【摘要】 基于完全对角化方法(complete diagonalization method,CDM),研究了6S(3d5)态离子在三角晶场(包括C3v,D3,D3d点群对称晶场)中零场分裂(zero-field splitting,ZFS)参量D和(a-F)的微观起源.研究中除了考虑研究者通常考虑的SO(spin-orbit)磁相互作用外,同时考虑了SS(spin-spin),SOO(spin-other-orbit),OO(orbit-orbit)磁相互作用.研究表明:在三角对称晶场中,6S(3d5)态离子的ZFS参量在所选晶场的大多部分区域主要起源于SO机理,但SS机理、SOO机理、OO机理对ZFS参量的贡献不能被忽略.此外研究表明:ZFS参量D和(a-F)主要来自纯自旋四重态及自旋二重态与自旋四重态联合作用的贡献,纯自旋二重态对ZFS参量D和(a-F)的贡献为零.我们发现二阶ZFS参量D与四阶ZFS参量(a-F)有不同的微观起源.二阶ZFS参量D主要来自自旋四重态的贡献,而四阶ZFS参量(a-F)主要来自自旋二重态与自旋四重态联合作用的贡献.作为本文理论的应用,研究了掺杂晶体材料Fe3+:Al2O3,理论与实验测量符合很好.更多还原

【Abstract】 The microscopic mechanism of the zero-field splitting parameters (ZFS) including D and (a-F) for 6S(3d5) state ion in trigonal-symmetry crystal field have been investigated using the complete diagonaliztion method ( CDM) by taking into account the spin-spin (SS),the spin-other-orbit (SOO) and the orbit-orbit (OO) magnetic interactions besides the well-known spin-orbit (SO) magnetic interaction. It was found that the contribution to the ZFS parameters D and (a-F) arising from the spin-orbit (SO) magnetic interaction is the most important in most of the crystal field ( CF) ranges,but the contribution to the zero-field splitting (ZFS) parameter D and (a-F) from the other three mechanisms,including the SS mechanism,SOO mechanism and OO mechanism,can’t be ignored. The ZFS parameters D and (a-F) arise from the net spin quartet states as well as the combined effects of the spin doublet states and the spin quartets states,and the contribution to the ZFS parameters from the net spin doublet states are zero. Our investigation shows that the rank-2 ZFS parameter D primarily results from the net spin quartet states whereas the rank-4 ZFS parameter (a-F) primarily results from the combined effect of the spin doublet states and the spin quartet states. An illustrative evaluation is performed for the typical crystal material Fe3 + : Al2O3. Good agreement between the theoretical values and the experimental finding are obtained.更多还原