Revealing an anisotropic electronic scattering rate in the "non-metallic" metal FeCrAs using the Hall effect

TL;DR

This study investigates the anisotropic electronic scattering in FeCrAs, a 'non-metallic' metal, revealing how magnetic fluctuations influence transport properties and Hall effect measurements, suggesting complex interplay between magnetism and electronic behavior.

Contribution

The paper uncovers anisotropic scattering rates in FeCrAs linked to magnetic fluctuations, highlighting their impact on Hall effect and transport properties, a novel insight into its non-metallic behavior.

Findings

Hall coefficient depends on crystal orientation

Two temperature-induced sign reversals in Hall coefficient within the ab-plane

Magnetic fluctuations cause momentum-dependent scattering

Abstract

We probe the relationship between magnetism and "non-metallic" transport in the magnetically frustrated metal FeCrAs using the low-field Hall effect. We find that the low-field Hall coefficient is dependent on crystal orientation, and exhibits two temperature-induced sign reversals when the current is within the $ab$-plane. We suggest that these observations are due to scattering from magnetic fluctuations that become momentum-dependent near the onset of long-range magnetic order. It seems, however, that this additional spin-fluctuation scattering rides on top of the non-metallic resistivity, and Hund's metal interorbital correlations remain a possible source of the non-metallic behaviour.