Thermoluminescence and radioluminescence of α-Al2O3:C,Mg at high temperatures

A α-Al2O3:C,Mg single crystal was investigated by means of optical absorption and photoluminescence measurements aimed at the identification of defects involved in the luminescence process. It was also investigated by thermoluminescence (TL) measurements as a function of the spectral emission in the 1.7-5.0 eV range. Radioluminescence measurements under X-ray excitation as a function of the temperature, from room temperature up to 400 °C were executed. These measurements revealed the presence of F, F-type, F-aggregate, and Mg-perturbed F-type and F-aggregate centers, and their thermal quenching behavior. Further, the role of these defects as recombination centers in the TL process was revealed.