Anomalous Nernst effect in epitaxial Fe and FexNi1-x alloy thin films

Abstract

The anomalous Nernst effect (ANE) is investigated experimentally in epitaxial fcc FexNi1-x (0≤x≤0.55) alloy thin films and bcc Fe thin film grown on MgO (001) substrates. The ANE measurements were performed at room temperature for various temperature gradients perpendicular to the film plane. The anomalous Nernst efficiency was indirectly characterized by the factor νN. It is found that both the ANE voltage VANE and the factor νN increase with raising the composition of Fe from 0 to 0.55, due to the presence of more abundant band structures. Moreover, the VANE and νN factor in bcc Fe thin film change sign and decrease sharply in magnitude compared to that of fcc FexNi1-x thin films, indicating that the tuning effects of the band filling near Fermi surface on ANE. The present results will facilitate the theoretical studies of ANE and provide means of manipulating ANE for technological application.