A theoretical study of the elastic properties of dysprosium antimonide
A theoretical study of the elastic properties of dysprosium antimonide
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锑化镝弹性性能的理论研究
DOI：
10.1088/0022-3719/6/24/015
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发表时间：
1973
期刊：
影响因子：
--
通讯作者：
P. Levy
中科院分区：
文献类型：
--
作者：
P. Levy
本文导出了锑化镝弹性常数软化的表达式。这种软化是由于磁性离子之间的Jahn-Teller耦合，其地面流形被晶体场分成几个级别。这个表达式在分子场近似下进行了评估，并进一步近似只考虑四极相互作用。通过适当选择本底弹性常数、Jahn-Teller应变耦合gtheta和双二次耦合I theta，可以很好地拟合锑化镝弹性常数C theta = 12（C_（11）-C_（12））的热变化。讨论了几种物理机制，这些机制导致参数的拟合值以及在9.5K下的结构和磁性相变。它的结论是，相变是由大约等量的应变耦合gtheta和交换相互作用。
The author develops an expression for the softening of an elastic constant of dysprosium antimonide. This softening is due to a Jahn-Teller coupling between magnetic ions whose ground manifolds are split into several levels by a crystalline field. This expression is evaluated in the molecular-field approximation and further approximated by considering only quadrupolar interactions. A good fit to the thermal variation of the elastic constant of dysprosium antimonide Ctheta =1/2(C11-C12) is obtained by suitably choosing the background elastic constant, the Jahn-Teller strain coupling gtheta and the biquadratic coupling Itheta . Several physical mechanisms are discussed which give rise to the fitted values of the parameters and to the structural and magnetic phase transition at 9.5K. It is concluded that the phase transition is driven by approximately equal amounts of strain coupling gtheta and exchange interactions.