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Study of the interface action between LaCoO 3 layer and Al 2 O 3 substrate
Author(s) -
Zhu Yongfa,
Tan Ruiqin,
Cao Lili
Publication year - 2001
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.1033
Subject(s) - x ray photoelectron spectroscopy , substrate (aquarium) , layer (electronics) , diffusion , catalysis , analytical chemistry (journal) , materials science , chemistry , chemical engineering , thermodynamics , nanotechnology , biochemistry , oceanography , physics , chromatography , geology , engineering
Thin‐film model catalysts of LaCoO 3 /Al 2 O 3 /Si were prepared successfully by using spin‐coating technique. The model catalysts were heated at various temperatures for various times to promote interaction between the active component of LaCoO 3 and the substrate of Al 2 O 3 . The interface action was investigated by using AES and angle‐dependent x‐ray photoelectron spectroscopy (ADXPS) techniques. The AES depth profile analysis showed that interface diffusion took place during the thermal treatment and an interlayer was formed. Linear least‐squares fitting of AES depth profile analysis and the AES line shape analysis indicated that the LaAlO 3 species was formed on the interface after the model catalyst was treated at 550 °C for 5 h. The interaction between the LaCoO 3 layer and the substrate was more serious when the heat treatment temperature was increased to 850 °C. The heating time also could intensify the interface diffusion and reaction. The results of ADXPS confirmed that Al diffused seriously into the active component layer and reacted with LaCoO 3 to form lanthanum aluminate species and CoO species after the sample was treated at a high temperature for 5 h. These results also indicated that AES was a useful tool to study interface species. Copyright © 2001 John Wiley & Sons, Ltd.