Anomalous Hall, Nernst, and spin Hall effects in CoMnCrGa: a first-principles study

Abstract The quaternary Heusler compound CoMnCrGa emerges as a highly promising candidate for spintronic and transverse thermoelectric applications, as revealed by comprehensive first-principles calculations. CoMnCrGa stabilizes in the Type-I cubic structure ( F 4 ¯ 3 m ) with a ferromagnetic ground state. The total magnetic moment of ∼ 1.09 μ B obeys the Slater–Pauling rule, indicating a nearly half-metallic character corroborated by high electronic spin polarization. Prominent Berry curvature (BC) hotspots near the Fermi level generate substantial anomalous transport responses, including an anomalous Hall conductivity of ∼ − 325.7 S cm −1 at −158.8 meV and an anomalous Nernst conductivity (ANC) of ∼ − 0.828 A m −1 K −1 at −55.6 meV at room temperature. The material also exhibits a remarkably large spin Hall conductivity of ∼ 128 ( ℏ / e ) (S cm −1 ) at 198.8 meV, driven by strong spin–orbit coupling and localized spin BC. Notably, the ANC demonstrates exceptional tunability and thermal stability, reaching ∼ 0.75 A m −1 K −1 at room temperature under optimal electron doping ( µ = 0.3 eV). The coexistence of robust ferromagnetism, high spin polarization, large spin Hall conductivity, and tunable anomalous Nernst effect positions CoMnCrGa as a premier material for next-generation spintronic and spin-caloritronic devices.