Liquid-Liquid Phase Transition in Undercooled Silicon: Structural, Electronic and Dynamical Aspects

摘要

We have proposed a new mixed approach by combining efficiently classical and first-principles molecular dynamics to study undercooling of liquid silicon, regardless of a specific empirical interaction model. Our results show an enhancement of the local tetrahedral ordering in the deep undercooled region associated to the appearance of propagating shear waves and give a strong support to the existence of a transition between a high density liquid to a low density liquid near 1050 K. An analysis of the structural, dynamics and electronic properties is proposed to elucidate these features.