Concentration dependence of magnetic susceptibility for the system of dilute magnetic impurities

The concentration dependence of the magnetic susceptibility for the system of randomly distributed dilute magnetic impurities in a d-dimensional metal or on a metal surface is studied at zero-temperature under the mean-random-field approximation. It is shown that, if the amplitude of the RKKY-type interaction between the magnetic impurities behaves like $\text{1}\text{r}{}^{\mathrm{n}}$ at a large distance r, the susceptibility is proportional to $\text{c}{}^{\mathrm{<mtext>1?(</mtext><mtext>n</mtext><mtext>d</mtext><mtext>)</mtext>}}$, where c is the concentration of the magnetic impurities.