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We study spin-orbit-torque (SOT)-driven magnetization switching in perpendicularly magnetized Ta/Mo/Co40Fe40B20 (CoFeB)/MgO films. The thermal tolerance of the perpendicular magnetic anisotropy (PMA) is enhanced, and the films sustain the PMA at annealing temperatures of up to 430 °C, due to the ultra-thin Mo layer inserted between the Ta and CoFeB layers. More importantly, the Mo insertion layer also allows for the transmission of the spin current generated in the Ta layer due to spin Hall effect, which generates a damping-like SOT and is able to switch the perpendicular magnetization. When the Ta layer is replaced by a Pt layer, i.e., in a Pt/Mo/CoFeB/MgO multilayer, the direction of the SOT-induced damping-like effective field becomes opposite because of the opposite sign of spin Hall angle in Pt, which indicates that the SOT-driven switching is dominated by the spin current generated in the Ta or Pt layer rather than the Mo layer. Quantitative characterization through harmonic measurements reveals that the large SOT effective field is preserved for high annealing temperatures. This work provides a route to applying SOT in devices requiring high temperature processing steps during the back-end-of-line processes. [ABSTRACT FROM AUTHOR]

Magnetic skyrmions, which are topologically protected spin textures, are promising candidates for ultralow-energy and ultrahigh-density magnetic data storage and computing applications. To date, most experiments on skyrmions have been carried out at low temperatures. The choice of available materials is limited, and there is a lack of electrical means to control skyrmions in devices. In this work, we demonstrate a new method for creating a stable skyrmion bubble phase in the CoFeB-MgO material system at room temperature, by engineering the interfacial perpendicular magnetic anisotropy of the ferromagnetic layer. Importantly, we also demonstrate that artificially engineered symmetry breaking gives rise to a force acting on the skyrmions, in addition to the current-induced spin-orbit torque, which can be used to drive their motion. This room-temperature creation and manipulation of skyrmions offers new possibilities to engineer skyrmionic devices. The results bring skyrmionic memory and logic concepts closer to realization in industrially relevant and manufacturable thin film material systems. [ABSTRACT FROM AUTHOR]