bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Technology That Began Steuben Glass
Authors: Favela Jacob Israel , Vandiver Pamela 
Published: April 2011

AbstractFrederick Carder popularized art glass in America and is remembered as the founder of Steuben Glass. He was a designer and glass technologist whose factory produced colored and highly decorated glass vessels that competed with but were less expensive than those of Tiffany Studios. To understand the differences in technology between the competing products of Carder and Tiffany, opalescent white glass formulations, fumed gold lusters and silver-containing glasses used in trailed decoration were analyzed and compared by electron beam microprobe analysis and scanning-electron microscopy with simultaneous energy dispersive x-ray analysis. Analytical results show standardized processing that includes opalescent compositions in a narrow range of soda-lime-silicate and lead-alkali-silicate glasses, fumed “golden” lusters made from tin and silver, and iridized surface layers formed by multiple heat treatments.
Growth Promotion and Etching of Carbon Nanotubes by Carbon Dioxide in Chemical Vapor Deposition using Methane Gas
Authors: Suda Yoshiyuki , Takayama Junichi , Saito Takeshi , Okita Atsushi , Nakamura Junji , Sakai Yosuke , Sugawara Hirotake 
Published: April 2011

ABSTRACTWe report the effect of CO2 addition to CO4 gas on carbon nanotube (CNT) growth by chemical vapor deposition. CO2 gas was introduced during the growth of CNTs on Fe0.05Mo0.025MgO0.925 and Ni0.05Mo0.025MgO0.925 catalysts by CO4 gas at a temperature of 800–850°C, and its concentration in a fraction of the gas flow rate was varied from 5×10−3 to 50%. In the experimental condition of the preferential growth of multi-walled CNTs, the carbon yield and the G/D ratio in the Raman spectra of the CNTs grown in 10%-CO2/CO4 were slightly higher than that grown in CO4 only. However, CNTs hardly grew when the CO2 concentration was more than 10%. We then prepared CO2 gas diluted with Ar gas (CO2/Ar) and varied its flow rate between 0 and 10 sccm. As the CO2/Ar gas flow rate was increased, the number of RBM peaks decreased even though the G/D ratio gradually decreased. The decrease in the RBM intensities of CNTs on the FeMoMgO catalyst was more significant than that of NiMoMgO.
Carbon Nanotube Growth on Different Types of Tool Steel Substrates
Authors: Nasuf Gulfem Ipek , Yen Max 
Published: April 2011

ABSTRACTThis paper investigates the effectiveness of different pretreatment methods applied on M50, M35, and W4 type of tool steel substrates for direct growth of carbon nanotubes. The pretreatments explored include treatment with sand paper polishing, nitric acid (HNO3) etching, and high temperature hydrogen gas treatment. Furthermore, in order to establish a correlation between the steel surface average roughness value and the carbon nanotube growth, surface topography of steel substrates created by mechanical polishing were measured before actual growth process. Grown carbon nanostructures were shown by SEM and TEM to be multi-walled carbon nanotubes (MWCNTs) and vapor grown carbon nanofibers (VGCFs). It was found that under the same pretreatment conditions, even when the same roughness values were achieved and the same thermal chemical vapor deposition conditions were applied, grown nanostructures on different types of tool steel substrates showed dissimilarity.
Gas Phase Electronic Sensing Using Single Wall Carbon Nanotube/Boipolymer Hybrids
Authors: Khamis Samuel M , Chen Michelle , Johnson A.T. Charlie 
Published: April 2011

ABSTRACTWe report on a class of hybrid sensors involving single-walled carbon nanotube field effect transistors (SWNT FET's) functionalized with various oligonucleotides. These oligonucleotides include ten sequences of single stranded DNA and two sequences of single stranded. We show that the sequence of the adsorbed oligonucleotide is the key component in determining the response that the hybrid will experience upon exposure to a panel of five volatile organic compounds (VOC's). Our sensors present a change in conductance, which is specific to the analyte being tested, and the adsorbed species. Our devices respond and recover quickly (seconds), and are reproducible over ∼100 cycles. These traits are highly desirable for the creation of a technology for use as an electronic nose. We present a database of responses involving hundreds of devices.
Nanotubules from a Self-Assembling Small Molecule
Authors: Johnson Ross S. , Moralez Jesus G. , Fenniri Hicham 
Published: April 2011

ABSTRACTControl over the dimensions of nanostructured materials is of critical importance for proper utilization in devices. There has been a number of systems reported that utilize amphiphilic molecules that organize themselves into nanotubes or tubules, as well as various polymers that can assemble into tubular nanoscale structures. The organization of these components into nanotubes is mainly driven by hydrophobic effects of the substituents in particular solvents, which contain polar and apolar portions. While studying a modification to a previously reported GC module that normally forms rosette nanotubes (RNTs) with diameters in the 4nm range, we discovered that a small modification led to the formation of nanotubes with diameters 10 times of that expected. These structures were studied by SEM, TEM, and AFM in an attempt to uncover the mechanism of their formation. It was determined that these chiral organic molecules first self-assemble into sheet-like structures, but due to an inherent curvature of the sheet, they roll into large nanotubules. This new type of self-assembled nanotube may have applications in host-guest chemistry and as templates for other nanoparticles and materials.
Epitaxial Growth of III-V Nanowires on Group IV Substrates
Authors: Bakkers Erik , Borgstrom Magnus , Verheijen Marcel 
Published: April 2011

ABSTRACTSemiconducting nanowires are emerging as a route to combine heavily mismatched materials. The high level of control on wire dimensions and chemical composition makes them promising materials to be integrated in future silicon technologies as well as to be the active element in optoelectronic devices.In this article, we review the recent progress in epitaxial growth of nanowires on non-corresponding substrates. We highlight the advantage of using small dimensions to facilitate accommodation of the lattice strain at the surface of the structures. More specifically, we will focus on the growth of III–V nanowires on group IV substrates. This approach enables the integration of high-performance III–V semiconductors monolithically into mature silicon technology, since fundamental issues of III–V integration on Si such as lattice and thermal expansion mismatch can be overcome. Moreover, as there will only be one nucleation site per crystallite, the system will not suffer from antiphase boundaries.Issues that affect the electronic properties of the heterojunction, such as the crystallographic quality and diffusion of elements across the heterointerface will be discussed. Finally, we address potential applications of vertical III–V nanowires grown on silicon.
InGaN Growth with Indium Content Controlled by GaN Growth Plane
Authors: Kanie Hisashi , Akashi Kenichi 
Published: April 2011

ABSTRACTHighly spatially resolved cathodoluminescence (HRCL) imaging and electron backscattering pattern (EBSP) study of InGaN microcrystals were achieved. InGaN grown by the nitridation of a mixture of GaN microcrystals and indium sulfide powders with ammonia at 1000°C had crystal habit with twelve prismatic planes. The prismatic planes were grouped into two groups: the first group is pentagonal shaped planes yielding blue CL (420nm) and rectangular planes without luminescence. EBSP showed that the pentagonal shaped planes are indexed to the {11-20} a-plane and the rectangular plane to the {1-100} m-plane. HRCL imaging showed InGaN accumulated at the V pits on the basal plane. The obevation indicated that the crystal qualty of InGaN and the indium contents incorpated were controlled by the indices of GaN growth planes on which InGaN grew.
Substantial Reduction of Reset Current in CoO RRAM with Ta Bottom Electrode
Authors: Shima Hisashi , Takano Fumiyoshi , Tamai Yukio , Muramatsu Hidenobu , Akinaga Hiroyuki , Inoue Isao H , Takagi Hidenori 
Published: April 2011

AbstractThe resistance switching in Pt/Co-O/Pt and Ta/Co-O/Pt has been investigated. Compared to Pt/Co-O/Pt, the reset current was more efficiently decreased in Ta/Co-O/Pt by using the load resistor in the forming process, indicating that the embedded resistance component with little parasitic capacitance effectively limits the current in the forming process. The reset process with the reset current lower than 0.15 mA was successfully demonstrated in Ta/Co-O/Pt. In addition, the high speed resistance switching by the voltage pulse with the pulse width of 20 ns was carried out, by investigating the pulse voltage height dependence of reset speed in Ta/Co-O/Pt.
From Micro to Nanometric Grain Size CVD Diamond Tools
Authors: Almeida Flávia A. , Amaral Margarida , Salgueiredo Ermelinda , Fernandes António J.S. , Costa Florinda M. , Oliveira Filipe J. , Silva Rui F. 
Published: April 2011

ABSTRACTCVD diamond coated tools are developed for applications as different as turning of cemented carbides and bone drilling. The diamond films are deposited by Hot Filament Chemical Vapor Deposition (HFCVD), with grain sizes varying from conventional micrometric (12 μm) to nanometric (< 100 nm) and film thickness up to 50 μm. Silicon nitride (Si3N4) ceramics are chosen for the base material in order to guarantee maximal adhesion. Both the micrometric and nanometric CVD diamond grades endure the cemented carbide turning showing slight cratering, having flank wear as the main wear mode. However, nanocrystalline diamond present the best behavior regarding cutting forces (<150 N) and tool wear (KM=30 μm, KT=2 μm and VB=110 μm) and workpiece surface finishing (Ra=0.2 μm). In the case of the dental drilling experiments, a polymeric laminated test block is used to simulate the human mandible and maxilla. The temperature rise during drilling is monitored to prevent overheating above 42–47 °C that is known to cause tissue death and implant failure. It is possible to drill with a CVD diamond Si3N4 coated tool with significantly lower forces (fourfold smaller), lower rise in temperature (4°C less), lower spindle speeds (100 rpm) and higher infeed rates (30 mm/min), when compared to the commercial steel (AISI 420) drill bits.
Trace Analysis of Nanoscale Materials by Analytical Electron Microscopy
Authors: Newbury Dale E. , Leapman Richard D. 
Published: April 2011

ABSTRACTTrace analysis of nanometer-scale objects can be performed with parallel-detection electron energy loss spectrometry in the analytical electron microscope. Spectra are collected in the second difference mode with the beam current chosen to maximize the spectral count rate. Numerous elements can be detected at trace levels below 100 parts per million atomic, including transition metal, alkali metal, alkaline earth, and rare earth elements, provided they have a “white line” resonance structure at the ionization edge. Trace nanoanalysis by AEM/PEELS permits direct examination of the microscopic distribution of trace constituents.
Selective Imaging of Metal Atoms in the Semiconducting Layered Compound MoS2 by STM/STS
Authors: Inoue S. , Kawami H. , Yoshimura M. , Yao T. 
Published: April 2011

ABSTRACTWe have investigated the valence band structure of MoS2, a transition-metal dichalcogenide, using scannino tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) for the first time. We have found characteristic peaks in the (dl/dV)/(I/V)-V characteristic at −1.0 and −1.4V below the fermi level, which correspond to the S Pz state and Mo dz2 state, respectively. Mo atoms are accessible only at the sampfe voltage of −1.4V in the range of −1.0 through − 1.5V, due to the strong localization of the Mo dz2 state with very small bandwidth.
Relationships Between Photoluminescence Spectra and Porosity of Porous Silicon
Authors: Song H.Z. , Zhang L.Z. , Zhang B.R. , Qin G.G. 
Published: April 2011

ABSTRACTIt was found that porous silicon (PS) layers formed on 0.01 Ωcm (111) and 0.02 Ωcm (100) Si substrates show high photoluminescence (PL) peak energies on both lower and higher porosity sides and a minimum of PL peak energy at the moderate porosity, while those formed on 0.8 and 10Ωcm (111) p-type Si substrates show an increase of PL peak energy with porosity on the lower side and a saturation of PL peak energy with porosity on the higher side. These experimental facts are not consistent with the quantum confinement model for light emission of PS, which predicts a monotonous increase of PL peak energy with PS porosity.
Grazing Incidence X-Ray Reflectance Measurement of Surface and Interface Roughness on the Sub-Nanometre Scale
Authors: Wormington M. , Sakurai K. , Bowen D.K. , Tanner B.K. 
Published: April 2011

ABSTRACTGrazing incidence X-ray reflectivity may be used to measure surface topography including roughness and correlation lengths to sub-nanometre precision. A study is made of a technically important surface, a carefully-polished specimen of Zerodur glass-ceramic, which has been measured by diffuse scatter of CuKα X-radiation and atomic-force profilometry methods. The data have been analysed in terms of a fractal representation of the surface correlation function. Results from the two methods agreed within their estimated errors, with the X-ray data showing roughnesses of 1.3 nm, correlation length of 1 μm and fractal parameter (bandwidth) of 0.35. The X-ray methods have a lower cut-off length, are much more rapid for averaged information and are both non-contacting and non-destructive. They also show potential for the study of interface roughness in thin films.
Molecular Dynamics Simulation of the Elastic Deformation of Nanometer Diameter Metal Clusters
Authors: Paithankar Dilip Y. , Talbot Julian , Andres Ronald P. 
Published: April 2011

ABSTRACTIndentation using the AFM is a powerful method for determining elastic properties of small supported clusters. However, a theoretical framework has yet to be developed to interpret such measurements. The elastic deformation of nanometer sized gold clusters are modeled using the Embedded Atom Method (EAM) potential of Foiles et al. [1]. Force versus deformation curves are obtained for a series of truncated octahedral clusters having FCC symmetry (N=38, 201, 586, 1289, 2406). It is found that the MD results both for static compression and for harmonic vibration can be analytically estimated by using an elastic constant for the clusters analogous to the elastic modulus of a bulk material. However MD predictions for static compression are not in agreement with the deformation results of Schaefer et al. [2].
Effects of Residual Stress on the Measurement of Hardness and Elastic Modulus using Nanoindentation
Authors: Pharr G.M. , Tsui T.Y. , Bolshakov A. , Oliver W.C. 
Published: April 2011

ABSTRACTThe effects of stress on the measurement of hardness and elastic modulus in aluminum alloy 8009 have been studied experimentally and by finite element simulation. The experiments were performed by making a linear array of nanoindentations on the side of a stressed bend bar, sampling regions of high uniaxial tension, high uniaxial compression, and a variety of stresses in between. When analyzed according to standard methods, the nanoindentation data reveal a decrease in both hardness and modulus with increasing stress from compression to tension. While the decrease in hardness is consistent with previous observations made in conventional hardness testing, the modulus decrease was unexpected. Finite element simulation revealed that the drops in hardness and modulus are not real, but occur because the procedure for determining contact area from the nanoindentation load-displacement data does not account for pileup around the indentation. The finite element simulation shows that large compressive stresses promote pileup while tensile stresses reduce it, and this must be properly accounted for if accurate hardnesses and moduli are to be obtained. Experimental results are presented which further support this point of view.
Modeling Electromigration-Induced Stress Buildup Due to Nonuniform Temperature
Authors: Clement J. J. , Thompson C. V. , Enver A. 
Published: April 2011

ABSTRACTAtomic transport due to electromigration in interconnect lines in integrated circuits depends strongly on temperature. Therefore temperature nonuniformities can create sites of atomic flux divergence resulting in material accumulation or depletion leading to failure. The mechanical stress which will evolve at the sites of material flux divergence will oppose the electromigration driving force. A model is developed to describe the stress evolution during electromigration in the presence of temperature nonuniformnities. Solutions of the differential equations describing the electromigration-induced stress buildup are calculated numerically. The solutions are compared to experimental data in the literature.
Anisotropy in Thermal, Electrical and Mechanical Properties of Spin-Coated Polymer Dielectrics
Authors: Bidstrup Sue Ann , Hodge Thomas C. , Lin Linda , Kohl Paul A. , Lee J.B. , Allen Mark G. 
Published: April 2011

ABSTRACTIn MCM-D applications, interlayer dielectrics separate and insulate metal conductors to form a three-dimensional interconnection structure. Due to the three-dimensional nature of these structures, the thermal, electrical and mechanical properties of the dielectricmaterials must be known for all orientations in order to correctly design and simulate devices. The most commonly used polymer in microelectronics, polyimide, exists in formulations which have been shown to have a high degree of orientation and exhibit anisotropicproperties.
Defect Analysis In Substrate Materials for High Tc Superconducting Thin Films
Authors: Fletcher P. R. , Leach C. , Wellhofer F. , Woodall P. 
Published: April 2011

AbstractMany defects in high Tc superconducting films propagate from the substrate through to the film surface, disturbing the epitaxy at the interface and adversely affecting the physical properties of the film, particularly Jc. In this study the surface of Magnesium Oxide (100) single crystal substrates with different preparative treatments have been investigated using optical cathodoluminescence microscopy (CL), with a view to establishing its effect on the deposition of thin films of YBa2Cu3O7-δ superconductors.CL excitations due to mechanically and chemically induced defects in the MgO substrate crystals are observed by optical CL microscopy. Several pre-deposition treatments have been compared in this way to determine the best preparation route for the substrates. Jc measurements indicate that the substrate surface quality is an important parameter in the production of high quality thin films especially for the fabrication of devices.It is concluded that CL provides a powerful and rapid tool for MgO quality assessment before thin film deposition.
Epitaxial Thin Films And Heterostrcutures of Various Isotropic Metallic Oxides for Device Applications
Authors: Eom C. B. , Phillips Julia M. , Cava R. J. 
Published: April 2011

AbstractWe have grown epitaxial thin films of various isotropic metallic oxides such as Sr1-xCaxRuO3 and La8-xSrxCu8O2Oin situ by 90° off-axis sputtering. These metallic oxides are pseudo-cubic perovskites with essentially isotropic properties, which could be ideal normal metals for SNS junctions in superconducting devices and for electrodes in ferroelectric devices. We have fabricated epitaxial ferroelectric heterostructures [SrRuO3/Pb(Zr0. 52 Ti0.4 8) O3 /SrRuO3] employing isotropic metallic oxide (SrRuO3) electrodes on substrates of (100) SrTiO3 and (100) Si with an yttria stabilized zirconia buffer layer. They exhibit superior fatigue characteristics over those made with metal electrodes, showing little degradation over 10 cycles, with a large remnant polarization (27 μC/cm2 ). We have also grown epitaxial superconducting heterostructures (YBa2Cu3O7 / La8-xSrxCu8O2O / YBa2Cu3O7 ) with a copper-oxide-based isotropic metallic oxide (La8-xSrxCu8O20) normal metal barrier. X-ray diffraction and cross-sectional transmission electron microscopy reveal these heterostructures to have high crystalline quality and clean interfaces. This material will facilitate fabrication of ideal SNS Josephson junctions with low boundary resistance due to its excellent chemical compatibility and lattice match with cuprate superconductors and will be useful for determining the source of interface resistance in such heterostructures.
Epitaxial Growth of CoO (001) and Co3O4 (001) Films on MgO (001) by Pulsed Laser Deposition
Authors: Feeler David , Williams R. Stanley 
Published: April 2011

AbstractSingle crystal films of both rocksalt CoO and spinel Co3O4 were epitaxially grown with (001) orientations on MgO(001) substrates by pulsed laser deposition from CoO targets. The samples were characterized with low energy electron diffraction to determine the parallel orientation of the films with respect to the substrate, and x-ray diffraction to determine the perpendicular structure of the films. Both films were determined to have undergone tetragonal distortions, although to different degrees, due to the biaxial stress present in these epitaxial films.
Growth and Characterization of Epitaxial PbTiO3Thin Films On Mgo
Authors: Zhang K. , Pashmakov B. , Mogilevsky R. , Jaeger H. M. , Xu Ming , Kramer M. J. , Goldman A. 
Published: April 2011

AbstractEpitaxial PbTiO3 thin films have been grown on single-crystal MgO (100) substrates using metalorganic chemical vapor deposition technique. The energy gap was determined from optical absorption data to be Eg= 3,425 eV. Secondary ion mass spectrometry data showed uniform distribution of Pb, Ti and O atoms with no traces of carbon contamination. Atomic force microscopy studies showed different surface morphology for different film growth rates. In-situ X-ray diffraction data indicate that the tetragonal-to-cubic structural phase transition occurs at about 500–520°C. Above 750 °C the films exhibit multi-phase character, the textured PbTiO3 phase co-existing with a polycrystalline Pb2Ti2O6 structure and a possible Mg-containing impurity phase.
Properties of Yttrium Oxide Thin Films on Silicon (100) Prepared by Evaporation of Yttrium in Atomic Oxygen
Authors: Hudner J. , Ohlsén H. , Fredriksson E. 
Published: April 2011

AbstractThin layers of Y2O3 have been prepared on silicon (100) by an activated reactive evaporation process involving evaporation of metal Y in an atomic oxygen plasma. The presence of the oxygen plasma was found to be crucial for the formation of homogeneous Y2O3 films on Si. The formation of Y2O3 films on Si (100) at different substrate temperatures was investigated. X-ray diffraction analysis showed that Y2O3 films formed between 300 °C and 650 °C were (111) textured while Y2O3 prepared at lower substrate temperatures (80 °C) exhibited mixed orientations. Rutherford backscattering spectrometry indicated that films were stoichiometric. No pronounced channeling was observed in films grown at 350 °C, suggesting polycrystalline film structures. Atomic force microscopy revealed very smooth surface morphologies with average surface roughness < 20 Å for films 700 Å thick deposited at 350 °C. Secondary ion mass spectroscopy indicated the abundance of intermediate layers in the film-substrate interface.