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Author	Morozov, V.A.; Lazoryak, B.I.; Shmurak, S.Z.; Kiselev, A.P.; Lebedev, O.I.; Gauquelin, N.; Verbeeck, J.; Hadermann, J.; Van Tendeloo, G.
Title	Influence of the structure on the properties of Na_xEu_y(MoO₄)_z red phosphors			Type	A1 Journal article
Year	2014	Publication	Chemistry of materials	Abbreviated Journal	Chem Mater
Volume	26	Issue	10	Pages	3238-3248
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	Scheelite related compounds (A',A '')(n)[(B',B '')O-4](m) with B', B '' = W and/or Mo are promising new materials for red phosphors in pc-WLEDs (phosphor-converted white-light-emitting-diode) and solid-state lasers. Cation substitution in CaMoO4 of Ca2+ by the combination of Na+ and Eu3+, with the creation of A cation vacancies, has been investigated as a factor for controlling the scheelite-type structure and the luminescent properties. Na5Eu(MoO4)(4) and NaxEu(2-x)/33+square(2-x)/3MoO4 (0.138 <= x <= 0.5) phases with a scheelite-type structure were synthesized by the solid state method; their structural characteristics were investigated using transmission electron microscopy. Contrary to powder synchrotron X-ray diffraction before, the study by electron diffraction and high resolution transmission electron microscopy in this paper revealed that Na0.286Eu0.571MoO4 has a (3 + 2)D incommensurately modulated structure and that (3 + 2)D incommensurately modulated domains are present in Na0.200Eu0.600MoO4. It also confirmed the (3 + 1)D incommensurately modulated character of Na(0.138)Eu(0.621)Mo04. The luminescent properties of all phases under near-ultraviolet (n-UV) light have been investigated. The excitation spectra of these phosphors show the strongest absorption at about 395 nm, which matches well with the commercially available n-UV-emitting GaN-based LED chip. The emission spectra indicate an intense red emission due to the D-5(0) -> F-7(2) transition of Eu3+, with local minima in the intensity at Na0.286Eu0.571MoO4 and Na0.200Eu0.600MoO4 for similar to 613 nm and similar to 616 nm bands. The phosphor Na5Eu(MoO4)(4) shows the brightest red light emission among the phosphors in the Na2MoO4-Eu2/3MoO4 system and the maximum luminescence intensity of Na5Eu(MoO4)(4) (lambda(ex) = 395 nm) in the D-5(0) -> F-7(2) transition region is close to that of the commercially used red phosphor YVO4:Eu3+ (lambda(ex) = 326 nm). Electron energy loss spectroscopy measurements revealed the influence of the structure and Na/Eu cation distribution on the number and positions of bands in the UV-optical-infrared regions of the EELS spectrum.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000336637000028	Publication Date	2014-05-01
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0897-4756;1520-5002;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	9.466	Times cited	53	Open Access
Notes	Fwo G039211n; Fwo G004413n; 278510 Vortex ECASJO_;			Approved	Most recent IF: 9.466; 2014 IF: 8.354
Call Number	UA @ lucian @ c:irua:117765UA @ admin @ c:irua:117765			Serial	1652
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Author	Volkova, N.E.; Lebedev, O.I.; Gavrilova, L.Y.; Turner, S.; Gauquelin, N.; Seikh, M.M.; Caignaert, V.; Cherepanov, V.A.; Raveau, B.; Van Tendeloo, G.
Title	Nanoscale ordering in oxygen deficient quintuple perovskite Sm_2-\epsilonBa_3+\epsilonFe₅O_15-\delta : implication for magnetism and oxygen stoichiometry			Type	A1 Journal article
Year	2014	Publication	Chemistry of materials	Abbreviated Journal	Chem Mater
Volume	26	Issue	21	Pages	6303-6310
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	The investigation of the system SmBaFe-O in air has allowed an oxygen deficient perovskite Sm2-epsilon Ba3+epsilon Fe5O15-delta (delta = 0.75, epsilon = 0.125) to be synthesized. In contrast to the XRPD pattern which gives a cubic symmetry (a(p) = 3.934 angstrom), the combined HREM/EELS study shows that this phase is nanoscale ordered with a quintuple tetragonal cell, a(p) X a(p) X 5(ap). The nanodomains exhibit a unique stacking sequence of the A-site cationic layers along the crystallographic c-axis, namely SmBaBa/SmBa/SmBaSm, and are chemically twinned in the three crystallographic directions. The nanoscale ordering of this perovskite explains its peculiar magnetic properties on the basis of antiferromagnetic interactions with spin blockade at the boundary between the nanodomains. The variation of electrical conductivity and oxygen content of this oxide versus temperature suggest potential SOFC applications. They may be related to the particular distribution of oxygen vacancies in the lattice and to the 3d(5)(L) under bar configuration of iron.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000344905600029	Publication Date	2014-10-07
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0897-4756;1520-5002;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	9.466	Times cited	16	Open Access
Notes	The UrFU authors were financially supported by the Ministry of Education and Science of Russian Federation (project N 4.1039.2014/K) and by UrFU under the Framework Program of development of UrFU through the «Young scientists UrFU» competition. The CRISMAT authors gratefully acknowledge the EC, the CNRS and the French Minister of Education and Research for financial support through their Research, Strategic and Scholarship programs. This work was supported by funding from the European Research Council under the Seventh Framework Program (FP7), ERC grant N°246791 – COUNTATOMS. S.T. gratefully acknowledges the fund for scientific research Flanders for a post-doctoral fellowship and for financial support under contract number G004413N. N.G. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC starting grant number 278510 – VORTEX; ECASJO_;			Approved	Most recent IF: 9.466; 2014 IF: 8.354
Call Number	UA @ lucian @ c:irua:122137			Serial	2269
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Author	Morozov, V.A.; Arakcheeva, A.V.; Pattison, P.; Meert, K.W.; Smet, P.F.; Poelman, D.; Gauquelin, N.; Verbeeck, J.; Abakumov, A.M.; Hadermann, J.
Title	KEu(MoO₄)₂ : polymorphism, structures, and luminescent properties			Type	A1 Journal article
Year	2015	Publication	Chemistry of materials	Abbreviated Journal	Chem Mater
Volume	27	Issue	27	Pages	5519-5530
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	In this paper, with the example of two different polymorphs of KEu(MoO4)2, the influence of the ordering of the A-cations on the luminescent properties in scheelite related compounds (A′,A″)n[(B′,B″)O4]m is investigated. The polymorphs were synthesized using a solid state method. The study confirmed the existence of only two polymorphic forms at annealing temperature range 9231203 K and ambient pressure: a low temperature anorthic α-phase and a monoclinic high temperature β-phase with an incommensurately modulated structure. The structures of both polymorphs were solved using transmission electron microscopy and refined from synchrotron powder X-ray diffraction data. The monoclinic β-KEu(MoO4)2 has a (3+1)-dimensional incommensurately modulated structure (superspace group I2/b(αβ0)00, a = 5.52645(4) Å, b = 5.28277(4) Å, c = 11.73797(8) Å, γ = 91.2189(4)o, q = 0.56821(2)a0.12388(3)b), whereas the anorthic α-phase is (3+1)-dimensional commensurately modulated (superspace group I1̅(αβγ)0, a = 5.58727(22) Å, b = 5.29188(18)Å, c = 11.7120(4) Å, α = 90.485(3)o, β = 88.074(3)o, γ = 91.0270(23)o, q = 1/2a* + 1/2c*). In both cases the modulation arises due to Eu/K cation ordering at the A site: the formation of a 2-dimensional Eu3+ network is characteristic for the α-phase, while a 3-dimensional Eu3+-framework is observed for the β-phase structure. The luminescent properties of KEu(MoO4)2 samples prepared under different annealing conditions were measured, and the relation between their optical properties and their structures is discussed.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000360323700011	Publication Date	2015-07-29
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0897-4756;1520-5002;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	9.466	Times cited	26	Open Access
Notes	278510 Vortex; Fwo G039211n; G004413n ECASJO_;			Approved	Most recent IF: 9.466; 2015 IF: 8.354
Call Number	c:irua:127244			Serial	3537
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Author	Morozov, V.A.; Arakcheeva, A.V.; Chapuis, G.; Guiblin, N.; Rossell, M.D.; Van Tendeloo, G.
Title	KNd(MoO₄)₂: a new incommensurate modulated structure in the scheelite family			Type	A1 Journal article
Year	2006	Publication	Chemistry of materials	Abbreviated Journal	Chem Mater
Volume	18	Issue	17	Pages	4075-4082
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author				Thesis
Publisher		Place of Publication	Washington, D.C.	Editor
Language		Wos	000239758300022	Publication Date	2006-07-28
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0897-4756;1520-5002;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	9.466	Times cited	46	Open Access
Notes	Iap V-1			Approved	Most recent IF: 9.466; 2006 IF: 5.104
Call Number	UA @ lucian @ c:irua:60688			Serial	3538
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Author	Benedet, M.; Andrea Rizzi, G.; Gasparotto, A.; Gauquelin, N.; Orekhov, A.; Verbeeck, J.; Maccato, C.; Barreca, D.
Title	Functionalization of graphitic carbon nitride systems by cobalt and cobalt-iron oxides boosts solar water oxidation performances			Type	A1 Journal article
Year	2023	Publication	Applied surface science	Abbreviated Journal
Volume	618	Issue		Pages	156652
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	The ever-increasing energy demand from the world population has made the intensive use of fossil fuels an overarching threat to global environment and human health. An appealing alternative is offered by sunlight-assisted photoelectrochemical water splitting to yield carbon-free hydrogen fuel, but kinetic limitations associated to the oxygen evolution reaction (OER) render the development of cost-effective, eco-friendly and stable electrocatalysts an imperative issue. In the present work, OER catalysts based on graphitic carbon nitride (g-C3N4) were deposited on conducting glass substrates by a simple decantation procedure, followed by functionalization with low amounts of nanostructured CoO and CoFe2O4 by radio frequency (RF)-sputtering, and final annealing under inert atmosphere. A combination of advanced characterization tools was used to investigate the interplay between material features and electrochemical performances. The obtained results highlighted the formation of a p-n junction for the g-C3N4-CoO system, whereas a Z-scheme junction accounted for the remarkable performance enhancement yielded by g-C3N4-CoFe2O4. The intimate contact between the system components also afforded an improved electrocatalyst stability in comparison to various bare and functionalized g-C3N4-based systems. These findings emphasize the importance of tailoring g-C3N4 chemico-physical properties through the dispersion of complementary catalysts to fully exploit its applicative potential.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000950654300001	Publication Date	2023-02-04
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0169-4332	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	6.7	Times cited	11	Open Access	OpenAccess
Notes	The authors gratefully acknowledge financial support from CNR (Progetti di Ricerca @CNR – avviso 2020 – ASSIST), Padova University (P-DiSC#04BIRD2020-UNIPD EUREKA, DOR 2020–2022), AMGA Foundation (NYMPHEA project), INSTM Consortium (INSTM21PDGASPAROTTO – NANOMAT, INSTM21PDBARMAC – ATENA) and the European Union's Horizon 2020 research and innovation program under grant agreement No 823717 – ESTEEM3. The FWO-Hercules fund G0H4316N 'Direct electron detector for soft matter TEM' is also acknowledged. Many thanks are due to Prof. Luca Gavioli (Università Cattolica del Sacro Cuore, Brescia, Italy) and Dr. Riccardo Lorenzin (Department of Chemical Sciences, Padova University, Italy) for their invaluable technical support.; esteem3reported; esteem3TA			Approved	Most recent IF: 6.7; 2023 IF: 3.387
Call Number	EMAT @ emat @c:irua:196150			Serial	7376
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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
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		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
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Author	Do, M.T.; Gauquelin, N.; Nguyen, M.D.; Blom, F.; Verbeeck, J.; Koster, G.; Houwman, E.P.; Rijnders, G.
Title	Interface degradation and field screening mechanism behind bipolar-cycling fatigue in ferroelectric capacitors			Type	A1 Journal article
Year	2021	Publication	Apl Materials	Abbreviated Journal	Apl Mater
Volume	9	Issue	2	Pages	021113
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	Polarization fatigue, i.e., the loss of polarization of ferroelectric capacitors upon field cycling, has been widely discussed as an interface related effect. However, mechanism(s) behind the development of fatigue have not been fully identified. Here, we study the fatigue mechanisms in Pt/PbZr0.52Ti0.48O3/SrRuO3 (Pt/PZT/SRO) capacitors in which all layers are fabricated by pulsed laser deposition without breaking the vacuum. With scanning transmission electron microscopy, we observed that in the fatigued capacitor, the Pt/PZT interface becomes structurally degraded, forming a 5 nm-10 nm thick non-ferroelectric layer of crystalline ZrO2 and diffused Pt grains. We then found that the fatigued capacitors can regain the full initial polarization switching if the externally applied field is increased to at least 10 times the switching field of the pristine capacitor. These findings suggest that polarization fatigue is driven by a two-step mechanism. First, the transient depolarization field that repeatedly appears during the domain switching under field cycling causes decomposition of the metal/ferroelectric interface, resulting in a non-ferroelectric degraded layer. Second, this interfacial non-ferroelectric layer screens the external applied field causing an increase in the coercive field beyond the usually applied maximum field and consequently suppresses the polarization switching in the cycled capacitor. Our work clearly confirms the key role of the electrode/ferroelectric interface in the endurance of ferroelectric-based devices.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000630052100006	Publication Date	2021-02-09
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	2166-532x	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	4.335	Times cited	5	Open Access	OpenAccess
Notes	This work was supported by the Nederlandse Organisatie voor Wetenschappelijk Onderzoek through Grant No. F62.3.15559. The Qu-Ant-EM microscope and the direct electron detector were partly funded by the Hercules fund from the Flemish Government. N.G. and J.V. acknowledge funding from the GOA project “Solarpaint” of the University of Antwerp. This work has also received funding from the European Union's Horizon 2020 research and innovation program under Grant No. 823717-ESTEEM3. We acknowledge D. Chezganov for his useful insights.			Approved	Most recent IF: 4.335
Call Number	UA @ admin @ c:irua:177663			Serial	6783
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Author	Verdierre, G.; Gauquelin, N.; Jannis, D.; Birkhölzer, Y.A.; Mallik, S.; Verbeeck, J.; Bibes, M.; Koster, G.
Title	Epitaxial growth of the candidate ferroelectric Rashba material SrBiO₃by pulsed laser deposition			Type	A1 Journal article
Year	2023	Publication	APL materials	Abbreviated Journal
Volume	11	Issue	3	Pages	031109
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	Among oxides, bismuthates have been gaining much interest due to their unique features. In addition to their superconducting properties, they show potential for applications as topological insulators and as possible spin-to-charge converters. After being first investigated in their bulk form in the 1980s, bismuthates have been successfully grown as thin films. However, most efforts have focused on BaBiO<sub>3</sub>, with SrBiO<sub>3</sub>receiving only little attention. Here, we report the growth of epitaxial films of SrBiO<sub>3</sub>on both TiO<sub>2</sub>-terminated SrTiO<sub>3</sub>and NdO-terminated NdScO<sub>3</sub>substrates by pulsed laser deposition. SrBiO<sub>3</sub>has a pseudocubic lattice constant of ∼4.25 Å and grows relaxed on NdScO<sub>3</sub>. Counter-intuitively, it grows with a slight tensile strain on SrTiO<sub>3</sub>despite a large lattice mismatch, which should induce compressive strain. High-resolution transmission electron microscopy reveals that this occurs as a consequence of structural domain matching, with blocks of 10 SrBiO<sub>3</sub>unit planes matching blocks of 11 SrTiO<sub>3</sub>unit planes. This work provides a framework for the synthesis of high quality perovskite bismuthates films and for the understanding of their interface interactions with homostructural substrates.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000953363800004	Publication Date	2023-03-01
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	2166-532X	ISBN		Additional Links	UA library record; WoS full record
Impact Factor	6.1	Times cited		Open Access	OpenAccess
Notes	This work received support from the ERC Advanced grant (Grant No. 833973) “FRESCO” and funding from the European Union’s Horizon 2020 Research and Innovation Program under Grant Agreement No. 823717—ESTEEM3, Van Gogh travel grant, Nuffic, The Netherlands (CF No. 42582SB).; esteem3reported; esteem3TA			Approved	Most recent IF: 6.1; 2023 IF: 4.335
Call Number	EMAT @ emat @c:irua:196135			Serial	7377
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Author	Ignatova, K.; Vlasov, E.; Seddon, S.D.; Gauquelin, N.; Verbeeck, J.; Wermeille, D.; Bals, S.; Hase, T.P.A.; Arnalds, U.B.
Title	Phase coexistence induced surface roughness in V2O3/Ni magnetic heterostructures			Type	A1 Journal Article
Year	2024	Publication	APL Materials	Abbreviated Journal
Volume	12	Issue	4	Pages
Keywords	A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract	We present an investigation of the microstructure changes in V2O3 as it goes through its inherent structural phase transition. Using V2O3 films with a well-defined crystal structure deposited by reactive magnetron sputtering on r-plane Al2O3 substrates, we study the phase coexistence region and its impact on the surface roughness of the films and the magnetic properties of overlying Ni magnetic layers in V2O3/Ni hybrid magnetic heterostructures. The simultaneous presence of two phases in V2O3 during its structural phase transition was identified with high resolution x-ray diffraction and led to an increase in surface roughness observed using x-ray reflectivity. The roughness reaches its maximum at the midpoint of the transition. In V2O3/Ni hybrid heterostructures, we find a concomitant increase in the coercivity of the magnetic layer correlated with the increased roughness of the V2O3 surface. The chemical homogeneity of the V2O3 is confirmed through transmission electron microscopy analysis. High-angle annular dark field imaging and electron energy loss spectroscopy reveal an atomically flat interface between Al2O3 and V2O3, as well as a sharp interface between V2O3 and Ni.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	001202661800003	Publication Date	2024-04-01
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	2166-532X	ISBN		Additional Links	UA library record; WoS full record
Impact Factor	6.1	Times cited		Open Access
Notes	This work was supported by the funding from the University of Iceland Research Fund, the Icelandic Research Fund Grant No. 207111. Instrumentation funding from the Icelandic Infrastructure Fund is acknowledged. This work was based on experiments per- formed at the BM28 (XMaS) beamline at the European Synchrotron Radiation Facility, Grenoble, France. XMaS is a National Research Facility funded by the UK EPSRC and managed by the Universi- ties of Liverpool and Warwick. This project has received funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 823717—ESTEEM3.			Approved	Most recent IF: 6.1; 2024 IF: 4.335
Call Number	EMAT @ emat @c:irua:205569			Serial	9120
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Author	Liao, Z.; Gauquelin, N.; Green, R.J.; Müller-Caspary, K.; Lobato, I.; Li, L.; Van Aert, S.; Verbeeck, J.; Huijben, M.; Grisolia, M.N.; Rouco, V.; El Hage, R.; Villegas, J.E.; Mercy, A.; Bibes, M.; Ghosez, P.; Sawatzky, G.A.; Rijnders, G.; Koster, G.
Title	Metal–insulator-transition engineering by modulation tilt-control in perovskite nickelates for room temperature optical switching			Type	A1 Journal article
Year	2018	Publication	America	Abbreviated Journal	P Natl Acad Sci Usa
Volume	115	Issue	38	Pages	9515-9520
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	In transition metal perovskites ABO3 the physical properties are largely driven by the rotations of the BO6 octahedra, which can be tuned in thin films through strain and dimensionality control. However, both approaches have fundamental and practical limitations due to discrete and indirect variations in bond angles, bond lengths and film symmetry by using commercially available substrates. Here, we introduce modulation tilt control as a new approach to tune the ground state of perovskite oxide thin films by acting explicitly on the oxygen octahedra rotation modes, i.e. directly on the bond angles. By intercalating the prototype SmNiO3 target material with a tilt-control layer, we cause the system to change the natural amplitude of a given rotation mode without affecting the interactions. In contrast to strain and dimensionality engineering, our method enables a continuous fine-tuning of the materials properties. This is achieved through two independent adjustable parameters: the nature of the tilt-control material (through its symmetry, elastic constants and oxygen rotation angles) and the relative thicknesses of the target and tilt-control materials. As a result, a magnetic and electronic phase diagram can be obtained, normally only accessible by A-site element substitution, within the single SmNiO3 compound. With this unique approach, we successfully adjusted the metal-insulator transition (MIT) to room temperature to fulfill the desired conditions for optical switching applications.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000447224900057	Publication Date	2018-09-05
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0027-8424	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	9.661	Times cited	50	Open Access	OpenAccess
Notes	We would like to acknowledge Prof. Z. Zhong for stimulated discussion. M.H., G.K. and G.R. acknowledge funding from DESCO program of the Dutch Foundation for Fundamental Research on Matter (FOM) with financial support from the Netherlands Organization for Scientific Research (NWO). This work was funded by the European Union Council under the 7th Framework Program (FP7) grant nr NMP3-LA-2010-246102 IFOX. J.V., S.V.A, N.G. and K.M.C. acknowledge funding from FWO projects G.0044.13N, G.0374.13N, G. 0368.15N, and G.0369.15N. The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. N.G. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. N.G. and J.V. acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative (Reference No. 312483- ESTEEM2). The Canadian work was supported by NSERC and the Max Planck-UBC Centre for Quantum Materials. Some experiments for this work were performed at the Canadian Light Source, which is funded by the Canada Foundation for Innovation, NSERC, the National Research Council of Canada, the Canadian Institutes of Health Research, the Government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan. MB acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC CoG grant MINT #615759. A.M. and Ph.G. were supported by the ARC project AIMED and F.R.S-FNRS PDR project HiT4FiT and acknowledge access to Céci computing facilities funded by F.R.S-FNRS (Grant No 2.5020.1), Tier-1 supercomputer of the Fédération Wallonie-Bruxelles funded by the Walloon Region (Grant No 1117545) and HPC resources from the PRACE project Megapasta.			Approved	Most recent IF: 9.661
Call Number	EMAT @ emat @c:irua:154784UA @ admin @ c:irua:154784			Serial	5059
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Author	Gauquelin, N.; Zhang, H.; Zhu, G.; Wei, J.Y.T.; Botton, G.A.
Title	Atomic-scale identification of novel planar defect phases in heteroepitaxial YBa₂Cu₃O_7-\delta thin films			Type	A1 Journal article
Year	2018	Publication	AIP advances	Abbreviated Journal	Aip Adv
Volume	8	Issue	5	Pages	055022
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	We have discovered two novel types of planar defects that appear in heteroepitaxial YBa2Cu3O7-delta(YBCO123) thin films, grown by pulsed-laser deposition (PLD) either with or without a La2/3Ca1/3MnO3 (LCMO) overlayer, using the combination of highangle annular dark-field scanning transmission electron microscopy (HAADF-STEM) imaging and electron energy loss spectroscopy (EELS) mapping for unambiguous identification. These planar lattice defects are based on the intergrowth of either a BaO plane between two CuO chains or multiple Y-O layers between two CuO2 planes, resulting in non-stoichiometric layer sequences that could directly impact the high-Tc superconductivity. (C) 2018 Author(s).
Address
Corporate Author				Thesis
Publisher	American Institute of Physics	Place of Publication	Melville, NY	Editor
Language		Wos	000433954000022	Publication Date	2018-05-21
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	2158-3226	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	1.568	Times cited	1	Open Access	OpenAccess
Notes	; We are thankful to Julia Huang for FIB TEM sample preparation. This work is supported by NSERC (through Discovery Grants to GAB and JYTW) and CIFAR. The electron microscopy work was carried out at the Canadian Centre for Electron Microscopy, a National Facility supported by McMaster University, the Canada Foundation for Innovation and NSERC. N.G. acknowledges H. Idrissi for useful discussions. ;			Approved	Most recent IF: 1.568
Call Number	UA @ lucian @ c:irua:152063			Serial	5013
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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
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		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
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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 PbZr_0.52Ti_0.48O₃ 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
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000423173800005	Publication Date	2017-11-27
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	2196-7350	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	4.279	Times cited	15	Open Access	Not_Open_Access
Notes	; L.L., Z.L.L., and N.G. contributed equally to this work. L.L. acknowledges financial support from Nano Next NL (Grant no. 7B 04). The authors acknowledge NXP for providing the GaN/AlGaN/Si (111) wafer. N.G. acknowledges funding from the Geconcentreerde Onderzoekacties (GOA) project “Solarpaint” of the University of Antwerp and J.V. acknowledges funding from the Research Foundation Flanders (FWO, Belgium) project 42/FA070100/6088 “nieuwe eigenschappen in complexe Oxides.” N.G. acknowledges the EUROTAPES project (FP7-NMP.2011.2.2-1 Grant no. 280432) which partly funded this study. ;			Approved	Most recent IF: 4.279
Call Number	UA @ lucian @ c:irua:148427UA @ admin @ c:irua:148427			Serial	4872
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Author	Conings, B.; Babayigit, A.; Klug, M. T.; Bai, S.; Gauquelin, N.; Sakai, N.; Wang, J. T.-W.; Verbeeck, J.; Boyen, H.-G.
Title	A Universal Deposition Protocol for Planar Heterojunction Solar Cells with High Efficiency Based on Hybrid Lead Halide Perovskite Families			Type	A1 Journal article
Year	2016	Publication	Advanced materials	Abbreviated Journal	Adv Mater
Volume	28	Issue	28	Pages	10701-10709
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	A robust and expedient gas quenching method is developed for the solution deposition of hybrid perovskite thin films. The method offers a reliable standard practice for the fabrication of a non-exhaustive variety of perovskites exhibiting excellent film morphology and commensurate high performance in both regular and inverted structured solar cell architectures.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000392728200014	Publication Date	2016-10-17
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1521-4095	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	19.791	Times cited	95	Open Access
Notes	This work was financially supported by BOF (Hasselt University) and the Research Fund Flanders (FWO). B.C. is a postdoctoral research fellow of the FWO. A.B. is financially supported by Imec and FWO. M.T.K. acknowledges funding from the EPSRC project EP/M024881/1 “Organic-inorganic Perovskite Hybrid Tandem Solar Cells”. S.B. is a VINNMER Fellow and Marie Skłodowska-Curie Fellow. J.V. and N.G. acknowledge funding from GOA project “Solarpaint” of the University of Antwerp and FWO project G.0044.13N “Charge ordering”. The Qu-Ant-EM microscope used for this study was partly funded by the Hercules fund from the Flemish Government. N.G. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant 278510 VORTEX. The authors thank Johnny Baccus and Jan Mertens for technical support.; ECASJO_;			Approved	Most recent IF: 19.791; 2016 IF: NA
Call Number	EMAT @ emat @ c:irua:138597			Serial	4318
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Author	Macke, S.; Radi, A.; Hamann-Borrero, J.E.; Verna, A.; Bluschke, M.; Brück, S.; Goering, E.; Sutarto, R.; He, F.; Cristiani, G.; Wu, M.; Benckiser, E.; Habermeier, H.-U.; Logvenov, G.; Gauquelin, N.; Botton, G.A; Kajdos, A.P.; Stemmer, S.; Sawatzky,G.A.; Haverkort, M.W.; Keimer, B.; Hinkov, V.
Title	Element Specific Monolayer Depth Profiling			Type	A1 Journal Article
Year	2014	Publication	Advanced Materials	Abbreviated Journal	Adv Mater
Volume	26	Issue	38	Pages	6554-6559
Keywords	A1 Journal Article; Electron Microscopy for Materials Science (EMAT)
Abstract	The electronic phase behavior and functionality of interfaces and surfaces in complex materials are strongly correlated to chemical composition profiles, stoichiometry and intermixing. Here a novel analysis scheme for resonant X-ray reflectivity maps is introduced to determine such profiles, which is element specific and non-destructive, and which exhibits atomic-layer resolution and a probing depth of hundreds of nanometers.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000343763200004	Publication Date	2014-08-08
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1521-4095	ISBN		Additional Links
Impact Factor	19.791	Times cited	34	Open Access
Notes				Approved	Most recent IF: 19.791; 2014 IF: NA
Call Number	EMAT @ emat @			Serial	4541
Permanent link to this record



Author	Gan, Y.; Christensen, D.V.; Zhang, Y.; Zhang, H.; Krishnan, D.; Zhong, Z.; Niu, W.; Carrad, D.J.; Norrman, K.; von Soosten, M.; Jespersen, T.S.; Shen, B.; Gauquelin, N.; Verbeeck, J.; Sun, J.; Pryds, N.; Chen, Y.
Title	Diluted oxide interfaces with tunable ground states			Type	A1 Journal article
Year	2019	Publication	Advanced materials	Abbreviated Journal	Adv Mater
Volume	31	Issue	10	Pages	1805970
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	The metallic interface between two oxide insulators, such as LaAlO3/SrTiO3 (LAO/STO), provides new opportunities for electronics and spintronics. However, due to the presence of multiple orbital populations, tailoring the interfacial properties such as the ground state and metal-insulator transitions remains challenging. Here, an unforeseen tunability of the phase diagram of LAO/STO is reported by alloying LAO with a ferromagnetic LaMnO3 insulator without forming lattice disorder and at the same time without changing the polarity of the system. By increasing the Mn-doping level, x, of LaAl1-xMnxO3/STO (0 <= x <= 1), the interface undergoes a Lifshitz transition at x = 0.225 across a critical carrier density of n(c) = 2.8 x 10(13) cm(-2), where a peak T-SC approximate to 255 mK of superconducting transition temperature is observed. Moreover, the LaAl1-xMnxO3 turns ferromagnetic at x >= 0.25. Remarkably, at x = 0.3, where the metallic interface is populated by only d(xy) electrons and just before it becomes insulating, a same device with both signatures of superconductivity and clear anomalous Hall effect (7.6 x 10(12) cm(-2) < n(s) <= 1.1 x 10(13) cm(-2)) is achieved reproducibly. This provides a unique and effective way to tailor oxide interfaces for designing on-demand electronic and spintronic devices.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000460329300004	Publication Date	2019-01-14
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0935-9648	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	19.791	Times cited	31	Open Access	Not_Open_Access
Notes	; The authors thank the technical help from J. Geyti. J.R.S. acknowledges the support of the National Basic Research of China (2016YFA0300701, 2018YFA0305704), the National Natural Science Foundation of China (11520101002), and the Key Program of the Chinese Academy of Sciences. N.G., D.K., and J.V. acknowledge funding from the Geconcentreerde Onderzoekacties (GOA) project “Solarpaint” of the University of Antwerp, Belgium. ;			Approved	Most recent IF: 19.791
Call Number	UA @ admin @ c:irua:158553			Serial	5245
Permanent link to this record



Author	Chen, B.; Gauquelin, N.; Jannis, D.; Cunha, D.M.; Halisdemir, U.; Piamonteze, C.; Lee, J.H.; Belhadi, J.; Eltes, F.; Abel, S.; Jovanovic, Z.; Spreitzer, M.; Fompeyrine, J.; Verbeeck, J.; Bibes, M.; Huijben, M.; Rijnders, G.; Koster, G.
Title	Strain-engineered metal-to-insulator transition and orbital polarization in nickelate superlattices integrated on silicon			Type	A1 Journal article
Year	2020	Publication	Advanced Materials	Abbreviated Journal	Adv Mater
Volume		Issue		Pages	2004995
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	Epitaxial growth of SrTiO3 (STO) on silicon greatly accelerates the monolithic integration of multifunctional oxides into the mainstream semiconductor electronics. However, oxide superlattices (SLs), the birthplace of many exciting discoveries, remain largely unexplored on silicon. In this work, LaNiO3/LaFeO3 SLs are synthesized on STO-buffered silicon (Si/STO) and STO single-crystal substrates, and their electronic properties are compared using dc transport and X-ray absorption spectroscopy. Both sets of SLs show a similar thickness-driven metal-to-insulator transition, albeit with resistivity and transition temperature modified by the different amounts of strain. In particular, the large tensile strain promotes a pronounced Ni 3dx2-y2 orbital polarization for the SL grown on Si/STO, comparable to that reported for LaNiO3 SL epitaxially strained to DyScO3 substrate. Those results illustrate the ability to integrate oxide SLs on silicon with structure and property approaching their counterparts grown on STO single crystal, and also open up new prospects of strain engineering in functional oxides based on the Si platform.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000588146500001	Publication Date	2020-11-11
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0935-9648	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	29.4	Times cited	18	Open Access	OpenAccess
Notes	; This work is supported by the international M-ERA.NET project SIOX (project 4288) and H2020 project ULPEC (project 732642). M.S. acknowledges funding from Slovenian Research Agency (Grants No. J2-9237 and No. P2-0091). This work received support from the ERC CoG MINT (#615759) and from a PHC Van Gogh grant. M.B. thanks the French Academy of Science and the Royal Netherlands Academy of Arts and Sciences for supporting his stays in the Netherlands. This project has received funding as a transnational access project from the European Union's Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3. N.G. and J.V. acknowledge GOA project “Solarpaint” of the University of Antwerp. ; esteem3TA; esteem3reported			Approved	Most recent IF: 29.4; 2020 IF: 19.791
Call Number	UA @ admin @ c:irua:173516			Serial	6617
Permanent link to this record



Author	Xu, H.; Li, H.; Gauquelin, N.; Chen, X.; Wu, W.-F.; Zhao, Y.; Si, L.; Tian, D.; Li, L.; Gan, Y.; Qi, S.; Li, M.; Hu, F.; Sun, J.; Jannis, D.; Yu, P.; Chen, G.; Zhong, Z.; Radovic, M.; Verbeeck, J.; Chen, Y.; Shen, B.
Title	Giant tunability of Rashba splitting at cation-exchanged polar oxide interfaces by selective orbital hybridization			Type	A1 Journal article
Year	2024	Publication	Advanced materials	Abbreviated Journal
Volume		Issue		Pages
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	The 2D electron gas (2DEG) at oxide interfaces exhibits extraordinary properties, such as 2D superconductivity and ferromagnetism, coupled to strongly correlated electrons in narrow d-bands. In particular, 2DEGs in KTaO3 (KTO) with 5d t2g orbitals exhibit larger atomic spin-orbit coupling and crystal-facet-dependent superconductivity absent for 3d 2DEGs in SrTiO3 (STO). Herein, by tracing the interfacial chemistry, weak anti-localization magneto-transport behavior, and electronic structures of (001), (110), and (111) KTO 2DEGs, unambiguously cation exchange across KTO interfaces is discovered. Therefore, the origin of the 2DEGs at KTO-based interfaces is dramatically different from the electronic reconstruction observed at STO interfaces. More importantly, as the interface polarization grows with the higher order planes in the KTO case, the Rashba spin splitting becomes maximal for the superconducting (111) interfaces approximately twice that of the (001) interface. The larger Rashba spin splitting couples strongly to the asymmetric chiral texture of the orbital angular moment, and results mainly from the enhanced inter-orbital hopping of the t2g bands and more localized wave functions. This finding has profound implications for the search for topological superconductors, as well as the realization of efficient spin-charge interconversion for low-power spin-orbitronics based on (110) and (111) KTO interfaces. An unambiguous cation exchange is discovered across the interfaces of (001), (110), and (111) KTaO3 2D electron gases fabricated at room temperature. Remarkably, the (111) interfaces with the highest superconducting transition temperature also turn out to show the strongest electron-phonon interaction and the largest Rashba spin splitting. image
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	001219658400001	Publication Date	2024-03-13
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	0935-9648	ISBN		Additional Links	UA library record; WoS full record
Impact Factor	29.4	Times cited		Open Access
Notes				Approved	Most recent IF: 29.4; 2024 IF: 19.791
Call Number	UA @ admin @ c:irua:206037			Serial	9152
Permanent link to this record



Author	Solmaz, A.; Huijben, M.; Koster, G.; Egoavil, R.; Gauquelin, N.; Van Tendeloo, G.; Verbeeck, J.; Noheda, B.; Rijnders, G.
Title	Domain Selectivity in BiFeO₃Thin Films by Modified Substrate Termination			Type	A1 Journal article
Year	2016	Publication	Advanced functional materials	Abbreviated Journal	Adv Funct Mater
Volume	26	Issue	26	Pages	2882-2889
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	Ferroelectric domain formation is an essential feature in ferroelectric thin films. These domains and domain walls can be manipulated depending on the growth conditions. In rhombohedral BiFeO3 thin films, the ordering of the domains and the presence of specific types of domain walls play a crucial role in attaining unique ferroelectric and magnetic properties. In this study, controlled ordering of domains in BiFeO3 film is presented, as well as a controlled selectivity between two types of domain walls is presented, i.e., 71° and 109°, by modifying the substrate termination. The experiments on two different substrates, namely SrTiO3 and TbScO3, strongly indicate that the domain selectivity is determined by the growth kinetics of the initial BiFeO3 layers.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000377587800011	Publication Date	2016-03-21
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1616-301X	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	12.124	Times cited	34	Open Access
Notes	The authors are grateful to Saeedeh Farokhipoor and Tamalika Banerjee for very useful discussions. This work was supported by the Netherlands Organization for Scientific Research NWO-FOM (under FOM-Nano project 10UNST04–2). The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. GOA project “Solarpaint” of the University of Antwerp. The electron microscopy part of the work was supported by funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant No. 246791– COUNTATOMS. Funding from the European Union Council under the 7th Framework Program (FP7) Grant No. NMP3-LA-2010–246102 FOX is acknowledged. The Fund for Scientific Research Flanders is acknowledged for FWO Project No. G.0044.13N.			Approved	Most recent IF: 12.124
Call Number	c:irua:132641UA @ admin @ c:irua:132641			Serial	4053
Permanent link to this record



Author	Liao, Z.L.; Green, R.J.; Gauquelin, N.; Gonnissen, J.; Van Aert, S.; Verbeeck, J.; et al.
Title	Engineering properties by long range symmetry propagation initiated at perovskite heterostructure interface			Type	A1 Journal article
Year	2016	Publication	Advanced functional materials	Abbreviated Journal	Adv Funct Mater
Volume		Issue		Pages	1-25
Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract	In epitaxial thin film systems, the crystal structure and its symmetry deviate from the bulk counterpart due to various mechanisms such as epitaxial strain and interfacial structural coupling, which induce an accompanying change in their properties. In perovskite materials, the crystal symmetry can be described by rotations of 6-fold coordinated transition metal oxygen octahedra, which are found to be altered at interfaces. Here, we unravel how the local oxygen octahedral coupling (OOC) at perovskite heterostructural interfaces initiates a different symmetry in epitaxial films and provide design rules to induce various symmetries in thin films by careful selecting appropriate combinations of substrate/buffer/film. Very interestingly we discovered that these combinations lead to symmetry changes throughout the full thickness of the film. Our results provide a deep insight into understanding the origin of induced crystal symmetry in a perovskite heterostructure and an intelligent route to achieve unique functional properties.
Address
Corporate Author				Thesis
Publisher		Place of Publication	Weinheim	Editor
Language		Wos		Publication Date
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1616-301x	ISBN		Additional Links	UA library record
Impact Factor	12.124	Times cited		Open Access
Notes				Approved	Most recent IF: 12.124
Call Number	UA @ lucian @ c:irua:134842			Serial	4176
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-T_CInterfacial 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
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000535358900008	Publication Date	2019-02-10
Series Editor		Series Title		Abbreviated Series Title
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



Author	Nerl, H.C.; Pokle, A.; Jones, L.; Müller‐Caspary, K.; Bos, K.H.W.; Downing, C.; McCarthy, E.K.; Gauquelin, N.; Ramasse, Q.M.; Lobato, I.; Daly, D.; Idrobo, J.C.; Van Aert, S.; Van Tendeloo, G.; Sanvito, S.; Coleman, J.N.; Cucinotta, C.S.; Nicolosi, V.
Title	Self‐Assembly of Atomically Thin Chiral Copper Heterostructures Templated by Black Phosphorus			Type	A1 Journal article
Year	2019	Publication	Advanced functional materials	Abbreviated Journal	Adv Funct Mater
Volume	29	Issue	37	Pages	1903120
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000478478400001	Publication Date	2019-07-17
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1616-301X	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	12.124	Times cited	1	Open Access	OpenAccess
Notes	European Research Council, 2DNanoCaps TC2D CoG 3D2DPrint CoG Picometrics grant agreement No. 770887; Engineering and Physical Sciences Research Council, EP/P033555/1 EP/R029431 ; Science Foundation Ireland, HPC1600932 ;			Approved	Most recent IF: 12.124
Call Number	EMAT @ emat @c:irua:161901			Serial	5362
Permanent link to this record



Author	Liao, Z.; Gauquelin, N.; Green, R.J.; Macke, S.; Gonnissen, J.; Thomas, S.; Zhong, Z.; Li, L.; Si, L.; Van Aert, S.; Hansmann, P.; Held, K.; Xia, J.; Verbeeck, J.; Van Tendeloo, G.; Sawatzky, G.A.; Koster, G.; Huijben, M.; Rijnders, G.
Title	Thickness dependent properties in oxide heterostructures driven by structurally induced metal-oxygen hybridization variations			Type	A1 Journal article
Year	2017	Publication	Advanced functional materials	Abbreviated Journal	Adv Funct Mater
Volume	27	Issue	17	Pages	1606717
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	Thickness-driven electronic phase transitions are broadly observed in different types of functional perovskite heterostructures. However, uncertainty remains whether these effects are solely due to spatial confinement, broken symmetry, or rather to a change of structure with varying film thickness. Here, this study presents direct evidence for the relaxation of oxygen-2p and Mn-3d orbital (p-d) hybridization coupled to the layer-dependent octahedral tilts within a La2/3Sr1/3MnO3 film driven by interfacial octahedral coupling. An enhanced Curie temperature is achieved by reducing the octahedral tilting via interface structure engineering. Atomically resolved lattice, electronic, and magnetic structures together with X-ray absorption spectroscopy demonstrate the central role of thickness-dependent p-d hybridization in the widely observed dimensionality effects present in correlated oxide heterostructures.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000400449200011	Publication Date	2017-03-15
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1616-301x	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	12.124	Times cited	55	Open Access
Notes	M.H., G.K., and G.R. acknowledge funding from DESCO program of the Dutch Foundation for Fundamental Research on Matter (FOM) with financial support from the Netherlands Organization for Scientific Research (NWO). This work was funded by the European Union Council under the 7th Framework Program (FP7) Grant No. NMP3-LA-2010-246102 IFOX. J.V. and S.V.A. acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (Grant Nos. G.0044.13N, G.0374.13N, G.0368.15N, and G.0369.15N). The Qu-Ant-EM microscope was partly funded by the Hercules fund from the Flemish Government. N.G. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Starting Grant No. 278510 VORTEX. N.G., J.G., S.V.A., and J.V. acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative (Reference No. 312483-ESTEEM2). The Canadian work was supported by NSERC and the Max Planck-UBC Centre for Quantum Materials. Some experiments for this work were performed at the Canadian Light Source, which was funded by the Canada Foundation for Innovation, NSERC, the National Research Council of Canada, the Canadian Institutes of Health Research, the Government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan.			Approved	Most recent IF: 12.124
Call Number	UA @ admin @ c:irua:152640			Serial	5367
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Author	Tran Phong Le, P.; Hofhuis, K.; Rana, A.; Huijben, M.; Hilgenkamp, H.; Rijnders, G.A.J.H.M.; ten Elshof, J.E.; Koster, G.; Gauquelin, N.; Lumbeeck, G.; Schuessler-Langeheine, C.; Popescu, H.; Fortuna, F.; Smit, S.; Verbeek, X.H.; Araizi-Kanoutas, G.; Mishra, S.; Vaskivskyi, I.; Duerr, H.A.; Golden, M.S.
Title	Tailoring vanadium dioxide film orientation using nanosheets : a combined microscopy, diffraction, transport, and soft X-ray in transmission study			Type	A1 Journal article
Year	2020	Publication	Advanced Functional Materials	Abbreviated Journal	Adv Funct Mater
Volume	30	Issue	1	Pages	1900028
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	Vanadium dioxide (VO2) is a much-discussed material for oxide electronics and neuromorphic computing applications. Here, heteroepitaxy of VO2 is realized on top of oxide nanosheets that cover either the amorphous silicon dioxide surfaces of Si substrates or X-ray transparent silicon nitride membranes. The out-of-plane orientation of the VO2 thin films is controlled at will between (011)(M1)/(110)(R) and (-402)(M1)/(002)(R) by coating the bulk substrates with Ti0.87O2 and NbWO6 nanosheets, respectively, prior to VO2 growth. Temperature-dependent X-ray diffraction and automated crystal orientation mapping in microprobe transmission electron microscope mode (ACOM-TEM) characterize the high phase purity, the crystallographic and orientational properties of the VO2 films. Transport measurements and soft X-ray absorption in transmission are used to probe the VO2 metal-insulator transition, showing results of a quality equal to those from epitaxial films on bulk single-crystal substrates. Successful local manipulation of two different VO2 orientations on a single substrate is demonstrated using VO2 grown on lithographically patterned lines of Ti0.87O2 and NbWO6 nanosheets investigated by electron backscatter diffraction. Finally, the excellent suitability of these nanosheet-templated VO2 films for advanced lensless imaging of the metal-insulator transition using coherent soft X-rays is discussed.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000505545800010	Publication Date	2019-10-31
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1616-301x	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	19	Times cited	1	Open Access	OpenAccess
Notes	P.T.P.L. and K.H. contributed equally to this work. The authors thank Mark A. Smithers for performing high-resolution scanning electron microscopy and electron backscattering diffraction. The authors also thank Dr. Nicolas Jaouen for his contribution to the soft X-ray imaging experiments. This work is part of the DESCO research program of the Foundation for Fundamental Research on Matter (FOM), which is part of the Netherlands Organisation for Scientific Research (NWO). P.T.P.L. acknowledges the NWO/CW ECHO grant ECHO.15.CM2.043. N.G. acknowledges funding from the Geconcentreerde Onderzoekacties (GOA) project “Solarpaint” of the University of Antwerp and the FLAG-ERA JTC 2017 project GRAPH-EYE. G.L. acknowledges financial support from the Flemish Research Fund (FWO) under project G.0365.15N. I.V. acknowledges support by the U.S. Department of Energy, Office of Science under Award Number 0000231415.			Approved	Most recent IF: 19; 2020 IF: 12.124
Call Number	UA @ admin @ c:irua:165705			Serial	6325
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Author	Zillner, J.; Boyen, H.-G.; Schulz, P.; Hanisch, J.; Gauquelin, N.; Verbeeck, J.; Kueffner, J.; Desta, D.; Eisele, L.; Ahlswede, E.; Powalla, M.
Title	The role of SnF₂ additive on interface formation in all lead-free FASnI₃ perovskite solar cells			Type	A1 Journal article
Year	2022	Publication	Advanced functional materials	Abbreviated Journal	Adv Funct Mater
Volume		Issue		Pages	2109649-9
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	Tin-based perovskites are promising alternative absorber materials for leadfree perovskite solar cells but need strategies to avoid fast tin (Sn) oxidation. Generally, this reaction can be slowed down by the addition of tin fluoride (SnF2) to the perovskite precursor solution, which also improves the perovskite layer morphology. Here, this work analyzes the spatial distribution of the additive within formamidinium tin triiodide (FASnI(3)) films deposited on top of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hole transporting layers. Employing time-of-flight secondary ion mass spectrometry and a combination of hard and soft X-ray photoelectron spectroscopy, it is found that Sn F2 preferably accumulates at the PEDOT:PSS/perovskite interface, accompanied by the formation of an ultrathin SnS interlayer with an effective thickness of approximate to 1.2 nm.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000779891000001	Publication Date	0000-00-00
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1616-301x	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	19	Times cited	22	Open Access	OpenAccess
Notes	J.Z. and H.-G.B. contributed equally to this work. This project received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 850937 (PERCISTAND). H.-G.B. and D.D. are very grateful to the Research Foundation Flanders (FWO) for funding the HAXPES-lab instrument within the HERCULES program for Large Research Infrastructure of the Flemish government. P.S. thanks the French Agence Nationale de la Recherche for funding under the contract number ANR-17-MPGA-0012. This work was supported by the Federal Ministry for Economic Affairs and Energy (BMWi) Germany under the contract number 03EE1038A (CAPITANO) and financed by the Ministry of Science, Research and the Arts of Baden-Württemberg as part of the sustainability financing of the projects of the Excellence Initiative II (KSOP).			Approved	Most recent IF: 19
Call Number	UA @ admin @ c:irua:187969			Serial	7067
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Author	Ghidelli, M.; Orekhov, A.; Bassi, A.L.; Terraneo, G.; Djemia, P.; Abadias, G.; Nord, M.; Béché, A.; Gauquelin, N.; Verbeeck, J.; Raskin, J.-p.; Schryvers, D.; Pardoen, T.; Idrissi, H.
Title	Novel class of nanostructured metallic glass films with superior and tunable mechanical properties			Type	A1 Journal article
Year	2021	Publication	Acta Materialia	Abbreviated Journal	Acta Mater
Volume		Issue		Pages	116955
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	A novel class of nanostructured Zr50Cu50 (%at.) metallic glass films with superior and tunable mechanical properties is produced by pulsed laser deposition. The process can be controlled to synthetize a wide range of film microstructures including dense fully amorphous, amorphous embedded with nanocrystals and amorphous nano-granular. A unique dense self-assembled nano-laminated atomic arrangement characterized by alternating Cu-rich and Zr/O-rich nanolayers with different local chemical enrichment and amorphous or amorphous-crystalline composite nanostructure has been discovered, while significant in-plane clustering is reported for films synthetized at high deposition pressures. This unique nanoarchitecture is at the basis of superior mechanical properties including large hardness and elastic modulus up to 10 and 140 GPa, respectively and outstanding total elongation to failure (>9%), leading to excellent strength/ductility balance, which can be tuned by playing with the film architecture. These results pave the way to the synthesis of novel class of engineered nanostructured metallic glass films with high structural performances attractive for a number of applications in microelectronics and coating industry.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000670077800004	Publication Date	2021-05-12
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1359-6454	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	5.301	Times cited	27	Open Access	OpenAccess
Notes	H.I. is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). This work was supported by the Fonds de la Recherche Scientifique – FNRS under Grant T.0178.19 and Grant CDR– J011320F. We acknowledge funding for the direct electron detector used in the 4D stem studies from the Hercules fund 'Direct electron detector for soft matter TEM' from the Flemish Government J.V acknowledges funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 823717 – ESTEEM3. A.O. has received partial funding from the GOA project “Solarpaint” of the University of Antwerp. A.B. and J.V. acknowledge funding through FWO project G093417N ('Compressed sensing enabling low dose imaging in transmission electron microscopy') from the Flanders Research Fund. M.G. and A.L.B acknowledge Chantelle Ekanem for support in PLD depositions.			Approved	Most recent IF: 5.301
Call Number	EMAT @ emat @c:irua:178142			Serial	6761
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Author	Mary Joy, R.; Pobedinskas, P.; Baule, N.; Bai, S.; Jannis, D.; Gauquelin, N.; Pinault-Thaury, M.-A.; Jomard, F.; Sankaran, K.J.; Rouzbahani, R.; Lloret, F.; Desta, D.; D’Haen, J.; Verbeeck, J.; Becker, M.F.; Haenen, K.
Title	The effect of microstructure and film composition on the mechanical properties of linear antenna CVD diamond thin films			Type	A1 Journal article
Year	2024	Publication	Acta materialia	Abbreviated Journal	Acta Materialia
Volume	264	Issue		Pages	119548
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	This study reports the impact of film microstructure and composition on the Young’s modulus and residual stress in nanocrystalline diamond (NCD) thin films ( thick) grown on silicon substrates using a linear antenna microwave plasma-enhanced chemical vapor deposition (CVD) system. Combining laser acoustic wave spectroscopy to determine the elastic properties with simple wafer curvature measurements, a straightforward method to determine the intrinsic stress in NCD films is presented. Two deposition parameters are varied: (1) the substrate temperature from 400 °C to 900 °C, and (2) the [P]/[C] ratio from 0 ppm to 8090 ppm in the H2/CH4/CO2/PH3 diamond CVD plasma. The introduction of PH3 induces a transition in the morphology of the diamond film, shifting from NCD with larger grains to ultra-NCD with a smaller grain size, concurrently resulting in a decrease in Young’s modulus. Results show that the highest Young’s modulus of (113050) GPa for the undoped NCD deposited at 800 °C is comparable to single crystal diamond, indicating that NCD with excellent mechanical properties is achievable with our process for thin diamond films. Based on the film stress results, we propose the origins of tensile intrinsic stress in the diamond films. In NCD, the tensile intrinsic stress is attributed to larger grain size, while in ultra-NCD films the tensile intrinsic stress is due to grain boundaries and impurities.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	001126632800001	Publication Date	2023-11-23
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1359-6454	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	9.4	Times cited		Open Access	Not_Open_Access
Notes	This work was financially supported by the Special Research Fund (BOF) via Methusalem NANO network, the Research Foundation – Flanders (FWO) via Project G0D4920N, and the CORNET project nr 263-EN “ULTRAHARD: Ultrahard optical diamond coatings” (2020–2021).			Approved	Most recent IF: 9.4; 2024 IF: 5.301
Call Number	EMAT @ emat @c:irua:202169			Serial	8989
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Author	Idrissi, H.; Béché, A.; Gauquelin, N.; Ul-Haq, I.; Bollinger, C.; Demouchy, S.; Verbeeck, J.; Pardoen, T.; Schryvers, D.; Cordier, P.
Title	On the formation mechanisms of intragranular shear bands in olivine by stress-induced amorphization			Type	A1 Journal article
Year	2022	Publication	Acta materialia	Abbreviated Journal	Acta Mater
Volume	239	Issue		Pages	118247-118249
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	Intragranular amorphization shear lamellae are found in deformed olivine aggregates. The detailed trans-mission electron microscopy analysis of intragranular lamella arrested in the core of a grain provides novel information on the amorphization mechanism. The deformation field is complex and heteroge-neous, corresponding to a shear crack type instability involving mode I, II and III loading components. The formation and propagation of the amorphous lamella is accompanied by the formation of crystal defects ahead of the tip. These defects are geometrically necessary [001] dislocations, characteristics of high-stress deformation in olivine, and rotational nanodomains which are tentatively interpreted as disclinations. We show that these defects play an important role in dictating the path followed by the amorphous lamella. Stress-induced amorphization in olivine would thus result from a direct crystal-to -amorphous transformation associated with a shear instability and not from a mechanical destabilization due to the accumulation of high number of defects from an intense preliminary deformation. The pref-erential alignment of some lamellae along (010) is a proof of the lower ultimate mechanical strength of these planes.(c) 2022 The Authors. Published by Elsevier Ltd on behalf of Acta Materialia Inc. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000861076600004	Publication Date	2022-08-05
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1359-6454	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	9.4	Times cited	5	Open Access	OpenAccess
Notes	The QuanTEM microscope was partially funded by the Flemish government. The K2 camera was funded by FWO Hercules fund G0H4316N 'Direct electron detector for soft matter TEM'. A. Beche acknowledges funding from FWO project G093417N ('Compressed sensing enabling low dose imaging in transmission electron microscopy'). H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). This work was supported by the FNRS under Grant PDR – T011322F and by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme under grant agreement No 787,198 Time Man. J-L Rouviere is acknowledged for his support with the GPA softawre.			Approved	Most recent IF: 9.4
Call Number	UA @ admin @ c:irua:191432			Serial	7186
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Author	Kante, M.V.; Weber, M.L.; Ni, S.; van den Bosch, I.C.G.; van der Minne, E.; Heymann, L.; Falling, L.J.; Gauquelin, N.; Tsvetanova, M.; Cunha, D.M.; Koster, G.; Gunkel, F.; Nemsak, S.; Hahn, H.; Estrada, L.V.; Baeumer, C.
Title	A high-entropy oxide as high-activity electrocatalyst for water oxidation			Type	A1 Journal article
Year	2023	Publication	ACS nano	Abbreviated Journal
Volume	17	Issue	6	Pages	5329-5339
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	High-entropy materials are an emerging pathway in the development of high-activity (electro)catalysts because of the inherent tunability and coexistence of multiple potential active sites, which may lead to earth-abundant catalyst materials for energy-efficient electrochemical energy storage. In this report, we identify how the multication composition in high-entropy perovskite oxides (HEO) contributes to high catalytic activity for the oxygen evolution reaction (OER), i.e., the key kinetically limiting half-reaction in several electrochemical energy conversion technologies, including green hydrogen generation. We compare the activity of the (001) facet of LaCr0.2Mn0.2Fe0.2Co0.2Ni0.2O3-delta with the parent compounds (single B-site in the ABO3 perovskite). While the single B-site perovskites roughly follow the expected volcano-type activity trends, the HEO clearly outperforms all of its parent compounds with 17 to 680 times higher currents at a fixed overpotential. As all samples were grown as an epitaxial layer, our results indicate an intrinsic composition-function relationship, avoiding the effects of complex geometries or unknown surface composition. In-depth X-ray photoemission studies reveal a synergistic effect of simultaneous oxidation and reduction of different transition metal cations during the adsorption of reaction intermediates. The surprisingly high OER activity demonstrates that HEOs are a highly attractive, earth-abundant material class for high-activity OER electrocatalysts, possibly allowing the activity to be fine-tuned beyond the scaling limits of mono-or bimetallic oxides.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	000953440900001	Publication Date	2023-03-13
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	1936-0851	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
Impact Factor	17.1	Times cited		Open Access	OpenAccess
Notes				Approved	Most recent IF: 17.1; 2023 IF: 13.942
Call Number	UA @ admin @ c:irua:196097			Serial	7390
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Author	Joy, R.M.; Pobedinskas, P.; Bourgeois, E.; Chakraborty, T.; Goerlitz, J.; Herrmann, D.; Noel, C.; Heupel, J.; Jannis, D.; Gauquelin, N.; D'Haen, J.; Verbeeck, J.; Popov, C.; Houssiau, L.; Becher, C.; Nesladek, M.; Haenen, K.
Title	Photoluminescence of germanium-vacancy centers in nanocrystalline diamond films : implications for quantum sensing applications			Type	A1 Journal article
Year	2024	Publication	ACS applied nano materials	Abbreviated Journal
Volume	7	Issue	4	Pages	3873-3884
Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract	Point defects in diamond, promising candidates for nanoscale pressure- and temperature-sensing applications, are potentially scalable in polycrystalline diamond fabricated using the microwave plasma-enhanced chemical vapor deposition (MW PE CVD) technique. However, this approach introduces residual stress in the diamond films, leading to variations in the characteristic zero phonon line (ZPL) of the point defect in diamond. Here, we report the effect of residual stress on germanium-vacancy (GeV) centers in MW PE CVD nanocrystalline diamond (NCD) films fabricated using single crystal Ge as the substrate and solid dopant source. GeV ensemble formation indicated by the zero phonon line (ZPL) at similar to 602 nm is confirmed by room temperature (RT) photoluminescence (PL) measurements. PL mapping results show spatial nonuniformity in GeV formation along with other defects, including silicon-vacancy centers in the diamond films. The residual stress in NCD results in shifts in the PL peak positions. By estimating a stress shift coefficient of (2.9 +/- 0.9) nm/GPa, the GeV PL peak position in the NCD film is determined to be between 598.7 and 603.2 nm. A larger ground state splitting due to the strain on a GeV-incorporated NCD pillar at a low temperature (10 K) is also reported. We also report the observation of intense ZPLs at RT that in some cases could be related to low Ge concentration and the surrounding crystalline environment. In addition, we also observe thicker microcrystalline diamond (MCD) films delaminate from the Ge substrate due to film residual stress and graphitic phase at the diamond/Ge substrate interface (confirmed by electron energy loss spectroscopy). Using this approach, a free-standing color center incorporated MCD film with dimensions up to 1 x 1 cm(2) is fabricated. Qualitative analysis using time-of-flight secondary ion mass spectroscopy reveals the presence of impurities, including Ge and silicon, in the MCD film. Our experimental results will provide insights into the scalability of GeV fabrication using the MW PE CVD technique and effectively implement NCD-based nanoscale-sensing applications.
Address
Corporate Author				Thesis
Publisher		Place of Publication		Editor
Language		Wos	001164609600001	Publication Date	2024-02-15
Series Editor		Series Title		Abbreviated Series Title
Series Volume		Series Issue		Edition
ISSN	2574-0970	ISBN		Additional Links	UA library record; WoS full record
Impact Factor	5.9	Times cited		Open Access
Notes				Approved	Most recent IF: 5.9; 2024 IF: NA
Call Number	UA @ admin @ c:irua:204826			Serial	9164
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