Local order and dynamic properties of liquid and undercooled CuxZr1-x alloys by ab initio molecular dynamics

We report the results of first-principles molecular-dynamics simulations for liquid and undercooled CuxZr1-x alloys at four different compositions. The local structure as defined by the partial pair-correlation functions and the Bhatia-Thornton partial structure factors is found to display a strong evolution as a function of composition. In addition, a structural analysis using three-dimensional pair-analysis techniques evidences an icosahedral short-range order much more pronounced around x(Cu)=0.64. In examining the dynamic properties of these alloys, we show a strong interplay between the structural changes and the evolution of the viscosity as a function of composition.