First-principles study of pressure-induced phase transition in silicon carbide

摘要: Abstract The phase transition of SiC from the zinc blende (ZB) structure to rocksalt (RS) under pressure is investigated by first principles plane-wave pseudopotential density functional theory method. results obtained are in good agreement with experimentally measured data and other theoretically calculated results. It found that pressures ZB RS 74.6 GPa total energy–volume 75.4 GPa enthalpy calculations. Moreover, through quasi-harmonic Debye model, which phononic effects considered, dependences relative volume V/V0 on P at T=0, 1400 K successfully obtained. reduction 18%. In particular, high-pressure elastic constants obtained, unstable when applied larger than 126.6 GPa. This value excellent experimental molecular dynamics (MD) simulation