Improvement in the transport critical current density and microstructure of isotopic Mg11B2monofilament wires by optimizing the sintering temperature.
Superconducting wires are widely used in fabricating magnetic coils in fusion reactors. In consideration of the stability of11B against neutron irradiation and lower induced radio-activation properties, MgB2superconductor with11B serving as boron source is an alternative candidate to be used in fusion reactor with severe irradiation environment. In present work, a batch of monofilament isotopic Mg11B2wires with amorphous11B powder as precursor were fabricated using powder-in-tube (PIT) process at different sintering temperature, and the evolution of their microstructure and corresponding superconducting properties was systemically investigated. Accordingly, the best transport critical current density (Jc) = 2 × 104A/cm2was obtained at 4.2 K and 5 T, which is even comparable to multi-filament Mg11B2isotope wires reported in other work. Surprisingly, transport Jcvanished in our wire which was heat-treated at excessively high temperature (800 °C). Combined with microstructure observation, it was found that lots of big interconnected microcracks and voids that can isolate the MgB2grains formed in this whole sample, resulting in significant deterioration in inter-grain connectivity. The results can be a constructive guide in fabricating Mg11B2wires to be used as magnet coils in fusion reactor systems such as ITER-type tokamak magnet.
Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials (AIIM), University of Wollongong, Squires Way, North Wollongong, NSW 2500, Australia.
Wenbin
W
Qiu
Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials (AIIM), University of Wollongong, Squires Way, North Wollongong, NSW 2500, Australia.
Hyunseock
H
Jie
Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials (AIIM), University of Wollongong, Squires Way, North Wollongong, NSW 2500, Australia.
Dipak
D
Patel
Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials (AIIM), University of Wollongong, Squires Way, North Wollongong, NSW 2500, Australia.
Yao
Y
Lu
Australian Nuclear Science Technology Organisation (ANSTO), Lucas Heights, NSW 2232, Australia.
Vladimir
V
Luzin
ITER Organization, 13115 Saint Paul Lez Durance, France.
Arnaud
A
Devred
Koc University, Chemistry Department, Rumelifeneri Yolu, TR-34450 Sariyer-Istanbul, Turkey.
Mehmet
M
Somer
Department of Physics and Astronomy, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
Mohammed
M
Shahabuddin
Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials (AIIM), University of Wollongong, Squires Way, North Wollongong, NSW 2500, Australia.
Jung Ho
JH
Kim
Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials (AIIM), University of Wollongong, Squires Way, North Wollongong, NSW 2500, Australia.
Zongqing
Z
Ma
Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials (AIIM), University of Wollongong, Squires Way, North Wollongong, NSW 2500, Australia.
Shi Xue
SX
Dou
Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials (AIIM), University of Wollongong, Squires Way, North Wollongong, NSW 2500, Australia.
Md Shahriar Al
MS
Hossain