Magnetic impurity scattering and DMR in highly dilute CuFe systems

Precise measurements of the electrical resistivity as a function of temperature on 16 samples with Fe concentrations varying between 0.2 and 12ppm have revealed a linear temperature dependence of the magnetic impurity scattering for Fe concentrations ⩽ 3 ppm. Deviations from Matthiessen's rule appear to become negligibly small below 5°K for all samples despite a variation of 2 orders of magnitude in the residual resistivities of the samples considered. Above 5°K the deviations from Matthiessen's rule are found to undergo a remarkably rapid increase with temperature yet their magnitudes appear to be unrelated to the residual resistivities or the Fe concentrations of the samples.