Anomalous heating rate dependence and analyses of thermoluminescence glow curves in Gd doped ZnB2O4 phosphors

Abstract

Here, we report the thermoluminescence (TL) characteristics and trapping parameters under beta ray excitations of pelletized Gd-incorporated ZnB2O4 synthesized through the gel combustion method. The chemical composition of the obtained Gd incorporated ZnB2O4 was confirmed using X-ray diffraction (XRD). The best doping concentration of Gd was 0.25 mass%, which resulted in the highest luminous efficiency. The glow curves of the pellet-formed samples exposed to β-irradiation at various doses showed glow peaks at about 79 °C, 133 °C and 276 °C with a heating rate of 2 °Cs−1. An anomalous heating rate effect was observed for the peak centered at 276 °C, but the TL intensity of the peak at 79 °C and 133 °C decreased with an increasing heating rate. The TL glow peaks were studied using Tm-Tstop, initial rise (IR), and variable heating rate (VHR) and Computerized glow curve deconvolution (CGCD) methods. In the range of 0.1–50 Gy, the total integral values of TL output increased linearly with increased dose. A complex glow curves are composed of six distinguishable peaks as revealed by the results obtained from IR and CGCD methods. The current results indicate that the ZnB2O4:Gd3+ phosphor is a suitable option in radiation dosimetry for environmental monitoring.