Effect of heat treatment on the crystal structure and FTIR spectra of Sm doped cerium dioxide film

The Sm doped cerium dioxide films were prepared with cerium foils as raw materials by anodization in Sm(NO₃)₃-Na₂C₂O₄-NH₃·H₂O-H₂O-(CH₂OH)₂ electrolyte. The anodic Sm doped cerium oxide films were heat treated in 100°C ~ 400°C. The heat treated anodic Sm doped cerium oxide films were characterized with X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques respectively. The heat treated anodic Sm doped cerium oxide film at 100°C is the semi crystalline film. As heat treatment temperatures being in 200°C ~ 400°C, the heat treated anodic Sm doped cerium oxide films have a structure of cubic fluorite respectively. The doping of Sm can be achieved well by anodization method and be recognized as replacement doping or caulking doping. The crystal structure of Sm doped cerium dioxide films become more complete with the increase of heat treatment temperature in 200 ~ 400 °C. The doping of Sm can improve the crystallinity of the cerium dioxide film. The presence of adsorbing water, ethylene glycol and CO₂ in the heat treated anodic Sm doped cerium oxide film at 100°C. The adsorbing ethylene glycols and water, CO₂ in the anodic Sm doped cerium oxide film are removed at 200°C and 300°C respectively.