Isothermal decay of thermoluminescence and energy distribution of traps in Al2O3–BeO ceramics.

We studied features of isothermal decay curves of thermoluminescence (TL) in the dosimetric peak at 525 K of Al 2 O 3 –BeO composite ceramics. The temperature ranges were revealed in which an anomalous drop in the TL decay rate was observed with increasing temperature. By using the data obtained with the Tm-Tstop and initial rise methods, we proved that there was a complex activation energy distribution of traps with the energies varying from 0.85 to 1.55 eV. We found that the anomalous decrease with temperature in the isothermal luminescence decay rate can be associated with the superposition of the contributions to the TL from several traps with different energy depth values. It was shown that the analysis of the TL isothermal decay rate change can be used as one of the methods for revealing the complex energy structure of traps in dosimetric phosphors. • Anomalous drop of isothermal TL decay rate is observed with increasing temperature. • Complex energy distribution of traps from 0.85 to 1.55 eV is found in the 525 K peak. • Anomalous decay of TL is due to presence several traps with different energy depth. [ABSTRACT FROM AUTHOR]