Preparation of a High Tc Superconductor by Oxidization of an Amorphous La1.8Sr0.2Cu Alloy Ribbon in Air

Abstract

A ductile La_1.8Sr_0.2Cu amorphous alloy with a long ribbon shape was prepared by melt spinning. Oxidization of the amorphous alloy ribbon at 1173 K for 1.2 ks in air results in formation of a tetragonal (La_1.8Sr_0.2Cu) _x O _y , oxide. Furthermore, the oxide ribbon was found to exhibit high T _c superconductivity with onset at 36 K, midpoint at 22 K and zero resistance at 9 K. It is therefore concluded that the new process consisting of the preparation of an amorphous alloy ribbon with good ductility, followed by the high temperature oxidization in air is useful for production of a superconducting oxide tape with high T _c.