掺Mo钨酸盐BaWO_4中g因子和局部结构的研究

Research on the g factors and local structure of the Mo^(5+) -doped BaWO_4 crystal

用建立在双机制模型的高阶微扰公式计算了X-射线照射的钨酸盐BaWO4中四角对称(MoO4)3#四面体基团的g因子,在这个模型中,不仅考虑了常用的晶场机制,而且还包括了常被忽略的荷移机制对g因子的贡献.计算结果表明,要合理和准确地计算高价态dn离子在晶体中的g因子,荷移机制的贡献应予考虑.通过计算,还获得了BaWO4中(MoO4)3#杂质中心的局部结构数据.

The high- order perturbation formulas based on the two-mechanism model are applied to cal- culate the g factors g//and g⊥ of the tetragonal （MOO4）3- center in BaWO4 crystal irradiated by X-ray. The model contains the contributions to g factors from both the crystal-field （CF） mechanism and charge-transfer （CT） mechanism （note： CT mechanism is neglected in the extensively-used CF theo- ry）. The calculated results are reasonably consistent with the experimental values. The calculations show that for the exact calculations of g factors of high valence state dn ions in crystals, the contribu- tions due to CT mechanism should also be considered. The local structure of （MOO4）3- center is also es- timated from the calculation.