关键词: 局域结构, 电子顺磁共振参量, Al₂O₃∶Ni²⁺晶体

Abstract:

The quantitative relationship between the Electron Paramagnetic Resona nce（EPR）parameters (D, g_∥, g_⊥) and the local structure parameters of  Ni²⁺ in Al₂O₃∶Ni²⁺ crystal is established according to the sup erposition model and perturbation theory. The local structure for Ni²⁺ par amagnetic center in Al₂O₃∶Ni²⁺ crystal has been determined from EPR parameters of Ni²⁺ ions. The very large zero-field splitting parameter D and  anisotropic g factors(g_∥, g_⊥) of Ni²⁺ ions in Al₂O₃∶Ni²⁺ crystals are explained by considering the suitable local lattice distorti on. We obtain that the three O^2- ions above Ni²⁺ rotate 0.603° toward ［111］-axis while the three O^2- ions below Ni²⁺ rotate 0. 598°toward it. 

Key words: Local structure, Electron paramagnetic resonance parameter, Al₂O₃∶Ni²⁺ crystal