Characterizing Structure in Simulated Silicon Under Shock Compression

Silicon is an important material used in many industries and is well studied. Here we use it as a baseline for shock simulations of materials with covalent bonding. The shock structure of silicon is investigated through classical molecular dynamics simulations in the range of 10-20 GPa using the modified Tersoff interatomic potential. Simulations in the literature have shown presence of amorphous regions at the areas with high dislocation density; however, the disordered structure outside of those amorphous regions was not fully identified. The structure is characterized here through the use of radial distribution and angular distribution functions comparing pristine silicon structures with those within the shocked silicon bulk. Additionally, measurements are made of the flow stress and energy stored by the phase change within the shocked regions.