Fluctuation-induced diamagnetism in bulk isotropic superconductors at high reduced temperatures

The short-wavelength effects on the fluctuation-induced diamagnetism (FD) in bulk isotropic three-dimensional (3D) superconductors are taken into account by introducing in the Gaussian-Ginzburg-Landau approach different cut-off conditions. These calculations, which extend to the 3D case our previous results on layered superconductors, are then used to briefly analyse the FD data measured for the low-temperature superconducting alloy Pb-8 at.% In. These analyses confirm the adequacy of a total-energy cut-off for explaining, for low-temperature 3D superconductors also, the,thermal fluctuation effects in the high-reduced-temperature region. These results thus provide further support to the recent proposal that, due to the localization energy, the size of the effective fluctuations cannot be appreciably smaller than the superconducting coherence length amplitude extrapolated to T = 0 K.