Spin-orbit torque induced magnetization switching in Pt/Co/Ta structures with perpendicular magnetic anisotropy
Abstract
Spin-orbit torque (SOT) induced magnetization switching is investigated in Pt/Co/Ta stacks with perpendicular magnetic anisotropy with the variation of the thickness of Ta layer (t Ta). SOT is characterized by an effective spin Hall angle θ SH, which is determined by an anomalous Hall resistance measurements method based on a macrospin model. A high charge current induced magnetization switching efficiency is achieved by the enhanced injection efficiency of spin currents from bottom Pt and top Ta with opposite signs of θ SH. When t Ta = 4 nm, the enhanced effective θ SH for Pt/Co/Ta shows a maximum value around 0.356, which is larger than the sum of |θ SH| for Pt and Ta and is ascribed to an additional interfacial SOT at Co/Ta interface. θ SH gradually decreases with increasing Ta layer thickness beyond 4 nm, which can be explained by the improved crystallinity of Ta layer. Our results confirm a way to decrease the switching current density in SOT-based spintronic devices.
- Publication:
-
Journal of Physics D Applied Physics
- Pub Date:
- October 2017
- DOI:
- 10.1088/1361-6463/aa8422
- Bibcode:
- 2017JPhD...50M5001Y