Emergence of anomalous Hall effect in Mn-doped kagome antiferromagnet FeSn thin films

Abstract

Kagome magnets provide a fertile platform for exploring the interplay between magnetic order and Berry-curvature-driven transport. Here, we report a systematic investigation of the structural, magnetic, and transport properties of epitaxial FeSn and Mn-doped Fe1−xMnxSn (x = 0.3) thin films grown on LaAlO3(111) substrates by molecular beam epitaxy. High crystalline quality and well-defined interfaces provide a reliable basis for a direct comparison between the collinear antiferromagnetic parent compound and its chemically substituted counterpart. While pristine FeSn exhibits compensated antiferromagnetism and a purely ordinary Hall response, Mn substitution induces a weak in-plane ferromagnetic component accompanied by pronounced magnetic anisotropy. Concomitantly, a clear anomalous Hall effect emerges in Fe0.7Mn0.3Sn over a broad temperature range. Scaling analysis of the anomalous Hall conductivity places Mn-doped FeSn in the intrinsic regime, indicating that the anomalous Hall effect is primarily driven by the intrinsic Berry-curvature mechanism, with additional contributions from extrinsic factors such as magnon scattering. These results demonstrate that chemical substitution provides an effective means to activate Berry-curvature-driven transport in a kagome antiferromagnet.