X-Ray absorption study on the local structures of fine particles of α-Fe2O3–SnO2gas sensors
- 1 January 1992
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of Materials Chemistry
- Vol. 2 (7) , 703-707
- https://doi.org/10.1039/jm9920200703
Abstract
X-Ray absorption spectra (EXAFS) have been recorded of the local structure around iron and tin in fine powdery α-Fe2O3–SnO2, prepared by thermal decomposition of coprecipitates from aqueous iron(III) sulfate and tin(IV) chloride solutions at pH 8. Tin atoms are substituted for iron atoms in the corundum structure of α-Fe2O3 below 15 mol% SnO2 which is the limit of dissolution. Further addition of SnO2 destabilises the system such that SnO2enters the lattice as a substitutional defect. At > 50 mol%, SnO2 forms a mixture of a rutile SnO2 phase and an SnO2 phase dissolved in α-Fe2O3. The Fe2O3(33 mol%)–SnO2(67 mol%) structure consists of rutile SnO2 and an irregular iron oxide phase. The high sensor sensitivity for CH4 is intimately correlated with the amount of SnO2 dissolved in α-Fe2O3.Keywords
This publication has 5 references indexed in Scilit:
- X-ray absorption (EXAFS/XANES) study of supported vanadium oxide catalysts. Structure of surface vanadium oxide species on silica and γ-alumina at a low level of vanadium loadingJournal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, 1988
- Characterization of fine particles of the α-Fe2O3-SnO2 system with residual SO2−4 ions on the surfaceJournal of Solid State Chemistry, 1987
- EXAFS: Basic Principles and Data AnalysisPublished by Springer Nature ,1986
- Effects of Sulfate Ion on Gas Sensitive Properties of α-Fe2O3 CeramicsJapanese Journal of Applied Physics, 1982
- Ab initio calculations of amplitude and phase functions for extended x-ray absorption fine structure spectroscopyJournal of the American Chemical Society, 1979