期刊
PHYSICAL REVIEW B
卷 84, 期 2, 页码 -出版社
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevB.84.024412
关键词
-
资金
- FEDER-MICINN [MAT2008-06542-C04-03]
- FICYT
A theoretical model including both crystal-field and exchange interactions that considers the effect of magnetic fluctuations is developed to evaluate the temperature dependence of the isothermal magnetic entropy changes in ferromagnetic rare-earth-based intermetallic compounds. The Green's functions are derived from their equation of motion. The magnetic moment correlation functions are determined beyond the random phase approximation by incorporating a measure of magnetic spontaneous fluctuations in a way that ensures self-consistency with regard to the fluctuation-dissipation theorem. In particular, the exact magnitude of the entropy change without magnetic moment fluctuations depends on the ratio of both the crystal-field first-and the crystal-field third-order magnetic susceptibilities at the Curie temperature, T-C. These theoretical predictions are compared with experimental data on cubic RM2 (R = rare earth and M = Al and Ni) compounds, where the principal crystal-field and exchange parameters are well known.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据