Akyol, MustafaJiang, WanjunYu, GuoqiangFan, YabinGunes, MustafaEkicibil, AhmetAmiri, Pedram Khalili2025-01-062025-01-0620160003-69511077-311810.1063/1.49582952-s2.0-84978414598https://doi.org/10.1063/1.4958295https://hdl.handle.net/20.500.14669/3248We study the heavy metal layer thickness dependence of the current-induced spin-orbit torque (SOT) in perpendicularly magnetized Hf broken vertical bar CoFeB broken vertical bar MgO multilayer structures. The damping-like (DL) current-induced SOT is determined by vector anomalous Hall effect measurements. A non-monotonic behavior in the DL-SOT is found as a function of the thickness of the heavy-metal layer. The sign of the DL-SOT changes with increasing the thickness of the Hf layer in the trilayer structure. As a result, in the current-driven magnetization switching, the preferred direction of switching for a given current direction changes when the Hf thickness is increased above similar to 7 nm. Although there might be a couple of reasons for this unexpected behavior in DL-SOT, such as the roughness in the interfaces and/or impurity based electric potential in the heavy metal, one can deduce a roughness dependence sign reversal in DL-SOT in our trilayer structure. Published by AIP Publishing.eninfo:eu-repo/semantics/openAccessDrıvenArticle2Q1109WOS:000381155200037Q1