New origin of spirals and new growth process of carbon whiskers

A new kind of carbon whisker, different from others, has been found by mean s of high resolution electron microscopy and field emission scanning electr on microscopy. Carbon layers are almost perpendicular to the whisker axis a nd a spiral structure is formed around it. Structure analysis indicates the growth process consists of two stages; firstly, carbon layers stacked in t urbostratic manner, and then gradually graphitized. Accordingly, the final structure of whiskers is perfect graphitized texture. The spirals are not s imilar to the so-called 'growth spirals' formed by the screw dislocation me chanism, and a more reasonable growth mechanism of whiskers is suggested in accordance with the analysis. (C) 2001 Elsevier Science Ltd. All rights re served.