Ab Initio Calculations of Partial Basal Dislocations in Bilayer Graphene

Graphite has been the material of choice in construction of nuclear reactors for many years due to its low neutron absorption cross-section and high scattering cross-section. The physical properties of a graphite moderator can greatly influence the cost, safety and lifespan of a reactor. Neutron collision damage in graphite results in the formation of basal dislocations. The subsequent interaction of basal dislocations with each other and the surrounding lattice causes severe dimensional changes along the basal direction. There has been a lot of interest recently in AB and AC stacking grain boundaries in bilayer graphene. Transition from AB to AC stacking can be described by the glide of basal dislocations resulting in expansion of dislocation cores and buckling of the bilayer. Herein we present a new model for the dimensional change of nuclear graphite which considers buckling and folding of graphene sheets due to the basal dislocations glide. Full ab initio and molecular dynamics calculations of oppositely sign on basal dislocations in bilayer graphene have been carried out. Analysis of dislocation cores and buckled sinusoidal harmonics has revealed absorbing results compared to previous theoretical works.
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