EPR Study of LiGa5O8: Cr3+

An EPR study has been undertaken of Cr³⁺ in LiGa₅O₈. The site symmetry is rhombic and the system can be described by the spin Hamiltonian, $\mathrm{H=g\beta }\mathrm{H}·\mathrm{S}{\mathrm{+D\; [S}}_z^2-\frac{1}{3}{\text{S (S+1)]+E (S}}_x^2{\mathrm{-\; S}}_y^2)$ , where $\text{D=0.331±0.002\hspace{0.17em}}{\mathrm{cm}}^{\text{−1}}\text{, E=0.018±0.002\hspace{0.17em}}{\mathrm{cm}}^{\text{−1}}$ , and the average g value, assumed isotropic, is $\text{1.980±0.005}$ . The axes of the spin Hamiltonian are tilted slightly from the expected crystallographic directions. The arrangement of Li⁺ and Ga³⁺ ions in next‐to‐nearest neighbor positions results in a large electrostatic field of odd parity at the site of the chromium ion.