We investigate spin-charge conversion in exchange-biased NiFe/IrMn heterostructures, where spin-polarized electrons are generated in the NiFe layer by ferromagnetic resonance and transferred by diffusion into adjacent layers. The conversion of spin current into charge current via the inverse spin Hall effect is governed by the competition between skew scattering and side-jump scattering, which produces a minimum in the temperature dependence of the conductivity. By introducing different nonmagnetic spacers, we identified the localization of the dominant scattering processes. In NiFe, NiFe/IrMn, and NiFe/Cu/IrMn structures, the conductivity minimum occurs at $T\approx 95$ K, reflecting scattering in the NiFe layer, with the amplitude gradually reduced by increasing Cu thickness. In contrast, insertion of a Ta spacer shifts the minimum to $T\approx 265$ K due to strong spin-orbit coupling and a short spin diffusion length that transfer the scattering into the Ta layer. These results demonstrate how the choice of spacer material enables control of spin scattering and spin-charge conversion, providing guidelines for the design of exchange-biased heterostructures for spintronic applications.

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• Electrical conductivity
• Exchange bias
• Spin Hall magnetoresistance
• Spin current
• Spin-orbit coupling
• Spin-orbit torque