Phase-field crystal model for heterostructures

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openAccess

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Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2019-10-16

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Mcode

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Language

en

Pages

15
1-15

Series

Physical Review B, Volume 100, issue 16

Abstract

Atomically thin two-dimensional heterostructures are a promising, novel class of materials with ground-breaking properties. The possibility of choosing many constituent components and their proportions allows optimization of these materials to specific requirements. The wide adaptability comes with a cost of large parameter space making it hard to experimentally test all the possibilities. Instead, efficient computational modeling is needed. However, large range of relevant time and length scales related to physics of polycrystalline materials poses a challenge for computational studies. To this end, we present an efficient and flexible phase-field crystal model to describe the atomic configurations of multiple atomic species and phases coexisting in the same physical domain. We extensively benchmark the model for two-dimensional binary systems in terms of their elastic properties and phase boundary configurations and their energetics. As a concrete example, we demonstrate modeling lateral heterostructures of graphene and hexagonal boron nitride. We consider both idealized bicrystals and large-scale systems with random phase distributions. We find consistent relative elastic moduli and lattice constants, as well as realistic continuous interfaces and faceted crystal shapes. Zigzag-oriented interfaces are observed to display the lowest formation energy.

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Keywords

HEXAGONAL BORON-NITRIDE, INPLANE HETEROSTRUCTURES, GRAPHENE, INTERFACE, TRANSPORT, DYNAMICS, GROWTH, ENERGY

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Citation

Hirvonen, P, Heinonen, V, Dong, H, Fan, Z, Elder, K R & Ala-Nissila, T 2019, ' Phase-field crystal model for heterostructures ', Physical Review B, vol. 100, no. 16, 165412, pp. 1-15 . https://doi.org/10.1103/PhysRevB.100.165412