bluuebunny/crossref_metadata_2025_split huggingface dataset:
Damage in Refractory Oxides and ion Beam Mixing at Metal-Oxide Interfaces Induced by Gev Ions and 20 Mev Cluster Beam
Authors: Thevenard P.A. , Beranger M. , Canut B. , Ramos S.M.M. 
Published: April 2011

AbstractDefect creation in refractory oxides known to be unsensitive to radiolysis, was shown to take place by high level electronic excitations induced by swift heavy ions or energetic cluster bombardments. Depending on the oxide a threshold in electronic energy loss for damage production was observed : MgO 22 keV/nm, AI2O3 20 keV/nm and LiNbO3 6 keV/nm. A very strong dependence on the energy deposited for the defect production was evidenced above the threshold. In MgO, both point and extended defects were created whereas in AI2O3 only extended defects were observed and in LiNbO3 amorphization in the ion track was evidenced.Atomic displacements due to the giant electronic excitations can be revealed at metal-oxide interfaces in the case of Na nanoprecipitates embedded in MgO single crystals.
Cantilever Beam Stress Measurements During Ion Irradiation
Authors: Van Sambeek A. I. , Averback R.S. 
Published: April 2011

AbstractIn-situ stress measurements on single crystal MgO and A1203 have been performed during ion irradiation. A cantilevered beam sample arrangement was used, with the stress in the implanted layer determined from the deflection of the sample as measured by the change in capacitance between the free end of the sample and a reference electrode. Point defect concentrations are obtained by dividing the volume strain by the defect relaxation volume, with saturation values of 0.8 to 1.2% obtained for 1.0 MeV Ne, Ar and Kr irradiations. Defect production is sublinear with dose, with an efficiency of less than 25% compared to Kinchin-Pease predictions. Ionization induced annealing is evaluated with 1.0 MeV He and 1.0 MeV H irradiations following heavy ion irradiation.
A Comparative Study of Radiation Damage In A12O3, FeTiO3, And MgTiO3
Authors: Mitchell Jeremy N. , Yu Ning , Sickafus Kurt E. , Nastasi Michael , Taylor Thomas N. , Mcclellan Kenneth J. , Nord Gordon L. 
Published: April 2011

AbstractOriented single crystals of synthetic alpha-alumina (α-Α12O3), geikielite (MgTiO3), and natural ilmenite (FeTiO3) were irradiated with 200 keV argon ions under cryogenic conditions (100 K) to assess their damage response. Using Rutherford backscattering spectrometry combined with ion channeling techniques, it was found that ilmenite amorphized readily at doses below 5×1014, alumina amorphized at a dose of 1-2x1015, and geikielite was amorphized at -2x1015 Ar cm-2 . The radiation damage response of the ilmenite crystal may be complicated by the presence of hematite exsolution lamellae and the experimentally induced oxidation of iron. The relative radiation-resistance of geikielite holds promise for similar behavior in other Mg-Ti oxides.
Interaction of Alpha Particle Beams with Fe-Based and FeNi-Based Glassy Ferromagnets
Authors: Sorescu Monica , Barb D. 
Published: April 2011

AbstractSamples of Fe78B13Si9 and Fe40Ni38Mo4B18 metallic glasses were irradiated with alpha particle beams (W=2.8 MeV) using radiation doses of 1016 and 1017 cm-2. Irradiation-induced effects on the magnetic texture and phase composition of alloy samples were studied by Mössbauer spectroscopy. Related morphological changes and resultant crystalline precipitates were characterized by scanning electron microscopy. The evolution of phases and microstructure during the radiation-induced amorphous-to-crystalline transformation was found to depend on the particle flux and sample composition. The lowest radiation dose employed was found to be more effective in inducing amorphous-to-crystalline transformations in both ferromagnetic alloys studied. In addition, the FeNi-based amorphous system investigated was found to be more stable than the Fe-based metallic glass, exposed to the same particle-beam irradiation conditions. By stimulating unconventional pathways for the crystallization process, the interaction of alpha particle beams with glassy ferromagnets offers unique opportunities to understand the fundamentals of nucleation and growth in amorphous magnets.
Dependence on Collision Time of Particle Ejection of Atom-Bombarded Single-Crystal Surfaces
Authors: Chang Che-Chen , Wang Shi-Wei 
Published: April 2011

AbstractEjection properties of particles emitted from a keV-atom-bombarded Ag{100} surface are calculated using classical dynamics to model the energy dissipation process. The ejection behavior of the sputtered particles depends strongly on the time interval between the instant of the primary impact on the surface and the moment when the emitting surface atom passes the cutoff boundary of the interaction potential. Both the sputtered neutrals and ions have a similar collision-time distribution. Most particles eject from the surface within 350 fsec after the primary impact. The sputter intensity maximized at around 145 fsec. For particles leaving the surface after -100 fsec of the primary impact, the preferred azimuths of ejection are not sensitive to the collision time. The angular distribution of sputtered particles is less dependent of the collision time than of the ejection energy. The angular anisotropy is also significantly enhanced at high collision times. The results find applications in the characterization and imaging of material surfaces.
Optical Switching of Coherent VO2 Precipitates Embedded in Sapphire
Authors: Gea L. A. , Boatner L. A. , Budai J. D. , Zuhr R. A. 
Published: April 2011

AbstractIn this work, we report the formation of a new type of active or “smart” surface that is produced by ion implantation and thermal processing. By co-implanting vanadium and oxygen into a single-crystal sapphire substrate and annealing the system under appropriate conditions, it was possible to form buried precipitates of vanadium dioxide that were crystallographically oriented with respect to the host AI2O3 lattice. The implanted VO2 precipitate system undergoes a structural phase transition that is accompanied by large variations in the optical transmission which are comparable to those observed for thin films of VO2 deposited on sapphire. Co-implantation with oxygen was found to be necessary to ensure good optical switching behavior.
Scanning Tunneling Microscopy and Atomic Force Microscopy of Au Implanted in Highly Oriented Pyrolytic Graphite
Authors: Tung Y S. , Ueda A. , Henderson D.O. , Mu R. , Gu Z. , White C.W. , Zuhr R. A. , Zhu Jane G. 
Published: April 2011

AbstractSurfaces of highly oriented pyrolytic graphite implanted with gold were studied by both constant current STM. constant force, and tapping mode AFM. Gold colloids were observed by both constant current STM and tapping mode AFM. The surfaces can be modified by applying currents of +4 V and 1 nA. In addition, pyramidal and faceted structures were observed on sample surfaces suggesting the presence of diamond microcrystals.
Modification of Magnetron Sputtered A-Si1-Xcx:H Films by Implantation of sn+
Authors: Tzenov N. , Dimova-Malinovska D. , Tsvetkova T. 
Published: April 2011

AbstractImplantation of Sn+ into a-Si1.xCx:H films deposited by RF magnetron sputtering of silicon and graphite was carried out in order to obtain optical contrast in the layers. The expected optical effect which is an absorption edge shift to the lower photon energies accompanied by a considerable increase of the absorption coefficient was observed even for the lowest dose - 1015cm-2. This effect is more pronounced with increase of the dose. Infrared (IR) and photoelectron spectroscopy (XPS) measurements was used to study the bond configurations of implanted films. These measurements reveal that ion implantation introduces an additional disorder in the films as well as leads to their chemical modification, which could be related to the changes of the optical properties.
A Novel Etching Method of Single Crystalline A12o3 Film on Si and Sapphire Using Si Ion Implantation
Authors: Kim H. , Ishida M. , Nakamura T. 
Published: April 2011

AbstractA new etching method for a single crystalline ΑI2O3(100) film grown on Si(100) by LPCVD and a sapphire wafer is established for the first time using Si ion-implantation and buffered hydrofluoric acid (HF+H2O) chemical etchant to develop many applications of the SOI structure. Line and space patterns of resist were transferred to sharp A12O3 and Si patterns. An etching of 0.1 2/μm-thick-Al2O3 films on Si substrates and sapphire wafers was observed very clearly. The etch rate is lOOÂ/min under implanted conditions of 80kV and 3×1015 cm-2.The implanted ΑI2O3 surfaces are investigated by SIMS and XPS. The change from AI2O3 to Al2O3 SiO2 (aluminosilicate), which can be easily etched HF+H2O, is considered to be a main reason, though bonds broken by implantation are also effective for this etching.
Development and Demonstration of a Two-Dimensional, Accurate and Computationally-Efficient Model for Boron Implantation into Single-Crystal Silicon Through Overlying Oxide Layers
Authors: Morris S. , Lim D. , Yang S.-H. , Tian S. , Parab K. , Tasch A. F. 
Published: April 2011

AbstractA 2-D model for boron implantation into (100) silicon through overlying oxide layers has been developed and implemented into the process simulator FLOOPS. This model is both accurate and computationally efficient and shows explicit dependencies on all of the key implant parameters: energy, dose, tilt and rotation angles, oxide layer thickness, mask height, mask edge orientation, and rotation of the wafer during implantation.
Surface Effects During Ion Beam Processing of Materials
Authors: Averback R.S. , Ghaly Mai , Zhu H. 
Published: April 2011

AbstractMicrostructural changes of surfaces during ion implantation have been investigated on the atomic level by molecular dynamics computer simulations. Unlike past surface studies, which have been focused on the problem of sputtering, the current work examines the effects of collective materials response on surface topography. Collective behavior has been noted for the crystal interior in the context of thermal spikes, but we show here that it can lead to far more dramatic consequences at the surface. The investigation includes implantation in several metals, but emphasizing Pt, Si and Ge. In addition, the study includes the first simulations of implantations of a metallic glass, CuTi, and amorphous Si.
Structuring of Conducting Polymers by Ion Implantation
Authors: Edinger Klaus , Schiestel Stefanie , Wolf Gerhard K. 
Published: April 2011

AbstractConducting polypyrrole polymer films have been modified by ion implantation. The resulting cross linking leads to changes in resistivity and electrochemical behaviour. By ion implantation through masks or with a focused ion beam lateral structures can be produced which can be imaged by scanning electron microscopy and optical absorption. The implanted polypyrrole layers can be removed by electrochemical treatment while not implanted regions can be electroplated. Therefore in combination with electrochemical treatment three dimensional structures have been generated and were investigated by atomic force microscopy. In order to study structures in the submicrometer range implantation experiments with a focused ion beam were performed and the minimal line widths were investigated by scanning electron microscopy.
Improving Adhesion of Polytetrafluoroethylene to Aluminum, Copper, and an Adhesive by Ar+ Irradiation with and without Oxygen Environment
Authors: Koh Seok-Keun , Park Sung-Chul , Choi Chang-Kyu , Song Seok-Kyun , Jung Hyung-Jin , Pae Kook D. 
Published: April 2011

AbstractA surface of thin square PTFE samples (1×1×0.2 cm3) was irradiated with Ar+ ion at 1 keV with varying ion dose from 5 x 1014 to 1 x 1017 ions/cm2 with and without oxygen environment. The chemical structure of the surface was examined by XPS. The high resolution XPS spectra showed decreased intensity of the Fls peak and formation of the Ol s peak when irradiated with O2 environment. The Ols peak reached the maximum height at the ion dose of 1 x l015 ions/cm2. The increase of the Ols peak may be attributed to the reaction of oxygen atoms and the free radicals created by Ar+ bombardment. Adhesion tests were conducted on 2000 Å thick Al or Cu film which was evaporated on the irradiated and unirradiated PTFE samples with and without O2 environment. Full detachment of the metal films was observed when PTFE samples were not modified. With regard to the Al film, partial detachment of the film occurred when PTFE was irradiated without O2 environment, regardless of ion dose. No detachment of the film occurred when PTFE was irradiated with O2 environment with the ion dose exceeding 1 x 1016 ions/cm2. As to the Cu film, partial detachment was observed with or without O2 environment when the ion dose was 5 x 1014 ions/cm2. No detachment occurred with or without O2 environment when the ion dose was 1 x 1015 ions/cm2 or greater. The adhesion of an adhesive (Crystal Bond) to the irradiated PTFE samples was found to increase significantly with increasing ion dose up to 1 x 1016 ions/cm2 in tensile tests. It appears that three separate mechanisms are at work in improving adhesion of Cu/PTFE and Al/PTFE system. The first is the surface roughness of PTFE caused by Ar+ bombardment, the second is the chemical changes on the PTFE surface, and the third is a change of the interface between the metal and PTFE. The wettability of the PTFE surface was also determined by dropping water droplets on the modified surfaces. The contact angle between water droplets and the irradiated surface of PTFE samples decreased with ion dose up to 1 x 1015ions/cm2, increased at higher dose, and finally increased to the extent that no wetting was possible at 1 x 1017 ions/cm2. The PTFE samples irradiated with Ar+ without O2 gas environment had lower contact angle than those with O2, even though the samples with O2 developed hydrophilic groups on the irradiated surface. This result on wettability is not consistent with our earlier results on PMMA and PC and is due to the unusually
high level of surface roughness of PTFE caused by Ar+ bombardment.
Changes of Wettability and Surface Energy of Polymer by keV Ar+ Ion Irradiation
Authors: Cho Jun-Sik , Choi Won-Kook , Yoon Ki Hyun , Jung Hyung-Jin , Koh Seok-Keun 
Published: April 2011

AbstractSurface modification of polycarbonate(PC) was performed to improve the wettability by Ar+ ion irradiation with 1 keV energy in oxygen environment. The ion dose ranged from 5 x 1014 to 5 x 1016 ions/cm2 and oxygen flow rate was also varied from 0 to 6 sccm(ml/min.). Contact angle was not much decreased from 78° to 48° for water and from 63° to 32° for formamide by Ar+ ion irradiation without oxygen gas, but largely reduced to 12° for water and to 8° for formamide as Ar+ ion irradiation with 4 seem oxygen gas. Surface energy of modified PC surface which was irradiated with oxygen gas was more increased than that of PC surface irradiated without oxygen gas. It is evident that the increase of surface energy for PC modified with oxygen gas is due to hydrophilic group which result from the chemical reaction between PC surface and oxygen gas. From X-ray photoelectron spectroscopy(XPS) analysis, the newly formed hydrophilic group is identified as hydrophilic C=0 bond, and atomic force microscope(AFM), it is found that the root mean square of surface roughness is changed from 14 Å to 22 ∼ 26 Å for Ar+ ion irradiation only and 26 ∼ 30 Å for Ar+ ion irradiation with 4 seem oxygen gas. Therefore wettability of PC surface is much more affected by newly formed hydrophilic group than surface roughness in keV energy Ar+ ion irradiation.
The Role of Glass Structure in the Formation of Implanted Gold Nanoclusters for Enhanced Nonlinear Optical Properties
Authors: Arnold G.W. , Battaglin G. , Boscolo-Boscoletto A. , Mazzoldi P. , Meneghini C. 
Published: April 2011

AbstractVarious silicate glasses (fused silica, soda-lime, Na- and K-borosilicates, lithia-alumina silicate, and Pyrex®) were implanted with 8 x 1015 285 keV Au/cm2. Colloid growth was monitored as a function of annealing and N implantation (2 x 1017 35 keV N/cm2). Annealing to 1040 °C for fused silica and to 600 °C for the other glasses resulted in Au aggregation and optical absorption. Radiation damage removal is associated with the fused silica annealing; the aggregation of Au at lower temperatures for the other glasses is expected because of the lower glass transition temperature. Phase-seption in the alkali-borosilicates may be important because of grain-boundary diffusion. N implantation did not significantly affect nanocluster growth.
Waveguide Formation in Silica by Implantation with Si, P and Geions
Authors: Leech Patrick W. , Ridgway Mark C. 
Published: April 2011

AbstractLow loss channel waveguides have been formed in substrates of fused silica and silica-on-silicon by the implantation of 5 MeV Si, P and Ge ions. The silica-on-silicon substrates comprised an upper core layer which was doped with either 3 or 7% Ge. Annealing of the implanted silica-on-silicon waveguides has defined a narrow range of temperature (500 - 600°C) over which the loss coefficient, α, was at a minimum of 0.10 - 0.20 dB/cm at wavelengths of λ = 1300 and 1550 nm. For the fused silica substrates, a similar minimum loss ( 0.10 - 0.20 dB/cm) was measured at 1300 nm. However, at λ = 1550 nm the value of α was significantly increased because of an absorption edge in the fused silica (Suprasil-2) at -1500 nm. The results show that the optical loss characteristics of the waveguides were essentially independent of the ion species.
Proton Induced Defect Formation in Quartz Glasses
Authors: Gulamova R.R. , Gasanov E.M. , Alimov R. 
Published: April 2011

AbstractThe contributions of ionization energy losses and elastic collisions to radiation induced defect formation along the proton track were considered in quartz glasses irradiated by protons with different energies. It is shown that on a larger part of the proton track the color and luminescence center formation by means of recharging of the native defects is due to the ionization energy losses. Generation of structural defects like displaced atoms and their vacancies by elastic collisions with protons and recoil atoms dominates for proton energies < 5 MeV. At proton energies 10 MeV the color and luminescence center formation due to ionization energy losses prevails, and generation of the alumina-alkaline centers, causing an increase of the optical absorption at 550 nm and the thermoluminescence peak at 360 C and a band at 460 nm, occurs. At the proton energies Ep 10 MeV generation of the displaced atoms and their vacancies by elastic collisions dominates, leading to an increase of the E'-centers and to the destruction and transformation of the alumina-alkaline centers.
Synthesis and Properties of GaAs Nanocrystals in Sio2 Formed by Ion Implantation
Authors: Zhu Jane G. , White C. W. , Wallis D. J. , Budai J. D. , Withrow S. P. 
Published: April 2011

AbstractGaAs nanocrystals have been formed by the sequential ion implantation method. The sequence of Ga and As ion implantation (i.e., Ga + As or As + Ga) is found to affect the size distributions of GaAs nanocrystals significantly. The nanocrystal sizes are much bigger in the samples with Ga implanted first than those with As implanted first. This phenomenon is explained by the different diffusion behaviors of Ga and As species. Different precipitate regions have been observed in the samples implanted with Ga first and then As. Optical absorption measurements show that Ga particles have already formed in the as-implanted stage.
Carbon Nitride Formation by Plasma Assisted Ion Beam Deposition
Authors: Tompa G.S. , Murzin I.H. , Kim S.I. , Ahn Y.O , Gallois B. , Fischer T.E. , Forsythe E.W. 
Published: April 2011

AbstractTheoretical works have indicated that carbon nitride, in a β-C4N4 phase, would have optical and mechanical properties comparable to or exceeding those of diamond. In this effort, the formation of carbon nitride thin films was investigated using a Plasma Assisted Ion Beam Deposition (PAIBD). In this technique, a C- ion beam combined with a N2 or NH3 RF plasma source is used to synthesize carbon nitride films. These films were investigated as a function of both C- ion beam energy and the power of the plasma source. The C- ion energy was found to be a key parameter in the formation of carbon nitride. The films were evaluated by a variety of diagnostic techniques including Raman, AES, XRD and FTIR. Analysis confirms high nitrogen concentration in the synthesized films and the major portion of carbon being single bonds in the sp3 bond configuration, which is a characteristic of the tetrahedral -C3N4 phase. Tribology tests confirmed that the friction coefficient and the wear rate are comparable to diamond. The results show that the higher C- ion beam energy (-150 eV) forms insulating films with the highest single bond percentages in the range studied. We believe beam energy control is critical to the types of bonds formed.
In-Situ Hvem Studies of Radiation-Induced Segregation In Ni-Al Alloys During Simultaneous Irradiation with Electrons and Ions
Authors: Giacobbe M. J. , Lam N. Q. , Okamoto P. R. , Stubbins J. F. 
Published: April 2011

AbstractThe effects of 75-keV Ne+ and 300-keV Ni+ bombardment on electron radiation-induced segregation (RIS) in a Ni-9at%Al alloy were investigated in-situ using the HVEM (high voltage electron microscope)/Tandem accelerator facility at Argonne National Laboratory. The radial component of defect fluxes generated by a highly-focused 900-keV electron beam was used to induce segregation of Al atoms towards the center of the electron irradiated area via the inverse-Kirkendall effect. The radial segregation rate was monitored by measuring the increase in the diameter of the Al enriched zone within which γ'-νi3αl precipitates form during irradiation. Both dual electron-ion and pre-implanted ion-electron irradiations were performed in an attempt to separate the contributions of energetic displacement cascades and implanted ions acting as defect trapping sites to RIS suppression. It was found that 75-keV Ne implantation has a retarding effect on RIS.
A Novel Rectilinear Negative Carbon Ion Beam Source for Large-Area Amorphous Diamond Like Carbon Coatings
Authors: Sohn M.H. , Ahn YO. , Ko Y.W. , Park Y. , Kim S.I. 
Published: April 2011

AbstractA novel rectilinear negative carbon ion beam source for large-area coatings has been developed, based on SKION's Solid State Ion Beam Technology. The negative carbon ion beam is effectively produced by a primary cesium ion bombardment and the secondary negative carbon ion yield has been observed to be about 0.5. The ion source produces a negative carbon ion current density of 0.25 mA/cm2 at the extraction voltage of 4 kV. The ion beam energy can be independently controlled from 0 eV to 300 eV. Due to the rectilinear geometry for the production of ion beams, the scale-up of the ion beam in length direction can be easily obtained with no limit. Furthermore, the ion source uses no gas discharge to generate ion beams and does not use any hydrogen gas. The ion source can be operated in a high vacuum (<10-7 Torr), and the cesium vapors are filtered and recirculated. The ion source produces ultra-hard (50 GPa), atomically smooth (< 1 nm Ra), and hydrogen-free amorphous diamond-like-carbon (DLC) films over large areas.