Revisiting Phase Diagrams of Two-Mode Phase-Field Crystal Models

TL;DR

This paper accurately determines phase diagrams of a modified two-mode phase-field crystal model, revealing various 2D and 3D crystal structures and their coexistence regions, aiding future studies on solidification and phase transformations.

Contribution

It introduces a method for exact free energy minimization in two-mode PFC models, enabling precise phase diagram calculations for multiple crystal structures.

Findings

Identified stable crystal structures including square, triangle, bcc, fcc, and stripe lattices.

Mapped coexistence regions between different crystal phases.

Provided phase diagrams as guidelines for solidification studies.

Abstract

In this work, phase diagrams of a modified two-mode phase-field crystal (PFC) that show two-dimensional (2D) and three-dimensional (3D) crystallographic structures were determined by utilizing a free energy minimization method. In this study the modified two-mode PFC model (presented by E. Asadi and M. Asle Zaeem, Comput. Mater. Sci. 2015) was used, in which the free energy can be exactly minimized in each stable crystal structure allowing calculation of accurate phase diagrams for two-mode PFC models. Different crystal structures, such as square, triangle, body-centered cubic (bcc), face-centered cubic (fcc), and stripe lattice structures as well as their coexistence regions were considered in the calculations. The model parameters were discussed to calculate phase diagrams that can be used as a guideline by other researchers for studying solidification and solid state phase transformation using two-mode PFC model.