Anomalous Hall effect and Lifshitz transition in Fe ₃ Sn ₂ nanosheets

Abstract Fe 3 Sn 2 , a ferromagnetic metal with a kagome lattice, serves as an ideal platform for exploring topological electronic states and Berry curvature due to its unique band structure. However, systematic reports on the transport properties of Fe 3 Sn 2 nanosheets remain scarce. We present temperature-dependent transport property measurements of Fe 3 Sn 2 nanosheets synthesized via chemical vapor deposition on Si/SiO 2 substrates. The samples exhibit a robust anomalous Hall effect from 40 K to 300 K, along with a magnetoresistance sign reversal at 40 K at high magnetic fields, indicating a spin reorientation from in-plane to out-of-plane. Notably, a sharp crossover in the dominant transport contribution from electrons to holes near 200 K is observed, accompanied by distinct anomalous Hall behaviors in the two regimes, indicating a temperature-induced Lifshitz transition within the multi-band system. This divergence is potentially linked to a topological reconstruction of the Fermi surface across the transition. Our findings highlight the tunability of topological transport in two-dimensional kagome magnets and provide new insights into the interplay between band topology, dimensionality and magnetic order.