AVS 47th International Symposium
    Processing at the Nanoscale/NANO 6 Wednesday Sessions
       Session NS+NANO6-WeA

Paper NS+NANO6-WeA9
Time Evolution of Ag Nanowires Grown on Ag/GaAs(110) Surfaces

Wednesday, October 4, 2000, 4:40 pm, Room 302

Session: Nanoscale Modification of Materials
Presenter: H.-B. Yu, University of Texas at Austin
Authors: H.-B. Yu, University of Texas at Austin
C.-S. Jiang, University of Texas at Austin
X.-D. Wang, University of Texas at Austin
C.-K. Shih, University of Texas at Austin
Correspondent: Click to Email
We have studied an unusual 'shrink-expand' behavior of Ag nanowires grown on Ag films using scanning tunneling microscope (STM). Ag films were prepared using low temperature deposition onto UHV in-situ cleaved GaAs(110) surfaces, followed by room temperature annealing. The film thus formed, below or around 6 ML, are atomically flat with voids distributed in the film. After the film becomes smooth, atoms inside the voids continue to transfer to the top Ag surface and form nanowires. Some of the nanowires have aspect ratios greater than 100:1. The nanowire length growth was monitored with STM, showing linear growth rate with time, while keeping the same width. After growing to certain length, the wires start to shrink, and at the same time, their widths expand by about 1.4 nm. After this shrinking process, the Ag wires continue to grow linearly in time before it takes on another 'shrink-expand' process. This 'shrink-expand' behavior can be observed on nanowires with no voids surrounded, but also on wires that are approaching the existing void edge, which indicating the repulsive interaction of nanowires with the edge of the voids. Detailed mechanism of this nanowire shape transition will be discussed.