Magnon, phonon and electron temperature profiles and the spin Seebeck effect in magnetic insulator/normal metal hybrid structures

TL;DR

This paper models temperature profiles of magnons, phonons, and electrons in yttrium iron garnet/platinum bilayers, revealing how interfacial thermal conductance influences the spin Seebeck effect and aligning well with experimental data.

Contribution

It introduces a diffusive model accounting for interfacial thermal resistances to analyze temperature profiles and spin Seebeck effect in magnetic insulator/metal hybrids.

Findings

Interfacial magnetic heat conductance significantly affects magnon temperature.

The model's spin Seebeck effect estimates agree with experimental measurements.

Temperature profiles differ between longitudinal and transverse spin Seebeck effects.

Abstract

We calculate the phonon, electron and magnon temperature profiles in yttrium iron garnet/platinum bilayers by diffusive theory with appropriate boundary conditions, in particular taking into account interfacial thermal resistances. Our calculations show that in thin film hybrids, the interface magnetic heat conductance qualitatively affects the magnon temperature. Based on published material parameters we assess the degree of non-equilibrium at the yttrium iron garnet/platinum interface. The magnitude of the spin Seebeck effect derived from this approach compares well with experimental results for the longitudinal spin Seebeck effect. Additionally we address the temperature profiles in the transverse spin Seebeck effect.