GROWTH-MECHANISM OF IRON-FILLED CARBON NANOTUBULES

Iron-filled nanotubules were synthesized in a carbon are in the presen ce of He and Fe(CO)(5) gases. The consumption of the Fe(CO)(5) inside the are chamber was controlled by the pressure of the pentacarbonyliro n Fe(CO)(5) gas. Different shapes and filling extents of nanotubules w ere found depending on the pentacarbonyliron concentration supplied. B ased on high-resolution transmission electron microscope images, we pr opose a growth model of iron-filled carbon nanotubules. The growth pro ceeds through the deposition and surface diffusion of carbon on the li quidlike metal. The hollow tubules probably grow spontaneously. (C) 19 96 American Institute of Physics.