Mechanical properties of PtS2 monolayer with rectangular defects: A molecular dynamics study

Abstract

Using the classical molecular dynamics simulations, the mechanical properties of the PtS2 monolayer with rectangular defects have been investigated. Particularly, a counterintuitive defect enlargement method to recover from defect-induced mechanical degradation has been explored. As the rectangular defects are enlarged along the zigzag direction, the uniaxial tension has been firstly applied in the same direction. It's found that the Young’s modulus (Ys) increases slightly with the size of the defects. However, both the fracture strain and stress are increased obviously as the length of the rectangular defect increasing, indicating the recovery of the mechanical properties for the defective PtS2 monolayer. And this degradation recovery could be attributed to the higher degree of geometric asymmetry when the defect being lengthened. Then, the mechanical properties of the defective PtS2 monolayer under uniaxial tension in the armchair direction have also been studied. The calculations show that the Ys, fracture strain and stress decrease significantly as the rectangular defect enlarging. These results suggest even though the defect itself can induce the mechanical degradation, enlargement of the defect along a direction may promote the mechanical recovery in the same direction.