Longitudinal spin Seebeck effect contribution in transverse spin Seebeck effect experiments in Pt/YIG and Pt/NFO

摘要

We investigate the inverse spin Hall voltage of a 10nm thin Pt stripdeposited on the magnetic insulators Y3Fe5O12 (YIG) and NiFe2O4 (NFO) with atemperature gradient in the film plane. We observe characteristics typical ofthe spin Seebeck effect, although we do not observe a change of sign of thevoltage at the Pt strip when it is moved from hot to cold side, which isbelieved to be the most striking feature of the transverse spin Seebeck effect.Therefore, we relate the observed voltages to the longitudinal spin Seebeckeffect generated by a parasitic out-of-plane temperature gradient, which can besimulated by contact tips of different material and heat conductivities and bytip heating. This work gives new insights into the interpretation of transversespin Seebeck effect experiments, which are still under discussion.