Complex order-parameter phase-field models derived from structural phase-field-crystal models

TL;DR

This paper derives a mesoscale complex order-parameter phase-field model from structural phase-field-crystal models, capturing atomic-scale features and microstructure evolution in materials.

Contribution

It introduces an amplitude expansion of XPFC models to create a mesoscale phase-field model for 2D structures, bridging atomistic and mesoscale modeling.

Findings

Successfully simulated peritectic solidification.

Demonstrated grain growth with secondary phase emergence.

Retained atomic-scale features in a mesoscale model.

Abstract

The phase-field-crystal (PFC) modeling paradigm is rapidly emerging as the model of choice when investigating materials phenomena with atomistic scale effects over diffusive time scales. Recent variants of the PFC model, so-called structural PFC (XPFC) models introduced by Greenwood et al., have further increased the capability of the method by allowing for easy access to various structural transformations in pure materials [Phys. Rev. Lett. 105, 045702 (2010)] and binary alloys [Phys. Rev. B. 84, 064104, (2011)]. We present an amplitude expansion of these XPFC models, leading to a mesoscale complex order-parameter (amplitude), i.e., phase-field representation, model for two dimensional square-triangular structures. Amplitude models retain the salient atomic scale features of the underlying PFC models, while resolving microstructures on mesoscales as in traditional phase-field models. The applicability and capability of this complex amplitude model is demonstrated with simulations of peritectic solidification and grain growth exhibiting the emergence of secondary phase structures.