Effect of anion concentration in BiF3 substitution for Bi2O3 in the Bi-Pb-Sr-Ca-Cu-O (2223-phase) system superconductor

Partial substitution of BiF3 for Bi2O3 has been studied on the high-T-c superconducting materials of the Bi-Pb-Sr-Ca-Cu-O system (2223 phase). D.c. electrical resistivity, critical current density and a.c. magnetic susceptibility were measured by means of the standard four point probe technique and the inductance method, respectively. It was found that small substitution of BiF3 enhanced slightly the critical transition temperature and decreased the critical current density. A significant change in the atomic concentration of each component with the substitution of BiF3 was observed by XPS scan.