Planar topological Hall effect in a hexagonal ferromagnetic Fe5Sn3 single crystal

TL;DR

This paper reports the experimental observation of the planar topological Hall effect in a hexagonal Fe5Sn3 single crystal, revealing how complex magnetic structures influence electron transport and potential spintronic applications.

Contribution

First experimental demonstration of PTHE in Fe5Sn3, linking noncoplanar spin structures to Hall signals in a ferromagnetic crystal.

Findings

PTHE observed with peaks near saturation field

PTHE more pronounced at higher temperatures

Noncoplanar spin structure induces scalar spin chirality

Abstract

The planar topological Hall effect (PTHE), appeared when the magnetic field tended to be along the current, is believed to result from the real-space Berry curvature of the spin spiral structure and has been experimentally observed in skyrmion-hosting materials. In this paper, we report an experimental observation of the PTHE in a hexagonal ferromagnetic Fe5Sn3 single crystal. With a current along the c axis of Fe5Sn3, the transverse resistivity curves exhibited obvious peaks near the saturation field as the magnetic field rotated to the current and appeared more obvious with increasing temperature, which was related to the noncoplanar spin structure in Fe5Sn3. This spin structure induced nonzero scalar spin chirality, which acted as fictitious magnetic fields to conduction electrons and contributed the additional transverse signal. These findings deepen the understanding of the interaction between conduction electrons and complex magnetic structures and are instructive for the design of next-generation spintronic devices.