High-temperature ferromagnetism and large anomalous Nernst effect above room temperature in (In,Fe)Sb ferromagnetic semiconductor

While the room-temperature anomalous Nernst effect (ANE) has been intensively studied in various ferromagnetic metals, it has never been studied in ferromagnetic semiconductors (FMSs) due to their low Curie temperature (TC). In this work, by optimizing the growth condition, we have grown an n-type (In,Fe)Sb FMS thin film with high TC ∼ 460 K at the Fe concentration of 30%, which is the highest TC reported so far in n-type FMSs. Using the high-TC (In,Fe)Sb thin film, we observe ANE with a large thermopower SxyANE = −3.2 μV/K at 332 K and −1.3 μV/K at 447 K. The large ANE in (In,Fe)Sb at room temperature is comparable to those observed in Mn3Sn and Co2MnGa topological materials.