Stochastic void coarsening

The random nature of diffusing jumps and cascade occurrence produce stochas tic fluctuations of the point-defect fluxes. The effect of such fluctuation s on the kinetics of void growth is investigated in the present paper. It i s found that the non-linear coupling between the stochastic fluctuations an d the void sizes may lead to the instability of void evolution within the m ean-field theory, when the sizes of voids and their growth rates are both r elatively small. The growth rate of voids becomes dominated by the stochast ic component, causing the smaller voids to shrink away. This effect is inve stigated in terms of a non-equilibrium phase transition induced by a purely random stochastic noise. The derived conditions for this non-equilibrium t ransition are compared favourably with experimental observations.