Ag nanocluster synthesis by laser ablation in Ar atmosphere: A plume dynamics analysis

Ag thin films were deposited by pulsed laser ablation in it controlled Ar atmosphere. The deposition process was performed Oil at different Ar pressure values in the range between 10 and 100 Pa to investigate the influence of ambient gas pressure on the plasma expansion dynamics and on the film structural properties. Position, velocity and volume of the laser generated plasma as functions of little were obtained by time resolved fast photography. The morphological properties of the films were investigated by transmission electron microscopy which shows that film growth proceeds via aggregation oil the substrates Of nanoclusters formed in the expanding plume. The formation of nanoparticles takes place as a consequence of plasma confinement induced in the interaction with ambient gas species. Data from fast photography analysis were used as input parameters to calculate the size of the nanoparticles using a model that takes into account the collisional nature of the laser generated silver plasma.