Investigations of the optical band positions, EPR parameters and defect structure for the trigonal Cr3+–Li+ centre in CsMgCl3 crystal

Abstract

A unified calculation of optical band positions and electron paramagnetic resonance (EPR) (or spin-Hamiltonian) parameters for the trigonal Cr3+–Li+ centre in CsMgCl3 crystal is made by using the complete diagonalisation (of energy matrix) method based on the two-spin–orbit-parameter model. In this model, the contributions from the spin–orbit parameter of central dn ion and that of ligand ion are included. From the calculation, the 11 observed optical and EPR data (eight optical band positions and three EPR parameters g//, g⊥, D) are reasonably explained with five adjustable parameters and the defect structure of the Cr3+–Li+ centre (which is consistent with the expectation based on the electrostatic interaction) in CsMgCl3 is acquired. The results are discussed.