Dynamics of interfaces and dislocations in disordered media

Abstract

The authors consider the motion of an interface and a dislocation in disordered media. They have shown that the low-frequency absorption gamma of an external field (ultrasound in the case of a dislocation) can be described by the general formula gamma approximately= omega 1n^alpha (1/ omega tau ₀) and the associated noise power spectrum is of a 1/f form with a logarithmic correction. The interface motion under the action of a moderate constant external field is shown to be a consequence of the thermally activated jumps and to demonstrate the power long-time behaviour: the mean interface of the dislocation displacement zeta is proportional to t^mu , mu <1.