Instability of the interface between a nonhydrostatically stressed elastic body and a melt

It has been noted in a previous study (Grinfeld, 1982) that the nonhydrostatic nature of solid phases may lead to the destabilization of heterogeneous phase equilibrium. It is shown here that, in the absence of surface tension, a plane interface between a crystal and its melt is unstable with respect to perturbations of any wavelength in the case of infinitely small nonhydrostatic stresses inside the solid phase. Surface tension suppresses this instability in the short-wave region of the spectrum; the critical wavelength is determined.