摘要 |
<p>Hollow carbon microcoils of which the pitch is substantially zero, and hollow ceramic microcoils or hollow ceramic microfibers obtained by metallizing the hollow carbon microcoils. In synthesizing the carbon microcoils by the catalytically activated pyrolysis of acetylene, the reaction conditions are strictly controlled, and the substrate is lowered accompanying the growth of the fibers in order to obtain hollow carbon microcoils which are very densely and regularly wound. Furthermore, these coils or fibers are subjected to the reaction/diffusion treatment in a gas containing various metal components, silicon, boron, carbon, nitrogen and/or oxygen atoms at a temperature of as high as 800 to 1700 DEG C, so that the starting gas reacts with, or substituted by, carbon, in order to obtain hollow ceramic microcoils or microfibers maintaining a completely hollow state in the fiber cores. <IMAGE></p> |