Crystal-field effects on the crossover temperature of Sm³⁺ magnetization in magnetically ordered samarium compounds

Abstract

White and Van Vleck have shown that in magnetically ordered samarium compounds, where the Sm³⁺ ion can be considered as a "free" ion, the exchange field acting alone produces a sign change or a crossover in Sm³⁺ magnetization at a temperature of about 300 K. This result is a consequence of the admixture of J=7/2 level into J=5/2 level of the Sm³⁺ ion by exchange fields. We show that the crystal-field interaction strongly influences the crossover temperature and the magnitude of Sm³⁺ magnetization. Samarium iron garnet is one of the systems where a crossover temperature has been observed.