SIZE EFFECTS IN CARBON NANOTUBES

The intershell spacing of multi-walled carbon nanotubes was determined by analyzing the high resolution transmission electron microscopy ima ges of these nanotubes. For the nanotubes that were studied, the inter shell spacing (d) over cap(002) is found to range from 0.34 to 0.39 nm , increasing with decreasing tube diameter. A model based on the resul ts from real space image analysis is used to explain the variation in intershell spacings obtained from reciprocal space periodicity analysi s. The increase in intershell spacing with decreased nanotube diameter is attributed to the high curvature, resulting in an increased repuls ive force, associated with the decreased diameter of the nanotube shel ls.