Ribbon-like nanostructures transformed from carbon nanotubes at high temperature and pressure

In this letter, the microstructural changes of catalytically grown carbon nanotubes are studied at high temperature and pressure by transmission electron microscopy (TEM). The nanotubes deform and one kind of ribbon-like nanostructure is transformed from carbon nanotubes directly when the annealing temperature is above 950 degrees C under 5.5 Gpa. It is suggested that pressure and temperature play an important role in the structural transformations of carbon nanotubes and ribbon-like nanostructure formation described here. (C) 1999 Acta Metallurgica Inc.