波谱学杂志 ›› 2008, Vol. 25 ›› Issue (2): 250-256.

• 研究论文 • 上一篇    下一篇

CaF2:Co2+光谱和顺磁 g 因子的统一解释

谢林华;朱世富   

  1. 四川大学 材料科学系,四川 成都 610064
  • 收稿日期:2007-04-25 修回日期:2007-05-25 出版日期:2008-06-05 发布日期:2009-12-05
  • 通讯作者: 朱世富

Unified Explanation of the Optical Spectra and Paramagnetic g Factor of CaF2:Co2+

XIE Lin-hua;ZHU Shi-fu   

  1. Material Science Department, Sichuan University, Chengdu 610064 China
  • Received:2007-04-25 Revised:2007-05-25 Online:2008-06-05 Published:2009-12-05
  • Contact: Zhu Shi-fu

摘要: 基于半自洽场d轨道理论和完全对角化方法,从杂质局部结构统一解释了CaF2:Co2+的光谱和顺磁 g 因子. 杂质局部结构存在塌缩效应,但仍保持八配位立方对称. 在此基础上,用微扰法和完全对角化方法讨论了g因子对晶场参量Dq的依赖关系. Macfarlane的 g 因子三阶微扰公式是好的近似公式,但随着Dq的减小,其有效性变差. 最后,文章讨论了基于完全对角化和自旋哈密顿理论的 g 因子公式的适用性,及其在轨道简并情况下的困难.

关键词: 晶体场, 顺磁 g 因子, 光学和磁学性质

Abstract: Based on the semi-self-constant-field (semi-SCF) d-orbital model and the complete energy matrix diagonalization procedure (CDP), the optical spectra and g factor of CaF2:Co2+ were explained from the local structure of the impurities. The local structure was shown to have collapse effects, but remain an eight-coordinate cubic symmetry. In addition, the dependence of the g factor on the crystal splitting parameter Dq was discussed by the perturbation method (PTM) and CDP. The third order perturbation formula proposed by Macfarlane was shown to be a good approximation, but its validity became worse with decreasing Dq. At last, the applicability of the g formulae constructed on the basis of CDP and spin Hamiltonian theory, together with the difficulties in the case of orbital degeneration, were discussed.

Key words: crystal field, EPR g factor, optical and magnetic properties