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Author Hadermann, J.; Abakumov, A.M.; Van Rompaey, S.; Mankevich, A.S.; Korsakov, I.E. doi  openurl
  Title Comment on ALaMn2O6-y (A = K, Rb): novel ferromagnetic manganites exhibiting negative giant magnetoresistance Type Editorial
  Year 2009 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 21 Issue 9 Pages 2000-2001  
  Keywords Editorial; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000265781000036 Publication Date 2009-04-14  
  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 4 Open Access  
  Notes Approved Most recent IF: 9.466; 2009 IF: 5.368  
  Call Number UA @ lucian @ c:irua:77055 Serial 411  
Permanent link to this record
 

 
Author Hadermann, J.; Abakumov, A.M.; Gillie, L.J.; Martin, C.; Hervieu, M. pdf  doi
openurl 
  Title Coupled cation and charge ordering in the CaMn306 tunnel structure Type A1 Journal article
  Year 2006 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 18 Issue 23 Pages 5530-5536  
  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 000241808600021 Publication Date 2006-10-15  
  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 33 Open Access  
  Notes Iap V-1 Approved Most recent IF: 9.466; 2006 IF: 5.104  
  Call Number UA @ lucian @ c:irua:61374 Serial 534  
Permanent link to this record
 

 
Author Morozov, V.A.; Raskina, M.V.; Lazoryak, B.I.; Meert, K.W.; Korthout, K.; Smet, P.F.; Poelman, D.; Gauquelin, N.; Verbeeck, J.; Abakumov, A.M.; Hadermann, J.; pdf  doi
openurl 
  Title Crystal Structure and Luminescent Properties of R2-xEux(MoO4)(3) (R = Gd, Sm) Red Phosphors Type A1 Journal article
  Year 2014 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 26 Issue 24 Pages 7124-7136  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The R-2(MoO4)(3) (R = rare earth elements) molybdates doped with Eu3+ cations are interesting red-emitting materials for display and solid-state lighting applications. The structure and luminescent properties of the R2-xEux(MoO4)(3) (R = Gd, Sm) solid solutions have been investigated as a function of chemical composition and preparation conditions. Monoclinic (alpha) and orthorhombic (beta') R2-xEux(MoO4)(3) (R = Gd, Sm; 0 <= x <= 2) modifications were prepared by solid-state reaction, and their structures were investigated using synchrotron powder X-ray diffraction and transmission electron microscopy. The pure orthorhombic beta'-phases could be synthesized only by quenching from high temperature to room temperature for Gd2-xEux(MoO4)(3) in the Eu3+-rich part (x > 1) and for all Sm2-xEux(MoO4)(3) solid solutions. The transformation from the alpha-phase to the beta'-phase results in a notable increase (similar to 24%) of the unit cell volume for all R2-xEux(MoO4)(3) (R = Sm, Gd) solid solutions. The luminescent properties of all R2-xEux(MoO4)(3) (R = Gd, Sm; 0 <= x <= 2) solid solutions were measured, and their optical properties were related to their structural properties. All R2-xEux(MoO4)(3) (R = Gd, Sm; 0 <= x <= 2) phosphors emit intense red light dominated by the D-5(0)-> F-7(2) transition at similar to 616 nm. However, a change in the multiplet splitting is observed when switching from the monoclinic to the orthorhombic structure, as a consequence of the change in coordination polyhedron of the luminescent ion from RO8 to RO7 for the alpha- and beta'-modification, respectively. The Gd2-xEux(MoO4)(3) solid solutions are the most efficient emitters in the range of 0 < x < 1.5, but their emission intensity is comparable to or even significantly lower than that of Sm2-xEux(MoO4)(3) for higher Eu3+ concentrations (1.5 <= x <= 1.75). Electron energy loss spectroscopy (EELS) measurements revealed the influence of the structure and element content on the number and positions of bands in the ultraviolet-visible-infrared regions of the EELS spectrum.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000347139700027 Publication Date 2014-11-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 9.466 Times cited 24 Open Access  
  Notes Fwo G039211n; G004413n; 278510 Vortex ECASJO_; Approved Most recent IF: 9.466; 2014 IF: 8.354  
  Call Number UA @ lucian @ c:irua:122829UA @ admin @ c:irua:122829 Serial 558  
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Author Abakumov, A.M.; Erni, R.; Tsirlin, A.A.; Rossell, M.D.; Batuk, D.; Nénert, G.; Van Tendeloo, G. pdf  doi
openurl 
  Title Frustrated octahedral tilting distortion in the incommensurately modulated Li3xNd2/3-xTiO3 perovskites Type A1 Journal article
  Year 2013 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 25 Issue 13 Pages 2670-2683  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Perovskite-structured titanates with layered A-site ordering form remarkably complex superstructures. Using transmission electron microscopy, synchrotron X-ray and neutron powder diffraction, and ab initio structure relaxation, we present the structural solution of the incommensurately modulated Li3xNd2/3xTiO3 perovskites (x = 0.05, superspace group Pmmm(α1,1/2,0)000(1/2,β2 0)000, a = 3.831048(5) Å, b = 3.827977(4) Å, c = 7.724356(8) Å, q1 = 0.45131(8)a* + 1/2b*, q2 = 1/2a* + 0.41923(4)b*). In contrast to earlier conjectures on the nanoscale compositional phase separation in these materials, all peculiarities of the superstructure can be understood in terms of displacive modulations related to an intricate octahedral tilting pattern. It involves fragmenting the pattern of the out-of-phase tilted TiO6 octahedra around the a- and b-axes into antiphase domains, superimposed on the pattern of domains with either pronounced or suppressed in-phase tilt component around the c-axis. The octahedral tilting competes with the second order JahnTeller distortion of the TiO6 octahedra. This competition is considered as the primary driving force for the modulated structure. The A cations are suspected to play a role in this modulation affecting it mainly through the tolerance factor and the size variance. The reported crystal structure calls for a revision of the structure models proposed for the family of layered A-site ordered perovskites exhibiting a similar type of modulated structure.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000321809700015 Publication Date 2013-06-04  
  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 23 Open Access  
  Notes Countatoms Approved Most recent IF: 9.466; 2013 IF: 8.535  
  Call Number UA @ lucian @ c:irua:109216 Serial 1292  
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Author Morozov, V.A.; Bertha, A.; Meert, K.W.; Van Rompaey, S.; Batuk, D.; Martinez, G.T.; Van Aert, S.; Smet, P.F.; Raskina, M.V.; Poelman, D.; Abakumov, A.M.; Hadermann, J.; doi  openurl
  Title Incommensurate modulation and luminescence in the CaGd2(1-x)Eu2x(MoO4)4(1-y)(WO)4y (0\leq x\leq1, 0\leq y\leq1) red phosphors Type A1 Journal article
  Year 2013 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 25 Issue 21 Pages 4387-4395  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Scheelite related compounds (A',A '') [(B',B '')O-4], with B', B '' = W and/or Mo are promising new light-emitting materials for photonic applications, including phosphor converted LEDs (light-emitting diodes). In this paper, 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 luminescent properties. CaGd2(1-x)Eu2x(MoO4)(4(1-y))(WO4)(4y) (0 <= x <= 1, 0 <= y <= 1) solid solutions with scheelite-type structure were synthesized by a solid state method, and their structures were investigated using a combination of transmission electron microscopy techniques and powder X-ray diffraction. Within this series all complex molybdenum oxides have (3 + 2)D incommensurately modulated structures with superspace group I4(1)/a(alpha,beta,0)00(-beta,alpha,0)00, while the structures of all tungstates are (3 + 1)D incommensurately modulated with superspace group I2/b(alpha beta 0)00. In both cases the modulation arises because of cation-vacancy ordering at the A site. The prominent structural motif is formed by columns of A-site vacancies running along the c-axis. These vacant columns occur in rows of two or three aligned along the [110] direction of the scheelite subcell. The replacement of the smaller Gd3+ by the larger Eu3+ at the A-sublattice does not affect the nature of the incommensurate modulation, but an increasing replacement of Mo6+ by W6+ switches the modulation from (3 + 2)D to (3 + 1)D regime. Thus, these solid solutions can be considered as a model system where the incommensurate modulation can be monitored as a function of cation nature while the number of cation vacancies at the A sites remain constant upon the isovalent cation replacement. All compounds' luminescent properties were measured, and the optical properties were related to the structural properties of the materials. CaGd2(1-x)(MoO4)(4(1-y))(WO4)(4y) phosphors emit intense red light dominated by the D-5(0)-F-7(2) transition at 612 nm, along with other transitions from the D-5(1) and D-5(0) excited states. The intensity of the 5D0-7F2 transition reaches a maximum at x = 0.5 for y = 0 and 1.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000327045000030 Publication Date 2013-09-24  
  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 63 Open Access  
  Notes Approved Most recent IF: 9.466; 2013 IF: 8.535  
  Call Number UA @ lucian @ c:irua:112776 Serial 1594  
Permanent link to this record
 

 
Author Batuk, M.; Batuk, D.; Tsirlin, A.A.; Filimonov, D.S.; Sheptyakov, D.V.; Frontzek, M.; Hadermann, J.; Abakumov, A.M. pdf  doi
openurl 
  Title Layered oxychlorides [PbBiO2]An+1BnO3n-1Cl2(A = Pb/Bi, B = Fe/Ti) : intergrowth of the hematophanite and sillen phases Type A1 Journal article
  Year 2015 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 27 Issue 27 Pages 2946-2956  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract New layered structures corresponding to the general formula [PbBiO2]A(n+1)B(n)O(3n-1)Cl(2) Were prepared. Pb5BiFe3O10Cl2 (n = 3) and Pb5Bi2Fe4O13Cl2 (n = 4) are built as a stacking of truncated A(n+1)B(n)O(3n-1) perovskite blocks and alpha-PbO-type [A(2)O(2)](2+) (A = Pb, Bi) blocks combined with chlorine sheets. The alternation of these structural blocks can be represented as an intergrowth between the hematophanite and Sullen-type structural blocks. The crystal and-Magnetic structures of Pb5BiFe3O10Cl2 and Pb5Bi2Fe4O13Cl2 were investigated in the temperature range of 1.5-700 K using X-ray and neutron powder diffraction, transmission electron microscopy and Fe-57 Mossbauer spectroscopy. Both compounds crystallize in the I4/mmm space group with the unit cell parameters a approximate to a(p) approximate to 3.92 angstrom (a unit-cell parameter of the perovskite-structure), c approximate to 43.0 angstrom for the n = 3 member and c approximate to 53.5 angstrom for the n = 4 member. Despite the large separation between the slabs containing the Fe3+ ions (nearly 14 angstrom), long-range antiferromagnetic order sets in below similar to 600 K with the G-type arrangement of the Fe magnetic moments aligned along the c-axis. The possibility of mixing d(0) and d(n) cations at the B sublattice of these structures was also demonstrated by preparing the Ti-substituted n = 4 member Pb6BiFe3TiO13Cl2.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000353865800028 Publication Date 2015-03-26  
  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 11 Open Access  
  Notes Approved Most recent IF: 9.466; 2015 IF: 8.354  
  Call Number c:irua:126060 Serial 1807  
Permanent link to this record
 

 
Author Dachraoui, W.; Hadermann, J.; Abakumov, A.M.; Tsirlin, A.A.; Batuk, D.; Glazyrin, K.; McCammon, C.; Dubrovinsky, L.; Van Tendeloo, G. pdf  doi
openurl 
  Title Local oxygen-vacancy ordering and twinned octahedral tilting pattern in the Bi0.81Pb0.19FeO2.905 cubic perovskite Type A1 Journal article
  Year 2012 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 24 Issue 7 Pages 1378-1385  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The structure of Bi0.81Pb0.19FeO2.905 was investigated on different length scales using a combination of electron diffraction, high-resolution scanning transmission electron microscopy, synchrotron X-ray powder diffraction, and Mössbauer spectroscopy. In the 80300 K temperature range, the average crystal structure of Bi0.81Pb0.19FeO2.905 is a cubic Pm3̅m perovskite with a = 3.95368(3) Å at T = 300 K. The (Pb2+, Bi3+) cations and O2 anions are randomly displaced along the 110 cubic directions, indicating the steric activity of the lone pair on the Pb2+ and Bi3+ cations and a tilting distortion of the perovskite framework. The charge imbalance induced by the heterovalent Bi3+ → Pb2+ substitution is compensated by the formation of oxygen vacancies preserving the trivalent state of the Fe cations. On a short scale, oxygen vacancies are located in anion-deficient (FeO1.25) layers that are approximately 6 perovskite unit cells apart and transform every sixth layer of the FeO6 octahedra into a layer with a 1:1 mixture of corner-sharing FeO4 tetrahedra and FeO5 tetragonal pyramids. The anion-deficient layers act as twin planes for the octahedral tilting pattern of adjacent perovskite blocks. They effectively randomize the octahedral tilting and prevent the cooperative distortion of the perovskite framework. The disorder in the anion sublattice impedes cooperative interactions of the local dipoles induced by the off-center displacements of the Pb and Bi cations. Magnetic susceptibility measurements evidence the antiferromagnetic ordering in Bi0.81Pb0.19FeO2.905 at low temperatures.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000302487500018 Publication Date 2012-03-13  
  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 27 Open Access  
  Notes Approved Most recent IF: 9.466; 2012 IF: 8.238  
  Call Number UA @ lucian @ c:irua:97389 Serial 1829  
Permanent link to this record
 

 
Author Abakumov, A.M.; Tsirlin, A.A.; Bakaimi, I.; Van Tendeloo, G.; Lappas, A. doi  openurl
  Title Multiple twinning as a structure directing mechanism in layered rock-salt-type oxides : NaMnO2 polymorphism, redox potentials, and magnetism Type A1 Journal article
  Year 2014 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 26 Issue 10 Pages 3306-3315  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract New polymorphs of NaMnO2 have been observed using transmission electron microscopy and synchrotron X-ray powder diffraction. Coherent twin planes confined to the (NaMnO2) layers, parallel to the (10 (1) over bar) crystallographic planes of the monoclinic layered rock-salt-type alpha-NaMnO2 (O3) structure, form quasi-periodic modulated sequences, with the known alpha-and beta-NaMnO2 polymorphs as the two limiting cases. The energy difference between the polymorphic forms, estimated using a DFT-based structure relaxation, is on the scale of the typical thermal energies that results in a high degree of stacking disorder in these compounds. The results unveil the remarkable effect of the twin planes on both the magnetic and electrochemical properties. The polymorphism drives the magnetic ground state from a quasi-1D spin system for the geometrically frustrated alpha-polymorph through a two-leg spin ladder for the intermediate stacking sequence toward a quasi-2D magnet for the beta-polymorph. A substantial increase of the equilibrium potential for Na deintercalation upon increasing the concentration of the twin planes is calculated, providing a possibility to tune the electrochemical potential of the layered rock-salt ABO(2) cathodes by engineering the materials with a controlled concentration of twins.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000336637000036 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 35 Open Access  
  Notes Approved Most recent IF: 9.466; 2014 IF: 8.354  
  Call Number UA @ lucian @ c:irua:117766 Serial 2232  
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Author Caignaert, V.; Abakumov, A.M.; Pelloquin, D.; Pralong, V.; Maignan, A.; Van Tendeloo, G.; Raveau, B. pdf  doi
openurl 
  Title A new mixed-valence ferrite with a cubic structure, YBaFe4O7: spin-glass-like behavior Type A1 Journal article
  Year 2009 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 21 Issue 6 Pages 1116-1122  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract A new mixed-valence ferrite, YBaFe4O7, has been synthesized. Its unique cubic structure, with a = 8.9595(2) Å, is closely related to that of the hexagonal 114 oxides YBaCo4O7 and CaBaFe4O7. It consists of corner-sharing FeO4 tetrahedra, forming triangular and kagome layers parallel to (111)C. In fact, the YBaFe4O7 and CaBaFe4O7 structures can be described as two different ccc and chch close packings of [BaO3]∞ and [O4]∞ layers, respectively, whose tetrahedral cavities are occupied by Fe2+/Fe3+ cations. The local structure of YBaFe4O7 is characterized by a large amount of stacking faults originating from the presence of hexagonal layers in the ccc cubic close-packed YBaFe4O7 structure. In this way, they belong to the large family of spinels and hexagonal ferrites studied for their magnetic properties. Differently from all the ferrites and especially from CaBaFe4O7, which are ferrimagnetic, YBaFe4O7 is an insulating spin glass with Tg = 50 K.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000264310900019 Publication Date 2009-02-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 9.466 Times cited 39 Open Access  
  Notes Esteem 026019 Approved Most recent IF: 9.466; 2009 IF: 5.368  
  Call Number UA @ lucian @ c:irua:76432 Serial 2325  
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Author Abakumov, A.M.; Erni, R.; Tsirlin, A.A. doi  openurl
  Title Reply to Comment on “Frustrated octahedral tilting distortion in the incommensurately modulated Li3xNd2/3-xTiO3 perovskites” Type Editorial
  Year 2014 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 26 Issue 2 Pages 1288  
  Keywords Editorial; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000330543600051 Publication Date 2014-01-03  
  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 1 Open Access  
  Notes Approved Most recent IF: 9.466; 2014 IF: 8.354  
  Call Number UA @ lucian @ c:irua:115730 Serial 2874  
Permanent link to this record
 

 
Author Hadermann, J.; Abakumov, A.M.; Turner, S.; Hafideddine, Z.; Khasanova, N.R.; Antipov, E.V.; Van Tendeloo, G. pdf  doi
openurl 
  Title Solving the structure of Li ion battery materials with precession electron diffraction : application to Li2CoPo4F Type A1 Journal article
  Year 2011 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 23 Issue 15 Pages 3540-3545  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The crystal structure of the Li2CoPO4F high-voltage cathode for Li ion rechargeable batteries has been completely solved from precession electron diffraction (PED) data, including the location of the Li atoms. The crystal structure consists of infinite chains of CoO4F2 octahedra sharing common edges and linked into a 3D framework by PO4 tetrahedra. The chains and phosphate anions together delimit tunnels filled with the Li atoms. This investigation demonstrates that PED can be successfully applied for obtaining structural information on a variety of Li-containing electrode materials even from single micrometer-sized crystallites.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000293357100019 Publication Date 2011-07-11  
  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 Fwo; Bof Approved Most recent IF: 9.466; 2011 IF: 7.286  
  Call Number UA @ lucian @ c:irua:90357 Serial 3053  
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Author Rusakov, D.; Abakumov, A.M.; Yamaura, K.; Belik, A.A.; Van Tendeloo, G.; Takayama-Muromachi, E. doi  openurl
  Title Structural evolution of the BiFeO3-LaFeO3 system Type A1 Journal article
  Year 2011 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 23 Issue 2 Pages 285-292  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The (1 − x)BiFeO3−xLaFeO3 system has been investigated and characterized by room-temperature and high-temperature laboratory and synchrotron powder X-ray diffraction, electron diffraction, high-resolution transmission electron microscopy, differential scanning calorimetry, and magnetization measurements. At room temperature, the ferroelectric R3c phase is observed for 0.0 ≤ x ≤ 0.10. The PbZrO3-related √2ap × 2√2ap × 4ap superstructure (where ap is the parameter of the cubic perovskite subcell) is observed for Bi0.82La0.18FeO3, while an incommensurately modulated phase is formed for 0.19 ≤ x ≤ 0.30 with the √2ap × 2ap × √2ap basic unit cell. The GdFeO3-type phase with space group Pnma (√2ap × 2ap × √2ap) is stable at 0.50 ≤ x ≤ 1. Bi0.82La0.18FeO3 has no detectable homogeneity range (space group Pnam, a = 5.6004(1) Å, b = 11.2493(3) Å, c = 15.6179(3) Å). The incommensurately modulated Bi0.75La0.25FeO3 structure was solved from synchrotron X-ray powder diffraction data (Imma(00γ)s00 superspace group, a = 5.5956(1) Å, b = 7.8171(1) Å, c = 5.62055(8) Å, q = 0.4855(4)c*, RP = 0.023, RwP = 0.033). In this structure, cooperative displacements of the Bi and O atoms occur, which order within the (AO) (where A = Bi, La) layers, resulting in an antipolar structure. Local fluctuations of the intralayer antipolar ordering are compensated by an interaction with the neighboring (AO) layers. A coupling of the antipolar displacements with the cooperative tilting distortion of the perovskite octahedral framework is proposed as the origin of the incommensurability. All the phases transform to the GdFeO3-type structure at high temperatures. Bi0.82La0.18FeO3 shows an intermediate PbZrO3-type phase with √2ap × 2√2ap × 2ap (space group Pbam; a = 5.6154(2) Å, b = 11.2710(4) Å, and c = 7.8248(2) Å at 570 K). The compounds in the compositional range of 0.18 ≤ x ≤ 0.95 are canted antiferromagnets.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000286160800021 Publication Date 2010-12-23  
  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 133 Open Access  
  Notes Approved Most recent IF: 9.466; 2011 IF: 7.286  
  Call Number UA @ lucian @ c:irua:88650 Serial 3236  
Permanent link to this record
 

 
Author Abakumov, A.M.; Rossell, M.D.; Gutnikova, O.Y.; Drozhzhin, O.A.; Leonova, L.S.; Dobrovolsky, Y.A.; Istomin, S.Y.; Van Tendeloo, G.; Antipov, E.V. pdf  doi
openurl 
  Title Superspace description, crystal structures, and electric conductiof the Ba4In6-xMgxO13-x/2 solid solutions Type A1 Journal article
  Year 2008 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 20 Issue 13 Pages 4457-4467  
  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 000257279200041 Publication Date 2008-06-18  
  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 15 Open Access  
  Notes Approved Most recent IF: 9.466; 2008 IF: 5.046  
  Call Number UA @ lucian @ c:irua:70141 Serial 3383  
Permanent link to this record
 

 
Author Abakumov, A.M.; Rozova, M.G.; Antipov, E.V.; Hadermann, J.; Van Tendeloo, G.; Lobanov, M.V.; Greenblatt, M.; Croft, M.; Tsiper, E.V.; Llobet, A.; Lokshin, K.A.; Zhao, Y. pdf  doi
openurl 
  Title Synthesis, cation ordering, and magnetic properties of the (Sb1-xPbx)2(Mn1-ySby)O4 solid solutions with the Sb2MnO4-type structure Type A1 Journal article
  Year 2005 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 17 Issue Pages 1123-1134  
  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 000227421300029 Publication Date 2005-03-01  
  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 16 Open Access  
  Notes Iap V-1 Approved Most recent IF: 9.466; 2005 IF: 4.818  
  Call Number UA @ lucian @ c:irua:51440 Serial 3446  
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Author Mandal, T.K.; Abakumov, A.M.; Hadermann, J.; Van Tendeloo, G.; Croft, M.; Greenblatt, M. pdf  doi
openurl 
  Title Synthesis, crystal structure, and magnetic properties of Srl.31Co0.63Mn0.3703: a reivative of the incommensurate composite hexagonal perovskite structure Type A1 Journal article
  Year 2007 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 19 Issue 25 Pages 6158-6167  
  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 000251422000019 Publication Date 2007-11-13  
  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 5 Open Access  
  Notes Approved Most recent IF: 9.466; 2007 IF: 4.883  
  Call Number UA @ lucian @ c:irua:67597 Serial 3449  
Permanent link to this record
 

 
Author d' Hondt, H.; Abakumov, A.M.; Hadermann, J.; Kalyuzhnaya, A.S.; Rozova, M.G.; Antipov, E.V.; Van Tendeloo, G. pdf  doi
openurl 
  Title Tetrahedral chain order in the Sr2Fe2O5 brownmillerite Type A1 Journal article
  Year 2008 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 20 Issue 22 Pages 7188-7194  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The crystal structure of the Sr2Fe2O5 brownmillerite has been investigated using electron diffraction and high resolution electron microscopy. The Sr2Fe2O5 structure demonstrates two-dimensional order: the tetrahedral chains with two mirror-related configurations (L and R) are arranged within the tetrahedral layers according to the −L−R−L−R− sequence, and the layers themselves are displaced with respect to each other over 1/2[111] or 1/2[11] vectors of the brownmillerite unit cell, resulting in different ordered stacking variants. A unified superspace model is constructed for ordered stacking sequences in brownmillerites based on the average brownmillerite structure with a = 5.5298(4)Å, b = 15.5875(12)Å, c = 5.6687(4)Å, and (3 + 1)-dimensional superspace group I2/m(0βγ)0s, q = βb* + γc*, 0 ≤ β ≤ 1/2, 0 ≤ γ ≤ 1.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000261002200039 Publication Date 2008-10-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 9.466 Times cited 64 Open Access  
  Notes Iap Vi Approved Most recent IF: 9.466; 2008 IF: 5.046  
  Call Number UA @ lucian @ c:irua:72945 Serial 3511  
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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. pdf  url
doi  openurl
  Title KEu(MoO4)2 : polymorphism, structures, and luminescent properties Type A1 Journal article
  Year 2015 Publication (up) 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.  
  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 Sun, M.; Rousse, G.; Abakumov, A.M.; Saubanere, M.; Doublet, M.-L.; Rodriguez-Carvajal, J.; Van Tendeloo, G.; Tarascon, J.-M. doi  openurl
  Title Li2Cu2O(SO4)2: a possible electrode for sustainable Li-based batteries showing a 4.7 V redox activity vs Li+/Li0 Type A1 Journal article
  Year 2015 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 27 Issue 27 Pages 3077-3087  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Li-ion batteries rely on the use of insertion positive electrodes with performances scaling with the redox potential of the 31) metals accompanying Liuptake/removal. Although not commonly studied, the Cu2+/Cu3+ redox potential has been predicted from theoretical calculations to possibly offer a high operating voltage redox couple. We herein report the synthesis and crystal structure of a hitherto-unknown oxysulfate phase, Li2Cu2O(SO4)(2), which contains infinite edgesharing CuO4 chains and presents attractive electrochemical redox activity with respect to Li+/Li, namely amphoteric characteristics. Li2Cu2O(SO4)(2) shows redox activity at 4.7 V vs Li+/Li corresponding to the oxidation of Cu2+ to Cu3+ enlisting ligand holes and associated with the reversible uptake-removal of 0.3 Li. Upon reduction, this compound reversibly uptakes similar to 2 Li at an average potential of about 2.5 V vs Li+/Li, associated with the Cu2+/Cu+ redox couple. The mechanism of the reactivity upon reduction is discussed in detail, with particular attention to the occasional appearance of an oscillation wave in the discharge profile. Our work demonstrates that Cu-based compounds can indeed be fertile scientific ground in the search for new high-energy-density electrodes.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000353865800043 Publication Date 2015-03-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 9.466 Times cited 20 Open Access  
  Notes Approved Most recent IF: 9.466; 2015 IF: 8.354  
  Call Number c:irua:126061 Serial 3541  
Permanent link to this record
 

 
Author Govorov, V.A.; Abakumov, A.M.; Rozova, M.G.; Borzenko, A.G.; Vassiliev, S.Y.; Mazin, V.M.; Afanasov, M.I.; Fabritchnyi, P.B.; Tsirlina, G.A.; Antipov, E.V.; Morozova, E.N.; Gippius, A.A.; Ivanov, V.V.; Van Tendeloo, G. pdf  doi
openurl 
  Title Sn2-2xSbxFexO4 solid solutions as possible inert anode materials in aluminum electrolysis Type A1 Journal article
  Year 2005 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 17 Issue 11 Pages 3004-3011  
  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 000229656000030 Publication Date 2005-05-24  
  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 11 Open Access  
  Notes Approved Most recent IF: 9.466; 2005 IF: 4.818  
  Call Number UA @ lucian @ c:irua:59053 Serial 3554  
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Author Abakumov, A.M.; Hadermann, J.; Van Tendeloo, G.; Kovba, M.L.; Skolis, Y.Y.; Mudretsova, S.N.; Antipov, E.V.; Volkova, O.S.; Vasiliev, A.N.; Tristan, N.; Klingeler, R.; Büchner, B. pdf  doi
openurl 
  Title [SrF0.8(OH)0.2]2.526[Mn6O12]: columnar rock-salt fragments inside the todorokite-type tunnel structure Type A1 Journal article
  Year 2007 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 19 Issue 5 Pages 1181-1189  
  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 000244467800035 Publication Date 2007-02-13  
  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 9 Open Access  
  Notes Iap V-1 Approved Most recent IF: 9.466; 2007 IF: 4.883  
  Call Number UA @ lucian @ c:irua:62525 Serial 3561  
Permanent link to this record
 

 
Author Kazakov, S.M.; Abakumov, A.M.; Perz-Mato, J.M.; Ovchinnikov, A.V.; Roslova, M.V.; Boltalin, A.I.; Morozov, I.V.; Antipov, E.V.; Van Tendeloo, G. doi  openurl
  Title Uniform patterns of Fe-vacancy ordering in the Kx(Fe,Co)2-ySe2 superconductors Type A1 Journal article
  Year 2011 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 23 Issue 19 Pages 4311-4316  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The Fe-vacancy ordering patterns in the superconducting KxFe2ySe2 and nonsuperconducting Kx(Fe,Co)2ySe2 samples have been investigated by electron diffraction and high angle annular dark field scanning transmission electron microscopy. The Fe-vacancy ordering occurs in the ab plane of the parent ThCr2Si2-type structure, demonstrating two types of patterns. Superstructure I retains the tetragonal symmetry and can be described with the aI = bI = as√5 (as is the unit cell parameter of the parent ThCr2Si2-type structure) supercell and I4/m space group. Superstructure II reduces the symmetry to orthorhombic with the aII = as√2, bII = 2as√2 supercell and the Ibam space group. This type of superstructure is observed for the first time in KxFe2ySe2. The Fe-vacancy ordering is inhomogeneous: the disordered areas interleave with the superstructures I and II in the same crystallite. The observed superstructures represent the compositionally dependent uniform ordering patterns of two species (the Fe atoms and vacancies) on a square lattice. More complex uniform ordered configurations, including compositional stripes, can be predicted for different chemical compositions of the KxFe2ySe2 (0 < y < 0.5) solid solutions.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000295487800005 Publication Date 2011-09-13  
  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 20 Open Access  
  Notes Approved Most recent IF: 9.466; 2011 IF: 7.286  
  Call Number UA @ lucian @ c:irua:92805 Serial 3810  
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Author Fedotov, S.S.; Khasanova, N.R.; Samarin, A.S.; Drozhzhin, O.A.; Batuk, D.; Karakulina, O.M.; Hadermann, J.; Abakumov, A.M.; Antipov, E.V. pdf  url
doi  openurl
  Title AVPO4F (A = Li, K): A 4 V Cathode Material for High-Power Rechargeable Batteries Type A1 Journal article
  Year 2016 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 28 Issue 28 Pages 411-415  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract A novel potassium-based fluoride-phosphate, KVPO4F, with a KTiOPO4 (KTP) type structure is synthesized and characterized. About 85% of potassium has been electrochemically extracted on oxidation producing a cathode material with attractive performance for Li-ion batteries. The material operates at the electrode potential near 4V vs Li/Li+ exhibiting a sloping voltage profile, extremely low polarization, small volume change of about 2% and excellent rate capability, maintaining more than 75% of the initial capacity at 40C discharge rate without significant fading.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000368949900002 Publication Date 2016-01-04  
  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 46 Open Access  
  Notes The authors kindly thank Dr. S. N. Putilin for XRD measurements, Dr. O. A. Shlyakhtin for the assistance in cryochemical synthesis, Ph.D. students A. A. Sadovnikov and E. A. Karpukhina for SEM imaging and FTIR spectra respectively. The work was partly supported by Russian Science Foundation (grant 16-19-00190), Skoltech Center for Electrochemical Energy Storage and Moscow State University Devel-opment Program up to 2020. J. Hadermann, O.M. Karakulina and A.M. Abakumov acknowledge support from FWO under grant G040116N. Approved Most recent IF: 9.466  
  Call Number c:irua:131583 Serial 4001  
Permanent link to this record
 

 
Author 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. pdf  url
doi  openurl
  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 (up) 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 Karakulina, O.M.; Khasanova, N.R.; Drozhzhin, O.A.; Tsirlin, A.A.; Hadermann, J.; Antipov, E.V.; Abakumov, A.M. pdf  url
doi  openurl
  Title Antisite Disorder and Bond Valence Compensation in Li2FePO4F Cathode for Li-Ion Batteries Type A1 Journal article
  Year 2016 Publication (up) Chemistry Of Materials Abbreviated Journal Chem Mater  
  Volume 28 Issue 28 Pages 7578-7581  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000387518500004 Publication Date 2016-11-08  
  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 10 Open Access  
  Notes Russian Science Foundation, 16-19-00190 ; Fonds Wetenschappelijk Onderzoek, G040116N ; Approved Most recent IF: 9.466  
  Call Number EMAT @ emat @ c:irua:139170 c:irua:138599 Serial 4320  
Permanent link to this record
 

 
Author 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. pdf  doi
openurl 
  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 (up) 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.  
  Address  
  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 Pimenta, V.; Sathiya, M.; Batuk, D.; Abakumov, A.M.; Giaume, D.; Cassaignon, S.; Larcher, D.; Tarascon, J.-M. pdf  doi
openurl 
  Title Synthesis of Li-Rich NMC : a comprehensive study Type A1 Journal article
  Year 2017 Publication (up) 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 Pearce, P.E.; Rousse, G.; Karakulina, O.M.; Hadermann, J.; Van Tendeloo, G.; Foix, D.; Fauth, F.; Abakumov, A.M.; Tarascon, J.-M. pdf  url
doi  openurl
  Title β-Na1.7IrO3: A Tridimensional Na-Ion Insertion Material with a Redox Active Oxygen Network Type A1 Journal article
  Year 2018 Publication (up) 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 Grimaud, A.; Iadecola, A.; Batuk, D.; Saubanere, M.; Abakumov, A.M.; Freeland, J.W.; Cabana, J.; Li, H.; Doublet, M.-L.; Rousse, G.; Tarascon, J.-M. pdf  doi
openurl 
  Title Chemical activity of the peroxide/oxide redox couple : case study of Ba5Ru2O11 in aqueous and organic solvents Type A1 Journal article
  Year 2018 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 30 Issue 11 Pages 3882-3893  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The finding that triggering the redox activity of oxygen ions within the lattice of transition metal oxides can boost the performances of materials used in energy storage and conversion devices such as Li-ion batteries or oxygen evolution electrocatalysts has recently spurred intensive and innovative research in the field of energy. While experimental and theoretical efforts have been critical in understanding the role of oxygen nonbonding states in the redox activity of oxygen ions, a clear picture of the redox chemistry of the oxygen species formed upon this oxidation process is still missing. This can be, in part, explained by the complexity in stabilizing and studying these species once electrochemically formed. In this work, we alleviate this difficulty by studying the phase Ba5Ru2O11, which contains peroxide O-2(2-) groups, as oxygen evolution reaction electrocatalyst and Li-ion battery material. Combining physical characterization and electrochemical measurements, we demonstrate that peroxide groups can easily be oxidized at relatively low potential, leading to the formation of gaseous dioxygen and to the instability of the oxide. Furthermore, we demonstrate that, owing to the stabilization at high energy of peroxide, the high-lying energy of the empty sigma* antibonding O-O states limits the reversibility of the electrochemical reactions when the O-2(2-)/O2- redox couple is used as redox center for Li-ion battery materials or as OER redox active sites. Overall, this work suggests that the formation of true peroxide O-2(2-) states are detrimental for transition metal oxides used as OER catalysts and Li-ion battery materials. Rather, oxygen species with O-O bond order lower than 1 would be preferred for these applications.  
  Address  
  Corporate Author Thesis  
  Publisher American Chemical Society Place of Publication Washington, D.C Editor  
  Language Wos 000435416600038 Publication Date 2018-05-21  
  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 2 Open Access Not_Open_Access  
  Notes ; We thank S. Belin of the ROCK beamline (financed by the French National Research Agency (ANR) as a part of the “Investissements d'Avenir” program, reference: ANR-10-EQPX-45; proposal no. 20160095) of synchrotron SOLEIL for her assistance during XAS measurements. Authors would also like to thank V. Nassif for her assistance on the D1B beamline. A.G, G.R, and J.-M.T. acknowledge funding from the European Research Council (ERC) (FP/2014)/ERC Grant Project 670116-ARPEMA. ; Approved Most recent IF: 9.466  
  Call Number UA @ lucian @ c:irua:151980 Serial 5016  
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Author De Sloovere, D.; Safari, M.; Elen, K.; D'Haen, J.; Drozhzhin, O.A.; Abakumov, A.M.; Simenas, M.; Banys, J.; Bekaert, J.; Partoens, B.; Van Bael, M.K.; Hardy, A. pdf  doi
openurl 
  Title Reduced Na2+xTi4O9 composite : a durable anode for sodium-ion batteries Type A1 Journal article
  Year 2018 Publication (up) Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 30 Issue 23 Pages 8521-8527  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Sodium-ion batteries (SIBs) are potential cost-effective solutions for stationary energy storage applications. Unavailability of suitable anode materials, however, is one of the important barriers to the maturity of SIBs. Here, we report a Na2+xTi4O9/C composite as a promising anode candidate for SIBs with high capacity and cycling stability. This anode is characterized by a capacity of 124 mAh g(-1) (plus 11 mAh g(-1) contributed by carbon black), an average discharge potential of 0.9 V vs Na/Na+, a good rate capability and a high stability (89% capacity retention after 250 cycles at a rate of 1 degrees C). The mechanisms of sodium insertion/deinsertion and of the formation of Na2+xTi4O9/C are investigated with the aid of various ex/in situ characterization techniques. The in situ formed carbon is necessary for the formation of the reduced sodium titanate. This synthesis method may enable the convenient synthesis of other composites of crystalline phases with amorphous carbon.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000453489300014 Publication Date 2018-11-29  
  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  
  Notes ; This work was supported by the FWO (Research Foundation Flanders, project G040116). O.A.D. and A.M.A. are grateful to the Russian Science Foundation for financial support (Grant 17-73-30006). The authors acknowledge Pieter Samyn for Raman spectroscopy, Fulya Ulu Okudur for preliminary TEM, Bart Ruttens for XRD, Hilde Pellaers for SEM, Tom Haeldermans for elemental analysis, and Karen Leyssen and Vera Meynen for physisorption measurements. ; Approved Most recent IF: 9.466  
  Call Number UA @ admin @ c:irua:156235 Serial 5227  
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Author Shevchenko, V.A.; Glazkova, I.S.; Novichkov, D.A.; Skvortsova, I.; V. Sobolev, A.; Abakumov, A.M.; Presniakov, I.A.; Drozhzhin, O.A.; V. Antipov, E. pdf  doi
openurl 
  Title Competition between the Ni and Fe redox in the O3-NaNi1/3Fe1/3Mn1/3O2 cathode material for Na-ion batteries Type A1 Journal article
  Year 2023 Publication (up) Chemistry of materials Abbreviated Journal  
  Volume 35 Issue 10 Pages 4015-4025  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Sodium-ion batteries are attracting great attention due to their low cost and abundance of sodium. The O3-type NaNi1/3Fe1/3Mn1/3O2 layered oxide material is a promising candidate for positive electrodes (cathodes) in Na-ion batteries. However, its stable electrochemical performance is restricted by the upper voltage limit of 4.0 V (vs Na/Na+), which allows for reversibly removing 0.5-0.55 Na+ per formula unit, corresponding to the capacity of 120-130 mAh.g(-1). Further reduction of sodium content inevitably accelerates capacity degradation, and this issue calls for a detailed study of the redox reactions that accompany the electrochemical (de)intercalation of a large amount of sodium. Here, we present operando and ex situ studies using powder X-ray diffraction and X-ray absorption spectroscopy combined with Fe-57 Mossbauer spectroscopy. Our approach reveals the sequence of the redox transitions that occur during the charge and discharge of O3-NaNi1/3Fe1/3Mn1/3O2. Our data show that in addition to nickel and iron cations oxidizing to M+4, a part of iron transforms into the “3 + delta” state owing to the fast electron exchange Fe3+ + Fe4+ <-> Fe4+ + Fe3+. This process freezes upon cooling the material to 35 K, producing Fe4+ cations, some of which occupy tetrahedral positions.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000985970200001 Publication Date 2023-05-04  
  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 Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:197352 Serial 9013  
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