Role of vanadium in Bi-2223 ceramics

The effect of substitution of vanadium in Bi1.6Pb0.4Sr2Ca2Cu3Odelta ceramic at Bi and Cu sites has been investigated for the resistivity, a.c. susceptibility, XRD and a.c. magnetization studies. Enhancement in T-c for the smaller concentrations of V at either of the two sites was observed which followed an expected lattice distortion and decrease in T-c for higher V concentrations. V plays a role of substituting element more than just a sintering agent as reflected in the more rapid decrease in T-c at Cu-site and further in the magnetization values that are higher compared to the values at the Bi-site. It indicates higher magnetization scattering at the Cu site. The results were explained keeping in mind the liquid phase mechanism behind the formation of the 2223 phase and the possibility of magnetic scattering.