Nanoscale view of shock-wave splitting in diamond

Molecular dynamics (MD) simulations of shock wave propagation in the 〈110〉 crystallographic direction of diamond were carried out using a reactive empirical bond order potential. A split two-wave shock structure due to a lattice transformation is observed above a piston velocity threshold of up ≈ 1.8 km/s corresponding to the Hugoniot elastic limit of 125 ± 15 GPa. This transition is triggered while the temperature increase in the leading shock remains negligibly small in comparison to the melting temperature of diamond and is limited to moderate shock strengths.