Electrical conductivity of sol-gel derived metal nanoparticles

Abstract

Electrically conducting films of thickness ∼ 2 μm have been prepared on ordinary glass slides by growing ultra-fine particles of iron and copper, respectively, from a suitable precursor sol. The diameters of metal particles can be varied from 3–13 nm by controlling the heat-treatment schedule of the sol coating. Resistivity measurements (d.c.) have been carried out over the temperature range 80–300 K. The resistivity values in the range 0.0001–0.0039 Ω cm have been obtained depending on the particle diameter and the type of metal used. The effective Debye temperature θ_D for the different nanoparticle systems have been estimated by fitting the experimental data to the Ziman equation. θ_D is found to vary from 346–408 K for iron with the particle size in the range 3.4–9.5 nm. The values obtained for copper are 243–307 K with particle diameters covering a range of 5.9–12.6 nm.