1073Kでか焼した場合のBi系2223相の生成過程

抄録

The formation process of the 2223 phase synthesis via conventional calcining condition has been systematically investigated using XRD, SEM/EDX, TG/DTA and TMA. The calcining powder prepared at 1073K for 18ks consists of 2201 phase, 2212 phase, Ca₂PbO₄, CaO, CuO and Sr_14-xCa_xCu₂₄O₄₁. With increasing a holding time in firing process at 1133K, 2212 phase, Ca₂PbO₄ and Sr_14-xCa_xCu₂₄O₄₁ did decrease, and 2223 phase, Ca_2-xSr_xCuO₃ and Bi_0.5Pb₃Sr_2.5Ca₂CuO_x increased. It was considered that 2223 phase, Ca_2-xSr_xCuO₃ and Bi_0.5Pb₃Sr_2.5Ca₂CuO_x were formed by reaction with 2212 phase, Ca₂PbO₄ and Sr_14-xCa_xCu₂₄O₄₁. The liquid phase was formed from 1113 to 1133K in firing process, and then Sr_14-xCa_xCu₂₄O₄₁ was drastically formed reaction with the liquid phase and CuO. The reason that needs long term-heat treatment to synthesize 2223 phase with conventional calcining condition is regarded as formation of Sr_14-xCa_xCu₂₄O₄₁.