NH_4I:Cu^(2+)(Ⅱ_4)的混合基态EPRg因子的研究  

Theoretical investigation for the EPR g -factors of the mixed ground state for NH_4I:Cu^(2+)(Ⅱ_4) crystals

作　　者：李福珍[1] 李兆民[2] 

机构地区：[1]四川师范大学物理系,成都610066 [2]四川师范大学科研处,成都610066

出　　处：《原子与分子物理学报》2004年第1期59-64,共6页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金 (10 2 470 0 6) ;四川省教育厅科研基金 ([2 0 0 2 ] 48)资助项目

摘　　要：考虑到NH4I :Cu2 + (Ⅱ4)晶体中 ,Cu2 + 离子替代NH+ 4 后在第四层邻近体出现一个NH+ 4 空位 ,以及络离子 (CuI6) 4 -中配体I的价电子有很强的自旋 -轨道 (SO)耦合相互作用 ,引进了2 B1g态混合进基态2 A1g的机制 ,用双自旋 -轨道耦合参数 (DSOP)模型和半经验分子轨道法研究了NH4I:Cu2 + (Ⅱ4)的EPRg因子。计算结果与实验值符合好 ,合理地解释了 g‖ 移动Δg‖(=g‖ - ge) >0的疑惑。In this paper, it is considered that the Cu^(2+) ion goes substitutionally for NH^+_4 and gets associated with a vacancy at the fourth-neighbour cation site in the NH_4I:Cu^(2+)(Ⅱ_4) crystals as well as the 5p electrons of the halogen ligands I possess the strong SO coupling interactions for the (CuI_6)^(4-) clusters. The mechanism for an admixture of the ()~2B__(1g) into ()~2A__(1g) (ground state) is introduced. The EPR g -factors for NH_4I:Cu^(2+)(Ⅱ_4) are studied by using the DSOP model and the method of a semiempirical molecular orbit. Thus, the calculated results show good agreement with the experimental data. The puzzle that the g_‖ -shift is positive is reasonably explained.

关 键 词：NH4Ⅰ:Cu^2+ DSOP模型 EPR G因子 

分 类 号：O737[理学—晶体学]