The authors demonstrated the mechanics of materials for crystalline whiskers composed of C 60 molecules; compressive deformation of the whiskers was observed by in situ transmission electron microscopy with simultaneous force measurement by means of an optical cantilever method, as used in atomic force microscopy. In response to compression along the long axis, the whiskers bent first elastically, then buckled. A whisker with 160 nm diameter fractured brittlely at a strain of 0.08. According to Euler's formula, Young's modulus of the whisker was estimated to be 32-54 GPa, which is 160%-650% of that of C 60 bulk crystals.

Abstract:We synthesized superconducting fullerene nanowhiskers (C 60 NWs) by potassium (K) intercalation. They showed large superconducting volume fractions, as high as 80%. The superconducting transition temperature at 17 K was independent of the K content (x) in the range between 1.6 and 6.0 in K-doped C 60 nanowhiskers (K x C 60 NWs), while the superconducting volume fractions changed with x. The highest shielding fraction of a full shielding volume was observed in the material of K 3.3 C 60 NW by heating at 200 °C. On the other hand, that of a K-doped fullerene (K-C 60 ) crystal was less than 1%. We report the superconducting behaviors of our newly synthesized K x C 60 NWs in comparison to those of K x C 60 crystals, which show superconductivity at 19 K in K 3 C 60 . The lattice structures are also discussed, based on the x-ray diffraction (XRD) analyses.

Filaments composed of multilayered carbon hollow capsules less than 10nm in diameter have been synthesized from crystalline whiskers of fullerene C60 of submicrometer in diameter by preliminary heating at 1373K and successive impression of current. The structural, electrical and optical properties of the filaments were studied by in situ transmission electron microscopy combined with the functions of scanning probe microscopy. We found that the filaments easily emit visible light at a maximum wavelength of 700-730 nm by the application of a few volts.

No abstract

No abstract