Up-hill diffusion in contact stress field in small particles under pressure

A review gives an analytical solution of the equation of diffusion of point lattice imperfection in the field of forces and presents the spatial and time dependence of their concentration after applying external hydrostatic pressure to the ensemble of small particles. The spatial--time dependence of the distribution of the second component atoms over the volume of small particles after application of an external pressure to their ensemble is obtained. The contact stresses appearing in the particles initiate the processes of up-hill diffusion of the second component, thus giving rise to the change of its initial distribution. The concentration of foreign atoms dilating the lattice of matrix is described by the curve possessing a minimum. The redistribution of second component over the particle volume leads to the relaxation of contact stresses, locally changes the elasticity moduli and permits the formation of new phases which influence a number of physical and mechanical properties of small particles, the conditions of formation and spread of dislocations, particularly. Graphs. 7 ref.--J.H.