单晶LiHSO_4:VO^(2+)的EPR谱及吸收光谱的理论研究

Theoretical studies of EPR and optical absorption spectra of LiHSO_4:VO^(2+) crystal

考虑到配体离子的自旋-轨道耦合作用对光谱和电子顺磁共振谱的贡献不可忽略,采用3d^1离子在四角对称下基于双自旋-轨道耦合模型的高阶微扰公式和晶场理论公式,理论计算了LiHSO_4:VO^(2+)晶体的光谱和电子顺磁共振(EPR)参量g因子g(?)、g_⊥和超精细结构常数A(?)A_⊥。计算结果与实验发现能很好地符合。由于晶体中过渡金属离子中心的EPR参量与其缺陷结构紧密相关,理论计算还获得了V^(4+)杂质中心缺陷结构的信息。对理论结果的合理性进行了讨论。

Since the contribution of the spin-orbital coupling interaction of the ligand to optical and electron paxamagnetic resonance （EPR） spectra can not be neglected, the optical and EPR spectra （g factors g‖、g⊥and hyperfine structure constant A‖、A⊥） of LiHSO4：VO^2＋ crystal axe calculated from the high-order perturbation formulas on the basis of double-spin-orbital coupling model and crystal-field theory for 3d^1 ion in tetragonal symmetry. The calculated results are in good agreement with the observed values. Since the EPR paxameters are sensitive to the local structure of a paramagnetic impurity center, the defect structure of V^4＋ center in LiHSO4 crystal is obtained. The validity of the results is discussed.