Atomic force microscopy study of nanocrystalline ceria thin films

This work reports on the structural and morphological characterization of ceria thin films grown by chemical solution deposition (CSD) techniques. The coating solution was prepared starting from cerium 2,4-pentadionate, Ce(CH3COCHCOCH3)3, and propionic acid, C2H5COOH, further concentrated by distillation. The as-prepared solution was spin coated on single crystalline (100) SrTiO3 (STO) substrates. The precursor films were heat treated in air at 9000C both by a rapid heating and quenching to room temperature (A) and annealing (B). The X-ray structural analysis and the SEM and AFM morphological analysis for the CeO2/STO thin film have revealed the influence of the thermal treatment on the growth mechanism. The as-obtained polycrystalline nanostructured ceria thin films present an average grain size of 40-50 nm and a roughness of 1.5-5.4 nm, depending on the thermal treatment. The annealing renders the ceria thin film a smoother surface with respect to the rapid heat treatment followed by quenching, performed both at the same temperature.