SYNTHESIS OF LOW-DENSITY CARBON CRYSTALS BY QUENCHING GASEOUS CARBON AND INTERCALATION OF ALKALI-METAL ATOMS INTO THESE CRYSTALS

A quasi I-dimensional carbon crystal has been synthesized by quenching of high temperature carbon gas on a room temperature metallic substrate. The structure is hexagonal and the sizes of the unit cell are 1. 193 nm along the a-direction and 1. 62 nm along the c-dirdtion. A parallel array of charbon chains is formed along the c-axis. The array is made of a triangular lattice of which inter-chain distance is 0. 344 nm and the mean inter-atomic C-C distance along the chain is 0. 133 nm. The crystal is half transparent in the visible region and has its specific weight as small as 1.46 g/cm(3). In order to test the possibility of intercalation, reactions with potassium, sodium and iodine have been performed. In every reaction, the material has converted from an insulator to a conductor.