|
Документ взят из кэша поисковой машины. Адрес
оригинального документа
: http://www.chem.msu.ru/eng/publ/r00-005.html
Дата изменения: Unknown Дата индексирования: Thu Feb 27 23:04:10 2014 Кодировка: |
P.E. Kazin, V.V. Poltavets, Yu.D. Tretyakov, M.Jansen, B.Freitag, M.Mader.
Supercond. Sci. Technol., v. 12 (8), p. 475-480 (1999)
ABSTRACT. Devitrification of glass with the cation ratio, corresponding to the {Bi2.18Sr2CaCu2Ox+0.4Sr1.7Ca1.3Al2O6} composition, was studied. At temperatures below 600oC, the phases crystallized in the following order: Bi-2201, Cu2O, CaO, (Sr,Ca)3Bi2O6, while Al-ions concentrated in the remaining glass. Above 600oC, Bi-2212 and (Sr,Ca)3Al2O6 formed simultaneously, so that at 750oC, the two-phase composite Bi-2212 - (Sr,Ca)3Al2O6 was obtained that contained grains of the aluminate phase 0.03-0.3 micron in size. The Al-rich phase surplus increased stability of the glass and accelerated Bi-2212 phase formation, while development of superconductivity in Bi-2212 was slowed down. It was shown that composite glass-ceramics with bulk superconductivity could be obtained at temperatures above 850oC.
Laboratory of Inorganic Materials Science