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

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 (F4¯3m) with a ferromagnetic ground state. The total magnetic moment of∼1.09μBobeys 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-1at -158.8 meV and an anomalous Nernst conductivity (ANC) of∼-0.828 A m-1K-1at -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-1K-1at 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.