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Author Tyablikov, O.A.; Batuk, D.; Tsirlin, A.A.; Batuk, M.; Verchenko, V.Y.; Filimonov, D.S.; Pokholok, K.V.; Sheptyakov, D.V.; Rozova, M.G.; Hadermann, J.; Antipov, E.V.; Abakumov, A.M.; pdf  url
doi  openurl
  Title {110}-Layered B-cation ordering in the anion-deficient perovskite Pb2.4Ba2.6Fe2Sc2TiO13 with the crystallographic shear structure Type A1 Journal article
  Year 2015 Publication Journal of the Chemical Society : Dalton transactions Abbreviated Journal Dalton T  
  Volume 44 Issue 44 Pages 10753-10762  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract A novel anion-deficient perovskite-based compound, Pb2.4Ba2.6Fe2Sc2TiO13, was synthesized via the citrate-based route. This compound is an n = 5 member of the A(n)B(n)O(3n-2) homologous series with unit-cell parameters related to the perovskite subcell a(p) approximate to 4.0 angstrom as a(p)root 2 x a(p) x 5a(p)root 2. The crystal structure of Pb2.4Ba2.6Fe2Sc2TiO13 consists of quasi-2D perovskite blocks with a thickness of three octahedral layers separated by the 1/2[110]((1) over bar 01)(p) crystallographic shear (CS) planes, which are parallel to the {110} plane of the perovskite subcell. The CS planes transform the corner-sharing octahedra into chains of edge-sharing distorted tetragonal pyramids. Using a combination of neutron powder diffraction, Fe-57 Mossbauer spectroscopy and atomic resolution electron energy-loss spectroscopy we demonstrate that the B-cations in Pb2.4Ba2.6Fe2Sc2TiO13 are ordered along the {110} perovskite layers with Fe3+ in distorted tetragonal pyramids along the CS planes, Ti4+ preferentially in the central octahedra of the perovskite blocks and Sc3+ in the outer octahedra of the perovskite blocks. Magnetic susceptibility and Mossbauer spectroscopy indicate a broadened magnetic transition around T-N similar to 45 K and the onset of local magnetic fields at low temperatures. The magnetic order is probably reminiscent of that in other A(n)B(n)O(3n-2) homologues, where G-type AFM order within the perovskite blocks has been observed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000355701000026 Publication Date 2015-01-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1477-9226;1477-9234; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.029 Times cited 1 Open Access  
  Notes (up) Approved Most recent IF: 4.029; 2015 IF: 4.197  
  Call Number c:irua:127001 Serial 22  
Permanent link to this record
 

 
Author Van Tendeloo, G.; Hadermann, J.; Abakumov, A.M.; Antipov, E.V. pdf  doi
openurl 
  Title Advanced electron microscopy and its possibilities to solve complex structures: application to transition metal oxides Type A1 Journal article
  Year 2009 Publication Journal of materials chemistry Abbreviated Journal J Mater Chem  
  Volume 19 Issue 18 Pages 2660-2670  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Design and optimization of materials properties can only be performed through a thorough knowledge of the structure of the compound. In this feature article we illustrate the possibilities of advanced electron microscopy in materials science and solid state chemistry. The different techniques are briefly discussed and several examples are given where the structures of complex oxides, often with a modulated structure, have been solved using electron microscopy.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000265740600002 Publication Date 2009-02-04  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0959-9428;1364-5501; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 9 Open Access  
  Notes (up) Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:77065 Serial 68  
Permanent link to this record
 

 
Author Sun, M.; Rousse, G.; Abakumov, A.M.; Van Tendeloo, G.; Sougrati, M.-T.; Courty, M.; Doublet, M.-L.; Tarascon, J.-M. doi  openurl
  Title An oxysulfate Fe2O(SO4)2 electrode for sustainable Li-based batteries Type A1 Journal article
  Year 2014 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc  
  Volume 136 Issue 36 Pages 12658-12666  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract High-performing Fe-based electrodes for Li-based batteries are eagerly pursued because of the abundance and environmental benignity of iron, with especially great interest in polyanionic compounds because of their flexibility in tuning the Fe3+/Fe2+ redox potential. We report herein the synthesis and structure of a new Fe-based oxysulfate phase, Fe2O(SO4)(2), made at low temperature from abundant elements, which electrochemically reacts with nearly 1.6 Li atoms at an average voltage of 3.0 V versus Li+/Li, leading to a sustained reversible capacity of similar to 125 mAh/g. The Li insertiondeinsertion process, the first ever reported in any oxysulfate, entails complex phase transformations associated with the position of iron within the FeO6 octahedra. This finding opens a new path worth exploring in the quest for new positive electrode materials.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000341544600029 Publication Date 2014-08-14  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 13.858 Times cited 11 Open Access  
  Notes (up) Approved Most recent IF: 13.858; 2014 IF: 12.113  
  Call Number UA @ lucian @ c:irua:119906 Serial 96  
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Author Abakumov, A.M.; Hadermann, J.; Van Tendeloo, G.; Shpanchenko, R.V.; Oleinikov, P.N.; Antipov, E.V. pdf  doi
openurl 
  Title Anion ordering in fluorinated La2CuO4 Type A1 Journal article
  Year 1999 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem  
  Volume 142 Issue Pages 311-322  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000078597400024 Publication Date 2002-10-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-4596; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.299 Times cited 20 Open Access  
  Notes (up) Approved Most recent IF: 2.299; 1999 IF: 1.547  
  Call Number UA @ lucian @ c:irua:29277 Serial 121  
Permanent link to this record
 

 
Author Hadermann, J.; Abakumov, A.M.; Van Tendeloo, G.; Shpanchenko, R.V.; Oleinikov, P.N.; Antipov, E.V. openurl 
  Title Anion ordering in fluorinated La2CuO4 Type H1 Book chapter
  Year 1999 Publication Abbreviated Journal  
  Volume Issue Pages 133-138  
  Keywords H1 Book chapter; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication s.l. Editor  
  Language Wos 000079308200022 Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record; WoS full record;  
  Impact Factor Times cited Open Access  
  Notes (up) Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:29278 Serial 122  
Permanent link to this record
 

 
Author Corbel, G.; Attfield, J.P.; Hadermann, J.; Abakumov, A.M.; Alekseeva, A.M.; Rozova, M.G.; Antipov, E.V. pdf  doi
openurl 
  Title Anion rearrangements in fluorinated Nd2CuO3.5 Type A1 Journal article
  Year 2003 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 15 Issue Pages 189-195  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000180368000029 Publication Date 2003-01-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 9.466 Times cited 9 Open Access  
  Notes (up) Approved Most recent IF: 9.466; 2003 IF: 4.374  
  Call Number UA @ lucian @ c:irua:40348 Serial 123  
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Author Abakumov, A.M.; Batuk, D.; Hadermann, J.; Rozova, M.G.; Sheptyakov, D.V.; Tsirlin, A.A.; Niermann, D.; Waschowski, F.; Hemberger, J.; Van Tendeloo, G.; Antipov, E.V. doi  openurl
  Title Antiferroelectric (Pb,Bi)1-xFe1+xO3-y perovskites modulated by crystallographic shear planes Type A1 Journal article
  Year 2011 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 23 Issue 2 Pages 255-265  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We demonstrate for the first time a possibility to vary the anion content in perovskites over a wide range through a long-range-ordered arrangement of crystallographic shear (CS) planes. Anion-deficient perovskites (Pb,Bi)1−xFe1+xO3−y with incommensurately modulated structures were prepared as single phases in the compositional range from Pb0.857Bi0.094Fe1.049O2.572 to Pb0.409Bi0.567Fe1.025O2.796. Using a combination of electron diffraction and high-resolution scanning transmission electron microscopy, we constructed a superspace model describing a periodic arrangement of the CS planes. The model was verified by refinement of the Pb0.64Bi0.32Fe1.04O2.675 crystal structure from neutron powder diffraction data ((3 + 1)D S.G. X2/m(α0γ), X = [1/2,1/2,1/2,1/2], a = 3.9082(1) Å, b = 3.90333(8) Å, c = 4.0900(1) Å, β = 91.936(2)°, q = 0.05013(4)a* + 0.09170(3)c* at T = 700 K, RP = 0.036, RwP = 0.048). The (Pb,Bi)1−xFe1+xO3−y structures consist of perovskite blocks separated by CS planes confined to nearly the (509)p perovskite plane. Along the CS planes, the perovskite blocks are shifted with respect to each other over the 1/2[110]p vector that transforms the corner-sharing connectivity of the FeO6 octahedra in the perovskite framework to an edge-sharing connectivity of the FeO5 pyramids at the CS plane, thus reducing the oxygen content. Variation of the chemical composition in the (Pb,Bi)1−xFe1+xO3−y series occurs mainly because of a changing thickness of the perovskite block between the interfaces, that can be expressed through the components of the q vector as Pb6γ+2αBi1−7γ−αFe1+γ−αO3−3γ−α. The Pb, Bi, and Fe atoms are subjected to strong displacements occurring in antiparallel directions on both sides of the perovskite blocks, resulting in an antiferroelectric-type structure. This is corroborated by the temperature-, frequency-, and field-dependent complex permittivity measurements. Pb0.64Bi0.32Fe1.04O2.675 demonstrates a remarkably high resistivity >0.1 T Ω cm at room temperature and orders antiferromagnetically below TN = 608(10) K.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000286160800018 Publication Date 2010-12-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 9.466 Times cited 29 Open Access  
  Notes (up) Approved Most recent IF: 9.466; 2011 IF: 7.286  
  Call Number UA @ lucian @ c:irua:88651 Serial 136  
Permanent link to this record
 

 
Author Belik, A.A.; Abakumov, A.M.; Tsirlin, A.A.; Hadermann, J.; Kim, J.; Van Tendeloo, G.; Takayama-Muromachi, E. doi  openurl
  Title Article Structure and magnetic properties of BiFe0.75Mn0.25O3 perovskite prepared at ambient and high pressure Type A1 Journal article
  Year 2011 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 23 Issue 20 Pages 4505-4514  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Solid solutions of BiFe1xMnxO3 (0.0 ≤ x ≤ 0.4) were prepared at ambient pressure and at 6 GPa. The ambient-pressure (AP) phases crystallize in space group R3c similarly to BiFeO3. The high-pressure (HP) phases crystallize in space group R3c for x = 0.05 and in space group Pnma for 0.15 ≤ x ≤ 0.4. The structure of HP-BiFe0.75Mn0.25O3 was investigated using synchrotron X-ray powder diffraction, electron diffraction, and transmission electron microscopy. HP-BiFe0.75Mn0.25O3 has a PbZrO3-related √2ap × 4ap × 2√2ap (ap is the parameter of the cubic perovskite subcell) superstructure with a = 5.60125(9) Å, b = 15.6610(2) Å, and c = 11.2515(2) Å similar to that of Bi0.82La0.18FeO3. A remarkable feature of this structure is the unconventional octahedral tilt system, with the primary ab0a tilt superimposed on pairwise clockwise and counterclockwise rotations around the b-axis according to the oioi sequence (o stands for out-of-phase tilt, and i stands for in-phase tilt). The (FeMn)O6 octahedra are distorted, with one longer metaloxygen bond (2.222.23 Å) that can be attributed to a compensation for covalent BiO bonding. Such bonding results in the localization of the lone electron pair on Bi3+ cations, as confirmed by electron localization function analysis. The relationship between HP-BiFe0.75Mn0.25O3 and antiferroelectric structures of PbZrO3 and NaNbO3 is discussed. On heating in air, HP-BiFe0.75Mn0.25O3 irreversibly transforms to AP-BiFe0.75Mn0.25O3 starting from about 600 K. Both AP and HP phases undergo an antiferromagnetic ordering at TN ≈ 485 and 520 K, respectively, and develop a weak net magnetic moment at low temperatures. Additionally, ceramic samples of AP-BiFe0.75Mn0.25O3 show a peculiar phenomenon of magnetization reversal.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000295897400015 Publication Date 2011-09-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 9.466 Times cited 57 Open Access  
  Notes (up) Approved Most recent IF: 9.466; 2011 IF: 7.286  
  Call Number UA @ lucian @ c:irua:93581 Serial 151  
Permanent link to this record
 

 
Author Abakumov, A.M.; Hadermann, J.; Van Tendeloo, G.; Antipov, E.V. pdf  doi
openurl 
  Title Chemistry and structure of anion-deficient perovskites with translational interfaces Type A1 Journal article
  Year 2008 Publication Journal of the American Ceramic Society Abbreviated Journal J Am Ceram Soc  
  Volume 91 Issue 6 Pages 1807-1813  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Columbus, Ohio Editor  
  Language Wos 000256410700010 Publication Date 2008-04-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0002-7820;1551-2916; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.841 Times cited 39 Open Access  
  Notes (up) Approved Most recent IF: 2.841; 2008 IF: 2.101  
  Call Number UA @ lucian @ c:irua:70088 Serial 355  
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Author Hadermann, J.; Abakumov, A.M.; Van Rompaey, S.; Mankevich, A.S.; Korsakov, I.E. doi  openurl
  Title Comment on ALaMn2O6-y (A = K, Rb): novel ferromagnetic manganites exhibiting negative giant magnetoresistance Type Editorial
  Year 2009 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 21 Issue 9 Pages 2000-2001  
  Keywords Editorial; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000265781000036 Publication Date 2009-04-14  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 9.466 Times cited 4 Open Access  
  Notes (up) Approved Most recent IF: 9.466; 2009 IF: 5.368  
  Call Number UA @ lucian @ c:irua:77055 Serial 411  
Permanent link to this record
 

 
Author Abakumov, A.M.; d' Hondt, H.; Rossell, M.D.; Tsirlin, A.A.; Gutnikova, O.; Filimonov, D.S.; Schnelle, W.; Rosner, H.; Hadermann, J.; Van Tendeloo, G.; Antipov, E.V. doi  openurl
  Title Coupled anion and cation ordering in Sr3RFe4O10.5 (R=Y, Ho, Dy) anion-deficientperovskites Type A1 Journal article
  Year 2010 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem  
  Volume 183 Issue 12 Pages 2845-2854  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The Sr3RFe4O10.5 (R=Y, Ho, Dy) anion-deficient perovskites were prepared using a solid-state reaction in evacuated sealed silica tubes. Transmission electron microscopy and 57Fe Mössbauer spectroscopy evidenced a complete A-cations and oxygen vacancies ordering. The structure model was further refined by ab initio structure relaxation, based on density functional theory calculations. The compounds crystallize in a tetragonal a≈2√2ap≈11.3 Å, с≈4сp≈16 Å unit cell (ap: parameter of the perovskite subcell) with the P42/mnm space group. Oxygen vacancies reside in the (FeO5/4□3/4) layers, comprising corner-sharing FeO4 tetrahedra and FeO5 tetragonal pyramids, which are sandwiched between the layers of the FeO6 octahedra. Smaller R atoms occupy the 9-fold coordinated position, whereas the 10-fold coordinated positions are occupied by larger Sr atoms. The Fe sublattice is ordered aniferromagnetically up to at least 500 K, while the rare-earth sublattice remains disordered down to 2 K.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000285431100014 Publication Date 2010-10-02  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-4596; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.299 Times cited 8 Open Access  
  Notes (up) Approved Most recent IF: 2.299; 2010 IF: 2.261  
  Call Number UA @ lucian @ c:irua:88071 Serial 533  
Permanent link to this record
 

 
Author Shpanchenko, R.V.; Chyornaya, V.V.; Abakumov, A.M.; Antipov, E.V.; Hadermann, J.; Van Tendeloo, G.; Kaul, E.; Geibel, C.; Sheptyakov, D.; Balagurov, A.M. doi  openurl
  Title Crystal structure and magnetic properties of novel reduced V(IV)-based oxide Pb2V5O12 Type A1 Journal article
  Year 2001 Publication Zeitschrift für anorganische und allgemeine Chemie Abbreviated Journal Z Anorg Allg Chem  
  Volume 627 Issue Pages 2143-2150  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Leipzig Editor  
  Language Wos 000171339000023 Publication Date 2002-08-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0044-2313;1521-3749; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.144 Times cited 4 Open Access  
  Notes (up) Approved Most recent IF: 1.144; 2001 IF: 1.165  
  Call Number UA @ lucian @ c:irua:36048 Serial 560  
Permanent link to this record
 

 
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. doi  openurl
  Title Crystal structure and phase transitions in Sr3WO6 Type A1 Journal article
  Year 2010 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 49 Issue 13 Pages 6058-6065  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000279211500036 Publication Date 2010-06-09  
  Series Editor Series Title Abbreviated Series Title  
  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 18 Open Access  
  Notes (up) Approved Most recent IF: 4.857; 2010 IF: 4.326  
  Call Number UA @ lucian @ c:irua:83877 Serial 562  
Permanent link to this record
 

 
Author Panin, R.V.; Khasanova, N.R.; Abakumov, A.M.; Schnelle, W.; Hadermann, J.; Antipov, E.V. doi  openurl
  Title Crystal structure and properties of the Na1-xRu2O4 phase Type A1 Journal article
  Year 2006 Publication Russian chemical bulletin Abbreviated Journal Russ Chem B+  
  Volume 55 Issue 10 Pages 1717-1722  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000245091400003 Publication Date 2007-03-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1066-5285;1573-9171; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 0.529 Times cited 5 Open Access  
  Notes (up) Approved Most recent IF: 0.529; 2006 IF: 0.505  
  Call Number UA @ lucian @ c:irua:63810 Serial 566  
Permanent link to this record
 

 
Author Abakumov, A.M.; King, G.; Laurinavichute, V.K.; Rozova, M.G.; Woodward, P.M.; Antipov, E.V. doi  openurl
  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  
  Volume 48 Issue 19 Pages 9336-9344  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000270091000039 Publication Date 2009-09-03  
  Series Editor Series Title Abbreviated Series Title  
  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 20 Open Access  
  Notes (up) Approved Most recent IF: 4.857; 2009 IF: 4.657  
  Call Number UA @ lucian @ c:irua:79733 Serial 568  
Permanent link to this record
 

 
Author Abakumov, A.M.; Van Tendeloo, G.; Scheglov, A.A.; Shpanchenko, R.V.; Antipov, E.V. pdf  doi
openurl 
  Title The crystal structure of Ba8Ta6NiO24: cation ordering in hexagonal perovskites Type A1 Journal article
  Year 1996 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem  
  Volume 125 Issue Pages 102-107  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos A1996VB31300015 Publication Date 2002-10-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-4596; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.133 Times cited 38 Open Access  
  Notes (up) Approved no  
  Call Number UA @ lucian @ c:irua:16868 Serial 569  
Permanent link to this record
 

 
Author Abakumov, A.M.; Shpanchenko, R.V.; Antipov, E.V.; Lebedev, O.I.; Van Tendeloo, G. openurl 
  Title The crystal structure of Ca3ReO6 Type A1 Journal article
  Year 1997 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem  
  Volume 131 Issue Pages 305-309  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos A1997XQ33000014 Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-4596 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.299 Times cited 10 Open Access  
  Notes (up) Approved Most recent IF: 2.299; 1997 IF: 1.486  
  Call Number UA @ lucian @ c:irua:21442 Serial 571  
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Author Reynaud, M.; Rousse, G.; Abakumov, A.M.; Sougrati, M.T.; Van Tendeloo, G.; Chotard, J.-N.; Tarascon, J.-M. doi  openurl
  Title Design of new electrode materials for Li-ion and Na-ion batteries from the bloedite mineral Na2Mg(SO4)2\cdot4H2O Type A1 Journal article
  Year 2014 Publication Journal of materials chemistry A : materials for energy and sustainability Abbreviated Journal J Mater Chem A  
  Volume 2 Issue 8 Pages 2671-2680  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Mineralogy offers a large database to search for Li- or Na-based compounds having suitable structural features for acting as electrode materials, LiFePO4 being one example. Here we further explore this avenue and report on the electrochemical properties of the bloedite type compounds Na2M(SO4)(2)center dot 4H(2)O (M = Mg, Fe, Co, Ni, Zn) and their dehydrated phases Na2M(SO4)(2) (M = Fe, Co), whose structures have been solved via complementary synchrotron X-ray diffraction, neutron powder diffraction and transmission electron microscopy. Among these compounds, the hydrated and anhydrous iron-based phases show electrochemical activity with the reversible release/uptake of 1 Na+ or 1 Li+ at high voltages of similar to 3.3 V vs. Na+/Na-0 and similar to 3.6 V vs. Li+/Li-0, respectively. Although the reversible capacities remain lower than 100 mA h g(-1), we hope this work will stress further the importance of mineralogy as a source of inspiration for designing eco-efficient electrode materials.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000331247500031 Publication Date 2013-11-22  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2050-7488;2050-7496; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 8.867 Times cited 56 Open Access  
  Notes (up) Approved Most recent IF: 8.867; 2014 IF: 7.443  
  Call Number UA @ lucian @ c:irua:115807 Serial 659  
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Author Rossell, M.D.; Abakumov, A.M.; Ramasse, Q.M.; Erni, R. doi  openurl
  Title Direct evidence of stacking disorder in the mixed ionic-electronic conductor Sr4Fe6O12+\delta Type A1 Journal article
  Year 2013 Publication ACS nano Abbreviated Journal Acs Nano  
  Volume 7 Issue 4 Pages 3078-3085  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Determining the structure-to-property relationship of materials becomes particularly challenging when the material under investigation is dominated by defects and structural disorder. Knowledge on the exact atomic arrangement at the defective structure is required to understand its influence on the functional properties. However, standard diffraction techniques deliver structural information that is averaged over many unit cells. In particular, information about defects and order-disorder phenomena is contained in the coherent diffuse scattering intensity which often is difficult to uniquely interpret. Thus, the examination of the local disorder in materials requires a direct method to study their structure on the atomic level with chemical sensitivity. Using aberration-corrected scanning transmission electron microscopy in combination with atomic-resolution electron energy-loss spectroscopy, we show that the controversial structural arrangement of the Fe2O2+delta layers in the mixed ionic-electronic conducting Sr4Fe6O12+delta perovskite can be unambiguously resolved. Our results provide direct experimental evidence for the presence of a nanomixture of “ordered” and “disordered” domains in an epitaxial Sr4Fe6O12+delta thin film. The most favorable arrangement is the disordered structure and is interpreted as a randomly occurring but well-defined local shift of the Fe-O chains in the Fe2O2+delta layers. By analyzing the electron energy-loss near-edge structure of the different building blocks in the Sr4Fe6O12+delta unit cell we find that the mobile holes in this mixed ionic-electronic conducting oxide are highly localized in the Fe2O2+delta layers, which are responsible for the oxide-ion conductivity. A possible link between disorder and oxygen-ion transport along the Fe2O2+delta layers is proposed by arguing that the disorder can effectively break the oxygen diffusion pathways.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000318143300021 Publication Date 2013-03-04  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1936-0851;1936-086X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 13.942 Times cited 4 Open Access  
  Notes (up) Approved Most recent IF: 13.942; 2013 IF: 12.033  
  Call Number UA @ lucian @ c:irua:108476 Serial 713  
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Author Meert, K.W.; Morozov, V.A.; Abakumov, A.M.; Hadermann, J.; Poelman, D.; Smet, P.F. url  doi
openurl 
  Title Energy transfer in Eu3+ doped scheelites : use as thermographic phosphor Type A1 Journal article
  Year 2014 Publication Optics express Abbreviated Journal Opt Express  
  Volume 22 Issue 9 Pages A961-A972  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract In this paper the luminescence of the scheelite-based CaGd2(1-x)Eu2x(WO4)4 solid solutions is investigated as a function of the Eu content and temperature. All phosphors show intense red luminescence due to the 5D0 7F2 transition in Eu3+, along with other transitions from the 5D1 and 5D0 excited states. For high Eu3+ concentrations the intensity ratio of the emission originating from the 5D1 and 5D0 levels has a non-conventional temperature dependence, which could be explained by a phonon-assisted cross-relaxation process. It is demonstrated that this intensity ratio can be used as a measure of temperature with high spatial resolution, allowing the use of these scheelites as thermographic phosphor. The main disadvantage of many thermographic phosphors, a decreasing signal for increasing temperature, is absent.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000335905300037 Publication Date 2014-04-22  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1094-4087; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.307 Times cited 47 Open Access  
  Notes (up) Approved Most recent IF: 3.307; 2014 IF: 3.488  
  Call Number UA @ lucian @ c:irua:117067 Serial 1044  
Permanent link to this record
 

 
Author Hadermann, J.; Abakumov, A.M.; Tsirlin, A.A.; Rozova, M.G.; Sarakinou, E.; Antipov, E.V. doi  openurl
  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  
  Volume 51 Issue 21 Pages 11487-11492  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000313220200036 Publication Date 2012-10-17  
  Series Editor Series Title Abbreviated Series Title  
  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 2 Open Access  
  Notes (up) Approved Most recent IF: 4.857; 2012 IF: 4.593  
  Call Number UA @ lucian @ c:irua:110121 Serial 1133  
Permanent link to this record
 

 
Author Kirsanova, M.A.; Olenev, A.V.; Abakumov, A.M.; Bykov, M.A.; Shevelkov, A.V. doi  openurl
  Title Extension of the clathrate family : the type X clathrate Ge79P29S18Te6 Type A1 Journal article
  Year 2011 Publication Angewandte Chemie: international edition in English Abbreviated Journal Angew Chem Int Edit  
  Volume 50 Issue 10 Pages 2371-2374  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Now they are 10! The title compound displays a new type of crystal structure and is labeled clathrate X according to the general classification of clathrate structures. In contrast to typical clathrates, this compound has three-coordinate atoms within the framework and combines distorted 24-vertex polyhedra (see picture, green) centered around tellurium guest atoms with very irregular 10-vertex polyhedra around sulfur atoms (yellow).  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Weinheim Editor  
  Language Wos 000288036300033 Publication Date 2011-01-31  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1433-7851; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 11.994 Times cited 23 Open Access  
  Notes (up) Approved Most recent IF: 11.994; 2011 IF: 13.455  
  Call Number UA @ lucian @ c:irua:88793 Serial 1158  
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Author Zaikina, J.V.; Batuk, M.; Abakumov, A.M.; Navrotsky, A.; Kauziarich, S.M. pdf  url
doi  openurl
  Title Facile synthesis of Ba1-xKxFe2As2 superconductors via hydride route Type A1 Journal article
  Year 2014 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc  
  Volume 136 Issue 48 Pages 16932-16939  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We have developed a fast, easy, and scalable synthesis method for Ba1xKxFe2As2 (0 ≤ x ≤ 1) superconductors using hydrides BaH2 and KH as a source of barium and potassium metals. Synthesis from hydrides provides better mixing and easier handling of the starting materials, consequently leading to faster reactions and/or lower synthesis temperatures. The reducing atmosphere provided by the evolved hydrogen facilitates preparation of oxygen-free powders. By a combination of methods we have shown that Ba1xKxFe2As2 obtained via hydride route has the same characteristics as when it is prepared by traditional solid-state synthesis. Refinement from synchrotron powder X-ray diffraction data confirms a linear dependence of unit cell parameters upon K content as well as the tetragonal to orthorhombic transition at low temperatures for compositions with x < 0.2. Magnetic measurements revealed dome-like dependence of superconducting transition temperature Tc upon K content with a maximum of 38 K for x close to 0.4. Electron diffraction and high-resolution high-angle annular dark-field scanning transmission electron microscopy indicates an absence of Ba/K ordering, while local inhomogeneity in the Ba/K distribution takes place at a scale of several angstroms along [110] crystallographic direction.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000345883900040 Publication Date 2014-11-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 13.858 Times cited 13 Open Access  
  Notes (up) Approved Most recent IF: 13.858; 2014 IF: 12.113  
  Call Number UA @ lucian @ c:irua:121331 Serial 1169  
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Author Abakumov, A.M.; Lebedev, O.I.; Nistor, L.; Van Tendeloo, G.; Amelinckx, S. pdf  doi
openurl 
  Title The ferroelectric phase transition in tridymite type BaAl2O4 studied by electron microscopy Type A1 Journal article
  Year 2000 Publication Phase transitions Abbreviated Journal Phase Transit  
  Volume 71 Issue Pages 143-160  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York Editor  
  Language Wos 000088795800005 Publication Date 2007-07-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0141-1594;1029-0338; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.06 Times cited 21 Open Access  
  Notes (up) Approved Most recent IF: 1.06; 2000 IF: NA  
  Call Number UA @ lucian @ c:irua:54724 Serial 1181  
Permanent link to this record
 

 
Author Navulla, A.; Tsirlin, A.A.; Abakumov, A.M.; Shpanchenko, R.V.; Zhang, H.; Dikarev, E.V. doi  openurl
  Title Fluorinated heterometallic \beta-diketonates as volatile single-source precursors for the synthesis of low-valent mixed-metal fluorides Type A1 Journal article
  Year 2011 Publication Journal of the American Chemical Society Abbreviated Journal J Am Chem Soc  
  Volume 133 Issue 4 Pages 692-694  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Hexafluoroacetylacetonates that contain lead and divalent first-row transition metals, PbM(hfac)4 (M = Ni (1), Co (2), Mn (3), Fe (4), and Zn (5)), have been synthesized. Their heterometallic structures are held together by strong Lewis acid−base interactions between metal atoms and diketonate ligands acting in chelating−bridging fashion. Compounds 1−5 are highly volatile and decompose below 350 °C. Fluorinated heterometallic β-diketonates have been used for the first time as volatile single-source precursors for the preparation of mixed-metal fluorides. Complex fluorides of composition Pb2MF6 have been obtained by decomposition of 1−5 in a two-zone furnace under low-pressure nitrogen flow. Lead−transition metal fluorides conform to orthorhombically distorted Aurivillius-type structure with layers of corner-sharing [MF6] octahedra separated by α-PbO-type (Pb2F2) blocks. Pb2NiF6 and Pb2CoF6 were found to exhibit magnetic ordering below 80 and 43 K, respectively. The ordering is antiferromagnetic, with a weak, uncompensated moment due to the canting of spins. The Pb2MF6 fluorides represent a new class of prospective magnetoelectric materials combining transition metals and lone-pair main-group cations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000287295300015 Publication Date 2010-12-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0002-7863;1520-5126; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 13.858 Times cited 28 Open Access  
  Notes (up) Approved Most recent IF: 13.858; 2011 IF: 9.907  
  Call Number UA @ lucian @ c:irua:88820 Serial 1236  
Permanent link to this record
 

 
Author Abakumov, A.M.; Batuk, D.; Tsirlin, A.A.; Prescher, C.; Dubrovinsky, L.; Sheptyakov, D.V.; Schnelle, W.; Hadermann, J.; Van Tendeloo, G. url  doi
openurl 
  Title Frustrated pentagonal Cairo lattice in the non-collinear antiferromagnet Bi4Fe5O13F Type A1 Journal article
  Year 2013 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 87 Issue 2 Pages 024423-24429  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We report on the crystal structure and magnetism of the iron-based oxyfluoride Bi4Fe5O13F, a material prototype of the Cairo pentagonal spin lattice. The crystal structure of Bi4Fe5O13F is determined by a combination of neutron diffraction, synchrotron x-ray diffraction, and transmission electron microscopy. It comprises layers of FeO6 octahedra and FeO4 tetrahedra forming deformed pentagonal units. The topology of these layers resembles a pentagonal least-perimeter tiling, which is known as the Cairo lattice. This topology gives rise to frustrated exchange couplings and underlies a sequence of magnetic transitions at T-1 = 62 K, T-2 = 71 K, and T-N = 178 K, as determined by thermodynamic measurements and neutron diffraction. Below T-1, Bi4Fe5O13F forms a fully ordered non-collinear antiferromagnetic structure, whereas the magnetic state between T-1 and T-N may be partially disordered according to the sizable increase in the magnetic entropy at T-1 and T-2. Bi4Fe5O13F reveals unanticipated magnetic transitions on the pentagonal Cairo spin lattice and calls for a further work on finite-temperature properties of this strongly frustrated spin model. DOI: 10.1103/PhysRevB.87.024423  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000314224800002 Publication Date 2013-02-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 17 Open Access  
  Notes (up) Approved Most recent IF: 3.836; 2013 IF: 3.664  
  Call Number UA @ lucian @ c:irua:107688 Serial 1293  
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Author Tsirlin, A.A.; Nath, R.; Abakumov, A.M.; Shpanchenko, R.V.; Geibel, C.; Rosner, H. url  doi
openurl 
  Title Frustrated square lattice with spatial anisotropy: crystal structure and magnetic properties of PbZnVO(PO4)2 Type A1 Journal article
  Year 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 81 Issue 17 Pages 174424,1-174424,13  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Crystal structure and magnetic properties of the layered vanadium phosphate PbZnVO(PO4)2 are studied using x-ray powder diffraction, magnetization and specific-heat measurements, as well as band-structure calculations. The compound resembles AA′VO(PO4)2 vanadium phosphates and fits to the extended frustrated square-lattice model with the couplings J1, J1′ between nearest neighbors and J2, J2′ between next-nearest neighbors. The temperature dependence of the magnetization yields estimates of averaged nearest-neighbor and next-nearest-neighbor couplings, J̅ 1≃−5.2 K and J̅ 2≃10.0 K, respectively. The effective frustration ratio α=J̅ 2/J̅ 1 amounts to −1.9 and suggests columnar antiferromagnetic ordering in PbZnVO(PO4)2. Specific-heat data support the estimates of J̅ 1 and J̅ 2 and indicate a likely magnetic ordering transition at 3.9 K. However, the averaged couplings underestimate the saturation field, thus pointing to the spatial anisotropy of the nearest-neighbor interactions. Band-structure calculations confirm the identification of ferromagnetic J1, J1′ and antiferromagnetic J2, J2′ in PbZnVO(PO4)2 and yield (J1′−J1)≃1.1 K in excellent agreement with the experimental value of 1.1 K, deduced from the difference between the expected and experimentally measured saturation fields. Based on the comparison of layered vanadium phosphates with different metal cations, we show that a moderate spatial anisotropy of the frustrated square lattice has minor influence on the thermodynamic properties of the model. We discuss relevant geometrical parameters, controlling the exchange interactions in these compounds and propose a strategy for further design of strongly frustrated square-lattice materials.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000278141600082 Publication Date 2010-05-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 27 Open Access  
  Notes (up) Approved Most recent IF: 3.836; 2010 IF: 3.774  
  Call Number UA @ lucian @ c:irua:83384 Serial 1294  
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Author Stefan, M.; Nistor, S.V.; Mateescu, D.C.; Abakumov, A.M. pdf  doi
openurl 
  Title Growth of pure and doped Rb2ZnCl4and K2ZnCl4 single crystals by Czochralski technique Type A1 Journal article
  Year 1999 Publication Journal of crystal growth Abbreviated Journal J Cryst Growth  
  Volume 200 Issue 1-2 Pages 148-154  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract High-quality single crystals of Rb2ZnCl4 and K2ZnCl4, pure or doped with Cu, Mn, Cd, Tl, Sn, Pb and In cations, were grown by Czochralski technique in argon atmosphere, using an experimental setup that allows direct visual access to the whole growth zone. Slowly cooled crystals exhibit excellent cleavage properties. Fastly cooled crystals do cleave poorly. As shown by X-ray diffraction studies, such K2ZnCl4 samples exhibit inclusions of the high-temperature Pmcn phase with lattice parameters a = 7.263(2) Angstrom, b = 12.562(2) Angstrom and c = 8.960(4) Angstrom in the P2(1) cn room temperature stable phase. ESR and optical spectroscopy studies revealed the localization and valence state of the cation dopants. (C) 1999 Elsevier Science B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000079840600021 Publication Date 2002-07-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-0248; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.751 Times cited 13 Open Access  
  Notes (up) Approved Most recent IF: 1.751; 1999 IF: 1.492  
  Call Number UA @ lucian @ c:irua:102909 Serial 1395  
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Author Ovsyannikov, S.V.; Karkin, A.E.; Morozova, N.V.; Shchennikov, V.V.; Bykova, E.; Abakumov, A.M.; Tsirlin, A.A.; Glazyrin, K.V.; Dubrovinsky, L. pdf  url
doi  openurl
  Title A hard oxide semiconductor with a direct and narrow bandgap and switchable pn electrical conduction Type A1 Journal article
  Year 2014 Publication Advanced materials Abbreviated Journal Adv Mater  
  Volume 26 Issue 48 Pages 8185-8191  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract An oxide semiconductor (perovskite-type Mn2O3) is reported which has a narrow and direct bandgap of 0.45 eV and a high Vickers hardness of 15 GPa. All the known materials with similar electronic band structures (e.g., InSb, PbTe, PbSe, PbS, and InAs) play crucial roles in the semiconductor industry. The perovskite-type Mn2O3 described is much stronger than the above semiconductors and may find useful applications in different semiconductor devices, e.g., in IR detectors.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Weinheim Editor  
  Language Wos 000346480800016 Publication Date 2014-10-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0935-9648; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 19.791 Times cited 27 Open Access  
  Notes (up) Approved Most recent IF: 19.791; 2014 IF: 17.493  
  Call Number UA @ lucian @ c:irua:122230 Serial 1408  
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Author King, G.; Abakumov, A.M.; Woodward, P.M.; Llobet, A.; Tsirlin, A.A.; Batuk, D.; Antipov, E.V. doi  openurl
  Title The high-temperature polymorphs of K3AlF6 Type A1 Journal article
  Year 2011 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 50 Issue 16 Pages 7792-7801  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The crystal structures of the three high-temperature polymorphs of K3AlF6 have been solved from neutron powder diffraction, synchrotron X-ray powder diffraction, and electron diffraction data. The β-phase (stable between 132 and 153 °C) and γ-phase (stable between 153 to 306 °C) can be described as unusually complex superstructures of the double-perovskite structure (K2KAlF6) which result from noncooperative tilting of the AlF6 octahedra. The β-phase is tetragonal, space group I4/m, with lattice parameters of a = 13.3862(5) Å and c = 8.5617(3) Å (at 143 °C) and Z = 10. In this phase, one-fifth of the AlF6 octahedra are rotated about the c-axis by 45° while the other four-fifths remain untilted. The large 45° rotations result in edge sharing between these AlF6 octahedra and the neighboring K-centered polyhedra, resulting in pentagonal bipyramidal coordination for four-fifths of the K+ ions that reside on the B-sites of the perovskite structure. The remaining one-fifth of the K+ ions on the B-sites retain octahedral coordination. The γ-phase is orthorhombic, space group Fddd, with lattice parameters of a = 36.1276(4) Å, b = 17.1133(2) Å, and c = 12.0562(1) Å (at 225 °C) and Z = 48. In the γ-phase, one-sixth of the AlF6 octahedra are randomly rotated about one of two directions by 45° while the other five-sixths remain essentially untilted. These rotations result in two-thirds of the K+ ions on the B-site obtaining 7-fold coordination while the other one-third remain in octahedral coordination. The δ-phase adopts the ideal cubic double-perovskite structure, space group Fmm, with a = 8.5943(1) Å at 400 °C. However, pair distribution function analysis shows that locally the δ-phase is quite different from its long-range average crystal structure. The AlF6 octahedra undergo large-amplitude rotations which are accompanied by off-center displacements of the K+ ions that occupy the 12-coordinate A-sites.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000293493100052 Publication Date 2011-07-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.857 Times cited 19 Open Access  
  Notes (up) Approved Most recent IF: 4.857; 2011 IF: 4.601  
  Call Number UA @ lucian @ c:irua:91131 Serial 1468  
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