Nanocomposite gel-derived films by fractal growth of silver

Abstract

Fractal growth of silver metal has been carried out by electrochemical deposition in gel-derived films of compositions given by x AgNO₃, (100-x) SiO₂ with x having values of 30, 40 and 50. The structure consists of silver particles with median diameters varying from 9.4 to 31.3 nm. The fractal dimension of the metal grown shows an oscillatory behaviour as a function of the electrodeposition voltage. The dielectric breakdown model (DBM) which describes the growth as arising due to a probabilistic nucleation on the border of the structure has been used to explain this unusual behaviour. The median particle size can be varied by a suitable combination of the silver ion concentration in the gel composition and the electrodeposition voltage.