Structure and properties of the Earth's Inner Core

Abstract

We have measured the sound velocity of hcp-Fe and Fe3S using the inelastic X-ray scattering study at high pressure. Based on the measurements and the phase relation of the Fe-Fe3S system, we presented a model of the inner core formation; the eastern-hemisphere of the inner core with a weak anisotropy and slightly lower sound velocity was formed by hcp-Fe crystallizing earlier, whereas the western hemisphere of the inner core with anisotropy and higher sound velocity might be composed of the two phase mixtures containing Fe and Fe3S crystallizing in the later stage.