Structural, morphological, C content and TC changes of the NbC superconductor prepared by Nb powder and carbon nanotubes

The structural, morphological, C content and TC changes of the NbC superconductor prepared by Nb powder and carbon nanotubes have been investigated. Our results indicate that high quality NbC superconductor can be obtained using Nb powder and carbon nanotubes as starting materials without the addition of iodine as a transport agent. The determined TC and upper critical field HC2(0) for the typical NbC superconductor prepared at 1100 °C are TC (R = 0) = 10.6 K, TC (M = onset) = 11.4 K and HC2(0) = 1.57 ± 0.15 T, respectively. The lattice parameter, TC and C content of the prepared samples increase with increasing synthesis temperature in the temperature range 850–1030 °C, and then remain constant in the range 1030–1100 °C.