Effect of aluminium doping and annealing on structural and optical properties of cerium oxide nanocrystals

Nanocrystalline fluorite-like structures of Ce1−xAlxO2−δ compounds were prepared by the chemical precipitation method using cerium chloride and aluminium chloride as precursors. The prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and diffuse reflectance spectroscopy (DRS). The effects of aluminium doping concentration and annealing on particle size, lattice parameter and band gap energies were investigated. The particle size of Al-doped CeO2 samples were found to decrease with Al concentration and it increases from 6 to 20 nm as annealing temperature increases to 900 °C.