Measuring the speed of sound in an iron-nickel alloy at high pressure by inelastic X-ray scattering

摘要

The cores of terrestrial planets and the Moon are nowadays generally believed [1] to be composed primarily of Fe–Ni alloys with a nickel content of 5–25% and trace amounts of the so-called light elements (most likely H, O, S, and C) [2]. The physical properties of Fe–Ni alloys and, especially, the velocities of seismic waves at high pressure and temperature are very important for geophysics, because our knowledge about the structure of the Earth’s core, whose substance is under extreme conditions, is based mostly on seismic data.Therefore, the phase relations, thermal equations of state, and elasticity parameters of Fe–Ni alloys at high pressure and temperature are necessary for interpreting seismological and magnetometric data and for developing models of the inner structure of the Earth and other terrestrial planets.