Study of Angular-Dependent Magnetic Anisotropy and Spin Pumping-Induced Inverse Spin Hall Effect (ISHE) in Py and Py/Pt Bilayer: Realization of Quantum Metrology

Angular-dependent magneto-optical Kerr effect (MOKE) and coplanar waveguide ferromagnetic resonance (CPW-FMR) measurements were performed to unravel the nature of anisotropy present in Ni _80 Fe _20 (Py) thin film. The “in-plane” angular variation of coercive field ( H^IP_c ) and resonance field ( H^IP_r ) confirms the magnetic anisotropy is negligible, where the spins are confined to the plane of the Py film. The variation of resonance field in “out-of-plane” geometry, H^OP_r , strongly indicates the presence of “out-of-plane” uniaxial anisotropy in the Py thin film. Also, the inverse spin Hall effect (ISHE) technique is employed to measure spin pumping-induced DC voltage, V _ISHE , generated across the Py/Pt bilayer. The line shape analysis method has been utilized to distinguish ISHE and spin rectification contributions. The measured V _ISHE at low (4 GHz) and high (35 GHz) frequencies confirm the pure spin current injected through the Py-Pt interface due to spin pumping using CPW-FMR setup, which has a direct bearing on the realization of quantum metrology through the spin current quantity.