Simulation of the phase transition of graphite to the diamond-like LA3 phase

Аннотация

The phase transition of graphite to a diamond-like LA3 phase is simulated by the methods of the density functional theory (DFT). The calculations are performed in the local density approximation (LDA) and the generalized gradient approximation (GGA). It is found that the structural transformation must occur at a pressure of 60 or 74 GPa according to calculations based on the DFT–LDA and DFT–GGA, respectively. The height of the potential barrier separating the structural state corresponding to the LA3 phase from the state corresponding to graphite exceeds 0.13 eV/atom. This indicates the possibility of stable existence of the diamond-like LA3 phase under standard conditions.