Studies on the photoluminescence and thermoluminescence properties of CaZrO3:xEu3+ phosphor for dosimetric applications

چکیده مقاله

Series of CaZrO3:xEu3+ (x = 0.01, 0.02, 0.03, 0.04 and 0.05) phosphors have been pre- pared by low temperature sol–gel auto combustion method. The structure and morphology of the samples were investigated by X-ray diffraction (XRD) and field-emission scanning electron microscope (FE-SEM). The energy-dispersive X-ray spectroscope (EDXS) was employed to analyze the elemental composition of the phosphor. The XRD patterns indi- cated that the sample was single phase at 350 ◦ C with a perovskite structure. The optimum temperature for the single-phase and crystalline phosphors of CaZrO3:xEu3+ was 700 ◦ C. Study of photoluminescence (PL) at room temperature showed that the phosphors can be excited by light with a wavelength of 391 nm. The results of emission spectrum showed that the red luminescence of CaZrO3:xEu3+ due to electric dipole transition of 5 D 0 → 7 F 2 was dominant at wavelength of 615 nm and weaker transition at wavelength of 590 nm which was due to magnetic dipole transition of 5 D 0 → 7 F 1 . For the thermoluminescence (TL) study the prepared sample irradiated by X-ray lamp, the TL curve was then recorded at fixed heating rate of 2 ◦C/s. The TL glow curve showed well single peak at a temperature of 165 ◦ C. The effect of Eu3+ concentration at fixed X-ray exposure time was studied and maximum TL occurred at x = 0.02. Also the variation of TL intensity with X-ray time (5 to 15 min) showed linear response with dose. The TL glow peak shows more stability and less fading in prepared phosphor which is suitable for TL dosimetry.