1994 年 41 巻 4 号 p. 396-399
Mechanical grinding and reforming process of the Pb-substituted 2223 phase has been studied for the monophasic samples with a composition of Bi0.9Pb0.2SrCaCu1.6OZ. The 2223 phase changes to ultla-fine powder by full grinding, exhibiting no magnetic response, while the ultra-fine powder and the small 2223 crystals coexist in samples ground for short periods. Some second phases were formed in the ground powder subjected to heating at temperatures between 500°C and 800°C. On the other hand, annealing of the bulk samples below 800°C leads to precipitation of the 3321 phase identified as Sr2.5Bi0.5Pb3Ca2CuOZ. Precipitation of second phases in the coexistent powder was interpreted by those in ultra-fine powder and bulk samples.