High resolution transmission electron microscopic study of some low‐dimensional nanostructures

Abstract

High-resolution transmission electron microscopy (HRTEM) study of some low-dimensional nanostructures, such as carbon nanotubules and silicon-based blue-light emitting β-SiC nanoparticles will be reported. We have shown that nested hollow tubules formed by successive cylindrical graphite sheets are found, frequently, to be polyhedral or elliptical in cross-section, which are perpendicular to the tube-axis. Varied spacing between adjacent tube sheets is observed and edge-type dislocations can be distinguished in some tubules. These abnormal structural features are related to accommodations of various strains taking place simultaneously in tube sheets. Blue-light emitting porous β-SiC formed by C+ implantation of a single crystal silicon wafer have also been investigated. Buried layer structures with different β-SiC concentration were formed in the implanted silicon substrate. These β-SiC nano-particles are 2–8 nm in size and formed epitaxially from the upper and lower damaged layers, respectively, but randomly in the middle layer. The structural characteristics of the layered structure may be responsible for the blue-light emitting effect of the porous β-SiC material. Microsc. Res. Tech. 40:163–176, 1998. © 1998 Wiley-Liss, Inc.