Thermal spin pumping and magnon-phonon-mediated spin-Seebeck effect

Uchida, Kenichi*; Ota, Takeru*; Adachi, Hiroto; Xiao, J.*; Nonaka, Tatsumi*; Kajiwara, Yosuke*; Bauer, G. E. W.*; Maekawa, Sadamichi; Saito, Eiji

The spin-Seebeck effect (SSE) in ferromagnetic metals and insulators has been investigated systematically by means of the inverse spin-Hall effect (ISHE) in paramagnetic metals. The SSE generates a spin voltage as a result of a temperature gradient in a ferromagnet, which injects a spin current into an attached paramagnetic metal. In the paramagnet, this spin current is converted into an electric field due to the ISHE, enabling the electric detection of the SSE. The observation of the SSE is performed in longitudinal and transverse configurations consisting of a ferromagnet/paramagnet hybrid structure, where thermally generated spin currents flowing parallel and perpendicular to a temperature gradient are detected, respectively.