Resistivity anomalies arising from spin correlations in magnetic metals

Some magnetic materials exhibit a pronounced peak or upturn in resistivity upon cooling through the ordering transition, while others do not. To explain and quantify this phenomenon, we develop a simple model in which the carrier lifetime is calculated from the scattering of conduction electrons by local magnetic moments. Within this framework, we derive a general formula for the electron scattering rate, applicable to arbitrary energy dispersions and magnetic structure factors. Using ferromagnets as an example, we show that a resistivity anomaly occurs at T c , arising from the rapid increase in the magnetic correlation length ξ . We find that this behavior is robust across dimensionality d and persists in anisotropic systems. The maximum resistivity is reached when 1 / ξ is comparable to the Fermi momentum k F , and the peak height scales inversely with k F d + 2 . As a result, the effect is most pronounced for smaller Fermi surfaces, where the anomaly can dominate over other resistivity contributions such as electron-phonon or electron-impurity scattering.