乙醇分子在Bi(111)表面上的吸附和自组装

On Adsorption and Self-Assembly of Ethanol Molecules on Bi(111)

利用低温扫描隧道显微镜研究乙醇分子在半金属Bi(111)表面的吸附和自组装.在低覆盖度下,乙醇分子主要以单体和二聚体的形式吸附在衬底表面.随着覆盖度的增加,形成少量的分子链和大量结构稳定的六聚体结构.高覆盖度下的乙醇自组装结构经310K退火2h后,得到大面积的乙醇自组装薄膜.乙醇自组装薄膜的晶格常数是:a=630pm,b=380pm,θ=89°,这与乙醇晶体的晶格常数不同.乙醇自组装薄膜的形成得益于分子间的较强的相互作用,这种作用力可以主导分子与衬底间的作用.

The adsorption and self-assembly of ethanol molecules on Bi（111）surface have been investigated by means of low-temperature scanning tunneling microscope（STM）.At low coverage,ethanol molecules have mainly been observed in the form of monomers and dimers.With increasing coverage,a small amount of molecular chains,massive identical and well-defined ethanol hexamers with stable structure were found.After the ethanol self-assembly at high coverage was annealed at 310 Kfor 2hours,large areas of self-assembled films of ethanol have been obtained.The lattice constant is a=630pm,b=380pm,θ=89°,which is different from that of ethanol crystal.The formation of the self-assembled film can be attributed to the strong inter-molecular interaction,which can dominate the molecular-substrate interaction.