The role of Eu on the thermoluminescence induced by gamma radiation in nano hydroxyapatite

Pure and Europium (Eu) doped hydroxyapatite (HAp) powders were prepared by microwave assisted hydrothermal method. A detailed structural examination of the HAp was performed through transmission electron microscopy and X-ray diffraction techniques. Analysis of thermoluminescent (TL) properties of the pure and Eu doped hydroxyapatite by exposing to different dosages of gamma radiation were also conducted. The characterization results show an appreciable influence of the Eu dopant on HAp TL signal, crystal sizes and the proportion of crystalline phases were identified. Rietveld analysis of the XRD patterns confirmed that the dominant hexagonal crystalline phase of pure HAp was diminished and an increase in monoclinic phase was observed accordingly with an increment in the Eu doping. This takes place due to the increment in crystal growth for monoclinic phase and a decrement in the crystal size of hexagonal phase. The thermoluminescence studies showed that Eu doped HAp (0.5 wt%) possess high intensity TL signal and there is a linear relationship between the TL Intensity and gamma radiation dosage in the range from 1.0 to 100 Gy. The results suggest that the Eu doped HAp can be considered as a radiation dosimeter material specifically for gamma radiation.