We prepared and characterized monofilamentary MgB2 wires with a mechanically reinforced composite sheath of Ta(Nb)/Cu/steel, which leads to dense filaments and correspondingly high transport currents up to Jc = 10^5 A/cm^2 at 4.2 K, self field. The reproducibility of the measured transport currents was excellent and not depending on the wire diameter. Using different precursors, commercial reacted powder or an unreacted Mg/B powder mixture, a strong influence on the pinning behaviour and the irreversibility field was observed. The critical transport current density showed a nearly linear temperature dependency for all wires being still 52 kA/cm^2 at 20 K and 23 kA/cm^2 at 30 K. Detailed data for Jc(B,T) and Tc(B) were measured.
@article{arxiv.cond-mat/0106226,
title = {High transport currents in mechanically reinforced MgB2 wires},
author = {W. Goldacker and S. I. Schlachter and S. Zimmer and H. Reiner},
journal= {arXiv preprint arXiv:cond-mat/0106226},
year = {2009}
}
Comments
21 pages, 13 figures, revised version, to be published in Supercond. Sci. Technol