Luminescence study of rare earth doped K2Ca2(SO4)3 phosphor

This paper reports the thermoluminescence (TL) characteristics of rare earths (Eu and Ce) doping on microcrystalline K2Ca2(SO4)3 phosphor. The phosphor K2Ca2(SO4)3:Eu is a well known TL phosphor that has been found to be more sensitive than even the commonly available standard dosimetry TL phosphor CaSO4:Dy. All the samples were prepared by solid state diffusion method and formation of compound and crystalline nature of the sample were confirmed by the XRD study. Samples were irradiated from gamma as well as proton beams and their thermoluminescence study was done by plotting the glow curves and the response curves. It has been found that, out of all the three phosphors i.e. K2Ca2(SO4)3:Eu, K2Ca2(SO4)3:Ce and K2Ca2(SO4)3:Eu,Ce, the co-doped phosphor K2Ca2(SO4)3:Eu,Ce showed the best characteristics in terms of TL intensity. The increase in peak intensity of the phosphor on co-doping it with Ce gives an insight into the emission mechanism of the phosphor which involves energy transfer from Eu2+ to Ce+3. The phosphor has a simple TL glow curve structure with a single prominent peak at around 152°C. The photoluminescence emission spectrum has also been examined and studied for the Eu2+ and Ce3+ emissions. The TL response for different doses has also been reported to check the linearity range and it is found that the phosphor is quite suitable for use in dosimetry of ionizing radiations. (author)