Plastic-deformation-induced low-temperature anomalies of the resistivity of polycrystalline copper and aluminum

The temperature dependence of the electrical resistivity rho of pure polycrystalline aluminum and copper after plastic deformation is investigated in the temperature interval 4.2-300 K. Using heat treatment as a tool for changing the crystallite size d and structural perfection of the sample, it is determined how rho depends on the ratio of d to the electron mean free path l(e) and on the degree of deformation of the Cu and Al. At temperatures below 10 K the rho (T) curves of the deformed samples of polycrystalline copper and aluminum exhibit minima and maxima. At higher temperatures a more complicated dependence of rho (d/l(e)) is observed. It is found that in the region of the anomalous skin effect the experimentally determined and theoretically calculated values of the surface resistance R-s agree only in the case when the electron mean free path is smaller than the size of the crystallites. (C) 2001 American Institute of Physics.