Surface segregation and phase separation in bismuth-tin pyrochlores
UNSPECIFIED. (1997) Surface segregation and phase separation in bismuth-tin pyrochlores. JOURNAL OF MATERIALS CHEMISTRY, 7 (5). pp. 837-841. ISSN 0959-9428Full text not available from this repository.
The pyrochlore Bi2Sn2-xBixO7-x/2, Which is a catalyst for the oxidative coupling of methane, has been studied in the range of composition - 0.2 less than or equal to x less than or equal to 1.0. When heated in air in the range 200-1000 degrees C, the surface cation concentration is enriched in bismuth. Combining X-ray photoelectron spectroscopy (XPS) surface analysis and X-ray diffraction (XRD) phase analysis has allowed a distinction to be drawn between mechanisms contributing to the segregation process. Dependant upon the composition and temperature, an underlying thermodynamically driven surface enrichment in bismuth may be supplemented by the nucleation, separation and growth of a discrete bismuth oxide phase.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry
T Technology > TA Engineering (General). Civil engineering (General)
|Journal or Publication Title:||JOURNAL OF MATERIALS CHEMISTRY|
|Publisher:||ROYAL SOC CHEMISTRY|
|Official Date:||May 1997|
|Number of Pages:||5|
|Page Range:||pp. 837-841|
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