OCCURRENCE OF SUPERCONDUCTIVITY IN Ca-DOPED (Pb,Cu)Sr₂PrCu₂O_z

Abstract

We have investigated the Ca -doping effects on the structural, electrical and magnetic properties of ( Pb 0.5 Cu 0.5 ) Sr 2 ( Pr 1-x Ca x Cu 2 O z ( x =0-0.5) bulk ceramic samples. The electrical resistivity, thermoelectric power and magnetic susceptibility measurements reveal that the Ca doping introduces holes into the system and thereby superconductivity with onset T c , of about 36 K is induced for a phase with x =0.5. These results are discussed in conjunction with the roles of hole doping, structural changes and Pr - O hybridization in CuO 2 layers.