Enhanced superconducting properties of pre-doped B powder type MgB2 strands

TL;DR

This study demonstrates that pre-doping boron powder with carbon results in more homogeneous doping and significantly enhances the superconducting properties of MgB2 strands, outperforming traditional doping methods.

Contribution

It introduces a pre-doping technique for boron powder that improves C substitution efficiency and superconducting performance in MgB2 strands.

Findings

Pre-doped B powder yields higher transport Jc at 13.3T.

Pre-doped MgB2 shows higher Birr compared to other doping methods.

Homogeneous C distribution enhances superconducting properties.

Abstract

Conventional doping methods that directly add C or a C-bearing species to Mg+B powder have the disadvantage of adding C inhomogeneously, yielding either under-reacted regions or blocking phases. Pre-doped B powder provides a more homogeneous distribution of the C dopant in MgB2. Powders containing varying amounts of C were used to produce in-situ MgB2 strands which showed high values of transport Jc (104 A/cm2 at 13.3T). Compared to SiC-added and malic acid-treated strands the pre-doped MgB2 showed both higher values of Birr and transport Jc, indicating that the pre-doping of B leads to more efficient C substitution into the B-sublattice.