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[Nettime-bold] http://meta.am/ - crystalline |
http://meta.am/image/video/ - crystalline.mov // Crystalline Ropes of Metallic Carbon Nanotubes Single-wall fullerene nanotubes (SWNT) have been produced in > 70% yield by condensation of a laser-vaporized carbon/Ni/Co mixture at 1200oC. X-ray diffraction and electron microscopy show that the SWNT are nearly uniform in diameter and self-organize into "ropes" consisting of 100 to 500 SWNT in a two-dimensional triangular lattice with a lattice constantof 17 angstroms (Å). The x-ray form factor is consistent with uniformly charged cylinders 13.8 0.2 Å in diameter. The ropes were metallic (single-rope resistivity 10-4 Ohm-cm at 300 Kelvin). Uniformity of SWNT diameter is attributed to efficient annealing of an initial fullerene tubelet kept open by a few metal atoms, the optimum being determined by competition between the strain energy of curvature of the graphene sheet and the dangling bond energy of the open edge. These factors strongly favor the metallic C5V symmetry tube (10,10) with an open growth edge stabilized by triple bonds. // //m 127.0.0.1 http://meta.am/ 216.71.169.143 / _______________________________________________ Nettime-bold mailing list Nettime-bold@nettime.org http://www.nettime.org/cgi-bin/mailman/listinfo/nettime-bold