THERMOLUMINESCENCE IN CALCIUM-PHOSPHATE DOPED WITH DY2O3

Thermoluminescence (TL) of calcium phosphate doped with Dy2O3 has been studied extensively. because their effective atomic numbers are close to human bones and teeth. TL glow curves measured with a heating rate of 20-degrees-C.min-1 after the samples were X irradiated at room temperature showed peaks at about 100, 130, 210 and 315-degrees-C, which may be used for dosimetry. The intensity of the peaks grows linearly at least to the dose of 100 C.kg-1 and gradually shows saturation, and no supralinearity is observed. The TL intensity depends on the concentration of Dy2O3 linearly up to about 0.2 wt% of Dy2O3. The TL emission spectrum shows peaks at about 480 and 580 nm, which are identified as the Dy3+ transition from the excited state F-4(9/2) to the ground states H-6(15/2) and H-6(13/2), respectively. The ESR spectrum after the X irradiation shows a doublet structure due to the H atom, which disappears by heating up to 130-degrees-C, suggesting the relation to the first TL glow peak.