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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. |
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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 |
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Year |
2016 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
55 |
Issue |
55 |
Pages |
1245-1257 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Center for Electrochemical Energy Storage, Skolkovo Institute of Science and Technology , Nobelya str. 3, 143026 Moscow, Russia |
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English |
Wos |
000369356800031 |
Publication Date |
2016-01-09 |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISSN |
0020-1669 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
3 |
Open Access |
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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 |
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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. |
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Title |
Layered-to-Tunnel Structure Transformation and Oxygen Redox Chemistry in LiRhO2upon Li Extraction and Insertion |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
55 |
Issue |
55 |
Pages |
7079-7089 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Layered Li(M,Li)O2 (where M is a transition metal) ordered rock-salt-type structures are used in advanced metal-ion batteries as one of the best hosts for the reversible intercalation of Li ions. Besides the conventional redox reaction involving oxidation/reduction of the M cation upon Li extraction/insertion, creating oxygen-located holes because of the partial oxygen oxidation increases capacity while maintaining the oxidized oxygen species in the lattice through high covalency of the M–O bonding. Typical degradation mechanism of the Li(M,Li)O2 electrodes involves partially irreversible M cation migration toward the Li positions, resulting in gradual capacity/voltage fade. Here, using LiRhO2 as a model system (isostructural and isoelectronic to LiCoO2), for the first time, we demonstrate an intimate coupling between the oxygen redox and M cation migration. A formation of the oxidized oxygen species upon electrochemical Li extraction coincides with transformation of the layered Li1–xRhO2 structure into the γ-MnO2-type rutile–ramsdellite intergrowth LiyRh3O6 structure with rutile-like [1 × 1] channels along with bigger ramsdellite-like [2 × 1] tunnels through massive and concerted Rh migration toward the empty positions in the Li layers. The oxidized oxygen dimers with the O–O distances as short as 2.26 Å are stabilized in this structure via the local Rh–O configuration reminiscent to that in the μ-peroxo-μ-hydroxo Rh complexes. The LiyRh3O6 structure is remarkably stable upon electrochemical cycling illustrating that proper structural implementation of the oxidized oxygen species can open a pathway toward deliberate employment of the anion redox chemistry in high-capacity/high-voltage positive electrodes for metal-ion batteries. Upon chemical or electrochemical oxidation, layered LiRhO2 shows a unique structural transformation that involves both cation migration and oxidation of oxygen resulting in a stable tunnel-like rutile−ramsdellite intergrowth LiyRh3O6 structure. This structure demonstrates excellent performance with the steady and reversible capacity of ∼200 mAh/g. The stability of LiyRh3O6 is rooted in the accommodation of partially oxidized oxygen species through the formation of short O−O distances that are compatible with the connectivity of RhO6 octahedra. |
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Wos |
000380181400035 |
Publication Date |
2016-07-18 |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
12 |
Open Access |
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Notes |
Bundesministerium fur Bildung und Forschung, 03SF0477B ; Fonds Wetenschappelijk Onderzoek, G040116N ; |
Approved |
Most recent IF: 4.857 |
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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. |
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Title |
Complex Microstructure and Magnetism in Polymorphic CaFeSeO |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
55 |
Issue |
55 |
Pages |
10714-10726 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Address |
Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford , South Parks Road, Oxford OX1 3QR, United Kingdom |
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English |
Wos |
000385785700085 |
Publication Date |
2016-10-05 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
6 |
Open Access |
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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 |
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Call Number |
EMAT @ emat @ c:irua:136823 |
Serial |
4312 |
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Author |
Tunca, B.; Lapauw, T.; Karakulina, O.M.; Batuk, M.; Cabioc’h, T.; Hadermann, J.; Delville, R.; Lambrinou, K.; Vleugels, J. |
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Title |
Synthesis of MAX Phases in the Zr-Ti-Al-C System |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
56 |
Issue |
56 |
Pages |
3489-3498 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
This study reports on the synthesis and characterization of MAX phases in the (Zr,Ti)n+1AlCn system. The MAX phases were synthesized by reactive hot pressing and pressureless sintering in the 1350–1700 °C temperature range. The produced ceramics contained large fractions of 211 and 312 (n = 1, 2) MAX phases, while strong evidence of a 413 (n = 3) stacking was found. Moreover, (Zr,Ti)C, ZrAl2, ZrAl3, and Zr2Al3 were present as secondary phases. In general, the lattice parameters of the hexagonal 211 and 312 phases followed Vegard’s law over the complete Zr-Ti solid solution range, but the 312 phase showed a non-negligible deviation from Vegard’s law around the (Zr0.33,Ti0.67)3Al1.2C1.6 stoichiometry. High-resolution scanning transmission electron microscopy combined with X-ray diffraction demonstrated ordering of the Zr and Ti atoms in the 312 phase, whereby Zr atoms occupied preferentially the central position in the close-packed M6X octahedral layers. The same ordering was also observed in 413 stackings present within the 312 phase. The decomposition of the secondary (Zr,Ti)C phase was attributed to the miscibility gap in the ZrC-TiC system. |
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Wos |
000397171100045 |
Publication Date |
2017-03-20 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
26 |
Open Access |
OpenAccess |
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Notes |
Fonds Wetenschappelijk Onderzoek, G.0431.10N.F ; Agentschap voor Innovatie door Wetenschap en Technologie, 131081 ; European Atomic Energy Community, 604862 ; SCK-CEN Academy for Nuclear Science and Technology; Hercules Foundation, Project/Award no: AKUL/1319 Project/Award no: ZW09-09 ; |
Approved |
Most recent IF: 4.857 |
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Call Number |
EMAT @ emat @ c:irua:141794 |
Serial |
4491 |
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Author |
Barreca, D.; Gri, F.; Gasparotto, A.; Altantzis, T.; Gombac, V.; Fornasiero, P.; Maccato, C. |
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Title |
Insights into the Plasma-Assisted Fabrication and Nanoscopic Investigation of Tailored MnO2Nanomaterials |
Type |
A1 Journal Article |
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Year |
2018 |
Publication |
Inorganic Chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
57 |
Issue |
23 |
Pages |
14564-14573 |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Abstract |
Among transition metal oxides, MnO2 is of considerable importance for various technological end-uses,from heterogeneous catalysis to gas sensing, owing to its
structural flexibility and unique properties at the nanoscale. In this work, we demonstrate the successful fabrication of supported MnO2 nanomaterials by a catalyst-free, plasmaassisted process starting from a fluorinated manganese(II)
molecular source in Ar/O2 plasmas. A thorough multitechnique characterization aimed at the systematic investigation of material structure, chemical composition, and
morphology revealed the formation of F-doped, oxygendeficient, MnO2-based nanomaterials, with a fluorine content tunable as a function of growth temperature (TG). Whereas phase-pure β-MnO2 was obtained for 100 °C ≤ TG ≤ 300 °C, the formation of mixed phase MnO2 + Mn2O3 nanosystems took place at 400 °C. In addition, the system nano-organization could be finely tailored, resulting in a controllable evolution from wheat-ear columnar arrays to high aspect ratio pointed-tip nanorod assemblies. Concomitantly, magnetic force microscopy analyses suggested the formation of spin domains with features dependent on material morphology. Preliminary tests in Vislight activated photocatalytic degradation of rhodamine B aqueous solutions pave the way to possible applications of the target materials in wastewater purification. |
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Wos |
000452344400016 |
Publication Date |
2018-12-03 |
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Abbreviated Series Title |
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Edition |
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ISSN |
0020-1669 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
The present work was financially supported by Padova University DOR 2016−2018 and P-DiSC #03BIRD2016- UNIPD projects. T.A. acknowledges a postdoctoral grant from the Research Foundation Flanders (FWO). Thanks are also due to Prof. Sara Bals (EMAT, University of Antwerp, Belgium) and to Dr. Giorgio Carraro (Department of Chemical Sciences, Padova University, Italy) for valuable support and experimental assistance. |
Approved |
Most recent IF: 4.857 |
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Call Number |
EMAT @ emat @c:irua:156245 |
Serial |
5147 |
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Author |
Jin, L.; Batuk, M.; Kirschner, F.K.K.; Lang, F.; Blundell, S.J.; Hadermann, J.; Hayward, M.A. |
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Title |
Exsolution of SrO during the Topochemical Conversion of LaSr3CoRuO8to the Oxyhydride LaSr3CoRuO4H4 |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
58 |
Issue |
21 |
Pages |
14863-14870 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Reaction of the n = 1 Ruddlesden-Popper oxide LaSr3CoRuO8 with CaH2 yields the oxyhydride phase LaSr3CoRuO4H4 via topochemical anion-exchange. Close inspection of X-ray and neutron powder diffraction data in combination with HAADF-STEM images reveals that nanoparticles of SrO are exsolved from the system during the reaction, with the change in cation stoichiometry accommodated by the inclusion of n > 1 (Co/Ru)nOn+1H2n ‘perovskite’ layers into the Ruddlesden-Popper stacking sequence. This novel pseudo-topochemical process offers a new route for the formation of n > 1 Ruddlesden-Popper structured materials. Magnetization data are consistent with a LaSr3Co1+Ru2+O4H4 (Co1+, d8, S = 1; Ru2+, d6, S = 0) oxidation/spin state combination. Neutron diffraction and μ+SR data show no evidence for long-range magnetic order down to 2 K, suggesting the diamagnetic Ru2+ centers impede the Co-Co magnetic exchange interactions. |
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Wos |
000494894400062 |
Publication Date |
2019-11-04 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
1 |
Open Access |
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Notes |
We thank P. Manuel for assistance collecting the neutron powder diffraction data. We thank The Leverhulme Trust grant award RPG-2014-366 “Topochemical reduction of 4d and 5d transition metal oxides” for supporting this work. Experiments at the Diamond Light Source were performed as part of the Block Allocation Group award “Oxford Solid State Chemistry BAG to probe composition-structure-property relationships in solids” (EE13284). Investigation by TEM was supported through the FWO grant G035619N. |
Approved |
Most recent IF: 4.857 |
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Call Number |
EMAT @ emat @c:irua:164625 |
Serial |
5434 |
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Author |
Xu, X.; Jones, M.A.; Cassidy, S.J.; Manuel, P.; Orlandi, F.; Batuk, M.; Hadermann, J.; Clarke, S.J. |
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Title |
Magnetic Ordering in the Layered Cr(II) Oxide Arsenides Sr2CrO2Cr2As2and Ba2CrO2Cr2As2 |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Inorganic Chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
59 |
Issue |
21 |
Pages |
15898-15912 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Sr2CrO2Cr2As2 and Ba2CrO2Cr2As2 with Cr2+ ions in CrO2 sheets and in CrAs layers crystallize with the Sr2Mn3Sb2O2 structure (space group I4/mmm, Z = 2) and lattice parameters a = 4.00800(2) Å, c = 18.8214(1) Å (Sr2CrO2Cr2As2) and a = 4.05506(2) Å, c = 20.5637(1) Å (Ba2CrO2Cr2As2) at room temperature. Powder neutron diffraction reveals checkerboard-type antiferromagnetic ordering of the Cr2+ ions in the arsenide layers below TN1Sr, of 600(10) K (Sr2CrO2Cr2As2) and TN1Ba 465(5) K (Ba2CrO2Cr2As2) with the moments initially directed perpendicular to the layers in both compounds. Checkerboard-type antiferromagnetic ordering of the Cr2+ ions in the oxide layer below 230(5) K for Ba2CrO2Cr2As2 occurs with these moments also perpendicular to the layers, consistent with the orientation preferences of d4 moments in the two layers. In contrast, below 330(5) K in Sr2CrO2Cr2As2, the oxide layer Cr2+ moments are initially oriented in the CrO2 plane; but on further cooling, these moments rotate to become perpendicular to the CrO2 planes, while the moments in the arsenide layers rotate by 90° with the moments on the two sublattices remaining orthogonal throughout [behavior recently reported independently by Liu et al. [Liu et al. Phys. Rev. B 2018, 98, 134416]]. In Sr2CrO2Cr2As2, electron diffraction and high resolution powder X-ray diffraction data show no evidence for a structural distortion that would allow the two Cr2+ sublattices to couple, but high resolution neutron powder diffraction data suggest a small incommensurability between the magnetic structure and the crystal structure, which may account for the coupling of the two sublattices and the observed spin reorientation. The saturation values of the Cr2+ moments in the CrO2 layers (3.34(1) μB (for Sr2CrO2Cr2As2) and 3.30(1) μB (for Ba2CrO2Cr2As2)) are larger than those in the CrAs layers (2.68(1) μB for Sr2CrO2Cr2As2 and 2.298(8) μB for Ba2CrO2Cr2As2) reflecting greater covalency in the arsenide layers. |
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Wos |
000588738100035 |
Publication Date |
2020-11-02 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.6 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
We thank the UK EPSRC (EP/M020517/1 and EP/P018874/ 1) and the Leverhulme Trust (RPG-2014-221) for funding and the ISIS pulsed neutron and muon source (RB1610357 and RB1700075) and the Diamond Light Source Ltd. (EE13284 and EE18786) for the award of beam time. We thank Dr. A. Baker and Dr. C. Murray for support on I11. |
Approved |
Most recent IF: 4.6; 2020 IF: 4.857 |
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Call Number |
EMAT @ emat @c:irua:176058 |
Serial |
6704 |
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Author |
Leinders, G.; Baldinozzi, G.; Ritter, C.; Saniz, R.; Arts, I.; Lamoen, D.; Verwerft, M. |
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Title |
Charge Localization and Magnetic Correlations in the Refined Structure of U3O7 |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Inorganic Chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
60 |
Issue |
14 |
Pages |
10550-10564 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Atomic arrangements in the mixed-valence oxide U3O7 are refined from high-resolution neutron scattering data. The crystallographic model describes a long-range structural order in a U60O140 primitive cell (space group P42/n) containing distorted cuboctahedral oxygen clusters. By combining experimental data and electronic structure calculations accounting for spin–orbit interactions, we provide robust evidence of an interplay between charge localization and the magnetic moments carried by the uranium atoms. The calculations predict U3O7 to be a semiconducting solid with a band gap of close to 0.32 eV, and a more pronounced charge-transfer insulator behavior as compared to the well-known Mott insulator UO2. Most uranium ions (56 out of 60) occur in 9-fold and 10-fold coordinated environments, surrounding the oxygen clusters, and have a tetravalent (24 out of 60) or pentavalent (32 out of 60) state. The remaining uranium ions (4 out of 60) are not contiguous to the oxygen cuboctahedra and have a very compact, 8-fold coordinated environment with two short (2 × 1.93(3) Å) “oxo-type” bonds. The higher Hirshfeld charge and the diamagnetic character point to a hexavalent state for these four uranium ions. Hence, the valence state distribution corresponds to 24/60 × U(IV) + 32/60 U(V) + 4/60 U(VI). The tetravalent and pentavalent uranium ions are predicted to carry noncollinear magnetic moments (with amplitudes of 1.6 and 0.8 μB, respectively), resulting in canted ferromagnetic order in characteristic layers within the overall fluorite-related structure. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
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Wos |
000675430900049 |
Publication Date |
2021-07-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0020-1669 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.857 |
Times cited |
|
Open Access |
OpenAccess |
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| |
Notes |
Financial support for this research was partly provided by the Energy Transition Fund of the Belgian FPS Economy (Project SF-CORMOD – Spent Fuel CORrosion MODeling). This work was performed in part using HPC resources from GENCI-IDRIS (Grants 2020-101450 and 2020-101601), and in part by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO-Vlaanderen and the Flemish Government-department EWI. GL thanks E. Suard and C. Schreinemachers for assistance during the neutron scattering experiments at the ILL. GB acknowledges V. Petříček for suggestions on using JANA2006. |
Approved |
Most recent IF: 4.857 |
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| |
Call Number |
EMAT @ emat @c:irua:179907 |
Serial |
6801 |
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| Permanent link to this record |
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| |
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Author |
Tobías, G.; Beltrán-Porter, D.; Lebedev, O.I.; Van Tendeloo, G.; Rodríguez-Carvajal, J.; Fuertes, A. |
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| |
Title |
Anion ordering and defect structure in Ruddlesden-Popper strontium niobium oxynitrides |
Type |
A1 Journal article |
| |
Year |
2004 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
|
| |
Volume |
43 |
Issue |
25 |
Pages |
8010-8017 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
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| |
Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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| |
Language |
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Wos |
000225717700020 |
Publication Date |
2004-12-06 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.857 |
Times cited |
31 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 4.857; 2004 IF: 3.454 |
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| |
Call Number |
UA @ lucian @ c:irua:54873 |
Serial |
120 |
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| Permanent link to this record |
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| |
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Author |
Batuk, M.; Turner, S.; Abakumov, A.M.; Batuk, D.; Hadermann, J.; Van Tendeloo, G. |
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| |
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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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| |
Language |
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Wos |
000332144100039 |
Publication Date |
2014-01-30 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
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 |
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| |
Call Number |
UA @ lucian @ c:irua:113507 |
Serial |
198 |
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| Permanent link to this record |
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| |
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Author |
Abakumov, A.M.; Morozov, V.A.; Tsirlin, A.A.; Verbeeck, J.; Hadermann, J. |
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Title |
Cation ordering and flexibility of the BO42- tetrahedra in incommensurately modulated CaEu2(BO4)4 (B = Mo, W) scheelites |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
|
| |
Volume |
53 |
Issue |
17 |
Pages |
9407-9415 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
The factors mediating cation ordering in the scheelite-based molybdates and tungstates are discussed on the basis of the incommensurately modulated crystal structures of the CaEu2(BO4)(4) (B = Mo, W) red phosphors solved from high-resolution synchrotron powder X-ray diffraction data. Monoclinic CaEu2(WO4)(4) adopts a (3 + 1)-dimensionally modulated structure [superspace group I2/b(alpha beta 0)00, a = 5.238 73(1)A, b = 5.266 35(1) A, c = 11.463 19(9) A, gamma = 91.1511(2)degrees, q = 0.56153(6)a* + 0.7708(9)b*, R-F = 0.050, R-p = 0.069], whereas tetragonal CaEu2(MoO4)(4) is (3 + 2)-dimensionally modulated [superspace group I4(1)/ a(alpha beta 0)00(-beta alpha 0)00, a = 5.238 672(7) A, c = 11.548 43(2) A, q(1) = 035331(8)a* + 0.82068(9)b*, q(2) = -0.82068(9)a* + 0.55331(8)b*, R-F = 0.061, R-p = 0.082]. In both cases the modulation arises from the ordering of the Ca/Eu cations and the cation vacancies at the A-sublattice of the parent scheelite ABO(4) structure. The cation ordering is incomplete and better described with harmonic rather than with steplike occupational modulation functions. The structures respond to the variation of the effective charge and cation size at the A-position through the flexible geometry of the MoO42- and WO42- tetrahedra demonstrating an alternation of stretching the B-O bond lengths and bending the O-B-O bond angles. The tendency towards A-site cation ordering in scheelites is rationalized using the difference in ionic radii and concentration of the A-site vacancies as parameters and presented in the form of a structure map. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000341229600068 |
Publication Date |
2014-08-21 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
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| |
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.857 |
Times cited |
48 |
Open Access |
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| |
Notes |
Fwo G039211n |
Approved |
Most recent IF: 4.857; 2014 IF: 4.762 |
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| |
Call Number |
UA @ lucian @ c:irua:119292UA @ admin @ c:irua:119292 |
Serial |
297 |
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| Permanent link to this record |
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Author |
Kirsanova, M.A.; Mori, T.; Maruyama, S.; Abakumov, A.M.; Van Tendeloo, G.; Olenev, A.; Shevelkov, A.V. |
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Title |
Cationic clathrate of type-III Ge172-xPxTey (y\approx21,5, x\approx2y) : synthesis, crystal structure and thermoelectric properties |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
|
| |
Volume |
52 |
Issue |
14 |
Pages |
8272-8279 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
A first germanium-based cationic clathrate of type-III, Ge129.3P42.7Te21.53, was synthesized and structurally characterized (space group P42/mnm, a = 19.948(3) Å, c = 10.440(2) Å, Z = 1). In its crystal structure, germanium and phosphorus atoms form three types of polyhedral cages centered with Te atoms. The polyhedra share pentagonal and hexagonal faces to form a 3D framework. Despite the complexity of the crystal structure, the Ge129.3P42.7Te21.53 composition corresponds to the Zintl counting scheme with a good accuracy. Ge129.3P42.7Te21.53 demonstrates semiconducting/insulating behavior of electric resistivity, high positive Seebeck coefficient (500 μV K1 at 300 K), and low thermal conductivity (<0.92 W m1 K1) within the measured temperature range. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000322087100052 |
Publication Date |
2013-06-26 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
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| |
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.857 |
Times cited |
3 |
Open Access |
|
|
| |
Notes |
Countatoms |
Approved |
Most recent IF: 4.857; 2013 IF: 4.794 |
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| |
Call Number |
UA @ lucian @ c:irua:109214 |
Serial |
301 |
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| Permanent link to this record |
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Author |
Nagy, N.V.; Van Doorslaer, S.; Szabó-Plánka, T.; Van Rompaey, S.; Hamza, A.; Fülöp, F.; Tóth, G.K.; Rockenbauer, A. |
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| |
Title |
Copper(II)-binding ability of stereoisomeric cis- and trans-2-aminocyclohexanecarboxylic acidl-phenylalanine dipeptides : a combined CW/pulsed EPR and DFT study |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
51 |
Issue |
3 |
Pages |
1386-1399 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
With the aim of an improved understanding of the metal-complexation properties of alicyclic β-amino acid stereoisomers, and their peptides, the complex equilibria and modes of coordination with copper(II) of l-phenylalanine (F) derivatives of cis/trans-2-aminocyclohexanecarboxylic acid (c/tACHC), i.e. the dipeptides F-c/tACHC and c/tACHC-F, were investigated by a combination of CW and pulsed EPR methods. For the interpretation of the experimental data, DFT quantum-chemical calculations were carried out. Simulation of a pH-dependent series of room-temperature CW-EPR spectra revealed the presence of EPR-active complexes ([Cu(aqua)]2+, [CuL]+, [CuLH1], [CuLH2]−, and [CuL2H1]−), and an EPR-inactive species ([Cu2L2H3]−) in aqueous solutions for all studied cases. [CuLH]2+ was included in the equilibrium model for the c/tACHC-Fcopper(II) systems, and [CuL2], together with two coordination isomers of [CuL2H1]−, were also identified in the F-tACHCcopper(II) system. Comparison of the complexation properties of the diastereomeric ligand pair F-(1S,2R)-ACHC and F-(1R,2S)-ACHC did not reveal significant differences. Considerably lower formation constants were obtained for the trans than for the cis isomers for both the F-c/tACHC and the c/tACHC-F pairs in the case of [CuLH1] involving tridentate coordination by the amino, the deprotonated peptide, and the carboxylate groups. A detailed structural analysis by pulsed EPR methods and DFT calculations indicated that there was no significant destabilization for the complexes of the trans isomers. The lower stability of their complexes was explained by the limitation that only the conformer with donor groups in equatorialequatorial ring positions can bind to copper(II), whereas both equatorial-axial conformers of the cis isomers are capable of binding. From a consideration of the proton couplings obtained with X-band 1H HYSCORE, 2H exchange experiments, and DFT, the thermodynamically most stable cyclohexane ring conformer was assigned for all four [CuLH1] complexes. For the F-cACHC case, the conformer did not match the most stable conformer of the free ligand. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000300474700029 |
Publication Date |
2012-01-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.857 |
Times cited |
18 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 4.857; 2012 IF: 4.593 |
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| |
Call Number |
UA @ lucian @ c:irua:96729 |
Serial |
515 |
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| Permanent link to this record |
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| |
|
Author |
King, G.; Abakumov, A.M.; Hadermann, J.; Alekseeva, A.M.; Rozova, M.G.; Perkisas, T.; Woodward, P.M.; Van Tendeloo, G.; Antipov, E.V. |
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Title |
Crystal structure and phase transitions in Sr3WO6 |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
49 |
Issue |
13 |
Pages |
6058-6065 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The crystal structures of the beta and gamma polymorphs of Sr3WO6 and the gamma <->beta phase transition have been investigated using electron diffraction, synchrotron X-ray powder diffraction, and neutron powder diffraction. The gamma-Sr3WO6 polymorph is stable above T-c approximate to 470 K and adopts a monoclinically distorted double perovskite A(2)BB'O-6= Sr2SrWO6 structure (space group Cc, a = 10.2363(1)angstrom, b= 17.9007(1)angstrom, c= 11.9717(1)angstrom, beta=125.585(1)degrees at T= 1373 K, Z=12, corresponding to a = a(p)+1/2b(p) – 1/2c(p), b =3/2b(p) + 3/2c(p), c =-b(p) + c(p), a(p),b(p), c(p), lattice vectors of the parent Fm (3) over barm double perovskite structure). Upon cooling it undergoes a continuous phase transition into the triclinically distorted beta-Sr3WO6 phase (space group Cl, a = 10.09497(3)angstrom, b = 17.64748(5)angstrom, c = 11.81400(3)angstrom, alpha = 89.5470(2)degrees, beta= 125.4529(2)degrees, gamma =90.2889(2)degrees at T= 300 K). Both crystal structures of Sr3WO6 belong to a family of double perovskites with broken corner sharing connectivity of the octahedral framework. A remarkable feature of the gamma-Sr3WO6 structure is a non-cooperative rotation of the WO6 octahedra. One third of the WO6 octahedra are rotated by 45 about either the bp or the cp axis of the parent double perovskite structure. As a result, the WO6 octahedra do not share corners but instead share edges with the coordination polyhedra of the Sr cations at the B positions increasing their coordination number from 6 to 7 or 8. The crystal structure of the beta-phase is very close to the structure of the gamma-phase; decreasing symmetry upon the gamma ->beta transformation occurs because of unequal octahedral rotation angles about the bp and cp axes and increasing distortions of the WO6 octahedra. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000279211500036 |
Publication Date |
2010-06-09 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.857 |
Times cited |
18 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 4.857; 2010 IF: 4.326 |
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| |
Call Number |
UA @ lucian @ c:irua:83877 |
Serial |
562 |
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| Permanent link to this record |
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Author |
Abakumov, A.M.; King, G.; Laurinavichute, V.K.; Rozova, M.G.; Woodward, P.M.; Antipov, E.V. |
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Title |
The crystal structure of \alpha-K3AIF6: elpasolites and double perovskites with broken corner-sharing connectivity of the octahedral framework |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
48 |
Issue |
19 |
Pages |
9336-9344 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The crystal structure of α-K3AlF6 was solved and refined from a combination of powder X-ray and neutron diffraction data (a = 18.8385(3)Å, c = 33.9644(6)Å, S.G. I41/a, Z = 80, RP(X-ray) = 0.037, RP(neutron) = 0.053). The crystal structure is of the A2BB′X6 elpasolite type with the a = b ≈ ae√5, c = 4ae superstructure (ae, parameter of the elpasolite subcell) and rock-salt-type ordering of the K and Al cations over the B and B′ positions, respectively. The remarkable feature of α-K3AlF6 is a rotation of 2/5 of the AlF6 octahedra by π/4 around one of the crystal axes of the elpasolite subcell, coinciding with the 4-fold symmetry axes of the AlF6 octahedra. The rotation of the AlF6 octahedra replaces the corner-sharing between the K and Al polyhedra by edge-sharing, resulting in an increase of coordination numbers of the K cations at the B positions up to 7 and 8. Due to significant deformations of the K polyhedra, the corner-sharing connectivity of the octahedral elpasolite framework is broken and the rotations of the AlF6 octahedra do not have a cooperative character. Elpasolites and double perovskites with similar structural organization are discussed. The difference in ionic radii of the B and B′ cations as well as the tolerance factor are proposed to be the parameters governing the formation of elpasolites and double perovskites with broken corner-sharing connectivity of the octahedral framework. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000270091000039 |
Publication Date |
2009-09-03 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.857 |
Times cited |
20 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 4.857; 2009 IF: 4.657 |
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| |
Call Number |
UA @ lucian @ c:irua:79733 |
Serial |
568 |
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| Permanent link to this record |
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Author |
Batuk, D.; Batuk, M.; Abakumov, A.M.; Tsirlin, A.A.; McCammon, C.M.; Dubrovinsky, L.; Hadermann, J. |
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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 |
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| |
Volume |
52 |
Issue |
17 |
Pages |
10009-10020 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000326129000037 |
Publication Date |
2013-08-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
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 |
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| |
Call Number |
UA @ lucian @ c:irua:111394 |
Serial |
822 |
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| Permanent link to this record |
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Author |
Hadermann, J.; Abakumov, A.M.; Tsirlin, A.A.; Rozova, M.G.; Sarakinou, E.; Antipov, E.V. |
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Title |
Expanding the Ruddlesden-Popper manganite family : the n=3 La3.2Ba0.8Mn3O10 Member |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
51 |
Issue |
21 |
Pages |
11487-11492 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
La3.2Ba0.8Mn3O10, a representative of the rare n = 3 members of the Ruddlesden-Popper manganites A(n+1)Mn(n)O(3n+1), was synthesized in an evacuated sealed silica tube. Its crystal structure was refined from a combination of powder X-ray diffraction (PXD) and precession electron diffraction (PED) data, with the rotations of the MnO6 octahedra described within the symmetry-adapted mode approach (space group Cccm, a = 29.068(1) angstrom, b = 5.5504(5) angstrom, c = 5.5412(5) angstrom; PXD RF = 0.053, RP = 0.026; PED RF = 0.248). The perovskite block in La3.2Ba0.8Mn3O10 features an octahedral tilting distortion with out-of-phase rotations of the Mn06 octahedra according to the (Phi,Phi,0)(Phi,Phi,0) mode, observed for the first time in the n = 3 Ruddlesden-Popper structures. The Mn06 octahedra demonstrate a noticeable deformation with the elongation of two apical Mn-O bonds due to the Jahn-Teller effect in the Mn3+ cations. The relationships between the octahedral tilting distortion, the ionic radii of the cations at the A- and B-positions, and the mismatch between the perovslcite and rock-salt blocks of the Ruddlesden-Popper structure are discussed. At low temperatures, La3.2Ba0.8Mn3O10 reveals a sizable remnant magnetization of about 1.3 mu(B)/Mn at 2K, and shows signatures of spin freezing below 150 K. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000313220200036 |
Publication Date |
2012-10-17 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.857 |
Times cited |
2 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 4.857; 2012 IF: 4.593 |
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Call Number |
UA @ lucian @ c:irua:110121 |
Serial |
1133 |
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| Permanent link to this record |
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Author |
King, G.; Abakumov, A.M.; Woodward, P.M.; Llobet, A.; Tsirlin, A.A.; Batuk, D.; Antipov, E.V. |
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Title |
The high-temperature polymorphs of K3AlF6 |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
50 |
Issue |
16 |
Pages |
7792-7801 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000293493100052 |
Publication Date |
2011-07-11 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.857 |
Times cited |
19 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 4.857; 2011 IF: 4.601 |
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| |
Call Number |
UA @ lucian @ c:irua:91131 |
Serial |
1468 |
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| Permanent link to this record |
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Author |
Retuerto, M.; Yin, Z.; Emge, T.J.; Stephens, P.W.; Li, M.R.; Sarkar, T.; Croft, M.C.; Ignatov, A.; Yuan, Z.; Zhang, S.J.; Jin, C.; Paria Sena, R.; Hadermann, J.; Kotliar, G.; Greenblatt, M.; |
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Title |
Hole doping and structural transformation in CsTl1-xHgxCl3 |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
54 |
Issue |
54 |
Pages |
1066-1075 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
CsTlCl3 and CsTlF3 perovskites have been theoretically predicted to be superconductors when properly hole-doped. Both compounds have been previously prepared as pure compounds: CsTlCl3 in a tetragonal (I4/m) and a cubic (Fm3̅m) perovskite polymorph and CsTlF3 as a cubic perovskite (Fm3̅m). In this work, substitution of Tl in CsTlCl3 with Hg is reported, in an attempt to hole-dope the system and induce superconductivity. The whole series CsTl1xHgxCl3 (x = 0.0, 0.1, 0.2, 0.4, 0.6, and 0.8) was prepared. CsTl0.9Hg0.1Cl3 is tetragonal as the more stable phase of CsTlCl3. However, CsTl0.8Hg0.2Cl3 is already cubic with the space group Fm3̅m and with two different positions for Tl+ and Tl3+. For x = 0.4 and 0.5, solid solutions could not be formed. For x ≥ 0.6, the samples are primitive cubic perovskites with one crystallographic position for Tl+, Tl3+, and Hg2+. All of the samples formed are insulating, and there is no signature of superconductivity. X-ray absorption spectroscopy indicates that all of the samples have a mixed-valence state of Tl+ and Tl3+. Raman spectroscopy shows the presence of the active TlClTl stretching mode over the whole series and the intensity of the TlClHg mode increases with increasing Hg content. First-principle calculations confirmed that the phases are insulators in their ground state and that Hg is not a good dopant in the search for superconductivity in this system. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000348887400048 |
Publication Date |
2014-12-09 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.857 |
Times cited |
5 |
Open Access |
|
|
| |
Notes |
|
Approved |
Most recent IF: 4.857; 2015 IF: 4.762 |
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| |
Call Number |
c:irua:124420 |
Serial |
1476 |
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| Permanent link to this record |
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Author |
Batuk, M.; Batuk, D.; Tsirlin, A.A.; Rozova, M.G.; Antipov, E.V.; Hadermann, J.; Van Tendeloo, G. |
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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 |
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| |
Volume |
52 |
Issue |
4 |
Pages |
2208-2218 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000315255200067 |
Publication Date |
2013-02-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
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 |
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| |
Notes |
Countatoms |
Approved |
Most recent IF: 4.857; 2013 IF: 4.794 |
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| |
Call Number |
UA @ lucian @ c:irua:106185 |
Serial |
1486 |
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| Permanent link to this record |
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Author |
Batuk, D.; Hadermann, J.; Abakumov, A.; Vranken, T.; Hardy, A.; van Bael, M.; Van Tendeloo, G. |
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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 |
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| |
Volume |
50 |
Issue |
11 |
Pages |
4978-4986 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000290978400038 |
Publication Date |
2011-04-29 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.857 |
Times cited |
16 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 4.857; 2011 IF: 4.601 |
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| |
Call Number |
UA @ lucian @ c:irua:90141 |
Serial |
1809 |
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| Permanent link to this record |
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Author |
Retuerto, M.; Li, M.R.; Go, Y.B.; Ignatov, A.; Croft, M.; Ramanujachary, K.V.; Hadermann, J.; Hodges, J.P.; Herber, R.H.; Nowik, I.; Greenblatt, M.; |
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Title |
Magnetic and structural studies of the multifunctional material SrFe0.75Mo0.25O3-\text{\textgreek{d}} |
Type |
A1 Journal article |
| |
Year |
2012 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
51 |
Issue |
22 |
Pages |
12273-12280 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
SrFe0.75Mo0.25O3-delta has been recently discovered as an extremely efficient electrode for intermediate temperature solid oxide fuel cells (IT-SOFCs). We have performed structural and magnetic studies to fully characterize this multifunctional material. We have observed by powder neutron diffraction (PND) and transmission electron microscopy (TEM) that its crystal symmetry is better explained with a tetragonal symmetry (I4/mcm space group) than with the previously reported orthorhombic symmetry (Pnma space group). The temperature dependent magnetic properties indicate an exceptionally high magnetic ordering temperature (T-N similar to 750 K), well above room temperature. The ordered magnetic structure at low temperature was determined by PND to be an antiferromagnetic coupling of the Fe cations. Mossbauer spectroscopy corroborated the PND results. A detailed study, with X-ray absorption spectroscopy (XAS), in agreement with the Mossbauer results, confirmed the formal oxidation states of the cations to be mixed valence Fe3+/4+ and Mo6+. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000311173700024 |
Publication Date |
2012-10-26 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.857 |
Times cited |
12 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 4.857; 2012 IF: 4.593 |
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| |
Call Number |
UA @ lucian @ c:irua:105142 |
Serial |
1862 |
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| Permanent link to this record |
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Author |
Zhang, H.; Yang, J.-H.; Shpanchenko, R.V.; Abakumov, A.M.; Hadermann, J.; Clérac, R.; Dikarev, E.V. |
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Title |
New class of single-source precursors for the synthesis of main group-transition metal oxides: heterobimetallic Pb-Mn \beta-diketonates |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
48 |
Issue |
17 |
Pages |
8480-8488 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Heterometallic lead−manganese â-diketonates have been isolated in pure form by several synthetic methods that include solid-state and solution techniques. Two compounds with different Pb/Mn ratios, PbMn2(hfac)6 (1) and PbMn(hfac)4 (2) (hfac = hexafluoroacetylacetonate), can be obtained in quantitative yield by using different starting materials. Single crystal X-ray investigation revealed that the solid-state structure of 1 contains trinuclear molecules in which lead metal center is sandwiched between two [Mn(hfac)3] units, while 2 consists of infinite chains of alternating [Pb(hfac)2] and [Mn(hfac)2] fragments. The heterometallic structures are held together by strong Lewis acid−base interactions between metal atoms and diketonate ligands acting in chelating-bridging fashion. Spectroscopic investigation confirmed the retention of heterometallic structures in solutions of non-coordinating solvents as well as upon sublimation-deposition procedure. Thermal decomposition of heterometallic diketonates has been systematically investigated in a wide range of temperatures and annealing times. For the first time, it has been shown that thermal decomposition of heterometallic diketonates results in mixed-metal oxides, while both the structure of precursors and the thermolysis conditions have a significant influence on the nature of the resulting oxides. Five different Pb−Mn oxides have been detected by X-ray powder diffraction when studying the decomposition of 1 and 2 in the temperature range 500−800 °C. The phase that has been previously reported as Pb0.43MnO2.18 was synthesized in the pure form by decomposition of 1, and crystallographically characterized. The orthorhombic unit cell parameters of this oxide, obtained by electron diffraction technique, have been subsequently refined using X-ray powder diffraction data. Besides that, a previously unknown lead−manganese oxide has been obtained at low temperature decomposition and short annealing times. The parameters of its monoclinically distorted unit cell have been determined. The EDX analysis revealed that this compound has a Pb/Mn ratio close to 1:4 and contains no appreciable amount of fluorine. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000269313500056 |
Publication Date |
2009-08-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.857 |
Times cited |
28 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 4.857; 2009 IF: 4.657 |
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| |
Call Number |
UA @ lucian @ c:irua:78486 |
Serial |
2308 |
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| Permanent link to this record |
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Author |
Panin, R.V.; Khasanova, N.R.; Bougerol, C.; Schnelle, W.; Van Tendeloo, G.; Antipov, E.V. |
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Title |
Ordering of Pd2+ and Pd4+ in the mixed-valent palladate KPd2O3 |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
49 |
Issue |
4 |
Pages |
1295-1297 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A new potassium palladate KPd2O3 was synthesized by the reaction of KO2 and PdO at elevated oxygen pressure. Its crystal structure was solved from powder X-ray diffraction data in the space group Rm (a = 6.0730(1) Å, c = 18.7770(7) Å, and Z = 6). KPd2O3 represents a new structure type, consisting of an alternating sequence of K+ and Pd2O3− layers with ordered Pd2+ and Pd4+ ions. The presence of palladium ions in di- and tetravalent low-spin states was confirmed by magnetic susceptibility measurements. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000274240700009 |
Publication Date |
2010-01-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
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 |
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| |
Notes |
Iap Iv |
Approved |
Most recent IF: 4.857; 2010 IF: 4.326 |
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| |
Call Number |
UA @ lucian @ c:irua:80990 |
Serial |
2507 |
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| Permanent link to this record |
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Author |
Retuerto, M.; Li, M.R.; Ignatov, A.; Croft, M.; Ramanujachary, K.V.; Chi, S.; Hodges, J.P.; Dachraoui, W.; Hadermann, J.; Tran, T.T.; Halasyamani, P.S.; Grams, C.P.; Hemberger, J.; Greenblatt, M.; |
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Title |
Polar and magnetic layered A-site and rock salt B-site-ordered NaLnFeWO6 (Ln = La, Nd) perovskites |
Type |
A1 Journal article |
| |
Year |
2013 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
52 |
Issue |
21 |
Pages |
12482-12491 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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| |
Abstract |
We have expanded the double perovskite family of materials with the unusual combination of layered order in the A sublattice and rock salt order over the B sublattice to compounds NaLaFeWO6 and NaNdFeWO6. The materials have been synthesized and studied by powder X-ray diffraction, neutron diffraction, electron diffraction, magnetic measurements, X-ray absorption spectroscopy, dielectric measurements, and second harmonic generation. At room temperature, the crystal structures of both compounds can be defined in the noncentrosymmetric monoclinic P2(1) space group resulting from the combination of ordering both in the A and B sublattices, the distortion of the cell due to tilting of the octahedra, and the displacement of certain cations. The magnetic studies show that both compounds are ordered antiferromagnetically below T-N approximate to 25 K for NaLaFeWO6 and at similar to 21 K for NaNdFeWO6. The magnetic structure of NaNdFeWO6 has been solved with a propagation vector k = (1/2 0 1/2) as an antiferromagnetic arrangement of Fe and Nd moments. Although the samples are potential multiferroics, the dielectric measurements do not show a ferroelectric response. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000326669200035 |
Publication Date |
2013-10-18 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.857 |
Times cited |
17 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 4.857; 2013 IF: 4.794 |
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Call Number |
UA @ lucian @ c:irua:112714 |
Serial |
2656 |
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Author |
Abakumov, A.M.; Hadermann, J.; Batuk, M.; d' Hondt, H.; Tyablikov, O.A.; Rozova, M.G.; Pokholok, K.V.; Filimonov, D.S.; Sheptyakov, D.V.; Tsirlin, A.A.; Niermann, D.; Hemberger, J.; Van Tendeloo, G.; Antipov, E.V. |
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Title |
Slicing the Perovskite structure with crystallographic shear planes : the AnBnO3n-2 homologous series |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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| |
Volume |
49 |
Issue |
20 |
Pages |
9508-9516 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A new AnBnO3n−2 homologous series of anion-deficient perovskites has been evidenced by preparation of the members with n = 5 (Pb2.9Ba2.1Fe4TiO13) and n = 6 (Pb3.8Bi0.2Ba2Fe4.2Ti1.8O16) in a single phase form. The crystal structures of these compounds were determined using a combination of transmission electron microscopy and X-ray and neutron powder diffraction (S.G. Ammm, a = 5.74313(7), b = 3.98402(4), c = 26.8378(4) Å, RI = 0.035, RP = 0.042 for Pb2.9Ba2.1Fe4TiO13 and S.G. Imma, a = 5.7199(1), b = 3.97066(7), c = 32.5245(8) Å, RI = 0.032, RP = 0.037 for Pb3.8Bi0.2Ba2Fe4.2Ti1.8O16). The crystal structures of the AnBnO3n−2 homologues are formed by slicing the perovskite structure with (01)p crystallographic shear (CS) planes. The shear planes remove a layer of oxygen atoms and displace the perovskite blocks with respect to each other by the 1/2[110]p vector. The CS planes introduce edge-sharing connections of the transition metal−oxygen polyhedra at the interface between the perovskite blocks. This results in intrinsically frustrated magnetic couplings between the perovskite blocks due to a competition of the exchange interactions between the edge- and the corner-sharing metal−oxygen polyhedra. Despite the magnetic frustration, neutron powder diffraction and Mssbauer spectroscopy reveal that Pb2.9Ba2.1Fe4TiO13 and Pb3.8Bi0.2Ba2Fe4.2Ti1.8O16 are antiferromagnetically ordered below TN = 407 and 343 K, respectively. The Pb2.9Ba2.1Fe4TiO13 and Pb3.8Bi0.2Ba2Fe4.2Ti1.8O16 compounds are in a paraelectric state in the 5−300 K temperature range. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000282783400051 |
Publication Date |
2010-09-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
23 |
Open Access |
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Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 4.857; 2010 IF: 4.326 |
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Call Number |
UA @ lucian @ c:irua:84963 |
Serial |
3041 |
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| Permanent link to this record |
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Author |
Malo, S.; Abakumov, A.M.; Daturi, M.; Pelloquin, D.; Van Tendeloo, G.; Guesdon, A.; Hervieu, M. |
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Title |
Sr21Bi8Cu2(CO3)(2)O-41, a Bi5+ Oxycarbonate with an Original 10L Structure |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
53 |
Issue |
19 |
Pages |
10266-10275 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The layered structure of Sr21Bi8Cu2(CO3)(2)O-41 (Z = 2) was determined by transmission electron microscopy, infrared spectroscopy, and powder X-ray diffraction refinement in space group P6(3)/mcm (No. 194), with a = 10.0966(3)angstrom and c = 26.3762(5)angstrom. This original 10L-type structure is built from two structural blocks, namely, [Sr15Bi6Cu2(CO3)O-29] and [Sr6Bi2(CO3)O-12]. The Bi5+ cations form [Bi2O10] dimers, whereas the Cu2+ and C atoms occupy infinite tunnels running along (c) over right arrow. The nature of the different blocks and layers is discussed with regard to the existing hexagonal layered compounds. Sr21Bi8Cu2(CO3)(2)O-41 is insulating and paramagnetic. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000342856800039 |
Publication Date |
2014-10-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
4.857 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 4.857; 2014 IF: 4.762 |
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Call Number |
UA @ lucian @ c:irua:121115 |
Serial |
3114 |
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| Permanent link to this record |
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Author |
Abakumov, A.M.; Batuk, M.; Tsirlin, A.A.; Tyablikov, O.A.; Sheptyakov, D.V.; Filimonov, D.S.; Pokholok, K.V.; Zhidal, V.S.; Rozova, M.G.; Antipov, E.V.; Hadermann, J.; Van Tendeloo, G.; |
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Title |
Structural and magnetic phase transitions in the AnBnO3n-2 anion-deficient perovskites Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
52 |
Issue |
14 |
Pages |
7834-7843 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Novel anion-deficient perovskite-based ferrites Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 were synthesized by solid-state reaction in air. Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 belong to the perovskite-based AnBnO3n2 homologous series with n = 5 and 6, respectively, with a unit cell related to the perovskite subcell ap as ap√2 × ap × nap√2. Their structures are derived from the perovskite one by slicing it with 1/2[110]p(1̅01)p crystallographic shear (CS) planes. The CS operation results in (1̅01)p-shaped perovskite blocks with a thickness of (n 2) FeO6 octahedra connected to each other through double chains of edge-sharing FeO5 distorted tetragonal pyramids which can adopt two distinct mirror-related configurations. Ordering of chains with a different configuration provides an extra level of structure complexity. Above T ≈ 750 K for Pb2Ba2BiFe5O13 and T ≈ 400 K for Pb1.5Ba2.5Bi2Fe6O16 the chains have a disordered arrangement. On cooling, a second-order structural phase transition to the ordered state occurs in both compounds. Symmetry changes upon phase transition are analyzed using a combination of superspace crystallography and group theory approach. Correlations between the chain ordering pattern and octahedral tilting in the perovskite blocks are discussed. Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 undergo a transition into an antiferromagnetically (AFM) ordered state, which is characterized by a G-type AFM ordering of the Fe magnetic moments within the perovskite blocks. The AFM perovskite blocks are stacked along the CS planes producing alternating FM and AFM-aligned FeFe pairs. In spite of the apparent frustration of the magnetic coupling between the perovskite blocks, all n = 4, 5, 6 AnFenO3n2 (A = Pb, Bi, Ba) feature robust antiferromagnetism with similar Néel temperatures of 623632 K. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000322087100006 |
Publication Date |
2013-02-13 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
10 |
Open Access |
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Notes |
Countatoms |
Approved |
Most recent IF: 4.857; 2013 IF: 4.794 |
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Call Number |
UA @ lucian @ c:irua:109213 |
Serial |
3196 |
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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.; |
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Title |
Synthesis, crystal structure, transport, and magnetic properties of novel ternary copper phosphides, A2Cu6P5(A = Sr, Eu) and EuCu4P3 |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
51 |
Issue |
16 |
Pages |
8948-8955 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000307606200042 |
Publication Date |
2012-07-31 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
13 |
Open Access |
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Notes |
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Approved |
Most recent IF: 4.857; 2012 IF: 4.593 |
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Call Number |
UA @ lucian @ c:irua:102217 |
Serial |
3453 |
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| Permanent link to this record |
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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. |
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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 |
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Year |
2013 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
52 |
Issue |
2 |
Pages |
577-588 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000314007500010 |
Publication Date |
2012-12-31 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
14 |
Open Access |
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Notes |
|
Approved |
Most recent IF: 4.857; 2013 IF: 4.794 |
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Call Number |
UA @ lucian @ c:irua:107689 |
Serial |
3463 |
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| Permanent link to this record |
