Effects of varying initial Bi stoichiometry on phase formation of partial melt-processed Bi2Sr2CaCu2Ox

✍ Scribed by S. Wu; J. Schwartz; G.W. Raban Jr.

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 574 KB
• Volume: 213
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(93)90469-7

✦ Synopsis

Phase formation and growth mechanisms of polycrystalline Bi2Sr2CaCu2Ox have been investigated over a broad range of sintering times at the partial melting temperature by scanning electron microscopy (SEM) with quantitative energy dispersive Xray spectroscopy (EDX), optical microscopy, and magnetization hysteresis measurements. It is observed that the initial powder experienced varying amounts of Bi loss during sintering, and microstructural studies showed the formation of non-superconducting phases (Srl _yCay),CuOx (n = 1, 2 ) in addition to the superconducting 2212 phase in all samples. The effects of varying initial Bi stoichiometry on the reduction of secondary phases are investigated. By increasing the Bi content in the starting powder, the number and size of the (Sr~ _yCay),CuOx grains was reduced and the volume fraction of 2212 phase was increased.