AVS 54th International Symposium | |
Nanometer-scale Science and Technology | Wednesday Sessions |
Session NS+EM-WeM |
Session: | Nanoscale Devices and Nanowires I |
Presenter: | P.T. Sprunger, Louisiana State University |
Authors: | P.T. Sprunger, Louisiana State University I. Senevirathne, Louisiana State University W. Zhao, Louisiana State University B.M. Watson, Louisiana State University O. Kizilkaya, Louisiana State University A.K. Sekharan, Louisiana State University R.L. Kurtz, Louisiana State University |
Correspondent: | Click to Email |
Epitaxial Ag nanowires have been found to self-assemble on Cu(110) for Ag coverages exceeding 1.2 ML. The electronic and plasmon loss structure of the nanowires have been characterized by ARPES and EELS. STM images reveal that Ag nanowires grown on Cu(110) are approximately 2 nm high and ~12 nm wide. The nanowires grow oriented with the long axis parallel to the [¯110] substrate direction and they have aspect ratios up to 20:1. The ARPES results show that the valence bands within the Ag nanowire are strongly anisotropic with clear band dispersion in the along-wire direction, but no dispersion in the across-wire direction. This strongly suggests that the valence electrons of Ag behave as quasi-one-D conductors along the wire yet confined with atomic-like states perpendicular. Fermi surface crossings have been observed, confirming that metallic behavior is realized along the wire axis. In accord with the ARPES measurements, EELS reveals that the plasmon excitation is red-shifted at the zone-center and is nearly dispersonless perpendicular to the nanowire direction. These results will be discussed in light of recent band-structure calculations of Ag nanowires and models for plasmon behavior in quasi-1D structures. We would like to acknowledge the support of the LSU CAMD synchrotron light source and the support of and LA-R&D and NSF through DMR-0504654.