Fabrication and characterization of Y2O3 stabilized ZrO2 films deposited with aerosol-assisted MOCVD

With Y(DPM)3 and Zr(DPM)4 as precursors, yttria-stabilized zirconia (YSZ) thin films were deposited onto NiO-SDC substrates using a modified aerosol-assisted metal-organic chemical vapor deposition (AAMOCVD) apparatus, where high power halogen lights were used as assisted heaters. Cubic structured YSZ was obtained when the films were deposited at 650 °C. The cubic YSZ transformed to tetragonal structure after annealed at 1100 °C for 3 h, possibly due to crystallite growth. Y/Zr mole ratio of the deposited film depends on the Y/Zr ratio of the precursors, indicating that the thin film composition can be effectively controlled. Scanning electron microscopy (SEM) analysis showed a strong bonding between the films and substrates. Thickness of the film was estimated to be about 9 μm with a high growth rate of 50 nm/min, which inferring the AAMOCVD is very effective in synthesis of YSZ films. AC impedance analyses showed that the ionic conductivity of the YSZ film is 0.034 S/cm at 800 °C, which is slightly less than that of bulk YSZ, and the conduction activation energy (Ea) changed from 80.8 kJ/mol to 138.8 kJ/mol at 640 °C with decreasing temperature.