Optimizing spin pumping and spin mixing conductance via Cu spacer layer in Mn₂Au/Py system

Switching magnetization with spin current via spin orbital torque is a novel approach towards energyefficient spintronics. In this regard, high spin-orbit coupling materials such as heavy metals are required to create the spin current via spin Hall effect. In recent times, a lot of attention has been paid to replace heavy metals by antiferromagnets to be considered as a spin sink. The bimetallic antiferromagnet, Mn2Au has attracted interest due to its high Neel temperature (TN > 1000K) and high spin Hall angle. Here, we present results from experiments on spin pumping and the inverse spin Hall effect (ISHE) employing ferromagnetic resonance inMn(2)Au/Py andMn(2)Au/Cu/Py systems. The values of Gilbert damping constant decrease while inverse spin Hall voltage increases with the insertion of Cu spacer layer. This unusual behaviour indicates that the interface plays an important role for tuning the spintronic parameters. Themaximumeffective spinmixing conductance (g(eff)(up down arrow)) has been evaluated to be 36.20x10(18) m(-2)