Magneto-thermal transport indicating enhanced Nernst response in FeCo/IrMn exchange coupled stacks

We present an analysis of magneto-thermal transport data in IrMn/FeCo bilayers based on the Mott relation and report an enhancement of the Nernst response in the vicinity of the blocking temperature. We measure all four transport coefficients of the longitudinal resistivity, anomalous Hall resistivity, Seebeck effect, and anomalous Nernst effect, and we show a deviation arising around the blocking temperature between the measured Nernst coefficient and the one calculated using the Mott rule. We attribute this discrepancy to spin fluctuations at the antiferromagnet/ferromagnet interface near the blocking temperature. The latter is estimated by magnetometry and magneto-transport measurements. (c) 2022 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http:// creativecommons.org/licenses/by/4.0/).

Automated summary

In this study, we analyze magneto-thermal transport data in IrMn/FeCo bilayers based on the Mott relation and observe an enhancement of the Nernst response near the blocking temperature. We measure all four transport coefficients and find a discrepancy between the measured Nernst coefficient and the one calculated using the Mott rule around the blocking temperature, which we attribute to spin fluctuations at the antiferromagnet/ferromagnet interface.