Possible Topological Hall Effect in a Spin Gapless Semiconducting Mn₂CoAl Heusler Compound

Abstract

Topological Hall effect (THE), induced by the interaction of charge carriers with mesoscopic or microscopic non‐coplanar spin structures, holds promising applications in the field of spintronics. In the present study, we report a giant THE of about 2 μΩ‐cm at room temperature in a bulk spin gapless semiconducting Mn2CoAl cubic Heusler compound. Temperature dependent investigation of magneto‐transport data reveals that the Mn2CoAl has the large THE over a wide temperature range of 2‐300 K. The AC susceptibility as a function of magnetic field exhibits a smooth and continuous response rather than any kink or anomaly, suggests that the observed THE in the Mn2CoAl compound results from the interaction of charge carriers with the microscopic non‐coplanar spin texture. The observed THE as a function of temperature follows the same behavior as the magnetocrystalline anisotropy (MCA) of the cubic Mn2CoAl, indicating the competition of the MCA with ferromagnetic and antiferromagnetic exchange interactions as the origin of the non‐coplanar spin texture and hence THE. Micromagnetic simulations further support the emergence of non‐coplanar spin structure as a result of the competition between different energies.This article is protected by copyright. All rights reserved.