Peierls stress and Peierls energy of a 70.5° ⟨1 1 1⟩ dislocation in Mo

Author(s)

Gunther Schoeck

Abstract

The Peierls potential and the Peierls stress of a

70.5° ⟨1 1 1⟩dislocation with line orientation along the [1 1 1]

direction and

Burgers vector in Mo are studied using two slightly different profiles

of the γ-surface from the literature. Since the Burgers vector has a

large edge component, the dislocation has a well-defined

glide plane. Therefore, its core structure can be studied following

the procedure of the Peierls model generalized as variational problem.

The model allows differentiating between the (long range) elastic

self-energy and the (local) atomic misfit energy in the glide plane.

When in the Rayleigh–Ritz method the variational trial functions are

assumed to be Peierls dislocations, it is possible to calculate

analytically the changes in elastic energy during the translation of the

dislocation centre. It turns out that these changes in elastic energy

can be very large and reduce the ‘effective Peierls energy’ to a small

fraction of the changes in atomic misfit energy. The results depend

sensitively on finer details of the γ-surface. The calculations can be

performed on a laptop in a time scale of minutes.

Organisation(s)

Physics of Nanostructured Materials

Journal

Philosophical Magazine

Volume

Pages

2363-2376

No. of pages

ISSN

1478-6435

DOI

https://doi.org/10.1080/14786435.2013.774466

Publication date

06-2013

Peer reviewed

Yes

Austrian Fields of Science 2012

103018 Materials physics

Keywords

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