The electron mean free path and superconductivity in Cu/Pb modulated films

Abstract

The electron mean free path L in the normal state and the critical temperature Tc as well as the parallel critical magnetic field Hc// and perpendicular critical magnetic field Hc perpendicular to were measured in equilayered Cu/Pb modulated films. The modulation period lambda varied from 59 to 1620 AA. Our films were fabricated by thermal evaporation. The electron mean free path in the component layers estimated following the Gurvitch model is markedly shortened as a result of electron scattering both at interfaces and at grain boundaries. The dependence of Tc on component layer thickness was compared with existing theoretical models. Our measurements of the parallel critical fields as a function of temperature revealed the crossover of superconductivity from three-dimensional to two-dimensional behaviour.