Efficient analytical approach for high-pressure melting properties of iron

Iron represents the principal constituent of the Earth's core, but its high-pressure melting diagram remains ambiguous. Here we present a simple analytical approach to predict the melting properties of iron under deep-Earth conditions. In our model, anharmonic free energies of the solid phase a...

Full description

Saved in:
Bibliographic Details
Main Authors: Tran Dinh Cuong, Anh D.Phan
Format: Bài trích
Language:eng
Published: Vacuum 2021
Subjects:
Online Access:https://www.sciencedirect.com/science/article/abs/pii/S0042207X20308605?via%3Dihub
https://dlib.phenikaa-uni.edu.vn/handle/PNK/2826
https://doi.org/10.1016/j.vacuum.2020.110001
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Iron represents the principal constituent of the Earth's core, but its high-pressure melting diagram remains ambiguous. Here we present a simple analytical approach to predict the melting properties of iron under deep-Earth conditions. In our model, anharmonic free energies of the solid phase are directly determined by the moment expansion technique in quantum statistical mechanics. This basis associated with the Lindemann criterion for a vibrational instability can deduce the melting temperature. Moreover, we correlate the thermal expansion process with the shear response to explain a discontinuity of atomic volume, enthalpy, and entropy upon melting. Our numerical calculations are quantitatively consistent with recent experiments and simulations. The obtained results would improve understanding of the Earth's structure, dynamics, and evolution.