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

We have measured the initial susceptibility $\chi$ and magnetization $M$ up to $H=50\mathrm{}$ kG of a series of AuMn alloys ($n=50-2000\mathrm{}-\mathrm{p}\mathrm{p}\mathrm{m}$ Mn) from 1.2 to about 100 K. Our results for $\chi$ and $M$ obey quite well the scaling laws predicted for magnetic impurities which interact via the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, viz., $\chi \mathrm{}(n,T)=F_1\left(\frac{T}{n}\right)$ and $\frac{M(n,T,H)\mathrm{}}{n}=F_2(\frac{T}{n},\frac{H}{n})$. From the observed decrease of the magnetization per impurity atom as the Mn concentration increases, $V_0=(2.4\mathrm{}\pm 0.3)\times {10}^{-37\mathrm{}}$ erg ${\mathrm{cm}}^3$ is determined for the strength of the RKKY interaction, $V\left(r\right)=\frac{\left(V_{0}cos2k_{F}r\right)}{r^3}$. The observed approach to saturation of $M$ is also consistent with this value for $V_0$. For the spin per Mn atom we find $S=2.25\mathrm{}\pm 0.1$, assuming $g=2\mathrm{}$.