The magnetic behaviour of superconducting and nonsuperconducting DyBa2Cu3O7-yand HoBa2Cu3O7-y

Abstract

The compounds DyBa2Cu3O7-y and HoBa2Cu3O7-y have been prepared in the orthorhombic form by slow cooling and in the tetragonal form by quenching from 900 degrees C to 77 K. The orthorhombic form exhibits superconductivity with Tc mid-points of 86 K in the Dy compound and 88 K in the Ho compound while the tetragonal form, for both compounds, is nonsuperconducting. The magnetic susceptibilities in each case are nearly independent of the structure and the presence or absence of superconductivity, indicating that the magnetism of the rare-earth ion has very little influence on the superconductivity, or lack of it, in these systems, and vice versa.