Nano Archive

Structural, electrical and gas-sensing properties of In2O3 : Ag composite nanoparticle layers

Mehta, B. R. and Singh, V. N (2005) Structural, electrical and gas-sensing properties of In2O3 : Ag composite nanoparticle layers. Pramana, 65 (5). pp. 949-958. ISSN 0304-4289 (Print) 0973-7111 (Online)

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Official URL: http://www.springerlink.com/content/n0100874007812...

Abstract

The central objective of this study is to investigate (i) size-dependent properties of In2O3 nanoparticles and (ii) the role of metal additives in enhancing the gas sensing response. For this purpose, In2O3 : Ag composite nanoparticle layers having welldefined individual nanoparticle size and composition have been grown by a two step synthesis method. Thermogravimetric analysis, X-ray diffraction and transmission electron microscopy have been used to study the effect of post-synthesis heat treatment on the size and structure of the nanoparticles. A first-time unambiguous observation of sizedependent lowering of transformation temperature has been explained in terms of lower cohesive energy of surface atoms and increase in surface-to-volume ratio with decrease in nanoparticle size. The gas sensing studies of In2O3 as well as the In2O3 : Ag composite nanoparticle layers have been studied as a function of size and composition. In2O3: Ag composite nanoparticle layers with 15% silver show a sensitivity of 436 and response time of 6 s for 1000 ppm of ethanol in air. Ag additives form a p-type Ag2O, which interact with n-type In2O3 to produce an electron-deficient space-charge layer. In the presence of ethanol, interfacial Ag2O reduces to Ag, creating an accumulation layer in In2O3 resulting in increased sensitivity

Item Type:Article
Subjects:Physical Science > Nanophysics
Physical Science > Nano objects
Material Science > Nanochemistry
Material Science > Nanostructured materials
Divisions:Faculty of Engineering, Science and Mathematics > School of Physics
Faculty of Engineering, Science and Mathematics > School of Chemistry
ID Code:5066
Deposited By:JNCASR
Deposited On:27 May 2009 10:19
Last Modified:27 May 2009 10:19

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