| Diamond/CNT Film Interface for Heat Dissipation in Electronic Devices |
29-Sep-2009 |
10 pages |
| Authors:
Phan Ngoc Minh; VIETNAM ACADEMY OF SCIENCE AND TECHNOLOGY HANOI INST OF MATERIALS SCIENCE (VAST)
|
 | Commercial thermal matching media such as thermal grease are normally basing on silver. By adding a suitable amount of the CNTs into the commercial silver paste, it is expected to improve the conductivity and the performance of any high power electronic components such as micro-processor, high power laser, high power LED for lighting, and so on. In this research, CNT materials were successfully functionalized to form CNT-COOH and CNT-C6H4NH2. The ... |
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| Solution Deposition Methods for Carbon Nanotube Field-Effect Transistors |
Jun-2009 |
32 pages |
| Authors:
Matthew Ervin; Natalie Salaets; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| This study evaluated different methods for controlled deposition of carbon nanotubes (CNTs) from solution onto a silicon substrate to make CNT field-effect transistors (FETs). The goal of this deposition was to achieve reproducible device properties through more uniform CNT densities and other traits. This method serves as an easier, room temperature alternative to chemical vapor deposition growth. Three different types of CNT solutions were spun onto substrates: pristine tubes solubilized ... |
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| Q5 Known Good Substrates Technical Report |
31-Mar-2009 |
12 pages |
| Authors:
Gilyong Chung; Mark J Loboda; Eric P Carlson; Rebecca S Lauer; DOW CORNING CORP MIDLAND MI
|
| The Known Good Substrates (KGS) Phase II program was initiated 29 August 2007. Subcontractor work on CVD modeling and analysis of epitaxy experiments have been the main focus of efforts in Q6. This technical report summarizes the progress by all team members against the tasks and milestones. This is the final technical quarterly summary for the KGS Phase II program. It is part of the contract extension where consideration was ... |
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| Studies on Enhancing Transverse Thermal Conductivity in Carbon/Carbon Composites |
01-Oct-2008 |
5 pages |
| Authors:
Lalit M Manocha; SOPHISTICATED INSTRUMENTS CENTER FOR APPLIED RESEARCH AND TESTING (SICART) VALLABH VIDYANAGAR (INDIA)
|
| In the present studies, attempts were made to prepare multi-walled carbon nanotubes (MWNTs) on a large scale in the form of aligned carbon nanotubes as arrays. Arrays of these carbon nanotubes were densified, like in carbon felt densification process by filling the space within the nanotubes. Therefore, the work undertaken in the present studies was to develop arrays of MWNTs and to develop aligned MWNTs composite films using chemical vapor ... |
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| Materials Design Through Chemical Control of Precursors |
22-Aug-2008 |
11 pages |
| Authors:
Charles H El Winter; Hani M Kadri; Dezelah; Charles L IV; WAYNE STATE UNIV DETROIT MI OFFICE OF RESEARCH AND SPONSORED PROGRAMS
|
| Our research project that was supported by the Army Research Office sought to develop improved metal-organic film growth precursors for Pb- and Ba-containing materials, lanthanide-containing materials, and semiconductors that contain small clusters of magnetic elements within the semiconductor matrix. These materials encompass a broad range of military and civilian applications, and their successful development will literally change the way we live. More broadly, we sought to develop chemical insight into ... |
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| Design and Fabrication of Microheaters for Localized Carbon Nanotube Growth |
Aug-2008 |
5 pages |
| Authors:
Y Zhou; J Johnson; L Wu; S Maley; A Ural; H Xie; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH
|
| This paper presents a reliable method for the growth of single-walled carbon nanotubes (SWNTs) at room temperature by using localized heating. A surface micromachining technique is used to create suspended microstructures for good thermal isolation. Pt resistors are integrated as the heating source, and the local growth temperature and electrical field can be controlled by the heater geometry and applied voltage. Growth of aligned nanotubes with diameters ranging from 1-10 ... |
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| High Yield Magnetic Nanoparticles Filled Multiwalled Carbon Nanotubes Using Pulsed Laser Deposition |
Aug-2008 |
3 pages |
| Authors:
Dereje Seifu; Shashi P Karna; MORGAN STATE UNIV BALTIMORE MD DEPT OF PHYSICS
|
| We present a high yield filling technique of multiwalled carbon nanotubes (MWNTs), grown vertically on a SiO2 substrate, with magnetic nanoparticles using pulsed laser deposition (PLD). Magnetization measurements in-plane and out-of- plane with respect to the sample surface indicate reasonable coercivity estimated at 0.4 T. The magnetic anisotropy is however found to be randomly oriented, indicating a polycrystalline structure. The unique difference between the in-plane and out-of-plane magnetizations is the ... |
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| Microstructural Effects on the Corrosion Behavior of Alloys and Ceramics |
30-Jun-2008 |
45 pages |
| Authors:
Todd Allen; Lizhen Tan; NATIONAL ASSOCIATION OF CORROSION ENGINEERS HOUSTON TX
|
| The objective of this research was to investigate the effect of microstructure on the corrosion behavior of metals and ceramics. Representative materials from the important engineering alloys and ceramics were studied to determine their corrosion behavior in supercritical water and during cyclic oxidation in air. The materials included Incoloy alloy 800H, Inconel alloy 617, 12%Cr ferritic-martensitic steel HCM12A, and silicon carbide fabricated by means of chemical vapor deposition (CVD). The ... |
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| Low Cost Zinc Sulfide Missile Dome Manufacturing |
21 APR 2008 |
6 pages |
| Authors:
Anthony Haynes; MISSILE RESEARCH DEVELOPMENT AND ENGINEERING CENTER REDSTONE ARSENAL AL MISSILE GUIDANCE DIRECTORATE
|
| In conclusion, the new Army ManTech Program "Low Cost Zinc Sulfide Missile Dome Manufacturing" is currently addressing advanced manufacturing methods for lower unit production cost of multispectral zinc sulfide domes. While Dome Program personnel are still working out some of the details of the program, the objectives and planned improvements have been provided along with a program schedule and potential transitions to current DoD programs. The recent emphasis on development ... |
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| Pendeo-Epitaxy Process Optimization of GaN for Novel Devices Applications |
APR 2008 |
22 pages |
| Authors:
Michael A. Derenge; Tsvetanka S. Zheleva; Kenneth A. Jones; Pankaj B. Shah; Daniel Ewing; J. Molstad; Unchul Lee; Matthew H. Ervin; David N. Stepp; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| A relatively new class of materials known as wide bandgap materials and the corresponding devices fabricated from them have extremely useful characteristics for high temperature, high-frequency, high-power applications in numerous army systems and components. However the technology for these new materials is not mature enough and these materials contain various types of structural defects in high concentrations. It is well known that structural defects degrade the performance of the electronic ... |
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| Carbon Nanotube Arrays for Thermal Management Applications |
04-Feb-2008 |
11 pages |
| Authors:
Pulickel M Ajayan; RENSSELAER POLYTECHNIC INST TROY NY
|
| The work was designed towards creating aligned multiwalled carbon nanotube arrays by chemical vapor deposition (CVD) of xylene hydrocarbon precursor and simultaneous vapor phase delivery of catalyst particles. Low density nanotube arrays as well as highly dense pyrolitic carbon coated nanotube arrays were produced. The nanotube arrays could be grown to several hundreds of microns long. The simultaneous growth of nanotubes and densification of the aligned carbon nanotube (ACNT) films ... |
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| Next Generation Nanotechnology Assembly Fabrication Methods: A Trend Forecast |
JAN 2008 |
46 pages |
| Authors:
Jr Jovene Vincent T.; AIR WAR COLL MAXWELL AFB AL CENTER FOR STRATEGY AND TECHNOLOGY
|
| Today, the continued success of many industries, especially the microelectronics industry, relies upon the ability to fabricate structures with nanometer precision. The efforts toward developing nanometer-scale fabrication methods fall loosely into two fields. One field seeks to extend the current planar, deposit-pattern-etch paradigm used for complementary metal oxide semiconductors (CMOS). This is a top-down approach. The other seeks new techniques to assemble structures without handling individual particles: self-assembly. These techniques ... |
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| Multi-channel ZnO Nanoconductors with Tunable Optoelectrical Properties |
06 DEC 2007 |
11 pages |
| Authors:
Chuan-Pu Liu; NATIONAL CHENG KUNG UNIV TAINAN (TAIWAN)
|
| A new doping technology for controlled growth has been developed recently. Successful doping of ZnO nanomaterials is still a challenge even today due to the vapor pressure difference by orders of magnitudes between dopants and Zn and literature reports of successful doping are scarce. The alloying evaporation deposition (AED) method was used to synthesize Al doped ZnO nanowires with various doping concentrations. Several types of single-crystalline Zn and Zn/ZnO core-shell ... |
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| A Nanocrystallite Si based Metal-Semiconductor-Metal Photosensors and Solar Energy Transformers with Enhanced Responsivity at UV-blue Wavelengths |
05 DEC 2007 |
15 pages |
| Authors:
Gong-Ru Lin; NATIONAL TAIWAN UNIV TAIPEI (TAIWAN) GRADUATE INST OF ELECTRO-OPTICAL ENGINEERING
|
| Structural damage enhanced near-infrared electroluminescence (EL) of a metal-oxide-semiconductor light emitting diode (MOSLED) made on SiOx film with buried nanocrystallite Si after CO2 laser rapid-thermal-annealing (RTA) at an optimized intensity of 6 kW/cm2 for 1 ms is demonstrated. CO2 laser RTA induced oxygen-related defects are capable of improving Fowler-Nordheim tunneling mechanism of carriers at metal/SiOx interface. The CO2 laser RTA SiOx film reduces Fowler-Nordheim tunneling threshold to 1.8 MV/cm, facilitating ... |
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| Growth and Characterization Studies of InGaN for Optoelectronics, Electronics and Photovoltaic Applications |
04 DEC 2007 |
10 pages |
| Authors:
Chih-Chung Yang; NATIONAL TAIWAN UNIV TAIPEI (TAIWAN) GRADUATE INST OF ELECTRO-OPTICAL ENGINEERING
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| In the past few years, we have been performing the research on the growth and characterization of InGaN/GaN nanostructures. Based on those nanostructures, we fabricated efficient dual-color and white-light light-emitting diodes. Meanwhile, we studied the coupling between surface plasmon and InGaN/GaN quantum wells for enhancing the emission efficiency. The detailed research topics are shown as follows 1. Prestrain growth of InGaN/GaN quantum wells for increasing indium incorporation 2. Fs pump-probe ... |
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| Multiscale Modeling and Process Optimization for Engineered Microstructural Complexity |
26 OCT 2007 |
18 pages |
| Authors:
Kaushik Bhattacharya; CALIFORNIA INST OF TECH PASADENA MECHANICAL ENGINEERING LAB
|
| This reports on the results of the MURI project on Engineering Microstructural Complexity in Ferroelectric Devices. |
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| Influence of Geometry on a High Surface Area-Solid Phase Microextraction Sampler for Chemical Vapor Collection |
04 JUN 2007 |
76 pages |
| Authors:
Robbie L. Wheeler; UNIFORMED SERVICES UNIV OF THE HEALTH SCIENCES BETHESDA MD DEPT OF PREVENTIVE MEDICINE AND BIOMETRICS
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| The High Surface Area Solid Phase Microextraction "HSA-SPME" device is an internally heated sampling device designed for high-volume, trace level air sampling. This study compared the analyte extraction and durability of five different HSA-SPME geometric configurations at two sample flow rates. Each HSA-SPME configuration was tested for its ability to extract a 10 ppbv 39-component gas mixture and thermally desorb into an analytical instrument. Differences in analyte recovery between the ... |
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| Fabrications and Characterizations of ZnO/Zn1-xMgxO Nanorod Quantum Structures |
15 MAY 2007 |
11 pages |
| Authors:
Gyu-Chul Yi; POHANG UNIV OF SCIENCE AND TECHNOLOGY (REPUBLIC OF KOREA) DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| Semiconductor nanorod heterostructures open up significant opportunities for fabrication of electronic and photonic nanodevices on single nanorods. The semiconductor nanorod quantum structures with well-defined interfaces are main components for nanoscale resonant tunneling devices, field effect transistors, and light-emitting devices since the nanorod quantum structures (QSs) enable novel physical properties such as quantum confinement and formation of minibands. In particular, spectral wavelength can be tuned by varying the well thickness, and ... |
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| Scaled up Fabrication of High-Throughout SWNT Nanoelectronics and Nanosensor Devices |
20-Apr-2007 |
6 pages |
| Authors:
Pulickel M Ajayan; RENSSELAER POLYTECHNIC INST TROY NY
|
| The project's primary goal was to build integrated, on-chip carbon nanotube based devices that could be used as multi-agent sensors. The main tasks were controlled growth of carbon nanotubes of various types, for integration into the on-chip sensor, fabrication of the carbon nanotube based sensor devices and, the electrical and other relevant characterization. The project was done in collaboration with personnel at the Army Research Laboratory. |
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| Fabrication for Nanotechnology |
01 MAR 2007 |
65 pages |
| Authors:
Henne van Heeren; ENABLINGMNT DORDRECHT (NETHERLANDS)
|
| There is much discussion what nanotechnology really is: anything produced in the nanometer scale, manipulating atoms or small particles. Seeing the wide variety of materials and fabrication technologies one could better speak of nanotechnologies. In general the fabrication technologies could be divided into four groups: (1) Top-down nanofabrication; (2) Nanoparticles; (3) Bottom up and (4) Nanotubes. |
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| Negative Thermal Expansion in Ultrathin Plasma Polymerized Films (Postprint) |
MAR 2007 |
6 pages |
| Authors:
Srikanth Singamaneni; Melburne C. LeMieux; Hao Jian; Timothy J. Bunning; Vladimir V. Tsukruk; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
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| Because of the increasing applications of polymer films with nanoscale thickness, it is imperative to fully characterize the physical properties in these films, which could be significantly different from the bulk properties due to the surface and interfacial effects. Interactions with the substrate and high specific surface area (film/air and film/substrate) can cause peculiar properties of the ultrathin polymer films. In a recent study the glass transition of a free ... |
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| Cobalt Doping of Semiconducting Boron Carbide Using Cobaltocene |
MAR 2007 |
100 pages |
| Authors:
Lonnie Carlson; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| The decomposition of cobaltocene and metacarborane (closo-1,7-dicarba-decaborane) under low energy electron irradiation at about 200 K results in a material with the Fermi level closer to the valence band than the material resulting from the decomposition of metacarborane alone. This indicates that cobaltocene provides a relatively p-type dopant as seen in ultraviolet photoemission spectroscopy/inverse photoemission spectroscopy. Upon warming to room temperature, however, the Fermi level shifts towards the conduction band, ... |
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| Dilute-Nitride Type-II Quantum Well Lasers Grown by MOCVD |
25 FEB 2007 |
31 pages |
| Authors:
Luke J. Mawst; WISCONSIN UNIV-MADISON
|
| One challenging goal remaining for GaAs-based InGaAsN QW lasers is to extend the emission wavelength beyond 1.3 m, while maintaining optical material quality for the realization of longer wavelength and high performance. Higher N-content leads to increased nonradiative monomolecular recombination, thus high performance at 1.55 m has not been achieved to date. Recently, we proposed a novel approach for realizing GaAs-based diode lasers with emission wavelengths beyond =1500 nm. This ... |
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| Correlation between Optoelectronic and Structural Properties Epilayer Thickness of AIN |
01-Jan-2007 |
4 pages |
| Authors:
B N Pantha; R Dahal; M L Nakarmi; N Nepal; J Li; J Y Lin; Quing S Paduano; David Weyburne; AIR FORCE RESEARCH LAB HANSCOM AFB MA OPTOELECTRONIC TECHNOLOGY BRANCH
|
| AlN epilayers were grown by metal organic chemical vapor deposition on sapphire substrates. X-ray diffraction measurements revealed that the threading dislocation (TD) density, in particular, the edge TD density, decreases considerably with increasing the epilayer thickness. Photoluminescence results showed that the intensity ratio of the band edge emission to the defect related emission increases linearly with increasing the epilayer thickness. Moreover, the dark current of the fabricated AlN metal-semiconductor-metal deep ... |
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| Fabrication of Highly Ordered Anodic Aluminium Oxide Templates on Silicon Substrates |
2007 |
6 pages |
| Authors:
A. Yin; M. Tzolov; D. Cardimona; L. Guo; J. Xu; BROWN UNIV PROVIDENCE RI DIV OF ENGINEERING
|
| The controlled fabrication of highly ordered anodic aluminium oxide (AAO) templates of unprecedented pore uniformity directly on Si, enabled by new advances on two fronts -- direct and timed anodisation of a high-purity Al film of unprecedented thickness (50 micrometres) on Si, and anodizing a thin but pre-textured Al film on Si, has been reported. To deposit high-quality and ultra-thick Al on a non-compliant substrate, a prerequisite for obtaining highly ... |
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| Overview on Pendeo-Epitaxy of GaN-Based Heterostructures for Novel Devices Applications |
NOV 2006 |
9 pages |
| Authors:
T. S. Zheleva; M. A. Derenge; K. A. Jones; P. B. Shah; D. Ewing; J. Molstad; U. LEE; M. H. Ervin; D. N. Stepp; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| A relatively new class of materials known as wide bandgap materials and the corresponding devices fabricated from them have extremely useful characteristics for high temperature, high-frequency, high-power applications in numerous army systems and components. However, the technology for these new materials is not mature enough and these materials contain various types of structural defects in high concentrations. It is well known that structural defects degrade the performance of the electronic ... |
|
| Dynamics of Epitaxy on the Nano-sized Semiconductor Surfaces |
05 SEP 2006 |
17 pages |
| Authors:
Deng-Sung Lin; NATIONAL CHIAO-TUNG UNIV HSINCHU (TAIWAN) INST OF PHYSICS
|
| Semiconductor self assembled quantum dots (QDs) have emerged as one of the simplest subjects for exploring and exploiting the physics and device applications of charge carriers and excitons in the three dimensional confinement regime. Nanoscale-sized surface in the form of mesa or ridges on patterned substrates offer opportunities not only for creating large densities of QDs with great homogeneity but also for novel growth-control engineering. This project aims at a ... |
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| Synthesis of Multifunctional Materials |
SEP 2006 |
23 pages |
| Authors:
Hadis Morkoc; VIRGINIA COMMONWEALTH UNIV RICHMOND
|
| Single-crystal PbTiO3 layers were grown on (001) SrTiO3 substrates by molecular beam epitaxy using hydrogen peroxide as an oxidant. Phase composition and structural properties of the films were examined as a function of growth parameters. It was found that single-phase PbTiO3 films grew epitaxially at substrate temperatures of 600 degrees C and higher, whereas layers grown at lower temperature contained PbO inclusions. Growth of Pb(ZrTi)O3 (PZT) films by molecular beam ... |
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| Continuation of the Program on Photoinduced Magnetism |
24 JUL 2006 |
15 pages |
| Authors:
Arthur J. Epstein; OHIO STATE UNIV COLUMBUS DEPT OF PHYSICS
|
| Photoinduced magnetism (PIM) studies were successfully extended to the class of organic-based high Tc magnetic semiconductors based on V[TCNE]2, with PIM discovered in the chemical vapor deposition (CVD) prepared films to nearly 150 K. A previously unknown phenomenon, photoinduced diamagnetism (reversible decrease in the magnetization) was revealed in these materials. We developed a powerful new experimental method to studies PIM, Photoinduced FerroMagnetic Resonance (PIFMR). PIFMR determined that the photoinduced decrease ... |
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| In Situ Studies of Defect Nucleation During the PVT and CVD Growth of Silicon Carbide Single Crystals |
MAR 2006 |
4 pages |
| Authors:
Michael Dudley; STATE UNIV OF NEW YORK AT STONY BROOK DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| A complete chemical vapor deposition (CVD) system for growing SiC epitaxial films and bulk crystals was set up using commercially procured gas flow controls and scrubber units, and integrating them with a modified in-house designed growth chamber that has options for in situ X-ray topographic study. This CVD system uses silicon tetrachloride (SiCl4), silane (SiH4), propane (C3H8), hydrogen (H2) and argon (Ar) gases. The aggressive SiCl4 corrosion in the chamber ... |
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| Hybrid Molecomputer Using Vapor Phase Assembly |
10 JAN 2006 |
25 pages |
| Authors:
Mark A. Reed; YALE UNIV NEW HAVEN CT GRANT AND CONTRACT ADMINISTRATION
|
| Current work on molecular electronics relies almost entirely on liquid phase processing. Gas phase processing offers far superior uniformity and reproducibility. The scope of this work was to investigate vapor phase process that will fully integrate the in-situ steps of sample preparation, active organic molecule deposition, and gentle gas-moderated metallic overcoating, which will enable our proposed multi-layer stacked device. The goal of this work is to mate these active molecular ... |
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| Nanostructured Protective Coatings |
JAN 2006 |
119 pages |
| Authors:
Douglas L. Schulz; Gregory J. McCarthy; Mark Horn; Paul Sunal; Russel Messier; Robert W. Collins; Chi Chen; Gary McGuire; Mark Ray; NORTH DAKOTA STATE UNIV FARGO
|
| Recent developments in the field of "superhard" coatings are of interest to the Air Force for their potential superior wear resistance properties. The Nanostructured Protective Coatings (NPC) program was designed to establish a collaborative team of three entities having complementary hard materials competencies. The long-term goal was to enhance the fundamental understanding of superhard coatings and utilize this understanding to develop practical coatings needed by the Air Force. Work during ... |
|
| Fabrication and Characterization of a Micro Turbine/Bearing Rig |
2006 |
6 pages |
| Authors:
Chuang-Chia Lin; Reza Ghodssi; Arturo A. Ayon; Dye-Zone Chen; Stuart Jacobson; Kenneth Breuer; Alan H. Epstein; Martin A. Schmidt; MASSACHUSETTS INST OF TECH CAMBRIDGE MICROSYSTEMS TECHNOLOGY LABS
|
| This paper reports on a process to build, package, and instrument a 5-level wafer-bonded micro-machined turbine/bearing rig. The process flow involves the use of 5 wafers, 16 masks, and 9 deep silicon etching steps. It also utilizes aligned wafer bonding, double-sided deep reactive ion etching (DRIE), and Laser-Assisted-Etching (LAE). The paper also presents experimental results on flow characteristics of the hydrostatic thrust bearings and the preliminary rotational performance of the ... |
|
| Direct-Write Assembly of Three-Dimensional Photonic Crystals: Conversion of Polymer Scaffolds to Silicon Hollow-Woodpile Structures |
20 DEC 2005 |
6 pages |
| Authors:
Gregory M. Gratson; Florencio Garcia-Santamaria; Virginie Lousse; Mingjie Xu; Shanhui Fan; Jennifer A. Lewis; Paul V. Braun; ILLINOIS UNIV AT URBANA-CHAMPAIGN BECKMAN INST AND COORDINATED SCIENCE LAB
|
| Impressive developments in silicon microfabrication are enabling new applications in photonics, microelectromechanical systems (MEMS), and biotechnology. Yet conventional Si microfabrication techniques require expensive masks and time-consuming procedures, including multiple planarization or bonding steps, to generate three-dimensional (3D) structures. In contrast, direct-write approaches, such as laser scanning and ink deposition, provide rapid, flexible routes for fabricating 3D micro-periodic structures. However, these approaches are currently limited to polymeric structures that lack the ... |
|
| Time-Adaptive Sampling of a Chemical Hazard Area |
20 SEP 2005 |
65 pages |
| Authors:
Jennifer R. Plourde; Jeffrey P. Kharoufeh; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH HUMAN EFFECTIVENESS DIRECTORATE
|
| SUMMARY/CONCLUSIONS: (1) Ignoring dynamics may lead to under- or over-estimation of the number of safe areas; (2) Spatiotemporal characteristics are critical in developing the sampling strategy; (3) Want to minimize Type II error; (4) Data was assumed to exist for illustrative purposes, however...(4) Real problem presents significant data requirements. |
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| Three-Dimensional Microstructural Characterization of GaN Nonplanar Substrate Laterally Epitaxially Overgrown by Metalorganic Chemical Vapor Deposition |
20 JUL 2005 |
11 pages |
| Authors:
Wei Zhou; Dawei Ren; P. D. Dapkus; UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES DEPT OF MATERIALS SCIENCE
|
| Transmission electron microscopy techniques are applied to investigate three-dimensional (3D) microstructures of the GaN nonplanar substrate selectively grown by metalorganic chemical vapor deposition. Two-step lateral epitaxial overgrowth (LEO) has been utilized and optimized to fabricate fully coalesced nonplanar mesa substrate templates with the trapezoidal cross-section. All threading dislocations (TDs) penetrating beyond the two adjacent mask windows are engineered to bend 901 in the lower TD bending layer after the rst ... |
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| Motion of Nanoparticles in Rarefied Gas Flows |
13 JUL 2005 |
7 pages |
| Authors:
K. Nanbu; T. Otsuka; TOHOKU UNIV SENDAI (JAPAN) INST OF FLUID SCIENCE
|
| Solar cells have been made from hydrogenated amorphous silicon (a-Si:H) films. The films including Si nanoparticles by 3% in the volume fraction have been found to possess good properties. In order to find the method to control this volume fraction, the motion of Si nanoparticles in the rarefied flow of H2 and SiH4 is examined for a CVD (chemical vapor depositiion) reactor by use of the DSMC method. |
|
| Alignment of Nanotube Arrays |
05 MAY 2005 |
4 pages |
| Authors:
David Goldhaber-Gordon; STANFORD UNIV CA GEBALLE LAB FOR ADVANCED MATERIALS
|
| 1. First crossed-nanotube transistor with gate dielectric. 2. First careful electrical measurements on nanotube peapods. 3. Novel technique for imaging local heating in narrow wires. |
|
| Detection of Residual Stress in SiC MEMS Using micro-Raman Spectroscopy |
MAR 2005 |
137 pages |
| Authors:
John C. Zingarelli; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT/DEPT OF ENGINEERING PHYSICS
|
| Micro-Raman (mu-Raman) spectroscopy is used to measure residual stress in two silicon carbide (SiC) poly-types: single-crystal, hexagonally symmetric 6H-SiC, and polycrystalline, cubic 3C-SiC thin films deposited on Si substrates. Both are used in micro-electrical-mechanical systems (MEMS) devices. By employing an incorporated piezoelectric stage with submicron positioning capabilities along with the Raman spectral acquisition, spatial scans are performed to reveal areas in the 6H-SiC MEMS structures that contain residual stress. Shifts ... |
|
| Experimental and Computational Studies of Oxidizer and Fuel Side Addition of Ethanol to Opposed Flow Air/Ethylene Flames |
FEB 2005 |
50 pages |
| Authors:
Kevin L. McNesby; Andrzej W. Miziolek; Thuvan Nguyen; Frank C. DeLucia; R. R. Skaggs; Thomas Litzinger; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Results of computations based upon a detailed chemical kinetic combustion mechanism and results of experiments are compared to understand the influence of ethanol vapor addition upon soot formation and OH radical concentration in opposed flow ethylene/air diffusion flames. For this work, ethanol vapor was added to either the fuel or the oxidizer gases. Experiment and calculations are in qualitative agreement, and both show differing concentrations of soot, soot precursors, and ... |
|
| New Lanthanide Precursors for Doping Semiconductor Films |
22 DEC 2004 |
8 pages |
| Authors:
Charles H. Winter; WAYNE STATE UNIV DETROIT MI DEPT OF CHEMISTRY
|
| The goal of this proposal was to synthesize new lanthanide and other source compounds for use in chemical vapor deposition and related processes using molecular precursors and to evaluate these compounds in materials growth processes. Specific objectives included the synthesis and characterization of lanthanide complexes that can be used to dope nitride and sulfide materials, materials growth using these precursors, and the synthesis and characterization of volatile, multimetallic first row ... |
|
| Chemical Vapor Deposition Grown Single-Walled Carbon Nanotube Junctions for Nano-Electronics and Sensors |
DEC 2004 |
3 pages |
| Authors:
Sarah Lastella; Govind Mallick; Shashi P. Karna; Yung Joon; Chang Ryu; Pulickel Ajayan; David Rider; Ian Manners; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| Using an Fe-containing diblock copolymer as the catalyst single walled carbon nanotubes (SWNTs) have been grown on Si/SiO2 substrate by chemical vapor deposition technique. Atomic force microscopic image of the grown samples exhibit interesting junction architectures in the form of T. Y. and X of small- diameter (approximately 2mn) SWNT bundles. |
|
| Magnetic and Optical Properties of MN-Doped GaN Thin Films and P-I-N devices |
DEC 2004 |
9 pages |
| Authors:
M. L. Reed; M. O. Luen; S. M. Bedair; M. J. Reed; F. E. Arkun; E. A. Berkman; N. A. El-Masry; J. M. Zavada; NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| In this paper, we report on the growth and characterization of single crystal GaMnN thin films and p-i-n junction devices grown by metal-organic chemical vapor deposition (MOCVD). Single crystal GaMnN films were achieved by optimizing the growth temperature, growth rate and the Mn:Ga gas phase ratio. A growth window for obtaining single crystal Ga(sub 1-x)Mn(sub x)N with 0. 006= |
|
| High Throughput Synthesis of Terahertz Quantum Cascade Lasers |
21 OCT 2004 |
23 pages |
| Authors:
Kurt J. Linden; SPIRE CORP BEDFORD MA
|
| This Phase I STTR program (Topic #AF03T024) was aimed at the design and synthesis of an AlGaAs/ GaAs-based epitaxial layer structure for terahertz quantum cascade lasers (THz QC lasers) that can be grown by metalorganic chemical vapor deposition (MOCVD). The program succeeded in growing two different THz QC laser structures by MOCVD. The wafer growths of these 10 micron thick epitaxial structures by MOCVD required 5 hours of growth time, ... |
|
| Thermal Expansion of Ti-Containing Hydrogenated Amorphous Carbon Nanocomposite Thin Films |
16 SEP 2004 |
4 pages |
| Authors:
B. Shi; W. J. Meng; T. L. Daulton; NATIONAL SCIENCE FOUNDATION WASHINGTON DC
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| The effective coefficients of thermal expansion (CTE) of Ti-containing hydrogenated amorphous carbon (Ti-C:H) thin films were measured. Ti-C:H thin films with compositions ranging from nearly pure alpha-C:H to nearly pure TiC were deposited on Si(100) substrates. Effective CTEs were determined from temperature induced changes in the curvature of film/substrate assemblies. Measured effective CTE values for Ti-C:H are 5.7 x 10(exp -6) K(exp -1), and show little dependence on the Ti ... |
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| Reactive Ion Etching of PECVD Silicon Dioxide (SiO2) Layer for MEMS application |
JUL 2004 |
23 pages |
| Authors:
Derwin Washington; ARMY RESEARCH LAB ADELPHI MD
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| A reactive ion etching (RIE) process has been developed to etch up to 1-micrometer (1 m) layer of low stress SiO2 (Silicon Dioxide) Plasma Enhanced Chemical Vapor Deposition (PECVD) film compatible for MEMS research applications. Etch rates from as low as 123 nm/min at 100 W to as high as 721 nm/min at 900 W powers were demonstrated using fluorocarbon (CF4) reactive gas plasma. RIE selectivity (SiO2/PR-Photoresist was 3:1 at ... |
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| Injection and Scattering of Polarized Spins at Nanoscale Polymer Interfaces |
31 MAY 2004 |
15 pages |
| Authors:
Arthur J. Epstein; OHIO STATE UNIV COLUMBUS DEPT OF PHYSICS
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| We made excellent progress several directions. We demonstrated that V[TCNE]~2 is a room temperature fully spin polarized magnetic semiconductor of interest for spintronic applications, including spin valves. We increased the coercivity (which is crucial for spintronics device) of the parent material V[TCNE]~2 by doping with ions that have large magnetocrystalline anisotropy (Co, Fe, etc.). For Co and Fe substantially higher coercive fields, Hc, than the pure V[TCNE]2 (275 Oe for ... |
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| Terahertz Devices: Tunable and Mode-Locked p-Ge THz Laser |
05 MAY 2004 |
11 pages |
| Authors:
J. Fredricksen; R. E. Peale; ZAUBERTEK INC ORLANDO FL
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| This Phase II STTR project developed and demonstrated a corn pact, turn-key, cryogen-free, p-type germanium laser, tunable over the range 1.5A.2 THz (70-200 micron wavelength), with I Watt peak power. A new type of intracavity gain modulator with potential application to active mode locking was discovered. improvement in the gain of the active p-Ge crystal by homogeneous neutron transmutation doping was experimentally shown. An alternative means of gain improvement, which ... |
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| Microstructural Studies of In-Situ Mesophase Transformation in the Fabrication of Carbon-Carbon Composites |
29 APR 2004 |
9 pages |
| Authors:
K. M. Chioujones; W. Ho; P. C. Chau; B. Fathollahi; P. G. Wapner; ENGINEERING RESEARCH AND CONSULTING INC(ERC INC) EDWARDS AFB CA
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| Injection of a low viscosity mesophase pitch into CVD-rigidized preforms can be an effective approach for fabrication of carbon-carbon composites. Here flow-induced microstructures are stabilized by oxidation such that upon carbonization the fibrous carbon needles running through the flow channels are retained. While the injection method is effective in making highly densified materials with controlled microstructure it is not without limitations. The method is best applied to well-defined geometries such ... |
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| Synthesis of Superhard Thin Films and Coatings Based on Light Elements |
18 APR 2004 |
8 pages |
| Authors:
J. Kouvetakis; I. S. Tsong; ARIZONA STATE UNIV TEMPE ARIZONA BOARDOF REGENTS
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| Superhard dielectric and optoelectronic materials in the Si-C-Al-N si-B-O-N and Zr-B/Ga-N systems were prepared as thin films via novel CVD and MBE routes. SiC and AlN, normally insoluble in each other below 2000 deg C are combined to form single phase SiCAlN by gas source MBE of SiH3CN and Al atoms at 75000. The growth of epitaxial material takes place on 6H SiC and Si(111). Commensurate heteroepitaxy between Si(111) and ... |
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