Dissertation/Thesis Abstract

Transport Measurements Of Gold Nanoparticle Wires
by Sun, Jianwei, Ph.D., The George Washington University, 2011, 206; 3468573
Abstract (Summary)

The electrical properties of granular systems display many interesting features, including the metal-insulator transition. A number of studies have approached the metal-insulator transition by measuring idealized samples ranging from highly ordered to slightly disordered, though, in practical reality, nanoscale systems are often highly disordered. This dissertation is based on measurements of the electrical transport properties of gold nanoparticle wires produced by a new method called Vertical Colloidal Deposition (VCD), which has been used to synthesize highly disordered films and wires from gold nanoparticles in a colloidal suspension. Measurements of the temperature dependent transport properties of conductance, thermopower, and magnetoresistance, between 20K and 260K are reported. The conductance measurements show that a metal-insulator transition occurs in the gold nanoparticle wires upon varying the size of the gold nanoparticles. The thermopower measurements give us information about the electron-phonon interaction within the wires. The magnetoresistance measurements enlighten the different scattering mechanisms in the gold nanoparticle wires, and give us information about the quantum interference within the wires. The study helps us to understand the transport mechanism of electrons in self-assembled, highly disordered systems.

My contribution to the experiment includes: (1) synthesizing and characterizing the samples, (2) taking and analyzing conductance and thermopower data, (3) analyzing magnetoresistance data, and (4) developing a self-consistent picture for understanding these three different types of measurements.

Indexing (document details)
Advisor: Reeves, Mark E.
Commitee: Goodrich, Roy, Griesshammer, Harald W., Parke, William, Qiu, Xiangyun, Tessema, Guebre X.
School: The George Washington University
Department: Physics
School Location: United States -- District of Columbia
Source: DAI-B 72/11, Dissertation Abstracts International
Subjects: Nanoscience, Electromagnetics, Nanotechnology, Materials science
Keywords: Gold nanoparticle wires, Granular materials, Magnetoresistance, Phonon confinement, Phonon drag, Thermopower, Transport measurements, Weak localization
Publication Number: 3468573
ISBN: 978-1-124-82683-7
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