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Titolo:
OXYGEN GAS-SENSING BEHAVIOR OF NANOCRYSTALLINE TIN OXIDE PREPARED BY THE GAS-PHASE CONDENSATION METHOD
Autore:
HERRMANN JM; DISDIER J; FERNANDEZ A; JIMENEZ VM; SANCHEZLOPEZ JC;
Indirizzi:
ECOLE CENT LYON,CNRS,URA PHOTOCATALYSE CATALYSE & ENVIRONM,BP 163 F-69131 ECULLY FRANCE UNIV SEVILLA,CSIC,INST CIENCIA MAT SEVILLA,CTR INVEST CIENT ISLA DE LA CARTUJA SEVILLE 41092 SPAIN
Titolo Testata:
Nanostructured materials
fascicolo: 6, volume: 8, anno: 1997,
pagine: 675 - 686
SICI:
0965-9773(1997)8:6<675:OGBONT>2.0.ZU;2-2
Fonte:
ISI
Lingua:
ENG
Soggetto:
PARTICLES; CONDUCTANCE; CATALYSTS; SENSORS; POWDERS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
24
Recensione:
Indirizzi per estratti:
Citazione:
J.M. Herrmann et al., "OXYGEN GAS-SENSING BEHAVIOR OF NANOCRYSTALLINE TIN OXIDE PREPARED BY THE GAS-PHASE CONDENSATION METHOD", Nanostructured materials, 8(6), 1997, pp. 675-686

Abstract

Nanocrystalline SnO2 powders have been synthesized by the gas phase condensation method. The synthesis consists of the evaporation of commercial SnO powders in a He atmosphere with calcination at 573 K of the collected ultrafine powder. The material obtained shows a fractal texture and contains small amounts of SnO in addition to the SnO2 cassiterite phase. At a temperature up to 573 K the surface interacts with gaseous oxygen and the electrical conductivity (sigma)follows a law of the type: sigma = P-o2(-1/4). Th, response of sigma varies reversibly with the oxygen pressure and rather rapidly for a powder sample. This has been explained by a combination of a high surface area with very good electrical interconnections between grains. This last effect has been attributed to the nanocrystalline character of the particles, their high degree of coalescence, and to the presence of small amounts of quasi-metallic SnO in the present material. The exponential variation ofsigma with temperature is evidence for the semiconductor character ofthe SnO2 nanocrystalline powder and allowed the determination of the enthalphy of formation of anionic vacancies. The electrical behavior of the stannic oxide sample has been compared with a commercial (Aldrich) SnO2 powder and the differences observed have been discussed. (C) 1997 Acta Metallurgica Inc.

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Documento generato il 27/11/20 alle ore 22:33:10