Discrete thinning dynamics in a continuum model of metallic nanowires
Abstract
Description
Transmission electron microscopy experiments have recently observed gold metal nanocylinders to thin down in a discrete manner: A kink--a step of order of one atomic layer--nucleates at one end and then moves along the wire, leaving a thinner cylinder behind it. In this paper, I show that a similar thinning process takes place within the nanoscale free-electron model, a structural and dynamical model of nanowires that treats the electron-confinement effects exactly while replacing the atomic structure by a continuum. Electron-shell effects, previously shown to be responsible for the stability of wires with magic radii, favor the formation of kinks connecting magic cylinders. A rich kink dynamics including interkink interactions ensues and is similar to that observed experimentally.
9 pages, 5 figures. Version accepted for publication by Phys. Rev. B. The section on instability propagation has been removed, and submitted as a separate manuscript (arXiv:0704.2227)
9 pages, 5 figures. Version accepted for publication by Phys. Rev. B. The section on instability propagation has been removed, and submitted as a separate manuscript (arXiv:0704.2227)