The magnetoconductivity (MC) of three-dimensional (3D) aluminum films with various dirtiness has been measured in wide ranges of temperature and magnetic field, (1) Near the superconducting transition temperature Tc, the MC takes the minimum at a temperature-independent field Hm0. (2) Above Hm0, MC shows H1/2 dependence. From the detailed analysis of the H dependence of MC, it has been found that the magnitude of the coefficient of H1/2 can be explained qualitatively by only the sum of contribution from the weak localization and electron-electron interaction. This experimental result indicates that the superconducting thermal fluctuation effect in the field is almost suppressed by this finite field Hm0, of which values are about two times as large as that of the mean-field upper critical field Hc2(0) as we reported for 2D aluminum films. This circumstance is consistent with the observation of a rapid suppression of the excess conductivity around 2Ac2(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].
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering