Localisation and superconducting fluctuations in Pb-Cu thin films

Thin discontinuous films of lead, of thickness 10-100 A, were evaporated onto 120 A copper films in order to examine the superconductivity and localisation effects. The temperature and magnetic field dependences of the resistance were studied. It was found that the addition of lead on the copper film increased the spin-orbit interaction, and that the inelastic scattering time was shortened at 10 K due to the additional contribution of phonons from the lead. Superconducting fluctuations in some films were observed far above Tsub(c) (T >approx. 3 Tsub(c)). The results are described well by localisation theories and by Larkin's theory of superconducting fluctuations. (author)