Assessing the dosimetric properties of CaSO4:Ce,Mn phosphors synthesized by different techniques

Abstract

Crystalline materials that exhibit luminescent properties are valuable for monitoring various physical phenomena and for applications such as ionizing radiation dose assessment. Optically stimulated luminescence (OSL) and thermoluminescence (TL) are two widely adopted radiation dosimetry techniques. This study reports on the synthesis and characterization of novel CaSO4:Ce,Mn phosphors obtained via solid-state diffusion, co-precipitation, and slow evaporation routes. Pellets were prepared by mixing Teflon with phosphor powders, then sintering the mixture at 400 °C for 1 h. The luminescent behavior was characterized using a TL/OSL reader equipped with Schott BG-39 and Hoya U-340 bandpass filters. TL measurements revealed that the synthesis route strongly affects trap distribution, luminescent efficiency, and signal stability, with the slow evaporation and co-precipitation methods yielding the most intense glow curves. Spectral discrimination confirmed the simultaneous contribution of Ce3+ and Mn2+ centers, enabling targeted analysis of recombination processes. OSL analyses under continuous blue LED stimulation revealed that all samples exhibited typical exponential decay, indicating effectively photoionized traps, with the slow evaporation route yielding the highest OSL intensity. The synthesized pellets displayed a linear response over a broad dose range (0.14 Gy–500 Gy), while samples produced via solid-state diffusion and co-precipitation demonstrated improved signal stability. Beyond the luminescent evaluation under beta irradiation, a preliminary assessment demonstrated the potential of these materials for radiation processing dosimetry. The enhanced OSL and UV TL emissions of CaSO4:Ce,Mn produced via the slow evaporation route demonstrate that Ce3+ co-doping improves charge trapping and recombination processes compared with CaSO4:Mn under the same synthesis conditions.