1. Carbon Nanotubes on SiC powder surface grown by vacuum heating process

Hiroifumi Takikawa, Ryuichi Miyano, Miki Yatsuki and Tateki Sakakibara

Silicon carbide (SiC) powders were baked on a resistively heated tungsten (W) boat at 1,600--1,700℃ for 10--15 min in vacuum. The surface morphology of the treated SiC powders was observed using a high resolution scanning electron microscope (HR-SEM). Carbon nanotubes were observed on the surface of 40 % of SiC powder.The nanotubes were dense, but slightly dispersed and their growth direction was almost perpendicular to the original surface. The nanotubes on SiC were considerably shorter than that prepared by carbon arc method, but significantly longer than that prepared by laser sublimation of SiC. Energy dispersive X-ray spectrometory (EDX) analysis suggested that W and O were doped on or in the vicinity of the powder surface.

(Jpn. J. Appl. Phys. Vol 37. (1998) pp. L187- L189)

2.Synthesis of Silicon Oxide Nanofiber by Sublimation of SiC in Medium Vacuum with Oxygen Flow

Hirofumi Takikawa, Miki Yatsuki and Tateki Sakakibara

Silicon carbide (SiC) particles mixed with/without cobalt (Co) powders as catalysts were heated on a carbon (C) boat at 1,400--1,650℃ 10 min in medium vacuum with small oxygen flow. A large quantity of fiber-like products was found on the SiC particles. The products were observed with a high-resolution scanning electron microscope (HR-SEM) and high-resolution transmission electron microscope (HR-TEM). Their compositions were also analyzed by electron diffraction analysis, energy dispersive X-ray spectroscopy (EDX) equipped with HR-TEM, and X-ray diffraction (XRD) analysis, showing amorphous SiO2.

(Jpn. J. Appl. Phys. Vol 38. (1999) pp. L401- L402)

3. Carbon Nanotubes and Nanocapsules Fabricated bu Cathodic Vacuum Arc

Hirofumi Takikawa, Osamu Kusano, Miki Yatsuki and Tateki Sakakibara

Cathodic vacuum arc plasmas with graphite and graphite-metal composite cathodes were ignited under medium vacuum filled with helium gas. The craters of cathode spots and their vicinities were observed with a high-resolution scanning electron microscope. Carbon nanotubes and nanocapsules were found at the rim of the cathode spot crater, when the graphite cathode contained both nickel and yttrium. The　nanotubes and nanocapsules were further observed with a high-resolution transmission electron microscope.

(Jpn. J. Appl. Phys. in press)