CRITICAL CURRENTS VERSUS NORMAL-STATE RESISTIVITY IN GRANULAR BIPB-BASED COPPER-OXIDE SUPERCONDUCTORS

Both the critical current intensity at zero applied magnetic field I c(T), from nitrogen temperature up to the critical temperature, and the normal-state resistivity ρn(T) have been measured in granular Bi1.5Pb0.5Sr2Ca2Cu 3Oy (BiPbSCCO) superconductors, with different granular characteristics. It is found that the combination [Ic(T)/P] [ρn(0)/ρ'n], where ρ(0) is the residual normal-state resistivity, ρ'n is the temperature derivative and P is the sample's perimeter, is essentially constant from sample to sample at any temperature. It thus constitutes a universal temperature-dependent critical current for the polycrystalline BiPbSCCO family. © 1995 American Institute of Physics.