Samples with a norminal composition of Bi1.6Pb 0.4Sr2Ca2Cu3Oy were prepared by using the solgel method. The growth of high-Tc superconducting phases (Bi,Pb)2Sr2Can-1CunO 2n+4+δ (n = 1, 2 and 3) and their particle size were observed for increasing sintering temperature by using x-ray powder diffraction and scanning electron microscopy. The superconductivity of the samples was obtained by using resistivity and ac-susceptibility measurements. The results showed the evident dependence of the superconducting transition characteristics on the particle size over a wide range from sub-micron to some tens of micrometers. The mixing on an atomic scale obtained by using the sol-gel method and the doped elements like Pb and Ag are the key technological elements that govern the growth rate of the high-Tc superconducting phases and their particle sizes.
