三角晶场中~6S态离子电子顺磁共振参量的分析

ANALYSIS FOR THE ELECTRON PARAMAGNETIC RESONANCE PARAMETERS OF S^6-STATE ION IN TRIGONAL CRYSTAL FIELDS

本文利用完全对角化d^5组态离子能量矩阵的方法,对三角对称下~6S态离子的电子顺磁共振(EPR)参量D.α-F进行了一般性研究,研究表明:EPR参量与其基态和激发态(自旋四重态和自旋二重态)有密切联系,且有如下规律:二阶参量D主要来自自旋四重态,自旋二重态贡献较之小得多;四阶参量α-F则主要来自二重态,四重态的贡献很微弱,但不能忽略.进一步考察表明,二重态对α-F参量的贡献总为正值.另外,某些文献处理α的方法在晶场畸变较弱时误差较大,为此,本文给出了其适用范围.

This paper presents a general study for the electron paramagnetic resonance (EPR) parameters Dand α-F of a ~6S-state ion in trigonal symmetry by completely diagonalizing the energy matrices of d^5 configuration. The obrained numerical results indicate that the EPR parameters are related tightly to the ground and excited states (ie, the spin-quarters and spin-doublets): The second rank parameter D comes mainly from the spin-quartets and negligibly from the spindoublets. The fourth rank parameter a-F, however, arises mostly from the spin-doublets. The spin-qarters' contribution to α-F cannot be neglected although it is small in magnitude. Furthere studies show that the spin-doublets contribute to the parameter α-F a value which is always positive. In addition, we have found a method suggested in some literature in calculation of a will caues large erros in cases of weak distortion. We have given the range in which the method is applicable.