2001 Volume 42 Issue 5 Pages 838-841
The synthesis of vapor-grown carbon fibers (VGCFs) using the nanocrystalline Fe75Si15B10 alloy as a novel catalyst has been investigated, and the growth process of VGCFs was discussed. The nanocrystalline Fe75Si15B10 alloy with fine bcc-Fe grains less than about 20 nm was prepared by the melt spinning technique followed by annealing. VGCFs with a diameter of less than about 40 nm were successfully prepared using the nanocrystalline Fe75Si15B10 catalyst at 773 K under 80%CO–20%H2 atmosphere. High-resolution transmission electron microscopic characterization indicated that the VGCFs catalytically generated over the Fe75Si15B10 nanocrystal surfaces at both 773 K and 873 K most likely have a tubular-type structure, in which the graphite sheets were stacked parallel to the fiber axis. The Fe75Si15B10 catalyst particles appear to be made of the single-phase Fe3C grains, which is in contrast to the Fe91Zr7B2 catalyst particles previously studied by us. The formation of Fe3C leads to the brittleness of catalyst particles and results in a growth of filamentous carbon.
