Shock compression of diamond: Molecular dynamics simulations using different interatomic potentials

Abstract

Two recently developed interatomic potentials for carbon, the screened environment dependent - reactive empirical bond order (SED-REBO) and the long-range carbon bond-order (LCBOPII), were used in molecular dynamics (MD) simulations of shocked diamond. Static uniaxial compressions showed that both potentials offer an improved accuracy compared to the commonly used REBO potential. MD simulations were run in the [110] direction, and a split elastic-elastic shock wave regime was observed with one of the potentials. Isothermal compression allowed us to explain the origin of this regime, characterized by a solidsolid phase transition, leading to a non-monotonic stress-strain response below the Hugoniot elastic limit of the material.