The effect of partial substitution of Cu in Bi1.7Pb0.3Sr2Ca2Cu3-xSbxOy at x = 0.0, 0.05, 0.1, 0.15, and 0.2 levels on the electrical and structural properties was investigated in this work. X-ray diffraction analysis shows that these materials have a multiphase structure. Two different:types of particles with different morphologies were observed in scanning electron micrographs. The T-c values decreased from 103.5 to 87 K for x = 0.1 Sb substitution level with a subsequent increase to 101K at x = 0.2
