Spin reorientation induced large spin memory loss at Py/Pd interface

Achieving spin current switching functionality is crucial for the development next-generation low power information storage. In this study, the spin reorientation and temperature dependence of spin Hall angle ?(SH) in the Permalloy (Py)/Pd bilayer were investigated by using ferromagnetic resonance, spin pumping, inverse spin Hall effect, and quantum interference transport. The uniaxial ferromagnetic perpendicular magnetic anisotropy (PMA) induced by spin reorientation persists at the Py/Pd interface below 30 K. This PMA further enhances the interfacial spin scattering, leading to a reduction of injected spin current, as indicated by the underestimated ?(SH) values. These experimental results demonstrate that the interfacial spin reorientation at the ferromagnet/heavy metal interface, commonly employed in spintronic devices, causes a significant spin memory loss effect. Our findings provide valuable insights into the influence of interlayer spin configuration on spin transport, which can be utilized in the rational design of spintronic devices based on pure spin current.