Direction of the nucleation current through the saddle point in the binary nucleation theory and the saddle point avoidance

Abstract

Careful analysis and reexamination of Stauffer’s theory of homogeneous binary nucleation is carried out. The possibility of deviation from Stauffer’s formula for the direction of nucleation current through the saddle point is indicated. We obtained the improved expression for the angle of the flow through the saddle point using a simple method based on the treatment of stochastic equations for the number of particles in the embryo. The limiting behavior of a binary homogeneous nucleation when concentration of one of the components in a vapor is much less than the other is studied. For this case we considered the possibility of a saddle point avoidance and transition to uniary nucleation. It is shown that the multidimensional theory of anomalous growth of the embryos, proposed by us recently, gives a good description of the limiting situations including the transition to a one-component nucleation. The result for binary nucleation rate obtained from our theory agrees well with that obtained earlier from the direct numerical solution of the Fokker–Planck equation.