Spectrally resolved thermoluminescence of anion-deficient Al${}_2$O${}_3$-BeO ceramics for high-dose dosimetry

Thermoluminescence (TL) curves of Al${}_2$O${}_3$-BeO ceramic samples synthesized during high-temperature treatment of nanostructured Al${}_2$O${}_3$ compacts in vacuum with the presence of graphite in BeO crucibles are studied. Temperature ranges of certain TL peaks emission at the synthesis temperature varied from 1200 to 1400 °C are found. A comparative analysis of the TL peaks temperature position and the nature of traps in the obtained ceramics with single crystalline Al${}_2$O${}_3$, BeO, and BeAl${}_2$O${}_4$ analogs is carried out. Spectral composition of different TL peaks is investigated. It is found that oxygen vacancies and their aggregates play the main role in the TL emission centers formation in the samples under study. A complex structure of the dominating luminescence band at 4.0 eV in the dosimetric peak at 530 K of the ceramics synthesized at 1400 °C is found. This band is shown to be a superposition of three bands with the maxima at 3.11, 3.80, and 4.17 eV, resulted from F, F${}^{+}$ centers and presumably from F${}_{cat}$-type centers in aluminum oxide. The obtained results are essential to control and modify TL properties of Al${}_2$O${}_3$-BeO ceramics to create luminescence detectors of high-dose radiation. (© 2020 Wiley‐VCH GmbH)