Records |
Author |
Dubrovinsky, L.; Dubrovinskaia, N.; Prakapenka, V.B.; Abakumov, A.M. |
Title |
Implementation of micro-ball nanodiamond anvils for high-pressure studies above 6 Mbar |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
Volume |
3 |
Issue |
|
Pages |
1163-1167 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Since invention of the diamond anvil cell technique in the late 1950s for studying materials at extreme conditions, the maximum static pressure generated so far at room temperature was reported to be about 400 GPa. Here we show that use of micro-semi-balls made of nanodiamond as second-stage anvils in conventional diamond anvil cells drastically extends the achievable pressure range in static compression experiments to above 600 GPa. Micro-anvils (10-50 mu m in diameter) of superhard nano-diamond (with a grain size below similar to 50 nm) were synthesized in a large volume press using a newly developed technique. In our pilot experiments on rhenium and gold we have studied the equation of state of rhenium at pressures up to 640 GPa and demonstrated the feasibility and crucial necessity of the in situ ultra high-pressure measurements for accurate determination of material properties at extreme conditions. |
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
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Editor |
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Language |
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Wos |
000313514100073 |
Publication Date |
2012-10-23 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2041-1723; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
12.124 |
Times cited |
150 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 12.124; 2012 IF: 10.015 |
Call Number |
UA @ lucian @ c:irua:110134 |
Serial |
1563 |
Permanent link to this record |
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Author |
Morozov, V.A.; Bertha, A.; Meert, K.W.; Van Rompaey, S.; Batuk, D.; Martinez, G.T.; Van Aert, S.; Smet, P.F.; Raskina, M.V.; Poelman, D.; Abakumov, A.M.; Hadermann, J.; |
Title |
Incommensurate modulation and luminescence in the CaGd2(1-x)Eu2x(MoO4)4(1-y)(WO)4y (0\leq x\leq1, 0\leq y\leq1) red phosphors |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
25 |
Issue |
21 |
Pages |
4387-4395 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Scheelite related compounds (A',A '') [(B',B '')O-4], with B', B '' = W and/or Mo are promising new light-emitting materials for photonic applications, including phosphor converted LEDs (light-emitting diodes). In this paper, the creation and ordering of A-cation vacancies and the effect of cation substitutions in the scheelite-type framework are investigated as a factor for controlling the scheelite-type structure and luminescent properties. CaGd2(1-x)Eu2x(MoO4)(4(1-y))(WO4)(4y) (0 <= x <= 1, 0 <= y <= 1) solid solutions with scheelite-type structure were synthesized by a solid state method, and their structures were investigated using a combination of transmission electron microscopy techniques and powder X-ray diffraction. Within this series all complex molybdenum oxides have (3 + 2)D incommensurately modulated structures with superspace group I4(1)/a(alpha,beta,0)00(-beta,alpha,0)00, while the structures of all tungstates are (3 + 1)D incommensurately modulated with superspace group I2/b(alpha beta 0)00. In both cases the modulation arises because of cation-vacancy ordering at the A site. The prominent structural motif is formed by columns of A-site vacancies running along the c-axis. These vacant columns occur in rows of two or three aligned along the [110] direction of the scheelite subcell. The replacement of the smaller Gd3+ by the larger Eu3+ at the A-sublattice does not affect the nature of the incommensurate modulation, but an increasing replacement of Mo6+ by W6+ switches the modulation from (3 + 2)D to (3 + 1)D regime. Thus, these solid solutions can be considered as a model system where the incommensurate modulation can be monitored as a function of cation nature while the number of cation vacancies at the A sites remain constant upon the isovalent cation replacement. All compounds' luminescent properties were measured, and the optical properties were related to the structural properties of the materials. CaGd2(1-x)(MoO4)(4(1-y))(WO4)(4y) phosphors emit intense red light dominated by the D-5(0)-F-7(2) transition at 612 nm, along with other transitions from the D-5(1) and D-5(0) excited states. The intensity of the 5D0-7F2 transition reaches a maximum at x = 0.5 for y = 0 and 1. |
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000327045000030 |
Publication Date |
2013-09-24 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
63 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 9.466; 2013 IF: 8.535 |
Call Number |
UA @ lucian @ c:irua:112776 |
Serial |
1594 |
Permanent link to this record |
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Author |
Shpanchenko, R.V.; Rozova, M.G.; Abakumov, A.M.; Ardashnikova, E.I.; Kovba, M.L.; Putilin, S.N.; Antipov, E.V.; Lebedev, O.I.; Van Tendeloo, G. |
Title |
Inducing superconductivity and structural transformations by fluorination of reduced YBCO |
Type |
A1 Journal article |
Year |
1997 |
Publication |
Physica: C : superconductivity |
Abbreviated Journal |
Physica C |
Volume |
280 |
Issue |
|
Pages |
272-280 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
A1997XX21600005 |
Publication Date |
0000-00-00 |
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 |
|
Edition |
|
ISSN |
0921-4534 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.404 |
Times cited |
35 |
Open Access |
|
Notes |
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Approved |
Most recent IF: 1.404; 1997 IF: 2.199 |
Call Number |
UA @ lucian @ c:irua:21449 |
Serial |
1604 |
Permanent link to this record |
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Author |
Tsirlin, A.A.; Abakumov, A.M.; Van Tendeloo, G.; Rosner, H. |
Title |
Interplay of atomic displacement in the quantum magnet (CuCI)LaNb2O7 |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
82 |
Issue |
5 |
Pages |
054107,1-054107,12 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We report on the crystal structure of the quantum magnet CuClLaNb2O7 that was controversially described with respect to its structural organization and magnetic behavior. Using high-resolution synchrotron powder x-ray diffraction, electron diffraction, transmission electron microscopy, and band-structure calculations, we solve the room-temperature structure of this compound -CuClLaNb2O7 and find two high-temperature polymorphs. The -CuClLaNb2O7 phase, stable above 640 K, is tetragonal with asub=3.889 Å, csub =11.738 Å, and the space group P4/mmm. In the -CuClLaNb2O7 structure, the Cu and Cl atoms are randomly displaced from the special positions along the 100 directions. The phase asub2asubcsub, space group Pbmm and the phase 2asub2asubcsub, space group Pbam are stable between 640 K and 500 K and below 500 K, respectively. The structural changes at 500 and 640 K are identified as order-disorder phase transitions. The displacement of the Cl atoms is frozen upon the → transformation while a cooperative tilting of the NbO6 octahedra in the phase further eliminates the disorder of the Cu atoms. The low-temperature -CuClLaNb2O7 structure thus combines the two types of the atomic displacements that interfere due to the bonding between the Cu atoms and the apical oxygens of the NbO6 octahedra. The precise structural information resolves the controversy between the previous computation-based models and provides the long-sought input for understanding CuClLaNb2O7 and related compounds with unusual magnetic properties. |
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
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Editor |
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Language |
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Wos |
000280849400001 |
Publication Date |
2010-08-12 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
Call Number |
UA @ lucian @ c:irua:83991 |
Serial |
1706 |
Permanent link to this record |
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Author |
Mazo, G.N.; Savvin, S.N.; Abakumov, A.M.; Hadermann, J.; Dobrovol'skii, Y.A.; Leonova, L.S. |
Title |
Lanthanum-strontium cuprate as a promising cathodic matreila for solid oxide fuel cells |
Type |
A1 Journal article |
Year |
2007 |
Publication |
Russian journal of electrochemistry |
Abbreviated Journal |
Russ J Electrochem+ |
Volume |
43 |
Issue |
4 |
Pages |
436-442 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
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Editor |
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Language |
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Wos |
000246338500010 |
Publication Date |
2007-05-09 |
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 |
|
Edition |
|
ISSN |
1023-1935;1608-3342; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
0.828 |
Times cited |
8 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 0.828; 2007 IF: 0.263 |
Call Number |
UA @ lucian @ c:irua:62062 |
Serial |
1777 |
Permanent link to this record |
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Author |
Batuk, M.; Batuk, D.; Tsirlin, A.A.; Filimonov, D.S.; Sheptyakov, D.V.; Frontzek, M.; Hadermann, J.; Abakumov, A.M. |
Title |
Layered oxychlorides [PbBiO2]An+1BnO3n-1Cl2(A = Pb/Bi, B = Fe/Ti) : intergrowth of the hematophanite and sillen phases |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
27 |
Issue |
27 |
Pages |
2946-2956 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
New layered structures corresponding to the general formula [PbBiO2]A(n+1)B(n)O(3n-1)Cl(2) Were prepared. Pb5BiFe3O10Cl2 (n = 3) and Pb5Bi2Fe4O13Cl2 (n = 4) are built as a stacking of truncated A(n+1)B(n)O(3n-1) perovskite blocks and alpha-PbO-type [A(2)O(2)](2+) (A = Pb, Bi) blocks combined with chlorine sheets. The alternation of these structural blocks can be represented as an intergrowth between the hematophanite and Sullen-type structural blocks. The crystal and-Magnetic structures of Pb5BiFe3O10Cl2 and Pb5Bi2Fe4O13Cl2 were investigated in the temperature range of 1.5-700 K using X-ray and neutron powder diffraction, transmission electron microscopy and Fe-57 Mossbauer spectroscopy. Both compounds crystallize in the I4/mmm space group with the unit cell parameters a approximate to a(p) approximate to 3.92 angstrom (a unit-cell parameter of the perovskite-structure), c approximate to 43.0 angstrom for the n = 3 member and c approximate to 53.5 angstrom for the n = 4 member. Despite the large separation between the slabs containing the Fe3+ ions (nearly 14 angstrom), long-range antiferromagnetic order sets in below similar to 600 K with the G-type arrangement of the Fe magnetic moments aligned along the c-axis. The possibility of mixing d(0) and d(n) cations at the B sublattice of these structures was also demonstrated by preparing the Ti-substituted n = 4 member Pb6BiFe3TiO13Cl2. |
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
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Editor |
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Language |
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Wos |
000353865800028 |
Publication Date |
2015-03-26 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
11 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 9.466; 2015 IF: 8.354 |
Call Number |
c:irua:126060 |
Serial |
1807 |
Permanent link to this record |
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Author |
Drozhzhin, O.A.; Vorotyntsev, M.A.; Maduar, S.R.; Khasanova, N.R.; Abakumov, A.M.; Antipov, E.V. |
Title |
Li-ion diffusion in LixNb9PO25 |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Electrochimica acta |
Abbreviated Journal |
Electrochim Acta |
Volume |
89 |
Issue |
|
Pages |
262-269 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Wadsley-Roth phase LixNb6PO25 has been studied as a potential candidate for anode material of Li-ion batteries. Its crystal structure, which consists of ReO3-type blocks of NbO6 octahedra connected with PO4 tetrahedra, provides a good stability and performance during Li+ insertion/removal. Li-ion chemical diffusion coefficient (D-chem) in LixNb6PO25 was determined by means of potentiostatic intermittent titration technique and electrochemical impedance spectroscopy. Different data treatments (classical Warburg equation or the model of an electrode system with ohmic potential drop and/or slow kinetics of the interfacial Li+ ion transfer across the electrode/electrolyte interface) were used for calculation of D-chem of the Li ion inside this material; their applicability is discussed in the article. D-chem changes with the Li-ion doping degree, x, in LixNb3PO25 and has a sharp minimum near the two-phase region at appr. 1.7V vs. Li+/Li. These values of D-chem in LixNb9PO25 (similar to 10(-9)-10(-11) cm(2) s(-1)) were found to be in average noticeably higher than in the widely studied anode material, Li4Ti5O12. (C) 2012 Elsevier Ltd. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000315558200034 |
Publication Date |
2012-11-14 |
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 |
|
ISSN |
0013-4686; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.798 |
Times cited |
11 |
Open Access |
|
Notes |
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Approved |
Most recent IF: 4.798; 2013 IF: 4.086 |
Call Number |
UA @ lucian @ c:irua:108312 |
Serial |
1816 |
Permanent link to this record |
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Author |
Dachraoui, W.; Hadermann, J.; Abakumov, A.M.; Tsirlin, A.A.; Batuk, D.; Glazyrin, K.; McCammon, C.; Dubrovinsky, L.; Van Tendeloo, G. |
Title |
Local oxygen-vacancy ordering and twinned octahedral tilting pattern in the Bi0.81Pb0.19FeO2.905 cubic perovskite |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
24 |
Issue |
7 |
Pages |
1378-1385 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The structure of Bi0.81Pb0.19FeO2.905 was investigated on different length scales using a combination of electron diffraction, high-resolution scanning transmission electron microscopy, synchrotron X-ray powder diffraction, and Mössbauer spectroscopy. In the 80300 K temperature range, the average crystal structure of Bi0.81Pb0.19FeO2.905 is a cubic Pm3̅m perovskite with a = 3.95368(3) Å at T = 300 K. The (Pb2+, Bi3+) cations and O2 anions are randomly displaced along the 110 cubic directions, indicating the steric activity of the lone pair on the Pb2+ and Bi3+ cations and a tilting distortion of the perovskite framework. The charge imbalance induced by the heterovalent Bi3+ → Pb2+ substitution is compensated by the formation of oxygen vacancies preserving the trivalent state of the Fe cations. On a short scale, oxygen vacancies are located in anion-deficient (FeO1.25) layers that are approximately 6 perovskite unit cells apart and transform every sixth layer of the FeO6 octahedra into a layer with a 1:1 mixture of corner-sharing FeO4 tetrahedra and FeO5 tetragonal pyramids. The anion-deficient layers act as twin planes for the octahedral tilting pattern of adjacent perovskite blocks. They effectively randomize the octahedral tilting and prevent the cooperative distortion of the perovskite framework. The disorder in the anion sublattice impedes cooperative interactions of the local dipoles induced by the off-center displacements of the Pb and Bi cations. Magnetic susceptibility measurements evidence the antiferromagnetic ordering in Bi0.81Pb0.19FeO2.905 at low temperatures. |
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000302487500018 |
Publication Date |
2012-03-13 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
27 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 9.466; 2012 IF: 8.238 |
Call Number |
UA @ lucian @ c:irua:97389 |
Serial |
1829 |
Permanent link to this record |
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Author |
Bezjak, J.; Abakumov, A.M.; Recnik, A.; Krzmanc, M.M.; Jancar, B.; Suvorov, D. |
Title |
The local structure and composition of Ba4Nb2O9-based oxycarbonates |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
183 |
Issue |
8 |
Pages |
1823-1828 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
X-ray powder-diffraction(XRD),high-resolutiontransmissionelectronmicroscopy(HRTEM),electron diffraction(ED),infraredspectroscopy(IR),thermogravimetry(TG)andmassspectroscopy(MS)were performedtoinvestigatethecompositionandthecrystalstructureoftetra-bariumdi-niobate(V) Ba4Nb2O9. TheTG,MSandIRstudiesrevealedthatthecompoundisahydratedoxycarbonate.Assuming that thecarbonatestoichiometricallyreplacesoxygen,thecompositionofthelow-temperature a-modification,obtainedbyslowcoolingfrom1100 1C, correspondstoBa4Nb2O8.8(CO3)0.2 0.1H2O, while thequenchedhigh-temperature g-modificationhastheBa4Nb2O8.42(CO3)0.58 0.38H2O composi- tion. The a-phase hasacompositeincommensuratelymodulatedstructureconsistingoftwomutually interacting[Ba]N and the[(Nb,)O3]N subsystems.Thecompositemodulatedcrystalstructureofthe a-phase canbedescribedwiththelatticeparameters a¼10.2688(1) A˚ , c¼2.82426(8) A˚ , q¼0.66774(2)c* and asuperspacegroup R3m(00g)0s. TheHRTEManalysisdemonstratesthenanoscale twinningofthetrigonaldomainsparalleltothe{100}crystallographicplanes.Thetwinningintroduces a one-dimensionaldisorderintothe[(Nb,)O3]N subsystem,whichresultsinanaverage P62c crystal structureofthe a-phase. Possibleplacesforthecarbonategroupinthestructurearediscussedusinga comparisonwithotherhexagonalperovskite-basedoxycarbonates. |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000280620300013 |
Publication Date |
2010-06-14 |
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 |
0022-4596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
10 |
Open Access |
|
Notes |
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Approved |
Most recent IF: 2.299; 2010 IF: 2.261 |
Call Number |
UA @ lucian @ c:irua:84046 |
Serial |
1830 |
Permanent link to this record |
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Author |
Hadermann, J.; Abakumov, A.M.; Nikolaev, I.V.; Antipov, E.V.; Van Tendeloo, G. |
Title |
Local structure of perovskite-based “Pb2Fe2O5” |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Solid state sciences |
Abbreviated Journal |
Solid State Sci |
Volume |
10 |
Issue |
4 |
Pages |
382-389 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000256200200003 |
Publication Date |
2008-01-20 |
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 |
|
ISSN |
1293-2558; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.811 |
Times cited |
29 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.811; 2008 IF: 1.742 |
Call Number |
UA @ lucian @ c:irua:69289 |
Serial |
1832 |
Permanent link to this record |
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Author |
Vassiliev, S.Y.; Laurinavichute, V.K.; Abakumov, A.M.; Govorov, V.A.; Bendovskii, E.B.; Turner, S.; Filatov, A.Y.; Tarasovskii, V.P.; Borzenko, A.G.; Alekseeva, A.M.; Antipov, E.V. |
Title |
Microstructural aspects of the degradation behavior of SnO2-based anodes for aluminum electrolysis |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Journal of the electrochemical society |
Abbreviated Journal |
J Electrochem Soc |
Volume |
157 |
Issue |
5 |
Pages |
C178-C186 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The performance of SnO2 ceramic anodes doped with copper and antimony oxides was examined in cryolite alumina melts under anodic polarization at different cryolite ratios, temperatures, times, and current densities. The corroded part consists of a narrow strong corrosion zone at the anode surface with damage of the intergrain contacts and a large increase in porosity, a wider moderate corrosion zone with a smaller porosity increase, and a Cu depletion zone, where the ceramic retains its initial microstructure and a slight porosity increase occurs due to the removal of the Cu-rich inclusions. Mechanical destruction of the anode was never observed in the 10100 h tests. A microstructural model of the ceramic was suggested, consisting of grains with an Sb-doped SnO2 grain core surrounded by an ~200 to 500 nm grain shell where SnO2 was simultaneously doped with Sb and Mn+ (M=Cu2+,Fe3+,Al3+). The grains were separated by a few nanometers thick Cu-enriched grain boundaries. Different secondary charge carrier (holes) concentrations and electric conductivities in the grain core and grain shell result in a higher current density at the intergrain regions that leads to their profound degradation, especially in the low temperature acidic melt. |
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000276555300037 |
Publication Date |
2010-04-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0013-4651; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.259 |
Times cited |
3 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.259; 2010 IF: 2.427 |
Call Number |
UA @ lucian @ c:irua:82260 |
Serial |
2040 |
Permanent link to this record |
|
|
|
Author |
Isaeva, A.A.; Makarevich, O.N.; Kutznetsov, A.N.; Doert, T.; Abakumov, A.M.; Van Tendeloo, G. |
Title |
Mixed tellurides Ni3-xGaTe2 (0\leq x\leq0.65): crystal and electronic structures, properties, and nickel deficiency effects on vacancy ordering |
Type |
A1 Journal article |
Year |
2010 |
Publication |
European journal of inorganic chemistry |
Abbreviated Journal |
Eur J Inorg Chem |
Volume |
|
Issue |
9 |
Pages |
1395-1404 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The Ni3-xGaTe2 series of compounds (0 x 0.65) was synthesized by a high-temperature ceramic technique at 750 °C. Crystal structures of three compounds in the series were determined by X-ray powder diffraction: Ni2.98(1)GaTe2 (RI = 0.042, Rp = 0.023, Rwp = 0.035), Ni2.79(1)GaTe2 (RI = 0.053, Rp = 0.028, Rwp = 0.039), Ni2.58(1)GaTe2 (RI = 0.081, Rp = 0.037, Rwp = 0.056); the structures were verified by electron diffraction and, for the former compound, high-resolution electron microscopy. The compounds crystallize in a hexagonal lattice with P63/mmc, and the structures can be regarded as a hexagonal close-packed array with a -Ga-Te-Te- stacking sequence. The octahedral and trigonal bipyramidal voids in the hcp structure are selectively filled with Ni atoms to form one entirely occupied and two partially occupied sites, thus allowing variations in the nickel content in the series of compounds Ni3-xGaTe2 (0 x 0.65). A superstructure with asup = 2asub (P63/mmc) has been identified for Ni3-xGaTe2 (0.5 x 0.65) by electron diffraction. Real-space, high-resolution images confirm an ordering of Ni atoms and vacancies inthe ab plane. Quantum-chemical calculations performed forNi3-xGaTe2 (x = 0, 0.25, 0.75, 1) suggest anisotropic metallic conductivity and Pauli paramagnetic behavior that are experimentally confirmed for Ni3GaTe2. |
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000276370300009 |
Publication Date |
2010-02-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1434-1948;1099-0682; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.444 |
Times cited |
8 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.444; 2010 IF: 2.910 |
Call Number |
UA @ lucian @ c:irua:82266 |
Serial |
2090 |
Permanent link to this record |
|
|
|
Author |
Abakumov, A.M.; Tsirlin, A.A.; Bakaimi, I.; Van Tendeloo, G.; Lappas, A. |
Title |
Multiple twinning as a structure directing mechanism in layered rock-salt-type oxides : NaMnO2 polymorphism, redox potentials, and magnetism |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
26 |
Issue |
10 |
Pages |
3306-3315 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
New polymorphs of NaMnO2 have been observed using transmission electron microscopy and synchrotron X-ray powder diffraction. Coherent twin planes confined to the (NaMnO2) layers, parallel to the (10 (1) over bar) crystallographic planes of the monoclinic layered rock-salt-type alpha-NaMnO2 (O3) structure, form quasi-periodic modulated sequences, with the known alpha-and beta-NaMnO2 polymorphs as the two limiting cases. The energy difference between the polymorphic forms, estimated using a DFT-based structure relaxation, is on the scale of the typical thermal energies that results in a high degree of stacking disorder in these compounds. The results unveil the remarkable effect of the twin planes on both the magnetic and electrochemical properties. The polymorphism drives the magnetic ground state from a quasi-1D spin system for the geometrically frustrated alpha-polymorph through a two-leg spin ladder for the intermediate stacking sequence toward a quasi-2D magnet for the beta-polymorph. A substantial increase of the equilibrium potential for Na deintercalation upon increasing the concentration of the twin planes is calculated, providing a possibility to tune the electrochemical potential of the layered rock-salt ABO(2) cathodes by engineering the materials with a controlled concentration of twins. |
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
|
Editor |
|
Language |
|
Wos |
000336637000036 |
Publication Date |
2014-05-01 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
35 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 9.466; 2014 IF: 8.354 |
Call Number |
UA @ lucian @ c:irua:117766 |
Serial |
2232 |
Permanent link to this record |
|
|
|
Author |
Erni, R.; Abakumov, A.M.; Rossell, M.D.; Batuk, D.; Tsirlin, A.A.; Nénert, G.; Van Tendeloo, G. |
Title |
Nanoscale phase separation in perovskites revisited |
Type |
L1 Letter to the editor |
Year |
2014 |
Publication |
Nature materials |
Abbreviated Journal |
Nat Mater |
Volume |
13 |
Issue |
3 |
Pages |
216-217 |
Keywords |
L1 Letter to the editor; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
|
Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000331945200002 |
Publication Date |
2014-02-20 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1476-1122;1476-4660; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
39.737 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 39.737; 2014 IF: 36.503 |
Call Number |
UA @ lucian @ c:irua:114579 |
Serial |
2270 |
Permanent link to this record |
|
|
|
Author |
Hervieu, M.; Damay, F.; Poienar, M.; Elkaim, E.; Rouquette, J.; Abakumov, A.M.; Van Tendeloo, G.; Maignan, A.; Martin, C. |
Title |
Nanostructures in LuFe2O4+\delta |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Solid state sciences |
Abbreviated Journal |
Solid State Sci |
Volume |
23 |
Issue |
|
Pages |
26-34 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A LuFe2O4+delta sample, previously characterized by X-ray synchrotron and neutron diffraction, has been studied by electron microscopy techniques, in order to get a precise description of its micro- and nanostructures at room temperature. The X-ray synchrotron data vs. temperature show that the monoclinic distortion is associated with the charge ordering; this distortion results in elongated twinning domains, which enhance the complexity of the microstructural state at room temperature. The structural modulation associated with oxygen excess is observed in large domains inside a non modulated matrix, in contrast with the modulations associated with the charge ordering of the Fe2+ and Fe3+ species, which are mostly short-range. The investigation of the nature and density of defects in the sample shows that they are nano-scaled, preserving the regularity of the layer stacking mode, and limited to the formation of one- or two-units large stacking faults, associated with gliding mechanisms. Based on these observations, an original description of the LuFe2O4 ferrite structure, through puckered [LuO4](infinity) sandwiching [Fe-2](infinity) layers, is proposed. (C) 2013 Elsevier Masson SAS. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000324156200005 |
Publication Date |
2013-06-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1293-2558; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.811 |
Times cited |
7 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.811; 2013 IF: 1.679 |
Call Number |
UA @ lucian @ c:irua:111196 |
Serial |
2276 |
Permanent link to this record |
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|
|
Author |
Prituzhalov, V.A.; Ardashnikova, E.I.; Vinogradov, A.A.; Dolgikh, V.A.; Videau, J.-J.; Fargin, E.; Abakumov, A.M.; Tarakina, N.V.; Van Tendeloo, G. |
Title |
New anion-conducting solid solutions Bi1-xTex(O,F)2+\delta (x > 0.5) and glassceramic material on their base |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Journal of fluorine chemistry |
Abbreviated Journal |
J Fluorine Chem |
Volume |
132 |
Issue |
12 |
Pages |
1110-1116 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The anion-excess fluorite-like solid solutions with general composition Bi1−xTex(O,F)2+δ (x > 0.5) have been synthesized by a solid state reaction of TeO2, BiF3 and Bi2O3 at 873 K with following quenching. The homogeneity areas and polymorphism of the I ↔ IV Bi1−xTex(O,F)2+δ phases were investigated. The crystal structure of the low temperature IV-Bi1−xTex(O,F)2+δ phase has been solved using electron diffraction and X-ray powder diffraction (a = 11.53051(9) Å, S.G. Ia-3, RI = 0.046, RP = 0.041). Glass formation area in the Bi2O3BiF3TeO2 (10% TiO2) system was investigated. IVBi1−xTex(O,F)2+δ phase starts to crystallize at short-time (0.53 h) annealing of oxyfluoride glasses at temperatures above Tg (600615 K). The ionic conductivity of the crystalline Bi1−xTex(O,F)2+δ phase and corresponding glass-ceramics was investigated. Activation energy of conductivity Ea = 0.41(2) eV for the IV-Bi1−xTex(O,F)2+δ crystalline samples and Ea = 0.73 eV for the glass-ceramic samples were obtained. Investigation of the oxyfluoride samples with a constant cation ratio demonstrates essential influence of excess fluorine anions on the ionic conductivity. |
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
Lausanne |
Editor |
|
Language |
|
Wos |
000296936300011 |
Publication Date |
2011-07-07 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0022-1139; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.101 |
Times cited |
2 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.101; 2011 IF: 2.033 |
Call Number |
UA @ lucian @ c:irua:93687 |
Serial |
2305 |
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. |
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 |
Volume |
48 |
Issue |
17 |
Pages |
8480-8488 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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. |
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
Easton, Pa |
Editor |
|
Language |
|
Wos |
000269313500056 |
Publication Date |
2009-08-04 |
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 |
28 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.857; 2009 IF: 4.657 |
Call Number |
UA @ lucian @ c:irua:78486 |
Serial |
2308 |
Permanent link to this record |
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|
Author |
Caignaert, V.; Abakumov, A.M.; Pelloquin, D.; Pralong, V.; Maignan, A.; Van Tendeloo, G.; Raveau, B. |
Title |
A new mixed-valence ferrite with a cubic structure, YBaFe4O7: spin-glass-like behavior |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
21 |
Issue |
6 |
Pages |
1116-1122 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A new mixed-valence ferrite, YBaFe4O7, has been synthesized. Its unique cubic structure, with a = 8.9595(2) Å, is closely related to that of the hexagonal 114 oxides YBaCo4O7 and CaBaFe4O7. It consists of corner-sharing FeO4 tetrahedra, forming triangular and kagome layers parallel to (111)C. In fact, the YBaFe4O7 and CaBaFe4O7 structures can be described as two different ccc and chch close packings of [BaO3]∞ and [O4]∞ layers, respectively, whose tetrahedral cavities are occupied by Fe2+/Fe3+ cations. The local structure of YBaFe4O7 is characterized by a large amount of stacking faults originating from the presence of hexagonal layers in the ccc cubic close-packed YBaFe4O7 structure. In this way, they belong to the large family of spinels and hexagonal ferrites studied for their magnetic properties. Differently from all the ferrites and especially from CaBaFe4O7, which are ferrimagnetic, YBaFe4O7 is an insulating spin glass with Tg = 50 K. |
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000264310900019 |
Publication Date |
2009-02-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
39 |
Open Access |
|
Notes |
Esteem 026019 |
Approved |
Most recent IF: 9.466; 2009 IF: 5.368 |
Call Number |
UA @ lucian @ c:irua:76432 |
Serial |
2325 |
Permanent link to this record |
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|
Author |
Hadermann, J.; Abakumov, A.M.; Perkisas, T.; d' Hondt, H.; Tan, H.; Verbeeck, J.; Filonenko, V.P.; Antipov, E.V.; Van Tendeloo, G. |
Title |
New perovskite-based manganite Pb2Mn2O5 |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
183 |
Issue |
183 |
Pages |
2190-2195 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A new perovskite based compound Pb2Mn2O5 has been synthesized using a high pressure high temperature technique. The structure model of Pb2Mn2O5 is proposed based on electron diffraction, high angle annular dark field scanning transmission electron microscopy and high resolution transmission electron microscopy. The compound crystallizes in an orthorhombic unit cell with parameters a=5.736(1)Å≈√2a p p p (a p the parameter of the perovskite subcell) and space group Pnma. The Pb2Mn2O5 structure consists of quasi two-dimensional perovskite blocks separated by 1/2[110] p (1̄01) p crystallographic shear planes. The blocks are connected to each other by chains of edge-sharing MnO5 distorted tetragonal pyramids. The chains of MnO5 pyramids and the MnO6 octahedra of the perovskite blocks delimit six-sided tunnels accommodating double chains of Pb atoms. The tunnels and pyramidal chains adopt two mirror-related configurations (left L and right R) and layers consisting of chains and tunnels of the same configuration alternate in the structure according to an -LRLR-sequence. The sequence is sometimes locally violated by the appearance of -LL- or -RR-fragments. A scheme is proposed with a JahnTeller distortion of the MnO6 octahedra with two long and two short bonds lying in the ac plane, along two perpendicular orientations within this plane, forming a d-type pattern. |
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000282139600041 |
Publication Date |
2010-07-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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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 |
Fwo; Bof; Esteem 026019 |
Approved |
Most recent IF: 2.299; 2010 IF: 2.261 |
Call Number |
UA @ lucian @ c:irua:85472UA @ admin @ c:irua:85472 |
Serial |
2332 |
Permanent link to this record |
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|
Author |
Khasanova, N.R.; Van Tendeloo, G.; Lebedev, O.I.; Amelinckx, S.; Grippa, A.Y.; Abakumov, A.M.; Istomin, S.Y.; D'yachenko, O.G.; Antipov, E.V. |
Title |
A new structure type of the ternary sulfide Eu1.3Nb1.9S5 |
Type |
A1 Journal article |
Year |
2002 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
164 |
Issue |
2 |
Pages |
345-353 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000174848000020 |
Publication Date |
2002-10-06 |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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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 |
2 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.299; 2002 IF: 1.671 |
Call Number |
UA @ lucian @ c:irua:54714 |
Serial |
2334 |
Permanent link to this record |
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|
Author |
Abakumov, A.M.; Alekseeva, A.M.; Rozova, M.G.; Antipov, E.V.; Lebedev, O.I.; Van Tendeloo, G. |
Title |
Ordering of tetrahedral chains in the Sr2MnGaO5 brownmillerite |
Type |
A1 Journal article |
Year |
2003 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
174 |
Issue |
2 |
Pages |
319-328 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Tetrahedral chain ordering in the Sr2MnGaO5 structure is studied using electron diffraction (ED) and high-resolution electron microscopy. The ED patterns show the presence of satellite reflections, which indicate a commensurately modulated structure with a = 5.4056(8) Angstrom b 16.171(3) Angstrom, c = 5.5592(7) Angstrom, q – 1/2c*, superspace group Immma(00gamma,)s00. The Superstructure arises due to ordering of the two types of symmetry related tetrahedral chains (L and R) according to a ... LRLR ... sequence, where L and R chains alternate along the c-axis within the same (GaO) layer. Numerous defects at different structural levels were observed, comprising interleaving L and R chains, violation of the ... LRLR ... chain sequence within one layer, different stacking modes of the ... LRLR ... ordered layers with subsequent alternation of blocks of different width along the h-axis of the brownmillerite subcell and island fragmentation of the modulated superstructure. By in situ heating ED experiments it is found that the long-range ordering of the tetrahedral chains is stable tip to 665degreesC and is completely suppressed at 905degreesC. (C) 2003 Elsevier Inc. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000185180500011 |
Publication Date |
2003-07-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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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 |
34 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.299; 2003 IF: 1.413 |
Call Number |
UA @ lucian @ c:irua:94846 |
Serial |
2506 |
Permanent link to this record |
|
|
|
Author |
Abakumov, A.M.; Hadermann, J.; Tsirlin, A.A.; Tan, H.; Verbeeck, J.; Zhang, H.; Dikarev, E.V.; Shpanchenko, R.V.; Antipov, E.V. |
Title |
Original close-packed structure and magnetic properties of the Pb4Mn9O20 manganite |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
182 |
Issue |
8 |
Pages |
2231-2238 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The crystal structure of the Pb4Mn9O20 compound (previously known as Pb0.43MnO2.18) was solved from powder X-ray diffraction, electron diffraction, and high resolution electron microscopy data (S.G. Pnma, a=13.8888(2) Å, b=11.2665(2) Å, c=9.9867(1) Å, RI=0.016, RP=0.047). The structure is based on a 6H (cch)2 close packing of pure oxygen h-type (O16) layers alternating with mixed c-type (Pb4O12) layers. The Mn atoms occupy octahedral interstices formed by the oxygen atoms of the close-packed layers. The MnO6 octahedra share edges within the layers, whereas the octahedra in neighboring layers are linked through corner sharing. The relationship with the closely related Pb3Mn7O15 structure is discussed. Magnetization measurements reveal a peculiar magnetic behavior with a phase transition at 52 K, a small net magnetization below the transition temperature, and a tendency towards spin freezing. |
Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000269066400035 |
Publication Date |
2009-06-12 |
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 |
0022-4596; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
5 |
Open Access |
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Notes |
The authors are grateful to Christoph Geibel for the help in magnetization measurements. A.Ts. acknowledges MPI CKS for hospitality and financial support during the stay. E.D. thanks the National Science Foundation (CHE-0718900) for financial support. This work was supported by the Russian Foundation of Basic Research (RFBR Grants 07-03-00664-a, 06-03-90168-a and 07-03-00890-a). The authors acknowledge financial support from the European Union under the Framework 6 program under a contract for an Integrated Infrastructure Initiative. Reference 026019 ESTEEM. |
Approved |
Most recent IF: 2.299; 2009 IF: 2.340 |
Call Number |
UA @ lucian @ c:irua:78935UA @ admin @ c:irua:78935 |
Serial |
2529 |
Permanent link to this record |
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Author |
Kaminsky, F.V.; Ryabchikov, I.D.; McCammon, C.A.; Longo, M.; Abakumov, A.M.; Turner, S.; Heidari, H. |
Title |
Oxidation potential in the Earth's lower mantle as recorded by ferropericlase inclusions in diamond |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Earth and planetary science letters |
Abbreviated Journal |
Earth Planet Sc Lett |
Volume |
417 |
Issue |
417 |
Pages |
49-56 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Ferropericlase (fPer) inclusions from kimberlitic lower-mantle diamonds recovered in the Juina area, Mato Grosso State, Brazil were analyzed with transmission electron microscopy, electron energy-loss spectroscopy and the flank method. The presence of exsolved non-stoichiometric Fe3+-enriched clusters, varying in size from 1-2 nm to 10-15 nm and comprising similar to 3.64 vol.% of fPer was established. The oxidation conditions necessary for fPer formation within the uppermost lower mantle (P = 25 GPa, T = 1960 K) vary over a wide range: Delta log f(o2) (IW) from 1.58 to 7.76 (Delta = 6.2), reaching the fayalite-magnetite-quartz (FMQ) oxygen buffer position. This agrees with the identification of carbonates and free silica among inclusions within lower-mantle Juina diamonds. On the other hand, at the base of the lower mantle Delta log f(o2) values may lie at and below the iron-wustite (IW) oxygen buffer. Hence, the variations of Delta log f(o2) values within the entire sequence of the lower mantle may reach ten logarithmic units, varying from the IW buffer to the FMQ buffer values. The similarity between lower- and upper-mantle redox conditions supports whole mantle convection, as already suggested on the basis of nitrogen and carbon isotopic compositions in lower- and upper-mantle diamonds. The mechanisms responsible for redox differentiation in the lower mantle may include subduction of oxidized crustal material, mechanical separation of metallic phase(s) and silicate-oxide mineral assemblages enriched in ferric iron, as well as transfer of fused silicate-oxide material presumably also enriched in ferric iron through the mantle. (C) 2015 Elsevier B.V. All rights reserved. |
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Corporate Author |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000351799400006 |
Publication Date |
2015-03-05 |
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 |
0012-821X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.409 |
Times cited |
23 |
Open Access |
|
Notes |
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Approved |
Most recent IF: 4.409; 2015 IF: 4.734 |
Call Number |
c:irua:125451 |
Serial |
2539 |
Permanent link to this record |
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Author |
Antipov, E.V.; Abakumov, A.M.; Alekseeva, A.M.; Rozova, M.G.; Hadermann, J.; Lebedev, O.I.; Van Tendeloo, G. |
Title |
Oxygen and fluorine doping in Sr2MnGaO5 brownmillerite |
Type |
A1 Journal article |
Year |
2004 |
Publication |
Physica status solidi: A: applied research |
Abbreviated Journal |
Phys Status Solidi A |
Volume |
201 |
Issue |
7 |
Pages |
1403-1409 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
Berlin |
Editor |
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Language |
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Wos |
000221836300008 |
Publication Date |
2004-04-21 |
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 |
0031-8965;1521-396X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
9 |
Open Access |
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Notes |
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Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:49464 |
Serial |
2544 |
Permanent link to this record |
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Author |
Mikhailova, D.; Reichel, P.; Tsirlin, A.A.; Abakumov, A.M.; Senyshyn, A.; Mogare, K.M.; Schmidt, M.; Kuo, C.Y.; Pao, C.W.; Pi, T.W.; Lee, J.F.; Hu, Z.; Tjeng, L.H.; |
Title |
Oxygen-driven competition between low-dimensional structures of Sr3CoMO6 and Sr3CoMO7-\delta with M = Ru,Ir |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
Dalton T |
Volume |
43 |
Issue |
37 |
Pages |
13883-13891 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We have realized a reversible structure transformation of one-dimensional 1D K4CdCl6-type Sr3CoMO6 with the Co2+/M4+ cation ordering into the two-dimensional 2D double layered Ruddlesden-Popper structure Sr3CoMO7-delta with a random distribution of Co and M (with M = Ru, Ir) upon increasing the partial oxygen pressure. The combined soft and hard X-ray absorption spectroscopy studies show that under transformation, Co and M cations were oxidized to Co3+ and M5+. During oxidation, high-spin Co2+ in Sr3CoMO6 first transforms into high-spin Co3+ in oxygen-deficient Sr3CoMO7-delta, and then further transforms into low-spin Co3+ in fully oxidized Sr3CoMO7 upon further increasing the partial pressure of oxygen. The 1D Sr3CoMO6 compound is magnetically ordered at low temperatures with the magnetic moments lying along the c-axis. Their alignment is parallel for Sr3CoRuO6 and antiparallel for Sr3CoIrO6. The 2D compounds reveal a spin-glass-like behavior related to the random distribution of magnetic cations in the structure. |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000342074100009 |
Publication Date |
2014-07-28 |
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 |
1477-9226;1477-9234; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.029 |
Times cited |
7 |
Open Access |
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Notes |
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Approved |
Most recent IF: 4.029; 2014 IF: 4.197 |
Call Number |
UA @ lucian @ c:irua:119960 |
Serial |
2545 |
Permanent link to this record |
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Author |
Frolov, D.D.; Kotovshchikov, Y.N.; Morozov, I.V.; Boltalin, A.I.; Fedorova, A.A.; Marikutsa, A.V.; Rumyantseva, M.N.; Gaskov, A.M.; Sadovskaya, E.M.; Abakumov, A.M. |
Title |
Oxygen exchange on nanocrystalline tin dioxide modified by palladium |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
186 |
Issue |
|
Pages |
1-8 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Temperature-programmed oxygen isotopic exchange study was performed on nanocrystalline tin dioxide-based materials synthesized via sol-gel route and modified by palladium. Such materials are widely used as resistive gas sensors. The experiments were carried out in a flow-reactor up to complete isotopic substitution of oxygen. Substantial rates of isotopic exchange for SnO2 were observed from about 700 K. The distribution of isotopic molecules O-16(2). (OO)-O-16-O-18 and O-18(2) corresponds to simple dioxygen heteroexchange mechanism with single lattice oxygen atom. The modification of SnO2 by Pd introduced multiple heteroexchange mechanism with preliminary O-2 dissociation on the clusters surface. Spill-over of atomic oxygen from Pd to the surface of SnO2 and fast exchange with lattice oxygen result in more than 100% increase of apparent heteroexchange rate. The exchange on SnO2/Pd was shown to be a complex process involving partial deactivation of the catalytic centers at temperature higher than 750 K. (C) 2011 Elsevier Inc. All rights reserved. |
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Corporate Author |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000299801400001 |
Publication Date |
2011-12-08 |
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 |
0022-4596; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
34 |
Open Access |
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Notes |
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Approved |
Most recent IF: 2.299; 2012 IF: 2.040 |
Call Number |
UA @ lucian @ c:irua:96202 |
Serial |
2546 |
Permanent link to this record |
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Author |
Gou, H.; Tsirlin, A.A.; Bykova, E.; Abakumov, A.M.; Van Tendeloo, G.; Richter, A.; Ovsyannikov, S.V.; Kurnosov, A.V.; Trots, D.M.; Konôpková, Z.; Liermann, H.P.; Dubrovinsky, L.; Dubrovinskaia, N.; |
Title |
Peierls distortion, magnetism, and high hardness of manganese tetraboride |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
89 |
Issue |
6 |
Pages |
064108-64109 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We report crystal structure, electronic structure, and magnetism of manganese tetraboride, MnB4, synthesized under high-pressure, high-temperature conditions. In contrast to superconducting FeB4 and metallic CrB4, which are both orthorhombic, MnB4 features a monoclinic crystal structure. Its lower symmetry originates from a Peierls distortion of the Mn chains. This distortion nearly opens the gap at the Fermi level, but despite the strong dimerization and the proximity of MnB4 to the insulating state, we find indications for a sizable paramagnetic effective moment of about 1.7 mu(B)/f.u., ferromagnetic spin correlations, and, even more surprisingly, a prominent electronic contribution to the specific heat. However, no magnetic order has been observed in standard thermodynamic measurements down to 2 K. Altogether, this renders MnB4 a structurally simple but microscopically enigmatic material; we argue that its properties may be influenced by electronic correlations. |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
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Editor |
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Language |
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Wos |
000332405000002 |
Publication Date |
2014-02-24 |
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 |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
39 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
Call Number |
UA @ lucian @ c:irua:115819 |
Serial |
2571 |
Permanent link to this record |
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Author |
Tsirlin, A.A.; Nath, R.; Abakumov, A.M.; Furukawa, Y.; Johnston, D.C.; Hemmida, M.; Krug von Nidda, H.-A.; Loidl, A.; Geibel, C.; Rosner, H. |
Title |
Phase separation and frustrated square lattice magnetism of Na1.5VOPO4F0.5 |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
84 |
Issue |
1 |
Pages |
014429-014429,16 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Crystal structure, electronic structure, and magnetic behavior of the spin-1/2 quantum magnet Na1.5VOPO4F0.5 are reported. The disorder of Na atoms leads to a sequence of structural phase transitions revealed by synchrotron x-ray powder diffraction and electron diffraction. The high-temperature second-order α↔β transition at 500 K is of the order-disorder type, whereas the low-temperature β↔γ+γ′ transition around 250 K is of the first order and leads to a phase separation toward the polymorphs with long-range (γ) and short-range (γ′) order of Na. Despite the complex structural changes, the magnetic behavior of Na1.5VOPO4F0.5 probed by magnetic susceptibility, heat capacity, and electron spin resonance measurements is well described by the regular frustrated square lattice model of the high-temperature α-polymorph. The averaged nearest-neighbor and next-nearest-neighbor couplings are J̅ 1≃−3.7 K and J̅ 2≃6.6 K, respectively. Nuclear magnetic resonance further reveals the long-range ordering at TN=2.6 K in low magnetic fields. Although the experimental data are consistent with the simplified square-lattice description, band structure calculations suggest that the ordering of Na atoms introduces a large number of inequivalent exchange couplings that split the square lattice into plaquettes. Additionally, the direct connection between the vanadium polyhedra induces an unusually strong interlayer coupling having effect on the transition entropy and the transition anomaly in the specific heat. Peculiar features of the low-temperature crystal structure and the relation to isostructural materials suggest Na1.5VOPO4F0.5 as a parent compound for the experimental study of tetramerized square lattices as well as frustrated square lattices with different values of spin. |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
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Editor |
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Language |
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Wos |
000293247400008 |
Publication Date |
2011-07-28 |
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 |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
47 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
Call Number |
UA @ lucian @ c:irua:91770 |
Serial |
2588 |
Permanent link to this record |
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Author |
Abakumov, A.M.; Shpanchenko, R.V.; Lebedev, O.I.; Van Tendeloo, G.; Amelinckx, S.; Antipov, E.V. |
Title |
The phase transition and crystal structures of Ba3RM2O7.5 complex oxides (R=rare-earth elements, M = Al,Ga) |
Type |
A1 Journal article |
Year |
1999 |
Publication |
Acta crystallographica: section A: foundations of crystallography |
Abbreviated Journal |
Acta Crystallogr A |
Volume |
55 |
Issue |
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Pages |
828-839 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
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Corporate Author |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
Copenhagen |
Editor |
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Language |
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Wos |
000082727000006 |
Publication Date |
2002-07-27 |
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 |
0108-7673; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.725 |
Times cited |
7 |
Open Access |
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Notes |
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Approved |
Most recent IF: 5.725; 1999 IF: 1.601 |
Call Number |
UA @ lucian @ c:irua:29716 |
Serial |
2591 |
Permanent link to this record |
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Author |
Abakumov, A.M.; Rossell, M.D.; Alekseeva, A.M.; Vassiliev, S.Y.; Mudrezova, S.N.; Van Tendeloo, G.; Antipov, E.V. |
Title |
Phase transitions in K3AlF6 |
Type |
A1 Journal article |
Year |
2006 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
Volume |
179 |
Issue |
2 |
Pages |
421-428 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher ![sorted by Publisher field, descending order (down)](img/sort_desc.gif) |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000235282400011 |
Publication Date |
2005-12-06 |
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 |
0022-4596; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.299 |
Times cited |
18 |
Open Access |
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Notes |
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Approved |
Most recent IF: 2.299; 2006 IF: 2.107 |
Call Number |
UA @ lucian @ c:irua:56561 |
Serial |
2597 |
Permanent link to this record |