Preparation and Properties of (Pb,Cu)(Sr,La)2(Y,Ca)Cu2Oz

Lead based copper oxide superconductors which are nominally represented by (Pb(1+x)/2Cu(1−x)/2)(Sr2-yLay)(Y1−(x+y)Cax+y)Cu2Oz, (Pb/Cu)-1212 are synthesized and characterized. Nearly single-phase samples were obtained in the range of x+y 0.6, and Tc on of multi-phase sample with x=0.5, y=0.2 was 65K. Tc decreased as La content,y, increased in Ca/(Ca+Y)=constant (x+y=constant). The increase in amount of positive charge in the (Pb/Cu) site and/or the decrease in amount of positive charge in the Sr site were thought to enhance Tc.