Field‐Free Magnetization Switching Driven by Spin–Orbit Torque in L10‐FeCrPt Single Layer

Abstract Electrical switching of magnetization through spin–orbit torque (SOT) induced by a composition gradient in single‐layer L 1 0 ‐FePt has garnered considerable research interest owing to its inherent superior perpendicular magnetic anisotropy (PMA) that provides ultrahigh capacity to magnetic storage and memory devices. However, a large in‐plane external magnetic field is typically required to assist SOT‐driven switching, which is still a limitation for the practical application of L 1 0 ‐FePt. This study reports realizable field‐free magnetization switching by SOT via Cr doping to form a single‐layer magnetic structure with an in‐plane magnetization component oriented toward L 1 0 ‐FeCrPt [110] direction that strongly depends on the magnetocrystalline anisotropy. The Cr doping yields a considerable in‐plane exchange‐coupling effective field that is conducive toward disintegrating the rotational switching symmetry and facilitates field‐free switching in single‐layer films with PMA. Furthermore, this in‐plane effective field exhibits a nonmonotonic evolution with respect to the Cr‐doping concentration, which is validated using first‐principles calculation with a frustration‐based model of magnetic exchange interactions. Thus, this study delivers an attractive method to facilitate the field‐free electrical manipulations of magnetization in single‐layer ferromagnets to motivate innovative designs for advanced spintronics devices.