Influence of magnetic interactions on the magnetic properties of dilute AuMn alloys

We have measured the initial susceptibility χ and magnetization M up to $H=50$ kG of a series of AuMn alloys (n=50-2000-ppm Mn) from 1.2 to about 100 K. Our results for χ and M obey quite well the scaling laws predicted for magnetic impurities which interact via the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, viz., χ(n,T)=F₁(T/n) and M(n,T,H)/n=F₂(T/n,H/n). From the observed decrease of the magnetization per impurity atom as the Mn concentration increases, V₀=(2.4±0.3)×10^-37 erg cm³ is determined for the strength of the RKKY interaction, V(r)=(V₀cos2kFr)r³. The observed approach to saturation of M is also consistent with this value for V₀. For the spin per Mn atom we find S=2.25±0.1, assuming $g=2$.