In this study, the spin-orbit torque (SOT) in light metal oxide systems is investigated using

an experimental approach based on harmonic Hall voltage techniques in out-of-plane

(OOP) angular geometry for samples with in-plane magnetic anisotropy. In parallel, an

analytical derivation of this alternative OOP harmonic Hall detection geometry has been

developed, followed by experimental validation to extract SOT effective fields. In addition

to accurately quantifying SOT, this method allows complete characterization of thermoelectric

effects, opening promising avenues for accurate SOT characterization in related

systems. In particular, this study corroborates the critical role of naturally oxidized copper

interfaced with metallic Cu in the generation of orbital current in Co(2)|Pt(4)|CuOx(3),

demonstrating a two-fold increase in damping-like torques compared to a reference sample

with an oxidized Al capping layer. These findings offer promising directions for future

research on the application aspect of non-equilibrium orbital angular momentum.

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