Crossover Behavior of the Anomalous Hall Effect and Anomalous Nernst Effect in Itinerant Ferromagnets

The anomalous Hall effect (AHE) and anomalous Nernst effect (ANE) are experimentally investigated in a variety of ferromagnetic metals including pure transition metals, oxides, and chalcogenides, whose resistivities range over 5 orders of magnitude. For these ferromagnets, the transverse conductivity sigmaxy versus the longitudinal conductivity sigmaxx shows a crossover behavior with three distinct regimes in accordance qualitatively with a recent unified theory of the intrinsic and extrinsic AHE. We also found that the transverse Peltier coefficient alphaxy for the ANE obeys the Mott rule. These results offer a coherent and semiquantitative understanding of the AHE and ANE to an issue of controversy for many decades.