High-energy ball milling and synthesi temperature study to improve superconducting properties of MgB2 ex-situ tapes and wires

Abstract

MgB2 monofilamentary nickel-sheated tapes and wires were fabricated by means of the ex-situ powder-in-tube method using either high-energy ball milled and low temperature synthesized powders. All sample were sintered at 920 C in Ar flow. The milling time and the revolution speed were tuned in order to maximize the critical current density in field (Jc): the maximum Jc value of 6 x 10e4 A/cm2 at 5 K and 4 T was obtained corresponding to the tape prepared with powders milled for 144h at 180rpm. Vorious synthesis temperature were also investigated (730-900 C) finding a best Jc value for the wire prepared with powders synthesized at 745 C. We speculate that this optimal temperature is due to the fluidifying effect of unreacted magnesium content before the sintering process which could better connect the grains.

References in corpus (6)

• Enhancement of the critical current density and flux pinning of MgB2 superconductor by nanoparticle SiC doping
• Large transport critical currents in unsintered MgB2 superconducting tapes
• Carbon doping of superconducting magnesium diboride
• Effects of neutron irradiation on polycrystalline Mg11B2
• The doping effect of multiwall carbon nanotube on MgB2/Fe superconductor wire
• Effect of grain refinement on enhancing critical current density and upper critical field in undoped MgB2 ex-situ tapes

Cited by in corpus (2)

• In-situ high energy synchrotron X-ray diffraction investigation of the MgB2 phase formation and MgB2 tapes sintering
• High temperature heat treatment of B precursor and P.I.T. process optimization to increase Jc performances of MgB2-based conductor