Anomalous and topological Hall effects of ferromagnetic Fe3Sn2 epitaxial films with kagome lattice

Abstract

Fe3Sn2, a ferromagnetic alloy with a kagome lattice, has attracted much attention from research communities owing to its special crystal structure and symmetry, which gives rise to numerous intriguing magneto-electronic properties, including the topological Hall effect, skyrmionic bubbles, Dirac cones, and Weyl points. To study such physical properties, Fe3Sn2 epitaxial films without buffer layers are in urgent need. In this work, we fabricated the Fe3Sn2 epitaxial films without buffer layers using the facing-target magnetron sputtering method, and their magneto-electronic transport properties were investigated systematically. It is found that the sign of the Hall resistivity slope in a high-field region is reversed when the temperature decreases below 100 K, suggesting a temperature-induced transition of charge carriers from electrons to holes. Moreover, a non-negligible topological Hall resistivity subtracted from the anomalous Hall resistivity is depicted, and its value is comparable to that of the Fe3Sn2 single crystals. These results not only offer a clear understanding of ferromagnetic Fe3Sn2 films with the kagome lattice but also provide guidance for fabrication and application of epitaxial Fe3Sn2 films.