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Author (up) Leenaerts, O.; Vercauteren, S.; Schoeters, B.; Partoens, B.
Title System-size dependent band alignment in lateral two-dimensional heterostructures Type A1 Journal article
Year 2016 Publication 2D materials Abbreviated Journal 2D Mater
Volume 3 Issue 3 Pages 025012
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The electronic band alignment in semiconductor heterostructures is a key factor for their use in electronic applications. The alignment problem has been intensively studied for bulk systems but is less well understood for low-dimensional heterostructures. In this work we investigate the alignment in two-dimensional lateral heterostructures. First-principles calculations are used to show that the electronic band offset depends crucially on the width and thickness of the heterostructure slab. The particular heterostructures under study consist of thin hydrogenated and fluorinated diamond slabs which are laterally joined together. Two different limits for the band offset are observed. For infinitely wide heterostructures the vacuum potential above the two materials is aligned leading to a large step potential within the heterostructure. For infinitely thick heterostructure slabs, on the other hand, there is no potential step in the heterostructure bulk, but a large potential step in the vacuum region above the heterojunction is observed. The band alignment in finite systems depends on the particular dimensions of the system. These observations are shown to result from an interface dipole at the heterojunction that tends to align the band structures.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000378571400032 Publication Date 2016-04-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2053-1583 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.937 Times cited 19 Open Access
Notes This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vl). The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Hercules Foundation and the Flemish Government— department EWI. Approved Most recent IF: 6.937
Call Number c:irua:132792 c:irua:132792 Serial 4055
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Author (up) Lei, C.H.; Van Tendeloo, G.; Siegert, M.; Schubert, J.
Title Microstructural investigation of BaTiO3 thin films deposited on (001) MgO Type A1 Journal article
Year 2002 Publication Journal of materials research Abbreviated Journal J Mater Res
Volume 17 Issue 8 Pages 1923-1931
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The microstructure of BaTiO3 thin films, epitaxially deposited on (001) MgO by pulsed laser ablation, has been investigated by transmission electron microscopy. The films are always c-axis-orientated, but dislocations, {111} stacking faults, and antiphase boundaries are frequently observed. Conventional TEM and high-resolution microscopy allow one to deduce the Burgers vectors of dislocations as b(1) = <100> or b(2) = <110>, both being perfect dislocations. Most extrinsic stacking faults are ending at 1/3<112> or 1/3<111> partial dislocations; the displacement vector of the antiphase boundaries is 1/2<101>. Studying the interfacial structure by means of zone images taken along [100] and [110] shows that the misfit is mainly released by dislocations with Burgers vectors of 1/2<110> and 1/2<101>.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000177208800010 Publication Date 2008-03-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0884-2914;2044-5326; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.673 Times cited 8 Open Access
Notes Approved Most recent IF: 1.673; 2002 IF: 1.530
Call Number UA @ lucian @ c:irua:103343 Serial 2044
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Author (up) Lepoittevin, C.; Malo, S.; Nguyen, N.; Hebert, S.; Van Tendeloo, G.; Hervieu, M.
Title A layered iron-rich 2234-type with a mixed valence of iron: the ferrimagnetic Tl-doped Fe2(Sr2-\varepsilonTl\varepsilon)Sr3Fe4O14.65 Type A1 Journal article
Year 2008 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 20 Issue 20 Pages 6468-6476
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A new Tl-doped strontium ferrite Fe2(Sr2-Tl)Sr3Fe4O14.65, with an original structure, has been synthesized and structurally characterized by powder X-ray diffraction and transmission electron microscopy. The TGA and Mssbauer studies evidence a mixed valence of iron. The structure exhibits a commensurate modulation, with a F-type subcell a ≈ b ≈ 5.4 Å (≈ ap√2), c ≈ 42 Å with a modulation vector q = αa* with α = 0.4. The supercell parameters have been refined as a= 27.1101(8) Å, b= 5.5187(2) Å and c= 42.0513(9) Å, in the space group Fmmm. The electron diffraction and electron microscopy data of this novel ferrite show that it can be described as a FeTl-2234-type structure corresponding to the intergrowth of a quadruple perovskite slice [(SrFeO2.8)4], with a complex rock salt related slice [Fe2(Sr2-Tl)O3.4]∞, built up of one double iron layer [Fe2O2.4] sandwiched between two [SrO] layers. The HRTEM images show that the oxygen atoms and vacancies are randomly distributed in the perovskite layers while the HAADF STEM images evidence the absence of Tl segregation in the matrix. Fe2(Sr2-Tl)Sr3Fe4O14.65 exhibits a very large value of χ (11emu/mol) at 5 K, which remains large at 400 K; the M(H) loop presents a shape characteristic of ferrimagnetism, with a large coercive field of 0.3 T. The value of magnetization saturates at 400 K at 0.68 μB/Fe. At 10 K, the value of magnetization reaches a maximum of 2 μB/Fe. The resistivity presents a semiconducting-like behavior, with ρ 800 Ω·cm at 300 K.
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Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000260254400030 Publication Date 2008-09-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 8 Open Access
Notes Approved Most recent IF: 9.466; 2008 IF: 5.046
Call Number UA @ lucian @ c:irua:76671 Serial 1804
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Author (up) Leroux, C.; Nihoul, G.; Van Tendeloo, G.
Title From VO2(B) to VO2(R): theoretical structures of VO2 polymorphs and in situ electron microscopy Type A1 Journal article
Year 1998 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 57 Issue 9 Pages 5111-5121
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
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Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000072358600037 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 3.836 Times cited 122 Open Access
Notes Approved Most recent IF: 3.836; 1998 IF: NA
Call Number UA @ lucian @ c:irua:25658 Serial 1290
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Author (up) Leroux, F.; Gysemans, M.; Bals, S.; Batenburg, K.J.; Snauwaert, J.; Verbiest, T.; van Haesendonck, C.; Van Tendeloo, G.
Title Three-dimensional characterization of helical silver nanochains mediated by protein assemblies Type A1 Journal article
Year 2010 Publication Advanced materials Abbreviated Journal Adv Mater
Volume 22 Issue 19 Pages 2193-2197
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract Characterization methods for the structural investigation of biotemplates for nanodevices remain widely unexplored, despite the fact that biotemplating methods for nanodevice fabrication are becoming more widespread. In this study several techniques are used to characterize the morphology and 3D distribution of silver nanoparticles deposited on insulin fibrils.
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Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000278601400016 Publication Date 2010-03-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648;1521-4095; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 19.791 Times cited 51 Open Access
Notes Esteem 026019; Fwo Approved Most recent IF: 19.791; 2010 IF: NA
Call Number UA @ lucian @ c:irua:83296 Serial 3645
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Author (up) Leus, K.; Dendooven, J.; Tahir, N.; Ramachandran, R.; Meledina, M.; Turner, S.; Van Tendeloo, G.; Goeman, J.; Van der Eycken, J.; Detavernier, C.; Van Der Voort, P.
Title Atomic Layer Deposition of Pt Nanoparticles within the Cages of MIL-101: A Mild and Recyclable Hydrogenation Catalyst Type A1 Journal article
Year 2016 Publication Nanomaterials Abbreviated Journal Nanomaterials-Basel
Volume 6 Issue 6 Pages 45
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract We present the in situ synthesis of Pt nanoparticles within MIL-101-Cr (MIL = Materials Institute Lavoisier) by means of atomic layer deposition (ALD). The obtained Pt@MIL-101 materials were characterized by means of N2 adsorption and X-ray powder diffraction (XRPD) measurements, showing that the structure of the metal organic framework was well preserved during the ALD deposition. X-ray fluorescence (XRF) and transmission electron microscopy (TEM) analysis confirmed the deposition of highly dispersed Pt nanoparticles with sizes determined by the MIL-101-Cr pore sizes and with an increased Pt loading for an increasing number of ALD cycles. The Pt@MIL-101 material was examined as catalyst in the hydrogenation of different linear and cyclic olefins at room temperature, showing full conversion for each substrate. Moreover, even under solvent free conditions, full conversion of the substrate was observed. A high concentration test has been performed showing that the Pt@MIL-101 is stable for a long reaction time without loss of activity, crystallinity and with very low Pt leaching.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000373533300009 Publication Date 2016-03-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2079-4991 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.553 Times cited 19 Open Access
Notes Karen Leus acknowledges the financial support from the Ghent University “Bijzonder Onderzoeksfonds” BOF post-doctoral Grant 01P06813T and UGent “Geconcentreeerde Onderzoekacties” GOA Grant 01G00710. Jolien Dendooven and Stuart Turner gratefully acknowledges the “Fonds Wetenschappelijk Onderzoek” FWO Vlaanderen for a post-doctoral scholarship. Christophe Detavernier thanks the FWO Vlaanderen, BOF-UGent (GOA 01G01513) and the Hercules Foundation (AUGE/09/014) for financial support. The Titan microscope used for this investigation was partially funded by the Hercules foundation of the Flemish government. This work was supported by the “Belgian Interuniversitaire Attractie Pool-Pôle d'Attraction Interuniversitaire” IAP-PAI network. Approved Most recent IF: 3.553
Call Number c:irua:131902 Serial 4015
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Author (up) Leus, K.; Folens, K.; Nicomel, N.R.; Perez, J.P.H.; Filippousi, M.; Meledina, M.; Dirtu, M.M.; Turner, S.; Van Tendeloo, G.; Garcia, Y.; Du Laing, G.; Van Der Voort, P.
Title Removal of arsenic and mercury species from water by covalent triazine framework encapsulated \gamma-Fe2O3 nanoparticles Type A1 Journal article
Year 2018 Publication Journal of hazardous materials Abbreviated Journal J Hazard Mater
Volume 353 Issue 353 Pages 312-319
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The covalent triazine framework, CTF-1, served as host material for the in situ synthesis of Fe2O3 nanoparticles. The composite material consisted of 20 +/- 2 m% iron, mainly in gamma-Fe2O3 phase. The resulting gamma-Fe2O3@CTF-1 was examined for the adsorption of As-III, As-V and H-II from synthetic solutions and real surface-, ground- and wastewater. The material shows excellent removal efficiencies, independent from the presence of Ca2+, Mg2+ or natural organic matter and only limited dependency on the presence of phosphate ions. Its adsorption capacity towards arsenite (198.0 mg g(-1)), arsenate (102.3 mg g(-1)) and divalent mercury (165.8 mg g(-1)) belongs amongst the best-known adsorbents, including many other iron-based materials. Regeneration of the adsorbent can be achieved for use over multiple cycles without a decrease in performance by elution at 70 degrees C with 0.1 M NaOH, followed by a stirring step in a 5 m% H2O2 solution for As or 0.1 M thiourea and 0.001 M HCl for Hg. In highly contaminated water (100 mu gL(-1)), the adsorbent polishes the water quality to well below the current WHO limits.
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Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000438002800035 Publication Date 2018-04-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3894 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.065 Times cited 22 Open Access OpenAccess
Notes ; Karen Leus acknowledges financial support from Ghent University. Nina Ricci Nicomel and Jeffrey Paulo H. Perez thank the funding of the VLIR-UOS. Marinela M. Dirtu acknowledges F.R.S.-FNRS for a Charge de recherches position. Stuart Turner gratefully acknowledges the FWO Vlaanderen for a post-doctoral scholarship. The Titan microscope used for this investigation was partially funded by the Hercules foundation of the Flemish government. This work was supported by the Belgian IAP-PAI network. ; Approved Most recent IF: 6.065
Call Number UA @ lucian @ c:irua:152430 Serial 5124
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Author (up) Leusink, D.P.; Coneri, F.; Hoek, M.; Turner, S.; Idrissi, H.; Van Tendeloo, G.; Hilgenkamp, H.
Title Thin films of the spin ice compound Ho2Ti2O7 Type A1 Journal article
Year 2014 Publication APL materials Abbreviated Journal Apl Mater
Volume 2 Issue 3 Pages 032101-32107
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The pyrochlore compounds Ho2Ti2O7 and Dy2Ti2O7 show an exotic form of magnetism called the spin ice state, resulting from the interplay between geometrical frustration and ferromagnetic coupling. A fascinating feature of this state is the appearance of magnetic monopoles as emergent excitations above the degenerate ground state. Over the past years, strong effort has been devoted to the investigation of these monopoles and other properties of the spin ice state in bulk crystals. Here, we report the fabrication of Ho2Ti2O7 thin films using pulsed laser deposition on yttria-stabilized ZrO2 substrates. We investigated the structural properties of these films by X-ray diffraction, scanning transmission electron microscopy, and atomic force microscopy, and the magnetic properties by vibrating sample magnetometry at 2 K. The films not only show a high crystalline quality, but also exhibit the hallmarks of a spin ice: a pronounced magnetic anisotropy and an intermediate plateau in the magnetization along the [111] crystal direction.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000334220300002 Publication Date 2014-03-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2166-532X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.335 Times cited 18 Open Access
Notes The authors acknowledge support from the Dutch FOM and NWO foundations and from the European Union under the Framework 7 program under a contract from an Integrated Infrastructure Initiative (Reference 312483 ESTEEM2). G.V.T. acknowledges the ERC Grant N246791- COUNTATOMS. S.T. gratefully acknowledges financial support from the Fund for Scientific Research Flanders (FWO). H.I. acknowledges the IAP program of the Belgian State Federal Office for Scientific, Technical and Cultural Affairs under Contract No. P7/21. The microscope used in this study was partially financed by the Hercules Foundation of the Flemish Government. The authors acknowledge fruitful interactions with A. Brinkman, M. G. Blamire, M. Egilmez, F. J. G. Roesthuis, J. N. Beukers, C. G. Molenaar, M. Veldhorst, and X. Renshaw Wang; esteem2_ta Approved Most recent IF: 4.335; 2014 IF: NA
Call Number UA @ lucian @ c:irua:115555 Serial 3641
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Author (up) Li, B.; Djotyan, A.P.; Hao, Y.L.; Avetisyan, A.A.; Peeters, F.M.
Title Effect of a perpendicular magnetic field on the shallow donor states near a semiconductor-metal interface Type A1 Journal article
Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 87 Issue 7 Pages 075313-75319
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate the influence of an external perpendicular magnetic field on the lowest-energy states of an electron bound to a donor which is located near a semiconductor-metal interface. The problem is treated within the effective mass approach and the lowest-energy states are obtained through (1) the “numerically exact” finite element method, and (2) a variational approach using a trial wave function where all image charges that emerge due to the presence of the metallic gate are taken into account. The trial wave functions are constructed such that they reduce to an exponential behavior for sufficiently small magnetic fields and become Gaussian for intermediate and large magnetic fields. The average electron-donor distance can be controlled by the external magnetic field. We find that the size of the 2p(z) state depends strongly on the magnetic field when the donor is close to the interface, showing a nonmonotonic behavior, in contrast with the ground and the other excited states. DOI: 10.1103/PhysRevB.87.075313
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000314874800017 Publication Date 2013-02-13
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 1 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 3.836; 2013 IF: 3.664
Call Number UA @ lucian @ c:irua:107664 Serial 793
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Author (up) Li, B.; Peeters, F.M.
Title Tunable optical Aharonov-Bohm effect in a semiconductor quantum ring Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 11 Pages 115448-115448,13
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract By applying an electric field perpendicular to a semiconductor quantum ring we show that it is possible to modify the single particle wave function between quantum dot (QD)-like and ring-like. The constraints on the geometrical parameters of the quantum ring to realize such a transition are derived. With such a perpendicular electric field we are able to tune the Aharanov-Bohm (AB) effect for both the single particle and for excitons. The tunability is in both the strength of the AB effect as well as in its periodicity. We also investigate the strain induce potential inside the self-assembled quantum ring and the effect of the strain on the AB effect.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000288855200012 Publication Date 2011-03-28
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 25 Open Access
Notes ; This work was supported by the EU-NoE: SANDiE, the Flemish Science Foundation (FWO-Vl), the Interuniversity Attraction Poles, Belgium State, Belgium Science Policy, and IMEC, vzw collaborative project. We are grateful to Prof. M. Tadic and Dr. Fei Ding for stimulating discussions. ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:89376 Serial 3744
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Author (up) Li, B.; Slachmuylders, A.F.; Partoens, B.; Magnus, W.; Peeters, F.M.
Title Dielectric mismatch effect on shallow impurity states in a semiconductor nanowire Type A1 Journal article
Year 2008 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 77 Issue Pages 115335,1-10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
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Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000254542800131 Publication Date 2008-03-19
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 24 Open Access
Notes Approved Most recent IF: 3.836; 2008 IF: 3.322
Call Number UA @ lucian @ c:irua:69630 Serial 692
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Author (up) Li, C.-F.; Zhao, K.; Liao, X.; Hu, Z.-Y.; Zhang, L.; Zhao, Y.; Mu, S.; Li, Y.; Li, Y.; Van Tendeloo, G.; Sun, C.
Title Interface cation migration kinetics induced oxygen release heterogeneity in layered lithium cathodes Type A1 Journal article
Year 2021 Publication Energy Storage Materials Abbreviated Journal
Volume 36 Issue Pages 115-122
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The irreversible release of the lattice oxygen in layered cathodes is one of the major degradation mechanisms of lithium ion batteries, which accounts for a number of battery failures including the voltage/capacity fade, loss of cation ions and detachment of the primary particles, etc. Oxygen release is generally attributed to the stepwise thermodynamic controlled phase transitions from the layered to spinel and rock salt phases. Here, we report a strong kinetic effect from the mobility of cation ions, whose migration barrier can be significantly modulated by the phase epitaxy at the degrading interface. It ends up with a clear oxygen release heterogeneity and completely different reaction pathways between the thin and thick areas, as well as the interparticle valence boundaries, both of which widely exist in the mainstream cathode design with the secondary agglomerates. This work unveils the origin of the heterogenous oxygen release in the layered cathodes. It also sheds light on the rational design of cathode materials with enhanced oxygen stability by suppressing the cation migration.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000620584300009 Publication Date 2020-12-24
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 Open Access OpenAccess
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:176654 Serial 6730
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Author (up) Li, H.; Pandey, T.; Jiang, Y.; Gu, X.; Lindsay, L.; Koh, Y.K.
Title Origins of heat transport anisotropy in MoTe₂ and other bulk van der Waals materials Type A1 Journal article
Year 2023 Publication Materials Today Physics Abbreviated Journal
Volume 37 Issue Pages 101196-101198
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Knowledge of how heat flows anisotropically in van der Waals (vdW) materials is crucial for thermal management of emerging 2D materials devices and design of novel anisotropic thermoelectric materials. Despite the importance, anisotropic heat transport in vdW materials is yet to be systematically studied and is often presumably attributed to anisotropic speeds of sound in vdW materials due to soft interlayer bonding relative to covalent in-plane networks of atoms. In this work, we investigate the origins of the anisotropic heat transport in vdW materials, through time-domain thermoreflectance (TDTR) measurements and first-principles calculations of anisotropic thermal conductivity of three different phases of MoTe2. MoTe2 is ideal for the study due to its weak anisotropy in the speeds of sound. We find that even when the speeds of sound are roughly isotropic, the measured thermal conductivity of MoTe2 along the c-axis is 5-8 times lower than that along the in-plane axes. We derive meaningful characteristic heat capacity, phonon group velocity, and relaxation times from our first principles calculations for selected vdW materials (MoTe2, BP, h-BN, and MoS2), to assess the contributions of these factors to the anisotropic heat transport. Interestingly, we find that the main contributor to the heat transport anisotropy in vdW materials is anisotropy in heat capacity of the dominant heat-carrying phonon modes in different directions, which originates from anisotropic optical phonon dispersion and disparity in the frequency of heat-carrying phonons in different directions. The discrepancy in frequency of the heat-carrying phonons also leads to similar to 2 times larger average relaxation times in the cross-plane direction, and partially explains the apparent dependence of the anisotropic heat transport on the anisotropic speeds of sound. This work provides insight into understanding of the anisotropic heat transport in vdW materials.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001093005700001 Publication Date 2023-08-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2542-5293 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 11.5 Times cited Open Access
Notes Approved Most recent IF: 11.5; 2023 IF: NA
Call Number UA @ admin @ c:irua:201295 Serial 9070
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Author (up) Li, K.; Idrissi, H.; Sha, G.; Song, M.; Lu, J.; Shi, H.; Wang, W.; Ringer, S.P.; Du, Y.; Schryvers, D.
Title Quantitative measurement for the microstructural parameters of nano-precipitates in Al-Mg-Si-Cu alloys Type A1 Journal article
Year 2016 Publication Materials characterization Abbreviated Journal Mater Charact
Volume 118 Issue 118 Pages 352-362
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Size, number density and volume fraction of nano-precipitates are important microstructural parameters controlling the strengthening of materials. In this work a widely accessible, convenient, moderately time efficient method with acceptable accuracy and precision has been provided for measurement of volume fraction of nano-precipitates in crystalline materials. The method is based on the traditional but highly accurate technique of measuring foil thickness via convergent beam electron diffraction. A new equation is proposed and verified with the aid of 3-dimensional atom probe (3DAP) analysis, to compensate for the additional error resulted from the hardly distinguishable contrast of too short incomplete precipitates cut by the foil surface. The method can be performed on a regular foil specimen with a modem LaB6 or field-emission-gun transmission electron microscope. Precisions around +/- 16% have been obtained for precipitate volume fractions of needle-like beta ''/C and Q precipitates in an aged Al-Mg-Si-Cu alloy. The measured number density is dose to that directly obtained using 3DAP analysis by a misfit of 45%, and the estimated precision for number density measurement is about +/- 11%. The limitations of the method are also discussed.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000383292000042 Publication Date 2016-06-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.714 Times cited 9 Open Access
Notes This work is financially supported by National Natural Science Foundation of China (51501230 and 51531009) and Postdoctoral Science Foundation of Central South University (502042057). H.I. acknowledges the IAP program of the Belgian State Federal Office for Scientific, Technical and Cultural Affairs under Contract No. P7/21 and FWO project G.0576.09N. Approved Most recent IF: 2.714
Call Number EMAT @ emat @ c:irua:137171 Serial 4334
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Author (up) Li, L.; Liao, Z.; Gauquelin, N.; Minh Duc Nguyen; Hueting, R.J.E.; Gravesteijn, D.J.; Lobato, I.; Houwman, E.P.; Lazar, S.; Verbeeck, J.; Koster, G.; Rijnders, G.
Title Epitaxial stress-free growth of high crystallinity ferroelectric PbZr0.52Ti0.48O3 on GaN/AlGaN/Si(111) substrate Type A1 Journal article
Year 2018 Publication Advanced Materials Interfaces Abbreviated Journal Adv Mater Interfaces
Volume 5 Issue 2 Pages 1700921
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract <script type='text/javascript'>document.write(unpmarked('Due to its physical properties gallium-nitride (GaN) is gaining a lot of attention as an emerging semiconductor material in the field of high-power and high-frequency electronics applications. Therefore, the improvement in the performance and/or perhaps even extension in functionality of GaN based devices would be highly desirable. The integration of ferroelectric materials such as lead-zirconate-titanate (PbZrxTi1-xO3) with GaN has a strong potential to offer such an improvement. However, the large lattice mismatch between PZT and GaN makes the epitaxial growth of Pb(Zr1-xTix)O-3 on GaN a formidable challenge. This work discusses a novel strain relaxation mechanism observed when MgO is used as a buffer layer, with thicknesses down to a single unit cell, inducing epitaxial growth of high crystallinity Pb(Zr0.52Ti0.48)O-3 (PZT) thin films. The epitaxial PZT films exhibit good ferroelectric properties, showing great promise for future GaN device applications.'));
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000423173800005 Publication Date 2017-11-27
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 Not_Open_Access
Notes ; L.L., Z.L.L., and N.G. contributed equally to this work. L.L. acknowledges financial support from Nano Next NL (Grant no. 7B 04). The authors acknowledge NXP for providing the GaN/AlGaN/Si (111) wafer. N.G. acknowledges funding from the Geconcentreerde Onderzoekacties (GOA) project “Solarpaint” of the University of Antwerp and J.V. acknowledges funding from the Research Foundation Flanders (FWO, Belgium) project 42/FA070100/6088 “nieuwe eigenschappen in complexe Oxides.” N.G. acknowledges the EUROTAPES project (FP7-NMP.2011.2.2-1 Grant no. 280432) which partly funded this study. ; Approved Most recent IF: 4.279
Call Number UA @ lucian @ c:irua:148427UA @ admin @ c:irua:148427 Serial 4872
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Author (up) Li, L.L.; Partoens, B.; Xu, W.; Peeters, F.M.
Title Electric-field modulation of linear dichroism and Faraday rotation in few-layer phosphorene Type A1 Journal article
Year 2019 Publication 2D materials Abbreviated Journal 2D Mater
Volume 6 Issue 1 Pages 015032
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Electro-optical modulators, which use an electric voltage (or an electric field) to modulate a beam of light, are essential elements in present-day telecommunication devices. Using a self-consistent tight-binding approach combined with the standard Kubo formula, we show that the optical conductivity and the linear dichroism of few-layer phosphorene can be modulated by a perpendicular electric field. We find that the field-induced charge screening plays a significant role in modulating the optical conductivity and the linear dichroism. Distinct absorption peaks are induced in the conductivity spectrum due to the strong quantum confinement along the out-of-plane direction and to the field-induced forbidden-to-allowed transitions. The field modulation of the linear dichroism becomes more pronounced with increasing number of phosphorene layers. We also show that the Faraday rotation is present in few-layer phosphorene even in the absence of an external magnetic field. This optical Hall effect is induced by the reduced lattice symmetry of few-layer phosphorene. The Faraday rotation is greatly influenced by the field-induced charge screening and is strongly dependent on the strength of perpendicular electric field and on the number of phosphorene layers.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000454321100002 Publication Date 2018-11-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2053-1583 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.937 Times cited 23 Open Access
Notes ; This work was financially supported by the Flemish Science Foundation (FWO-Vl) and by the FLAG-ERA project TRANS-2D-TMD. ; Approved Most recent IF: 6.937
Call Number UA @ admin @ c:irua:156776 Serial 5207
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Author (up) Li, L.L.; Xu, W.; Peeters, F.M.
Title Intrinsic optical anisotropy of [001]-grown short-period InAs/GaSb superlattices Type A1 Journal article
Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 82 Issue 23 Pages 235422-235422,10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We theoretically investigate the intrinsic optical anisotropy or polarization induced by the microscopic interface asymmetry (MIA) in no-common-atom (NCA) InAs/GaSb superlattices (SLs) grown along the [001] direction. The eight-band K⋅P model is used to calculate the electronic band structures and incorporates the MIA effect. A Boltzmann equation approach is employed to calculate the optical properties. We found that in NCA InAs/GaSb SLs, the MIA effect causes a large in-plane optical anisotropy for linearly polarized light and the largest anisotropy occurs for light polarized along the [110] and [11̅ 0] directions. The relative difference between the optical-absorption coefficient for [110]-polarized light and that for [11̅ 0]-polarized light is found to be larger than 50%. The dependence of the in-plane optical anisotropy on temperature, photoexcited carrier density, and layer width is examined in detail. This study is important for optical devices which require the polarization control and selectivity.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000286768800007 Publication Date 2010-12-13
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 18 Open Access
Notes ; This work was supported partly by the Flemish Science Foundation (FWO-VL), the Belgium Science Policy (IAP), the NSF of China (Grants No. 10664006, No. 10504036, and No. 90503005), Special Funds of 973 Project of China (Grant No. 2005CB623603), and Knowledge Innovation Program of the Chinese Academy of Sciences. ; Approved Most recent IF: 3.836; 2010 IF: 3.774
Call Number UA @ lucian @ c:irua:88909 Serial 1717
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Author (up) Li, W.; Tong, W.; Yadav, A.; Bladt, E.; Bals, S.; Funston, A.M.; Etheridge, J.
Title Shape control beyond the seeds in gold nanoparticles Type A1 Journal article
Year 2021 Publication Chemistry Of Materials Abbreviated Journal Chem Mater
Volume 33 Issue 23 Pages 9152-9164
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In typical seed-mediated syntheses of metal nanocrystals, the shape of the nanocrystal is determined largely by the seed nucleation environment and subsequent growth environment (where “environment” refers to the chemical environment, including the surfactant and additives). In this approach, crystallinity is typically determined by the seeds, and surfaces are controlled by the environment(s). However, surface energies, and crystallinity, are both influenced by the choice of environment(s). This limits the permutations of crystallinity and surface facets that can be mixed and matched to generate new nanocrystal morphologies. Here, we control post-seed growth to deliberately incorporate twin planes during the growth stage to deliver new final morphologies, including twinned cubes and bipyramids from single-crystal seeds. The nature and number of twin planes, together with surfactant control of facet growth, define the final nanoparticle morphology. Moreover, by breaking symmetry, the twin planes introduce new facet orientations. This additional mechanism opens new routes for the synthesis of different morphologies and facet orientations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000753956100012 Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756; 1520-5002 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 3 Open Access Not_Open_Access
Notes This work was supported by the Australian Research Council (ARC) Grants DP160104679 and CE170100026 and used microscopes at the Monash Centre for Electron Microscopy funded by ARC Grants LE0454166, LE110100223, and LE140100104. W.L. thanks the support of the Australian Government Research Training Program (RTP) scholarship. W.T. thanks the Australian Department of Education and Monash University for the IPRS and APA scholarships. E.B. acknowledges financial support and a post-doctoral grant from the Research Foundation Flanders (FWO, Belgium). The authors thank Dr. Matthew Weyland and Dr. Tim Peterson for helpful discussions. A.Y. thanks the support from Post Graduation Publication Award (PPA) scholarship from Monash University. Approved Most recent IF: 9.466
Call Number UA @ admin @ c:irua:187229 Serial 7065
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Author (up) Li, Y.; Yang, X.-Y.; Tian, G.; Vantomme, A.; Yu, J.; Van Tendeloo, G.; Su, B.-L.
Title Chemistry of trimethyl aluminum: a spontaneous route to thermally stable 3D crystalline macroporous alumina foams with a hierarchy of pore sizes Type A1 Journal article
Year 2010 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 22 Issue 10 Pages 3251-3258
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract A simple and spontaneous one-pot self-formation procedure that is easy to scale up has been developed based on the chemistry of trimethylaluminum (TMA), leading to thermally stable macroporous crystalline alumina with a very unique and unprecedented three-dimensional (3D) hierarchical pore structure consisting of well-defined wormlike mesopores. TMA is the precursor of both product and porogene (viz, two working functions within the same molecule (2 in 1)). The materials obtained have been intensively characterized by powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), N2 adsorption−desorption, and mercury porosimetry. The open cagelike macrocavities are self-constructed by mesoporous nanorods (diameter of ca. 40−70 nm), which are themselves formed by a random assembly of fibrous nanoparticles 5−6 nm in size. Optical microscopy (OM) has been used in situ to follow the synthesis procedure, which led to the proposal of the formation mechanism. Methane molecules as porogens, which were instantaneously released because of the fast hydrolysis of the chemical precursor, were the key factor in producing these 3D structures with uniform co-continuous macropores that interconnected directly with the wormlike mesopores. The important characteristic of this procedure is the concurrent formation of a multiscaled porous network. The material exhibits great thermal stability. The hierarchically mesoporous−macroporous Al2O3 obtained is quite attractive for a myriad of applications, from catalysis to biomedicine. The present work illustrates that the one-pot self-formation concept, based on the chemistry of alkyl metals, is a versatile method to design industrially valuable hierarchically porous materials.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000277635000030 Publication Date 2010-04-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 38 Open Access
Notes Approved Most recent IF: 9.466; 2010 IF: 6.400
Call Number UA @ lucian @ c:irua:82760 Serial 356
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Author (up) Li, Z.; Covaci, L.; Berciu, M.; Baillie, D.; Marsiglio, F.
Title Impact of spin-orbit coupling on the Holstein polaron Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 83 Issue 19 Pages 195104-195104,9
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We utilize an exact variational numerical procedure to calculate the ground state properties of a polaron in the presence of a Rashba-like spin-orbit interaction. Our results corroborate previous work performed with the momentum average approximation and with weak-coupling perturbation theory. We find that spin-orbit coupling increases the effective mass in the regime with weak electron-phonon coupling, and decreases the effective mass in the regimes of intermediate and strong electron-phonon coupling. Analytical strong-coupling perturbation theory results confirm our numerical results in the small-polaron regime. A large amount of spin-orbit coupling can lead to a significant lowering of the polaron effective mass.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000290162500001 Publication Date 2011-05-03
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 9 Open Access
Notes ; This work was supported in part by the Natural Sciences and Engineering Research Council of Canada (NSERC), by ICORE (Alberta), by Alberta Ingenuity, by the Flemish Science Foundation (FWO-Vl), and by the Canadian Institute for Advanced Research (CIfAR). ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:89718 Serial 1561
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Author (up) Li, Z.; Covaci, L.; Marsiglio, F.
Title Impact of Dresselhaus versus Rashba spin-orbit coupling on the Holstein polaron Type A1 Journal article
Year 2012 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 85 Issue 20 Pages 205112-205112,5
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We utilize an exact variational numerical procedure to calculate the ground-state properties of a polaron in the presence of Rashba and linear Dresselhaus spin-orbit coupling. We find that when the linear Dresselhaus spin-orbit coupling approaches the Rashba spin-orbit coupling, the Van Hove singularity in the density of states will be shifted away from the bottom of the band and finally disappear when the two spin-orbit couplings are tuned to be equal. The effective mass will be suppressed; the trend will become more significant for low phonon frequency. The presence of two dominant spin-orbit couplings will make it possible to tune the effective mass with more varied observables.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000303794900003 Publication Date 2012-05-09
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 18 Open Access
Notes ; This work was supported in part by the Natural Sciences and Engineering Research Council of Canada (NSERC), by ICORE (Alberta), by the Flemish Science Foundation (FWO-Vl), and by the Canadian Institute for Advanced Research (CIfAR). ; Approved Most recent IF: 3.836; 2012 IF: 3.767
Call Number UA @ lucian @ c:irua:99121 Serial 1558
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Author (up) Li, Z.Z.; Raffy, H.; Bals, S.; Van Tendeloo, G.; Megtert, S.
Title Interplay of doping and structural modulation in superconducting Bi2Sr2-xLaxCuO6+\delta thin films Type A1 Journal article
Year 2005 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 71 Issue 17 Pages 174503,1-7
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract We have studied the evolution of the structural modulation in epitaxial, c-axis-oriented, Bi2Sr2-xLaCuO6+delta thin films when varying the La content x and for a given x as a function of oxygen content. A series of thin films with 0 <= x <= 0.8 has been prepared in situ by rf-magnetron sputtering and characterized by R(T) measurements, Rutherford backscattering spectroscopy, transmission electron microscopy, and x-ray diffraction techniques. The oxygen content of each individual film was varied by thermal annealing across the phase diagram. The evolution of the structural modulation has been thoroughly studied by x-ray diffraction in determining the variation of the amplitude of satellite reflections in special two axes 2 theta/theta-theta scans (reciprocal space scans). It is shown that the amplitude of the modulation along the c axis decreases strongly when x increases from 0 to 0.2. It is demonstrated that this variation is essentially governed by La content x and that changing the oxygen content by thermal treatments has a much lower influence, even becoming negligible for x > 0.2. Such study is important to understand the electronical properties of Bi2Sr2-xLaxCuO6+gamma thin films.
Address
Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000229935000092 Publication Date 2005-05-06
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 11 Open Access
Notes Approved Most recent IF: 3.836; 2005 IF: 3.185
Call Number UA @ lucian @ c:irua:54746 Serial 1707
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Author (up) Liang, Q.; Yang, D.; Xia, F.; Bai, H.; Peng, H.; Yu, R.; Yan, Y.; He, D.; Cao, S.; Van Tendeloo, G.; Li, G.; Zhang, Q.; Tang, X.; Wu, J.
Title Phase-transformation-induced giant deformation in thermoelectric Ag₂Se semiconductor Type A1 Journal article
Year 2021 Publication Advanced Functional Materials Abbreviated Journal Adv Funct Mater
Volume Issue Pages 2106938
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract In most semiconducting metal chalcogenides, a large deformation is usually accompanied by a phase transformation, while the deformation mechanism remains largely unexplored. Herein, a phase-transformation-induced deformation in Ag2Se is investigated by in situ transmission electron microscopy, and a new ordered high-temperature phase (named as alpha '-Ag2Se) is identified. The Se-Se bonds are folded when the Ag+-ion vacancies are ordered and become stretched when these vacancies are disordered. Such a stretch/fold of the Se-Se bonds enables a fast and large deformation occurring during the phase transition. Meanwhile, the different Se-Se bonding states in alpha-, alpha '-, beta-Ag2Se phases lead to the formation of a large number of nanoslabs and the high concentration of dislocations at the interface, which flexibly accommodate the strain caused by the phase transformation. This study reveals the atomic mechanism of the deformation in Ag2Se inorganic semiconductors during the phase transition, which also provides inspiration for understanding the phase transition process in other functional materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000695142800001 Publication Date 2021-09-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-301x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 12.124
Call Number UA @ admin @ c:irua:181527 Serial 6879
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Author (up) Liao, T.-W.; Verbruggen, S.; Claes, N.; Yadav, A.; Grandjean, D.; Bals, S.; Lievens, P.
Title TiO2 Films Modified with Au Nanoclusters as Self-Cleaning Surfaces under Visible Light Type A1 Journal article
Year 2018 Publication Nanomaterials Abbreviated Journal Nanomaterials-Basel
Volume 8 Issue 8 Pages 30
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL)
Abstract In this study, we applied cluster beam deposition (CBD) as a new approach for fabricating efficient plasmon-based photocatalytic materials. Au nanoclusters (AuNCs) produced in the gas phase were deposited on TiO2 P25-coated silicon wafers with coverage ranging from 2 to 8 atomic monolayer (ML) equivalents. Scanning Electron Microscopy (SEM) images of the AuNCs modified TiO2 P25 films show that the surface is uniformly covered by the AuNCs that remain isolated at low coverage (2 ML, 4 ML) and aggregate at higher coverage (8 ML). A clear relationship between AuNCs coverage and photocatalytic activity towards stearic acid photo-oxidation was measured, both under ultraviolet and green light illumination. TiO2 P25 covered with 4 ML AuNCs showed the best stearic acid photo-oxidation performance under green light illumination (Formal Quantum Efficiency 1.6 x 10-6 over a period of 93 h). These results demonstrate the large potential of gas-phase AuNCs beam deposition technology for the fabrication of visible light active plasmonic photocatalysts.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000424131600030 Publication Date 2018-01-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2079-4991 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.553 Times cited 29 Open Access OpenAccess
Notes The research leading to these results has received funding from the European Union’s Seventh Framework Programme (FP7/2007-2013) under grant agreement n 607417 (Catsense). We also thank the Research Foundation—Flanders (FWO, Belgium), the Flemish Concerted Action (BOF KU Leuven, Project No. GOA/14/007) research program, and the microscope was partly funded by the Hercules Fund from the Flemish Government for the support. N.C. and S.B. acknowledge financial support from European Research Council (ERC Starting Grant #335078-COLOURATOM). ECAS_Sara (ROMEO:green; preprint:; postprint:can ; pdfversion:can); Approved Most recent IF: 3.553
Call Number EMAT @ emat @c:irua:147898UA @ admin @ c:irua:147898 Serial 4805
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Author (up) Liao, Z.; Gauquelin, N.; Green, R.J.; Macke, S.; Gonnissen, J.; Thomas, S.; Zhong, Z.; Li, L.; Si, L.; Van Aert, S.; Hansmann, P.; Held, K.; Xia, J.; Verbeeck, J.; Van Tendeloo, G.; Sawatzky, G.A.; Koster, G.; Huijben, M.; Rijnders, G.
Title Thickness dependent properties in oxide heterostructures driven by structurally induced metal-oxygen hybridization variations Type A1 Journal article
Year 2017 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
Volume 27 Issue 17 Pages 1606717
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Thickness-driven electronic phase transitions are broadly observed in different types of functional perovskite heterostructures. However, uncertainty remains whether these effects are solely due to spatial confinement, broken symmetry, or rather to a change of structure with varying film thickness. Here, this study presents direct evidence for the relaxation of oxygen-2p and Mn-3d orbital (p-d) hybridization coupled to the layer-dependent octahedral tilts within a La2/3Sr1/3MnO3 film driven by interfacial octahedral coupling. An enhanced Curie temperature is achieved by reducing the octahedral tilting via interface structure engineering. Atomically resolved lattice, electronic, and magnetic structures together with X-ray absorption spectroscopy demonstrate the central role of thickness-dependent p-d hybridization in the widely observed dimensionality effects present in correlated oxide heterostructures.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000400449200011 Publication Date 2017-03-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-301x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 55 Open Access
Notes M.H., G.K., and G.R. acknowledge funding from DESCO program of the Dutch Foundation for Fundamental Research on Matter (FOM) with financial support from the Netherlands Organization for Scientific Research (NWO). This work was funded by the European Union Council under the 7th Framework Program (FP7) Grant No. NMP3-LA-2010-246102 IFOX. J.V. and S.V.A. acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (Grant Nos. G.0044.13N, G.0374.13N, G.0368.15N, and G.0369.15N). The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. N.G. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510 VORTEX. N.G., J.G., S.V.A., and J.V. acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative (Reference No. 312483-ESTEEM2). The Canadian work was supported by NSERC and the Max Planck-UBC Centre for Quantum Materials. Some experiments for this work were performed at the Canadian Light Source, which was funded by the Canada Foundation for Innovation, NSERC, the National Research Council of Canada, the Canadian Institutes of Health Research, the Government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan. Approved Most recent IF: 12.124
Call Number UA @ admin @ c:irua:152640 Serial 5367
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Author (up) Liao, Z.; Huijben, M.; Zhong, Z.; Gauquelin, N.; Macke, S.; Green, R.J.; Van Aert, S.; Verbeeck, J.; Van Tendeloo, G.; Held, K.; Sawatzky, G.A.; Koster, G.; Rijnders, G.
Title Controlled lateral anisotropy in correlated manganite heterostructures by interface-engineered oxygen octahedral coupling Type A1 Journal article
Year 2016 Publication Nature materials Abbreviated Journal Nat Mater
Volume 15 Issue 15 Pages 425-431
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Controlled in-plane rotation of the magnetic easy axis in manganite heterostructures by tailoring the interface oxygen network could allow the development of correlated oxide-based magnetic tunnelling junctions with non-collinear magnetization, with possible practical applications as miniaturized high-switching-speed magnetic random access memory (MRAM) devices. Here, we demonstrate how to manipulate magnetic and electronic anisotropic properties in manganite heterostructures by engineering the oxygen network on the unit-cell level. The strong oxygen octahedral coupling is found to transfer the octahedral rotation, present in the NdGaO3 (NGO) substrate, to the La2/3Sr1/3MnO3 (LSMO) film in the interface region. This causes an unexpected realignment of the magnetic easy axis along the short axis of the LSMO unit cell as well as the presence of a giant anisotropic transport in these ultrathin LSMO films. As a result we possess control of the lateral magnetic and electronic anisotropies by atomic-scale design of the oxygen octahedral rotation.
Address MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000372591700017 Publication Date 2016-03-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1476-1122 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 39.737 Times cited 273 Open Access
Notes We would like to acknowledge Dr. Evert Houwman for stimulated discussion. M.H., G.K. and G.R. acknowledge funding from DESCO program of the Dutch Foundation for Fundamental Research on Matter (FOM) with financial support from the Netherlands Organization for Scientific Research (NWO). This work was funded by the European Union Council under the 7th Framework Program (FP7) grant nr NMP3-LA-2010- 246102 IFOX. J.V. and S.V.A. acknowledges funding from FWO project G.0044.13N and G. 0368.15N. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. N.G. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. N.G., S.V.A., J.V. and G.V.T. acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative (Reference No. 312483-ESTEEM2). The Canadian work was supported by NSERC and the Max Planck-UBC Centre for Quantum Materials. Some experiments for this work were performed at the Canadian Light Source, which is funded by the Canada Foundation for Innovation, NSERC, the National Research Council of Canada, the Canadian Institutes of Health Research, the Government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan. Z.Z. acknowledges funding from the SFB ViCoM (Austrian Science Fund project ID F4103- N13), and Calculations have been done on the Vienna Scientific Cluster (VSC).; esteem2jra2; esteem2jra3 ECASJO_; Approved Most recent IF: 39.737
Call Number c:irua:133190 c:irua:133190UA @ admin @ c:irua:133190 Serial 4041
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Author (up) Liao, Z.L.; Green, R.J.; Gauquelin, N.; Gonnissen, J.; Van Aert, S.; Verbeeck, J.; et al.
Title Engineering properties by long range symmetry propagation initiated at perovskite heterostructure interface Type A1 Journal article
Year 2016 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
Volume Issue Pages 1-25
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In epitaxial thin film systems, the crystal structure and its symmetry deviate from the bulk counterpart due to various mechanisms such as epitaxial strain and interfacial structural coupling, which induce an accompanying change in their properties. In perovskite materials, the crystal symmetry can be described by rotations of 6-fold coordinated transition metal oxygen octahedra, which are found to be altered at interfaces. Here, we unravel how the local oxygen octahedral coupling (OOC) at perovskite heterostructural interfaces initiates a different symmetry in epitaxial films and provide design rules to induce various symmetries in thin films by careful selecting appropriate combinations of substrate/buffer/film. Very interestingly we discovered that these combinations lead to symmetry changes throughout the full thickness of the film. Our results provide a deep insight into understanding the origin of induced crystal symmetry in a perovskite heterostructure and an intelligent route to achieve unique functional properties.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-301x ISBN Additional Links UA library record
Impact Factor 12.124 Times cited Open Access
Notes Approved Most recent IF: 12.124
Call Number UA @ lucian @ c:irua:134842 Serial 4176
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Author (up) Liao, Z; , Green, R.J; Gauquelin, N; Macke, S.; Li, L.; Gonnissen, J; Sutarto, R.; Houwman, E.P.; Zhong, Z.; Van Aert, S.; Verbeeck, J.; Sawatzky, G.A.; Huijben, M.; Koster, G.; Rijnders, G.
Title Long-Range Domain Structure and Symmetry Engineering by Interfacial Oxygen Octahedral Coupling at Heterostructure Interface Type A1 Journal article
Year 2016 Publication Advanced functional materials Abbreviated Journal Adv Funct Mater
Volume 26 Issue 26 Pages 6627-6634
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract In epitaxial thin film systems, the crystal structure and its symmetry deviate from the bulk counterpart due to various mechanisms such as epitaxial strain and interfacial structural coupling, which is accompanyed by a change in their properties. In perovskite materials, the crystal symmetry can be described by rotations of sixfold coordinated transition metal oxygen octahedra, which are found to be altered at interfaces. Here, it is unraveled how the local oxygen octahedral coupling at perovskite heterostructural interfaces strongly influences the domain structure and symmetry of the epitaxial films resulting in design rules to induce various structures in thin films using carefully selected combinations of substrate/buffer/film. Very interestingly it is discovered that these combinations lead to structure changes throughout the full thickness of the film. The results provide a deep insight into understanding the origin of induced structures in a perovskite heterostructure and an intelligent route to achieve unique functional properties.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000384809800010 Publication Date 2016-06-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-301x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 23 Open Access
Notes We thank B. Keimer for valuable discussions. M.H., G.K. and G.R. acknowledge funding from DESCO program of the Dutch Foundation for Fundamental Research on Matter (FOM) with financial support from the Netherlands Organization for Scientific Research (NWO). This work was funded by the European Union Council under the 7th Framework Program (FP7) grant nr NMP3-LA-2010-246102 IFOX. J.V. and S.V.A. acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0044.13N, G.0374.13N, G.0368.15N, G.0369.15N). The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. N.G. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. N.G., J.G., S.V.A., J.V. acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative (Reference No. 312483-ESTEEM2). The Canadian work was supported by NSERC and the Max Planck-UBC Centre for Quantum Materials. Some experiments for this work were performed at the Canadian Light Source, which is funded by the Canada Foundation for Innovation, NSERC, the National Research Council of Canada, the Canadian Institutes of Health Research, the Government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan.; esteem2jra2; esteem2jra3; ECASJO_; Approved Most recent IF: 12.124
Call Number EMAT @ emat @ c:irua:144663UA @ admin @ c:irua:144663 Serial 4106
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Author (up) Lin, F.; Meng, X.; Kukueva, E.; Kus, M.; Mertens, M.; Bals, S.; Van Doorslaer, S.; Cool, P.
Title Novel method to synthesize highly ordered ethane-bridged PMOs under mild acidic conditions : taking advantages of phosphoric acid Type A1 Journal article
Year 2015 Publication Microporous and mesoporous materials: zeolites, clays, carbons and related materials Abbreviated Journal Micropor Mesopor Mat
Volume 207 Issue 207 Pages 61-70
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA)
Abstract Highly ordered SBA-15-type ethane-bridged PMOs have been obtained by employing H3PO4 as acid to tune the pH in the presence of copolymer surfactant P123. The effects of the acidity and the addition of inorganic salt on the formation of the mesostructure are investigated. It is found that, compared with HCl, the polyprotic weak acid H3PO4 is preferable for the synthesis of highly ordered SBA-15-type ethane-bridged PMOs with larger pore size and surface areas under mild acidic conditions. Moreover, taking the advantages of the mild acidic condition, vanadium-containing SBA-15-type ethane-bridged PMOs were successfully prepared through a direct synthesis approach. The XRD, N2-sorption, UVVis and CW-EPR studies of the V-PMO show that part of the vanadium species are present in polymeric (VOV)n clusters, while part of the vanadium centers are well-dispersed and immobilized on the inner surface of the mesopores.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000350518600009 Publication Date 2015-01-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1387-1811; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.615 Times cited 5 Open Access OpenAccess
Notes ; The Erasmus Mundus CONNEC program is acknowledged for PhD funding of F.Lin. Furthermore, the authors acknowledge support by the GOA-BOF project 'Optimization of the structure-activity relation in nanoporous materials', funded by the University of Antwerp. ; Approved Most recent IF: 3.615; 2015 IF: 3.453
Call Number c:irua:123910 Serial 2379
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Author (up) Lin, N.S.; Heitmann, T.W.; Yu, K.; Plourde, B.L.T.; Misko, V.R.
Title Rectification of vortex motion in a circular ratchet channel Type A1 Journal article
Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 84 Issue 14 Pages 144511-144511,12
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We study the dynamics of vortices in an asymmetric (i.e., consisting of triangular cells) ring channel driven by an external ac current I in a Corbino setup. The asymmetric potential rectifies the motion of vortices and induces a net vortex flow without any unbiased external drive, i.e., the ratchet effect. We show that the net flow of vortices strongly depends on vortex density and frequency of the driving current. Depending on the density, we distinguish a single-vortex rectification regime (for low density, when each vortex is rectified individually) determined by the potential-energy landscape inside each cell of the channel (i.e., hard and easy directions) and multi-vortex, or collective, rectification (high-density case) when the inter-vortex interaction becomes important. We analyze the average angular velocity ω of vortices as a function of I and study commensurability effects between the numbers of vortices and cells in the channel and the role of frequency of the applied ac current. We have shown that the commensurability effect results in a stepwise ω-I curve. Besides the integer steps, i.e., the large steps found in the single-vortex case, we also found fractional steps corresponding to fractional ratios between the numbers of vortices and triangular cells. We have performed preliminary measurements on a device containing a single weak-pinning circular ratchet channel in a Corbino geometry and observed a substantial asymmetric vortex response.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000295795500010 Publication Date 2011-10-07
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 ; We thank Peter Kes and Marcel Hesselberth for providing the superconducting films from which the Corbino ratchet sample was fabricated. This work was supported by the “Odysseus” Program of the Flemish Government and the Flemish Science Foundation (FWO-Vl), the Interuniversity Attraction Poles (IAP) Programme-Belgian State-Belgian Science Policy, and the FWO-Vl (Belgium). T. W. H., K.Y., and B. L. T. P acknowledge support from the National Science Foundation under Grant DMR-0547147 as well as the use of the Cornell NanoScale Facility, a member of the National Nanotechnology Infrastructure Network, which is supported by the National Science Foundation (Grant ECS-0335765). ; Approved Most recent IF: 3.836; 2011 IF: 3.691
Call Number UA @ lucian @ c:irua:92809 Serial 2848
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