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

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.