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arXiv · 1806.03017

Helium-iron compounds at terapascal pressures

Bartomeu Monserrat·Miguel Martinez-Canales·Richard J. Needs·Chris J. Pickard
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Abstract

We investigate the binary phase diagram of helium and iron using first-principles calculations. We find that helium, which is a noble gas and inert at ambient conditions, forms stable crystalline compounds with iron at terapascal pressures. A FeHe compound becomes stable above 4 TPa, and a FeHe$_2$ compound above 12 TPa. Melting is investigated using molecular dynamics simulations, and a superionic phase with sublattice melting of the helium atoms is predicted. We discuss the implications of our predicted helium-iron phase diagram for interiors of giant (exo)planets and white dwarf stars.

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Bartomeu Monserrat, Miguel Martinez-Canales, Richard J. Needs, Chris J. Pickard. 2018-06-08. Helium-iron compounds at terapascal pressures. https://doi.org/10.1103/physrevlett.121.015301

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