# Grain Boundary Structures and Collective Dynamics of Inversion Domains in Binary Two-Dimensional Materials

## TL;DR

This paper develops a phase field crystal model to study grain boundary structures and dynamics in binary two-dimensional materials, revealing new dislocation core structures and defect-mediated growth mechanisms related to inversion symmetry breaking.

## Contribution

It introduces a novel phase field crystal model tailored for binary 2D materials, uncovering new dislocation structures and defect-driven growth processes not previously documented.

## Key findings

- Discovery of new dislocation core structures at grain boundaries.
- Identification of defect-mediated growth dynamics of inversion domains.
- Linking inversion symmetry breaking to atomic migration at grain boundaries.

## Abstract

Understanding and controlling the properties and dynamics of topological defects is a lasting challenge in the study of two-dimensional materials, and is crucial to achieve high-quality films required for technological applications. Here grain boundary structures, energies, and dynamics of binary two-dimensional materials are investigated through the development of a phase field crystal model that is parameterized to match the ordering, symmetry, energy and length scales of hexagonal boron nitride. Our studies reveal some new dislocation core structures for various symmetrically and asymmetrically tilted grain boundaries, in addition to those obtained in previous experiments and first-principles calculations. We also identify a defect-mediated growth dynamics for inversion domains governed by the collective atomic migration and defect core transformation at grain boundaries and junctions, a process that is related to inversion symmetry breaking in binary lattice.