on the skyrmion type and the skyrmion topological number N-Sk. The probability densities of the bound electrons are also derived where it is shown that they are localized within the skyrmion region. Published by AIP Publishing. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | American Institute of Physics | Place of Publication | New York, N.Y. | Editor | |
Language | Wos | 000377718100013 | Publication Date | 2016-05-18 | |
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 | 8 | Open Access | |
Notes | ; ; | Approved | Most recent IF: 2.068 | ||
Call Number | UA @ lucian @ c:irua:134607 | Serial | 4244 | ||
Permanent link to this record |