Growth of palladium nanoparticles: An experimental and numerical study

We study the effect of varying deposition time and temperature on the formation of palladium nanoparticles in an attempt to identify microscopic process which contribute towards their evolution. Computer simulations of a stochastic lattice model with the basic mechanisms of adsorption, diffusion and irreversible aggregation have been performed to mimic the underlying mechanism of particle growth. We propose a mass and temperature dependent diffusion term of the form D(m,T)proportional to D-0(T)m(-gamma) in order to obtain qualitative agreement with experimental data. The possibility of tuning deposition time, temperature and flux to obtain narrow particle size distributions has been explored. Wherever pertinent, simple analytical arguments have been presented.