Two good metals make a semiconductor: A potassium-nickel compound under pressure

Adebayo A. Adeleke, Elissaios Stavrou, Adebayo O. Adeniyi, Biao Wan, Huiyang Gou, Yansun Yao*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

We predict a potassium-nickel intermetallic compound K2Ni at high pressure and identify it as the long-sought structure of the only known K-Ni compound to date [Parker, Science 273, 95 (1996)10.1126/science.273.5271.95]. Although both constituent elements are metallic, K2Ni exhibits a semiconducting ground state with an indirect band gap of 0.65 eV. Electron instability due to the degeneracy at the Fermi level arises from the particular motif of the structure, which in turn induces symmetry-breaking Peierls distortion and a nonmetallic ground state. The results indicate that the chemical properties of elements can change dramatically under extreme conditions and have significant implications for the postulation that potassium is incorporated in Earth's core.

Original languageEnglish
Article number134120
JournalPhysical Review B
Volume102
Issue number13
DOIs
StatePublished - 29 Oct 2020
Externally publishedYes

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