Suppression of superconductivity in orthorhombic La(2-x)M(x)CuO4

摘要

We have extended the calcium solid-solubility limit in La(2-x)M(x)CuO4 to x = 0.2 using synthesis at high oxygen pressure. The superconducting transition temperature increases with doping to 34 K at x = 0.15 and is suppressed for x > 0.15, similar to the Sr-substituted material. At a fixed doping level, the optimum superconducting properties (the highest (Tc)) are found for flat and square CuO(sub 2)planes.