INFLUENCE OF CU CONTENT ON THE FORMATION AND MICROSTRUCTURES OF (BI,PB)-2223 PHASE IN THE PARTIAL-MELTING AND SINTERING PROCESS

The influence of Cu content on the formation and microstructures of (B i,Pb)-2223 phase upon sintering at 840 degrees C for 240 hours, after partial-melting at 875 degrees C for I hour, was studied using XRD, DT A, high-temperature optical microscope and AC susceptibility measureme nt. The compositions which ate rich in Cu are favorable for the format ion of the 2223 phase,and the optimum composition for preparation of t he 2223 phase in Bi1.8Pb0.4Sr1.9 Ca2.1Cu3+cOy is Bi1.8Pb0.4Sr1.9Ca2.1C u3.5Oy. The relative amounts of the (Sr,Ca)2CuO3 and (Sr,Ca)CuO2 in mi crosructures before sintering at 840 degrees C have a strong effect on the formation of the (Bi,Pb)-2223 phase.