Luminescent and dosimetric properties of transition phases of nanostructured aluminum oxide

摘要

The luminescent and dosimetric properties of nanostructured aluminum oxide which contains a mixture of metastable transition 0, 6, and kappa-phases were investigated. To vary the phase composition of the samples, they were annealed in air at 850-1200 degrees C. It was found that annealing the samples at T = 850-1100 degrees C in air results in a change in the percentages of kappa and 6-phases with a slight variation in the theta-phase concentration. Alpha-phase begins to form in the samples at T = 1100 degrees C, its concentration reaches 100% at T = 1200 degrees C. The PCL spectra featured bands associated with Fand F-2-type centers, the intensity of which decreased with increasing annealing temperature due to thermal destruction of centers. Kinetic TL parameters of the samples irradiated with a pulsed electron beam (130 keV) were found by deconvoluting TL curves into elementary peaks of general order kinetics. These parameters change insignificantly when the annealing temperature increases up to 1000 degrees C and they change greatly when the temperature grows further and alpha-phase is formed in the samples. The presence of sublinear sections of the TL dose response at doses of 1.5-45 kGy shows that the use of nanostructured aluminum oxide which contains transition phases for high-dose TL dosimetry of pulsed electron beams is promising.