掺有Ni^(2+)的α-Al_2O_3晶体的基态精细光谱、晶体局域结构和Jahn-Teller效应

Spectral Fine Structure,Local Structure and Jahn-Teller Effect of α-Al_2O_3 Crystal Doped with Ni^(2+)

应用晶体场理论和不可约张量算符方法构造了3d2/3d8态离子在C3v对称晶场中包含自旋-轨道相互作用、自旋-自旋相互作用、自旋-其它轨道相互作用和其它轨道-其它轨道相互作用四种微观磁效应的45阶可完全对角化的能量哈密顿矩阵.利用该矩阵,计算了Ni2+∶α-Al2O3晶体的光谱精细结构和晶体局域结构,深入研究了Ni2+∶α-Al2O3晶体的自旋-轨道相互作用、自旋-自旋相互作用、自旋-其它轨道相互作用和其它轨道-其它轨道相互作用和它们对光谱精细结构的影响及Jahn-Teller效应.理论计算值和实验值相符合.研究发现,掺杂没有改变晶体的对称性、同时发现并合理解释了Ni2+对α-Al2O3晶体基态精细光谱中Jahn-Teller效应的存在机理.

The completely diagonalized Hamiltonian matrixes of order 45 of 3d^2/3d^8 ion configurations in the trigonal symmetry sites were established by means of crystal field theory and irreducible representation method.The Hamiltonian matrixes include four kinds of microscopic magnetic interactions： spin-orbit interaction,spin-spin interaction,spin-other-orbit interaction and other-orbit-other-orbit interaction.The spectral fine structure and crystal local structure of Ni^2＋∶α-Al2O3 crystal were calculated by the Hamiltonian matrixes.Meanwhile,the four kinds of interactions and their effects to the spectral fine structure and the Jahn-Teller effect were also analyzed.The calculated values were conformed with the experimental values.The results show that doping Ni^2＋ ions cannot change the symmetry,and it was discovered and explained the existence mechanism of Jahn-Teller effect in spectral fine structure of α-Al2O3 doped with Ni^2＋.