bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling of Neptunium(V) Sorption Behavior onto Iron-Containing Minerals
Authors: Fujita T. , Tsukamoto M. , Ohe T. , Nakayama S. , Sakamoto Y. 
Published: April 2011

AbstractSorption behaviors of neptunium (V) on naturally-occurring magnetite (Fe3O4) and goethite (α-FeOOH) in 0.1M NaN03electrolyte solution under aerobic conditions were interpreted using the surface complexation model (SCM). The surface properties of these materials were experimentally investigated by C02-free potentiometric titration, and SCM parameters for the constant capacitance model, such as protonation/deprotonation constants of the surface hydroxyl group, were determined. The number of negatively charged sorption sites of goethite rapidly increased with the increase of the bulk solution pH compared with that of magnetite and this tendency was similar to the pH dependence of neptunium sorption. This implies that the neptunyl cation, NpO2+, plays a dominant role in possible sorption reactions. Assuming that the dominant surface complex is XO-NpO2, modeling by means of SCM was carried out, and the results were found to agree with experimental data.
Nucleation, Growth and Ostwald Ripening of Cosi2 Precipitates During Co Ion Implantation In Si
Authors: Reiss S. , Ruault M. O. , Clayton J. , Kaitasov O. , Heinig K.-H. , Bernas H. 
Published: April 2011

AbstractThe experimental conditions during the implantation step of Ion Beam Synthesis influence crucially the formation of a buried structure in subsequent annealing steps. Due to of the complexity of the in-beam nucleation and evolution of precipitates of new phases there is still a low level of understanding.
In this paper we present results of direct experimental investigations as well as results of computer simulations of in-beam nucleation and growth. The evolution of an ensemble of C0SÌ2 precipitates is mainly controlled by nucleation and diffusion. The observed decrease of the nucleation rate at high fluences can be explained by the decrease of the supersaturation of implanted atoms due to diffusion towards earlier nucleated precipitates.
Formation of Excess Donors During High-Dose 74Ge+ Ion Implantation
Authors: Xia Z. , Ristolainen E. , Elliman R. , Ronkainen H. , Eränen S. , Kuivalainen P. , Sopanen M. , Tuomi T. , Holloway P. 
Published: April 2011

AbstractRecently observations that high-dose Ge implantations into Si substrates caused the n-type carrier concentration to increase were attributed to residual structural defects after activation annealing [7,12]. However, co-implantation of an n-type impurity is another possibility. The origin of this excess donor concentration has been studied in this work. The possibilities of residual defects versus implantation of impurities have been investigated using two different implanters and materials analysis. Comparison of data from different implanters showed that the concentration of excess donors was sensitive to the implanter configuration. Furthermore, transmission electron microscopy (TEM), Rutherford backscattering channeling (RBS-C), and spreading resistance profiling (SRP) data showed that the excess donor effect was related to impurities rather than residual defects. Secondary-ion mass spectroscopy (SIMS) and SRP measurements confirmed that impurities such as 75As ions were present after implants. This impurity easily explains the excess donor concentration when 75Ge implants are performed into silicon wafers doped with phosphorous.
Defects Related To Electrical-Leakage In Tmos Structures
Authors: Knoch Lynnita , David Theodore N. , Tam Pak , Yamamoto Taku 
Published: April 2011

AbstractTMOS devices for power applications use ion-implantation for doped layers. Implant-damage can increase electrical leakage of devices. Transmission electron microscopy was used to study the effect of dose (4E14 - 2E15 cm-2) and energy (20-40 keV) of p+ implants on damage related to leakage in TMOS structures. TEM reveals a high density of boron implant-induced defects such as end-of-range and peak-of-implant damage, boron implant-induced stacking faults and dislocations. End-of-range defects also arise from an arsenic implant, and mask-edge defects arise where arsenic-amorphized Si and crystalline Si meet in the source region. Some defects extend >0.5 μπι into the substrate. The density and the extent of defect penetration decrease with decreasing implant-dose and energy. These data correlate well with the electrical data, which show that Idss leakage decreases with decreasing p+ implant-energy and dose.
Residual Deformations Induced By The Thermal Shock During Pulsed Ion Implantation
Authors: Feugeas Jorge N. , BrÜhl S. P. , Sanchez G. , Kaufmann G. H. 
Published: April 2011

AbstractSamples of AISI 316 Stainless Steel were nitrogen and argon ion implanted with pulsed beams generated with a Plasma Gun operated in the detonation mode. The residual deformations induced by the beams were studied by double exposure (before and after implantation) holographic interferometry.The results showed residual deformations corresponding to a concave situation, with the total value depending on the number of single pulses accumulated. A saturation in the deformation is observed when the number of pulses is > 20. A model of the process of pulsed irradiation (based on the strong thermal effect due to the short duration of pulses) and the state of stresses induced in the surface layers is presented.
Sputtering Induced Changes in Defect Morphology and Dopant Diffusion for Si Implanted GaAs: Influence of Ion Energy and Implant Temperature
Authors: Robinson H.G. , Lee C.C. , Haynes T.E. , Allen E.L. , Deal M.D. , Jones K.S. 
Published: April 2011

AbstractExperimental observations of dopant diffusion and defect formation are reported as a function of ion energy and implant temperature in Si implanted GaAs. In higher energy implants (>100 keV), little or no diffusion occurs, while at energies less than 100 keV, the amount of dopant redistribution is inversely proportional to energy. The extended defect density shows the opposite trend, increasing with increasing ion energy. Similarly, the diffusion of Si during post implant annealing decreases by a factor of 2.5 as the implant temperature increases from -2 to 40°C. In this same temperature range, the maximum depth and density of extrinsic dislocation loops increases by factors of 3 and 4, respectively. Rutherford Backscattering (RBS) channeling measurements indicate that Si implanted GaAs undergoes an amorphous to crystalline transition at Si implant temperatures between -51 and 40°C. A unified explanation of the effects of ion energy and implant temperature on both diffusion and dislocation formation is proposed based on the known differences in sputter yields between low and high energy ions and crystalline and amorphous semiconductors. The model assumes that the sputter yield is enhanced at low implant energies and by amorphization, thus increasing the excess vacancy concentration. Estimates of excess vacancy concentration are obtained by simulations of the diffusion profiles and are quantitatively consistent with a realistic sputter yield enhancement. Removal of the vacancy rich surface by etching prior to annealing completely suppresses the Si diffusion and increases the dislocation density, lending further experimental support to the model.
Depth-Dependent Hardness Improvements in Ion Irradiated Polystyrene
Authors: Rao Gopal R. , Riester Laura , Lee Eal H. 
Published: April 2011

AbstractPolystyrene (PS) was irradiated with 2 MeV He+ ions to a fluence of 3.3×1019 ions/m2. A cross-section of the irradiated layer was subjected to hardness measurements across the section using a nanoindentation technique. Results showed that hardness increased as a function of irradiation depth and showed a maximum value of 12 GPa at a depth of approximately 6.5 μπι, for a total ion penetration range of 9 μιη, as compared to a hardness of 0.45 GPa for unirradiated PS. The hardness variation with depth followed the trend for Linear Energy Transfer (LET) for ionization from the energetic ions to substrate atoms. This investigation showed for the first time how hardness varies as a function of depth for ion-irradiated polymers; this variation approximately follows the ionization LET profile, suggesting that cross-linking in the polymers could be proportional to ionization.
Observation of Semiconductor Superstructures With Backscattered Electrons in a Scanning Electron Microscope
Authors: Bosacchi A. , Franchi S. , Govoni D. , Mattei G. , Merli P.G. , Migliori A. , Nacucchi M. 
Published: April 2011

AbstractObservations of semiconductor superstructures with backscattered electrons in a scanning electron microscope have been used to revisit the concept of resolution of the backscattering imaging mode. It will be shown that the generation volume doesn't represent in itself a limit to the resolution, which depends only on the beam size and the signal to noise ratio.
Structural Differences Between Cvd And Thermally Grown Amorphous SiO2
Authors: Makabe M. , Hirose K. , Ishikawa H. , Ono H. , Ishitani A. , Mizuki J. 
Published: April 2011

AbstractThe structure and density of amorphous S1O2 films grown by chemical vapor deposition (CVD) or thermal oxidation are studied by Fourier-transform infrared (FT-IR) absorption, neutron diffraction, and Rutherford backscattering (RBS) measurements. CVD oxides, formed in an atmospheric-pressure CVD reactor with a SiH4-O2 gas mixture at 400 °C, are compared with thermal oxides, grown at 980 °C in H2-O2 atmosphere. The average Si-O-Si bond angle deduced from the stretching frequency of FT-IR is found to be smaller in CVD oxides than in thermal oxides, and the density revealed by RBS measurements is found to be a little lower in CVD oxides than in thermal oxides. These differences are explained by the medium-range structural disorder revealed by FT-IR measurements as well as by neutron diffraction measurements. The medium-range structural disorder in CVD oxides is responsible for large silanol content in the oxides and is the origin in difference between CVD and thermal oxides.
Backside Sims Study Of Ge/Pd Non-Alloyed Ohmic Contacts On InGaAs
Authors: Schwarz S.A. , Pahnstrom C.J. , Bhat R. , Koza M. , Wang L.C. , Park M.H. 
Published: April 2011

AbstractBackside secondary ion mass spectrometry (SIMS) is employed to examine the Ge/Pd non-alloyed ohmic contact on InGaAs. 130 nm Ge/ 50 nm Pd contacts were deposited on an InP/InGaAs marker layer structure. The contacts were annealed for various times at 200°C and 325°C. Samples were mechanically and chemically thinned to facilitate sputter profiling from the backside, thereby avoiding problems such as roughening or non-uniformity of the metallic layers. Subsequent to depth profiling, additional anneals were performed on the thinned samples, and the samples were reexamined. Extensive reaction of Pd with InGaAs is observed on deposition. Little additional reaction occurs at 200°C. At 325°C, Pd is reclaimed from the reacted surface region, forming PdGe with some excess Ge at the interface. In-diffiision of Pd and Ge into InGaAs is observed at longer annealing times. The results are contrasted with prior studies on GaAs, InP, and InGaAs.
Quantifying The Effects Of Amorphous Layers on Image Contrast Using Energy Filtered Transmission Electron Microscopy
Authors: Boothroyd C. B. , Dunin-borkowski R. E. , Stobbs W. M. , Humphreys C. J. 
Published: April 2011

AbstractHigh resolution images of a block oxide, (Nb205)çi(W03)8, with and without a superposed carbon film are compared both energy filtered and including the inelastic scattering. The differences between the images are quantified on an absolute intensity scale and possible origins of the differences in atomic level contrast are assessed using multislice simulations.
Modelling of Multi-Ion-Beam Reactive Cosputtering for Metal Oxide Thin Films
Authors: Xiao D. Q. , Zhu J. G. , Qian Z. H. , Peng W. B. , Wei L. F. , Li Z. S. 
Published: April 2011

AbstractVery recently a new technique named multi-ion-bram reactive cosputtering(MIBRECS) was developed for preparing multi-component metal oxide thin films. Epitaxial or highly oriented (Pb,La) TiO3 thin films sputtered from pure metals of lead, titanium and lathanium were deposited by using this technique. In order to consummate the technique and to study the mechanism of reactive cosputtering, a general model of multi-ion-beam reactive cosputter-ing was proposed for the first time based on the well-known gas kinetics under stable sputtering circumstances, and a computer numerical simulation of the model was carried out with the parameters adopted in our experiments. The relationships among the sputtering ratioes of the targets, and the coverage ratioes of simple substances and oxides of the target metals on substrate surface with the total reactive gas flux and the densities of the sputtering ion beam were obtained respectively, and the hysteresis effect of the characteristic of reactive sputtering and the interactions during multi-ion-beam reactive cosputtering processes were also obtained. The numerical simulation results are at least qualitively in agreement with the experiments.
Copper Metallization of Polyimide Film by Excimer Laser Irradiation and Electrodeposition
Authors: Hohman James L. , Keating Kenneth B. , Kelley Michael J. 
Published: April 2011

AbstractSevere excimer laser irradiation is reported to impart electrical conductivity to Kapton* polymide films. We find that a proper choice of pretreatment and irradiation practice reduces the required dose markedly. Such films have sufficient conductivity to permit direct, good-quality, adherent copper electroplating.H.M.Phillips, D.L.Callahan, R.Sauerbrey, G.Szabo and Z.Bor; Appl.Phys.Lett.58, 2761 (1991).
Laser-Ablated Particles From Porous Silicon
Authors: Nonaka Hidehiko , Sekine Shigeyuki 
Published: April 2011

AbstractIn order to search for the possibility to synthesize materials with new functions by laser deposition using source materials consisting of characterized microstructures, the porous silicon was ablated in ultrahigh vacuum with ultraviolet lasers of fluence as low as a few Jem”2. The ablated particles were analyzed by the time of flight method and the main species detected were atoms and small molecules such as Si, SÍ2, and SiO. The kinetics of the laser ablation of porous silicon in comparison with crystal silicon was also studied.
Laser-Modified Chemical Beam Epitaxy of InGaAs/GaAs Multiple Quantum Wells Using Tris-Dimethylaminoarsenic
Authors: Dong H.K. , Li N.Y. , Tu C.W. 
Published: April 2011

AbstractWe report for the first time laser-modified chemical beam epitaxy (CBE) of InGaAs/GaAs multiple quantum well (MQW) structures using trimethylindium (TMIn), triethylgallium (TEGa), and tris-dimethylaminoarsenic (TDMAAs), a safer alternative to arsine. X-ray rocking curve (XRC) and low-temperature photoluminescence (PL) measurements were used to characterize the pseudomorphic strained quantum well structures. As determined by the X-ray simulation, laser irradiation during the InGaAs well growth was found to enhance the InGaAs growth rate and reduce the indium concentration in the substrate temperature range studied, 440-S00°C, where good interfaces can be achieved. We attribute these changes to laser-enhanced decomposition of TEGa and laser-enhanced desorption of TDMAAs. With laser irradiation, lateral variation of PL exciton peaks was observed, and the PL peaks became narrower.
Uniform And Large Area Deposition Of Diamond-Like Carbon Using Rf Source Ion Beam
Authors: Wu Richard L.C. , Lanter William , Miyoshi K. , Heidger S.L. , Bletzinger P. , Garscadden A. 
Published: April 2011

AbstractWe have designed and constructed a large area ion beam apparatus to deposit DLC films onto 1000 cm2surfaces with various geometries. The use of an efficient RF excited ion gun (13.56 MHz, 1 kW power, 50-3000 eV ion energy) with a diameter of 20 cm, enables us to generate various hydrocarbon ions with high ion beam currents, varying ionic species and less maintenance. The use of a four axis (Χ-ϒ-Θϒ-ΘZ) substrate scanner with computer control can produce uniform DLC films on large areas and curved surfaces. The effects of RF power, ion energy, gaseous composition, and total pressure on the properties of DLC have been systematically investigated.
Studies of Cn1 Films Deposited by Ion-Beam-Assisted Laser Ablation of Graphite
Authors: Ren Zhong-Min , Du Yuan-Cheng , Xiong Xia-Xing , Wu Jia-Da , Ying Zhi-Feng , Qiu Yuan-Xun , Li Fu-Ming 
Published: April 2011

AbstractCN1 thin films have been synthesized by ion-beam-assisted laser ablation of graphite. Films with N-concentration of 45% are obtained, indicated by high energy backseattering spectrum (HEBS). Raman and X-ray photoelectron spectroscopy (XPS) data confirm the existence of carbon-nitrogen bonds. Polycrystallites beta-CjNi structure has been detected in the amorphous matrix of the films, as indicated by transmission electron microscopy (TEM) and electron diffraction. Qualitative tests indicate that the films are relatively hard and adhesive.
Microraman Study of Laser Ablated Gaas
Authors: García C. , Jiménez J. , Prieto A.C. , Ramos J. , Sanz L.F. 
Published: April 2011

AbstractMorphologic and structural changes induced by UV pulsed laser beams on GaAs are studied by means of surface inspection (optical interferometry) and MicroRaman spectroscopy. Crystal order and chemical composition (dopant distribution ) are shown to be changed by the ablation.
Some Insights Into the Process of E-beam Generation of Metal Nanoparticles From Binary Metal Hydride and Azide Precursors
Authors: Herley Patrick J. , Jones William 
Published: April 2011

AbstractExposure of micron-sized particles of inorganic metal hydrides and azides to an intense electron beam within a transmission electron microscope results in melting followed by accelerated decomposition. The energy density localized in the specimen is considerable - arguably from one of the most intense energy deposition sources available. The induced effects have been evaluated using electron beam theory and it is concluded that, to a first approximation, the phenomena are attributable to extremely rapid heating. Criteria for the use of this technique to other possible systems are identified and future experiments applying this unique technique to other materials systems are proposed.
Electron Beam Processing of ZnGeP2: A Nonlinear Optical Material for the Infrared
Authors: Schunemann P.G. , Drevinsky P.J. , Ohmer M.C. , Mitchel W.C. , Fernelius N.C. 
Published: April 2011

AbstractZinc germanium phosphide, an important frequency-conversion material for producing mid-infrared lasers, is plaqued by a detect-related absorption band extending from the fundamental edge (0.62 microns) to ∼3 microns. The level of absorption varies with melt composition, and can be reduced by post-growth annealing treatments. In these experiments, further reduction of the near-band-edge absorption was achieved by irradiating with 1-1.5 MeV electrons at cumulative fluence levels up to 2.75xlOI8cm2. Ge-rich, ZnP2-rich, and both as-grown and annealed stoichiometric crystals were studied. The near-edge absorption of the higher-loss, nonstoichiometric samples decreased monotonically with each subsequent irradiation, whereas the absorption in the lower-loss, stoichiometric samples was minimized after cumulative electron fluences of 2 x 10I8cnv2 and 1 x 10I8cm2 for as-grown and annealed material respectively. The minimum absorption coefficient achieved at 1/im was ∼4.4cnr’ in both stoichiometric samples, representing a factor two decrease for the as-grown crystal. Further exposure after reaching saturation served only to increase the losses at longer wavelengths.
Niobium Nitride Thin Films Deposition using Radical Beam Assisted Deposition
Authors: Murzin Ivan H. , Hayashl Nobuyuki , Sakamoto Isao , Ohkubo Matsataka 
Published: April 2011

AbstractWe have employed a radical beam assisted deposition technique to prepare single-crystalline niobium nitride thin films on MgO (100) substrates. The radical beam containing excited species of nitrogen was produced by an ECR plasma source and used to irradiate the growing Nb film, which was simultaneously deposited by an electron-gun vapor source. The nitride film was found to grow epitaxially on the substrates heated to 600 – 650°C. It has resulted in the formation of NbN having predominantly Bl structure, resistivity of 44 (μΩcm at 20 K, and almost equiatomic composition.
The Diffusion Bonding Interface Structure of Yttria Stabilized Zirconia
Authors: Kim Young J. , Yoo Young Sung , Kim Hwan 
Published: April 2011

AbstractThe specimens of Yttria Stabilized Zirconia(3Y-TZP) were bonded by a diffusion process. The microstructural evolution at the bonded interfaces was examined for the bonding conditions. We confirmed that above general sintering temperature(1500 °C), grain coarsening, which enhances the size fluctuation at the bonding interface, not only eliminates free surfaces but also is the main mechanism of bonding. In order to enhance the diffusion rate at the bonding interface, Ceria was added as a dopant, and grain boundary undulation was examined. We found that the bonding characteristics were improved by the Ceria doping. Specimens with an undulating bonded interface exhibited transgranular fracture, while specimens with a straight interface showed intergranular fracture. The undulation at the bonded interface is suggested to improve ceramic to ceramic bonding.
Kink and Crack Interfaces in Deformed 6H-SiC Single Crystals
Authors: Ning X. J. , Pirouz P. 
Published: April 2011

AbstractWhen a 6H-SiC single crystal is deformed under indentation or uniaxial compression in orientations not favorable for the activation of the 1/3[1120](0001) easy glide system, the secondary slip system is activated. Additionally, for low- temperature deformations, “kinks” and/or micro-cracks form in the crystal. In this paper, experimental results on relatively lowtemperature compression and indentation tests of single crystal 6H-SiC, and the microstructure of the deformed crystals, are presented. Based on the results, the secondary slip system in 6HSiC has been determined to be 1/3[1120](1100), which may actually be a combination of alternate glide of 1/3[1120] dislocations on the (1102) and (1102) planes. Further, dislocation mechanisms for the nucleation of prism-plane and basal-plane cracks, and for the process of kinking, in deformed 6H-SiC are proposed.
Reactive Wetting Taxonomy
Authors: Cannon R. M. , Saiz E. , Tomsia A. P. , Carter W.C. 
Published: April 2011

AbstractContact angles and spreading rates of liquids on solids are oft characterized owing to the widespread importance of wetting. Particularly with dissimilar materials, such as liquid metals on ceramics, where wetting can be poor, additives that can induce various reactions often promote wetting, even if it preceeds the reaction. However, excessive or unwanted reaction can equally well be detrimental in other metallic or ceramic systems. Despite obvious needs, mechanisms of reactive wetting are poorly known.An effort is described to categorize sessile or spreading drop situations having a potential for some degree of reaction and ways wherein the driving force for reaction can actually couple with or parallel that for fluid flow. Several categories where reactivity enhances or retards spreading are described for which the very existence typically depends upon kinetic or nucleation limitations; this includes defining situations in which metastable interfaces have a meaningful context and unique properties. Examples use pairs of inorganic materials, for which the solid may only rarely be truly inert.