Inverse Spin Hall Effect in a Ferromagnetic Metal

The inverse spin Hall effect (ISHE) has been observed only in nonmagnetic metals, such as Pt and Au, with a strong spin-orbit coupling. We report the observation of ISHE in a ferromagnetic permalloy (Py) on ferromagnetic insulator yttrium iron garnet (YIG). Through controlling the spin current injection by altering the Py-YIG interface, we have isolated the spin current contribution and demonstrated the ISHE in a ferromagnetic metal, the reciprocal phenomenon of the anomalous Hall effect. A large spin Hall angle in Py, determined from Py thin films of different thicknesses, indicates many other ferromagnetic metals may be exploited as superior pure spin current detectors and for applications in spin current.