Effect on the EPR and site symmetry of Cr3+ ions doping spinel crystals: A complete energy matrices study

The EPR parameters (D, g∥, g⊥) for chromium doped in spinels (MgAl2O4, ZnAl2O4 and ZnGa2O4) have been calculated by diagonalizing the 120 × 120 complete energy matrices for d3 configuration ion in trigonal crystal field. The Zeeman effect of Cr3+ ion in the trigonally distorted octahedral site of spinels has been studied, suggesting that there is a nonlinear relation between the Δg (Δg = g∥ − g⊥) and orbital reduction factor k. Both the site symmetries D3d and C3v of this impurity have been discussed for the three host lattices, and the local lattice structure around the impurity has also been determined.