Coexistence of Magnetism and Superconductivity in a YBa₂Cu₃O_7-x Compound

Abstract

Since the discovery of the superconductor YBa₂Cu₃O_7−x with transition temperatures above 90 K, similar compounds have been prepared with a number of rare-earth elements substituting the Y. Surprisingly, no depression of critical temperature was observed for magnetic ions with high magnetic moment such as Gd and others. Antiferromagnetic ordering has been reported for GdBa₂Cu₃O_7−x at a temperature of 2.3 K². Furthermore, it has been found that changes in oxygen content of these materials strongly affect their electrical and magnetic properties. The question of possible interplay between superconductivity and magnetism therefore requires close scrutiny.