bluuebunny/crossref_metadata_2025_split huggingface dataset:
Giant Magnetoresistance and Structural Study of Permalloy/Silver Multilayers During Rapid Thermal Annealing
Authors: Roozeboom F. , Gideonse I. , Duchateau J.P.W.B. , Neerinck D.G. , Munsters H.T. 
Published: April 2011

ABSTRACTThe Giant Magnetoresistance effect with high field-sensitivity was recently discovered in multilayers of alternating ferromagnetic and non-ferromagnetic layers. Some of these layer structures may find industrial application in miniaturized sensor and high-density digital magnetic recording technologies which require materials with large changes in electrical resistance at low magnetic fields.In this paper we report on Rapid Thermal Annealing experiments done on a series of multilayers of alternating thin permalloy (Ni80Fe20) and silver films. The layers were sputter deposited on thermally oxidized Si (100) substrates. Samples were annealed in nitrogen at temperatures ranging from 280 to 340 °C for 30 seconds to 10 minutes, yielding magnetoresistance data as high as 5% and a maximum field sensitivity of 4.6% per kA.m-1. X-Ray diffraction analysis, showing the gradual formation of an Ag (111) shoulder peak at 20 = 38.3° upon annealing, supports a recently published hypothesis that the appearance of the GMR effect is annealinduced by a change of the microstructure due to diffusion, causing notching and disruption of the permalloy layers in the superlattice.
An Environmentally Clean Liquid Precursor of Sulfur for Metalorganic Chemical Vapor Deposition (MOCVD) of Transition Metal Di-Sulfide Thin Films.
Authors: Gadgil Prasad N. 
Published: April 2011

AbstractA three member ring compound propylene sulfide, C3H6S is employed as a sulfur source for the Metalorganic Chemical Vapor Deposition (MOCVD) of stoichiometric thin films of iron pyrite (FeS2). Iron pentacarbonyl Fe(CO)5, a liquid, was precursor for iron. Propylene sulfide, (PS) a liquid ( b. p. = 72–75 °C, v. p. ∼ 87 torr @ 20°C ) decomposes cleanly and quantitatively as S2 and C3H6 (propylene) above 250°C. Deposition of thin films of pyrite and their analysis by X-ray diffraction and Mossbauer and X-ray Photoelectron spectroscopy is described. Liquid state, long term stability, clean and low temperature generation of active S2 species in vapor phase and gaseous by product C3H6 which can be burned to CO2 and H2O are the key advantages offered by propylene sulfide as a sulfur source.
Multiphase Electrodispersion Precipitation of Zirconia
Powders
Authors: Harris Michael T. , Sisson Warren G. , Scott Timothy C. , Basaran Osman A. , Byers Charles H. , Ren W. , Meek Thomas T. 
Published: April 2011

ABSTRACTThe multiphase electrodispersion precipitation of zirconia powders has been
done in the electric dispersion reactor (EDR). This paper presents the first
results obtained where the bench-scale EDR unit was operated in the
continuous mode to synthesize 130 ± 2 g of ZrO2 powder in
approximately 12 h. An aqueous solution of zirconyl nitrate was dispersed
and precipitated in a 2-ethyl-l-hexanol continuous phase containing 0.012
M to 0.12 M ammonia. A
gravity settler was used to remove soft agglomerates of the ZrO2
particles from the organic solvent. Electric bed filtration was employed to
remove the fines from the solvent, which was then recycled.The particle-size distribution was varied by changing the electric field
strength. At high field strengths (approximately 20 kV/cm), the particle
sizes ranged from approximately 0.1 to 5 μm. The dried powder had a
consistency of talcum powder. Microwave and conventional heating experiments
showed that the powders were sinterable. The BET surface area of the powders
ranged from approximately 20 to 90 m2/g.
Processing Effects on the Microstructure of Sol-Gel Derived SBN
Thin Films
Authors: Momoda L.A. , Gust M.C. , Mecartney M.L. 
Published: April 2011

ABSTRACTMicrostructural changes in sol-gel derived
SrxBa1-xNb2O6 (SBN) thin
films were monitored as a function of chemical variations in the precursor
sol and of processing variations of the thin films. 6000À
Sr0.5Ba0.5Nb2O6 thin films
were deposited from different alkoxide based precursors under various
hydrolysis conditions. The tetragonal tungsten bronze structure was achieved
in films at temperatures on the order of 700°C. Preferential (001)
orientation of the tetragonal lattice was found to be very dependent upon
the substrate orientation as well as thermal treatment schedule.
Transmission electron microscopy (TEM) was used to examine the film
microstructure. Orientational effects were verified by TEM as well as a
tendency for a porous structure in the alkoxide derived films. Substrate and
processing dependent grain size and size distributions were also noted.
The Alkoxides of Molybdenum, Tungsten and Vanadium and their
Hydrolysis Products
Authors: Kessler Vadim G. , Turevskaya Eugenia P. , Kucheiko Sergei I. , Kozlova Natalya I. , Turova Nataliya Ya. , Obvintseva Irina E. , Yanovskaya Mary I. 
Published: April 2011

ABSTRACT
Grain-Size Effects on Diffuse Phase Transitions of
Batio3 Ceramics Obtained by Alkoxide
Precursors
Authors: Lobo R. P. S. M. , Moreira R. L. , Mohallem N. D. S. 
Published: April 2011

ABSTRACTBarium titanate ceramics have been obtained by sol-gel methods. The
dielectric investigations of these materials revealed the existence of
diffuse ferroelectric transitions. By using a phenomenological model, we
could demonstrate the existence of a simple relationship between the diffuse
character of the transition and the sample grain-size. This effect has been
attributed to interactions between charged defects on the grain surfaces and
the spontaneous polarization of the material.
Novel Phases in the V-P-O Catalytic System from Oxovanadium
Hydrogenphosphate Precursors
Authors: Amoros P. , Marcos M. D. , Alamo J. , Beltran A. , Beltran P. 
Published: April 2011

ABSTRACTSeveral biphasic VOP04/(VO)2P2O7
redox partners seem to be active in the catalytic cycles involved in the
mild oxidation of simple hydrocarbons to maleic anhydride. The present X-ray
time resolved thermal-diffractometric study reveals the existence of a new
anhydrous variety of the oxidized form, ω-VOPO4, which may appear
as an intermediate in the formation of the well known β-VOPO4.
This new phase only remains well crystallized at relatively high
temperatures, and when it is allowed to cool down in wet air
VOPO4·2H2O results. In turn, another well defined
phase, VOPO4·1.58H2O, can be recognized in the course
of the hydration process.
Spinnability of Silica Sols: the Role of Alkoxy Group
Exchange
Authors: Prabakar S. , Assink R.A. , Irwin A.D. 
Published: April 2011

ABSTRACTThe exchange and spinnability of several systems with the general form
Si(OR)4 (where R = CH3, C2H5)
in ethanol, propanol and butanol were investigated. We have followed the
alkoxy group exchange, the hydrolysis and condensation reactions and the Q
distributions of these systems using 29Si and 17O NMR.
The observed differences in spinnability of the various sol-gel systems are
attributed to the effect of the bulkiness of the alkoxy group on its
reactivity.
Nano-Crystalline Powders and Suspensions Generated Using A
Flow-Through Hydrothermal Process, Part I: Characterization
Authors: Darab John G. , Buehler M. F. , Linehan J. C. , Matson D. W. 
Published: April 2011

ABSTRACTA wide range of ultra-fine, nano-crystalline powders and suspensions have
been produced using the Rapid Thermal Decomposition of precursors in
Solution (RTDS) technology. These materials include single and
multi-component iron-, zirconium-, titanium-, nickel-, and
chromium-oxide/oxyhydroxide powders. RTDS, which was developed at Pacific
Northwest Laboratory, is a flow-through hydrothermal process capable of
producing nano-crystalline particulate material at rates of up to 100 grams
of solid per hour. We present the results of characterization efforts on
RTDS iron oxyhydroxide and zirconium oxide systems. As-collected RTDS
suspensions were characterized using optical light scattering. Separated
RTDS powders were evaluated using X-ray diffraction, electron microscopy,
gas adsorption analysis, thermal gravimetric analysis, and chemical
analysis.
Recent Developments in Organically Doped Sol-Gel Sensors: A
Microns-Scale Probe; Successful Trapping of Purified Polyclonal Antibodies;
Solutions to the Dopant-Leaching Problem
Authors: Aharonson N. , Altstein M. , Avidan G. , Avnir D. , Bronshtein A. , Lewis A. , Liberman K. , Ottolenghi M. , Polevaya Y. , Rottman C. , Samuel J. , Shalom S. , Strinkovski A. , Turniansky A. 
Published: April 2011

ABSTRACTWe describe recent advances made in our laboratories in the general field of
organically and bio-organically doped sol-gel sensors. The developments
described are: (a) The first miniaturization of a sol-gel sensor down to the
microns scale, with potential applications to near-field optical microscopy,
using a fluorescent pH-indicator. (b) The first successful sol-gel
encapsulation of purified polyclonal antibodies, and in particular an
anti-nitroaromatics immunoglobulin, with which selective sensing of
nitroaromatics, an important class of environmental pollutants, was
demonstrated, (c) The leaching problem, occasionally encountered in doping
procedures, is solved by two methodologies: First, TMOS polymerization at
high acidity and low water content was found to result in non-leachable yet
reactive matrices, as demonstrated with O2 sensing by excited
state pyrene and with H+ sensing by excited state pyranine; and
second, doping with molecules capable of forming a covalent bond within the
encapsulating cage results in the permanent anchoring of the dopant. Thus,
Methyl-Red, a pH indicator, was derivatized with a silylating residue, and a
polymerizing TMOS was doped with it forming a pH-shifted indicator. With
both methodologies, leachability was practically zero.
Photochemical Formation of V4+ in a Layered Vanadium
Pentoxide Hydrate
Authors: Kittaka S. , Sumida M. , Kuroda Y. 
Published: April 2011

ABSTRACTFormation of V4+ upon UV-irradiation in the
V2O5 · n H2O was
confirmed and the layered structure of this material was discussed on the
basis of an ESR analysis of the species produced therefrom in combination
with spectral change upon H2O adsorption.
Epitaxy in the Crystallization of Feldspar Gels and
Glasses
Authors: Liu Chunling , Komarneni Sridhar , Roy Rustum 
Published: April 2011

ABSTRACTThe crystallization behaviors of stoichiometric feldspar gels and glasses
before and after seeding have been compared, and the role of epitaxy in
their crystallization upon seeding has been studied. The crystallization
products were mainly determined by X-ray diffraction (XRD) analysis and
epitaxy upon seeding was examined with a scanning electron microscope (SEM),
and energy dispersive spectrometry (EDS). It was found that upon
isostructural seeding, Na-and K-feldspars crystallized epitaxially from
their gels and/or glasses. Little or no seeding effect was found in
CaAl2Si2O8 and
SrAl2Si2O8 gels and glasses.
Isostructural seeding in BaAl2Si2O8 gels
increased the formation of Ba-feldspar (monoclinic celsian) epitaxially,
whereas without seeding hexacelsian was the crystallization product.
Fluorescence Line Narrowing Studies of Eu3+-Doped
Silica Gel-Glasses
Authors: Lochhead M. J. , Bray K. L. 
Published: April 2011

ABSTRACTBroadband fluorescence and fluorescence line narrowing (FLN) spectra are
presented for Eu3+ ions in
Eu2O3-SiO3 and
Eu2O3-Al2O3-SiO3
systems prepared by the sol-gel process. Clustering of rare earth ions in
silica glass can be a limiting factor in the design and engineering of
optical device materials. The addition of Al2O3 is
known to help disperse rare earth ions in sol-gel silica. In order to
develop a more detailed understanding of how Eu3+ is incorporated
in these materials, time-resolved, laser-induced FLN studies at 77 K have
been performed using a pulsed dye laser to selectively excite subsets of
ions in the inhomogeneously broadened 7F0⇆
5D0 manifold. Fluorescence spectra are discussed in
terms of rare earth ion clustering, energy transfer, and bonding site
symmetry. It is concluded that Eu3+ ions cluster in sol-gel
silica and that the addition of alumina assists in dispersing
Eu3+ ions.
Process Dependence of Orientation of Ribbon-Like Aromatic Molecules in Glassy Carbon
Authors: Maleki H. , Ila D. , Holland L. R. , Zimmerman R. L. , Jenkins G. M. 
Published: April 2011

ABSTRACTFlat glassy polymeric carbon samples were prepared from phenolic resin by three techniques: spray coating, spin coating and molding. Cured at 110°C-180°C and pyrolyzed in argon at 600°C or at 1000°C, samples then were studied by RBS for trace impurities, by ESCA for surface oxidation and contamination and by Raman microprobe of the top surface and perpendicular to that for preferred orientation of aromatic ribbons. An increase of 13% to 24% in the relative area under the corresponding Raman peaks indicates increased orientation of the ribbon-like aromatic molecules in the sprayed and spin coated samples as compared with the molded sample.
Carbon Fibers Produced from Graphite Fluoride by Thermal Decomposition in an Inert Environment
Authors: Hung Ching-Cheh 
Published: April 2011

ABSTRACTSlow defluorination of graphite fluoride fibers during nitrogen heating produces both graphitized carbon fibers having high defect density and a yellow film which may contain fullerenerelated materials. The carbon fibers thus obtained can pick up some copper and form aluminum composite during direct molten metal exposure. Explosion of graphite fluoride fibers during quick nitrogen heating produced amorphous carbon containing very little fluorine. They cannot be wetted by copper, but pick up some aluminum during direct molten metal exposure. By either spreading the graphite fluoride fibers apart or adding a small amount of bromoform into the graphite fluoride fibers before the quick nitrogen heating, the possibility of explosion can be reduced.
Nickel Mediated Transformation of Amorphous Carbon to Graphite
Authors: Itoh Toshio , Sinclair Robert 
Published: April 2011

ABSTRACTReactions between Ni and amorphous carbon (a-C) below 600°C have been investigated using differential scanning calorimetry (DSC) and in situ annealing in a transmission electron microscopy (TEM) of Ni/a-C layered films deposited by DC sputtering. DSC data show that there are two exothermic peaks in the temperature range around 200-600°C. One is a weak and broad peak below 500°C and the other is a strong and sharp peak at around 530°C. In situ heating in the TEM revealed that the low temperature peak corresponds to a series of reactions for nickel carbide (Ni3C) formation and decomposition into Ni and carbon, most likely in a glassy state. The higher temperature peak was found to correspond to graphitization of a-C by a solution-precipitation mechanism. Graphite formed in this process is strongly textured with the (0002) graphite basal planes parallel to the original Ni/a-C interface.
Deuteron Magnetic Resonance and Infrared Absorption Studies of Structure and Dynamics in Amorphous Hydrogenated Carbon and Carbon Nitride
Authors: Lin Shu-Han , Feldman Bernard J. , Bodart J. R. , Bork V. P. , Kernan M. J. , Fedders P. A. , Norberg R. E. 
Published: April 2011

ABSTRACTDeuteron magnetic resonance (DMR) and infrared absorption spectra have been measured in amorphous hydrogenated carbon (a-C:H and a-C:D,H) and amorphous hydrogenated carbon nitride (a-CN:D,H) films plasma-deposited onto room-temperature substrates from feedstock mixtures of CH4, N2, and D2. DMR spectra and transient magnetization recoveries were measured between room temperature and 4 K. Recoveries are dominated by magnetization transport under extreme inhomogeneity. Methyl rotors CDx H3-x freeze out below 77 K. From the infrared absorption spectra, NH2, CHx, double bonded C-C, and triple bonded C-N stretching modes are observed. As a function of increasing nitrogen concentrations, the NH2 and C-N intensities dramatically increase while the CHx and C-C intensities decrease. In films where the ratio of nitrogen to carbon plus nitrogen is greater than 25%, the absorption spectra are dominated by NH2 stretching and bending modes; in contrast, the DMR spectra show many CDxHy configurations and a broader NDxHy structure. Proton NMR shows significant hydrogen clustering in a-CN:D,H.
Distribution Function, Density and Hydrogen Content of Amorphous, Diamond-Like, Carbon Films Obtained by X-Ray and Neutron Scattering
Authors: Findeisen E. , Feidenhans'l R. , Vigild M. E. , Nielsen M. , Clausen K. N. , Foss M. 
Published: April 2011

ABSTRACTThe structure of amorphous, diamond-like carbon films is described by the distribution function, obtained by X-ray scattering experiments. In particular the nearest neighbor distance and the average coordination number are determined. A combination of specular reflectivity of neutrons and X-rays enables us to measure not only the mass density, but also the concentration of hydrogen in the films, which varies in our case between 0 and 30 at. %.
Elastic Properties of Silicate Glass and Spin-On Glass Thin Films
Authors: Doucet L. , Carlotti G. 
Published: April 2011

AbstractThe elastic properties of dielectric films used in microelectronics, such as undoped, phosphorous doped and boron-phosphorous doped silicate glass, as well as spin-on glass, have been studied by means of the Brillouin light scattering technique. The phase velocity of both the surface Rayleigh wave and of the longitudinal wave in the film material have been measured and the two independent elastic constants c11 and c44 evaluated. This permitted us to derive the values of the Young’s modulus and of the Poisson’s ratio which are useful quantities for the modelling of the elastic properties of multilevel structures used in electronics. Moreover, the biaxial stress in the films has been measured by the substrate curvature method. This enabled us to study the evolution of the intrinsic stress with time, caused by water adsorption into the films. The evolution of the stress during thermal cycles has been also analyzed and the thermal expansion coefficient of the films estimated.
Composition Dependence of Hardness and Moduli in GeSi/Si-Heterostructures Measured by Nanoindentation
Authors: Roos B. S. , Richter H. , Morgenstern T. , Tillack B. 
Published: April 2011

AbstractGexSi1-x layers (0 ≤ × ≤ 1), with thicknesses ranging from 0.1 to 1.2 µm, were grown on Si(100) and Si(lll) by chemical vapor deposition (APCVD, LP/RTCVD) and liquid phase epitaxy (LPE), respectively. A NanoTest 500 machine served for nanoindentation measurements to evaluate the hardness and elastic moduli. The GeSi layers show strong alloy hardening with an increase varying proportional to x(l-x) as reported for III-V and H-VI-semiconductors. Maximum hardness is close to x = 0.45 at one and a half of the silicon hardness. For binary alloys such as Ge-Si, which show complete solid solubility, the elastic moduli are generally assumed to vary linearly with composition. In contrast to that we found for the indentation modulus E/(l-v2) a positive deviation of 30 % from linear interpolation (Vegard’s law), proportional to x(l-x). The increase in the elastic constants is explained by the structural properties of the Ge-Si alloy.
Stress and its Effect on Intermixing in Si1-xGex/Si Superlattices
Authors: Prokes S. M. 
Published: April 2011

AbstractInterdiffusion behavior in long-period Si1-xGex/Si as a function of growth conditions and external stress is examined using x-ray diffraction and Raman Spectroscopy. Both symmetrically and asymmetrically-strained superlattices have been examined, and an activation energy for interdiffusion of 3.9 eV and 4.6 eV have been obtained, respectively. In addition, an enhanced interdiffusion has also been measured in an externally stressed asymmetric superlattice. In both cases, enhanced interdiffusion has been measured whenever the Si barrier layers experience tensile stress during annealing. The Raman spectroscopy supports this result, showing an enhanced Ge diffusion into the Si barriers when these barriers are put under tensile stress. This result will be discussed in terms of the kinetics of defect formation and motion in the strained Si barriers.
Thermal Stresses in Passivated AlSiCu-Lines From Wafer Curvature Measurement
Authors: Burges U. , Helneder H. , Schneegans M. , Beckers D. , Hallerbach M. , Schroeder H. , Schilling W. 
Published: April 2011

AbstractA wafer curvature technique was used to measure the mechanical stresses during thermal cycling and the isothermal stress relaxation in passivated Ti/TiN/AlSi(l%)Cu(0.5%)-lines (aspect ratio: 0.92) in the in-plane directions, parallel and perpendicular to the lines. The evaluation of the measured curvature data is explained in detail. The evaluation procedure was tested with the help of passivated SiO2-lines in which the stresses can be calculated because both, the SiO2-lines and the passivation, behave elastically. Comparision to elastic Finite-Element-Method calculations show excellent agreement. The main results are:
a)During thermal cycling all stresses in the AlSiCu-lines vary linearly with temperature without significant hysteresis. The stress parallel to the lines is higher than perpendicular to the lines. X-ray stress data from the same sample confirm the wafer curvature data and show, additionally, that the stresses in the two directions perpendicular to the lines are equal.b)The isothermal stress relaxation depends strongly on the temperature with a maximum at 250°C. Void formation and growth probably control the observed relaxation.
Correlation of the Stress-Temperature History with Microstructure in A1-0.5Cu and A1-0.15Pd Thin Films
Authors: Knorr D. D. , Rodbell K.P. 
Published: April 2011

AbstractBlanket films (1 μm thick) of both A1-0.5Cu and A1-0.15Pd were deposited at room temperature, 150°C, and 300°C. Stress in the as-deposited wafers increased with substrate temperature, as expected from the thermal expansion mismatch on cooling. All conditions were tiicrmally cycled to 450°C three times while continuously monitoring stress. The shapes of the curves were different for the two alloys because precipitates dissolve and reprecipitate in AlCu, but are present over the entire temperature range in AlPd. Lesser differences were evident comparing the stress-temperature behavior for the various substrate temperatures within a single alloy. The precipitate structure also influences the grain growth during thermal cycling, where substantially larger median grain sizes are found in AlCu compared to AlPd.
Influence of a Capping Layer on the Mechanical Properties of Copper Films
Authors: Keller R.-M. , Bader S. , Vinci R. P. , Arzt E. 
Published: April 2011

AbstractThe substrate curvature technique was employed to study the mechanical properties of 0.6 μm and 1.0 μm Cu films capped with a 50 nm thick Si3N4layer and to compare them with the mechanical properties of uncapped Cu films. The microstructures of these films were also investigated. Grain growth, diffusional creep and dislocation processes are impeded by the cap layer. This is evident in the form of high stresses at high temperatures on heating and at low temperatures on cooling. At intermediate temperatures on heating and cooling, stress plateaus a relatively low stresses exist. This can be explained by the so-called Bauschinger effect. A film thickness dependence of the stresses in the film could not be observed for capped Cu films.