Static and Fluctuating Magnetic Moments in the Ferroelectric Metal LiOsO$_3$

TL;DR

This study investigates the magnetic properties of the ferroelectric metal LiOsO$_3$, revealing coexistence of static nuclear and dynamic electronic moments, with slow-down of Os fluctuations at very low temperatures.

Contribution

First detailed magnetic ground state analysis of LiOsO$_3$, combining $bc$SR measurements with electronic structure and dipole field calculations.

Findings

LiOsO$_3$ contains static Li nuclear and dynamic Os electronic moments.

Os moments slow down below 0.7 K but remain dynamic down to 0.08 K.

Potential for a frozen, disordered magnetic ground state at lower temperatures.

Abstract

LiOsO$_3$ is the first example of a new class of material called a ferroelectric metal. We performed zero-field and longitudinal-field $\mu$SR, along with a combination of electronic structure and dipole field calculations, to determine the magnetic ground state of LiOsO$_3$. We find that the sample contains both static Li nuclear moments and dynamic Os electronic moments. Below $\approx 0.7\,$K, the fluctuations of the Os moments slow down, though remain dynamic down to 0.08$\,$K. We expect this could result in a frozen-out, disordered ground state at even lower temperatures.