Zero-Field Hybridization of Anomalous Nernst and Off-diagonal Seebeck Effects in Artificially Tilted Multilayers

Abstract

Hybrid transverse thermoelectric conversion driven by simultaneous action of multiple phenomena offers a promising route for efficient energy conversion. This study demonstrates magnetic-field-free hybrid transverse thermoelectric conversion based on the anomalous Nernst and off-diagonal Seebeck effects in artificially tilted multilayers comprising SmCo₅/Bi_0.2Sb_1.8Te₃ junctions, where the remanent magnetization of SmCo₅ induces the anomalous Nernst effect in the absence of an external magnetic field. The thermoelectric figure of merit is observed to be 0.299 ± 0.005 at room temperature owing to the additive contribution of the anomalous Nernst effect, indicating that the excellent figure of merit due to the off-diagonal Seebeck effect can further be enhanced by hybridizing the anomalous Nernst effect. These results establish a new approach for high-performance transverse thermoelectric materials, enabling energy harvesting and cooling applications that leverage magnetically controlled thermoelectric effects without requiring an external magnetic field.