bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sorption of Plutonium and Americium on Repository, Backfill and Geological Materials Relevant to The JNFL Low-Level Radioactive Waste Repository at Rokkasho-Mura
Authors: Baston G M N , Berry J A , Brownsword M , Heath T G , Tweed C J , Williams S J 
Published: April 2011

AbstractAn integrated programme of batch sorption experiments and mathematical modelling has been carried out to study the sorption of plutonium and americium on a series of repository, backfill and geological materials relevant to the JNFL low-level radioactive waste repository at Rokkasho-Mura.The sorption of plutonium and americium on samples of concrete, mortar, sand/bentonite, tuff, sandstone and cover soil has been investigated. In addition, specimens of bitumen, cation and anion exchange resins, and polyester were chemically degraded. The resulting degradation product solutions, alongside solutions of humic and iso-saccharinic acids were used to study the effects on plutonium sorption onto concrete, sand/bentonite and sandstone.The sorption behaviour of plutonium and americium has been modelled using the geochemical speciation program HARPHRQ in conjunction with the HATCHES database.
The Sorption of Uranium and Technetium on Bentonite, Tuff and Granodiorite
Authors: Baston G. M. N. , Berry J. A. , Brownsword M. , Cowper M. M. , Heath T. G. , Tweed C. J. 
Published: April 2011

AbstractA combined experimental and modelling study of the sorption of uranium and technetium on geological materials has been carried out as part of the PNC programme to increase confidence in the performance assessment for a high-level radioactive waste (HLW) repository in Japan. Batch sorption experiments have been performed in order to study the sorption of uranium and technetium onto bentonite, tuff and granodiorite from both equilibrated seawater and de-ionised water under strongly-reducing and non-reducing conditions.A preliminary study of the sorption of uranium on mineral surfaces in granodiorite has also been undertaken using a nuclear microprobe.Mathematical modelling using the geochemical speciation program HARPHRQ in conjunction with the HATCHES database has been carried out in order to interpret the results of the sorption experiments.
Applications of MeV Ion Implantation in Semiconductor Device Manufacturing
Authors: Borland John O. 
Published: April 2011

AbstractUse of MeV ion implantation for mass production of CMOS devices at 0.5um design rule and beyond is now being accepted around the world for 16Mb DRAM, 16Mb Flash memory and CMOS logic/microprocessor technologies. Incorporating MeV well formation for twin well and triple well results in a reduction of up to 3 masking layers corresponding to process simplification and manufacturing cost reduction of 10% to 16%. For CMOS logic application, a new structure called BILLI (Buriedjmplanted Layer for Lateral Isolation) is showing great promise for latch-up free CMOS and when combined with hydrogen denuded bulk Czochraliski (CZ) grown silicon wafers, has the potential to replace epitaxial wafers with improved device performance. This paper will review MeV ion implantation use for these various CMOS applications.
Luminescence During Tb-Ion Implantation into Sapphire
Authors: Kumagai Makoto , Iwaki Masaya 
Published: April 2011

AbstractA study has been made of the luminescence during Tb-ion implantation in Al2O3 or by Ar- or He-ions bombardment to Tb-ion implanted Al2O3. The substrates used were colorless and transparent single crystal ɑ-Al2O3 with (0001) or (1102) surface orientation. Ion implantations of Tb-ions in Al2O3 were carried out at fluences of 1x1013 to 1x1017 Tb/cm2 at 100 keV at nearly room temperature. Change in color of Al2O3, substrates by Tb implantation was invisible to the naked eye. The luminescence spectra were measured by Ar (100 keV) or He (50 keV) bombardment to Tb implanted Al2O3 or during Tb implantation into Al2O3 using a spectroscopy with three optical filters and photomultiplier. The luminescence spectra during Tb implantation into AljOj have four clear peaks identified as emission due to D-F transitions of Tb3+ state. The luminescence spectra of Tb implanted A12O3 excited by He, Ar and Tb bombardment were almost the same except for the luminescence at the wavelength ranging from 300 to 450 nm, which is caused by strong emission from A12O3 itself. The peak of the luminescence appears at 550 nm, and its intensity depends on the Tb dose. The maximum intensity of luminescence during Tb implantation at room temperature is obtained as the maximum atomic ratio of implanted Tb is 2–3 atomic %.
Spreading Resistance Profiling Study of GeSi/Si Structures by High Dose Ge Implantation into Si
Authors: Cheung W.Y. , Wong S.P. , Wilson I.H. , Zhang Tonghe , Chu Paul K. 
Published: April 2011

AbstractHetero-structures of GeSi layers on Si have been produced by high dose Ge implantation into p-type (100) Si wafers at 150 or 300 keV at various doses. From spreading resistance profiling measurements, it is found that for samples implanted at 300 keV at a sufficiently high dose, there is an unexpected resistivity type conversion due to the Ge implantation. The depths of the n-p junction formed as-implanted can be larger than 1.5 /xm, far beyond the Ge projected range. Upon annealing, the junction position moves toward the surface and eventually stops at a depth corresponding to the thickness of the GeSi layer. However, no such n-p junction formation was observed in the spreading resistance profiles of the 150 keV implanted samples. These spreading resistance results are discussed in conjunction with results from RBS and SIMS experiments.
Oxidation of Silicon Implanted with High-Dose Aluminum
Authors: Yang Zunde , Du Honghua , Withrow Stephen P. 
Published: April 2011

AbstractSi (100) wafers were implanted with Al at 500°C to high doses at multi-energies and were oxidized in 1 atm flowing oxygen at 1000°–1200°C. The morphology, structure, and oxidation behavior of the implanted and oxidized Si were studied using optical microscopy, atomic force microscopy, and cross-sectional transmission electron microscopy in conjunction with selected area electron diffraction and energy dispersive x-ray analysis. Large Al precipitates were formed and embedded near the surface region of the implanted Si. The oxidation rate of the Al-implanted Si wafers was lower than that of virgin Si. The unique morphology of the implanted Si results from rapid Al diffusion and segregation promoted by hot implantation. The reduction of the oxidation rate of Si by Al implantation is attributed to the preferential oxidation of Al and formation of a continuous difiusion barrier of Al2O3.
Raman Spectroscopic Study of Ag-, W- and Pd-Ions Implanted Polyimde Films
Authors: Watanabe Hiroshi , Takahashl Katsuo , Iwaki Masaya 
Published: April 2011

AbstractA study has been made of the carbon formation in the surface layer of Ag-, W- and Pd-ions implanted polyimide films. The doses of 130 KeV Ag-ions and 190 KeV W-ions ranged from lxlO16 to 5×1017 atoms/cm2. The doses of 100 KeV Pd-ions ranged from 5×1016 to 2×1017 atoms/cm2. The carbon structure in implanted layers was characterized by laser Raman spectroscopy (LRS). Non-implanted polyimide film has very strong intensity of fluorescence, and the intensity of all W-, Ag- and Pd-ions implanted specimens decreases with the increase in dose. The intensity of Raman spectra for both W- and Ag-ions implanted specimens increases with the increase in dose. For Pd-ion implanted specimens, the Raman spectrum of carbon is hardly observed even with a high dose. Raman spectra for W- or Ag-ions implanted specimens with a high dose show that the diamond-like carbon (DLC) exist in the implanted layers. It is found that the DLC structures in the W- and Ag-ions implanted layers have graphite-like and amorphous-like structures, respectively. We propose that transparency carbon structure in implanted layers is generated by Pd-ion implantation. It is concluded that marked DLC formation in surface layer of polyimide films can be caused by Ag- or W-ions implantation except Pd-ion implantation, and carbon structure in implanted layers depends strongly on the implanted elements.
Neutron Depth Profiling by Large Angle Coincidence Spectroscopy
Authors: Vacík J. , Cervenä J. , Hnatowicz V. , Havränek V. , Fink D. 
Published: April 2011

AbstractExtremely low concentrations of several technologically important elements (mainly lithium and boron) have been studied by a modified neutron depth profiling technique. Large angle coincidence spectroscopy using neutrons to probe solids with a thickness not exceeding several micrometers has proved to be a powerful analytical method with an excelent detection sensitivity. Depth profiles in the ppb atomic range are accessible for any solid material. A depth resolution of about 20 nanometers can be achieved.
The Characterisation of The Compositional and Electronic Profiles of Delta-Doped Layers Using Transmission Electron Microscopy
Authors: Dunin-Borkowski R.E. , Stobbs W.M. 
Published: April 2011

AbstractThe compositional profile of an interlayer inferred from Fresnel contrast data is usually determined assuming that the variation in the measured mean forward scattering potential is associated with changes in neutral atom scattering factor and atomic density. However, the technique is currently being applied to systems for which the form and the magnitude of the potential at the layer can be affected strongly by changes in ionicity. Here, we show how the analysis of ‘delta-doped’ layers in semiconductors, which contain thin layers of impurity ions at low concentrations, requires the analysis of not only the effect of strains on the density but also the contribution to the potential from charged ions surrounded by a wider spread of free carriers.
Chemistry and Deposition Driven by Monoenergetic Synchrotron Radiation: Initial Studies of Condensed Silanes and Water on Noble Metals
Authors: Moore J.F. , Chaturvedi Sanjay , Strongest DR. 
Published: April 2011

AbstractWe extend previous work in broadband synchrotron radiation (SR) excitation of condensed multilayers to the study of reactions driven by monoenergetic SR. The long term goal of this work is to understand the importance of core-level excitation on the reactions that lead to materials growth. Results are presented for two systems of interest: formation of silica from Si(CH3)4 and H20 mixtures with 90 eV irradiation (below the core levels) and the energy dependence of the reaction of SiH4 and H2O.
Equal Thickness Contours of Films Deposited on Inclined Substrates by Evaporation and Ion Beam Assisted Deposition
Authors: Franzen W. , Demaree J.D. , Fountzoulas C.G. , Hirvonen J.K. 
Published: April 2011

AbstractA study is presented of the geometrical shape of deposition contours that arise when material is evaporated from a point source onto an inclined substrate, an arrangement common in ion-assisted deposition. The shape of the contours, as determined by the inverse square law and the angles of emission and incidence, is described by a fourth-order algebraic equation in polar coordinates on the surface of the substrate. The equation defines a family of distorted ellipses whose form depends on the angle of tilt. An experimental test of these relations by electron-beam deposition of an ion-bombarded oil film on a tilted silicon wafer will be reported.
Morphology and Microstructure of (111) Crystalline CeO2 Films Grown on Amorphous SiO2 Substrates by Pulsed-Laser Ablation
Authors: Zhu S. , Lowndes Douglas H. , Budai J.D. , Thundat T. , Norton D.P. , Warmack R.J. 
Published: April 2011

AbstractThe surface morphology and microstructure of (lll)-oriented CeO2 thin films, grown on amorphous fused silica (S1O2) substrates by low-energy-ion-beam assisted pulsed laser ablation, have been studied by atomic force microscopy (AFM) and x-ray diffraction (XRD). These CeO2 films are aligned with respect to a single in-plane axis despite being deposited on an amorphous substrate. There is a honeycomb-like growth morphology to the films and island-growth can be observed in thicker films. These islands, inside of which are high density of honeycomb-like clusters, are separated by a void network with ∼700nm width. However, on the surface of the thinnest film (∼3nm), only very small clusters (diameter <60nm) appear, and the boundaries of the void network are undefined, which implies that the film is just beginning to coalesce into clusters (grains). The combined AFM images and XRD pattern suggest these clusters probably are the initial seeds for the subsequent island growth. Based on these results, the growth mechanism of oriented CeO2 films on amorphous fused silica substrates is discussed.
Study of Wsi2 and Cosi2 Thin Films Deposited by Laser Ablation
Authors: Glebovsky V.G. , Ermolov S.N. , Oganyan R.A. , Stinov E.D. 
Published: April 2011

AbstractIt has been shown, that pure massive targets of tungsten and cobalt disilicide can be obtain from the liquid state by means of a set of metallurgical methods. The conditions of laser ablation of the targets ensuring the preparation of tungsten and cobalt suicide films of the specific electric resistance 50 and 30 μΩ cm respectivly have been studied. The grazing beam X-ray difractometry were used to investigate their phase and elemental composition of the films. The method in question has been shown to be promising for the preparation of films of other refractory - metal suicides.
Ion-Beam Polishing of Diamond Thin Films
Authors: Lee Dong-Gu , Singh Rajiv K. 
Published: April 2011

AbstractPlanarization of diamond thin films has been carried out using a remote electron cyclotron resonance (ECR) oxygen plasma under a negative bias. Diamond thin films were synthesized by hot filament chemical vapor deposition (HFCVD). The surface roughness (RJ of the diamond films could be considerably reduced from 0.2 μπι to 0.05 μπι using the ECR oxygen plasma. Low planarization and a high etching rate of diamond films were observed for an incident angle of the ion beam to the film surface normal below 45 degrees. High applied bias above -600 V caused secondary discharge effects, resulting in inhomogeneous etching. With an increase in incident angle, needlelike morphology was observed in the diamond film.
1XThin Films Prepared By Mass Separated Ion Beam Deposition
Authors: Hofsäss H. C. , Ronntng C. , Griesmeier U. , Gross M. 
Published: April 2011

AbstractWe have studied the growth and the properties of CN films prepared by deposition of mass separated12C+and14N+ions. The film thickness and density were determined as a function of ion energy between 20 eV and 500 eV and for substrate temperatures of 20 °C and 350 °C. Sputtering effects limit the maximum N concentration to about 30 - 40 at.% even for ion energies as low as 20 eV. IR absorption measurements indicate predominantly C-N and C=N bonding and an amorphous or strongly disordered CN-network. For room temperature deposited CN films with N concentrations up to 25 at.% I-V curves of metal-CN-metal devices show Frenkel-Poole behavior due to field-enhanced thermal activation of localized electrons. Films deposited at 350 °C have N concentrations below 15 at.% and graphitic properties like low resistivity and a density close to graphite.
A Study of the Interface Between SnF2 Particles and Air in Stannous Fluoride Heated in Air
Authors: Denes Georges , Laou E. 
Published: April 2011

AbstractStannous fluoride SnF2 and mixed fluorides containing divalent tin are the highest performance fluoride ion conductors known to date. Since the fluoride ion mobility increases with temperature, and that these materials are sensitive to hydrolysis of the Sn-F bonds and oxidation of tin(II) to tin(IV) when heated, there is a significant chance of material degradation on heating. Surface oxidation provides a thin coating of highly refractory Sn02, which passivates against further degradation. The details and limits of this protection in SnF2 have been studied and are presented here.
Direct Determination of Grain Boundary Atomic Structure in SrTiO3
Authors: McGibbon M.M. , Browning N.D. , McGibbon A.J. , Chisholm M.F. , Pennycook S.J. 
Published: April 2011

AbstractIn the electroceramic SrTiO3 the grain boundary atomic structure governs a variety of electrical properties such as non-linear I-V characteristics. An understanding of this atomic structure-property relationship for individual grain boundaries requires a technique which probes both composition and chemical bonding on an atomic scale. Atomic structure models for [001] tilt boundaries in SrTiO3 bicrystals have been determined directly from experimental data, by combining high-resolution Z-contrast imaging to locate the cation columns at the boundary, with simultaneous electron energy loss spectroscopy to examine light element coordination at atomic resolution. In this paper we compare and contrast the grain boundary structure models of symmetric and asymmetric boundaries in SrTiO3.
Investigation of Interfaces in Ceramics by Electron Spectroscopic Imaging
Authors: Mayer J. , Plitzko J. , Steinbach F. , Kohl H. 
Published: April 2011

AbstractElectron Spectroscopic Imaging (ESI) in an energy filtering TEM is a new analytical technique which allows one to obtain two-dimensional elemental distribution images. In the present paper the detection limits of the new technique will be discussed. Si3N4ceramics with different thicknesses of the amorphous oxide grain boundary layers have been chosen as a model system. Quantitative results have been obtained on three different energy filtering instruments and will be compared with the results of theoretical calculations. The application of ESI for the mapping of near edge fine structure will be discussed.
The Morphology of Cu Clusters on SrTiO3(001) at Initial Stages of Metal Film Growth
Authors: Liang Y. , Carroll D. L. , Bonnell D. A. 
Published: April 2011

AbstractCopper overlayers deposited on nearly stoichiometric SrTiO3(001) have been investigated with scanning tunneling microscopy (STM). Vapor deposition of Cu on a SrTiO3(001) surface at ambient temperature leads to the formation of three dimensional islands (clusters). The distribution of Cu islands appears to be inhomogeneous with two characteristic morphologies. In regions with a low density of Cu islands the Cu was always associated with step edges or defect sites. In regions with a high density of Cu islands the islands exhibit a random but nearly close packed morphology. The variation of Cu island density is indicative of diffusion of Cu clusters on the SrTiO3(001) surface. Diffusion was further confirmed by annealing the Cu/SrTiO3 at elevated temperatures yielding agglomeration of Cu clusters.
Pressure-Induced Migration of Ferroelectric Interfaces
Authors: Gordon Alex , Dorfman Simon 
Published: April 2011

AbstractThe study of the migration of the first-order paraelectric-ferroelectric interfaces in BaTiO3 under the hydrostatic pressure is provided in the framework of the time-dependent Ginzburg-Landau theory. The analytical solution describing the interphase boundary is applied for the calculations of its width and velocity at different pressures. The calculations are based on the experimental data for BaTiO3. The parameters of the power law of the temperature and pressure dependences of the interface velocity under the temperature and pressure were obtained. Using the BaTiO3 example we illustrate the ability of the suggested approach in the description of the kinetics of the first-order ferroelectric phase transition in perovskites.
The Structure of Spinel/Oxide Reaction Fronts During Spinel-Forming Solid State Reactions
Authors: Hesse D. , Scholz R. , Senz S. , Sieber H. , Werner P. , Heydenreich J. 
Published: April 2011

AbstractA series of spinels were grown by topotaxial solid state reaction on MgO(001) and sapphire(11.2) substrates. The structure of the various spinel/oxide reaction fronts was investigated by cross-sectional high resolution electron microscopy and other methods. While for extremely low misfit the reaction front is completely coherent, different interfacial defects form in other cases, depending on sign and amount of the spinel/oxide lattice misfit. For a large positive misfit, a network of misfit dislocations occured all running along <100<, with Burgers vectors of types a/2[101] and a/2[011] pointing out of the interface. The perpendicular Burgers vector component along [001] permits these dislocations to glide in order to cope with the advancing reaction front, avoiding kinetically unfavourable climb processes. The latter have, however, been observed in negative misfit, where the interfacial dislocations run along <110>, with their Burgers vectors lying in the interface plane. At the sapphire/MgAl2O4 front the structure is completely different. Here the h.c.p.-type oxygen sublattice of sapphire is reconstructed into the f.c.c-type oxygen sublattice of the spinel, which requires a tilt of the MgAl2O4 lattice and the formation of interfacial ledges.
Oxidation of Coo Into Co3O4 in CoO-ZrO2(CaO) and Co1-xNixO-ZrO2(CaO) Lamellar Eutectic Structures
Authors: Lafleurielle M. , Dhalenne G. , Millot F. , Revcolevschi A. 
Published: April 2011

AbstractUnidirectional solidification experiments were carried out at the eutectic composition of the systems CoO-ZrO2(CaO) and Co1-xNixO-ZrO2(CaO) yielding materials made of regularly aligned lamellar structures. These eutectic samples were submitted to a high temperature chemical oxidation treatment under oxygen, in conditions where CoO should be oxidized into Co3O4. The study of partially oxidized samples shows that Co3O4 is formed by two mechanisms which are presented together with the corresponding kinetics.
XPS Studies at the Interface of Ti/AIN Ceramic
Authors: Shen Dian Hong , Bao Changlin , Lu Hua , Lin Zhangda 
Published: April 2011

AbstractThe photoelectron spectra for titanium deposition on a AIN ceramic substrate at room temperature have been measured. Before deposition, the binding energies of Ols and Al 2p show that the substrate contained oxygen as a major impurity and a top layer of degeneration was formed. After deposition of a small amount of titanium, it was found that the Nls separated into two peaks(396.5 eV and 402 eV) and Ti 2p corresponded to the oxide state. With an increase of titanium coverage, the Ti 2p peak shifted toward a lower energy. The peak at 402 eV dominated at a titanium coverage of 0.9 nm, showing the nitrogen-oxygen binding character. For a titanium coverage of 3.0 nm, a new peak at 406 eV was formed. These results suggest that during deposition of Ti onto the AIN substrate which has a top hydrated alumina layer, some of nitrogen atoms tend to be bound with oxygen and to form an interfacial oxynitride layer between the metallic titanium and substrate.
Chemical Bonding, Structure, and Morphology of Mg/∝-Al2O3 and MGO / ∝-Al2O3 Interfaces
Authors: Yu Yan , Lad R.J. 
Published: April 2011

AbstractUltra-thin films of Mg and MgO were grown on ∝-Al2O3 (1012) surfaces (r-cut sapphire) and studied using reflection high energy electron diffraction (RHEED) and x-ray photoelectron spectroscopy (XPS). When Mg is deposited at 30°C in ultra-high vacuum (UHV), the first monolayer of Mg atoms chemically bonds to the oxygen anions of the sapphire surface. At Mg coverages above a monolayer, a polycrystalline metallic Mg overlayer is formed. Annealing above 250°C in UHV causes the metallic Mg to desorb from the surface. However, annealing above 250°C in 10−6 torr O2 produces a polycrystalline MgO film. This MgO film recrystallizes after annealing in O2 at 900°C for 60 minutes and exhibits a crystallographic orientation of MgO (100) // ∝-Al2O3 (1012). RHEED indicates that the recrystallized MgO layer dewets the sapphire surface and forms islands. When Mg is deposited at 30°C in 10−6 torr O2, a polycrystalline MgO layer is created. This layer also becomes recrystallized and dewets the sapphire surface after extended annealing in O2 at 900°C. No evidence for a MgAl2O4 spinel phase was observed.