Spin-Fluctuation Effects in the Resistivity of DilutePtFeAlloys

Abstract

Measurements are presented of the electrical resistivity of a series of dilute $\mathrm{Pt}\mathrm{Fe}$ alloys containing between 0.03- and 1.0-at.% Fe, over the temperature range 0.4 to 50 °K. The alloys containing less than 0.1-at.% Fe have a resistivity which increases approximately logarithmically with increasing temperature, and which scales linearly with concentration. Results are consistent with a spin-fluctuation model for the $\mathrm{Pt}\mathrm{Fe}$ system with a characteristic spin-fluctuation temperature of (0.4 ± 0.2) °K, a value which is supported by recent Mössbauereffect and thermoelectric-power measurements. The effect of interactions on the resistivities of the more concentrated alloys is discussed, and a simple phase-shift calculation is presented which relates the temperature dependence of the non-spin-flip scattering to the temperature dependence of the impurity magnetic moment, and which accounts qualitatively for the sign of the temperature coefficient in the resistivities of the $\mathrm{Pt}\mathrm{Fe}$ and other Pt- and Pd-based alloys.