Abstract
The data on iron melting temperatures at high pressure in a laser-heated diamond-anvil cell, along with the previously existing static pressure data on phase equilibrium reiations, have been used to obtain an internally consistent thermodynamic data base. With such a data base, it is not only possible to calculate phase equilibrium relations among the four well known phases (BCC, 6-BCC, FCC and HCP) but also to consider the effect of introducing additional possible phases yet to be verified. For the DHCP structure we have used a combination of recent X ray as well as laser-heating data to define an approximate field of stability. Similarly for explaining the disparity between the shock wave and static pressure data at pressures above 200 GPa, we have created a thermodynamically stable phase θ. This phase is stabilized because of high enthalpy and entropy; it melts at the core-mantle boundary at 6000 K or above which is much closer to the melting temperature from shock wave data than from the extrapolated static pressure data on melting of HCP (or DHCP).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.