Adjustable Current-Induced Magnetization Switching Utilizing Interlayer Exchange Coupling

Abstract Electrical current–induced deterministic magnetization switching in a magnetic multilayer structure without any external magnetic field is realized by utilizing interlayer exchange coupling. Two ferromagnetic Co layers, with in‐plane and out‐of‐plane anisotropy, respectively, are separated by a spacer Ta layer, which plays a dual role in inducing antiferromagnetic interlayer coupling, and contributing to the current‐induced effective magnetic field through the spin Hall effect. The current‐induced magnetization switching behavior can be tuned by premagnetizing the in‐plane Co layer. The antiferromagnetic exchange coupling field increases with decreasing thickness of the Ta layer, reaching 630 ± 5 Oe for a Ta thickness of 1.5 nm. A model is developed to separate the Joule heating and spin–orbit torques caused by the electrical current. The magnitude of the current‐induced perpendicular effective magnetic field from spin–orbit torque is 9.2 Oe/(10 7 A cm −2 ). The large spin Hall angle of Ta, opposite in sign to that of Pt, results in a low critical current density of 9 × 10 6 A cm −2 . This approach is promising for the electrical switching of magnetic memory elements without any external magnetic field.