Electrical Resistivity of DilutePdNiAlloys; Local Exchange Enhancement Effects

The contribution to the electrical resistivity of transition-metal alloys from scattering of $s$ electrons from spin-density fluctuations in the $d$ band is discussed. The resistivity is expressed in terms of the dynamic magnetic susceptibility of the alloy. A time-dependent molecular-field approximation is employed to obtain an approximate expression for the dynamic susceptibility, valid in the dilute limit, for host materials in which exchange-enhancement effects are important. If the isolated impurity center is almost magnetic, a large concentration-dependent contribution to the resistivity proportional to $T^2$ is found. The theory is shown to account for the recent measurements by Schindler and Rice of the temperature dependence of the electrical resistivity of dilute $\mathrm{Pd}\mathrm{Ni}$ alloys.