Luminescence properties of Tb and Eu activated CaSO₄ phosphor

In this study, the precipitation technique was used for the synthesis of calcium sulfate (CaSO4) phosphor. Eu and Tb lanthanide ions were included as dopants to achieve the high-performance phosphorous material. We observed the influence of dopant contents controlling luminescence intensity of CaSO4:Tb,Eu phosphor. The X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques were used to characterize the struc-tural analyses and surface morphology of the material, respectively. Spectroscopic analysis was performed using the radioluminescence (RL) measurement. Under X-ray excitation, the strongest emission line located at similar to 369 nm was assigned as the (F6D1)-F-4-D-5 -> F-4(7) transition of Eu2+ ions. Eu3+ ions showed emissions at 592, 618, and 696 nm which originate its D-5(0)-> F-7(j), (j = 1-3) transitions. The probable correlation between the OSL signal and the peaks in the TL glow curve was also examined. The OSL signal was found to be originated from the traps between 80 and 360 degrees C. The OSL dose-response of the CaSO4:Tb-0.01%,Eu-0.1% was found to be linear up to 20 Gy. The minimum detectable dose (MDD) value was estimated at the mGy level. The fading amount was 11% after 4 weeks of storage in dark. The lifetimes of the OSL decay components were determined as 0.06, 0.98, and 14.68 s using the curve fitting method. The conclusion from these data verifies the suitability of using CaSO4:Tb-0.01%, Eu-0.1% phosphor for radiation dosimetry, and the possibility of its development for this use.