Search

Samples of ZrO2 ceramics with different concentrations of impurity titanium ions were synthesized by mixing zirconium and titanium oxide powders in different mass ratios. The X-ray diffraction analysis was used to determine the phase composition, lattice parameters, and crystallite size of the ceramics with varying dopant concentrations. Upon irradiation of the samples with 220 MeV Xe ions to a fluence of 1010 ions/cm2, a decrease in the intensity of the pulsed cathodoluminescence band at 2.5 eV was observed. Additionally, ion irradiation resulted in the emergence of a new thermoluminescence peak at 450–650 K attributed to radiation-induced traps of charge carriers. Further analysis revealed that the thermoluminescence curves of samples irradiated with electrons and ions comprise a superposition of several elementary peaks. Notably, a complex non-monotonic dependence of cathodo- and thermoluminescence intensity on titanium concentration was observed, suggesting the influence of concentration quenching and the presence of tunneling transitions. [ABSTRACT FROM AUTHOR]

Thermoluminescence (TL) curves of Al2O3–BeO ceramic samples synthesized during high‐temperature treatment of nanostructured Al2O3 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 Al2O3, BeO, and BeAl2O4 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 Fcat‐type centers in aluminum oxide. The obtained results are essential to control and modify TL properties of Al2O3–BeO ceramics to create luminescence detectors of high‐dose radiation. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]