Unified path for high-pressure transitions of SiC polytypes to the rocksalt structure

A common strain induced transition path is proposed for the high pressure transformation of the various tetrahedrally bonded polytypes of SiC to the rocksalt structure. The energy barriers associated with these transition paths are calculated using a first principles pseudopotential method, including suitably constrained relaxations. The 3C transition is found to have a lower enthalpy barrier than the other polytypes at pressures above the equilibrium transition pressure.