Formation of gold nanoparticles and their aggregates in a liquid at magnetron deposition

The influence of magnetron deposition conditions on the size of Au nanoparticles and their aggregates obtained by condensation in a neutral liquid is studied experimentally. A model is suggested in which the nanoparticles and aggregates form in a thin subsurface layer, which becomes oversaturated by atoms and resulting nanoparticles when the liquid flows through a localized deposition zone. The process stops when the products leave this zone because of stirring. The size of nanoparticles and aggregates depends on the particle flux density and exposure time in the deposition zone. The final size of nanoparticles depends on the exposure time only slightly, while that of aggregates significantly depends on the exposure time. This allows one to prepare a concentrated solution of almost monodisperse nanoparticles with a low degree of aggregation by properly selecting deposition conditions and multiply passing the liquid through the deposition zone.