Spin-Seebeck effects in Ni81Fe19/Pt films

The spin-Seebeck effect (SSE) converts a heat current into a spin current, a flow of spin angular momentum, and spin voltage, the driving force for nonequilibrium spin currents, in a ferromagnetic metal. In this study, the SSE in a ferromagnetic Ni81Fe19 film has been investigated by means of the inverse spin-Hall effect (ISHE) in a Pt film at room temperature. The experimental results measured in the Ni81Fe19/Pt system show that the sign of the thermally induced spin voltage is reversed between the higher- and lower-temperature ends of the Ni81Fe19 film. The ISHE in the Pt film allows us to detect the SSE signal with high sensitivity and to separate it from extrinsic thermoelectric effects. (C) 2009 Elsevier Ltd. All rights reserved.