Non-free gas of dipoles of non-singular screw dislocations and the shear modulus near the melting

TL;DR

This paper models how non-singular screw dislocation dipoles affect the shear modulus near melting, using a Coulomb gas analogy with smoothed interactions to account for finite core size effects.

Contribution

It introduces a model for non-singular screw dislocation dipoles using a Coulomb gas framework with smoothed coupling, and calculates the shear modulus considering finite core effects.

Findings

Shear modulus behavior near melting is influenced by dislocation dipoles.

A convolution integral involving Bessel functions is derived for shear modulus calculation.

Finite core size of dislocations removes singularities, affecting material properties.

Abstract

The behavior of the shear modulus caused by proliferation of dipoles of non-singular screw dislocations with finite-sized core is considered. The representation of two-dimensional Coulomb gas with smoothed-out coupling is used, and the stress-stress correlation function is calculated. A convolution integral expressed in terms of the modified Bessel function $K_0$ is derived in order to obtain the shear modulus in approximation of interacting dipoles. Implications are demonstrated for the shear modulus near the melting transition which are due to the singularityless character of the dislocations.