The consistent behavior of negative Poisson's ratio with interlayer interactions

Abstract

A negative Poisson's ratio (NPR) is of great interest due to having novel applications in lots of fields. Films are the most commonly used form in practical applications, which involve multiple layers. However, the effect of interlayer interactions on the NPR is still unclear. In this study, based on first principles calculations, we systematically investigate the effect of interlayer interactions on the NPR by comparably studying single-layer graphene, few-layer graphene, single-layer h-BN, bilayer h-BN, and a graphene-BN heterostructure. It is found that they almost have the same geometry-strain response. Consequently, the NPRs in bilayer graphene, triple-layer graphene, bilayer h-BN, and the graphene-BN heterostructure are consistent with those in single-layer graphene and h-BN. The fundamental mechanism lies in the responses to strain of the orbital coupling being consistent under the effect of interlayer interactions. The deep understanding of the NPR with the effect of interlayer interactions as achieved in this study is beneficial for the future design and development of micro-/nanoscale electromechanical devices with novel functions based on nanostructures.