resumo
Protective Zr(Y)O(2-delta)-based films sputter-deposited onto apatite-type lanthanum silicate ceramics were appraised for potential applications in solid oxide fuel cells with silicate-based solid electrolytes, where the performance may suffer from surface decomposition processes in reducing atmospheres. Dense and crystalline coatings were deposited using radio-frequency magnetron sputtering from an yttria-stabilized zirconia target. On the basis of microstructural analysis and profile measurements, a sputtering power of 300 W was selected in order to achieve deposition rates in the range 0.50-0.75 mu m/h. The surface morphology studies using an atomic force microscope revealed typical film structures with small (<50 nm) grains. The polarization of model electrochemical cells with cermet anodes comprising Ni, yttria-stabilized zirconia and Ce(0.8)Gd(0.2)O(2-delta) (50:30:20 wt.%), deposited onto the protective zirconia films, was found quite similar to that of copper-zirconia cermets without interlayers, suggesting that the electrochemical reaction is essentially governed by the oxygen anion transfer from zirconia phase and/or hydrogen oxidation in the vicinity of zirconia film surface. (C) 2009 Elsevier Ltd. All rights reserved.
palavras-chave
ELECTRONIC TRANSPORT; IONIC-CONDUCTIVITY; LANTHANUM SILICATES; OXIDE; ELECTROLYTES; ZIRCONIA; COMPONENTS; CERAMICS; SYSTEMS
categoria
Materials Science; Physics
autores
Shaula, AL; Oliveira, JC; Kolotygin, VA; Louro, C; Kharton, VV; Cavaleiro, A
nossos autores
Vladislav Kharton
Investigador Principal CovidadoGrupos