Theoretical Study of the Heat of Transport in a Liquid Ni50Al50 Alloy: Green-Kubo Approach

Abstract

We analyse the formalism of transport in a binary system especially focussing on a detailed consideration of the heat of transport parameter characterizing diffusion driven by a temperature gradient. We introduce the reduced heat of transport parameter Qc*' which characterizes part of the interdiffusion flux that is proportional to the temperature gradient. In an isothermal system Qc*' represents the reduced heat flow (pure heat conduction) consequent upon unit interdiffusion flux. We demonstrate that Qc*' is independent of reference frame and is practically useful for direct comparison of simulation and experimental data from different sources obtained in different reference frames. Then, we use equilibrium molecular dynamics simulations in conjunction with the Green-Kubo formalism to study the heat transport properties of a model of the liquid Ni50Al50alloy at three state points within the temperature range 1500 – 4000 K. Our results predict that in the liquid Ni50Al50alloy in the presence of a temperature gradient Ni tends to diffuse from the cold end to the hot end whilst Al tends to diffuse from the hot end to the cold end.