Crystal-field analysis of the Cr⁴⁺ absorption and excitation spectrum in LiGaO₂ oxide crystal

Groupe de Physique Théorique, Département de Physique, Faculté des Sciences de Sfax, BP 802, 3018 Sfax, Tunisia

Corresponding author: Souha.Kammoun@fss.rnu.tn

Received: 1 February 2003
Revised: 17 April 2003
Accepted: 20 June 2003
Published online: 16 September 2003

Abstract

The absorption and excitation spectra of the tetrahedrally coordinated Cr⁴⁺ ions doped in LiGaO₂ oxide crystal are measured by Kück and Hartung at room temperature. Using the experimentally determined data from these spectra, a theoretical calculation for the crystal-field levels of Cr⁴⁺:LiGaO₂ was performed by Kück and Hartung, based on the angular overlap model theory (AOM). The calculation reveals an important discrepancy between the theoretical and the experimental energies. A detailed crystal-field analysis of electronic energy levels of Cr⁴⁺ doped in LiGaO₂ oxide crystal based on the Racah theory is proposed in this work. The observed crystalline-field splitting of the Cr⁴⁺ terms was accounted for using a C₁ symmetric Hamiltonian. In turn, reliable crystal-field and Racah parameters have been obtained. This theoretical analysis confirms the observed crystalline-field splittings of the ³F and ³P terms of the Cr⁴⁺ ion doped in the oxide crystal LiGaO₂.