Achieving Uniaxial In-Plane Magnetocrystalline Anisotropy to Enable Scalable SOT-MRAM Devices

In this work, we examine in-plane spin-orbit-torque magnetic random-access-memory (SOT-MRAM) devices stabilized by in-plane uniaxial magnetocrystalline anisotropy. This concept enables in-plane device stabilization without external fields or constraints on shape, paving the way for scalable and uniform magnetic memories, as well as novel spin-torque devices. Uniaxial in-plane anisotropy is generated through crystalline epitaxy between platinum and cobalt layers on a single-crystal substrate. The presence of in-plane anisotropy is confirmed by crystalline characterization and hysteresis measurements. Furthermore, we investigate the interaction between this uniaxial in-plane anisotropy and the spin-transfer torque in a spin Hall switching device – an interaction whose fundamental behavior is currently unknown. To this end, we fabricate an array of nanoscale pillar-and-channel switching devices from the epitaxial film stack and examine the angular dependence of the critical current pulse required to switch state.