Structural and optical properties of α-Fe2O3 nanoparticles, influence by holmium ions

α-Fe2O3 and α-Fe2O3 doped with different concentration of holmium ions were synthesized by a simple sol-gel method. The XRD data confirmed the hexagonal structure of α-Fe2O3 for un-doped and holmium doped samples. The crystallite size was found to be decreasing with increasing holmium concentration. The amount of holmium was quantified using an EDS, which shows an increase in holmium quantity as concentration increases. The UV-Vis measurement shows an absorption edge around 570 nm. The band gap was estimated using the Kubelka-Munk relation and it was found to be fluctuating between 1.94 eV and 2.04 eV. The PL spectra confirmed the effect of holmium ions on luminescence properties of α-Fe2O3 which showed a maximum intensity at 0.1 mol% Holmium, and quenching as the concentration is increased from 0.3 mol% to 0.9 mol%.