We describe a general method to model multicomponent ordered crystals using the phase-field crystal (PFC) formalism. As a test case, a generic B2 compound is investigated. We are able to produce a line of either first-order or second-order order-disorder phase transitions, features that have not been incorporated in existing PFC approaches. Further, it is found that the only elastic constant for B2 that depends on ordering is C11. This B2 model was then used to study antiphase boundaries (APBs). The APBs were shown to reproduce classical mean field results. Dynamical simulations of ordering across small-angle grain boundaries predict that dislocation cores pin the evolution of APBs.
@article{arxiv.1610.06556,
title = {Phase-field crystal model for ordered crystals},
author = {Eli Alster and K. R. Elder and Jeffrey J. Hoyt and Peter W. Voorhees},
journal= {arXiv preprint arXiv:1610.06556},
year = {2017}
}