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Full-Text Articles in Nanoscience and Nanotechnology

Experimental And Computational Study On Magnetic Nanowires Of Layered Titanates, Caleb Layne Heath May 2019

Experimental And Computational Study On Magnetic Nanowires Of Layered Titanates, Caleb Layne Heath

Theses and Dissertations

The intricate nanostructures of layered titanates are unique among nanomaterials due to their easy and inexpensive syntheses. These nanomaterials have been proven valuable for use in industries as varied as energy, water treatment, and healthcare, and can be produced at industrial scales using already existent equipment. They have complex morphology, and surface structure well suited to chemical modification and doping. However, there is a longstanding debate on their lattice structure after the doping. There is a long-unmet need to understand, using both experimental and simulation methods, how dopants alter the clay-like layered crystal structure and associated physical and chemical properties ...


Nanowire-Based Light-Emitting Diodes: A New Path Towards High-Speed Visible Light Communication, Mohsen Nami Sep 2017

Nanowire-Based Light-Emitting Diodes: A New Path Towards High-Speed Visible Light Communication, Mohsen Nami

Physics & Astronomy ETDs

Nano-scale optoelectronic devices have gained significant attention in recent years. Among these devices are semiconductor nanowires, whose dimeters range from 100 to 200 nm. Semiconductor nanowires can be utilized in many different applications including light-emitting diodes and laser diodes. Higher surface to volume ratio makes nanowire-based structures potential candidates for the next generation of photodetectors, sensors, and solar cells. Core-shell light-emitting diodes based on selective-area growth of gallium nitride (GaN) nanowires provide a wide range of advantages. Among these advantages are access to non-polar m-plane sidewalls, higher active region area compared to conventional planar structures, and reduction of threading ...


Dynamic Atomistic Study Of Tunnel Functions In Nanostructured Transitional Metal Oxides, Yifei Yuan Jan 2016

Dynamic Atomistic Study Of Tunnel Functions In Nanostructured Transitional Metal Oxides, Yifei Yuan

Dissertations, Master's Theses and Master's Reports

Alpha (α-) MnO2 is a well know transitional metal oxide possessing one dimensional 2×2 (4.6 × 4.6 Å2) tunnels for accommodation of various ions. Such a characteristic tunneled structure has enabled the wide applications of α-MnO2 in the fields of ion exchange, molecular sieves, biosensor, catalysis and energy storage. This PhD dissertation focuses on the dynamic study of ion transport functionality of α-MnO2 at atomic level using an aberration corrected scanning transmission electron microscopy equipped with a special holder with a scanning tunneling microscopy probe.

The wide application of in situ TEM studying the ...


Merging Bottom-Up With Top-Down: Continuous Lamellar Networks And Block Copolymer Lithography, Ian Patrick Campbell Jan 2014

Merging Bottom-Up With Top-Down: Continuous Lamellar Networks And Block Copolymer Lithography, Ian Patrick Campbell

Chemical & Biological Engineering Graduate Theses & Dissertations

Block copolymer lithography is an emerging nanopatterning technology with capabilities that may complement and eventually replace those provided by existing optical lithography techniques. This bottom-up process relies on the parallel self-assembly of macromolecules composed of covalently linked, chemically distinct blocks to generate periodic nanostructures. Among the myriad potential morphologies, lamellar structures formed by diblock copolymers with symmetric volume fractions have attracted the most interest as a patterning tool. When confined to thin films and directed to assemble with interfaces perpendicular to the substrate, two-dimensional domains are formed between the free surface and the substrate, and selective removal of a single ...


Enhancing Phase-Change Heat Transfer With Copper Nanowire-Structured Surfaces, Qian Li Jan 2014

Enhancing Phase-Change Heat Transfer With Copper Nanowire-Structured Surfaces, Qian Li

Mechanical Engineering Graduate Theses & Dissertations

As energy consumption drastically increases in the electronics and energy conversion systems, heat dissipation becomes increasingly important for device reliability and system efficiency. Phase change heat transfer, which takes advantage of the latent heat during the phase change process, is the most promising method to efficiently remove high heat fluxes. Nano structures, which provide extended surface areas and enhanced hydrophilicity or hydrophobicity have been widely used in phase change heat transfer enhancement. Copper nanowires are one of the most promising nano structures due to ease of fabrication, controllable structure dimensions, and high thermal conductivity. In this study, the heat transfer ...


Nanowire Arrays And 3d Porous Conducting Networks For Li-Ion Battery Electrodes, Miao Tian Jan 2014

Nanowire Arrays And 3d Porous Conducting Networks For Li-Ion Battery Electrodes, Miao Tian

Mechanical Engineering Graduate Theses & Dissertations

There have been growing interests in developing high-capacity, high-power, and long-cycle-life lithium-ion (Li-ion) batteries due to the increasing power requirements of portable electronics and electrical vehicles. Various efforts have been made to utilize nano-structured electrodes since they can improve the performance of Li-ion batteries compared to bulk materials in many ways: fast electrode reaction due to the large surface area, efficient volume-change accommodation due to the small size, and fast Li-ion transport along the nanoscale gaps. Among various nanostructures, nanowire arrays present an excellent candidate for high performance lithium-ion battery electrodes, which have attracted intensive research over the past few ...


Advancing Microscope And Probe Design For Near-Field Scanning Microwave Microscopy, Joel C. Weber Jan 2014

Advancing Microscope And Probe Design For Near-Field Scanning Microwave Microscopy, Joel C. Weber

Mechanical Engineering Graduate Theses & Dissertations

In this thesis, we address the design and application of a microscope and probes for near-field scanning microwave microscopy. We provide an introduction to the development of microwave microscopy and its contributions to material metrology. In particular, we focus on its application to the study of photovoltaics. We then expand beyond these studies to the fabrication of nanowire-based probes for microwave microscopy. These probes provide avenues for advancing an array of scanning probe techniques, including continued measurements on photovoltaics with improved resolution.

To begin, we present a near-field scanning microwave microscope that has been configured for imaging photovoltaic samples. Our ...


Nucleation And Growth Of Metals On Carbon Surfaces, David Victor Appy Jan 2014

Nucleation And Growth Of Metals On Carbon Surfaces, David Victor Appy

Graduate Theses and Dissertations

This thesis work presents an investigation of the basic interaction between metals and the carbon surfaces HOPG and amorphous carbon. This work was motivated by the discovery of a family of metal nanowires which grow as single crystals protruding substantially perpendicular to a substrate, where the substrate is held at elevated temperature (800-1100 K). The most prolific growth is seen for Cu on amorphous carbon substrates. The fabrication and properties of these wires have been pioneered by our collaborator, Dr. Gunther Richter, at the Max Planck Institute for Intelligent Systems in Stuttgart, Germany. They have potential uses in nanoscale mechanical ...


Vibration And Buckling Of Carbon Nanotube, Graphene, And Nanowire, Mohammad Hadi Mahdavi Jan 2013

Vibration And Buckling Of Carbon Nanotube, Graphene, And Nanowire, Mohammad Hadi Mahdavi

Electronic Thesis and Dissertation Repository

Nanostructured materials with superior physical properties hold promise for the development of novel nanodevices. Full potential applications of such advanced materials require accurate characterization of their physical properties, which in turn necessitates the development of computer-based simulations along with novel experimental techniques. Since controlled experiments are difficult for nanoscale materials and atomic studies are computationally expensive, continuum mechanics-based simulations of nanomaterials and nanostructures have become the focal points of computational nano-science and materials modelling.

In this study, emphasis is given to predicting the mechanical behaviour of carbon nanotube (CNT), graphene, nanowire (NW), and nanowire encapsulated in carbon nanotube (NW@CNT ...


Development Of Advanced Polymer Nanocomposite Capacitors, Miguel Mendoza Jan 2012

Development Of Advanced Polymer Nanocomposite Capacitors, Miguel Mendoza

Open Access Theses & Dissertations

The current development of modern electronics has driven the need for new series of energy storage devices with higher energy density and faster charge/discharge rate. Batteries and capacitors are two of the most widely used energy storage devices. Compared with batteries, capacitors have higher power density and significant higher charge/discharge rate. Therefore, high energy density capacitors play a significant role in modern electronic devices, power applications, space flight technologies, hybrid electric vehicles, portable defibrillators, and pulse power applications. Dielectric film capacitors represent an exceptional alternative for developing high energy density capacitors due to their high dielectric constants, outstanding ...


Development Of Nanocomposites For Energy Storage Devices, Md Ashiqur Rahaman Khan Jan 2012

Development Of Nanocomposites For Energy Storage Devices, Md Ashiqur Rahaman Khan

Open Access Theses & Dissertations

With the ever-increasing need in improving the performance and operation life of future mobile devices, developing higher power density energy storage devices has been receiving more attention. Lithium ion battery (LIB) and capacitor are two of the most widely used energy storage devices and have attracted increasing interest from both industrial and academic fields. Batteries have higher power density than capacitor but significantly longer charge/discharge rates. In order to further improve the performance of these energy storage devices, one of the approaches is to use high specific surface area nano-materials. Among all the nano-materials developed so far, one-dimensional nanowires ...


Synthesis And Characterization Of One- And Two-Dimensional Novel Nanomaterials, Yu Zhong Dec 2011

Synthesis And Characterization Of One- And Two-Dimensional Novel Nanomaterials, Yu Zhong

Electronic Thesis and Dissertation Repository

Nanomaterials have attracted extensive interest due to their unique structure and excellent properties compared with their bulk counterparts. To obtain nanodevices with controlled properties, it is prerequisite to synthesize nanostructured materials with designed architecture.

In this work, low (one- and two-) dimensional nanomaterials with controlled structures have been synthesized and characterized based on chemical vapour deposition strategy. Our research targets cover one-dimensinoal hollow, solid, and solid @ hollow heterostructural nanomaterials including carbon nanotubes (CNTs), nitrogen-doped carbon nanotubes (NCNTs), SnO2 nanowires, Mo doped-SnO2 nanowires, Sn nanowires encapsulated in CNTs (Sn@CNTs), and two-dimensional Mo2S3 nanopetals. Dependence of ...


Atomic Layer Deposition Enabled Interconnect And Packaging Technologies For As-Grown Nanowire Devices, Jen-Hau Cheng Jan 2010

Atomic Layer Deposition Enabled Interconnect And Packaging Technologies For As-Grown Nanowire Devices, Jen-Hau Cheng

Mechanical Engineering Graduate Theses & Dissertations

Nanowires (NWs) have attracted considerable interests in many applications due to their small size, extremely high surface-to-volume ratio, and superior material properties. They are promising material candidates as fundamental building blocks for future electronic, optoelectronic, energy, sensor, and biomedical applications. The majority of research activities have focused on the synthesis of NWs. With the advent of high-performance NWs, interconnect and packaging of NWs are becoming increasingly important for device applications. Vertical NW array devices, compared with horizontal NW configurations, are of great importance for achieving ultra-high integration density at the device level without the need of additional assembly and rearrangement ...


Nanomaterial Characterization Using Actuated Microelectromechanical Testing Stages, Joseph James Brown Jan 2010

Nanomaterial Characterization Using Actuated Microelectromechanical Testing Stages, Joseph James Brown

Mechanical Engineering Graduate Theses & Dissertations

In this work, microfabricated mechanical systems have been created in a variety of forms and operated to perform nanomaterials characterization tests. A simplified integrated test system was developed and used to collect data from a range of materials including gallium nitride nanowires. A new force estimation approach was developed which enables estimation of the forces provided by electrothermal microelectromechanical (MEMS) actuators, and with knowledge of a material specimen cross-section area, an estimation of the engineering stress within the nanomaterial specimen.

In an expanded design, a MEMS micromanipulator probe interfaced with a removable specimen holder, also known as a test coupon ...