Anodic Electrodeposition of Cerium Oxide Thin Films

Cerium oxide thin films have been produced by anodic electrodeposition with a preferred orientation onto a variety of substrates. The Ce(III) ions are complexed with suitable organic ligands in solution to form stable complexes in basic pH solutions. Ligands with mild complexing power are suitable for the formation of cerium oxide films by anodic electrodeposition. The deposition conditions investigated include deposition modes, substrates, complexing agents, pH, temperature, and current density. X-ray diffraction (XRD) and scanning electron microscopy characterizations of the cerium oxide films show that the texture of the films can be controlled by temperature, pH, and current density. XRD analysis reveals that thin films deposited with crystallite sizes as small as 6 nm are possible with this method. A preferred (111) orientation of polycrystalline is formed when the plating bath temperature is higher than 50°C and the current density lower than XPS results reveal that the cerium oxide films deposited at room temperature are nonstoichiometric.