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.