CVD of CeO_2-Doped Y_2O_3-StaMIlzed Zirconia onto Dense and Porous Substrates

摘要

Fabrication of dense films of mixed-conducting oxides on porous surfaces is of interest for membrane, sensor fuel cell, and battery applications. In this work, atmospheric-pressure metal-organic chemical vapor deposition was used to fabricate CeO2-doped Y2O3-stabilized ZrO2 films on dense silicon and porous alumina substrates. Aerosol-assisted delivery of a toluene solution of the precursors Zr(tfac)4,Y(hfac)a, and Ce(tmhd)4 was used to deposit films with thicknesses around 1 urn. The effects of carrier gas O2 content (0-5 mol-), H2O vapor (0-3.4 mol-), deposition temperature (300-600 ℃). and the type of substrate on film morphology, composition, and purity were investigated. The porous substrate had a marked effect on the film morphology, producing a columnar film structure with column diameters that roughly approximated the particle diameter of the substrate (-0.5 μm). Lower temperatures (300 ℃) provided a more uniform film with better connectivity between columnar structures than deposition at 400 and 600 ℃, and higher precursor concentrations produced very non-uniform films with exaggerated growth features.