bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Temperature Properties of Equialomic FeAl with Ternary Additions
Authors: Titran R. H. , Vedula K. M. , Anderson G. G. 
Published: March 2011

ABSTRACTThe aluminide intermetallic compounds are considered potential structural materials for aerospace applications. The B2 binary aluminide FeAl has a melting point in excess of 1500 K, is of simple cubic structure, exist over a wide range of composition with solubility for third elements and is potentially self-protecting in extreme environments. The B2 FeAl compound has been alloyed with 1 to 5 at % ternary additions of Si, Ti, Zr, Hf, Cr, Ni, Co, Nb, Ta, Mo, W, and Re. The alloys were prepared by blending a third elemental powder with pre-alloyed binary FeAl powder. Consolidation was by hot extrusion at 1250 K.Annealing studies on the extruded rods showed that the third element addition can be classified into three categories based upon the amount of homogenization and the extent of solid solutioning. Constant strain rate compression tests were performed to determine the flow stress as a function of temperature and composition. The mechanical strength behavior was dependent upon the third element homogenization classification.
Design of Ductile Polycrystalline Ni3Al Alloys
Authors: Liu C. T. , White C. L. 
Published: March 2011

ABSTRACTThis paper provides a comprehensive review of current efforts on design of ductile polycrystalline Ni3AI alloys. Microalloying has proven to be very effective in alleviating the grain-boundary emibrittlement problem. The ductility and fabricability of Ni3Al (24 at. % Al) are dramatically improved by adding a few hundred parts per million of boron. The beneficial effect of boron is related to its unusual segregation behavior as predicted from the theory of grain-boundary cohesion developed by Rice, based on thermodynamic analyses. Alloy stoichiometry strongly influences grain-boundary chemistry, which, in turn, affects the boundary cohesion and overall ductility of Ni3Al.The solid-solution hardening of Ni3AI depends on the substitutional behavior of alloying elements, atomic size misfit, and the degree of nonstoichiometry of the alloy. Hafnium additions are very effective in improving high-temperature properties of ternary Ni3Al (Al + Hf = 24 at. %) doped with boron. Alloying with <2% Hf substantially increases the yield stress and raises the peak-strength temperature. In addition, hafnium substantially improves creep properties and oxidation resistance. The Ni3Al aluminides truly represent a new series of heat resistant materials which do not depend on chromium for oxidation resistance.
The Oxidation of Nickel-Aluminum and Iron-Aluminum Alloys
Authors: Cathcart John V. 
Published: March 2011

ABSTRACTThe high-temperature oxidation behavior of several ordered alloys in the Ni-Al and Fe-Al systems is reviewed with special emphasis on Ni3Al and NiAl. Ordering influences oxidation through its effect on the activities of the alloy components and by changing the point defect concentration in an alloy. Three categories of Ni-Al alloys are distinguished based on Al content and oxidation behavior. A characteristic feature of the oxidation of high-aluminum Ni-Al and Fe-Al alloys is the formation of voids in the substrate at the oxide-metal interface. The mechanism of void formation and its suppression by minor additions of oxygen-active elements is discussed. A brief description of the effect of preoxidation on the reactions of Ni3Al-base alloys in SO2/O2 environments is also included.
Interatomic Interaction in Transition and Noble Metal Alloys and the Stability of the Ordered State
Authors: Dementyev V. M. , Kozlov E. V. , Kolodeznaya S. F. 
Published: March 2011

ABSTRACTThe nature and the role of the pair interatomic interaction of the noble and transition metal ordering alloys are considered. The determining role in the electron susceptibility in the behaviour of the interatomic interaction is shown. The important role of the Fermi surface local geometry in the definition of superstructure periods is established. Illustrating calculations are made. It is shown that in the noble and transition metal alloys with complicated Fermi surface the oscillations of the pair interatomic interaction are of essentially nonfriedel character.
Computer Modelling of Laser Annealing
Authors: Baeri P. 
Published: March 2011

ABSTRACTHeat flow calculations, based on the main assumption that the energy of the incident pulse is instantaneously and locally converted into heat, are used to review the results of laser pulse annealing and impurities behaviour in ion implanted semiconductors. The crystallization behaviour of amorphous layers, the velocity of the solid-liquid interface and impurity redistribution are detailed with the main emphasis on the relevance of the parameters (laser wavelen gth, pulse duration and energy density, substrate temperature, etc.) that can be experimentally controlled. Comparison with the latest experimental results is also given.
Solute Segregation and Dynamics of Solid-Phase Crystallization In in and Sb-Implanted Silicon
Authors: Narayan J. , Olson G. L. , Holland O. W. 
Published: March 2011

ABSTRACTTime-resolved-reflectivity measurements have been combined with transmission electron microscopy (cross-section and plan-view), Rutherford backscattering and ion channeling techniques to study the details of laser induced solid phase epitaxial growth in In+ and Sb+ implanted silicon in the temperature range from 725 to 1500 °K. The details of microstructures including the formation of polycrystals, precipitates, and dislocations have been correlated with the dynamics of crystallization. There were limits to the dopant concentrations which could be incorporated into substitutional lattice sites; these concentrations exceeded retrograde solubility limits by factors up to 70 in the case of the Si-In system. The coarsening of dislocation loops and the formation of a/2<110>, 90° dislocations in the underlying dislocation-loop bands are described as a function of laser power.
Light Absorption Effects on the Nd Laser Annealing of Ion Implanted Silicon
Authors: Baeri P. , Bapbarino A.E. , Campisano S.U. , Grimaldi M.G. , Foti G. , Rimini E. 
Published: March 2011

ABSTRACTThe crystallization onset and the annealing thresholds have been nmeasured as a function of the absorbed energy density in ion implanted amorphous silicon irradiated with nanosecond Nd pulse. Thin amorphous layers (∼500 Å) require higher thresholds ccapared with thick (∼4000 Å) amorphous layers. This result can be explained in terms of balance between absorbed energy and heat flow. For a given thickness of the amorphous layer the thresholds depend on the absorption coefficient of the amorphous material. This last parameter has been varied frcm 104 to 102 CM−1 by low temperature (T<400°C) pre-treatment of the ion implanted sample. The observed drastic variations of both crystallizazion and annealing thresholds agree well with nunerical evaluation of heat flow.
Silicon Melts During Pulsed Ruby Laser Annealing
Authors: Stritzker B , Pospieszczyk A , Tagle J. A. 
Published: March 2011

ABSTRACTThe lattice temperature of silicon was measured during pulsed ruby laser annealing (-20 ns pulse, spot diameter ≥ 5 mm) using a classical time of flight method to determine the velocity distribution of Si atoms evaporated from the hot surface. The maximum of this Maxwell type distribution was used to calculate the temperature of the Si surface. The resulting lattice temperatures vary between 1200 and 2500 K for energy densities between 1.0 and 2.0 J/cm2 , i.e., Si is molten for energy densities ≥ 1.4 J/cm2 . This result clearly supports the strictly thermal annealing model [1] and contradicts the non-thermal-equilibrium model [2] as well as Raman measurements [3].
Periodic Surface Damage in Germanium: The Spectrum in K→ Space and its Theoretical Interpretation
Authors: Young Jeff F. , Sipe J. E. , Gallant M. I. , Preston J. S. , Van Driel H. M. 
Published: March 2011

ABSTRACTThe Fourier transforms of the grating-like damage patterns formed on the surface of Ge by single 1.06μm YAG laser pulses reveal a great deal of information about the damage structure. A theory is presented based on scattering from surface roughness which accurately accounts for both the spacing and orientation of the fringes produced at various angles of incidence by beams of different polarizations.
Residual Defects in Virgin and Implanted Si After Laser Processing
Authors: Mesli A. , Goltzene A. , Muller J.C. , Meyer B. , Schwab C. , Siffert P. 
Published: March 2011

ABSTRACTEPR, photocarrier cyclotron resonance and DLTS measurements have been performed on laser-annealed Si wafers.In virgin Si, an isotropic EPR line at g1 = 2.0055± 0.0005 and a carrier lifetime decrease, assessed by cyclotron resonance, are correlated to the creation of vacancy complexes associated to Oxygen.In implanted Si, only defects due to the tailing effect of implantation process are observed by DLTS. These levels can be divided into two groups, one of them is stronglycorrelated with the implanted parameter. They are ascribed to primary or complex associations of point defects.
Modelling of CW Laser Annealing of Multilayer Structures
Authors: Calder I.D. , Sue R. , Aly Emad-Eldin A.A. 
Published: March 2011

ABSTRACTA thermal model is developed for cw laser annealing of multilayer structures. Each layer has arbitrary thickness, thermal conductivity and optical properties. Steady state conditions with no phase transition are assumed. A procedure is presented for obtaining the temperature distribution in any system and explicit integral expressions are developed for the two and three layer cases. Results are calculated for the Si/glass and Si/SiO2 /Si systems.
CW Annealing Techniques for Junction Formation in Ge
Authors: Lorenzo J.P. , Soda K. J. , Eirug Davies D. 
Published: March 2011

ABSTRACTCW scanned Argon laser annealing is used to form photo diodes in single crystal Boron implanted germanium. The starting material is doped n–type to 4 × 1015 cm−3 and oriented 2° off the <100>. For annealing, a substrate temperature of 250°C is employed in conjunction with a beam spot diameter of 50 μm and scan speeds in the vicinity of 1 cm/sec. Pyrolytic oxides are deposited to provide a protective and antireflective coating. Devices are fabricated and display dark leakage characteristics of the order of ∼ 10−4 A/cm2 which is comparable to diodes made by more conventional techniques.
Material-Process Interactions in the Annealing of Gallium Arsenide
Authors: Lawrence Anderson C. 
Published: March 2011

ABSTRACTThis review article provides an overview of the current understanding of the physical mechanisms involved in the annealing of ion implanted GaAs by thermal techniques and by CW and pulsed laser and electron beams. The successfulness of these techniques is evaluated in terms of the electrical and optical properties of the annealed layers. Promising areas of investigation for the improvement of the electrical properties of n-type layers produced by pulsed annealing are identified.
Diffusion of Si in GaAs From a Thin Si Film by Pulsed Laser Irradiation
Authors: Nissim Y. I. , Greiner M. , Falster R. J. , Gibbons J. F. , Chye P. , Huang C. 
Published: March 2011

ABSTRACTThe diffusion of Si into GaAs from a thin source has been investigated. Electron beam evaporated Si films were deposited on chromium–doped GaAs wafers. Pulsed irradiation from a Q–switched Nd:YAG laser resulted in the formation of n+ layers. After metal evaporation these layers displayed nonalloyed ohmic contact behavior of very low contact resistance (5×10−7 Ω−cm2 ) and good thermal stability at 300°C. SIMS analysis of these layers revealed a steplike Si profile and significant chromium redistribution within the laser induced molten layer. A major improvement in surface morphology was obtained using Si02 encapsulants.
A New Electron Beam Polishing Technique for Heteroepitaxial Thin Films
Authors: Tobin S. P. , Greenwald A. C. , Wolfson R. G. , Wong T. T. 
Published: March 2011

ABSTRACTWe have developed a novel technique for improving the morphology of as-grown monocrystalline thin films on foreign substrates. A pulsed electron beam briefly heats the surface of the film above its melting temperature, allowing surface tension in the liquid to erase irregular features. Crystallinity of the layer is preserved by rapid resolidification with the underlying material acting as a seed. Pulse polishing has been applied to two heteroepitaxial systems exhibiting rough as-deposited surfaces: germanium on silicon and cadmium telluride on mica. In both cases the surface morphology was dramatically improved while crystallinity and other critical properties of the layers were maintained. We believe this technique has potentially wide application to many thin film systems and should allow a greater degree of freedom in the growth conditions for heteroepitaxial thin films.
Supersaturated Substitutional Solid Solution after Solid Phase Epitaxial Regrowth by Incoherent Light Scanning.
Authors: Pedulli L. , Correra L. 
Published: March 2011

ABSTRACTSupersaturated substitutional solid solutions of 2×101531P+ /cm2 implanted at 10 keV in (100) Silicon were obtained after solid phase epitaxial regrowth using a scanning beam of incoherent light. The main results are: a) the maximum P+ concentration exceeds of about 5 times the maximum solid solubility at the temperature reached by the sample; b) the carrier concentration profile shows a complete dopant activation without diffusion of the implanted ions; c) an improvement of minority carriers diffusion length in the bulk is often observed; d) the values of carrier mobilities are similar to those obtained after liquid phase regrowth by pulsed ruby laser; e) a very good recovery of the damage is obtained: Rutherford backscattering spectra show that the dechanneling fraction is very close to the value of virgin samples and Trasmission Electron Microscopy analysis shows that the residual damage consists of dislocation loops of about 30 Å diameter confined in a region at about 500 Å depth.
Dual Electron Beam Processing System for Semiconductor Materials
Authors: McMahon R.A. , Davis J.R. , Ahmed H. 
Published: March 2011

ABSTRACTThis paper describes a semiconductor processing system using two electron beams. One beam provides uniform heating of the bulk of the specimen, whilst the other performs localized heating, for example as a spot, a line beam, or as an inset scan. The annealing of localized regions in ion-implanted silicon and SOS, by local heating above the bulk temperature, illustrates the application of the system. Other applications of the systems are also considered.
A Study of Intermetallic Compound Development In Nickel-Tin Interfacial Zones
Authors: Allen Charles W. , Fulcher Mark R. , Rai Amarjit S. , Sargent Gordon A. , Miller Albert E. 
Published: March 2011

AbstractInterdiffusion and intermetallic formation in Ni-Sn interfacial zones are examined by X-ray diffraction in samples prepared by electroplating of Sn at room temperature. For the case of plating directly onto electropolished nickel, only very sluggish formation of Ni3Sn4 was observed at 190 C. In contrast, when the nickel surface is chemicaly or chemically-abrasively activated prior to plating, a thin layer of Ni3Sn forms at the initial interface at room temperature, and subsequent annealing at 100 and 190 C produces all intermetallics predicted by the equilibrium phase diagram including Ni3Sn, indicating that the absence of Ni3Sn usually observed arises from its failure to nucleate.
Fracture Mechanics of Interface Failure
Authors: Kendall Kevin 
Published: March 2011

AbstractInterfaces are important in ceramic and other composite materials because they can be used to control cracks, the major source of weakness and unreliability in brittle solids. Brittle materials fracture catastrophically, but may be converted into tough composites by the injection of interfaces which retard or deflect the cracks. This paper examines the behaviour of cracks at interfaces and demonstrates several mechanisms for crack control in brittle systems. Crack stopping, dislocation formation, and crack deflection at interfaces have been illustrated by experiments on rubber models and analysed by the energy balance theory of fracture.
Determination of Time-Dependent Plastic Properties of Metals by Indentation Load Relaxation Techniques
Authors: Hannula Simo-Pekka , Stone Donald , Li Che-Yu 
Published: March 2011

AbstractLoad relaxation testing has been demonstrated to be useful for characterizing the time dependent plastic properties of metals. However, for testing of small material volumes, such as thin film metallizations, thin films, and contact surfaces, conventional load relaxation techniques cannot be used. For such applications an indentation test offers an attractive means for obtaining data necessary for materials characterization. This work shows that an indentation load relaxation test is experimentally feasible for thin film testing. Experiments on brass and beryllium copper samples with or without a gold/nickel plating illustrate different relaxation properties of the substrates and the surface layers. Furthermore, results of experiments on some fcc metals suggest rather simple relations between the conventional uniaxial load relaxation (LR) test and the indentation load relaxation (ILR) test.
Acid-Base and Electrostatic Contributions to the Adhesion of Polymers to Metal and Ceramic Substrates
Authors: Fowkes Frederick M. 
Published: March 2011

The strength of interfacial bonding between polymers and inorganic substrates is very appreciably enhanced when polymers are acidic and substrates are basic, or vice versa. The interaction is of two kinds, an increased thermodynamic work of adhesion resulting from large exothermic interactions at the interface, and an increased tensile strength resulting from electrical charge injection into the polymer from the substrate.The exothermic interfacial interactions between acidic and basic sites are easily measured by calorimetry or by infrared spectral shifts. The enthalpies of adsorption can be correlated and predicted by the Drago equation, −Δ H = CACB+ EAEB, where the CA and EA for the acidic member can be measured by enthalpies determined with basic molecular probes of known CB and EB. Heats of adsorption of polymers onto inorganic substrates are precisely predictable with the above equation once E and C values are known for the polymer and substrate.
Effect of Interfacial Characteristics of Metal Clad Polymeric Substrates on Electrical High Frequency Interconnection Performance
Authors: Bhasin K. B. , Romanofsky R. R. , Ponchak G. E. , Liu D. C. 
Published: March 2011

AbstractEtched metallic conductor lines on metal clad polymeric substrates are used for electronic component interconnections. Significant signal losses are observed for microstrip conductor lines used for interconnecting high Frequency (above 20 GHz) devices. At these frequencies, the electronic signal travels closer to the metal-polymer interface due to the skin effect. Copper-teflon interfaces were characterized by SEM and AES to determine the interfacial properties. Data relating roughness of the copper film to signal losses was compared to theory. Films used to enhance adhesion, were also found, to a lesser extent, to contribute to these losses.
Direct Concentration Measurement of Hydrogen Electromigration Using Nuclear Reaction Analysis
Authors: Benenson R. E. , Berning P. , Wielunski L. 
Published: March 2011

AbstractLateral concentration profiles of hydrogen (1H) have been measured using nuclear recoil analysis on electrolytically charged metal (V, Nb, Ta) foils subjected to current densities of order 103 amps/cm2 for various times in order to study the electromigration of hydrogen. Initially uniformly loaded foils exhibited a dramatic redistribution of the hydrogen. Numerical analysis of these data using the conventional solution of the electromigration equation is used to extract the hydrogen effective charge (Z*) from the steady state data and the diffusion coefficient from the time-dependent data. The nuclear technique permits rapid and accurate direct concentration measurements capable of distinguishing surface and subsurface transport.
Universal Binding Energy Relations in Metallic Adhesion
Authors: Ferrante John , Smith John R. , Rose James H. 
Published: March 2011

AbstractRose, Smith, and Ferrante have discovered scaling relations which map the adhesive binding energy calculated by Ferrante and Smith onto a single universal binding energy curve. These binding energies are calculated for all combinations of Al(111), Zn(0001), Mg(0001), and Na(110) in contact. The scaling involves normalizing the energy by the maximum binding energy and normalizing distances by a suitable combination of Thomas-Fermi screening lengths. Rose et al. have also found that the calculated cohesive energies of K, Ba, Cu, Mo, and Sm scale by similar simple relations, suggesting the universal relation may be more general than for the simple free-electron metals for which it was derived. In addition, the scaling length was defined more generally in order to relate it to measurable physical properties. Further this universality can be extended to chemisorption and molecular binding. The implications of this scaling have been explored and have produced some interesting results and verifications. A simple and yet quite accurate prediction of a zero temperature equation of state (volume as a function of pressure for metals and alloys) is presented. Thermal expansion coefficients and melting temperatures are predicted by simple, analytic expressions, and results compare favorably with experiment for a broad range of metals. All of these predictions are made possible by the discovery of universality in binding energy relations for metals. Finally some results of other researchers concerning universality In Van der Waals forces are referred to
The Role of Material Properties in Adhesion
Authors: Buckley Donald H. 
Published: March 2011

AbstractWhen two solid surfaces are brought into contact strong adhesive bond forces can develop between the materials. The magnitude of the forces will depend upon the state of the surfaces, cleanliness and the fundamental properties of the two solids, both surface and bulk. Adhesion between solids is addressed from a theoretical consideration of the electronic nature of the surfaces and experimentally relating bond forces to the nature of the interface resulting from solid state contact. Surface properties correlated with adhesion include, atomic or molecular orientation, reconstruction and segregation as well as the chemistry of the surface specie. Where dissimilar solids are in contact the contribution of each is considered as is the role of their interactive chemistry on bond strength. Bulk properties examined include elastic and plastic behavior in'the surficial regions, cohesive binding energies, crystal structure, crystallographic orientation and state. Materials examined with respect to interfacial adhesive interactions include metals, alloys, ceramics, polymers and diamond. They are reviewed both in single and polycrystalline form. The surfaces of the contacting solids are studied both in the atomic or molecularly clean state and in the presence of selected surface contaminants. Topography effects are obviously complex and their detailed consideration is beyond the scope of this paper.