Comparative Characteristics of Bi- and La- Doped (Ca/Sr)MoO4-Based Materials with a Defect Scheelite-Type Structure
Электронный научный архив УРФУ
Информация об архиве | Просмотр оригинала| Поле | Значение | |
| Заглавие |
Comparative Characteristics of Bi- and La- Doped (Ca/Sr)MoO4-Based Materials with a Defect Scheelite-Type Structure
|
|
| Автор |
Mikhaylovskaya, Z. A.
Klimova, A. V. Petrova, S. A. Pankrushina, E. A. Buyanova, E. S. |
|
| Тематика |
STRONTIUM BISMUTH MOLYBDATE
CALCIUM BISMUTH MOLYBDATE X-RAY DIFFRACTION RAMAN SPECTROSCOPY AUTOCORRELATION FUNCTION CONDUCTIVITY ENERGY GAP |
|
| Описание |
The AAF demonstrated that the isolated electron pair of bismuth plays a key role in the distortion of the Mo–O sublattice.
The decrease in the calculated energy gap with increasing x-value is observed both for the (Ca/Sr)1−3xLa2xФxMoO4 and Sr1−3xBi2xФxMoO4 systems. In contrast to Sr1−3xBi2xФxMoO4 compositions, (Ca/Sr)1−3xLa2xФxMoO4 show the general decrease of conductivity. Received: 20.10.23. Revised: 17.11.23. Accepted: 27.11.23. Available online: 06.12.23. CaMoO4- and SrMoO4-based scheelite-type phases are noteworthy functional materials, whose properties strongly correlate with their structure. This work is devoted to La- or Bi-doped scheelite-type molybdates. The purpose of the present study is to quantify the effect of isolated electron pairs of bismuth on the distortion of the structure and related properties. Conventional solid-state technology was used for the synthesis of (Ca/Sr)1–3xLa2xФxMoO4 and Sr1–3xBi2xФxMoO4, (0.025≤ x ≤ 0.275). The structure was investigated by X-ray powder diffraction and Raman spectroscopy. Rates of structure distortion were characterised by the analysis of the autocorrelation function (AAF) of Raman spectra. Energy gaps were calculated by the Kubelka-Munk method. The conductivity was studied with a.c. impedance spectroscopy. For (Ca/Sr)1−3x(Bi/La)2xФxMoO4 series 0.025 ≤ x ≤ 0.15 compositions show a basic defect scheelite structure, while 0.15 < x ≤ 0.225 compositions of Bi-doped samples exhibit tetragonal supercells. The chemical compression of unit cell is more evident in the case of Bi-doping, indicating the preferred orientation of the isolated electron pairs. The distortion of MoO4 polyhedra showed by AAF was more significant for Sr1−3xBi2xФxMoO4 than for Sr1−3xLa2xФxMoO4, the Δcorr parameters for Bi-doped compositions were almost double in comparison with La-doped one in the range of 50–600 cm–1 of the Raman shift. The «critical» x = 0.15 point was also clearly indicated by Δcorr parameter. The AAF of the Raman spectra of solid oxides was shown to be a good tool for prediction of properties and points of phase transitions in solid oxides. This work was fulfilled as part of the Government task to the Institute of Geology and Geochemistry (theme No. AAAA-A19-119071090011-6). The retrofit and development of the Geoanalitik Shared Facilities Center of the Institute of Geology and Geochemistry is carried out under a grant from the Ministry of Higher Education and Science of the Russian Federation (agreement No. 075-15-2021-680). The XRD data were obtained in Ural-M center of Institute for Metallurgy, Ural Branch of RAS, the Raman data were obtained in Geoanalytic center of Zavaritsky Institute of Geology and Geochemistry, Ural Branch of RAS. |
|
| Дата |
2024-01-18T12:45:22Z
2024-01-18T12:45:22Z 2023 |
|
| Тип |
Article
Journal article (info:eu-repo/semantics/article) Published version (info:eu-repo/semantics/publishedVersion) |
|
| Идентификатор |
Comparative Characteristics of Bi- and La- Doped (Ca/Sr)MoO4-based Materials with a Defect Scheelite-Type Structure / Z. A. Mikhaylovskaya, A. V. Klimova, S. A. Petrova, E. A. Pankrushina, E. S. Buyanova // Chimica Techno Acta. — 2023. — Vol. 10, No. 4. — № 202310411.
2411-1414 http://elar.urfu.ru/handle/10995/129329 https://www.elibrary.ru/item.asp?id=60040553 10.15826/chimtech.2023.10.4.11 |
|
| Язык |
en
|
|
| Связанные ресурсы |
Chimica Techno Acta. 2023. Vol. 10. № 4
|
|
| Формат |
application/pdf
|
|
| Издатель |
Уральский федеральный университет
Ural Federal University |
|