Pressure Dependence of Superconductivity of the 90 K-Superconductors, Ba-Y-Cu-O

Abstract
Pressure dependences of superconductivity as well as that of normal state conductivity of the 90 K-superconductors, Ba x Y1-x CuO3-y (x=0.6, y∼1) in ceramic form is reported. Change of the transition temperature with pressure is small and slightly negative as -0.25 K/kbar or less, contrary to the 40 K-superconductors, while the normal state conductivity at 300 K increases with pressure by 1.27%/kbar.