Ni~(2 )∶CsMgCl_3晶体的光谱精细结构、零场分裂参量及Jahn-Teller效应

应用不可约张量理论构造了三角对称晶场中3d2/3d8态离子的45阶可完全对角化的微扰哈密顿矩阵,研究了CsNiCl3单晶掺入Cs MgCl3晶体后光谱精细结构、晶体结构、零场分裂参量、Jahn-Teller效应以及自旋单重态对Ni2 离子基态能级的影响,理论与实验相符合.研究了自旋-自旋耦合作用和Trees修正对Ni2 :Cs MgCl3晶体的光谱精细结构和零场分裂参量的影响,发现有五种机理会影响零场分裂参量:(1)自旋-轨道耦合机理;(2)自旋-自旋耦合机理;(3)自旋-轨道与自旋-自旋联合耦合机理;(4)自旋-轨道与Trees修正联合耦合机理,(5)自旋-自旋作用与Trees联合耦合机理.其中自旋-轨道耦合机理是最主要的,其它几种机理也是不可忽略的.

Spectrum Hyper-fine Structure and Zero-field Splitting Parameters with Jahn-teller Effect of CsNiCl_3 Crystal

The 45 ranks complete diagonalized Hamiltonian matrixes of 3d2/3d8 ions configuration in the trigonal symmetry have been established by irreducible representation method. The spectra hyper-fine structure and the constants of crystal structure and zero-field splitting parameters of CsNiCl3 crystal doped with CsMgCl3 crystal have been studied as well as Jahn-Teller effect and the influence of the spin singlet to the ground levels of Ni2 ion. The results agree with the experimental findings. Besides, taking into account the influence of the spin-spin (SS) coupling interactions and Trees correction omitted in previous publication.It is found that zero-field splitting parameters arise from five mechanisms; (1) Spin-orbit coupling mechanism; (2) Spin-spin coupling mechanism; (3) Spin-orbit and spin-spin combined coupling mechanism; (4) Spin-orbit and Trees correction combined coupling mechanism, (5)Spin-spin and Trees correction combined coupling mechanism. The spin-orbit coupling mechanism is the most important and other mechanisms can not be omitted.