Cathodoluminescence of Mn2+ centers in MgAl2O4 spinels

MgAl2O4:Mn spinels containing between 0 and 8% Mn by weight were prepared (a) by growth from an induction melt, and (b) by Mn+ implantation into nonstoichiometric spinel crystals. Cathodolumenescence brightness measurements (520 nm emission band) were made as a function of Mn concentration on both (a) and (b), revealing increasing brightness to even the highest Mn concentrations. This suggests that MgAl2O4:Mn is not susceptible to strong concentration quenching phenomena, and might be useful for highly efficient phosphors.