Magnetic Interactions in DiluteAgMnAlloys

Measurements are presented of the magnetization $M$ up to 50 kG between 1.8 and 4.2 K and the susceptibility $\chi$ from 1.8 to 100 K of three dilute $\mathrm{Ag}\mathrm{Mn}$ alloys of nominal concentrations 630, 1000, and 1370 ppm Mn. Both $M$ and $\chi$ follow scaling laws well. The strength $V_0$ of the Ruderman-Kittel-Kasuya-Yosida interaction between two Mn impurities has been determined from expressions for the high-field behavior of $M$ in the presence of such interaction, yielded by a virial expansion of the free energy. The value for $V_0$ is (2.4±0.4) × ${10}^{-25\mathrm{}}$ eV ${\mathrm{cm}}^3$. The effective $\mathrm{}\left|J\right|\mathrm{}$ value estimated from $V_0$ is 0.7±0.1 eV.