Electronic Transport and Microstructure of Chiral Antiferromagnet Mn₃Sn

Mn₃Sn, a non-collinear antiferromagnet (AFM) with Weyl fermions, has drawn significant attention due to its complex magnetic structure and Berry phase-controlled charge dynamics. Thin films of this Kagome AFM show the potential to exhibit bias-free magnetization switching and large anomalous Hall effect (AHE) when grown along a specific crystallographic direction. Here, a comparison of electron transport and dc magnetization in Mn₃Sn films grown on different crystallographic orientations is presented and compared with polycrystalline films. Our magneto-transport studies on Mn₃Sn/MgO(100) films reveal a robust zero-field anomalous Hall resistivity at room temperature, as well as the signatures of topological Hall effect and non-zero scalar spin chirality at lower temperatures. These films exhibit a residual resistivity ratio ρ_xx(300 K)/ρ_xx(5 K) of 1.18 and a Hall loop coercivity μ₀H_C » 1 tesla, indicating the epitaxial growth of metallic Mn₃Sn along the preferred easy ab-plane. Conversely, the AHE at room temperature is absent in films where Kagome planes are parallel to the plane of substrate i.e., films grown on (111) STO and c-plane sapphire. A quantitative comparison of the electronic transport in ab-plane, c-plane, and polycrystalline films will be presented at the meeting.