Xiang Chengxiang, Kim Jung Yun, Penner Reginald M
Department of Chemistry, University of California, Irvine, California 92697-2025, USA.
Nano Lett. 2009 May;9(5):2133-8. doi: 10.1021/nl900698s.
A protocol is described for forming reconnectable sub-5 nm nanogaps in single ultralong (>100 microm) gold nanowires fabricated by lithographically patterned nanowire electrodeposition (LPNE). During an initial computer-controlled electromigration process, gold nanowires with a rectangular cross-section were transformed by the formation of a constriction at a single point along the 250 microm length of the nanowire, and within this constriction a nanogap of width <5 nm. After this initial nanogap formation, 42% (19 of 45) of the gaps could be reconnected by applying a voltage ramp, restoring the electrical resistance of the original nanowire to within 10%. The voltage threshold for nanogap reconnection was narrowly distributed across multiple wires and nanogaps and in the range from 2 to 3 V. Using voltage programming, it was possible to cycle between the open and closed states for some nanogaps more than 100 times. We propose that the mechanism for reconnection involves the field evaporation of gold, qualitatively as observed previously for metal transfer from the tip of a scanning tunneling microscope.
本文描述了一种用于在通过光刻图案化纳米线电沉积（LPNE）制造的单根超长（>100微米）金纳米线中形成可重新连接的亚5纳米纳米间隙的协议。在初始的计算机控制电迁移过程中，具有矩形横截面的金纳米线通过在纳米线250微米长度上的单个点处形成收缩而发生转变，并且在该收缩内形成宽度<5纳米的纳米间隙。在最初形成纳米间隙之后，通过施加电压斜坡，42%（45个中的19个）的间隙可以重新连接，将原始纳米线的电阻恢复到10%以内。纳米间隙重新连接的电压阈值在多根导线和纳米间隙上分布狭窄，范围为2至3伏。使用电压编程，对于一些纳米间隙，可以在打开和关闭状态之间循环100多次。我们提出重新连接的机制涉及金的场蒸发，定性地如先前在扫描隧道显微镜尖端的金属转移中所观察到的那样。
