Synthesis of metallic particles in erosive laser plasma in a high-pressure reducing atmosphere

Abstract

A study was made of the synthesis of ultrafine metallic particles as a result of condensation in an erosive jet in the laser vaporization of an oxide in a reducing gas at high pressures. The granulometric, phase, and chemical compositions of the condensate particles were analyzed in relation to the irradiation conditions. It was found that the mean dimensions of the condensate particles increased with an increase in the pressure of the reducing gas. A particle nucleation and growth theory was used to describe the formation of the dispersed condensate in the erosive plasma. It was shown that the resulting particle size distribution is determined by the dependence of the cooling rate of the vapor-gas mixture on the pressure of the surrounding gas.A study was made of the synthesis of ultrafine metallic particles as a result of condensation in an erosive jet in the laser vaporization of an oxide in a reducing gas at high pressures. The granulometric, phase, and chemical compositions of the condensate particles were analyzed in relation to the irradiation conditions. It was found that the mean dimensions of the condensate particles increased with an increase in the pressure of the reducing gas. A particle nucleation and growth theory was used to describe the formation of the dispersed condensate in the erosive plasma. It was shown that the resulting particle size distribution is determined by the dependence of the cooling rate of the vapor-gas mixture on the pressure of the surrounding gas.