TL glow curve analysis and kinetics of UV, β and γ irradiated YBO3:Eu3+ and Y2O3:Eu3+ phosphors

Abstract

This paper reports on the thermoluminescence (TL) properties of Eu3+ doped in two different host matrix phosphors (Y2O3 and YBO3). The phosphors were prepared by a high temperature solid state reaction method. The method is suitable for a large scale production. The samples were characterized by X-ray diffraction and Rietveld refinement. The different concentration of Eu3+ samples were also examined by TL glow curve analysis for UV, β and γ irradiation. The Y2O3 samples showed well resolved broad peaks that covered the temperature range from 50 to 350 °C and the peak temperature was found at 157 °C for the γ irradiation. For the UV irradiated samples a well resolved peak at 121 °C was found for the Y2O3:Eu3+ doped phosphors. The β irradiated samples showed a resolved peak at 182 °C. A different behaviour was observed for the YBO3:Eu3+ doped phosphors which showed both higher temperature peaks and lower temperature peaks for UV, β and γ irradiation. Here UV irradiated sample showed the formation of shallow trap (surface trapping) and the γ irradiated sample showed the formation of deep trapping. The estimation of the trap formation was evaluated by the calculation of the trapping parameters. The trapping parameters such as activation energy, order of kinetics and frequency factor were calculated by the peak shape method using the computerized glow curve deconvolution technique. Here most of the peak showed second order of kinetics. The effect of γ, β and UV dose exposure on the TL studies was also examined and it showed a linear response with dose which indicated that the samples might be useful for TL dosimetry. The possible mechanics and information about traps formation are presented in detail.