Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 9 of 9

Full-Text Articles in Engineering

Silver-Coated Tio2 Nanostructured Anode Materials For Lithium Ion Batteries, - Md. Mokhlesur Rahman, Jiazhao Wang, David Wexler, Yuyuan Zhang, Xinjun Li, Shulei Chou, Hua Liu Nov 2012

Silver-Coated Tio2 Nanostructured Anode Materials For Lithium Ion Batteries, - Md. Mokhlesur Rahman, Jiazhao Wang, David Wexler, Yuyuan Zhang, Xinjun Li, Shulei Chou, Hua Liu

Shulei Chou

Anatase TiO2 nanoribbons/nanotubes (TiO2-NRTs) have been synthesised successfully via a reflux method followed by drying in a vacuum oven, and then, silver-coated TiO2 NRTs (Ag/TiO2-NRTs) were prepared by coating silver particles onto the TiO2-NRTs surface by the traditional silver mirror reaction. The physical properties of the synthesised products were examined in detail using X-ray diffraction, field emission gun scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy, respectively. The results indicated that the Ag nanoparticles were uniformly deposited on the surface of the TiO2 nanoribbons/nanotubes. The electrochemical properties were investigated …


Negative Index Metamaterials Based On Metal-Dielectric Nanocomposites For Imaging Applications, L. Menon, W. T. Lu, A. L. Friedman, S. P. Bennett, D. Heiman, S. Sridhar Oct 2012

Negative Index Metamaterials Based On Metal-Dielectric Nanocomposites For Imaging Applications, L. Menon, W. T. Lu, A. L. Friedman, S. P. Bennett, D. Heiman, S. Sridhar

Srinivas Sridhar

Negative index metamaterials are demonstrated based on metal-dielectric nanocomposites prepared using a versatile bottom-up nanofabrication approach. The method involves the incorporation of vertically aligned metal nanowires such as Au and Ag inside dielectric aluminum oxide nanotemplates. Optical absorbance measurements show resonance peaks corresponding to the transverse and longitudinal surface plasmon modes. A quantitative model based on effective medium theory is in excellent agreement with experimental data, and points to specific composite configurations and wavelength regimes where such structures can have applications as negative refraction media for imaging.


Negative Index Metamaterials Based On Metal-Dielectric Nanocomposites For Imaging Applications, L. Menon, W. T. Lu, A. L. Friedman, S. P. Bennett, D. Heiman, S. Sridhar Oct 2012

Negative Index Metamaterials Based On Metal-Dielectric Nanocomposites For Imaging Applications, L. Menon, W. T. Lu, A. L. Friedman, S. P. Bennett, D. Heiman, S. Sridhar

Donald Heiman

Negative index metamaterials are demonstrated based on metal-dielectric nanocomposites prepared using a versatile bottom-up nanofabrication approach. The method involves the incorporation of vertically aligned metal nanowires such as Au and Ag inside dielectric aluminum oxide nanotemplates. Optical absorbance measurements show resonance peaks corresponding to the transverse and longitudinal surface plasmon modes. A quantitative model based on effective medium theory is in excellent agreement with experimental data, and points to specific composite configurations and wavelength regimes where such structures can have applications as negative refraction media for imaging.


Negative Index Metamaterials Based On Metal-Dielectric Nanocomposites For Imaging Applications, L. Menon, W. T. Lu, A. L. Friedman, S. P. Bennett, D. Heiman, S. Sridhar Oct 2012

Negative Index Metamaterials Based On Metal-Dielectric Nanocomposites For Imaging Applications, L. Menon, W. T. Lu, A. L. Friedman, S. P. Bennett, D. Heiman, S. Sridhar

Latika Menon

Negative index metamaterials are demonstrated based on metal-dielectric nanocomposites prepared using a versatile bottom-up nanofabrication approach. The method involves the incorporation of vertically aligned metal nanowires such as Au and Ag inside dielectric aluminum oxide nanotemplates. Optical absorbance measurements show resonance peaks corresponding to the transverse and longitudinal surface plasmon modes. A quantitative model based on effective medium theory is in excellent agreement with experimental data, and points to specific composite configurations and wavelength regimes where such structures can have applications as negative refraction media for imaging.


Stability Of Molybdenum Nanoparticles In Sn-3.8ag-0.7cu Solder During Multiple Reflow And Their Influence On Interfacial Intermetallic Compounds Feb 2012

Stability Of Molybdenum Nanoparticles In Sn-3.8ag-0.7cu Solder During Multiple Reflow And Their Influence On Interfacial Intermetallic Compounds

A.S. Md Abdul Haseeb

This work investigates the effects of molybdenum nanoparticles on the growth of interfacial intermetallic compound between Sn-3.8Ag-0.7Cu solder and copper substrate during multiple reflow. Molybdenum nanoparticles were mixed with Sn-3.8Ag-0.7Cu solder paste by manual mixing. Solder samples were reflowed on a copper substrate in a 250 °C reflow oven up to six times. The molybdenum content of the bulk solder was determined by inductive coupled plasma-optical emission spectrometry. It is found that upon the addition of molybdenum nanoparticles to Sn-3.8Ag-0.7Cu solder, the interfacial intermetallic compound thickness and scallop diameter decreases under all reflow conditions. Molybdenum nanoparticles do not appear to …


Nanostructured Columnar Thin Films Using Oblique Angle Deposition: Growth, Sers Characterization And Lithographic Processing, Piyush J. Shah Jan 2012

Nanostructured Columnar Thin Films Using Oblique Angle Deposition: Growth, Sers Characterization And Lithographic Processing, Piyush J. Shah

Browse all Theses and Dissertations

Oblique angle physical vapor deposition technique has led to the evolution of new class of nanostructured thin films. These films posses' novel anisotropic electrical, magnetic, optical, properties which could be potentially engineered based on the growth conditions and the deposition parameters. The technique is based on the atomistic level self-shadowing principle. In the oblique angle deposition (OAD) technique, the substrate is held at an oblique angle with respect to the incoming vapor flux. As the vapor atoms condense and nucleate on the substrate, the shadowed regions behind each site stop receiving the subsequent vapor atoms. Instead, they land on the …


Optical Detection Of Melting Point Depression For Silver Nanoparticles Via In Situ Real Time Spectroscopic Ellipsometry, S. A. Little, T. Begou, R. W. Collins, S. Marsillac Jan 2012

Optical Detection Of Melting Point Depression For Silver Nanoparticles Via In Situ Real Time Spectroscopic Ellipsometry, S. A. Little, T. Begou, R. W. Collins, S. Marsillac

Electrical & Computer Engineering Faculty Publications

Silver nanoparticle films were deposited by sputtering at room temperature and were annealed while monitoring by real time spectroscopic ellipsometry (SE). The nanoparticle dielectric functions (0.75 eV-6.5 eV) obtained by SE were modeled using Lorentz and generalized oscillators for the nanoparticle plasmon polariton (NPP) and interband transitions, respectively. The nanoparticle melting point could be identified from variations in the oscillator parameters during annealing, and this identification was further confirmed after cooling through significant, irreversible changes in these parameters relative to the as-deposited film. The variation in melting point with physical thickness, and thus average nanoparticle diameter, as measured by SE …


Growth Analysis Of (Ag,Cu)Inse2 Thin Films Via Real Time Spectroscopic Ellipsometry, S. A. Little, V. Ranjan, R. W. Collins, S. Marsillac Jan 2012

Growth Analysis Of (Ag,Cu)Inse2 Thin Films Via Real Time Spectroscopic Ellipsometry, S. A. Little, V. Ranjan, R. W. Collins, S. Marsillac

Electrical & Computer Engineering Faculty Publications

In situ and ex situ characterization methods have been applied to investigate the properties of (Ag,Cu)InSe2 (ACIS) thin films. Data acquired from real time spectroscopic ellipsometry (RTSE) experiments were analyzed to extract the evolution of the nucleating, bulk, and surface roughness layer thicknesses. The evolution of these layer thicknesses suggests a transition from Volmer-Weber to Stranski-Krastanov type behavior when Cu is replaced by Ag. The complex dielectric functions of ACIS at both deposition and room temperature as a function of film composition were also extracted from the RTSE data, enabling parameterization of the alloy optical properties.


Effects Of Addition Of Copper Particles Of Different Size To Sn-3.5ag Solder Dec 2011

Effects Of Addition Of Copper Particles Of Different Size To Sn-3.5ag Solder

A.S. Md Abdul Haseeb

No abstract provided.