Self-organization of spatially inhomogeneous structures during volume crystallization of polydisperse systems

Abstract

The kinetic instability arising during crystallization of metastable supercooled binary melts (produced by applying laser radiation to respective binary compounds) and culminating in the formation of ordered structures is studied. The nonlinear self-organization of inhomogeneous structures in a polydisperse system is statistically simulated using (i) a self-consistent set of kinetic equations for the cluster distributions in space and size and (ii) balance equations for the temperature and concentration of dissolved impurities. Allowance is made for cluster growth and evaporation, dependence of the phase transition temperature on the curvature of the cluster surface and impurity concentration, diffusion mobility of the clusters, and their withdrawal from the nucleation zone. The domain of the kinetic instability and the scale of the resulting inhomogeneous structures are determined.