Thermoluminescence properties of CaSO4:Dy synthesized by wet chemical synthesis route with pH adjustment.

The crystal of dysprosium doped CaSO4 (CaSO4:Dy) is preferable for personal radiation dosimetry application due to its sensitive response to low-dose radiation. A simple wet chemical synthesis route was carried out at pH 5 to obtain CaSO4:Dy. This study was conducted as preliminary work to analyze the properties of the thermoluminescent crystal. Fine particle powder with prismatic morphology was observed using SEM with the magnification of 2,000x and 5,000x. The elemental composition of the specific area of the BSD image was analyzed using the EDS point, which confirmed the existence of Dy in several spots. A high concentration of anhydrite with a crystallite size of 101.5 nm was identified from a semi-quantitative analysis of XRD. The preferred orientation of the crystal growth was the (002) plane, indicated by the peak at 2θ of 25.46°. The XRF measurement showed the atomic percentage of Dy/Ca was more than half of the experimental calculation. The thermoluminescence properties of the crystal were analyzed using the Harshaw 3500 TLD reader after irradiation by Sr-90 for 5 mGy. The powder exhibited the most dominant glow peak near 230 °C with a high intensity of total luminescence, indicating a good response sensitivity to the low-dose beta radiation. [ABSTRACT FROM AUTHOR]