The photoluminescence of MgGa sO4:Ni2+ are presented in this article. The observed bands are attributed to the ¹T2 (¹D) <FONT FACE=Symbol>®</FONT> ³T2 (³F) and ¹T2 (¹D) <FONT FACE=Symbol>®</FONT> ³T1 (³F) spin-forbidden transitions and located in the visible and infrared regions, respectively. Absorption spectra obtained from diffuse reflectance measurements show bands associated with ³A2 (³F) <FONT FACE=Symbol>®</FONT> ³T1 (³F) and ³A2 (³F) <FONT FACE=Symbol>®</FONT> ³T2 (³F) transitions and a weak structure assigned to ³A2 (³F) <FONT FACE=Symbol>®</FONT> ¹E (¹D) transition. All the observed transitions are identified with energy levels of Ni2+ in octahedral sites of magnesium gallate. From the Tanabe-Sugano energy diagrams for a d8 configuration, the crystal field Dq and interelectronic repulsion B and C parameters were calculated. We also present, for comparison, previous results of Cr3+ (d³ electronic configuration), Fe3+ (d5) and Co2+ (d7) ions in this host lattice for samples prepared with the same ceramic method.
photoluminescence; absorption; ceramic materials; transition metals
