Superconducting fluctuation, localization and electron-electron interaction corrections to the magnetoconductivity in three-dimensional aluminum films

The magnetoconductivity (MC) of three-dimensional (3D) aluminum films with various dirtiness has been measured in wide ranges of temperature and magne tic field. (I) Near the superconducting transition temperature T-c, the MC takes the minimum at a temperature-independent field H-m0. (2) Above H-m0, MC shows H-1/2 dependence. From the detailed analysis of the H dependence o f MC, it has been found that the magnitude of the coefficient of H-1/2 can be explained qualitatively by only the sum of contribution from the weak lo calization and electron-electron interaction. This experimental result indi cates that the superconducting thermal fluctuation effect in the field is a lmost suppressed by this finite field H-m0, of which values are about two t imes as large as that of the mean-field upper critical field H-c2(0) as we reported for 2D aluminum films. This circumstance is consistent with the ob servation of a rapid suppression of the excess conductivity around 2H(c2)(0 ) for 3D type II superconductors by Lue et al. [J.W. Lue, A.G. Montgomery, R.E. Hake, Phys. Rev. B 11 (1975) 3393]. (C) 1999 Published by Elsevier Sci ence B.V. All rights reserved.