Formation of structures from amorphous metallic nanoparticles by dispersing metal drops continuously charging in an electron beam

Abstract

The formation of amorphous metal nanoparticles by the method of electrohydrodynamic disper� sion is studied. In this method, fine liquid metal drops are generated, charged in an electron beam to an unsta� ble state, and dispersed into nanometer droplets. Rapid cooling of these nanometer droplets results in the for� mation of amorphous metal nanoparticles. The chief problem in the formation of such particles is that it is difficult to charge molten metal drops to an unstable state, since the bombardment of the drop by an electron beam may cause intense emission of electrons. To overcome this difficulty, the drops are charged by a beam of slow electrons. Charging proceeds in such a way that the electron energy rises with the drop's charge. It is shown that this method makes it possible to obtain granulated films made up of amorphous metal particles. Copper films with a nanoparticle mean size of 2 nm and a small dimensional variation are prepared.