ErMn6Sn6: A Promising Kagome Antiferromagnetic Candidate for Room-Temperature Nernst Effect-based thermoelectrics

The Nernst effect, the generation of a traverse electric voltage in the presence of longitudinal thermal gradient, has garnered significant attention in the realm of magnetic topological materials due to its superior potential for thermoelectric applications. In this work, we investigate electronic and thermoelectric transport properties of a Kagome magnet ErMn6Sn6, a compound showing an incommensurate antiferromagnetic phase followed by a ferrimagnetic phase transition upon cooling. We show that in the antiferromagnetic phase ErMn6Sn6 exhibits both topological Nernst effect and anomalous Nernst effect, analogous to the electric Hall effects, with the Nernst coefficient reaching 1.71 µV K⁻¹ at 300 K and 3 T. This value surpasses that of most of previously reported state-of-the-art canted antiferromagnetic materials and is comparable to recently reported other members of RMn6Sn6 (R = rare-earth, Y, Lu, Sc) compounds, which makes ErMn6Sn6 a promising candidate for advancing the development of Nernst effect-based thermoelectric devices.