Vapor phase synthesis of fine particles

Abstract

Aluminum nitride (AlN) ultrafine powder is synthesized in a new concept plasma reactor whose reaction section is separated from the plasma chamber, Aluminum is evaporated using a transferred-arc in either an Ar or Ar/H/sub 2/ atmosphere. The hot gas carrying metal vapor is mixed with radial jets of NH/sub 3//Ar mixture. A mathematical model of the reaction zone is developed, which includes the calculation of fluid flow, temperature, and concentration fields, followed by the nucleation and growth of fine particles, using the method of moments. The initial results of the experimental and modeling study on the influence of temperature and nitriding jet intensity on particle size and conversion are presented. The powder produced has a specific surface area (SSA) in the range of 40-280 m/sup 2//g.