Adsorption of aspartic acid on Cu(001) studied by scanning tunneling microscopy

用扫描隧道显微镜 (STM)研究了室温下天冬氨酸在Cu(0 0 1)表面的吸附行为 .实验发现 ,在较低的覆盖度下 ,天冬氨酸分子在Cu(0 0 1)表面存在两种吸附状态 .从STM数据估算出两种吸附状态下天冬氨酸分子在Cu(0 0 1)表面的扩散激活能分别为 0 79± 0 0 1eV ,0 88± 0 0 5eV .随着覆盖度的提高 ,天冬氨酸分子最终在Cu(0 0 1)表面形成一均匀衬度的吸附层 ,但并不形成有序吸附结构 ,也不能使台阶发生小面化 .天冬氨酸分子的这些吸附特点是迄今研究过的所有氨基酸在Cu(0 0 1)表面吸附时不具有的 .Scanning tunneling microscopy (STM) has been used to study the adsorption of aspartic acid on the Cu(001) surface at room temperature. At lower coverage,there exist two different bonding states and the corresponding diffusion activation energies are 0.79 +/- 0.01 eV and 0.88 +/- 0.05 eV,respectively. When the coverage is increased,the aspartic acid molecules can finally form an overlayer with uniform contrast but could never form any ordered structures. It has been also found that the adsorption of aspartic acid cannot make steps faceted. It is interesting that all these features are quite different from the adsorption behaviors of other amino acids on Cu(001),such as glycine,alanine, phenylalanine and lysine,which do not have the beta-caboxylate.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000088125500021&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701SCI(E)EI中文核心期刊要目总览(PKU)中国科学引文数据库(CSCD)8071316-13204