With the relatively high critical temperature (Tc) of 39 K1 and the high critical current density (Jc) of > 100000 A/cm2 in moderate fields, magnesium diboride (MgB2) superconductors could offer the promise of important large-scale and electronic device applications to be operated at 20 K. A significant enhancement in the electromagnetic properties of MgB2 has been achieved through doping with various form of carbon (C). However, doping effect has been limited by the agglomeration of nano-sized dopants and the poor reactivity of C containing dopants with MgB2. Un-reacted dopants result in a reduction of superconductor volume. In this work, we demonstrate the advantages of carbohydrate doping over other dopants, resulting in an increase of in-field Jc by more than one order of magnitude without any degradation of self-field Jc. As there are numerous carbohydrates readily available this finding has significant ramifications not only for the fabrication of MgB2 but also for many C based compounds and composites.
@article{arxiv.cond-mat/0607350,
title = {Strong enhancement of critical current density in MgB2 superconductor using carbohydrate doping},
author = {J. H. Kim and S. Zhou and M. S. A. Hossain and A. V. Pan and S. X. Dou},
journal= {arXiv preprint arXiv:cond-mat/0607350},
year = {2007}
}