Metal oxide films prepared by thin film technology have been reported for the potential applications on thin solid electrolyte layers for solid oxide fuel cells(SOFCs). Gadolinia-doped ceria(GDC) thin films and Al2O3 layers on SiO2/Si substrates are successively deposited by RF reactive magnetron sputtering from a cerium-gadolinium (90:10 at.%) alloy target and Al target in O2/Ar gas mixture and then perform post-thermal treatments at 300-700 ℃ and 900 ℃ for 2 h, respectively. Materials characteristics and chemical compositions of GDC films and Al2O3 layers are investigated by X-ray photoelectron spectroscopy(XPS), cross-sectional scanning electron microscopy(SEM), X-ray diffraction(XRD), and atomic force microscopy(AFM). Stoichiometric Al2O3 layers with polycrystalline structures are firstly prepared onto SiO2/Si substrates. A cubic fluorite structure with columnar crystallites of GDC films is successfully deposited on Al2O3/SiO2/Si systems. The chemical composition of 700 ℃-annealed GDC films is (Ce0.91Gd0.09)O1.94 and possesses a higher film density of 7.257 g/cm3. As a result, GDC thin films prepared by RF reactive magnetron sputtering and post-thermal treatments can be used as thin solid electrolyte layers for intermediate temperature SOFCs system as compared to the well-known yttria-stabilized zirconia(YSZ). Metal oxide films prepared by thin film technology have been reported for the potential applications on thin solid electrolyte layers for solid oxide fuel cells (SOFCs). Gadolinia-doped ceria (GDC) thin films and Al2O3 layers on SiO2 / Si substrates are planted by RF reactive magnetron sputtering from a cerium-gadolinium (90:10 at.%) Alloy target and Al target in O2 / Ar gas mixture and then perform post-thermal treatments at 300-700 ° C and 900 ° C for 2 h, respectively. Materials characteristics and chemical compositions of GDC films and Al2O3 layers are investigated by X-ray photoelectron spectroscopy (XPS), cross-sectional scanning electron microscopy (SEM), X-ray diffraction (XRD), and atomic force microscopy (AFM) A cubic fluorite structure with columnar crystallites of GDC films is successfully deposited on Al2O3 / SiO2 / Si systems. The chemical composition of 700 ° C. -ann As a result, GDC thin films prepared by RF reactive magnetron sputtering and post-thermal treatments can be used as thin solid (Ce 0.91 Gd 0.09) O 1.94 and possesses higher film density of 7.257 g / cm 3. electrolyte layers for intermediate temperature SOFCs system as compared to the well-known yttria-stabilized zirconia (YSZ).