The pair-breaking critical current density j_{d} of magnesium diboride was determined over its entire temperature range by a pulsed dc transport measurement. At fixed low values of current density j, the resistive transition temperature Tc shifts in the classic \Delta T_{C}(j)/T_{C}(0) \propto -[j/j_{d}(0)]^{2/3} manner, with a projected j_{d}(0) \approx 2 \times 10^{7}A/cm2.Thedirectlymeasuredjd(0),fromcurrent−voltage(I−V$)curves at different fixed temperatures, has a similar value and the overall temperature dependence j_{d}(T) and magnitude are consistent with Ginzburg-Landau theory. Keywords: pair, breaking, depairing, superconductor, superconductivity, flux, fluxon, vortex, mgb2
@article{arxiv.cond-mat/0212108,
title = {The pair-breaking critical current density of magnesium diboride},
author = {Milind N. Kunchur and Sung-Ik Lee and W. N. Kang},
journal= {arXiv preprint arXiv:cond-mat/0212108},
year = {2009}
}
Comments
Submitted to Phys. Rev. Lett. Related preprints/reprints by our group can be found on http://www.physics.sc.edu/kunchur