A ferroelectric-like structural transition in a metal

TL;DR

This paper reports the discovery of a ferroelectric-like structural transition in the metallic compound LiOsO3, demonstrating a phenomenon previously theorized but not observed in metals, thus opening new avenues for material properties.

Contribution

The study provides the first clear example of a ferroelectric-like transition in a metal, confirming a long-standing theoretical prediction by Anderson and Blount.

Findings

Structural transition from centrosymmetric to non-centrosymmetric in LiOsO3

Continuous shift of Li+ ions below 140K

Establishment of a new class of ferroelectric-like metals

Abstract

Metals cannot exhibit ferroelectricity because static internal electric fields are screened by conduction electrons, but in 1965, Anderson and Blount predicted the possibility of a ferroelectric metal, in which a ferroelectric-like structural transition occurs in the metallic state. Up to now, no clear example of such a material has been identified. Here we report on a centrosymmetric (R-3c) to non-centrosymmetric (R3c) transition in metallic LiOsO3 that is structurally equivalent to the ferroelectric transition of LiNbO3. The transition involves a continuous shift in the mean position of Li+ ions on cooling below 140K. Its discovery realizes the scenario described by Anderson and Blount, and establishes a new class of materials whose properties may differ from those of normal metals.