Relationship between Faraday Rotation and Hall Effect in Amorphous Rare-Earth—Transition-Metal Alloys

Abstract

The Faraday rotation and spontaneous Hall effect were investigated in amorphous thin films with compositions ${(\mathrm{GdFe})}_{1\ensuremath{-}x}{M}_{x}$ ($M=\mathrm{B}\mathrm{i},\phantom{\rule{0ex}{0ex}}\mathrm{S}\mathrm{n},\phantom{\rule{0ex}{0ex}}\mathrm{A}\mathrm{u}$). Bismuth and tin are found to increase the Faraday rotation, ${\ensuremath{\phi}}_{\mathrm{F}}$, the Hall resistivity, ${\ensuremath{\rho}}_{\mathrm{H}}$, and the sample resistivity, $\ensuremath{\rho}$, while Au decreases ${\ensuremath{\phi}}_{\mathrm{F}}$, ${\ensuremath{\rho}}_{\mathrm{H}}$, and $\ensuremath{\rho}$ as compared to values observed for GdFe. Specifically, ${\ensuremath{\phi}}_{\mathrm{F}}$ is proportional to the Hall angle ($\frac{{\ensuremath{\rho}}_{\mathrm{H}}}{\ensuremath{\rho}}$). A model first proposed by Voigt is developed to account for this proportionality.