We have performed a magnetic study of a bulk metallic sample of Nb with critical temperature Tc=8.5 K. Magnetization versus temperature (M {\it vs} T) data obtained for fixed magnetic fields above 1 kOe show a superconducting transition which becomes broader as the field is increased. The data are interpreted in terms of the diamagnetic lowest Landau level (LLL) fluctuation theory. The scaling analysis gives values of the superconducting transition temperature Tc(H) consistent with Hc2(T)% . We search for universal 3D LLL behavior by comparing scaling results for Nb and YBaCuO, but obtain no evidence for universality.
@article{arxiv.cond-mat/0209468,
title = {Experimental observation of high field diamagnetic fluctuations in Niobium},
author = {S. Salem-Sugui, and Mark Friesen and A. D. Alvarenga and F. G. Gandra and M. M. Doria and O. F. Schilling},
journal= {arXiv preprint arXiv:cond-mat/0209468},
year = {2012}
}
Comments
5 pages, 6 figures, Accepted for publication in Phys.Rev. B