Effects of strain on defect-graphene superlattices

Defects in graphene provide both a challenge and an opportunity for scientists and engineers. Here, we report first-principles calculations of the mechanical, electronic, and magnetic properties of defect-graphene superlattices involving periodic arrays of vacancy and ring disorder defects. Using the relationship between energy and strain, we quantify the elastic moduli for these defect-graphene superlattices. Compared to pure graphene, the di-vacancy defect superlattice shows the largest change in lattice vectors but only a modest deviation in mechanical properties. Young's modulus for the Stone-Thrower-Wales defect superlattice is found to be dramatically lower than for pure graphene. Strain has only a modest effect on the electronic structure of the defect-graphene superlattices, except for single vacancies in graphene, which display a strain-induced Jahn-Teller bond reconfiguration resulting in a discontinuous magnetic response. The effects detailed here may be exploited for device applications employing defect-graphene superlattices.