Meandering C 60 Chains on Organic Film Substrates

摘要: Meandering chains of C 60 molecules are observed following vapor deposition of C 60 on a variety of organic molecular films including pentacene and zinc phthalocyanine, as well as previously reported a-sexithiophene. Such filamentous structures are in complete contrast to C 60's typical close-packed growth habit, but are reminiscent of dipole fluids. We present STM images and a statistical analysis of chain structures observed for 0.2-0.9 mL C 60 on the square ZnPc overlayer (a= 13.6 A& o circ;, b= 14.5 A& o circ;, α= 89^ o) on Ag (111). Large islands of meandering C 60 islands indicate> 50 nm C60 diffusion lengths on this ZnPc film. The C 60 chain length, l∼ 20 nm, depends weakly on coverage, reflecting the∼ constant C 60 density within these islands, and exhibits multiple branches. Chain structures are compared to the molecular dynamics predictions of a 2-d dipole fluid with the C 60-C 60 interaction …