Enhanced thermoluminescence of magnesia-doped zirconia nanoparticles exposed to ultraviolet/beta irradiation

Abstract

In this study, magnesia-doped zirconia nanoparticles were synthesized via the sol-gel method, and this was followed by pellet manufacturing for ultraviolet (UV) and beta ray dosimetry. The raw materials included zirconium(IV) propoxide, isopropyl alcohol, acetic acid, nitric acid, and magnesium nitrate hexahydrate. Taguchi experimental design with an L9 orthogonal array and variance analysis was used to optimize the essential parameters and achieve the smallest sol average particle size. Isopropyl alcohol to zirconium(IV) propoxide (ISP/ZPP) volume ratio, MgO mole ratio, and reaction temperature were the three critical factors considered in this study. The sol average particle size, type of molecule bonds in the gel, calcination temperature, phase study, morphology, and thermoluminescence properties were determined by a wide range of analyses such as dynamic light scattering, Fourier-transform infrared spectroscopy, static timing analysis, x-ray diffraction, field-emission scanning electron microscopy, and thermoluminescent dosimetry (TLD). The optimized conditions for obtaining the smallest sol average particle size were an ISP/ZPP volume ratio of 30, 3% magnesium mole, and 70 °C reaction temperature. The ISP/ZPP volume ratio, with 51.38% participation, was identified as the most influential parameter. The crystallization temperature occurred at 560 °C, showing the tetragonal phase. The average crystalline size was found to be 15 nm. TLD analysis showed that the prepared pellets were 250 times more sensitive than pure zirconia synthesized via the same method, and displayed two thermoluminescent (TL) maxima located at 130 °C and 185 °C for UV irradiation, and one TL maximum for beta irradiation located at 180 °C. The presence of relatively lowtemperature peaks and high sensitivity in both UV and beta irradiation suggested that magnesiadoped zirconia pellets can be suitable candidates for dosimetry applications.