Unimodal and Bimodal Distributions of Silver Nanoparticles in a-C:Ag Structures with Different sp.sup.2/sp.sup.3 Carbon Ratios Produced by Low Energy Ion Assisted Pulse-Plasma Deposition

Amorphous carbon coatings with encapsulated silver nanoparticles (a-C:Ag) are studied. It is shown by transmission electron microscopy that the introduction of low-energy (100-300 eV) ion assistance into the process of pulse-plasma deposition in different cases lead to either the unimodal or bimodal size distributions of silver inclusions. It is established that the type of distribution is determined by the power of the pulse-plasma source. The effect of the variation of the flow of deposited particles on the process of ion induced surface diffusion over the coating surface is analyzed. It is shown that this process along with the ion induced formation of nucleation sites affects the nature of size distribution of silver inclusions. It is found using the spectroscopy of characteristic electron energy losses that the change in the surface concentration of silver nanoparticles correlates with the ratio of sp.sup.2 and sp.sup.3 hybridized carbon atoms.