Improved critical current densities in B₄C doped MgB₂based wires

Abstract

An improvement of the transport critical current density, J c , of MgB 2 wires was obtained after

Effect of processing temperature on high field critical current density and upper critical field of nanocarbon doped MgB2

“…Similar variation was obtained for all other fields between 8 and 12 T. We note that an Fe 2 B interface layer may occur in MgB 2 / Fe wires. 13,23,24 However, there was no observable interface layer in any of our samples, presumably due to shorter sintering time and different boron powder than in Refs. 13, 23, and 24.…”

“…[1][2][3][4][5] Substitution of C in the B site also significantly increases the upper critical field, H c2 . [6][7][8][9] Despite numerous reports on carbon substitution, [10][11][12][13][14] no optimization of the processing temperature has been reported yet. In this work, we demonstrate that nano-C doping can be one of the most promising procedures, besides nano-SiC doping, for the enhancement of flux pinning in MgB 2 at high magnetic fields.…”

Enhancement of flux pinning and high critical current density in graphite doped MgB2 superconductor

“…Furthermore, flux pinning strength was found to be enhanced by carbon substitution 6,19,20,23,24 . These positive effects of carbon substitution indicate that doping of carbon has a great potential to enhance superconducting properties of MgB 2 superconductor.…”

Superconducting Properties of Carbonaceous Chemical Doped MgB2

“…Substantially enhanced J c properties under high magnetic fields were observed in the B 4 C doped samples due to the relatively low processing temperature and carbon substitution effects. Lezza et al successfully obtained a J c value of 1 × 10 4 A cm −2 at 4.2 K and 9 T for 10 wt% B 4 C powders added to MgB 2 /Fe wires at a reaction temperature of 800 °C (Lezza et al, 2006). Despite the carbon substitution effects, the homogeneous microstructure of the dopants provides the MgB 2 composites with good grain connection for the MgB 2 phase and a high density of flux pinning centers.…”