Computational Analysis of Silicon Nanoelectromechanical Systems

Next, we extend the quasicontinuum (QC) approach for multiscale analysis of silicon nanostructures at finite temperature. Three models, namely the real space quasiharmonic (QHM) model, the local quasiharmonic (LQHM) model, and the reciprocal space quasiharmonic (QHMK) model are investigated. Within this framework, we compute the effect of the temperature and strain on mechanical properties of silicon. We also compute the mechanical response of silicon nanostructures for various external loads. Furthermore, a more efficient multiscale model is presented for mechanical analysis of nanostructures at finite temperature, by combining the QHMK and LQHM models. Finally, we investigate thermodynamic and mechanical properties of silicon nanostructures at finite temperature by using a QHMG approach - where the quasiharmonic approximation is combined with the local phonon density of states (LPDOS). The LPDOS is efficiently calculated from the phonon Green's function by using a recursion technique. Considering different surfaces of a silicon nanowire, we calculate the local thermodynamic properties at finite temperature and observe that the surface effects on the local thermal and mechanical properties are localized to within one or two atomic layers of the nanowire.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Tang, Zhi

Contributors dc:contributor

• Aluru, Narayana R.

• Physics, Atomic

Language dc:language

eng

Identifier

(MiAaPQ)AAI3314913

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/83908