Two sets of MgB2 samples doped with up to 5 at. % of Al were prepared in different laboratories using different procedures. Decreases in the a and c lattice parameters were observed with Al doping confirming Al substitution onto the Mg site. The critical temperature (Tc) remained largely unchanged with Al doping. For 1 - 2.5 at.% doping, at 20K the in-field critical current densities (Jc's) were enhanced, particularly at lower fields. At 5K, in-field Jc was markedly improved, e.g. at 5T Jc was enhanced by a factor of 20 for a doping level of 1 at.% Al. The improved Jcs correlate with increased sample resistivity indicative of an increase in the upper critical field, Hc2, through alloying.
@article{arxiv.cond-mat/0405567,
title = {Enhancement of Critical Current Density in low level Al-doped MgB2},
author = {A. Berenov and A. Serquis and X. Z. Liao and Y. T. Zhu and D. E. Peterson and Y. Bugoslavsky and K. A. Yates and M. G. Blamire and L. F. Cohen and J. L. MacManus-Driscoll},
journal= {arXiv preprint arXiv:cond-mat/0405567},
year = {2009}
}
Comments
17 pages, 4 figures, to be published in Superconductor Science and Technology