bluuebunny/crossref_metadata_2025_split huggingface dataset:
RBS Analysis of Elements in the Fingernai
Authors: Madakson Peter 
Published: March 2011

ABSTRACTFingernails from several sources were studied to determine elemental compositions. The common elements were found to be H, C, N, O, Ca and Fe. The elements Si, Bi, S, Mo, Ti, Zn, Pb, P and Nd were found on some of the nails; these are considered to result from environmental contamination, food and water intake. The compositions of H, C, N and O correlate with those in the hemoglobin molecule and, they do not vary significantly with time. This suggests that they are associated with dead blood cells. The other common elements, such as Ca and Fe, show variations in composition with time, probably because their amount in the body is determined by food and water intake. Fingernails from female sources have a higher concentration of Ca than those from male sources. Also, the concentration of Ca is generally higher on the outer than the inner surface of the nail, probably to provide a stronger bony structure and mechanical strength on the outside.
Characterization of Pulsed Laser Beam Mixed AuTe/GaAs Ohmic Contacts
Authors: Wuyts K. , Silverans R.E. , Van Hove M. , Van Hove Van Rossum 
Published: March 2011

ABSTRACTThe formation of pulsed laser processed AuTe/n—GaAs ohmic contacts was investigated using I—V measurements, Rutherford Backscattering, and Mössbauer spectroscopy. Ohmic contact resistances comparable to those of furnace processed AuTe and AuGe/GaAs contacts were measured; however, a much thinner intermixed layer was obtained by the laser processing. No evidence for the formation of a n++—GaAs layer could be derived from the experimental data. The results are more consistent with the model explaining the ohmic conduction mechanism by the formation of a graded heterojunction structure.
Melting of Ion Implanted and Relaxed Amorphous Silicon
Authors: Grimaldi M.G. , Baeri P. , Baratta G. 
Published: March 2011

ABSTRACTThe difference in the melting temperature of ion implanted and relaxed amorphous silicon has been measured. Pulsed laser irradiation (λ=347 nm, τ=30 ns) has been used to induce surface melting in the amorphous layer and time resolved reflectivity to detect the melting onset. The threshold energy density for surface melting in the relaxed amorphous was found 15.9±.3% higher than that in the unrelaxed one. The estimate of the variation of the thermal parameters in amorphous silicon upon relaxation allowed a determination of ΔTM=45±10 K between relaxed and unrelaxed amorphous silicon.
Subnanosecond Time-Resolved Electron Diffraction from Thin Crystalline Gold Films
Authors: Chen Hsiu-Cheng , Mourou Gerard A. , Knox Robert S. 
Published: March 2011

ABSTRACTA 100-ps-resolution electron pulse was used to study a 25-nm thick gold single crystal irradiated by a synchronized infrared optical pulse. The change in electron diffraction intensity following laser heating (the Debye-Waller effect) was measured as a function of delay time. The relaxation of a crystal lattice distortion in the surface region appears to explain an observed oscillation in time of the scattered electron intensity. This novel technique provides a sensitive structure probe for short-time dynamics and is, we believe, the fastest lattice temperature probe.
Parametric Study of Zone-Melting-Recrystallization Processing of Silicon on Insulator Structures
Authors: Lipman Joseph , Miaoulis Ioannis N. , Im James S. 
Published: March 2011

ABSTRACTThe effects of four thermal parameters on the temperature distribution during Zone-Melting-Recrystalllzation processing of Slllcon-On-Insulator devices with graphite strip as the heat source were investigated numerically. Results indicate that the convective heat losses, the variability of the thermal conductivity of silicon as a function of temperature, and the multilayer nature of the structure do not affect the temperature distribution significantly. However, the velocity of the graphite strip can significantly affect the temperature distribution. The temperature profile remains the same for graphite strip velocities below 0.03 cm/sec. The relationship between required graphite strip temperature and velocity of the strip for film melting to occur is presented in graphical form.
Effects of Laser Surface Melting on Structure Character and Erosion Resistance of Plasma Sprayed Ceramic Coatings
Authors: Sun Jia-Shu 
Published: March 2011

ABSTRACTIn this work the effects of laser melting on the micro-morphology, structures and solid particle erosion behaviors of plasma spray alumina, alumina-titania and zirconia coatings have been studied. The results have indicated that laser melting has modified the micro-mophologies and structures of coatings, eliminated the porosity of sprayed coatings and increased the erosion resistance of ceramic coatings. The erosion mechanisms of ceramic coatings have been investigated.
Crystalline Polyimide Thin Film Deposition by Ionized Cluster Bean
Authors: Cho S.J. , Choe H.S. , Jang H.G. , Iim S.S. , Whang C.N. 
Published: March 2011

ABSTRACTPolyimide thin films are deposited by the ionized cluster beam deposition( ICBD ) technique. Polymerization and crystallization of polyimide were investigated using TEN, IR, and the electronic structure of the polyimide film was investigated using XPS. Films deposited at optimum ion acceleration voltage showed strong preferential crystal orientation. Crystalline polyimide film was obtained at ion acceleration voltage of 700 V.
Ion Beam Modification of High-Tc Superconductors
Authors: Meyer O. , Geerk J. , Kroner T. , Li Q. , Linker G. , Strehlau B. , Xi X.X. 
Published: March 2011

ABSTRACTIon irradiation and implantation experiments of high temperature superconductors (HTSC) thin films resulted in many interesting effects. Among those are: (i) the superlinear increase of the resistivity, p, with ion fluence, φ, leading to a metal to insulator transformation, (ii) the large recovery above 150 K of the radiation induced changes of ρ and Tc observed in low temperature irradiation experiments, and (iii) the large structural changes such as the increase of the c-axis lattice parameter with φ, the radiation induced orthorhombic to tetragonal phase transition, and the amorphization. Displaced oxygen atoms play an important role for the observed property changes.
The Importance of Self-Sputtering by Low Energy Ions in Partially Ionized Beam Deposition
Authors: Bai P. , SteinbrÜChel CH. , Lu T.-M. 
Published: March 2011

ABSTRACTIn ion-assisted deposition techniques such as partially ionized beam deposition, ions derived from the depositing material itself concurrently bombard the surface during thin film growth. The ion percentage in the deposition beam ranges from less than 0.1% to 100% (Ion Beam Deposition) with the ion energy varying between a few eV and several keV. When the sputtering yield of the self-sputtering is greater than one, there is a critical ion percentage, for a given ion energy, above which no net deposition can be obtained. The self-sputtering yield is shown to have a square root dependence on the ion energy above the threshold energy by fitting the experimental data obtained from the literature. The critical ion percentage for Al, Cu, Au, Ag, and C is then calculated and plotted as a function of the ion energy so that deposition and no-deposition regions are illustrated in terms of the ion energy and ion percentage.
Electron Beam Induced Oxygen Disordering in Yba2cu307-X Superconductors
Authors: Basu S. N. , Roy T. , Mitchell T. E. , Nastasi M. 
Published: March 2011

ABSTRACTThin foils of bulk YBa2Cu3O7–x (YBCO) superconductors were subjected to electron irradiation in a Transmission Electron Microscope (TEM). The resulting disordering of the oxygen atoms and vacancies in the Cu-0 planes was monitored by measuring the splitting of the (110) diffraction spots in the [001] diffraction pattern. Samples were irradiated at 83K with 100, 150, 200 and 300kV electrons. The 100kV electrons did not cause any disordering, even after prolonged irradiation. The results of the higher energy irradiations showed an excellent fit to a disordering model, indicating a lack of radiation assisted reordering at 83K. This was further confirmed by the insensitivity of the disordering to the dose rate of 300kV electrons at 83K. However, at 300K, an increase in the dose rate of 300kV electrons increased the disordering rate, indicating that radiation assisted reordering was occuring at that temperature.
In-Situ Study of Radiation Damage in V2os Induced by Low Energy Electrons
Authors: Ai R. , Fan H.-J. , Stair P.C. , Marks L.D. 
Published: March 2011

ABSTRACTRadiation damage in V2Os induced by electrons in the energy range 0-3 keV has been studied by high resolution electron microscopy, X-ray photoelectron spectroscopy and mass spectrometry. Different phase transformations were observed when V205 was irradiated by electrons of different energies. The damage kinetics and the role of electron radiation enhanced diffusion were investigated. It was found that nucleation and growth of lower oxides was driven by electron radiation enhanced diffusion.
Dopant Site Location in Dual-Implanted Gap using {111} Planar Channeling
Authors: Parikh N.R. , Kao C.T. , Lee D.R. , Muse J. , Swanson M. L. , Haynes T.E. , Venkatasubramanian R. , Timmons M. 
Published: March 2011

ABSTRACTPrevious studies have indicated that dual implantation can efficiently introduce group IV dopant onto selected sub-lattice sites in m-V compound semiconductors, thus enhancing electrical activation. We studied this phenomenon in GaP using Rutherford Backscattering Spectroscopy (RBS) to determine the lattice location of Sn atoms. We used single crystals of GaP (100) which had been implanted at 400° C with120 Sn+ following previously implanted69 Ga+ or 31P+. Energies were selected for euivalent projected ranges, and all species were implanted with doses of 1 × 1015 atoms/cm2 . Asymmetry in the angular scan of the {111} planar channel was then used to determine the sub-lattice location of the implanted Sn. RBS results indicated that for all implants Sn atoms were substituting Ga and P sites eually. However, Hall effect measurements gave p type conduction for GaP implanted with Sn alone, while those with prior implants of Ga or P resulted in n-type conduction. RBS and Hall effect results are explained by a vacancy complex model.
Low-Energy Implantation of Si and Sn into GaAs
Authors: Rubart W.S. , Jones K.S. , Seiberling L. , Sadana D.K. 
Published: March 2011

ABSTRACT(100) GaAs was implanted with 29Si+ at energies of 10keV or 20keV and 119Sn+ at an energy of 60keV. The doses used for the Si+ implants were from 1 × 1013 crrr2 to 1 × 1016 cm-2, whereas the Sn+ doses ranged from 1.5×1012 cm-2 to 1.5×1015 cm-2. Implanted samples were rapidly thermal annealed (RTA) in either an argon or arsine ambient at 950°C or 900°C for 12 seconds. Transmission electron microscopy (TEM) results indicate that the annealing ambient has a dramatic effect on the defect annealing kinetics for 10keV implants but not the 20keV Si+ implants. For the 10keV implants reducing arsenic loss via use of an arsine ambient or a Si3N4 cap results in a dramatic decrease in the dislocation loop density. The defect morphology is not related to the as implanted morphology (amorphous or crystalline) but is related to the species. Hall effect measurements revealed an increase in the mobility by a factor of 1.5 times for high dose Si+ and Sn+ implanted samples when RTA was carried out in an arsine instead of an argon ambient. This is despite little or no change in the extended defect morphology or carrier concentration, indicating that the point defect concentration influences the mobility.
Density Measurements of Ion Implanted Amorphous Silicon
Authors: Custer J. S. , Thompson Michael O. , Jacobson D. C. , Poate J. M. , Roorda S. , Sinke W. C. , Spaepen F. 
Published: March 2011

ABSTRACTThe density of amorphous Si was measured. Continuous and buried amorphous Si films were produced by 0.5-8 MeV Si implantation through a steel contact mask. Surface steps of amorphous Si stripes with initial thicknesses from 0.9 to ∼ 5.0 μm were measured using a surface profilometer. For implants up to 5 MeV, the amorphous Si is constrained laterally by the surrounding crystal and deforms plastically. The density of amorphous Si deduced from the surface step heights is 4.91 × 1022 cm-3, 1.7 ± 0.1 % less than the density of crystal Si (5.00 × 1022 cm-3).
Avoiding Transient Diffusion of Boron in Si(100)
Authors: Schreutelkamp R.J. , Lu W.X. , Saris F.W. , Janssen K.T.F. , Ottenheim J.J.M. , Kaim R.E. , Westendorp J.F.M. 
Published: March 2011

ABSTRACTThe diffusion of boron ions implanted in Si(100) during high temperature treatment has been studied by means of Secondary Ion Mass Spectrometry. The boron ions were implanted at energies of 5 and 10 keV along random direction and along [100]. The implantation dose amounted to 1×1013/cm2. During annealing an enhanced diffusion of boron is observed in the tail region of the implantation profiles. In all cases the enhanced diffusion is completed after Rapid Thermal Annealing at 900°Cfor 10”. The enhanced diffusion is largest for the channeled ion implantations. Channeling analysis shows that the transient diffusion is not correlated with the annihilation of defects near the projected range. Therefore, the observed diffusion tail is attributed to rapidly diffusing interstitial boron. Post-amorphization of boron implanted silicon with Si+ ions is used to prevent transient diffusion. Thus a very sharp pn-junction is obtained at a depth of 03 jim and the effective number of charge carriers equals the implanted dose after annealing at 550°Cfor 5hrs and 1000°Cfor 10”.
Characteristics of Metal/P+-Gaas Schottky Barrier Junction Formed by Focused-Ion-Beam Implantation
Authors: Watanabe N. , Tsukamoto T. , Okunuki M. 
Published: March 2011

ABSTRACTBeryllium (Be) depth profiles, carrier profiles, ideality factors (deviation from thermionic emission and diffusion theory) and Schottky barrier heights of Al/p+-GaAs Schottky diodes were investigated by using focused ion beam (FIB) and de-focused ion beam (DFIB) of 40keV Be+, with dose range from 5.0×1012ions/cm2 to 3.4×1014ions/cm2. Differences of the depth profiles between FIB implantation and DFIB implantation were observed, and it was confirmed that depth profiles of the ion implantations were affected by current densities of the ion probes. The other side, it was recognized that the ideality factors and the Schottky barrier heights of the Schottky diodes were depended on effect of thermionic field emission.
Rapid Thermal Annealing of Si+ and P+ Dually Implanted InP
Authors: Honglie Shen , Genqing Yang , Zuyao Zhou , Shichang Zou 
Published: March 2011

ABSTRACT150keV Si* ions and 160keV P* ions were implanted at 200°C with doses ranging from 5x1013 to 1x1015/cm2 to study the effect of dual implantations on the electrical properties of Fe doped InP. Samples encapsulated with Si3N4 films of about 1000Å were annealed in a halogen tungsten lamp RTA system under flowing N2 at different temperatures from 700 to 900°C for 5s. It has been found that Si*+P* dual implantations into InP can result in an enhanced activation, particularly significant at high dose of implantation. The maximum dopant activation and average electron mobility for Si*+P* dual implants at a dose of 1×1015/cm2 are 70% and 750cm2/vs, which corresponds to a peak electron concentration of 5×1019/cm3 while that for Si* single implant at the same dose are 29% and 870cm2/vs, which corresponds to a peak electron concentration of 1.2×10 19/cm3. The improvement of the electrical properties is discussed in terms of amphoteric behavior of silicon in InP.
Oxidation Behavior of Pure Titanium Surfaces Coated with Boron Compounds
Authors: Elena M. , Guzman L.A. , Tomasi A. , Gialanella S. , Scardi P. 
Published: March 2011

ABSTRACTBoron nitride and titanium-boron multilayers (some of which were implanted with nitrogen- or argon ions) have been deposited on pure titanium substrates with an RF sputtering technique. The high temperature (850 °C) behavior of these samples in an oxidizing atmosphere has been studied. While the boron nitride coatings decompose rapidly, with boron diffusing to the surface, an important role for nitrogen has been evidenced. The concentration of nitrogen found at the interface, forming a diffusion barrier, can account for a certain degree of protection.
Martensitic transformations in ion implanted stainless steels
Authors: Johnson Erik 
Published: March 2011

ABSTRACTUsing ion implantation it is possible to induce a variety of phase transformations in the surfaces of stainless steels. The implanted layer can be either amorphized, undergo an fee (γ) => bec (α') martensitic transformation, or compounds can be formed between implanted atoms and target atoms. Stress provides a dominant contribution to the driving forces for amorphization and martensitic transformations. Implantation-induced alloying is important for obtaining the right composition in the implanted layer, whereby the transformation conditions can be optimized. Amorphization is best achieved by implantation of metalloids or other conventionally known glass forming elements. Martensitic transformations in austenitic steels are most easily induced after implantations with noble gases — including helium, where highly pressurized noble gas inclusions are formed. Implantations at high fluences with compound forming species such as nitrogen, boron or phosphorus, will often produce an implanted layer with a structure resembling a ceramic glazing which, depending on the implant species, will be amorphous or crystalline.In order to understand and predict changes in the surface properties of implanted stainless steels, a detailed knowledge of the implantation induced microstructures is essential. The implanted surface will often have a multiphase structure giving only moderate improvements in corrosion properties, and in particular, resistance to pitting corrosion will often be reduced or only slightly improved. Surface hardness will, on the other hand, in many cases be increased, and large improvements will often be observed in wear and friction properties of the implanted surfaces. Under conditions where formation of a homogeneous surface layer is facilitated, the fatique life of implanted samples may also be extended.
Hardness-Damage Correlations in Ta Implanted Single Crystal Ni3Al
Authors: Was Gary S. , Mantl Siegfried , Oliver Warren 
Published: March 2011

ABSTRACTImplantation of Ta into single crystal Ni3Al was conducted to determine whether this would be an effective means of producing surface hardening in monolithic alloys. Ta was implanted at 400 keV to doses of 0.7, 3.6 and 25.2 × 1015 cm2 along the <100> axis of a <100> crystal of Ni3A1 at room temperature. Composition vs depth profiles were determined by RBS and lattice location of Ta was determined by channeling angular yield scans about the <100> axis. The hardness of the surface was measured by ultra-low load indentation. Results show that implantation softens the surface and that the Ta is randomly distributed between Ni and A1 sites. Annealing at 1000°C/1h significantly reduces the damage and causes preferential occupation of A1 sites by Ta. It also results in a slight increase in surface hardness. Further annealing at 1200°C/0.25 h increases the surface hardness substantially. The results indicate that the as-implanted surface is softened by disordering and subsequent diffusion of Ta to A1 sites causes hardening of the surface.
Ion Beam Induced Conductivity Changes in Glassy Carbon
Authors: McCulloch D. , Prawer S. 
Published: March 2011

ABSTRACTIon beam irradiation of Glassy Carbon is shown to increase its resistivity by up to eight orders of magnitude. These changes in resistivity are correlated with results obtained from Raman spectroscopy and Reflection High Energy Electron Diffraction. At high doses of C implantation there is convincing evidence that ion beam irradiation partially graphitizes the surface of Glassy Carbon.
Laser Writing of High Purity Gold Lines
Authors: Jubber M. , Wilson J.I.B. , Davidson J.L. , John P. , Roberts P.G. 
Published: March 2011

ABSTRACTGold tracks have been deposited on thermally oxidised and single crystal silicon, gold and nichrome coated silicon wafers by pyrolytic decomposition of gaseous alkyl (triethyl phosphine) gold(I) complexes using focussed 514 nm radiation from an argon ion laser. The precursors, RAu(I)Et3P, R = CH3, C2H5 are low melting point crystalline solids with relatively high vapour pressures (∼5 mtorr). They are representative of a class of compounds being evaluated for laser deposition of gold. Differential scanning calorimetry, DSC, shows that the thermal decomposition of MeAu(I)Et3P in the solid state is a two-stage process. The decomposition temperature is 63 ± 1°C. Tracks were deposited at laser scan speeds up to 35 μm s−1 with a beam diameter (1/e2) at the focus of ∼12 μm. SIMS, EDX and laser ionisation microprobe analysis, LIMA, were used to determine the chemical composition of the tracks. The purity of >98% is consistent with the measured resistivities (4.2 μΩ cm) at room temperature compared to bulk gold (∼2 μΩ cm). These resistivities were achieved without post deposition annealing. Stylus profilimetry and SEM data showed the lines produced from MeAu(I)Et3P have a virtually rectangular cross-section. Together with the absence of the ubiquitous λ-ripples, this feature suggests that deposition is more rapid on the gold surface than on the SiO2 substrate. Laser power thresholds are lower for silicon substrates coated with thin (5 - 10°A) films of gold or nichrome.
Krf Excimer Laser Deposition of Titanium from Tici4
Authors: Izquierdo R. , Lavoie C. , Meunier M. 
Published: March 2011

ABSTRACTWe have investigated the deposition of titanium lines from TiCl4 induced by KrF excimer laser (248 nm). Substrates are primarily LiNbO3, for the possible formation of Ti:LiNbO3 optical waveguides, as well as silicon and glass. Titanium lines contain [Cl] < 2 at% and are typically 200 to 1000 Angstroms thick with a width ranging from 3 to 20 μm. Results suggest that the process is controlled by photochemistry of TiCl4 but it is difficult at this point to assert which of the gas or adsorbed layer is the primary source of thin film growth.
Laser-Induced Local Decomposition of Adsorbed Tungsten Fluorine Molecules for Metal Deposition on Silicon
Authors: Auvert Geoffroy , Pauleau Yves , Tonneau Didier 
Published: March 2011

ABSTRACTDecomposition of tungsten hexafluoride on silicon substrates under CW argon laser irradiation in the visible domain has been extensively studied in presence of various buffer or reactive gases. The decomposition rate is found to be limited either by a mass transport phenomena or by a thermally activated process. It has been found that no photolytic decomposition can be invoked as the limiting step in the decomposition rate. Depending on the partial pressure of added hydrogen, irradiation results in a local deposition of tungsten, having good electrical properties. In the high pressure domain, deposition kinetics are consistent with mechanisms invoked in conventional chemical vapor deposition reactors. A different mechanism appearing in a lower hydrogen pressure domain will be tentatively interpreted in correlation with the laser-induced temperature.