用扫描隧道显微镜针尖操纵金岛

用扫描隧道显微镜，在小隧道阻抗的条件下（小偏压和大隧道电流），通过移动针尖，实现了在室温下对真空蒸镀在高定向石墨上的、由几万个原子组成的纳米尺度金岛的操纵．在大隧道阻抗的情形下，用同一个针尖可对操纵的结果进行观察，而不会对金岛产生扰动．这种可控的操纵是通过当钨针尖与金岛间距离很近时形成的金属间黏附力大于金岛与石墨间的摩擦力而实现的 关键词：

MANIPULATION OF GOLD SINGLE CRYSTAL ISLANDS- ON HOPG SURFACE WITH A STM TIP

It is demonstrated that nanometer-sized gold single crystal islands or even clusters of the islands,which were formed by deposition of gold onto an air-cleaved highly oriented pyrolytic graphite (HOPG) surface,can be manipulated on the surface in a controllable manner with the tip of a scanning tunneling microscope when the tunneling conductance is set to a large value. Since the tip does not disturb the islands if the tunneling conductance is small enough,even the islands are repeatedly scanned over by the tip, the results of the manipulation can thus be imaged with the same tip. The mechanism of the manipulation is suggested to be that at large tunneling conductance a metallic cohesive force may form between the tip and islands and may exceed the frictional force between the islands and the HOPG surface.