Strong influence of boron precursor powder on the critical current density of MgB2

Abstract

The influence of the nature of the boron precursor on the superconducting properties of polycrystalline MgB2 was studied. Critical current densities for the MgB2 made from high purity amorphous boron are at least a factor of three higher than typical values measured for standard MgB2 samples made from amorphous precursors. Two possible mechanisms are proposed to account for this difference. Samples made from crystalline boron powders have around an order of magnitude lower Jc compared to those made from amorphous precursors. X-ray, Tc and resistivity studies indicate that this is as a result of reduced current cross section due to the formation of Mg-B-O phases. The samples made from amorphous B contain far fewer Mg-B-O phases than crystalline B despite the fact that the amorphous B contains more B2O3. The different reactivity rates of the precursor powders accounts for this anomaly.

17 pages, 2 tables, 5 figures, submitted to Superconductor Science and Technology

References in corpus (7)

• Enhancement of the critical current density and flux pinning of MgB2 superconductor by nanoparticle SiC doping
• High Critical Current Density and Improved Irreversibility Field in Bulk MgB2 Made By A Scaleable, Nanoparticle Addition Route
• Nanoscale-SiC doping for enhancing Jc and Hc2 in the Superconducting MgB2
• Effect of nano-carbon particle doping on the flux pinning properties of MgB2 superconductor
• Synthesis and Stoichiometry of MgB2
• Effects of Boron Purity, Mg Stoichiometry and Carbon Substitution on Properties of Polycrystalline MgB${}_2$
• Enhancement of Critical Current Density in low level Al-doped MgB2

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