Plastic Deformation of Single‐Crystal Diamond Nanopillars. Issue 9 (28th January 2020) - Regan, Blake
Abstract: Diamond is known to possess a range of extraordinary properties that include exceptional mechanical stability. In this work, it is demonstrated that nanoscale diamond pillars can undergo not only elastic deformation (and brittle fracture), but also a new form of plastic deformation that depends critically on the nanopillar dimensions and crystallographic orientation of the diamond. The plastic deformation can be explained by the emergence of an ordered allotrope of carbon that is termed O8‐carbon. The new phase is predicted by simulations of the deformation dynamics, which show how the sp 3 bonds of (001)‐oriented diamond restructure into O8‐carbon in localized regions of deforming diamond nanopillars. The results demonstrate unprecedented mechanical behavior of diamond, and provide important insights into deformation dynamics of nanostructured materials. Abstract : Plastic deformation of nanoscale diamond pillars is reported. Atomistic modeling reveals that the deformation is associated with a formation of a new phase of carbon—O8‐carbon. This new phase is predicted by simulations of the deformation dynamics, which show how the sp3 bonds of (001)‐oriented diamond restructure into O8‐carbon in localized regions of the deforming diamond nanopillars.