Agglomeration of mesoscopic particles in plasma

Abstract

We disclose the basic mechanism of agglomeration of nano-sized particles. While for weakly coupled, mono-dispersed particles the electrostatic agglomeration has always been found to be unlikely, in strongly coupled complex (dusty) plasmas the occupation of positive states for small particles is relevant, leading to electrostatic attraction between differently charged particles. The occupation of positively charged states is further enhanced by dispersed distribution of size. The smaller particles are trapped by the larger, the accretion of which gives a positive feedback on the probability of positively charged small grains and then further accretion. Experiments on growth of carbon particles from sputtered graphite in RF and dc Argon plasma confirm the general theoretical prediction when the energy of the ions corresponds to plasma boundaries. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.