RESUMO
New Al2O3-BeO ceramics were synthesized from alumina nanopowder in BeO crucibles by high-temperature treatment in reducing conditions. It was found that the TL curve of these ceramics is characterized by a dosimetric peak at 520-530â¯K for a heating rate of 2â¯K/s. The integrated TL of the peak is not influenced by the heating rate of the samples, unlike that in anion-defective alumina and beryllia crystals. The presence of an energy distribution of the traps which cause dosimetric TL peak is verified by Tm-Tstop and initial rise methods. Linear dependence on dose of the intensity of TL peak at 520-530â¯K is observed in the 10-300â¯Gyâ¯gamma-dose range. The diversity of TL sensitivity of the ceramic samples synthesized in one cycle does not exceed 10%. The results obtained show that the newly synthesized Al2O3-BeO ceramics are promising materials for TL dosimetry of high doses of ionizing radiation.
RESUMO
Variations of the particle size and porosity of the alumina ceramics synthesized by annealing compacted nanopowder at 1500-1700°Ð¡ in vacuum for various periods of time have been studied by SEM. Particle size distributions, which depend on the conditions of the ceramics synthesis, were obtained and discussed. The formation of fine grains and the growth of their fraction with the increasing annealing temperature increase the thermoluminescence intensity and expands the usable dose range upwards.
