Diffusion, the Diffusion Coefficient, and Mechanisms of Diffusion

Abstract

Diffusion is the way in which matter is transported through matter. It occurs by approximately random motions of the atoms in a crystal lattice. The net result of many such random movements of a large number of atoms is actual displacement of matter, the movement being activated by the thermal energy of the crystal. In a pure material any particular atom is continually moving from one position to another in the material. This is called self-diffusion and can be studied experimentally by the use of radioactive tracers.