bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dependence of Cu/Sn and Cu/60Sn40Pb Solder Joint Strength on Diffusion Controlled Growth of Cu3Sn and Cu6Sn5
Authors: Dunn D. S. , Marinis T. F. , Sherry W. M. , Williams C. J. 
Published: March 2011

AbstractThe growth of intermetallic compounds and the strength of Cu/ Sn and Cu/ 60Sn40Pb butt joints were studied as a function of isothermal aging. The effects of single-crystal (100), (110), and (111) oriented copper on the growth rates of Cu3Sn and Cu6Sn5 intermetallic compounds are characterized and the influence of elevated temperature aging on the tensile strength of butt joints analyzed. Substrate orientation appears to influence the growth rate. Metallographic measurements showed that the intermetallic compounds grew at a rate proportional to the square root of time. Tensile tests of aged butt joints revealed a more complex time dependence.
Thermomechanical Relaxation of Thin-Film Metallizations
Authors: Hieber Hartmann 
Published: March 2011

AbstractPure Al and Cu films evaporated on thin glass and thermally oxidized silicon substrates are subject to changes in temperature Ṫ>100Ks-1. With constant temperature the stress relaxation is between 1 and 10 % of the thermally induced stress. The stationary creep rates are comparable to diffusion controlled power-law creep. The discontinuous grain growth during the T cycling shifts the transient amplitudes and the stationary slopes of stress to negative values. DC resistance measurements indicate the production and annihilation of vacancies.
Characterization of the Adherence of Metals to Ceramics by a Fracture Mechanics Concept
Authors: Suga Tadatomo , Elssner Gerhard 
Published: March 2011

AbstractThe adherence and the bond strength of metal-to-ceramic joints are described in terms of the fracture energy Gcand the fracture resistance Kc. Small three- or four-point bend test specimens of 30 to 60 mm length notched or precracked at the metal-ceramic interface are used to determine the Gcand Kcdata. Examples of bond strength measurements on metal-to-ceramic joints and plasma-sprayed ceramic layer-metal substrate combinations aim to demonstrate the applicability of the method.
The Microstructure of Copper Films Deposited by E-Beam Evaporation onto Thin Polyimide Films
Authors: Wetzel J. T. , Smith D. A. , Appleby-Mougham G. 
Published: March 2011

AbstractCopper was deposited by electron beam evaporation onto both freshly cleaved bare and polyimide-coated (001) NaCl at substrate temperatures of 20°, 100°, 200° and 300°C at rates of 2 and 20,Åsec−1. For all substrate temperatures and deposition rates investigated, the Volmer-Weber mode of film growth was observed for copper both on polyimide and on NaCl. Comparisons of film growth on the two substrates for a constant substrate temperature revealed differences in film thickness at which copper became continuous or formed a completely coalesced film. It was found that copper grown on polyimide formed continuous and completely coalesced films at smaller film thicknesses than on NaCI. However once a completely coalesced film was obtained, grain growth in the copper films proceeded more rapidly on NaC1 substrates than on polyimide substrates.
On the Selection Rules for the Identification of “Special” Interfaces
Authors: Wolf D. 
Published: March 2011

AbstractIt is demonstrated that the most important geometrical parameter governing the identification of “special” interfaces is the interplanar spacing of the lattice planes parallel to the interfacial plane and not, as often assumed, the inverse density of coincident-site lattice points, Σ. A simple geometrical selection rule for the identification of “special” or “favored” boundaries is formulated on the basis of the interplanar lattice constant.
Successful Design of New Very Low Thermal Expansion Ceramics
Authors: Roy Rustum , Agrawal D. K. 
Published: March 2011

AbstractIn the last few years we have succeeded in developing three separate groups of near-zero-expansion ceramics. These are based on: (1) Modification by crystalline solution of GeO2 for SiO2 in the well-known cordierite phase. (2) Discovery of a new structural family known as [NZP] or [CTP], many members of which have near-zero values of a and very extensive crystalline solution possibilities permitting continuous control of α. (3) Di- (or multi) pfiasic composites of phases, one with negative and one with positive a to give a net-zero-α ceramic material.
Corrosion Protection of at Alloys by Solution Cast Ta2O5
Authors: Lin Yeong C. , Wellinghoff Stephen T. 
Published: March 2011

AbstractA newly developed amorphous, corrosion resistant Ta2O5 coating in saturated H2/H2O/Cl2 environment was studied by scanning and transmission electron microscopy and surface spectroscopy. Although Ta2O5 films formed on polished Al single crystal surfaces by sputter deposition of Ta and subsequent anodization effectively prevent the Al from corrosion by water saturated with chlorine, Al alloy surfaces are not protected, since the anodic film formed over grain boundaries, processing lines, and emergent Precipitates is poorly adherent, thus providing loci for corrosion. This problem was eliminated by casting a 400Å layer of tantalum oxyhydroxide polymer from ethanol solution onto the Al alloy substrate and curing to a Ta2O5 layer that effectively resisted attack by wet chlorine.
Synchrotron Section Topographic Study of the Denuded Zone Formation in Annealed Silicon
Authors: Tuomi T. , Tilli M. , Anttila O. 
Published: March 2011

AbstractHigh resolution section topographs are made with synchrotron radiation using exposure times that are 1/1000 or less of those necessary with conventional x-ray sources. The imaging technique is employed to study oxygenrelated defects and their spatial distribution in a large number of annealed p-type (100) Czochralski silicon wafers. A two-step annealing in nitrogen consisted of a nucleation cycle at 800 °C and at 825 °C for 20 h followed by a denuding cycle at 1100 °C for 6 h. Denuded zones measuring from zero to 100 μm are seen in the synchrotron section topographs made after oxidation of the wafers at 1100 °C for 2 h. The denuded zone formation is found to depend strongly on the part of the crystal from which the wafer is cut. The wafers have the same interstitial oxygen concentration but different carbon concentrations. Large spatial variations up to 100 μm of the denuded zone width are observed in some wafers. Synchrotron section topographs of the wafers in which CMOS devices were fabricated showed a denuded zone only if the wafers were thremally annealed before the IC process.
Surface Steps on α-Alumina Films
Authors: Morrissey K. J. , Carter C. B. 
Published: March 2011

AbstractThin films of α-alumina have been produced by annealing oxide films produced by the thermal oxidation of aluminum substrates. Grains of αalumina which formed in the basal orientation show well-defined surface steps. When these steps move they interact with particles which have nucleated on the surface. Further annealing allows direct observation of the movement of these surface steps.
Grain Boundaries in NiO
Authors: Merkle Karl L. , Reddy J. F. , Wiley C. L. 
Published: March 2011

AbstractDefocus-imaging and high-resolution electron microscopy (HREM) are used to study tilt grain boundaries (GB) in NiO near the <001> axis over the whole range of possible misorientation. Faceting and structural periodicities within facets are observed in high- and low-angle GBs. A reduced atomic density at high-angle GBs is suggested by the defocus behavior.
Microanalytical Tem Studies of Ceramic Materials
Authors: Bischoff Ewald , Rühle Manfred 
Published: March 2011

AbstractFrequently, the processing of dense, strong, and tough ceramics requires the addition of sintering aids. The materials are therefore composed of various components. For the understanding of the properties of the ceramics it is essential that the microstructure and the distribution of the different components within the material are known. The possibilities and limitations of microanalytical TEM studies will be described for different structural ceramics, e.g. ZrO2 , NiO, SiC, and SiAlON.
Thermal Annealing of Vacancy and Interstitial Loops in Ion Irradiated Copper
Authors: Larson B. C. , Noggle T. S. , Barhorst J. F. 
Published: March 2011

AbstractX-ray diffuse scattering has been used to study the thermal annealing of vacancy and interstitial loops in Ni-ion irradiated copper. The diffuse scattering formalism is reviewed and diffuse scattering measurements are reported on liquid-He temperature Ni-ion irradiated copper after annealing to 40, 275, and 300 °C. Size distributions are presented for vacancy and interstitial loops after each anneal and the thermal-induced changes are discussed in terms of loop dissolution and coalescence.
Characterization of Tilt Boundaries by Ultra High Resolution Electron Microscopy
Authors: Krakow W. , Wetzel J. T. , Smith D. A. , Trafas G. 
Published: March 2011

AbstractA high resolution electron microscope study of grain boundary structures in Au thin films has been undertaken from both a theoretical and experimental point of view. The criteria necessary to interpret images of tilt boundaries at the atomic level, which include electron optical and specimen effects, have been considered for both 200kV and the newer 400kV medium voltage microscopes. So far, the theoretical work has concentrated on two different [001] tilt bounda-ries where a resolution of 2.03Å is required to visualize bulk lattice structures on either side of the interface. Both a high angle boundary, (210) σ=5, and a low angle boundary, (910) σ=41, have been considered. Computational results using multislice dynamical diffraction and image simulations of relaxed bounda-ries viewed edge-on and with small amounts of beam and/or specimen inclina-tion have been obtained. It will be shown that some structural information concerning grain boundary dislocations can be observed at 200kV. However, many difficulties occur in the exact identification of the interface structure viewed experimentally for both [001] and [011] boundaries since the resolution required is near the performance limit of a 200kV microscope. The simulated results at 400kV indicate a considerable improvement will be realized in obtain-ing atomic structure information at the interface.
High Resolution Z-Contrast Imaging and Lattice Location Analysis of Dopants in Ion-Implanted Silicon
Authors: Pennycook S. J. , Narayan J. , Cijlbertson R. J. , Fogarassy E. , Batson P. E. 
Published: March 2011

AbstractTwo new electron microscopy techniques have been developed which greatly extend the capabilities for the micro-characterization of semiconductors. The first is a technique for the direct imaging of dopants in semiconductors, whether or not they are in solution, using Z-contrast, and the second is a technique for determining the substitutional fraction of dopant. Both techniques are capable of nanometer spatial resolution and allow the detailed study of dopant segregation, precipitation, and clustering effects.
The Use of Ion Channeling Axial Scans in the Study of Ion-Implanted Al2O3
Authors: Farlow G. C. , White C. W. , Appleton B. R. , Sklad P. S. , McHargue C. J. 
Published: March 2011

AbstractRutherford backscattering and ion channeling-axial scans have been used to study lattice sites for several impurities implanted into A12O3. The case of Ga implanted in A12O3 is discussed and is shown to be substitutional on the Al sublattice. Additionally, the use of this technique in the study of precipitates in A12O3 is discussed with reference to Fe implanted A12O3 which was annealed in either oxygen or hydrogen.
Exafs Studies of Defects in β-Alumina Superionic Conductors
Authors: Roth W. L. , Wong R. 
Published: March 2011

AbstractThe local structures of Zn and Co in solid solution in Na βN–alumina have been investigated using EXAFS spectroscopy. These additives are members of a group that must be incorporated in βN–alumina to stabilize the rhombohedral structure. It is found that they are tetrahedrally coordinated to four oxygen atoms. The N–O bond distances are larger than the Al–O distance in β–alumina and larger than the Al(2)–O distances in disordered crystals determined by x-ray and neutron diffraction. The bonds about individual ions and mixtures of ions are consistent with predictions from bond-strength-bonddistance theory. A preliminary study of Na β–alumina that has been implanted with in and annealed indicates that a substantial fraction of the Mn is tetrahedrally coordinated.
Fim/Iap/Tem Studies of Ion Implanted Nickel Emitters
Authors: Walck S. D. , Hren J. J. 
Published: March 2011

AbstractAccurate depth profiling of implanted hydrogen and its isotopes in metals is extremely important. Field ion microscopy and atom-probe techniques provide the most accurate depth profiling analytical method of any available. In addition, they are extremely sensitive to hydrogen. This paper reports our early work on hydrogen trapping at defects in metals using the Field Ion Microscope/Imaging Atom Probe (FIM/IAP). Our results deal primarily with the control experiments required to overcome instrumental difficulties associated with in situ implantation and the influence of a high electric field. Transmission Electron Microscopy (TEM) has been used extensively to independently examine the influence of high electric fields on emitters.
Electronic and Chemical Analysis of a Metal-Insulator Interface Utilizing Transmission Electron Energy Loss Spectroscopy at 5Å Spatial Resolution
Authors: Scheinfein Michael , Isaacson Michael 
Published: March 2011

AbstractUsing a 0.5 nm diameter probe of 100 keV electrons, we have been able to detect significant changes in the transmission electron energy loss spectra in the region of valence shell and L23 shell excitation within a spatial extent of 0.4 nm of an Al-AlF3 interface. The spectra have been recorded with a dose significantly less than the critical dose for destruction of the AlF3.
Experimental Analysis of Fracture in High Strength Cementitious Composites
Authors: Ansari Farhad 
Published: March 2011

AbstractCharacterization of cementitious composites by their fracture properties has been difficult due to controversial results reported in the technical literature. Existing studies on the fracture behavior of plain concrete reveal some fracture characteristics that differ from those normally observed in metallic materials. Among these characteristics is the existence of a micro-cracking zone or process zone at the tip of an advancing crack. The determination of the fracture process zone in concrete is a difficult experimental problem, because the resulting deformation is strongly localized.In the present study, in-plane displacements in front of notched high strength concrete have been monitored. Laser speckle metrology, which is a special technique utilizing the speckle patterns of laser light for measurement of in-plane displacements, is employed. Experimental results indicate that a precise description of the fracture process zone is possible by speckle metrology.
Porosity and its Relationship to the Strength of Hydraulic Cement Pastes
Authors: Kendall K , Birchall J D 
Published: March 2011

AbstractThe concept of ‘intrinsic strength’ of cement was addressed by testing the bending strength propertes of MDF cement pastes[1–5], containing no organic material, over a range of pore volumes and flaw lengths. The MDF pastes, made only of cement and water, exhibited interesting behaviour, particularly the well packed compositions which gave remarkably low porosity, about 1%, and high modulus, 75 GPa. It was demonstrated that the bending strength of these materials depended on flaw size in a brittle fashion, and that the toughness increased as the volume porosity fell. Fracture mechanics described the results satisfactorily. Therefore, theories based on intrinsic strength, or on the need for polymers to provide high strength [7, 10] are unnecessary.
Fracture Behavior of Lightweight Aggregate Concrete Under Multiaxial Compressive Stress
Authors: Grübl Peter 
Published: March 2011

AbstractLightweight aggregate concrete under triaxial compressive load shows a different failure behavior compared with normalweight concrete. The increase of strength due to confining pressure is not as large as it is with normalweight concrete. It depends on the type of aggregate. The larger the stiffness of the aggregate the larger the increase of strenoth. Under hydrostatic pressure the low strength lightweight aggregate concrete (Bc ∼ 15 N/mm2 ) showed a confining strength which was about 2 to 2,5 times higher than the urfiaxial strength. Concrete with aggregates with high stiffness (E ∼ 14,000 N/mm2 ) and a uniaxial strength between 33 and 48 N/mm2 reached at a confining factor of 25% a strength increasing factor of about 4. The volumetric change curves show two remarkable facts. With confining factors of 0,05 and 0,10 lightweight aggregate concrete has at a stress level of 80% to 90% of the confining strength a volumetric increase which changes into a volumetric decrease shortly before reaching the ultimate load. With a confininn factor of 0.25 the volume decreases constantly until the fracture happens. The temporary volumetric increase is caused by a widening of the cracks. The fracture of lightweight aggregate concrete under confining pressure is mainly caused by an internal collapse of the aggregate grains.
High Stpength Fiber Reinforced Cement Composites
Authors: Naamian Antoine E. 
Published: March 2011

AbstractThe effects of fiber reinforcenent; on the response of high strength fiber reinforced concrete in conmpression, tension and flexure are reviewed. Tradeoffs between the use of high fiber contents to achieve comiposite strength and ductility, and a reduction in matrix porosity to achieve high matrix strength are discussed. Methods used to increase composite strength include application of pressure after casting, addition of fly-ash, silica fumes and or sulerplasticizers to the cement matrix, and mixing high volurite contents of high strength stiff fibers.
Reactions in the Setting of High Strength Cement Pastes
Authors: Rodger S. A. , Sinclair W. , Groves G. W. , Brooks S. A. , Double D. D. 
Published: March 2011

AbstractMaterials of very high flexural strengths (> IOOMPa) can be made by high shear mixing of cement pastes with small amounts of water soluble polymer. Two such systems - high alumina cement/partially hydrolysed polyvinyl acetate and OPC/polyacrylamide - have been examined using a variety of techniques including isothermal calorimetry, infra-red spectroscopy and X-ray diffraction. In both systems the polymer addition appears to become cross-linked by ions released by the cement powder leading to an increase in stiffness of the material. In particular the reactions involved in the OPC system are analogous to those occurring in certain dental cements. The importance of removing excess water from the pastes is demonstrated.
Moving Boundary Model for Leaching of Nuclear Waste Glass
Authors: Banba T. , Murakami T. , Kimura H. 
Published: March 2011

AbstractThe leaching experiments of Soxhlet type have been carried out[l, 2] and on the basis of the results we developed the mathematical leaching model which used one dimensional diffusion and could treat the growth of surface layers. The model adopted the following assumptions: 1) The velocity of the bulk glass-surfacé layers boundary depends on time alone. 2) Some of the diffusing substances are immobilized in the surface layers by an irreversible first-order reaction. 3) A fictitious film exists at the solution-surface layers interface. The fundamental equations were established based on these assumptions and the numerical solutions were obtained by the Crank-Nicholson implicit method. The values of the diffusion coefficient, the reaction rate and the film mass transfer coefficient were obtained by a trial-and-error method. The applicability of the model was confirmed by the fact that the leaching mechanisms deduced from the calculated results were consistent with those mechanisms deduced from the experimental results. The present study showed the proposed model was valid for calculation of the leach rates of waste glasses when surface layers grew during leaching, and the study also indicated which parameters should be measured experimentally to predict the leach rates.
Detailed Processes of Surface Layer Formation in Borosilicate Waste Glass Dissolution
Authors: Flintoff John F. , Harker Alan B. 
Published: March 2011

AbstractThe morphology and chemical structure of surface layers formed during the aqueous leaching of the SRP-type borosilicate waste glass in simulated ground waters have been studied by SEM/EDXS, XRD, and surface spectroscopy. Comparison of layers formed in deionized, silicate, and brine waters shows the processes of both corrosion and precipitation to be highly localized. The corrosion process proceeds on the glass surface preferentially at points of stress and inhomogeneity. Crystalline and noncrystalline precipitates form in well-defined regions within the surface layers indicating the layer development process to be dominated by species migration and local saturation effects.
A General Rate Equation for Nuclear Waste Glass Corrosion
Authors: Grambow B. 
Published: March 2011

AbstractA general rate equation was developed to describe the reaction of nuclear waste glasses with aqueous solutions as a function of pH, the ratio of sample surface area to solution volume, temperature, time, glass- and solution composition. Thermodynamic and kinetic models have been combined in a new model. Glass network dissolution, pH variation, precipitation of stable or metastable solid reaction products, silica saturation at the glass and solution interface (reaction zone) and a residual affinity for the long term reaction under near saturation conditions have been addressed. The model has been successfully used to interpret a great number of experimental data reported in literature.
A Kinetic Model of Nuclear Waste Glass Dissolution in Flowing Water Environments
Authors: Barkatt Aaron , Gibson Barbara C. , Brandys Marek 
Published: March 2011

AbstractA simple kinetic model for the description of the interaction of nuclear waste borosilicate glass with water has been developed. In the case of SRL TDS-131 glass leached in water at 70°C over a broad range of flow rates this model was found useful both in describing the evolution of leachate composition as a function of exposure time at a particular flow rate and in describing the dependence of the steady-state concentrations of the leached elements in solution on flow rate in a series of flow experiments.
Solubility Limits. on Radionuclide Dissolution
Authors: Kerrisk Jerry F. 
Published: March 2011

AbstractThis paper examines the effects of solubility in limiting dissolution rates of a number of important radionuclides from spent fuel and high-level waste. Two simple dissolution models were used for calculations that would be characteristic of a Yucca Mountain repository. A saturation-limited dissolution model, in which the water flowing through the repository is assumed to be saturated with each waste element, is very conservative in that it overestimates dissolution rates. A diffusion-limited dissolution model, in which element-dissolution rates are limited by diffusion of waste elements into water flowing past the waste, is more realistic, but it is subject to some uncertainty at this time. Dissolution rates of some elements (Pu, Am, Sn, Th, Zr, Sm) are always limited by solubility. Dissolution rates of other elements (Cs, Tc, Np, Sr, C, I) are never solubility limited; their release would be limited by dissolution of the bulk waste form. Still other elements (U, Cm, Ni, Ra) show solubility-limited dissolution under some conditions.