Structural, optical, and magnetic properties of Gd doped CeO₂ nano powders prepared by solid-state reaction

The study involves the synthesis and analysis of nanopowders of Gd-doped CeO₂-dilute magnetic semiconductors (DMS). Nanopowder samples of Ce_1−xGd_xO₂ were generated using the solid-state reaction approach with varying concentrations of Gd dopant (x = 2%, 4%, 6%, and 8%). This study inspects the structural, optical, and photoluminescence properties of Ce_1−xGd_xO₂ nanoparticles through the utilization of X-ray diffraction, UV spectrometry, and SEM. The crystalline structure of Ce_1−xGd_xO₂ powders was determined to be cubic using X-ray diffraction investigation. The optical band gap was seen to vary from 2.87 eV to 3.20 eV as the concentration of the dopant was altered at values of x = 0, 0.02, 0.04, 0.06, and 0.08. The investigation of photoluminescence (PL) in Ce_1−xGd_xO₂ nanoparticles was conducted using an excitation wavelength of 415 nm. The observed emission spectra ranged from 450 to 782 nm, displaying blue, green, and red emissions. The analysis of surface shape and chemical composition was conducted using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The powder sample of Ce_1−xGd_xO₂ was examined, and it was noted that the surface morphology exhibited a spherical shape. The nanopowder samples exhibit paramagnetic properties. The magnetic moment of Ce_1−xGd_xO₂ nanoparticles that have not undergone annealing exhibited a range of magnetization values, from 4.79 × 10^–3 to 61.05 × 10^–3 emu/g. Additionally, the coercivity of these nanoparticles varied from 1.07 to 11.50 Oe, while the retentivity ranged from 1.55 × 10^–6 to 14.58 × 10^–6 emu/g.