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Displaying 1301 - 1325 of 2122

Faceting Control in Core/Shell GaN micropillars using Selective Epitaxy

October 15, 2014
Author(s)
Sergiy Krylyuk, Heayoung Yoon, Baomei Wen, Abhishek Motayed, Albert Davydov, Matt N. King
We report on fabricating large-area, vertically aligned GaN epitaxial core-shell micropillar arrays. The two-step process consisted of inductively coupled plasma (ICP) etch of lithographically patterned n-type GaN substrate followed by selective growth of

Universal scaling law for the flow of non-Newtonian colloidal suspension

October 1, 2014
Author(s)
Nicos Martys, William L. George, Maxime Liard, Pascal Hebraud, Didier Lootens
It has been observed that flow curves (viscosity vs shear-rate) of spherical non-colloidal particles suspended in a non-Newtonian fluid matrix can be rescaled so as to collapse onto the flow curve of the matrix fluid. This result is surprising given the

Testing of Small-Sized Specimens

September 26, 2014
Author(s)
Enrico Lucon
An extensive review of the current state-of-the-art of small specimen test technology (SSTT) has been presented, covering a number of experimental techniques aimed at characterizing the mechanical properties of materials and components through the use of

High-efficiency WSi superconducting nanowire single-photon detectors operating at 2.5 K

September 24, 2014
Author(s)
Varun B. Verma, Boris Korzh, Felix Bussieres, Robert D. Horansky, Adriana E. Lita, Francesco Marsili, Hugo Zbinden, Richard P. Mirin, Sae Woo Nam
We demonstrate that superconducting nanowire single photon detectors (SNSPDs) fabricated from amorphous WSi may be operated with > 75 % system detection efficiency at a temperature approaching seventy percent of the superconducting transition temperature

Methods for the Measurement of Release of MWCNTs from MWCNT-Polymer Composites

September 18, 2014
Author(s)
Debra L. Kaiser, Aleksandr B. Stefaniak, Keana C. Scott, Tinh Nguyen, Jurg Schutz
Multi-wall carbon nanotube (MWCNT)/polymer composites hold great promise as advanced materials for consumer and industrial applications. Throughout the life cycle of these composites, there is opportunity for release of particles that may contain MWCNT and

Physics-based Electro-thermal Saber Model and Parameter Extraction for High-Voltage SiC Buffer IGBTs

September 15, 2014
Author(s)
Tam H. Duong, Allen R. Hefner Jr., Jose M. Ortiz, Sei-Hyung Ryu , Edward VanBrunt, Lin Cheng, Scott Allen, John W. Palmour
The purpose of this paper is to present a physics-based electro-thermal Saber model and parameter extraction sequence for high-voltage SiC buffer layer n-channel insulated gate bipolar transistors (IGBTs). This model was developed by modifying and

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

Fullerene-free polymer solar cells with strongly reduced bimolecular recombination and field- independent charge carrier generation

August 21, 2014
Author(s)
Steffen Roland, Marcel Schubert, Brian A. Collins, Jona Kurpiers, Zhihua Chen, Antonio Facchetti, Harald Ade, Dieter Neher
Photogeneration, recombination and transport of free charge carriers in all-polymer bulk heterojunction solar cells incorporating P3HT as donor and P(NDI2OD-T2) as acceptor polymer have been investigated by the use of time delayed collection field (TDCF)

Combining nanocalorimetry and dynamic transmission electron microscopy for in situ characterization of materials processes under rapid heating and cooling

August 18, 2014
Author(s)
Michael D. Grapes, Thomas LaGrange, Lawrence Henry Friedman, Bryan W. Reed, Geoffrey H. Campbell, Timothy P. Weihs, David A. LaVan
Nanocalorimetry is a chip-based thermal analysis technique capable of analyzing endothermic and exothermic reactions at very high heating and cooling rates. Here we couple a nanocalorimeter with an extremely fast in situ microstructural characterization

Development of Low Carrier Density Graphene Devices

August 1, 2014
Author(s)
Yanfei Yang, Lung-I Huang, David B. Newell, Yasuhiro Fukuyama, Mariano A. Real, Randolph Elmquist
Epitaxial graphene on SiC(0001) is used to fabricate Hall bar structures for metrological applications with a fabrication process that has been developed to eliminate organic chemical contamination of the graphene. Before any lithographic patterning a

International comparison of measurements of hard magnets with the Vibrating Sample Magnetometer

August 1, 2014
Author(s)
F. Fiorillo, C. Beatrice, D. Son, Franz Josef Ahlers, R. Groessinger, F. Albertini, Y. P. Liu, A Lin, E. Patroi, Robert D. Shull, O. Thomas
We present the results of an international comparison regarding the magnetic properties of hard magnets, measured using the Vibrating Sample Magnetometer. The comparison involved eight different international laboratories, plus two laboratories using the

Dielectric characterization by microwave cavity perturbation corrected for non-uniform fields

July 23, 2014
Author(s)
Nathan D. Orloff, Jan Obrzut, Christian J. Long, Thomas F. Lam, James C. Booth, David R. Novotny, James A. Liddle, Pavel Kabos
The non-uniform fields that occur due to the slot in the cavity through which the sample is inserted and those due to the sample geometry itself decrease the accuracy of dielectric characterization by cavity perturbation at microwave frequencies. To

Superconducting nanowire single photon detectors fabricated from an amorphous Mo0.75Ge0.25 thin-film

July 15, 2014
Author(s)
Varun B. Verma, Adriana E. Lita, Michael R. Vissers, Francesco Marsili, David P. Pappas, Richard P. Mirin, Sae Woo Nam
We present the characteristics of superconducting nanowire single photon detectors (SNSPDs) fabricated from amorphous Mo0.75Ge0.25 thin -films. Fabricated devices show a saturation of the internal detection efficiency at temperatures below 1 K, with system

Structures and thermoelectric properties of double-filled (CaxCe1-x)Fe4Sb12 skutterudites

July 9, 2014
Author(s)
Yonggao Y. Yan, Winnie Wong-Ng, James A. Kaduk, Matthew Suchomel, Xiang Sun, Gangjian Tan, Xinfeng Tang, Lan (. Li, Igor Levin
The structures and thermoelectric properties of double-filled (CaxCe1-x)Fe4Sb12 series (x=0, 0.25, 0.5, 0.75, and 1) have been investigated using the combination of experimental and computational approaches. Structural analysis shows that single phases of
Displaying 1301 - 1325 of 2122