Magnetization of DiluteAuFeAlloys

Abstract

Magnetization measurements are presented of $\mathrm{Au}\mathrm{Fe}$ alloys containing 0.002, 0.005, and 0.01 at.% Fe over the temperature range 1.5-120 °K and in magnetic fields up to 60 kG. From low-field susceptibility measurements we find a spin $S$ of 1.29 ± 0.03 and a Kondo temperature $T_K$ of (0.10 ± 0.01) °K for the $\mathrm{Au}\mathrm{Fe}$ system. It is shown that recent perturbation calculations of the magnetization for $T\gg T_K$ can be expressed as a Brillouin function with spin $S$ and a modified $g$ factor dependent on temperature, applied field, and $T_K$. Magnetization curves computed from the values of $T_K$ and $S$ determined from low-field susceptibility measurements are found to be in good agreement with the measured magnetization over a wide range of fields and temperatures.