扫描隧道显微镜分辨能力的研究:对Si(111)-(7×7)表面的观察

用超高真空扫描隧道显微镜首次同时清晰地分辨出Si(111) (7×7)表面每个元胞中的 12个顶戴原子和 6个静止原子,这 6个静止原子的亮度与无层错半元胞内中心顶戴原子的亮度基本相同. 第一性原理计算图像和STM实验结果完全符合,针尖的尺度小于 7 时,可以完全同时分辨出Si(111) (7×7)表面的静止原子.     

电化学沉积金纳米线结构及其电学特性

用电化学沉积方法，在有机介孔模板上制备出直径为90 nm的金纳米线.透射电子显微镜（TEM）分析结果表明，纳米线表面光滑并呈单晶结构.去除有机模板的金纳米线阵列用扫描电子显微镜（SEM）测试，纳米线顶端呈平台状，直径分布均一.我们利用原子力显微镜（AFM）测量了金纳米线阵列的微观结构，得到与SEM相一致的结果.在大气和室温条件下，用导电AFM针尖在接触模式下测量了单根纳米线的轴向I－V特性曲线，其结果为金属性.     

巴基葱的微观形态与电学特性研究

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INVESTIGATION ON THE STRUCTURE AND ELECTRIC PROPERTIES OF BUCKY ONIONS

Bucky onions were fabricated by the DC discharge method and their behaviors and electric properties on Highly Oriented Pyrolytic Graphite (HOPG) were studied by using an atomic force microscope (AFM), a scanning tunneling microscope (STM) and a transmission electron microscope (TEM). Small-sized Bucky onions demonstrated the properties of semiconductors and as the size increased their metallicity became stronger. AFM and STM images revealed the tendency of Bucky onions to form dimers.     

Reversible,electical and optical switching on silver 3—phenyl—1—ureidonitrile complex thin films

We report on the reversible, electrical and optical switching on silver 3-phenyl-1-ureidonitrile complex thin films. The films can switch from a high impedance state to a low impedance state with an applied electric field at the threshold of 3.5×10⁷V/m. Furthermore, the films can be switched back to the original state by treating the samples at about 80℃. The optical recording is fulfilled using a semiconductor laser with a wavelength of 780 nm. Erasure can be accomplished by bulk heating or by the laser working with the power beneath the threshold. No loss of the organic was found in the experiments. This material may have a potential application in ultrahigh data density storage.