Effect of high pressure on the electrical resistivity behaviour of (Pb_0.5,Cd_0.5)Sr₂(Y_1-x,Ca_x)-Cu₂O_7-δ/Ag₂O superconducting composites

Abstract

The effect of high pressure on the electrical resistivity behaviour of (Pb 0.5 , Cd 0.5 )Sr 2 (Y 1−x , Ca x )Cu 2 O 7−δ (x = 0.3, 0.4 and 0.5) superconductor with, and without, 10 mol% Ag 2 O addition has been studied. At room temperature, there was an initial drop in the resistivity of the pure superconductor up to 2 GPa, followed by a nearly constant value up to 8 GPa pressure. The steady value of resistivity observed between 2 and 8 GPa decreased with increasing calcium content. The superconducting composite formed with the addition of 10 mol% Ag 2 O to the (Pb, Cd)-1212 phase (x = 0.3) exhibited a metallic nature under pressure up to 8 GPa, but the high-pressure resistivity behaviour of the superconducting composites with x = 0.4 and 0.5 was found to be semiconducting.