CVD processing of carbon fiber superconductors

NbC1-yNysuperconductors are possible candidates for high magnetic field applications because of the high Bc2> 25 T. The deposition of NbC1-yNyon carbon fiber bundles with more than 1000 fibers using a two stage chemical vapor deposition process: NbCl5+ 5/2 H2350 - 1000 ° C, N2Nb + 5 HCl; Nb + (1-y) CH4+ yNH31100 °C NbC1-yNyhas been investigated. The deposition process is carried out at total pressures 0.1 mbartot< ~ 10%). The main parameters, which influence the microstructure are discussed. The superconducting properties of NbC1-yNydeposited without the gas discharge are measured. The critical temperature Tcwas in the range of 15 Kcc(O T) = 106Acm-2jc(13 T) = 104Acm-2. The extrapolated maximum critical magnetic field was Bc2= 21 T at 4.2 K.