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

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

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.

The 45 ranks complete diagonalized Hamiltonian matrixes of 3d^2/3d^8 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 CsNiCla crystal doped with CsMgCla crystal have been studied as well as Jahn-Teller effect and the influence of the spin singlet to the ground levels of Ni^2＋ 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.