Creation of flexible spin-caloritronic material with giant transverse thermoelectric conversion by nanostructure engineering

TL;DR

This paper demonstrates how nanostructure engineering transforms simple magnetic alloys into highly efficient spin-caloritronic materials with giant transverse thermoelectric effects, especially enhancing the anomalous Nernst effect in Fe-based amorphous alloys.

Contribution

It introduces nanostructure engineering as a method to significantly improve the anomalous Nernst effect in amorphous alloys without changing their composition.

Findings

Enhanced anomalous Nernst coefficients in Fe-based amorphous materials.

Cu nano-clustering facilitates efficient transverse thermoelectric conversion.

Achieved values comparable to single crystals, surpassing previous amorphous alloys.

Abstract

Functional materials such as magnetic, thermoelectric, and battery materials have been revolutionized through nanostructure engineering. However, spin caloritronics, an advancing field based on spintronics and thermoelectrics with fundamental physics studies, has focused only on uniform materials without complex microstructures. Here, we show how nanostructure engineering enables transforming simple magnetic alloys into spin-caloritronic materials displaying significantly large transverse thermoelectric conversion properties. The anomalous Nernst effect (ANE), a promising transverse thermoelectric phenomenon for energy harvesting and heat sensing, has been challenging to utilize due to the scarcity of materials with large anomalous Nernst coefficients. We demonstrate a remarkable improvement in the anomalous Nernst coefficients in flexible Fe-based amorphous materials through nanostructural engineering, without altering their composition. This surpasses all reported amorphous alloys and is comparable to single crystals showing large ANE. The enhancement is attributed to Cu nano-clustering, facilitating efficient transverse thermoelectric conversion. This discovery advances the materials science of spin caloritronics, opening new avenues for designing high-performance transverse thermoelectric devices for practical applications.