Transport properties of undercooled liquid copper:: A molecular dynamics study

By using the embedded-atom method (EAM), a series of molecular dynamics (MD) simulations are carried out to calculate the viscosity and self-diffusion coefficient of liquid copper from the normal to the undercooled states. The simulated results are in reasonable agreement with the experimental values available above the melting temperature that is also predicted from a solid-liquid-solid sandwich structure. The relationship between the viscosity and the self-diffusion coefficient is evaluated. It is found that the Stokes-Einstein and Sutherland-Einstein relations qualitatively describe this relationship within the simulation temperature range. However, the predicted constant from MD simulation is close to 1/(3 pi), which is larger than the constants of the Stokes-Einstein and Sutherland-Einstein relations.