MORPHOLOGY AND GROWTH DEFECTS OF C 60 CRYSTALS

Millimeter-sized C 60 single crystals with regular, shiny and smooth faces were grown from vapor phase. The structure of C 60 crystals was confirmed to be face-centered-cubic (fcc, a = 1. 4199(4) nm) by X-ray diffraction at room temperature. The morphologies and growth defects were studied by both the scanning electron microscope and the optical microscope. In addition to the typical stable {111} and {200} faces and twins for fcc crystals, we also observed the dentrites,ridge like defects and growth hillocks on {111} faces and dentrites,growth hillocks and swimming-pool-like defects on {200} faces. The morphologies appeared were compared with the theoretical equilibrium forms. The mechanism of the formation of the growth defects were analysed. The effects of growth conditions on the growth morphology of C 60 crystals were discussed. These results will be helpful for the investigation or the growth mechanism of C 60 single crystals by vapor transport method.