Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
Cu, Mg Codoped Bismuth Tantalate Pyrochlores : Crystal Structure, XPS Spectra, Thermal Expansion, and Electrical Properties. / Zhuk, Nadezhda A.; Krzhizhanovskaya, Maria G.; Koroleva, Alexandra V.; Sekushin, Nikolay A.; Nekipelov, Sergey V.; Kharton, Vladislav V.; Makeev, Boris A.; Lutoev, Vladimir P.; Sennikova, Yana D.
в: Inorganic Chemistry, Том 61, № 10, 14.03.2022, стр. 4270–4282.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Cu, Mg Codoped Bismuth Tantalate Pyrochlores
T2 - Crystal Structure, XPS Spectra, Thermal Expansion, and Electrical Properties
AU - Zhuk, Nadezhda A.
AU - Krzhizhanovskaya, Maria G.
AU - Koroleva, Alexandra V.
AU - Sekushin, Nikolay A.
AU - Nekipelov, Sergey V.
AU - Kharton, Vladislav V.
AU - Makeev, Boris A.
AU - Lutoev, Vladimir P.
AU - Sennikova, Yana D.
N1 - Publisher Copyright: © 2022 American Chemical Society.
PY - 2022/3/14
Y1 - 2022/3/14
N2 - The pyrochlore-type solid-solution formation in a Bi1.6Mg0.8-xCuxTa1.6O7.2- system, synthesized for the first time, is observed at x ≤ 0.56. High-temperature X-ray diffraction showed that the pyrochlore phase exists in air up to 1080 °C, where its thermal decomposition leads to the segregation of (Mg,Cu)Ta2O6. The thermal expansion coefficients of the end member, Bi1.6Mg0.24Cu0.56Ta1.6O7.2-, increase from 3.3 × 10-6 °C-1 at room temperature up to 8.7 × 10-6 °C-1 at 930 °C. Rietveld refinement confirmed that the pyrochlore crystal structure is disordered with space group Fd3¯ m:2 (Z = 8, no. 227). Doping with copper results in a modest expansion of the cubic unit cell, promotes sintering of the ceramic materials, and induces their red-brown color. X-ray photoelectron spectroscopy demonstrated that the states of Bi(III) and Mg(II) are not affected by doping, and the effective charge of tantalum cations is lower than +5, while the Cu(II) states coexist with Cu(I). The electron spin resonance spectra display a single line with g = 2.2, ascribed to the dipole-broadened Cu2+ signal. The dielectric permittivity of Bi1.6Mg0.8-xCuxTa1.6O7.2- ceramics may achieve up to 105, with the dielectric loss tangent varying in the range from 0.2 up to 12. Multiple dielectric relaxations are found at room temperature and above for all samples.
AB - The pyrochlore-type solid-solution formation in a Bi1.6Mg0.8-xCuxTa1.6O7.2- system, synthesized for the first time, is observed at x ≤ 0.56. High-temperature X-ray diffraction showed that the pyrochlore phase exists in air up to 1080 °C, where its thermal decomposition leads to the segregation of (Mg,Cu)Ta2O6. The thermal expansion coefficients of the end member, Bi1.6Mg0.24Cu0.56Ta1.6O7.2-, increase from 3.3 × 10-6 °C-1 at room temperature up to 8.7 × 10-6 °C-1 at 930 °C. Rietveld refinement confirmed that the pyrochlore crystal structure is disordered with space group Fd3¯ m:2 (Z = 8, no. 227). Doping with copper results in a modest expansion of the cubic unit cell, promotes sintering of the ceramic materials, and induces their red-brown color. X-ray photoelectron spectroscopy demonstrated that the states of Bi(III) and Mg(II) are not affected by doping, and the effective charge of tantalum cations is lower than +5, while the Cu(II) states coexist with Cu(I). The electron spin resonance spectra display a single line with g = 2.2, ascribed to the dipole-broadened Cu2+ signal. The dielectric permittivity of Bi1.6Mg0.8-xCuxTa1.6O7.2- ceramics may achieve up to 105, with the dielectric loss tangent varying in the range from 0.2 up to 12. Multiple dielectric relaxations are found at room temperature and above for all samples.
UR - http://www.scopus.com/inward/record.url?scp=85126385339&partnerID=8YFLogxK
UR - https://www.mendeley.com/catalogue/248b8465-e554-3a43-9398-81dbf832f239/
U2 - 10.1021/acs.inorgchem.1c03053
DO - 10.1021/acs.inorgchem.1c03053
M3 - Article
C2 - 35239334
AN - SCOPUS:85126385339
VL - 61
SP - 4270
EP - 4282
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 10
ER -
ID: 93874578