Resonant Kondo Scattering of Weakly Localized Electrons

Measurements of the magnetic scattering time in very thin Cu films (thickness $t\simeq 5$ nm), homogeneously doped with magnetic Cr atoms (concentration ≲100 ppm), are reported. The weak electron localization causes an anomalous magnetoresistance which is very sensitive to the spin-flip scattering of the conduction electrons. The maximum in the temperature dependence of the spin-flip scattering rate is in excellent agreement with the Suhl-Nagaoka approximation for the resonant Kondo scattering in the vicinity of the Kondo temperature $T_{\mathrm{K}}\simeq 2$ K.