Luminescent properties of alumina ceramics doped with manganese and magnesium

Alumina ceramics doped with a different concentration of magnesium and manganese were synthesized at a different annealing temperature and medium. An increase in the dopant concentration leads to an increase in the pulsed cathodoluminescence intensity of impurity centers at 515 nm (Mg) and 678 nm (Mn). The concentration quenching of the luminescence in the 678 nm band occurs for Al2O3:Mn ceramics. The dopants affect the luminescence intensity in the F-center band differently. An increase in the concentration of an impurity from 0.001 to 18.77 wt % in Al2O3:Mn ceramics leads to a 4-fold decrease in the luminescence intensity of the F-center. On the other hand there is a maximum of the luminescence intensity of the F-center for Al2O3:Mg ceramics with a dopant concentration of 1 wt %. The luminescence bands of Cr3+ (687 nm) and most likely F-centers (670 nm) are dominated depending on the excitation energy in photoluminescence spectra of both Al2O3:Mg and Al2O3:Mn ceramics. The low luminescence intensity of the magnesium band (750 nm) is detected upon the excitation in the band of 325 nm. The luminescence bands of Mn2+ (540 nm) and Mn4+ (650 nm) with low intensity are found in the photoluminescence spectrum too.