Sm-Co-based amorphous alloy films for zero-field operation of transverse thermoelectric generation

TL;DR

This paper explores Sm-Co-based amorphous alloy films that exhibit strong transverse thermoelectric effects, enabling zero-field heat flux sensing and flexible device applications through systematic high-throughput investigation.

Contribution

It introduces a new class of amorphous Sm-Co-based alloys with enhanced thermoelectric properties and zero-field operation, suitable for flexible and scalable thermal management devices.

Findings

High ANE and AEE in Sm-Co alloys identified

Amorphous structure enables flexible device fabrication

Large in-plane coercivity and remanent magnetization observed

Abstract

Transverse thermoelectric generation using magnetic materials is essential to develop active thermal engineering technologies, for which the improvements of not only the thermoelectric output but also applicability and versatility are required. In this study, using combinatorial material science and lock-in thermography technique, we have systematically investigated the transverse thermoelectric performance of Sm-Co-based alloy films. The high-throughput material investigation revealed the best Sm-Co-based alloys with the large anomalous Nernst effect (ANE) as well as the anomalous Ettingshausen effect (AEE). In addition to ANE/AEE, we discovered unique and superior material properties in these alloys: the amorphous structure, low thermal conductivity, and large in-plane coercivity and remanent magnetization. These properties make it advantageous over conventional materials to realize heat flux sensing applications based on ANE, as our Sm-Co-based films can generate thermoelectric output without an external magnetic field. Importantly, the amorphous nature enables the fabrication of these films on various substrates including flexible sheets, making the large-scale and low-cost manufacturing easier. Our demonstration will provide a pathway to develop flexible transverse thermoelectric devices for smart thermal management.