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Author (up) McCalla, E.; Abakumov, A.M.; Saubanere, M.; Foix, D.; Berg, E.J.; Rousse, G.; Doublet, M.-L.; Gonbeau, D.; Novak, P.; Van Tendeloo, G.; Dominko, R.; Tarascon, J.-M.
Title Visualization of O-O peroxo-like dimers in high-capacity layered oxides for Li-ion batteries Type A1 Journal article
Year 2015 Publication Science Abbreviated Journal Science
Volume 350 Issue 350 Pages 1516-1521
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Lithium-ion (Li-ion) batteries that rely on cationic redox reactions are the primary energy source for portable electronics. One pathway toward greater energy density is through the use of Li-rich layered oxides. The capacity of this class of materials (>270 milliampere hours per gram) has been shown to be nested in anionic redox reactions, which are thought to form peroxo-like species. However, the oxygen-oxygen (O-O) bonding pattern has not been observed in previous studies, nor has there been a satisfactory explanation for the irreversible changes that occur during first delithiation. By using Li2IrO3 as a model compound, we visualize the O-O dimers via transmission electron microscopy and neutron diffraction. Our findings establish the fundamental relation between the anionic redox process and the evolution of the O-O bonding in layered oxides.
Address College de France, Chimie du Solide et de l'Energie, FRE 3677, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05, France. ALISTORE-European Research Institute, FR CNRS 3104, 80039 Amiens, France. Reseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, France. Sorbonne Universites-UPMC Univ Paris 06, 4 Place Jussieu, F-75005 Paris, France. jean-marie.tarascon@college-de-france.fr
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000366591100056 Publication Date 2015-12-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0036-8075 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 37.205 Times cited 281 Open Access
Notes E.M. thanks the Fonds de Recherche du Québec–Nature et Technologies and ALISTORE–European Research Institute for funding this work, as well as the European community I3 networks for funding the neutron scattering research trip. This work was also funded by the Slovenian Research Agency research program P2-0148. This work is partially based on experiments performed at the Institut Laue Langevin. We thank J. Rodriguez-Carvajal for help with neutron scattering experiments and for fruitful discussions. We also thank M. T. Sougrati for performing the Sn-Mössbauer measurements. Use of the Advanced Photon Source at Argonne National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract no. DE-AC02- 06CH11357. M.S. and M.-L.D. acknowledge high-performance computational resources from GENCI-CCRT/CINES (grant cmm6691). J.-M.T. acknowledges funding from the European Research Council (ERC) (FP/2014-2020)/ERC Grant-Project670116-ARPEMA. Approved Most recent IF: 37.205; 2015 IF: 33.611
Call Number c:irua:130202 Serial 4005
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Author (up) Meert, K.W.; Morozov, V.A.; Abakumov, A.M.; Hadermann, J.; Poelman, D.; Smet, P.F.
Title Energy transfer in Eu3+ doped scheelites : use as thermographic phosphor Type A1 Journal article
Year 2014 Publication Optics express Abbreviated Journal Opt Express
Volume 22 Issue 9 Pages A961-A972
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract In this paper the luminescence of the scheelite-based CaGd2(1-x)Eu2x(WO4)4 solid solutions is investigated as a function of the Eu content and temperature. All phosphors show intense red luminescence due to the 5D0 7F2 transition in Eu3+, along with other transitions from the 5D1 and 5D0 excited states. For high Eu3+ concentrations the intensity ratio of the emission originating from the 5D1 and 5D0 levels has a non-conventional temperature dependence, which could be explained by a phonon-assisted cross-relaxation process. It is demonstrated that this intensity ratio can be used as a measure of temperature with high spatial resolution, allowing the use of these scheelites as thermographic phosphor. The main disadvantage of many thermographic phosphors, a decreasing signal for increasing temperature, is absent.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000335905300037 Publication Date 2014-04-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1094-4087; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.307 Times cited 47 Open Access
Notes Approved Most recent IF: 3.307; 2014 IF: 3.488
Call Number UA @ lucian @ c:irua:117067 Serial 1044
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Author (up) Mefford, J.T.; Kurilovich, A.A.; Saunders, J.; Hardin, W.G.; Abakumov, A.M.; Forslund, R.P.; Bonnefont, A.; Dai, S.; Johnston, K.P.; Stevenson, K.J.
Title Decoupling the roles of carbon and metal oxides on the electrocatalytic reduction of oxygen on La1-xSrxCoO3-\delta perovskite composite electrodes Type A1 Journal article
Year 2019 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 21 Issue 6 Pages 3327-3338
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Perovskite oxides are active room-temperature bifunctional oxygen electrocatalysts in alkaline media, capable of performing the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with lower combined overpotentials relative to their precious metal counterparts. However, their semiconducting nature necessitates the use of activated carbons as conductive supports to generate applicably relevant current densities. In efforts to advance the performance and theory of oxide electrocatalysts, the chemical and physical properties of the oxide material often take precedence over contributions from the conductive additive. In this work, we find that carbon plays an important synergistic role in improving the performance of La1-xSrxCoO3- (0 x 1) electrocatalysts through the activation of O-2 and spillover of radical oxygen intermediates, HO2- and O-2(-), which is further reduced through chemical decomposition of HO2- on the perovskite surface. Through a combination of thin-film rotating disk electrochemical characterization of the hydrogen peroxide intermediate reactions (hydrogen peroxide reduction reaction (HPRR), hydrogen peroxide oxidation reaction (HPOR)) and oxygen reduction reaction (ORR), surface chemical analysis, HR-TEM, and microkinetic modeling on La1-xSrxCoO3- (0 x 1)/carbon (with nitrogen and non-nitrogen doped carbons) composite electrocatalysts, we deconvolute the mechanistic aspects and contributions to reactivity of the oxide and carbon support.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000459584900049 Publication Date 2019-01-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 5 Open Access OpenAccess
Notes ; Financial support for this work was provided by the R. A. Welch Foundation (grants F-1529 and F-1319). S. D. was supported as part of the Fluid Interface Reactions, Structures and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences. ; Approved Most recent IF: 4.123
Call Number UA @ admin @ c:irua:158625 Serial 5244
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Author (up) Mefford, J.T.; Rong, X.; Abakumov, A.M.; Hardin, W.G.; Dai, S.; Kolpak, A.M.; Johnston, K.P.; Stevenson, K.J.
Title Water electrolysis on La1-xSrxCoO3-\delta perovskite electrocatalysts Type A1 Journal article
Year 2016 Publication Nature communications Abbreviated Journal Nat Commun
Volume 7 Issue 7 Pages 11053
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Perovskite oxides are attractive candidates as catalysts for the electrolysis of water in alkaline energy storage and conversion systems. However, the rational design of active catalysts has been hampered by the lack of understanding of the mechanism of water electrolysis on perovskite surfaces. Key parameters that have been overlooked include the role of oxygen vacancies, B-O bond covalency, and redox activity of lattice oxygen species. Here we present a series of cobaltite perovskites where the covalency of the Co-O bond and the concentration of oxygen vacancies are controlled through Sr2+ substitution into La1 – xSrxCoO3 – delta. We attempt to rationalize the high activities of La1 – xSrxCoO3 – delta through the electronic structure and participation of lattice oxygen in the mechanism of water electrolysis as revealed through ab initio modelling. Using this approach, we report a material, SrCoO2.7, with a high, room temperature-specific activity and mass activity towards alkaline water electrolysis.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000372721700001 Publication Date 2016-03-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 12.124 Times cited 278 Open Access
Notes Financial support for this work was provided by the R.A. Welch Foundation (grants F-1529 and F-1319). X.R. and A.M.K. acknowledge support from the Skoltech-MIT Center for Electrochemical Energy Storage. Computations were performed using computational resources from XSEDE and NERSC. S.D. was supported as part of the Fluid Interface Reactions, Structures and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences. We thank D.W. Redman for help with the RHE measurements. Approved Most recent IF: 12.124
Call Number UA @ lucian @ c:irua:133242 Serial 4276
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Author (up) Mikhailova, D.; Karakulina, O.M.; Batuk, D.; Hadermann, J.; Abakumov, A.M.; Herklotz, M.; Tsirlin, A.A.; Oswald, S.; Giebeler, L.; Schmidt, M.; Eckert, J.; Knapp, M.; Ehrenberg, H.
Title Layered-to-Tunnel Structure Transformation and Oxygen Redox Chemistry in LiRhO2upon Li Extraction and Insertion Type A1 Journal article
Year 2016 Publication Inorganic chemistry Abbreviated Journal Inorg Chem
Volume 55 Issue 55 Pages 7079-7089
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Layered Li(M,Li)O2 (where M is a transition metal) ordered rock-salt-type structures are used in advanced metal-ion batteries as one of the best hosts for the reversible intercalation of Li ions. Besides the conventional redox reaction involving oxidation/reduction of the M cation upon Li extraction/insertion, creating oxygen-located holes because of the partial oxygen oxidation increases capacity while maintaining the oxidized oxygen species in the lattice through high covalency of the M–O bonding. Typical degradation mechanism of the Li(M,Li)O2 electrodes involves partially irreversible M cation migration toward the Li positions, resulting in gradual capacity/voltage fade. Here, using LiRhO2 as a model system (isostructural and isoelectronic to LiCoO2), for the first time, we demonstrate an intimate coupling between the oxygen redox and M cation migration. A formation of the oxidized oxygen species upon electrochemical Li extraction coincides with transformation of the layered Li1–xRhO2 structure into the γ-MnO2-type rutile–ramsdellite intergrowth LiyRh3O6 structure with rutile-like [1 × 1] channels along with bigger ramsdellite-like [2 × 1] tunnels through massive and concerted Rh migration toward the empty positions in the Li layers. The oxidized oxygen dimers with the O–O distances as short as 2.26 Å are stabilized in this structure via the local Rh–O configuration reminiscent to that in the μ-peroxo-μ-hydroxo Rh complexes. The LiyRh3O6 structure is remarkably stable upon electrochemical cycling illustrating that proper structural implementation of the oxidized oxygen species can open a pathway toward deliberate employment of the anion redox chemistry in high-capacity/high-voltage positive electrodes for metal-ion batteries. Upon chemical or electrochemical oxidation, layered LiRhO2 shows a unique structural transformation that involves both cation migration and oxidation of oxygen resulting in a stable tunnel-like rutile−ramsdellite intergrowth LiyRh3O6 structure. This structure demonstrates excellent performance with the steady and reversible capacity of ∼200 mAh/g. The stability of LiyRh3O6 is rooted in the accommodation of partially oxidized oxygen species through the formation of short O−O distances that are compatible with the connectivity of RhO6 octahedra.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000380181400035 Publication Date 2016-07-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-1669 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.857 Times cited 12 Open Access
Notes Bundesministerium fur Bildung und Forschung, 03SF0477B ; Fonds Wetenschappelijk Onderzoek, G040116N ; Approved Most recent IF: 4.857
Call Number EMAT @ emat @ c:irua:140848 Serial 4424
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Author (up) Mikhailova, D.; Kuratieva, N.N.; Utsumi, Y.; Tsirlin, A.A.; Abakumov, A.M.; Schmidt, M.; Oswald, S.; Fuess, H.; Ehrenberg, H.
Title Composition-dependent charge transfer and phase separation in the V1-xRexO2 solid solution Type A1 Journal article
Year 2017 Publication Journal of the Chemical Society : Dalton transactions Abbreviated Journal
Volume 46 Issue 5 Pages 1606-1617
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The substitution of vanadium in vanadium dioxide VO2 influences the critical temperatures of structural and metal-to-insulator transitions in different ways depending on the valence of the dopant. Rhenium adopts valence states between + 4 and + 7 in an octahedral oxygen surrounding and is particularly interesting in this context. Structural investigation of V1-xRexO2 solid solutions (0.01 <= x <= 0.30) between 80 and 1200 K using synchrotron X-ray powder diffraction revealed only two polymorphs that resemble VO2: the low-temperature monoclinic MoO2-type form (space group P2(1)/c), and the tetragonal rutile-like form (space group P4(2)/mnm). However, for compositions with 0.03 < x <= 0.15 a phase separation in the solid solution was observed below 1000 K upon cooling down from 1200 K, giving rise to two isostructural phases with slightly different lattice parameters. This is reflected in the appearance of two metal-toinsulator transition temperatures detected by magnetization and specific heat measurements. Comprehensive X-ray photoelectron spectroscopy studies showed that an increased amount of Re leads to a change in the Re valence state from solely Re6+ at a low doping level (<= 3 at% Re) via mixed-valence states Re4+/Re6+ for at least 0.03 < x <= 0.10, up to nearly pure Re4+ in V0.70Re0.30O2. Thus, compositions V1-xRexO2 with only one valence state of Re in the material (Re6+ or Re4+) can be obtained as a single phase, while intermediate compositions are subjected to a phase separation, presumably due to different valence states of Re.
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Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000395442700030 Publication Date 2016-12-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0300-9246; 1477-9226; 1472-7773 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.029 Times cited 1 Open Access Not_Open_Access
Notes ; The authors are indebted to Dr G. Auffermann (Max Planck Institute for Chemical Physics of Solids, Dresden, Germany) for performing the ICP-OES analyses. This research has received a partial funding from the BMBF, project grant number 03SF0477B (DESIREE). AT acknowledges financial support from Federal Ministry for Education and Research under Sofja Kovalevksaya Award of Alexander von Humboldt Foundation. AMA is grateful to the Russian Science Foundation (grant 14-13-00680) for financial support. ; Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:142580 Serial 4642
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Author (up) 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)a*0.12388(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.
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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 (up) Morozov, V.A.; Batuk, D.; Batuk, M.; Basovich, O.M.; Khaikina, E.G.; Deyneko, D.V.; Lazoryak, B.I.; Leonidov, I.I.; Abakumov, A.M.; Hadermann, J.
Title Luminescence Property Upgrading via the Structure and Cation Changing in AgxEu(2–x)/3WO4and AgxGd(2–x)/3–0.3Eu0.3WO4 Type A1 Journal article
Year 2017 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 29 Issue 20 Pages 8811-8823
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The creation and ordering of A-cation vacancies and the effect of cation substitutions in the scheelite-type framework are investigated as a factor for controlling the scheelite-type structure and luminescence properties. AgxEu3+(2−x)/3□(1−2x)/3WO4 and AgxGd(2−x)/3−0.3Eu3+0.3□(1−2x)/3WO4 (x = 0.5−0) scheelite-type phases were synthesized by a solid state method, and their structures were investigated using a combination of transmission electron microscopy techniques and powder synchrotron X-ray diffraction. Transmission electron microscopy also revealed the (3 + 1)D incommensurately modulated character of AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.286, 0.2) phases. The crystal structures of the scheelite-based AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.5, 0.286, 0.2) red phosphors have been refined from high resolution synchrotron powder X-ray diffraction data. The luminescence properties of all phases under near-ultraviolet (n-UV) light have been investigated. The excitation spectra of AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.5, 0.286,0.2) phosphors show the strongest absorption at 395 nm, which matches well with the commercially available n-UV-emitting GaN-based LED chip. The excitation spectra of the Eu2/3□1/3WO4 and Gd0.367Eu0.30□1/3WO4 phases exhibit the highest contribution of the charge transfer band at 250 nm and thus the most efficient energy transfer mechanism between the host and the luminescent ion as compared to direct excitation. The emission spectra of all samples indicate an intense red emission due to the 5D0 → 7F2 transition of Eu3+. Concentration dependence of the 5D0 → 7F2 emission for AgxEu(2−x)/3□(1−2x)/3WO4 samples differs from the same dependence for the earlier studied NaxEu3+(2−x)/3□(1−2x)/3MoO4 (0 ≤ x ≤ 0.5) phases. The intensity of the 5D0 → 7F2 emission is reduced almost 7 times with decreasing x from 0.5 to 0, but it practically does not change in the range from x = 0.286 to x = 0.200. The emission spectra of Gd-containing samples show a completely different trend as compared to only Eu-containing samples. The Eu3+ emission under excitation of Eu3+(5L6) level (λex = 395 nm) increases more than 2.5 times with the increasing Gd3+ concentration from 0.2 (x = 0.5) to 0.3 (x = 0.2) in the AgxGd(2−x)/3−0.3Eu3+0.3□(1−2x)/3WO4, after which it remains almost constant for higher Gd3+ concentrations.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000413884900028 Publication Date 2017-10-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 7 Open Access Not_Open_Access
Notes This research was supported by FWO (project G039211N), Flanders Research Foundation. V.A.M. is grateful for financial support of the Russian Foundation for Basic Research (Grant 15-03-07741). E.G.K. and O.M.B. are grateful for financial support of the Russian Foundation for Basic Research (Grants 13-03-01020 and 16-03-00510). D.V.D. is grateful for financial support of the Russian Foundation for Basic Research (Grant 16-33-00197) and the Foundation of the President of the Russian Federation (Grant MK-7926.2016.5.). We are grateful to the ESRF for granting the beamtime. Experimental support of Andy Fitch at the ID31 beamline of ESRF is kindly acknowledged. Approved Most recent IF: 9.466
Call Number EMAT @ emat @c:irua:147241 Serial 4768
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Author (up) Napolsky, P.S.; Drozhzhin, O.A.; Istomin, S.Y.; Kazakov, S.M.; Antipov, E.V.; Galeeva, A.V.; Gippius, A.A.; Svensson, G.; Abakumov, A.M.; Van Tendeloo, G.
Title Structure and high-temperature properties of the (Sr,Ca,Y)(Co,Mn)O3-y perovskites – perspective cathode materials for IT-SOFC Type A1 Journal article
Year 2012 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume 192 Issue Pages 186-194
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Oxygen deficient perovskites Sr0.75Y0.25Co1-xMnxO3-y, x=0.5 and 0.75, were prepared by using the citrate route at 1373-1573 K for 48 h. The cubic Pm-3m perovskite structure for x=0.5 was confirmed by electron diffraction study and refined using neutron powder diffraction (NPD) data. For x=0.75, the superstructure corresponding to a=root 2 x a(per), b=2 x a(per), c=root 2 x a(per) (a(0)b(-)b(-) tilt system, space group Imma) was revealed by electron diffraction. The solid solution Sr0.75-xCaxY0.25Co0.25Mn0.75O3-y, 0.1 <= x <= 0.6 and compound Ca0.75Y0.25Mn0.85Co0.15O2.92 were prepared in air at 1573 K for 48 h. The crystal structure of Ca0.75Y0.25Mn0.85Co0.15O2.92 was refined using NPD data (S.G. Pnma, a=5.36595(4), b=7.5091(6), c=5.2992(4) angstrom, R-p=0.057, R-wp=0.056, chi(2)=4.26). High-temperature thermal expansion properties of the prepared compounds were studied in air using both dilatometry and high-temperature X-ray powder diffraction data (HTXRPD). They expanding non-linearly at 298-1073 K due to the loss of oxygen at high temperatures. Calculated average thermal expansion coefficients (TECs) for Sr0.75Y0.25Co1-xMnxO3-y, x=0.5, 0.75 and Ca0.75Y0.25Mn0.85Co0.15O2.92(1) are 15.5, 15.1, and 13.8 ppm K-1, respectively. Anisotropy of the thermal expansion along different unit cell axes was observed for Sr0.15Ca0.6Y0.25Co0.25Mn0.75O3-y, and Ca0.75Y0.25Mn0.85Co0.15O2.92. Conductivity of Sr0.75Y0.25Co1-xMnxO3-y, x=0.5 and 0.75 increases with the temperature reaching 110 S/cm for x=0.5 and 44 S/cm for x=0.75 at 1173 K. Samples of Sr0.75-xCaxY0.25Co0.25Mn0.75O3-y, 0.1 <= y <= 0.6 were found to be n-type conductors at room temperature with the similar temperature dependence of the conductivity and demonstrated the increase of the sigma value from similar to 1 to similar to 50 S/cm as the temperature increases from 300 to 1173 K. Their conductivity is described in terms of the small polaron charge transport with the activation energy (E-p) increasing from 340 to 430 meV with an increase of the calcium content from x=0 to x=0.6. (C) 2012 Elsevier Inc. All rights reserved.
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Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000307028300030 Publication Date 2012-03-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 5 Open Access
Notes Approved Most recent IF: 2.299; 2012 IF: 2.040
Call Number UA @ lucian @ c:irua:101119 Serial 3279
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Author (up) Navulla, A.; Tsirlin, A.A.; Abakumov, A.M.; Shpanchenko, R.V.; Zhang, H.; Dikarev, E.V.
Title Fluorinated heterometallic \beta-diketonates as volatile single-source precursors for the synthesis of low-valent mixed-metal fluorides Type A1 Journal article
Year 2011 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
Volume 133 Issue 4 Pages 692-694
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Hexafluoroacetylacetonates that contain lead and divalent first-row transition metals, PbM(hfac)4 (M = Ni (1), Co (2), Mn (3), Fe (4), and Zn (5)), have been synthesized. Their heterometallic structures are held together by strong Lewis acid−base interactions between metal atoms and diketonate ligands acting in chelating−bridging fashion. Compounds 1−5 are highly volatile and decompose below 350 °C. Fluorinated heterometallic β-diketonates have been used for the first time as volatile single-source precursors for the preparation of mixed-metal fluorides. Complex fluorides of composition Pb2MF6 have been obtained by decomposition of 1−5 in a two-zone furnace under low-pressure nitrogen flow. Lead−transition metal fluorides conform to orthorhombically distorted Aurivillius-type structure with layers of corner-sharing [MF6] octahedra separated by α-PbO-type (Pb2F2) blocks. Pb2NiF6 and Pb2CoF6 were found to exhibit magnetic ordering below 80 and 43 K, respectively. The ordering is antiferromagnetic, with a weak, uncompensated moment due to the canting of spins. The Pb2MF6 fluorides represent a new class of prospective magnetoelectric materials combining transition metals and lone-pair main-group cations.
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Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000287295300015 Publication Date 2010-12-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.858 Times cited 28 Open Access
Notes Approved Most recent IF: 13.858; 2011 IF: 9.907
Call Number UA @ lucian @ c:irua:88820 Serial 1236
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Author (up) Nikolaev, I.V.; d' Hondt, H.; Abakumov, A.M.; Hadermann, J.; Balagurov, A.M.; Bobrikov, I.A.; Sheptyakov, D.V.; Pomjakushin, V.Y.; Pokholok, K.V.; Filimonov, D.S.; Van Tendeloo, G.; Antipov, E.V.
Title Crystal structure, phase transition, and magnetic ordering in perovskitelike Pb2-xBaxFe2O5 solid solutions Type A1 Journal article
Year 2008 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 78 Issue 2 Pages 024426,1-12
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
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Corporate Author Thesis
Publisher Place of Publication Lancaster, Pa Editor
Language Wos 000258190200085 Publication Date 2008-07-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 29 Open Access
Notes Iap Vi Approved Most recent IF: 3.836; 2008 IF: 3.322
Call Number UA @ lucian @ c:irua:70580 Serial 576
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Author (up) Niu, H.; Pitcher, M.J.; Corkett, A.J.; Ling, S.; Mandal, P.; Zanella, M.; Dawson, K.; Stamenov, P.; Batuk, D.; Abakumov, A.M.; Bull, C.L.; Smith, R.I.; Murray, C.A.; Day, S.J.; Slater, B.; Cora, F.; Claridge, J.B.; Rosseinsky, M.J.
Title Room Temperature Magnetically Ordered Polar Corundum GaFeO3 Displaying Magnetoelectric Coupling Type A1 Journal article
Year 2017 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc
Volume 139 Issue 4 Pages 1520-1531
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The polar corundum structure type offers a route to new room temperature multiferroic materials, as the partial LiNbO3-type cation ordering that breaks inversion symmetry may be combined with long-range magnetic ordering of high spin d(5) cations above room temperature in the AFeO(3) system. We report the synthesis of a polar corundum GaFeO3 by a high-pressure, high-temperature route and demonstrate that its polarity arises from partial LiNbO3 -type cation ordering by complementary use of neutron, X-ray, and electron diffraction methods. In situ neutron diffraction shows that the polar corundum forms directly from AlFeO3-type GaFeO3 under the synthesis conditions. The A(3+)/Fe3+ cations are shown to be more ordered in polar corundum GaFeO3 than in isostructural ScFeO3. This is explained by DFT calculations which indicate that the extent of ordering is dependent on the configurational entropy available to each system at the very different synthesis temperatures required to form their corundum structures. Polar corundum GaFeO3 exhibits weak ferromagnetism at room temperature that arises from its Fe2O3-like magnetic ordering, which persists to a temperature of 408 K. We demonstrate that the polarity and magnetization are coupled in this system with a measured linear magnetoelectric coupling coefficient of 0.057 ps/m. Such coupling is a prerequisite for potential applications of polar corundum materials in multiferroic/magnetoelectric devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000393355600034 Publication Date 2016-12-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-7863 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.858 Times cited 12 Open Access OpenAccess
Notes This work was funded by the EPSRC under EP/N004884. We thank the STFC for provision of beam time at ISIS and Diamond Light Source. We thank the Materials Chemistry Consortium (EPSRC, EP/L000202) for access to computer time on the ARCHER UK National Supercomputing Service (http://www.archer.ac.uk). A.M.A. is grateful to the Russian Science Foundation (Grant 14-13-00680) for financial support. MJ.R is a Royal Society Research Professor. We wish to thank Dr. Ming Li (University of Nottingham, UK) for helpful discussion and advice. Original data is available at the University of Liverpool's DataCat repository at DOI: 10.17638/datacat.liverpool.ac.uk/235. The supporting crystallographic information file may also be obtained from FIZ Karlsruhe, 76344 Eggenstein-Leopoldshafen, Germany (e-mail: crysdata@fiz-karlsruhe.de), on quoting the deposition number CSD-432419. Approved Most recent IF: 13.858
Call Number EMAT @ emat @c:irua:147507 Serial 4777
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Author (up) O'Sullivan, M.; Hadermann, J.; Dyer, M.S.; Turner, S.; Alaria, J.; Manning, T.D.; Abakumov, A.M.; Claridge, J.B.; Rosseinsky, M.J.
Title Interface control by chemical and dimensional matching in an oxide heterostructure Type A1 Journal article
Year 2016 Publication Nature chemistry Abbreviated Journal Nat Chem
Volume 8 Issue 8 Pages 347-353
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Interfaces between different materials underpin both new scientific phenomena, such as the emergent behaviour at oxide interfaces, and key technologies, such as that of the transistor. Control of the interfaces between materials with the same crystal structures but different chemical compositions is possible in many materials classes, but less progress has been made for oxide materials with different crystal structures. We show that dynamical self-organization during growth can create a coherent interface between the perovskite and fluorite oxide structures, which are based on different structural motifs, if an appropriate choice of cations is made to enable this restructuring. The integration of calculation with experimental observation reveals that the interface differs from both the bulk components and identifies the chemical bonding requirements to connect distinct oxide structures.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000372505500013 Publication Date 2016-02-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1755-4330; 1755-4349 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 25.87 Times cited 28 Open Access
Notes Approved Most recent IF: 25.87
Call Number UA @ lucian @ c:irua:133189 Serial 4199
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Author (up) Oleynikov, P.N.; Shpanchenko, R.V.; Rozova, M.G.; Abakumov, A.M.; Antipov, E.V.; Hadermann, J.; Lebedev, O.I.; Van Tendeloo, G.
Title Synthesis and structure of fluorinated RBa2Cu2O6+. (R=Dy, Ho and Tm) phases Type A1 Journal article
Year 2001 Publication Russian journal of inorganic chemistry Abbreviated Journal Russ J Inorg Chem+
Volume 46 Issue 2 Pages 153-158
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0036-0236 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 0.787 Times cited Open Access
Notes Approved Most recent IF: 0.787; 2001 IF: NA
Call Number UA @ lucian @ c:irua:36045 Serial 3443
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Author (up) Ovsyannikov, S.V.; Abakumov, A.M.; Tsirlin, A.A.; Schnelle, W.; Egoavil, R.; Verbeeck, J.; Van Tendeloo, G.; Glazyrin, K.V.; Hanfland, M.; Dubrovinsky, L.
Title Perovskite-like Mn2O3 : a path to new manganites Type A1 Journal article
Year 2013 Publication Angewandte Chemie Abbreviated Journal Angew Chem Int Edit
Volume 52 Issue 5 Pages 1494-1498
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Korund-artiges ε-Mn2O3 und Perowskit-artiges ζ-Mn2O3, zwei neue Phasen von Mn2O3, wurden unter hohen Drücken bei hohen Temperaturen synthetisiert. Die Manganatome können vollständig die A- und B-Positionen der Perowskitstruktur besetzen. ζ-Mn2O3 (siehe Bild, A-Positionsordnung) enthält Mn in den drei Oxidationsstufen +II, +III und +IV.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000313913300027 Publication Date 2012-12-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1433-7851; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 11.994 Times cited 84 Open Access
Notes This work was supported by the DFG (project OV-110/1-1), Alexander von Humboldt foundation, European Union Council (FP7)-Grant no. 246102 IFOX, European Research Council (FP7)-ERC Starting Grant no. 278510 VORTEX and ERC Grant no. 246791-COUNTATOMS, and Hercules fund from the Flemish Government. ECASJO_; Approved Most recent IF: 11.994; 2013 IF: 11.336
Call Number UA @ lucian @ c:irua:108765UA @ admin @ c:irua:108765 Serial 2573
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Author (up) Ovsyannikov, S.V.; Bykov, M.; Bykova, E.; Kozlenko, D.P.; Tsirlin, A.A.; Karkin, A.E.; Shchennikov, V.V.; Kichanov, S.E.; Gou, H.; Abakumov, A.M.; Egoavil, R.; Verbeeck, J.; McCammon, C.; Dyadkin, V.; Chernyshov, D.; van Smaalen, S.; Dubrovinsky, L.S.
Title Charge-ordering transition in iron oxide Fe4O5 involving competing dimer and trimer formation Type A1 Journal article
Year 2016 Publication Nature chemistry Abbreviated Journal Nat Chem
Volume 8 Issue 8 Pages 501-508
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Phase transitions that occur in materials, driven, for instance, by changes in temperature or pressure, can dramatically change the materials' properties. Discovering new types of transitions and understanding their mechanisms is important not only from a fundamental perspective, but also for practical applications. Here we investigate a recently discovered Fe4O5 that adopts an orthorhombic CaFe3O5-type crystal structure that features linear chains of Fe ions. On cooling below approximately 150 K, Fe4O5 undergoes an unusual charge-ordering transition that involves competing dimeric and trimeric ordering within the chains of Fe ions. This transition is concurrent with a significant increase in electrical resistivity. Magnetic-susceptibility measurements and neutron diffraction establish the formation of a collinear antiferromagnetic order above room temperature and a spin canting at 85 K that gives rise to spontaneous magnetization. We discuss possible mechanisms of this transition and compare it with the trimeronic charge ordering observed in magnetite below the Verwey transition temperature.
Address Bayerisches Geoinstitut, Universitat Bayreuth, Universitatsstrasse 30, D-95447, Bayreuth, Germany
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000374534100019 Publication Date 2016-04-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1755-4330 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 25.87 Times cited 51 Open Access
Notes S.V.O. acknowledges the financial support of the Deutsche Forschungsgemeinschaft (DFG) under project OV-110/1-3. A.E.K. and V.V.S. acknowledge the support of the Russian Foundation for Basic Research (Project 14–02–00622a). H.G. acknowledges the support from the Alexander von Humboldt (AvH) Foundation and the National Natural Science Foundation of China (No. 51201148). A.M.A., R.E. and J.V. acknowledge financial support from the European Commission (EC) under the Seventh Framework Programme (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483- ESTEEM2. R.E. acknowledges support from the EC under FP7 Grant No. 246102 IFOX. A.M.A. acknowledges funding from the Russian Science Foundation (Grant No. 14-13- 00680). A.A.T. acknowledges funding and from the Federal Ministry for Education and Research through the Sofja Kovalevkaya Award of the AvH Foundation. Funding from the Fund for Scientific Research Flanders under FWO Project G.0044.13N is acknowledged. M.B. and S.v.S. acknowledge support from the DFG under Project Sm55/15-2. We acknowledge the European Synchrotron Radiation Facility for the provision of synchrotron radiation facilities.; esteem2jra2; esteem2jra3 Approved Most recent IF: 25.87
Call Number c:irua:133593 c:irua:133593UA @ admin @ c:irua:133593 Serial 4068
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Author (up) Ovsyannikov, S.V.; Karkin, A.E.; Morozova, N.V.; Shchennikov, V.V.; Bykova, E.; Abakumov, A.M.; Tsirlin, A.A.; Glazyrin, K.V.; Dubrovinsky, L.
Title A hard oxide semiconductor with a direct and narrow bandgap and switchable pn electrical conduction Type A1 Journal article
Year 2014 Publication Advanced materials Abbreviated Journal Adv Mater
Volume 26 Issue 48 Pages 8185-8191
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract An oxide semiconductor (perovskite-type Mn2O3) is reported which has a narrow and direct bandgap of 0.45 eV and a high Vickers hardness of 15 GPa. All the known materials with similar electronic band structures (e.g., InSb, PbTe, PbSe, PbS, and InAs) play crucial roles in the semiconductor industry. The perovskite-type Mn2O3 described is much stronger than the above semiconductors and may find useful applications in different semiconductor devices, e.g., in IR detectors.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000346480800016 Publication Date 2014-10-27
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 27 Open Access
Notes Approved Most recent IF: 19.791; 2014 IF: 17.493
Call Number UA @ lucian @ c:irua:122230 Serial 1408
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Author (up) Pachoud, E.; Bréard, Y.; Martin, C.; Maignan, A.; Abakumov, A.M.; Suard, E.; Smith, R.I.; Suchomel, M.R.
Title Bi0.75Sr0.25FeO3-\delta : revealing order/disorder phenomena by combining diffraction techniques Type A1 Journal article
Year 2012 Publication Solid state communications Abbreviated Journal Solid State Commun
Volume 152 Issue 5 Pages 331-336
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The local and long range structure of polycrystalline samples of Bi0.75Sr0.25FeO3-delta has been probed by neutron and synchrotron X-ray diffraction coupled with transmission electron microscopy. It is found that the long range structure on average can be described by the cubic space group Pm-3m (a(p) congruent to 3.951 angstrom). However, the refinements revealed large atomic displacements for the (Bi, Sr) cations and the oxygen atoms from their ideal positions. The electron microscopy study indicates the existence of local phenomena like local ordering of oxygen vacancies, which are segregated at the randomly spaced parallel (FeO2-delta) planes, or the existence of region of different symmetry, probably R3c. At room temperature, the compound exhibits G-type antiferromagnetism (T-N congruent to 650 K) with a magnetic moment of congruent to 3.7 mu(B). (C) 2012 Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000301329200001 Publication Date 2011-12-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0038-1098; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.554 Times cited 6 Open Access
Notes Approved Most recent IF: 1.554; 2012 IF: 1.534
Call Number UA @ lucian @ c:irua:97820 Serial 3516
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Author (up) Panin, R.V.; Khasanova, N.R.; Abakumov, A.M.; Antipov, E.V.; Van Tendeloo, G.; Schnelle, W.
Title Synthesis and crystal structure of the palladium oxides NaPd3O4, Na2PdO3 and K3Pd2O4 Type A1 Journal article
Year 2007 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume 180 Issue 5 Pages 1566-1574
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000246892800007 Publication Date 2007-03-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 24 Open Access
Notes Approved Most recent IF: 2.299; 2007 IF: 2.149
Call Number UA @ lucian @ c:irua:64740 Serial 3429
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Author (up) Panin, R.V.; Khasanova, N.R.; Abakumov, A.M.; Schnelle, W.; Hadermann, J.; Antipov, E.V.
Title Crystal structure and properties of the Na1-xRu2O4 phase Type A1 Journal article
Year 2006 Publication Russian chemical bulletin Abbreviated Journal Russ Chem B+
Volume 55 Issue 10 Pages 1717-1722
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000245091400003 Publication Date 2007-03-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1066-5285;1573-9171; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 0.529 Times cited 5 Open Access
Notes Approved Most recent IF: 0.529; 2006 IF: 0.505
Call Number UA @ lucian @ c:irua:63810 Serial 566
Permanent link to this record
 
 
Author (up) Paria Sena, R.; Babaryk, A.A.; Khainakov, S.; Garcia-Granda, S.; Slobodyanik, N.S.; Van Tendeloo, G.; Abakumov, A.M.; Hadermann, J.
Title A pseudo-tetragonal tungsten bronze superstructure: a combined solution of the crystal structure of K6.4(Nb,Ta)36.3O94 with advanced transmission electron microscopy and neutron diffraction Type A1 Journal article
Year 2016 Publication Journal of the Chemical Society : Dalton transactions Abbreviated Journal Dalton T
Volume 45 Issue 45 Pages 973-979
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The crystal structure of the K6.4Nb28.2Ta8.1O94 pseudo-tetragonal tungsten bronze-type oxide was determined using a combination of X-ray powder diffraction, neutron diffraction and transmission electron microscopy techniques, including electron diffraction, high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), annular bright field STEM (ABF-STEM) and energy-dispersive X-ray compositional mapping (STEM-EDX). The compound crystallizes in the space group Pbam with unit cell parameters a = 37.468(9) A, b = 12.493(3) A, c = 3.95333(15) A. The structure consists of corner sharing (Nb,Ta)O6 octahedra forming trigonal, tetragonal and pentagonal tunnels. All tetragonal tunnels are occupied by K(+) ions, while 1/3 of the pentagonal tunnels are preferentially occupied by Nb(5+)/Ta(5+) and 2/3 are occupied by K(+) in a regular pattern. A fractional substitution of K(+) in the pentagonal tunnels by Nb(5+)/Ta(5+) is suggested by the analysis of the HAADF-STEM images. In contrast to similar structures, such as K2Nb8O21, also parts of the trigonal tunnels are fractionally occupied by K(+) cations.
Address Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020, Antwerp, Belgium. joke.hadermann@uantwerpen.be babaryk@univ.kiev.ua
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000367614700018 Publication Date 2015-11-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1477-9226 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.029 Times cited 6 Open Access
Notes We thank Dr E. Suard and Dr O. Fabello for assistance in collecting the neutron diffraction data. R.P.S. acknowledges funding from the European Research Council under the 7th Framework Program (FP7), ERC Grant No. 246791-COUNTATOMS. The titan microscope was partly funded by the Hercules fund from the Flemish Government. The authors acknowledge financial support from the European Union under the Seventh Framework Program under a contract for an Integrated Infrastructure Initiative. Reference No. 312483-ESTEEM2. AAB acknowledges the JSPDS ICDD Grant-in-Aid program (12-02).; esteem2jra1; esteem2jra2 Approved Most recent IF: 4.029
Call Number c:irua:130408 c:irua:130408 Serial 3998
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Author (up) Paulus, A.; Hendrickx, M.; Bercx, M.; Karakulina, O.M.; Kirsanova, M.A.; Lamoen, D.; Hadermann, J.; Abakumov, A.M.; Van Bael, M.K.; Hardy, A.
Title An in-depth study of Sn substitution in Li-rich/Mn-rich NMC as a cathode material for Li-ion batteries Type A1 Journal article
Year 2020 Publication Journal of the Chemical Society : Dalton transactions Abbreviated Journal
Volume 49 Issue 30 Pages 10486-10497
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Layered Li-rich/Mn-rich NMC (LMR-NMC) is characterized by high initial specific capacities of more than 250 mA h g(-1), lower cost due to a lower Co content and higher thermal stability than LiCoO2. However, its commercialisation is currently still hampered by significant voltage fade, which is caused by irreversible transition metal ion migration to emptied Li positionsviatetrahedral interstices upon electrochemical cycling. This structural change is strongly correlated with anionic redox chemistry of the oxygen sublattice and has a detrimental effect on electrochemical performance. In a fully charged state, up to 4.8 Vvs.Li/Li+, Mn4+ is prone to migrate to the Li layer. The replacement of Mn4+ for an isovalent cation such as Sn4+ which does not tend to adopt tetrahedral coordination and shows a higher metal-oxygen bond strength is considered to be a viable strategy to stabilize the layered structure upon extended electrochemical cycling, hereby decreasing voltage fade. The influence of Sn4+ on the voltage fade in partially charged LMR-NMC is not yet reported in the literature, and therefore, we have investigated the structure and the corresponding electrochemical properties of LMR-NMC with different Sn concentrations. We determined the substitution limit of Sn4+ in Li1.2Ni0.13Co0.13Mn0.54-xSnxO2 by powder X-ray diffraction and transmission electron microscopy to be x approximate to 0.045. The limited solubility of Sn is subsequently confirmed by density functional theory calculations. Voltage fade for x= 0 andx= 0.027 has been comparatively assessed within the 3.00 V-4.55 V (vs.Li/Li+) potential window, from which it is concluded that replacing Mn4+ by Sn4+ cannot be considered as a viable strategy to inhibit voltage fade within this window, at least with the given restricted doping level.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000555330900018 Publication Date 2020-07-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0300-9246; 1477-9226; 1472-7773 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4 Times cited Open Access OpenAccess
Notes ; The authors acknowledge Research Foundation Flanders (FWO) project number G040116N for funding. The authors are grateful to Dr Ken Elen and Greet Cuyvers (imo-imomec, UHasselt and imec) for respectively preliminary PXRD measurements and performing ICP-AES on the monometal precursors. Dr Dmitry Rupasov (Skolkovo Institute of Science and Technology) is acknowledged for performing TGA measurements on the metal sulfate precursors. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO-Vlaanderen and the Flemish Government-department EWI. ; Approved Most recent IF: 4; 2020 IF: 4.029
Call Number UA @ admin @ c:irua:171149 Serial 6450
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Author (up) Paulus, A.; Hendrickx, M.; Mayda, S.; Batuk, M.; Reekmans, G.; von Holst, M.; Elen, K.; Abakumov, A.M.; Adriaensens, P.; Lamoen, D.; Partoens, B.; Hadermann, J.; Van Bael, M.K.; Hardy, A.
Title Understanding the Activation of Anionic Redox Chemistry in Ti4+-Substituted Li2MnO3as a Cathode Material for Li-Ion Batteries Type A1 Journal article
Year 2023 Publication ACS applied energy materials Abbreviated Journal ACS Appl. Energy Mater.
Volume 6 Issue 13 Pages 6956-6971
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract Layered Li-rich oxides, demonstrating both cationic and anionic redox chemistry being used as positive electrodes for Li-ion batteries,have raised interest due to their high specific discharge capacities exceeding 250 mAh/g. However, irreversible structural transformations triggered by anionic redox chemistry result in pronounced voltagefade (i.e., lowering the specific energy by a gradual decay of discharge potential) upon extended galvanostatic cycling. Activating or suppressing oxygen anionic redox through structural stabilization induced by redox-inactivecation substitution is a well-known strategy. However, less emphasishas been put on the correlation between substitution degree and theactivation/suppression of the anionic redox. In this work, Ti4+-substituted Li2MnO3 was synthesizedvia a facile solution-gel method. Ti4+ is selected as adopant as it contains no partially filled d-orbitals. Our study revealedthat the layered “honeycomb-ordered” C2/m structure is preserved when increasing the Ticontent to x = 0.2 in the Li2Mn1-x Ti (x) O-3 solidsolution, as shown by electron diffraction and aberration-correctedscanning transmission electron microscopy. Galvanostatic cycling hintsat a delayed oxygen release, due to an improved reversibility of theanionic redox, during the first 10 charge-discharge cyclesfor the x = 0.2 composition compared to the parentmaterial (x = 0), followed by pronounced oxygen redoxactivity afterward. The latter originates from a low activation energybarrier toward O-O dimer formation and Mn migration in Li2Mn0.8Ti0.2O3, as deducedfrom first-principles molecular dynamics (MD) simulations for the“charged” state. Upon lowering the Ti substitution to x = 0.05, the structural stability was drastically improvedbased on our MD analysis, stressing the importance of carefully optimizingthe substitution degree to achieve the best electrochemical performance.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001018266700001 Publication Date 2023-07-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2574-0962 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.4 Times cited Open Access Not_Open_Access: Available from 24.12.2023
Notes Universiteit Hasselt, AUHL/15/2 – GOH3816N ; Russian Science Foundation, 20-43-01012 ; Fonds Wetenschappelijk Onderzoek, AUHL/15/2 – GOH3816N G040116N ; The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO Vlaanderen and the Flemish Government-department EWI. Approved Most recent IF: 6.4; 2023 IF: NA
Call Number EMAT @ emat @c:irua:198160 Serial 8809
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Author (up) Pearce, P.E.; Perez, A.J.; Rousse, G.; Saubanère, M.; Batuk, D.; Foix, D.; McCalla, E.; Abakumov, A.M.; Van Tendeloo, G.; Doublet, M.-L.; Tarascon, J.-M.
Title Evidence for anionic redox activity in a tridimensional-ordered Li-rich positive electrode β-Li2IrO3 Type A1 Journal article
Year 2017 Publication Nature materials Abbreviated Journal Nat Mater
Volume 16 Issue 5 Pages 580-586
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Lithium-ion battery cathode materials have relied on cationic redox reactions until the recent discovery of anionic redox activity in Li-rich layered compounds which enables capacities as high as 300 mAh g(-1). In the quest for new high-capacity electrodes with anionic redox, a still unanswered question was remaining regarding the importance of the structural dimensionality. The present manuscript provides an answer. We herein report on a beta-Li2IrO3 phase which, in spite of having the Ir arranged in a tridimensional (3D) framework instead of the typical two-dimensional (2D) layers seen in other Li-rich oxides, can reversibly exchange 2.5 e(-) per Ir, the highest value ever reported for any insertion reaction involving d-metals. We show that such a large activity results from joint reversible cationic (Mn+) and anionic (O-2)(n-) redox processes, the latter being visualized via complementary transmission electron microscopy and neutron diffraction experiments, and confirmed by density functional theory calculations. Moreover, beta-Li2IrO3 presents a good cycling behaviour while showing neither cationic migration nor shearing of atomic layers as seen in 2D-layered Li-rich materials. Remarkably, the anionic redox process occurs jointly with the oxidation of Ir4+ at potentials as low as 3.4 V versus Li+/Li-0, as equivalently observed in the layered alpha-Li2IrO3 polymorph. Theoretical calculations elucidate the electrochemical similarities and differences of the 3D versus 2D polymorphs in terms of structural, electronic and mechanical descriptors. Our findings free the structural dimensionality constraint and broaden the possibilities in designing high-energy-density electrodes for the next generation of Li-ion batteries.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000400004200018 Publication Date 2017-02-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1476-1122 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 39.737 Times cited Open Access Not_Open_Access
Notes The authors thank Q. Jacquet for fruitful discussions and V. Pomjakushin for his valuable help in neutron diffraction experiments. This work is based on experiments performed at the Swiss Spallation Neutron Source SINQ, Paul Scherrer Institute, Villigen, Switzerland. Use of the 11-BM mail service of the APS at Argonne National Laboratory was supported by the US Department of Energy under contract No. DE-AC02-06CH11357 and is greatly acknowledged. J.-M.T. acknowledges funding from the European Research Council (ERC) (FP/2014)/ERC Grant-Project 670116-ARPEMA. E.M. acknowledges financial support from the Fonds de Recherche du Quebec-Nature et Technologies. Approved Most recent IF: 39.737
Call Number EMAT @ emat @c:irua:147502 Serial 4773
Permanent link to this record
 
 
Author (up) Pearce, P.E.; Rousse, G.; Karakulina, O.M.; Hadermann, J.; Van Tendeloo, G.; Foix, D.; Fauth, F.; Abakumov, A.M.; Tarascon, J.-M.
Title β-Na1.7IrO3: A Tridimensional Na-Ion Insertion Material with a Redox Active Oxygen Network Type A1 Journal article
Year 2018 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 30 Issue 10 Pages 3285-3293
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The revival of the Na-ion battery concept has prompted an intense search for new high capacity Na-based positive electrodes. Recently, emphasis has been placed on manipulating Na-based layered compounds to trigger the participation of the anionic network. We further explored this direction and show the feasibility of achieving anionic-redox activity in three-dimensional Na-based compounds. A new 3D β-Na1.7IrO3 phase was synthesized in a two-step process, which involves first the electrochemical removal of Li from β-Li2IrO3 to produce β-IrO3, which is subsequently reduced by electrochemical Na insertion. We show that β-Na1.7IrO3 can reversibly uptake nearly 1.3 Na+ per formula unit through an uneven voltage profile characterized by the presence of four plateaus related to structural transitions. Surprisingly, the β-Na1.7IrO3 phase was found to be stable up to 600 °C, while it could not be directly synthesized via conventional synthetic methods. Although these Na-based iridate phases are of limited practical interest, they help to understand how introducing highly polarizable guest ions (Na+) into host rocksalt-derived oxide structures affects the anionic redox mechanism.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000433403800014 Publication Date 2018-05-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 6 Open Access OpenAccess
Notes The authors thank A. Perez for fruitful discussions and his valuable help in synchrotron XRD experiment and Matthieu Courty for carrying out the DSC measurements. The authors also greatly thank Matthieu Saubanère and Marie-Liesse Doublet for valuable discussions on theoretical aspects of this work. This work is based on experiments performed on the Materials Science and Powder Diffraction Beamline at ALBA synchrotron (Proposal 2016091814), Cerdanyola del Vallès, E- 08290 Barcelona, Spain. J.-M.T. acknowledges funding from the European Research Council (ERC) (FP/2014)/ERC Grant- Project 670116-ARPEMA. G.R. acknowledges funding from ANR DeliRedox. O.M.K., J.H., and A.M.A. are grateful to FWO Vlaanderen for financial support under Grant G040116N. Approved Most recent IF: 9.466
Call Number EMAT @ emat @c:irua:152048 Serial 4996
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Author (up) Perez, A.J.; Batuk, D.; Saubanère, M.; Rousse, G.; Foix, D.; Mc Calla, E.; J. Berg, E.; Dugas, R.; van den Bos, K. H. W.; Doublet, M.-L.; Gonbeau, D.; Abakumov, A.M.; Van Tendeloo, G.; Tarascon, J.-M.
Title Strong oxygen participation in the redox governing the structural and electrochemical properties of Na-rich layered oxide Na2IrO3 Type A1 Journal article
Year 2016 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 28 Issue 28 Pages 8278-8288
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The recent revival of the Na-ion battery concept has prompted intense activities in the search for new Na-based layered oxide positive electrodes. The largest capacity to date was obtained for a Na-deficient layered oxide that relies on cationic redox processes only. To go beyond this limit, we decided to chemically manipulate these Na-based layered compounds in a way to trigger the participation of the anionic network. We herein report the electrochemical properties of a Na-rich phase Na2IrO3, which can reversibly cycle 1.5 Na+ per formula unit while not suffering from oxygen release nor cationic migrations. Such large capacities, as deduced by complementary XPS, X-ray/neutron diffraction and transmission electron microscopy measurements, arise from cumulative cationic and anionic redox processes occurring simultaneously at potentials as low as 3.0 V. The inability to remove more than 1.5 Na+ is rooted in the formation of an O1-type phase having highly stabilized Na sites as confirmed by DFT calculations, which could rationalize as well the competing metal/oxygen redox processes in Na2IrO3. This work will help to define the most fertile directions in the search for novel high energy Na-rich materials based on more sustainable elements than Ir.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000388914500021 Publication Date 2016-10-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 45 Open Access
Notes The authors thank Montse Casas-Cabanas and Marine Reynaud for discussions about the FAULTS program, Sandra Van Aert for her great help in guiding us towards the use of the statistical parameter estimation method for establishing the O-O histogram, and Thomas Hansen and Vladimir Pomjakushin for their precious help in neutron diffraction experiments. This work is based on experiments performed at the Swiss spallation neutron source SINQ, Paul Scherrer Institute, Villigen, Switzerland, and at Institut Laue Langevin, Grenoble, France. Use of the 11-BM mail service of the APS at Argonne National Laboratory was supported by the U.S. department of Energy under contract No. DE-AC02-06CH11357 and is greatly acknowledged. Approved Most recent IF: 9.466
Call Number EMAT @ emat @ c:irua:135994 Serial 4287
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Author (up) Pimenta, V.; Sathiya, M.; Batuk, D.; Abakumov, A.M.; Giaume, D.; Cassaignon, S.; Larcher, D.; Tarascon, J.-M.
Title Synthesis of Li-Rich NMC : a comprehensive study Type A1 Journal article
Year 2017 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 29 Issue 23 Pages 9923-9936
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract <script type='text/javascript'>document.write(unpmarked('Li-rich NMC are considered nowadays as one of the most promising candidates for high energy density cathodes. One significant challenge is nested in adjusting their synthesis conditions to reach optimum electrochemical performance, but no consensus has been reached yet on the ideal synthesis protocol. Herein, we revisited the elaboration of Li-rich NMC electrodes by focusing on the science involved through each synthesis steps using carbonate Ni0.1625Mn0.675Co0.1625CO3 precursor coprecipitation combined with solid state synthesis. We demonstrated the effect of precursors concentration on the kinetics of the precipitation reaction and provided clues to obtain spherically agglomerated NMC carbonates of different sizes. Moreover, we highlighted the strong impact of the Li2CO3/NMC carbonate ratio on the morphology and particles size of Li-rich NMC and subsequently on their electrochemical performance. Ratio of 1.35 was found to reproducibly give the best performance with namely a first discharge capacity of 269 mAh g(-1) and capacity retention of 89.6% after 100 cycles. We hope that our results, which reveal how particle size, morphology, and phase composition affect the materials electrochemical performance, will help in reconciling literature data while providing valuable fundamental information for up scaling approaches.'));
Address
Corporate Author Thesis
Publisher American Chemical Society Place of Publication Washington, D.C Editor
Language Wos 000418206600010 Publication Date 2017-11-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 23 Open Access Not_Open_Access
Notes ; The authors acknowledge the French Research Network on Electrochemical Energy Storage (RS2E). V.P and J.-M.T. acknowledges funding from the European Research Council (ERC) (FP/2014)/ERC Grant-Project 670116-ARPEMA. The authors are thankful to Dr. G. Rousse for the help on Rietveld refinements. ; Approved Most recent IF: 9.466
Call Number UA @ lucian @ c:irua:148530 Serial 4899
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Author (up) Pinheiro, C.B.; Abakumov, A.M.
Title Superspace crystallography : a key to the chemistry and properties Type A1 Journal article
Year 2015 Publication IUCrJ Abbreviated Journal Iucrj
Volume 2 Issue 2 Pages 137-154
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract An overview is given of the recent advances in the field of modulated molecular and inorganic crystals with an emphasis on the links between incommensurability, intermolecular and interatomic interactions and, wherever possible, the properties of the materials. The importance of detailed knowledge on the modulated structure for understanding the crystal chemistry and the functional properties of modulated phases is shown using selected examples of incommensurate modulations in organic molecular compounds and inorganic complex oxides.
Address
Corporate Author Thesis
Publisher Int union crystallography Place of Publication Chester Editor
Language Wos 000356865900016 Publication Date 2014-12-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2052-2525; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.793 Times cited 15 Open Access
Notes Approved Most recent IF: 5.793; 2015 IF: NA
Call Number c:irua:127058 Serial 3382
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Author (up) Prituzhalov, V.A.; Abakumov, A.M.; Ardashnikova, E.I.; Dolgikh, V.A.; Van Tendeloo, G.
Title :Ba2.1Bi0.9(O, F)6.8-\delta: a new ordered anion-excess fluorite Type A1 Journal article
Year 2007 Publication Materials research bulletin Abbreviated Journal Mater Res Bull
Volume 42 Issue 5 Pages 861-869
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000245842600010 Publication Date 2006-10-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0025-5408; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.446 Times cited 4 Open Access
Notes Approved Most recent IF: 2.446; 2007 IF: 1.484
Call Number UA @ lucian @ c:irua:64724 Serial 3515
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Author (up) Prituzhalov, V.A.; Ardashnikova, E.I.; Vinogradov, A.A.; Dolgikh, V.A.; Videau, J.-J.; Fargin, E.; Abakumov, A.M.; Tarakina, N.V.; Van Tendeloo, G.
Title New anion-conducting solid solutions Bi1-xTex(O,F)2+\delta (x > 0.5) and glassceramic material on their base Type A1 Journal article
Year 2011 Publication Journal of fluorine chemistry Abbreviated Journal J Fluorine Chem
Volume 132 Issue 12 Pages 1110-1116
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The anion-excess fluorite-like solid solutions with general composition Bi1−xTex(O,F)2+δ (x > 0.5) have been synthesized by a solid state reaction of TeO2, BiF3 and Bi2O3 at 873 K with following quenching. The homogeneity areas and polymorphism of the I ↔ IV Bi1−xTex(O,F)2+δ phases were investigated. The crystal structure of the low temperature IV-Bi1−xTex(O,F)2+δ phase has been solved using electron diffraction and X-ray powder diffraction (a = 11.53051(9) Å, S.G. Ia-3, RI = 0.046, RP = 0.041). Glass formation area in the Bi2O3BiF3TeO2 (10% TiO2) system was investigated. IVBi1−xTex(O,F)2+δ phase starts to crystallize at short-time (0.53 h) annealing of oxyfluoride glasses at temperatures above Tg (600615 K). The ionic conductivity of the crystalline Bi1−xTex(O,F)2+δ phase and corresponding glass-ceramics was investigated. Activation energy of conductivity Ea = 0.41(2) eV for the IV-Bi1−xTex(O,F)2+δ crystalline samples and Ea = 0.73 eV for the glass-ceramic samples were obtained. Investigation of the oxyfluoride samples with a constant cation ratio demonstrates essential influence of excess fluorine anions on the ionic conductivity.
Address
Corporate Author Thesis
Publisher Place of Publication Lausanne Editor
Language Wos 000296936300011 Publication Date 2011-07-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-1139; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.101 Times cited 2 Open Access
Notes Approved Most recent IF: 2.101; 2011 IF: 2.033
Call Number UA @ lucian @ c:irua:93687 Serial 2305
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