Characterization of ripplocation mobility in graphite

Abstract

Recent work suggests that layered solids deform through buckling of basal planes. When isolated locally, as in graphite, these buckles, termed ripplocations, behave superficially similar to dislocations, but have no Burgers vectors. Through atomistic simulations, we demonstrate the easy transitions of ripplocations in graphite between many closely-spaced energy states, even at low temperatures. Between 60 and 350 K, their migration barrier is estimated at 32 meV, independent of segment length. Ripplocations spontaneously migrate towards vacancies and away from compressive stresses. These results shed more light on this new micromechanism and potentially explain experimental observations that evade sufficient description through dislocation-based models.

Keywords

• layered solids
• deformation mechanisms
• buckling
• ripplocations