Observation of anomalous Ettingshausen effect and large transverse thermoelectric conductivity in permanent magnets

TL;DR

This paper demonstrates that SmCo$_5$-type permanent magnets exhibit a large anomalous Ettingshausen effect at room temperature, with a charge-to-heat current conversion efficiency much higher than typical ferromagnetic metals, opening new avenues in thermoelectric energy conversion.

Contribution

It reveals that SmCo$_5$-type magnets have an intrinsic transverse thermoelectric conductivity responsible for a large AEE, a feature not observed in other permanent magnets, suggesting potential for thermoelectric applications.

Findings

SmCo$_5$ exhibits a large AEE at room temperature.

The charge-to-heat current conversion coefficient exceeds that of typical ferromagnetic metals.

The large AEE is due to intrinsic transverse thermoelectric conductivity in SmCo$_5$.

Abstract

This study focuses on the potential of permanent magnets as thermoelectric converters. It is found that a SmCo$_5$-type magnet exhibits the large anomalous Ettingshausen effect (AEE) at room temperature and that its charge-to-heat current conversion coefficient is more than one order of magnitude greater than that of typical ferromagnetic metals. The large AEE is an exclusive feature of the SmCo$_5$-type magnet among various permanent magnets in practical use, which is independent of the conventional performance of magnets based on static magnetic properties. The experimental results show that the large AEE originates from the intrinsic transverse thermoelectric conductivity of SmCo$_5$. This finding makes a connection between permanent magnets and thermal energy engineering, providing the basis for creating "thermoelectric permanent magnets."