Luminescence of impurity and intrinsic defects of Na-doped alumina ceramic

Abstract

Ceramics from alumina nanopowder doped with a different Na concentration were synthesized at high-temperature sintering under vacuum and in air at a varying temperature. Pulsed cathodoluminescence spectra and thermoluminescence curves were measured to study effects based either on the formation of new defects or on the modification of alumina intrinsic defects. In fact, the emission bands with maxima of 400, 510 and 693 nm are recorded on pulsed cathodoluminescence spectra of Al2O3:Na ceramics, which are respectively responsible for their intrinsic centers of alumina (F-centers), Na and Cr impurity centers. A decrease in the synthesis temperature results in an increase in the intensity of the 510 nm band. Sodium impurity concentration growth in ceramics results in the intensity growth of the given band. It is also shown that an increase in the sintering temperature causes an increase in the intensity of all thermoluminescence peaks. Thermoluminescence curves are also changed under β-irradiation.