Observation of the Out-of-Plane Polarized Spin Current from CVD Grown WTe₂

Weyl semimetal Td-phase WTe₂ possesses the spin-resolved band structure with strong spin–orbit coupling, holding promises as a useful spin source material. The noncentrosymmetric crystalline structure of Td-WTe₂ endows the generation of the out-of-plane polarized spin, which is of great interest in magnetic memory applications. Previously, WTe₂ was explored in spin devices based on mechanically exfoliated single crystal flakes with a size of micrometers. For practical spintronics applications, it is highly desirable to implement wafer-scale thin films. In this work, centimeter-scale chemical vapor deposition (CVD) grown Td-WTe₂ thin films are used and the spin current generation is studied by the spin torque ferromagnetic resonance (ST-FMR) technique. The in-plane and out-of-plane spin conductivities of 7.36 × 10³ ((Formula presented.)) (Ωm)^–1 and 1.76 × 10³ ((Formula presented.)) (Ωm)^–1, respectively, are found in CVD-growth 5 nm-WTe₂. The current-induced magnetization switching in WTe₂/NiFe is demonstrated at room temperature in the domain wall motion regime, which may invigorate potential spintronic device innovations based on Weyl semimetals.