室温下单个甘氨酸分子在Cu(111)表面的操纵研究

先用低能电子衍射(LEED)证明了甘氨酸(NH₂-CH₂-COOH)能在室温下在Cu单晶表面产生比较稳定的吸附，然后用扫描隧道显微镜(STM)进一步研究了其吸附情况，看到单个甘氨酸分子在Cu(111)面上吸附稳定并至少有三种吸附状态.分子操纵研究结果表明，甘氨酸分子是被针尖“推着”移动的，它在Cu(111)面有固定的吸附位，并且移动时其吸附状态可以不变.研究结果表明，甘氨酸适合做室温下小分子的可控操纵研究，并且也说明室温下小分子的可控操纵是可能的. 关键词：

ROOM TEMPERATURE MANIPULATION OF INDIVIDUAL GLYCINE MOLECULES ADSORBED ON THE Cu(111) SURFACE

Low-energy electron diffraction (LEED) shows that glycine molecules can stick onto the Cu(100) substrate at room temperature forming ordered structures, while their binding to the substrate is fairly weak as evidenced by the quick degradation of the adsorbing structures and in turn the LEED pattern induced by the incident electron beam. Scanning tunneling microscopy (STM) observation shows that the molecules can also adsorb on the Cu(111) substrate at room temperature, and the binding is strong enough to be imaged with not too small a tunnel resistance but is weak enough to be manipulated by the tip with a small tunnel resistance. Careful inspections of the STM images allow us to further conclude the following.(i) At least three adsorption geometries with different apparent heights have been identified, although the details of the molecular images are often dominated by the tip shape.(ii) It is possible to move the molecules without changing their adsorbing geometry. (iii) In manipulation the molecules are pushed forward by the tip.(iv) Each glycine molecule forms at least two bonds with the substrate. During controllable manipulations the molecules remain at least one bond unbroken. (v) Electrostatic forces between the tip and sample do not play an important role in manipulations, as changing bias polarity seems to have almost no influences.(vi) In manipulations the higher the tunnel resistance the better our control on the molecules, as long as the molecules can be moved.