Shock induced phase transformation of single crystal Silicon – Molecular dynamic investigations

At ambient temperature and pressure conditions, single crystal Si exists in a diamond cubic structure. Experimental investigation reports that Si can exist in many different phases (beta-tin, orthorhombic, HCP, FCC) under different pressure conditions. Molecular dynamic simulations have been carried out in this study upto 80 Gpa pressure to observe and characterize different phases of Si under shock compression. The characterization of different phases has been done using various mechanistic perspectives such as radial distribution function, neighbor based structural identification, x-ray diffraction etc. Two different interatomic potential -- Tersoff and Stillinger-Weber has been utilized to explore capability, accuracy and applicability of these potentials for typical dynamic shock study in three different directions <100>, <110> and <111>.