Phase behavior and kinetics of a new bond-order potential for silicon

We investigate the thermodynamics and kinetics of a new bond-order potential for silicon recently published by Kumagai et al. [T. Kumagai, S. Izumi, S. Hara, S. Sakai, Comp. Mater. Sci. 39 (2007) 457]. This new potential is modified from the standard Tersoff potential. We find that the model performs extremely well in describing the crystalline, liquid, and amorphous phases. The phase transitions are also studied using the new bond-order potential. Comparison is made to previously-published results obtained using the Tersoff, Stillinger–Weber and environment-dependent interatomic potentials for silicon, and also experiment. The new bond-order potential is found to perform much better that the Tersoff and environment-dependent interatomic potentials, and at least as well as the Stillinger–Weber potential. In one respect, the new potential appears to be significantly superior to other empirical potentials. In particular, the structure of the liquid phase predicted using the new bond-order potential seems to be in better agreement with experiment. An amorphous phase is readily formed from the quenched melt. However, it is unclear whether the new potential provides a better description of amorphous silicon than other popular empirical potentials.