Mechanics of penta-graphene with vacancy defects under large amplitude tensile and shear loading

Abstract Penta-graphene is a new two-dimensional metastable carbon allotrope composed entirely of pentagons with unique electronic and mechanical properties. In this work we evaluate the properties classes defective penta-graphene (DPG) subjected to tensile shear loading by using molecular dynamics simulations. The types defects considered here are monovacancy at either 4-coordinated C1 site or 3-coordinated C2 site, double vacancy (DV). We focus in particular on effects different topologies their concentrations elastic constants nonlinear mechanics allotropic form carbon. results indicate that DPG has plastic behavior similar pristine penta-graphene, which caused irreversible pentagon-to-polygon structural transformation occurring during loading. moduli decrease linearly concentration defects. Monotonic reductions yield stresses also present but less pronounced, while strains unaffected. DVs feature change Poisson’s ratio from negative positive when defect rises about 3% 6%. Temperature can trigger reconstruction for free-standing DPG. critical transition temperature increases due delay structure transition. These findings expected provide important guidelines practical applications based micro/nano electromechanical systems.