Studies of the optical and EPR data and the defect structure for the trigonal Cr3+ center in LaMgAl11O19 crystal

The complete diagonalization (of energy matrix) method based on the two-spin-orbit-parameter model (which takes into account of the contributions from both the spin-orbit parameter of dn ions in the traditional crystal field theory and that of ligand ions via covalence effect) is adopted to calculate uniformly the optical and EPR data of the trigonal Cr3+ center in LaMgAl11O19 crystal. The calculated results demonstrate that the observed nine optical and EPR data (six optical bands and three spin-Hamiltonian parameters g//, g⊥ and D) can be explained reasonably, which proves the effectiveness and practicality of the method in the unified calculations of optical and EPR data for crystals doped with d3 ions. The defect structure of Cr3+ center in LaMgAl11O19 crystal due to the size mismatch is also estimated.