Intrinsic anomalous Hall effect in thin films of topological kagome ferromagnet Fe3Sn2†
Fe3Sn2, 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 Fe3Sn2 remains relatively unexplored. Here, we investigate the effect of two different seed layers (Ta and Pt) on the growth of Fe3Sn2 thin films. We demonstrate the growth of polycrystalline Fe3Sn2 thin films on Si/SiO2 substrates by room temperature sputter deposition, followed by in situ annealing at 500 °C. Our structural and magnetic measurements indicate that a pure ferromagnetic phase is formed for the Pt/Fe3Sn2 thin films with higher saturation magnetization of Ms = 464 emu cc−1, while a mixed-phase (consisting of ferromagnetic, Fe3Sn2 and antiferromagnetic, FeSn) is formed for the Ta/Fe3Sn2 thin films with a lower Ms of 240 emu cc−1. The Pt/Fe3Sn2 thin films also exhibit an anomalous Hall coefficient, Rs ≈ 2.6 × 10−10 Ω cm−1 G−1 at room temperature, which is two order of magnitude higher compared to 3d-transition metal ferromagnets. A non-zero temperature-independent anomalous Hall conductivity σintxy = (23 ± 11) Ω−1 cm−1 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.