Thermoluminescence Studies of High Energy X-Rays Irradiated Dy3+ Doped Mg0.65Zn0.3Al2O4:0.05Dy Nanophosphor

The solution combustion synthesis method is employed to prepare Magnesium,  Zinc, Aluminate doped with dysprosium (Dy³⁺) using the general formula Mg_(1-x-y) Zn_(y)Al₂O₄:xDy (x = 0.05 and y = 0.3 mol%). From X-ray diffraction studies, the crystal structure belongs to a cubic close-packed spinel structure with space group Fd3ˉm and an average crystallite size is 26.18 nm. In the Fourier transform infrared spectra, the peaks at 683.69 cm⁻¹, 503.12 cm⁻¹ correspond to the AlO₆ groups. The peak temperature (Tm) from the Thermoluminescent glow curve is recorded at 235°C, 237°C, and 235°C, at irradiation doses of 600 Gy, 800 Gy, and 1000 Gy, respectively. The kinetic parameters are evaluated from the thermoluminescent glow curve by calculating the activation energy (E), order of kinetics (b), and frequency factor (s⁻¹). Nanophosphor Mg_0.65Zn_0.3Al₂O₄:0.05Dy shows sub linear dose relationship at doses 600–675 Gy and 925–1000 Gy. Further, at doses between 675 and 925 Gy, it shows a super linear relationship. The optimum activation energy (E) of 0.77–0.82 eV and negligible fading make it suitable for high radiation thermoluminescent dosimetry.