Pressure effects on T c of superconducting La 2−xCa 1+xCu 2O 6

Abstract

The superconducting transition temperature T c was measured as a function of pressure (P) up to 2 GPa for Ca-based 2-1-2-6 compounds, La 2−xCa 1+xCu 2O 6 (0.15≤x≤0.25). The T c's of these compounds were weakly dependent on pressure. The pressure coefficients of T c changed sign from positive to negative with increasing pressure at P≈1 GPa for each composition studied. The results can be explained by only small changes of hole concentration in this pressure region.