Superconductivity of MgB2 with embedded multiwall carbon nanotube

• Published in: Physica. C, Superconductivity Vol. 449; no. 2; pp. 133 - 138
• Main Authors: Kim, J.H., Yeoh, W.K., Xu, X., Dou, S.X., Munroe, P., Rindfleisch, M., Tomsic, M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.11.2006; Elsevier Science
• Subjects: Carbon substitution; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Critical currents; Exact sciences and technology; Mesoscopic and nanoscale systems; MgB2; Multiwall carbon nanotube; Physics; Properties of type I and type II superconductors; Superconducting films and low-dimensional structures; Superconductivity; 74.25.Sv; 74.70.Ad; Carbon substitution; Multiwall carbon nanotube; 73.63.Fg; MgB2; 74.25.Ha; Powder in tube technique; Critical current density; Lattice distortion; Superconductivity; Carbon nanotubes; Crystallinity; Critical field; Lattice parameters; Multiwalled nanotube; High-Tc superconductors; Microstructure; Irreversibility line; Magnesium borides
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/j.physc.2006.08.003

We studied the effects of MgB2 with embedded multiwall carbon nanotubes (MWCNTs) on the crystallinity, lattice parameters, critical current density (Jc), upper critical field (Hc2), irreversibility field (Hirr), and microstructure of MgB2. Fe sheathed un-doped and MWCNT doped MgB2 wires were fabricated by the powder-in-tube (PIT) method and sintered at the high sintering temperatures of 900°C. We observed that for the MWCNT doped sample high temperature sintering resulted in depressed crystallinity, shrinkage of the a-lattice parameter, higher Jc up to 12T, and lower critical temperature (Tc) values. Specifically, MWCNT doped samples sintered at 900°C exhibited excellent Jc, ∼104Acm−2 up to 9T at 4.2K. This can be explained by lattice distortion and poor crystallinity due to carbon (C) substitution from the MWCNT.