Thickness dependence of spin Peltier effect visualized by thermal imaging technique

Abstract

Magnon propagation length in a ferrimagnetic insulator yttrium iron garnet (YIG) has been investigated by measuring and analyzing the YIG-thickness tYIG dependence of the spin Peltier effect (SPE) in a Pt/YIG junction system. By means of the lock-in thermography technique, we measured the spatial distribution of the SPE-induced temperature modulation in the Pt/YIG system with the tYIG gradation, allowing us to obtain the accurate tYIG dependence of SPE with high tYIG resolution. Based on the tYIG dependence of SPE, we verified the applicability of several phenomenological models to estimate the magnon diffusion length in YIG.