Motion of a perfect screw dislocation through the Peierls barrier in α-Fe by tunnelling

1974 ◽  
Vol 24 (7) ◽  
pp. 823-824 ◽  
Author(s):  
L. Lejček
Keyword(s):  
Screw Dislocation ◽  
Peierls Barrier

Temperature and Stress Dependence of Mobility of Screw Dislocation in BCC Iron

2016 ◽  
Vol 258 ◽  
pp. 17-20
Author(s):  
Hideki Mori
Keyword(s):  
Screw Dislocation ◽  
Unit Length ◽  
Peierls Stress ◽  
Body Centered Cubic ◽  
Entropy Term ◽  
Energy Gradient ◽  
Bcc Iron ◽  
Peierls Barrier ◽  
Entropic Effect ◽  
Increasing Temperature

The Peierls stress and barrier of a screw dislocation in body-centered cubic iron at finite temperature is investigated by using the free energy gradient method. The Peierls barrier is shown to decrease from 12 to 5 meV per unit length of the Burgers vector with increasing temperature from 0 to 400 K. The entropy term of the Peierls barrier is estimated to be 0.2kB. The Peierls stress also decreases from 900 to 400 MPa with increasing temperature from 0 to 300 K. The change in the Peierls stress due to the entropic effect is larger than that of the Peierls barrier because of thermal softening.

Surface effect on the screw dislocation mobility over the Peierls barrier

2012 ◽  
Vol 92 (6) ◽  
pp. 270-277 ◽  
Author(s):  
Xi Cheng ◽  
Yao Shen ◽  
Lei Zhang ◽  
Xiaohui Liu
Keyword(s):  
Screw Dislocation ◽  
Surface Effect ◽  
Dislocation Mobility ◽  
Peierls Barrier

scholarly journals The Properties of Shuffle Screw Dislocations in Semiconductors Silicon and Germanium

2015 ◽  
Vol 9 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Huili Zhang ◽  
Chun Zhang ◽  
Chunhua Zeng ◽  
Lumei Tong
Keyword(s):  
Screw Dislocation ◽  
Peierls Stress ◽  
Diamond Structure ◽  
Screw Dislocations ◽  
Burgers Vector ◽  
Peierls Barrier ◽  
Silicon And Germanium

The dislocation widths, Peierls barriers and Peierls stresses for shuffle screw dislocations in diamond structure crystals, Si and Ge, have been calculated by the improved P-N theory. The widths are about 0.6b, where b is the Burgers vector. The Peierls barrier for shuffle screw dislocation in Si and Ge, is about 3.61~4.61meV/Å and 5.31~13.32meV/Å, respectively. The Peierls stress is about 0.28~0.33GPa and 0.31~0.53GPa, respectively. The calculated Peierls barriers and stresses are likely the results of shuffle screw dislocation with metastable core which is centered on the bond between two atoms.

A New Defect in Polyethylene Single Crystals

1973 ◽  
Vol 31 ◽  
pp. 70-71
Author(s):  
E. L. Thomas ◽  
S. L. Sass
Keyword(s):  
Single Crystals ◽  
Screw Dislocation ◽  
Small Distance ◽  
Dipole Model ◽  
Dislocation Dipole ◽  
Chain Folding ◽  
Black And White ◽  
Polymer Crystal ◽  
Different Types

In polyethylene single crystals pairs of black and white lines spaced 700-3,000Å apart, parallel to the [100] and [010] directions, have been identified as microsector boundaries. A microsector is formed when the plane of chain folding changes over a small distance within a polymer crystal. In order for the different types of folds to accommodate at the boundary between the 2 fold domains, a staggering along the chain direction and a rotation of the chains in the plane of the boundary occurs. The black-white contrast from a microsector boundary can be explained in terms of these chain rotations. We demonstrate that microsectors can terminate within the crystal and interpret the observed terminal strain contrast in terms of a screw dislocation dipole model.

Action-Minimizing Curves for Tonelli Lagrangians

2017 ◽  
Author(s):  
Alfonso Sorrentino
Keyword(s):  
Critical Value ◽  
The Other ◽  
Invariant Sets ◽  
Simple Pendulum ◽  
New Concepts ◽  
Peierls Barrier ◽  
Average Action

This chapter discusses the notion of action-minimizing orbits. In particular, it defines the other two families of invariant sets, the so-called Aubry and Mañé sets. It explains their main dynamical and symplectic properties, comparing them with the results obtained in the preceding chapter for the Mather sets. The relation between these new invariant sets and the Mather sets is described. As a by-product, the chapter introduces the Mañé's potential, Peierls' barrier, and Mañé's critical value. It discusses their properties thoroughly. In particular, it highlights how this critical value is related to the minimal average action and describes these new concepts in the case of the simple pendulum.

scholarly journals Noninertial effects on a scalar field in a spacetime with a magnetic screw dislocation

2019 ◽  
Vol 79 (10) ◽  
Author(s):  
Ricardo L. L. Vitória
Keyword(s):  
Scalar Field ◽  
Screw Dislocation ◽  
Bound States ◽  
Charged Scalar ◽  
Wall Potential ◽  
Noninertial Effects ◽  
Klein Gordon ◽  
Coulomb Type ◽  
Charged Scalar Field ◽  
Type Potential

Abstract We investigate rotating effects on a charged scalar field immersed in spacetime with a magnetic screw dislocation. In addition to the hard-wall potential, which we impose to satisfy a boundary condition from the rotating effect, we insert a Coulomb-type potential and the Klein–Gordon oscillator into this system, where, analytically, we obtain solutions of bound states which are influenced not only by the spacetime topology, but also by the rotating effects, as a Sagnac-type effect modified by the presence of the magnetic screw dislocation.

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