Electrical conduction in glass ceramics containing metal nanodispersoids

Abstract

Silver particles of diameters ranging from 3.4 to 25.8 nm have been grown within a glass ceramic by controlling the morphology of the crystalline phase. The fractal dimension of the crystal phase has a marked effect on the particle diameter. The DC electrical resistivity of the glass–ceramic metal nanocomposites has been measured over the temperature range from 100 to 300 K. A variable-range hopping conduction between localized states generated by silver nanoparticles within the glass determines the resistivity behavior in the temperature range from 235 to 333 K. Electrical resistivity in the range from 110 to 235 K arises due to the contribution of both large and small metallic particles (∼3 nm) in a percolative configuration. The smaller particles show semiconducting behavior due to a quantum size effect. In the specimen containing 25.8-nm-median-diameter nanoparticles of silver, the resistivity arises through an electron tunnelling mechanism.