Morphological instabilities of moving extended defects

¹ Institute for Problems of Mechanical Engineering, RAS Bol'shoi prosp. V. O., 61 St Petersburg, 199178, Russia
² Institut für Theoretische Physik IV, Heinrich-Heine-Universität Düsseldorf Universitätsstrasse 1, D-40225 Düsseldorf, Germany
³ Institut für Theoretische Physik A, RWTH Aachen Templergraben 55, D-52056 Aachen, Germany

Received: 28 January 2002
Accepted: 16 May 2002

Abstract

Moving extended defects experience, via continuous energy exchange with the host material, a viscous-friction force which, depending on the nature of the exchange, can lead to unexpected acceleration effects. These occur at well-defined velocity thresholds where they imply phase-transition–like dynamic instabilities of the defect morphology. The apparent universal character of these phenomena is used to exemplify them by the simple scenario of a moving domain boundary which is coupled to a Ginzburg-Landau field of the bulk material.