Coagulation of gold nanoparticles in thin amorphous films under irradiation with a fast electron beam

Results of in situ studies into the coagulation of gold nanoparticles in amorphous carbon and silicon dioxide films exposed to an electron beam are presented. Special attention is paid to the final stage of coagulation (nanoparticle merging). The results clearly demonstrate the possibility of modifying the structure in a local film region by exposing it to an electron beam. Binary interparticle collisions are prevalent in the studied films. It is found that the rate of nanoparticle aggregation depends on the difference in their diameters and the orientation relationship at the moment of contact between the merging nanoparticles. It is also found that some nanoparticles are enlarged much in the same way as is done under recrystallization, i.e., via the migration of nanocrystal boundaries.