Magnetic characteristics of superconducting RBa2Cu3O6+y (R = Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm and Yb)

Abstract

Magnetic properties of superconducting RBa 2 Cu 3 O 6+y compounds ( R = Nd , Sm, Eu, Gd, Dy, Ho, Er, Tm and Yb) have been studied by using a SQUID magnetometer in the temperature range of 3 – 400 K. The susceptibility data of most of the samples can be well described by the Curie-Weiss relation. The rare earth ions exhibit essentially the full magnetic moments expected for the R 3+ states, while the superconducting transition temperature remains in the 88 – 94 K range. The rare earth moments are generally found to interact antiferromagnetically. However, no magnetic order is observed in the temperature range studied. The Eu samples exhibited anomalous susceptibilities which we ascribe to the low-lying states of the 7 F J manifold of Eu 3+ .