Premelting disordering of the Si(113) surface studied by tight-binding molecular dynamics

The tight-binding molecular-dynamics method is used to study melting of the reconstructed Si(113) surface. It is found that the surface starts to disorder at about 950 K which is consistent with recent low-energy-electron-diffraction and x-ray chiral melting studies. The behaviour of the simulated mean square atomic displacement and static structure factor indicate that the surface disorders anisotropically. A surface quasi-liquid which exhibits properties of both crystalline and liquid phase is observed between 1000 K and 1400 K. Surface-initiated melting of the crystal is expected to take place at a temperature slightly above 1400 K but lower than the bulk melting temperature.