OSTWALD RIPENING IN DISORDERED-SYSTEMS

A theory of Ostwald ripening in disordered systems is proposed aimed a t describing the ripening in amorphous solids and doped crystals. Whet her frozen or caused by impurities, the disorder causes the surface en ergy to become a random quantity. Ripening in disordered systems is de scribed in terms of the Fokker-Planck equation, in which the effective diffusion coefficient depends on the disorder. In case the disorder i s infinitesimal the approach developed reduces to the classic Lifshitz -Slyozov theory, while it predicts considerable deviations from that t heory for the case of moderately small disorder. The coarsening rate i s found to increase with the disorder increase. Also, the disorder inc reases the size distribution function in the range of large radii, whi le shifting its maximum to the left. As a result the distribution beco mes broader and more symmetric as compared to that of the classic theo ry.