Exploring beta irradiation responses in Sr 2+-Doped hydroxyapatite: A thermoluminescence study

Abstract

This research investigates the structural and thermoluminescence (TL) properties of Sr2+-doped Ca5(PO4)3OH (HAp) phosphors. X-ray diffraction (XRD) analysis confirms that HAp has a hexagonal structure with a P63/m space group. The TL behaviour of HAp:Sr2+ phosphors is examined under beta irradiation in the temperature range of 25–500 °C. The study reveals three TL glow peaks at temperatures of 75, 212, and 296 °C. Investigation of TL responses across heating rates (HR) ranging from 0.1 to 5 °C/s shows that higher HRs result in increased maximum TL peak temperatures and reduced TL intensities. This trend suggests an augmented contribution from non-radiative transitions as the heating rate increases. Importantly, no evidence of thermal quenching is found in the HAp samples. Two different methods, Hoogenstraaten's and Booth-Bohun-Porfianovitch, yield consistent activation energy values of 0.50, 1.22, 1.67 eV, and 0.48, 1.19, 1.63 eV, respectively. Reusability assessments indicate a standard deviation of less than 5 %, confirming the reliability of the materials. Tm−Tstop analysis reveals a continuous distribution of trap levels. TL properties in HAp samples have been comprehensively characterized, contributing not only to enhancing our understanding of their behaviour, but also highlighting their potential applications in various areas. The findings of this study have provided valuable insight into the development of efficient catalysts that are suitable for a variety of applications.