Control of out-of-plane anti-damping spin torque with a canted ferromagnetic spin source

High-density magnetic random-access memory must be based on magnetic materials with perpendicular magnetic anisotropy, to allow thermal stability and scalability. To achieve efficient anti-damping switching of such nanomagnets with spin-orbit torque requires that the anti-damping torque have a strong out-of-plane component. The spin-current versions of the anomalous and planar Hall effects are candidate mechanisms to produce out-of-plane anti-damping torque, but both require the magnetic moment of a spin-source layer be canted partly out-of-plane at zero magnetic field. Here we demonstrate a canted magnetic anisotropy stabilized by magnetocrystalline anisotropy for ferromagnetic SrRuO₃, and we measure that this canted SrRuO₃ can generate an out-of-plane component of the anti-damping torque with efficiency of 0.020+/-0.002. We verify that this out-of-plane anti-damping torque is highly tunable with the orientation of magnetic moment, with significant contributions from both anomalous and planar Hall effects.