CHARACTERIZATION OF POINT-CONTACTS SHOWING SIZE-EFFECT IN ELECTRON-SCATTERING BY MAGNETIC-IMPURITIES

It is shown that in mechanically controllable break-junctions made fro m CuMn dilute alloys the intensity of Kondo-effect structure in the dV /dI(V) characteristics follows an anomalous dependence on the concentr ation of magnetic impurities although the regime of current how can be characterized as ballistic or close to it. Along with the earlier obs erved anomalous dependence of the Kondo-peak intensity on the contact size, this suggests that the theory based on an assumption that the el ectron-impurity scattering may occur essentially at any point in the m etal is not applicable.