Metal-organic chemical vapor deposition of Sr–Co–Fe–O films on porous substrates

Aerosol-assisted chemical vapor deposition using the β-diketonate precursors Sr(tmhd)₂ · 2H₂O, Fe(tmhd) ₃, and Co(tmhd) ₃ was investigated for depositing thin films of the mixed-conducting ceramic SrCo_yFe_1−yO_3−δ onto porous α–Al₂O₃ substrates. Single-phase SrCo_yFe_1−yO_3−δ perovskite films were obtained at a deposition temperature of 550 °C and pressure of 15 mm Hg, whereas deposition at atmospheric pressure produced mixed-phase films. The Co/Fe elemental ratios in the films reflected those in the precursor solution, but the films were depleted in Sr. Reduced-pressure deposition provided a more uniform film morphology than atmospheric pressure, and led to a supported film which was leak-tight to N₂ flow.