Using 80 kV electron beam irradiation
we have created graphene
blister defects of additional carbon atoms incorporated into a graphene
lattice. These structures are the antithesis of the vacancy defect
with blister defects observed to contain up to six additional carbon
atoms. We present aberration-corrected transmission electron microscopy
data demonstrating the formation of a blister from an existing divacancy,
together with further examples that undergo reconfiguration and annihilation
under the electron beam. The relative stability of the observed variations
of blister are discussed and considered in the context of previous
calculations. It is shown that the blister defect is seldom found
in isolation and is more commonly coupled with dislocations where
it can act as an intermediate state, permitting dislocation core climb
without the atom ejection from the graphene lattice required for nonconservative
motion