Investigation of structural properties of metal nanorods: molecular dynamics simulations

Yağlı, Hüseyin
After recent advances in microscopy and characterization techniques reached smaller length scales down to individual atoms, nanowires attracted a large interest. The material properties that are not changeable in bulk materials can be controlled in nanowires to fit the requirements of the intended application area. Characterization of nanowires is important in order to establish a reproducible relationship with their characteristics and their desired functionality. In this thesis, structural properties of copper, silver and gold nanowires with three different widths generated from low-index surfaces (100), (110), (111) under strain have been investigated. Classical molecular dynamics simulations have been performed at 1 K and 300 K using an atomistic potential consisting of two body interactions among the atoms. Strain has been applied to the nanowires along the uniaxial wire direction. It has been found that uniaxial strain shows cross section geometry and temperature dependent characteristics. The nanowires generated from (100) and (110) surfaces are relatively stronger against uniaxial strain than the nanowires generated from (111) surface. Temperature has a positive effect to the ductility of the nanowires. The nanowires could not form 1-D structures without fragmentation.


Investigation of HMO spectra of Huckel and Mobius type cyclacenes
Turker, L; Erkoç, Şakir (1997-01-01)
The Huckel molecular orbital spectra (HMO) of Huckel- and Mobius-type cyclacenes having 3-15 benzenoid rings were investigated and it was found that certain eigenvalues are topologically invariant, whereas others exhibit topological periodicity. Fbr example, Huckel-type cyclacenes having 2r (r: 2,3,4,...) benzenoid rings which possess nonbonding molecular orbitals (NBMO) and are thus expected to be open shell structures.
Investigation of the structural properties of low dimensional nanostructures : molecular dynamics simulations
Özdamar, Burak; Erkoç, Şakir; Department of Physics (2013)
This study aims to investigate the structural and thermodynamic properties of nanostructures which are generated from different atoms and geometries. The nanostructures in question are boron nitride nanoparticles, silicon nanowires along with sawtooth-like graphene nanoribbons. The goal is to calculate the specific heat values of boron nitride nanoparticles while the mechanical properties of the other nanostructures are investigated under uniaxial strain. The structural behaviors of these generated nanopart...
Empirical Comparison of Random and Periodic Surface Light-Trapping Structures for Ultrathin Silicon Photovoltaics
BRANHAM, Matthew; HSU, WeiCsun; Yerci, Selçuk; LOOMİS, James; BORİSKİNA, Svetlana; HOARD, Brittany; HAN, Sang Eon; EBONG, Abasifreke; CHEN, Gang (2016-06-01)
Pyramidal light-trapping structures of a range of length scales — and both periodic and random arrangements — are shown to yield similarly high absorption in thin film crystalline silicon photovoltaics. Through the combination of results from experiment and simulation, the trade-off between absorption effectiveness and ease of fabrication of various pyramidal light-trapping structures is investigated for application in thin-film crystalline silicon solar cells.
Study of the Influence of Transition Metal Atoms on Electronic and Magnetic Properties of Graphyne Nanotubes Using Density Functional Theory
Alaei, Sholeh; Jalili, Seifollah; Erkoç, Şakir (Informa UK Limited, 2015-01-01)
Density functional theory calculations were used to study the adsorption of three transition metal atoms (Fe, Co, and Ni) on the external surface of two zigzag and two armchair graphyne nanotubes. The most stable position for the adsorption of all three metal atoms on all nanotubes is on the acetylenic ring. The metal atom remains in the plane of the acetylenic ring and makes six bonds with neighboring carbon atoms. Fe and Co complexes are magnetic and show different properties such as metal, semimetal, hal...
Dielectric and Thermal Effects on the Optical Properties of Natural Dyes: A Case Study on Solvated Cyanin
Malcıoğlu, Osman Barış; Gebauer, Ralph; Varsano, Daniele; Baroni, Stefano (2011-10-05)
The optical properties of the flavylium state of the cyanin dye are simulated numerically by combining Car-Parrinello molecular dynamics and linear-response time-dependent density functional theory calculations. The spectrum of the dye calculated in the gas phase is characterized by two peaks in the yellow and in the blue (green and violet), using a GGA-PBE (hybrid-B3LYP) DFT functional, which would bring about a greenish (bright orange) color incompatible with the dark purple hue observed in nature. Descri...
Citation Formats
H. Yağlı, “Investigation of structural properties of metal nanorods: molecular dynamics simulations,” M.S. - Master of Science, Middle East Technical University, 2014.