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Displaying 376 - 400 of 882

Electron and Hole Photoemission Detection for Band Offset Determination of Tunnel Field-Effect Transistor Heterojunctions

November 24, 2014
Author(s)
Wei Li, Qin Zhang, R. Bijesh, Oleg A. Kirillov, Yiran Liang, Igor Levin, Lianmao Peng, Xuelei Liang, S. Datta, David J. Gundlach, Nhan V. Nguyen
The electrical performance of a tunnel field-effect transistor depends critically on the band offset at their semiconductor heterojunction interface. Historically, it has been difficult to experimentally determine how the electronic bands align at the

Accurate determination of the size distribution for polydisperse, cationic metallic nanomaterials by asymmetric-flow field flow fractionation

November 13, 2014
Author(s)
Julien C. Gigault, Thao M. Nguyen, John M. Pettibone, Vincent A. Hackley
In this work we have developed and validated a methodology for determining the size distribution in polydisperse cationic nanoparticle (NP) samples using asymmetric-flow field flow fractionation (A4F), where known compositional influence of previously used

Mechanisms of aging and release from weathered nanocomposites

October 31, 2014
Author(s)
Tinh Nguyen, Wendel Wohlleben, Li Piin Sung
Polymer nanocomposites are increasingly used in outdoor structures. However, polymers are susceptible to degradation by solar ultraviolet (UV) radiation, which potentially releases nanofiller during polymer nanocomposites' life cycle. Such release may pose

Nanoparticle size determination using optical microscopes

October 27, 2014
Author(s)
Ravikiran Attota, Richard J. Kasica, Premsagar P. Kavuri, Hyeong G. Kang, Lei Chen
We present a simple method for size determination of nanoparticles using conventional optical microscopes. The method, called through-focus scanning optical microscopy (TSOM), makes use of the four-dimensional optical information collected at different

Phase-Sensitive Detection of Spin Pumping via the ac Inverse Spin Hall Effect

October 6, 2014
Author(s)
Thomas J. Silva, Justin M. Shaw, Hans T. Nembach, Mathias A. Weiler
Sources of pure spin currents are a fundamental building block of spintronic devices. In ferromagnet/normal metal heterostructures, spin currents are generated at ferromagnetic resonance. This is known as spin pumping, where spin currents of both dc and ac

The DNA Damaging Potential of Photoactivated P25 Titanium Dioxide Nanoparticles

September 30, 2014
Author(s)
Elijah Petersen, Vytas Reipa, Stephanie S. Watson, Deborah Jacobs, Savelas A. Rabb, Bryant C. Nelson
Titanium dioxide nanoparticles (TiO2 NPs) are found in numerous commercial and personal care products. Thus, it is necessary to understand and characterize their potential environmental health and safety risks. It is well known that photoactivated TiO2 NPs

Photoelectron spectroscopy of wet and gaseous samples through electron transparent graphene membranes

September 22, 2014
Author(s)
Jurgen Kraus, Robert Reichelt, Sebastian Gunther, Luca Gregoratti, Tang Lin Teo, Maya Kiskinova, Alexander Yulaev, Ivan Vlassiouk, Andrei Kolmakov
Photoelectron spectroscopy (PES) and microscopy are highly demanded for exploring morphologically complex solid-gas and solid-liquid interfaces under realistic conditions but the very small electron mean free path inside the dense media imposes serious

Optimization of Focused Ion Beam-Tomography for Superconducting Electronics

August 27, 2014
Author(s)
Aric W. Sanders, Anna E. Fox, Paul D. Dresselhaus, Alexandra Curtin
Superconducting electronics play an important role in quantum computation, ultra-low power electronics, voltage standards and magnetic sensors. Many of these applications rely on the microfabrication of superconducting circuits with multiple wiring layers

Multiscale Correlative Measurements of Nanoparticles in Cells

August 26, 2014
Author(s)
Aric W. Sanders, Kavita M. Jeerage, Cindi Schwartz, Alexandra E. Curtin, Ann C. Chiaramonti Debay
Nanoparticles are emerging as invaluable tools in disease diagnosis, disease treatment and imaging contrast enhancement agents. The interactions of nanoparticles with host organisms are complex and affect biological systems over length scales that vary

Electronic Structure and Band Alignment at Epitaxial Co3O4/SrTiO3 Heterojunction

July 21, 2014
Author(s)
Liang Qiao, Wei Li, Haiyan xiao, Harry M. Meyer, Xuelei Liang, Nhan Van Nguyen, Michael D. Biegalski
The electronic properties of solid-solid interfaces play critical roles in a variety of technological applications. Recent advance of film epitaxy and characterization techniques have demonstrated a wealthy of exotic phenomena at interfaces of oxide

Influence of morphology on current-voltage behavior of GaN nanowires

July 1, 2014
Author(s)
Paul T. Blanchard, Kristine A. Bertness, Matthew D. Brubaker, Todd E. Harvey, Aric W. Sanders, Norman A. Sanford
We demonstrate the effect that the different morphologies of MBE-grown GaN nanowires (NWs) can have upon current-voltage (I-V) behavior. Two main aspects of NW morphology were investigated. The first aspect was the NW diameter, dNW. For single-crystal Si

State of the Art Raman Techniques for Biological Applications

July 1, 2014
Author(s)
Angela R. Hight Walker, Alasdair Rae, Rainer Stosch, Petr Klapetek, Debdulal Roy
Raman spectroscopy is a powerful tool for the elucidation of qualitative and quantitative information from biological systems and has huge potential in areas such as biotechnologies, drug discovery, agro-chemical research and clinical diagnostics. This

Effects of Temperature on Surface Accumulation and Release of Silica Nanoparticles in an Epoxy Nanocoating Exposed to UV Radiation

June 16, 2014
Author(s)
Chun-Chieh Tien, Ching-Hsuan Chang, Bernard Hao-Chih Liu, Deborah Jacobs, Savelas A. Rabb, Lee L. Yu, Tinh Nguyen, Li Piin Sung
Polymer nanocoatings are increasingly used outdoors and in harsh environments. However, because most common polymers degraded by the weathering elements, nanoparticles in polymer nanocoatings may be released into the environments. Such nanoparticle release

Multi-method analysis of multiwall carbon nanotube polymer nanocomposite samples after photodegradation

June 16, 2014
Author(s)
Elijah Petersen, Thomas F. Lam, Justin Gorham, Keana Scott, Chris Long, Renu Sharma, Li Piin Sung, James Alexander Liddle, Tinh Nguyen
Nanomaterials can be used as nanofillers to enhance the properties of polymeric materials. However, the effect of weathering on nanocomposites and the potential for nanomaterial release is not yet well understood. Multiple analytical methods are needed to

Use of Single Particle Inductively Coupled Plasma Mass Spectrometry to Characterize a New Silver Nanoparticle Reference Material

June 11, 2014
Author(s)
Karen E. Murphy, Jingyu Liu, William F. Guthrie, Justin M. Gorham, John E. Bonevich, Andrew J. Allen, Michael R. Winchester, Vincent A. Hackley, Robert MacCuspie
In this study we use inductively coupled plasma mass spectrometry operated in single particle mode (spICP-MS) to simultaneously characterize the size distribution and dissolved silver fraction of a new silver nanoparticle (AgNP) candidate reference

Does Your SEM Really Tell the Truth? How Would You Know? Part 2

May 30, 2014
Author(s)
Michael T. Postek, Andras Vladar, Premsagar P. Kavuri
The scanning electron microscope (SEM)has gone through a tremendous evolution to become indispensable for many and diverse scientific and industrial applications. The improvements have significantly enriched and augmented the overall SEM performance and

Localization and electron-electron interactions in few-layer epitaxial graphene

May 28, 2014
Author(s)
Randolph E. Elmquist, Fan-Hung Liu, Lung-I Huang, Yasuhiro Fukuyama, Chi-Te Liang, Yanfei Yang
We study the quantum corrections caused by electron-electron (e-e) interactions and localization to the conductivity in few-layer epitaxial graphene, in which the carriers responsible for transport are massive. Our results demonstrate that the diffusive
Displaying 376 - 400 of 882