Liu, Yan TingYan TingLiuHuang, Yu HaoYu HaoHuangHuang, Chao ChungChao ChungHuangLi, Yung ChengYung ChengLiCheng, Chih LinChih LinChengCHI-FENG PAI2023-06-162023-06-162022-09-012331-7019https://scholars.lib.ntu.edu.tw/handle/123456789/632784The current-induced type-x spin-orbit-torque (SOT) switching configuration describes the orthogonal relationship between the magnetic easy axis (EA) of a ferromagnetic (FM) layer and the injected spin polarization, σ, from a heavy-metal (HM) layer, which has the potential to eclipse the conventional type-y scenario (EA parallel to σ) at the sub-nanosecond pulse regime. Here, we show that, in HM/FM bilayer heterostructures, current-driven differential planar Hall signals can serve as efficient means to probe type-x SOT switching in a simple measurement fashion. Through this approach, we demonstrate field-free type-x SOT switching in all devices with a canted EA, which are engineered via field-annealing processes. By analyzing the switching-phase diagrams, we further verify that such field-free switching stems from a z-direction effective field contributed to by both the dampinglike torque and the canted EA. Our work indicates that the canted EA, as engineered by a field-annealing process, can give rise to a robust field-free SOT switching and further reduce the critical switching current density.PERPENDICULAR MAGNETIZATION; DRIVENjournal article10.1103/PhysRevApplied.18.0340192-s2.0-85138452729WOS:000863104400004https://api.elsevier.com/content/abstract/scopus_id/85138452729