Intrinsic and extrinsic anomalous transport properties of the Heusler ferromagnets <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>Fe</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:mi>CoAl</mml:mi></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>Fe</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:mi>NiAl</mml:mi></mml:math> from first principles

Recently, Heusler ferromagnets have been found to exhibit unconventional anomalous electric, thermal, and thermoelectric transport properties. In this study, we employed first-principles density functional theory calculations systematically investigate both intrinsic extrinsic contributions the Hall effect (AHE), Nernst (ANE), thermal (ATHE) in two ferromagnets: Fe$_2$CoAl Fe$_2$NiAl. Our analysis reveals that mechanism originating from disorder dominates AHE ATHE , primarily due steep band dispersions across Fermi energy corresponding high longitudinal electronic conductivity. Conversely, Berry phase mechanism, physically linked nearly flat bands around gapped by spin-orbit interaction crossings, governs With respect ANE, mechanisms are competing as well Furthermore, Fe$_2$NiAl tunable remarkably pronounced For instance, conductivities attain giant values of 8.29 A/Km 1.19 W/Km, respectively, at room temperature. To provide a useful comparison, also thoroughly investigated properties Co$_2$MnGa. findings suggest promising candidates for spintronics spin-caloritronics applications.