Molecular dynamics simulations for mechanical properties of the monolayer PtS2 with line defect

Abstract

By using the classical molecular dynamics simulations, the mechanical properties of the monolayer (ML) PtS2 with the line defect of different tilting angles have been investigated. It has been found that mechanical properties including the fracture strain, fracture stress, toughness and Young's modulus in armchair and zigzag directions have been affected in very different levels. With the tilting angle being from 0° to45°, the mechanical properties in armchair direction is more superior compared to those in the zigzag direction. On the contrary, the mechanical properties in the zigzag direction are much stronger as tilting angle increasing from 45° to90°. Tilting angle of 45° has been received unrivalled attention, where the ML PtS2 with the line defect has presented isotropic mechanical properties in armchair and zigzag directions. The systematically parametric study on the line defect has been demonstrated that the tilting angle may change the isotropic property of the ML PtS2, resulting from its large length–width ratio and orientation of the line defect to the loading direction. The simulations in this paper shed light on a new possibility of fine-tuning mechanical properties and the realization of the isotropy-to-anisotropy of ML PtS2 and other two-dimensional materials via line defect, which may expand the potential application these materials in the future nanometer devices.