/Pt heterostructures*

Van der Waals (vdW) layered ferromagnets have become a hot topic of research lately within the two-dimensional materials community due to the ability to study magnetic properties from a single atomic layer. Fe₃GeTe₂ (FGT) is one of very few known metallic members of the vdW ferromagnetic materials family. It has strong perpendicular magnetic anisotropy (PMA) and Curie temperature, T_C ~ 220 K, which makes FGT a good candidate material to study the effect of spin-orbit torque (SOT) on the magnetization of 2D ferromagnet in FGT/heavy metal heterostructures. For this study we fabricated heterostructures of FGT/Pt with 5 nm of Pt sputtered onto the surface of ~ 15 nm – 50 nm flakes of FGT. We measured the first and second harmonic Hall responses to an applied magnetic field in the in-plane parallel and perpendicular to current directions. We also measured the angular dependence of the 2 ω signal with fixed in-plane fields larger than the field required to saturate the magnetization in the hard axis direction. Our analysis of the 2 ω signals show that damping-like SOT is at least an order of magnitude greater than the negligible field-like SOT and thus it is the dominant mechanism acting on the magnetization of FGT.