Synthesis of CeO or α-MnO nanoparticles via sol-gel process and their optical properties.

Nanocrystalline cubic fluorite/bixbyite CeO or α-MnO has been successfully synthesized by using methanol as a solvent via sol-gel method calcined at 400 °C. The obtained products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), UV-vis absorption and Photoluminescence (PL) spectroscopy. TEM reveals that the as-synthesized ultra-fine samples consist of elliptical/spherical and sheet-like morphology of crystalline particles of 8/30 nm, which are weakly aggregated. Optical absorbance spectra reveal that the absorption of ceria in the UV region originates from the charge- transfer transition between the O (2p) and Ce (4f) orbit in CeO. However, α-MnO nanostructures with nearly pure band gap emission should be of importance for their applications as UV emitters. [ABSTRACT FROM AUTHOR]