Melting at dislocations and grain boundaries: A phase field crystal study

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 angle to intermediate 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.