ZnO∶V^(3+)晶体光谱和电子顺磁共振谱的理论研究

Investigation of Optical and EPR Spectra of ZnO∶V^(3+) Crystal

采用强场耦合图像,建立了3d2电子组态在三角对称中的45×45能量矩阵,通过对角化完全能量矩阵的方法,计算出了ZnO∶V3+晶体的45条光谱能级和5个电子顺磁共振谱参量(零场分裂D,g因子g∥,g⊥和超精细结构常数A∥,A⊥),计算结果与实验数值能很好地符合。计算中还发现V3+杂质中心的局部结构与基质晶体的结构不一致,即V3+在ZnO中并不占据准确的Zn2+位置,而是沿c3轴方向位移一段距离ΔZ≈0.003 nm。作者对上述这些结果的合理性进行了讨论。

In the present paper,the 45×45 energy matrix of the 3d2 ions in trigonal symmetry with the strong-field-coupling mechanism is established.The forty-five optical energy levels and five EPR parameters（including the zero-field splitting D,g factors g∥,g⊥ and hyperfine structure constants A∥,A⊥） of ZnO∶V^3＋ cryst are calculated from the diagonalization of this complete energy matrix.The calculated results are in agreement with the observed values.Based on the calculation,it was found that the local structure of V^3＋ impurity center is different from the corresponding structure in the host crystal,i.e.,the V^3＋ ion in ZnO does not occupy the exact Zn^2＋ site,but is displaced by ΔZ≈0.003 nm along the c3 axis.The reasonableness of these results is discussed.