The Oxygen-Deficient Perovskite Solid Solution Nd1+xBa2-xCu3Oy and Its Superconductivity

Abstract

The Nd_1+x Ba_2-x Cu₃O _y system and its superconductivity were studied. This system forms a solid solution within the x range of 0.00 to 0.80. At room temperature, it has orthorhombic symmetry for x ranging from 0.00 to 0.14 and tetragonal symmetry for x not less than 0.20. All specimens at 900°C in air have tetragonal symmetry. It is a superconductor in the region of x less than 0.50. The superconducting onset temperature decreases from 93.5 to 40.0 K with increasing x. In comparison with the superconductivity of the La_1+x Ba_2-x Cu₃O _y system, there appears to be little influence of the magnetic ion Nd³⁺ on the T _c in the Nd_1+x Ba_2-x Cu₃O _y system.