Particles synthesis in erosive laser plasma in a high pressure atmosphere

Abstract

Synthesis of ultrafine particles as a result of condensation in an erosive jet at laser vaporization of materials (metals, metal oxides, carbon) in gases (hydrogen, oxygen, helium, argon, xenon and air) at high pressures is investigated. The granulometric, phase, and chemical composition of the condensate particles is analyzed in relation to the elaboration conditions. It is found that the mean dimensions of the condensate particles increase with increasing the ambient gas pressure. A particle nucleation and growth theory is used to describe the formation of the dispersed condensate in the erosive plasma. It is shown that the resulting particle size distribution is determined by the cooling rate dependence of the vapor-gas mixture on the pressure of the surrounding gas.