Evidence for the role of the magnon energy relaxation length in the spin Seebeck effect

Arati Prakash, Benedetta Flebus, Jack Brangham, Fengyuan Yang, Yaroslav Tserkovnyak, Joseph P. Heremans
2018 Physical review B  
Temperature-dependent spin-Seebeck effect data on Pt|YIG (Y$_3$Fe$_5$O$_{12}$)|GGG (Gd$_3$Ga$_5$O$_{12}$) are reported for YIG films of various thicknesses. The effect is reported as a spin-Seebeck resistivity (SSR), the inverse spin-Hall field divided by the heat flux, to circumvent uncertainties about temperature gradients inside the films. The SSR is a non-monotonic function of YIG thickness. A diffusive model for magnon transport demonstrates how these data give evidence for the existence
more » ... for the existence of two distinct length scales in thermal spin transport, a spin diffusion length and a magnon energy relaxation length.
doi:10.1103/physrevb.97.020408 fatcat:pq2qb26fxncydcd7burgfk4t6a