Pressure induced crossing of the core-levels in 5d metals

TL;DR

This study systematically investigates pressure-induced core-level crossing in 5d metals, revealing it as a common phenomenon with varying transition pressures, including potential occurrence at ambient conditions in Re.

Contribution

It provides a comprehensive first-principles analysis of core-level crossing across the entire 5d metal series, highlighting its generality and pressure dependence.

Findings

CLC occurs in all 5d metals studied.

Transition pressures vary widely, from 80 GPa in Ir to 1500 GPa in Pt.

Re may exhibit CLC at ambient pressure.

Abstract

Pressure induced interaction between core electrons, the core level crossing (CLC) transition has been observed in hcp Os at P~400 GPa [L. Dubrovinksy, et al., Nature 525, 226-229 (2015)]. In this work, we carry out a systematic study of the influence of pressure on the electronic structure in all metals of the 5d series (Hf,Ta,W,Re,Os,Ir,Pt,Au) using first-principles electronic structure calculations. We have found that CLC is a general effect for this series of metals. While in Pt it occurs at ~1500 GPa, at a pressure substantially higher than in Os, in Ir it occurs already at 80 GPa. Moreover, we predict that in Re the CLC transition may appear at ambient pressure. We analyze the shifts of the CLC transition pressure across the series within the Thomas-Fermi model, and show that the effect has many common features to the atomic collapse in the rare-earth elements.