Melting at dislocations and grain boundaries: A Phase Field Crystal study

TL;DR

This paper investigates the melting behavior of dislocations and grain boundaries in three dimensions using the Phase Field Crystal method, revealing how localized elastic energy influences melting and wetting transitions.

Contribution

It introduces a detailed 3D Phase Field Crystal simulation of dislocation and grain boundary melting, including the effects of elastic energy and wetting transitions.

Findings

Dislocations melt radially outward from their core.

Low-to-mid angle grain boundaries undergo angle-dependent wetting transitions.

High angle boundaries are analyzed with a screening approximation.

Abstract

Dislocation and grain boundary melting are studied in three dimensions using the Phase Field Crystal method. Isolated dislocations are found to melt radially outward from their core, as the localized excess elastic energy drives a power law divergence in the melt radius. Dislocations within low-to-mid angle grain boundaries melt similarly until an angle-dependent first order wetting transition occurs when neighboring melted regions coalesce. High angle boundaries are treated within a screening approximation, and issues related to ensembles, metastability, and grain size are discussed.