Diffusion in metals

In crystalline solids and particularly in metals atom displacements are produced by point defects. At thermal equilibrium vacancies are mainly concerned, when temperature increases the proportion of divacancies increases and near the melting point their contribution to diffusion can be important. In metals, outside of equilibrium i.e. when point defects are produced. Only by temperature but by external conditions, for example plastic deformation or irradiation, vacancies and interstitials are created simultaneously and they both contribute to diffusion. Results concerning autodiffusion, heterodiffusion, chemical diffusion, electromigration and thermomigration are examined