Magnetic Susceptibility Studies on CsCrCl₃ and RbCrCl₃

Abstract

Magnetic susceptibility studies are made in 4.2 K≤T≤573 K on single crystals of linear chain Heisenberg antiferromagnets CsCrCl₃ and RbCrCl₃. Anomalies in the temperature variation of the susceptibility are observed at temperatures where crystallographic phase transitions caused by cooperative Jahn-Teller effect take place. The anomaly is a discontinuous jump or a turning point according as the transition is of first or second order, respectively. The data are fitted to Fisher’s classical theory, and temperature variations of the intrachain exchange interaction constants of the two magnets are evaluated. The constant changes discontinously at the first order transition temperature, and continuously in a temperature range below the second order transition temperature.