Fabrication of thin and dense nano-crystalline membranes on porous substrates

✍ Scribed by V. Faucheux; M. Audier; L. Rapenne; S. Pignard

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 632 KB
• Volume: 204
• Category: Article
• ISSN: 0924-0136
• DOI: 10.1016/j.jmatprotec.2007.11.037

✦ Synopsis

A fabrication process is proposed for obtaining thin and dense nano-crystalline membranes on porous substrates. The key issue of this process implies the formation of a layer of composite structure in between membrane and substrate in order to reach a high mechanical stability of the membrane through heating and cooling cycling treatments. The membrane is obtained by metal-organic chemical vapour deposition in an amorphous state. The intermediate composite layer is formed by creep of the amorphous membrane through the substrate porosity, followed by a thermal treatment for crystallisation. This process was applied with success to a fabrication of La 0.7 Sr 0.3 Fe 0.8 Co 0.2 O 3-ı and La 0.4 Sr 0.6 Fe 0.25 Co 0.75 O 3-ı nano-crystalline membranes of less than 1 m thickness on porous yttria-stabilised zirconia substrates. Catalytic measurements performed on these thin membranes show that ionic conductivities measured at 500 • C are comparable with values reported in the literature obtained on thick membranes of similar composition.