Thermoluminescence characteristics of K2Ca2(SO4)3 doped with rare earths Eu and Dy

Abstract

The effects of Dy co-doping on the thermoluminescence (TL) characteristics of K2Ca2(SO4)3 : Eu phosphor are studied. Though the sensitivity of the K2Ca2(SO4)3 : Eu phosphor is decreased by five times to get the sensitivity slightly less than that of CaSO4 : Dy, the broadness of the glow peak is increased. The decrease in peak intensity of the phosphor on co-doping it with Dy gives an insight into the emission mechanism of the phosphor which involves energy transfer from Eu2+ to Dy3+. The phosphor has a simple TL glow curve structure with a single prominent peak at around 430 K. The photoluminescence emission spectra has three peaks (440, 475 and 570 nm) which could be attributed to the Eu2+ and Dy3+ emissions. Fading and reusability characteristics of the new phosphor are also studied and it is found that the phosphor is quite suitable for use in dosimetry of ionizing radiations.