FORMATION PROCESS OF 2223-PHASE IN BI-PB- SR-CA-CU-O SYSTEM VIA CALCINING AT 1073 K

The formation process of the 2223 phase synthesis via conventional cal cining condition has been systematically investigated using XRD, SEM/E DX, TG/DTA and TMA, The calcining powder prepared at 1073 K for 18 ks consists of 2201 phase, 2212 phase, Ca2PbO4, CaO, CuO and Sr14-xCaxCu2 4O41. With increasing a holding time in firing process at 1133 K, 2212 phase, Ca2PbO4 and Sr14-xCaxCu24O41 did decrease, and 2223 phase, Ca2 -xSrxCuO3 and Bi0.5Pb3Sr2.5Ca2CuOx increased, It was considered that 2 223 phase, Ca2-xSrxCuO3 and Bi0.5Pb3Sr2.5Ca2CuOx were formed by reacti on with 2212 phase, Ca2PbO4 and Sr14-xCaxCu24O41 The liquid phase was formed from 1113 to 1133 K in firing process, and then Sr14-xCaxCaxCu2 4O41 was drastically formed reaction with the liquid phase and CuO, Th e reason that needs long term-heat treatment to synthesize 2223 phase with conventional calcining condition is regarded as formation of Sr14 -xCaxCu24O41.