Mechanochemical Influence on the Graphite to Diamond Phase Transformation via Controlled Out of Plane Strain

Mechanical strain in covalent bonds is well-known to accelerate chemical reactions and alter reaction pathways. Previous results have shown that rotational and bending strains can result in the lowering of the total energy needed to induce reaction. However, it is not entirely clear how this effect influences and couples with other condensed phase effects that alter reaction kinetics and energetics. Hence, we utilize steered molecular dynamics to impose out-of-plane strains throughout a graphite lattice at a variety of levels of strain. These strained systems are then compressed at high strain rates to form diamond phases. We assess the level of compression and compressive work necessary to induce phase transformation for various out of plane strains. This results in a consistent lowering of the necessary work/compression needed to begin diamond formation. However, beyond a certain level of out of plane strain, it also increases defect nucleation and forms disordered regions, which leads to slowed transformation rates.