Dissertation/Thesis Abstract

Magnetic nanotubes and nanoporous gold nanowire sensors
by Liu, Zhu, Ph.D., The Johns Hopkins University, 2008, 119; 3309802
Abstract (Summary)

Nanostructured materials are fundamental building blocks for a wide range of nanodevices. Template synthesis is used to fabricate a broad range of nanostructured materials, including single component nanowires, multilayer and multisegment nanowires, nanotubes and nanoporous nanowires. Here two examples of nanowires with unique structure and properties are presented. The first example exploits a novel core/shell microstructure in Cu-Ni films to form magnetic nanotubes. The core/shell microstructure is the result of differences in the nucleation and growth rates of Cu and Ni. By exploiting confinement inside a template, we are able to fabricate nickel nanotubes by selective etching of the Cu in core/shell Ni/Cu nanowires. We report on a novel TEM FIB lift-out method for characterization of the composition and microstructure of the core/shell nanowires. The second example exploits surface scattering in nanoporous gold nanowires for chemical sensing. The feature sizes in nanoporous gold are sufficiently small that the resistance is dominated by surface scattering. An in situ dealloying process has developed to monitor and control the porosity of nanoporous gold nanowire devices. Single nanoporous gold nanowires are demonstrated as chemical sensors for the detection of sulfhydryl molecules.

Indexing (document details)
Advisor: Searson, Peter
School: The Johns Hopkins University
School Location: United States -- Maryland
Source: DAI-B 69/04, Dissertation Abstracts International
Subjects: Chemical engineering, Electromagnetics, Materials science
Keywords: Copper-nickel phase separation, Electrodeposition, Focused ion beams, Gold, Magnetic nanotubes, Nanotubes, Nanowire sensors, Porous gold nanowires
Publication Number: 3309802
ISBN: 978-0-549-57831-4
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