Preparation and characterization of Li2B4O7 nanoparticles co-doped with Mg and Cu for thermoluminescence dosimetry of gamma-rays

Abstract

Lithium tetraborate nanoparticles co-doped with various percentages of Cu and Mg impurities were synthesized through the combustion process. Scanning electron microscopy images along with X-ray diffraction patterns confirmed the shape and structure of the products. Williamson-Hall equation was used to measure the nanoparticles size that resulted in approximately 55 nm for the crystallite size. The optical band gap of about 3.7 eV was obtained for the nanostructures from the UV–visible spectrum. Furthermore, the thermoluminescence features of the samples under gamma irradiation were studied at ambient conditions. The highest thermoluminescence sensitivity was achieved at 0.02 % wt Cu and 0.5 % wt Mg impurities simultaneously. The results show that the co-doped nanoparticles have a linear dose-response up to an administrated dose of 30 kGy. About 10% of the thermoluminescence signal fades after 30 days of storage at room temperature.