中国物理B ›› 2010, Vol. 19 ›› Issue (6): 67103-067103.doi: 10.1088/1674-1056/19/6/067103
李成刚, 邝小渝, 段美玲, 张彩霞, 柴瑞鹏
Li Cheng-Gang(李成刚), Kuang Xiao-Yu(邝小渝)†, Duan Mei-Ling(段美玲), Zhang Cai-Xia(张彩霞), and Chai Rui-Peng(柴瑞鹏)
摘要: This paper systematically investigates the local distortion and electron paramagnetic resonance (EPR) parameter for CdCl2:V2= and CsMgX3:V2= (X=Cl, Br) systems on the basis of the complete energy matrix, in which not only the contributions due to the spin--orbit coupling of the central ions but also that of the ligands are considered. To describe the difference of overlapping between d-orbits and p orbit, two spin--orbit coupling coefficients are introduced. By simulating the crystal field parameter and EPR parameter, the local distortion parameters are studied and the relationships between the EPR parameter and the spin--orbit coupling coefficients as well as divergent parameter are discussed. These results show that the local structures exhibit compression distortion for CdCl2:V2= and elongation distortions for CsMgX3:V^{2 + } (X=Cl, Br), respectively. It notes that the empirical formula R \approx R_{\rm H} + (r_{\rm i} - r_{\rm h} ) / 2 is not suitable for CdCl2:V2= and CsMgX3:V2= (X=Cl, Br) systems. The contributions of ligand to spin--orbit coupling interaction cannot be neglected for strong covalent systems, especially for V2= doped in CsMgBr3:V2=.
中图分类号: (Other ions and impurities)