Structural (XRD and HRTEM) investigations of fullerite C60 and C70 samples

Since the carbon states on the basis of C-60 and C-70 exhibit very interesting physical properties such as hardness exceeding diamond, we focused our investigations on the comparison of structures of the C-60 and C-70 hard phases synthesized at high pressure and high temperatures. X-ray diffraction (XRD) and high-resolution transmission electron microscope (HRTEM) investigations have revealed that two states (amorphous and nanocrystalline) co-exist in samples of both kinds of fullerites. The difference between the diffraction patterns of C-60 and C-70 has been ascribed mainly to the grade of disorder. The XRD and HRTEM results have been correlated with the transport proper-ties (electrical and thermal conductivity) of the samples. (C) 2002 Elsevier Science B.V. All rights reserved.