Current-induced magnetization switching in a chemically disordered A1 CoPt single layer

We report the first demonstration of current-induced magnetization switching in a perpendicularly magnetized A1 CoPt single layer. We show that good perpendicular magnetic anisotropy can be obtained over a wide composition range of A1 Co1-xPtx single layers, which allows the fabrication of a perpendicularly magnetized CoPt single layer with a composition gradient that breaks the inversion symmetry of the structure. By fabricating a CoPt single layer with a gradient, we were able to evaluate spin-orbit torque (SOT) efficiency and successfully realize SOT-induced magnetization switching. Our study provides an approach for realizing current-induced magnetization in ferromagnetic single layers without attaching SOT source materials.