Composite structures of carbon nanotubes (CNTs) and metal carbides include a helical nanotube/carbide composite fiber, and a film. The composite fiber was prepared by pulling/twisting carbon nanotubes from an array of nanotubes to form an as-spun fiber and soaking it a metal precursor solution, and then heating it under a reducing atmosphere with a carbon source. The composite fiber had a higher tensile strength, a higher conductivity, and a higher tensile modulus than the as-spun fiber. A composite structure in the form of parallel ribbons of aligned carbon nanotubes embedded in a film of NbC showed an enhanced conductivity along the CNT axial direction, and improved superconducting properties. The enhanced upper critical field of NbC/CNT suggested that the inclusion of CNTs in the NbC matrix reduced the coherence length of the NbC. Nanomechanical testing also demonstrated the potential for enhanced fracture toughness of NbC/CNT composites.
STATEMENT REGARDING FEDERAL RIGHTS
 This invention was made with government support under Contract No. DE-AC52-06NA25396 awarded by the U.S. Department of Energy. The government has certain rights in the invention.