Melting of iron at the physical conditions of the Earth's core

摘要: Seismological data can yield physical properties of the Earth's core, such as its size and seismic anisotropy1,2,3. A well-constrained iron phase diagram, however, is essential to determine temperatures at core boundaries crystal structure solid inner core. To date, diagram high pressure has been investigated experimentally through both laser-heated diamond-anvil cell shock-compression techniques, well theoretical calculations4,5,6,7,8,9,10,11,12,13,14,15,16,17. Despite these contributions, a consensus on melt line or high-pressure, high-temperature lacking. Here we report new re-analysed sound velocity measurements shock-compressed Earth-core conditions15. We show that melting starts 225 ± 3 GPa (5,100 500 K) complete 260 (6,100 500 K), Hugoniot curve—the locus states. This lower than previously reported16, find no evidence for reported solid–solid transition curve near 200 GPa (ref. 16).