title: Transport coefficients and entropy-scaling law in liquid iron up to Earth-core pressures.
abstract: Molecular dynamics simulations were applied to study the structural and transport properties, including the pair distribution function, the structure factor, the pair correlation entropy, self-diffusion coefficient, and viscosity, of liquid iron under high temperature and high pressure conditions. Our calculated results reproduced experimentally determined structure factors of liquid iron, and the calculated self-diffusion coefficients and viscosity agree well with previous simulation results. We show that there is a moderate increase of self-diffusion coefficients and viscosity along the melting curve up to the Earth-core pressure. Furthermore, the temperature dependencies of the pair correlation entropy, self-diffusion, and viscosity under high pressure condition have been investigated. Our results suggest that the temperature dependence of the pair correlation entropy is well described by T(-1) scaling, while the Arrhenius law well describes the temperature dependencies of self-diffusion coefficients and viscosity under high pressure. In particular, we find that the entropy-scaling laws, proposed by Rosenfeld [Phys. Rev. A 15, 2545 (1977)] and Dzugutov [Nature (London) 381, 137 (1996)] for self-diffusion coefficients and viscosity in liquid metals under ambient pressure, still hold well for liquid iron under high temperature and high pressure conditions. Using the entropy-scaling laws, we can obtain transport properties from structural properties under high pressure and high temperature conditions. The results provide a useful ingredient in understanding transport properties of planet's cores.
authors.affiliation: Key Laboratory of Computational Physics, Yibin University, Yibin 644000, China.
authors.forename: Qi-Long
authors.initials: QL
authors.lastname: Cao
authors.affiliation: Centre for Experimental and Teaching Resource Management, Yibin University, Yibin 644000, China.
authors.forename: Pan-Pan
authors.initials: PP
authors.lastname: Wang
authors.affiliation: Key Laboratory of Computational Physics, Yibin University, Yibin 644000, China.
authors.forename: Duo-Hui
authors.initials: DH
authors.lastname: Huang
authors.affiliation: Key Laboratory of Computational Physics, Yibin University, Yibin 644000, China.
authors.forename: Jun-Sheng
authors.initials: JS
authors.lastname: Yang
authors.affiliation: Key Laboratory of Computational Physics, Yibin University, Yibin 644000, China.
authors.forename: Ming-Jie
authors.initials: MJ
authors.lastname: Wan
authors.affiliation: Key Laboratory of Computational Physics, Yibin University, Yibin 644000, China.
authors.forename: Fan-Hou
authors.initials: FH
authors.lastname: Wang