Kink pair production and dislocation motion

Abstract

The motion of extended defects called dislocations controls the mechanical properties of crystalline materials such as strength and ductility. Under moderate applied loads, this motion proceeds via the thermal nucleation of kink pairs. The nucleation rate is known to be a highly nonlinear function of the applied load, and its calculation has long been a theoretical challenge. In this article, a stochastic path integral approach is used to derive a simple, general, and exact formula for the rate. The predictions are in excellent agreement with experimental and computational investigations, and unambiguously explain the origin of the observed extreme nonlinearity. The results can also be applied to other systems modelled by an elastic string interacting with a periodic potential, such as Josephson junctions in superconductors.

Dislocations and Plastic Deformation in MgO Crystals: A Review

“…Nevertheless, there is still scope to improvement. With the rapid increase of atomistic simulation capabilities, the shape and energy of kinks could be determined by atomistic simulations following the recent scheme proposed in bcc metals or covalent materials (see [92,[102][103][104] for instance).…”

The low temperature epitaxy of Ge on Si (1 0 0) substrate using two different precursors of GeH4 and Ge2H6

“…By using SiGe buffer layers, threading dislocations can be confined at interfaces, and they reported the reduction of TDD in the top Ge layer to the value on the order of 10 6 cm À2 [18]. However, the lm-range thick SiGebased buffer layer and the rough surface caused by cross-hatch patterns are not appropriate [19,20]. Also, in order to grow high quality Ge layers, thermal annealing process or chemicalmechanical polishing is required [21].…”

Exact Topological Soliton Solutions to the Strongly Perturbed Family of Sine-Gordon Type Equations

“…Studying these dislocations can help material scientists improve the strength of metals. The kink solitons of the SGE can be used to model the interactions of these dislocations [4].…”