Evidence for a solid phase of dodecahedral C-20

• Evidence is presented for the formation of a solid phase based on the smallest fullerene, C-20, in thin diamond-like carbon films deposited by ultraviolet laser ablation from diamond onto nickel substrates at room temperature in the presence of 10(-4) torr of cyclohexane or benzene. Laser desorption mass spectrometry from the films shows the presence of C-20, C-21 and C-22 species, while micro-Raman spectroscopy and electron diffraction from selected particles together with first principle density-functional calculations, indicate a cubic solid with dodecahedral C-20 Cages as building blocks. Unlike solid C-60 and fully protonated C-20, which are bound by van der Waals forces, the proposed structure is stabilized by linking of the C-20 dodecahedra with bridging carbon atoms at interstitial tetrahedral sites to form a face-centered-cubic lattice with 22 carbon atoms per unit cell.

Nyckelord

smallest fullerene

gas-phase

carbon

superconductivity

raman

c-60

c-36

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