Synthesis of vapor-grown carbon fibers using nanocrystalline Fe75Si15B10 alloy as a catalyst

synthesis of vapor-grown carbon fibers (VGCFs) using the nanocrystalline Fe 75Si15B10 alloy as a novel catalyst has been investigated. and the growth p rocess of VGCFs was discussed. The nanocrystalline Fe75Si15B10 alloy with f ine bcc-Fe grains less than about 20 nm was prepared by the melt spinning t echnique followed by annealing. VGCFs with a diameter of less than about 40 nm were successfully prepared using the nanocrystalline Fe75Si15B10 cataly st at 773 K under 80%CO-20%H-2 atmosphere. High-resolution transmission ele ctron microscopic characterization indicated that the VGCFs catalytically g enerated over the Fe75Si15B10 nanocrystal surfaces at both 773 K and 873 K most likely have a tubular-type structure, in which the graphite sheets wer e stacked parallel to the fiber axis. The Fe75Si15B10 catalyst particles ap pear to be made of the single-phase Fe3C grains, which is in contrast to th e Fe91Zr7B2 catalyst particles previously studied by us. The formation of F e3C leads to the brittleness of catalyst particles and results in a growth of filamentous carbon.