Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki, Japan.
J Phys Condens Matter. 2010 Aug 4;22(30):304010. doi: 10.1088/0953-8984/22/30/304010. Epub 2010 Jul 13.
Supersonic He and Ar atomic beam scattering from C(60) and graphene monolayers adsorbed on a Pt(111) surface are demonstrated in order to obtain detailed insight into a gas-molecule collision that has not been studied in detail so far. The effective masses and phonon spectral densities of the monolayers seen by different projectiles are discussed based on classical models such as the hard cube model and the recently developed smooth surface model. Large effective masses are deduced for both the monolayers, suggesting collective effects of surface atoms in the single collision event. The effective Debye temperature of graphene was found to be similar to that reported in highly oriented pyrolytic graphite (HOPG), indicating that the graphene is decoupled well from the Pt substrate. A much smaller Debye-Waller factor was found for the C(60) layer, probably reflecting the strong C(60)-Pt(111) interaction.
为了深入了解迄今为止尚未详细研究过的气体分子碰撞，我们演示了从 C(60)和单层石墨烯吸附在 Pt(111)表面的超音速 He 和 Ar 原子束散射。基于硬立方模型和最近开发的光滑表面模型等经典模型，讨论了不同弹体看到的单层的有效质量和声子谱密度。对于两种单层，都推导出了较大的有效质量，表明在单个碰撞事件中表面原子的集体效应。发现石墨烯的有效德拜温度与高取向热解石墨 (HOPG) 中的报道相似，表明石墨烯与 Pt 衬底很好地解耦。对于 C(60)层，发现了小得多的德拜-沃勒因子，这可能反映了 C(60)-Pt(111)的强相互作用。
