Temperature effect on the local order of liquid Ni, Ag, and Pb: A molecular dynamics study

In this work we calculate structural properties as a function of temperature for liquid Ni, Ag, and Pb using constant-energy molecular dynamics. The metallic interaction is mimicked by a tight-binding n-body potential, based on the second-moment approximation of the density of states. The inherent structures of the liquid state are analyzed through a common-neighbor analysis to extract the microstructural order as a function of temperature. For each liquid metal, our simulations show that the icosahedral order has a significant presence, on the order of 65%, and that the crystalline order is about 25% in the range of temperatures studied here. The icosahedral order remains constant with temperature for the three liquid metals, but changes in the type of crystalline order occur for Ag and Pb at 1500 and 900 K, respectively.