Kondo effect in Cu(Fe) films

Recent experiments have shown that the Kondo effect is suppressed in thin films, a result which has so far eluded theoretical explanation. The previous experiments have been limited to the regime T≳${\mathit{T}}_{\mathit{K}}$, where ${\mathit{T}}_{\mathit{K}}$ is the Kondo temperature. In this paper we present new results for T≲${\mathit{T}}_{\mathit{K}}$ which demonstrate that even when the Kondo contribution to the resistivity, Δ${\mathrm{\rho }}_{\mathit{K}}$ is greatly suppressed, the Kondo temperature itself is not affected. We also present the results of experiments involving bilayer samples, i.e., Kondo films covered by nonmagnetic layers, which demonstrate the existence of a Kondo ‘‘proximity effect.’’