Quantitative Temperature Dependence of Longitudinal Spin Seebeck Effect at High Temperatures

TL;DR

This study investigates how the longitudinal spin Seebeck effect in Pt/YIG/Pt systems varies with temperature, revealing a rapid decrease and disappearance above the Curie temperature, with a critical exponent indicating a complex mechanism beyond static magnetization.

Contribution

It provides the first detailed temperature dependence of LSSE in Pt/YIG/Pt systems up to above the Curie temperature, highlighting a nontrivial mechanism behind the effect.

Findings

LSSE voltage decreases rapidly with temperature

LSSE disappears above the Curie temperature of YIG

Critical exponent of LSSE voltage is 3, exceeding that of magnetization

Abstract

This article reports temperature-dependent measurements of longitudinal spin Seebeck effects (LSSEs) in Pt/Y$_3$Fe$_5$O$_{12}$ (YIG)/Pt systems in a high temperature range from room temperature to above the Curie temperature of YIG. The experimental results show that the magnitude of the LSSE voltage in the Pt/YIG/Pt systems rapidly decreases with increasing the temperature and disappears above the Curie temperature. The critical exponent of the LSSE voltage in the Pt/YIG/Pt systems at the Curie temperature was estimated to be 3, which is much greater than that for the magnetization curve of YIG. This difference highlights the fact that the mechanism of the LSSE cannot be explained in terms of simple static magnetic properties in YIG.