Citation

Motojima S. Journal of the Ceramic Society of Japan 2008; 116(1357): 921-927.

Copyright

(Copyright © 2008)

DOI

10.2109/jcersj2.116.921

PMID

unavailable

Abstract

Various modified CVD processes, such as modified hot filament method, vapor phase diffusion process, in-situ CVD process, catalytic CVD process, for the preparation of ceramics single crystals and fibers were developed. The preparation conditions, morphologies, microstructure and properties of transition metal carbides, nitrides, borides, suicides, sulfides, etc were examined. We have first found that various ceramic fibers with 3D-helical/spiral structure, such as Si3N4, carbon, TiC, TiO2, etc. were obtained using metal-catalyzed CVD and/or vapor phase diffusion processes under critically controlled reaction conditions. Carbon microcoils (CMC) with double-helical structure were obtained with high reproducibility by metal catalyzed pyrolysis of acetylene. The CMCs have many interesting and eminent characteristics, such as 3D-helical/spiral microstructure with μm orders in coil diameters, diverse microstructures from amorphous to graphite structure, changing in electrical parameters under the application of various stimuli, high microwave absorption and microwave heating abilities, breeding or anti-breeding effect on cells, fibrils of organisms, etc. ©2008 The Ceramic Society of Japan. All rights reserved.

Language: en

Keywords

Diffusion; Chemical vapor deposition; Carbides; Microstructure; Transition metals; Ceramic materials; Catalysis; Single crystals; CVD; Carbon microcoil; Controlled reaction conditions; Diffusion in gases; Double-helical structures; Electric coils; Electromagnetic wave absorber; Electromagnetic waves; Helical substance; Microstructure and properties; Microwave heating; Single crystal; Tactile sensor; Tactile sensors; Transition metal carbide