Temperature-evolution of structure and diffusion properties of liquid transition metals

The temperature-evolution of the atomic structure and diffusivity of several liquid transition metals (Ag, Cd and Cu) have been studied with molecular dynamics. It is found that the relative low order atomic clusters of rhombohedra-related structures increase with an increase in temperature according to Honeycutt-Andersen indices analysis. The local distortion would largely enhance the self diffusivity in the liquid metals. The excess entropy and the diffusion coefficients are well agreement with the universal scaling law proposed by Dzugutov. The comparison of the calculated diffusivity with predictions of four diffusion models show that the agreement of the density fluctuation model is found to be extremely good. Our results present a good understanding of the diffusion mechanism in liquid metals. (C) 2010 Elsevier B.V. All rights reserved.