bluuebunny/crossref_metadata_2025_split huggingface dataset:
Initial growth stages of CeO2 nanosystems by Plasma-Enhanced Chemical Vapor Deposition
Authors: Barreca Davide , Gasparotto Alberto , Tondello Eugenio , Polizzi Stefano , Benedetti Alvise , Sada Cinzia , Bruno Giovanni , Losurdo Maria 
Published: April 2011

ABSTRACTNanocrystalline CeO2 thin films were synthesized by Plasma-Enhanced Chemical Vapor Deposition using Ce(dpm)4 as precursor. Film growth was accomplished at 150–300°C either in Ar or in Ar-O2 plasmas on SiO2 and Si(100) with the aim of studying the effects of substrate temperature and O2 content on coating characteristics. Film microstructure as a function of the synthesis conditions was investigated by Glancing Incidence X-Ray Diffraction (GIXRD) and Transmission Electron Microscopy (TEM), while surface morphology was analyzed by Atomic Force Microscopy (AFM). Surface and in-depth chemical composition was studied by X-ray Photoelectron Spectroscopy (XPS) and Secondary Ion Mass Spectrometry (SIMS).
Enhanced Graphite Fiber Electrodes for a Microbial Biofuel Cell Employing Marine Sediments
Authors: Konesky Gregory 
Published: April 2011

ABSTRACTA microbial biofuel cell has been demonstrated utilizing organic material in the sediment as fuel and dissolved oxygen in the overlying seawater as the oxidizer. A graphite electrode placed in the sediment acts as the anode and collects electrons both by mediated and non-mediated processes. Another graphite electrode suspended in the seawater above the sediment acts as the cathode and transfers these electrons to oxygen in the seawater. The sediment serves as a natural permeable membrane that permits hydrogen ions to flow from within the sediment and combine with the oxygen to produce water. Electrons which flow from the anode to the cathode through an interconnecting wire are used to power external circuits. Both fuel and oxidizer are naturally present and self-renewing, and the graphite electrodes are inexpensive and non-toxic. Overall, this is a very “green” fuel cell. A significant improvement in collection efficiency is demonstrated by using graphite fiber electrodes.
Nucleation And Growth of Yttria-Stabilized Zirconia Thin Films Using Combustion Chemical Vapor Deposition
Authors: Xu Zhigang , Sankar Jag , Yarmolenko Sergey , Wei Qiuming 
Published: April 2011

ABSTRACTLiquid fuel combustion chemical vapor deposition technique was successfully used for YSZ thin film processing. The nucleation rates were obtained for the samples processed at different temperatures and total-metal-concentrations in the liquid fuel. An optimum substrate temperature was found for the highest nucleation rate. The nucleation rate was increased with the total-metal-concentration. Structural evolution of the thin film in the early processing stage was studied with regard to the formation of nuclei, crystallites and final crystals on the films. The films were found to be affected by high temperature annealing. The crystals and the thin films were characterized with scanning electron microscopy.
Metal Dusting Problem with Metallic Interconnects for Solid Oxide Fuel Cell
Authors: Zeng Z. , Natesan K. 
Published: April 2011

ABSTRACTMetallic interconnects in the solid oxide fuel cell (SOFC) are oxidized on the cathode side by air and carburized on the anode side by natural gas. Metallic alloys can be attacked by metal dusting corrosion in carbonaceous gases of high carbon activity in the temperature range of 350–1000°C. Under these conditions, pits form on the alloy surface and can become large holes through the alloy plate, with subsequent disintegration into a powdery mixture composed of carbon, fine particles of metal, and carbide. Fe and Ni-base alloys were tested in carbonaceous gases around the SOFC operating temperature. It was found that the oxide scales on the alloy surface prevent metal dusting corrosion. If the major phase in the oxide scale is chromic oxide, the alloys have good resistance to metal dusting corrosion. However, the alloys are easily attacked if the major phase is spinel.
Self-Assembly of Iron Nanoparticle Arrays
Authors: Majetich S. A. , Farrell D. F. 
Published: April 2011

ABSTRACTSurfactant-coated spherical iron-based nanoparticles 3.0–9.5 nm in diameter were synthesized and dispersed in hexane. TEM images of dried particle assemblies were taken and analyzed to discover the structure of the assemblies, and to establish the relationship between particle concentration, surfactant type, and conditions of drying and array structure.
The Effect of a Non-Equipartition of Energy on Multi-component Flows
Authors: Galvin J. E. , Dahl S. R. , Hrenya C. M. 
Published: April 2011

ABSTRACTRapid granular flows of two species with different material densities are examined via three-dimensional, hard-sphere simulations of simple shear flow. Simulation results are compared with existing theories for binary systems based on the kinetic theory analogy. The comparison between simulation data and theoretical predictions indicate that although non-equipartition is observed and well-predicted by the theory which accounts for its effects, the influence of non-equipartition on stress predictions is fairly small. The influence of non-Maxwellian effects, however, are critical for accurate stress predictions.
Development of shear bands in annular shear granular flows
Authors: Jalali Payman , Li Mo 
Published: April 2011

ABSTRACTUsing hard-disk simulations of relatively dense packs of mono-sized system in an annular Couette geometry the formation of dilute regions inside the granular media, namely shear bands, are investigated. The results represent the influence of entire system characteristics such as solid area fraction and shear rate on the development of shear bands as well as the local properties of grains that cause them to participate in the formation of a shear band. Moreover, simulations have been performed for binary-sized system, which revealed that the formation of such diluted shear bands is unlikely.
Mechanical Behavior Of Energetic Materials During High Acceleration
Authors: Lanzerotti Y. , Sharma J. 
Published: April 2011

ABSTRACTThe mechanical behavior of explosives subjected to high acceleration has been studied in an ultracentrifuge at –10°C and 25°C. Melt-cast TNAZ and pressed TNAZ, LX-14, Composition A3 Type II, PAX-2A, and PAX-3 have been studied. Failure occurs when the shear or tensile strength of the explosive is exceeded. The fracture acceleration of melt-cast TNAZ is greater than that of pressed TNAZ at –10°C and 25°C. The fracture acceleration of PAX-3 is greater than that of Composition A3 Type II at –10°C and 25°C. The fracture acceleration of melt-cast TNAZ and pressed TNAZ at –10°C is about 10% less than at 25°C. The fracture acceleration of PAX-3 at –10°C is about 2.6 times that at 25°C. The fracture acceleration of Composition A3 Type II at –10°C is about 1.7 times that at 25°C.
Managing Student Group Projects in an Introductory Materials Science Course
Authors: Isaacs Jacqueline A. 
Published: April 2011

ABSTRACTIn an introductory materials science course for mechanical and industrial engineering sophomores, a term-long student team project is included as a graded activity. Successful completion of the project fulfills three course objectives where students learn 1) to compose professional reports in teams and demonstrate effective communication skills, 2) to apply introductory concepts of materials science well enough to follow technical articles on various topics, and 3) to locate resources to gather additional information related to a topic. To help students learn to research a topic, to write, to work in teams, and to speak publicly, the course includes guest lectures with various instructors with expertise in library research skills, technical writing, and communication studies. Course assessment indicates that sophomores find their projects interesting and they report learning a lot about the topics they selected. Interventions in the early stages of the curriculum allow the students to perform better during their senior year Capstone Design Project. The details of how the projects are managed will be described.
A Multi-functional Introductory Materials Science Course: Emphasizing Engineering and Achieving Accreditation Objectives
Authors: Chen Katherine C. , Vanasupa Linda S. , Orling Timothy T. 
Published: April 2011

ABSTRACTIn efforts to serve more engineering students and to achieve accreditation objectives, we have redesigned our introductory materials course to be more engineering-oriented and relevant to other disciplines. The fundamental materials science concepts have been regrouped into five, 2-week sections that emphasize applications: Materials Basics; Mechanical Strength; Thermo-mechanical Treatments; Electrical Properties; and Economic, Environmental and Societal Issues. Although the topics that are covered are similar to those in most introductory materials science courses, the presentation of the topics has been re-arranged to create clearer links between materials science and materials engineering. We have also identified accreditation criteria within each section and have built in mechanisms for providing feedback for accreditation processes. In addition, learning objectives for each section ensure standardization among different sections and instructors. Results on students' performances are reported.
Microscopic study of electrical transport through single molecules with metallic contacts: Organic molecules and finite carbon nanotube
Authors: Xue Yongqiang , Ratner Mark A. 
Published: April 2011

ABSTRACTWe present microscopic study of electronic and transport properties of single molecules sandwiched between two metallic contacts using Green's function based modeling approach within both ab initio and self-consistent semi-empirical framework. The methods are applied to thiol-based organic molecules and finite-size single-wall carbon nanotubes respectively. Results on electrostatics, transmission and current-voltage characteristics are presented.
Conductance Microscopy for Electric Conduction Study of Bio-Inspired Hybrid Nanostructures under Ambient Conditions
Authors: Setyawan Wahyu , Rao Saleem , Hong Seunghun 
Published: April 2011

ABSTRACTElectrical conductance of single stranded DNA (5′-TTT TTT TTT T/3 Thio MC3-D/-3′) monolayer patterns on Au surface is compared with those of various organic molecular patterns via the conductance microscope (CM) technique that allows one to take nanoscale conductance images utilizing a conducting AFM tip in contact mode AFM. In the experiment, reference molecules and ssDNA are patterned on the same substrate via direct deposition methods such as dip-pen nanolithography and microcontact printing. Then, conductance microscope image is recorded revealing the relative conductivity of ssDNA patterns relative to various reference molecules. 16-mercaptohexadecanoic acid and 2-mercaptobenzimidazole patterns are found conducting better than the ssDNA patterns. This result indicates that the ssDNA with 10T bases is a relatively poor electrical conductor. The capabilities of CM technique are also tested on various nanostructures including the single wall carbon nanotube junction.
Focused Ion Beam Nano-Machined Structures For Strain Analysis By A Moiré Technique
Authors: Li Biao , Xie Huimin , Zhang Xin 
Published: April 2011

ABSTRACTThe accurate determination of residual stress/strain in thin films is especially important in the emerging field of MicroElectroMechanical Systems (MEMS). In this article, a focused ion beam (FIB) moiré method is proposed and demonstrated to measure the strain in MEMS structures. This technique is based on the advantages of the FIB system in nano-fabrication, imaging, in-situ deposition, and fine adjustment. Nano-grating lines with 70 nm width and 140 nm spacing are directly written on the top of the MEMS structures by ion milling without the requirement of an etch mask. The FIB moiré pattern is formed by the interference between a prepared specimen grating and FIB raster scan lines. The strain of the MEMS structures is derived by calculating the average spacing of moiré fringes. Since the local strain of a MEMS structure itself can be monitored during the process, the FIB moiré technique has many potential applications in the mechanical metrology of MEMS. As an example, the strain distribution along the sticking MEMS structures, and the contribution of surface oxidization and mass loading to the cantilever strain is determined by this FIB moiré technique.
High-Q integrated RF passives and RF-MEMS on silicon
Authors: van Beek Joost T.M. , van Delden Marc H.W.M. , van Dijken Auke , van Eerd Patrick , Jansman Andre B.M. , Kemmeren Anton L.A.M. , Rijks Theo G.S.M. , Steeneken Peter G. , den Toonder Jaap , Ulenaers Mathieu J.E. , den Dekker Arnold , Lok Pieter , Pulsford Nick , van Straten Freek , van Teeffelen Lenhard , de Coster Jeroen , Puers Robert 
Published: April 2011

ABSTRACTA technology platform is described for the integration of low-loss inductors, capacitors, and MEMS capacitors on a high-resistivity Si substrate. Using this platform the board space area taken up by e.g. a DCS PA output impedance matching circuit can be reduced by 50%. The losses of passive components that are induced by the semi-conducting Si substrate can effectively be suppressed using a combination of surface amorphisation and the use of poly crystalline Si substrates. A MEM switchable capacitor with a capacitance switching factor of 40 and an actuation voltage of 5V is demonstrated. A continuous tuneable dual-gap capacitor is demonstrated with a tuning ratio of 9 using actuation voltages below 15V.
Passive Isolators Based On Barium Ferrite Sputtered Films
Authors: Le Berre M. , Capraro S. , Chatelon J. P. , Joisten H. , Rouiller T. , Bayard B. , Barbier D. , Rousseau J. J. 
Published: April 2011

ABSTRACTFerrites have magnetic properties suitable for electronic applications, especially in the microwave range (circulators and isolators). Hexagonal ferrite, such as barium ferrite (BaFe12O19 or BaM), are of great interest for microwave device applications because of their large resistivity and high permeability at high frequencies.This contribution focuses on BaM films, 1 to 10 microns thick, which were deposited under optimized conditions by RF magnetron sputtering on alumina or silicon substrates. In order to crystallize the films that were amorphous after deposition, a post deposition annealing at 800°C was implemented. Optimized samples presented a good crystallization, a smooth surface and no cracks. The films were either randomly oriented or showed slight preferential orientations among the crystallographic planes (101), (200), (206), (102), (110) and (205) when the substrates were heated up to 400°C during the deposition. Ba, Fe and O depth profiles obtained by Secondary Ion Mass Spectroscopy (SIMS) showed that the films have a good in-depth uniformity. The magnetic properties of BaM films determined by VSM, showed that the optimized coercive force and the saturation magnetization reached 330 kA/m and about 500 mT respectively. These values are closed to that of the bulk BaM.Isolators were then realized using patterning of coplanar metallic lines with standard lift-off technique. The slots and the central width were set to 300 μm, gold was used for the lines. First results on transmission coefficients showed a non reciprocal effect, which reaches 3.3 dB/cm at 50 GHz. This proved that such a component behaves like an isolator in the 50 GHz band.
Pulsed DC Reactive Magnetron Sputtering of AlN Thin Films on High Frequency LTCC Substrates
Authors: Lee Jung W. , Cuomo Jerome J. , Moody Baxter F. , Cho Yong S. , Keusseyan Roupen L. 
Published: April 2011

ABSTRACTThis preliminary work reports the preparation of AlN thin films on an LTCC (low temperature co-fired ceramics) substrate by pulsed dc reactive magnetron sputtering and the limited characterization focusing on microstructure and crystal orientation. The main focus will be placed on the effects of changing pulsed frequency. The AlN thin film showed good adhesion with the substrate and columnar structures having small grains regardless of pulsed frequency. The crystal orientation of AlN thin films was dependent on pulsed frequency according to the result of XRD patterns. The preferred (002) orientation was obtained at a pulsed frequency of 100 kHz. The broad band of 300 to 650 nm observed in photoluminescence spectrum was believed due to defects associated with the presence of oxygen impurities.
The Microstructures and Grain Boundary Segregations of Ceramic Barium Titanate Processed in Microwave Field
Authors: Liu Hanxing , Tian Zhongqin , Zhou Jian , Yu Hongtao , Zou Long , Ouyang Shixi 
Published: April 2011

ABSTRACTCeramic sintering in microwave field is a new ceramic processing method. In present paper, we detected the microstructures and boundary segregation of BaTiO3 ceramics which were sintered in microwave field. Scanning electron microscopy(SEM), and transmission electron microscopy(TEM), and chemical analysis methods were employed to detect the microstructure of BaTiO3, element distribution near the boundary of BaTiO3 ceramic. The results shown growth of grain of the ceramic was influenced by impurities such as acceptor, benefactor et al, and the element distribution near the grain boundary of BaTiO3 sintered in microwave field were different with that sintered in conventional method. The boundary segregations of BaTiO3 sintered in microwave field were not obvious as compared to the conventional method because the diffusion was enhanced due to the microwave field.
Growth Model of Epitaxial Pb(Zr0.52Ti0.48)O3 Nanoislands
Authors: Chu Ming-Wen , Szafraniak Izabela , Scholz Roland , Hesse Dietrich , Alexe Marin , Gösele Ulrich 
Published: April 2011

ABSTRACTSingle-crystalline, single-c-domain Pb(Zr0.52Ti0.48)O3 nanoislands (truncated-pyramid in shape) with an average height of ∼9 nm and a base length of ∼50 nm were grown on compressive niobium-doped SrTiO3(001) substrates using chemical solution deposition. Cross-sectional highresolution electron microscopy investigations allowed to propose a growth model of the islands, and they proved the existence of edge-type misfit dislocations at the interface.
Shape of piezoelectric hysteresis loop for non-ferroelastic switching
Authors: Tagantsev A. K. , Muralt P. , Fousek J. 
Published: April 2011

ABSTRACTA simple theory for the shape of the piezoelectric hysteresis loops (piezoelectric coefficient d vs. applied electric field E) is developed for the case of non-ferroelelastic 180° switching in ferroelectrics. The theory provides explanations for specific features of piezoelectric hysteresis loops, which have been observed in single crystals, thin films and in ceramics in particular. The piezoelectric coefficient may show a “hump”, i.e. when E decreases from the tip of the loop down to zero, d passes through a maximum, and a “nose”, i.e. a self-crossing of the loop close to its tips. The theory also explains the difference in the coercive fields seen in the polarization and piezoelectric loops.
Local Hysteresis Behavior of Ferroelectric Thin Films of Si added PbTiO3
Authors: Palkar V. R. , Higgins M. , Purandare S. C. , Pinto R. , Bhattacharya S. 
Published: April 2011

ABSTRACTWe report ferroelectric properties and local hysteresis behavior of 2 mole percent Si added PbTiO3 thin films grown on Pt/TiO2/SiO2/Si substrate by using pulsed laser deposition technique. The ferroelectric hysteresis loop and scanning piezoresponce images obtained on these films by using AFM with conducting tip demonstrate excellent properties, which are equivalent to any other established ferroelectric material like PZT. Si segregating at the grain boundaries controls grain growth. The grain size and grain boundaries play a crucial role in determining ferroelectric hysteresis properties. The presence of Si in the matrix can be useful in tuning the properties.
Comparison of Titanium Precursors in the Sol-Gel Synthesis of Pb0.5Ba0.5TiO3 Powders and Thin Films
Authors: Boland Stacey W. , Haile Sossina M. 
Published: April 2011

ABSTRACTTwo sol-gel processes for producing Pb1-xBaxTiO3 (PBT), a ferroelectric material of interest for sensor and actuator applications, are investigated. Each system incorporates lead nitrate and barium acetate as metal sources and ethylene glycol as a solvent. Diethanolamine is used as a chelating agent for titanium isopropoxide or titanium butoxide. Precursor chemistry was systematically varied and the resulting sols and powders were studied using TGA/DSC, FTIR, and XRD. Thin films were prepared using both precursor sources by spin coating onto single crystal (100) MgO. Spin speed and pyrolysis temperature were optimized to produce oriented thin films with thicknesses of up to approximately 500nm. Sols incorporating titanium isopropoxide and a large excess of diethanolamine were particularly stable against hydrolysis.
Laser Annealing of Ferroelectric SrBi2Ta2O9, Pb(ZrXTi1-X)O3 and CeMnO3 Thin Films
Authors: Sbrockey N. M. , Cuchiaro J. D. , Provost L. G. , Rice C. E. , Sun S. , Tompa G. S. , DeLeon R. L. , Kalkur T. S. 
Published: April 2011

ABSTRACTExcimer laser annealing studies were conducted of SrBi2Ta2O9, Pb(ZrxTi1-x)O3 and CeMnO3 thin films. The main incentive was to develop a low temperature process for SrBi2Ta2O9 thin films, which typically require a 750 C anneal to crystallize and achieve optimum ferroelectric properties. The results show that room temperature laser annealing can crystallize SrBi2Ta2O9, with a strong (200) preferred orientation. The Pb(ZrxTi1-x)O3 and CeMnO3 thin films investigated in this study were crystalline as deposited. Laser annealing of the Pb(ZrxTi1-x)O3 and CeMnO3 films did not result in a significant increase in crystallinity, as evidenced by the intensities of the x-ray diffraction peaks. Electrical characterization of laser annealed SrBi2Ta2O9 thin films showed good dielectric properties and the onset of ferroelectric behavior. Low temperature laser annealing is shown to be a viable approach to enable integration of ferroelectric SrBi2Ta2O9 films with silicon based micro-electronics, for ferroelectric memory applications.
Effect of Deposition Parameters on the Microstructural Evolution and Electrical Properties of Charge-Balanced Barium Strontium Titanate Ferroelectric Thin Films Deposited on Ceramic Substrates by Pulsed Laser Deposition
Authors: Fountzoulas Costas G. , Tidrow Steven C. , Hatzistergos Michael , Efstathiadis Harry 
Published: April 2011

ABSTRACTBarium strontium titanate (Ba0.60Sr0.40TiO3) thin films are the main materials of interest in tunable phase shifter for microwave antenna applications. Ba0.60Sr0.40Y0.05Ta0.05Ti0.90O3 thin films, of nominal thickness ranging from 1.7 μm to 2.3 μm, were synthesized on MgO (100) substrates, at substrate temperatures ranging from 500°C to 900°C, at oxygen partial pressures 20 and 50 mTorr, at 500 mJ energy fluence on 3 mm x 1 mm spot size and 10 pulses per second using the pulsed laser deposition technique. All film synthesized at temperatures greater than 500°C were crystalline. The effect of the ionic substitution and substrate temperature in conjunction with the effect of the oxygen partial pressure on the microstructure, and mechanical and electrical properties of the thin films have been studied using shallow angle x-ray diffraction, SEM, nanoindentation, atomic force microscopy (AFM), and focused ion beam analysis (FIB) and are reported in detail. We are currently in the process of measuring the capacitance of these films by various methods.