Prediction of giant anomalous Nernst effect in Sm(Co,Ni)5

Abstract

Sm-Co bulk alloys are well-known permanent magnets having large remanent magnetizations and coercive forces and are widely used in many industrial products. Recently, a large transverse thermoelectric conversion was observed for SmCo5 over a wide temperature range in the absence of magnetic fields. The large thermoelectric conductivity tensors (αxy) was also confirmed by the first-principles density functional theory (DFT) calculations. In this study, we predicted further enhancement of the αxy by including Ni in Co site of SmCo5. We showed that the αxy of Sm(Co1−xNix)5 increases with increasing the Ni ratio and takes the maximum value αxy = 11.3 A K−1 m−1 around x = 0.08 at 300 K, which is about 77% enhancement of αxy = 6.4 A K−1 m−1 in SmCo5. We clarified that the band proximity points near the nodal line of Sm(Co0.92Ni0.08)5 are the main contributing factor to the large Berry curvature, providing the steep slope of the energy dependence in the anomalous Hall conductivity around the Fermi energy.