A Simple Dislocation Theory of Melting

Abstract

The ratio of volume increment to energy for the introduction of a simple dislocation to a crystal is used in the Clausius-Clapeyron equation to determine the pressure dependence of the equilibrium phase boundary between a perfect crystal and a completely dislocated crystal. It yields the Lindemann melting formula, which is thermodynamically valid for materials with central atomic forces in which melting involves no gross changes in coordination. It is concluded that melting is properly described as the free proliferation of dislocations and that melting point is the temperature at which the free energies of dislocations vanish.