Microscopic mechanisms of Strong Electron Scattering and Giant Anomalous Hall Effect in high-Curie-temperature Fe3GaTe2 van der Waals Films

Abstract: Van der Waals ferromagnet Fe3GaTe2 with room-temperature perpendicular magnetic anisotropy and strong anomalous Hall effect has attracted considerable interest for their potential in spintronics. However, the microscopic mechanisms and manipulation of the electron scattering and the anomalous Hall effect of Fe3GaTe2 have remained unsettled. Here, we demonstrate strong tuning of the electron scattering and anomalous Hall effect of pattern-defined Fe3GaTe2 Hall-bar devices with perpendicular magnetic anisotropy, high Curie temperature (340 K, as high as that of Fe3GaTe2 bulk), and giant anomalous Hall effect by varying the layer thickness and temperature. Temperature-dependent resistivity experiments reveal that the electron scattering of the high-quality Fe3GaTe2 is dominated by impurity scattering and phonon scattering, regardless of the thickness. Combined temperature- and thickness-dependent scaling analyses of the anomalous Hall resistivity reveal that the anomalous Hall effect of the Fe3GaTe2 is predominantly from the positive, temperature-independent skew-scattering contribution that competes with negative temperature-independent, side-jump contribution, and negative, temperature-dependent intrinsic Berry-curvature contribution. The intrinsic anomalous Hall conductivity decreases rapidly with increasing impurity scattering, which is consistent with the characteristic variation of intrinsic Hall conductivities in the dirty-metal regime. These findings advance the understanding of electron scattering and the anomalous Hall effect in van der Waals magnets and would benefit the application of the Fe3GaTe2 in spintronics.