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Author Batuk, D. openurl 
  Title Modular structures with lone electron pair cations Type Doctoral thesis
  Year 2014 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords Doctoral thesis; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Antwerpen Editor  
  Language Wos Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:116936 Serial 2162  
Permanent link to this record
 

 
Author Mikita, R.; Aharen, T.; Yamamoto, T.; Takeiri, F.; Ya, T.; Yoshimune, W.; Fujita, K.; Yoshida, S.; Tanaka, K.; Batuk, D.; Abakumov, A.M.; Brown, C.M.; Kobayashi, Y.; Kageyama, H.; pdf  doi
openurl 
  Title Topochemical nitridation with anion vacancy -assisted N3-/O2- exchange Type A1 Journal article
  Year 2016 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc  
  Volume 138 Issue 138 Pages 3211-3217  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We present how the introduction of anion vacancies in oxyhydrides enables a route to access new oxynitrides, by conducting ammonolysis of perovskite oxyhydride EuTiO3-xHx (x similar to 0.18). At 400 degrees C, similar to our studies on BaTiO3-xHx, hydride lability enables a low temperature direct ammonolysis of EUTi3.82+O-2.82/H-0.18, leading to the N3-/H--exchanged product EuTi4+O2.82No0.12 square 0.06 center dot When the ammonolysis temperature was increased up to 800 degrees C, we observed a further nitridation involving N3-/O2- exchange, yielding a fully oxidized Eu3+Ti4+O2N with the GdFeO3-type distortion (Pnma) as a metastable phase, instead of pyrochlore structure. Interestingly, the same reactions using the oxide EuTiO3 proceeded through a 1:1 exchange of N3- with O-2 only above 600 degrees C and resulted in incomplete nitridation to EuTi02.25N0.75, indicating that anion vacancies created during the initial nitridation process of EuTiO2.82H0.18 play a crucial role in promoting anion (N3-/O2-) exchange at high temperatures. Hence, by using (hydride-induced) anion-deficient precursors, we should be able to expand the accessible anion composition of perovskite oxynitrides.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000371945800055 Publication Date 2016-02-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0002-7863 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  
  Call Number UA @ lucian @ c:irua:133156 Serial 4266  
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Author Kuno, Y.; Tassel, C.; Fujita, K.; Batuk, D.; Abakumov, A.M.; Shitara, K.; Kuwabara, A.; Moriwake, H.; Watabe, D.; Ritter, C.; Brown, C.M.; Yamamoto, T.; Takeiri, F.; Abe, R.; Kobayashi, Y.; Tanaka, K.; Kageyama, H. pdf  doi
openurl 
  Title ZnTaO2N: Stabilized High-Temperature LiNbO3-type Structure Type A1 Journal article
  Year 2016 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc  
  Volume 138 Issue 138 Pages 15950-15955  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract By using a high-pressure reaction, we prepared a new oxynitride ZnTaO2N that crystallizes in a centrosymmetric (R (3) over barc) high-temperature LiNbO3-type structure (HTLN-type). The stabilization of the HTLN-type structure down to low temperatures (at least 20 K) makes it possible to investigate not only the stability of this phase, but also the phase transition to a noncentrosymmetric (R3c) LiNbO3-type structure (LN-type) which is yet to be clarified. Synchrotron and neutron diffraction studies in combination with transmission electron microscopy show that Zn is located at a disordered 12c site instead of 6a, implying an order disorder mechanism of the phase transition. It is found that the dosed d-shell of Zn2+, as well as the high-valent Ta5+ ion, is responsible for the stabilization of the HTLN-type structure, affording a novel quasitriangular ZnO2N coordination. Interestingly, only 3% Zn substitution for MnTaO2N induces a phase transition from LN- to HTLN-type structure, implying the proximity in energy between the two structural types, which is supported by the first-principles calculations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000389962800032 Publication Date 2016-11-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0002-7863 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 13.858 Times cited 13 Open Access  
  Notes Approved Most recent IF: 13.858  
  Call Number UA @ lucian @ c:irua:140298 Serial 4452  
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Author 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. url  doi
openurl 
  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 (up) 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 Batuk, D.; Tsirlin, A.A.; Filimonov, D.S.; Zakharov, K.V.; Volkova, O.S.; Vasiliev, A.; Hadermann, J.; Abakumov, A.M. pdf  doi
openurl 
  Title Bi(3n+1)Ti7Fe(3n-3)O(9n+11) Homologous Series: Slicing Perovskite Structure with Planar Interfaces Containing Anatase-like Chains Type A1 Journal article
  Year 2016 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 55 Issue 55 Pages 1245-1257  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The n = 3-6 members of a new perovskite-based homologous series Bi(3n+1)Ti7Fe(3n-3)O(9n+11) are reported. The crystal structure of the n = 3 Bi10Ti7Fe6O38 member is refined using a combination of X-ray and neutron powder diffraction data (a = 11.8511(2) A, b = 3.85076(4) A, c = 33.0722(6) A, S.G. Immm), unveiling the partially ordered distribution of Ti(4+) and Fe(3+) cations and indicating the presence of static random displacements of the Bi and O atoms. All Bi(3n+1)Ti7Fe(3n-3)O(9n+11) structures are composed of perovskite blocks separated by translational interfaces parallel to the (001)p perovskite planes. The thickness of the perovskite blocks increases with n, while the atomic arrangement at the interfaces remains the same. The interfaces comprise chains of double edge-sharing (Fe,Ti)O6 octahedra connected to the octahedra of the perovskite blocks by sharing edges and corners. This configuration shifts the adjacent perovskite blocks relative to each other over a vector (1/2)[110]p and creates S-shaped tunnels along the [010] direction. The tunnels accommodate double columns of the Bi(3+) cations, which stabilize the interfaces owing to the stereochemical activity of their lone electron pairs. The Bi(3n+1)Ti7Fe(3n-3)O(9n+11) structures can be formally considered either as intergrowths of perovskite modules and polysynthetically twinned modules of the Bi2Ti4O11 structure or as intergrowths of the 2D perovskite and 1D anatase fragments. Transmission electron microscopy (TEM) on Bi10Ti7Fe6O38 reveals that static atomic displacements of Bi and O inside the perovskite blocks are not completely random; they are cooperative, yet only short-range ordered. According to TEM, the interfaces can be laterally shifted with respect to each other over +/-1/3a, introducing an additional degree of disorder. Bi10Ti7Fe6O38 is paramagnetic in the 1.5-1000 K temperature range due to dilution of the magnetic Fe(3+) cations with nonmagnetic Ti(4+). The n = 3, 4 compounds demonstrate a high dielectric constant of 70-165 at room temperature.  
  Address Center for Electrochemical Energy Storage, Skolkovo Institute of Science and Technology , Nobelya str. 3, 143026 Moscow, Russia  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Wos 000369356800031 Publication Date 2016-01-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0020-1669 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.857 Times cited 3 Open Access  
  Notes We are grateful to the Laboratory for Neutron Scattering and Imaging of Paul Scherrer Institut (LNS PSI, Villigen, Switzerland) for granting beam time at the HRPT diffrac- tometer and to Dr. Denis Sheptyakov for the technical support during the experiment. We are also grateful to Valery Verchenko for his help with magnetization measurements. The work has been supported by the Russian Science Foundation (grant 14-13-00680). A.A.T. was partly supported by the Federal Ministry for Education and Science through a Sofja Kovalevskaya Award of Alexander von Humboldt Foundation. Approved Most recent IF: 4.857  
  Call Number c:irua:132247 Serial 4073  
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Author 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. pdf  url
doi  openurl
  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.  
  Address  
  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 (up) 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 Cassidy, S.J.; Batuk, M.; Batuk, D.; Hadermann, J.; Woodruff, D.N.; Thompson, A.L.; Clarke, S.J. pdf  doi
openurl 
  Title Complex Microstructure and Magnetism in Polymorphic CaFeSeO Type A1 Journal article
  Year 2016 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 55 Issue 55 Pages 10714-10726  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The structural complexity of the antiferromagnetic oxide selenide CaFeSeO is described. The compound contains puckered FeSeO layers composed of FeSe2O2 tetrahedra sharing all their vertexes. Two polymorphs coexist that can be derived from an archetype BaZnSO structure by cooperative tilting of the FeSe2O2 tetrahedra. The polymorphs differ in the relative arrangement of the puckered layers of vertex-linked FeSe2O2 tetrahedra. In a noncentrosymmetric Cmc21 polymorph (a = 3.89684(2) A, b = 13.22054(8) A, c = 5.93625(2) A) the layers are related by the C-centering translation, while in a centrosymmetric Pmcn polymorph, with a similar cell metric (a = 3.89557(6) A, b = 13.2237(6) A, c = 5.9363(3) A), the layers are related by inversion. The compound shows long-range antiferromagnetic order below a Neel temperature of 159(1) K with both polymorphs showing antiferromagnetic coupling via Fe-O-Fe linkages and ferromagnetic coupling via Fe-Se-Fe linkages within the FeSeO layers. The magnetic susceptibility also shows evidence for weak ferromagnetism which is modeled in the refinements of the magnetic structure as arising from an uncompensated spin canting in the noncentrosymmetric polymorph. There is also a spin glass component to the magnetism which likely arises from the disordered regions of the structure evident in the transmission electron microscopy.  
  Address Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford , South Parks Road, Oxford OX1 3QR, United Kingdom  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Wos 000385785700085 Publication Date 2016-10-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0020-1669 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.857 Times cited 6 Open Access  
  Notes We acknowledge the financial support of the EPSRC (Grants EP/I017844/1 and EP/M020517/1), the Leverhulme Trust (RPG-2014-221), and the Diamond Light Source (studentship support for S. J. Cassidy). We thank the ESTEEM2 network for enabling the electron microscopy investigations and the ISIS facility and the Diamond Light Source Ltd. for the award of beam time. We thank Dr. P. Manuel for assistance on WISH, Dr. R. I. Smith for assistance on GEM and POLARIS, and Dr. C. Murray and Dr. A. Baker for assistance on I11. Approved Most recent IF: 4.857  
  Call Number EMAT @ emat @ c:irua:136823 Serial 4312  
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Author Batuk, D.; Batuk, M.; Filimonov, D.S.; Zakharov, K.V.; Volkova, O.S.; Vasiliev, A.N.; Tyablikov, O.A.; Hadermann, J.; Abakumov, A.M. pdf  doi
openurl 
  Title Crystal Structure, Defects, Magnetic and Dielectric Properties of the Layered Bi3n+1Ti7Fe3n-3,O9n+11 Perovskite-Anatase lntergrowths Type A1 Journal article
  Year 2017 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 56 Issue 56 Pages 931-942  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The Bi3n+1Ti7Fe3n-3,O9n+11 materials are built of (001)(p) plane parallel perovskite blocks with a thickness of n (Ti,Fe)O-6 octahedra, separated by periodic translational interfaces. The interfaces are based on anatase-like chains of edge -sharing (Ti,Fe)O-6 octahedra. Together with the octahedra of the perovskite blocks, they create S-shaped tunnels stabilized by lone pair Bi3+ cations. In this work, the structure of the n = 4-6 Bi3n+1Ti7Fe3n-3,O9n+11 homologues is analyzed in detail using advanced transmission electron microscopy, powder X-ray diffraction, and Mossbauer spectroscopy. The connectivity of the anatase-like chains to the perovskite blocks results in,a 3ap periodicity along the interfaces, so that they can be located either on top of each other or with shifts of +/- a(p) along [100](p). The ordered arrangement of the interfaces gives rise to orthorhombic Immm and monoclinic A2/m polymorphs with the unit cell parameters a = 3a(p), b = b(p), c = 2(n + 1)c(p) and a = 3a(p), b = b(p), c = 2(n + 1)c(p) – a(p), respectively. While the n = 3 compound is orthorhombic, the monoclinic modification is more favorable in higher homologues. The Bi3n+1Ti7Fe3n-3,O9n+11 structures demonstrate intricate patterns of atomic displacements in the perovskite blocks, which are supported by the stereochemical activity of the Bi3+ cations. These patterns are coupled to the cationic coordination of the oxygen atoms in the (Ti,Fe)O-2 layers at the border of the perovskite blocks. The coupling is strong in the 1/ = 3, 4 homologues, but gradually reduces with the increasing thickness of the perovskite blocks, so that, in the n = 6 compound, the dominant mode of atomic displacements is aligned along the interface planes. The displacements in the adjacent perovskite blocks tend to order antiparallel, resulting in an overall antipolar structure. The Bi3n+1Ti7Fe3n-3,O9n+11 materials demonstrate an unusual diversity of structure defects. The n = 4-6 homologues are robust antiferromagnets below T-N = 135, 220, and 295 K, respectively. They show a high dielectric constant that weakly increases with temperature and is relatively insensitive to the Ti/Fe ratio.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000392262400029 Publication Date 2016-12-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0020-1669 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.857 Times cited 3 Open Access Not_Open_Access  
  Notes ; The work was supported by the Russian Science Foundation (grant 14-13-00680). ; Approved Most recent IF: 4.857  
  Call Number UA @ lucian @ c:irua:141471 Serial 4495  
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Author Lander, L.; Rousse, G.; Batuk, D.; Colin, C.V.; Dalla Corte, D.A.; Tarascon, J.-M. pdf  doi
openurl 
  Title Synthesis, structure, and electrochemical properties of k-based sulfates K2M2(SO4)3) with M = Fe and Cu Type A1 Journal article
  Year 2017 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 56 Issue 4 Pages 2013-2021  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Stabilizing new host structures through potassium extraction from K-based polyanionic materials has been proven to be an interesting approach to develop new Li+/Na+ insertion materials. Pursuing the same trend, we here report the feasibility of preparing langbeinite “Fe-2(SO4)(3)” via electrochemical and chemical oxidation of K2Fe2(SO4)(3). Additionally, we succeeded in stabilizing a new K2Cu2(SO4)(3) phase via a solid-state synthesis approach. This novel compound crystallizes in a complex orthorhombic structure that differs from that of langbeinite as deduced from synchrotron X-ray and neutron powder diffraction. Electrochemically, the performance of this new phase is limited, which we explain in terms of sluggish diffusion kinetics. We further show that K2Cu2(SO4)(3) decomposes into K2Cu3O(SO4)(3) on heating, and we report for the first time the synthesis of fedotovite K2Cu3O(SO4)(3). Finally, the fundamental attractiveness of these S = 1/2 systems for physicists is examined by neutron magnetic diffraction, which reveals the absence of a long-range ordering of Cu2+ magnetic moments down to 1.5 K.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000394736600027 Publication Date 2017-01-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0020-1669 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.857 Times cited 13 Open Access Not_Open_Access  
  Notes ; We thank Matthieu Courty for performing TGA/DSC measurements. 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 DE-AC02-06CH11357 and is acknowledged. The French CRG D1B is acknowledged for allocating neutron beamtime. L.L. thanks the ANR “Hipolite” for the Ph.D. funding. ; Approved Most recent IF: 4.857  
  Call Number UA @ lucian @ c:irua:142531 Serial 4692  
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Author Batuk, M.; Turner, S.; Abakumov, A.M.; Batuk, D.; Hadermann, J.; Van Tendeloo, G. pdf  doi
openurl 
  Title Atomic structure of defects in anion-deficient perovskite-based ferrites with a crystallographic shear structure Type A1 Journal article
  Year 2014 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 53 Issue 4 Pages 2171-2180  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Crystallographic shear (CS) planes provide a new structure-generation mechanism in the anion-deficient perovskites containing lone-pair cations. Pb2Sr2Bi2Fe6O16, a new n = 6 representative of the AnBnO3n2 homologous series of the perovskite-based ferrites with the CS structure, has been synthesized using the solid-state technique. The structure is built of perovskite blocks with a thickness of four FeO6 octahedra spaced by double columns of FeO5 edge-sharing distorted tetragonal pyramids, forming 1/2[110](101)p CS planes (space group Pnma, a = 5.6690(2) Å, b = 3.9108(1) Å, c = 32.643(1) Å). Pb2Sr2Bi2Fe6O16 features a wealth of microstructural phenomena caused by the flexibility of the CS planes due to the variable ratio and length of the constituting fragments with {101}p and {001}p orientation. This leads to the formation of waves, hairpins, Γ-shaped defects, and inclusions of the hitherto unknown layered anion-deficient perovskites Bi2(Sr,Pb)Fe3O8.5 and Bi3(Sr,Pb)Fe4O11.5. Using a combination of diffraction, imaging, and spectroscopic transmission electron microscopy techniques this complex microstructure was fully characterized, including direct determination of positions, chemical composition, and coordination number of individual atomic species. The complex defect structure makes these perovskites particularly similar to the CS structures in ReO3-type oxides. The flexibility of the CS planes appears to be a specific feature of the Sr-based system, related to the geometric match between the SrO perovskite layers and the {100}p segments of the CS planes.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000332144100039 Publication Date 2014-01-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.857 Times cited 6 Open Access  
  Notes Countatoms; FWO Approved Most recent IF: 4.857; 2014 IF: 4.762  
  Call Number UA @ lucian @ c:irua:113507 Serial 198  
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Author Batuk, D.; Batuk, M.; Abakumov, A.M.; Tsirlin, A.A.; McCammon, C.M.; Dubrovinsky, L.; Hadermann, J. pdf  doi
openurl 
  Title Effect of lone-electron-pair cations on the orientation of crystallographic shear planes in anion-deficient perovskites Type A1 Journal article
  Year 2013 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 52 Issue 17 Pages 10009-10020  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Factors affecting the structure and orientation of the crystallographic shear (CS) planes in anion-deficient perovskites are investigated using the (Pb1−zSrz)1−xFe1+xO3−y perovskites as a model system. The orientation of the CS planes in the system varies unevenly with z. A comparison of the structures with different CS planes revels that the orientation of the CS planes is governed mainly by the stereochemical activity of the lone-electron-pair cations inside the perovskite blocks.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000326129000037 Publication Date 2013-08-22  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.857 Times cited 11 Open Access  
  Notes Fwo Approved Most recent IF: 4.857; 2013 IF: 4.794  
  Call Number UA @ lucian @ c:irua:111394 Serial 822  
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Author King, G.; Abakumov, A.M.; Woodward, P.M.; Llobet, A.; Tsirlin, A.A.; Batuk, D.; Antipov, E.V. doi  openurl
  Title The high-temperature polymorphs of K3AlF6 Type A1 Journal article
  Year 2011 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 50 Issue 16 Pages 7792-7801  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The crystal structures of the three high-temperature polymorphs of K3AlF6 have been solved from neutron powder diffraction, synchrotron X-ray powder diffraction, and electron diffraction data. The β-phase (stable between 132 and 153 °C) and γ-phase (stable between 153 to 306 °C) can be described as unusually complex superstructures of the double-perovskite structure (K2KAlF6) which result from noncooperative tilting of the AlF6 octahedra. The β-phase is tetragonal, space group I4/m, with lattice parameters of a = 13.3862(5) Å and c = 8.5617(3) Å (at 143 °C) and Z = 10. In this phase, one-fifth of the AlF6 octahedra are rotated about the c-axis by 45° while the other four-fifths remain untilted. The large 45° rotations result in edge sharing between these AlF6 octahedra and the neighboring K-centered polyhedra, resulting in pentagonal bipyramidal coordination for four-fifths of the K+ ions that reside on the B-sites of the perovskite structure. The remaining one-fifth of the K+ ions on the B-sites retain octahedral coordination. The γ-phase is orthorhombic, space group Fddd, with lattice parameters of a = 36.1276(4) Å, b = 17.1133(2) Å, and c = 12.0562(1) Å (at 225 °C) and Z = 48. In the γ-phase, one-sixth of the AlF6 octahedra are randomly rotated about one of two directions by 45° while the other five-sixths remain essentially untilted. These rotations result in two-thirds of the K+ ions on the B-site obtaining 7-fold coordination while the other one-third remain in octahedral coordination. The δ-phase adopts the ideal cubic double-perovskite structure, space group Fmm, with a = 8.5943(1) Å at 400 °C. However, pair distribution function analysis shows that locally the δ-phase is quite different from its long-range average crystal structure. The AlF6 octahedra undergo large-amplitude rotations which are accompanied by off-center displacements of the K+ ions that occupy the 12-coordinate A-sites.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000293493100052 Publication Date 2011-07-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.857 Times cited 19 Open Access  
  Notes Approved Most recent IF: 4.857; 2011 IF: 4.601  
  Call Number UA @ lucian @ c:irua:91131 Serial 1468  
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Author Batuk, M.; Batuk, D.; Tsirlin, A.A.; Rozova, M.G.; Antipov, E.V.; Hadermann, J.; Van Tendeloo, G. pdf  doi
openurl 
  Title Homologous series of layered perovskites An+1BnO3n-1Cl : crystal and magnetic structure of a new oxychloride Pb4BiFe4O11Cl Type A1 Journal article
  Year 2013 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 52 Issue 4 Pages 2208-2218  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The nuclear and magnetic structure of a novel oxychloride Pb4BiFe4O11Cl has been studied over the temperature range 1.5700 K using a combination of transmission electron microscopy and synchrotron and neutron powder diffraction [space group P4/mbm, a = 5.5311(1) Å, c = 19.586(1) Å, T = 300 K]. Pb4BiFe4O11Cl is built of truncated (Pb,Bi)3Fe4O11 quadruple perovskite blocks separated by CsCl-type (Pb,Bi)2Cl slabs. The perovskite blocks consist of two layers of FeO6 octahedra located between two layers of FeO5 tetragonal pyramids. The FeO6 octahedra rotate about the c axis, resulting in a √2ap × √2ap × c superstructure. Below TN = 595(17) K, Pb4BiFe4O11Cl adopts a G-type antiferromagnetic structure with the iron magnetic moments confined to the ab plane. The ordered magnetic moments at 1.5 K are 3.93(3) and 3.62(4) μB on the octahedral and square-pyramidal iron sites, respectively. Pb4BiFe4O11Cl can be considered a member of the perovskite-based An+1BnO3n1Cl homologous series (A = Pb/Bi; B = Fe) with n = 4. The formation of a subsequent member of the series with n = 5 is also demonstrated.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000315255200067 Publication Date 2013-02-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.857 Times cited 6 Open Access  
  Notes Countatoms Approved Most recent IF: 4.857; 2013 IF: 4.794  
  Call Number UA @ lucian @ c:irua:106185 Serial 1486  
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Author Batuk, D.; Hadermann, J.; Abakumov, A.; Vranken, T.; Hardy, A.; van Bael, M.; Van Tendeloo, G. doi  openurl
  Title Layered perovskite-like Pb2Fe2O5 structure as a parent matrix for the nucleation and growth of crystallographic shear planes Type A1 Journal article
  Year 2011 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 50 Issue 11 Pages 4978-4986  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The Pb2Fe2O5 compound with a layered intergrowth structure has been prepared by a solid-state reaction at 700 °C. The incommensurate compound crystallizes in a tetragonal system with a = 3.9037(2) Å, c = 3.9996(4) Å, and q = 0.1186(4)c*, or when treated as a commensurate approximant, a = 3.9047(2) Å, c = 36.000(3) Å, space group I4/mmm. The crystal structure of Pb2Fe2O5 was resolved from transmission electron microscopy data. Atomic coordinates and occupancies of the cation positions were estimated from high-angle annular dark-field scanning transmission electron microscopy data. Direct visualization of the positions of the oxygen atoms was possible using annular bright-field scanning transmission electron microscopy. The structure can be represented as an intergrowth of perovskite blocks and partially disordered blocks with a structure similar to that of the Bi2O2 blocks in Aurivillius-type phases. The A-cation positions at the border of the perovskite block and the cation positions in the Aurivillius-type blocks are jointly occupied by Pb2+ and Fe3+ cations, resulting in a layer sequence along the c axis: PbOFeO2PbOFeO2Pb7/8Fe1/8O1xFe5/8Pb3/8O2Fe5/8Pb3/8. Upon heating, the layered Pb2Fe2O5 structure transforms into an anion-deficient perovskite modulated by periodically spaced crystallographic shear (CS) planes. Considering the layered Pb2Fe2O5 structure as a parent matrix for the nucleation and growth of CS planes allows an explanation of the specific microstructure observed for the CS structures in the PbFeO system.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000290978400038 Publication Date 2011-04-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.857 Times cited 16 Open Access  
  Notes Approved Most recent IF: 4.857; 2011 IF: 4.601  
  Call Number UA @ lucian @ c:irua:90141 Serial 1809  
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Author Charkin, D.O.; Urmanov, A.V.; Kazakov, S.M.; Batuk, D.; Abakumov, A.M.; Knöner, S.; Gati, E.; Wolf, B.; Lang, M.; Shevelkov, A.V.; Van Tendeloo, G.; Antipov, E.V.; doi  openurl
  Title Synthesis, crystal structure, transport, and magnetic properties of novel ternary copper phosphides, A2Cu6P5(A = Sr, Eu) and EuCu4P3 Type A1 Journal article
  Year 2012 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 51 Issue 16 Pages 8948-8955  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Three new ternary copper phosphides, Sr2Cu6P5, Eu2Cu6P5, and EuCu4P3, have been synthesized from the elements in evacuated silica capsules. Eu2Cu6P5 and Sr2Cu6P5 adopt the Ca2Cu6P5-type structure, while EuCu4P3 is isostructural to BaMg4Si3 and still remains the only representative of this structure type among the ternary Cu pnictides. All three materials show metallic conductivity in the temperature range 2 K <= T <= 290 K, with no indication for superconductivity. For Eu2Cu6P5 and EuCu4P3, long-range magnetic order was observed, governed by 4f local moments on the Eu atoms with predominant ferromagnetic interactions. While Eu2Cu6P5 shows a single ferromagnetic transition at T-C = 34 K, the magnetic behavior of EuCu4P3 is more complex, giving rise to three consecutive magnetic phase transitions at 70, 43, and 18 K.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000307606200042 Publication Date 2012-07-31  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.857 Times cited 13 Open Access  
  Notes Approved Most recent IF: 4.857; 2012 IF: 4.593  
  Call Number UA @ lucian @ c:irua:102217 Serial 3453  
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Author Kirsanova, M.A.; Mori, T.; Maruyama, S.; Matveeva; Batuk, D.; Abakumov, A.M.; Gerasimenko, A.V.; Olenev, A.V.; Grin, Y.; Shevelkov, A.V. doi  openurl
  Title Synthesis, structure, and transport properties of type-I derived clathrate Ge46-xPxSe8-y (x=15.4(1); y=0-2.65) with diverse host-guest bonding Type A1 Journal article
  Year 2013 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 52 Issue 2 Pages 577-588  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract A first clathrate compound with selenium guest atoms, [Ge46-xPx]Se8-y square(y) (x = 15.4(1); y = 0-2.65; square denotes a vacancy), was synthesized as a single-phase and structurally characterized. It crystallizes in the space group Fm (3) over bar with the unit cell parameter a varying from 20.310(2) to 20.406(2) angstrom and corresponding to a 2 x 2 x 2 supercell of a usual clathrate-I structure. The superstructure is formed due to the symmetrical arrangement of the three-bonded framework atoms appearing as a result of the framework transformation of the parent clathrate-I structure. Selenium guest atoms occupy two types of polyhedral cages inside the positively charged framework; all selenium atoms in the larger cages form a single covalent bond with the framework atoms, relating the title compounds to a scanty family of semiclathrates. According to the measurements of electrical resistivity and Seebeck coefficient, [Ge46-xPx]Se8-y square(y) is an n-type semiconductor with E-g = 0.41 eV for x = 15.4(1) and y = 0; it demonstrates the maximal thermoelectric power factor of 2.3 x 10(-5) W K-2 m(-1) at 660 K.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000314007500010 Publication Date 2012-12-31  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.857 Times cited 14 Open Access  
  Notes Approved Most recent IF: 4.857; 2013 IF: 4.794  
  Call Number UA @ lucian @ c:irua:107689 Serial 3463  
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Author Charkin, D.O.; Demchyna, R.; Prots, Y.; Borrmann, H.; Burkhardt, U.; Schwarz, U.; Schnelle, W.; Plokhikh, I.V.; Kazakov, S.M.; Abakumov, A.M.; Batuk, D.; Verchenko, V.Y.; Tsirlin, A.A.; Curfs, C.; Grin, Y.; Shevelkov, A.V.; doi  openurl
  Title Two New Arsenides, Eu7Cu44As23 and Sr7Cu44As23, With a New Filled Variety of the BaHg11 Structure Type A1 Journal article
  Year 2014 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 53 Issue 20 Pages 11173-11184  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Two new ternary arsenides, namely, Eu7Cu44As23 and Sr7Cu44As23, were synthesized from elements at 800 degrees C. Their crystal structure represents a new filled version of the BaHg11 motif with cubic voids alternately occupied by Eu(Sr) and As atoms, resulting in a 2 x 2 x 2 superstructure of the aristotype: space group Fm (3) over barm, a = 16.6707(2) angstrom and 16.7467(2) angstrom, respectively. The Eu derivative exhibits ferromagnetic ordering below 17.5 K. In agreement with band structure calculations both compounds are metals, exhibiting relatively low thermopower, but high electrical and low thermal conductivity.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000343527700049 Publication Date 2014-09-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.857 Times cited 9 Open Access  
  Notes Approved Most recent IF: 4.857; 2014 IF: 4.762  
  Call Number UA @ lucian @ c:irua:121141 Serial 3784  
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Author Li, D.Y.; Zeng, Y.J.; Pereira, L.M.C.; Batuk, D.; Hadermann, J.; Zhang, Y.Z.; Ye, Z.Z.; Temst, K.; Vantomme, A.; Van Bael, M.J.; Van Haesendonck, C.; pdf  doi
openurl 
  Title Anisotropic magnetism and spin-dependent transport in Co nanoparticle embedded ZnO thin films Type A1 Journal article
  Year 2013 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 114 Issue 3 Pages 033909-6  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Oriented Co nanoparticles were obtained by Co ion implantation in crystalline ZnO thin films grown by pulsed laser deposition. Transmission electron microscopy revealed the presence of elliptically shaped Co precipitates with nanometer size, which are embedded in the ZnO thin films, resulting in anisotropic magnetic behavior. The low-temperature resistance of the Co-implanted ZnO thin films follows the Efros-Shklovskii type variable-range-hopping. Large negative magnetoresistance (MR) exceeding 10% is observed in a magnetic field of 1 T at 2.5K and the negative MR survives up to 250K (0.3%). The negative MR reveals hysteresis as well as anisotropy that correlate well with the magnetic properties, clearly demonstrating the presence of spin-dependent transport. (C) 2013 AIP Publishing LLC.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000322202700071 Publication Date 2013-07-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.068 Times cited 10 Open Access  
  Notes Approved Most recent IF: 2.068; 2013 IF: 2.185  
  Call Number UA @ lucian @ c:irua:110765 Serial 126  
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Author Batuk, M.; Batuk, D.; Abakumov, A.M.; Hadermann, J. pdf  doi
openurl 
  Title Pb5Fe3TiO11Cl : a rare example of Ti(IV) in a square pyramidal oxygen coordination Type A1 Journal article
  Year 2014 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem  
  Volume 215 Issue Pages 245-252  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract A new oxychloride Pb5Fe3TiO11Cl has been synthesized using the solid state method. Its crystal and magnetic structure was investigated in the 1.5550 K temperature range using electron diffraction, high angle annular dark field scanning transmission electron microscopy, atomic resolution energy dispersive X-ray spectroscopy, neutron and X-ray powder diffraction. At room temperature Pb5Fe3TiO11Cl crystallizes in the P4/mmm space group with the unit cell parameters a=3.91803(3) Å and c=19.3345(2) Å. Pb5Fe3TiO11Cl is a new n=4 member of the oxychloride perovskite-based homologous series An+1BnO3n−1Cl. The structure is built of truncated Pb3Fe3TiO11 quadruple perovskite blocks separated by CsCl-type Pb2Cl slabs. The perovskite blocks consist of two layers of (Fe,Ti)O6 octahedra sandwiched between two layers of (Fe,Ti)O5 square pyramids. The Ti4+ cations are preferentially located in the octahedral layers, however, the presence of a noticeable amount of Ti4+ in a five-fold coordination environment has been undoubtedly proven using neutron powder diffraction and atomic resolution compositional mapping. Pb5Fe3TiO11Cl is antiferromagnetically ordered below 450(10) K. The ordered Fe magnetic moments at 1.5 K are 4.06(4) μB and 3.86(5) μB on the octahedral and square-pyramidal sites, respectively.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000336891300037 Publication Date 2014-04-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0022-4596; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.299 Times cited 4 Open Access  
  Notes Fwo G.0184.09n. Approved Most recent IF: 2.299; 2014 IF: 2.133  
  Call Number UA @ lucian @ c:irua:117066 Serial 3551  
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Author Batuk, D.; de Dobbelaere, C.; Tsirlin, A.A.; Abakumov, A.M.; Hardy, A.; van Bael, M.K.; Greenblatt, M.; Hadermann, J. pdf  doi
openurl 
  Title Crystal structure and magnetic properties of the Cr-doped spiral antiferromagnet BiMnFe2O6 Type A1 Journal article
  Year 2013 Publication Materials research bulletin Abbreviated Journal Mater Res Bull  
  Volume 48 Issue 9 Pages 2993-2997  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We report the Cr3+ for Mn3+ substitution in the BiMnFe2O6 structure. The BiCrxMn1-xFe2O6 solid solution is obtained by the solution-gel synthesis technique for the x values up to 0.3. The crystal structure investigation using a combination of X-ray powder diffraction and transmission electron microscopy demonstrates that the compounds retain the parent BiMnFe2O6 structure (for x = 0.3, a = 5.02010(6)angstrom, b = 7.06594(7)angstrom, c = 12.6174(1)angstrom, S.G. Pbcm, R-1 = 0.036, R-p = 0.011) with only a slight decrease in the cell parameters associated with the Cr3+ for Mn3+ substitution. Magnetic susceptibility measurements suggest strong similarities in the magnetic behavior of BiCrxMn1-xFe2O6 (x = 0.2; 0.3) and parent BiMnFe2O6. Only T-N slightly decreases upon Cr doping that indicates a very subtle influence of Cr3+ cations on the magnetic properties at the available substitution rates. (C) 2013 Elsevier Ltd. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000322354000002 Publication Date 2013-04-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0025-5408; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.446 Times cited 3 Open Access  
  Notes Fwo Approved Most recent IF: 2.446; 2013 IF: 1.968  
  Call Number UA @ lucian @ c:irua:109755 Serial 561  
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Author Gou, H.; Dubrovinskaia, N.; Bykova, E.; Tsirlin, A.A.; Kasinathan, D.; Schnelle, W.; Richter, A.; Merlini, M.; Hanfland, M.; Abakumov, A.M.; Batuk, D.; Van Tendeloo, G.; Nakajima, Y.; Kolmogorov, A.N.; Dubrovinsky, L.; url  doi
openurl 
  Title Discovery of a superhard iron tetraboride superconductor Type A1 Journal article
  Year 2013 Publication Physical review letters Abbreviated Journal Phys Rev Lett  
  Volume 111 Issue 15 Pages 157002-157005  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Single crystals of novel orthorhombic (space group Pnnm) iron tetraboride FeB4 were synthesized at pressures above 8 GPa and high temperatures. Magnetic susceptibility and heat capacity measurements demonstrate bulk superconductivity below 2.9 K. The putative isotope effect on the superconducting critical temperature and the analysis of specific heat data indicate that the superconductivity in FeB4 is likely phonon mediated, which is rare for Fe-based superconductors. The discovered iron tetraboride is highly incompressible and has the nanoindentation hardness of 62(5) GPa; thus, it opens a new class of highly desirable materials combining advanced mechanical properties and superconductivity.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000325371500011 Publication Date 2013-10-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0031-9007;1079-7114; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 8.462 Times cited 127 Open Access  
  Notes Countatoms Approved Most recent IF: 8.462; 2013 IF: 7.728  
  Call Number UA @ lucian @ c:irua:110820 Serial 729  
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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 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 (up) 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  
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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 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 (up) 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 Sathiya, M.; Thomas, J.; Batuk, D.; Pimenta, V.; Gopalan, R.; Tarascon, J.-M. pdf  doi
openurl 
  Title Dual stabilization and sacrificial effect of Na2CO3 for increasing capacities of Na-Ion cells based on P2-NaxMO2 electrodes Type A1 Journal article
  Year 2017 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 29 Issue 14 Pages 5948-5956  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Sodium ion battery technology is gradually advancing and can be viewed as a viable alternative to lithium ion batteries in niche applications. One of the promising positive electrode candidates is P2 type layered sodium transition metal oxide, which offers attractive sodium ion conductivity. However, the reversible capacity of P2 phases is limited by the inability to directly synthesize stoichiometric compounds with a sodium to transition metal ratio equal to 1. To alleviate this issue, we report herein the in situ synthesis of P2-NaxO2 (x <= 0.7, M = transition metal ions)-Na2CO3 composites. We find that sodium carbonate acts as a sacrificial salt, providing Na+ ion to increase the reversible capacity of the P2 phase in sodium ion full cells, and also as a useful additive that stabilizes the formation of P2 over competing P3 phases. We offer a new phase diagram for tuning the synthesis of the P2 phase under various experimental conditions and demonstrate, by in situ XRD analysis, the role of Na2CO3 as a sodium reservoir in full sodium ion cells. These results provide insights into the practical use of P2 layered materials and can be extended to a variety of other layered phases.  
  Address  
  Corporate Author Thesis  
  Publisher American Chemical Society Place of Publication Washington, D.C Editor  
  Language Wos 000406573200026 Publication Date 2017-07-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 9.466 Times cited 26 Open Access Not_Open_Access  
  Notes ; M.S., J.T., and R.G. acknowledge the financial support received from the Department of Science and Technology (DST-SERC), Government of India under the funding from the TRC Grant Agreement No. AI/1/65/ARCI/2014. The authors are thankful to Dr. Sundararajan, Chairman, TRC and Dr. G. Padmanabham, Director, ARCI for helpful discussions. Initial microscopy analysis by Dr. M. B. Sahana, Dr. Prabu, and Mr. Ravi Gautham of ARCI are greatly acknowledged. The elemental analysis by Dr. Domitille Giaume, IRCP – ENSCP, Chimie Paris Tech, Paris is greatly acknowledged. ; Approved Most recent IF: 9.466  
  Call Number UA @ lucian @ c:irua:145759 Serial 4740  
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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 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 (up) 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 Jacquet, Q.; Perez, A.; Batuk, D.; Van Tendeloo, G.; Rousse, G.; Tarascon, J.-M. url  doi
openurl 
  Title The Li3RuyNb1-yO4 (0 ≤y≤ 1) System: Structural Diversity and Li Insertion and Extraction Capabilities Type A1 Journal article
  Year 2017 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 29 Issue 12 Pages 5331-5343  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Searching for novel high-capacity electrode materials combining cationic and anionic redox processes is an ever-growing activity within the field of Li-ion batteries. In this respect, we report on the exploration of the Li3RuyNb1-yO4 (O <= y <= 1) system with an O/M ratio of 4 to maximize the number of oxygen lone pairs, responsible for the anionic redox. We show that this system presents a very rich crystal chemistry with the existence of four structural types, which derive from the rocksalt structure but differ in their cationic arrangement, creating either zigzag, helical, jagged chains or clusters. From an electrochemical standpoint, these compounds are active on reduction via a classical cationic insertion process. The oxidation process is more complex, because of the instability of the delithiated phase. Our results promote the use of the rich Li3MO4 family as a viable platform for a better understanding of the relationships between structure and anionic redox activity.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000404493100036 Publication Date 2017-06-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 9.466 Times cited 17 Open Access Not_Open_Access  
  Notes The authors thank Paul Pearce, Alexis Grimaud, Matthieu Saubanere, and Marie-Liesse Doublet for fruitful discussions, Vivian Nassif for her help in neutron diffraction experiment at the D1B diffractometer at ILL, and Dominique Foix for XPS analysis. 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. Q.J. thanks the ANR “Deli-Redox” for Ph.D. funding. J.-M.T. and D.B. acknowledge funding from the European Research Council (ERC) (FP/2014)/ERC Grant -Project 670116-ARPEMA. Approved Most recent IF: 9.466  
  Call Number EMAT @ emat @c:irua:147506 Serial 4776  
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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 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 (up) 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 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 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 (up) 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 Abakumov, A.M.; Batuk, D.; Hadermann, J.; Rozova, M.G.; Sheptyakov, D.V.; Tsirlin, A.A.; Niermann, D.; Waschowski, F.; Hemberger, J.; Van Tendeloo, G.; Antipov, E.V. doi  openurl
  Title Antiferroelectric (Pb,Bi)1-xFe1+xO3-y perovskites modulated by crystallographic shear planes Type A1 Journal article
  Year 2011 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 23 Issue 2 Pages 255-265  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We demonstrate for the first time a possibility to vary the anion content in perovskites over a wide range through a long-range-ordered arrangement of crystallographic shear (CS) planes. Anion-deficient perovskites (Pb,Bi)1−xFe1+xO3−y with incommensurately modulated structures were prepared as single phases in the compositional range from Pb0.857Bi0.094Fe1.049O2.572 to Pb0.409Bi0.567Fe1.025O2.796. Using a combination of electron diffraction and high-resolution scanning transmission electron microscopy, we constructed a superspace model describing a periodic arrangement of the CS planes. The model was verified by refinement of the Pb0.64Bi0.32Fe1.04O2.675 crystal structure from neutron powder diffraction data ((3 + 1)D S.G. X2/m(α0γ), X = [1/2,1/2,1/2,1/2], a = 3.9082(1) Å, b = 3.90333(8) Å, c = 4.0900(1) Å, β = 91.936(2)°, q = 0.05013(4)a* + 0.09170(3)c* at T = 700 K, RP = 0.036, RwP = 0.048). The (Pb,Bi)1−xFe1+xO3−y structures consist of perovskite blocks separated by CS planes confined to nearly the (509)p perovskite plane. Along the CS planes, the perovskite blocks are shifted with respect to each other over the 1/2[110]p vector that transforms the corner-sharing connectivity of the FeO6 octahedra in the perovskite framework to an edge-sharing connectivity of the FeO5 pyramids at the CS plane, thus reducing the oxygen content. Variation of the chemical composition in the (Pb,Bi)1−xFe1+xO3−y series occurs mainly because of a changing thickness of the perovskite block between the interfaces, that can be expressed through the components of the q vector as Pb6γ+2αBi1−7γ−αFe1+γ−αO3−3γ−α. The Pb, Bi, and Fe atoms are subjected to strong displacements occurring in antiparallel directions on both sides of the perovskite blocks, resulting in an antiferroelectric-type structure. This is corroborated by the temperature-, frequency-, and field-dependent complex permittivity measurements. Pb0.64Bi0.32Fe1.04O2.675 demonstrates a remarkably high resistivity >0.1 T Ω cm at room temperature and orders antiferromagnetically below TN = 608(10) K.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000286160800018 Publication Date 2010-12-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (up) 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 9.466 Times cited 29 Open Access  
  Notes Approved Most recent IF: 9.466; 2011 IF: 7.286  
  Call Number UA @ lucian @ c:irua:88651 Serial 136  
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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 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 (up) 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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