Fluctuations in the Resistive Transition in Aluminum Films

The excess conductivity due to the thermodynamic fluctuations in aluminum films is experimentally investigated. The excess conductivity is described by the sum of the Aslamazov-Larkin and the Maki-Thompson terms. An empirical formula is found on the relation between the pair-breaking parameter delta(0) in the absence of the magnetic field and the normal-state film resistance R-N(sq) delta(0) = 6 x 10(-4) R-N(sq). This formula might be explained in terms of the localized moments and the proximity effect in films. The result of the magnetic field dependence of the pair-breaking parameter revealed that delta(0) cannot be described by an effective magnetic field. The temperature dependence of the excess conductivity at higher temperatures systematically deviates from the theoretical values due to the breakdown of the mean-field theory.