Formation of Bi-2212 phase and phase assemblage in Ga-doped BSCCO system

P.E. Kazin, V.V. Poltavets, O.N. Poltavets, A.A. Kovalevsky, Yu.D. Tretyakov, M.Jansen

Physica C, v. 324 (1), p. 30-38 (1999)

ABSTRACT. Phase relations in the Bi-Sr-Ca-Cu-Ga-O system were investigated at 850-900^oC. Two Ga-containing phases were found to be compatible with Bi-2212. Compositions of these phases were estimated as Bi0.2Sr1.8-xCaxGa2Oz and Bi1.7Sr2.3Ca0.6Cu1.6Ga0.4Oz. The Ga content in Bi-2212 was limited to 15-25 mol %. The mixture of Bi-2212 with the Ga-containing phases started to melt around 870^oC, at 890^oC yielding liquid and (Sr,Ca)3Ga2O6 phase. The superconducting composites Bi-2212/Bi0.2Sr1.8-xCaxGa2Oz were prepared using partial melting procedure. The dopant had only a slight effect on Tc, the flux pinning in the material was not improved at all.

Laboratory of Inorganic Materials Science