Effect of band filling on anomalous Hall conductivity and magneto-crystalline anisotropy in NiFe epitaxial thin films

Abstract

The anomalous Hall effect (AHE) and magneto-crystalline anisotropy (MCA) are investigated in epitaxial NixFe1-x thin films grown on MgO (001) substrates. The scattering independent term b of anomalous Hall conductivity shows obvious correlation with cubic magneto-crystalline anisotropy K1. When nickel content x decreasing, both b and K1 vary continuously from negative to positive, changing sign at about x = 0.85. Ab initio calculations indicate NixFe1-x has more abundant band structures than pure Ni due to the tuning of valence electrons (band fillings), resulting in the increased b and K1. This remarkable correlation between b and K1 can be attributed to the effect of band filling near the Fermi surface.