Low-Temperature Susceptibility in Dilute Systems of Magnetic Impurities in Noble Metals

Together with already published results on the Cu‐Mn system, we present new measurements at very low temperatures on Au‐Fe and Cu‐Fe alloys. The classical model of the molecular field distribution $\mathrm{p(H,\hspace{0.17em}T)}$ gives a good description of the specific heat and magnetic properties of Cu‐Mn alloys down to 200 ppm and Au‐Fe alloys down to 1000 ppm. The abrupt fall at very low concentrations of the initial susceptibility of Au‐Fe and Cu‐Fe alloys is a good evidence in favor of a spin‐compensated state as suggested by recent theories.