Crystal field analysis of energy level structure of LiAlO 2:V 3+ and LiGaO 2:V 3+

Abstract

A detailed analysis of the energy level structure of tetrahedrally coordinated V 3+ ion in lithium aluminum oxide LiAlO 2 (γ-phase) and lithium dioxogallate LiGaO 2 is performed using the exchange charge model of the crystal field theory. The parameters of the crystal field acting on the V 3+ optical electrons are calculated from crystal structure data assuming C 1 point symmetry of the [VO 4] 5− impurity center in LiAlO 2 and LiGaO 2. Crystal field splitting of all five LS terms of the V 3+ ion ( 3F, 3P, 1S, 1D, 1G) is calculated. The energy levels obtained are compared with experimental absorption spectra and results of application of other crystal field models (the angular overlap model and Racah theory) to the considered crystals; though only one fitting parameter of the exchange charge model was used, a good agreement with experimental data on the ground and excited state absorption is demonstrated.