Journal ArticleDOI
Electrical conduction in sol-gel derived glass-metal nanocomposites
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In this paper, a glass-metal nanocomposites involving iron, nickel and copper in a silica glass matrix have been prepared as films on glass substrates by the sol-gel route.Abstract:
Glass-metal nanocomposites involving iron, nickel and copper in a silica glass matrix have been prepared as films on glass substrates by the sol-gel route. The metal phase is introduced as chloride and silicon tetraethoxide is used as the glass precursor. DC electrical resistivity of these nanocomposites has been measured over the temperature range 100 to 350 K. Resistivities varying from 10 Omega m to 106 Omega m have been obtained by controlling the volume fraction of the different metal phases within the silica glass. Low-temperature resistivities of the samples are controlled by a simple activation with energies in the range 0.01-0.1 eV. At temperatures above 150 K some of the nanocomposites exhibit another activated mechanism. The latter is believed to arise due to hopping of electrons between the localised states formed by the distributed metal atoms within the silica glass matrix.read more
Citations
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The Sol–Gel Route to Advanced Silica-Based Materials and Recent Applications
Rosaria Ciriminna,Alexandra Fidalgo,Valerica Pandarus,François Béland,Laura M. Ilharco,Mario Pagliaro +5 more
TL;DR: Applications Rosaria Ciriminna,† Alexandra Fidalgo,‡ Valerica Pandarus, Franco̧is Beĺand, Laura M. Ilharco,*,‡ and Mario Pagliaro*.
Journal ArticleDOI
Feature article. Nanocomposites
TL;DR: In this paper, a review deals with a variety of nanocomposites such as sol-gel, intercalation, entrapment, electroceramic and structural ceramic types, which exhibit superior properties when compared to the monophasic or microcomposite alternatives.
Journal ArticleDOI
Synthesis and structural and optical properties of mesoporous silica containing silver nanoparticles
Cai Weiping,Zhang Lide +1 more
TL;DR: In this article, a mesoporous silica with silver (Ag) nanoparticles within its pores was synthesized by thermal decomposition of silver nitrate, and the structure of this new material was examined by x-ray diffraction, transmission electron microscope and Brunauer - Emmett - Teller techniques.
Journal ArticleDOI
Optical measurements of oxidation behavior of silver nanometer particle within pores of silica host
TL;DR: In this paper, the oxidation behavior of silver nanoparticles within a silica host in ambient air (298 K) was investigated from optical absorption measurements, and it was shown that in air at room temperature oxidation occurs in surface layers of Ag particles in the form of a dense Ag2O film.
Journal ArticleDOI
Fabrication and mechanical properties of fine-tungsten-dispersed alumina-based composites
Tohru Sekino,Koichi Niihara +1 more
TL;DR: In this paper, the mechanical properties and microstructure of fine-tungsten-dispersed alumina-based composites, which were fabricated by hot pressing a mixture of fine α-Al2O3 and W powders, have been investigated.
References
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Ping Sheng,B. Abeles,Y. Arie +2 more
TL;DR: In this paper, it was shown that the observed temperature dependence of low-field conductivity in granular metals can be attributed to a relationship between the separation of neighboring metal grains and the electrostatic energy required to create a positive-negative charged pair of grains.
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TL;DR: In this paper, the authors investigated the electrical conduction mechanism in the film plane of ultrathin, evaporated metal films and showed that the conductivity depends exponentially on reciprocal temperature, and it should be independent of field at low fields.
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Effective medium models for the optical properties of inhomogeneous materials
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Photoemission of Electrons from Silicon into Silicon Dioxide
TL;DR: In this article, it was shown that the current is due to photoemission of electrons from the silicon into the Si${\mathrm{O}}_{2}$ conduction band.