Spectra of Tetrahedral Fe2+ in MgAl2O4

Abstract

Visible absorption features in (Mg, Fe) ${\mathrm{Al}}_2$ ${\mathrm{O}}_4$ are assigned to spin-forbidden electronic transitions on tetrahedral ${\mathrm{Fe}}^{2+}$. Values of the Racah parameters $B$ and $C$ are fitted to the observed spectrum. The spin-allowed transitions indicate an appreciable nonionic character to the Fe-O bands.