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arXiv · 2202.11956

In-plane epitaxy strain tuning intralayer and interlayer magnetic couplings in CrSe2 and CrTe2 mono- and bi-layers

Wu Linlu·Zhou Linwei·Zhou Xieyu·Wang Cong·Ji Wei
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Abstract

Mismatched lattice-constants at a van-der-Waals epitaxy interface often introduce in-plane strains to the lattice of the epitaxial layer, termed epitaxy-strain, where the strains do not follow the intra-layer Poisson's relation. Here, we presented the magnetic phase diagrams of the CrSe2 and CrTe2 mono- and bi-layers under epitaxy-strain up to 8 %, as predicted using density-functional-theory calculations. They show that the in-plane epitaxy-strain manipulates either the intra- or inter-layer magnetism of them. The in-plane strain varies the interlayer distance, defined using an inter-layer Poisson's ratio, which governs the inter-layer magnetism in two opposite ways depending on the in-plane magnetism. The tunability of the intra-layer magnetism is a result of competing intra-layer Cr-Cr super-exchange interactions. A graphene substrate was introduced to examine the validity of our diagrams in practice. Our work also gives a tentative explanation on the controversially reported magnetizations in CrSe2 and CrTe2 epitaxial mono- or bi-layers under epitaxy-strains.

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Wu Linlu, Zhou Linwei, Zhou Xieyu, Wang Cong, Ji Wei. 2022-02-24. In-plane epitaxy strain tuning intralayer and interlayer magnetic couplings in CrSe2 and CrTe2 mono- and bi-layers. https://doi.org/10.1103/physrevb.106.l081401

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