  This letter provides evidence for intrinsic longitudinal spin Seebeck effects
(LSSEs) that are free from the anomalous Nernst effect (ANE) caused by an
extrinsic proximity effect. We report the observation of LSSEs in Au/Y3Fe5O12
(YIG) and Pt/Cu/YIG systems, showing that LSSE appears even when the mechanism
of the proximity ANE is clearly removed. In the conventional Pt/YIG structure,
furthermore, we separate the LSSE from the ANE by comparing the voltages in
different magnetization and temperature-gradient configurations; the ANE
contamination was found to be negligibly small even in the Pt/YIG structure.

Materials Science;Mesoscale and Nanoscale Physics