| Records |
| 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 |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
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 |
Avila-Brande, D.; Otero-Díaz, L.C.; Landa-Cánovas, A.R.; Bals, S.; Van Tendeloo, G. |
| Title |
A new Bi4Mn1/3W2/3O8Cl Sillén-Aurivillius intergrowth: synthesis and structural characterisation by quantitative transmission electron microscopy |
Type |
A1 Journal article |
| Year |
2006 |
Publication |
European journal of inorganic chemistry |
Abbreviated Journal |
Eur J Inorg Chem |
| Volume |
|
Issue |
9 |
Pages |
1853-1858 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The synthesis and structural characterisation of a new phase with nominal composition Bi4Mn1/3W2/3O8Cl is presented. Conventional and analytical transmission electron microscopy are used to determine the composition, unit-cell symmetry and space group of the compound, whereas a structural model is deducted by exit-wave reconstruction in the transmission electron microscope. This technique allows the microscope information limit of 1.1 angstrom to be reached and the (light) oxygen atoms in the presence of heavier atoms (Bi, W, Mn) to be imaged. The average structure is refined from Xray powder diffraction data using the Rietveld method yielding an orthorhombic unit cell with lattice parameters a 5.467(4) angstrom, b = 5.466(7) angstrom and c = 14.159(3) angstrom and space group Cm2m, which could be described as a Sillen-Aurivillius intergrowth. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
| Language |
|
Wos |
000237617800016 |
Publication Date |
2006-03-13 |
| 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 |
12 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.444; 2006 IF: 2.704 |
| Call Number |
UA @ lucian @ c:irua:59436 |
Serial |
2335 |
| Permanent link to this record |
| |
|
| |
| Author |
Morozov, V.; Arakcheeva, A.; Redkin, B.; Sinitsyn, V.; Khasanov, S.; Kudrenko, E.; Raskina, M.; Lebedev, O.; Van Tendeloo, G. |
| Title |
Na2/7Gd4/7MoO4 : a modulated scheelite-type structure and conductivity properties |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
| Volume |
51 |
Issue |
9 |
Pages |
5313-5324 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Scheelite-type compounds with the general formula (A1,A2)n[(B1,B2)O4]m (2/3 ≤ n/m ≤ 3/2) are the subject of large interest owing to their stability, relatively simple preparation, and optical properties. The creation of cation vacancies (□) in the scheelite-type framework and the ordering of A cations and vacancies can be a new factor in controlling the scheelite-type structure and properties. For a long time, cation-deficient Nd3+:M2/7Gd4/7□1/7MoO4 (M = Li, Na) compounds were considered as potential lasers with diode pumping. They have a defect scheelite-type 3D structure (space group I41/a) with a random distribution of Li+(Na+), Gd3+, and vacancies in the crystal. A Na2/7Gd4/7MoO4 single crystal with scheelite-type structure has been grown by the Czochralski method. Transmission electron microscopy revealed that Na2/7Gd4/7MoO4 has a (3 + 2)D incommensurately modulated structure. The (3 + 2)D incommensurately modulated scheelite-type cation-deficient structure of Na2/7Gd4/7MoO4 [super space group I4̅ (αβ0,βα0)00] has been solved from single-crystal diffraction data. The solution of the (3 + 2)D incommensurately modulated structure revealed the partially disordered distribution of vacancies and Na and Gd cations. High-temperature conductivity measurements performed along the [100] and [001] orientation of the single crystal revealed that the conductivity of Na2/7Gd4/7MoO4 at T = 973 K equals σ = 1.13 × 105 Ω1 cm1. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Easton, Pa |
Editor |
|
| Language |
|
Wos |
000303952900055 |
Publication Date |
2012-04-19 |
| 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 |
37 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 4.857; 2012 IF: 4.593 |
| Call Number |
UA @ lucian @ c:irua:98385 |
Serial |
3547 |
| Permanent link to this record |
