Atomic scale design and stability of quantum nanowires at epitaxial interfaces and free-standing in space
| Date/Time: | Monday, 16 Sep 2019 from 11:00 am to 11:50 am |
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| Location: | Physics 18/19 |
| Phone: | 515-294-7377 |
| Channel: | College of Liberal Arts and Sciences |
| Actions: | Download iCal/vCal | Email Reminder |
Metal nanowires excite remarkable academic curiosity as physical systems with confined geometry, reduced dimensionality and peculiar quantum properties. The exotic features of the nanowires are strongly dependent on their size, shape and morphology, and therefore detailed knowledge of the nanowire fine atomic structure is indispensable. The present lecture gives an overview on the problem of structural instability, spontaneous breakdown and complete disintegration of metal nanowires located on epitaxial interfaces or free-standing in space. The introduced new physical model reveals specific multi-step vacancy-mediated mechanism of thermally activated nanowire rupture. Accounting for the impact of essential physical quantities on the nanowire instability including system temperature, number of defects, lattice mismatch, interface anisotropy, atomic interactions, ridgidity and flexibility, this model identify a general scenario of nanowire decomposition. The complete rupture kinetics of monatomic nanowire breakdown is described by a set of rate equations and on that background expressions are derived for physically important and experimentally accessible quantities including time-dependent probability for nanowire breakdown and nanowire mean lifetime. The presented ensemble of studies contributes to a new type atomic-scale design of epitaxial interfaces, giving insight into thermal instability, rupture mechanism and fine tuning of the structural, morphological and thermodynamic properties of a large variety of metal nanowires.