Crystal field analysis of energy level structure of LiAlO2:V3+ and LiGaO2:V3+

A detailed analysis of the energy level structure of tetrahedrally coordinated V3+ ion in lithium aluminum oxide LiAlO2 (γ-phase) and lithium dioxogallate LiGaO2 is performed using the exchange charge model of the crystal field theory. The parameters of the crystal field acting on the V3+ optical electrons are calculated from crystal structure data assuming C1 point symmetry of the [VO4]5− impurity center in LiAlO2 and LiGaO2. Crystal field splitting of all five LS terms of the V3+ 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.