A Molecular Dynamics Study on the Constraint Conditions of the Particle Growth Process in Laser Synthesis of Nanopowders

Abstract

Laser-induced chemical vapor deposition (LICVD) is a nanopowder synthesis method in which the nanoparticles of a synthetic product undergo nucleation, growth, and agglomeration. The growth process is crucial because it directly determines the growth rate and final size of nanoparticles. In this paper, the nanoparticle growth process is analyzed through a molecular dynamics study, and the process is divided into five steps. In addition, this study explains the microscopic heat and mass transfer processes that occur in the surrounding space and on the particulate surface. Three constraint conditions that may restrict the growth process, namely, transfer constraint, surface constraint, and temperature constraint conditions, are proposed and modeled. To calculate the final diameter and the nanoparticle growth rate, formulae for the constraint conditions are developed. The behavior of four gases in the particulate growth zone is discussed in detail.