The kinetics of colloid formation in solids under irradiation

Results of the first-principles study of diffusion-controlled aggregation of Frenkel defects-interstitial atoms and vacancies-under irradiation of solids are presented. A novel theory is based on the discrete-lattice formalism for the single-defect densities (concentrations) and the coupled joint densities of similar and dissimilar defects, treated in terms of the Kirkwood superposition approximation. Conditions for the efficient aggregation of vacancies and interstitials are studied and the cooperative character of the aggregation process is discovered.