Effect of annealing conditions on particle size, magnetic and optical properties of Gd2O3 nanoparticles

Gadolinium oxide (Gd2O3) nanoparticles were successfully synthesized by sol-gel method under different annealing conditions for constant reaction time. Even though the reactions were carried out at different annealing temperatures, XRD confirmed the formation of cubic phase Gd2O3 for all samples with an increase in the crystallite size and enhancement in the crystalline nature with the increase in annealing temperatures. UV-Visible absorption and Photoluminescence spectra suggest that the band gap slightly decreases with the increase in annealing temperatures. X-ray photoelectron spectroscopy results reveal the presence of oxygen defects at the oxygen site in Gd2O3 nanoparticles. Field variation of magnetization curves measured at room temperature suggests the paramagnetic behavior with a slight coercivity which is observed for all the samples and the magnetic behavior is unaltered with the annealing temperatures.