Carbothermal reduction synthesis of alumina ceramics for luminescent dosimetry

A method of carbothermal reduction in vacuum was used to synthesize oxygen-deficient alumina ceramics with blue luminescence. It was synthesized from nanopowder at varying temperatures and annealing time. The structure of the samples, particle size distribution, changes in density and mass of the samples at different synthesis temperatures were studied. In the obtained ceramics the spectra of pulse cathodoluminescence and photoluminescence are registered in the emission band centered at 420 nm, which is associated with the F-centers created by oxygen vacancies. The luminescent intensity grows with increasing temperature and annealing time. The thermoluminescence curves feature two peaks whose intensities depend on the temperature of the ceramics synthesis. The yield of the thermoluminescence peak at 410 K increases linearly with a growing dose in the range of 0.03–300 Gy under β-irradiation. - Highlights: • Oxygen-deficient Al₂O_3-x ceramics was synthesized by carbothermal reduction. • Microstructure, particle size of the ceramics depend on temperature of synthesis. • Luminescence centers are created by oxygen vacancies arising during the synthesis. • Luminescence of ceramics is observed at 420 nm under different kinds of excitation. • The synthesized ceramics is a dosimetric phosphor in the range of 0.03–300 Gy.