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Synthesis and properties of NbM(2)RCu(2)O(8) and TaM(2)RCu(2)O(8) phases (M=Ba, Sr; R=Pr, Nd, Sm, Eu and Gd)статья
Информация о цитировании статьи получена из
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Web of Science
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
- Авторы: Kopnin E.M., Lobanov M.V., Abakumov A.M., Lubarskii S.V., Lebedev O.I., Antipov E.V., Capponi J.J.
- Журнал: Journal of Alloys and Compounds
- Том: 241
- Номер: 1-2
- Год издания: 1996
- Издательство: Elsevier BV
- Местоположение издательства: Netherlands
- Первая страница: 63
- Последняя страница: 68
- DOI: 10.1016/0925-8388(96)02288-8
- Аннотация: NbM(2)RCu(2)O(8) and TaM(2)RCu(2)O(8) (M = Ba, Sr; R = Pr, Nd, Sm, Eu and Gd) phases were synthesized. Electron diffraction study of TaSr2EuCu2O8 showed the presence of a weak superstructure (a approximate to root 2a(per)), like that found for a number of similar phases. Rietveld refinement of this structure based on X-ray powder diffraction data was carried out in the space group P4/mmm (R(I) = 0.038, R(P) = 0.037) since no superstructure reflections were observed. Various types of cation replacement were performed in order to increase the copper valence. Monophasic Nb(Ta)(1-x)TixSr2EuCu2O8 samples were synthesized at P(O-2) = 1 bar and T = 1050 degrees C up to x = 0.1 (Nb) and 0.3 (Ta), but no superconductivity was detected down to 12 K. High pressure syntheses were carried out to obtain Nb(Ta)Sr2Eu1-xCaxCu2O8 phases, but they were found to have a narrow homogeneity range that provides no opportunity of inducing superconductivity in such a way.
- Добавил в систему: Лобанов Максим Владимирович