Phase transition and deformation behaviors in 2D materials

Taking graphene sheets and single-layer molybdenum disulfide (SLMoS2) as examples, the deformation behaviors of two-dimensional (2D) materials under tensile and compressive loading are studied by molecular dynamics (MD) simulations and, size, temperature, loading direction dependent mechanical properties are discussed. Fantastic behaviors different from bulk materials are evidenced, such as, lattice shearing induced hexagonal-to-orthorhombic phase transformation is observed in single-crystal graphene nanoribbons and nano-grained graphene sheets upon mechanical loading, size and chirality dependent elastic modulus is illustrated inSLMoS2sheets with a width of less than 10 nm. The results are explored from the point of view of bond rearrangement at edges and grain boundaries.