Giant transverse thermoelectric conductivity in L12-type Fe3Ga: A first-principles study

Abstract

Anomalous Nernst effect (ANE), a transverse thermoelectric effect, has attracted attention as a promising route for thermoelectric applications. While intrinsic components of ANE can be understood through Berry phase concepts in the electronic structure; however, systematic investigations of its enhancement mechanisms remain limited. Here, we demonstrate the giant transverse thermoelectric conductivity ${\alpha }_{xy}\sim 3.0$ AK⁻¹m⁻¹ in ferromagnetic L1₂-type Fe₃Ga at room temperature, and it reaches ∼4.0 AK⁻¹m⁻¹ at high-temperature region (500 K). Moreover, electron carrier doping can also enhance its response to reach ∼4.5 AK⁻¹m⁻¹. Our detailed analysis reveals that this enhancement originates from nodal lines in the band structure, which generate large Berry curvature. The results established a clear physics between topological electronic structures and enhanced thermoelectric responses and provide valuable insights for designing high-performance ANE-based magnetic thermoelectric materials.