Large Spin Pumping and Inverse Spin Hall Effect in Ta/Py Bilayer Structures

Abstract

Spin mixing conductance at the ferromagnet (FM)/heavy metal (HM) interface is a key parameter to estimate the spin current injection into heavy metal. The electrical detection of such injected spin current in heavy metal is possible via inverse spin Hall effect (ISHE). Herein, a large spin mixing conductance in the range of (4.956.52) 1018 m−2 in Ta/permalloy(Py) bilayer structures is reported. In‐plane angular‐dependent ISHE voltage measurements in Ta/Py samples reveal the dominance of spin pumping voltage component over the other spin rectification contributions. Voltage contribution due to spin pumping and anisotropic magnetoresistance (AMR) increases with the Py thickness due to the enhancement in spin pumping and increase in spin‐dependent scattering, respectively. Anomalous Hall effect (AHE) contribution in Py is found to be relatively small.