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arXiv · 0908.0214

On the phases of Polonium

Matthieu J. Verstraete
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Abstract

The thermodynamical properties of the main phases of metallic polonium are examined using Density Functional Theory. The exceptional nature of the solid-solid phase transition of $α$ to $β$ Po is underlined: it induces a lowering in symmetry, from cubic to rhombohedral, with increasing temperature. This is explained as the result of a delicate balance between relativistic and entropic effects. Overall agreement with existing experimental data is very good by state-of-the-art standards. The phonons of Po present Kohn anomalies, and it is shown that the effect of spin-orbit interactions is the inverse of that in normal metals: due to the non-spherical nature of the Fermi Surface, spin-orbit effects reduce nesting and harden most phonon frequencies.

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Matthieu J. Verstraete. 2009-08-03. On the phases of Polonium. https://arxiv.org/abs/0908.0214

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