Shock compression of Fe-FeS mixture up to 204 GPa

Abstract

Using a two-stage light gas gun, we obtained new shock wave Hugoniot data for an iron-sulfur alloy (Fe-11.8wt%S) over the pressure range of 94-204 GPa. A least-squares fit to the Hugoniot data yields a linear relationship between shock velocity D S and particle velocity u, D S (km/s) =3.60(0.14) +1.57(0.05) u. The measured Hugoniot data for Fe-11.8wt%S agree well with the calculated results based on the thermodynamic parameters of Fe and FeS using the additive law. By comparing the calculated densities along the adiabatic core temperature with the PREM density profile, an iron core with 10 wt.% sulfur (S) provides the best solution for the composition of the Earth's outer core. Key Points New equation of state for Fe-11.8wt%S at high pressure The experimental data show the ideal mixing relative to Fe and FeS Fe-10S provides the best fit to the density profile of the Earth's outer core. ©2013. American Geophysical Union. All Rights Reserved.