Thermoluminescence analysis of beta irradiated ZnB2O4: Pr3+ phosphors synthesized by a wet-chemical method

Abstract

In this paper we describe the thermoluminescence (TL) characteristics of ZnB2O4 :Pr3+ phosphors with Pr concentrations varying between 0.2 and 1 mol% prepared by a wet-chemical method. The TL glow curves of the phosphor sample consisted of three peaks located at 71 degrees C (P1), 124 degrees C (P2) and 233 degrees C (P3). The TL intensity increased with the beta dose ranging from similar to 0.1 to similar to 20 Gy. Dose response, reproducibility and trapping parameters of TL glow curves were evaluated to clearly reveal thermoluminescence features. We observed that TL intensity of P2 and P3 peaks decreases as the heating rate increases. Trap parameters were estimated via the Hoogenstraaten, Booth-Bohun-Parfianovitch, the initial rise methods combined with T-m - T-stop experiment and TLanal CGCD program. Heating rates were varied to use in the Hoogenstraaten analyses. The T-m - T-stop, investigations on regenerated TL signals for P1 and P2 peaks indicated that ZnB2O4:Pr3+ phosphor has four electron trap levels with energy values in the range of 0.5-1.5 eV These four traps have first order kinetic and are formed at high temperature region. Resulting values are utilized as a reference for the CGCD procedure and the trapping parameters from the TL glow curves are calculated. The figure of merit (FOM) of the TL glow curve during curve fitting procedures is found to be 2.019%. The intensities of the main dosimetric peaks appeared at 124 degrees C and 233 degrees C exhibits good linear dose response up to 20 Gy. These results provide valuable knowledge for use of the characteristics of Pr doped ZnB2O4 in dosimetry research, just need to eliminate low temperature TL peak.