Magnetic Properties of GdCo₂ and Gd_1-xY_xCo₂

Abstract

The magnetic properties of GdCo 2 and Gd 1- x Y x Co 2 have been observed and discussed in terms of the molecular field approximation. An appropriate set of interaction parameters reproduces the temperature dependence of the magnetization of GdCo 2 and the concentration dependence of the Curie temperature of Gd 1- x Y x Co 2 for x < 0.2. Among the three kinds of interaction, the interaction between Gd and Co atoms plays the most important role in determining the Curie temperature. A negative deviation of the Curie temperature form the molecular field estimation, observed for x > 0.2, suggests that the Co moment is suppressed by Y substitution and quite sensitive to magnetic environments. A stepwise anomaly in the temperature dependence of the magnetization previously reported could not be observed.