Intrinsic anomalous Hall effect in thin films of topological kagome ferromagnet FeSn.

FeSn, a kagome ferromagnet, is a potential quantum material with intriguing topological features. Despite substantial experimental work on the bulk single crystals, the thin film growth of FeSn remains relatively unexplored. Here, we investigate the effect of two different seed layers (Ta and Pt) on the growth of FeSn thin films. We demonstrate the growth of polycrystalline FeSn thin films on Si/SiO substrates by room temperature sputter deposition, followed by annealing at 500 °C. Our structural and magnetic measurements indicate that a pure ferromagnetic phase is formed for the Pt/FeSn thin films with higher saturation magnetization of = 464 emu cc, while a mixed-phase (consisting of ferromagnetic, FeSn and antiferromagnetic, FeSn) is formed for the Ta/FeSn thin films with a lower of 240 emu cc. The Pt/FeSn thin films also exhibit an anomalous Hall coefficient, ≈ 2.6 × 10 Ω cm G at room temperature, which is two order of magnitude higher compared to 3d-transition metal ferromagnets. A non-zero temperature-independent anomalous Hall conductivity intxy = (23 ± 11) Ω cm indicates an intrinsic mechanism of anomalous Hall effect originating from Berry curvature. These results are important for realizing novel topological spintronic devices on a CMOS-compatible substrate.