| Records |
| Author |
Jany, B.R.; Gauquelin, N.; Willhammar, T.; Nikiel, M.; van den Bos, K.H.W.; Janas, A.; Szajna, K.; Verbeeck, J.; Van Aert, S.; Van Tendeloo, G.; Krok, F. |
| Title |
Controlled growth of hexagonal gold nanostructures during thermally induced self-assembling on Ge(001) surface |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
| Volume |
7 |
Issue |
7 |
Pages |
42420 |
Keywords  |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Nano-sized gold has become an important material in various fields of science and technology, where control over the size and crystallography is desired to tailor the functionality. Gold crystallizes in the face-centered cubic (fcc) phase, and its hexagonal closed packed (hcp) structure is a very unusual and rare phase. Stable Au hcp phase has been reported to form in nanoparticles at the tips of some Ge nanowires. It has also recently been synthesized in the form of thin graphene-supported sheets which are unstable under electron beam irradiation. Here, we show that stable hcp Au 3D nanostructures with well-defined crystallographic orientation and size can be systematically created in a process of thermally induced self-assembly of thin Au layer on Ge(001) monocrystal. The Au hcp crystallite is present in each Au nanostructure and has been characterized by different electron microscopy techniques. We report that a careful heat treatment above the eutectic melting temperature and a controlled cooling is required to form the hcp phase of Au on a Ge single crystal. This new method gives scientific prospects to obtain stable Au hcp phase for future applications in a rather simple manner as well as redefine the phase diagram of Gold with Germanium. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000393940700001 |
Publication Date |
2017-02-14 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.259 |
Times cited |
25 |
Open Access |
OpenAccess |
| Notes |
The authors gratefully acknowledge the financial support from the Polish National Science Center, grant no. DEC-2012/07/B/ST5/00906. N.G., G.V.T. and J.V. acknowledge the European Union (EU) Council under the 7th Framework Program (FP7) ERC Starting Grant 278510 VORTEX for support. The Research Foundation Flanders is acknowledged through project fundings (G.0374.13N, G.0368.15N, G.0369.15N) and for a Ph.D. research grant to K.H.W.v.d.B. The microscope was partly funded by the Hercules Fund from the Flemish Government. T.W. acknowledges the Swedish Research Council for an international postdoc grant. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483–ESTEEM2 (Integrated Infrastructure Initiative–I3). Part of the research was carried out with equipment purchased with financial support from the European Regional Development Fund in the framework of the Polish Innovation Economy Operational Program (Contract No. POIG.02.01.00-12-023/08). |
Approved |
Most recent IF: 4.259 |
| Call Number |
EMAT @ emat @ c:irua:140846UA @ admin @ c:irua:140846 |
Serial |
4423 |
| Permanent link to this record |
| |
|
| |
| Author |
Smolin, S.Y.; Choquette, A.K.; Wilks, R.G.; Gauquelin, N.; Félix, R.; Gerlach, D.; Ueda, S.; Krick, A.L.; Verbeeck, J.; Bär, M.; Baxter, J.B.; May, S.J. |
| Title |
Energy Level Alignment and Cation Charge States at the LaFeO3/LaMnO3(001) Heterointerface |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
Advanced Materials Interfaces |
Abbreviated Journal |
Adv Mater Interfaces |
| Volume |
4 |
Issue |
4 |
Pages |
1700183 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The electronic properties of LaFeO 3 /LaMnO 3 epitaxial heterojunctions are investigated to determine the valence and conduction band offsets and the nominal Mn and Fe valence states at the interface. Studying a systematic series of (LaFeO 3 ) n /(LaMnO 3 ) m bilayers (m ≈ 50) epitaxially grown in the (001) orientation using molecular beam epitaxy, layer-resolved electron energy loss spectroscopy reveals a lack of significant interfacial charge transfer, with a nominal 3+ valence state observed for both Mn and Fe across the interface. Through a combination of variable angle spectroscopic ellipsometry and hard X-ray photoelectron spectroscopy, type I energy level alignments are obtained at the LaFeO 3 /LaMnO 3 interface with positive valence and conduction band offsets of (1.20 ± 0.07) eV and (0.5–0.7 ± 0.3) eV, respectively, with minimal band bending. Variable temperature resistivity measurements reveal that the bilayers remain insulating and that the presence of the heterojunction does not result in a conducting interface. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000406068400011 |
Publication Date |
2017-04-26 |
| 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 |
14 |
Open Access |
Not_Open_Access |
| Notes |
The authors thank Dmytro Nykypanchuk for assistance with the near- infrared ellipsometry measurement of the LaMnO 3 film. S.Y.S., A.K.C., J.B.B, and S.J.M. acknowledge funding from the National Science Foundation under grant number ECCS-1201957. S.Y.S. acknowledges additional funding from the German Academic Exchange Service (DAAD) through the Research Internships in Science and Engineering (RISE) professional program 2015 ID 5708457. A.L.K. was funded by the National Science Foundation under grant number DMR-1151649. J.V. and N.G. acknowledge funding through the GOA project “Solarpaint” of the University of Antwerp and from the FWO project G.0044.13N (Charge ordering). The microscope used in this work was partly funded by the Hercules Fund from the Flemish Government. Ellipsometry measurements of the LaMnO 3 film were carried out at the Center for Functional Nanomaterials, Brookhaven National Laboratory, which is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-ACO2-98CH10886. S.U. would like to thank the staff of HiSOR, Hiroshima University, and JAEA/Spring-8 for the development of HAXPES at BL15XU of SPring-8. The HAXPES measurements were performed with approval of NIMS Synchrotron X-ray Station (Proposal No. 2015B4601), and were partly supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. The authors also thank HZB for the allocation of synchrotron radiation beamtime for HAXPES/XANES measurements. R.G.W., R.F, and M.B. are grateful to the Impuls- und Vernetzungsfonds of the Helmholtz Association (VH-NG-423).; National Science Foundation, ECCS-1201957 DMR-1151649 ; Deutscher Akademischer Austauschdienst, 2015 ID 5708457 ; GOA project; Fonds Wetenschappelijk Onderzoek, G.0044.13N ; Flemish Government; U.S. Department of Energy, DE-ACO2-98CH10886 ; Vernetzungsfonds of the Helmholtz Association, VH-NG-423 ; |
Approved |
Most recent IF: 4.279 |
| Call Number |
EMAT @ emat @ c:irua:142346UA @ admin @ c:irua:142346 |
Serial |
4553 |
| Permanent link to this record |
| |
|
| |
| Author |
Gauquelin, N.; van den Bos, K.H.W.; Béché, A.; Krause, F.F.; Lobato, I.; Lazar, S.; Rosenauer, A.; Van Aert, S.; Verbeeck, J. |
| Title |
Determining oxygen relaxations at an interface: A comparative study between transmission electron microscopy techniques |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
| Volume |
181 |
Issue |
181 |
Pages |
178-190 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Nowadays, aberration corrected transmission electron microscopy (TEM) is a popular method to characterise nanomaterials at the atomic scale. Here, atomically resolved images of nanomaterials are acquired, where the contrast depends on the illumination, imaging and detector conditions of the microscope. Visualization of light elements is possible when using low angle annular dark field (LAADF) STEM, annular bright field (ABF) STEM, integrated differential phase contrast (iDPC) STEM, negative spherical aberration imaging (NCSI) and imaging STEM (ISTEM). In this work, images of a NdGaO3-La0.67Sr0.33MnO3 (NGO-LSMO) interface are quantitatively evaluated by using statistical parameter estimation theory. For imaging light elements, all techniques are providing reliable results, while the techniques based on interference contrast, NCSI and ISTEM, are less robust in terms of accuracy for extracting heavy column locations. In term of precision, sample drift and scan distortions mainly limits the STEM based techniques as compared to NCSI. Post processing techniques can, however, partially compensate for this. In order to provide an outlook to the future, simulated images of NGO, in which the unavoidable presence of Poisson noise is taken into account, are used to determine the ultimate precision. In this future counting noise limited scenario, NCSI and ISTEM imaging will provide more precise values as compared to the other techniques, which can be related to the mechanisms behind the image recording. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000411170800022 |
Publication Date |
2017-06-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.843 |
Times cited |
34 |
Open Access |
OpenAccess |
| Notes |
The authors acknowledge financial support from Flanders (FWO, Belgium) through project fundings (G.0044.13N, G.0374.13N, G.0368.15N, G.0369.15N), and by a Ph.D. grant to K.H.W.v.d.B. The Qu-Ant-EM microscope used for this study was partly funded by the Hercules fund from the Flemish Government. A.B. and N.G. acknowledge the EUROTAPES project (FP7-NMP.2011.2.2-1 Grant no.280432) which partly funded this study. N.G., A.B. and J.V. acknowledge funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. The research leading to these results has received funding from the Deutsche Forschungsgemeinschaft under Contract No. RO 2057/4-2 and the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2. We thank Prof. G. Koster from the University of Twente for kindly providing us with the LSMO-NGO test sample. |
Approved |
Most recent IF: 2.843 |
| Call Number |
EMAT @ emat @ c:irua:144435UA @ admin @ c:irua:144435 |
Serial |
4620 |
| Permanent link to this record |
| |
|
| |
| Author |
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.')); |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000423173800005 |
Publication Date |
2017-11-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| 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 |
| Permanent link to this record |
| |
|
| |
| Author |
Groenendijk, D.J.; Autieri, C.; Girovsky, J.; Martinez-Velarte, M.C.; Manca, N.; Mattoni, G.; Monteiro, A.M.R.V.L.; Gauquelin, N.; Verbeeck, J.; Otte, A.F.; Gabay, M.; Picozzi, S.; Caviglia, A.D. |
| Title |
Spin-orbit semimetal SrIrO3 in the two-dimensional limit |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
| Volume |
119 |
Issue |
25 |
Pages |
256403 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
<script type='text/javascript'>document.write(unpmarked('We investigate the thickness-dependent electronic properties of ultrathin SrIrO3 and discover a transition from a semimetallic to a correlated insulating state below 4 unit cells. Low-temperature magnetoconductance measurements show that spin fluctuations in the semimetallic state are significantly enhanced while approaching the transition point. The electronic properties are further studied by scanning tunneling spectroscopy, showing that 4 unit cell SrIrO(3)d is on the verge of a gap opening. Our density functional theory calculations reproduce the critical thickness of the transition and show that the opening of a gap in ultrathin SrIrO3 requires antiferromagnetic order.')); |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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| Language |
|
Wos |
000418619100014 |
Publication Date |
2017-12-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| 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 |
79 |
Open Access |
OpenAccess |
| Notes |
; This work was supported by The Netherlands Organisation for Scientific Research (NWO/OCW) as part of the Frontiers of Nanoscience program (NanoFront), by the Dutch Foundation for Fundamental Research on Matter (FOM), and by the European Research Council under the European Union's H2020 programme/ERC Grant Agreement No. [677458]. The authors thank R. Claessen, P. Schutz, D. Di Sante, G. Sangiovanni, and A. Santander Syro for useful discussions. M. G. gratefully acknowledges support from the French National Research Agency (ANR) (Project LACUNES No. ANR-13-BS04-0006-01). C. A. and S. P. acknowledge financial support from Fondazione Cariplo via the project Magister (Project No. 2013-0726) and from CNR-SPIN via the Seed Project “CAMEO”. N. G. and J. V. acknowledge support from the GOA project “Solarpaint” of the University of Antwerp. The Qu-AntEM microscope was partly funded by the Hercules fund from the Flemish Government. ; |
Approved |
Most recent IF: 8.462 |
| Call Number |
UA @ lucian @ c:irua:148510 |
Serial |
4897 |
| Permanent link to this record |
| |
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| |
| Author |
Zhang, H.; Gauquelin, N.; McMahon, C.; Hawthorn, D.G.; Botton, G.A.; Wei, J.Y.T. |
| Title |
Synthesis of high-oxidation Y-Ba-Cu-O phases in superoxygenated thin films |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Physical review materials |
Abbreviated Journal |
|
| Volume |
2 |
Issue |
3 |
Pages |
033803 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
It is known that solid-state reaction in high-pressure oxygen can stabilize high-oxidation phases of Y-Ba-Cu-O superconductors in powder form. We extend this superoxygenation concept of synthesis to thin films which, due to their large surface-to-volume ratio, are more reactive thermodynamically. Epitaxial thin films of YBa2Cu3O7-delta grown by pulsed laser deposition are annealed at up to 700 atm O-2 and 900 degrees C, in conjunction with Cu enrichment by solid-state diffusion. The films show the clear formation of Y2Ba4Cu7O15-delta and Y2Ba4Cu8O16 as well as regions of YBa2Cu5O9-delta and YBa2Cu6O10-delta phases, according to scanning transmission electron microscopy, x-ray diffraction, and x-ray absorption spectroscopy. Similarly annealed YBa2Cu3O7-delta powders show no phase conversion. Our results demonstrate a route of synthesis towards discovering more complex phases of cuprates and other superconducting oxides. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
American Physical Society |
Place of Publication |
College Park, Md |
Editor |
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| Language |
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Wos |
000428244900004 |
Publication Date |
2018-03-26 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2475-9953 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
2 |
Open Access |
Not_Open_Access |
| Notes |
; This work is supported by NSERC, CFI-OIT, and CIFAR. The electron microscopy work was carried out at the Canadian Centre for Electron Microscopy, a National Facility supported by the Canada Foundation for Innovation under the Major Science Initiative program, McMaster University, and NSERC. The XAS work was performed at the Canadian Light Source, which is supported by NSERC, NRC, CIHR, and the University of Saskatchewan. ; |
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:150829 |
Serial |
4982 |
| Permanent link to this record |
| |
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| |
| Author |
Bhat, S.G.; Gauquelin, N.; Sebastian, N.K.; Sil, A.; Béché, A.; Verbeeck, J.; Samal, D.; Kumar, P.S.A. |
| Title |
Orthorhombic vs. hexagonal epitaxial SrIrO3 thin films : structural stability and related electrical transport properties |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Europhysics letters |
Abbreviated Journal |
Epl-Europhys Lett |
| Volume |
122 |
Issue |
2 |
Pages |
28003 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Metastable orthorhombic SrIrO3 (SIO) is an arch-type spin-orbit coupled material. We demonstrate here a controlled growth of relatively thick (200 nm) SIO films that transform from bulk “6H-type” structure with monoclinic distortion to an orthorhombic lattice by controlling growth temperature. Extensive studies based on high-resolution X-ray diffraction and transmission electron microscopy infer a two distinct structural phases of SIO. Electrical transport reveals a weak temperature-dependent semi-metallic character for both phases. However, the temperature-dependent Hall-coefficient for the orthorhombic SIO exhibits a prominent sign change, suggesting a multiband character in the vicinity of E-F. Our findings thus unravel the subtle structure-property relation in SIO epitaxial thin films. Copyright (C) EPLA, 2018 |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Paris |
Editor |
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| Language |
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Wos |
000435517300001 |
Publication Date |
2018-06-18 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0295-5075 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.957 |
Times cited |
4 |
Open Access |
Not_Open_Access |
| Notes |
; SGB and DS acknowledge useful discussions with E. P. Houwman, University of Twente, on X-ray diffraction. DS would like to thank H. Takagi, Max-Planck Institute for Solid State Research, Stuttgart, for the fruitful discussion on the transport properties of SIO thin films. SGB and NKS thank A. Aravind, Bishop Moore College, Mavelikara, for his valuable inputs while depositing the thin films of SIO. SGB, NKS and PSAK acknowledge Nano Mission Council, Department of Science & Technology, India, for the funding. DS acknowledges the financial support from Max-Planck Society through MaxPlanck Partner Group. NG, AB and JV acknowledge funding from GOA project “Solarpaint” of the University of Antwerp and FWO project G093417N. ; |
Approved |
Most recent IF: 1.957 |
| Call Number |
UA @ lucian @ c:irua:152074UA @ admin @ c:irua:152074 |
Serial |
5034 |
| Permanent link to this record |
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| |
| Author |
Hasanli, N.; Gauquelin, N.; Verbeeck, J.; Hadermann, J.; Hayward, M.A. |
| Title |
Small-moment paramagnetism and extensive twinning in the topochemically reduced phase Sr2ReLiO5.5 |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
Dalton T |
| Volume |
47 |
Issue |
44 |
Pages |
15783-15790 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Reaction of the cation-ordered double perovskite Sr2ReLiO6 with dilute hydrogen at 475 degrees C leads to the topochemical deintercalation of oxide ions from the host lattice and the formation of a phase of composition Sr2ReLiO5.5, as confirmed by thermogravimetric and EELS data. A combination of neutron and electron diffraction data reveals the reduction process converts the -Sr2O2-ReLiO4-Sr2O2-ReLiO4- stacking sequence of the parent phase into a -Sr2O2-ReLiO3-Sr2O2-ReLiO4-, partially anion-vacant ordered sequence. Furthermore a combination of electron diffraction and imaging reveals Sr2ReLiO5.5 exhibits extensive twinning – a feature which can be attributed to the large, anisotropic volume expansion of the material on reduction. Magnetisation data reveal a strongly reduced moment of (eff) = 0.505(B) for the d(1) Re6+ centres in the phase, suggesting there remains a large orbital component to the magnetism of the rhenium centres, despite their location in low symmetry coordination environments. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000450208000019 |
Publication Date |
2018-10-18 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1477-9226 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
4.029 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
Experiments at the Diamond Light Source were performed as part of the Block Allocation Group award “Oxford Solid State Chemistry BAG to probe composition-structure-property relationships in solids” (EE13284). Experiments at the ISIS pulsed neutron facility were supported by a beam time allocation from the STFC. NH acknowledges funding from the “State Programme on Education of Azerbaijani Youth Abroad in 2007-2015” by the Ministry of Education of Azerbaijan. J. V. and N. G. acknowledge funding through the GOA project “Solarpaint” of the University of Antwerp. The microscope used in this work was partly funded by the Hercules Fund from the Flemish Government. |
Approved |
Most recent IF: 4.029 |
| Call Number |
EMAT @ emat @c:irua:155771 |
Serial |
5137 |
| Permanent link to this record |
| |
|
| |
| Author |
Godet, M.; Vergès-Belmin, V.; Gauquelin, N.; Saheb, M.; Monnier, J.; Leroy, E.; Bourgon, J.; Verbeeck, J.; Andraud, C. |
| Title |
Nanoscale investigation by TEM and STEM-EELS of the laser induced yellowing |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Micron |
Abbreviated Journal |
Micron |
| Volume |
115 |
Issue |
|
Pages |
25-31 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Nd-YAG QS laser cleaning of soiled stone at 1064 nm can sometimes result in a more yellow appearance compared to other cleaning techniques. Especially in France, this yellowing effect is still considered as a major aesthetic issue by the architects and conservators. One explanation states that the yellowing is linked to the formation of iron-rich nanophase(s) through the laser beam interaction with black crusts that would re-deposit on the cleaned substrate after irradiation. To characterize these nanophases, a model crust containing hematite was elaborated and laser irradiated using a Nd-YAG QS laser. The color of the sample shifted instantaneously from red to a bright yellow and numerous particles were ablated in a visible smoke. Transmission electron microscopy (TEM) was used to examine the morphology and the crystallinity of the neo-formed compounds, both on the surface of the samples and in the ablated materials. In addition, an investigation of the chemical and structural properties of the nanophases was conducted by X-ray dispersive energy (EDX) and electron energy loss (EELS) spectroscopies. It was found that both the surface of the sample and the ablated materials are covered by crystallized nano-spheres and nano-residues, all containing iron and oxygen, sometimes along with calcium and sulfur. In particular an interfacial area containing the four elements was evidenced between some nanostructures and the substrate. Magnetite Fe3O4 was also identified at the nanoscale. This study demonstrates that the laser yellowing of a model crust is linked to the presence of iron-rich nanophases including CaxFeySzOδ nanostructures and magnetite Fe3O4 at the surface after irradiation. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000449125600004 |
Publication Date |
2018-08-18 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0968-4328 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
1.98 |
Times cited |
9 |
Open Access |
Not_Open_Access: Available from 19.08.2020
|
| Notes |
The authors wish to thank Valérie Lalanne for the sample preparation for TEM and Stijn Van den Broeck for the FIB cut elaboration. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative–I3). |
Approved |
Most recent IF: 1.98 |
| Call Number |
EMAT @ emat @c:irua:154356UA @ admin @ c:irua:154356 |
Serial |
5056 |
| Permanent link to this record |
| |
|
| |
| Author |
Müller-Caspary, K.; Grieb, T.; Müßener, J.; Gauquelin, N.; Hille, P.; Schörmann, J.; Verbeeck, J.; Van Aert, S.; Eickhoff, M.; Rosenauer, A. |
| Title |
Electrical Polarization in AlN/GaN Nanodisks Measured by Momentum-Resolved 4D Scanning Transmission Electron Microscopy |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
| Volume |
122 |
Issue |
10 |
Pages |
106102 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We report the mapping of polarization-induced internal electric fields in AlN/GaN nanowire heterostructures at unit cell resolution as a key for the correlation of optical and structural phenomena in semiconductor optoelectronics. Momentum-resolved aberration-corrected scanning transmission electron microscopy is employed as a new imaging mode that simultaneously provides four-dimensional data in real and reciprocal space. We demonstrate how internal mesoscale and atomic electric fields can be separated in an experiment, which is verified by comprehensive dynamical simulations of multiple electron scattering. A mean difference of 5.3 +- 1.5 MV/cm is found for the polarization-induced electric fields in AlN and GaN, being in accordance with dedicated simulations and photoluminescence measurements in previous publications. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000461067700007 |
Publication Date |
2019-03-11 |
| 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 |
26 |
Open Access |
OpenAccess |
| Notes |
The authors gratefully acknowledge the help of Natalie Claes for analyzing the EDX data. K. M.-C. acknowledges funding from the Initiative and Network Fund of the Helmholtz Association within the Helmholtz Young Investigator Group moreSTEM under Contract No. VHNG- 1317 at Forschungszentrum Jülich in Germany. The direct electron detector (Medipix3, Quantum Detectors) was funded by the Hercules fund from the Flemish Government. N. G. and J. V. acknowledge funding from the Geconcentreerde Onderzoekacties project Solarpaint of the University of Antwerp. T. G. and A. R. acknowledge support from the Deutsche Forschungsgemeinschaft (Germany) under Contract No. RO2057/8-3. This work also received funding from the European Research Council under the European Union’s Horizon 2020 research and innovation programme (Contract No. 770887). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project funding (G.0368.15N).; Helmholtz Association, VH-NG-1317 ; Forschungszentrum Jülich; Flemish Government; Universiteit Antwerpen; Deutsche Forschungsgemeinschaft, RO2057/8-3 ; H2020 European Research Council, 770887 ; Fonds Wetenschappelijk Onderzoek, G.0368.15N ; |
Approved |
Most recent IF: 8.462 |
| Call Number |
UA @ lucian @UA @ admin @ c:irua:158120 |
Serial |
5157 |
| Permanent link to this record |
| |
|
| |
| Author |
Yin, C.; Krishnan, D.; Gauquelin, N.; Verbeeck, J.; Aarts, J. |
| Title |
Controlling the interfacial conductance in LaAlO3/SrTiO3 in 90 degrees off-axis sputter deposition |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Physical review materials |
Abbreviated Journal |
|
| Volume |
3 |
Issue |
3 |
Pages |
034002 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We report on the fabrication of conducting interfaces between LaAlO3 and SrTiO3 by 90 degrees off-axis sputtering in an Ar atmosphere. At a growth pressure of 0.04 mbar the interface is metallic, with a carrier density of the order of 1 x 10(13) cm(-2) at 3 K. By increasing the growth pressure, we observe an increase of the out-of-plane lattice constants of the LaAlO3 films while the in-plane lattice constants do not change. Also, the low-temperature sheet resistance increases with increasing growth pressure, leading to an insulating interface when the growth pressure reaches 0.10 mbar. We attribute the structural variations to an increase of the La/Al ratio, which also explains the transition from metallic behavior to insulating behavior of the interfaces. Our research shows that the control which is furnished by the Ar pressure makes sputtering as versatile a process as pulsed laser deposition, and emphasizes the key role of the cation stoichiometry of LaAlO3 in the formation of the conducting interface. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000461077100002 |
Publication Date |
2019-03-12 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2475-9953 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.926 |
Times cited |
4 |
Open Access |
Not_Open_Access |
| Notes |
; We thank Nikita Lebedev, Aymen Ben Hamida, and Prateek Kumar for useful discussions and Giordano Mattoni, Jun Wang, Vincent Joly, and Hozanna Miro for their technical assistance. We also thank Jean-Marc Triscone and his group for sharing their design of the sputtering system with us. This work is part of the FOM research programme DESCO with Project No. 149, which is (partly) financed by the Netherlands Organisation for Scientific Research (NWO). C.Y. is supported by China Scholarship Council (CSC) with Grant No. 201508110214. N.G., D.K., and J.V. acknowledge financial support from the GOA project “Solarpaint” of the University of Antwerp. ; |
Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:158547 |
Serial |
5243 |
| Permanent link to this record |
| |
|
| |
| Author |
O'Donnell, D.; Hassan, S.; Du, Y.; Gauquelin, N.; Krishnan, D.; Verbeeck, J.; Fan, R.; Steadman, P.; Bencok, P.; Dobrynin, A.N. |
| Title |
Etching induced formation of interfacial FeMn in IrMn/CoFe bilayers |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
| Volume |
52 |
Issue |
16 |
Pages |
165002 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The effect of ion etching on exchange bias in IrMn3/Co70Fe30 bilayers is investigated. In spite of the reduction of saturation magnetization caused by the embedding of Tr from the capping layer into the Co70Fe30 layer during the etching process, the exchange bias in samples with the same thickness of the Co70Fe30 layer is reducing in proportion to the etching power. X-ray magnetic circular dichroism measurements revealed the emergence of an uncompensated Mn magnetization after etching, which is antiferromagnetically coupled to the ferromagnetic layer. This suggests etching induced formation of small interfacial FeMn regions which leads to the decrease of effective exchange coupling between ferromagnetic and antiferromagnetic layers. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000458524800001 |
Publication Date |
2019-01-31 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0022-3727 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
2.588 |
Times cited |
|
Open Access |
OpenAccess |
| Notes |
; This work was supported by Seagate Technology (Ireland). Beamline I10, Diamond Light Source, is acknowledged for provided beamtime. ; |
Approved |
Most recent IF: 2.588 |
| Call Number |
UA @ admin @ c:irua:157458 |
Serial |
5247 |
| Permanent link to this record |
| |
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| |
| Author |
Behera, B.C.; Jana, S.; Bhat, S.G.; Gauquelin, N.; Tripathy, G.; Kumar, P.S.A.; Samal, D. |
| Title |
Evidence for exchange bias coupling at the perovskite/brownmillerite interface in spontaneously stabilized SrCoO3-\delta/SrCoO2.5 bilayers |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
99 |
Issue |
2 |
Pages |
024425 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Interface effect in complex oxide thin-film heterostructures lies at the vanguard of current research to design technologically relevant functionality and explore emergent physical phenomena. While most of the previous works focus on the perovskite/perovskite heterostructures, the study of perovskite/brownmillerite interfaces remains in its infancy. Here, we investigate spontaneously stabilized perovskite-ferromagnet (SrCoO3-delta)/brownmillerite-antiferromagnet (SrCoO2.5) bilayer with T-N > T-C and discover an unconventional interfacial magnetic exchange bias effect. From magnetometry investigations, it is rationalized that the observed effect stems from the interfacial ferromagnet/antiferromagnet coupling. The possibility for coupled ferromagnet/spin-glass interface engendering such effect is ruled out. Strikingly, a finite coercive field persists in the paramagnetic state of SrCoO3-delta,whereas the exchange bias field vanishes at T-C . We conjecture the observed effect to be due to the effective external quenched staggered field provided by the antiferromagnetic layer for the ferromagnetic spins at the interface. Our results not only unveil a paradigm to tailor the interfacial magnetic properties in oxide heterostructures without altering the cations at the interface, but also provide a purview to delve into the fundamental aspects of exchange bias in such unusual systems, paving a big step forward in thin-film magnetism. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000456481900003 |
Publication Date |
2019-01-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| 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 |
2 |
Open Access |
OpenAccess |
| Notes |
; We are grateful to Sachin Sarangi for his superb technical support during magnetic measurements. We thank Gopal Pradhan for fruitful discussion. We thank Zhicheng Zhong for reading the manuscript and for suggestions. We thank T. Som for extending laboratory facility. D.S. and B.C.B. acknowledge the financial support from Max-Planck Society through Max Planck Partner Group. S.G.B. acknowledges the INSPIRE Faculty Fellowship Programme (DSTO1899) for the financial support. ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:157562 |
Serial |
5248 |
| Permanent link to this record |
| |
|
| |
| Author |
Das, S.; Rata, A.D.; Maznichenko, I., V; Agrestini, I.S.; Pippel, E.; Gauquelin, N.; Verbeeck, J.; Chen, K.; Valvidares, S.M.; Vasili, H.B.; Herrero-Martin, J.; Pellegrin, E.; Nenkov, K.; Herklotz, A.; Ernst, A.; Mertig, I.; Hu, Z.; Doerr, K. |
| Title |
Low-field switching of noncollinear spin texture at La0.7Sr0.3MnO3-SrRuO3interfaces |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
99 |
Issue |
2 |
Pages |
024416 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Interfaces of ferroic oxides can show complex magnetic textures which have strong impact on spintronics devices. This has been demonstrated recently for interfaces with insulating antiferromagnets such as BiFeO3. Here, noncollinear spin textures which can be switched in very low magnetic field are reported for conducting ferromagnetic bilayers of La0.7Sr0.3MnO3-SrRuO3 (LSMO-SRO). The magnetic order and switching are fundamentally different for bilayers coherently grown in reversed stacking sequence. The SRO top layer forms a persistent exchange spring which is antiferromagnetically coupled to LSMO and drives switching in low fields of a few milliteslas. Density functional theory reveals the crucial impact of the interface termination on the strength of Mn-Ru exchange coupling across the interface. The observation of an exchange spring agrees with ultrastrong coupling for the MnO2/SrO termination. Our results demonstrate low-field switching of noncollinear spin textures at an interface between conducting oxides, opening a pathway for manipulating and utilizing electron transport phenomena in controlled spin textures at oxide interfaces. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000455821400005 |
Publication Date |
2019-01-15 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| 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 |
19 |
Open Access |
OpenAccess |
| Notes |
; The research in Halle was supported by Deutsche Forschungsgemeinschaft (DFG), SFB 762 Functional Oxide Interfaces (Projects No. A9 and No. B1). K.C. benefited from support of the DFG (Project 600575). Discussions with M. Trassin, M. Ziese, H. M. Christen, E.-J. Guo, F. Grcondciel, M. Bibes, and H. N. Lee are gratefully acknowledged. N. G. and J. V. acknowledge funding under the GOA project “Solarpaint” of the University of Antwerp. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:156717 |
Serial |
5255 |
| Permanent link to this record |
| |
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| |
| Author |
Wang, J.; Shin, Y.; Gauquelin, N.; Yang, Y.; Lee, C.; Jannis, D.; Verbeeck, J.; Rondinelli, J.M.; May, S.J. |
| Title |
Physical properties of epitaxial SrMnO2.5−δFγoxyfluoride films |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
31 |
Issue |
36 |
Pages |
365602 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Recently, topotactic fluorination has become an alternative way of doping epitaxial perovskite oxides through anion substitution to engineer their electronic properties instead of the more commonly used cation substitution. In this work, epitaxial oxyfluoride SrMnO2.5−δ F γ films were synthesized via topotactic fluorination of SrMnO2.5 films using polytetrafluoroethylene as the fluorine source. Oxidized SrMnO3 films were also prepared for comparison with the fluorinated samples. The F content, probed by x-ray photoemission spectroscopy, was systematically controlled by adjusting fluorination conditions. Electronic transport measurements reveal that increased F content (up to γ = 0.14) systematically increases the electrical resistivity, despite the nominal electron-doping induced by F substitution for O in these films. In contrast, oxidized SrMnO3 exhibits a decreased resistivity and conduction activation energy. A blue-shift of optical absorption features occurs with increasing F content. Density functional theory calculations indicate that F acts as a scattering center for electronic transport, controls the observed weak ferromagnetic behavior of the films, and reduces the inter-band optical transitions in the manganite films. These results stand in contrast to bulk electron-doped La1−x Ce x MnO3, illustrating how aliovalent anionic substitutions can yield physical behavior distinct from A-site substituted perovskites with the same nominal B-site oxidation states. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000472232000002 |
Publication Date |
2019-09-11 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| 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 |
5 |
Open Access |
|
| Notes |
Work at Drexel was supported by the National Science Foundation (NSF), grant number CMMI-1562223. Thin film synthesis utilized deposition instrumentation acquired through an Army Research Office DURIP grant (W911NF-14-1-0493). Y.S and J.M.R. were supported by NSF (Grant No. DMR-1454688). Calculations were performed using the QUEST HPC Facility at Northwestern, the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by NSF Grant No. ACI-1053575, and the Center for Nanoscale Materials (Carbon Cluster). Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. J.V. and N. G. acknowledge funding from a GOA project “Solarpaint” of the University of Antwerp. D.J. acknowledges funding from FWO project G093417N from the Flemish fund for scientific research. |
Approved |
Most recent IF: 2.649 |
| Call Number |
EMAT @ emat @UA @ admin @ c:irua:161174 |
Serial |
5293 |
| Permanent link to this record |
| |
|
| |
| Author |
Keunecke, M.; Lyzwa, F.; Schwarzbach, D.; Roddatis, V.; Gauquelin, N.; Müller-Caspary, K.; Verbeeck, J.; Callori, S.J.; Klose, F.; Jungbauer, M.; Moshnyaga, V. |
| Title |
High-TCInterfacial Ferromagnetism in SrMnO3/LaMnO3Superlattices |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Advanced functional materials |
Abbreviated Journal |
Adv. Funct. Mater. |
| Volume |
|
Issue |
|
Pages |
1808270 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Heterostructures of strongly correlated oxides demonstrate various intriguing and potentially useful interfacial phenomena. LaMnO3/SrMnO3 superlattices are presented showcasing a new high‐temperature ferromagnetic phase with Curie temperature, TC ≈360 K, caused by electron transfer from the surface of the LaMnO3 donor layer into the neighboring SrMnO3 acceptor layer. As a result, the SrMnO3 (top)/LaMnO3 (bottom) interface shows an enhancement of the magnetization as depth‐profiled by polarized neutron reflectometry. The length scale of charge transfer, λTF ≈2 unit cells, is obtained from in situ growth monitoring by optical ellipsometry, supported by optical simulations, and further confirmed by high resolution electron microscopy and spectroscopy. A model of the inhomogeneous distribution of electron density in LaMnO3/SrMnO3 layers along the growth direction is concluded to account for a complex interplay between ferromagnetic and antiferromagnetic layers in superlattices. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000535358900008 |
Publication Date |
2019-02-10 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1616301X |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
15.621 |
Times cited |
26 |
Open Access |
|
| Notes |
The authors thank EU FP7 Framework (Project IFOX) and DFG (SFB 1073, TP B04, A02, Z02) for the financial support. J.V., K.M.C and N.G. acknowledge funding through the GOA project “Solarpaint” of the University of Antwerp and from the FWO project G.0044.13N (Charge ordering). The microscope used in this work was partly funded by the Hercules Fund from the Flemish Government. The PNR experiment was funded by the Australian Nuclear Science and Technology Organization (proposal number P3985). |
Approved |
Most recent IF: NA |
| Call Number |
EMAT @ emat @UA @ admin @ c:irua:162108 |
Serial |
5294 |
| Permanent link to this record |
| |
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| |
| Author |
Kuo, C.-T.; Lin, S.-C.; Ghiringhelli, G.; Peng, Y.; De Luca, G.M.; Di Castro, D.; Betto, D.; Gehlmann, M.; Wijnands, T.; Huijben, M.; Meyer-Ilse, J.; Gullikson, E.; Kortright, J.B.; Vailionis, A.; Gauquelin, N.; Verbeeck, J.; Gerber, T.; Balestrino, G.; Brookes, N.B.; Braicovich, L.; Fadley, C.S. |
| Title |
Depth-resolved resonant inelastic x-ray scattering at a superconductor/half-metallic-ferromagnet interface through standing wave excitation |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
98 |
Issue |
23 |
Pages |
235146 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We demonstrate that combining standing wave (SW) excitation with resonant inelastic x-ray scattering (RIXS) can lead to depth resolution and interface sensitivity for studying orbital and magnetic excitations in correlated oxide heterostructures. SW-RIXS has been applied to multilayer heterostructures consisting of a superconductor La1.85Sr0.15CuO4 (LSCO) and a half-metallic ferromagnet La0.67Sr0.33MnO3 (LSMO). Easily observable SW effects on the RIXS excitations were found in these LSCO/LSMO multilayers. In addition, we observe different depth distribution of the RIXS excitations. The magnetic excitations are found to arise from the LSCO/LSMO interfaces, and there is also a suggestion that one of the dd excitations comes from the interfaces. SW-RIXS measurements of correlated-oxide and other multilayer heterostructures should provide unique layer-resolved insights concerning their orbital and magnetic excitations, as well as a challenge for RIXS theory to specifically deal with interface effects. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000454160800004 |
Publication Date |
2018-12-21 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| 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 |
J.V. and N.G. acknowledge ˝ funding through the GOA project “Solarpaint” of the University of Antwerp. The microscope used in this work was partly funded by the Hercules Fund from the Flemish Government. |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:156784 |
Serial |
5363 |
| Permanent link to this record |
| |
|
| |
| Author |
Wang, J.; Nguyen, M.D.; Gauquelin, N.; Verbeeck, J.; Do, M.T.; Koster, G.; Rijnders, G.; Houwman, E. |
| Title |
On the importance of the work function and electron carrier density of oxide electrodes for the functional properties of ferroelectric capacitors |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physica Status Solidi-Rapid Research Letters |
Abbreviated Journal |
Phys Status Solidi-R |
| Volume |
14 |
Issue |
14 |
Pages |
1900520 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
It is important to understand the effect of the interfaces between the oxide electrode layers and the ferroelectric layer on the polarization response for optimizing the device performance of all-oxide ferroelectric devices. Herein, the effects of the oxide La0.07Ba0.93SnO3 (LBSO) as an electrode material in an PbZr0.52Ti0.48O3 (PZT) ferroelectric capacitor are compared with those of the more commonly used SrRuO3 (SRO) electrode. SRO (top)/PZT/SRO (bottom), SRO/PZT/LBSO, and SRO/PZT/2 nm SRO/LBSO devices are fabricated. Only marginal differences in crystalline properties, determined by X-ray diffraction and scanning transmission electron microscopy, are found. High-quality polarization loops are obtained, but with a much larger coercive field for the SRO/PZT/LBSO device. In contrast to the SRO/PZT/SRO device, the polarization decreases strongly with increasing field cycling. This fatigue problem can be remedied by inserting a 2 nm SRO layer between PZT and LBSO. It is argued that strongly increased charge injection into the PZT occurs at the bottom interface, because of the low PZT/LBSO interfacial barrier and the much lower carrier density in LBSO, as compared with that in SRO, causing a low dielectric constant, depleted layer in LBSO. The charge injection creates a trapped space charge in the PZT, causing the difference in fatigue behavior. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
|
| Language |
|
Wos |
000506195600001 |
Publication Date |
2019-12-12 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1862-6254 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.8 |
Times cited |
6 |
Open Access |
OpenAccess |
| Notes |
; This work was supported by Nederlandse Organisatie voor Wetenschappelijk Onderzoek through grant no.13HTSM01. ; |
Approved |
Most recent IF: 2.8; 2020 IF: 3.032 |
| Call Number |
UA @ admin @ c:irua:165681 |
Serial |
6316 |
| Permanent link to this record |
| |
|
| |
| Author |
Chen, B.; Gauquelin, N.; Reith, P.; Halisdemir, U.; Jannis, D.; Spreitzer, M.; Huijben, M.; Abel, S.; Fompeyrine, J.; Verbeeck, J.; Hilgenkamp, H.; Rijnders, G.; Koster, G. |
| Title |
Thermal-strain-engineered ferromagnetism of LaMnO3/SrTiO3 heterostructures grown on silicon |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical review materials |
Abbreviated Journal |
Phys. Rev. Materials |
| Volume |
4 |
Issue |
2 |
Pages |
024406 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The integration of oxides on Si remains challenging, which largely hampers the practical applications of oxide-based electronic devices with superior performance. Recently, LaMnO3/SrTiO3 (LMO/STO) heterostructures have gained renewed interest for the debating origin of the ferromagnetic-insulating ground state as well as for their spin-filter applications. Here we report on the structural and magnetic properties of high-quality LMO/STO heterostructures grown on silicon. The chemical abruptness across the interface was investigated by atomic-resolution scanning transmission electron microscopy. The difference in the thermal expansion coefficients between LMO and Si imposed a large biaxial tensile strain to the LMO film, resulting in a tetragonal structure with c/a∼ 0.983. Consequently, we observed a significantly suppressed ferromagnetism along with an enhanced coercive field, as compared to the less distorted LMO film (c/a∼1.004) grown on STO single crystal. The results are discussed in terms of tensile-strain enhanced antiferromagnetic instabilities. Moreover, the ferromagnetism of LMO on Si sharply disappeared below a thickness of 5 unit cells, in agreement with the LMO/STO case, pointing to a robust critical behavior irrespective of the strain state. Our results demonstrate that the growth of oxide films on Si can be a promising way to study the tensile-strain effects in correlated oxides, and also pave the way towards the integration of multifunctional oxides on Si with atomic-layer control. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
|
Wos |
000513552900003 |
Publication Date |
2020-02-12 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2475-9953 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.4 |
Times cited |
6 |
Open Access |
Not_Open_Access |
| Notes |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek; Universiteit Antwerpen; Vlaamse regering; Fonds Wetenschappelijk Onderzoek, G093417N ; Javna Agencija za Raziskovalno Dejavnost RS, J2-9237 P2-0091 ; European Commission, H2020-ICT-2016-1-732642 ; |
Approved |
Most recent IF: 3.4; 2020 IF: NA |
| Call Number |
EMAT @ emat @c:irua:167782 |
Serial |
6375 |
| Permanent link to this record |
| |
|
| |
| Author |
Araizi-Kanoutas, G.; Geessinck, J.; Gauquelin, N.; Smit, S.; Verbeek, X.H.; Mishra, S.K.; Bencok, P.; Schlueter, C.; Lee, T.-L.; Krishnan, D.; Fatermans, J.; Verbeeck, J.; Rijnders, G.; Koster, G.; Golden, M.S. |
| Title |
Co valence transformation in isopolar LaCoO3/LaTiO3 perovskite heterostructures via interfacial engineering |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical review materials |
Abbreviated Journal |
Phys. Rev. Materials |
| Volume |
4 |
Issue |
2 |
Pages |
026001 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We report charge transfer up to a single electron per interfacial unit cell across nonpolar heterointerfaces from the Mott insulator LaTiO3 to the charge transfer insulator LaCoO3. In high-quality bi- and trilayer systems grown using pulsed laser deposition, soft x-ray absorption, dichroism, and scanning transmission electron microscopy-electron energy loss spectroscopy are used to probe the cobalt-3d electron count and provide an element-specific investigation of the magnetic properties. The experiments show the cobalt valence conversion is active within 3 unit cells of the heterointerface, and able to generate full conversion to 3d7 divalent Co, which displays a paramagnetic ground state. The number of LaTiO3/LaCoO3 interfaces, the thickness of an additional, electronically insulating “break” layer between the LaTiO3 and LaCoO3, and the LaCoO3 film thickness itself in trilayers provide a trio of control knobs for average charge of the cobalt ions in LaCoO3, illustrating the efficacy of O−2p band alignment as a guiding principle for property design in complex oxide heterointerfaces. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
|
Wos |
000513551200007 |
Publication Date |
2020-02-10 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2475-9953 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.4 |
Times cited |
13 |
Open Access |
OpenAccess |
| Notes |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek; Universiteit Antwerpen; Horizon 2020, 730872 ; Department of Science and Technology, Ministry of Science and Technology, SR/NM/Z-07/2015 ; Jawaharlal Nehru Centre for Advanced Scientific Research; |
Approved |
Most recent IF: 3.4; 2020 IF: NA |
| Call Number |
EMAT @ emat @c:irua:167787 |
Serial |
6376 |
| Permanent link to this record |
| |
|
| |
| Author |
Groenendijk, D.J.; Autieri, C.; van Thiel, T.C.; Brzezicki, W.; Hortensius, J.R.; Afanasiev, D.; Gauquelin, N.; Barone, P.; van den Bos, K.H.W.; van Aert, S.; Verbeeck, J.; Filippetti, A.; Picozzi, S.; Cuoco, M.; Caviglia, A.D. |
| Title |
Berry phase engineering at oxide interfaces |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
|
Abbreviated Journal |
Phys. Rev. Research |
| Volume |
2 |
Issue |
2 |
Pages |
023404 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Three-dimensional strontium ruthenate (SrRuO3) is an itinerant ferromagnet that features Weyl points acting as sources of emergent magnetic fields, anomalous Hall conductivity, and unconventional spin dynamics. Integrating SrRuO3 in oxide heterostructures is potentially a novel route to engineer emergent electrodynamics, but its electronic band topology in the two-dimensional limit remains unknown. Here we show that ultrathin SrRuO3 exhibits spin-polarized topologically nontrivial bands at the Fermi energy. Their band anticrossings show an enhanced Berry curvature and act as competing sources of emergent magnetic fields. We control their balance by designing heterostructures with symmetric (SrTiO3/SrRuO3/SrTiO3 and SrIrO3/SrRuO3/SrIrO3) and asymmetric interfaces (SrTiO3/SrRuO3/SrIrO3). Symmetric structures exhibit an interface-tunable single-channel anomalous Hall effect, while ultrathin SrRuO3 embedded in asymmetric structures shows humplike features consistent with multiple Hall contributions. The band topology of two-dimensional SrRuO3 proposed here naturally accounts for these observations and harmonizes a large body of experimental results. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
|
Wos |
000603642700008 |
Publication Date |
2020-06-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2643-1564 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
58 |
Open Access |
OpenAccess |
| Notes |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek; Fonds Wetenschappelijk Onderzoek; European Research Council; Horizon 2020, 677458 770887 731473 ; Fondazione Cariplo, 2013-0726 ; Narodowe Centrum Nauki, 2016/23/B/ST3/00839 ; Fundacja na rzecz Nauki Polskiej; Universiteit Antwerpen; Vlaamse regering; |
Approved |
Most recent IF: NA |
| Call Number |
EMAT @ emat @c:irua:172462 |
Serial |
6401 |
| Permanent link to this record |
| |
|
| |
| Author |
Wang, J.; Gauquelin, N.; Huijben, M.; Verbeeck, J.; Rijnders, G.; Koster, G. |
| Title |
Metal-insulator transition of SrVO 3 ultrathin films embedded in SrVO 3 / SrTiO 3 superlattices |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Applied Physics Letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
117 |
Issue |
13 |
Pages |
133105 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The metal-insulator transition (MIT) in strongly correlated oxides is a topic of great interest for its potential applications, such as Mott field effect transistors and sensors. We report that the MIT in high quality epitaxial SrVO3 (SVO) thin films is present as the film thickness is reduced, lowering the dimensionality of the system, and electron-electron correlations start to become the dominant interactions. The critical thickness of 3 u.c is achieved by avoiding effects due to off-stoichiometry using optimal growth conditions and excluding any surface effects by a STO capping layer. Compared to the single SVO thin films, conductivity enhancement in SVO/STO superlattices is observed. This can be explained by the interlayer coupling effect between SVO sublayers in the superlattices. Magnetoresistance and Hall measurements indicate that the dominant driving force of MIT is the electron–electron interaction. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000577126100001 |
Publication Date |
2020-09-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0003-6951 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4 |
Times cited |
8 |
Open Access |
OpenAccess |
| Notes |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek, 13HTSM01 ; |
Approved |
Most recent IF: 4; 2020 IF: 3.411 |
| Call Number |
EMAT @ emat @c:irua:172461 |
Serial |
6415 |
| Permanent link to this record |
| |
|
| |
| Author |
Jovanović, Z.; Gauquelin, N.; Koster, G.; Rubio-Zuazo, J.; Ghosez, P.; Verbeeck, J.; Suvorov, D.; Spreitzer, M. |
| Title |
Simultaneous heteroepitaxial growth of SrO (001) and SrO (111) during strontium-assisted deoxidation of the Si (001) surface |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Rsc Advances |
Abbreviated Journal |
Rsc Adv |
| Volume |
10 |
Issue |
52 |
Pages |
31261-31270 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Epitaxial integration of transition-metal oxides with silicon brings a variety of functional properties to the well-established platform of electronic components. In this process, deoxidation and passivation of the silicon surface are one of the most important steps, which in our study were controlled by an ultra-thin layer of SrO and monitored by using transmission electron microscopy (TEM), electron energy-loss spectroscopy (EELS), synchrotron X-ray diffraction (XRD) and reflection high energy electron diffraction (RHEED) methods. Results revealed that an insufficient amount of SrO leads to uneven deoxidation of the silicon surface<italic>i.e.</italic>formation of pits and islands, whereas the composition of the as-formed heterostructure gradually changes from strontium silicide at the interface with silicon, to strontium silicate and SrO in the topmost layer. Epitaxial ordering of SrO, occurring simultaneously with silicon deoxidation, was observed. RHEED analysis has identified that SrO is epitaxially aligned with the (001) Si substrate both with SrO (001) and SrO (111) out-of-plane directions. This observation was discussed from the point of view of SrO desorption, SrO-induced deoxidation of the Si (001) surface and other interfacial reactions as well as structural ordering of deposited SrO. Results of the study present an important milestone in understanding subsequent epitaxial integration of functional oxides with silicon using SrO. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000566579400025 |
Publication Date |
2020-08-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2046-2069 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.9 |
Times cited |
1 |
Open Access |
OpenAccess |
| Notes |
Vlaamse regering, Hercules Fund ; Ministarstvo Prosvete, Nauke i Tehnološkog Razvoja, III 45006 ; Javna Agencija za Raziskovalno Dejavnost RS, J2-9237 P2-0091 ; Fonds Wetenschappelijk Onderzoek, G.0044.13N ; Ministerio de Ciencia, Innovación y Universidades; Universiteit Antwerpen, GOA project Solarpaint ; F.R.S.-FNRS, PDR project PROMOSPAN ; Consejo Superior de Investigaciones Cientificas; University of Liège, ARC project AIMED ; Ministry of Education, Science and Sport, M.ERA-NET project SIOX ; |
Approved |
Most recent IF: 3.9; 2020 IF: 3.108 |
| Call Number |
EMAT @ emat @c:irua:172059 |
Serial |
6416 |
| Permanent link to this record |
| |
|
| |
| Author |
Lebedev, N.; Stehno, M.; Rana, A.; Gauquelin, N.; Verbeeck, J.; Brinkman, A.; Aarts, J. |
| Title |
Inhomogeneous superconductivity and quasilinear magnetoresistance at amorphous LaTiO₃/SrTiO₃ interfaces |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of Physics-Condensed Matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
33 |
Issue |
5 |
Pages |
055001 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
We have studied the transport properties of LaTiO3/SrTiO3 (LTO/STO) heterostructures. In spite of 2D growth observed in reflection high energy electron diffraction, transmission electron microscopy images revealed that the samples tend to amorphize. Still, we observe that the structures are conducting, and some of them exhibit high conductance and/or superconductivity. We established that conductivity arises mainly on the STO side of the interface, and shows all the signs of the two-dimensional electron gas usually observed at interfaces between STO and LTO or LaAlO3, including the presence of two electron bands and tunability with a gate voltage. Analysis of magnetoresistance (MR) and superconductivity indicates the presence of spatial fluctuations of the electronic properties in our samples. That can explain the observed quasilinear out-of-plane MR, as well as various features of the in-plane MR and the observed superconductivity. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000588209300001 |
Publication Date |
2020-10-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.7 |
Times cited |
1 |
Open Access |
OpenAccess |
| Notes |
; NL and JA gratefully acknowledge the financial support of the research program DESCO, which is financed by the Netherlands Organisation for Scientific Research (NWO). The authors thank J Jobst, S Smink, K Lahabi and G Koster for useful discussion. ; |
Approved |
Most recent IF: 2.7; 2020 IF: 2.649 |
| Call Number |
UA @ admin @ c:irua:173679 |
Serial |
6545 |
| Permanent link to this record |
| |
|
| |
| Author |
Lin, S.-C.; Kuo, C.-T.; Shao, Y.-C.; Chuang, Y.-D.; Geessinck, J.; Huijben, M.; Rueff, J.-P.; Graff, I.L.; Conti, G.; Peng, Y.; Bostwick, A.; Gullikson, E.; Nemsak, S.; Vailionis, A.; Gauquelin, N.; Verbeeck, J.; Ghiringhelli, G.; Schneider, C.M.; Fadley, C.S. |
| Title |
Two-dimensional electron systems in perovskite oxide heterostructures : role of the polarity-induced substitutional defects |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical review materials |
Abbreviated Journal |
|
| Volume |
4 |
Issue |
11 |
Pages |
115002 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The discovery of a two-dimensional electron system (2DES) at the interfaces of perovskite oxides such as LaAlO3 and SrTiO3 has motivated enormous efforts in engineering interfacial functionalities with this type of oxide heterostructures. However, the fundamental origins of the 2DES are still not understood, e.g., the microscopic mechanisms of coexisting interface conductivity and magnetism. Here we report a comprehensive spectroscopic investigation on the depth profile of 2DES-relevant Ti 3d interface carriers using depthand element-specific techniques like standing-wave excited photoemission and resonant inelastic scattering. We found that one type of Ti 3d interface carriers, which give rise to the 2DES are located within three unit cells from the n-type interface in the SrTiO3 layer. Unexpectedly, another type of interface carriers, which are polarity-induced Ti-on-Al antisite defects, reside in the first three unit cells of the opposing LaAlO3 layer (similar to 10 angstrom). Our findings provide a microscopic picture of how the localized and mobile Ti 3d interface carriers distribute across the interface and suggest that the 2DES and 2D magnetism at the LaAlO3/SrTiO3 interface have disparate explanations as originating from different types of interface carriers. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000592432200004 |
Publication Date |
2020-11-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2475-9953 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.4 |
Times cited |
7 |
Open Access |
OpenAccess |
| Notes |
; We thank G. M. De Luca and L. Braicovich for discussions. Charles S. Fadley was deceased on August 1, 2019. We are grateful for his significant contributions to this work. We thank Advanced Light Source for the access to Beamline 8.0.3 (qRIXS) via Proposal No. 09892 and beamline 7.0.2 (MAESTRO) via Proposal No. RA-00291 that contributed to the results presented here. We thank synchrotron SOLEIL (via Proposal No. 99180118) for the access to Beamline GALAXIES. This work was supported by the U.S. Department of Energy (DOE) under Contract No. DE-AC02-05CH11231 (Advanced Light Source), and by DOE Contract No. DE-SC0014697 through the University of California, Davis (S.-C.L., C.-T.K, and C.S.F.), and from the Julich Research Center, Peter Grunberg Institute, PGI-6. I. L. G. wishes to thank Brazilian scientific agencies CNPQ (Project No. 200789/2017-1) and CAPES (CAPES-PrInt-UFPR) for their financial support. J.V. and N.G. acknowledge funding from the Geconcentreerde Onderzoekacties (GOA) project “Solarpaint” of the University of Antwerp and the European Union's horizon 2020 research and innovation program ES-TEEM3 under grant agreement no 823717. The Qu-Ant-EM microscope used in this study was partly funded by the Hercules fund from the Flemish Government. ; esteem3TA; esteem3reported |
Approved |
Most recent IF: 3.4; 2020 IF: NA |
| Call Number |
UA @ admin @ c:irua:174316 |
Serial |
6713 |
| Permanent link to this record |
| |
|
| |
| Author |
van Thiel, T. c.; Brzezicki, W.; Autieri, C.; Hortensius, J. r.; Afanasiev, D.; Gauquelin, N.; Jannis, D.; Janssen, N.; Groenendijk, D. j.; Fatermans, J.; Van Aert, S.; Verbeeck, J.; Cuoco, M.; Caviglia, A. d. |
| Title |
Coupling Charge and Topological Reconstructions at Polar Oxide Interfaces |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys Rev Lett |
| Volume |
127 |
Issue |
12 |
Pages |
127202 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
In oxide heterostructures, different materials are integrated into a single artificial crystal, resulting in a breaking of inversion symmetry across the heterointerfaces. A notable example is the interface between polar and nonpolar materials, where valence discontinuities lead to otherwise inaccessible charge and spin states. This approach paved the way for the discovery of numerous unconventional properties absent in the bulk constituents. However, control of the geometric structure of the electronic wave functions in correlated oxides remains an open challenge. Here, we create heterostructures consisting of ultrathin SrRuO3, an itinerant ferromagnet hosting momentum-space sources of Berry curvature, and
LaAlO3, a polar wide-band-gap insulator. Transmission electron microscopy reveals an atomically sharp LaO/RuO2/SrO interface configuration, leading to excess charge being pinned near the LaAlO3/SrRuO3 interface. We demonstrate through magneto-optical characterization, theoretical calculations and transport measurements that the real-space charge reconstruction drives a reorganization of the topological charges in the band structure, thereby modifying the momentum-space Berry curvature in SrRuO3. Our results illustrate how the topological and magnetic features of oxides can be manipulated by engineering charge discontinuities at oxide interfaces. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000704665000010 |
Publication Date |
2021-09-16 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| 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 |
17 |
Open Access |
OpenAccess |
| Notes |
The authors thank E. Lesne, M. Lee, H. Barakov, M. Matthiesen and U. Filippozzi for discussions. The authors are grateful to E.J.S. van Thiel for producing the illustration in Fig. 4a. This work was supported by the European Research Council under the European Unions Horizon 2020 programme/ERC Grant agreements No. [677458], [770887] and No. [731473] (Quantox of QuantERA ERA-NET Cofund in Quantum Technologies) and by the Netherlands Organisation for Scientific Research (NWO/OCW) as part of the Frontiers of Nanoscience (NanoFront) and VIDI program. The authors acknowledge funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. [823717] – ESTEEM3. N. G., J. V., and S. V. A. acknowledge funding from the University of Antwerp through the Concerted Research Actions (GOA) project Solarpaint and the TOP project. C. A. and W. B. are supported by the Foundation for Polish Science through the International Research Agendas program co-financed by the European Union within the Smart Growth Operational Programme. C. A. acknowledges access to the computing facilities of the Interdisciplinary Center of Modeling at the University of Warsaw, Grant No. G73-23 and G75-10. W.B. acknowledges support from the Narodowe Centrum Nauk (NCN, National Science Centre, Poland) Project No. 2019/34/E/ST3/00404'; esteem3TA; esteem3reported |
Approved |
Most recent IF: 8.462 |
| Call Number |
EMAT @ emat @c:irua:182595 |
Serial |
6824 |
| Permanent link to this record |
| |
|
| |
| Author |
Bouwmeester, R.L.; de Hond, K.; Gauquelin, N.; Verbeeck, J.; Koster, G.; Brinkman, A. |
| Title |
Stabilization of the perovskite phase in the Y-Bi-O system by using a BaBiO₃ buffer layer |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Physica status solidi: rapid research letters |
Abbreviated Journal |
|
| Volume |
13 |
Issue |
7 |
Pages |
1800679 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
A topological insulating phase has theoretically been predicted for the thermodynamically unstable perovskite phase of YBiO3. Here, it is shown that the crystal structure of the Y-Bi-O system can be controlled by using a BaBiO3 buffer layer. The BaBiO3 film overcomes the large lattice mismatch of 12% with the SrTiO3 substrate by forming a rocksalt structure in between the two perovskite structures. Depositing an YBiO3 film directly on a SrTiO3 substrate gives a fluorite structure. However, when the Y-Bi-O system is deposited on top of the buffer layer with the correct crystal phase and comparable lattice constant, a single oriented perovskite structure with the expected lattice constants is observed. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000477671800005 |
Publication Date |
2019-03-06 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1862-6254 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
11 |
Open Access |
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| Notes |
The work at the University of Twente is financially supported by NWO through a VICI grant. N.G. and J.V. acknowledge financial support from the GOA project “Solarpaint” of the University of Antwerp. The microscope used for this experiment has been partially financed by the Hercules Fund from the Flemish Government. L. Ding is acknowledge for his help with the GPA analysis. |
Approved |
no |
| Call Number |
UA @ admin @ c:irua:181236 |
Serial |
6889 |
| Permanent link to this record |
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| Author |
Chen, B.; Gauquelin, N.; Green, R.J.; Verbeeck, J.; Rijnders, G.; Koster, G. |
| Title |
Asymmetric Interfacial Intermixing Associated Magnetic Coupling in LaMnO3/LaFeO3 Heterostructures |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Frontiers in physics |
Abbreviated Journal |
Front. Phys. |
| Volume |
9 |
Issue |
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Pages |
|
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The structural and magnetic properties of LaMnO<sub>3</sub>/LaFeO<sub>3</sub>(LMO/LFO) heterostructures are characterized using a combination of scanning transmission electron microscopy, electron energy-loss spectroscopy, bulk magnetometry, and resonant x-ray reflectivity. Unlike the relatively abrupt interface when LMO is deposited on top of LFO, the interface with reversed growth order shows significant cation intermixing of Mn<sup>3+</sup>and Fe<sup>3+</sup>, spreading ∼8 unit cells across the interface. The asymmetric interfacial chemical profiles result in distinct magnetic properties. The bilayer with abrupt interface shows a single magnetic hysteresis loop with strongly enhanced coercivity, as compared to the LMO plain film. However, the bilayer with intermixed interface shows a step-like hysteresis loop, associated with the separate switching of the “clean” and intermixed LMO sublayers. Our study illustrates the key role of interfacial chemical profile in determining the functional properties of oxide heterostructures. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000745284500001 |
Publication Date |
2021-12-14 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2296-424X |
ISBN |
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Additional Links |
UA library record; WoS full record |
| Impact Factor |
|
Times cited |
1 |
Open Access |
OpenAccess |
| Notes |
This work is supported by the international M-ERA.NET project SIOX (project 4288) and H2020 project ULPEC (project 732642). The X-Ant-EM microscope and the direct electron detector were partly funded by the Hercules fund from the Flemish Government. NG and JV acknowledge funding from GOA project “Solarpaint” of the University of Antwerp. RG was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC). Part of the research described in this paper was performed at the Canadian Light Source, a national research facility of the University of Saskatchewan, which is supported by the Canada Foundation for Innovation (CFI), NSERC, the National Research Council (NRC), the Canadian Institutes of Health Research (CIHR), the Government of Saskatchewan, and the University of Saskatchewan. |
Approved |
Most recent IF: NA |
| Call Number |
EMAT @ emat @c:irua:185176 |
Serial |
6901 |
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| Author |
Poulain, R.; Lumbeeck, G.; Hunka, J.; Proost, J.; Savolainen, H.; Idrissi, H.; Schryvers, D.; Gauquelin, N.; Klein, A. |
| Title |
Electronic and chemical properties of nickel oxide thin films and the intrinsic defects compensation mechanism |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
ACS applied electronic materials |
Abbreviated Journal |
|
| Volume |
4 |
Issue |
6 |
Pages |
2718-2728 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Although largely studied, contradictory results on nickel oxide (NiO) properties can be found in the literature. We herein propose a comprehensive study that aims at leveling contradictions related to NiO materials with a focus on its conductivity, surface properties, and the intrinsic charge defects compensation mechanism with regards to the conditions preparation. The experiments were performed by in situ photo-electron spectroscopy, electron energy loss spectroscopy, and optical as well as electrical measurements on polycrystalline NiO thin films prepared under various preparation conditions by reactive sputtering. The results show that surface and bulk properties were strongly related to the deposition temperature with in particular the observation of Fermi level pinning, high work function, and unstable oxygen-rich grain boundaries for the thin films produced at room temperature but not at high temperature (>200 degrees C). Finally, this study provides substantial information about surface and bulk NiO properties enabling to unveil the origin of the high electrical conductivity of room temperature NiO thin films and also for supporting a general electronic charge compensation mechanism of intrinsic defects according to the deposition temperature. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000819431200001 |
Publication Date |
2022-06-07 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2637-6113 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
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Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:189555 |
Serial |
7081 |
| Permanent link to this record |
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| Author |
Lebedev, N.; Huang, Y.; Rana, A.; Jannis, D.; Gauquelin, N.; Verbeeck, J.; Aarts, J. |
| Title |
Resistance minimum in LaAlO3/Eu1-xLaxTiO3/SrTiO3 heterostructures |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Physical review materials |
Abbreviated Journal |
|
| Volume |
6 |
Issue |
7 |
Pages |
075003-75010 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
In this paper we study LaAlO3/Eu1-xLaxTiO3/SrTiO3 structures with nominally x = 0, 0.1 and different thicknesses of the Eu1-xLaxTiO3 layer. We observe that both systems have many properties similar to previously studied LaAlO3/EuTiO3/SrTiO3 and other oxide interfaces, such as the formation of a two-dimensional electron liquid for two unit cells of Eu1-xLaxTiO3; a metal-insulator transition driven by the increase in thickness of the Eu1-xLaxTiO3 layer; the presence of an anomalous Hall effect when driving the systems above the Lifshitz point with a back-gate voltage; and a minimum in the temperature dependence of the sheet resistance below the Lifshitz point in the one-band regime, which becomes more pronounced with increasing negative gate voltage. However, and notwithstanding the likely presence of magnetism in the system, we do not attribute that minimum to the Kondo effect, but rather to the properties of the SrTiO3 crystal and the inevitable effects of charge trapping when using back gates. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000834035300001 |
Publication Date |
2022-07-12 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2475-9953 |
ISBN |
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Additional Links |
UA library record; WoS full record |
| Impact Factor |
3.4 |
Times cited |
|
Open Access |
OpenAccess |
| Notes |
N.L. and J.A. gratefully acknowledge the financial support of the research program DESCO, which is financed by the Netherlands Organisation for Scientific Research (NWO). J.V. and N.G. acknowledge funding from the Geconcentreerde Onderzoekacties (GOA) project “Solarpaint” of the University of Antwerp and the European Union’s horizon 2020 research and innovation programme under grant agreement №823717 – ESTEEM3. The QuAnt-EM microscope used in this study was partly funded by the Hercules fund from the Flemish Government. The authors want to thank M. Stehno, G. Koster, and F.J.G. Roesthuis for useful discussions.; esteem3reported; esteem3TA |
Approved |
Most recent IF: 3.4 |
| Call Number |
UA @ admin @ c:irua:189674 |
Serial |
7094 |
| Permanent link to this record |
