Synthesis and characterization of apatite structure sputter deposited coatings dedicated to intermediate temperature solid oxide fuel cells
Idioma
en
Article de revue
Este ítem está publicado en
Journal of The Electrochemical Society. 2011, vol. 158, n° 12, p. B1479-B1484
Electrochemical Society
Resumen en inglés
La-Si<sup> </sup>metallic coatings with La/Si ratios between 1.55 and 1.66 were<sup> </sup>synthesized by Direct Current Magnetron Sputtering of lanthanum and silicon<sup> </sup>targets in pure argon atmosphere. After the ...Leer más >
La-Si<sup> </sup>metallic coatings with La/Si ratios between 1.55 and 1.66 were<sup> </sup>synthesized by Direct Current Magnetron Sputtering of lanthanum and silicon<sup> </sup>targets in pure argon atmosphere. After the deposition stage, the<sup> </sup>ceramic apatite-structure coatings were obtained by thermal oxidation in air<sup> </sup>for 2 hours at 1173 K. The structural and chemical<sup> </sup>features of these films have been assessed by X-Ray Diffraction<sup> </sup>(XRD) and Scanning Electron Microscopy (SEM) equipped with Energy Dispersive<sup> </sup>Spectroscopy (EDS). The electrical properties were determined by Complex Impedance<sup> </sup>Spectroscopy in planar configuration. The films with near apatite structure<sup> </sup>La/Si atomic ratio in range of La<sub>10</sub>Si<sub>6</sub>0<sub>27</sub> and La<sub>9.33</sub>Si<sub>6</sub>0<sub>26</sub> deposited<sup> </sup>on different substrates were initially amorphous. After thermal oxidation at<sup> </sup>1173 K in air, the coating crystallised under the expected<sup> </sup>apatite structure. SEM observation revealed that the film compactness and<sup> </sup>thickness increased after thermal oxidation. The film adhesion on SOFCs<sup> </sup>material is guaranteed if the anode support was not reduced<sup> </sup>before the deposition stage. A specific method was performed to<sup> </sup>measure the electrical conductivity, <i>i.e.</i> to determine the ionic conductivity<sup> </sup>of the film: it uses the four-point probe technique combined<sup> </sup>with ac impedance spectroscopy. The good agreement between measurements performed<sup> </sup>in this work (Ea = 0.75 eV, 973 K, <sup> </sup>= 3-4 10<sup>−3</sup> S*cm<sup>−1</sup>) and literature data allows concluding that<sup> </sup>deposited layers are of good quality and should be used<sup> </sup>as electrolyte in an Intermediate Temperature Solid Oxide Fuel Cell<sup> </sup>(IT-SOFC).< Leer menos
Palabras clave en inglés
SOFC
Apatite
Coating
Synthesis
Characterization
Orígen
Importado de HalCentros de investigación