The ZnGa2O4:Cr3+ powder is synthesized through a solid state reaction process. The raw materials, ZnO (99.99%), Ga2O3 (99.99%),
and Cr2O3 (99.99%) are mixed thoroughly in 1:1:0.01 mole ratio and ball milled with alcohol for 10 h. The mixtures are dried and sintered at 1000 °C for 5 h in air to form ZnGa2O4:Cr3+ powder. The powder is pressed into a disk of a 30-mm diameter and a 3-mm thickness, and then sintered at 1000 °C in air for 5 h. A single phase dense ZnGa2O4:Cr3+ ceramic is used as a target.