Effect of melting time on the superconductivity in Bi1.7Pb0.3Sr2CaCu2O8 superconducting system

We reported here the effect of melting time (1.5-5 min + 5 s) in air and at 920 degrees C on the normal and superconducting properties of Bi1.7Pb0.3Sr2CaCu2O8 (Bi (Pb): 2212) system. The results of X-ray diffraction, microhardness, resistivity and Hall effect are presented in details. Furthermore, the superconducting critical temperature T-c, normal resistivity rho(300), residual resistivity rho(0), and resistivity slope corresponding to the linear rho-T region and width of transition Delta T-c are extracted from resistivity data. Moreover, various normal state parameters, such as density of holes, Fermi energy and density of states at the Fermi level are calculated for all samples. These results shows a correlation between the above measured parameters against melting time, and indicate that 3.5 min is the suitable melting time to optimizing T-c at 89 K for Bi (Pb): 2212 superconducting system. (C) 2010 Elsevier B.V. All rights reserved.