Large Anomalous Nernst Conductivity in Pt ₂ CoNi Permanent Magnet Films with High In‐Plane and Out‐Of‐Plane Coercivities

ABSTRACT The anomalous Nernst effect (ANE) garners considerable attention owing to its capacity to generate a transverse electric field, which facilitates the development of advanced thermoelectric devices with simplified structures, such as heat flux sensors. Nevertheless, despite the advantages of ANE‐based thermoelectric technologies, the need for external magnetic fields in most ANE materials hinders their practical applications. The advancement of permanent magnets showing excellent ANE performance is a crucial solution. In this study, we introduce Pt 2 CoNi‐based thermoelectric permanent magnet thin films that demonstrate substantial in‐plane and out‐of‐plane coercivities (exceeding 1 T) and exhibit impressive ANE performance with a thermopower exceeding 1.8 µV K −1 . A comprehensive evaluation of the electrical/thermoelectric transport reveals that these films possess a giant transverse thermoelectric conductivity of 4.1 Am −1 K −1 at room temperature, which is among the highest values for permanent magnet films. Furthermore, through systematic and high‐throughput investigations, we identify a broad range of compositions for Pt 2‐ q ‐ p Co 1+ q Ni 1+ p films with tunable coercivity and comparable ANE performance, and propose a conceptual design for a single‐material‐based thermopile utilizing these newly developed materials. This study offers a pathway for the development of efficient and sustainable ANE‐based thermoelectric technologies that do not require an external magnetic field.