Characterization of the Anisotropic Anomalous Nernst Effect in Antiferromagnetic YbMnBi₂ and YbMnSb₂

This work characterizes thermoelectric transport properties of antiferromagnetic topological semimetals YbMnSb₂ and YbMnBi₂, which exhibit large anomalous effects with simultaneously low magnetization and high mobility. Polycrystalline samples of YbMnBi₂ are synthesized for the first time, and the anomalous Nernst and magneto-Seebeck effects are characterized as a function of temperature and magnetic field. Previous work in single-crystalline YbMnBi₂ [1] indicated anisotropy in the Nernst effect, and emphasis is placed here on its removal in polycrystalline samples. Similarly, the anomalous Nernst and magneto-Seebeck effects are characterized in single crystalline YbMnSb₂ as a function of temperature, magnetic field, and crystallographic orientation such that the relationship between the orientation of the net Berry curvature and fluxes/fields associated with thermomagnetic transport can be determined.

[1] Y. Pan et al. Nat. Mater 21, 203-209 (2022).