Understanding and controlling the properties and dynamics of topologicaldefects is a lasting challenge in the study of two-dimensional materials, andis crucial to achieve high-quality films required for technologicalapplications. Here grain boundary structures, energies, and dynamics of binarytwo-dimensional materials are investigated through the development of a phasefield crystal model that is parameterized to match the ordering, symmetry,energy and length scales of hexagonal boron nitride. Our studies reveal somenew dislocation core structures for various symmetrically and asymmetricallytilted grain boundaries, in addition to those obtained in previous experimentsand first-principles calculations. We also identify a defect-mediated growthdynamics for inversion domains governed by the collective atomic migration anddefect core transformation at grain boundaries and junctions, a process that isrelated to inversion symmetry breaking in binary lattice.
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