Near infrared spectroscopy of divalent cobalt in polycrystalline magnesium and zinc gallate

Infrared luminescence of MgGa2 O4 :Co2+ and ZnGa2 O4 :Co2+ polycrystalline samples is presented. The bands observed in these cobalt compounds are assigned to the 4 T1 (4 P) 4 T1 (4 F) transition of the tetrahedrally coordinated Co2+ ions.