The generation and detection of pure spin currents in magnetic heterostructures – i.e., the directed flow of spin angular momentum – has developed into a fascinating research field and may find useful appplications. In ferromagnet/normal metal thin film bilayers, pure spin currents can be generated by means of a nonequilibrium situation induced, e.g., by spin pumping, or via the application of thermal gradients in the so-called spin Seebeck effect. An elegant scheme for detecting spin currents is based on the inverse spin Hall effect: because of spin-orbit coupling, a spin current also induces a charge current, which then can be detected using conventional electronics.
I will discuss our recent experimental investigations of spin current-related phenomena in ferromagnet/normal metal thin film devices. Our results show that spin current generation is possible from both electrically conductive as well as electrically insulating ferromagnets (so-called ferromagnetic insulators). In particular, I will address spin Seebeck and spin Nernst effect experiments in magnetic insulator/normal metal heterostructures. Moreover, I will discuss a novel magneto-resistance effect arising from the interplay between spin and charge currents.