The viscous drag of dislocations is known to increase when a phase transition of the host material is approached. Previous discussions of this effect, however, have overlooked that, above the bulk transition point, the ordered phase can already nucleate along the dislocations. The viscous-drag component due to energy dissipation in such nuclei is shown to clearly dominate the previously known fluctuation-induced contributions at low dislocation velocities.

• Received 26 November 2002

DOI:https://doi.org/10.1103/PhysRevB.67.100103