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Sample records for beam deposited mgf

  1. Ion assistance effects on electron beam deposited MgF sub 2 films

    CERN Document Server

    Alvisi, M; Della Patria, A; Di Giulio, M; Masetti, E; Perrone, M R; Protopapa, M L; Tepore, A

    2002-01-01

    Thin films of MgF sub 2 have been deposited by the ion-assisted electron-beam evaporation technique in order to find out the ion beam parameters leading to films of high laser damage threshold whose optical properties are stable under uncontrolled atmosphere conditions. It has been found that the ion-assisted electron-beam evaporation technique allows getting films with optical properties (refraction index and extinction coefficient) of high environmental stability by properly choosing the ion-source voltage and current. But, the laser damage fluence at 308 nm was quite dependent on the assisting ion beam parameters. Larger laser damage fluences have been found for the films deposited by using assisting ion beams delivered at lower anode voltage and current values. It has also been found that the films deposited without ion assistance were characterized by the highest laser damage fluence (5.9 J/cm sup 2) and the lowest environmental stability. The scanning electron microscopy analysis of the irradiated areas...

  2. Ultraviolet optical and microstructural properties of MgF2 and LaF3 coatings deposited by ion-beam sputtering and boat and electron-beam evaporation

    International Nuclear Information System (INIS)

    Single layers of MgF2 and LaF3 were deposited upon superpolished fused-silica and CaF2 substrates by ion-beam sputtering (IBS) as well as by boat and electron beam (e-beam) evaporation and were characterized by a variety of complementary analytical techniques. Besides undergoing photometric and ellipsometric inspection, the samples were investigated at 193 and 633 nm by an optical scatter measurement facility. The structural properties were assessed with atomic-force microscopy, x-ray diffraction, TEM techniques that involved conventional thinning methods for the layers. For measurement of mechanical stress in the coatings, special silicon substrates were coated and analyzed. The dispersion behavior of both deposition materials, which was determined on the basis of various independent photometric measurements and data reduction techniques, is in good agreement with that published in the literature and with the bulk properties of the materials. The refractive indices of the MgF2 coatings ranged from 1.415 to 1.440 for the wavelength of the ArF excimer laser (193 nm) and from 1.435 to 1.465 for the wavelength of the F2 excimer laser (157 nm). For single layers of LaF3 the refractive indices extended from 1.67 to 1.70 at 193 nm to ∼1.80 at 157 nm. The IBS process achieves the best homogeneity and the lowest surface roughness values (close to 1 nmrms) of the processes compared in the joint experiment. In contrast to MgF2 boat and e-beam evaporated coatings, which exhibit tensile mechanical stress ranging from 300 to 400 MPa, IBS coatings exhibit high compressive stress of as much as 910 MPa. A similar tendency was found for coating stress in LaF3 single layers. Experimental results are discussed with respect to the microstructural and compositional properties as well as to the surface topography of the coatings

  3. Performance improvement of LiCoO2 by MgF2 surface modification and mechanism exploration

    International Nuclear Information System (INIS)

    Highlights: • MgF2 is coated on the surface of LiCoO2 via simple chemical deposition. • MgF2 coating enhances the cycling and thermal stabilities of LiCoO2. • The optimum coating content of MgF2 is found to be 1 wt.%. • MgF2 coating can effectively suppress the undesirable growth of SEI layer. - Abstract: LiCoO2 cathode material synthesized by a sol-gel method is modified by different contents of MgF2 via simple chemical deposition. The structure and morphology of pristine and MgF2-coated LiCoO2 are investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM). It is found that the homogeneous MgF2 surface modification does not change the bulk structure of LiCoO2. The effects of MgF2 on the electrochemical behaviors of LiCoO2 are studied. Comparatively, 1 wt.% MgF2-coated LiCoO2 exhibits the best electrochemical performances. Cyclic voltammetry (CV) results confirm that MgF2 surface coating decreases the electrode polarization and improves the structural stability of LiCoO2 during cycling. The results of electrochemical impedance spectroscopy (EIS) and Fourier transform infrared (FTIR) for pristine and 1 wt.% MgF2-coated LiCoO2 further demonstrates that modification layer suppresses the undesirable growth of solid electrolyte interface (SEI) film, which greatly contributes to the improved electrochemical performances after surface modification. Differential scanning calorimetry (DSC) tests show that MgF2 coating also improves the thermal stability of LiCoO2 electrode

  4. Improvement of MgF 2 thin coating films for laser applications

    Science.gov (United States)

    Perales, F.; Herrero, J. M.; Jaque, D.; de las Heras, C.

    2007-03-01

    MgF2 thin films have been deposited by physical vapor deposition on different substrates (laser crystals, a saturable absorber crystal and glasses), in order to investigate the best conditions for antireflection coatings. The relevance of using these MgF2 coatings has been evidenced by different laser gain experiments performed on different coated and uncoated elements such as Nd:CGGG, Nd:LiNbO3 and Cr4+:YAG. Then the optical properties of the MgF2 films have been systematically investigated for different annealing temperatures and ion bombardment treatments. A substantial improvement in the films transmission has been demonstrated. The obtained results are correlated to morphologic changes in the MgF2 films.

  5. Lifetime obtained by ion beam assisted deposition

    International Nuclear Information System (INIS)

    We have fabricated green organic light-emitting diodes based on tris-(8-hydroxyquinoline)aluminium (Alq3) thin films. In order to favor the charge carriers transport from the anode, we have deposited a N,N'-diphenyl-N,N'-bis (3-methylphenyl)-1,1'-diphenyl-4,4'-diamine (TPD) layer (hole transport layer) on a ITO anode. Cathode is obtained with a calcium layer covered with a silver layer. This silver layer is used to protect the other layers against oxygen during the OLED use. All the depositions are performed under vacuum and the devices are not exposed to air during their realisation. In order to improve the silver layer characteristics, we have realized this layer with the ion beam assisted deposition process. The aim of this process is to densify the layer and then reduce the permeation of H2O and O2. We have used argon ions to assist the silver deposition. All the OLEDs optoelectronic characterizations (I = f(V), L = f(V)) are performed in the ambient air. We compare the results obtained with the assisted layer with those obtained with a classical cathode realized by thermal unassisted evaporation. We have realized lifetime measurements in the ambient air and we discuss about the assisted layer influence on the OLEDs performances

  6. Dual ion beam assisted deposition of biaxially textured template layers

    Energy Technology Data Exchange (ETDEWEB)

    Groves, James R.; Arendt, Paul N.; Hammond, Robert H.

    2005-05-31

    The present invention is directed towards a process and apparatus for epitaxial deposition of a material, e.g., a layer of MgO, onto a substrate such as a flexible metal substrate, using dual ion beams for the ion beam assisted deposition whereby thick layers can be deposited without degradation of the desired properties by the material. The ability to deposit thicker layers without loss of properties provides a significantly broader deposition window for the process.

  7. Patterned electrochemical deposition of copper using an electron beam

    Directory of Open Access Journals (Sweden)

    Mark den Heijer

    2014-02-01

    Full Text Available We describe a technique for patterning clusters of metal using electrochemical deposition. By operating an electrochemical cell in the transmission electron microscope, we deposit Cu on Au under potentiostatic conditions. For acidified copper sulphate electrolytes, nucleation occurs uniformly over the electrode. However, when chloride ions are added there is a range of applied potentials over which nucleation occurs only in areas irradiated by the electron beam. By scanning the beam we control nucleation to form patterns of deposited copper. We discuss the mechanism for this effect in terms of electron beam-induced reactions with copper chloride, and consider possible applications.

  8. Preparation and properties of MgF2 anti-reflective thin film by sol-gel process

    International Nuclear Information System (INIS)

    MgF2 anti-reflective thin films were successfully prepared in methanol media via sol-gel process using magnesium acetate and hydrofluoric acid as reactants. The influence of processing temperature on MgF2 sols was investigated. As-synthesized MgF2 sol was used to deposit AR films on quartz substrate, which could be applied for 355 nm UV laser. The results showed that MgF2 thin films had low refractive index, small surface roughness and good anti-reflective property in the UV region and high la- ser-induced damage threshold (LIDT) at 355 nm (6 ns pulses). The refractive index at 355 nm wavelength of film decreased with the increase of processing temperature. The transmittance and LIDT of quartz substrate with double-side MgF2 films both reached the maximum value, that is, 99.4% for transmittance and 10.85 J·cm-2 (6 ns pulses) for LIDT when the processing temperature was 120 degree C. (authors)

  9. Patterned electrochemical deposition of copper using an electron beam

    OpenAIRE

    Mark den Heijer; Ingrid Shao; Alex Radisic; Reuter, Mark C.; Ross, Frances M.

    2014-01-01

    We describe a technique for patterning clusters of metal using electrochemical deposition. By operating an electrochemical cell in the transmission electron microscope, we deposit Cu on Au under potentiostatic conditions. For acidified copper sulphate electrolytes, nucleation occurs uniformly over the electrode. However, when chloride ions are added there is a range of applied potentials over which nucleation occurs only in areas irradiated by the electron beam. By scanning the beam we contro...

  10. Calculation of neutral beam deposition accounting for excited states

    International Nuclear Information System (INIS)

    Large-scale neutral-beam auxillary heating of plasmas has led to new plasma operational regimes which are often dominated by fast ions injected via the absorption of an energetic beam of hydrogen neutrals. An accurate simulation of the slowing down and transport of these fast ions requires an intimate knowledge of the hydrogenic neutral deposition on each flux surface of the plasma. As a refinement to the present generation of transport codes, which base their beam deposition on ground-state reaction rates, a new set of routines, based on the excited states of hydrogen, is presented as mechanism for computing the attenuation and deposition of a beam of energetic neutrals. Additionally, the numerical formulations for the underlying atomic physics for hydrogen impacting on the constiuent plasma species is developed and compiled as a numerical database. Sample results based on this excited state model are compared with the ground-state model for simple plasma configurations

  11. Calculation of neutral beam deposition accounting for excited states

    Energy Technology Data Exchange (ETDEWEB)

    Gianakon, T.A.

    1992-09-01

    Large-scale neutral-beam auxillary heating of plasmas has led to new plasma operational regimes which are often dominated by fast ions injected via the absorption of an energetic beam of hydrogen neutrals. An accurate simulation of the slowing down and transport of these fast ions requires an intimate knowledge of the hydrogenic neutral deposition on each flux surface of the plasma. As a refinement to the present generation of transport codes, which base their beam deposition on ground-state reaction rates, a new set of routines, based on the excited states of hydrogen, is presented as mechanism for computing the attenuation and deposition of a beam of energetic neutrals. Additionally, the numerical formulations for the underlying atomic physics for hydrogen impacting on the constiuent plasma species is developed and compiled as a numerical database. Sample results based on this excited state model are compared with the ground-state model for simple plasma configurations.

  12. NbN superconducting nanowire single-photon detector fabricated on MgF2 substrate

    Science.gov (United States)

    Wu, J. J.; You, L. X.; Zhang, L.; Zhang, W. J.; Li, H.; Liu, X. Y.; Zhou, H.; Wang, Z.; Xie, X. M.; Xu, Y. X.; Fang, W.; Tong, L. M.

    2016-06-01

    The performance of superconducting nanowire single-photon detectors (SNSPDs) relies on substrate materials. Magnesium fluoride (MgF2) exhibits outstanding optical properties, such as large optical transmission range and low refractive index (n = 1.38), making it an attractive substrate. We present the fabrication and the performance of SNSPDs made of a 4.5 nm thick NbN thin film deposited on MgF2 substrate for the wavelength of 1550 nm. The front-side illuminated SNSPDs without an optical cavity showed a maximal detection efficiency of 12.8% at a system dark count rate (DCR) of 100 Hz, while the backside illuminated SNSPDs with a SiO2/Au optical cavity atop displayed a maximal detection efficiency of 33% at a DCR of 100 Hz.

  13. Processes leading to enhanced energy deposition by particle beams

    International Nuclear Information System (INIS)

    Range shortening of electron and proton beams due to target temperature and density effects is calculated. The effect on target hydrodynamics is calculated for a proton beam. The effect of the penetration of an electron beam self magnetic field into the target is shown to cause effective range shortening. Enhanced energy deposition by a pinched electron beam in a foil target is studied numerically and experimentally. The target expansion velocity measured by laser flash photography is used to determine the enhancement factor. Bremsstrahlung measurements are used to study the electron trajectories

  14. Ion beam deposition of calcium hydroxyapatite

    International Nuclear Information System (INIS)

    Calcium hydroxyapatite has been sputtered on glass and Ti-6Al-4V substrates using a 1.5 kV argon ion beam. The films have been examined by X- ray diffraction analysis, energy dispersive spectroscopy, scanning electron microscopy, and adhesion testing. Results of this experimentation are presented

  15. Silicon nitride layers on tool steel produced by ion beam mixing and ion beam assisted deposition

    International Nuclear Information System (INIS)

    Silicon nitride layers on tool steel are produced both, by Kr+ implantation into reactively sputtered Si3N4 on steel (ion beam mixing) and N2+ implantation into evaporated Si on steel (ion beam assisted deposition). Atomic concentration profiles of Fe and Si measured by RBS and XPS show interface mixing. After ion beam assisted deposition complete Si-N compound formation takes place as shown by XPS. Ion beam mixing of Si3N4/steel decreases the etch rate in hydrochloric acid by 50% with respect to uncovered steel. After flash lamp annealing the ion irradiated silicon nitride layer becomes stable against the aggressive acid used. (author)

  16. Use of beam deflection to control an electron beam wire deposition process

    Science.gov (United States)

    Taminger, Karen M. (Inventor); Hofmeister, William H. (Inventor); Hafley, Robert A. (Inventor)

    2013-01-01

    A method for controlling an electron beam process wherein a wire is melted and deposited on a substrate as a molten pool comprises generating the electron beam with a complex raster pattern, and directing the beam onto an outer surface of the wire to thereby control a location of the wire with respect to the molten pool. Directing the beam selectively heats the outer surface of the wire and maintains the position of the wire with respect to the molten pool. An apparatus for controlling an electron beam process includes a beam gun adapted for generating the electron beam, and a controller adapted for providing the electron beam with a complex raster pattern and for directing the electron beam onto an outer surface of the wire to control a location of the wire with respect to the molten pool.

  17. Hydrogenated amorphous silicon deposited by ion-beam sputtering

    Science.gov (United States)

    Lowe, V. E.; Henin, N.; Tu, C.-W.; Tavakolian, H.; Sites, J. R.

    1981-01-01

    Hydrogenated amorphous silicon films 1/2 to 1 micron thick were deposited on metal and glass substrates using ion-beam sputtering techniques. The 800 eV, 2 mA/sq cm beam was a mixture of argon and hydrogen ions. The argon sputtered silicon from a pure (7.6 cm) single crystal wafer, while the hydrogen combined with the sputtered material during the deposition. Hydrogen to argon pressure ratios and substrate temperatures were varied to minimize the defect state density in the amorphous silicon. Characterization was done by electrical resistivity, index of refraction and optical absorption of the films.

  18. Direct deposition of gold on silicon with focused ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Nebiker, P.W.; Doebeli, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Muehle, R. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-09-01

    Irradiation with ions at very low energies (below 500 eV) no longer induces a removal of substrate material, but the ions are directly deposited on the surface. In this way, gold has been deposited on silicon with focused ion beam exposure and the properties of the film have been investigated with atomic force microscopy and Auger electron spectroscopy. (author) 3 figs., 1 ref.

  19. Nanopillar growth by focused helium ion-beam-induced deposition

    Energy Technology Data Exchange (ETDEWEB)

    Chen Ping; Salemink, Huub W M; Alkemade, Paul F A [Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Veldhoven, Emile van; Maas, Diederik J [TNO Science and Industry, Stieltjesweg 1, 2628 CK Delft (Netherlands); Sanford, Colin A [Carl Zeiss SMT, Inc., One Corporation Way, Peabody, MA 01960 (United States); Smith, Daryl A; Rack, Philip D, E-mail: p.f.a.alkemade@tudelft.nl [Department of Material Science and Engineering, University of Tennessee, Knoxville, TN 37996-2200 (United States)

    2010-11-12

    A 25 keV focused helium ion beam has been used to grow PtC nanopillars on a silicon substrate by beam-induced decomposition of a (CH{sub 3}){sub 3}Pt(C{sub P}CH{sub 3}) precursor gas. The ion beam diameter was about 1 nm. The observed relatively high growth rates suggest that electronic excitation is the dominant mechanism in helium ion-beam-induced deposition. Pillars grown at low beam currents are narrow and have sharp tips. For a constant dose, the pillar height decreases with increasing current, pointing to depletion of precursor molecules at the beam impact site. Furthermore, the diameter increases rapidly and the total pillar volume decreases slowly with increasing current. Monte Carlo simulations have been performed with realistic values for the fundamental deposition processes. The simulation results are in good agreement with experimental observations. In particular, they reproduce the current dependences of the vertical and lateral growth rates and of the volumetric deposition efficiency. Furthermore, the simulations reveal that the vertical pillar growth is due to type-1 secondary electrons and primary ions, while the lateral outgrowth is due to type-2 secondary electrons and scattered ions.

  20. Nanopillar growth by focused helium ion-beam-induced deposition

    International Nuclear Information System (INIS)

    A 25 keV focused helium ion beam has been used to grow PtC nanopillars on a silicon substrate by beam-induced decomposition of a (CH3)3Pt(CPCH3) precursor gas. The ion beam diameter was about 1 nm. The observed relatively high growth rates suggest that electronic excitation is the dominant mechanism in helium ion-beam-induced deposition. Pillars grown at low beam currents are narrow and have sharp tips. For a constant dose, the pillar height decreases with increasing current, pointing to depletion of precursor molecules at the beam impact site. Furthermore, the diameter increases rapidly and the total pillar volume decreases slowly with increasing current. Monte Carlo simulations have been performed with realistic values for the fundamental deposition processes. The simulation results are in good agreement with experimental observations. In particular, they reproduce the current dependences of the vertical and lateral growth rates and of the volumetric deposition efficiency. Furthermore, the simulations reveal that the vertical pillar growth is due to type-1 secondary electrons and primary ions, while the lateral outgrowth is due to type-2 secondary electrons and scattered ions.

  1. Superconducting nanowires by electron-beam-induced deposition

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, Shamashis, E-mail: shamashis.sengupta@u-psud.fr [CSNSM, Univ. Paris-Sud, IN2P3, UMR 8609, F-91405 Orsay Cedex (France); LPS, Univ. Paris-Sud, CNRS, UMR 8502, F-91405 Orsay Cedex (France); Li, Chuan; Guéron, S.; Bouchiat, H. [LPS, Univ. Paris-Sud, CNRS, UMR 8502, F-91405 Orsay Cedex (France); Baumier, Cedric; Fortuna, F. [CSNSM, Univ. Paris-Sud, IN2P3, UMR 8609, F-91405 Orsay Cedex (France); Kasumov, Alik [LPS, Univ. Paris-Sud, CNRS, UMR 8502, F-91405 Orsay Cedex (France); Institute of Microelectronics Technology and High Purity Materials, RAS, ac. Ossipyan, 6, Chernogolovka, Moscow Region 142432 (Russian Federation)

    2015-01-26

    Superconducting nanowires can be fabricated by decomposition of an organometallic gas using a focused beam of Ga ions. However, physical damage and unintentional doping often result from the exposure to the ion beam, motivating the search for a means to achieve similar structures with a beam of electrons instead of ions. This has so far remained an experimental challenge. We report the fabrication of superconducting tungsten nanowires by electron-beam-induced-deposition, with critical temperature of 2.0 K and critical magnetic field of 3.7 T, and compare them with superconducting wires made with ions. This work is an important development for the template-free realization of nanoscale superconducting devices, without the requirement of an ion beam column.

  2. Superconducting nanowires by electron-beam-induced deposition

    International Nuclear Information System (INIS)

    Superconducting nanowires can be fabricated by decomposition of an organometallic gas using a focused beam of Ga ions. However, physical damage and unintentional doping often result from the exposure to the ion beam, motivating the search for a means to achieve similar structures with a beam of electrons instead of ions. This has so far remained an experimental challenge. We report the fabrication of superconducting tungsten nanowires by electron-beam-induced-deposition, with critical temperature of 2.0 K and critical magnetic field of 3.7 T, and compare them with superconducting wires made with ions. This work is an important development for the template-free realization of nanoscale superconducting devices, without the requirement of an ion beam column

  3. Solid gold nanostructures fabricated by electron beam deposition

    DEFF Research Database (Denmark)

    Mølhave, Kristian; Madsen, Dorte Nørgaard; Rasmussen, A.M.;

    2003-01-01

    Direct writing with gold by electron beam deposition is a method for rapid fabrication of electrically conducting nanostructures. An environmental scanning electron microscope (ESEM) equipped with a source of the precursor gas dimethylacetylacetonate gold(Ill) was used to fabricate nanoscale tips...

  4. Microcracking in electron beam deposited scandia-stabilised zirconia electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Lugovy, Mykola; Slyunyayev, Viktor [Institute for Problems of Materials Science, 3 Krzhizhanovskii Str, 03142 Kiev (Ukraine); Steinberger-Wilckens, Robert [Forschungszentrum Jueelich, Jueelich (Germany)

    2009-12-01

    It is the aim of the present work to address some of the aspects of microcracking in electron beam deposited scandia-stabilised zirconia electrolyte applied for solid oxide fuel cells (SOFC) where a thin electrolyte layer is deposited on a relatively thick anode substrate. A model of microcracking for the electrolyte material is proposed which takes into account the statistical distribution of grain sizes, the stress redistribution due to failure of individual structural elements as well as the local criterion of grain fracture. The combination of electron microscopy research with model calculations permits both the specific energy of new surface creation in the electrolyte and critical parameters of the microcracking process to be determined. The annealing-induced electrolyte microcracking discussed in this work corresponds to localised microcracking, where each next structural element fails mainly at an existing microcrack tip. The features of localised microcracking in electron beam deposited scandia-stabilised zirconia electrolyte are analysed. (author)

  5. Kinetics of ion beam deposition of carbon at room temperature

    International Nuclear Information System (INIS)

    Growth rates of carbon films grown by ion beam deposition using methane gas were measured in situ as a function of deposition conditions. The methane pressure dependence of the growth rate was used to measure the cross-section for charge exchange. Variations in deposition rate per incident energetic particle found for each ion energy were related to ion current density. It was found that rates of growth per incident energetic specie were (i) largest for the smallest current densities, (ii) decreased monotonically with increasing current density, and (iii) were consistently larger than can be explained by deposition directly from the energetic flux alone. These observations were interpreted in terms of irradiation-induced surface interactions which promote chemisorption of methane physisorbed from the ambient atmosphere. (orig.)

  6. Optical Properties of MgF2 / MgF2 / Glass and MgF2 / TiO2 / Glass

    Directory of Open Access Journals (Sweden)

    S. Ghahramani

    2014-01-01

    Full Text Available MgF2 thin films by thickness of 93 nm were deposited on MgF2 / glass and TiO2 / glass thin layers by resistance evaporation method under ultra-high vacuum (UHV conditions, rotating pre layer for sample one and normal deposition for second one. Optical properties were measured via spectrophotometer in spectral range of 300-1100 nm wave length. The optical constants such as, real part of refractive index (n, imaginary part of refractive index (k, real and imaginary parts of dielectric function ε1, ε2 respectively and absorption coefficient (, were obtained from Kramers-Kronig analysis of reflectivity curves. Band-gap energy was also estimated for these films.

  7. Multi-electron beam system for high resolution electron beam induced deposition

    OpenAIRE

    Van Bruggen, M.J.

    2008-01-01

    The development of a multi-electron beam system is described which is dedicated for electron beam induced deposition (EBID) with sub-10 nm resolution. EBID is a promising mask-less nanolithography technique which has the potential to become a viable technique for the fabrication of 20-2 nm structures after 2013, as described by the International Technology Roadmap for Semiconductors (ITRS), or can be used for rapid prototyping in research applications. The key point is to combine the throughp...

  8. Hydrogen removal from e-beam deposited alumina thin films by oxygen ion beam

    International Nuclear Information System (INIS)

    Hydrogen interstitials and oxygen vacancies defects create energy levels in the band gap of alumina. This limits the application of alumina as a high-k dielectric. A low thermal budget method for removal of hydrogen from alumina is discussed. It is shown that bombardment of alumina films with low energy oxygen ion beam during electron beam evaporation deposition decreases the hydrogen concentration in the film significantly

  9. Electron-beam deposition of vanadium dioxide thin films

    International Nuclear Information System (INIS)

    Developing a reliable and efficient fabrication method for phase-transition thin-film technology is critical for electronic and photonic applications. We demonstrate a novel method for fabricating polycrystalline, switchable vanadium dioxide thin films on glass and silicon substrates and show that the optical switching contrast is not strongly affected by post-processing annealing times. The method relies on electron-beam evaporation of a nominally stoichiometric powder, followed by fast annealing. As a result of the short annealing procedure we demonstrate that films deposited on silicon substrates appear to be smoother, in comparison to pulsed laser deposition and sputtering. However, optical performance of e-beam evaporated film on silicon is affected by annealing time, in contrast to glass. (orig.)

  10. Electron-beam deposition of vanadium dioxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Marvel, R.E.; Appavoo, K. [Vanderbilt University, Interdisciplinary Materials Science Program, Nashville, TN (United States); Choi, B.K. [Vanderbilt University, Department of Electrical Engineering and Computer Science, Nashville, TN (United States); Nag, J. [Vanderbilt University, Department of Physics and Astronomy, Nashville, TN (United States); Haglund, R.F. [Vanderbilt University, Interdisciplinary Materials Science Program, Nashville, TN (United States); Vanderbilt University, Institute for Nanoscale Science and Engineering, Nashville, TN (United States); Vanderbilt University, Department of Physics and Astronomy, Nashville, TN (United States)

    2013-06-15

    Developing a reliable and efficient fabrication method for phase-transition thin-film technology is critical for electronic and photonic applications. We demonstrate a novel method for fabricating polycrystalline, switchable vanadium dioxide thin films on glass and silicon substrates and show that the optical switching contrast is not strongly affected by post-processing annealing times. The method relies on electron-beam evaporation of a nominally stoichiometric powder, followed by fast annealing. As a result of the short annealing procedure we demonstrate that films deposited on silicon substrates appear to be smoother, in comparison to pulsed laser deposition and sputtering. However, optical performance of e-beam evaporated film on silicon is affected by annealing time, in contrast to glass. (orig.)

  11. Optical and structural properties of Sb2S3/MgF2 multilayers for laser applications

    Science.gov (United States)

    Perales, F.; Agulló-Rueda, F.; Lamela, J.; de las Heras, C.

    2008-02-01

    Multilayers of MgF2 and Sb2S3 have been obtained by physical vapour deposition on glass substrates. Changes in the optical and structural properties have been studied as a function of annealing temperature and the number of layers. A drastic variation in optical transmission, microstrain and grain size is observed at a temperature near 225 °C. A comparison of the material properties of multilayers and a monolayer is carried out.

  12. An optimized nanoparticle separator enabled by electron beam induced deposition

    International Nuclear Information System (INIS)

    Size-based separations technologies will inevitably benefit from advances in nanotechnology. Direct-write nanofabrication provides a useful mechanism for depositing/etching nanoscale elements in environments otherwise inaccessible to conventional nanofabrication techniques. Here, electron beam induced deposition was used to deposit an array of nanoscale features in a 3D environment with minimal material proximity effects outside the beam-interaction region. Specifically, the membrane component of a nanoparticle separator was fabricated by depositing a linear array of sharply tipped nanopillars, with a singular pitch, designed for sub-50 nm nanoparticle permeability. The nanopillar membrane was used in a dual capacity to control the flow of nanoparticles in the transaxial direction of the array while facilitating the sealing of the cellular-sized compartment in the paraxial direction. An optimized growth recipe resulted which (1) maximized the growth efficiency of the membrane (which minimizes proximity effects) and (2) preserved the fidelity of the spacing between nanopillars (which maximizes the size-based gating quality of the membrane) while (3) maintaining sharp nanopillar apexes for impaling an optically transparent polymeric lid critical for device sealing.

  13. Magnetron deposition of TCO films using ion beam

    Science.gov (United States)

    Asainov, O.; Umnov, S.; Chinin, A.

    2015-11-01

    Thin films of tin oxide (TO) were deposited on the glass substrates at room temperature using reactive magnetron sputtering at various oxygen partial pressures. After the deposition the films were irradiated with argon ions beam. The change of the optical and electrical properties of the films depending on the irradiation time was studied. Films optical properties in the range of 300-1100 nm were investigated by photometry as well as their structural properties were studied using X-ray diffraction. Diffractometric research showed that the films, deposited on a substrate, have a crystal structure, and after argon ions irradiation they become quasi-crystalline (amorphous). It was found that the transmission increases proportionally with the irradiation time, but the surface resistance -disproportionally.

  14. A critical literature review of focused electron beam induced deposition

    Science.gov (United States)

    van Dorp, W. F.; Hagen, C. W.

    2008-10-01

    An extensive review is given of the results from literature on electron beam induced deposition. Electron beam induced deposition is a complex process, where many and often mutually dependent factors are involved. The process has been studied by many over many years in many different experimental setups, so it is not surprising that there is a great variety of experimental results. To come to a better understanding of the process, it is important to see to which extent the experimental results are consistent with each other and with the existing model. All results from literature were categorized by sorting the data according to the specific parameter that was varied (current density, acceleration voltage, scan patterns, etc.). Each of these parameters can have an effect on the final deposit properties, such as the physical dimensions, the composition, the morphology, or the conductivity. For each parameter-property combination, the available data are discussed and (as far as possible) interpreted. By combining models for electron scattering in a solid, two different growth regimes, and electron beam induced heating, the majority of the experimental results were explained qualitatively. This indicates that the physical processes are well understood, although quantitatively speaking the models can still be improved. The review makes clear that several major issues remain. One issue encountered when interpreting results from literature is the lack of data. Often, important parameters (such as the local precursor pressure) are not reported, which can complicate interpretation of the results. Another issue is the fact that the cross section for electron induced dissociation is unknown. In a number of cases, a correlation between the vertical growth rate and the secondary electron yield was found, which suggests that the secondary electrons dominate the dissociation rather than the primary electrons. Conclusive evidence for this hypothesis has not been found. Finally

  15. Ion beam sputter deposition of optical interference coatings

    International Nuclear Information System (INIS)

    Full text: Optical coatings produced by ion beam sputter deposition (IBSD) of oxide layers exhibit low scatter, low absorption, and environmental durability comparable to bulk materials. IBSD utilizes a broad beam ion source to sputter target materials in the presence of oxygen, producing oxide films. The process allows for the independent control of ion beam current, energy, and background gas pressure. The resulting films exhibit low defect densities, high purity, correct stoichiometry, amorphous structure, and high packing density. These properties allow the production of optical coatings with attributes highly desirable in a variety of scientific and industrial applications. Optical cavities utilizing low loss mirrors are used in gravitational wave research, quantum optics, spectroscopy, and numerous other areas of research. Industrial applications of IBSD coatings include the production of mirrors for lasers, including ring laser gyroscopes, corrosion resistant components for semiconductor process tools, and components for optical telecommunications. The IBSD process is easy to automate in contrast to other common processes of deposition which almost always require the presence of skilled operators. The ease of automation is a key factor in the economic viability of IBSD and its recent proliferation. The properties of IBSD coatings and the manufacturability and reproducibility made possible by full automation allow this process to play key enabling roles in research and industry. A review of the IBSD process, its history, and applications will be presented

  16. Substrate heating measurements in pulsed ion beam film deposition

    Energy Technology Data Exchange (ETDEWEB)

    Olson, J.C.; Davis, H.A.; Rej, D.J.; Waganaar, W.J. [Los Alamos National Lab., NM (United States); Tallant, D.R. [Cornell Univ., Ithaca, NY (United States). Materials Science and Engineering Dept.; Thompson, M.O. [Sandia National Labs., Albuquerque, NM (United States)

    1995-05-01

    Diamond-like Carbon (DLC) films have been deposited at Los Alamos National Laboratory by pulsed ion beam ablation of graphite targets. The targets were illuminated by an intense beam of hydrogen, carbon, and oxygen ions at a fluence of 15-45 J/cm{sup 2}. Ion energies were on the order of 350 keV, with beam current rising to 35 kA over a 400 ns ion current pulse. Raman spectra of the deposited films indicate an increasing ratio of sp{sup 3} to sp{sup 2} bonding as the substrate is moved further away from the target and further off the target normal. Using a thin film platinum resistor at varying positions, we have measured the heating of the substrate surface due to the kinetic energy and heat of condensation of the ablated material. This information is used to determine if substrate heating is responsible for the lack of DLC in positions close to the target and near the target normal. Latest data and analysis will be presented.

  17. Hemocompatibility of DLC coatings synthesized by ion beam assisted deposition

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Ion beam-assisted diamond-like carbon (DLC) coatings have beenused for growing the human platelet, fibrinogen, and albumin in the control environment in order to assess their hemocompatibility. The hard carbon films were prepared on polymethylmethacrylate (PMMA) at room temperature using ion beam assisted deposition (IBAD). Raman spectroscopic analysis proved that the carbon films on PMMA are diamond-like with a higher fraction of sp\\+3 bonds in the structure of mixed sp\\+2+sp\\+3 bonding. The blood protein adsorption tests showed that DLC coatings can adsorb more albumin and are slightly more fibrinogen than the PMMA chosen as a control sample. The platelets adhered on DLC coatings were reduced significantly in number. These results indicate good hemocompatibility of DLC coatings.

  18. Ion beam induced conductivity in chemically vapor deposited diamond films

    International Nuclear Information System (INIS)

    Polycrystalline diamond films deposited by the microwave plasma chemical vapor deposition (CVD) technique onto quartz substrates have been irradiated with 100 keV C and 320 keV Xe ions at room temperature and at 200 degree C. The dose dependence of the electrical conductivity measured in situ exhibited complicated, nonmonotonic behavior. High doses were found to induce an increase of up to ten orders of magnitude in the electrical conductivity of the film. The dose dependence of the conductivity for the CVD films was found to be very similar to that measured for natural, type IIa, single-crystal diamonds irradiated under identical conditions. This result suggests that the conduction mechanism in ion beam irradiated polycrystalline CVD diamond films is not dominated by grain boundaries and graphitic impurities as one might have expected, but rather is determined by the intrinsic properties of diamond itself

  19. Chemical vapour deposited diamonds for dosimetry of radiotherapeutical beams

    Energy Technology Data Exchange (ETDEWEB)

    Bucciolini, M.; Mazzocchi, S. [Firenze Univ., Firenze (Italy). Dipartimento di Fisiopatologia Clinica; INFN, Firenze (Italy); Borchi, E.; Bruzzi, M.; Pini, S.; Sciortino, S. [Firenze Univ., Firenze (Italy). Dipartimento di Energetica; INFN, Firenze (Italy); Cirrone, G.A.P.; Guttone, G.; Raffaele, L.; Sabini, M.G. [INFN, Catania (Italy). Laboratori Nazionali del Sud

    2002-07-01

    This paper deals with the application of synthetic diamond detectors to the clinical dosimetry of photon and electron beams. It has been developed in the frame of INFN CANDIDO project and MURST Cofin. Diamonds grown with CVD (Chemical Vapour Deposition) technique have been studied; some of them are commercial samples while others have been locally synthesised. Experiments have been formed using both on-line and off-line approaches. For the off-line measurements, TL (thermoluminescent) and TSC (thermally stimulated current) techniques have been used.

  20. Chemical vapour deposited diamonds for dosimetry of radiotherapeutical beams

    International Nuclear Information System (INIS)

    This paper deals with the application of synthetic diamond detectors to the clinical dosimetry of photon and electron beams. It has been developed in the frame of INFN CANDIDO project and MURST Cofin. Diamonds grown with CVD (Chemical Vapour Deposition) technique have been studied; some of them are commercial samples while others have been locally synthesised. Experiments have been formed using both on-line and off-line approaches. For the off-line measurements, TL (thermoluminescent) and TSC (thermally stimulated current) techniques have been used

  1. Growth of Ge films by cluster beam deposition

    CERN Document Server

    Xu, J L; Feng, J Y

    2002-01-01

    Ge epitaxial layers with reasonable quality were grown on the Si(1 1 1) substrates by cluster beam deposition (CBD) process. The growth temperature plays a dominant role in the epitaxial growth of Ge films. The substrate temperature for epitaxial growth is about 500 deg. C, which is lower than the reported critical temperature of Ge epitaxial growth by MBE and CVD. A stress induced phase transition of Ge lattice from cubic to tetragonal is also observed in the CBD process, and the mechanism is discussed.

  2. Radiation effects of electron-beam metal depositions on IGFET's

    International Nuclear Information System (INIS)

    Electron-beam radiation effects on n-channel IGFET parameters were studied. This paper summarizes the resulting surface- and dielectric-radiation effects obtained with a series of experiments incorporating e-gun metal deposition on MOS, MNOS, and SNOS structures. The results are compared with those using resistance-heated metal deposition for various thin-film compositions between the metal and silicon surfaces. A comparison is also made with the effects of controlled direct e-beam irradiation of the structures. The efficiency of quartz and aluminum thin films over MNOS structures, in reducing e-gun radiation effects, is evaluated for double-level metallurgy structures. The effect of different thermal-annealing conditions for offsetting the radiation effects is determined. It is concluded that e-gun metallization causes large negative voltage shifts in MOS, MNOS, and SNOS devices. While MOS threshold shifts are fully ''annealable'', residual MNOS and SNOS V/sub T/ shifts are observed after an anneal of 3500/4500C. Thin films of quartz and aluminum over MOS and MNOS structures effectively reduce radiation effects. Other IGFET parameters are not substantially affected by e-gun radiation

  3. Beam non-uniformity smoothing using density valley formed by heavy ion beam deposition in inertial confinement fusion fuel pellet

    International Nuclear Information System (INIS)

    We study the beam nonuniformity smoothing effect of radiation transport in the density valley formed by an ion-beam deposition in a heavy ion-beam inertial confinement fusion pellet by numerical simulations. The simulation results show that the radiation energy is confined in the density valley, and the beam nonuniformity can be smoothed out by the radiation transport along the density valley. In addition, an estimation for the Rayleigh-Taylor instability during the implosion phase is also presented. (author)

  4. Energy deposition studies for the LBNE beam absorber

    Energy Technology Data Exchange (ETDEWEB)

    Rakhno, Igor L.; Mokhov, Nikolai V.; Tropin, Igor S.

    2015-01-29

    Results of detailed Monte Carlo energy deposition studies performed for the LBNE absorber core and the surrounding shielding with the MARS15 code are described. The model of the entire facility, that includes a pion-production target, focusing horns, target chase, decay channel, hadron absorber system – all with corresponding radiation shielding – was developed using the recently implemented ROOT-based geometry option in the MARS15 code. This option provides substantial flexibility and automation when developing complex geometry models. Both normal operation and accidental conditions were studied. Various design options were considered, in particular the following: (i) filling the decay pipe with air or helium; (ii) the absorber mask material and shape; (iii) the beam spoiler material and size. Results of detailed thermal calculations with the ANSYS code helped to select the most viable absorber design options.

  5. Energy deposition studies for the LBNE beam absorber

    CERN Document Server

    Rakhno, Igor L; Tropin, Igor S

    2015-01-01

    Results of detailed Monte Carlo energy deposition studies performed for the LBNE absorber core and the surrounding shielding with the MARS15 code are described. The model of the entire facility, that includes a pion-production target, focusing horns, target chase, decay channel, hadron absorber system -- all with corresponding radiation shielding -- was developed using the recently implemented ROOT-based geometry option in the MARS15 code. This option provides substantial flexibility and automation when developing complex geometry models. Both normal operation and accidental conditions were studied. Various design options were considered, in particular the following: (i) filling the decay pipe with air or helium; (ii) the absorber mask material and shape; (iii) the beam spoiler material and size. Results of detailed thermal calculations with the ANSYS code helped to select the most viable absorber design options.

  6. Dual ion beam deposition of carbon films with diamondlike properties

    Science.gov (United States)

    Mirtich, M. J.; Swec, D. M.; Angus, J. C.

    1984-01-01

    A single and dual ion beam system was used to generate amorphous carbon films with diamond like properties. A methane/argon mixture at a molar ratio of 0.28 was ionized in the low pressure discharge chamber of a 30-cm-diameter ion source. A second ion source, 8 cm in diameter was used to direct a beam of 600 eV Argon ions on the substrates (fused silica or silicon) while the deposition from the 30-cm ion source was taking place. Nuclear reaction and combustion analysis indicate H/C ratios for the films to be 1.00. This high value of H/C, it is felt, allowed the films to have good transmittance. The films were impervious to reagents which dissolve graphitic and polymeric carbon structures. Although the measured density of the films was approximately 1.8 gm/cu cm, a value lower than diamond, the films exhibited other properties that were relatively close to diamond. These films were compared with diamondlike films generated by sputtering a graphite target.

  7. Cobalt cluster-assembled thin films deposited by low energy cluster beam deposition: Structural and magnetic investigations of deposited layers

    International Nuclear Information System (INIS)

    Cobalt cluster-assembled thin films were deposited on amorphous-carbon-coated copper grids and on silicon substrates at room temperature by low energy cluster beam deposition. Characterizations using high-resolution transmission electronic microscopy and atomic force microscopy reveal randomly stacked agglomerates of 9-11 nm diameter, which are themselves composed of small 3.6 nm diameter fcc cobalt clusters. The films are ferromagnetic up to room temperature and above, which implies that the clusters are exchange coupled. The approach to saturation is analyzed within the random anisotropy model. The values of the exchange coefficient A and the anisotropy constant K then derived are discussed. The temperature dependence of the coercivity below 100 K is discussed in terms of thermal activation effects. All results indicate that the fundamental entity governing the magnetic behaviors is constituted by the 9-11 nm diameter agglomerates rather than by the clusters themselves

  8. Nanostructured component fabrication by electron beam-physical vapor deposition

    Science.gov (United States)

    Singh, Jogender; Wolfe, Douglas E.

    2005-08-01

    Fabrication of cost-effective, nano-grained net-shaped components has brought considerable interest to Department of Defense, National Aeronautics and Space Administration, and Department of Energy. The objective of this paper is to demonstrate the versatility of electron beam-physical vapor deposition (EB-PVD) technology in engineering new nanostructured materials with controlled microstructure and microchemistry in the form of coatings and net-shaped components for many applications including the space, turbine, optical, biomedical, and auto industries. Coatings are often applied on components to extent their performance and life under severe environmental conditions including thermal, corrosion, wear, and oxidation. Performance and properties of the coatings depend upon their composition, microstructure, and deposition condition. Simultaneous co-evaporation of multiple ingots of different compositions in the high energy EB-PVD chamber has brought considerable interest in the architecture of functional graded coatings, nano-laminated coatings, and design of new structural materials that could not be produced economically by conventional methods. In addition, high evaporation and condensate rates allowed fabricating precision net-shaped components with nanograined microstructure for various applications. Using EB-PVD, nano-grained rhenium (Re) coatings and net-shaped components with tailored microstructure and properties were fabricated in the form of tubes, plates, and Re-coated spherical graphite cores. This paper will also present the results of various metallic and ceramic coatings including chromium, titanium carbide (TiC), titanium diboride (TiB2), hafnium nitride (HfN), titanium-boron-carbonitride (TiBCN), and partially yttria stabilized zirconia (YSZ) TBC coatings deposited by EB-PVD for various applications.

  9. Focused electron beam induced deposition as a tool to create electron vortices.

    Science.gov (United States)

    Béché, A; Winkler, R; Plank, H; Hofer, F; Verbeeck, J

    2016-01-01

    Focused electron beam induced deposition (FEBID) is a microscopic technique that allows geometrically controlled material deposition with very high spatial resolution. This technique was used to create a spiral aperture capable of generating electron vortex beams in a transmission electron microscope (TEM). The vortex was then fully characterized using different TEM techniques, estimating the average orbital angular momentum to be ∼0.8ℏ per electron with almost 60% of the beam ending up in the ℓ=1 state. PMID:26432987

  10. Optical properties of MgF2 nano-composite films dispersed with noble metal nanoparticles synthesized by sol-gel method

    Science.gov (United States)

    Wakaki, Moriaki; Soujima, Nobuaki; Shibuya, Takehisa

    2015-03-01

    Porous MgF2 films synthesized by a sol-gel method exhibit the lowest refractive index among the dielectric optical materials and are the most useful materials for the anti-reflection coatings. On the other hand, surface plasmon resonance (SPR) absorptions of noble metal nanoparticles in various solid matrices have been extensively studied. New functional materials like a SERS (Surface Enhanced Raman Spectroscopy) tips are expected by synthesizing composite materials between porous MgF2 films featured by the network of MgF2 nanoparticles and noble metal nanoparticles introduced within the network. In this study, fundamental physical properties including morphology and optical properties are characterized for these materials to make clear the potential of the composite system. Composite materials of MgF2 films dispersed with noble metal (Ag, Au) nanoparticles were prepared using the sol-gel technique with various annealing temperatures and densities of noble metal nanoparticles. The structural morphology was analyzed by an X-ray diffractometer (XRD) and a scanning electron microscope (SEM). The size and shape distributions of the metal nanoparticles were observed using a transmission electron microscope (TEM). The optical properties of fabricated composite films were characterized by UV-Vis-NIR and FT-IR spectrophotometers. The absorption spectra due to the surface plasmon resonance (SPR) of the metal nanoparticles were analyzed using the dielectric function considering the effective medium approximation, typically Maxwell-Garnett model. The Raman scattering spectra were also studied to check the enhancement effect of specimen dropped on the MgF2: Ag nano-composite films deposited on Si substrate. Enhancement of the Raman intensity of pyridine solution specimen was observed.

  11. Texture development of CeO2 thin films deposited by ion beam assisted deposition

    International Nuclear Information System (INIS)

    CeO2 thin films were prepared on amorphous quartz glass substrates by the ion beam assisted deposition (IBAD) technique at room temperature. In order to control both the in-plane and out-of-plane texture of the films, a special geometrical arrangement of the ion sources, the target, and the substrate was used. A new concept, considering the role of reflected particles from the target, which we call self-IBAD, was introduced. The structural properties of the CeO2 films were investigated by x-ray diffraction. Good biaxially textured films were obtained with out-of-plane mosaic spreads of 3.0 deg. and in-plane alignment of 10.8 deg. C

  12. Characteristics of MoSx films deposited by ion beam assistance

    International Nuclear Information System (INIS)

    For MoSx films deposited by ion beam assistance, the effect of bombarded ion species, deposition mode, substrate materials and humidity of store environment etc on the properties of these films has been studied. Experimental results indicated that the effect of these factors on films can not be ignored both in the film's deposition and in uses

  13. Indium Tin Oxide-Magnesium Fluoride Co-Deposited Films for Spacecraft Applications

    Science.gov (United States)

    Dever, Joycer A.; Rutledge, Sharon K.; Hambourger, Paul D.; Bruckner, Eric; Ferrante, Rhea; Pal, Anna Marie; Mayer, Karen; Pietromica, Anthony J.

    1998-01-01

    Highly transparent coatings with a maximum sheet resistivity between 10(exp 8) and 10(exp 9) ohms/square are desired to prevent charging of solar arrays for low Earth polar orbit and geosynchronous orbit missions. Indium tin oxide (ITO) and magnesium fluoride (MgF2) were ion beam sputter co-deposited onto fused silica substrates and were evaluated for transmittance, sheet resistivity and the effects of simulated space environments including atomic oxygen (AO) and vacuum ultraviolet (VUV) radiation. Optical properties and sheet resistivity as a function of MgF2 content in the films will be presented. Films containing 8.4 wt.% MgF2 were found to be highly transparent and provided sheet resistivity in the required range. These films maintained a high transmittance upon exposure to AO and to VUV radiation, although exposure to AO in the presence of charged species and intense electromagnetic radiation caused significant degradation in film transmittance. Sheet resistivity of the as-fabricated films increased with time in ambient conditions. Vacuum beat treatment following film deposition caused a reduction in sheet resistivity. However, following vacuum heat treatment, sheet resistivity values remained stable during storage in ambient conditions.

  14. Beam-Induced Deposition of Thin Metallic Films.

    Science.gov (United States)

    Funsten, Herbert Oliver, III

    1990-01-01

    Ion and electron beam induced deposition (BID) of thin (1 μm), conductive films is accomplished by dissociating and removing the nonmetallic components of an adsorbed, metal-based, molecular gas. Current research has focused primarily on room temperature (monolayer adsorption) BID using electrons and slow, heavy ions. This study investigates low temperature (50 to 200 K) BID in which the condensation of the precursor gases (SnCl _4 and (CH_3) _4Sn) maximizes the efficiency of the incident radiation which can create and remove nonmetallic fragments located several monolayers below the film surface. The desired properties of the residual metallic films are produced by using as incident radiation either nuclear (35 keV Ar ^+) or electronic (2 keV electrons, 25 keV H^+, or 50 keV H ^+) energy loss mechanisms. Residual films are analyzed ex situ by Scanning Electron Microscopy (SEM), thickness measurements, resistivity measurements, Rutherford Backscattering Spectroscopy (RBS), and infrared spectroscopy. Low temperature BID film growth models, which are derived from both a computer simulation and a mathematical analysis, closely agree. Both the fragmentation and sputtering cross sections for a particular ion and energy are derived for films created from (CH_3) _4Sn. The fragmentation cross section, which corresponds to film growth, is roughly related to the electronic stopping power by the 1.9 power. The loss of carbon in films which were created from (CH_3) _4Sn is strongly dependent on the nuclear stopping power. Film growth rates for low temperature BID have been found to be 10 times those of room temperature BID.

  15. Ion-beam-assisted deposition and ion beam synthesis of wear resistant coatings on technical surfaces

    International Nuclear Information System (INIS)

    An ion implanter with a non-mass-separated ion beam, already used for experiments as well as industrial applications, was equipped with an electron-gun evaporator to allow for simultaneous or sequential implantation and coating. Using this equipment, ion-beam-assited deposition (IBAD) of different layers, and in particular the formation of layers of TiN on steel with very good adhesion, was possible. To produce TiN, titanium was evaporated and nitrogen was implanted. The maximum growth rate of the TiN films was 1 nm s-1. Examinations showed superior wear properties in comparison with ion-plated layers and an unusual high Knoop microhardness. Under certain experimental conditions, the stoichiometric ratio was found to be 1:1 even if the ion density was varied slightly, making the IBAD process easily controllable. The layers did not have the yellow color typical of ion-plated TiN layers but were neutral gray. Nevertheless, electron diffraction investigations confirmed the typical crystalline structure of TiN. Analytical investigations were performed and compared with those of ion-plated TiN. Details of the equipment, including operation conditions, as well as experimental results of film properties will be reported. (orig.)

  16. Effects of oxygen pressure in reactive ion beam sputter deposition of zirconium oxides

    International Nuclear Information System (INIS)

    The mechanism of reactive ion beam sputtering is investigated. The experimental results indicate that the pressure decrease during sputtering, the properties of Zr--O films, and the deposition rate are all strongly influenced by oxygen partial pressure. A new model which takes into account the gettering action of the deposition material and deals with the number of sputtered and gaseous particles is presented for reactive ion beam sputtering of metal. The theoretical values are compared with experimental results of the reactive ion beam sputtering. It is found that the calculated values agree extremely well with the oxygen partial pressure decrease and the deposition rate measured experimentally

  17. Diffusion and Interface Reaction of Cu/Si(100) Films Prepared by Cluster Beam Deposition

    Institute of Scientific and Technical Information of China (English)

    GAO Xing-Xin; JIA Yan-Hui; LI Gong-Ping; CHO Seong-Jin; KIM Hee

    2011-01-01

    Cu thin films are deposited on Si(100) substrates by neutral cluster beams and ionized cluster beams. The atomic diffusion and interface reaction between the Cu films and the Si substrates of as-deposited and annealed at different temperatures(230℃, 450℃, 500℃and 600℃) are investigated by Rutherford backscatteringspectrometry(RBS)and x-ray diffraction(XRD). Some significant results are obtained on the following aspects:(1) For the Cu/Si(100)samples prepared by neutral cluster beams and ionized cluster beams at Va=0 kV, atomic diffusion phenomena are observed clearly in the as-deposited samples. With the increase of annealing temperature, the interdiffusion becomes more apparent. However, the diffusion intensities of the RBS spectra of the Cu/Si(100) films using neutral cluster beams are always higher than that of the Cu/Si(100) films using ionized cluster beams at Va=OkV in the as-deposited and samples annealed at the same temperature. The compound of Cu3Si is observed in the as-deposited samples.(2) For the Cu/Si(100) samples prepared by ionized cluster beams at Va=1, 3, 5 kV,atomic diffusion phenomena are observed in the as-deposited samples at Va=1, 5 kV. For the samples prepared at Va=3 kV, the interdiffusion phenomenon is observed until 500℃ annealing temperature. The reason for the difference is discussed.

  18. Microstructure-related properties of magnesium fluoride films at 193nm by oblique-angle deposition.

    Science.gov (United States)

    Guo, Chun; Kong, Mingdong; Lin, Dawei; Liu, Cunding; Li, Bincheng

    2013-01-14

    Magnesium fluoride (MgF2) films deposited by resistive heating evaporation with oblique-angle deposition have been investigated in details. The optical and micro-structural properties of single-layer MgF2 films were characterized by UV-VIS and FTIR spectrophotometers, scanning electron microscope (SEM), atomic force microscope (AFM), and x-ray diffraction (XRD), respectively. The dependences of the optical and micro-structural parameters of the thin films on the deposition angle were analyzed. It was found that the MgF2 film in a columnar microstructure was negatively inhomogeneous of refractive index and polycrystalline. As the deposition angle increased, the optical loss, extinction coefficient, root-mean-square (rms) roughness, dislocation density and columnar angle of the MgF2 films increased, while the refractive index, packing density and grain size decreased. Furthermore, IR absorption of the MgF2 films depended on the columnar structured growth. PMID:23388989

  19. Indium-tin-oxide thin film deposited by a dual ion beam assisted e-beam evaporation system

    International Nuclear Information System (INIS)

    Indium-tin-oxide (ITO) thin films were deposited on polycarbonate (PC) substrates at low temperatures (<90 deg. C) by a dual ion beam assisted e-beam evaporation system, where one gun (gun 1) is facing ITO flux and the other gun (gun 2) is facing the substrate. In this experiment, effects of rf power and oxygen flow rate of ion gun 2 on the electrical and optical properties of depositing ITO thin films were investigated. At optimal deposition conditions, ITO thin films deposited on the PC substrates larger than 20 cmx20 cm showed the sheet resistance of less than 40 Ω/sq., the optical transmittance of above 90%, and the uniformity of about 5%

  20. Physico-chemical study of the focused electron beam induced deposition process

    OpenAIRE

    Bret, Tristan; Hoffmann, Patrik

    2007-01-01

    The focused electron beam induced deposition process is a promising technique for nano and micro patterning. Electrons can be focused in sub-angström dimensions, which allows atomic-scale resolution imaging, analysis, and processing techniques. Before the process can be used in controlled applications, the precise nature of the deposition mechanism must be described and modelled. The aim of this research work is to present a physical and chemical description of the focused electron beam induc...

  1. Laser controlled deposition of metal microstructures via nondiffracting Bessel beam illumination

    Science.gov (United States)

    Drampyan, Rafael; Leonov, Nikita; Vartanyan, Tigran

    2016-04-01

    The technique of the laser controlled deposition of sodium and rubidium deposits on the sapphire substrate is presented. The metals were deposited on the clean sapphire substrate from the vapor phase contained in the evacuated and sealed cell. We use an axicon to produce a non-diffracting Bessel beam out of the beam got from the cw diode laser with 200 mW power at the wavelength of 532 nm. After 30 minutes of the laser-controlled deposition the substrates were examined in the optical microscope. The obtained metal deposits form the sharp-cut circles with the pitch of 10 μm, coincident with the tens of dark rings of the Bessel beam. Reduction of the laser power leads to the build up of the continuous metal film over the whole substrate.

  2. Friction and Wear of Ion-Beam-Deposited Diamondlike Carbon on Chemical-Vapor-Deposited, Fine-Grain Diamond

    Science.gov (United States)

    Miyoshi, Kazuhisa; Wu, Richard L. C.; Lanter, William C.

    1996-01-01

    Friction and wear behavior of ion-beam-deposited diamondlike carbon (DLC) films coated on chemical-vapor-deposited (CVD), fine-grain diamond coatings were examined in ultrahigh vacuum, dry nitrogen, and humid air environments. The DLC films were produced by the direct impact of an ion beam (composed of a 3:17 mixture of Ar and CH4) at ion energies of 1500 and 700 eV and an RF power of 99 W. Sliding friction experiments were conducted with hemispherical CVD diamond pins sliding on four different carbon-base coating systems: DLC films on CVD diamond; DLC films on silicon; as-deposited, fine-grain CVD diamond; and carbon-ion-implanted, fine-grain CVD diamond on silicon. Results indicate that in ultrahigh vacuum the ion-beam-deposited DLC films on fine-grain CVD diamond (similar to the ion-implanted CVD diamond) greatly decrease both the friction and wear of fine-grain CVD diamond films and provide solid lubrication. In dry nitrogen and in humid air, ion-beam-deposited DLC films on fine-grain CVD diamond films also had a low steady-state coefficient of friction and a low wear rate. These tribological performance benefits, coupled with a wider range of coating thicknesses, led to longer endurance life and improved wear resistance for the DLC deposited on fine-grain CVD diamond in comparison to the ion-implanted diamond films. Thus, DLC deposited on fine-grain CVD diamond films can be an effective wear-resistant, lubricating coating regardless of environment.

  3. Enhancement of neutral beam deposition in hydrogen discharge using carbon pellet injection in LHD

    International Nuclear Information System (INIS)

    The central ion temperature in the large helical device (LHD), as measured by charge-exchange recombination spectroscopy, has been improved to a record 5.6 keV by combining 21 MW of neutral beam heating with the injection of a carbon pellet. The intensity of the neutral beam emission of the hydrogen Balmer line (Hα: n=3 → 2) was observed to weaken along the beam injection axis following the carbon pellet injection due to the increased beam attenuation. The beam-emission intensity was reconstructed by calculating the density distribution, and the beam-stopping coefficients, along a beam injection axis and was found to fit well to the measured beam-emission for a mixed hydrogen and carbon target plasma. The dynamics of the neutral beam deposition power and the carbon fraction were estimated from the beam-emission measurements using data from ADAS. We conclude that the beam deposition power in a carbon pellet discharge is enhanced over that of a pure hydrogen discharge. (author)

  4. Characteristics of deposition process of thin films by ion-beam evaporation

    International Nuclear Information System (INIS)

    Intense pulsed ion-beam evaporation (IBE) has been proposed as one of the new techniques for the preparation of thin films. To understand the basic process of thin film deposition, the energy deposition on the substrate surface by ablation plasma was measured by using calorimetric technique. The characteristics of prepared thin films were studied with deposition energy. In addition, the substrate temperature was calculated, based on the experimental results, by using one-dimensional simulations only considering heat conduction. (author)

  5. Lateral resolution in focused electron beam-induced deposition: scaling laws for pulsed and static exposure

    International Nuclear Information System (INIS)

    In this work, we review the single-adsorbate time-dependent continuum model for focused electron beam-induced deposition (FEBID). The differential equation for the adsorption rate will be expressed by dimensionless parameters describing the contributions of adsorption, desorption, dissociation, and the surface diffusion of the precursor adsorbates. The contributions are individually presented in order to elucidate their influence during variations in the electron beam exposure time. The findings are condensed into three new scaling laws for pulsed exposure FEBID (or FEB-induced etching) relating the lateral resolution of deposits or etch pits to surface diffusion and electron beam exposure dwell time for a given adsorbate depletion state. (orig.)

  6. Microstructure and properties of silver films obtained using ion beam composite deposition

    International Nuclear Information System (INIS)

    Using ion beam composite deposition method Magnetron sputtering deposition, soft metal solid lubricant of Ag film was grown on 9Crl8 steel substrate. The microstructures and friction properties were measured by means of the hundred cell knife scratch method, MS-T3000 multi-meter friction and wear testing and scanning electron microscopy. The results showed that compared with the magnetron sputtering method, a transition layer bonded with chemical metallurgy and mechanical engagement is formed after ion beam composite deposition. The transition layer can be attributed to the strong adhesion between the film and the substrate. (authors)

  7. Beam-induced energy deposition issues in the Very Large Hadron Collider

    CERN Document Server

    Mokhov, N V; Foster, G W

    2001-01-01

    Energy deposition issues are extremely important in the Very Large Hadron Collider (VLHC) with huge energy stored in its 20 TeV (Stage-1) and 87.5 TeV (Stage-2) beams. The status of the VLHC design on these topics, and possible solutions of the problems are discussed. Protective measures are determined based on the operational and accidental beam loss limits for the prompt radiation dose at the surface, residual radiation dose, ground water activation, accelerator components radiation damage and quench stability. The beam abort and beam collimation systems are designed to protect accelerator from accidental and operational beam losses, IP region quadrupoles from irradiation by the products of beam-beam collisions, and to reduce the accelerator-induced backgrounds in the detectors. (7 refs).

  8. Electron-stimulated purification of platinum nanostructures grown via focused electron beam induced deposition

    Directory of Open Access Journals (Sweden)

    Brett B. Lewis

    2015-04-01

    Full Text Available Platinum–carbon nanostructures deposited via electron beam induced deposition from MeCpPt(IVMe3 are purified during a post-deposition electron exposure treatment in a localized oxygen ambient at room temperature. Time-dependent studies demonstrate that the process occurs from the top–down. Electron beam energy and current studies demonstrate that the process is controlled by a confluence of the electron energy loss and oxygen concentration. Furthermore, the experimental results are modeled as a 2nd order reaction which is dependent on both the electron energy loss density and the oxygen concentration. In addition to purification, the post-deposition electron stimulated oxygen purification process enhances the resolution of the EBID process due to the isotropic carbon removal from the as-deposited materials which produces high-fidelity shape retention.

  9. Structural properties of thermoelectric CoSb3 skutterudite thin films prepared by molecular beam deposition

    International Nuclear Information System (INIS)

    Highlights: • Different methods were used to deposit Co–Sb thin film by molecular beam deposition. • The phase formation is strongly dependent on the Sb content of the film. • The fabrication of high-quality single phase skutterudite thin films could be shown. • The grain size of the films is very sensitive to the used deposition parameters. • It was shown, that large deposition rates support the formation of parasitic phases. - Abstract: The research field of thermoelectricity was renewed by the progress made in nanostructuring approaches and by the investigation of new material groups as skutterudites, whose most promising representative is CoSb3. In this work Co–Sb thin films with a thickness of 30 nm were deposited by molecular beam deposition at different substrate temperatures as well as on non-heated substrates followed by a post-annealing step. An extended investigation of the phase formation in dependence of deposition method and parameters, film composition, and post-treatment is given. The presented results provide different routes to achieve high quality single phase films. It was also demonstrated that the grain size of the CoSb3 thin films is very sensitive to the used deposition method and especially on the substrate temperature during deposition. A controllable grain size by changing the deposition parameters could be a key feature for the optimization of the thermoelectric properties, since especially the thermal conductivity should strongly depend on the grain size due to enhanced grain boundary scattering of phonons

  10. Beam induced deposition of platinum using a helium ion microscope

    NARCIS (Netherlands)

    Sanford, C.A.; Stern, L.; Barriss, L.; Farkas, L.; DiManna, M.; Mello, R.; Maas, D.J.; Alkemade, P.F.A.

    2009-01-01

    Helium ion microscopy is now a demonstrated practical technology that possesses the resolution and beam currents necessary to perform nanofabrication tasks, such as circuit edit applications. Due to helium’s electrical properties and sample interaction characteristics relative to gallium, it is like

  11. Beam induced deposition of platinum using a helium ion microscope

    NARCIS (Netherlands)

    Sanford, C.A.; Stern, L.; Barriss, L.; Farkas, L.; DiManna, M.; Mello, R.; Maas, D.J.; Alkemade, P.F.A.

    2009-01-01

    Helium ion microscopy is now a demonstrated practical technology that possesses the resolution and beam currents necessary to perform nanofabrication tasks, such as circuit edit applications. Due to helium's electrical properties and sample interaction characteristics relative to gallium, it is like

  12. Energy deposition, heat flow, and rapid solidification during laser and electron beam irradiation of materials

    International Nuclear Information System (INIS)

    The fundamentals of energy deposition, heat flow, and rapid solidification during energy deposition from lasers and electron beams is reviewed. Emphasis is placed on the deposition of energy from pulsed sources (10 to 100 ns pulse duration time) in order to achieve high heating and cooling rates (108 to 10100C/s) in the near surface region. The response of both metals and semiconductors to pulsed energy deposition is considered. Guidelines are presented for the choice of energy source, wavelength, and pulse duration time

  13. Diffusion and Interface Reaction of Cu/Si (100) Films Prepared by Cluster Beam Deposition

    International Nuclear Information System (INIS)

    Cu thin films are deposited on Si (100) substrates by neutral cluster beams and ionized cluster beams. The atomic diffusion and interface reaction between the Cu films and the Si substrates of as-deposited and annealed at different temperatures (230°C, 450°C, 500°C and 600°C) are investigated by Rutherford backscattering spectrometry (RBS) and x-ray diffraction (XRD). Some significant results are obtained on the following aspects: (1) For the Cu/Si(100) samples prepared by neutral cluster beams and ionized cluster beams at Va = 0kV, atomic diffusion phenomena are observed clearly in the as-deposited samples. With the increase of annealing temperature, the interdiffusion becomes more apparent. However, the diffusion intensities of the RBS spectra of the Cu/Si(100) films using neutral cluster beams are always higher than that of the Cu/Si(100) films using ionized cluster beams at Va=0kV in the as-deposited and samples annealed at the same temperature. The compound of Cu3Si is observed in the as-deposited samples. (2) For the Cu/Si(100) samples prepared by ionized cluster beams at Va=1, 3, 5kV, atomic diffusion phenomena are observed in the as-deposited samples at Va=1, 5kV. For the samples prepared at Va = 3kV, the interdiffusion phenomenon is observed until 500°C annealing temperature. The reason for the difference is discussed. (atomic and molecular physics)

  14. Enhanced solar water splitting of electron beam irradiated titania photoanode by electrostatic spray deposition

    International Nuclear Information System (INIS)

    Highlights: • TiO2 thin-film photoelectrodes were prepared by electrostatic spray deposition (ESD). • Photoactivity of an electrosprayed titania film could be greatly enhanced by the use of electron beam irradiation. • The application of the electron beam was found to increase the photocurrent density threefold over a non-electron beam-treated film. - Abstract: Surface modifications are often made to titania films to improve its photocatalytic performance in water splitting. We herein introduced electron beam irradiation to enhance the photocatalytic activities of an electro-sprayed titania film for solar water splitting application. The film was fabricated by a facile and scalable electrostatic spraying deposition. According to SEM, X-ray diffraction, and Raman data, electron beam densified the film and improved its crystallinity. Absorbance data indicated that the band gap of the E-beam film reduced, which in turn covered the wider range of absorbed light. These modifications increased oxygen vacancies or defects, which enhanced mobility and separation of electrons and holes. As a result, the E-beam film exhibited a threefold increase in the photocurrent density, compared to that of the non-E-beam film. This electrosprayed titania film was used as a photoanode while the reference and counter electrodes involved in the generation of hydrogen were made of Ag/AgCl and platinum, respectively. The intensity of the UV light illumination used was 1 mW/cm2

  15. Electrochemical evaluation of under-deposit corrosion and its inhibition using the wire beam electrode method

    Energy Technology Data Exchange (ETDEWEB)

    Tan Yongjun, E-mail: yj.tan@curtin.edu.a [Western Australian Corrosion Research Group, Department of Chemistry, Curtin University, GPO Box U1987, Perth (Australia); Fwu, Young; Bhardwaj, Kriti [Western Australian Corrosion Research Group, Department of Chemistry, Curtin University, GPO Box U1987, Perth (Australia)

    2011-04-15

    Research highlights: A new experiment method for evaluating under-deposit corrosion and its inhibitors. Under-deposit corrosion did not occur in a CO{sub 2} saturated pure brine solution. Inhibitor imidazoline addition and O{sub 2} contamination initiated under-deposit corrosion. Inhibitor imidazoline reduced general corrosion but enhanced localised corrosion. - Abstract: A new experimental method has been applied to evaluate under-deposit corrosion and its inhibition by means of an electrochemically integrated multi-electrode array, namely the wire beam electrode (WBE). Maps showing galvanic current and corrosion potential distributions were measured from a WBE surface that was partially covered by sand. Under-deposit corrosion did not occur during the exposure of the WBE to carbon dioxide saturated brine under ambient temperature. The introduction of corrosion inhibitor imidazoline and oxygen into the brine was found to significantly affect the patterns and rates of corrosion, leading to the initiation of under-deposit corrosion over the WBE.

  16. Tribological properties of ion beam deposited diamond-like carbon film on silicon nitride

    International Nuclear Information System (INIS)

    The present article reports on the physical characterization and tribological properties of diamond-like carbon (DLC) films deposited on structural Si3N4 substrates. The films were deposited by the direct ion beam deposition technique. The ion beam was produced by plasma discharge of pre-mixed methane and hydrogen gas in a Kaufman-type ion source. The deposited films were found to be amorphous and contained about 70% carbon and 30% hydrogen. The friction coefficient of an uncoated Si3N4 ball on a DLC coated Si3N4 disc starts at about 0.2, then decreases rapidly to 0.1-0.15 with increasing sliding distance. Increasing humidity results in a slight increase in friction coefficient, but a significant decrease in wear factor. The wear factor for the tests at ≅60% rh (relative humidity) are about an order of magnitude smaller than the tests at 3% rh. (orig.)

  17. Birth: A Neutral Beam Deposition Code for Non-Circular Tokamak Plasma

    International Nuclear Information System (INIS)

    A new neutral beam deposition code has been developed which is capable of calculating fast ion deposition profiles including the orbit correction. The code incorporates any injection geometry and a non-circular cross-section plasma with a variable elongation and an outward shift of the magnetic flux surface. Typical CPU time on a KL DEC-10 computer is 10--20 s and 5--10 s with and without the orbit correction, respectively. This is shorter by an order of magnitude than that of other codes, e.g., Monte Carlo beam deposition codes. The power deposition profile calculated by this code is in good agreement with that calculated by the Monte Carlo code which was developed to calculate the complete behaviors of the fast ions in circular plasmas

  18. Thermal stability of AlN films prepared by ion beam assisted deposition

    International Nuclear Information System (INIS)

    Highlights: • AlN films were deposited by dual ion beam sputtering. • Optical constants were measured by spectroscopic ellipsometry. • Diffuse reflection was measured by UV–vis spectroscopy. • Oxidized process of the AlN films was studied. - Abstract: The thermal stability of AlN films deposited by ion beam assisted deposition was performed at 600 °C for 192 h under air ambient. The composition, morphology and optical properties were studied by X-ray photoelectron spectrometer, transmission electron microscopy, scanning electron microscopy, spectroscopic ellipsometry and UV–vis spectroscopy. The results show that the deposited film is polycrystalline, smooth, dense and homogenous. The oxidation of grain boundary takes place due to the element diffusion in the polycrystalline material. Oxidation produces amorphous oxide layers on the surface of film. As annealing time increases, surface roughness and diffuse reflection increase. Annealing has little influence on refractive index and extinction coefficient

  19. Thermal stability of AlN films prepared by ion beam assisted deposition

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Jian-ping [Department of Energy Material and Technology, General Research Institute for Nonferrous Metals, Beijing 100088 (China); Liu, Xiao-peng, E-mail: xpgliu@yahoo.com.cn [Department of Energy Material and Technology, General Research Institute for Nonferrous Metals, Beijing 100088 (China); Fu, Zhi-qiang, E-mail: fuzq@cugb.edu.cn [School of Engineering and Technology, China University of Geosciences (Beijing), Beijing 100083 (China); Wang, Xiao-jing; Hao, Lei [Department of Energy Material and Technology, General Research Institute for Nonferrous Metals, Beijing 100088 (China)

    2015-08-30

    Highlights: • AlN films were deposited by dual ion beam sputtering. • Optical constants were measured by spectroscopic ellipsometry. • Diffuse reflection was measured by UV–vis spectroscopy. • Oxidized process of the AlN films was studied. - Abstract: The thermal stability of AlN films deposited by ion beam assisted deposition was performed at 600 °C for 192 h under air ambient. The composition, morphology and optical properties were studied by X-ray photoelectron spectrometer, transmission electron microscopy, scanning electron microscopy, spectroscopic ellipsometry and UV–vis spectroscopy. The results show that the deposited film is polycrystalline, smooth, dense and homogenous. The oxidation of grain boundary takes place due to the element diffusion in the polycrystalline material. Oxidation produces amorphous oxide layers on the surface of film. As annealing time increases, surface roughness and diffuse reflection increase. Annealing has little influence on refractive index and extinction coefficient.

  20. Electron-beam-directed vapor deposition of multifunctional structures for electrochemical storage

    Science.gov (United States)

    Queheillalt, Douglas T.; Hass, Derek D.; Wadley, Haydn N. G.

    2002-07-01

    Multifunctional structures are those, which combine load- bearing support in addition to additional functions such as mechanical actuation, distributed power supply or thermal management. Electron beam - directed vapor deposition technology has been used to investigate deposition methodologies for two multifunctional battery concepts: a linear/truss base nickel - metal hydride and a fiber based solid-state Li+ ion multifunctional battery. Porous nickel coatings for the cathodes and porous rare earth metal coatings based on La and Ni or Ti and Zr for the anodes are being investigated for the nickel - metal hydride system; where LiV2O5, LiPON, and Sn3N4 are being investigated for the Li+ ion based system. Electron beam - directed vapor deposition is being used for deposition of all cathode/anode structures to provide an economical method for the development of these novel multifunctional structures.

  1. Maskless formation of tungsten films by ion beam assisted deposition technique

    International Nuclear Information System (INIS)

    W films were deposited on n-GaAs by ion beam assisted deposition technique using low energy H2+ and Ar+, and film properties and residual damage in the substrate were investigated by measuring x-ray photoemission, current-voltage characteristics and deep level transient spectroscopy. Films with a resistivity of 10-5ohm · cm were formed. This paper reports that it was observed that damage can be reduced using the low energy beams and that Schottky contacts with n-factor of almost 1 and barrier height of 0.88 eV were formed

  2. Optical and Scratch Resistant Properties of Diamondlike Carbon Films Deposited with Single and Dual Ion Beams

    Science.gov (United States)

    Kussmaul, Michael T.; Bogdanski, Michael S.; Banks, Bruce A.; Mirtich, Michael J.

    1993-01-01

    Amorphous diamond-like carbon (DLC) films were deposited using both single and dual ion beam techniques utilizing filament and hollow cathode ion sources. Continuous DLC films up to 3000 A thick were deposited on fused quartz plates. Ion beam process parameters were varied in an effort to create hard, clear films. Total DLC film absorption over visible wavelengths was obtained using a Perkin-Elmer spectrophotometer. An ellipsometer, with an Ar-He laser (wavelength 6328 A) was used to determine index of refraction for the DLC films. Scratch resistance, frictional, and adherence properties were determined for select films. Applications for these films range from military to the ophthalmic industries.

  3. Biaxially textured Ag films by grazing ion beam assisted deposition

    International Nuclear Information System (INIS)

    The effect of grazing incidence 4 keV Ar+ ion irradiation on the early stage of Ag thin film growth on amorphous Si was investigated. The double effect of axial and surface channeling resulted in grains oriented along the axis in-plane, while the (111) out-of-plane texture was maintained. A slight average tilt of the (111) out-of-plane texture axis towards the ion beam direction is proposed to result from the difference between terrace and step edge sputtering yield. The observed tilt is consistent with a minimum erosion orientation of the surface profile.

  4. Wide band antireflective coatings Al2O3 / HfO2 / MgF2 for UV region

    Science.gov (United States)

    Winkowski, P.; Marszałek, Konstanty W.

    2013-07-01

    Deposition technology of the three layers antireflective coatings consists of hafnium compound are presented in this paper. Oxide films were deposited by means of e-gun evaporation in vacuum of 5x10-5 mbar in presence of oxygen and fluoride films by thermal evaporation. Substrate temperature was 250°C. Coatings were deposited onto optical lenses made from quartz glass (Corning HPFS). Thickness and deposition rate were controlled by thickness measuring system Inficon XTC/2. Simulations leading to optimization of thickness and experimental results of optical measurements carried during and after deposition process were presented. Physical thickness measurements were made during deposition process and were equal to 43 nm/74 nm/51 nm for Al2O3 / HfO2 / MgF2 respectively. Optimization was carried out for ultraviolet region from 230nm to the beginning of visible region 400 nm. In this region the average reflectance of the antireflective coating was less than 0.5% in the whole range of application.

  5. Prolactin induces phosphorylation of Tyr694 of Stat5 (MGF), a prerequisite for DNA binding and induction of transcription.

    OpenAIRE

    Gouilleux, F; Wakao, H; Mundt, M; Groner, B.

    1994-01-01

    Mammary gland factor (MGF) is a transcription factor discovered initially in the mammary epithelial cells of lactating animals. It confers the lactogenic hormone response to the milk protein genes. We reported recently the isolation of the cDNA encoding MGF. MGF is a novel member of the cytokine-regulated transcription factor gene family. Members of this gene family mediate interferon alpha/beta and interferon gamma induction of gene transcription, as well as the response to epidermal growth ...

  6. Energy deposition of heavy ions in the regime of strong beam-plasma correlations.

    Science.gov (United States)

    Gericke, D O; Schlanges, M

    2003-03-01

    The energy loss of highly charged ions in dense plasmas is investigated. The applied model includes strong beam-plasma correlation via a quantum T-matrix treatment of the cross sections. Dynamic screening effects are modeled by using a Debye-like potential with a velocity dependent screening length that guarantees the known low and high beam velocity limits. It is shown that this phenomenological model is in good agreement with simulation data up to very high beam-plasma coupling. An analysis of the stopping process shows considerably longer ranges and a less localized energy deposition if strong coupling is treated properly. PMID:12689203

  7. Ion Beam Induced Surface Modulations from Nano to Pico: Optimizing Deposition During Erosion and Erosion During Deposition

    International Nuclear Information System (INIS)

    Ion beams of sufficient energy to erode a surface can lead to surface modulations that depend on the ion beam, the material surface it impinges, and extrinsic parameters such as temperature and geometric boundary conditions. Focused Ion Beam technology both enables site-specific placement of these modulations and expedites research through fast, high dose and small efficient use of material. The DualBeam (FIB/SEM) enables in situ metrology, with movies observing ripple formation, wave motion, and the influence of line defects. Nanostructures (ripples of >400nm wavelength to dots spaced o etching enables deposition of organized structures 1000 times smaller than the aforementioned, video-recorded nanostructures. Orientation and position of these picostructures (naturally quantized by their atomic spacings) may be controlled by the same parameters as for nanostructures (e.g. ion inclination and imposed boundary conditions, which are flexibly regulated by FIB). Judicious control of angles during FIB-CVD growth stimulates erosion with directionality that produces surface modulations akin to those observed for sputtering. Just as a diamond surface roughens from 1-D ripples to 2-D steps with increasing angle of ion sputtering, so do ripples and steps appear on carbon-grown surfaces with increase in angle of FIB-CVD. Ion beam processing has been a stalwart of the microelectronics industry, is now a vital tool for research of self-organizing nanostructures, and promises to be a focus for future picotechnology

  8. BIRTH: a beam deposition code for non-circular tokamak plasmas

    International Nuclear Information System (INIS)

    A new beam deposition code has been developed which is capable of calculating fast ion deposition profiles including the orbit correction. The code incorporates any injection geometry and a non-circular cross section plasma with a variable elongation and an outward shift of the magnetic flux surface. Typical cpu time on a DEC-10 computer is 10 - 20 seconds and 5 - 10 seconds with and without the orbit correction, respectively. This is shorter by an order of magnitude than that of other codes, e.g., Monte Carlo codes. The power deposition profile calculated by this code is in good agreement with that calculated by a Monte Carlo code. (author)

  9. Electronic properties of ion implanted crystalline polymer thin film deposited by ionized cluster beam

    International Nuclear Information System (INIS)

    Polyethylene thin film deposited by the ionized cluster beam deposition technique shows preferential crystal orientation at optimum deposit condition, and the lattice parameters of the crystalline PE film are in good agreement with those of the single crystal PE. The crystalline PE film reveals that the number of side chains is reduced. The conductivity of Li+, Na+ and K+ implanted crystalline PE films has a close correlation with defects generated by ion irradiation, and the conduction mechanism turns out to be the one-dimensional hopping conduction. (orig.)

  10. Texture-Induced Anisotropy in an Inconel 718 Alloy Deposited Using Electron Beam Freeform Fabrication

    Science.gov (United States)

    Tayon, W.; Shenoy, R.; Bird, R.; Hafley, R.; Redding, M.

    2014-01-01

    A test block of Inconel (IN) 718 was fabricated using electron beam freeform fabrication (EBF(sup 3)) to examine how the EBF(sup 3) deposition process affects the microstructure, crystallographic texture, and mechanical properties of IN 718. Tests revealed significant anisotropy in the elastic modulus for the as-deposited IN 718. Subsequent tests were conducted on specimens subjected to a heat treatment designed to decrease the level of anisotropy. Electron backscatter diffraction (EBSD) was used to characterize crystallographic texture in the as-deposited and heat treated conditions. The anisotropy in the as-deposited condition was strongly affected by texture as evidenced by its dependence on orientation relative to the deposition direction. Heat treatment resulted in a significant improvement in modulus of the EBF(sup 3) product to a level nearly equivalent to that for wrought IN 718 with reduced anisotropy; reduction in texture through recrystallization; and production of a more homogeneous microstructure.

  11. Interfacial electrical properties of ion-beam sputter deposited amorphous carbon on silicon

    Science.gov (United States)

    Khan, A. A.; Woollam, J. A.; Chung, Y.; Banks, B.

    1983-01-01

    Amorphous, 'diamond-like' carbon films have been deposited on Si substrates, using ion-beam sputtering. The interfacial properties are studied using capacitance and conductance measurements. Data are analyzed using existing theories for interfacial electrical properties. The density of electronic states at the interface, along with corresponding time constants are determined.

  12. Research of photon beam dose deposition kernel based on Monte Carlo method

    International Nuclear Information System (INIS)

    Using Monte Carlo program BEAMnrc to simulate Siemens accelerator 6 MV photon beam, using BEAMdp program to analyse the energy spectrum distribution and mean energy from phase space data of different field sizes, then building beam source, energy spectrum and mono-energy source, to use DOSXYZnrc program to calculate the dose deposition kernels at dmax in standard water phantom with different beam sources and make comparison with different dose deposition kernels. The results show that the dose difference using energy spectrum source is small, the maximum percentage dose discrepancy is 1.47%, but it is large using mono-energy source, which is 6.28%. The maximum dose difference for the kernels derived from energy spectrum source and mono-energy source of the same field is larger than 9%, up to 13.2%. Thus, dose deposition has dependence on photon energy, it can lead to larger errors only using mono-energy source because of the beam spectrum distribution of accelerator. A good method to calculate dose more accurately is to use deposition kernel of energy spectrum source. (authors)

  13. Coating of pellet pressing tool with 12C by ion beam deposition

    International Nuclear Information System (INIS)

    The pressing tools, used in the preparation of the samples needed for example for such nuclear elemental analysis methods as PIXE, PIGE and RBS, have been coated with a diamond-type 12C-layer by ion beam deposition. Using carbon-coated pressing tools prepared in this way contamination of the sample surfaces during the pill pressing operation is avoided. (orig.)

  14. Copper thin films by ion beam assisted deposition: Strong texture, superior thermal stability and enhanced hardness

    International Nuclear Information System (INIS)

    Nanocrystalline metals generally exhibit exceptionally high strength. However, their susceptibility to grain growth restricts their applications in high temperature environments. The current study presents that nanocrystalline Cu thin films produced by ion beam assisted deposition (IBAD) are able to sustain their as-deposited microstructure and high hardness upon annealing at high temperatures. IBAD-Cu films exhibit a strong (1 1 1) fiber texture, which is caused by the ion beam induced effects of substrate cleaning, preferential damage and preferential sputtering. The microstructure of the IBAD-Cu films is stable at temperatures up to 800 °C (80% of the melting point of Cu). The hardness of the as-deposited IBAD-Cu films can reach a maximum value of 3.85 GPa. Even after annealing, their hardness is still much higher than that of the normally deposited (without ion beam) films as well as their bulk nanocrystalline counterparts before heat treatment. The excellent thermal stability of microstructure is attributed to the formation of nanometer-sized voids and their pinning effect on grain boundary migration. The kinetics of void formation, the contribution of twin boundaries and ion beam induced defects to the hardness are analyzed and discussed. The findings in this study demonstrate that IBAD is an effective method for the stabilization of microstructure and mechanical properties of nanocrystalline metal thin films

  15. Suspended nanostructures grown by electron beam-induced deposition of Pt and TEOS precursors

    International Nuclear Information System (INIS)

    Suspended nanostructures (SNSs) are grown by electron beam-induced deposition (EBID) of Pt and tetra-ethyl-ortho-silicate (TEOS) gas precursors on nanopillar tips, by lateral shifting of a scanning electron microscope beam. Shape evolution of SNSs is characterized as a function of electron energy (5, 10, 15 keV) and electron charge deposited per unit length (CDL, 1-9 pC nm-1 range) along the beam track. Pt SNSs grow as single nanowires, evolving from thin (15-20 nm) and horizontal to thick (up to 70 nm) and inclined (up to 600) geometry as CDL increases. TEOS SNSs consist of multiple nanowires arranged in a stack: horizontal and parallel along the beam shift direction and aligned on top of each other along the beam incidence axis. As the CDL increases, the number of nanowires increases and the top edge of the stack progressively inclines, taking the form of a hand-fan. Deposition yield and overall size of SNSs are found to be proportional to CDL and inversely proportional to electron energy for both Pt and TEOS precursors. As an example of 3D nanoarchitectures achievable by this lateral EBID approach, a 'nano-windmill' TEOS structure is presented

  16. Ion beam assisted deposition of Ti–Si–C thin films

    Directory of Open Access Journals (Sweden)

    A. Twardowska

    2009-11-01

    Full Text Available Purpose: Deposition of hard thin multilayer coatings is a common practice in improving the performance of tools for many different applications. From this aspect Ti3SiC2, due to its lamellar structure and unique combination of properties is a potential interlayer material candidate for thermo-mechanical application.Design/methodology/approach: Multiphase Ti–Si–C thin films were deposited by the ion beam assisted deposition (IBAD technique from a single Ti3SiC2 compound target on an AISI 316L steel substrate. To optimize the deposition process, Monte Carlo simulations were performed; the range of the deposition parameters was determined and then experimentally verified. Scanning and transmission electron microscopies were used to examine the microstructure and quality of the deposited films. Mechanical properties were determined by nanoindentation tests.Findings: The deposited film was flat, smooth and dense with small crystalline particles. The hardness HIT of coated substrates was in the range 2.7 to 5.3 GPa. The average calculated value reduced elastic modulus EIT for coated substrates was 160 GPa. The hardness and reduced elastic modulus for uncoated substrates were HIT = 4.4 GPa and EIT = 250 GPa, respectively.Practical implications: PVD techniques enable low substrate temperature deposition, preferred due to the thermal limitations of the metallic substrates commonly used in industrial applications. The aim of this work is low temperature deposition of Ti-Si-C film, from a single Ti3SiC2 compound target, on 316L steel substrate, using the IBAD technique, known for excellent film connection to the substrate.Originality/value: Ion beam assisted deposition parameters were calculated and experimentally verified.

  17. Nitrogen ion energy dependencies of dielectric constants and compositions of barium carbide-barium nitrate mixed films deposited on silicon wafers by an ion beam assisted deposition technique

    International Nuclear Information System (INIS)

    Thin BaC6-BaN2O4 mixed films with a thickness of 25-60 nm were deposited on Si wafers by evaporating BaCO3 with electron beams and simultaneously applying a mixed beam of N2 molecules and nitrogen ions (an ion beam assisted deposition technique). BaC6 films deposited on Si wafers by evaporating only BaCO3 had low-k values, such as 1.3. In contrast, mixed films containing a small amount of BaC6 and a large amount of BaN2O4 had mild k values, such as 5.6

  18. Effect of focused ion beam deposition induced contamination on the transport properties of nano devices

    International Nuclear Information System (INIS)

    Focused ion beam (FIB) deposition produces unwanted particle contamination beyond the deposition point. This is due to the FIB having a Gaussian distribution. This work investigates the spatial extent of this contamination and its influence on the electrical properties of nano-electronic devices. A correlation study is performed on carbon-nanotube (CNT) devices manufactured using FIB deposition. The devices are observed using transmission electron microscopy (TEM) and these images are correlated with device electrical characteristics. To discover how far Pt-nanoparticle contamination occurs along a CNT after FIB electrical contact deposition careful TEM inspections are performed. The results show FIB deposition efficiently improves electrical contact; however, the practice is accompanied by serious particle contamination near deposition points. These contaminants include metal particles and amorphous elements originating from precursor gases and residual water molecules in the vacuum chamber. Pt-contamination extends for approximately 2 μm from the point of FIB contact deposition. These contaminants cause current fluctuations and alter the transport characteristics of devices. It is recommended that nano-device fabrication occurs at a distance greater than 2 μm from the FIB deposition of an electrical contact. (paper)

  19. Electron-beam induced deposition and autocatalytic decomposition of Co(CO3NO

    Directory of Open Access Journals (Sweden)

    Florian Vollnhals

    2014-07-01

    Full Text Available The autocatalytic growth of arbitrarily shaped nanostructures fabricated by electron beam-induced deposition (EBID and electron beam-induced surface activation (EBISA is studied for two precursors: iron pentacarbonyl, Fe(CO5, and cobalt tricarbonyl nitrosyl, Co(CO3NO. Different deposits are prepared on silicon nitride membranes and silicon wafers under ultrahigh vacuum conditions, and are studied by scanning electron microscopy (SEM and scanning transmission X-ray microscopy (STXM, including near edge X-ray absorption fine structure (NEXAFS spectroscopy. It has previously been shown that Fe(CO5 decomposes autocatalytically on Fe seed layers (EBID and on certain electron beam-activated surfaces, yielding high purity, polycrystalline Fe nanostructures. In this contribution, we investigate the growth of structures from Co(CO3NO and compare it to results obtained from Fe(CO5. Co(CO3NO exhibits autocatalytic growth on Co-containing seed layers prepared by EBID using the same precursor. The growth yields granular, oxygen-, carbon- and nitrogen-containing deposits. In contrast to Fe(CO5 no decomposition on electron beam-activated surfaces is observed. In addition, we show that the autocatalytic growth of nanostructures from Co(CO3NO can also be initiated by an Fe seed layer, which presents a novel approach to the fabrication of layered nanostructures.

  20. The electron beam deposition of titanium on polyetheretherketone (PEEK) and the resulting enhanced biological properties.

    Science.gov (United States)

    Han, Cheol-Min; Lee, Eun-Jung; Kim, Hyoun-Ee; Koh, Young-Hag; Kim, Keung N; Ha, Yoon; Kuh, Sung-Uk

    2010-05-01

    The surface of polyetheretherketone (PEEK) was coated with a pure titanium (Ti) layer using an electron beam (e-beam) deposition method in order to enhance its biocompatibility and adhesion to bone tissue. The e-beam deposition method was a low-temperature coating process that formed a dense, uniform and well crystallized Ti layer without deteriorating the characteristics of the PEEK implant. The Ti coating layer strongly adhered to the substrate and remarkably enhanced its wettability. The Ti-coated samples were evaluated in terms of their in vitro cellular behaviors and in vivo osteointegration, and the results were compared to a pure PEEK substrate. The level of proliferation of the cells (MC3T3-E1) was measured using a methoxyphenyl tetrazolium salt (MTS) assay and more than doubled after the Ti coating. The differentiation level of cells was measured using the alkaline phosphatase (ALP) assay and also doubled. Furthermore, the in vivo animal tests showed that the Ti-coated PEEK implants had a much higher bone-in-contact (BIC) ratio than the pure PEEK implants. These in vitro and in vivo results suggested that the e-beam deposited Ti coating significantly improved the potential of PEEK for hard tissue applications. PMID:20153890

  1. Selective atomic layer deposition with electron-beam patterned self-assembled monolayers

    International Nuclear Information System (INIS)

    The authors selectively deposited nanolines of titanium oxide (TiO2) through atomic layer deposition (ALD) using an octadecyltrichlorosilane (OTS) self-assembled monolayer (SAM) as a nucleation inhibition layer. Electron-beam (e-beam) patterning is used to prepare nanoline patterns in the OTS SAM on SiO2/Si substrates suitable for selective ALD. The authors have investigated the effect of an e-beam dose on the pattern width of the selectively deposited TiO2 lines. A high dose (e.g., 20 nC/cm) causes broadening of the linewidth possibly due to scattering, while a low dose (e.g., 5 nC/cm) results in a low TiO2 deposition rate because of incomplete exposure of the OTS SAMs. The authors have confirmed that sub-30 nm isolated TiO2 lines can be achieved by selective ALD combined with OTS patterned by EBL at an accelerating voltage of 2 kV and line dose of 10 nC/cm. This research offers a new approach for patterned gate dielectric layer fabrication, as well as potential applications for nanosensors and solar cells.

  2. Study of electron-beam-pumped KrF laser kinetics and calculation of energy deposition

    International Nuclear Information System (INIS)

    The program of the electron-beam-pumped KrF laser kinetics has been developed. By using this program the relation of relaxation rate of upper laser level to the optimum output condition of the KrF laser is studied. It is expected that the laser output will be directly proportional to the relaxation rate under a given condition when the laser flux is near saturation. The numerical simulation showed that a rise (or drop) in pump rate is faster than that of the relaxation rate, the laser output rises (or drops) as well. The optimum condition of output is obtained. The pressure (5 ∼ 6 atm*), the pump power and the Ar, Kr, F2 mixture ratio are determined for the optimum condition. In order to study the energy deposition of the electron-beam-pumped KrF gas laser, the SANDYL and the ITS programs have been developed. The latter is the program with the axial magnetic field applied, while the former without any field. The energy depositions of two kinds of Ar/Kr/F2 mixtures at various pressures of the electron-beam-pumped cylindrical KrF laser are calculated with the SANDYL program. The results show that under the same conditions, the energy deposition with the axial magnetic field applied is 3 times larger than that without any magnetic field. The energy depositions of two kinds of Ar/Kr/F2

  3. Fabrication and characterization of graded calcium phosphate coatings produced by ion beam sputtering/mixing deposition

    International Nuclear Information System (INIS)

    Ion beam sputtering/mixing deposition was used to produce thin calcium phosphate coatings on titanium substrate from the hydroxyapatite target. It was found that as-deposited coatings were amorphous. No distinct absorption band of the hydroxyl group was observed in FTIR spectra of the coatings but new absorption bands were present for CO32-, which was brought about during the deposition process. Scanning electron microscopy revealed that the deposited coatings had a uniform and dense structure. The calcium to phosphorous ratio of these coatings varied between 2.0 and 8.0. Analyses of XPS data revealed that the coating could be divided into four distinctive zones, and a graded structure was achieved in the as-received coating. Scratch tests showed that the coatings adhered well to the substrate

  4. Nanoscale Soldering of Positioned Carbon Nanotubes using Highly Conductive Electron Beam Induced Gold Deposition

    DEFF Research Database (Denmark)

    Madsen, Dorte Nørgaard; Mølhave, Kristian; Mateiu, Ramona Valentina; Bøggild, Peter; Rasmussen, A.M.; Appel, C.C.; Brorson, M; Jacobsen, C.J.H.

    2003-01-01

    We have developed an in-situ method for controlled positioning of carbon nanotubes followed by highly conductive contacting of the nanotubes, using electron beam assisted deposition of gold. The positioning and soldering process takes place inside an Environmental Scanning Electron Microscope (E...... embedded in a carbon matrix. Nanoscale soldering of multi-walled carbon nanotubes (MWNT) onto microelectrodes was achieved by deposition of a conducting gold line across a contact point between nanotube and electrode. The solderings were found to be mechanically stronger than the carbon nanotubes. We have......-SEM) in the presence of a source of gold-organic precursor gas. Bridges deposited between suspended microelectrodes show resistivities down to 10-4 Ωcm and Transmission Electron Microscopy (TEM) of the deposits reveals a dense core of gold particles surrounded by a crust of small gold nanoparticles...

  5. An orientation competition in yttria-stabilized zirconia thin films fabricated by ion beam assisted sputtering deposition

    International Nuclear Information System (INIS)

    A previously found orientation competition in ion beam sputtered yttria-stabilized zirconia thin films was studied in detail. The effects of sputtering energy and deposition angle were analyzed in ion sputtered films without assisting ions bombardment. It is found that for normally deposited films, (001) and (011) orientations are favored at low and high sputtering energy respectively. For inclined substrate deposited films, as deposition angle increases, (001), (011) and (111) orientations are advantaged in turn. The results can be attributed to the in-plane energy exchange of deposition atom and adatoms. In ion beam assisting deposited YSZ films of low assisting ions energy and current, a (001) oriented biaxial texture is gradually induced as ion energy increased. In the case of ion beam assisted inclined deposition of 45°, (001) orientation is enhanced and two preferential in-plane orientations are found coexist.

  6. Angular distribution of species in pulsed energy beam deposition of oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Nistor, M., E-mail: mnistor@infim.ro [National Institute for Lasers, Plasmas and Radiation Physics, L22 P.O. Box MG-36, 77125 Bucharest-Magurele (Romania); Gherendi, F.; Mandache, N.B. [National Institute for Lasers, Plasmas and Radiation Physics, L22 P.O. Box MG-36, 77125 Bucharest-Magurele (Romania)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Thickness profiles of Ba{sub x}Sr{sub 1-x}TiO{sub 3} thin films were measured. Black-Right-Pointing-Pointer Comparison between pulsed laser (PLD) and pulsed electron beam deposition (PED). Black-Right-Pointing-Pointer The film thicknesses profile of PED has a slightly broader shape than that of PLD. Black-Right-Pointing-Pointer The film stoichiometry is preserved at all angles. - Abstract: Pulsed energy beam deposition methods like pulsed-laser deposition (PLD) or pulsed-electron beam deposition (PED) allow the formation of smooth, dense and crystalline oxide thin films. The angular distribution of the ablated flux from the target and the thin film thickness profile were extensively studied for PLD for a wide range of materials and growth conditions. In the case of complex oxide compounds, the angular distribution of the various species emitted by the target will determine the precise composition of the films. In this work we report on the determination of the angular distributions of the species emitted from a Ba{sub x}Sr{sub 1-x}TiO{sub 3} (BST) target. A comparison between these results obtained by PED and PLD methods is presented and discussed in the frame of Anisimov's model. A slightly broader shape of the angular distribution for PED than that for PLD is explained taking into account the differences in the spot size and fluence between the pulsed electron beam and laser beam and a small collisional broadening of the angular distribution in the case of PED. The stoichiometry is preserved at all angles.

  7. Role of MgF2 on properties of glass–ceramics

    Indian Academy of Sciences (India)

    M Ghasemzadeh; A Nemati

    2012-10-01

    Formation of machinable glass–ceramic in the system MgO–SiO2–Al2O3–K2O–B2O3–F with and without addition of MgF2 has been investigated. Crystallization of glass sample was done by controlled thermal heat treatment at nucleation and crystallization temperatures. The results showed that MgF2 in high concentration had a synergistic effect and enhanced the formation of interlockedmica crystals. Non-isothermal DTA experiments showed that the crystallization activation energies of base glasses were changed in the range of 235–405 kJ/mol, while the crystallization activation energies of samples with addition of MgF2 were changed in the range of 548–752 kJ/mol.

  8. Vacuum ultraviolet thin films. I - Optical constants of BaF2, CaF2, LaF3, MgF2, Al2O3, HfO2, and SiO2 thin films. II - Vacuum ultraviolet all-dielectric narrowband filters

    Science.gov (United States)

    Zukic, Muamer; Torr, Douglas G.; Spann, James F.; Torr, Marsha R.

    1990-01-01

    An iteration process matching calculated and measured reflectance and transmittance values in the 120-230 nm VUV region is presently used to ascertain the optical constants of bulk MgF2, as well as films of BaF2, CaF2, LaF3, MgF2, Al2O3, HfO2, and SiO2 deposited on MgF2 substrates. In the second part of this work, a design concept is demonstrated for two filters, employing rapidly changing extinction coefficients, centered at 135 nm for BaF2 and 141 nm for SiO2. These filters are shown to yield excellent narrowband spectral performance in combination with narrowband reflection filters.

  9. Deposition of diamond like carbon films by using a single ion gun with varying beam source

    Institute of Scientific and Technical Information of China (English)

    JIANG Jin-qiu; Chen Zhu-ping

    2001-01-01

    Diamond like carbon films have been successfully deposited on the steel substrate, by using a single ion gun with varying beam source. The films may appear blue, yellow and transparent in color, which was found related to contaminants from the sample holder and could be avoided. The thickness of the films ranges from tens up to 200 nanometers, and the hardness is in the range 20 to 30 GPa. Raman analytical results reveal the films are in amorphous structure. The effects of different beam source on the films structure are further discussed.

  10. Site control technique for quantum dots using electron beam induced deposition

    Science.gov (United States)

    Iizuka, Kanji; Jung, JaeHun; Yokota, Hiroshi

    2014-05-01

    To develop simple and high throughput sit definition technique for quantum dots (QDs), the electron beam induced deposition (EBID) method was used as desorption guide of phosphorus atoms form InP substrate. As the results one or a few indium (In) droplets (DLs) were created in the carbon grid pattern by thermal annealing at a temperature of 450°C for 10 min in the ultra high vacuum condition. The size of In DLs was larger than QDs, but arsenide DLs by molecular beam in growth chamber emitted wavelength of 1.028μm at 50K by photoluminescence measurement.

  11. Functional nickel-based deposits synthesized by focused beam induced processing

    Science.gov (United States)

    Córdoba, R.; Barcones, B.; Roelfsema, E.; Verheijen, M. A.; Mulders, J. J. L.; Trompenaars, P. H. F.; Koopmans, B.

    2016-02-01

    Functional nanostructures fabricated by focused electron/ion beam induced processing (FEBIP/FIBIP) open a promising route for applications in nanoelectronics. Such developments rely on the exploration of new advanced materials. We report here the successful fabrication of nickel-based deposits by FEBIP/FIBIP using bis(methyl cyclopentadienyl)nickel as a precursor. In particular, binary compounds such as nickel oxide (NiO) are synthesized by using an in situ two-step process at room temperature. By this method, as-grown Ni deposits transform into homogeneous NiO deposits using focused electron beam irradiation under O2 flux. This procedure is effective in producing highly pure NiO deposits with resistivity of 2000 Ωcm and a polycrystalline structure with face-centred cubic lattice and grains of 5 nm. We demonstrate that systems based on NiO deposits displaying resistance switching and an exchange-bias effect could be grown by FEBIP using optimized parameters. Our results provide a breakthrough towards using these techniques for the fabrication of functional nanodevices.

  12. Growth of textured MgO through e-beam evaporation and inclined substrate deposition

    International Nuclear Information System (INIS)

    Long length textured MgO template on Hastelloy C276(TM) (HC) has been successfully deposited in a reel-to-reel (R2R) electron beam (e-beam) evaporation system by inclined substrate deposition (ISD). High deposition rate up to 10 nm s-1 with exposure length of 7 cm has been realized. The MgO template showed good in-plane texture of 9.5 deg. -11.5 deg. measured from the (002) phi scans. Experimental results reveal that MgO in-plane texture is formed by the preferred growth direction of [11n] parallel substrate normal and one of the MgO {200} planes rotates to the in-flux direction. A new expression, termed the 'two-thirds relationship', between the inclination angle α and the tilted angle of the (00l) plane from the substrate normal, β, has been summarized. YBa2Cu3O7-δ (YBCO) film deposited by pulsed laser deposition (PLD) on strontium ruthenate (SRO) buffered ISD MgO showed Tc of 91 K with transition width of 1 K. Critical current measurement indicated an Ic of 110 A cm-1 at 77 K in self-field for 0.68 μm YBCO film, corresponding to a Jc of 1.6 MA cm-2

  13. Growth of textured MgO through e-beam evaporation and inclined substrate deposition

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y [Materials Research Lab, UES Inc. Dayton, OH 45432 (United States); Lei, C H [Department of MSE, University of Illinois, Urbana, IL 61801 (United States); Ma, B [Argonne National Laboratory, Argonne, IL 60439 (United States); Evans, H [Materials Research Lab, UES Inc. Dayton, OH 45432 (United States); Efstathiadis, H [Albany Nanotech, Albany, NY 12203 (United States); Manisha, R [Albany Nanotech, Albany, NY 12203 (United States); Massey, M [Materials Research Lab, UES Inc. Dayton, OH 45432 (United States); Balachandran, U [Argonne National Laboratory, Argonne, IL 60439 (United States); Bhattacharya, R [Materials Research Lab, UES Inc. Dayton, OH 45432 (United States)

    2006-08-15

    Long length textured MgO template on Hastelloy C276(TM) (HC) has been successfully deposited in a reel-to-reel (R2R) electron beam (e-beam) evaporation system by inclined substrate deposition (ISD). High deposition rate up to 10 nm s{sup -1} with exposure length of 7 cm has been realized. The MgO template showed good in-plane texture of 9.5 deg. -11.5 deg. measured from the (002) phi scans. Experimental results reveal that MgO in-plane texture is formed by the preferred growth direction of [11n] parallel substrate normal and one of the MgO {l_brace}200{r_brace} planes rotates to the in-flux direction. A new expression, termed the 'two-thirds relationship', between the inclination angle {alpha} and the tilted angle of the (00l) plane from the substrate normal, {beta}, has been summarized. YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) film deposited by pulsed laser deposition (PLD) on strontium ruthenate (SRO) buffered ISD MgO showed T{sub c} of 91 K with transition width of 1 K. Critical current measurement indicated an I{sub c} of 110 A cm{sup -1} at 77 K in self-field for 0.68 {mu}m YBCO film, corresponding to a J{sub c} of 1.6 MA cm{sup -2}.

  14. Growth of textured MgO through e-beam evaporation and inclined substrate deposition

    Science.gov (United States)

    Xu, Y.; Lei, C. H.; Ma, B.; Evans, H.; Efstathiadis, H.; Manisha, R.; Massey, M.; Balachandran, U.; Bhattacharya, R.

    2006-08-01

    Long length textured MgO template on Hastelloy C276™ (HC) has been successfully deposited in a reel-to-reel (R2R) electron beam (e-beam) evaporation system by inclined substrate deposition (ISD). High deposition rate up to 10 nm s-1 with exposure length of 7 cm has been realized. The MgO template showed good in-plane texture of 9.5°-11.5° measured from the (002) phi scans. Experimental results reveal that MgO in-plane texture is formed by the preferred growth direction of [11n]\\parallel \\mathrm {substrate} normal and one of the MgO {200} planes rotates to the in-flux direction. A new expression, termed the 'two-thirds relationship', between the inclination angle α and the tilted angle of the (00l) plane from the substrate normal, β, has been summarized. YBa2Cu3O7-δ (YBCO) film deposited by pulsed laser deposition (PLD) on strontium ruthenate (SRO) buffered ISD MgO showed Tc of 91 K with transition width of 1 K. Critical current measurement indicated an Ic of 110 A cm-1 at 77 K in self-field for 0.68 µm YBCO film, corresponding to a Jc of 1.6 MA cm-2.

  15. Electron beam evaporated LaF3 thin films prepared by different temperatures and deposition rates

    International Nuclear Information System (INIS)

    LaF3 thin films were prepared by electron beam evaporation with different temperatures and deposition rates. Microstructure properties including crystalline structure and surface roughness were investigated by X-ray diffraction (XRD) and optical profilograph. X-ray photoelectron spectroscopy (XPS) was employed to study the chemical composition of the films. Optical properties (transmittance and refractive index) and laser induce damage threshold (LIDT) at 355 nm of the films were also characterized. The effects of deposition rate and substrate temperature on microstructure, optical properties and LIDT of LaF3 thin films were discussed, respectively.

  16. Adherence of ion beam sputter deposited metal films on H-13 steel

    Science.gov (United States)

    Mirtich, M. J.

    1980-01-01

    An electron bombardment argon ion source was used to sputter deposit 17 different metal and metal oxide films ranging in thickness from 1 to 8 micrometers on H-13 steel substrates. The film adherence to the substrate surface was measured using a tensile test apparatus. Comparisons in bond strength were made between ion beam, ion plating, and RF deposited films. A protective coating to prevent heat checking in H-13 steel dies used for aluminum die casting was studied. The results of exposing the coated substrates to temperatures up to 700 degrees are presented.

  17. Microanalyses of the hydroxyl—poly—calcium sodium phosphate coatings produced by ion beam assisted deposition

    Institute of Scientific and Technical Information of China (English)

    LIUZhong-Yang; WANGChang-Xing; 等

    2002-01-01

    Thin calcium phosphate catings on titanium alloy substrates were prepared by Ar+ ion beam assisted deposition(IBAD) from hydroxyl-poly-calcium sodium phosphate(HPPA) target.The coatings were analyzed by XRD,FTIR,XPS,These analyses revealed that the as-deposited films were amorphous or no apparent crystallinity.No distinct absorption band of the hydroxyl group was observed in FTIR spectra of the coatings but new absorption bands were presented for CO3-2,The calcium to phosphorous ratio of these catings in different IBAD conditions varied from 0.46 to 3.36.

  18. Novel MGF-based expressions for the average bit error probability of binary signalling over generalized fading channels

    KAUST Repository

    Yilmaz, Ferkan

    2014-04-01

    The main idea in the moment generating function (MGF) approach is to alternatively express the conditional bit error probability (BEP) in a desired exponential form so that possibly multi-fold performance averaging is readily converted into a computationally efficient single-fold averaging - sometimes into a closed-form - by means of using the MGF of the signal-to-noise ratio. However, as presented in [1] and specifically indicated in [2] and also to the best of our knowledge, there does not exist an MGF-based approach in the literature to represent Wojnar\\'s generic BEP expression in a desired exponential form. This paper presents novel MGF-based expressions for calculating the average BEP of binary signalling over generalized fading channels, specifically by expressing Wojnar\\'s generic BEP expression in a desirable exponential form. We also propose MGF-based expressions to explore the amount of dispersion in the BEP for binary signalling over generalized fading channels.

  19. Ion-beam inertial fusion: the requirements posed by target and deposition physics

    International Nuclear Information System (INIS)

    The demonstration of ICF scientific feasibility requires success in target design, driver development and target fabrication. Since these are interrelated, we present here some results of ion beam target studies and relate them to parameters of interest to ion accelerators. Ion deposition physics have long been a well known subject apart from high beam currents. Recent NRL experiments at up to 250 kA/cm2 ions confirm the classical deposition physics now at current densities which are comparable to most ion targets. On the other hand, GSI data at low current density but 1 to 10 MeV/nucleon are continually being accumulated. They have yet to find anomalous results. Relying on target concepts outlined briefly, we report on the energy gain of ion-driven fusion targets as a function of input energy, ion ranges and focal spot radius. We also comment on some consequences of target gain versus driver and reactor requirements

  20. Atomic layer deposition of HfO2 on graphene through controlled ion beam treatment

    Science.gov (United States)

    Kim, Ki Seok; Oh, Il-Kwon; Jung, Hanearl; Kim, Hyungjun; Yeom, Geun Young; Kim, Kyong Nam

    2016-05-01

    The polymer residue generated during the graphene transfer process to the substrate tends to cause problems (e.g., a decrease in electron mobility, unwanted doping, and non-uniform deposition of the dielectric material). In this study, by using a controllable low-energy Ar+ ion beam, we cleaned the polymer residue without damaging the graphene network. HfO2 grown by atomic layer deposition on graphene cleaned using an Ar+ ion beam showed a dense uniform structure, whereas that grown on the transferred graphene (before Ar+ ion cleaning) showed a non-uniform structure. A graphene-HfO2-metal capacitor fabricated by growing 20-nm thick HfO2 on graphene exhibited a very low leakage current (graphene, whereas a similar capacitor grown using the transferred graphene showed high leakage current.

  1. Ion beam deposition of amorphous carbon films with diamond like properties

    Science.gov (United States)

    Angus, John C.; Mirtich, Michael J.; Wintucky, Edwin G.

    1982-01-01

    Carbon films were deposited on silicon, quartz, and potassium bromide substrates from an ion beam. Growth rates were approximately 0.3 micron/hour. The films were featureless and amorphous and contained only carbon and hydrogen in significant amounts. The density and carbon/hydrogen ratio indicate the film is a hydrogen deficient polymer. One possible structure, consistent with the data, is a random network of methylene linkages and tetrahedrally coordinated carbon atoms.

  2. The Energy Deposition for No-air-gap Design of the TESLA Beam Dump

    International Nuclear Information System (INIS)

    In the linear electron- positron collider project TESLA, the beam dump designed as a water tank is working in a very special regime. Each pulse of the electron or positron beam should, after crossing the interaction region, be dumped in a cylindrical 10-m long water dump. The mean power to be absorbed is important being 8 MW for 250 GeV beam energy (intensity 2.04 * 1014 electrons/s) and for 400 GeV case it will be 12 MW and 2.8*1014 electrons/s. The initial project was providing a 20-cm wide air gap between the titanium vessel containing water and the concentrate outer shield. Energy deposition calculations using FLUKA code showed that the energy deposited in and thus temperature rise of the concrete shield were very high. Additional solid inner shield made of aluminium (or iron) has to be placed just behind the titanium vessel. The important production of radioactive nuclei in the air has prompted the designers to minimize the air gap. Realistically, this minimal size of the air gap was assessed to be a 2-cm wide. Also new thickness of the inner shield has been proposed - 60 cm for aluminium and 20 cm for iron. These changes called for a new set of calculations for energy deposition in both the concentrate and aluminum iron) shields. (author)

  3. Ion beam deposition and surface characterization of thin multi-component oxide films during growth.

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, A.R.; Im, J.; Smentkowski, V.; Schultz, J.A.; Auciello, O.; Gruen, D.M.; Holocek, J.; Chang, R.P.H.

    1998-01-13

    Ion beam deposition of either elemental targets in a chemically active gas such as oxygen or nitrogen, or of the appropriate oxide or nitride target, usually with an additional amount of ambient oxygen or nitrogen present, is an effective means of depositing high quality oxide and nitride films. However, there are a number of phenomena which can occur, especially during the production of multicomponent films such as the ferroelectric perovskites or high temperature superconducting oxides, which make it desirable to monitor the composition and structure of the growing film in situ. These phenomena include thermodynamic (Gibbsian), and oxidation or nitridation-driven segregation, enhanced oxidation or nitridation through production of a highly reactive gas phase species such as atomic oxygen or ozone via interaction of the ion beam with the target, and changes in the film composition due to preferential sputtering of the substrate via primary ion backscattering and secondary sputtering of the film. Ion beam deposition provides a relatively low background pressure of the sputtering gas, but the ambient oxygen or nitrogen required to produce the desired phase, along with the gas burden produced by the ion source, result in a background pressure which is too high by several orders of magnitude to perform in situ surface analysis by conventional means. Similarly, diamond is normally grown in the presence of a hydrogen atmosphere to inhibit the formation of the graphitic phase.

  4. Relativistic electron beam energy deposition in thin gold and aluminum targets

    International Nuclear Information System (INIS)

    Relativistic electron beam (REB) energy deposition in thin gold and aluminum targets has been investigated experimentally using radiation temperature measurements in the soft x-ray, vacuum ultraviolet (XUV) and optical spectral regions on two different particle accelerators. Energy deposition measurements were compared with numerical calculations utilizing particle-in-cell (PIC) diode codes, condensed history Monte-Carlo codes, and coupled radiation-hydrodynamic codes. The specific power deposited (i.e., power deposited/unit mass) was observed to be greater than that due to an average electron making a single pass through a thin target (6.4 μm thick gold foil on the Hydra accelerator and 38 and 6 μm thick aluminum foils on the Proto I accelerator). Self-magnetic field effects were primarily responsible for deposition enhancement in 6.4 μm gold foils on the Hydra accelerator (ν/γ approx. = 2.5). Reduction of electron scattering with aluminum foils on Proto I where ν/γ approx. = 1 led to deposition enhancement due to both self electric and magnetic fields

  5. Ion beam sputter deposition of TiNi shape memory alloy thin films

    Science.gov (United States)

    Davies, Sam T.; Tsuchiya, Kazuyoshi

    1999-08-01

    The development of functional or smart materials for integration into microsystem is of increasing interest. An example is the shape memory effect exhibited by certain metal alloys which, in principle, can be exploited in the fabrication of micro-scale manipulators or actuators, thereby providing on-chip micromechanical functionality. We have investigated an ion beam sputter deposition process for the growth of TiNi shape memory alloy thin films and demonstrated the required control to produce equiatomic composition, uniform coverage and atomic layer-by-layer growth rates on engineering surfaces. The process uses argon ions at intermediate energy produced by a Kaufman-type ion source to sputter non-alloyed targets of high purity titanium and nickel. Precise measurements of deposition rates allows compositional control during thin film growth. As the sputtering targets and substrates are remote from the discharge plasma, deposition occurs under good vacuum of approximately 10-6 mtorr thus promoting high quality films. Furthermore, the ion beam energetics allow deposition at relatively low substrate temperatures of heat capacity and thermal conductivity as the TiNi shape memory alloy undergoes martensitic to austenitic phase transformations.

  6. Unveiling the optical properties of a metamaterial synthesized by electron-beam-induced deposition.

    Science.gov (United States)

    Woźniak, P; Höflich, K; Brönstrup, G; Banzer, P; Christiansen, S; Leuchs, G

    2016-01-15

    Direct writing using a focused electron beam allows for fabricating truly three-dimensional structures of sub-wavelength dimensions in the visible spectral regime. The resulting sophisticated geometries are perfectly suited for studying light-matter interaction at the nanoscale. Their overall optical response will strongly depend not only on geometry but also on the optical properties of the deposited material. In the case of the typically used metal-organic precursors, the deposits show a substructure of metallic nanocrystals embedded in a carbonaceous matrix. Since gold-containing precursor media are especially interesting for optical applications, we experimentally determine the effective permittivity of such an effective material. Our experiment is based on spectroscopic measurements of planar deposits. The retrieved permittivity shows a systematic dependence on the gold particle density and cannot be sufficiently described using the common Maxwell-Garnett approach for effective medium. PMID:26629782

  7. Unveiling the optical properties of a metamaterial synthesized by electron-beam-induced deposition

    CERN Document Server

    Woźniak, Paweł; Brönstrup, Gerald; Banyer, Peter; Christiansen, Silke; Leuchs, Gerd

    2015-01-01

    The direct writing using a focused electron beam allows for fabricating truly three-dimensional structures of sub-wavelength dimensions in the visible spectral regime. The resulting sophisticated geometries are perfectly suited for studying light-matter interaction at the nanoscale. Their overall optical response will strongly depend not only on geometry but also on the optical properties of the deposited material. In case of the typically used metal-organic precursors, the deposits show a substructure of metallic nanocrystals embedded in a carbonaceous matrix. Since gold-containing precursor media are especially interesting for optical applications, we experimentally determine the effective permittivity of such an effective material. Our experiment is based on spectroscopic measurements of planar deposits. The retrieved permittivity shows a systematic dependence on the gold particle density and cannot be sufficiently described using the common Maxwell-Garnett approach for effective medium.

  8. Processing-structure-property relationships in electron beam physical vapor deposited yttria stabilized zirconia coatings

    International Nuclear Information System (INIS)

    The physical and mechanical properties of yttria stabilized zirconia (YSZ) coatings deposited by the electron beam physical vapor deposition technique have been investigated by varying the key process variables such as vapor incidence angle and sample rotation speed. The tetragonal zirconia coatings formed under varying process conditions employed were found to have widely different surface and cross-sectional morphologies. The porosity, phase composition, planar orientation, hardness, adhesion, and surface residual stresses in the coated specimens were comprehensively evaluated to develop a correlation with the process variables. Under transverse scratch test conditions, the YSZ coatings exhibited two different crack formation modes, depending on the magnitude of residual stress. The influence of processing conditions on the coating deposition rate, column orientation angle, and adhesion strength has been established. Key relationships between porosity, hardness, and adhesion are also presented.

  9. Design of semi industrial radium separator by a new bacterium MGF-48

    International Nuclear Information System (INIS)

    Following of a research work which has been recently published in AEOI scientific Bulletin no. 14, a semi industrial bioreactor has been designed for separation of radium using a new bacterium MGF-48. This bioreactor could be utilized for a high rate separation of radium in semi industrial scale. (author)

  10. Preparation of MgF2 Translucent Ceramic by Hot Pressing Sintering

    Institute of Scientific and Technical Information of China (English)

    PENG Minhong; CAO Weiping; SONG Jinhong

    2015-01-01

    The aim of this work was to prepare MgF2 translucent ceramic by using nanopowders as raw materials and to study its properties.The MgF2 nanopowders were prepared using chemical precipitation and the translucent ceramics were fabricated by hot-pressing sintering in a vacuum environment. X-ray diffraction analysis showed that the powders were homogeneous with an average particles size about 13 nm. By comparing the results of transmission electron microscopy, it could be concluded that the porous structure of precursor powders could be improved by calcination. The SEM images of MgF2 indicated that the as-prepared ceramics were well densified at 900℃. The photo of the ceramic sample showed that high translucence is a main breakthrough in the ifeld of MgF2 materials preparation. For the translucent ceramic sample sintered at 900℃, the Vickers hardness and density were 5.55 GPa and 98.74%, respectively, and its highest transmittance with thickness of 1mm reached 87% in the wavelength from 2.5 µm to 10 µm, all which made it advantageous to be a kind of infrared windows and dome materials.

  11. Mechanical and tribological properties of carbon thin film with tungsten interlayer prepared by Ion beam assisted deposition

    Czech Academy of Sciences Publication Activity Database

    Vlčák, P.; Černý, F.; Tolde, Z.; Sepitka, J.; Gregora, Ivan; Daniš, S.

    2013-01-01

    Roč. 2013, FEB (2013). ISSN 2314-4874 Institutional support: RVO:68378271 Keywords : carbon coatings * ion beam deposition * XRD * nanoindentation Subject RIV: BM - Solid Matter Physics ; Magnetism http://dx.doi.org/10.1155/2013/630156

  12. Thermal conductivity and nanocrystalline structure of platinum deposited by focused ion beam

    International Nuclear Information System (INIS)

    Pt deposited by focused ion beam (FIB) is a common material used for attachment of nanosamples, repair of integrated circuits, and synthesis of nanostructures. Despite its common use little information is available on its thermal properties. In this work, Pt deposited by FIB is characterized thermally, structurally, and chemically. Its thermal conductivity is found to be substantially lower than the bulk value of Pt, 7.2 W m−1 K−1 versus 71.6 W m−1 K−1 at room temperature. The low thermal conductivity is attributed to the nanostructure of the material and its chemical composition. Pt deposited by FIB is shown, via aberration corrected TEM, to be a segregated mix of nanocrystalline Pt and amorphous C with Ga and O impurities. Ga impurities mainly reside in the Pt while O is homogeneously distributed throughout. The Ga impurity, small grain size of the Pt, and the amorphous carbon between grains are the cause for the low thermal conductivity of this material. Since Pt deposited by FIB is a common material for affixing samples, this information can be used to assess systematic errors in thermal characterization of different nanosamples. This application is also demonstrated by thermal characterization of two carbon nanofibers and a correction using the reported thermal properties of the Pt deposited by FIB. (paper)

  13. Spatial chemistry evolution during focused electron beam-induced deposition: origins and workarounds

    International Nuclear Information System (INIS)

    The successful application of functional nanostructures, fabricated via focused electron-beam-induced deposition (FEBID), is known to depend crucially on its chemistry as FEBID tends to strong incorporation of carbon. Hence, it is essential to understand the underlying mechanisms which finally determine the elemental composition after fabrication. In this study we focus on these processes from a fundamental point of view by means of (1) varying electron emission on the deposit surface; and (2) changing replenishment mechanism, both driven by the growing deposit itself. First, we revisit previous results concerning chemical variations in nanopillars (with a quasi-1D footprint) depending on the process parameters. In a second step we expand the investigations to deposits with a 3D footprint which are more relevant in the context of applications. Then, we demonstrate how technical setups and directional gas fluxes influence final chemistries. Finally, we put the findings in a bigger context with respect to functionalities which demonstrates the crucial importance of carefully set up fabrication processes to achieve controllable, predictable and reproducible chemistries for FEBID deposits as a key element for industrially oriented applications. (orig.)

  14. Electrochemical impedance spectroscopy on nanostructured carbon electrodes grown by supersonic cluster beam deposition

    Energy Technology Data Exchange (ETDEWEB)

    Bettini, Luca Giacomo; Bardizza, Giorgio; Podesta, Alessandro; Milani, Paolo; Piseri, Paolo, E-mail: piseri@mi.infn.it [Universita degli Studi di Milano, Dipartimento di Fisica and CIMaINa (Italy)

    2013-02-15

    Nanostructured porous films of carbon with density of about 0.5 g/cm{sup 3} and 200 nm thickness were deposited at room temperature by supersonic cluster beam deposition (SCBD) from carbon clusters formed in the gas phase. Carbon film surface topography, determined by atomic force microscopy, reveals a surface roughness of 16 nm and a granular morphology arising from the low kinetic energy ballistic deposition regime. The material is characterized by a highly disordered carbon structure with predominant sp2 hybridization as evidenced by Raman spectroscopy. The interface properties of nanostructured carbon electrodes were investigated by cyclic voltammetry and electrochemical impedance spectroscopy employing KOH 1 M solution as aqueous electrolyte. An increase of the double layer capacitance is observed when the electrodes are heat treated in air or when a nanostructured nickel layer deposited by SCBD on top of a sputter deposited film of the same metal is employed as a current collector instead of a plain metallic film. This enhancement is consistent with an improved charge injection in the active material and is ascribed to the modification of the electrical contact at the interface between the carbon and the metal current collector. Specific capacitance values up to 120 F/g have been measured for the electrodes with nanostructured metal/carbon interface.

  15. Thermal conductivity and nanocrystalline structure of platinum deposited by focused ion beam

    KAUST Repository

    Alaie, Seyedhamidreza

    2015-02-04

    Pt deposited by focused ion beam (FIB) is a common material used for attachment of nanosamples, repair of integrated circuits, and synthesis of nanostructures. Despite its common use little information is available on its thermal properties. In this work, Pt deposited by FIB is characterized thermally, structurally, and chemically. Its thermal conductivity is found to be substantially lower than the bulk value of Pt, 7.2 W m-1 K-1 versus 71.6 W m-1 K-1 at room temperature. The low thermal conductivity is attributed to the nanostructure of the material and its chemical composition. Pt deposited by FIB is shown, via aberration corrected TEM, to be a segregated mix of nanocrystalline Pt and amorphous C with Ga and O impurities. Ga impurities mainly reside in the Pt while O is homogeneously distributed throughout. The Ga impurity, small grain size of the Pt, and the amorphous carbon between grains are the cause for the low thermal conductivity of this material. Since Pt deposited by FIB is a common material for affixing samples, this information can be used to assess systematic errors in thermal characterization of different nanosamples. This application is also demonstrated by thermal characterization of two carbon nanofibers and a correction using the reported thermal properties of the Pt deposited by FIB.

  16. Ion beam assisted deposition of nano-structured C:Ni films

    International Nuclear Information System (INIS)

    Nanostructures influence material properties dramatically due to size, shape and interface effects. Thus the control of the structure at the nanoscale is a key issue in nanomaterials science. The interaction of hyperthermal ions with solids is confined to the nanometer scale. Thus, it can be used to control the morphology evolution during multiphase film deposition. Ion-induced displacements occur in a thin surface layer of the growing film where they increase the atomic mobility for the phase separation. Here the growth-structure relationship of C:Ni (15 at.%) nanocomposite films grown by oblique incidence (45 ) ion beam assisted deposition is reported. The influences of the flux of an assisting Ar+ ion beam (0-140 eV) as well as of an elevated substrate temperature have been studied. The formation of elongated nickel nanoparticles is strongly promoted by the ion beam assistance. Moreover, the metal nanocolumns no longer align with the advancing surface, but with the incoming ions. A window of conditions is established within which the ion assistance leads to the formation of regular composition modulations with a well defined periodicity and tilt. As the dominating driving force for the pattern formation is of physical origin, this approach might be applicable to other immiscible systems.

  17. Energy distribution of secondary particles in ion beam deposition process of Ag: experiment, calculation and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Bundesmann, C.; Feder, R.; Lautenschlaeger, T.; Neumann, H. [Leibniz-Institute of Surface Modification, Leipzig (Germany)

    2015-12-15

    Ion beam sputter deposition allows tailoring the properties of the film-forming, secondary particles (sputtered target particles and backscattered primary particles) and, hence, thin film properties by changing ion beam (ion energy, ion species) and geometrical parameters (ion incidence angle, polar emission angle). In particular, the energy distribution of secondary particles and their influence on the ion beam deposition process of Ag was studied in dependence on process parameters. Energy-selective mass spectrometry was used to measure the energy distribution of sputtered and backscattered ions. The energy distribution of the sputtered particles shows, in accordance with theory, a maximum at low energy and an E{sup -2} decay for energies above the maximum. If the sum of incidence angle and polar emission angle is larger than 90 , additional contributions due to direct sputtering events occur. The energy distribution of the backscattered primary particles can show contributions by scattering at target particles and at implanted primary particles. The occurrence of these contributions depends again strongly on the scattering geometry but also on the primary ion species. The energy of directly sputtered and backscattered particles was calculated using equations based on simple two-particle-interaction whereas the energy distribution was simulated using the well-known Monte Carlo code TRIM.SP. In principal, the calculation and simulation data agree well with the experimental findings. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Thickness effect on properties of titanium film deposited by d.c. magnetron sputtering and electron beam evaporation techniques

    Indian Academy of Sciences (India)

    Nishat Arshi; Junqing Lu; Chan Gyu Lee; Jae Hong Yoon; Bon Heun Koo; Faheem Ahmed

    2013-10-01

    This paper reports effect of thickness on the properties of titanium (Ti) film deposited on Si/SiO2 (100) substrate using two different methods: d.c. magnetron sputtering and electron beam (e-beam) evaporation technique. The structural and morphological characterization of Ti film were performed using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). XRD pattern revealed that the films deposited using d.c. magnetron sputtering have HCP symmetry with preferred orientation along (002) plane, while those deposited with e-beam evaporation possessed fcc symmetry with preferred orientation along (200) plane. The presence of metallic Ti was also confirmed by XPS analysis. FESEM images depicted that the finite sized grains were uniformly distributed on the surface and AFM micrographs revealed roughness of the film. The electrical resistivity measured using four-point probe showed that the film deposited using d.c. magnetron sputtering has lower resistivity of ∼13 cm than the film deposited using e-beam evaporation technique, i.e. ∼60 cm. The hardness of Ti films deposited using d.c. magnetron sputtering has lower value (∼7.9 GPa) than the film deposited using e-beam technique (∼9.4 GPa).

  19. Effect of e-beam irradiation on graphene layer grown by chemical vapor deposition

    International Nuclear Information System (INIS)

    We have grown graphene by chemical vapor deposition (CVD) and transferred it onto Si/SiO2 substrates to make tens of micron scale devices for Raman spectroscopy study. The effect of electron beam (e-beam) irradiation of various doses (600 to 12 000 μC/cm2) on CVD grown graphene has been examined by using Raman spectroscopy. It is found that the radiation exposures result in the appearance of the strong disorder D band attributed the damage to the lattice. The evolution of peak frequencies, intensities, and widths of the main Raman bands of CVD graphene is analyzed as a function of defect created by e-beam irradiation. Especially, the D and G peak evolution with increasing radiation dose follows the amorphization trajectory, which suggests transformation of graphene to the nanocrystalline and then to amorphous form. We have also estimated the strain induced by e-beam irradiation in CVD graphene. These results obtained for CVD graphene are in line with previous findings reported for the mechanically exfoliated graphene [D. Teweldebrhan and A. A. Balandin, Appl. Phys. Lett. 94, 013101 (2009)]. The results have important implications for CVD graphene characterization and device fabrication, which rely on the electron microscopy.

  20. The role of electron-stimulated desorption in focused electron beam induced deposition

    DEFF Research Database (Denmark)

    van Dorp, Willem F.; Hansen, Thomas Willum; Wagner, Jakob Birkedal;

    2013-01-01

    We present the results of our study about the deposition rate of focused electron beam induced processing (FEBIP) as a function of the substrate temperature with the substrate being an electron-transparent amorphous carbon membrane. When W(CO)6 is used as a precursor it is observed that the growth...... experiments compared to literature values is consistent with earlier findings by other authors. The discrepancy is attributed to electron-stimulated desorption, which is known to occur during electron irradiation. The data suggest that, of the W(CO)6 molecules that are affected by the electron irradiation......, the majority desorbs from the surface rather than dissociates to contribute to the deposit. It is important to take this into account during FEBIP experiments, for instance when determining fundamental process parameters such as the activation energy for desorption....

  1. Nanomanufacturing of titania interfaces with controlled structural and functional properties by supersonic cluster beam deposition

    Energy Technology Data Exchange (ETDEWEB)

    Podestà, Alessandro, E-mail: alessandro.podesta@mi.infn.it, E-mail: pmilani@mi.infn.it; Borghi, Francesca; Indrieri, Marco; Bovio, Simone; Piazzoni, Claudio; Milani, Paolo, E-mail: alessandro.podesta@mi.infn.it, E-mail: pmilani@mi.infn.it [Centro Interdisciplinare Materiali e Interfacce Nanostrutturati (C.I.Ma.I.Na.), Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano (Italy)

    2015-12-21

    Great emphasis is placed on the development of integrated approaches for the synthesis and the characterization of ad hoc nanostructured platforms, to be used as templates with controlled morphology and chemical properties for the investigation of specific phenomena of great relevance in interdisciplinary fields such as biotechnology, medicine, and advanced materials. Here, we discuss the crucial role and the advantages of thin film deposition strategies based on cluster-assembling from supersonic cluster beams. We select cluster-assembled nanostructured titania (ns-TiO{sub 2}) as a case study to demonstrate that accurate control over morphological parameters can be routinely achieved, and consequently, over several relevant interfacial properties and phenomena, like surface charging in a liquid electrolyte, and proteins and nanoparticles adsorption. In particular, we show that the very good control of nanoscale morphology is obtained by taking advantage of simple scaling laws governing the ballistic deposition regime of low-energy, mass-dispersed clusters with reduced surface mobility.

  2. Influence of laser power on deposition of the chromium atomic beam in laser standing wave

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    One-dimensional deposition of collimated Cr atomic beam focused by a near-resonant Gaussian standing-laser field with wavelength of 425.55 nm is examined from particle-optics approach by using an adaptive step size,fourth-order Runge-Kutta type algorithm.The influence of laser power on deposition of atoms in laser standing wave is discussed and the simulative result shows that the FWHM of nanometer stripe is 102 nm and contrast is 2:1 with laser power equal to 3 mW,the FWHM is 1.2 nm and contrast is 32:1 with laser power equal to 16 mW,but with laser power increase,equal to 50 mW,the nonmeter structure forms the multi-crests and exacerbates.

  3. Laser assisted modification and chemical metallization of electron-beam deposited ceria thin films

    International Nuclear Information System (INIS)

    Excimer laser processing is applied for tailoring the surface morphology and phase composition of CeO2 ceramic thin films. E-beam evaporation technique is used to deposit samples on stainless steel and silicate glass substrates. The films are then irradiated with ArF* excimer laser pulses under different exposure conditions. Scanning electron microscopy, optical spectrophotometry, X-ray diffractometry and EDS microanalysis are used to characterize the non-irradiated and laser-processed films. Upon UV laser exposure there is large increase of the surface roughness that is accompanied by photo-darkening and ceria reduction. It is shown that the laser induced changes in the CeO2 films facilitate the deposition of metal nano-aggregates in a commercial copper electroless plating bath. The significance of laser modification as a novel approach for the production of CeO2 based thin film catalysts is discussed.

  4. Antibacterial and corrosion resistance of TiN/Ag multilayers by ion beam assisted deposition

    International Nuclear Information System (INIS)

    TiN/Ag multilayers were deposited on medical stainless steel 317L by ion beam assisted deposition (IBAD). Standard agar dilution method was used to test antibacterial ratio using E.coil and S.aureus. Electro-chemical method was used to test corrosion resistance of the film in Hank's simulated human plasma. The structure and depth profile of the elements were investigated by XPS, XRD and ALES. The results show that a strong antibacterial ratio (>99%) can be obtained when the modulation period of TiN/Ag multilayers is 8 nm (5 nm TiN and 3 nm Ag). Its corrosion resistance is better than medical stainless steel 317L, approaching monolayer TiN. (authors)

  5. Ion beam sputter deposition of V 2O 5 thin films

    Science.gov (United States)

    Gallasch, T.; Stockhoff, T.; Baither, D.; Schmitz, G.

    V 2O 5 thin films were deposited by means of dc-ion beam sputtering. To determine the influence of various deposition parameters, samples were characterized by X-ray diffractometry and transmission electron microscopy. Using electron energy loss spectroscopy, the oxidation state of vanadium was quantified based on the chemical shift of absorption edges. Measurement of in-plane direct current showed that the electronic conductivity varies over several orders of magnitude depending on the preparation conditions. The desired structure suitable for battery applications is achieved by sputtering under partial pressure of oxygen and suitable post-annealing under ambient atmosphere. Reversible intercalation of Li into the produced thin films was demonstrated.

  6. Nanomanufacturing of titania interfaces with controlled structural and functional properties by supersonic cluster beam deposition

    International Nuclear Information System (INIS)

    Great emphasis is placed on the development of integrated approaches for the synthesis and the characterization of ad hoc nanostructured platforms, to be used as templates with controlled morphology and chemical properties for the investigation of specific phenomena of great relevance in interdisciplinary fields such as biotechnology, medicine, and advanced materials. Here, we discuss the crucial role and the advantages of thin film deposition strategies based on cluster-assembling from supersonic cluster beams. We select cluster-assembled nanostructured titania (ns-TiO2) as a case study to demonstrate that accurate control over morphological parameters can be routinely achieved, and consequently, over several relevant interfacial properties and phenomena, like surface charging in a liquid electrolyte, and proteins and nanoparticles adsorption. In particular, we show that the very good control of nanoscale morphology is obtained by taking advantage of simple scaling laws governing the ballistic deposition regime of low-energy, mass-dispersed clusters with reduced surface mobility

  7. Mechanical properties of silicon oxynitride thin films prepared by low energy ion beam assisted deposition

    International Nuclear Information System (INIS)

    Silicon oxynitride (SiOxNy) films (0.1-0.7 μm) were produced on Si (1 0 0), glass and 316L stainless steel substrates by ion beam assisted deposition (IBAD) using Si evaporation and the concurrent bombardment with a mixture of 200 eV N2 and Ar, or O2 and Ar ions. Adhesion was evaluated by pull-off tests. Film hardness was measured by a nanoindentation system with AFM. The measurement of internal stress in the films was carried out by the Stoney method. The film structure was examined by GXRD. XPS was employed to measure the composition of films and to analyze the chemical bonds. The dependence of mechanical properties on the film thickness and the processing temperature during deposition was studied. Finally, the relations between the mechanical properties of the films and the correlation with corrosion-protection ability of films are discussed and summarized

  8. Mechanical properties of silicon oxynitride thin films prepared by low energy ion beam assisted deposition

    Science.gov (United States)

    Shima, Yukari; Hasuyama, Hiroki; Kondoh, Toshiharu; Imaoka, Yasuo; Watari, Takanori; Baba, Koumei; Hatada, Ruriko

    1999-01-01

    Silicon oxynitride (SiO xN y) films (0.1-0.7 μm) were produced on Si (1 0 0), glass and 316L stainless steel substrates by ion beam assisted deposition (IBAD) using Si evaporation and the concurrent bombardment with a mixture of 200 eV N 2 and Ar, or O 2 and Ar ions. Adhesion was evaluated by pull-off tests. Film hardness was measured by a nanoindentation system with AFM. The measurement of internal stress in the films was carried out by the Stoney method. The film structure was examined by GXRD. XPS was employed to measure the composition of films and to analyze the chemical bonds. The dependence of mechanical properties on the film thickness and the processing temperature during deposition was studied. Finally, the relations between the mechanical properties of the films and the correlation with corrosion-protection ability of films are discussed and summarized.

  9. Optimization of Energy Scope for Titanium Nitride Films Grown by Ion Beam-Assisted Deposition

    Institute of Scientific and Technical Information of China (English)

    LI Wei; MA Zhong-Quan; WANG Ye; WANG De-Ming

    2006-01-01

    The deposited energy during film growth with ion bombardment, correlated to the atomic displacement on the surface monolayer and the underlying bulk, has been calculated by a simplified ion-solid interaction model under binary collision approximation. The separated damage energies caused by Ar ion, different for the surface and the bulk, have been determined under the standard collision cross section and a well-defined surface and bulk atom displacement threshold energy of titanium nitride (TiN). The optimum energy scope shows that the incident energy of Ar+ around 110eV for TiN (111) and 80eV for TiN (200) effectively enhances the mobility of adatom on surface but excludes the damage in underlying bulk. The theoretical prediction and the experimental result are in good agreement in low energy ion beam-assisted deposition.

  10. Electroluminescence and its excitation mechanism of SiOx films deposited by electron-beam evaporation

    International Nuclear Information System (INIS)

    Blue electroluminescence from SiOx films deposited by electron beam evaporation was observed. This blue emission blueshifted from 450 to 410 nm with increasing applied voltage. The dependences of blue emission on applied voltage, frequency and conduction current were studied. Our experimental data support that blue emission from SiOx films is the result of both recombination of charge carriers injected from opposite electrodes and impact excitation of hot electrons, the recombination of carriers injected is dominant in low and medium electric fields but hot electron impact excitation is dominant under high electric fields

  11. MoSx films deposited on different matrices by ion beam technique

    International Nuclear Information System (INIS)

    MoSx(x = 1.79∼2.34) films of 200 nm thickness are deposited onto brass and C20 steel substrates by the ion beam assisted technique, respectively. Structures and compositions of these films, and changes in valence states of the Mo element are examined by XRD and XPS before and after wear. The lubrication properties and wear resistances for two kinds of samples are evaluated using a pin-on-disk installation in atmosphere at the room temperature. Tribo-wear behaviours and the microstructures between two kinds of samples exhibit obvious differences

  12. Energy deposition in selected-mammalian cell for several-MeV single-proton beam

    Science.gov (United States)

    Ding, K.; Yu, Z.

    2007-05-01

    The phenomena resulting from interaction between ion beam and mammalian cell pose important problems for biological applications. Classic Bethe-Bloch theory utilizing attached V79 mammalian cell has been conducted in order to establish the stopping powers of the mammalian cell for several-MeV single-proton microbeam. Based on the biological structure of the mammalian cell, a physical model is proposed which presumes that the attached cell is simple MWM model. According to this model and Monte Carlo simulation, we studied the energy deposition and its ratio on the selected attached mammalian cell for MeV proton implantation.

  13. Analyses of the microstructures of Si3N4 film by ion beam enhanced deposition

    International Nuclear Information System (INIS)

    TEM, SEM and X-ray have been used to investigate the microstructures of the silicon ntiride film by Ion Beam Enhanced Deposition (IBED) on surface of 1 Cr19Ni9Ti. Observation reveals that Si3N4 is the amorphous structure and have a little dispersed single crystal phase β-Si3N4 in the film. The physiognomy of Si3N4, interface shape of Si3N4/1Cr18Ni9Ti and the factors influencing on the formation were discussed

  14. Dispersive ground plane core-shell type optical monopole antennas fabricated with electron beam induced deposition.

    Science.gov (United States)

    Acar, Hakkı; Coenen, Toon; Polman, Albert; Kuipers, Laurens Kobus

    2012-09-25

    We present the bottom-up fabrication of dispersive silica core, gold cladding ground plane optical nanoantennas. The structures are made by a combination of electron-beam induced deposition of silica and sputtering of gold. The antenna lengths range from 300 to 2100 nm with size aspect ratios as large as 20. The angular emission patterns of the nanoantennas are measured with angle-resolved cathodoluminescence spectroscopy and compared with finite-element methods. Good overall correspondence between the the measured and calculated trends is observed. The dispersive nature of these plasmonic monopole antennas makes their radiation profile highly tunable. PMID:22889269

  15. Atomic layer deposition of an Al2O3 dielectric on ultrathin graphite by using electron beam irradiation

    Institute of Scientific and Technical Information of China (English)

    Jiang Ran; Meng Lingguo; Zhang Xijian; Hyung-Suk Jung; Cheol Seong Hwang

    2012-01-01

    Atomic layer deposition ofan Al2O3 dielectric on ultrathin graphite is studied in order to investigate the integration of a high k dielectric with graphite-based substrates.Electron beam irradiation on the graphite surface is followed by a standard atomic layer deposition of Al2O3.Improvement of the Al2O3 layer deposition morphology was observed when using this radiation exposure on graphite.This result may be attributed to the amorphous change of the graphite layers during electron beam irradiation.

  16. Substrate effects on the electron-beam-induced deposition of platinum from a liquid precursor

    Science.gov (United States)

    Donev, Eugenii U.; Schardein, Gregory; Wright, John C.; Hastings, J. Todd

    2011-07-01

    Focused electron-beam-induced deposition using bulk liquid precursors (LP-EBID) is a new nanofabrication technique developed in the last two years as an alternative to conventional EBID, which utilizes cumbersome gaseous precursors. Furthermore, LP-EBID using dilute aqueous precursors has been demonstrated to yield platinum (Pt) nanostructures with as-deposited metal content that is substantially higher than the purity achieved by EBID with currently available gaseous precursors. This advantage of LP-EBID--along with the ease of use, low cost, and relative innocuousness of the liquid precursors--holds promise for its practical applicability in areas such as rapid device prototyping and lithographic mask repair. One of the feasibility benchmarks for the LP-EBID method is the ability to deposit high-fidelity nanostructures on various substrate materials. In this study, we report the first observations of performing LP-EBID on bare and metal-coated silicon-nitride membranes, and compare the resulting Pt deposits to those obtained by LP-EBID on polyimide membranes in terms of nucleation, morphology, size dependence on electron dose, and purity.

  17. Beam steering laser assisted deposition system for high-Tc superconducting thin film devices

    International Nuclear Information System (INIS)

    We present the design and construction of a beam steering laser-assisted deposition system (LAD) for high quality epitaxial YBaCuO superconducting thin film production suitable for commercial application. Deposition of single layer or multilayer YBaCuO superconducting thin film on large and complex surfaced substrate is now feasible. Expitaxial and polycrystaline films with onsets at 90 K having 6 K transition widths have been produced. Dome-shaped magnetic shield enclosures, microwave cavity resonant in the TM010 mode, and short dipole antennas have been fabricated. The advantages of the laser ablation deposition method [J. T. Cheung and D. T. Chueng, J. Vac. Sci. Technol. 21, 182 (1982)] are its simplicity and cleanliness. Laser ablation deposition is a viable method to produce high quality thin film of the Tl-based compound [S. H. Liou and K. D. Aylesworth, Appl. Phys. Lett. 54, 760 (1989)] by using a small target in a sealed environment which is important in handling toxic material of a Tl-based compounds

  18. Flexible, ionic liquid-based micro-supercapacitor produced by supersonic cluster beam deposition

    International Nuclear Information System (INIS)

    Highlights: • We exploited Supersonic Cluster Beam Deposition for the fabrication of a flexible, planar micro-supercapacitor featuring nanostructured carbon electrodes deposited on a plastic Mylar substrate and N-trimethyl-N-propyl-ammonium bis(trifluoromethanesulfonyl) imide (N1113TFSI) ionic liquid electrolyte. • The micro-supercapacitor operates at 3 V above RT up to 80 °C with a capacitance density approaching 10 F cm−3 and delivering maximum specific energy and power densities of 10 mWh cm−3 and 8-10 W cm−3. • The micro-supercapacitor features long cycling stability over 2x104cycle on flat and bent configuration. -- Graphical abstract: Display Omitted -- Abstract: Power generation and storage in electronics require flexible, thin micro-electrochemical energy storage/conversion systems. Micro-supercapacitors (μSCs) with double-layer capacitance carbon electrodes are attracting much attention for their capability of delivering short power pulses with high stability over repeated charge/discharge cycling. Supersonic Cluster Beam Deposition (SCBD) is an effective strategy for the development of nanostructured, binder-free porous carbon electrodes on temperature sensitive substrates including polymers. We exploited SCBD for the development of a flexible, planar μSC featuring nanostructured carbon (ns-C) electrodes deposited on a plastic Mylar substrate and N-trimethyl-N-propyl-ammonium bis(trifluoromethanesulfonyl) imide (N1113TFSI) ionic liquid electrolyte. The electrochemical performance at different temperatures of the μSC which operates at 3 V above RT up to 80 °C with a capacitance density approaching 10 F cm−3 and delivering maximum specific energy and power densities of 10 mWh cm−3 and 8-10 W cm−3 with long cycling stability over 2 × 104 cycles is here reported and discussed

  19. Mechanical properties and thermal stability of TiAlN/Ta multilayer film deposited by ion beam assisted deposition

    International Nuclear Information System (INIS)

    Highlights: • Nanohardness of the TiAlN/Ta multilayer film was 29% higher than that of the TiAlN monolayer film. • Compared to the TiAlN monolayer film, a 47% increase of elastic modulus was achieved. • Bonding strength of the TiAlN/Ta multilayer film was higher than that of the TiAlN monolayer film. • The TiAlN/Ta multilayer film has better thermal stability than the TiAlN monolayer film. - Abstract: TiAlN/Ta multilayer film with the total thickness of 2 μm was deposited onto silicon (1 0 0) wafer by ion beam assisted deposition using Ti0.5Al0.5 and Ta as the target materials. Observation of the cross-sectional microstructure and XRD pattern showed that the Ta sub-layer restrained the growth of TiAlN crystal, and decreased the grain size. Nanohardness (H) of the TiAlN/Ta multilayer film was 29% higher and the elastic modulus (E) was 47% higher than that of the TiAlN monolayer film. The critical fracture load (Lc) of 72 mN for the TiAlN/Ta multilayer film was achieved, much higher than that of the monolayer TiAlN film (30 mN), indicated a significant increase of bonding strength. Results of DSC analysis indicated that the TiAlN/Ta multilayer film had the exothermic peak at around 935 °C, 75 °C above that for the TiAlN monolayer film. Existence of the Ta sub-layers behaved as the barrier layers to prevent oxygen from diffusing into inner layers, resulted in the improvement of thermal stability

  20. Infrared and ion beam analysis of SI/sub x/N/sub 1-x/ alloys grown by ion beam assisted deposition

    International Nuclear Information System (INIS)

    Thin films of amorphous Si/sub x/N/sub 1-x/ alloys were produced by nitrogen ion beam assisted deposition of electron beam evaporated silicon. Infrared reflection spectra were measured in the range 600 to 10000 cm/sup -1/. Fringes were observed due to interference between light multiply-reflected from the front surface and film-substrate (single crystal silicon) interface. Similar measurements were performed on films crystallized by post-deposition furnace anneals. Analyses of the reflection spectra were used to obtain refractive index profiles. Profiles were correlated with nitrogen content as measured by Rutherford Backscattering Spectometry (RBS) and Auger Electron Spectroscopy (AES). Film adhesion, density, and purity were found to be improved for depositions assisted by nitrogen ion beams (1000 to 25,000 eV) relative to unassisted evaporation, and the index of refraction decreases monotonically with increasing nitrogen content

  1. Ion beams as a means of deposition and in-situ characterization of thin films and thin film layered structures

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, A.R.; Rangaswamy, M.; Gruen, D.M. (Argonne National Lab., IL (United States)); Lin, Y.P. (Argonne National Lab., IL (United States) Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science); Schultz, J.A. (Ionwerks, Inc., Houston, TX (United States)); Schmidt, H. (Schmidt Instruments, Inc., Houston, TX (United States)); Liu, Y.L. (Argonne National Lab., IL (United States

    1992-01-01

    Ion beam-surface interactions produce many effects in thin film deposition which are similar to those encountered in plasma deposition processes. However, because of the lower pressures and higher directionality associated with the ion beam process, it is easier to avoid some sources of film contamination and to provide better control of ion energies and fluxes. Additional effects occur in the ion beam process because of the relatively small degree of thermalization resulting from gas phase collisions with both the ion beam and atoms sputtered from the target. These effects may be either beneficial or detrimental to the film properties, depending on the material and deposition conditions. Ion beam deposition is particularly suited to the deposition of multi-component films and layered structures, and can in principle be extended to a complete device fabrication process. However, complex phenomena occur in the deposition of many materials of high technical interest which make it desirable to monitor the film growth at the monolayer level. It is possible to make use of ion-surface interactions to provide a full suite of surface analytical capabilities in one instrument, and this data may be obtained at ambient pressures which are far too high for conventional surface analysis techniques. Such an instrument is under development and its current performance characteristics and anticipated capabilities are described.

  2. Ion beams as a means of deposition and in-situ characterization of thin films and thin film layered structures

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, A.R.; Rangaswamy, M.; Gruen, D.M. [Argonne National Lab., IL (United States); Lin, Y.P. [Argonne National Lab., IL (United States)]|[Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science; Schultz, J.A. [Ionwerks, Inc., Houston, TX (United States); Schmidt, H. [Schmidt Instruments, Inc., Houston, TX (United States); Liu, Y.L. [Argonne National Lab., IL (United States)]|[Wisconsin Univ., Milwaukee, WI (United States). Dept. of Materials Science; Auciello, O. [Microelectronics Center of North Carolina, Research Triangle Park, NC (United States); Barr, T. [Wisconsin Univ., Milwaukee, WI (United States). Dept. of Materials Science; Chang, R.P.H. [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science

    1992-08-01

    Ion beam-surface interactions produce many effects in thin film deposition which are similar to those encountered in plasma deposition processes. However, because of the lower pressures and higher directionality associated with the ion beam process, it is easier to avoid some sources of film contamination and to provide better control of ion energies and fluxes. Additional effects occur in the ion beam process because of the relatively small degree of thermalization resulting from gas phase collisions with both the ion beam and atoms sputtered from the target. These effects may be either beneficial or detrimental to the film properties, depending on the material and deposition conditions. Ion beam deposition is particularly suited to the deposition of multi-component films and layered structures, and can in principle be extended to a complete device fabrication process. However, complex phenomena occur in the deposition of many materials of high technical interest which make it desirable to monitor the film growth at the monolayer level. It is possible to make use of ion-surface interactions to provide a full suite of surface analytical capabilities in one instrument, and this data may be obtained at ambient pressures which are far too high for conventional surface analysis techniques. Such an instrument is under development and its current performance characteristics and anticipated capabilities are described.

  3. Structural changes of electron and ion beam-deposited contacts in annealed carbon-based electrical devices

    KAUST Repository

    Batra, Nitin M

    2015-10-09

    The use of electron and ion beam deposition to make devices containing discrete nanostructures as interconnectors is a well-known nanofabrication process. Classically, one-dimensional materials such as carbon nanotubes (CNTs) have been electrically characterized by resorting to these beam deposition methods. While much attention has been given to the interconnectors, less is known about the contacting electrodes (or leads). In particular, the structure and chemistry of the electrode–interconnector interface is a topic that deserves more attention, as it is critical to understand the device behavior. Here, the structure and chemistry of Pt electrodes, deposited either with electron or ion beams and contacted to a CNT, are analyzed before and after thermally annealing the device in a vacuum. Free-standing Pt nanorods, acting as beam-deposited electrode models, are also characterized pre- and post-annealing. Overall, the as-deposited leads contain a non-negligible amount of amorphous carbon that is consolidated, upon heating, as a partially graphitized outer shell enveloping a Pt core. This observation raises pertinent questions regarding the definition of electrode–nanostructure interfaces in electrical devices, in particular long-standing assumptions of metal-CNT contacts fabricated by direct beam deposition methods.

  4. Structural changes of electron and ion beam-deposited contacts in annealed carbon-based electrical devices

    Science.gov (United States)

    Batra, Nitin M.; Patole, Shashikant P.; Abdelkader, Ahmed; Anjum, Dalaver H.; Deepak, Francis L.; Costa, Pedro M. F. J.

    2015-11-01

    The use of electron and ion beam deposition to make devices containing discrete nanostructures as interconnectors is a well-known nanofabrication process. Classically, one-dimensional materials such as carbon nanotubes (CNTs) have been electrically characterized by resorting to these beam deposition methods. While much attention has been given to the interconnectors, less is known about the contacting electrodes (or leads). In particular, the structure and chemistry of the electrode-interconnector interface is a topic that deserves more attention, as it is critical to understand the device behavior. Here, the structure and chemistry of Pt electrodes, deposited either with electron or ion beams and contacted to a CNT, are analyzed before and after thermally annealing the device in a vacuum. Free-standing Pt nanorods, acting as beam-deposited electrode models, are also characterized pre- and post-annealing. Overall, the as-deposited leads contain a non-negligible amount of amorphous carbon that is consolidated, upon heating, as a partially graphitized outer shell enveloping a Pt core. This observation raises pertinent questions regarding the definition of electrode-nanostructure interfaces in electrical devices, in particular long-standing assumptions of metal-CNT contacts fabricated by direct beam deposition methods.

  5. Further studies on MgF(2)-overcoated aluminum mirrors with highest reflectance in the vacuum ultraviolet.

    Science.gov (United States)

    Canfield, L R; Hass, G; Waylonis, J E

    1966-01-01

    MgF(2)-overcoated aluminum films with high-vacuum ultraviolet reflectance have been the subject of further investigations of the preparation parameters affecting their reflectance, and of the effect of aging and exposure to conditions likely to be encountered in their applications. Techniques for monitoring the thickness of MgF(2) by reflectance measurements with ultraviolet light and by complete evaporation of weighed quantities of MgF(2) are described. It is shown that MgF(2)-protected aluminum mirrors retain their high-vacuum ultraviolet reflectance during extended exposure to air, ultraviolet irradiation, and bombardment with 1-MeV electrons and 5-MeV protons, and that such mirrors can be easily cleaned if contaminated with oil. PMID:20048784

  6. Laser beam soldering of fine-pitch technology packages with solid solder deposits

    Science.gov (United States)

    Pucher, Hans-Joerg; Glasmacher, Mathias; Geiger, Manfred

    1996-04-01

    Micro electronics is a key technology attracting the attention of information, communication, automation and data processing technologies. Ongoing miniaturization combined with an increasing number of I/Os has inevitably lead to ever finer lead geometries. Therefore the demands put upon the surface mount technology are increasing continuously. Processing of high lead count fine pitch packages, for example those which are applied in high-capacity computers, has not increased the demands put upon the assembly process only, but also on the connecting techniques. By reflow soldering with laser beam radiation the benefits from the tool `laser beam' are used extensively, for example contact and force free processing, strictly localized heating and the good controllability thereof, formation of fine crystalline and homogeneous structures, etc. Within the scope of this paper the fundamentals of laser beam soldering are discussed for fine pitch lead frames (pitch 300 micrometers ) for plastic packages, made by a modified CuFe2P alloy with a 5 micrometers Sn90Pb plating, on solid solder depths (Sn63Pb) performed by the so called High-Pad process. These investigations are unique in the field of laser beam soldering and are carried out by means of a Nd:YAG-laser. A pyrometer is used for detection of the emission of the temperature radiation of the joining area for process control. The additional use of a high-speed camera gives a detailed description of the melting and wetting process. The influence of laser beam parameters and the volume of the solid solder deposits on the joining result are presented.

  7. Biaxial Texture Evolution in MgO Films Fabricated Using Ion Beam-Assisted Deposition

    Science.gov (United States)

    Xue, Yan; Zhang, Ya-Hui; Zhao, Rui-Peng; Zhang, Fei; Lu, Yu-Ming; Cai, Chuan-Bing; Xiong, Jie; Tao, Bo-Wan

    2016-04-01

    The growth of multifunctional thin films on flexible substrates is important technologically, because flexible electronics require such a platform. In this study, we examined the evolution of biaxial texture in MgO films prepared using ion beam-assisted deposition (IBAD) on a Hastelloy substrate. Texture and microstructure developments were characterized through in situ reflection high-energy electron diffraction monitoring, x-ray diffraction, and atomic force microscopy, which demonstrated that biaxial texture was developed during the nucleation stage (~2.2 nm). The best biaxial texture was obtained with a thickness of approximately 12 nm. As MgO continued to grow, the influence of surface energy was reduced, and film growth was driven by the attempt to minimize volume free-energy density. Thus the MgO grains were subsequently rotated at the (002) direction toward the ion beam. In addition, an approach was developed for accelerating in-plane texture evolution by pre-depositing an amorphous MgO layer before IBAD.

  8. Ion beam deposition of DLC and nitrogen doped DLC thin films for enhanced haemocompatibility on PTFE

    International Nuclear Information System (INIS)

    Diamond-like carbon (DLC) and N-doped DLC (DLC:N) thin films have been synthesized on polytetrafluroethylene (PTFE) and silicon wafers using ion beam deposition. Raman spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy and scanning electron microscopy were used to study the structural and morphological properties of the coated surface. The results show that the ion beam deposited DLC thin films exhibit high hardness and Young's modulus, low coefficient of friction and high adhesion to the substrate. Low concentration of nitrogen doping in DLC improves the mechanical properties and reduces the surface roughness. DLC coating decreases the surface energy and improves the wettability of PTFE. The platelet adhesion results show that the haemocompatibility of DLC coated PTFE, especially DLC:N coated PTFE, has been significantly enhanced as compared with uncoated PTFE. SEM observations show that the platelet reaction on the DLC and DLC:N coated PTFE was minimized as the platelets were much less aggregated and activated.

  9. Biaxial Texture Evolution in MgO Films Fabricated Using Ion Beam-Assisted Deposition

    Science.gov (United States)

    Xue, Yan; Zhang, Ya-Hui; Zhao, Rui-Peng; Zhang, Fei; Lu, Yu-Ming; Cai, Chuan-Bing; Xiong, Jie; Tao, Bo-Wan

    2016-07-01

    The growth of multifunctional thin films on flexible substrates is important technologically, because flexible electronics require such a platform. In this study, we examined the evolution of biaxial texture in MgO films prepared using ion beam-assisted deposition (IBAD) on a Hastelloy substrate. Texture and microstructure developments were characterized through in situ reflection high-energy electron diffraction monitoring, x-ray diffraction, and atomic force microscopy, which demonstrated that biaxial texture was developed during the nucleation stage (~2.2 nm). The best biaxial texture was obtained with a thickness of approximately 12 nm. As MgO continued to grow, the influence of surface energy was reduced, and film growth was driven by the attempt to minimize volume free-energy density. Thus the MgO grains were subsequently rotated at the (002) direction toward the ion beam. In addition, an approach was developed for accelerating in-plane texture evolution by pre-depositing an amorphous MgO layer before IBAD.

  10. Magnetotransport properties of high-quality cobalt nanowires grown by focused-electron-beam-induced deposition

    International Nuclear Information System (INIS)

    High-quality cobalt nanowires have been grown by focused-electron-beam-induced deposition (FEBID) and their magnetic and transport properties determined. The nanowires contain up to about 95% Co atomic percentage, as measured by EDX spectroscopy, which remarkably represents a high value compared with other metal deposits grown by the same technique. The Co content has been found to correlate with the beam current used for the growth. The magnetotransport properties have been studied on individual nanowires through 4-probe measurements. For the nanowires with the highest Co content, the resistivity at room temperature is low (∼40 μΩ cm), and shows metallic temperature dependence. The magnetotransport properties clearly demonstrate the ferromagnetic nature of the nanowire, with a saturation magnetization of Ms = 1329 ± 20 emu cm-3, very close to the bulk one. Due to the local character of this type of growth at targeted places and its high lateral resolution, these results pave the way for the creation of magnetic nanostructures and devices with the full potentiality of high-quality Co.

  11. Laser conditioning of LaF 3 MgF 2 dielectric coatings at 248 nm

    Science.gov (United States)

    Eva, E.; Mann, K.; Kaiser, N.; Anton, B.; Henking, R.; Ristau, D.; Weissbrodt, P.; Mademann, D.; Raupach, L.; Hacker, E.

    1996-10-01

    Highly reflective LaF3/MgF2 systems for a wavelength of 248 nm on MgF2 and crystalline quartz substrates were investigated. The influence of laser conditioning on damage threshold and absorptance was remarkable in those coatings that had a high initial absorptance. Monitoring with a laser calorimeter revealed the conditioning effect to be a function of the irradiation dose rather than of energy density or pulse rate. Furthermore, x-ray photoelectron spectroscopy and transmission electron microscopy investigations showed that conditioning induces stoichiometric and structural changes in the multilayers, especially in near-surface sublayers, whereas scanning electron microscopy and atomic force microscopy investigations indicated that the surface remains unchanged.

  12. Ion-beam analysis of CuInSe2 solar cells deposited on polyimide foil.

    Science.gov (United States)

    Spemann, D; Lorenz, M; Butz, T; Otte, K

    2004-06-01

    CuInSe(2) (CIS) solar cells deposited on polyimide foil by the Solarion company in a web-coater-based process using sputter and evaporation techniques were investigated in the ion beam laboratory LIPSION of the University of Leipzig by means of Rutherford backscattering spectrometry (RBS) and particle-induced X-ray emission (PIXE) using high-energy broad ion beams and microbeams. From these measurements the composition of the absorber and the lateral homogeneity and film thicknesses of the individual layers could be determined on the basis of some reasonable assumptions. For the first time, quantitative depth profiling of the individual elements was performed by microPIXE measurements on a beveled section prepared by ion-beam etching of a CIS solar cell. Within the CIS absorber layer no significant concentration-depth gradients were found for Cu, In, and Se, in contrast with results from secondary neutral mass spectrometry (SNMS) depth profiling, which was applied to the same samples for comparison. Furthermore, both PIXE and SNMS showed the presence of a remarkable amount of Cd from the CdS buffer layer in the underlying absorber. PMID:15179537

  13. Ion-beam-induced epitaxial crystallization of implanted and chemical vapor deposited amorphous silicon

    Science.gov (United States)

    La Ferla, A.; Priolo, F.; Spinella, C.; Rimini, E.; Baroetto, F.; Ferla, G.

    1989-03-01

    The dependence of ion-beam enhanced epitaxial growth of amorphous Si layers on impurities either dissolved in the film or present at the film-substrate interface is considered. In the case of ion implanted layers, electrically active dopants, like B, P, As at concentrations above 1 × 10 20/cm 3, enhance the rate by a factor of 2 with respect to the undoped layer. The enhancement shows also a weak dependence on the dopant concentration. Inert impurities, like Ar, which prevent pure thermal regrowth, do not show any appreciable influence on the ion-beam-induced growth rate. Chemical vapor deposited Si layers with a thin native interfacial oxide layer can also be epitaxially regrown under ion irradiation. A critical fluence is needed before the interfacial oxide breaks down and broadens, allowing the epitaxial crystallization to take place. This process is characterized by an activation energy of 0.44 eV. The complex phenomenon of ion-beam-induced crystallization involves a dynamical interaction between production and annealing of point defects. The presence of electrically active dopants probably influences the lifetime of point defects. Impurities which prevent thermal regrowth are instead dissolved by ballistic effects and/or radiation-enhanced mixing.

  14. Influence of deposition rate on the properties of ZrO2 thin films prepared in electron beam evaporation method

    Institute of Scientific and Technical Information of China (English)

    Dongping Zhang(张东平); Meiqiong Zhan(占美琼); Ming Fang(方明); Hongbo He(贺洪波); Jianda Shao(邵建达); Zhengxiu Fan(范正修)

    2004-01-01

    ZrO2 thin films were prepared in electron beam thermal evaporation method. And the deposition rate changed from 1.3 to 6.3 nm/s in our study. X-ray diffractometer and spectrophotometer were employed to characterize the films. X-ray diffraction (XRD) spectra pattern shows that films structure changed from amorphous to polycrystalline with deposition rate increasing. The results indicate that internal stresses of the films are compressive in most case. Thin films deposited in our study are inhomogeneous, and the inhomogeneity is enhanced with the deposition rate increasing.

  15. Thermoluminescence of Y2O3:Tb3+ thin films deposited by electron beam evaporation

    International Nuclear Information System (INIS)

    Most thermoluminescent materials are created using crystal growth techniques; however, it would be of great utility to identify those few thermoluminescent materials that can be deposited using simpler methods, for example to be compatible with the early portions of a silicon integrated circuit or microelectromechanical fabrication process. In this work, thin films of yttrium oxide with a terbium impurity (Y2O3:Tb) were deposited on silicon wafers by electron beam evaporation. The source for the Y2O3:Tb was made by combining Y2O3 and Tb4O7 powders. The approximate thicknesses of the deposited films were 350 nm. After deposition, the films were annealed at 1100 °C for 30 s to improve crystallinity. There is a strong correlation between the x-ray diffraction (XRD) peak intensity and the thermoluminescent glow curve intensity. The glow curve displays at least two peaks at 140 °C and 230 °C. The emission spectra was measured using successive runs with a monochromator set to a different wavelength for each run. There are two main emission peaks at 490 nm and 540 nm. The terbium impurity concentration of approximately 1 mol% was measured using Rutherford backscattering spectrometry (RBS). The Y2O3:Tb is sensitive to UV, x-ray, and gamma radiation. The luminescent intensity per unit mass of UV irradiated Y2O3:Tb was about 2 times that of x-ray irradiated TLD-100. -- Highlights: • Y2O3:Tb3+ thin film can be deposited using the common microfabrication technique of electron beam evaporation. • The Y2O3:Tb3+ requires an anneal of at least 900 °C to show thermoluminescence and 1100 °C anneal for the strongest thermoluminescent signal. • The Y2O3:Tb3+ will show a glow curve after being exposed to ionizing radiation from UV, x-ray, and gamma ray sources. • The luminescent intensity per unit mass of the UV irradiated Y2O3:Tb3+ is twice that of x-ray irradiated TLD-100(LiF:Ti, Mg)

  16. Energy deposition measurements of a large-diameter, intense relativistic electron beam for high-power gas laser excitation

    International Nuclear Information System (INIS)

    Measurements of electron-beam (e-beam) energy deposition in gaseous medium by a segmented totally stopping calorimeter and a pressure jump method are described, both of which gave the same values. Typical e-beam parameters are 2 MV, 80 kA, and 65 ns (FWHM). The e-beam cross-sectional area is 10 cm in diameter. First, the radial distribution of the e-beam current generated from the field-emission diode as a function of the axial magnetic field was measured. Next, for applications to longitudinal excitation of the high-power gas lasers, the e-beam energy deposition characteristics are measured in N2 for the propagation distance up to 2.3 m in terms of the axial magnetic field, the N2 gas pressure, and the radial e-beam distribution. As a result, the axial field equivalent to the self-magnetic field of the electron beam can acceptably control the e-beam generation and propagation uniformities

  17. Material properties of ion beam deposited oxides for the optoelectronic industry

    International Nuclear Information System (INIS)

    High quality, dense films of SiO2, Al2O3, Ta2O5, and TiO2 were deposited with an ion beam deposition system (IBD). IBD has significant advantages over other techniques in terms of directionality, stress control, repeatability, thermal stability, and film uniformity [J. J. Cuomo, J. M. E. Harper, C. R. Guarnieri, D. S. Yee, L. J. Atanasio, J. Angilello, C. T. Wu, and R. H. Hammond, J. Vac. Sci. Technol. 20, 349 (1982)]. To decrease the surface damage induced by ion bombardment, a multi-energy process was developed. This is especially important for laser facet coatings. The oxide films were optimized for the desired refractive index and zero absorption. Stress values of -0.2 to -0.5 GPa (compressive) and extremely good uniformity (2, all films remained in compressive stress after annealing. TiO2 turned tensile. With the variety of oxide materials developed, designing an anti-reflective or highly reflective stack, which satisfies requirements of stress, uniformity, deposition rate, and reflectance, becomes a matter of choosing the appropriate material set

  18. Structural transitions in electron beam deposited Co–carbonyl suspended nanowires at high electrical current densities

    Directory of Open Access Journals (Sweden)

    Gian Carlo Gazzadi

    2015-06-01

    Full Text Available Suspended nanowires (SNWs have been deposited from Co–carbonyl precursor (Co2(CO8 by focused electron beam induced deposition (FEBID. The SNWs dimensions are about 30–50 nm in diameter and 600–850 nm in length. The as-deposited material has a nanogranular structure of mixed face-centered cubic (FCC and hexagonal close-packed (HCP Co phases, and a composition of 80 atom % Co, 15 atom % O and 5 atom % C, as revealed by transmission electron microscopy (TEM analysis and by energy-dispersive X-ray (EDX spectroscopy, respectively. Current (I–voltage (V measurements with current densities up to 107 A/cm2 determine different structural transitions in the SNWs, depending on the I–V history. A single measurement with a sudden current burst leads to a polycrystalline FCC Co structure extended over the whole wire. Repeated measurements at increasing currents produce wires with a split structure: one half is polycrystalline FCC Co and the other half is graphitized C. The breakdown current density is found at 2.1 × 107 A/cm2. The role played by resistive heating and electromigration in these transitions is discussed.

  19. Structural transitions in electron beam deposited Co-carbonyl suspended nanowires at high electrical current densities.

    Science.gov (United States)

    Gazzadi, Gian Carlo; Frabboni, Stefano

    2015-01-01

    Suspended nanowires (SNWs) have been deposited from Co-carbonyl precursor (Co2(CO)8) by focused electron beam induced deposition (FEBID). The SNWs dimensions are about 30-50 nm in diameter and 600-850 nm in length. The as-deposited material has a nanogranular structure of mixed face-centered cubic (FCC) and hexagonal close-packed (HCP) Co phases, and a composition of 80 atom % Co, 15 atom % O and 5 atom % C, as revealed by transmission electron microscopy (TEM) analysis and by energy-dispersive X-ray (EDX) spectroscopy, respectively. Current (I)-voltage (V) measurements with current densities up to 10(7) A/cm(2) determine different structural transitions in the SNWs, depending on the I-V history. A single measurement with a sudden current burst leads to a polycrystalline FCC Co structure extended over the whole wire. Repeated measurements at increasing currents produce wires with a split structure: one half is polycrystalline FCC Co and the other half is graphitized C. The breakdown current density is found at 2.1 × 10(7) A/cm(2). The role played by resistive heating and electromigration in these transitions is discussed. PMID:26199833

  20. Stability of a current carrying single nanowire of tungsten (W) deposited by focused ion beam

    Science.gov (United States)

    Mandal, Pabitra; Das, Bipul; Raychaudhuri, A. K.

    2016-02-01

    We report an investigation on the stability of single W nanowire (NW) under direct current stressing. The NW of width ≈ 80 nm and thickness ≈ 100 nm was deposited on a SiO2/Si substrate by Focused Ion Beam (FIB) of Ga ions using W(CO)6 as a precursor. Such nanowires, used as interconnects in nanoelectronics, contain C and Ga in addition to W. The stability studies, done for the first time in such FIB deposited NWs, show that under current stressing these NWs behave very differently from that observed in conventional metal NWs or interconnects. The failure of such FIB deposited NW occurs at a relatively low current density (˜1011 A/m2) which is an order or more less than that seen in conventional metal NWs. The failure accompanies with formation of voids and hillocks, suggesting ionic migration as the cause of failure. However, the polarities of void and hillock formations are opposite to those observed in conventional metal interconnects. This observation along with preferential agglomeration of Ga ions in hillocks suggests that the ionic migration in such NWs is dominated by direct force as opposed to the migration driven by electron wind force in conventional metal interconnects.

  1. Ion beams application to modification of surface layer of solids with particular regard to IBAD method - ion beam assisted deposition realized in the INP; Zastosowanie wiazek jonowych do modyfikowania warstwy wierzchniej cial stalych, ze szczegolnym uwzglednieniem metody IBAD - Ion Beam Assisted Deposition, realizowanej w IFJ

    Energy Technology Data Exchange (ETDEWEB)

    Drwiega, M.; Lipinska, E.

    1992-12-31

    The different trends in ion engineering such as: dynamic ion mixing, ionized cluster beam deposition and ion beam assisted deposition are described. Some examples of properties of surface coatings are given and their applications are presented. The future of ion engineering is described. 48 refs, 12 figs, 4 tabs.

  2. Progress on channel spark development and application of pulsed electron beam deposition (PED) in the field of medical coating work

    International Nuclear Information System (INIS)

    A promising source for Pulsed Electron Beam Deposition (PED) is the channel spark. Recent improvements helped to reduce beam instabilities which up to now have limited the life time of the system. The beam power could be increased and because of better beam quality the transport length of the beam is increased from 1 to several centimeters (up to 10 cm). Together with other improvements on the triggering system and beam transport in dielectric tubes, the channel spark approaches industrial standards. An overview of actual applications in research and industry will be presented. An attractive feature of the pulsed electron beam thin film deposition is the conservation of stoichiometry even during deposition of multi-component earth-alkali and alkali glasses. Specially developed glasses like BIOGLAS registered have the ability to anchor soft living tissue at the surface. In form of a bulk material bio active glasses are brittle limiting its applications. Contrary to brittle bulk material a thin layers on medical implants exhibits reliable bio-functionality. Coating of implants with this category of materials is subject of the European INCOMED project (Innovative Coating of Medical Implants with Soft Tissue Anchoring Ability) which just has started

  3. Non-linear current-voltage characteristics of NS-tunnel junctions prepared by focused ion beam induced deposition

    International Nuclear Information System (INIS)

    We used a focused Ga-ion beam and the precursor W(CO)6 -injected into a vacuum chamber nearby the focal area of the beam- to create tungsten containing superconducting deposits with a critical temperature of about 5.2 K. The deposits were fabricated onto oxidized aluminum contacts pre-patterned by UV-photolithography. I-V- and V-dI/dV- measurements have been performed between 0.3 K and 6 K using a He3-cryostat. For selected beam energies used during deposition the samples show Josephson-junction like behaviour or tunneling of quasiparticles for temperatures below the superconducting transition of aluminum at about 2 K. In the temperature range between the superconducting transitions of the two electrodes Andreev-reflection was observed.

  4. High aspect ratio AFM Probe processing by helium-ion-beam induced deposition.

    Science.gov (United States)

    Onishi, Keiko; Guo, Hongxuan; Nagano, Syoko; Fujita, Daisuke

    2014-11-01

    A Scanning Helium Ion Microscope (SHIM) is a high resolution surface observation instrument similar to a Scanning Electron Microscope (SEM) since both instruments employ finely focused particle beams of ions or electrons [1]. The apparent difference is that SHIMs can be used not only for a sub-nanometer scale resolution microscopic research, but also for the applications of very fine fabrication and direct lithography of surfaces at the nanoscale dimensions. On the other hand, atomic force microscope (AFM) is another type of high resolution microscopy which can measure a three-dimensional surface morphology by tracing a fine probe with a sharp tip apex on a specimen's surface.In order to measure highly uneven and concavo-convex surfaces by AFM, the probe of a high aspect ratio with a sharp tip is much more necessary than the probe of a general quadrangular pyramid shape. In this paper we report the manufacture of the probe tip of the high aspect ratio by ion-beam induced gas deposition using a nanoscale helium ion beam of SHIM.Gas of platinum organic compound was injected into the sample surface neighborhood in the vacuum chamber of SHIM. The decomposition of the gas and the precipitation of the involved metal brought up a platinum nano-object in a pillar shape on the normal commercial AFM probe tip. A SHIM system (Carl Zeiss, Orion Plus) equipped with the gas injection system (OmniProbe, OmniGIS) was used for the research. While the vacuum being kept to work, we injected platinum organic compound ((CH3)3(CH3C5H4)Pt) into the sample neighborhood and irradiated the helium ion beam with the shape of a point on the apex of the AFM probe tip. It is found that we can control the length of the Pt nano-pillar by irradiation time of the helium ion beam. The AFM probe which brought up a Pt nano-pillar is shown in Figure 1. It is revealed that a high-aspect-ratio Pt nano-pillar of ∼40nm diameter and up to ∼2000 nm length can be grown. In addition, for possible heating

  5. Liquid phase deposition of polymers on arbitrary shaped surfaces and their suitability for e-beam patterning

    Energy Technology Data Exchange (ETDEWEB)

    Paeivaenranta, B; Leinonen, K; Kuittinen, M [University of Joensuu, Department of Physics and Mathematics, PO Box 111, FL-80101 Joensuu (Finland); Pudas, M; Pitkaenen, O [University of Oulu Microelectronics and Material Physics Laboratories and Empart Research Group of Infotech Oulu, Linnanmaa, PO Box 4500, FL-90014 Oulu (Finland); Baroni, P-Y; Scharf, T; Herzig, H-P [University of Neuchatel, Institute of MicroTechnology, A.-L. Breguet 2, 2000 Neuchatel (Switzerland)], E-mail: birgit.paivanranta@joensuu.fi

    2009-06-03

    We present a straightforward low cost liquid phase deposition method to coat arbitrary-shaped dielectric substrates with uniform electron beam sensitive polymer films. Furthermore, we investigate the use of electron beam lithography to pattern the coated pre-form substrates. The polymers studied are poly-methyl-methacrylate with different molecular weights, poly(methyl methacrylate-co-ethyl acrylate) and methyl methacrylate. The polymer coverage over the whole surface area is shown to be uniform and the thickness of the film dependent on the concentration of the polymer liquid used. As the uniform polymer layer is deposited on non-flat surfaces, we show that with an electron beam various surfaces, e.g. microlens arrays, can be re-patterned accurately with nanoscale features. Furthermore, we show the required dose for electron beam exposure to be dependent on the concentration and on the molecular weight of the polymer used.

  6. The role of low-energy electrons in focused electron beam induced deposition: four case studies of representative precursors

    Directory of Open Access Journals (Sweden)

    Rachel M. Thorman

    2015-09-01

    Full Text Available Focused electron beam induced deposition (FEBID is a single-step, direct-write nanofabrication technique capable of writing three-dimensional metal-containing nanoscale structures on surfaces using electron-induced reactions of organometallic precursors. Currently FEBID is, however, limited in resolution due to deposition outside the area of the primary electron beam and in metal purity due to incomplete precursor decomposition. Both limitations are likely in part caused by reactions of precursor molecules with low-energy (3, Pt(PF34, Co(CO3NO, and W(CO6. Through these case studies, it is evident that this combination of studies can provide valuable insight into potential mechanisms governing deposit formation in FEBID. Although further experiments and new approaches are needed, these studies are an important stepping-stone toward better understanding the fundamental physics behind the deposition process and establishing design criteria for optimized FEBID precursors.

  7. Low-temperature transport in ultra-thin tungsten films grown by focused-ion-beam deposition

    OpenAIRE

    Chiatti, O.; Warburton, P. A.

    2010-01-01

    We have fabricated tungsten-containing films by focused-ion-beam (FIB)-induced chemical vapour deposition. By using ion-beam doses below 50 pC/μm² on a substrate of amorphous silicon, we have grown continuous films with thickness below 20 nm. The low-temperature electron transport properties were investigated by measuring current-voltage characteristics for temperatures down to 400 mK and in magnetic fields up to 8 T. FIB-deposited tungsten films are known to have an enhanced transition tem­p...

  8. Continuous electropolishing of Hastelloy substrates for ion-beam assisted deposition of MgO

    Energy Technology Data Exchange (ETDEWEB)

    Kreiskott, Sascha; Arendt, Paul N; Bronisz, Lawrence E; Foltyn, Steve R; Matias, Vladimir [Superconductivity Technology Center, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2003-05-01

    We demonstrate the applicability of continuous electropolishing for the preparation of metal tapes for ion-beam assisted deposition of MgO for the fabrication of in-plane textured template layers. These templates are used for the fabrication of second generation high temperature superconducting wires utilizing YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} coatings on metallic substrates. Surface roughness values below 1 nm and local slopes of less than 1 deg. could be achieved with the electropolishing process. Mean surface roughness values are lower with the use of electropolishing and slopes of surface roughness inclines are significantly reduced compared to the best results of mechanical polishing (3.5 nm and 5 deg., respectively). The cost-effective process of electropolishing shows great promise for the fabrication of second generation high temperature superconducting wire.

  9. Continuous electropolishing of Hastelloy substrates for ion-beam assisted deposition of MgO

    International Nuclear Information System (INIS)

    We demonstrate the applicability of continuous electropolishing for the preparation of metal tapes for ion-beam assisted deposition of MgO for the fabrication of in-plane textured template layers. These templates are used for the fabrication of second generation high temperature superconducting wires utilizing YBa2Cu3O7-δ coatings on metallic substrates. Surface roughness values below 1 nm and local slopes of less than 1 deg. could be achieved with the electropolishing process. Mean surface roughness values are lower with the use of electropolishing and slopes of surface roughness inclines are significantly reduced compared to the best results of mechanical polishing (3.5 nm and 5 deg., respectively). The cost-effective process of electropolishing shows great promise for the fabrication of second generation high temperature superconducting wire

  10. Characterisation of molecular thin films grown by organic molecular beam deposition

    CERN Document Server

    Bayliss, S M

    2000-01-01

    This work concerns the growth and characterisation of molecular thin films in an ultra high vacuum regime by organic molecular beam deposition (OMBD). Films of three different molecular materials are grown, namely free base phthalocyanine (H sub 2 Pc), perylene 3,4,9,10-tetracarboxylic dianhydride (PTCDA) and aluminium tris-8-hydroxyquinoline (Alq sub 3). The relationship between the growth parameters such as film thickness, growth rate, and substrate temperature during and after growth, and the structural, optical and morphological properties of the film are investigated. These investigations are carried out using various ex-situ techniques. X-ray diffraction, Raman spectroscopy and electronic absorption spectroscopy are used to probe the bulk film characteristics, whilst Nomarski microscopy and atomic force microscopy are used to study the surface morphology. Three different levels of influence of the growth parameters on the film properties are observed. In the case of H sub 2 Pc, two crystal phases are fo...

  11. Focused-electron-beam-induced-deposited cobalt nanopillars for nanomagnetic logic

    Science.gov (United States)

    Sharma, N.; van Mourik, R. A.; Yin, Y.; Koopmans, B.; Parkin, S. S. P.

    2016-04-01

    Nanomagnetic logic (NML) intends to alleviate problems of continued miniaturization of CMOS-based electronics, such as energy dissipation through heat, through advantages such as low power operation and non-volatile magnetic elements. In line with recent breakthroughs in NML with perpendicularly magnetized elements formed from thin films, we have fabricated NML inverter chains from Co nanopillars by focused electron beam induced deposition (FEBID) that exhibit shape-induced perpendicular magnetization. The flexibility of FEBID allows optimization of NML structures. Simulations reveal that the choice of nanopillar dimensions is critical to obtain the correct antiferromagnetically coupled configuration. Experiments carrying the array through a clocking cycle using the Oersted field from an integrated Cu wire show that the array responds to the clocking cycle.

  12. Focused-electron-beam-induced-deposited cobalt nanopillars for nanomagnetic logic.

    Science.gov (United States)

    Sharma, N; van Mourik, R A; Yin, Y; Koopmans, B; Parkin, S S P

    2016-04-22

    Nanomagnetic logic (NML) intends to alleviate problems of continued miniaturization of CMOS-based electronics, such as energy dissipation through heat, through advantages such as low power operation and non-volatile magnetic elements. In line with recent breakthroughs in NML with perpendicularly magnetized elements formed from thin films, we have fabricated NML inverter chains from Co nanopillars by focused electron beam induced deposition (FEBID) that exhibit shape-induced perpendicular magnetization. The flexibility of FEBID allows optimization of NML structures. Simulations reveal that the choice of nanopillar dimensions is critical to obtain the correct antiferromagnetically coupled configuration. Experiments carrying the array through a clocking cycle using the Oersted field from an integrated Cu wire show that the array responds to the clocking cycle. PMID:26941232

  13. Potency of Full- Length MGF to Induce Maximal Activation of the IGF-I R Is Similar to Recombinant Human IGF-I at High Equimolar Concentrations.

    Directory of Open Access Journals (Sweden)

    Joseph A M J L Janssen

    Full Text Available To compare full-length mechano growth factor (full-length MGF with human recombinant insulin-like growth factor-I (IGF-I and human recombinant insulin (HI in their ability to activate the human IGF-I receptor (IGF-IR, the human insulin receptor (IR-A and the human insulin receptor-B (IR-B, respectively. In addition, we tested the stimulatory activity of human MGF and its stabilized analog Goldspink-MGF on the IGF-IR.The effects of full-length MGF, IGF-I, human mechano growth factor (MGF, Goldspink-MGF and HI were compared using kinase specific receptor activation (KIRA bioassays specific for IGF-I, IR-A or IR-B, respectively. These assays quantify activity by measuring auto-phosphorylation of the receptor upon ligand binding.IGF-IR: At high equimolar concentrations maximal IGF-IR stimulating effects generated by full-length MGF were similar to that of IGF-I (89-fold vs. 77-fold, respectively. However, EC50 values of IGF-I and full-length MGF for the IGF-I receptor were 0.86 nmol/L (95% CI 0.69-1.07 and 7.83 nmol/L (95% CI: 4.87-12.58, respectively. No IGF-IR activation was observed by human MGF and Goldspink-MGF, respectively. IR-A/IR-B: At high equimolar concentrations similar maximal IR-A stimulating effects were observed for full -length MGF and HI, but maximal IR-B stimulation achieved by full -length MGF was stronger than that by HI (292-fold vs. 98-fold. EC50 values of HI and full-length MGF for the IR-A were 1.13 nmol/L (95% CI 0.69-1.84 and 73.11 nmol/L (42.87-124.69, respectively; for IR-B these values were 1.28 nmol/L (95% CI 0.64-2.57 and 35.10 nmol/L (95% 17.52-70.33, respectively.Full-length MGF directly stimulates the IGF-IR. Despite a higher EC50 concentration, at high equimolar concentrations full-length MGF showed a similar maximal potency to activate the IGF-IR as compared to IGF-I. Further research is needed to understand the actions of full-length MGF in vivo and to define the physiological relevance of our in vitro findings.

  14. Potency of Full- Length MGF to Induce Maximal Activation of the IGF-I R Is Similar to Recombinant Human IGF-I at High Equimolar Concentrations

    OpenAIRE

    Janssen, Joseph A. M. J. L.; Hofland, Leo J.; Strasburger, Christian J.; Elisabeth S R van den Dungen; Mario Thevis

    2016-01-01

    textabstractAims To compare full-length mechano growth factor (full-length MGF) with human recombinant insulin-like growth factor-I (IGF-I) and human recombinant insulin (HI) in their ability to activate the human IGF-I receptor (IGF-IR), the human insulin receptor (IR-A) and the human insulin receptor-B (IR-B), respectively. In addition, we tested the stimulatory activity of human MGF and its stabilized analog Goldspink-MGF on the IGF-IR. Methods The effects of full-length MGF, IGF-I, human ...

  15. Potency of Full- Length MGF to Induce Maximal Activation of the IGF-I R Is Similar to Recombinant Human IGF-I at High Equimolar Concentrations

    Science.gov (United States)

    Janssen, Joseph A. M. J. L.; Hofland, Leo J.; Strasburger, Christian J.; van den Dungen, Elisabeth S. R.; Thevis, Mario

    2016-01-01

    Aims To compare full-length mechano growth factor (full-length MGF) with human recombinant insulin-like growth factor-I (IGF-I) and human recombinant insulin (HI) in their ability to activate the human IGF-I receptor (IGF-IR), the human insulin receptor (IR-A) and the human insulin receptor-B (IR-B), respectively. In addition, we tested the stimulatory activity of human MGF and its stabilized analog Goldspink-MGF on the IGF-IR. Methods The effects of full-length MGF, IGF-I, human mechano growth factor (MGF), Goldspink-MGF and HI were compared using kinase specific receptor activation (KIRA) bioassays specific for IGF-I, IR-A or IR-B, respectively. These assays quantify activity by measuring auto-phosphorylation of the receptor upon ligand binding. Results IGF-IR: At high equimolar concentrations maximal IGF-IR stimulating effects generated by full-length MGF were similar to that of IGF-I (89-fold vs. 77-fold, respectively). However, EC50 values of IGF-I and full-length MGF for the IGF-I receptor were 0.86 nmol/L (95% CI 0.69–1.07) and 7.83 nmol/L (95% CI: 4.87–12.58), respectively. No IGF-IR activation was observed by human MGF and Goldspink-MGF, respectively. IR-A/IR-B: At high equimolar concentrations similar maximal IR-A stimulating effects were observed for full -length MGF and HI, but maximal IR-B stimulation achieved by full -length MGF was stronger than that by HI (292-fold vs. 98-fold). EC50 values of HI and full-length MGF for the IR-A were 1.13 nmol/L (95% CI 0.69–1.84) and 73.11 nmol/L (42.87–124.69), respectively; for IR-B these values were 1.28 nmol/L (95% CI 0.64–2.57) and 35.10 nmol/L (95% 17.52–70.33), respectively. Conclusions Full-length MGF directly stimulates the IGF-IR. Despite a higher EC50 concentration, at high equimolar concentrations full-length MGF showed a similar maximal potency to activate the IGF-IR as compared to IGF-I. Further research is needed to understand the actions of full-length MGF in vivo and to define the

  16. Influence of deposition temperature on the microstructure and thermoelectric properties of antimonide cobalt thin films prepared by ion beam sputtering deposition

    International Nuclear Information System (INIS)

    Highlights: • Co–Sb films were prepared by ion beam sputtering using fan-shape target. • The carrier concentration is suitable for obtaining high-quality sample. • Co–Sb thin film with mixed CoSb3 and Sb phase has highest power factor. - Abstract: Antimonide cobalt thin films were deposited on BK7 glass substrates at various substrate temperatures by ion beam sputtering deposition with a fan-shape target. The influence of deposition temperature on the microstructure and thermoelectric properties of antimonide cobalt thin films were systematically investigated. It is found that the Seebeck coefficient of the thin film increases at first and then decreases with the increasing deposition temperature. The Seebeck coefficient of the sample deposited at 250 °C has maximum value and increases stably when the measuring temperature increased from room-temperature to 600 K. The electrical conductivity of the thin film increases significantly to 5.6 × 104 S cm−1 when the deposition temperature was 450 °C and then decreases greatly when the temperature increased to 500 °C and 550 °C. The behavior of electrical conductivity of the sample deposited at 250 °C changes from metallic to semiconducting after the measuring temperature exceeded 540 K. The power factor of antimonide cobalt thin film deposited at 250 °C has a maximum value of 0.93 × 10−4 W m−1 K−2 at room-temperature and then increases to 3.5 × 10−4 W m−1 K−2 when the measuring temperature was 540 K

  17. Electron-beam-induced deposition and post-treatment processes to locally generate clean titanium oxide nanostructures on Si(100)

    Science.gov (United States)

    Schirmer, M.; Walz, M.-M.; Vollnhals, F.; Lukasczyk, T.; Sandmann, A.; Chen, C.; Steinrück, H.-P.; Marbach, H.

    2011-02-01

    We have investigated the lithographic generation of TiOx nanostructures on Si(100) via electron-beam-induced deposition (EBID) of titanium tetraisopropoxide (TTIP) in ultra-high vacuum (UHV) by scanning electron microscopy (SEM) and local Auger electron spectroscopy (AES). In addition, the fabricated nanostructures were also characterized ex situ via atomic force microscopy (AFM) under ambient conditions. In EBID, a highly focused electron beam is used to locally decompose precursor molecules and thereby to generate a deposit. A drawback of this nanofabrication technique is the unintended deposition of material in the vicinity of the impact position of the primary electron beam due to so-called proximity effects. Herein, we present a post-treatment procedure to deplete the unintended deposits by moderate sputtering after the deposition process. Moreover, we were able to observe the formation of pure titanium oxide nanocrystals (<100 nm) in situ upon heating the sample in a well-defined oxygen atmosphere. While the nanocrystal growth for the as-deposited structures also occurs in the surroundings of the irradiated area due to proximity effects, it is limited to the pre-defined regions, if the sample was sputtered before heating the sample under oxygen atmosphere. The described two-step post-treatment procedure after EBID presents a new pathway for the fabrication of clean localized nanostructures.

  18. Electron-beam-induced deposition and post-treatment processes to locally generate clean titanium oxide nanostructures on Si(100)

    Energy Technology Data Exchange (ETDEWEB)

    Schirmer, M; Walz, M-M; Vollnhals, F; Lukasczyk, T; Sandmann, A; Steinrueck, H-P; Marbach, H [Lehrstuhl fuer Physikalische Chemie II and Interdisciplinary Center for Molecular Materials (ICMM), Universitaet Erlangen-Nuernberg, Egerlandstrasse 3, D-91058 Erlangen (Germany); Chen, C, E-mail: marbach@chemie.uni-erlangen.de [Department of Chemistry, Stanford University, Stanford, CA 94305 (United States)

    2011-02-25

    We have investigated the lithographic generation of TiO{sub x} nanostructures on Si(100) via electron-beam-induced deposition (EBID) of titanium tetraisopropoxide (TTIP) in ultra-high vacuum (UHV) by scanning electron microscopy (SEM) and local Auger electron spectroscopy (AES). In addition, the fabricated nanostructures were also characterized ex situ via atomic force microscopy (AFM) under ambient conditions. In EBID, a highly focused electron beam is used to locally decompose precursor molecules and thereby to generate a deposit. A drawback of this nanofabrication technique is the unintended deposition of material in the vicinity of the impact position of the primary electron beam due to so-called proximity effects. Herein, we present a post-treatment procedure to deplete the unintended deposits by moderate sputtering after the deposition process. Moreover, we were able to observe the formation of pure titanium oxide nanocrystals (<100 nm) in situ upon heating the sample in a well-defined oxygen atmosphere. While the nanocrystal growth for the as-deposited structures also occurs in the surroundings of the irradiated area due to proximity effects, it is limited to the pre-defined regions, if the sample was sputtered before heating the sample under oxygen atmosphere. The described two-step post-treatment procedure after EBID presents a new pathway for the fabrication of clean localized nanostructures.

  19. Closed-Loop Process Control for Electron Beam Freeform Fabrication and Deposition Processes

    Science.gov (United States)

    Taminger, Karen M. (Inventor); Hafley, Robert A. (Inventor); Martin, Richard E. (Inventor); Hofmeister, William H. (Inventor)

    2013-01-01

    A closed-loop control method for an electron beam freeform fabrication (EBF(sup 3)) process includes detecting a feature of interest during the process using a sensor(s), continuously evaluating the feature of interest to determine, in real time, a change occurring therein, and automatically modifying control parameters to control the EBF(sup 3) process. An apparatus provides closed-loop control method of the process, and includes an electron gun for generating an electron beam, a wire feeder for feeding a wire toward a substrate, wherein the wire is melted and progressively deposited in layers onto the substrate, a sensor(s), and a host machine. The sensor(s) measure the feature of interest during the process, and the host machine continuously evaluates the feature of interest to determine, in real time, a change occurring therein. The host machine automatically modifies control parameters to the EBF(sup 3) apparatus to control the EBF(sup 3) process in a closed-loop manner.

  20. Dual-ion-beam deposition of carbon films with diamond-like properties

    Science.gov (United States)

    Mirtich, M. J.; Swec, D. M.; Angus, J. C.

    1985-01-01

    A single and dual ion beam system was used to generate amorphous carbon films with diamond like properties. A methane/argon mixture at a molar ratio of 0.28 was ionized in the low pressure discharge chamber of a 30-cm-diameter ion source. A second ion source, 8 cm in diameter was used to direct a beam of 600 eV Argon ions on the substrates (fused silica or silicon) while the deposition from the 30-cm ion source was taking place. Nuclear reaction and combustion analysis indicate H/C ratios for the films to be 1.00. This high value of H/C, it is felt, allowed the films to have good transmittance. The films were impervious to reagents which dissolve graphitic and polymeric carbon structures. Although the measured density of the films was approximately 1.8 gm/cu cm, a value lower than diamond, the films exhibited other properties that were relatively close to diamond. These films were compared with diamond like films generated by sputtering a graphite target.

  1. Microstructural Characterization of Au-In Thin Film Deposited by Electron Beam Evaporation

    International Nuclear Information System (INIS)

    The microstructure and phase formation of Au-In thin film deposited by e-beam evaporation technique has been studied. Single crystals of rock salt were used as the substrates. The chamber pressure during deposition was about 2.5 x 10-5 torr and substrate temperature was 35 degree Celsius. Three types of samples were prepared namely Au, In and Au-In thin films. Microstructure and chemical composition of these thin films were characterized by transmission electron microscopy (TEM) and X-ray photoelectron spectrometer (XPS) respectively. TEM micrograph reveals island structures for both Au and In thin film on the rock salt substrate, with the In island size distribution is about 9-30 nm compared to Au island in the range of 3-10 nm. The growth of islands instead of smooth film indicates that Au and In thin films follow the Volmer-Weber growth mode. However, island structures were not present on Au-In thin films which most probably follow the Frank van de Merwe growth mode. XPS analysis indicates intermetallic compound was not present in the Au-In thin film suggesting that diffusion process in the interface of Au and In films is minimal. (author)

  2. Mechanical properties of silicon oxynitride thin films prepared by low energy ion beam assisted deposition

    Energy Technology Data Exchange (ETDEWEB)

    Shima, Yukari; Hasuyama, Hiroki E-mail: hasuyama@cc.kurume-it.ac.jp; Kondoh, Toshiharu; Imaoka, Yasuo; Watari, Takanori; Baba, Koumei; Hatada, Ruriko

    1999-01-02

    Silicon oxynitride (SiO{sub x}N{sub y}) films (0.1-0.7 {mu}m) were produced on Si (1 0 0), glass and 316L stainless steel substrates by ion beam assisted deposition (IBAD) using Si evaporation and the concurrent bombardment with a mixture of 200 eV N{sub 2} and Ar, or O{sub 2} and Ar ions. Adhesion was evaluated by pull-off tests. Film hardness was measured by a nanoindentation system with AFM. The measurement of internal stress in the films was carried out by the Stoney method. The film structure was examined by GXRD. XPS was employed to measure the composition of films and to analyze the chemical bonds. The dependence of mechanical properties on the film thickness and the processing temperature during deposition was studied. Finally, the relations between the mechanical properties of the films and the correlation with corrosion-protection ability of films are discussed and summarized.

  3. Structural and electrical properties of ion beam sputter deposited tantalum films

    Energy Technology Data Exchange (ETDEWEB)

    Sajovec, F.; Meuffels, P.M.; Schober, T. (Forschungszentrum Juelich G.m.b.H., Inst. fuer Festkoerperforschung, Juelich (Germany))

    1992-10-30

    In situ resistance measurements during the growth of ion beam sputter deposited tantalum films have been employed to elucidate the conditions necessary for the formation of either the b.c.c. ([alpha]-Ta) or the tetragonal ([beta]-Ta) structure. Tantalum films condense at room temperature onto sputter-cleaned fused silica substrates as the [beta] phase with resistivities [rho] in the range 200-220 [mu][Omega] cm. [alpha]-Ta films with [rho] between 40 and 55 [mu][Omega] cm can be prepared if the films are deposited on top of thin (more than 3 nm) niobium underlayers. The niobium underlayer thickness is very critical with respect to the nucleation process of tantalum. When it is less than 3 nm, tantalum films consisting of mixtures of [alpha]-Ta and [beta]-Ta result. This is because niobium on fused silica nucleates first in a structure differing from the common b.c.c. structure. This phase cannot promote the nucleation of pure [alpha]-Ta. It converts to b.c.c.-Nb if the layer thickness exceeds 3 nm.

  4. Post-growth purification of Co nanostructures prepared by focused electron beam induced deposition

    Science.gov (United States)

    Begun, E.; Dobrovolskiy, O. V.; Kompaniiets, M.; Sachser, R.; Gspan, Ch; Plank, H.; Huth, M.

    2015-02-01

    In the majority of cases nanostructures prepared by focused electron beam induced deposition (FEBID) employing an organometallic precursor contain predominantly carbon-based ligand dissociation products. This is unfortunate with regard to using this high-resolution direct-write approach for the preparation of nanostructures for various fields, such as mesoscopic physics, micromagnetism, electronic correlations, spin-dependent transport and numerous applications. Here we present an in situ cleaning approach to obtain pure Co-FEBID nanostructures. The purification procedure lies in the exposure of heated samples to a H2 atmosphere in conjunction with the irradiation by low-energy electrons. The key finding is that the combination of annealing at 300 °C, H2 exposure and electron irradiation leads to compact, carbon- and oxygen free Co layers down to a thickness of about 20 nm starting from as-deposited Co-FEBID structures. In addition to this, in temperature-dependent electrical resistance measurements on post-processed samples we find a typical metallic behavior. In low-temperature magnetoresistance and Hall effect measurements we observe ferromagnetic behavior.

  5. Chemical composition, morphology and optical properties of zinc sulfide coatings deposited by low-energy electron beam evaporation

    International Nuclear Information System (INIS)

    The research determines the features of formation, morphology, chemical composition and optical properties of the coatings deposited by the method, proposed for the first time, of the exposure of mechanical mixture of zinc and sulfur powders to low-energy electron beam evaporation. The findings show that the deposited coatings are characterized by high chemical and structural homogeneity in thickness. The study considers the influence of substrate temperature and thickness of the deposited layer on the morphology and the width of the formed ZnS thin layers band gap. Also was shown the possibility to form ZnS coatings with this method using the mixture of zinc and copper sulfide powders.

  6. Chemical composition, morphology and optical properties of zinc sulfide coatings deposited by low-energy electron beam evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Ragachev, A.V. [International Chinese-Belorussian scientific laboratory on vacuum-plasma technology, College of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Francisk Skorina Gomel State University, 104, Sovetskaya Street, Gomel 246019 (Belarus); Yarmolenko, M.A., E-mail: simmak79@mail.ru [International Chinese-Belorussian scientific laboratory on vacuum-plasma technology, College of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Francisk Skorina Gomel State University, 104, Sovetskaya Street, Gomel 246019 (Belarus); Rogachev, A.A. [International Chinese-Belorussian scientific laboratory on vacuum-plasma technology, College of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Francisk Skorina Gomel State University, 104, Sovetskaya Street, Gomel 246019 (Belarus); Gorbachev, D.L. [Francisk Skorina Gomel State University, 104, Sovetskaya Street, Gomel 246019 (Belarus); Zhou, Bing [International Chinese-Belorussian scientific laboratory on vacuum-plasma technology, College of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China)

    2014-06-01

    The research determines the features of formation, morphology, chemical composition and optical properties of the coatings deposited by the method, proposed for the first time, of the exposure of mechanical mixture of zinc and sulfur powders to low-energy electron beam evaporation. The findings show that the deposited coatings are characterized by high chemical and structural homogeneity in thickness. The study considers the influence of substrate temperature and thickness of the deposited layer on the morphology and the width of the formed ZnS thin layers band gap. Also was shown the possibility to form ZnS coatings with this method using the mixture of zinc and copper sulfide powders.

  7. Computational study of transport and energy deposition of intense laser-accelerated proton beams in solid density matter

    Science.gov (United States)

    Kim, J.; McGuffey, C.; Qiao, B.; Beg, F. N.; Wei, M. S.; Grabowski, P. E.

    2015-11-01

    With intense proton beams accelerated by high power short pulse lasers, solid targets are isochorically heated to become partially-ionized warm or hot dense matter. In this regime, the thermodynamic state of the matter significantly changes, varying the proton stopping power where both bound and free electrons contribute. Additionally, collective beam-matter interaction becomes important to the beam transport. We present self-consistent hybrid particle-in-cell (PIC) simulation results of proton beam transport and energy deposition in solid-density matter, where the individual proton stopping and the collective effects are taken into account simultaneously with updates of stopping power in the varying target conditions and kinetic motions of the beam in the driven fields. Broadening of propagation range and self-focusing of the beam led to unexpected target heating by the intense proton beams, with dependence on the beam profiles and target conditions. The behavior is specifically studied for the case of an experimentally measured proton beam from the 1.25 kJ, 10 ps OMEGA EP laser transporting through metal foils. This work was supported by the U.S. DOE under Contracts No. DE-NA0002034 and No. DE-AC52-07NA27344 and by the U.S. AFOSR under Contract FA9550-14-1-0346.

  8. An ultra-low energy (30-200 eV) ion-atomic beam source for ion-beam-assisted deposition in ultrahigh vacuum.

    Science.gov (United States)

    Mach, Jindrich; Samoril, Tomás; Voborný, Stanislav; Kolíbal, Miroslav; Zlámal, Jakub; Spousta, Jirí; Dittrichová, Libuse; Sikola, Tomás

    2011-08-01

    The paper describes the design and construction of an ion-atomic beam source with an optimized generation of ions for ion-beam-assisted deposition under ultrahigh vacuum (UHV) conditions. The source combines an effusion cell and an electron impact ion source and produces ion beams with ultra-low energies in the range from 30 eV to 200 eV. Decreasing ion beam energy to hyperthermal values (≈10(1) eV) without loosing optimum ionization conditions has been mainly achieved by the incorporation of an ionization chamber with a grid transparent enough for electron and ion beams. In this way the energy and current density of nitrogen ion beams in the order of 10(1) eV and 10(1) nA/cm(2), respectively, have been achieved. The source is capable of growing ultrathin layers or nanostructures at ultra-low energies with a growth rate of several MLs/h. The ion-atomic beam source will be preferentially applied for the synthesis of GaN under UHV conditions. PMID:21895238

  9. Structural and growth aspects of electron beam physical vapor deposited NiO-CeO2 nanocomposite films

    International Nuclear Information System (INIS)

    Deposition of composite materials as thin film by electron beam physical vapor deposition technique (EB-PVD) still remains as a challenge. Here, the authors report the deposition of NiO-CeO2 (30/70 wt. %) composites on quartz substrate by EB-PVD. Two NiO-CeO2 nanocomposite targets—one as green compact and the other after sintering at 1250 °C—were used for the deposition. Though the targets varied with respect to physical properties such as crystallite size (11–45 nm) and relative density (44% and 96%), the resultant thin films exhibited a mean crystallite size in the range of 20–25 nm underlining the role of physical nature of deposition. In spite of the crystalline nature of the targets and similar elemental concentration, a transformation from amorphous to crystalline structure was observed in thin films on using sintered target. Postannealing of the as deposited film at 800 °C resulted in a polycrystalline structure consisting of CeO2 and NiO. Deposition using pure CeO2 or NiO as target resulted in the preferential orientation toward (111) and (200) planes, respectively, showing the influence of adatoms on the evaporation and growth process of NiO-CeO2 composite. The results demonstrate the influence of electron beam gun power on the adatom energy for the growth process of composite oxide thin films

  10. Fabrication of speckle patterns by focused ion beam deposition and its application to micro-scale residual stress measurement

    Science.gov (United States)

    Zhu, Ronghua; Xie, Huimin; Xue, Yunfei; Wang, Liang; Li, YanJie

    2015-09-01

    This paper deals with the characterization of influence parameters on the fabrication of speckle patterns using FIB deposition. In many manufacturing processes the presence of residual stress is disturbing, and can significantly affect the mechanical properties of materials and structures. Digital image correlation (DIC) is validated to be an effective approach for the determination of micro-scale residual stress under the dual-beam microscope (FIB-EB). Considering the high-quality micro-scale speckle pattern is the prerequisite in DIC measurement, the influence parameters on the deposited speckle patterns, such as the quality of the speckle template, total deposition time, ion beam current density, and dwell time, are primarily discussed. Moreover, in the measurement of residual stress, the integrated fabrication technique under the FIB-EB dual-beam system is also explained, covering the following steps: fabrication of the speckle pattern by FIB deposition, slot milling for stress release by FIB, high-resolution SEM imaging before and after stress release as well as the deformation analysis by DIC. As application, the optimized micro-scale speckle patterns are deposited on the surface of laser shock peened metallic glass, and the residual stress distribution on the sample surface is successfully measured.

  11. Study of the growth of biaxially textured CeO2 films during ion-beam-assisted deposition

    International Nuclear Information System (INIS)

    Biaxially textured CeO2 films were deposited on Hastelloy C276 substrates at room temperature using ion-beam-assisted e-beam evaporation with the ion beam directed at 55 deg. to the normal of the film plane. The crystalline structure and in-plane orientation of films were investigated by x-ray diffraction 2θ-scan and φ-scan. The orientation of the films was studied as a function of ion-to-atom ratio and film thickness. The ion-to-atom ratio was varied by independently adjusting the deposition rate and the ion current density. Under optimum condition, (200) textured CeO2 films have been successfully grown on Hastelloy C276

  12. Study of the growth of biaxially textured CeO{sub 2} films during ion-beam-assisted deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chang Su [Department of Metallurgical Engineering, Yonsei University, Seodaemoon Ku, Shinchon Dong 134, Seoul 120-749 (Korea, Republic of); Jo, Sung Jin [Department of Metallurgical Engineering, Yonsei University, Seodaemoon Ku, Shinchon Dong 134, Seoul 120-749 (Korea, Republic of); Jeong, Soon Moon [Department of Metallurgical Engineering, Yonsei University, Seodaemoon Ku, Shinchon Dong 134, Seoul 120-749 (Korea, Republic of); Kim, Woo Jin [Department of Metallurgical Engineering, Yonsei University, Seodaemoon Ku, Shinchon Dong 134, Seoul 120-749 (Korea, Republic of); Baik, Hong Koo [Department of Metallurgical Engineering, Yonsei University, Seodaemoon Ku, Shinchon Dong 134, Seoul 120-749 (Korea, Republic of); Lee, Se Jong [Department of Materials Science and Engineering, Kyungsung University, Busan 608-736 (Korea, Republic of); Song, Kie Moon [Department of Applied Physics, Konkuk University, Chungju 380-701 (Korea, Republic of)

    2005-03-01

    Biaxially textured CeO{sub 2} films were deposited on Hastelloy C276 substrates at room temperature using ion-beam-assisted e-beam evaporation with the ion beam directed at 55 deg. to the normal of the film plane. The crystalline structure and in-plane orientation of films were investigated by x-ray diffraction 2{theta}-scan and {phi}-scan. The orientation of the films was studied as a function of ion-to-atom ratio and film thickness. The ion-to-atom ratio was varied by independently adjusting the deposition rate and the ion current density. Under optimum condition, (200) textured CeO{sub 2} films have been successfully grown on Hastelloy C276.

  13. Study of the growth of biaxially textured CeO2 films during ion-beam-assisted deposition

    Science.gov (United States)

    Kim, Chang Su; Jo, Sung Jin; Jeong, Soon Moon; Kim, Woo Jin; Baik, Hong Koo; Lee, Se Jong; Song, Kie Moon

    2005-03-01

    Biaxially textured CeO2 films were deposited on Hastelloy C276 substrates at room temperature using ion-beam-assisted e-beam evaporation with the ion beam directed at 55° to the normal of the film plane. The crystalline structure and in-plane orientation of films were investigated by x-ray diffraction 2θ-scan and phgr-scan. The orientation of the films was studied as a function of ion-to-atom ratio and film thickness. The ion-to-atom ratio was varied by independently adjusting the deposition rate and the ion current density. Under optimum condition, (200) textured CeO2 films have been successfully grown on Hastelloy C276.

  14. High-Q MgF$_2$ whispering gallery mode resonators for refractometric sensing in aqueous environment

    CERN Document Server

    Sedlmeir, Florian; Leuchs, Gerd; Schwefel, Harald G L

    2014-01-01

    We present our experiments on refractometric sensing with ultrahigh-Q, crystalline, birefringent magnesium fluoride (MgF$_2$) whispering gallery mode resonators. The difference to fused silica which is most commonly used for sensing experiments is the small refractive index of MgF$_2$ which is very close to that of water. Compared to fused silica this leads to more than 50% longer evanescent fields and a 4.25 times larger sensitivity. Moreover the birefringence amplifies the sensitivity difference between TM and TE type modes which will enhance sensing experiments based on difference frequency measurements. We estimate the performance of our resonators and compare them with fused silica theoretically and present experimental data showing the interferometrically measured evanescent decay and the sensitivity of mm-sized MgF$_2$ whispering gallery mode resonators immersed in water. They show reasonable agreement with the developed theory. Furthermore, we observe stable Q factors in water well above $1 \\times 10^...

  15. High-purity 3D nano-objects grown by focused-electron-beam induced deposition

    Science.gov (United States)

    Córdoba, Rosa; Sharma, Nidhi; Kölling, Sebastian; Koenraad, Paul M.; Koopmans, Bert

    2016-09-01

    To increase the efficiency of current electronics, a specific challenge for the next generation of memory, sensing and logic devices is to find suitable strategies to move from two- to three-dimensional (3D) architectures. However, the creation of real 3D nano-objects is not trivial. Emerging non-conventional nanofabrication tools are required for this purpose. One attractive method is focused-electron-beam induced deposition (FEBID), a direct-write process of 3D nano-objects. Here, we grow 3D iron and cobalt nanopillars by FEBID using diiron nonacarbonyl Fe2(CO)9, and dicobalt octacarbonyl Co2(CO)8, respectively, as starting materials. In addition, we systematically study the composition of these nanopillars at the sub-nanometer scale by atom probe tomography, explicitly mapping the homogeneity of the radial and longitudinal composition distributions. We show a way of fabricating high-purity 3D vertical nanostructures of ∼50 nm in diameter and a few micrometers in length. Our results suggest that the purity of such 3D nanoelements (above 90 at% Fe and above 95 at% Co) is directly linked to their growth regime, in which the selected deposition conditions are crucial for the final quality of the nanostructure. Moreover, we demonstrate that FEBID and the proposed characterization technique not only allow for growth and chemical analysis of single-element structures, but also offers a new way to directly study 3D core–shell architectures. This straightforward concept could establish a promising route to the design of 3D elements for future nano-electronic devices.

  16. High-purity 3D nano-objects grown by focused-electron-beam induced deposition.

    Science.gov (United States)

    Córdoba, Rosa; Sharma, Nidhi; Kölling, Sebastian; Koenraad, Paul M; Koopmans, Bert

    2016-09-01

    To increase the efficiency of current electronics, a specific challenge for the next generation of memory, sensing and logic devices is to find suitable strategies to move from two- to three-dimensional (3D) architectures. However, the creation of real 3D nano-objects is not trivial. Emerging non-conventional nanofabrication tools are required for this purpose. One attractive method is focused-electron-beam induced deposition (FEBID), a direct-write process of 3D nano-objects. Here, we grow 3D iron and cobalt nanopillars by FEBID using diiron nonacarbonyl Fe2(CO)9, and dicobalt octacarbonyl Co2(CO)8, respectively, as starting materials. In addition, we systematically study the composition of these nanopillars at the sub-nanometer scale by atom probe tomography, explicitly mapping the homogeneity of the radial and longitudinal composition distributions. We show a way of fabricating high-purity 3D vertical nanostructures of ∼50 nm in diameter and a few micrometers in length. Our results suggest that the purity of such 3D nanoelements (above 90 at% Fe and above 95 at% Co) is directly linked to their growth regime, in which the selected deposition conditions are crucial for the final quality of the nanostructure. Moreover, we demonstrate that FEBID and the proposed characterization technique not only allow for growth and chemical analysis of single-element structures, but also offers a new way to directly study 3D core-shell architectures. This straightforward concept could establish a promising route to the design of 3D elements for future nano-electronic devices. PMID:27454835

  17. Structure and electrical properties of quaternary Cr–Si–Ni–W films prepared by ion beam sputter deposition

    International Nuclear Information System (INIS)

    Highlights: • Quaternary Cr–Si–Ni–W thin film was prepared by IBSD. • As-deposited Cr–Si–Ni–W films show nanocrystalline state in XRD analysis. • Big massive particles in Cr–Si–Ni–W films are mainly formed in deposition process. • Conduction mechanism was discussed based on microscopic analysis. - Abstract: Si-rich Cr–Si–Ni–W films were deposited by ion beam sputter deposition (IBSD) using a mother alloy target on polished Al2O3 substrates. Effects of ion beam voltage, annealing temperature and deposition time on sheet resistance and TCR of Cr–Si–Ni–W films were studied. Experimental results reveal that the as-deposited Cr–Si–Ni–W films obtained by IBSD show a crystalline state because of a high mobility of deposition atoms and molecules with more energy obtained from high energy ions. XRD and AFM analysis show that the big massive particles mainly composed of Si and CrSi2 in Cr–Si–Ni–W films are formed in the process of IBSD rather than in post-annealing stage. Long deposition time is significantly important to a decrease of the number and size of gaps between big particles in Cr–Si–Ni–W films and to an improvement of the continuity and compactness of film structure, influencing resistivity and TCR of deposition film. The conduction mechanism was discussed based on microscopic analysis and the conductive model proposed for Cr–Si–Ni–W films mainly composed of big particles

  18. Mossbauer investigation of Fe1-x Crx films grown by ion-beam sputter deposition

    International Nuclear Information System (INIS)

    Fe1-xCrx (02 substrates were prepared using ion-beam sputter deposition, and their structural properties were determined by 57Fe conversion electron Mossbauer spectroscopy (CEMS) and X-ray diffraction experiments (XRD) at room temperature. CEM spectra show magnetic ordering for 0< x=<0.28, and the BCC α-phase is evidenced through XRD diagrams in all cases. The general trend for the films is that the average hyperfine magnetic field (HMF) values are lower compared to bulk counterparts. Moreover, a parabolic change in average HMF with Cr content x could be established. For 0.32=< x<0.70, the CEM spectra exhibit a pseudo-single line, which denotes paramagnetic state. Between x=0.32 and x=0.38, there exists a multiphase region where the alloys mainly consist of α and δ (A15-type) phases. Then, in the concentration range x=0.38-0.58, the films only display the metastable δ-phase. For 0.58=< x=<0.66, there appears a new transition region where α- and δ-phases coexist. Finally, the domain of the paramagnetic α-phase alone stretches from x=0.66 to at least x=0.70. Emphasis is placed on the metastable δ-phase which appears over a wide monophase region. Particularly, the site occupancy could be determined through the CEM spectrum for x=0.49

  19. Optical properties of ion-beam-deposited ion-modified diamondlike (a-C:H) carbon

    International Nuclear Information System (INIS)

    Diamondlike carbon (DLC) is a hard, semitransparent material usually containing varying amounts of hydrogen. These materials have numerous potential applications, including use as coatings for infrared optics, and as such, the effects of damaging irradiation is of practical interest. In this paper we present results of variable angle spectroscopic ellipsometric (VASE) studies of ion-beam-deposited DLC films. These films have been further modified by directing 1-MeV gold ions, as well as 6.4-MeV fluorine ions, through the DLC and into the underlying silicon substrates, and the percentage of hydrogen in the film was measured versus fluence using proton recoil analysis. Optical analysis was performed assuming the Lorentz oscillator model. Three versions were used: one oscillator, two oscillator (with one fixed in energy), and two oscillator with all parameter variable. The latter model fits the VASE data extremely well, and the two oscillators can be interpreted as involving π to π* and σ to σ* band transitions. With ion modification the oscillators shift to lower photon energy, consistent with reduction in hydrogen concentration and possible increased graphitization

  20. Tribological coatings for complex mechanical elements produced by supersonic cluster beam deposition of metal dichalcogenide nanoparticles

    International Nuclear Information System (INIS)

    Fullerene-like MoS2 and WS2 nanoparticles can be used as building blocks for the fabrication of fluid and solid lubricants. Metal dichalcogenide films have a very low friction coefficient in vacuum, therefore they have mostly been used as solid lubricants in space and vacuum applications. Unfortunately, their use is significantly hampered by the fact that in the presence of humidity, oxygen and moisture, the low-friction properties of these materials rapidly degrade due to oxidation. The use of closed-cage MoS2 and WS2 nanoparticles may eliminate this problem, although the fabrication of lubricant thin films starting from dichalcogenide nanoparticles is, to date, a difficult task. Here we demonstrate the use of supersonic cluster beam deposition for the coating of complex mechanical elements (angular contact ball bearings) with nanostructured MoS2 and WS2 thin films. We report structural and tribological characterization of the coatings in view of the optimization of tribological performances for aerospace applications. (paper)

  1. Electrochemical characteristics of CrN thin films prepared by ion-beam-enhanced deposition

    International Nuclear Information System (INIS)

    It has been known that CrN has high hardness and high resistance against wear, oxidation and corrosion. Although many studies have been done on its mechanical and high temperature oxidation properties, studies on its electrochemical and corrosion properties in aqueous solutions are still limited. The aim of this study is to produce CrN thin films by ion-beam-enhanced deposition (IBED) and to make clear the corrosion behavior of CrN by electrochemical measurements. CrN thin films were prepared by IBED under various conditions and their polarization curves were measured in 1 kmol·m-3 H2SO4 and 12 kmol·m-3 HCl. Changes in the surface of the thin films by polarization were examined by XPS and in-situ ellipsometry. The thin films prepared by IBED were composed of the large amount of CrN and small amounts of Cr2N and Cr. The fraction of CrN in the films increased with increasing flow rate of nitrogen. Potentiodynamic polarization curves exhibited that the active dissolution rate of the films decreased with increasing CrN content of the films. The films with high CrN content showed excellent corrosion resistance up to the start potential of transpassive dissolution without formation of passive films. That is, the excellent corrosion resistance of CrN results from the intrinsic inactive nature of CrN surface. (author)

  2. Tribological coatings for complex mechanical elements produced by supersonic cluster beam deposition of metal dichalcogenide nanoparticles

    Science.gov (United States)

    Piazzoni, C.; Buttery, M.; Hampson, M. R.; Roberts, E. W.; Ducati, C.; Lenardi, C.; Cavaliere, F.; Piseri, P.; Milani, P.

    2015-07-01

    Fullerene-like MoS2 and WS2 nanoparticles can be used as building blocks for the fabrication of fluid and solid lubricants. Metal dichalcogenide films have a very low friction coefficient in vacuum, therefore they have mostly been used as solid lubricants in space and vacuum applications. Unfortunately, their use is significantly hampered by the fact that in the presence of humidity, oxygen and moisture, the low-friction properties of these materials rapidly degrade due to oxidation. The use of closed-cage MoS2 and WS2 nanoparticles may eliminate this problem, although the fabrication of lubricant thin films starting from dichalcogenide nanoparticles is, to date, a difficult task. Here we demonstrate the use of supersonic cluster beam deposition for the coating of complex mechanical elements (angular contact ball bearings) with nanostructured MoS2 and WS2 thin films. We report structural and tribological characterization of the coatings in view of the optimization of tribological performances for aerospace applications.

  3. Visible light active TiO2 films prepared by electron beam deposition of noble metals

    International Nuclear Information System (INIS)

    TiO2 films prepared by sol-gel method were modified by electron beam deposition of noble metals (Pt, Pd, and Ag). Effects of noble metals on the chemical and surface characteristics of the films were studied using XPS, TEM and UV-Vis spectroscopy techniques. Photocatalytic activity of modified TiO2 films was evaluated by studying the degradation of methyl orange dye solution under visible light UV irradiation. The result of TEM reveals that most of the surface area of TiO2 is covered by tiny particles of noble metals with diameter less than 1 nm. Broad red shift of UV-Visible absorption band of modified photocatalysts was observed. The catalytic degradation of methyl orange in aqueous solutions under visible light illumination demonstrates a significant enhancement of photocatalytic activity of these films compared with the un-loaded films. The photocatalytic efficiency of modified TiO2 films by this method is affected by the concentration of impregnating solution.

  4. Visible light active TiO 2 films prepared by electron beam deposition of noble metals

    Science.gov (United States)

    Hou, Xing-Gang; Ma, Jun; Liu, An-Dong; Li, De-Jun; Huang, Mei-Dong; Deng, Xiang-Yun

    2010-03-01

    TiO 2 films prepared by sol-gel method were modified by electron beam deposition of noble metals (Pt, Pd, and Ag). Effects of noble metals on the chemical and surface characteristics of the films were studied using XPS, TEM and UV-Vis spectroscopy techniques. Photocatalytic activity of modified TiO 2 films was evaluated by studying the degradation of methyl orange dye solution under visible light UV irradiation. The result of TEM reveals that most of the surface area of TiO 2 is covered by tiny particles of noble metals with diameter less than 1 nm. Broad red shift of UV-Visible absorption band of modified photocatalysts was observed. The catalytic degradation of methyl orange in aqueous solutions under visible light illumination demonstrates a significant enhancement of photocatalytic activity of these films compared with the un-loaded films. The photocatalytic efficiency of modified TiO 2 films by this method is affected by the concentration of impregnating solution.

  5. Synthesis of MoSi2 by energetic molybdenum cluster beam deposited on monocrystalline silicon at room temperature

    International Nuclear Information System (INIS)

    Mon- cluster beam was produced by a new type magnetron sputter gas aggregation cluster source. The beam was accelerated by the voltage of 0, 1, 3, 5, 10 kV and deposited onto polished p-type Si(111) substrate surface at room temperature, respectively, and then the thin film samples of Mo/Si(111) were prepared. X-ray diffraction analysis showed that there was no MoSi2 thin film formation in the area interface of Mo/Si(111) samples deposited by using both regular magnetron sputter and new type cluster source when the accelerated voltage was no more than 5 kV, whereas at the voltage of about 10 kV, there was MoSi2 thin film formed in the area interface of Mo/Si(111) samples deposited by using the new type cluster source. Only for the accelerated voltage higher than a threshold voltage (≥3 kV in this experiment), can the (110) oriented Mo thin film by the cluster beam deposition grow up. (authors)

  6. Focused-electron-beam-induced deposition of freestanding three-dimensional nanostructures of pure coalesced copper crystals

    International Nuclear Information System (INIS)

    We report on direct writing of three-dimensional freestanding nanostructures of Cu by use of a focused electron beam (FEB) and the metalorganic precursor hfac-Cu-TMVS. Freestanding horizontal rods were deposited over about 10 μm length and consist of small 2-5 nm Cu nanocrystals dispersed in an amorphous matrix containing carbon, fluorine, silicon, and oxygen. The freestanding horizontal rods were used as support for further vertical deposits resulting in tips of coalesced facetted Cu nanocrystals of up to 100 nm in size. The almost constant deposition rate of 5-6 nm/s is in contrast to vertical tips on bulk supports, which show a deposition rate decreasing from 23 to 10 nm/s. The above results suggest a thermal decomposition process induced by electron energy absorption

  7. Electrical performance of phase change memory cells with Ge3Sb2Te6 deposited by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Here, we report on the electrical characterization of phase change memory cells containing a Ge3Sb2Te6 (GST) alloy grown in its crystalline form by Molecular Beam Epitaxy (MBE). It is found that the high temperature growth on the amorphous substrate results in a polycrystalline film exhibiting a rough surface with a grain size of approximately 80–150 nm. A detailed electrical characterization has been performed, including I-V characteristic curves, programming curves, set operation performance, crystallization activation at low temperature, and resistance drift, in order to determine the material related parameters. The results indicate very good alignment of the electrical parameters with the current state-of-the-art GST, deposited by physical vapor deposition. Such alignment enables a possible employment of the MBE deposition technique for chalcogenide materials in the phase change memory technology, thus leading to future studies of as-deposited crystalline chalcogenides as integrated in electrical vehicles

  8. Room-Temperature Growth of SiC Thin Films by Dual-Ion-Beam Sputtering Deposition

    Directory of Open Access Journals (Sweden)

    C. G. Jin

    2008-01-01

    Full Text Available Silicon carbide (SiC films were prepared by single and dual-ion-beamsputtering deposition at room temperature. An assisted Ar+ ion beam (ion energy Ei = 150 eV was directed to bombard the substrate surface to be helpful for forming SiC films. The microstructure and optical properties of nonirradicated and assisted ion-beam irradicated films have been characterized by transmission electron microscopy (TEM, scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FTIR, and Raman spectra. TEM result shows that the films are amorphous. The films exposed to a low-energy assisted ion-beam irradicated during sputtering from a-SiC target have exhibited smoother and compacter surface topography than which deposited with nonirradicated. The ion-beam irradicated improves the adhesion between film and substrate and releases the stress between film and substrate. With assisted ion-beam irradicated, the density of the Si–C bond in the film has increased. At the same time, the excess C atoms or the size of the sp2 bonded clusters reduces, and the a-Si phase decreases. These results indicate that the composition of the film is mainly Si–C bond.

  9. Ion beam-assisted deposition of boron nitride from a condensed layer of diborane and ammonia at 78 K

    International Nuclear Information System (INIS)

    This paper examines the ion beam-assisted deposition (IBAD) of thin boron nitride films using cryogenically condensed precursors. Low energy (1100 eV) argon ad (2000 eV) deuterated ammonia beams with currents of 600--850 nA were used to mix and initiate reactions in frozen (90 K) layers of diborane (B2H6 and ammonia (NH3) or only B2H6, respectively. The resulting film is shown to be an amorphous BN coating approximately 30 Angstrom thick

  10. The Post—deposition Anneal Effects on the Electrical Properties of HfO2 Gate Dielectric Deposited by Ion Beam Sputtering at Room Temperature

    Institute of Scientific and Technical Information of China (English)

    KANGJinfeng; LIUXiaoyan; TIANDayu; WANGWei; LIANGuijun; XIONGGuangcheng; HANRuqi

    2003-01-01

    HfO2 high K gate dielectric films were fab-ricated on p-Si(100) substrates by ion beam sputtering at room temperature followed by a post-deposition anneal-ing (PDA). The PDA effects on the electrical properties of HfO2 gate dielectric films were studied. High quality HfO2 gate dielectric with small equivalent oxide thickness (EOT = 2.3nm), small hystereis (△VFB<50mV), and lowleakage current (< 1× 10-4A/cm2@lV) was fabricated.The studies of PDA effects on the electrical properties in-dicate that the PDA process in nitrogen ambient will be necessary for the HfO2 gate dielectric films deposited by ion beam sputtering the sintered target at room temper-ature in order to obtain small equivalent oxide thickness and low leakage currents, whereas a PDA in oxygen ambi-ent will be not required. The results also means that there is less oxygen vacancy defect produced in the HfO2 gate dielectric films during the deposition at room temperature.

  11. Reel-to-reel preparation of ion-beam assisted deposition (IBAD)-MgO based coated conductors

    International Nuclear Information System (INIS)

    We report on our efforts in developing and scaling-up the systems for IBAD-MgO based coated conductor fabrication. The overall fabrication process involves a number of different processes including: electropolishing of the substrates; barrier-layer, seed-layer, and IBAD-MgO deposition by e-beam evaporation; and pulsed laser deposition of buffer and YBCO layers. All processes are realized in reel-to-reel processing systems. Latest results have shown that the IBAD-MgO approach yields coated conductor performance comparable to the best results achieved elsewhere to date

  12. Reel-to-reel preparation of ion-beam assisted deposition (IBAD)-MgO based coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Kreiskott, Sascha; Arendt, Paul N; Coulter, J Yates; Dowden, Paul C; Foltyn, Stephen R; Gibbons, Brady J; Matias, Vladimir; Sheehan, Chris J [Superconductivity Technology Center, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2004-05-01

    We report on our efforts in developing and scaling-up the systems for IBAD-MgO based coated conductor fabrication. The overall fabrication process involves a number of different processes including: electropolishing of the substrates; barrier-layer, seed-layer, and IBAD-MgO deposition by e-beam evaporation; and pulsed laser deposition of buffer and YBCO layers. All processes are realized in reel-to-reel processing systems. Latest results have shown that the IBAD-MgO approach yields coated conductor performance comparable to the best results achieved elsewhere to date.

  13. Effects of oxygen on electron beam induced deposition of SiO2 using physisorbed and chemisorbed tetraethoxysilane

    Science.gov (United States)

    Bishop, James; Toth, Milos; Phillips, Matthew; Lobo, Charlene

    2012-11-01

    Electron beam induced deposition (EBID) is limited by low throughput and purity of as-grown material. Co-injection of O2 with the growth precursor is known to increase both the purity and deposition rate of materials such as SiO2 at room temperature. Here, we show that O2 inhibits rather than enhances EBID from tetraethoxysilane (TEOS) precursor at elevated temperatures. This behavior is attributed to surface site competition between chemisorbates at elevated temperature, and TEOS decomposition by atomic oxygen produced through electron dissociation of physisorbed O2 at room temperature.

  14. Effects of oxygen on electron beam induced deposition of SiO{sub 2} using physisorbed and chemisorbed tetraethoxysilane

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, James; Toth, Milos; Phillips, Matthew; Lobo, Charlene [School of Physics and Advanced Materials, University of Technology, Sydney, P.O. Box 123, Broadway, New South Wales 2007 (Australia)

    2012-11-19

    Electron beam induced deposition (EBID) is limited by low throughput and purity of as-grown material. Co-injection of O{sub 2} with the growth precursor is known to increase both the purity and deposition rate of materials such as SiO{sub 2} at room temperature. Here, we show that O{sub 2} inhibits rather than enhances EBID from tetraethoxysilane (TEOS) precursor at elevated temperatures. This behavior is attributed to surface site competition between chemisorbates at elevated temperature, and TEOS decomposition by atomic oxygen produced through electron dissociation of physisorbed O{sub 2} at room temperature.

  15. Structure and interfacial analysis of nanoscale TiNi thin film prepared by biased target ion beam deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Huilong; Hamilton, Reginald F., E-mail: rfhamilton@psu.edu; Horn, Mark W. [Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

    2015-07-15

    Ultrathin, 65 nm thick, TiNi alloy films were fabricated by cosputtering Ti and Ni targets using the recently developed biased target ion beam deposition technique. Preheating the substrate by exposure to a low energy ion source resulted in as-deposited films with a pure B2 atomic crystal structure containing no secondary crystal structures or precipitates. Continuous films were produced with a smooth surface and minimal substrate/film interfacial diffusion. The diffusion layer was a small ratio of film thickness, which is a prerequisite for the B2 phase to undergo the martensitic transformation in ultrathin films.

  16. Ion beam co-deposition of HTSC films on SrTiO3 and ITO/Si

    International Nuclear Information System (INIS)

    Superconducting YBa2Cu3O7-δ (YBCO) thin films were grown on Si with transparent, conducting Indium Tin Oxide (ITO) buffer layers. The onset temperature at 92K and zero resistance at 68K were measured. Both, ITO and YBCO films were deposited by ion beam co-deposition. The YBCO/ITO films exhibit metallic resistivity with positive slopes (∼0.055 Ω/K). The YBCO is uniform, textured and polycrystalline. In this paper the relevance for hybrid opto-electronic device structures is briefly discussed

  17. Tilting of carbon encapsulated metallic nanocolumns in carbon-nickel nanocomposite films by ion beam assisted deposition

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Matthias [Helmholtz-Zentrum Dresden-Rossendorf, PF-510119, 01314 Dresden (Germany); Technische Universitaet Dresden, D-01062 Dresden (Germany); Muecklich, Arndt; Zschornak, Matthias; Wintz, Sebastian; Gemming, Sibylle; Abrasonis, Gintautas [Helmholtz-Zentrum Dresden-Rossendorf, PF-510119, 01314 Dresden (Germany); Oates, Thomas W. H. [Leibniz-Institut fuer Analytische Wissenschaft, ISAS e.V., Albert-Einstein-Str. 9, 12489 Berlin (Germany); Luis Endrino, Jose [Surfaces and Coatings Department, Instituto de Ciencia de Materiales de Madrid, c/Sor Juana Ines de la Cruz 3, Cantoblanco, 28049 Madrid (Spain); Baehtz, Carsten; Shalimov, Artem [Helmholtz-Zentrum Dresden-Rossendorf, PF-510119, 01314 Dresden (Germany); Rossendorf Beamline, European Synchrotron Radiation Facility, F-38043 Grenoble (France)

    2012-07-30

    The influence of assisting low-energy ({approx}50-100 eV) ion irradiation effects on the morphology of C:Ni ({approx}15 at. %) nanocomposite films during ion beam assisted deposition (IBAD) is investigated. It is shown that IBAD promotes the columnar growth of carbon encapsulated metallic nanoparticles. The momentum transfer from assisting ions results in tilting of the columns in relation to the growing film surface. Complex secondary structures are obtained, in which a significant part of the columns grows under local epitaxy via the junction of sequentially deposited thin film fractions. The influence of such anisotropic film morphology on the optical properties is highlighted.

  18. Adhesion-enhanced thick copper film deposition on aluminum oxide by an ion-beam-mixed Al seed layer

    International Nuclear Information System (INIS)

    We report a highly-adherent 30-μm Cu conductive-path coating on an aluminum-oxide layer anodized on an aluminum-alloy substrate for a metal-printed circuit-board application. A 50-nm Al layer was first coated with an e-beam evaporative deposition method on the anodized oxide, followed by ion bombardment to mix the interfacial region. Subsequently, a Cu coating was deposited onto the mixed seed layer to the designed thickness. Adhesions of the interface were tested by using tape adhesion test, and pull-off tests and showed commercially acceptable adhesions for such thick coating layers. The ion beam mixing (IBM) plays the role of fastening the thin seed coating layer to the substrate and enhancing the adhesion of the Cu conductive path on the anodized aluminum surface.

  19. Structural and growth aspects of electron beam physical vapor deposited NiO-CeO{sub 2} nanocomposite films

    Energy Technology Data Exchange (ETDEWEB)

    Kuanr, Sushil Kumar; K, Suresh Babu, E-mail: sureshbabu.nst@pondiuni.edu.in [Centre for Nanoscience and Technology, Madanjeet School of Green Energy Technologies, Pondicherry University, Puducherry 605 014 (India)

    2016-03-15

    Deposition of composite materials as thin film by electron beam physical vapor deposition technique (EB-PVD) still remains as a challenge. Here, the authors report the deposition of NiO-CeO{sub 2} (30/70 wt. %) composites on quartz substrate by EB-PVD. Two NiO-CeO{sub 2} nanocomposite targets—one as green compact and the other after sintering at 1250 °C—were used for the deposition. Though the targets varied with respect to physical properties such as crystallite size (11–45 nm) and relative density (44% and 96%), the resultant thin films exhibited a mean crystallite size in the range of 20–25 nm underlining the role of physical nature of deposition. In spite of the crystalline nature of the targets and similar elemental concentration, a transformation from amorphous to crystalline structure was observed in thin films on using sintered target. Postannealing of the as deposited film at 800 °C resulted in a polycrystalline structure consisting of CeO{sub 2} and NiO. Deposition using pure CeO{sub 2} or NiO as target resulted in the preferential orientation toward (111) and (200) planes, respectively, showing the influence of adatoms on the evaporation and growth process of NiO-CeO{sub 2} composite. The results demonstrate the influence of electron beam gun power on the adatom energy for the growth process of composite oxide thin films.

  20. Fabricating Arrays of Vanadium Dioxide Nanodisks by Focused Ion-Beam Lithography and Pulsed-Laser Deposition

    International Nuclear Information System (INIS)

    Vanadium dioxide undergoes a structural (monoclinic to tetragonal) insulator-to-metal transition at 70 C, accompanied by large changes in electrical and optical properties. By combining focused ion-beam lithography and pulsed laser depo-sition, patterned arrays of vanadium dioxide nanoparticles are created that can be used for studies of linear and nonlinear optical physics, as well as demonstrating the potential for a variety of applications.

  1. Crystalline garnet Bragg reflectors for high power, high temperature, and integrated applications fabricated by multi-beam pulsed laser deposition

    OpenAIRE

    Sloyan, Katherine A.; May-Smith, Timothy C.; Zervas, Michalis N.; Eason, Robert W.

    2012-01-01

    Crystalline Bragg reflectors are of interest for high power, high temperature and integrated applications. We demonstrate the automated growth of such structures by shuttered multi-beam Pulsed Laser Deposition (PLD). Geometries include 145 layer stacks exhibiting >99.5% reflection and ? phase-shifted designs. A crystalline grating strength-apodized sample was grown by mixing plumes to obtain layers with custom refractive indices. Peak reflection wavelength was tuneable with incident position,...

  2. Megaelectron volt ion beam-induced epitaxy of deposited silicon and germanium-silicon alloys on (100) silicon substrates

    International Nuclear Information System (INIS)

    Solid phase heteroepitaxial crystallization of GexSi1-x/(100) Si was induced by MeV ion bombardment while heating the substrate at low temperatures. Rutherford Backscatter Spectrometry (RBS), Ion Channeling, Secondary Ion Mass Spectroscopy (SIMS) and transmission electron microscopy (TEM) techniques were used to investigate the kinetics of the reordering process as well as characterize the strain in the resultant epitaxial layer. The epitaxial recrystallization of amorphous silicon and silicon-germanium layers on (100)silicon, deposited under medium (10-7 torr) vacuum conditions, was induced by 2.5 MeV Ar beam irradiation in the low temperature range of 200-400C. The regrowth follows an Arrhenius dependence with temperature and activation energies of ∼0.3 eV were determined for the regrowth of deposited Si and a Ge38Si62 alloy. Ion beam induced heteroepitaxy was found to be sensitive to interfacial contaminants. In addition, the resultant crystalline quality for Ge-rich alloys was poor after irradiation. Ion beam induced heteroepitaxy of MBE-deposited GexSi1-x/(100) Si, deposited under high vacuum conditions after strict interfacial preparation, resulted in layer-by-layer reordering for alloys up to 65 at. % Ge. Coherently strained epilayers were reported for ion beam annealed GeSi alloys with germanium concentration less than 15 at. %. The pseudomorphic epilayers were characterized by planar and axial channeling to measure the tetragonal distortion in the strained overlayers. Strained films, produced by MeV Ar bombardment while heating the substrate at temperatures as low as 300C, were observed to relax following extended furnace anneals at temperatures of 800-900C. Such results offer the possibility of extending defect-free growth of metastable strained layers to other lattice mismatched systems

  3. Silver nano-particles in fluoride films fabricated by Pulsed Laser Deposition with auxiliary Electron Beam Evaporation

    Czech Academy of Sciences Publication Activity Database

    Novotný, Michal; Lančok, Ján; Bulíř, Jiří; Hruška, Petr; Fekete, Ladislav; Fitl, Přemysl

    Strasbourg: European Materials Research Society, 2013. [E- MRS 2013 Spring Meeting. 27.05.2013-31.05.2013, Strasbourg] R&D Projects: GA MŠk(CZ) 7AMB12FR034; GA ČR(CZ) GAP108/11/1312 Grant ostatní: AVČR(CZ) M100101271 Institutional support: RVO:68378271 Keywords : lanthanum fluoride * calcium fluoride * thin film * silver nanoparticles * pulsed laser deposition * electron beam evaporation Subject RIV: BM - Solid Matter Physics ; Magnetism

  4. Comparison of Morphology Evolution of Ge(001) Homoepitaxial Films Grown by Pulsed Laser Deposition and Molecular Beam Epitaxy

    OpenAIRE

    McCamy, James W.; Shin, Byungha; Leonard, John P.; Aziz, Michael

    2005-01-01

    Using a dual Molecular Beam Epitaxy (MBE)-Pulsed Laser Deposition (PLD) Ultra-High Vacuum chamber, we have conducted the first experiments under identical thermal, background, and surface preparation conditions to compare Ge(001) homoepitaxial growth morphology in PLD and MBE. We find that in PLD with low kinetic energy and in MBE the film morphology evolves in a similar fashion: initially irregularly shaped mounds form, followed by pyramidal mounds with edges of the square-base along direc...

  5. Luminescence and stimulated emission of M/sub A/ colour centers in MgF2:Li crystal

    International Nuclear Information System (INIS)

    Spectral and lasing M/sub A/ center characteristics in uniaxial γ-irradiated MgF2:Li crystals of rutile structure are presented. Measurements of absorption spectra, luminescence, and excitation spectra are carried out. It is shown that the centers are characterized by a strong dichroism and oriented normally to the optical axis and that they possess a low photostability

  6. Uranium purification process in the 'FLUOREX' system. Adsorption mechanism of MoF6 on MgF2

    International Nuclear Information System (INIS)

    The nuclear fuel reprocessing technology FLUOREX is a hybrid system based on a fluoride volatility and a solvent extraction technique. Most of the uranium in the spent nuclear fuel is fluorinated, and recovered as UF6 gas. Because UF6 contains some volatile fluorides of fission products (FPs), we proposed to eliminate the FPs from UF6 by adsorbing them on fluoride adsorbents. We experimentally examined the adsorption amount of MoF6, one of the volatile FPs, on MgF2 adsorbent and considered the adsorption structure by the first principle calculation code ABINIT. The saturated adsorption amount at 423 K was constant at 1.3 ± 0.4 mg/m2 with no dependence on MoF6 pressure from 10-4 to 10-1 kPa, which covered the MoF6 partial pressure range in the actual process. According to the saturated adsorption amount, we supposed that only a mono layer of MoF6 molecules was adsorbed on the MgF2 surface. The calculation results showed that MoF6 was adsorbed on MgF2 by bonding F atoms of MoF6 with Mg atoms of the MgF2 surface and that the MoF6 adsorption on MoF6 layer occurred with some difficulty; these results explained the adsorption structure suggested by the saturated adsorption amount. (author)

  7. Improved Performance of Organic Light-Emitting Diodes with MgF2 as the Anode Buffer Layer

    Institute of Scientific and Technical Information of China (English)

    XIE Jing; ZHANG De-Qiang; WANG Li-Duo; DUAN Lian; QIAO Juan; QIU Yong

    2006-01-01

    @@ Organic light-emitting diodes (OLEDs) based on N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB) and tris (8-hydroxyquinoline) aluminium (Alq3) are improved by using a thin MgF2 buffer layer sandwiched between the indium tin oxide (ITO) anode and hole transporting layer (HTL) of NPB.

  8. Comparative analysis of electrophysical properties of ceramic tantalum pentoxide coatings, deposited by electron beam evaporation and magnetron sputtering methods

    Science.gov (United States)

    Donkov, N.; Mateev, E.; Safonov, V.; Zykova, A.; Yakovin, S.; Kolesnikov, D.; Sudzhanskaya, I.; Goncharov, I.; Georgieva, V.

    2014-12-01

    Ta2O5 ceramic coatings have been deposited on glass substrates by e-beam evaporation and magnetron sputtering methods. For the magnetron sputtering process Ta target was used. X-ray diffraction measurements show that these coatings are amorphous. XPS survey spectra of the ceramic Ta2O5 coatings were obtained. All spectra consist of well-defined XPS lines of Ta 4f, 4d, 4p and 4s; O 1s; C 1s. Ta 4f doublets are typical for Ta2O5 coatings with two main peaks. Scanning electron microscopy and atomic force microscopy images of the e-beam evaporated and magnetron sputtered Ta2O5 ceramic coatings have revealed a relatively flat surface with no cracks. The dielectric properties of the tantalum pentoxide coatings have been investigated in the frequency range of 100 Hz to 1 MHz. The electrical behaviour of e-beam evaporated and magnetron sputtered Ta2O5 ceramic coatings have also been compared. The deposition process conditions principally effect the structure parameters and electrical properties of Ta2O5 ceramic coatings. The coatings deposited by different methods demonstrate the range of dielectric parameters due to the structural and stoichiometric composition changes

  9. Mechanical properties and wear resistance of ion-beam-assisted sputter-deposited NiTi(N) coatings

    International Nuclear Information System (INIS)

    Thin films are deposited on an austenitic type 304L stainless steel using the sputtering of an Ni49Ti51 target with 1.5 keV N+ ions. The influence of a simultaneous 160 keV Ar+ implantation on hardness and wear resistance is studied. Hardness is measured with a nanoindenter. N+ reactive sputtering forms a coating harder than the substrate. The hardness increases by 80% when the eposit is ion beam assisted. Transmission electron microscopy analyses of the thin films reveal that the N+ sputtered films present a large content of nitrogen which forms with titanium strong disorganized metal-metalloid Ti-N bonds; when ion implantation is simultaneously used, very tiny crystalline TiN precipitates embedded in an amorphous matrix are observed. This could explain the increase in hardness. The simultaneous ion irradiation would favour TiN precipitation through an enhanced diffusion mechanism in the cascades. Subsequent wear resistance of these coatings is measured through three-dimensional profile analyses of the wear tracks obtained after tests performed on a pin-on-disc machine. It is shown that sputtered NiTi(N) coatings largely increase the wear resistance. When the deposit is ion beam assisted, the improvement is much more pronounced; it can be related to either the increase in the hardness or the ion beam mixing of the interface, or both these processes. The influence of the coating thickness and the ratio of the implanted ions to the deposited atoms are also studied. (orig.)

  10. The Effect of Annealing on the Structural and Optical Properties of Titanium Dioxide Films Deposited by Electron Beam Assisted PVD

    Directory of Open Access Journals (Sweden)

    Yaser M. Abdulraheem

    2013-01-01

    Full Text Available Titanium dioxide thin films were deposited on crystalline silicon substrates by electron beam physical vapor deposition. The deposition was performed under vacuum ranging from 10−5 to 10−6 Torr without process gases, resulting in homogeneous TiO2-x layers with a thickness of around 100 nm. Samples were then annealed at high temperatures ranging from 500°C to 800°C for 4 hours under nitrogen, and their structural and optical properties along with their chemical structure were characterized before and after annealing. The chemical and structural characterization revealed a substoichiometric TiO2-x film with oxygen vacancies, voids, and an interface oxide layer. It was found from X-ray diffraction that the deposited films were amorphous and crystallization to anatase phase occurred for annealed samples and was more pronounced for annealing temperatures above 700°C. The refractive index obtained through spectroscopic ellipsometry ranged between 2.09 and 2.37 in the wavelength range, 900 nm to 400 nm for the as-deposited sample, and jumped to the range between 2.23 and 2.65 for samples annealed at 800°C. The minimum surface reflectance changed from around 0.6% for the as-deposited samples to 2.5% for the samples annealed at 800°C.

  11. On the magnetic properties of iron nanostructures fabricated via focused electron beam induced deposition and autocatalytic growth processes.

    Science.gov (United States)

    Tu, F; Drost, M; Vollnhals, F; Späth, A; Carrasco, E; Fink, R H; Marbach, H

    2016-09-01

    We employ Electron beam induced deposition (EBID) in combination with autocatalytic growth (AG) processes to fabricate magnetic nanostructures with controllable shapes and thicknesses. Following this route, different Fe deposits were prepared on silicon nitride membranes under ultra-high vacuum conditions and studied by scanning electron microscopy (SEM) and scanning transmission x-ray microspectroscopy (STXM). The originally deposited Fe nanostructures are composed of pure iron, especially when fabricated via autocatalytic growth processes. Quantitative near-edge x-ray absorption fine structure (NEXAFS) spectroscopy was employed to derive information on the thickness dependent composition. X-ray magnetic circular dichroism (XMCD) in STXM was used to derive the magnetic properties of the EBID prepared structures. STXM and XMCD analysis evinces the existence of a thin iron oxide layer at the deposit-vacuum interface, which is formed during exposure to ambient conditions. We were able to extract magnetic hysteresis loops for individual deposits from XMCD micrographs with varying external magnetic field. Within the investigated thickness range (2-16 nm), the magnetic coercivity, as evaluated from the width of the hysteresis loops, increases with deposit thickness and reaches a maximum value of ∼160 Oe at around 10 nm. In summary, we present a viable technique to fabricate ferromagnetic nanostructures in a controllable way and gain detailed insight into their chemical and magnetic properties. PMID:27454990

  12. Improved electrochemical performance of spinel LiMn(1.5)Ni(0.5)O4 through MgF2 nano-coating.

    Science.gov (United States)

    Wu, Qing; Zhang, Xiaoping; Sun, Shuwei; Wan, Ning; Pan, Du; Bai, Ying; Zhu, Huiyuan; Hu, Yong-Sheng; Dai, Sheng

    2015-10-14

    A spinel LiMn1.5Ni0.5O4 (LMNO) cathode material synthesized by a sol-gel method is modified by MgF2 nano-coating via a wet coating strategy. The results of X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM) showed that the MgF2 nano-coating layers do not physically change the bulk structure of the pristine material. Compared with the pristine compound, the MgF2-coated LMNO electrodes display enhanced cycling stabilities. Particularly, the 5 wt% MgF2-coated LMNO demonstrates the best reversibility, with a capacity retention of 89.9% after 100 cycles, much higher than that of the pristine material, 69.3%. The dQ/dV analysis and apparent Li(+) diffusion coefficient calculation prove that the kinetic properties are enhanced after MgF2 surface modification, which partly explains the improved electrochemical performances. Electrochemical impedance spectroscopy (EIS) and Fourier transform infrared spectroscopy (FTIR) data confirm that the MgF2 coating layer helps in suppressing the fast growth of the solid electrolyte interface (SEI) film in repeated cycling, which effectively stabilizes the spinel structure. Additionally, differential scanning calorimetry (DSC) tests show that the MgF2 nano-coating layer also helps in enhancing the thermal stability of the LMNO cathode. PMID:26204097

  13. Microstructure and thermal cycling behavior of CeO2 coatings deposited by the electron beam physical vapor technique

    International Nuclear Information System (INIS)

    Excellent thermal shock resistance is required for thermal protection coatings experiencing high/low temperature cycles. In this paper, the pure ceria oxide coatings were deposited by electron beam physical vapor technique at different power densities. The grain orientation, morphology, hardness and thermal cycling oxidation behavior of CeO2 coatings were systematically studied. The deposition power density has remarkable influence on the preferred crystal orientation and morphology of the coatings. The heating–cooling test cycles from 1000 °C to room temperature indicate that the CeO2 coatings with the columnar structure show excellent thermal shock resistance. The hardness of the CeO2 coating varies with thermal cycling. - Highlights: • Electron-beam physical vapor deposited CeO2 coatings show preferred orientation. • Surface morphology of CeO2 coatings is deeply influenced by the deposition power. • CeO2 coatings with columnar structure exhibit excellent thermal shock resistance. • The hardness increases initially and then decreases during thermal cycling

  14. Thickness and component distributions of yttrium-titanium alloy films in electron-beam physical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    LI ShuaiHui; SHU YongHua; FAN Jing

    2008-01-01

    Thickness and component distributions of large-area thin films are an issue of in-ternational concern in the field of material processing. The present wor0k employs experiments and direct simulation Monte Carlo (DSMC) method to investigate three-dimensional low-density, non-equilibrium jets of yttrium and titanium vapor atoms in an electron-beams physical vapor deposition (EBPVD) system furnished with two or three electron-beams, and obtains their deposition thickness and component distributions onto 4-inch and 6-inch mono-crystal silicon wafers. The DSMC results are found in excellent agreement with our measurements, such as evaporation rates of yttrium and titanium measured in-situ by quartz crystal reso-nators, deposited film thickness distribution measured by Rutherford backscat-tering spectrometer (RBS) and surface profilometer and deposited film molar ratio distribution measured by RBS and inductively coupled plasma atomic emission spectrometer (ICP-AES). This can be taken as an indication that a combination of DSMC method with elaborate measurements may be satisfactory for predicting and designing accurately the transport process of EBPVD at the atomic level.

  15. Ion-beam assisted deposition of MgO with in situ RHEED monitoring to control Bi-axial texture

    Energy Technology Data Exchange (ETDEWEB)

    Arendt, P. N. (Paul N.); Foltyn, S. R. (Stephen R.); Jia, Quanxi; DePaula, R. F. (Raymond Felix); Dowden, P. C. (Paul C.); Kung, H. (Harriett); Holesinger, T. G. (Terry G.); Stan, L. (Liliana); Emmert, L. A. (Luke A.); Peterson, E. J. (Eric J.); Groves, J. R. (James R.)

    2001-01-01

    We have studied the growth of magnesium oxide using ion-beam assisted deposition (IBAD) to achieve (100) oriented, bi-axially textured films with low mosaic spread, for film thicknesses of 10 nm on silicon substrates. We have refined the process by using reflected high-energy electron diffraction (RHEED) to monitor the growth of IBAD MgO films and found that the diffracted intensity can be used to determine (and ultimately control) final in-plane texture of the film. Here we present results on our work to develop the use of real-time RHEED monitoring to deposit well-oriented IBAD MgO films. The results have been corroborated with extensive grazing-incidence X-ray diffraction (GID). Results of these analyses have allowed us to deposit films on metallic substrates with in-plane mosaic spread less than 7{sup o}.

  16. Plasmonic Gold Helices for the visible range fabricated by oxygen plasma purification of electron beam induced deposits

    CERN Document Server

    Haverkamp, Caspar; Jäckle, Sara; Manzoni, Anna; Christiansen, Silke

    2016-01-01

    Electron beam induced deposition (EBID) currently provides the only direct writing technique for truly three-dimensional nanostructures with geometrical features below 50 nm. Unfortunately, the depositions from metal-organic precursors suffer from a substantial carbon content. This hinders many applications, especially in plasmonics where the metallic nature of the geometric surfaces is mandatory. To overcome this problem a post-deposition treatment with oxygen plasma at room temperature was investigated for the purification of gold containing EBID structures. Upon plasma treatment, the structures experience a shrinkage in diameter of about 18 nm but entirely keep their initial shape. The proposed purification step results in a core-shell structure with the core consisting of mainly unaffected EBID material and a gold shell of about 20 nm in thickness. These purified structures are plasmonically active in the visible wavelength range as shown by dark field optical microscopy on helical nanostructures. Most no...

  17. Molecular beam epitaxy deposition of Gd2O3 thin films on SrTiO3 (100) substrate

    Science.gov (United States)

    Wang, Jinxing; Hao, Jinghua; Zhang, Yangyang; Wei, Hongmei; Mu, Juyi

    2016-06-01

    Gd2O3 thin films are grown on the SrTiO3 (100) substrate by molecular beam epitaxy (MBE) deposition. X-ray diffraction (XRD) analysis, conventional transmission electron microscopy (TEM) and aberration-corrected scanning transmission electron microscopy (STEM) are performed to investigate the microstructure of deposited thin films. It is found that the as-deposited thin film possesses a very uniform thickness of ∼40 nm and is composed of single cubic phase Gd2O3 grains. STEM and TEM observations reveal that Gd2O3 thin film grows epitaxially on the SrTiO3 (100) substrate with (001)Gd2O3//(100)STO and [110]Gd2O3//[001]STO orientations. Furthermore, the Gd atoms are found to diffuse into the SrTiO3 substrate for a depth of one unit cell and substitute for the Sr atoms near the interface.

  18. Investigation of chemical vapour deposition diamond detectors by X- ray micro-beam induced current and X-ray micro-beam induced luminescence techniques

    CERN Document Server

    Olivero, P; Vittone, E; Fizzotti, F; Paolini, C; Lo Giudice, A; Barrett, R; Tucoulou, R

    2004-01-01

    Tracking detectors have become an important ingredient in high-energy physics experiments. In order to survive the harsh detection environment of the Large Hadron Collider (LHC), trackers need to have special properties. They must be radiation hard, provide fast collection of charge, be as thin as possible and remove heat from readout electronics. The unique properties of diamond allow it to fulfill these requirements. In this work we present an investigation of the charge transport and luminescence properties of "detector grade" artificial chemical vapour deposition (CVD) diamond devices developed within the CERN RD42 collaboration, performed by means of X-ray micro-beam induced current collection (XBICC) and X-ray micro- beam induced luminescence (XBIL) techniques. XBICC technique allows quantitative estimates of the transport parameters of the material to be evaluated and mapped with micrometric spatial resolution. In particular, the high resolution and sensitivity of the technique has allowed a quantitati...

  19. MGF Approach to the Analysis of Generalized Two-Ray Fading Models

    KAUST Repository

    Rao, Milind

    2015-01-01

    We analyze a class of Generalized Two-Ray (GTR) fading channels that consist of two line of sight (LOS) components with random phase plus a diffuse component. We derive a closedform expression for the moment generating function (MGF) of the signal-to-noise ratio (SNR) for this model, which greatly simplifies its analysis. This expression arises from the observation that the GTR fading model can be expressed in terms of a conditional underlying Rician distribution. We illustrate the approach to derive simple expressions for statistics and performance metrics of interest such as the amount of fading, the level crossing rate, the symbol error rate, and the ergodic capacity in GTR fading channels. We also show that the effect of considering a more general distribution for the phase difference between the LOS components has an impact on the average SNR.

  20. Automation of MgF2 crushing plant to reduce down time

    International Nuclear Information System (INIS)

    This paper gives the description of a PLC based automated system to reduce the down time of uranium extraction plant. This plant handles MgF2, which is a byproduct of the uranium metal extraction process. The plant is under remote supervision during operation as the area contains inhalable dust and radioactivity. Various failure modes of the plant have been studied and Petri net based modeling has been used to methodical programming of the PLC to reduce human interface even in case of any malfunctioning of the plant. PLC based control has been programmed to intelligently decide and control the situation during malfunctioning of any equipment depending on the number and gravity of the failures. CCTV and external safety interlocks have been used to ensure second layer of protective control over the unmanned plant. (author)

  1. Effects of deposition conditions on gas-barrier performance of SiOxNy thin films formed via ion-beam-assisted vapor deposition

    International Nuclear Information System (INIS)

    SiOxNy thin films were synthesized via ion-beam-assisted vapor deposition (IVD) where deposition of SiOx was irradiated by nitrogen ions. Firstly, reasonable-cost evaporation materials showing less splashing for the SiOx films were investigated by selecting appropriate sintering condition regimes of Si and SiO2 mixed powders. The SiOxNy thin films on a polyethylene terephtalate film substrate obtained via IVD showed a low oxygen transmission rate (OTR) of less than 1 cm3/m2 day. Effective nitrogen ion irradiation energy per atom was 8 eV/at. or greater, which is consistent with regimes where densification of thin films is reported to occur. Higher N2 partial pressure yielded a lower OTR and a higher nitrogen atomic ratio of the films obtained. It is suggested that the improvement in gas-barrier performance resulted from densification and chemical change of the films due to energy addition and nitrification produced by nitrogen ion-beam irradiation

  2. Influence of deposition parameters on surface roughness and mechanical properties of boron carbon nitride coatings synthesized by ion beam assisted deposition

    International Nuclear Information System (INIS)

    Boron carbon nitride (BCN) coatings were deposited on Si(100) wafers and Si3N4 disks by using ion beam assisted deposition from a boron carbide target. The BCN coatings were synthesized by the reaction between boron and carbon vapor as well as nitrogen ion simultaneously. The influence of deposition parameters such as ion acceleration voltage, ion acceleration current density and deposition ratio on the surface roughness and mechanical properties of the BCN coatings was investigated. The surface roughness was determined by using atomic force microscopy and the mechanical properties of the BCN coatings were evaluated by nano-indentation tests and friction tests in N2 gas. The composition and chemical bonding of the BCN coatings were analyzed by using X-ray photoelectron spectroscopy. The results showed that the lower deposition rate, the smaller surface roughness and higher nano-hardness the BCN coatings were. The BCN coating with the smoothest surface (R a = 0.25 nm and R P-V = 2.8 nm) and the highest nanohardness of 33 GPa as well as excellent friction property were obtained at 0.5 nm/s and the nitrogen ions were generated at 2.0 kV and 60 μA/cm2, and the chemical composition of this BCN coating was 49 at.% B, 42 at.% C and 9 at.% N. Moreover, there were several bonding states such as B-N, B-C and C-N with B-C-N hybridization in this BCN coating

  3. Structural, compositional, mechanical characterization and biological assessment of bovine-derived hydroxyapatite coatings reinforced with MgF2 or MgO for implants functionalization.

    Science.gov (United States)

    Mihailescu, Natalia; Stan, G E; Duta, L; Chifiriuc, Mariana Carmen; Bleotu, Coralia; Sopronyi, M; Luculescu, C; Oktar, F N; Mihailescu, I N

    2016-02-01

    Hydroxyapatite (HA) is a consecrated biomaterial for bone reconstruction. In the form of thin films deposited by pulsed laser technologies, it can be used to cover metallic implants aiming to increase biocompatibility and osseointegration rate. HA of animal origin (bovine, BHA) reinforced with MgF2 (2wt.%) or MgO (5wt.%) were used for deposition of thin coatings with improved adherence, biocompatibility and antimicrobial activity. For pulsed laser deposition experiments, a KrF* (λ=248nm, τFWHM≤25ns) excimer laser source was used. The deposited structures were characterized from a physical-chemical point of view by X-Ray Diffraction, Fourier Transform Infra-Red Spectroscopy, Scanning Electron Microscopy in top- and cross-view modes, Energy Dispersive X-Ray Spectroscopy and Pull-out adherence tests. The microbiological assay using the HEp-2 cell line revealed that all target materials and deposited thin films are non-cytotoxic. We conducted tests on three strains isolated from patients with dental implants failure, i.e. Microccocus sp., Enterobacter sp. and Candida albicans sp. The most significant anti-biofilm effect against Microcococcus sp. strain, at 72h, was obtained in the presence of BHA:MgO thin films. For Enterobacter sp. strain a superior antimicrobial activity at 72h was noticed, in respect with simple BHA or Ti control. The enhanced antimicrobial performances, correlated with good cytocompatibility and mechanical properties recommend these biomaterials as an alternative to synthetic HA for the fabrication of reliable implant coatings for dentistry and other applications. PMID:26652442

  4. MGF-Ct24E改性聚乳酸的合成、表征及其对成骨细胞增殖的评价%Synthesis, characterization and osteoblasts proliferation of a novel biomimetic material based on MGF-Ct24E modified poly (D, L-lactic acid)

    Institute of Scientific and Technical Information of China (English)

    罗嘉; 李玉筱; 王品品; 王远亮

    2013-01-01

    力生长因子(MGF)是骨修复重建的一种重要生长因子.以二环己基碳二亚胺为缩合剂,将MGF羧基端E结构域24肽(MGF-Ct24E)共价接枝到丁二胺改性的聚乳酸上(DPLA),制得了新型MGF-Ct24E改性聚乳酸仿生材料(MGF Ct24E-DPLA).采用氨基酸分析和高效液相色谱对MGF-Ct24E含量进行了定性定量表征,静态水接触角和吸水率测定了MGF-Ct24E DPLA材料的亲水性,MTT法评价了其对成骨细胞的增殖作用.结果表明,MGF-Ct24E成功引入到DPLA中,接枝效率为24.7%,并且和DPLA相比,MGF-Ct24E-DPLA材料具有更好的亲水性和促进成骨细胞增殖的能力.因此这种新型MGF-Ct24E改性聚乳酸仿生材料有望成为骨组织工程领域中一种卓越的生物材料.%Mechano-growth factor (MGF) is one of the most important growth factors of bone regeneration. A novel biomimetic poly (D, L-lactic acid) (PDLLA) modification was designed and synthesized based on MGF-Ct24E grafted butanediamine modified PDLLA (DPLA). MGF-Ct24Es were grafted into the side chain of DP-LA via a stable covalent amide bond by using dicyclohexylcarbodiimide (DCC) as the condensing agent to produce biomimetic DPLA materials (MGF-Ct24E-DPLA). Amino acid analyzer (AAA) and high performance liquid chromatography (HPLC) were used to characterize the MGF-Ct24E-DPLA. The hydrophilicity of MGF-Ct24E-DPLA was evaluated by means of the water-uptake ratios and static water contact angle. Data revealed that the grafting efficiency of MGF-Ct24E was about 24. 7%. MGF-Ct24E-MPLA had better hydrophilicity than DPLA. The osteoblasts behavior of proliferation, on glass, DPLA and MGF-Ct24E-DPLA films was investigated and the results indicated that the introduction of MGF-Ct24E could improve osteoblasts proliferation. The MGF-Ct24EMPLA with higher bioactivity may have potential application for bone tissue engineering.

  5. On the magnetic properties of iron nanostructures fabricated via focused electron beam induced deposition and autocatalytic growth processes

    Science.gov (United States)

    Tu, F.; Drost, M.; Vollnhals, F.; Späth, A.; Carrasco, E.; Fink, R. H.; Marbach, H.

    2016-09-01

    We employ Electron beam induced deposition (EBID) in combination with autocatalytic growth (AG) processes to fabricate magnetic nanostructures with controllable shapes and thicknesses. Following this route, different Fe deposits were prepared on silicon nitride membranes under ultra-high vacuum conditions and studied by scanning electron microscopy (SEM) and scanning transmission x-ray microspectroscopy (STXM). The originally deposited Fe nanostructures are composed of pure iron, especially when fabricated via autocatalytic growth processes. Quantitative near-edge x-ray absorption fine structure (NEXAFS) spectroscopy was employed to derive information on the thickness dependent composition. X-ray magnetic circular dichroism (XMCD) in STXM was used to derive the magnetic properties of the EBID prepared structures. STXM and XMCD analysis evinces the existence of a thin iron oxide layer at the deposit–vacuum interface, which is formed during exposure to ambient conditions. We were able to extract magnetic hysteresis loops for individual deposits from XMCD micrographs with varying external magnetic field. Within the investigated thickness range (2–16 nm), the magnetic coercivity, as evaluated from the width of the hysteresis loops, increases with deposit thickness and reaches a maximum value of ∼160 Oe at around 10 nm. In summary, we present a viable technique to fabricate ferromagnetic nanostructures in a controllable way and gain detailed insight into their chemical and magnetic properties.

  6. Very high temperature chemical vapor deposition of new carbon thin films using organic semiconductor molecular beam sources

    Energy Technology Data Exchange (ETDEWEB)

    Noguchi, Takuya [Department of Chemistry, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 (Japan); Shimada, Toshihiro, E-mail: shimada@chem.s.u-tokyo.ac.j [Department of Chemistry, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 (Japan); Hanzawa, Akinori; Hasegawa, Tetsuya [Department of Chemistry, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 (Japan)

    2009-11-30

    We carried out the preparation and characterization of new carbon films deposited using an organic molecular beam deposition apparatus with very high substrate temperature (from room temperature to 2670 K), which we newly developed. When we irradiated molecular beam of organic semiconductor perylene tetracarboxylic acid dianhydride (PTCDA) on Y{sub 0.07}Zr{sub 0.93}O{sub 2} (111) at 2170 K, a new carbon material was formed via decomposition and fusing of the molecules. The films were characterized with an atomic force microscope (AFM), Raman spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Zirconium carbide (ZrC) films were identified beneath the topmost carbon layer by XRD and XPS analyses, which results from chemical reactions of the substrate and the molecules. Partially graphitized aromatic rings of PTCDA were observed from Raman spectroscopy. The present technique - very high temperature chemical vapor deposition using organic semiconductor sources - will be useful to study a vast unexplored field of covalent carbon solids.

  7. Artificial granularity in two-dimensional arrays of nanodots fabricated by focused-electron-beam-induced deposition

    Energy Technology Data Exchange (ETDEWEB)

    Porrati, F; Sachser, R; Huth, M [Physikalisches Institut, Goethe-Universitaet, Max-von-Laue-Strasse 1, D-60438 Frankfurt am Main (Germany); Strauss, M [Max-Planck-Institut fuer Biophysik, Max-von-Laue-Strasse 3, D-60438 Frankfurt am Main (Germany); Andrusenko, I; Gorelik, T; Kolb, U [Institut fuer Physikalische Chemie, Johannes Gutenberg-Universitaet Mainz, Welderweg 11, D-55099 Mainz (Germany); Bayarjargal, L; Winkler, B [Institut fuer Geowissenschaften, Abt. Kristallographie, Goethe-Universitaet, Altenhoeferallee 1, D-60438 Frankfurt am Main (Germany)

    2010-09-17

    We have prepared 2D arrays of nanodots embedded in an insulating matrix by means of focused-electron-beam-induced deposition using the W(CO){sub 6} precursor. By varying the deposition parameters, i.e. the electron beam current and energy and the raster constant, we obtain an artificial granular material with tunable electrical properties. The analysis of the temperature dependence of the conductivity and of the current-voltage characteristic suggests that the transport mechanism is governed by electron tunneling between artificial grains. In order to understand the nature of the granularity and thus the microstructural origin of the electronic transport behavior, we perform TEM and micro-Raman investigations. Independent of the deposition parameters, TEM measurements show that the dots are constituted of amorphous tungsten carbide clusters embedded in an amorphous carbonaceous matrix. Micro-Raman spectra show two peaks, around 690 and 860 cm{sup -1} associated with the W-C stretching modes. Higher frequency peaks give information on the composition of the matrix. In particular, we measure a peak at about 1290 cm{sup -1}, which is associated with sp{sup 3} carbon bonds. Furthermore we detect the so-called D and G peaks, at about 1350 and 1560 cm{sup -1}, associated with the vibration modes of the sp{sup 2} carbon bonds. The analysis of the position of the peaks and of their relative intensity suggests that the composition of the matrix is between nanocrystalline graphite and amorphous carbon.

  8. Processing for optically active erbium in silicon by film co-deposition and ion-beam mixing

    International Nuclear Information System (INIS)

    Techniques of film deposition by co-evaporation, ion-beam assisted mixing, oxygen ion implantation, and thermal annealing were been combined in a novel way to study processing of erbium-in-silicon thin-film materials for optoelectronics applications. Structures with erbium concentrations above atomic solubility in silicon and below that of silicide compounds were prepared by vacuum co-evaporation from two elemental sources to deposit 200-270 nm films on crystalline silicon substrates. Ar+ ions were implanted at 300 keV. Oxygen was incorporated by O+-ion implantation at 130 keV. Samples were annealed at 600 deg. C in vacuum. Concentration profiles of the constituent elements were obtained by Rutherford backscattering spectrometry. Results show that diffusion induced by ion-beam mixing and activated by thermal annealing depends on the deposited Si-Er profile and reaction with implanted oxygen. Room temperature photoluminescence spectra show Er3+ transitions in a 1480-1550 nm band and integrated intensities that increase with the oxygen-to-erbium ratio.

  9. Simulation of the secondary electrons energy deposition produced by proton beams in PMMA: influence of the target electronic excitation description

    International Nuclear Information System (INIS)

    We have studied the radial dependence of the energy deposition of the secondary electron generated by swift proton beams incident with energies T = 50 keV - 5 MeV on poly(methylmethacrylate) (PMMA). Two different approaches have been used to model the electronic excitation spectrum of PMMA through its energy loss function (ELF), namely the extended-Drude ELF and the Mermin ELF. The singly differential cross section and the total cross section for ionization, as well as the average energy of the generated secondary electrons, show sizeable differences at T ≤ 0.1 MeV when evaluated with these two ELF models. In order to know the radial distribution around the proton track of the energy deposited by the cascade of secondary electrons, a simulation has been performed that follows the motion of the electrons through the target taking into account both the inelastic interactions (via electronic ionizations and excitations as well as electron-phonon and electron trapping by polaron creation) and the elastic interactions. The radial distribution of the energy deposited by the secondary electrons around the proton track shows notable differences between the simulations performed with the extended-Drude ELF or the Mermin ELF, being the former more spread out (and, therefore, less peaked) than the latter. The highest intensity and sharpness of the deposited energy distributions takes place for proton beams incident with T ∼ 0.1 - 1 MeV. We have also studied the influence in the radial distribution of deposited energy by using a full energy distribution of secondary electrons generated by proton impact or by using a single value (namely, the average value of the distribution); our results show that differences between both simulations become important for proton energies larger than ∼ 0.1 MeV. The results presented in this work have potential applications in materials science, as well as hadron therapy (due to the use of PMMA as a tissue phantom) in order to properly

  10. Double-beam pulsed laser deposition for the growth of Al-incorporated ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, L. [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, AP 70-186, C.P. 04510 México D.F., México (Mexico); Sánchez-Aké, C., E-mail: citlali.sanchez@ccadet.unam.mx [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, AP 70-186, C.P. 04510 México D.F., México (Mexico); Bizarro, M. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-186, C.P. 04510 México D.F., México (Mexico)

    2014-05-01

    Pulsed laser deposition in a delayed-double beam configuration is used to incorporate in situ Al in ZnO thin films. In this configuration, two synchronized pulsed-laser beams are employed to ablate independently a ZnO and an Al target. We investigated the effects of relative time delay of plasma plumes on the composition of the films with the aim of evaluating the performance of this technique to produce doped materials. Relative delay between plumes was found to control the incorporation of Al in the film in the range from 14% to 30%. However, to produce low impurity concentration of Al-doped ZnO (with Al incorporation less than 2%) the fluence used to produce the plasmas has more influence over the film composition than the relative plume delay. The minimum incorporation of Al corresponded to a relative delay of 0 μs, due to the interaction between plumes during their expansion.

  11. Ferroelectric polarization and resistive switching characteristics of ion beam assisted sputter deposited BaTiO3 thin films

    Science.gov (United States)

    Silva, J. P. B.; Kamakshi, Koppole; Sekhar, K. C.; Moreira, J. Agostinho; Almeida, A.; Pereira, M.; Gomes, M. J. M.

    2016-05-01

    In this work, 150 nm thick polycrystalline BaTiO3 (BTO) films were deposited on Pt/TiO2/SiO2/Si substrate by ion beam assisted sputter deposition technique. The bias voltage dependent resistive switching (RS) and ferroelectric polarization characteristics of Au/BTO/Pt devices are investigated. The devices display the stable bipolar RS characteristics without an initial electroforming process. Fittings to current-voltage (I-V) curves suggest that low and high resistance states are governed, respectively, by filamentary model and trap controlled space charge limited conduction mechanism, where the oxygen vacancies act as traps. Presence of oxygen vacancies is evidenced from the photoluminescence spectrum. The devices also display P-V loops with remnant polarization (Pr) of 5.7 μC/cm2 and a coercive electric field (Ec) of 173.0 kV/cm. The coupling between the ferroelectric polarization and RS effect in BTO films is demonstrated.

  12. Reversible wettability of electron-beam deposited indium-tin-oxide driven by ns-UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Persano, Luana [NNL, National Nanotechnology Laboratory of CNR-Istituto Nanoscienze, Universita del Salento, via Arnesano, I-73100 Lecce (Italy); Center for Biomolecular Nanotechnologies UNILE, Istituto Italiano di Tecnologia, Via Barsanti, I-73010 Arnesano-LE (Italy); Del Carro, Pompilio [NNL, National Nanotechnology Laboratory of CNR-Istituto Nanoscienze, Universita del Salento, via Arnesano, I-73100 Lecce (Italy); Pisignano, Dario [NNL, National Nanotechnology Laboratory of CNR-Istituto Nanoscienze, Universita del Salento, via Arnesano, I-73100 Lecce (Italy); Center for Biomolecular Nanotechnologies UNILE, Istituto Italiano di Tecnologia, Via Barsanti, I-73010 Arnesano-LE (Italy); Dipartimento di Matematica e Fisica ' ' Ennio De Giorgi' ' , Universita del Salento, via Arnesano, I-73100 Lecce (Italy)

    2012-04-09

    Indium tin oxide (ITO) is one of the most widely used semiconductor oxides in the field of organic optoelectronics, especially for the realization of anode contacts. Here the authors report on the control of the wettability properties of ITO films deposited by reactive electron beam deposition and irradiated by means of nanosecond-pulsed UV irradiation. The enhancement of the surface water wettability, with a reduction of the water contact angle larger than 50 deg., is achieved by few tens of seconds of irradiation. The analyzed photo-induced wettability change is fully reversible in agreement with a surface-defect model, and it can be exploited to realize optically transparent, conductive surfaces with controllable wetting properties for sensors and microfluidic circuits.

  13. Reversible wettability of electron-beam deposited indium-tin-oxide driven by ns-UV irradiation

    International Nuclear Information System (INIS)

    Indium tin oxide (ITO) is one of the most widely used semiconductor oxides in the field of organic optoelectronics, especially for the realization of anode contacts. Here the authors report on the control of the wettability properties of ITO films deposited by reactive electron beam deposition and irradiated by means of nanosecond-pulsed UV irradiation. The enhancement of the surface water wettability, with a reduction of the water contact angle larger than 50 deg., is achieved by few tens of seconds of irradiation. The analyzed photo-induced wettability change is fully reversible in agreement with a surface-defect model, and it can be exploited to realize optically transparent, conductive surfaces with controllable wetting properties for sensors and microfluidic circuits.

  14. Molecular beam deposition of high-permittivity polydimethylsiloxane for nanometer-thin elastomer films in dielectric actuators

    DEFF Research Database (Denmark)

    M. Weiss, Florian; Madsen, Frederikke Bahrt; Töpper, Tino;

    2016-01-01

    dielectric properties. To produce elastomer layers nanometers thin, molecular beam deposition was introduced. We pursue the synthesis of a high-permittivity oligomer, namely a chloropropyl-functional, vinyl-terminated siloxane to be thermally evaporated and subsequent UV curing to form an elastomer. The......To realize low-voltage dielectric elastomer actuators (DEAs) for artificial muscles, a high-permittivity elastomer and a related thin-film deposition technique must be selected. For polydimethylsiloxane, fillers or functionalized crosslinkers have been incorporated into the elastomer to improve...... monitoring. Using atomic force microscopy, the film surface morphology and mechanics were characterized after growth termination and subsequent curing. The Young's modulus of the elastomer corresponded to (1.8 ± 0.2) MPa and is thus a factor of two lower than that of DMS-V05. Consequently, the properties of...

  15. Energy band alignment of atomic layer deposited HfO2 on epitaxial (110)Ge grown by molecular beam epitaxy

    OpenAIRE

    Hudait, Mantu K.; Zhu, Y.; Maurya, Deepam; Priya, Shashank

    2013-01-01

    The band alignment properties of atomic layer HfO2 film deposited on epitaxial (110)Ge, grown by molecular beam epitaxy, was investigated using x-ray photoelectron spectroscopy. The cross-sectional transmission electron microscopy exhibited a sharp interface between the (110)Ge epilayer and the HfO2 film. The measured valence band offset value of HfO2 relative to (110)Ge was 2.28 +/- 0.05 eV. The extracted conduction band offset value was 2.66 +/- 0.1 eV using the bandgaps of HfO2 of 5.61 eV ...

  16. Superconducting YBa2Cu3O7 thin films grown in-situ by ion beam co-deposition

    International Nuclear Information System (INIS)

    Superconducting YBCO thin films have been grown in-situ by three ion beam co-deposition sputtering. Both metal and oxide targets of Cu and Y and BaF2 and BaCO3 targets have been investigated. Film composition was determined by RBS and AES analysis. Films grown using BaF2 show fluorine contamination, whereas the carbon concentration in films grown using BaCO3 is beneath the Auger detection limit. Superconducting films have been grown on SrTiO3(Tco = 78K) and on Si with SiO2 or Y2O3 buffer layers(Tco = 35K)

  17. Comparison of the dose deposited between the OBI system and the Varian TrueBeam Imaging system

    International Nuclear Information System (INIS)

    The use of imaging systems for positioning kilovoltage radiotherapy treatments has experienced a peak in recent years. Techniques such as IMRT, these systems are applied to a large number of sessions to ensure accurate positioning. This makes it increased the interest to know the dose deposited in the patient. Companies involved in developing new designs focus their efforts on reducing the dose due to these positioning systems. The aim of this study is to compare the dose delivered by the OBI image guidance system with the new system image TrueBeam, both of Varian, both planar imaging as CT (CBCT).

  18. Oxidation of nanostructured Ti films produced by low energy cluster beam deposition: An X-ray Photoelectron Spectroscopy characterization

    Energy Technology Data Exchange (ETDEWEB)

    Simone, Monica de, E-mail: desimone@tasc.infm.it [CNR-IOM Laboratorio TASC, Area Science Park Basovizza, 34149 Trieste (Italy); Snidero, Elena [CNR-IOM Laboratorio TASC, Area Science Park Basovizza, 34149 Trieste (Italy); Coreno, Marcello [CNR-IMIP, c/o Laboratorio TASC Area Science Park Basovizza, 34149 Trieste (Italy); Sincrotrone Trieste ScpA, Area Science Park Basovizza, 34149 Trieste (Italy); Bongiorno, Gero [Fondazione Filarete, v.le Ortles 22/4, 20139 Milano (Italy); Giorgetti, Luca [Istituto Europeo di Oncologia, Dip. di Oncologia Sperimentale, Via Adamello 16, 20139, Milano (Italy); Amati, Matteo [Sincrotrone Trieste ScpA, Area Science Park Basovizza, 34149 Trieste (Italy); Cepek, Cinzia [CNR-IOM Laboratorio TASC, Area Science Park Basovizza, 34149 Trieste (Italy)

    2012-05-01

    We used in-situ X-ray Photoelectron Spectroscopy (XPS) to study the oxidation process of a cluster-assembled metallic titanium film exposed to molecular oxygen at room temperature. The nanostructured film has been grown on a Si(111) substrate, in ultra high vacuum conditions, by coupling a supersonic cluster beam deposition system with an XPS experimental chamber. Our results show that upon in-situ oxygen exposure Ti{sup 3+} is the first oxidation state observed, followed by Ti{sup 4+}, whereas Ti{sup 2+} is practically absent during the whole process. Our results compare well with the existing literature on Ti films produced using other techniques.

  19. Transition between wurtzite and zinc-blende GaN: An effect of deposition condition of molecular-beam epitaxy

    OpenAIRE

    Xie, MH; Wu, HS; Shi, BM; Wang, N.; Tong, SY

    2006-01-01

    GaN exists in both wurtzite and zinc-blende phases and the growths of the two on its (0001) or (111) surfaces are achieved by choosing proper deposition conditions of molecular-beam epitaxy (MBE). At low substrate temperatures but high gallium fluxes, metastable zinc-blende GaN films are obtained, whereas at high temperatures and/or using high nitrogen fluxes, equilibrium wurtzite phase GaN epilayers resulted. This dependence of crystal structure on substrate temperature and source flux is no...

  20. Oxidation of nanostructured Ti films produced by low energy cluster beam deposition: An X-ray Photoelectron Spectroscopy characterization

    International Nuclear Information System (INIS)

    We used in-situ X-ray Photoelectron Spectroscopy (XPS) to study the oxidation process of a cluster-assembled metallic titanium film exposed to molecular oxygen at room temperature. The nanostructured film has been grown on a Si(111) substrate, in ultra high vacuum conditions, by coupling a supersonic cluster beam deposition system with an XPS experimental chamber. Our results show that upon in-situ oxygen exposure Ti3+ is the first oxidation state observed, followed by Ti4+, whereas Ti2+ is practically absent during the whole process. Our results compare well with the existing literature on Ti films produced using other techniques.

  1. Influence of a thin interfacial oxide layer on the ion beam assisted epitaxial crystallization of deposited Si

    Science.gov (United States)

    Priolo, F.; La Ferla, A.; Spinella, C.; Rimini, E.; Ferla, G.; Baroetto, F.; Licciardello, A.

    1988-12-01

    The epitaxial crystallization of chemical vapor deposited Si layers on Si substrates with a thin interfacial oxide layer was induced by a 600 keV Kr beam in the temperature range 350-500 °C. During irradiation the single crystal-amorphous interface velocity was measured in situ by monitoring the reflectivity of He-Ne laser light. We show that a critical irradiation dose is needed before the interfacial oxide breaks down and epitaxial regrowth can take place. This critical dose depends exponentially on the reciprocal temperature with an activation energy of 0.44 eV.

  2. Relation between electrical resistivity and argon concentration of copper thin films prepared by ion-beam-assisted deposition

    International Nuclear Information System (INIS)

    Particle Induced X-ray Emission (PIXE) measurements were applied to the evaluation of the argon concentration in the copper thin films prepared by Ion-Beam-Assisted Deposition (IBAD) technique. The relation between electrical resistivity and argon concentration in the films were investigated. The crystallinity and the atomic density were also examined with x-ray diffraction and Rutherford Backscattering Spectrometry (RBS). The obtained results indicated that although the grain size of the films becomes larger with the ion irradiation, electrical resistivity increases with an increase in the ion quantity. (author)

  3. Effect of Hydrogen ion beam irradiation onto the FIR reflectivity of pulsed laser deposited mirror like Tungsten films

    International Nuclear Information System (INIS)

    Graphical abstract: The specular FIR reflectivity of the W1, W2, W3 and W4 mirrors before and after 8 keV Hydrogen ion beam irradiation. Highlights: ► Mirror like W thin films were obtained via PLD. ► The maximum thickness of the Tungsten thin film was ∼324 nm. ► Effect of H-ion beam irradiation on the quality of PLD W mirror is reported. ► Post exposure reflectivity of Tungsten thin films was hardly changed by 2%. - Abstract: The optical quality of the First Mirrors (FMs) of a fusion device (burning plasma experiments, ITER) deteriorates due to the erosion by charge exchange neutrals, re-deposition of the eroded material and the lattice damage by the bombardment of the high energetic particles. This degradation of the optical quality of the plasma facing components in such a harsh environment is a serious concern for the reliability of the spectroscopic based optical diagnostics using FM of a fusion device. In this paper, the effect of 8 keV Hydrogen ion beam irradiation onto the FIR reflectivity of Tungsten thin film mirror is presented. The Tungsten thin films were prepared via Pulsed Laser Deposition (PLD) technique. The Tungsten mirrors were subjected to X-ray Diffraction (XRD), Energy Dispersive X-ray (EDX), Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM) for characterization. The specular reflectivities of the Tungsten mirrors before and after exposure to ion beam were recorded with Fourier Transform of Infra-Red (FTIR) technique. The ion penetration depth and straggle into Tungsten thin film and stainless steel (SS) substrate were estimated by Transport of Ions in Matter (TIRM) simulation code. The changes in post exposure IR reflectivity were interpreted in terms of these parameters.

  4. Damage evaluation in metal structures subjected to high energy deposition due to particle beams

    CERN Document Server

    Peroni, L; Dallocchio, A

    2011-01-01

    The unprecedented energy intensities of modern hadron accelerators yield special problems with the materials that are placed close to or into the high intensity beams. The energy stored in a single beam of LHC particle accelerator is equivalent to about 80 kg of TNT explosive, stored in a transverse beam area with a typical value of 0.2 mm×0.2 mm. The materials placed close to the beam are used at, or even beyond, their damage limits. However, it is very difficult to predict structural efficiency and robustness accurately: beam-induced damage for high energy and high intensity occurs in a regime where practical experience does not exist. The interaction between high energy particle beams and metals induces a sudden non uniform temperature increase. This provokes a dynamic response of the structure entailing thermal stress waves and thermally induced vibrations or even the failure of the component. This study is performed in order to estimate the damage on a copper component due to the impact with a 7 TeV pro...

  5. Characterization of ion-beam-induced carbon deposition on WC-Co hard metal by microhardness, scratch and abrasive wear tests

    International Nuclear Information System (INIS)

    Diamond-like ion-beam-deposited carbon (i-C) layers were obtained on WC-Co cemented carbide using a mass-separated 12C beam at an energy of 500 eV and a deposition rate of 3 A s-1. The mechanical properties of these layers were probed using microhardness and scratch tests and abrasive wear measurements. All these tests revealed that the depositions possess an extremely high hardness and good adhesion to the substrate. In particular, a hardness of 75 GPa was obtained, which is considerably higher than that found on i-C films involving hydrogen. (orig.)

  6. Effect of substrate temperature on the texture of MgO films grown by ion beam assisted deposition

    International Nuclear Information System (INIS)

    In this paper, the role of substrate temperature in the crystalline texture of MgO films grown by ion beam assisted deposition (IBAD) is investigated. This study reveals that the best in-plane alignment for MgO films grown on Y2O3/Si is obtained at ∼25 deg. C. At this temperature, MgO films with an in-plane orientation distribution as low as 3.70 full width at half maximum (FWHM) have been attained. MgO films deposited at temperatures higher than 100 deg. C have broad in-plane alignment. Although the deposition at the lowest temperature (-150 deg. C) did not improve the in-plane texture, the acceptable deviation from the optimum ion to molecule ratio for achieving biaxially textured films was the largest. As a trend, the acceptable ion to molecule deviation decreases with increasing substrate temperature. This study is especially important for continuous IBAD MgO depositions where less restrictive conditions are desired

  7. Effect of substrate temperature on the texture of MgO films grown by ion beam assisted deposition

    Energy Technology Data Exchange (ETDEWEB)

    Stan, Liliana; Arendt, Paul N; DePaula, Raymond F; Usov, Igor O; Groves, James R [Superconductivity Technology Center, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2006-04-15

    In this paper, the role of substrate temperature in the crystalline texture of MgO films grown by ion beam assisted deposition (IBAD) is investigated. This study reveals that the best in-plane alignment for MgO films grown on Y{sub 2}O{sub 3}/Si is obtained at {approx}25 deg. C. At this temperature, MgO films with an in-plane orientation distribution as low as 3.7{sup 0} full width at half maximum (FWHM) have been attained. MgO films deposited at temperatures higher than 100 deg. C have broad in-plane alignment. Although the deposition at the lowest temperature (-150 deg. C) did not improve the in-plane texture, the acceptable deviation from the optimum ion to molecule ratio for achieving biaxially textured films was the largest. As a trend, the acceptable ion to molecule deviation decreases with increasing substrate temperature. This study is especially important for continuous IBAD MgO depositions where less restrictive conditions are desired.

  8. Structural, optical, and conducting properties of crystalline ZnO:Co thin films grown by reactive electron beam deposition

    Energy Technology Data Exchange (ETDEWEB)

    Gürbüz, Osman; Güner, Sadık, E-mail: sguner@fatih.edu.tr; Büyükbakkal, Ömer; Çalışkan, Serkan

    2015-01-01

    We deposited an undoped ZnO and 6 different Co doped ZnO (ZnO:Co) thin films on fused silica (SiO{sub 2}) substrates with ∼100 nm thickness at substrate temperature of 125 °C using a Reactive Electron Beam Deposition technique. Energy-Dispersive X-ray Spectroscopy (EDS) was used to analyze the elemental composition rates of films. Elemental Co concentration varies from 4.62 to 28.77 at. %. The surface morphologies and grain sizes of thin films were investigated by Scanning Electron Microscope (SEM). The crystal and phase structures of the ZnO:Co thin films were characterized using X-ray diffraction (XRD). The films have single crystal and polycrystalline structures due to Co concentrations. Theoretical crystallite size and strain calculations were performed by applying the Scherrer and Williamson–Hall (W–H) methods. The grain sizes are 2–4 times greater than the crystalline sizes for ZnO:Co films. Optical properties of the films were studied by absorbance measurements using a UV–vis spectrophotometer. The analysis of the optical absorption spectra indicated that the energy band gap of the bulk ZnO film increased from 3.22 eV to maximum 4.17 eV upon Co deposition. Co{sup 2+} ion replaces Zn{sup 2+} ion in the structure without causing any remarkable defect for its hexagonal Wurtzite structure. Electrical conducting properties were investigated by using a Four Point Probe (FPP) technique. The conductivity depends on crystalline quality and Co concentration. - Highlights: • Fabrication of ZnO and ZnO:Co films through the Reactive Electron Beam deposition technique. • Reproducible single crystalline structured films. • Optical properties and band gap values were specified. • The conductivity depends on crystalline quality and Co concentration. • The films have potential for optoelectronic applications.

  9. Progress in a-SiOx:H thin film solar cells with patterned MgF2 dielectric for top cell of multi-junction system

    Science.gov (United States)

    Kang, Dong-Won; Sichanugrist, Porponth; Konagai, Makoto

    2016-07-01

    We successfully designed and experimentally demonstrated an application of patterned MgF2 dielectric material at rear Al-doped ZnO (AZO)/Ag interface in thin film amorphous silicon oxide ( a-SiOx:H) solar cells. When it was realized in practical device process, MgF2 coverage with patterned morphology was employed to allow for current flow between the AZO and Ag against highly resistive MgF2 material. On the basis of the suggested structure, we found an improvement in quantum efficiency of the solar cells with the patterned MgF2. In addition, an enhancement of open circuit voltage ( V oc ) and fill factor ( FF) was observed. A remarkable increase in shunt resistance of the cells with the MgF2 would possibly indicate that the highly resistive MgF2 layer can partly suppress physical shunting across top and bottom electrodes caused by very thin absorber thickness of only 100 nm. The approach showed that our best-performing device revealed an essential improvement in conversion efficiency from 7.83 to 8.01% with achieving markedly high V oc (1.013 V) and FF (0.729). [Figure not available: see fulltext.

  10. An MGF-based unified framework to determine the joint statistics of partial sums of ordered random variables

    KAUST Repository

    Nam, Sungsik

    2010-11-01

    Order statistics find applications in various areas of communications and signal processing. In this paper, we introduce an unified analytical framework to determine the joint statistics of partial sums of ordered random variables (RVs). With the proposed approach, we can systematically derive the joint statistics of any partial sums of ordered statistics, in terms of the moment generating function (MGF) and the probability density function (PDF). Our MGF-based approach applies not only when all the K ordered RVs are involved but also when only the Ks(Ks < K) best RVs are considered. In addition, we present the closed-form expressions for the exponential RV special case. These results apply to the performance analysis of various wireless communication systems over fading channels. © 2006 IEEE.

  11. Interaction, composition, and optical properties of the MgF2(MgO)-EuF3 system

    International Nuclear Information System (INIS)

    Processes of interaction between MgO and EuF3 are studied. Results of these processes are formation of magnesium fluorides and europium(III) oxyfluorides of variable composition. It is determined that there is considerable difference in spectra of diffusion reflection of fluoride and oxyfluoride phases of Eu(III). Effect of silicon and deep vacuum on systems containing oxide phase is studied. It is determined that in such system presence of Eu(II) compounds are observed. Fundamentally different character of thermogravimetric curves is detected in the MgF2-EuF3-Si and MgO-EuF3-Si systems. That permits to propose the method of MgO content estimation in MgF2

  12. ESR of dislocation defects in MgF2 crystals--with more than 130 line peaks

    Institute of Scientific and Technical Information of China (English)

    Hou Bi-Hui; Zheng Ying-Guang; Shao Meng; Liu Feng-Yan; Fan Zhi-Da

    2005-01-01

    In this work, more than 130 line peaks in electron spin resonance (ESR) spectra have been discovered of the laser material MgF2 crystal in room-temperature experiments. A sample is cut from the shoulder part of the MgF2 crystal,and another is from the MgF2:Co crystal. The samples were not treated by any irradiation. The same anisotropic ESR spectra of the two samples indicate that the dopant Co2+ introduces defects which induce the same multinuclear free radicals as in dislocations in the sample of MgF2. These paramagnetic solid multinuclear free radicals show good stability, and their ESR spectra are found to be anisotropic. ESR signals are derived from three different types of multinuclear free radicals from a tentative simulation analysis.When the direction of the applied magnetic field is along the [100] or [010] orientation of the crystal, the magnetic field at which the ESR signals are detected ranges from 0.2294T to 0.4654T and the width of this range is 0.2362T (corresponding to an energy band of 0.233eV); the most narrow peak in the ESR spectra has a width △H about 1.28 × 10-3T.This width △H, equivalent to the energy difference of two neighbouring levels, is very small, only 1.85× 10-7eV (or 1.46 × 10-3cm- 1 ).This fact indicates that the ground state is highly degenerate, and splits into nearly quasi-continuous energy levels like an energy band in an applied magnetic field. It may be served as a new starting point of solid laser exciter frequency modulation.

  13. ESR of dislocation defects in MgF2 crystals—with more than 130 line peaks

    Science.gov (United States)

    Hou, Bi-Hui; Zheng, Ying-Guang; Shao, Meng; Liu, Feng-Yan; Fan, Zhi-Da

    2005-07-01

    In this work, more than 130 line peaks in electron spin resonance (ESR) spectra have been discovered of the laser material MgF2 crystal in room-temperature experiments. A sample is cut from the shoulder part of the MgF2 crystal and another is from the MgF2:Co crystal. The samples were not treated by any irradiation. The same anisotropic ESR spectra of the two samples indicate that the dopant Co2+ introduces defects which induce the same multinuclear free radicals as in dislocations in the sample of MgF2. These paramagnetic solid multinuclear free radicals show good stability and their ESR spectra are found to be anisotropic. ESR signals are derived from three different types of multinuclear free radicals from a tentative simulation analysis. When the direction of the applied magnetic field is along the [100] or [010] orientation of the crystal, the magnetic field at which the ESR signals are detected ranges from 0.2294T to 0.4654T and the width of this range is 0.2362T (corresponding to an energy band of 0.233eV); the most narrow peak in the ESR spectra has a width ΔH about 1.28×10-3T. This width ΔH, equivalent to the energy difference of two neighbouring levels, is very small, only 1.85×10-7eV (or 1.46×10-3cm-1). This fact indicates that the ground state is highly degenerate and splits into nearly quasi-continuous energy levels like an energy band in an applied magnetic field. It may be served as a new starting point of solid laser exciter frequency modulation.

  14. Synthesis of in-plane and stacked graphene/hexagonal boron nitride heterostructures by combining with ion beam sputtering deposition and chemical vapor deposition

    Science.gov (United States)

    Meng, Jun Hua; Zhang, Xing Wang; Wang, Hao Lin; Ren, Xi Biao; Jin, Chuan Hong; Yin, Zhi Gang; Liu, Xin; Liu, Heng

    2015-09-01

    Graphene/hexagonal boron nitride (h-BN) heterostructures have attracted a great deal of attention in recent years due to their unique and complementary properties for use in a wide range of potential applications. However, it still remains a challenge to synthesize large-area high quality samples by a scalable growth method. In this work, we present the synthesis of both in-plane and stacked graphene/h-BN heterostructures on Cu foils by sequentially depositing h-BN via ion beam sputtering deposition (IBSD) and graphene with chemical vapor deposition (CVD). Due to a significant difference in the growth rate of graphene on h-BN and Cu, the in-plane graphene/h-BN heterostructures were rapidly formed on h-BN domain/Cu substrates. The large-area vertically stacked graphene/h-BN heterostructures were obtained by using the continuous h-BN film as a substrate. Furthermore, the well-designed sub-bilayered h-BN substrates provide direct evidence that the monolayered h-BN on Cu exhibits higher catalytic activity than the bilayered h-BN on Cu. The growth method applied here may have great potential in the scalable preparation of large-area high-quality graphene/h-BN heterostructures.Graphene/hexagonal boron nitride (h-BN) heterostructures have attracted a great deal of attention in recent years due to their unique and complementary properties for use in a wide range of potential applications. However, it still remains a challenge to synthesize large-area high quality samples by a scalable growth method. In this work, we present the synthesis of both in-plane and stacked graphene/h-BN heterostructures on Cu foils by sequentially depositing h-BN via ion beam sputtering deposition (IBSD) and graphene with chemical vapor deposition (CVD). Due to a significant difference in the growth rate of graphene on h-BN and Cu, the in-plane graphene/h-BN heterostructures were rapidly formed on h-BN domain/Cu substrates. The large-area vertically stacked graphene/h-BN heterostructures were

  15. Growth of Biaxially Textured Yttria-Stabilized Zirconia Thin Films on Si(111) Substrate by Ion Beam Assisted Deposition

    Institute of Scientific and Technical Information of China (English)

    MU Hai-Chuan; REN Cong-Xin; JIANG Bing-Yao; DING Xing-Zhao; YU Yue-Hui; WANG Xi; LIU Xiang-Huai; ZHOU Gui-En; JIA Yun-Bo

    2000-01-01

    The (001) oriented yttria-stabilized zirconia (YSZ) films with in-plane biaxial texture have been deposited on Si(lll ) substrates by ion beam assisted deposition at ambient temperature. The effects of ion/atom arrival rate ratio (R=(Ar+ +O2+)/ZrO2) and incident angle of bombarding ion beam on the film texture development were investigated. It was found that the in-plane biaxial texture of the films was improved gradually with increasing ion/atom arrival rate ratio R up to a critical value 1.9, but it was degraded with the further increase of R. The optimal in-plane biaxial texture, whose full width at half maximum of the (lll) φ-scan spectrum is 14°, can be obtained at R=1.9 and incident angle of 55°. For a fixed R, the optimal crystallinity and in-plane biaxial alignment of the YSZ films did not appear at the same incident angle and showed an opposite variation with the change of the incident angle from 51° to 55°. C-axis lignment (perpendicular to substrate surface) does not show any substantial variation with the change of incident angle within the range of 47° - 56°.

  16. AMORPHIZATION IN Nb-M (M=Fe, Co, Ni) BINARY METAL SYSTEMS INDUCED BY ION BEAM ASSISTED DEPOSITION (IBAD)

    Institute of Scientific and Technical Information of China (English)

    F. Pan; F. Zeng; B. Zhao

    2002-01-01

    Ion beam assisted deposition technique (IBAD) was utilized to systematically studyamorphization in binary metal systems of Nb-magnetic element, i.e., Nb-M (M=Fe,Co or Ni). The glass forming range terned as Nb fraction of Nb-Fe system was about34at.% to 56at.%, that of Nb-Co system was about 32at.% to 72at.% and that of Nb-Ni about 20at.% to 80at.%. Similar percolation patterns were found in amorphousalloy films. The fractal dimensions of the percolation patterns approach to 2, whichindicates 2-D layer growth for amorphous phases. It is regarded that the assistedAr+ ion beam duringthe deposition process plays important role for the 2-D layergrowth. Some metastable crystalline phases were obtained in these three systems byIBAD, e.g., bcc supersaturated solid solutions in Nb-Fe and Nb-Co systems, fcc andhcp phases in Nb-Co and Nb-Ni systems. The formation and competing between theamorphous and the metastable crystalline phases were determined by both the phases'thermodynamic states in binary metal systems and kinetics during IBAD process.

  17. Fabrication of single TiO2 nanotube devices with Pt interconnections using electron- and ion-beam-assisted deposition

    Science.gov (United States)

    Lee, Mingun; Cha, Dongkyu; Huang, Jie; Ha, Min-Woo; Kim, Jiyoung

    2016-06-01

    Device fabrication using nanostructured materials, such as nanotubes, requires appropriate metal interconnections between nanotubes and electrical probing pads. Here, electron-beam-assisted deposition (EBAD) and ion-beam-assisted deposition (IBAD) techniques for fabrication of Pt interconnections for single TiO2 nanotube devices are investigated. IBAD conditions were optimized to reduce the leakage current as a result of Pt spreading. The resistivity of the IBAD-Pt was about three orders of magnitude less than that of the EBAD-Pt, due to low carbon concentration and Ga doping, as indicated by X-ray photoelectron spectroscopy analysis. The total resistances of single TiO2 nanotube devices with EBAD- or IBAD-Pt interconnections were 3.82 × 1010 and 4.76 × 108 Ω, respectively. When the resistivity of a single nanotube is low, the high series resistance of EBAD-Pt cannot be ignored. IBAD is a suitable method for nanotechnology applications, such as photocatalysis and biosensors.

  18. High-throughput shadow mask printing of passive electrical components on paper by supersonic cluster beam deposition

    Science.gov (United States)

    Caruso, Francesco; Bellacicca, Andrea; Milani, Paolo

    2016-04-01

    We report the rapid prototyping of passive electrical components (resistors and capacitors) on plain paper by an additive and parallel technology consisting of supersonic cluster beam deposition (SCBD) coupled with shadow mask printing. Cluster-assembled films have a growth mechanism substantially different from that of atom-assembled ones providing the possibility of a fine tuning of their electrical conduction properties around the percolative conduction threshold. Exploiting the precise control on cluster beam intensity and shape typical of SCBD, we produced, in a one-step process, batches of resistors with resistance values spanning a range of two orders of magnitude. Parallel plate capacitors with paper as the dielectric medium were also produced with capacitance in the range of tens of picofarads. Compared to standard deposition technologies, SCBD allows for a very efficient use of raw materials and the rapid production of components with different shape and dimensions while controlling independently the electrical characteristics. Discrete electrical components produced by SCBD are very robust against deformation and bending, and they can be easily assembled to build circuits with desired characteristics. The availability of large batches of these components enables the rapid and cheap prototyping and integration of electrical components on paper as building blocks of more complex systems.

  19. Evaluation of Beam Loss and Energy Depositions for a Possible Phase II Design for LHC Collimation

    Energy Technology Data Exchange (ETDEWEB)

    Lari, L.; /EPFL-ISIC, Lausanne /CERN; Assmann, R.; /CERN; Bracco, C.; /EPFL-ISIC, Lausanne /CERN; Brugger, M.; /CERN; Cerutti, F.; /CERN; Doyle, E.; /SLAC; Ferrari, A.; /CERN; Keller, L.; Lundgren, S.; Markiewicz, Thomas W.; /SLAC; Mauri, M.; Redaelli, S.; Sarchiapone, L.; /CERN; Smith, J.; /SLAC; Vlachoudis, V.; Weiler, T.; /CERN

    2011-11-07

    The LHC beams are designed to have high stability and to be stored for many hours. The nominal beam intensity lifetime is expected to be of the order of 20h. The Phase II collimation system has to be able to handle particle losses in stable physics conditions at 7 TeV in order to avoid beam aborts and to allow correction of parameters and restoration to nominal conditions. Monte Carlo simulations are needed in order to evaluate the behavior of metallic high-Z collimators during operation scenarios using a realistic distribution of losses, which is a mix of the three limiting halo cases. Moreover, the consequences in the IR7 insertion of the worst (case) abnormal beam loss are evaluated. The case refers to a spontaneous trigger of the horizontal extraction kicker at top energy, when Phase II collimators are used. These studies are an important input for engineering design of the collimation Phase II system and for the evaluation of their effect on adjacent components. The goal is to build collimators that can survive the expected conditions during LHC stable physics runs, in order to avoid quenches of the SC magnets and to protect other LHC equipments.

  20. Evaluation of Beam Losses And Energy Deposition for a Possible Phase II Design for LHC Collimation

    Energy Technology Data Exchange (ETDEWEB)

    Lari, L.; Assmann, R.W.; Bracco, C.; Brugger, M.; Cerutti, F.; Ferrari, A.; Mauri, M.; Redaelli, S.; Sarchiapone, L.; Vlachoudis, Vasilis; Weiler, Th.; /CERN; Doyle, J.E.; Keller, L.; Lundgren, S.A.; Markiewicz, Thomas W.; Smith, J.C.; /SLAC; Lari, L.; /LPHE, Lausanne

    2011-11-01

    The Large Hadron Collider (LHC) beams are designed to have high stability and to be stored for many hours. The nominal beam intensity lifetime is expected to be of the order of 20h. The Phase II collimation system has to be able to handle particle losses in stable physics conditions at 7 TeV in order to avoid beam aborts and to allow correction of parameters and restoration to nominal conditions. Monte Carlo simulations are needed in order to evaluate the behavior of metallic high-Z collimators during operation scenarios using a realistic distribution of losses, which is a mix of the three limiting halo cases. Moreover, the consequences in the IR7 insertion of the worst (case) abnormal beam loss are evaluated. The case refers to a spontaneous trigger of the horizontal extraction kicker at top energy, when Phase II collimators are used. These studies are an important input for engineering design of the collimation Phase II system and for the evaluation of their effect on adjacent components. The goal is to build collimators that can survive the expected conditions during LHC stable physics runs, in order to avoid quenches of the SC magnets and to protect other LHC equipments.

  1. Distribution of Energy Deposited in Plastic Tubing and Copper-Wire Insulation by Electron Beam Irradiation

    DEFF Research Database (Denmark)

    Pedersen, Walther Batsberg; Miller, Arne; Pejtersen, K.;

    1978-01-01

    uniformly as possible, usually by means of a multipass arrangement. In the present study, using irradiation by a scanned 0.4 MeV electron beam, measurements were made of high-resolution distributions of absorbed dose in polyethylene tubing and copper wire coated with polyethylene, nylon, or polyvinyl...

  2. Low temperature Ti-Si-C thin film deposition by ion beam assisted methods

    Science.gov (United States)

    Twardowska, Agnieszka; Rajchel, Boguslaw; Jaworska, Lucyna

    2010-11-01

    Thin, multiphase Ti-Si-C coatings were formed by IBSD or by IBAD methods on AISI 316L steel substrates in room temperature, using single Ti3SiC2 target. In those methods the TiXSiCY coatings were formed from the flux of energetic atoms and ions obtained by ion sputtering of the Ti3SiC2 compound sample. As sputtering beam the beam of Ar+ ions at energy of 15keV was applied. In the IBAD method the dynamically formed coatings were additionally bombarded by beam of Ar+ ions at energy of 15keV. The ion beams parameters were obtained by using Monte Carlo computer simulations. The morphology (SEM, TEM), chemical (EDS/EDX) and phase composition (XRD) examinations of formed coatings were provided as well as confocal Raman microspectroscopy. Analyzed coatings were relatively thin (150nm-1μm), flat and dense. XRD analysis indicated in amorphous TiSi, the traces of Ti5Si3 and other phases from Ti-Si-C system (TiSi, TiSi2,Ti3SiC2). For chemical bonds investigation, the laser beam with length of 532nm was used. Those analyses were performed in the low (LR) or in high (HR) resolution modes in room temperature and in 4000C. In the HR mode the spectral resolution was close to 2 cm-1. In Raman spectra peaks at: 152cm-1, 216cm-1, 278cm-1, 311 cm-1, 608cm-1, 691cm-1 were recorded. Nanoindentation tests were done on coated and uncoated substrates with diamond, Berkovich-type indenter. Vickers hardness HIT and reduced elastic modulus EIT were calculated using Olivier& Pharr method. HIT for coated substrates was in the range 2.7 to 5.3 GPa, EIT was 160 GPa.

  3. Low temperature Ti-Si-C thin film deposition by ion beam assisted methods

    International Nuclear Information System (INIS)

    Thin, multiphase Ti-Si-C coatings were formed by IBSD or by IBAD methods on AISI 316L steel substrates in room temperature, using single Ti3SiC2 target. In those methods the TiXSiCY coatings were formed from the flux of energetic atoms and ions obtained by ion sputtering of the Ti3SiC2 compound sample. As sputtering beam the beam of Ar+ ions at energy of 15keV was applied. In the IBAD method the dynamically formed coatings were additionally bombarded by beam of Ar+ ions at energy of 15keV. The ion beams parameters were obtained by using Monte Carlo computer simulations. The morphology (SEM, TEM), chemical (EDS/EDX) and phase composition (XRD) examinations of formed coatings were provided as well as confocal Raman microspectroscopy. Analyzed coatings were relatively thin (150nm-1μm), flat and dense. XRD analysis indicated in amorphous TiSi, the traces of Ti5Si3 and other phases from Ti-Si-C system (TiSi, TiSi2,Ti3SiC2). For chemical bonds investigation, the laser beam with length of 532nm was used. Those analyses were performed in the low (LR) or in high (HR) resolution modes in room temperature and in 400deg. C. In the HR mode the spectral resolution was close to 2 cm-1. In Raman spectra peaks at: 152cm-1, 216cm-1, 278cm-1, 311 cm-1, 608cm-1, 691cm-1 were recorded. Nanoindentation tests were done on coated and uncoated substrates with diamond, Berkovich-type indenter. Vickers hardness HIT and reduced elastic modulus EIT were calculated using Olivier and Pharr method. HIT for coated substrates was in the range 2.7 to 5.3 GPa, EIT was 160 GPa.

  4. Integration of biaxally aligned conducting oxides with silicon using ion-beam assisted deposited MgO templates

    Energy Technology Data Exchange (ETDEWEB)

    Park, B. H. (Bae Ho); Groves, J. R. (James R.); DePaula, R. F. (Raymond Felix); Jia, Quanxi; Arendt, P. N. (Paul N.); Emmert, L. A. (Luke A.)

    2001-01-01

    Two conducting oxides, La{sub 0.5}Sr{sub 0.5}CoO{sub 3}(LSCO) and SrRuO{sub 3}, were deposited by pulsed laser ablation onto silicon substrates coated with biaxially textured MgO on an amorphous silicon nitride isolation layer. Comparison is made between templates using just 10 nm of ion-beam assisted deposited (IBAD) MgO and substrates with an additional 100 nm of homoepitaxial MgO. Both of these conducting oxide layers exhibited in-plane and out-of-plane texture, on the order of that obtained by the underlying MgO. The SrRuO{sub 3} was c-axis oriented on both substrates, but exhibited a slightly sharper out-of-plane texture when the homoepitaxial MgO layer was included. On the other hand, the LSCO showed only (100) orientation when deposited directly on the IBAD-MgO templates, whereas a significant (110) peak was observed for films on the homoepitaxial MgO. A simple calculation of the distribution of grain boundary angles, assuming a normal distribution of grains, is also presented.

  5. The energy dependence on microstructure of (Ti-Al-V) nitrides deposited by dual ion beam sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Huebler, R.; Tentardini, E.K.; Blando, E. [Rio Grande do Sul Univ., Porto Alegre (Brazil). Inst. de Fisica; Teixeira, S.R.; Vasconcellos, M.Z.; Soares, M. [Instituto de Fisica da Universidade Federal do Rio Grande do Sul, 90619900, Porto Alegre (Brazil); Kamijo, E.; Fujiwara, M. [Faculty of Science and Technology, Ryokoku University, Seta, Otsu (Japan)

    1999-09-01

    Ti-6Al-4V alloys and their nitrides are of wide interest in technological applications because of their exceptional properties. The structure and composition of these alloys are strongly dependent on the deposition conditions. In this work, we report the influence of the ion energy on the film characteristics. We have used a dual ion beam sputtering (DIBS) equipment where the reactive ion (N{sub 2}) acceleration voltage was changed in the range of 200 to 400 V. The film structure was studied by means of an X-ray diffractometer (XRD) and the chemical composition and nitration degree were measured by X-ray photoelectron spectroscopy (XPS) and by a microprobe spectrometer. Coating hardness was checked using an ultramicrohardness tester equipped with a Vickers' indentor, and the corrosion resistance power was studied by means of cyclic voltammetry. The substrates used here were stainless steel ISO 316, the same used in most femoral prosthesis, and silicon monocrystals for the analytical tests. We compare the results of the coatings deposited by DIBS with films deposited by reactive magnetron sputtering. (orig.)

  6. Composition, structure and properties of gradient thermal barrier coatings (TBCs) produced by electron beam physical vapor deposition (EB-PVD)

    International Nuclear Information System (INIS)

    Gradient thermal barrier coatings (TBCs) along with the bond coat were produced by one and the same technological cycle using electron beam physical vapor deposition (EB-PVD) of an MCrAlY ingot, then of an Al-Al2O3-ZrO2(Y2O3) tablet (pressed multicomponent powder mixture) and finally of a ZrO2-7 wt.% Y2O3 ceramic ingot. At the evaporation temperature used, vapor pressures of the tablet components decrease in the direction: AlapproachesAl2O3approachesZrO2(Y2O3). The evaporation of these constituents also proceeds in the same order. As a result, a transition zone [with composition and structure gradients - transition gradient zone (TGZ)] - forms between the bond coat and outer ZrO2-7 wt.% Y2O3 ceramic layer during deposition. The TGZ constitution and structure are primarily determined by the aluminum, Al2O3 and ZrO2 contents of the tablet. As a consequence of liquid aluminum participation in the coating deposition process, a thin layer of β-phase (NiAl), smoothly transitions to an Al2O3 layer and then to ZrO2-7 wt.% Y2O3. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  7. Dependence of resistivity on structure and composition of AZO films fabricated by ion beam co-sputtering deposition

    International Nuclear Information System (INIS)

    The correlation between the resistivity and the structure/composition in the aluminum doped zinc oxide (AZO) films fabricated by the ion beam co-sputtering deposition at room temperature was investigated. The various compositions of AZO films were controlled by the sputtered area ratio of Al to Zn target. The structure, Al concentrations and resistivities of the as-deposited films were determined by X-ray diffractometer (XRD), energy dispersive spectrometer (EDS) and four-point probe station, respectively. The lowest resistivity of the deposited film was 5.66 x 10-4 Ω-cm at the 0.7 wt.% aluminum concentration. The most intense ZnO (0 0 2) diffraction peak, the largest grain size, the longest mean free path, and the highest free carrier concentration in the film result in the lowest resistivity of 5.66 x 10-4 Ω-cm at room temperature; simultaneously, the thermal stability of the resistivity of the AZO film as a function of the sample temperature was investigated. Below 200 deg. C the film's resistivity was almost kept at a fixed value and the lowest resistivity of 4.64 x 10-4 Ω-cm at 247 deg. C was observed.

  8. Improved electrochemical performance of spinel LiMn1.5Ni0.5O4 through MgF2 nano-coating

    Science.gov (United States)

    Wu, Qing; Zhang, Xiaoping; Sun, Shuwei; Wan, Ning; Pan, Du; Bai, Ying; Zhu, Huiyuan; Hu, Yong-Sheng; Dai, Sheng

    2015-09-01

    A spinel LiMn1.5Ni0.5O4 (LMNO) cathode material synthesized by a sol-gel method is modified by MgF2 nano-coating via a wet coating strategy. The results of X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM) showed that the MgF2 nano-coating layers do not physically change the bulk structure of the pristine material. Compared with the pristine compound, the MgF2-coated LMNO electrodes display enhanced cycling stabilities. Particularly, the 5 wt% MgF2-coated LMNO demonstrates the best reversibility, with a capacity retention of 89.9% after 100 cycles, much higher than that of the pristine material, 69.3%. The dQ/dV analysis and apparent Li+ diffusion coefficient calculation prove that the kinetic properties are enhanced after MgF2 surface modification, which partly explains the improved electrochemical performances. Electrochemical impedance spectroscopy (EIS) and Fourier transform infrared spectroscopy (FTIR) data confirm that the MgF2 coating layer helps in suppressing the fast growth of the solid electrolyte interface (SEI) film in repeated cycling, which effectively stabilizes the spinel structure. Additionally, differential scanning calorimetry (DSC) tests show that the MgF2 nano-coating layer also helps in enhancing the thermal stability of the LMNO cathode.A spinel LiMn1.5Ni0.5O4 (LMNO) cathode material synthesized by a sol-gel method is modified by MgF2 nano-coating via a wet coating strategy. The results of X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM) showed that the MgF2 nano-coating layers do not physically change the bulk structure of the pristine material. Compared with the pristine compound, the MgF2-coated LMNO electrodes display enhanced cycling stabilities. Particularly, the 5 wt% MgF2-coated LMNO demonstrates the best reversibility

  9. Low-energy ion beam-based deposition of gallium nitride

    Science.gov (United States)

    Vasquez, M. R.; Wada, M.

    2016-02-01

    An ion source with a remote plasma chamber excited by a 13.56 MHz radio frequency power was used for low-energy broad ion beam extraction. Optical emission spectral analyses showed the sputtering and postionization of a liquid gallium (Ga) target placed in a chamber separated from the source bombarded by argon (Ar) plasma guided by a bent magnetic field. In addition, an E × B probe successfully showed the extraction of low-energy Ga and Ar ion beams using a dual-electrode extractor configuration. By introducing dilute amounts of nitrogen gas into the system, formation of thin Ga-based films on a silicon substrate was demonstrated as determined from X-ray diffraction and X-ray reflectivity studies.

  10. Low-energy ion beam-based deposition of gallium nitride

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, M. R., E-mail: mrvasquez@coe.upd.edu.ph [Department of Mining, Metallurgical, and Materials Engineering, College of Engineering, University of the Philippines, Diliman, Quezon City 1101 (Philippines); Wada, M. [Graduate School of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan)

    2016-02-15

    An ion source with a remote plasma chamber excited by a 13.56 MHz radio frequency power was used for low-energy broad ion beam extraction. Optical emission spectral analyses showed the sputtering and postionization of a liquid gallium (Ga) target placed in a chamber separated from the source bombarded by argon (Ar) plasma guided by a bent magnetic field. In addition, an E × B probe successfully showed the extraction of low-energy Ga and Ar ion beams using a dual-electrode extractor configuration. By introducing dilute amounts of nitrogen gas into the system, formation of thin Ga-based films on a silicon substrate was demonstrated as determined from X-ray diffraction and X-ray reflectivity studies.

  11. Low-energy ion beam-based deposition of gallium nitride.

    Science.gov (United States)

    Vasquez, M R; Wada, M

    2016-02-01

    An ion source with a remote plasma chamber excited by a 13.56 MHz radio frequency power was used for low-energy broad ion beam extraction. Optical emission spectral analyses showed the sputtering and postionization of a liquid gallium (Ga) target placed in a chamber separated from the source bombarded by argon (Ar) plasma guided by a bent magnetic field. In addition, an E × B probe successfully showed the extraction of low-energy Ga and Ar ion beams using a dual-electrode extractor configuration. By introducing dilute amounts of nitrogen gas into the system, formation of thin Ga-based films on a silicon substrate was demonstrated as determined from X-ray diffraction and X-ray reflectivity studies. PMID:26932113

  12. Understanding the electron-stimulated surface reactions of organometallic complexes to enable design of precursors for electron beam-induced deposition

    International Nuclear Information System (INIS)

    Standard practice in electron beam-induced deposition (EBID) is to use precursors designed for thermal processes, such as chemical vapor deposition (CVD). However, organometallic precursors that yield pure metal deposits in CVD often create EBID deposits with high levels of organic contamination. This contamination negatively impacts the deposit's properties (e.g., by increasing resistivity or decreasing catalytic activity) and severely limits the range of potential applications for metal-containing EBID nanostructures. To provide the information needed for the rational design of precursors specifically for EBID, we have employed an ultra-high vacuum (UHV) surface science approach to identify the elementary reactions of organometallic precursors during EBID. These UHV studies have demonstrated that the initial electron-induced deposition of the surface-bound organometallic precursors proceeds through desorption of one or more of the ligands present in the parent compound. In specific cases, this deposition step has been shown to proceed via dissociative electron attachment, involving low-energy secondary electrons generated by the interaction of the primary beam with the substrate. Electron beam processing of the surface-bound species produced in the initial deposition event usually causes decomposition of the residual ligands, creating nonvolatile fragments. This process is believed to be responsible for a significant fraction of the organic contaminants typically observed in EBID nanostructures. A few ligands (e.g., halogens) can, however, desorb during electron beam processing while other ligands (e.g., PF3, CO) can thermally desorb if elevated substrate temperatures are used during deposition. Using these general guidelines for reactivity, we propose some design strategies for EBID precursors. The ultimate goal is to minimize organic contamination and thus overcome the key bottleneck for fabrication of relatively pure EBID nanostructures. (orig.)

  13. Understanding the electron-stimulated surface reactions of organometallic complexes to enable design of precursors for electron beam-induced deposition

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, Julie A.; Rosenberg, Samantha G.; Barclay, Michael; Fairbrother, D. Howard [Johns Hopkins University, Department of Chemistry, Baltimore, MD (United States); Wu, Yung-Chien; McElwee-White, Lisa [University of Florida, Department of Chemistry, Gainesville, FL (United States)

    2014-12-15

    Standard practice in electron beam-induced deposition (EBID) is to use precursors designed for thermal processes, such as chemical vapor deposition (CVD). However, organometallic precursors that yield pure metal deposits in CVD often create EBID deposits with high levels of organic contamination. This contamination negatively impacts the deposit's properties (e.g., by increasing resistivity or decreasing catalytic activity) and severely limits the range of potential applications for metal-containing EBID nanostructures. To provide the information needed for the rational design of precursors specifically for EBID, we have employed an ultra-high vacuum (UHV) surface science approach to identify the elementary reactions of organometallic precursors during EBID. These UHV studies have demonstrated that the initial electron-induced deposition of the surface-bound organometallic precursors proceeds through desorption of one or more of the ligands present in the parent compound. In specific cases, this deposition step has been shown to proceed via dissociative electron attachment, involving low-energy secondary electrons generated by the interaction of the primary beam with the substrate. Electron beam processing of the surface-bound species produced in the initial deposition event usually causes decomposition of the residual ligands, creating nonvolatile fragments. This process is believed to be responsible for a significant fraction of the organic contaminants typically observed in EBID nanostructures. A few ligands (e.g., halogens) can, however, desorb during electron beam processing while other ligands (e.g., PF{sub 3}, CO) can thermally desorb if elevated substrate temperatures are used during deposition. Using these general guidelines for reactivity, we propose some design strategies for EBID precursors. The ultimate goal is to minimize organic contamination and thus overcome the key bottleneck for fabrication of relatively pure EBID nanostructures. (orig.)

  14. A Comparison of the Effects of RF Plasma Discharge and Ion Beam Supply on the Growth of Cubic Boron Nitride Films Formed by Laser Physical Vapor Deposition

    Science.gov (United States)

    Kaneda, Kayo; Shibata, Kimihiro

    1994-01-01

    This paper presents a comparison of the effects of RF plasma discharge and ion beam supply on the growth of cubic boron nitride films formed by excimer laser physical vapor deposition (laser PVD). The film structure was analyzed by fourier transformation infrared region (FT-IR) spectroscopy and thin-film X-ray diffraction analysis. The structure of the film deposited with an RF plasma discharge provided between the substrate and target was hexagonal BN. On the other hand, that of the film deposited by irradiating the substrate directly with an ion beam was hexagonal BN (hBN) and cubic BN (cBN). It is thought that direct irradiation of the vapor generated from the target by accelerated ions increased the activation energy of the vapor, with the result that the film structure was changed. Besides irradiating the substrate directly with the ion beam resulted primarily in the etching of hBN while cBN remained.

  15. Hyperthermal Pulsed-Laser Ablation Beams for Film Deposition and Surface Microstructural Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Lowndes, D.H.

    1999-11-08

    This paper presents an overview of pulsed-laser ablation for film deposition and surface microstructure formation. By changing the ambient gas pressure from high vacuum to several Torr (several hundred Pa) and by selecting the pulsed-laser wavelength, the kinetic energy of ablated atoms/ions can be varied from several hundred eV down to {approximately}0.1 eV and films ranging from superhard to nanocrystalline may be deposited. Furthermore, cumulative (multi-pulse) irradiation of a semiconductor surface (e.g. silicon) in an oxidizing gas (0{sub 2}, SF{sub 6}) et atmospheric pressure can produce dense, self-organized arrays of high-aspect-ratio microcolumns or microcones. Thus, a wide range of materials synthesis and processing opportunities result from the hyperthermal flux and reactive growth conditions provided by pulsed-laser ablation.

  16. Modification of properties of TiB2 coatings by ion beam mixing during deposition

    International Nuclear Information System (INIS)

    We have deposited TiB2 ceramic coatings at room temperature using the dynamic ion-mixing (DIM) technique. The influence of a high energy, heavy ion bombardment of the growing film was investigated and the structural characterization performed by means of transmission electron microscopy either on thin films or on cross-sectional preparations. The TiB2 coatings prepared by DIM are crystallized with a hexagonal structure whereas those prepared without ion mixing are principlally amorphous. Scratch adhesion tests indicate that the adhesion can be greatly improved by intermixing of the film and substrate during the earliest stages of the deposition. The relative hardness increase of the coated tool steel substrate was of the order of 15%-22% and the true film hardness was deduced either by calculation from a composite model or by ultralow load indentations. (orig.)

  17. Low temperature Ti-Si-C thin film deposition by ion beam assisted methods

    Energy Technology Data Exchange (ETDEWEB)

    Twardowska, Agnieszka; Rajchel, Boguslaw; Jaworska, Lucyna, E-mail: atwardow@up.krakow.pl

    2010-11-15

    Thin, multiphase Ti-Si-C coatings were formed by IBSD or by IBAD methods on AISI 316L steel substrates in room temperature, using single Ti{sub 3}SiC{sub 2} target. In those methods the Ti{sub X}SiC{sub Y} coatings were formed from the flux of energetic atoms and ions obtained by ion sputtering of the Ti{sub 3}SiC{sub 2} compound sample. As sputtering beam the beam of Ar{sup +} ions at energy of 15keV was applied. In the IBAD method the dynamically formed coatings were additionally bombarded by beam of Ar{sup +} ions at energy of 15keV. The ion beams parameters were obtained by using Monte Carlo computer simulations. The morphology (SEM, TEM), chemical (EDS/EDX) and phase composition (XRD) examinations of formed coatings were provided as well as confocal Raman microspectroscopy. Analyzed coatings were relatively thin (150nm-1{mu}m), flat and dense. XRD analysis indicated in amorphous TiSi, the traces of Ti{sub 5}Si{sub 3} and other phases from Ti-Si-C system (TiSi, TiSi{sub 2},Ti{sub 3}SiC{sub 2}). For chemical bonds investigation, the laser beam with length of 532nm was used. Those analyses were performed in the low (LR) or in high (HR) resolution modes in room temperature and in 400deg. C. In the HR mode the spectral resolution was close to 2 cm{sup -1}. In Raman spectra peaks at: 152cm{sup -1}, 216cm{sup -1}, 278cm{sup -1}, 311 cm{sup -1}, 608cm{sup -1}, 691cm{sup -1} were recorded. Nanoindentation tests were done on coated and uncoated substrates with diamond, Berkovich-type indenter. Vickers hardness H{sub IT} and reduced elastic modulus E{sub IT} were calculated using Olivier and Pharr method. H{sub IT} for coated substrates was in the range 2.7 to 5.3 GPa, E{sub IT} was 160 GPa.

  18. Electrospray ion beam deposition and mass spectrometry of nonvolatile molecules and nanomaterials

    OpenAIRE

    Rauschenbach, Stephan; Kern, Klaus

    2008-01-01

    The vacuum deposition of complex functional molecules and nanoparticles by thermal sublimation is often hindered due to their extremely low vapor pressure. This especially impedes the application of ultrahigh vacuum (UHV) based analytical and surface modification techniques for the investigation of these extremely interesting systems. On the other hand, specimen prepared under ambient conditions or in solution are typically not sufficiently well-defined and clean to allow a thorough and preci...

  19. Self-organized 2D Ni particles deposited on titanium oxynitride-coated Si sculpted by a low energy ion beam

    International Nuclear Information System (INIS)

    Self-ordered Ni nanoparticles grown on TiNxOy-coated crystalline silicon previously sculpted by ion beam bombardment are reported. The samples are obtained following a sequential in situ routine deposition procedure. First, crystalline Si is Xe+ bombarded, generating regular patterns. Second, a thin TiNxOy film is grown on the patterned Si substrate. Immediately, nano-sized nickel particles are deposited by ion beam sputtering and temperature-annealed forming a 2D lattice. The self-organized Ni islands are induced by preferential Ni site nucleation on the coated sculpted Si grooves. (paper)

  20. Effect of ion-beam assisted deposition on the film stresses of TiO2 and SiO2 and stress control

    Institute of Scientific and Technical Information of China (English)

    Yu-Qiong Li; Hua-Qing Wang; Wu-Yu Wang; Zhi-Nong Yu; He-Shan Liu; Gang Jin

    2012-01-01

    Based on Hartmann-Shack sensor technique,an online thin film stress measuring system was introduced to measure the film stresses of TiO2 and SiO2,and comparison was made between the film stresses prepared respectively by the conventional process and the ion-beam assisted deposition.The effect of ion-beam assisted deposition on the film stresses of TiO2 and SiO2 was investigated in details,and the stress control methodologies using on-line adjustment and film doping were put forward.The results show that the film stress value of TiO2 prepared by ion-beam assisted deposition is 40 MPa lower than that prepared by conventional process,and the stress of TiO2 film changes gradually from tensile stress into compressive stress with increasing ion energy; while the film stress of SiO2 is a tensile stress under ion-beam assisted deposition because of the ion-beam sputtering effect,and the film refractive index decreases with increasing ion energy.A dynamic film stress control can be achieved through in-situ adjustment of the processing parameters based on the online film stress measuring technique,and the intrinsic stress of film can be effectively changed through film doping.

  1. Study of TiCxNy films formed by ion beam assisted deposition on 9Cr18 steel

    International Nuclear Information System (INIS)

    The TiCxNy films were formed on 9Cr18 steel matrix using the ion beam assisted deposition. The TEM analysis revealed the films with a polycrystalline structure with (111), (200) and (220) preferred orientation. The fact that TiCxNy films contain oxygen coordination was further confirmed by AES and XPS. It was found that microhardness of the films was dependent on its N content, and it was decreased for an excessively high N content. An assisted dose of 3 x 1017/cm2 is optimum in this experiment. A dry friction test indicated that oxidation resistance of the films is excellent, and oxidation of the steel matrix in the friction process can be obviously inhibited. Both the abrasive and adhesive wears of matrix are improved, and a trend of transformation from adhesive into abrasive wear appears for the steel matrix

  2. Optical and structural properties of silicon-rich silicon oxide films: Comparison of ion implantation and molecular beam deposition methods

    Energy Technology Data Exchange (ETDEWEB)

    Nikitin, Timur; Raesaenen, Markku; Khriachtchev, Leonid [Department of Chemistry, University of Helsinki (Finland); Aitola, Kerttu; Velagapudi, Rama; Sainio, Jani; Lahtinen, Jouko [Department of Applied Physics, Aalto University (Finland); Novikov, Sergei [Electron Physics Laboratory, Aalto University (Finland); Mizohata, Kenichiro; Ahlgren, Tommy [Accelerator Laboratory, University of Helsinki (Finland)

    2011-09-15

    We compare optical and structural properties of silicon-rich silicon oxide (SiO{sub x}, x {proportional_to} 1.8) films obtained by ion implantation and molecular beam deposition (MBD). Before annealing, amorphous clusters ({>=}2 nm) are present in the MBD samples whereas these are absent for ion implantation, and the absorption at 488 nm is much stronger for MBD. Upon annealing, the absorption coefficient increases for the implanted material but the opposite change occurs for MBD. For both preparation methods, annealing at {proportional_to}1100 C produces silicon nanocrystals (Si-nc) and enhances the 1.5-eV photoluminescence (PL) whereas annealing at 1200 C decreases the PL, especially for the implanted sample. The Si-SiO{sub 2} phase separation is not complete even after annealing at 1200 C. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. The effect of oxygen flow rate on refractive index of aluminum oxide film deposited by electron beam evaporation technique

    Directory of Open Access Journals (Sweden)

    R Shakouri

    2016-02-01

    Full Text Available The effects of oxygen flow rate on refractive index of aluminum oxide film have been investigated. The Al2O3 films are deposited by electron beam on glass substrate at different oxygen flow rates. The substrate was heated to reach  and the temperature was constant during the thin film growth. The transmittance spectrum of samples was recorded in the wavelength 400-800 nm.  Then, using the maxima and minima of transmittance the refractive index and the extinction coefficient of samples were determined. It has been found that if we reduce the oxygen flow, while the evaporation rate is kept constant, the refractive index of Al2O3 films increases. On the other hand, reduced oxygen pressure causes the Al2O3 films to have some absorption.

  4. Preparation of diamond-like carbon and boron nitirde films by high-intensity pulsed ion beam deposition

    Energy Technology Data Exchange (ETDEWEB)

    Rej, D.J.; Davis, H.A. [Los Alamos National Lab., NM (United States); Remnev, G.E. [Tomsk Polytechnic Univ., Tomsk (Russian Federation). Nuclear Physics Institute.] [and others

    1995-05-01

    Intense ion beams (300-keV C{sup +}, O{sup +}, and H{sup +}, 20--30 kA, 50 to 400-ns pulsewidth, up to 0.3-Hz repetition rate) were used to prepare diamond-like carbon (DLC) and boron nitride (BN) films. Deposition rates of up to 25{plus_minus}5 nm/pulse were obtained with instantaneous rates exceeding 1 mm/s. Most films were uniform, light brown, translucent, and nonporous with some micron-size particulates. Raman and parallel electron energy loss spectroscopy indicated the presence of DLC. The films possessed favorable electron field-emission characteristics desirable for cold-cathode displays. Transmission electron microscopy (TEM) and transmission electron diffraction (TED) revealed that the C films contained diamond crystals with 25 to 125-nm grain size. BN films were composed of hexagonal, cubic and wurtzite phases.

  5. Simulation of Fine Resist Profile Formation by Electron Beam Drawing and Development with Solubility Rate Based on Energy Deposition Distribution

    Science.gov (United States)

    Zhang, Hui; Komori, Takuya; Zhang, Yulong; Yin, You; Hosaka, Sumio

    2013-12-01

    We proposed a model for calculating the resist profile in electron beam drawing. The model predicts the solubility rate on the basis of the energy deposition distribution (EDD) for the development of latent patterns in the resist. By unifying the exposure dose D (via experiments) and EDDs (via calculations), we roughly determined solubility rates for three-dimensional EDDs, and established the proposed model. The development simulation was achieved by the sequential calculation method for solubility rates based on EDD which was calculated by Monte Carlo simulation. By determining a suitable EDD region to achieve good patterning, we obtained a sharp nanodot pattern of the resist. This simulation results are in good agreement with the experimental results obtained using a combination of 2.3 wt % tetramethylammonium hydroxide (TMAH) and 4 wt % NaCl as the developer. The model was demonstrated to be useful for predicting resist profiles with different experimental solubility rates of developers.

  6. Electron Beam-Physical Vapor Deposited TiAl-based Laminated Composite Sheet with Nb Layer Toughening

    Institute of Scientific and Technical Information of China (English)

    ZHANG De-ming; CHEN Gui-qing; HAN Jie-cai; MENG Song-he

    2006-01-01

    The TiAl-based laminated composite sheet of 150 mm × 100 mm × 0.2 mm, with 24 TiAl layers and 23 Nb layers laid alternately one on another, was successfully fabricated using the electron beam-physical vapor deposition (EB-PVD) method. The microstructure and properties of the sheet were investigated on an atomic force microscope (AFM), a scanning electron microscope (SEM) and a tensile testing machine. The results indicate that the evenly distributed Nb layers are well joined with the TiAl layers, and the interfaces between layers are transparent, and every interlayer spacing is of about 8 μm. The fractures appear to be a mixture of intergranular fractures and somewhat ductile quasi-cleavage ones. Despite its slight influence on ultimate tensile strength, the inserts of Nb layers efficiently increase the room temperature ductility of TiAl-based alloys due to the crack deflection effect.

  7. Surface roughness of MgO thin film and its critical thickness for optimal biaxial texturing by ion-beam-assisted deposition

    International Nuclear Information System (INIS)

    We investigated the deposition time dependences of the in-plane grain alignment (Δφ) and the surface roughness (w) of biaxially textured MgO thin films fabricated by ion-beam-assisted deposition (IBAD) and found a strong correlation between them. The time evolution of the surface roughness of IBAD-MgO showed an abrupt increase at the same time corresponding to the beginning of the deterioration in Δφ. The roughness versus thickness profiles obtained under different deposition conditions with different assisting ion-beam currents collapsed to a single curve, even though the deposition rates were significantly different in each condition. This implies that the abrupt increase in roughness occurred at the same thickness--of about 4 nm--irrespective of the deposition rate. The result also indicated that the Δφ deterioration began with the same thickness of about 4 nm. This ''critical'' thickness of about 4 nm might be related to the completion of the crystallization of the film. Further, deposition beyond the critical thickness, therefore, became merely a homoepitaxial deposition under the ''IBAD'' condition, which was far from optimal because of the ion bombardment and low temperature (no-heating), and thus Δφ deteriorated. Based on these considerations, we propose an approach to attain a sharp texture in a IBAD-MgO-based biaxial substrate; moreover, we demonstrated this approach using a two-step deposition process.

  8. Hydroxyapatite coating on the Ti-35Nb-xZr alloy by electron beam-physical vapor deposition

    International Nuclear Information System (INIS)

    The aim of this study was to investigate the hydroxyapatite coating on the Ti-35Nb-xZr alloy by electron beam-physical vapor deposition. The Ti-35Nb-xZr ternary alloys contained from 3 wt.% to 10 wt.% Zr content were manufactured by arc melting furnace. Hydroxyapatite (HA) coatings were prepared by electron-beam physical vapor deposition (EB-PVD) method, and crystallization treatment was performed in Ar atmosphere at 300 and 500 deg. C for 1 h. The coated surface morphology of Ti-35Nb-xZr alloy was examined by FE-SEM, EDX and XRD, respectively. In order to evaluate the corrosion behavior, the tests were performed by potentiodynamic, cyclic polarization and AC impedance test. All the electrochemical data were obtained using a potentiostat. The Ti-35Nb-xZr alloys exhibited equiaxed structure with β phase, the peak of β phase increased with Zr contents. The hardness and elastic modulus of Ti-35Nb-xZr alloys decreased as Zr content increased. The HA coated layer was approximately 150 nm and Ca/P ratio of HA coated surface after heat treatment at 500 deg. C was around 1.67. The HA thin film consisted of small droplets with spherical shape by crystallization. From the anodic polarization curves, HA coated and heat treated Ti-35Nb-10Zr alloy showed higher corrosion potential than other samples. HA coated film on the Ti-35Nb-10Zr alloy can be shown high polarization resistance by crystallization.

  9. Hydroxyapatite coating on the Ti-35Nb-xZr alloy by electron beam-physical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Yong-Hoon [Division of Restorative and Prosthetic Dentistry, College of Dentistry, The Ohio State University, 305 W. 12th Ave. Columbus, OH (United States); Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials and Research Center for Oral Disease Regulation of the Aged, Chosun University, Gwangju (Korea, Republic of); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials and Research Center for Oral Disease Regulation of the Aged, Chosun University, Gwangju (Korea, Republic of); Eun, Sang-Won [Department of Applied Advanced Materials, Korea Polytechnic V Colleges (Korea, Republic of)

    2011-08-01

    The aim of this study was to investigate the hydroxyapatite coating on the Ti-35Nb-xZr alloy by electron beam-physical vapor deposition. The Ti-35Nb-xZr ternary alloys contained from 3 wt.% to 10 wt.% Zr content were manufactured by arc melting furnace. Hydroxyapatite (HA) coatings were prepared by electron-beam physical vapor deposition (EB-PVD) method, and crystallization treatment was performed in Ar atmosphere at 300 and 500 deg. C for 1 h. The coated surface morphology of Ti-35Nb-xZr alloy was examined by FE-SEM, EDX and XRD, respectively. In order to evaluate the corrosion behavior, the tests were performed by potentiodynamic, cyclic polarization and AC impedance test. All the electrochemical data were obtained using a potentiostat. The Ti-35Nb-xZr alloys exhibited equiaxed structure with {beta} phase, the peak of {beta} phase increased with Zr contents. The hardness and elastic modulus of Ti-35Nb-xZr alloys decreased as Zr content increased. The HA coated layer was approximately 150 nm and Ca/P ratio of HA coated surface after heat treatment at 500 deg. C was around 1.67. The HA thin film consisted of small droplets with spherical shape by crystallization. From the anodic polarization curves, HA coated and heat treated Ti-35Nb-10Zr alloy showed higher corrosion potential than other samples. HA coated film on the Ti-35Nb-10Zr alloy can be shown high polarization resistance by crystallization.

  10. Mechanical and thermoelastic characteristics of optical thin films deposited by dual ion beam sputtering.

    Science.gov (United States)

    Cetinörgü, Eda; Baloukas, Bill; Zabeida, Oleg; Klemberg-Sapieha, Jolanta E; Martinu, Ludvik

    2009-08-10

    Mechanical and thermoelastic properties of optical films are very important to ensure the performance of optical interference filters and optical coating systems. We systematically study the growth and the mechanical and thermoelastic characteristics of niobium oxide (Nb(2)O(5)), tantalum oxide (Ta(2)O(5)), and silicon dioxide (SiO(2)) thin films prepared by dual ion beam sputtering. First, we investigate the stress (sigma), hardness (H), reduced Young's modulus (E(r)), and scratch resistance. Second, we focus on the methodology and assessment of the coefficient of thermal expansion (CTE) and Poisson's ratio (nu) using the two-substrate method. For the high refractive index films, namely, Nb(2)O(5) (n at 550 nm=2.30) and Ta(2)O(5) (n at 550 nm=2.13), we obtained H approximately 6 GPa, E(r) approximately 125 GPa, CTE=4.9x10(-6) degrees C(-1), nu=0.22, and H approximately 7 GPa, E(r) approximately 133 GPa, CTE=4.4x10(-6) degrees C(-1), and nu=0.27, respectively. In comparison, for SiO(2) (n at 550 nm=1.48), these values are H approximately 9.5 GPa, E(r) approximately 87 GPa, CTE=2.1x10(-6) degrees C(-1), and nu=0.11. Correlations between the growth conditions (secondary beam ion energy and ion current), the microstructure, and the film properties are discussed. PMID:19668268

  11. Effects of N+2 ion irradiation during AlN film growth by dual ion-beam deposition

    International Nuclear Information System (INIS)

    We report on the composition, chemical state, and structure of the AlN films grown with concurrent N2+ ion bombardment during film growth using a dual ion-beam deposition system. The AlN films prepared at various bombarding ion-beam conditions were characterized by RBS, XPS, and TEM. The analytical results of RBS spectra performed using rump code represented that the composition ratio (N/Al) of the AlN films grown with concurrent N2+ ion bombardment could be controlled from N/Al 1, depending on both the energy and the flux of N+2 ions incident on the growing film, and the value of N/Al ratio reached to 1.6 at higher energy and flux. XPS analysis also showed a good agreement with these RBS results. TEM diffraction patterns indicated that film orientation varied from a c-axis normal to the film surface to a c-axis parallel to the film surface as the energy of the irradiated N+2 ion increased from 200 eV to 500 eV. This preferential growth was explained in terms of ion channeling

  12. Study of Sb/SnO2 bi-layer films prepared by ion beam sputtering deposition technique

    International Nuclear Information System (INIS)

    In the present work, bi-layer thin films of Sb/SnO2 were produced on unheated glass substrates using ion beam sputtering (IBS) technique without post annealing treatment. The thickness of Sb layers was varied from 2 to 10 nm and the Sb layers were deposited on SnO2 layers having thicknesses of 40 nm to 115 nm. The effect of thickness was studied on the morphological, electrical and optical properties. The Sb/SnO2 bi-layer resulted in lowering the electrical resistivity as well as reducing the optical transmittance. However, the optical and electrical properties of the bi-layer films were mainly influenced by the thickness of Sb layers due to progressive transfer in structures from aggregate to continuous films. The bi-layer films show the electrical resistivity of 1.4 × 10−3 Ω cm and an optical transmittance of 26% for Sb film having 10 nm thickness. - Highlights: • Bi-layer Sb/SnO2 structures were synthesized by ion beam sputtering (IBS) technique. • The 6 nm-thick Sb film is a transition region in this study. • The conductivity of the bi-layer films is increased as Sb thickness increases. • The transmittance of the bi-layer films is decreased as Sb thickness increases

  13. Electron beam-physical vapor deposition of SiC/SiO 2 high emissivity thin film

    Science.gov (United States)

    Yi, Jian; He, XiaoDong; Sun, Yue; Li, Yao

    2007-02-01

    When heated by high-energy electron beam (EB), SiC can decompose into C and Si vapor. Subsequently, Si vapor reacts with metal oxide thin film on substrate surface and formats dense SiO 2 thin film at high substrate temperature. By means of the two reactions, SiC/SiO 2 composite thin film was prepared on the pre-oxidized 316 stainless steel (SS) substrate by electron beam-physical vapor deposition (EB-PVD) only using β-SiC target at 1000 °C. The thin film was examined by energy dispersive spectroscopy (EDS), grazing incidence X-ray asymmetry diffraction (GIAXD), scanning electron microscopy (SEM), atomic force microscopy (AFM), backscattered electron image (BSE), electron probe microanalysis (EPMA), X-ray photoelectron spectroscopy (XPS) and Fourier transformed infra-red (FT-IR) spectroscopy. The analysis results show that the thin film is mainly composed of imperfect nano-crystalline phases of 3C-SiC and SiO 2, especially, SiO 2 phase is nearly amorphous. Moreover, the smooth and dense thin film surface consists of nano-sized particles, and the interface between SiC/SiO 2 composite thin film and SS substrate is perfect. At last, the emissivity of SS substrate is improved by the SiC/SiO 2 composite thin film.

  14. A study of the thin film battery electrolyte lithium phosphorus oxynitride deposited by an ion beam assisted process

    Science.gov (United States)

    Vereda-Moratilla, Fernando

    Thin film Li-ion batteries are currently the subject of a world-wide research effort because of their many potential applications as portable energy sources. One of the key elements of these batteries is the electrolyte. Since it was first produced in the early 1990's, the preferred solid state thin film Li-ion electrolyte is lithium phosphorus oxynitride (LiPON), which is normally grown by means of reactive rf sputtering of a Li3PO 4 target in an N2 atmosphere. Solid electrolytes such as LiPON have several advantages compared to the liquid electrolytes normally used in bulk batteries. Solid electrolytes avoid leakage and have excellent charge-discharge cycling properties. Furthermore, sputtered-deposited LiPON proved to be stable versus Li+/Li from 0 to +5.5 V, which exceeded the stability window of any of the liquid electrolytes. In this work we present a general study of the properties of LiPON thin films deposited by an alternative process: ion beam assisted deposition (IBAD). In this process Li3PO4 is vacuum thermally evaporated and the condensing film is simultaneously bombarded with nitrogen ions which incorporate to form LiPON. Because of its application as an electrolyte and because of a previous study in which we showed that tensile stress led to cracking of the LiPON films and subsequently to shorting of the battery devices, the emphasis of the study was placed on improving the electrochemical properties of the films and on reducing their residual stress. Additional effort was aimed at learning about the structure and the composition of our films. It has been shown that IBAD LiPON thin films are undoubtedly capable of high quality performance as the electrolyte in Li-ion thin film batteries. Their ionic conductivity is almost as high, and their electronic conductivity as low, as those of the sputtered films. Their major advantages when compared to sputtered LiPON films are: (i) a higher deposition rate; (ii) a lower concentration of reduced-phosphorus in

  15. Study on suppression mechanism of electron emission from Mo grid coated with carbon film by dual ion beam deposition

    International Nuclear Information System (INIS)

    It is problematic that electrons are emitted from the Mo grid of pulsed-controlled grid traveling wave tubes, caused by the contamination of cathode evaporation material, i.e. BaO. Some studies show that a Mo grid coated with carbon can greatly suppress grid electron emission. However, the reason for the electron emission suppression is not completely clear. To understand the mechanism of electron emission suppression of a BaO/C/Mo system, carbon films were prepared on Mo substrates at room temperature by means of DIBSD (dual ion beam sputtering deposition), and BaO layers were coated by using a chemical method. Post-annealing was conducted under a flowing nitrogen ambient at 700 .deg. C for 1.5 hours. The structure of the as-deposited carbon films was evaluated by TEM, AES and Raman spectroscopy. The annealed samples, the BaO/ Mo and BaO/C/Mo systems, were analyzed by XPS. The results suggest that the chemical reaction between BaO and C at high temperature eliminates the concentrations of Ba or BaO on the surface of the C/Mo system. It can be believed that the high work function material used as the grid surface coating and elimination of BaO on its surface have a critical effect on grid electron emission suppression. Moreover, the carbon film was characterized by density, homogeneity and high adhesion, owing to the features of DIBSD.

  16. Molecular beam deposition of LaLuO3 thin films with high dielectric constant and low leakage current

    International Nuclear Information System (INIS)

    Although the introduction of hafnium-based high-κ dielectrics in the next CMOS generation has been announced, the implementation of materials with a dielectric constant even higher than 20 will be required in order to satisfy the future demands in CMOS applications. In this contribution, we report on lanthanum lutetium oxide, a ternary rare-earth based material that has recently appeared as a promising candidate1. LaLuO3 thin films were grown on (100) Si substrates by molecular beam deposition and electrically characterized by capacitance-voltage (C-V) and current-voltage (I-V) measurements. Additionally, a combination of characterization methods such as Rutherford backscattering spectrometry, transmission electron microscopy, X-ray reflectometry, and X-ray diffraction were used to study their composition and microstructural characteristics. We will present results of a systematic investigation on the film preparation, which allowed the deposition of LaLuO3 thin films with EOT ≤1.5 nm, low leakage current densities of about 5 mA/cm2 at -1 V gate bias, and higher κ-values around 30

  17. Enhanced activity and interfacial durability study of ultra low Pt based electrocatalysts prepared by ion beam assisted deposition (IBAD) method

    International Nuclear Information System (INIS)

    Ultra low loading noble metal (0.04-0.12 mgPt/cm2) based electrodes were obtained by direct metallization of non-catalyzed gas diffusion layers via dual ion beam assisted deposition (IBAD) method. Fuel cell performance results reported earlier indicate significant improvements in terms of mass specific power density of 0.297 gPt/kW with 250 A thick IBAD deposit (0.04 mgPt/cm2 for a total MEA loading of 0.08 mgPt/cm2) at 0.65 V in contrast to the state of the art power density of 1.18 gPt/kW using 1 mgPt(MEA)/cm2 at 0.65 V. In this article we report the peroxide radical initiated attack of the membrane electrode assembly utilizing IBAD electrodes in comparison to commercially available E-TEK (now BASF Fuel Cell GmbH) electrodes and find the pathway of membrane degradation as well. A novel segmented fuel cell is used for this purpose to relate membrane degradation to peroxide generation at the electrode/electrolyte interface by means of systematic pre and post analyses of the membrane are presented. Also, we present the results of in situ X-ray absorption spectroscopy (XAS) experiments to elucidate the structure/property relationships of these electrodes that lead to superior performance in terms of gravimetric power density obtained during fuel cell operation.

  18. Direct writing of CoFe alloy nanostructures by focused electron beam induced deposition from a heteronuclear precursor

    Science.gov (United States)

    Porrati, F.; Pohlit, M.; Müller, J.; Barth, S.; Biegger, F.; Gspan, C.; Plank, H.; Huth, M.

    2015-11-01

    Recently, focused electron beam-induced deposition has been employed to prepare functional magnetic nanostructures with potential in nanomagnetic logic and sensing applications by using homonuclear precursor gases like Fe(CO)5 or Co2(CO)8. Here we show that an extension towards the fabrication of bi-metallic compounds is possible by using a single-source heteronuclear precursor gas. We have grown CoFe alloy magnetic nanostructures from the HFeCo3(CO)12 metal carbonyl precursor. The compositional analysis indicates that the samples contain about 80 at% of metal and 10 at% of carbon and oxygen. Four-probe magnetotransport measurements are carried out on nanowires of various sizes down to a width of 50 nm, for which a room temperature resistivity of 43 μΩcm is found. Micro-Hall magnetometry reveals that 50 nm × 250 nm nanobars of the material are ferromagnetic up to the highest measured temperature of 250 K. Finally, the transmission electron microscopy (TEM) microstructural investigation shows that the deposits consist of a bcc Co-Fe phase mixed with a FeCo2 O4 spinel oxide phase with nanograins of about 5 nm diameter.

  19. Approaching Defect-free Amorphous Silicon Nitride by Plasma-assisted Atomic Beam Deposition for High Performance Gate Dielectric.

    Science.gov (United States)

    Tsai, Shu-Ju; Wang, Chiang-Lun; Lee, Hung-Chun; Lin, Chun-Yeh; Chen, Jhih-Wei; Shiu, Hong-Wei; Chang, Lo-Yueh; Hsueh, Han-Ting; Chen, Hung-Ying; Tsai, Jyun-Yu; Lu, Ying-Hsin; Chang, Ting-Chang; Tu, Li-Wei; Teng, Hsisheng; Chen, Yi-Chun; Chen, Chia-Hao; Wu, Chung-Lin

    2016-01-01

    In the past few decades, gate insulators with a high dielectric constant (high-k dielectric) enabling a physically thick but dielectrically thin insulating layer, have been used to replace traditional SiOx insulator and to ensure continuous downscaling of Si-based transistor technology. However, due to the non-silicon derivative natures of the high-k metal oxides, transport properties in these dielectrics are still limited by various structural defects on the hetero-interfaces and inside the dielectrics. Here, we show that another insulating silicon compound, amorphous silicon nitride (a-Si3N4), is a promising candidate of effective electrical insulator for use as a high-k dielectric. We have examined a-Si3N4 deposited using the plasma-assisted atomic beam deposition (PA-ABD) technique in an ultra-high vacuum (UHV) environment and demonstrated the absence of defect-related luminescence; it was also found that the electronic structure across the a-Si3N4/Si heterojunction approaches the intrinsic limit, which exhibits large band gap energy and valence band offset. We demonstrate that charge transport properties in the metal/a-Si3N4/Si (MNS) structures approach defect-free limits with a large breakdown field and a low leakage current. Using PA-ABD, our results suggest a general strategy to markedly improve the performance of gate dielectric using a nearly defect-free insulator. PMID:27325155

  20. Thermal shock behavior of platinum aluminide bond coat/electron beam-physical vapor deposited thermal barrier coatings

    International Nuclear Information System (INIS)

    Highlights: • TBCs of (Ni, Pt)Al bond coat with grit blasting process and YSZ ceramic coating. • Grain boundary ridges are the sites for spallation damage initiation in TBCs. • Ridges removed, cavities formation appeared and the damage initiation deteriorated. • Damage initiation and progression at interface lead to a buckling failure. - Abstract: Thermal barrier coating systems (TBCs) including of chemical vapor deposited (Ni, Pt)Al bond coat with grit blasting process and electron beam physical vapor deposited Y2O3-stabilized-ZrO2 (YSZ) ceramic coating were investigated. The phase structures, surface and cross-sectional morphologies, thermal shock behaviors and residual stresses of the coatings were studied in detail. Grain boundary ridges still remain on the surface of bond coat prior to the deposition of the ceramic coating, which are shown to be the major sites for spallation damage initiation in TBCs. When these ridges are mostly removed, they appear some of cavities formation and then the damage initiation mode is deteriorated. Damage initiation and progression occurs at the bond coat to thermally grown oxide (TGO) interface leading to a buckling failure behavior. A buckle failure once started may be arrested when it runs into a region of high bond coat to TGO interface toughness. Thus, complete failure requires further loss in toughness of the bond coat to TGO interface during cooling. The suppressed cavities formation, the removed ridges at the grain boundaries, the relative high TGO to bond coat interface toughness, the uniform growth behavior of TGO thickening and the lower of the residual stress are the primary factors for prolonging the lifetime of TBCs

  1. Thermal shock behavior of platinum aluminide bond coat/electron beam-physical vapor deposited thermal barrier coatings

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhenhua, E-mail: zhxuciac@163.com [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Dai, Jianwei [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Niu, Jing [Shenyang Liming Aero-engine (Group) Corporation Ltd., Institute of Metallurgical Technology, Technical Center, Shengyang 110043 (China); Li, Na; Huang, Guanghong; He, Limin [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China)

    2014-12-25

    Highlights: • TBCs of (Ni, Pt)Al bond coat with grit blasting process and YSZ ceramic coating. • Grain boundary ridges are the sites for spallation damage initiation in TBCs. • Ridges removed, cavities formation appeared and the damage initiation deteriorated. • Damage initiation and progression at interface lead to a buckling failure. - Abstract: Thermal barrier coating systems (TBCs) including of chemical vapor deposited (Ni, Pt)Al bond coat with grit blasting process and electron beam physical vapor deposited Y{sub 2}O{sub 3}-stabilized-ZrO{sub 2} (YSZ) ceramic coating were investigated. The phase structures, surface and cross-sectional morphologies, thermal shock behaviors and residual stresses of the coatings were studied in detail. Grain boundary ridges still remain on the surface of bond coat prior to the deposition of the ceramic coating, which are shown to be the major sites for spallation damage initiation in TBCs. When these ridges are mostly removed, they appear some of cavities formation and then the damage initiation mode is deteriorated. Damage initiation and progression occurs at the bond coat to thermally grown oxide (TGO) interface leading to a buckling failure behavior. A buckle failure once started may be arrested when it runs into a region of high bond coat to TGO interface toughness. Thus, complete failure requires further loss in toughness of the bond coat to TGO interface during cooling. The suppressed cavities formation, the removed ridges at the grain boundaries, the relative high TGO to bond coat interface toughness, the uniform growth behavior of TGO thickening and the lower of the residual stress are the primary factors for prolonging the lifetime of TBCs.

  2. Properties of CdTe films deposited by electron beam evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Murali, K.R.; Radhakrishna, I.; Nagaraja Rao, K.; Venkatesan, V.K. (Central Electrotechnical Research Inst., Karaikudi (India))

    1990-04-01

    Cadmium telluride thin films were prepared by electron beam evaporation on glass substrates kept at different temperatures in the range 30-300degC. The films were characterized by X-ray diffraction, scanning electron microscopy and optical absorption measurements. The conductivity of the films was measured in the temperature range 100-300 K. While the low temperature data (100-200 K) could be explained by the variable range hopping process, the high temperature data (200-300 K) could be explained on the basis of Seto's model for thermionic emission of the carriers over the grain boundaries. Transmission spectra have indicated a direct and gap around 1.55 eV. (orig.).

  3. Structural properties of MgF2 and ZnS in thin film and in multilayer optical coatings

    Science.gov (United States)

    Perales, F.; de las Heras, C.; Agulló-Rueda, F.

    2008-11-01

    Different techniques of x-ray diffraction line profile analysis have been used to study the microstructural parameters of the MgF2 and ZnS thin films as well as MgF/ZnS multilayers. The crystallite size and microstrain of the samples have been estimated from x-ray diffraction by applying Scherrer, Scherrer-Wilson and Williamson-Hall formulae respectively. The effects of thermal annealing at different temperatures on the structure in the material in thin films and in multilayers are studied and compared by the three mentioned relations. Although some different values have been obtained from each expression, the same temperature tendency is observed.

  4. Synthesis and evaluation of MgF2 coatings by chemical conversion on magnesium alloys for producing biodegradable orthopedic implants of temporary use

    International Nuclear Information System (INIS)

    The aim of the present work was the synthesis of biodegradable MgF2 coatings by chemical conversion on the commercial Elektron 21 and AZ91D magnesium alloys, in aqueous HF solutions for different concentrations and temperatures. The chemical composition and morphology of the coatings were analyzed by scanning electron microscopy (SEM-EDX) and X-ray diffraction (XRD). On the other hand, their corrosion behavior was evaluated by gravimetric and electrochemical measurements in Hank's solution at 37°C for different immersion times. The experimental results revealed that chemical conversion in HF produced MgF2 coatings which corrosion resistance was enhanced by increasing the HF concentration. Further, the microstructure and composition of the base alloy played a key role on the growth and degradation mechanisms of the MgF2 coatings

  5. Preparation and characterization of BaMgAl10O17:Eu phosphor coated with MgF2 by sol-gel process

    Institute of Scientific and Technical Information of China (English)

    LI Feng; WANG Yu-hua

    2005-01-01

    In order to prevent BaMgAl10 O17 : Eu (BAM) phosphor from thermal degradation, MgF2-coatings on the surface of BAM were prepared by a sol-gel process. The coatings were characterized by X-ray photoelectron spectroscopy and scanning electron microscopy. The results indicate that BAM is successfully coated with homogenous, close MgF2 coatings. The photoluminescence and anti-thermal degradation properties of coated BAM were investigated under 254 and 147 nm excitations. The optimum anti-thermal degradation properties are obtained at the mass ratio of MgF2 to BAM 0. 2% under 254 nm excitation and 0. 5% under 147 nm excitation, respectively. It is considered that trace MgO formed after baked would cause different optimum coating thicknesses under 254 and 147 nm excitations.

  6. Synthesis and evaluation of MgF2 coatings by chemical conversion on magnesium alloys for producing biodegradable orthopedic implants of temporary use

    Science.gov (United States)

    Casanova, P. Y.; Jaimes, K. J.; Parada, N. J.; Hernández-Barrios, C. A.; Aparicio, M.; Viejo, F.; Coy, A. E.

    2013-11-01

    The aim of the present work was the synthesis of biodegradable MgF2 coatings by chemical conversion on the commercial Elektron 21 and AZ91D magnesium alloys, in aqueous HF solutions for different concentrations and temperatures. The chemical composition and morphology of the coatings were analyzed by scanning electron microscopy (SEM-EDX) and X-ray diffraction (XRD). On the other hand, their corrosion behavior was evaluated by gravimetric and electrochemical measurements in Hank's solution at 37°C for different immersion times. The experimental results revealed that chemical conversion in HF produced MgF2 coatings which corrosion resistance was enhanced by increasing the HF concentration. Further, the microstructure and composition of the base alloy played a key role on the growth and degradation mechanisms of the MgF2 coatings.

  7. Structure and properties of the combined coatings deposited by the beams and plasma technologies

    International Nuclear Information System (INIS)

    Full text: The purpose of the given work is realization of complex researches of morphological features of a surface of powder coverings, definition of dependence of phase structure and mechanical characteristics (microhardness, wear resistance) from density of capacity of thermal influence on a surface of coverings of nickel alloys. In the given work it is submitted results of researches of three series of samples: a series No 1 - a covering in an initial condition, a series No 2 - pulsed-plasma melting a powder covering with partial melting surfaces of a substrate (depth melting made about 4 ·10-5 m), a series No 3 - full melting coverings an electron beam with melting substrates thickness from 1,5 up to 2·10-4 m. In work experimental results of research of structure, morphology and phase structure of plasma-detonation coverings from a powder on basis Ni, melted off by the concentrated streams of energy (a high-speed pulsed-plasma jet, an electron beam) are submitted. Element compositions of the surfaces were studied using electronic microscope REMMA-102. The phase structure of a surface was determined by means of x-ray diffraction (DRON-2). The microhardness was measured using PMT-3 with a diamond Vickers pyramid over the surface and the transversal and angular cross-sections. It is established, that duplex updating of a surface of plasma-detonation coverings on the basis of nickel is accompanied by the number of phase transformations in an initial material of a powder (formation of inter-metalloid compounds Cr2Ni2, CrB), and also enrichment of structure of a covering by an initial element of a matrix of a substrate (a-Fe) and its formation inter-metalloid connections with molybdenum (Fe7 Mo6, Fe3Mo and, probably, FeMo). Influence of phase structure on microhardness and wear resistance of the generated coatings is revealed. It is established, that electron melting surfaces it is accompanied by triple increase of microhardness of a superficial layer and twenty

  8. Ion-beam-assisted deposition of Al films with strong preferential orientation

    International Nuclear Information System (INIS)

    Preferential crystal orientation of Al films deposited under simultaneous argon-ion irradiation has been investigated by changing both the ion-to-atom arrival rate ratio (ion-atom ratio) and the ion energy. The intensity of the reflection, I(111), obtained from X-ray diffraction shows a drastic increase with ion irradiation, although the effect on other reflection peaks such as I(200) is only slight. The intensity ratio I(111)/I(200), a parameter for the electromigration resistance of Al films, has shown the highest value at a certain optimum ion-atom ratio. This optimum ion-atom ratio for each ion energy is found to shift toward lower values with increasing ion energy. Under the optimum conditions, the average ion energy per neutral atom after cascade collisions is found to be about 1.2 eV irrespective of the primary ion energy, which is comparable with the energy for the self-diffusion of Al (1.4 eV). The electrical measurements have shown that the resistivity of Al films increases considerably with simultaneous ion irradiation, however, it recovers to a level comparable with that of unassisted films by annealing at 400degC. (orig.)

  9. Using ion beams to tune the nanostructure and optical response of co-deposited Ag : BN thin films

    Energy Technology Data Exchange (ETDEWEB)

    Toudert, J [Laboratoire de Metallurgie Physique, UMR CNRS 6630, Batiment SP2MI, Boulevard Marie et Pierre Curie, Teleport 2 Futuroscope, 86962 Chasseneuil (France); Babonneau, D [Laboratoire de Metallurgie Physique, UMR CNRS 6630, Batiment SP2MI, Boulevard Marie et Pierre Curie, Teleport 2 Futuroscope, 86962 Chasseneuil (France); Camelio, S [Laboratoire de Metallurgie Physique, UMR CNRS 6630, Batiment SP2MI, Boulevard Marie et Pierre Curie, Teleport 2 Futuroscope, 86962 Chasseneuil (France); Girardeau, T [Laboratoire de Metallurgie Physique, UMR CNRS 6630, Batiment SP2MI, Boulevard Marie et Pierre Curie, Teleport 2 Futuroscope, 86962 Chasseneuil (France); Yubero, F [Instituto de Ciencia de Materiales de Sevilla, CSIC, Isla de la Cartuja, 41092 Isla de la Cartuja, Sevilla (Spain); Espinos, J P [Instituto de Ciencia de Materiales de Sevilla, CSIC, Isla de la Cartuja, 41092 Isla de la Cartuja, Sevilla (Spain); Gonzalez-Elipe, A R [Instituto de Ciencia de Materiales de Sevilla, CSIC, Isla de la Cartuja, 41092 Isla de la Cartuja, Sevilla (Spain)

    2007-08-07

    The present study is devoted to co-deposited Ag : BN nanocermet thin films and is focused on the influence of ion irradiation conditions on their structural and linear optical properties. Ion irradiation was performed in situ during the growth of the nanocermets using a 50 eV assistance beam (nitrogen/argon or nitrogen-ion assistance) and ex situ on as-grown films using a 120 keV argon-ion beam (post-irradiation). Grazing incidence small-angle x-ray scattering measurements show that (i) as-grown N-assisted films contain prolate spheroidal clusters (height-to-diameter ratio H/D {approx} 1.8), (ii) N/Ar-ion assistance leads to the formation of more elongated clusters (H/D {approx} 2.1) and (iii) post-irradiation leads to a decrease of H/D to a value close to 1. These results are discussed on the basis of atomic diffusion processes involved during the growth of the nanocermets and during the post-irradiation. The optical transmittance spectra of these films measured at normal incidence display one absorption band, due to the excitation of the (1,1) plasmon mode of the clusters. In the case of the as-grown films, an additional band appears at oblique incidence for P-polarized light, as a consequence of the excitation of the (1,0) plasmon mode of the clusters. Our results show that the spectral position of the absorption bands (which can be tuned in the 400-600 nm range) depends on the H/D ratio of the clusters, in good agreement with calculations of optical transmittance considering the nanocomposite layer as a uniaxial anisotropic medium whose dielectric tensor is described by an anisotropic Maxwell-Garnett model.

  10. Using ion beams to tune the nanostructure and optical response of co-deposited Ag : BN thin films

    International Nuclear Information System (INIS)

    The present study is devoted to co-deposited Ag : BN nanocermet thin films and is focused on the influence of ion irradiation conditions on their structural and linear optical properties. Ion irradiation was performed in situ during the growth of the nanocermets using a 50 eV assistance beam (nitrogen/argon or nitrogen-ion assistance) and ex situ on as-grown films using a 120 keV argon-ion beam (post-irradiation). Grazing incidence small-angle x-ray scattering measurements show that (i) as-grown N-assisted films contain prolate spheroidal clusters (height-to-diameter ratio H/D ∼ 1.8), (ii) N/Ar-ion assistance leads to the formation of more elongated clusters (H/D ∼ 2.1) and (iii) post-irradiation leads to a decrease of H/D to a value close to 1. These results are discussed on the basis of atomic diffusion processes involved during the growth of the nanocermets and during the post-irradiation. The optical transmittance spectra of these films measured at normal incidence display one absorption band, due to the excitation of the (1,1) plasmon mode of the clusters. In the case of the as-grown films, an additional band appears at oblique incidence for P-polarized light, as a consequence of the excitation of the (1,0) plasmon mode of the clusters. Our results show that the spectral position of the absorption bands (which can be tuned in the 400-600 nm range) depends on the H/D ratio of the clusters, in good agreement with calculations of optical transmittance considering the nanocomposite layer as a uniaxial anisotropic medium whose dielectric tensor is described by an anisotropic Maxwell-Garnett model

  11. Formation of pure Cu nanocrystals upon post-growth annealing of Cu–C material obtained from focused electron beam induced deposition: comparison of different methods

    Science.gov (United States)

    Szkudlarek, Aleksandra; Rodrigues Vaz, Alfredo; Zhang, Yucheng; Rudkowski, Andrzej; Kapusta, Czesław; Erni, Rolf; Moshkalev, Stanislav

    2015-01-01

    Summary In this paper we study in detail the post-growth annealing of a copper-containing material deposited with focused electron beam induced deposition (FEBID). The organometallic precursor Cu(II)(hfac)2 was used for deposition and the results were compared to that of compared to earlier experiments with (hfac)Cu(I)(VTMS) and (hfac)Cu(I)(DMB). Transmission electron microscopy revealed the deposition of amorphous material from Cu(II)(hfac)2. In contrast, as-deposited material from (hfac)Cu(I)(VTMS) and (hfac)Cu(I)(DMB) was nano-composite with Cu nanocrystals dispersed in a carbonaceous matrix. After annealing at around 150–200 °C all deposits showed the formation of pure Cu nanocrystals at the outer surface of the initial deposit due to the migration of Cu atoms from the carbonaceous matrix containing the elements carbon, oxygen, and fluorine. Post-irradiation of deposits with 200 keV electrons in a transmission electron microscope favored the formation of Cu nanocrystals within the carbonaceous matrix of freestanding rods and suppressed the formation on their surface. Electrical four-point measurements on FEBID lines from Cu(hfac)2 showed five orders of magnitude improvement in conductivity when being annealed conventionally and by laser-induced heating in the scanning electron microscope chamber. PMID:26425404

  12. Mechanical strength and tribological behavior of ion-beam deposited boron nitride films on non-metallic substrates

    International Nuclear Information System (INIS)

    An investigation was conducted to examine the mechanical strength and tribological properties of boron nitride (BN) films ion-beam deposited on silicon (Si), fused silica (SiO2), gallium arsenide (GaAs), and indium phosphide (InP) substrates in sliding contact with a diamond pin under a load. The results of the investigation indicate that BN films on nonmetallic substrates, like metal films on metallic substrates, deform elastically and plastically in the interfacial region when in contact with a diamond pin. However, unlike metal films and substrates, BN films on nonmetallic substrates can fracture when they are critically loaded. Not only does the yield pressure (hardness) of Si and SiO2 substrates increase by a factor of 2 in the presence of a BN film, but the critical load needed to fracture increases as well. The presence of films on the brittle substrates can arrest crack formation. The BN film reduces adhesion and friction in the sliding contact. BN adheres to Si and SiO2 and forms a good quality film, while it adheres poorly to GaAs and InP. The interfacial adhesive strengths were 1 GPa for a BN film on Si and appreciably higher than 1 GPa for a BN film on SiO2

  13. Direct growth of Ge quantum dots on a graphene/SiO2/Si structure using ion beam sputtering deposition.

    Science.gov (United States)

    Zhang, Z; Wang, R F; Zhang, J; Li, H S; Zhang, J; Qiu, F; Yang, J; Wang, C; Yang, Y

    2016-07-29

    The growth of Ge quantum dots (QDs) using the ion beam sputtering deposition technique has been successfully conducted directly on single-layer graphene supported by SiO2/Si substrate. The results show that the morphology and size of Ge QDs on graphene can be modulated by tuning the Ge coverage. Charge transfer behavior, i.e. doping effect in graphene has been demonstrated at the interface of Ge/graphene. Compared with that of traditional Ge dots grown on Si substrate, the positions of both corresponding photoluminescence (PL) peaks of Ge QDs/graphene hybrid structure undergo a large red-shift, which can probably be attributed to the lack of atomic intermixing and the existence of surface states in this hybrid material. According to first-principles calculations, the Ge growth on the graphene should follow the so-called Volmer-Weber mode instead of the Stranski-Krastanow one which is observed generally in the traditional Ge QDs/Si system. The calculations also suggest that the interaction between Ge and graphene layer can be enhanced with the decrease of the Ge coverage. Our results may supply a prototype for fabricating novel optoelectronic devices based on a QDs/graphene hybrid nanostructure. PMID:27302495

  14. Thermal barrier coating of lanthanum-zirconium-cerium composite oxide made by electron beam-physical vapor deposition

    International Nuclear Information System (INIS)

    Lanthanum-zirconium-cerium composite oxide (La2(Zr0.7Ce0.3)2O7, LZ7C3) as a candidate material for thermal barrier coatings (TBCs) was prepared by electron beam-physical vapor deposition (EB-PVD). The composition, crystal structure, thermophysical properties, surface and cross-sectional morphologies and cyclic oxidation behavior of the LZ7C3 coating were studied. The results indicated that LZ7C3 has a high phase stability between 298 K and 1573 K, and its linear thermal expansion coefficient (TEC) is similar to that of zirconia containing 8 wt% yttria (8YSZ). The thermal conductivity of LZ7C3 is 0.87 W m-1 K-1 at 1273 K, which is almost 60% lower than that of 8YSZ. The deviation of coating composition from the ingot can be overcome by the addition of excess CeO2 and ZrO2 during ingot preparation or by adjusting the process parameters. The failure of the LZ7C3 coating is mainly a result of the occurrence of micro-cracks inside ceramic topcoat, which cause the abnormal oxidation of bond coat.

  15. Direct growth of Ge quantum dots on a graphene/SiO2/Si structure using ion beam sputtering deposition

    Science.gov (United States)

    Zhang, Z.; Wang, R. F.; Zhang, J.; Li, H. S.; Zhang, J.; Qiu, F.; Yang, J.; Wang, C.; Yang, Y.

    2016-07-01

    The growth of Ge quantum dots (QDs) using the ion beam sputtering deposition technique has been successfully conducted directly on single-layer graphene supported by SiO2/Si substrate. The results show that the morphology and size of Ge QDs on graphene can be modulated by tuning the Ge coverage. Charge transfer behavior, i.e. doping effect in graphene has been demonstrated at the interface of Ge/graphene. Compared with that of traditional Ge dots grown on Si substrate, the positions of both corresponding photoluminescence (PL) peaks of Ge QDs/graphene hybrid structure undergo a large red-shift, which can probably be attributed to the lack of atomic intermixing and the existence of surface states in this hybrid material. According to first-principles calculations, the Ge growth on the graphene should follow the so-called Volmer–Weber mode instead of the Stranski–Krastanow one which is observed generally in the traditional Ge QDs/Si system. The calculations also suggest that the interaction between Ge and graphene layer can be enhanced with the decrease of the Ge coverage. Our results may supply a prototype for fabricating novel optoelectronic devices based on a QDs/graphene hybrid nanostructure.

  16. Optical switching properties of VOx thin films deposited on Si3N4 substrates using ion beam sputtering

    Science.gov (United States)

    Lu, Jianing; Hu, Ming; Liang, Jiran; Chen, Tao; Tan, Lei

    2009-07-01

    Vanadium dioxide (VO2) thin films, for their property of metal-insulator transition (MIT), have drawn many researchers' attention on optical devices study. Nowadays it is complicated to fabricate single-phase VO2) thin films. Ion beam sputtering is adopted to deposit VOx thin films (main component is VO2) ) on Si3N4, while sputtering power, substrate temperature and partial oxygen pressure of VOx are adjusted. Then annealing technology is utilized to improve the parameter property of VOx thin films. The thin films are tested by AFM, XPS, XRD, Fourier transform infrared spectrometry, tunable semiconductor laser and optical power meter. Both temperature-driven phasetransition and photoexcitation phasetransition of VOx thin films are applied. The samples are heated from 20°C to 80°C, discovering that the phasetransition temperature is about 59°C and the value of resistance before the phasetransition is two orders of magnitude over the value of resistance after the phasetransition. At the wavelength of 1550 nm, the transmission is from 32% to 1%. Besides, the extinction ratio of the thin films sample is obtained. The optical properties show that the VOx thin films have an apparent switching effect in the optical communication fields.

  17. Crystal structure and microwave resistance of YBa2Cu3O7-δ films prepared by cross-beam pulsed-laser deposition

    International Nuclear Information System (INIS)

    High-Tc superconducting YBa2Cu3O7-δ (YBCO) films were prepared by a unique pulsed-laser deposition using crossed-laser-beam technique onto LaAlO3 substrates in order to develop a basic technology for microwave-device application. The pulsed-laser deposition set-up uses two Nd-YAG lasers with 1064 nm wavelength and 0.3 J/pulse power. The unique feature of this method is a possibility to get a plasma plume with a low level of 'droplet', which essentially improves the film-surface quality. Transmission-electron microscopy and x-ray data show that YBCO films deposited at substrate temperature (Ts) of 780 deg. C exhibit a minimal density of dislocations in the crystal. YBCO films deposited at Ts = 780 deg. C with a cooling rate of V = 3 K min-1 have the smallest surface resistance below the transition temperature

  18. Growth of MgF2 optical crystals and their ionic conductivity in the as-grown state and after partial pyrohydrolysis

    Science.gov (United States)

    Karimov, D. N.; Sorokin, N. I.; Chernov, S. P.; Sobolev, B. P.

    2014-11-01

    MgF2 single crystals have been grown from melt by the Bridgman technique in a fluorinating atmosphere. To control the presence of oxygen impurity, it was first suggested to measure the ionic conductivity in MgF2 crystals by impedance spectroscopy. The characteristics of ionic conductivity of " as grown" (i.e., without thermal treatment) crystals and crystals obtained by commercial vacuum technology practically coincide: the volume conductivity σv = 1.4 × 10-7 S/cm at 773 K and the ion-transport activation energy E a = 1.40 ± 0.05 eV. Annealing MgF2 crystals during electrophysical studies upon heating from 293 to 823 K in vacuum (residual pressure ˜1 Pa) for 4 h led to their partial pyrohydrolisis. The influence of this thermal treatment of MgF2 crystals on their optical transmission is studied in the wavelength range of 115-300 nm.

  19. Ion-beam-assisted deposition of biaxially aligned yttria-stabilized zirconia template films on metallic substrates for YBCO-coated conductors

    Science.gov (United States)

    Ma, B.; Li, M.; Fisher, B. L.; Balachandran, U.

    2002-07-01

    Biaxially textured yttria-stabilized zirconia (YSZ) films were grown on mechanically polished Hastelloy C276 (HC) substrates by ion-beam-assisted deposition and electron-beam evaporation. The surface root-mean-square (RMS) roughness of the polished HC substrates was ≈3 nm, as measured by atomic force microscopy (AFM). A water-cooled sample stage was used to hold the substrate temperature below 100 °C during deposition. RMS roughness of ≈3.3 nm was measured on the deposited YSZ films by AFM. X-ray pole figures were conducted for texture analysis; in-plane texture measured from YSZ (111) φ-scan FWHM was 13.2° and out-of-plane texture from the YSZ (002) ω-scan FWHM was 7.7°. An ≈10 nm thick CeO2 buffer layer was deposited on the YSZ film at 800 °C before YBCO films were ablated by pulsed laser deposition at 780 °C in a 250 mTorr flowing oxygen environment. Good in-plane texture with FWHM ≈ 7° was observed in YBCO films. Tc = 90 K, with sharp transition, and transport Jc of ≈2.2 × 106 A cm-2 were observed in a 0.5 μm thick, 5 mm wide, and 1 cm long sample at 77 K in self-field.

  20. Ion-beam-assisted deposition of biaxially aligned yttria-stabilized zirconia template films on metallic substrates for YBCO-coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Ma, B. [Energy Technology Division, Argonne National Laboratory, Argonne, IL (United States)]. E-mail: bma@anl.gov; Li, M.; Fisher, B.L.; Balachandran, U. [Energy Technology Division, Argonne National Laboratory, Argonne, IL (United States)

    2002-07-01

    Biaxially textured yttria-stabilized zirconia (YSZ) films were grown on mechanically polished Hastelloy C276 (HC) substrates by ion-beam-assisted deposition and electron-beam evaporation. The surface root-mean-square (RMS) roughness of the polished HC substrates was {approx}3 nm, as measured by atomic force microscopy (AFM). A water-cooled sample stage was used to hold the substrate temperature below 100 deg. C during deposition. RMS roughness of {approx}3.3 nm was measured on the deposited YSZ films by AFM. X-ray pole figures were conducted for texture analysis; in-plane texture measured from YSZ (111) {phi}-scan FWHM was 13.2 deg. and out-of-plane texture from the YSZ (002) {omega}-scan FWHM was 7.7 deg. An {approx}10 nm thick CeO{sub 2} buffer layer was deposited on the YSZ film at 800 deg. C before YBCO films were ablated by pulsed laser deposition at 780 deg. C in a 250 mTorr flowing oxygen environment. Good in-plane texture with FWHM {approx}7 deg. was observed in YBCO films. T{sub c} 90 K, with sharp transition, and transport J{sub c} of {approx}2.2x10{sup 6} A cm{sup -2} were observed in a 0.5 {mu}m thick, 5 mm wide, and 1 cm long sample at 77 K in self-field. (author)

  1. Ion-beam-assisted deposition of biaxially aligned yttria-stabilized zirconia template films on metallic substrates for YBCO-coated conductors

    International Nuclear Information System (INIS)

    Biaxially textured yttria-stabilized zirconia (YSZ) films were grown on mechanically polished Hastelloy C276 (HC) substrates by ion-beam-assisted deposition and electron-beam evaporation. The surface root-mean-square (RMS) roughness of the polished HC substrates was ∼3 nm, as measured by atomic force microscopy (AFM). A water-cooled sample stage was used to hold the substrate temperature below 100 deg. C during deposition. RMS roughness of ∼3.3 nm was measured on the deposited YSZ films by AFM. X-ray pole figures were conducted for texture analysis; in-plane texture measured from YSZ (111) φ-scan FWHM was 13.2 deg. and out-of-plane texture from the YSZ (002) ω-scan FWHM was 7.7 deg. An ∼10 nm thick CeO2 buffer layer was deposited on the YSZ film at 800 deg. C before YBCO films were ablated by pulsed laser deposition at 780 deg. C in a 250 mTorr flowing oxygen environment. Good in-plane texture with FWHM ∼7 deg. was observed in YBCO films. Tc 90 K, with sharp transition, and transport Jc of ∼2.2x106 A cm-2 were observed in a 0.5 μm thick, 5 mm wide, and 1 cm long sample at 77 K in self-field. (author)

  2. Investigation of ZnO thin films deposited on ferromagnetic metallic buffer layer by molecular beam epitaxy toward realization of ZnO-based magnetic tunneling junctions

    International Nuclear Information System (INIS)

    Deposition of ZnO thin films on a ferromagnetic metallic buffer layer (Co3Pt) by molecular beam epitaxy technique was investigated for realization of ZnO-based magnetic tunneling junctions with good quality hexagonal ZnO films as tunnel barriers. For substrate temperature of 600 °C, ZnO films exhibited low oxygen defects and high electrical resistivity of 130 Ω cm. This value exceeded that of hexagonal ZnO films grown by sputtering technique, which are used as tunnel barriers in ZnO-MTJs. Also, the effect of oxygen flow during deposition on epitaxial growth conditions and Co3Pt surface oxidation was discussed.

  3. Evolution of microstructure during the growth of thermal barrier coatings by electron-beam physical vapor deposition

    Science.gov (United States)

    Terry, Scott Gregory

    2001-12-01

    The mechanisms responsible for the formation of porosity and crystallographic orientation (texture) in the microstructure of thermal barrier coatings (TBCs) grown by electron-beam physical vapor deposition (EB-PVD) are investigated. A matrix of 7 wt.% Y2O3-ZrO2 TBC specimens was generated by independently varying two processing parameters: substrate temperature (Ts) and pattern of vapor incidence. TBCs deposited on stationary substrates oriented normal to the vapor source yielded columnar microstructures possessing fiber textures. Growth directions changed from to + to + as Ts increased from 900-1100°C. Increasing the angle of vapor incidence to 45° favored biaxially aligned columnar growth in the direction, while rotating the substrates produced biaxially aligned columns. The texture orientation is correlated with the observed column tip morphologies by considering the growth directions defined by symmetric arrangements of {111} preferred growth planes about a column axis. The change in texture orientation with increasing Ts under normal incidence on stationary substrates is linked to changes in the mechanism of crystal growth. The pattern of vapor incidence on stationary oblique and rotated substrates has a stronger influence on texture than Ts. Here, the requirement that faces composing a column tip receive equal amounts of vapor flux determines the outcome of a competitive growth process yielding the observed biaxial orientations. The formation of porosity is in general attributed to shadowing of the incident vapor by geometric features of the TBC surface. These features are crystallographic in nature such that the formation of porosity is intimately tied to the crystallographic texture of the coating. Intercolumnar gaps are generated by the interaction between the pattern of vapor incidence and the column tip morphology, whereas the feather-like shape of the open intracolumnar porosity evolves from shadows cast by steps on the column tip faces. Closed

  4. Optical properties of organic films, multilayers and plasmonic metal-organic waveguides fabricated by organic molecular beam deposition

    Science.gov (United States)

    Wickremasinghe, Niranjala D.

    In this thesis, the optical properties of tris (8-hydroxyquinoline) aluminum (Alq3) and 3,5,9,10-perylentetracarboxylic dianhydride (PTCDA) organic films, PTCDA/ Alq3 multilayers and plasmonic Alq3 -metal waveguides are investigated. The organic films and heterostructures used for this work were fabricated by organic molecular beam deposition (OMBD). We investigated the quenching of the light emission in Alq3 films grown on a Si substrate as a function of cw laser excitation intensity at varying temperatures from 15 to 300 K. The saturation of the singlet-singlet annihilation coefficient was measured with spectrally-integrated (SI) photoluminescence (PL) using a photodiode. The bimolecular quenching coefficient was further studied with time-resolved (TR) PL as a function of 100 fs pulse fluences. The PL quenching is attributed to the annihilation of trapped excitons at Alq3 nanocrystal grain boundaries. The saturation is explained by the limited density of available trapping states at the grain boundaries. Our interpretation is supported by structural investigations of ultrathin Alq3 films with atomic force microscopy (AFM), scanning electron microscopy (SEM) and by comparing the experimental data with calculations using a coupled rate equation model. The wavelength dispersion of the refractive indices of PTCDA and Alq 3 layers and of PTCDA/Alq3 multilayer waveguides grown on Pyrex substrates was investigated. The m-line technique, an evanescent prism coupling technique, was used to determine the layers' thickness and the in-plane (TE modes) and normal (TM modes) refractive indices. The potential for controlling the refractive index dispersion and anisotropy by tailored organic multilayer waveguides is discussed.

  5. Mossbauer investigation of Fe{sub 1-x} Cr{sub x} films grown by ion-beam sputter deposition

    Energy Technology Data Exchange (ETDEWEB)

    Eymery, J.P. [Laboratoire de Metallurgie Physique, UMR 6630 CNRS, Universite de Poitiers, batiment SP2MI, Teleport 2, boulevard Marie et Pierre Curie, BP 30179, F-86962 Futuroscope-Chasseneuil Cedex (France); Al-Khoury, W. [Laboratoire de Metallurgie Physique, UMR 6630 CNRS, Universite de Poitiers, batiment SP2MI, Teleport 2, boulevard Marie et Pierre Curie, BP 30179, F-86962 Futuroscope-Chasseneuil Cedex (France); Atomic Energy Commission of Syria, PO Box 6091, Damascus, Syria (Syrian Arab Republic); Goudeau, Ph. [Laboratoire de Metallurgie Physique, UMR 6630 CNRS, Universite de Poitiers, batiment SP2MI, Teleport 2, boulevard Marie et Pierre Curie, BP 30179, F-86962 Futuroscope-Chasseneuil Cedex (France)]. E-mail: philippe.goudeau@univ-poitiers.fr; Fnidiki, A. [Groupe de Physique des Materiaux, UMR 6634 CNRS, Universite de Rouen, site universitaire du Madrillet, avenue de l' Universite, BP 12, F-76801 Saint-Etienne du Rouvray Cedex (France)

    2006-05-31

    Fe{sub 1-x}Cr{sub x} (0beam sputter deposition, and their structural properties were determined by {sup 57}Fe conversion electron Mossbauer spectroscopy (CEMS) and X-ray diffraction experiments (XRD) at room temperature. CEM spectra show magnetic ordering for 0

  6. Failure mechanisms of platinum aluminide bond coat/electron beam-physical vapor deposited thermal barrier coatings

    Science.gov (United States)

    Vaidyanathan, Krishnakumar

    Thermal barrier coatings (TBCs) allow operation of structural components, such as turbine blades and vanes in industrial and aircraft gas engines, at temperatures close to the substrate melting temperatures. They consist of four different layers; a high strength creep-resistant nickel-based superalloy substrate, an oxidation resistant bond coat (BC), a low thermal conductivity ceramic topcoat and a thermally grown oxide (TGO), that is predominantly alpha-Al 2O3, that forms between the BC and the TBC. Compressive stresses (3--5 GPa) that are generated in the thin TGO (0.25--8 mum) due to the mismatch in thermal coefficient of expansion between the TGO and BC play a critical role in the failure of these coatings. In this study, the failure mechanisms of a commercial yttria-stabilized zirconia (7YSZ) electron beam-physical vapor deposited (EB-PVD) coating on platinum aluminide (beta-(Ni,Pt)Al) bond coat have been identified. Two distinct mechanisms have been found responsible for the observed damage initiation and progression at the TGO/bond coat interface. The first mechanism leads to localized debonding at TGO/bond coat interface due to increased out-of-plane tensile stress, along bond coat features that manifest themselves as ridges. The second mechanism causes cavity formation at the TGO/bond coat interface, driven by cyclic plasticity of the bond coat. It has been found that the debonding at the TGO/bond coat interface due to the first mechanism is solely life determining. The final failure occurs by crack extension along either the TGO/bond coat interface or the TGO/YSZ interface or a combination of both, leading to large scale buckling. Based on these mechanisms, it is demonstrated that the bond coat grain size and the aspect ratio of the ridges have a profound influence on spallation lives of the coating. The removal of these ridges by fine polishing prior to TBC deposition led to a four-fold improvement in life. The failure mechanism identified for the

  7. Growth modes and epitaxy of FeAl thin films on a-cut sapphire prepared by pulsed laser and ion beam assisted deposition

    International Nuclear Information System (INIS)

    FeAl films around equiatomic composition are grown on a-cut (112¯0) sapphire substrates by ion beam assisted deposition (IBAD) and pulsed laser deposition (PLD) at ambient temperature. Subsequent successive annealing is used to establish chemical order and crystallographic orientation of the films with respect to the substrate. We find a strongly [110]-textured growth for both deposition techniques. Pole figures prove the successful preparation of high quality epitaxial films by PLD with a single in-plane orientation. IBAD-grown films, however, exhibit three in-plane orientations, all of them with broad angular distributions. The difference of the two growth modes is attributed to the existence of a metastable intermediate crystalline orientation as concluded from nonassisted sputter depositions at different substrate temperatures. The formation of the chemically ordered crystalline B2 phase is accompanied by the expected transition from ferromagnetic to paramagnetic behavior of the films. In accordance with the different thermally induced structural recovery, we find a step-like magnetic transition to paramagnetic behavior after annealing for 1 h at TA = 300 °C for IBAD deposition, while PLD-grown films show a gradual decrease of ferromagnetic signals with rising annealing temperatures

  8. Graphene crystal growth by thermal precipitation of focused ion beam induced deposition of carbon precursor via patterned-iron thin layers

    Directory of Open Access Journals (Sweden)

    Rius Gemma

    2014-01-01

    Full Text Available Recently, relevant advances on graphene as a building block of integrated circuits (ICs have been demonstrated. Graphene growth and device fabrication related processing has been steadily and intensively powered due to commercial interest; however, there are many challenges associated with the incorporation of graphene into commercial applications which includes challenges associated with the synthesis of this material. Specifically, the controlled deposition of single layer large single crystal graphene on arbitrary supports, is particularly challenging. Previously, we have reported the first demonstration of the transformation of focused ion beam induced deposition of carbon (FIBID-C into patterned graphitic layers by metal-assisted thermal treatment (Ni foils. In this present work, we continue exploiting the FIBID-C approach as a route for graphene deposition. Here, thin patterned Fe layers are used for the catalysis of graphenization and graphitization. We demonstrate the formation of high quality single and few layer graphene, which evidences, the possibility of using Fe as a catalyst for graphene deposition. The mechanism is understood as the minute precipitation of atomic carbon after supersaturation of some iron carbides formed under a high temperature treatment. As a consequence of the complete wetting of FIBID-C and patterned Fe layers, which enable graphene growth, the as-deposited patterns do not preserve their original shape after the thermal treatment

  9. Cupric and cuprous oxide by reactive ion beam sputter deposition and the photosensing properties of cupric oxide metal–semiconductor–metal Schottky photodiodes

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Min-Jyun; Lin, Yong-Chen; Chao, Liang-Chiun, E-mail: lcchao@mail.ntust.edu.tw; Lin, Pao-Hung; Huang, Bohr-Ran

    2015-08-15

    Highlights: • CuO and Cu{sub 2}O were deposited by reactive ion beam sputter deposition. • Single phase CuO thin film is obtained with Ar:O{sub 2} = 2:1. • CuO MSM PD shows photoresponse from 400 nm to 1.30 μm. • CuO MSM PD is RC limited with a decay time less than 1 μs. - Abstract: Cupric (CuO) and cuprous (Cu{sub 2}O) oxide thin films have been deposited by reactive ion beam sputter deposition at 400 °C with an Ar:O{sub 2} ratio from 2:1 to 12:1. With an Ar:O{sub 2} ratio of 2:1, single phase polycrystalline CuO thin films were obtained. Decreasing oxygen flow rate results in CuO + Cu{sub 2}O and Cu{sub 2}O + Cu mixed thin films. As Ar:O{sub 2} ratio reaches 12:1, Cu{sub 2}O nanorods with diameter of 250 nm and length longer than 1 μm were found across the sample. Single phase CuO thin film exhibits an indirect band gap of 1.3 eV with a smooth surface morphology. CuO metal–semiconductor–metal (MSM) Schottky photodiodes (PD) were fabricated by depositing Cu interdigitated electrodes on CuO thin films. Photosensing properties of the CuO PD were characterized from 350 to 1300 nm and a maximum responsivity of 43 mA/W was found at λ = 700 nm. The MSM PD is RC limited with a decay time constant less than 1 μs.

  10. Application of dynamic scaling theory for growth kinetic studies of AlN-thin films deposited by ion beam sputtering in reactive assistance of nitrogen plasma

    International Nuclear Information System (INIS)

    Highlights: • Growth kinetics of ion beam sputtered AlN-thin films by dynamic scaling theory. • AFM measurements show different morphologies due to varying deposition times 3, 5, 8 and 15 min. • Growth governing static (α) and dynamic (β) scaling exponents were determined in each case. • Four smoothening/roughening mechanisms are plastic flow, evaporation-recondensation, bulk-diffusion and surface diffusion. • Removal of over-hanging atoms, near surface defects, surface collision cascade and assistive ion-induced dissociation of clusters are the responsible phenomenona for the transition between different growth stages. - Abstract: Ion beam sputter deposition of AlN thin films to different time scales was carried out in reactive assistance of N+/N2+ ions. The incipient stages of the growth morphology were characterized using atomic force microscopy. Dynamic scaling theory was invoked to analyze the evolution of surface roughness and the growth mechanism therein. Two distinct exponents ‘α’ (static) and ‘β’ (dynamic) were used to unravel the film growth characteristics. Our results show that as the deposition time (t) increases, ‘α’ decreases gradually and substrate surface coverage increases indicated by a decrease in critical length Lc. Dynamic scaling exponent ‘β’ was estimated to be 0.36 for the deposition from isolated nuclei to full surface coverage of the substrate. During the growth, rms roughness of the film was increased from 1.99 to 3.42 nm as the deposition time was increased from 3 min to 15 min. Surface diffusion becomes the major roughening phenomenon while bulk diffusion subside it at each stage by smoothening to yield corresponding rms roughness

  11. Complete filling of 41 nm trench pattern using Cu seed layer deposited by SAM-modified electroless plating and electron-beam evaporation

    International Nuclear Information System (INIS)

    To overcome the limitation of the sputtered Cu seed layer in electroplating of Cu interconnects imposed by the shadow effect, a new method for depositing a Cu seed layer on a 41 nm trench pattern based on combination of electroless plating (ELP) and electron-beam (E-Beam) evaporation was developed. A Cu seed layer formed by ELP alone was too thin to be used for electroplating due to its high resistivity. To solve this problem, an additional Cu layer was deposited on top of the trench by E-Beam evaporator to enhance the electrical conductivity of the Cu seed layer. The electrical resistivity of the resulting Cu layer was reduced to 4.8 μΩ cm, which was sufficient for the conductive seed layer for electroplating the 41 nm trench pattern. The gap-filling capability also improved and there were no voids or seams in the 41 nm trench pattern. The proposed method can be an effective solution for fabrication of a conductive seed layer to fill a 41 nm trench pattern by electroplating.

  12. Modular ultrahigh vacuum-compatible gas-injection system with an adjustable gas flow for focused particle beam-induced deposition

    International Nuclear Information System (INIS)

    A gas-injection system (GIS) heats up a powdery substance and transports the resulting gas through a capillary into a vacuum chamber. Such a system can be used to guide a (metal)organic precursor gas very close to the focal area of an electron or ion beam, where a permanent deposit is created and adheres to the substrate. This process is known as focused particle beam-induced deposition. The authors present design principles and give construction details of a GIS suitable for ultrahigh vacuum usage. The GIS is composed of several self-contained components which can be customized rather independently. It allows for a continuously adjustable gas-flow rate. The GIS was attached to a standard scanning electron microscope (JEOL 6100) and tested with the tungsten precursor W(CO)6. The analysis of the deposits by means of atomic force microscopy and energy dispersive x-ray spectroscopy provides clear evidence that excellent gas-flow-rate stability and ensuing growth rate and metal-content reproducibility are experienced.

  13. Direct formation of thin films and epitaxial overlayers at low temperatures using a low-energy (10-500 eV) ion beam deposition system

    International Nuclear Information System (INIS)

    A low-energy ion beam deposition system has been developed at Oak Ridge National Laboratory and has been applied successfully to the growth of epitaxial films at low temperatures for a number of different elements. The deposition system utilizes the ion source and optics of a commercial ion implantation accelerator. The 35 keV mass- and energy-analyzed ion beam from the accelerator is decelerated in a four-element electrostatic lens assembly to energies between 10 and 500 eV for direct deposition onto a target under UHV conditions. Current densities on the order of 10 μA/cm2 are achieved with good uniformity over a 1.4 cm diameter spot. The completed films are characterized by Rutherford backscattering, ion channeling, cross-section transmission electron microscopy, and x-ray diffraction. The effects of substrate temperature, ion energy, and substrate cleaning have been studied. Epitaxial overlayers which show good minimum yields by ion channeling (3 to 4%) have been produced at temperatures as low as 3750C for Si on Si(100) and 2500C for Ge on Ge(100) at growth rates that exceed the solid-phase epitaxy rates at these temperatures by more than an order of magnitude

  14. Structural properties and surface wettability of Cu-containing diamond-like carbon films prepared by a hybrid linear ion beam deposition technique

    International Nuclear Information System (INIS)

    Cu-containing diamond-like carbon (Cu-DLC) films were deposited on Si/glass substrate by a hybrid ion beam deposition system. The Cu concentration (0.1–39.7 at.%) in the film was controlled by varying the sputtering current. The microstructure and composition of Cu-DLC films were investigated systematically. The surface topography, roughness and surface wettability of the films were also studied. Results indicated that with increasing the Cu concentration, the water contact angle of the films changed from 66.8° for pure carbon film to more than 104.4° for Cu-DLC films with Cu concentration larger than 24.4 at.%. In the hydrophilic region, the polar surface energy decreased from 30.54 mJ/m2 for pure carbon film to 2.48 mJ/m2 for the film with Cu 7.0 at.%. - Highlights: • Cu-containing diamond-like carbon (DLC) films were deposited by a hybrid ion beam system. • Cu-containing DLC films exhibited a wide range of water contact angle. • The water contact angles vary with the surface energies and surface roughness

  15. Preparation of MgF2-SiO2 thin films with a low refractive index by a solgel process.

    Science.gov (United States)

    Ishizawa, Hitoshi; Niisaka, Shunsuke; Murata, Tsuyoshi; Tanaka, Akira

    2008-05-01

    Porous MgF(2)-SiO(2) thin films consisting of MgF(2) particles connected by an amorphous SiO(2) binder are prepared by a solgel process. The films have a low refractive index of 1.26, sufficient strength to withstand wiping by a cloth, and a high environmental resistance. The refractive index of the film can be controlled by changing the processing conditions. Films can be uniformly formed on curved substrates and at relatively low temperatures, such as 100 degrees C. The low refractive index of the film, which cannot be achieved by conventional dry processes, is effective in improving the performance of antireflective coatings. PMID:18449247

  16. MgF2-coated porous magnesium/alumina scaffolds with improved strength, corrosion resistance, and biological performance for biomedical applications.

    Science.gov (United States)

    Kang, Min-Ho; Jang, Tae-Sik; Kim, Sung Won; Park, Hui-Sun; Song, Juha; Kim, Hyoun-Ee; Jung, Kyung-Hwan; Jung, Hyun-Do

    2016-05-01

    Porous magnesium (Mg) has recently emerged as a promising biodegradable alternative to biometal for bone ingrowth; however, its low mechanical properties and high corrosion rate in biological environments remain problematic. In this study, porous magnesium was implemented in a scaffold that closely mimics the mechanical properties of human bones with a controlled degradation rate and shows good biocompatibility to match the regeneration rate of bone tissue at the affected site. The alumina-reinforced Mg scaffold was produced by spark plasma sintering and coated with magnesium fluoride (MgF2) using a hydrofluoric acid solution to regulate the corrosion rate under physiological conditions. Sodium chloride granules (NaCl), acting as space holders, were leached out to achieve porous samples (60%) presenting an average pore size of 240μm with complete pore interconnectivity. When the alumina content increased from 0 to 5vol%, compressive strength and stiffness rose considerably from 9.5 to 13.8MPa and from 0.24 to 0.40GPa, respectively. Moreover, the biological response evaluated by in vitro cell test and blood test of the MgF2-coated porous Mg composite was enhanced with better corrosion resistance compared with that of uncoated counterparts. Consequently, MgF2-coated porous Mg/alumina composites may be applied in load-bearing biodegradable implants. PMID:26952467

  17. Nonlinear absorption in single LaF3 and MgF2 layers at 193 nm measured by surface sensitive laser induced deflection technique

    International Nuclear Information System (INIS)

    We report nonlinear absorption data of LaF3 and MgF2 single layers at 193 nm. A highly surface sensitive measurement strategy of the laser induced deflection technique is introduced and applied to measure the absorption of highly transparent thin films independently of the substrate absorption. Linear absorptions k=(αxλ)/4π of 2x10-4 and 8.5x10-4 (LaF3) and 1.8x10-4 and 6.9x10-4 (MgF2) are found. Measured two photon absorption (TPA) coefficients are β=1x10-4 cm/W (LaF3), 1.8x10-5, and 5.8x10-5 cm/W (MgF2). The TPA coefficients are several orders of magnitude higher than typical values for fluoride single crystals, which is likely to result from sequential two step absorption processes.

  18. Novel application of MgF2 as a back reflector in a-SiOx:H thin-film solar cells

    Science.gov (United States)

    Kang, Dong-Won; Sichanugrist, Porponth; Konagai, Makoto

    2014-08-01

    We present high-quality a-SiOx:H solar cells with a very thin i-layer of 100 nm fabricated at a low temperature of 100 °C. To boost the photocurrent with such a thin absorber, we suggested the application of a low-index MgF2 buffer at the n-type nanocrystalline silicon oxide (n-nc-SiOx:H)/Ag nanotextured interface to suppress the absorption loss at the Ag back contact. The introduction of MgF2 of only a few nanometers (˜4 nm) thickness enhanced the reflection at the n-nc-SiOx:H/Ag interface, which resulted in the reinforcement of the short-circuit current by about 7.3% from 9.60 to 10.30 mA/cm2 while almost maintaining Voc and FF. We demonstrated the efficiency improvement of up to 7.66% by MgF2 at the back contact.

  19. Vertical alignment of liquid crystal through ion beam exposure on oxygen-doped SiC films deposited at room temperature

    International Nuclear Information System (INIS)

    The authors report the vertical alignment of liquid crystal (LC) through the ion beam exposure on amorphous oxygen-doped SiC (SiOC) film surfaces deposited at room temperature. The optical transmittance of these films was similar to that of polyimide layers, but much higher than that of SiOx films. The light leakage of a LC cell aligned vertically on SiOC films was much lower than those of a LC cell aligned on polyimide layers or other inorganic films. They found that LC molecules align vertically on ion beam treated SiOC film when the roughness of the electrostatic force microscopy (EFM) data is high on the SiOC film surface, while they align homogeneously when the roughness of the EFM data is low

  20. Effect of deposition temperature on electron-beam evaporated polycrystalline silicon thin-film and crystallized by diode laser

    Energy Technology Data Exchange (ETDEWEB)

    Yun, J., E-mail: j.yun@unsw.edu.au; Varalmov, S.; Huang, J.; Green, M. A. [School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney, New South Wales 2052 (Australia); Kim, K. [School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney, New South Wales 2052 (Australia); Suntech R and D Australia, Botany, New South Wales 2019 (Australia)

    2014-06-16

    The effects of the deposition temperature on the microstructure, crystallographic orientation, and electrical properties of a 10-μm thick evaporated Si thin-film deposited on glass and crystallized using a diode laser, are investigated. The crystallization of the Si thin-film is initiated at a deposition temperature between 450 and 550 °C, and the predominant (110) orientation in the normal direction is found. Pole figure maps confirm that all films have a fiber texture and that it becomes stronger with increasing deposition temperature. Diode laser crystallization is performed, resulting in the formation of lateral grains along the laser scan direction. The laser power required to form lateral grains is higher in case of films deposited below 450 °C for all scan speeds. Pole figure maps show 75% occupancies of the (110) orientation in the normal direction when the laser crystallized film is deposited above 550 °C. A higher density of grain boundaries is obtained when the laser crystallized film is deposited below 450 °C, which limits the solar cell performance by n = 2 recombination, and a performance degradation is expected due to severe shunting.

  1. High temperature stability, interface bonding, and mechanical behavior in (beta)-NiAl and Ni3Al matrix composites with reinforcements modified by ion beam enhanced deposition

    Science.gov (United States)

    Grummon, D. S.

    1993-01-01

    Diffusion-bonded NiAl-Al2O3 and Ni3Al-Al2O3 couples were thermally fatigued at 900 C for 1500 and 3500 cycles. The fiber-matrix interface weakened after 3500 cycles for the Saphikon fibers, while the Altex, PRD-166, and FP fibers showed little, if any, degradation. Diffusion bonding of fibers to Nb matrix is being studied. Coating the fibers slightly increases the tensile strength and has a rule-of-mixtures effect on elastic modulus. Push-out tests on Sumitomo and FP fibers in Ni aluminide matrices were repeated. Al2O3 was evaporated directly from pure oxide rod onto acoustically levitated Si carbide particles, using a down-firing, rod-fed electron beam hearth; superior coatings were subsequently produced using concurrent irradiation with 200-eV argon ion-assist beam. The assist beam produced adherent films with reduced tensile stresses. In diffusion bonding in B-doped Ni3Al matrices subjected to compressive bonding at 40 MPa at 1100 C for 1 hr, the diffusion barriers failed to prevent catastrophic particle-matrix reaction, probably because of inadequate film quality. AlN coatings are currently being experimented with, produced by both reactive evaporation and by N(+)-ion enhanced deposition. A 3-kW rod-fed electron-beam-heated evaporation source has been brought into operation.

  2. Formation of (Ti,Al)N/Ti2AlN multilayers after annealing of TiN/TiAl(N) multilayers deposited by ion beam sputtering

    International Nuclear Information System (INIS)

    By using ion beam sputtering, TiN/TiAl(N) multilayers of various modulation wavelengths (Λ=8, 13, and 32 nm) were deposited onto silicon substrates at room temperature. After annealing at 600 deg. C in vacuum, one obtains for Λ=13 nm a (Ti,Al)N/Ti2AlN multilayer as it is evidenced from x-ray diffraction, high resolution transmission electron microscopy, and energy filtered electron imaging experiments. X-ray photoelectron spectroscopy (XPS) experiments show that the as-deposited TiAl sublayers contain a noticeable amount of nitrogen atoms which mean concentration varies with the period Λ. They also evidenced the diffusion of aluminum into TiN sublayers after annealing. Deduced from these observations, we propose a model to explain why this solid-state phase transformation depends on the period Λ of the multilayer

  3. The Influences of Thickness on the Optical and Electrical Properties of Dual-Ion-Beam Sputtering-Deposited Molybdenum-Doped Zinc Oxide Layer

    Directory of Open Access Journals (Sweden)

    Chin-Chiuan Kuo

    2011-01-01

    Full Text Available The thickness of transparent conductive oxide (TCO layer significantly affects not only the optical and electrical properties, but also its mechanical durability. To evaluate these influences on the molybdenum-doped zinc oxide layer deposited on a flexible polyethersulfone (PES substrate by using a dual-ion-beam sputtering system, films with various thicknesses were prepared at a same condition and their optical and electrical performances have been compared. The results show that all the deposited films present a crystalline wurtzite structure, but the preferred orientation changes from (002 to (100 with increasing the film thickness. Thicker layer contains a relative higher carrier concentration, but the consequently accumulated higher internal stress might crack the film and retard the carrier mobility. The competition of these two opposite trends for carrier concentration and carrier mobility results in that the electrical resistivity of molybdenum-doped zinc oxide first decreases with the thickness but suddenly rises when a critical thickness is reached.

  4. Energy deposition of ions in materials, and numerical simulations of compression, ignition, and burn of ion beam driven inertial confinement fusion pellets

    International Nuclear Information System (INIS)

    In this article various aspects of ion beam inertial confinement fusion are discussed. In particular a very thorough discussion of aspects of energy deposition of ions in hot plasmas and cold materials is given. Using energy deposition profiles given by these calculations, computer simulations of the compression, ignition and burn phases have been carried out for a single shell, pusher-tamper-DT fuel, multi-layered spherical pellet, suitable for use in a fusion reactor. The gain of this pellet was calculated to be 97 for an input energy of 7.38 MJ and an output energy of 715 MJ. This pellet has several other attractive features, including being environmentally attractive because of minimal radioactivity production and being insensitive to pusher-fuel instabilities. (orig.)

  5. Efficient focusing of 8 keV X-rays with multilayer Fresnel zone plates fabricated by atomic layer deposition and focused ion beam milling

    OpenAIRE

    Mayer, Marcel; Keskinbora, Kahraman; Grévent, Corinne; Szeghalmi, Adriana; Knez, Mato; Weigand, Markus; Snigirev, Anatoly; Snigireva, Irina; Schütz, Gisela

    2013-01-01

    Fresnel zone plates (FZPs) recently showed significant improvement by focusing soft X-rays down to ∼10 nm. In contrast to soft X-rays, generally a very high aspect ratio FZP is needed for efficient focusing of hard X-rays. Therefore, FZPs had limited success in the hard X-ray range owing to difficulties of manufacturing high-aspect-ratio zone plates using conventional techniques. Here, employing a method of fabrication based on atomic layer deposition (ALD) and focused ion beam (FIB) milling,...

  6. Properties of TiN coatings deposited by the method of condensation with ion bombardment accompanied by high-energy ion beam

    International Nuclear Information System (INIS)

    Vacuum-sputtering adapted commercial facility based coating of stainless steel with titanium nitride followed two procedures: ion bombardment condensation (IBC) and IBC under simultaneous effect of ion beam (IB). The deposition rate was equal to 0.1 μm min-1; the investigated coatings were characterized by 2.5 μm depth. Comparison analysis of features and characteristics of the specimens, as well as, full-scale tests of a coated cutting tool enabled to make conclusions about advantages of application of IB assisted IBC technology in contrast to the reference IBC technology

  7. Effect of Substrate Temperature on Structural and Optical Properties of Nanocrystalline CdTe Thin Films Deposited by Electron Beam Evaporation

    Directory of Open Access Journals (Sweden)

    M. Rigana Begam

    2013-07-01

    Full Text Available Nanocrystalline Cadmium Telluride (CdTe thin films were deposited onto glass substrates using electron beam evaporation technique. The effect of substrate temperature on the structural, morphological and optical properties of CdTe thin films has been investigated. All the CdTe films exhibited zinc blende structure with (111 preferential orientation. The crystallite size of the films increased from 35 nm to 116 nm with the increase of substrate temperature and the band gap of the films decreased from 2.87 eV to 2.05 eV with the increase of the crystallite size.

  8. Improvement and characterization of high-reflective and anti-reflective nanostructured mirrors by ion beam assisted deposition for 944 nm high power diode laser

    Science.gov (United States)

    Ghadimi-Mahani, A.; Farsad, E.; Goodarzi, A.; Tahamtan, S.; Abbasi, S. P.; Zabihi, M. S.

    2015-11-01

    Single-layer and multi-layer coatings were applied on the surface of diode laser facets as mirrors. This thin film mirrors were designed, deposited, optimized and characterized. The effects of mirrors on facet passivation and optical properties of InGaAs/AlGaAs/GaAs diode lasers were investigated. High-Reflective (HR) and Anti-Reflective (AR) mirrors comprising of four double-layers of Al2O3/Si and a single layer of Al2O3, respectively, were designed and optimized by Macleod software for 944 nm diode lasers. Optimization of Argon flow rate was studied through Alumina thin film deposition by Ion Beam Assisted Deposition (IBAD) for mirror improvement. The nanostructured HR and AR mirrors were deposited on the front and back facet of the laser respectively, by IBAD system under optimum condition. Atomic Force Microscope (AFM), Vis-IR Spectrophotometer, Field Emission Scanning Electron Microscopy (FESEM) and laser characterization Test (P-I) were used to characterize various properties of mirrors and lasers. AFM images show mirror's root mean square roughness is nearly 1 nm. The Spectrophotometer results of the front facet transmission and the back facet reflection are in good agreement with the simulation results. Optical output power (P) versus driving current (I) characteristics, measured before and after coating the facet, revealed a significant output power enhancement due to optimized AR and HR optical coatings on facets.

  9. Ion beam sputter deposited TiAlN films for metal-insulator-metal (Ba,Sr)TiO3 capacitor application

    International Nuclear Information System (INIS)

    The present study evaluated the feasibility of TiAlN films deposited using the ion beam sputter deposition (IBSD) method for metal-insulator-metal (MIM) (Ba,Sr)TiO3 (BST) capacitors. The BST films were crystallized at temperatures above 650 deg. C. TiAlN films deposited using the IBSD method were found having smooth surface and low electrical resistivity at high temperature conditions. TiAlN films showed a good diffusion barrier property against BST components. The J-E (current density-electric field) characteristics of Al/BST/TiAlN capacitors were good, with a high break down electric field of ± 2.5 MV/cm and a leakage current density of about 1 x 10-5 A/cm2 at an applied field of ± 0.5 MV/cm. Thermal stress and lateral oxidation that occurred at the interface damaged the capacitor stacking structure. Macro holes that dispersed on the films resulted in higher leakage current and inconsistent J-E characteristics. Vacuum annealing with lower heating rate and furnace cooling, and a Ti-Al adhesion layer between TiAlN and the SiO2/Si substrate can effectively minimize the stress effect. TiAlN film deposited using IBSD can be considered as a potential electrode and diffusion barrier material for MIM BST capacitors

  10. Electrical performance of phase change memory cells with Ge{sub 3}Sb{sub 2}Te{sub 6} deposited by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Boschker, Jos E.; Riechert, Henning; Calarco, Raffaella [Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany); Boniardi, Mattia; Redaelli, Andrea [Micron Semiconductor Italia S.r.l., Via C. Olivetti, 2, 20864, Agrate Brianza, MB (Italy)

    2015-01-12

    Here, we report on the electrical characterization of phase change memory cells containing a Ge{sub 3}Sb{sub 2}Te{sub 6} (GST) alloy grown in its crystalline form by Molecular Beam Epitaxy (MBE). It is found that the high temperature growth on the amorphous substrate results in a polycrystalline film exhibiting a rough surface with a grain size of approximately 80–150 nm. A detailed electrical characterization has been performed, including I-V characteristic curves, programming curves, set operation performance, crystallization activation at low temperature, and resistance drift, in order to determine the material related parameters. The results indicate very good alignment of the electrical parameters with the current state-of-the-art GST, deposited by physical vapor deposition. Such alignment enables a possible employment of the MBE deposition technique for chalcogenide materials in the phase change memory technology, thus leading to future studies of as-deposited crystalline chalcogenides as integrated in electrical vehicles.

  11. The structural transition from epitaxial Fe/Pt multilayers to an ordered FePt film using low energy ion beam sputtering deposition with no buffer layer

    International Nuclear Information System (INIS)

    An epitaxial L10 FePt thin film grown from an [Fe(10 Å)/Pt(10 Å)]15 multilayer with the orientation of (001) was prepared by an ion beam sputtering deposition method without buffer layer. From the measurement data of X-ray diffraction and X-ray reflectivity, the multilayer structure was totally disappeared and a uniform FePt alloy thin film was formed at temperatures higher than 600 °C. For the as-deposited thin film grown at 100 °C, the multilayer already possesses an epitaxial structure. The epitaxial relation is FePt(001)[100]//MgO(001)[100] and this epitaxial relation persists after sequential high temperature annealing. An epitaxial L10 ordered FePt(001) film with order parameter of 0.95 was obtained when the annealing temperature reached 650 °C. The ordered FePt(001) thin film has a perpendicular magnetic anisotropy with a squareness of 0.95 ± 0.03 on the magnetic hysteresis loop. This experiment demonstrates that the low energy ion beam sputtering deposition will preserve the epitaxial relation with no buffer layer between multilayer and substrate. - Highlights: • The Fe/Pt films using ion sputtering deposition with no buffer layer is epitaxial. • Multilayer structure was totally disappeared at temperatures higher than 600 °C. • Order parameter reach 0.95 after annealing at 650 °C. • Interfacial epitaxial FePt alloy already formed at 100 °C

  12. Influence of ion/atom arrival ratio on structure and optical properties of AlN films by ion beam assisted deposition

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Jian-ping [Department of Energy Material and Technology, General Research Institute for Nonferrous Metals, Beijing 100088 (China); School of Engineering and Technology, China University of Geosciences, Beijing 100083 (China); Fu, Zhi-qiang, E-mail: fuzq@cugb.edu.cn [School of Engineering and Technology, China University of Geosciences, Beijing 100083 (China); Liu, Xiao-peng [Department of Energy Material and Technology, General Research Institute for Nonferrous Metals, Beijing 100088 (China); Yue, Wen; Wang, Cheng-biao [School of Engineering and Technology, China University of Geosciences, Beijing 100083 (China)

    2014-10-30

    Highlights: • AlN films were fabricated by dual ion beam sputtering. • Chemical bond status and phase composition of the films were studied by XPS and XRD. • Optical constants were measured by spectroscopic ellipsometry. • Influence of ion/atom arrival ratio on the films was studied. - Abstract: In order to improve the optical properties of AlN films, the influence of the ion/atom arrival ratio on the structure and optical characteristics of AlN films deposited by dual ion beam sputtering was studied by using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, spectroscopic ellipsometry and UV–vis spectroscopy. The films prepared at the ion/atom arrival ratio of 1.4 are amorphous while the crystalline quality is improved with the increase of the ion/atom arrival ratio. The films deposited at the ion/atom arrival ratio of no less than 1.8 have an approximately stoichiometric ratio and mainly consist of aluminum nitride with little aluminum oxynitride, while metallic aluminum component appears in the films deposited at the ion/atom arrival ratio of 1.4. When the ion/atom arrival ratio is not less than 1.8, films are smooth, high transmitting and dense. The films prepared with high ion/atom arrival ratio (≥1.8) display the characteristic of a dielectric. The films deposited at the ion/atom arrival ratio of 1.4 are coarse, opaque and show characteristic of cermet.

  13. Development of Self Fire Retardant Melamine-Animal Glue Formaldehyde (MGF) Resin for the Manufacture of BWR Ply Board

    Science.gov (United States)

    Khatua, Pijus Kanti; Dubey, Rajib Kumar; Roymahapatra, Gourisankar; Mishra, Anjan; Shahoo, Shadhu Charan; Kalawate, Aparna

    2016-06-01

    Wood is one of the most sustainable, naturally growing materials that consist mainly of combustible organic carbon compounds. Since plywood are widely used nowadays especially in buildings, furniture and cabinets. Too often the fire behavior of ply-board may be viewed as a drawback. Amino-plastic based thermosetting resin adhesives are the important and most widely used in the plywood panel industries. The fire retardant property of wood panel products by adding animal glue as an additive in the form of MGF resin and used as substitute of melamine for manufacture of plywood. Environment concerns and higher cost of petroleum based resins have resulted in the development of technologies to replace melamine partially by biomaterials for the manufacturing of resin adhesive. Natural bio-based materials such as tannin, CNSL (cardanol), lignin, soya etc. are used as partial substitution of melamine. This article presents the development of melamine-animal glue formaldehyde resin as plywood binder. About 30 % melamine was substituted by animal glue and optimized. The different physico-mechanical and fire retardant property properties tested as per IS: 1734-1983 and IS: 5509-2000 respectively are quite satisfactory. The production of adhesive from melamine with compatible natural proteinous material is cost effective, eco-friendly and enhance the fire retardant property.

  14. Double-ceramic-layer thermal barrier coatings based on La2(Zr0.7Ce0.3)2O7/La2Ce2O7 deposited by electron beam-physical vapor deposition

    International Nuclear Information System (INIS)

    Double-ceramic-layer (DCL) thermal barrier coatings (TBCs) of La2(Zr0.7Ce0.3)2O7 (LZ7C3) and La2Ce2O7 (LC) were deposited by electron beam-physical vapor deposition (EB-PVD). The composition, interdiffusion, surface and cross-sectional morphologies, cyclic oxidation behavior of DCL coating were studied. Energy dispersive spectroscopy and X-ray diffraction analyses indicate that both LZ7C3 and LC coatings are effectively fabricated by a single LZ7C3 ingot with properly controlling the deposition energy. The chemical compatibility of LC coating and thermally grown oxide (TGO) layer is unstable. LaAlO3 is formed due to the chemical reaction between LC and Al2O3 which is the main composition of TGO layer. Additionally, the thermal cycling behavior of DCL coating is influenced by the interdiffusion of Zr and Ce between LZ7C3 and LC coatings. The failure of DCL coating is a result of the sintering of LZ7C3 coating surface, the chemical incompatibility of LC coating and TGO layer and the abnormal oxidation of bond coat. Since no single material that has been studied so far satisfies all the requirements for high temperature applications, DCL coating is an important development direction of TBCs.

  15. Hydrogen Charging Effects in Pd/Ti/TiO2/Ti Thin Films Deposited on Si(111 Studied by Ion Beam Analysis Methods

    Directory of Open Access Journals (Sweden)

    K. Drogowska

    2012-01-01

    Full Text Available Titanium and titanium dioxide thin films were deposited onto Si(111 substrates by magnetron sputtering from a metallic Ti target in a reactive Ar+O2 atmosphere, the composition of which was controlled by precision gas controllers. For some samples, 1/3 of the surface was covered with palladium using molecular beam epitaxy. Chemical composition, density, and layer thickness of the layers were determined by Auger electron spectroscopy (AES and Rutherford backscattering spectrometry (RBS. The surface morphology was studied using high-resolution scanning electron microscopy (HRSEM. After deposition, smooth, homogenous sample surfaces were observed. Hydrogen charging for 5 hours under pressure of 1 bar and at temperature of 300°C results in granulation of the surface. Hydrogen depth profile was determined using secondary ion mass spectrometry (SIMS and nuclear Reaction Analysis (N-15 method, using a 15N beam at and above the resonance energy of 6.417 MeV. NRA measurements proved a higher hydrogen concentration in samples with partially covered top layers, than in samples without palladium. The highest value of H concentration after charging was about 50% (in the palladium-covered part and about 40% in titanium that was not covered by Pd. These values are in good agreement with the results of SIMS measurements.

  16. Characterization of silicon dioxide deposited by low-temperature CVD using TEOS and ozone by monoenergetic positron beams

    International Nuclear Information System (INIS)

    Monoenergetic positrons were used as a nondestructive probe for SiO2 films deposited on Si substrates by atmospheric-pressure chemical vapor deposition using tetraethylorthosilicate (TEOS, Si(OC2H5)4) and O3. The formation of positronium (Ps) in the SiO2 films was found from measurements of Doppler broadening profiles of the annihilation radiation and lifetime spectra of positrons. A clear correlation between the formation probability of Ps and the concentration of H2O in the SiO2 films was established. (orig.)

  17. Erosion/re-deposition modeling in an ITER divertor-like high-density, low-temperature plasma beam

    NARCIS (Netherlands)

    van Swaaij, G. A.; Kirschner, A.; Borodin, D.; W. J. Goedheer,; Bystrov, K.; De Temmerman, G.

    2014-01-01

    Transport of hydrocarbon impurities in a high-density (>10 20 m−3), low-temperature (<2 eV) plasma beam was studied with the ERO code. The high ion density and low temperature cause strong Coulomb collisionality between plasma ions and impurity ions. The collisionality is so strong tha

  18. TEM investigations of Ni-Cu thin film coatings, obtained by multilayer technique, coevaporation, and ion beam assisted deposition

    International Nuclear Information System (INIS)

    The microstructural aspects of three different thin film coatings of NiCu at the equiatomic concentration are studied by TEM investigations. Those coatings are: multilayered samples, coevaporated samples, and ion beam assisted codeposited samples. In all cases, under certain experimental conditions of irradiation and annealing, an unexpected L10 ordered phase precipitates in the solid solution matrix of NiCu. (author)

  19. Thermoluminescence of Y{sub 2}O{sub 3}:Tb{sup 3+} thin films deposited by electron beam evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Philip R., E-mail: armst230@umn.edu; Mah, Merlin L.; Kim, Sangho S.; Talghader, Joseph J.

    2014-04-15

    Most thermoluminescent materials are created using crystal growth techniques; however, it would be of great utility to identify those few thermoluminescent materials that can be deposited using simpler methods, for example to be compatible with the early portions of a silicon integrated circuit or microelectromechanical fabrication process. In this work, thin films of yttrium oxide with a terbium impurity (Y{sub 2}O{sub 3}:Tb) were deposited on silicon wafers by electron beam evaporation. The source for the Y{sub 2}O{sub 3}:Tb was made by combining Y{sub 2}O{sub 3} and Tb{sub 4}O{sub 7} powders. The approximate thicknesses of the deposited films were 350 nm. After deposition, the films were annealed at 1100 °C for 30 s to improve crystallinity. There is a strong correlation between the x-ray diffraction (XRD) peak intensity and the thermoluminescent glow curve intensity. The glow curve displays at least two peaks at 140 °C and 230 °C. The emission spectra was measured using successive runs with a monochromator set to a different wavelength for each run. There are two main emission peaks at 490 nm and 540 nm. The terbium impurity concentration of approximately 1 mol% was measured using Rutherford backscattering spectrometry (RBS). The Y{sub 2}O{sub 3}:Tb is sensitive to UV, x-ray, and gamma radiation. The luminescent intensity per unit mass of UV irradiated Y{sub 2}O{sub 3}:Tb was about 2 times that of x-ray irradiated TLD-100. -- Highlights: • Y{sub 2}O{sub 3}:Tb{sup 3+} thin film can be deposited using the common microfabrication technique of electron beam evaporation. • The Y{sub 2}O{sub 3}:Tb{sup 3+} requires an anneal of at least 900 °C to show thermoluminescence and 1100 °C anneal for the strongest thermoluminescent signal. • The Y{sub 2}O{sub 3}:Tb{sup 3+} will show a glow curve after being exposed to ionizing radiation from UV, x-ray, and gamma ray sources. • The luminescent intensity per unit mass of the UV irradiated Y{sub 2}O{sub 3}:Tb{sup 3

  20. Protective Sliding Carbon-Based Nanolayers Prepared by Argon or Nitrogen Ion-Beam Assisted Deposition on Ti6Al4V Alloy

    Directory of Open Access Journals (Sweden)

    Petr Vlcak

    2016-01-01

    Full Text Available The microstructure and the surface properties of samples coated by carbon-based nanolayer were investigated in an effort to increase the surface hardness and reduce the coefficient of friction of the Ti6Al4V alloy. Protective carbon-based nanolayers were fabricated by argon or nitrogen ion-beam assisted deposition at ion energy of 700 eV on Ti6Al4V substrates. The Raman spectra indicated that nanolayers had a diamond-like carbon character with sp2 rich bonds. The TiC and TiN compounds formed in the surface area were detected by X-ray diffraction. Nanoscratch tests showed increased adhesion of a carbon-based nanolayer deposited with ion assistance in comparison with a carbon nanolayer deposited without ion assistance. The results showed that argon ion assistance leads to greater nanohardness than a sample coated by a carbon-based nanolayer with nitrogen ion assistance. A more than twofold increase in nanohardness and a more than fivefold decrease in the coefficient of friction were obtained for samples coated by a carbon-based nanolayer with ion assistance, in comparison with the reference sample.

  1. Effect of titanium incorporation on the structural, mechanical and biocompatible properties of DLC thin films prepared by reactive-biased target ion beam deposition method

    Science.gov (United States)

    Bharathy, P. Vijai; Nataraj, D.; Chu, Paul K.; Wang, Huaiyu; Yang, Q.; Kiran, M. S. R. N.; Silvestre-Albero, J.; Mangalaraj, D.

    2010-10-01

    Amorphous diamond like carbon (DLC) and titanium incorporated diamond like carbon (Ti-DLC) thin films were deposited by using reactive-biased target ion beam deposition method. The effects of Ti incorporation and target bias voltage on the microstructure and mechanical properties of the as-deposited films were investigated by means of X-ray photoelectron spectroscopy, Raman spectroscopy, transmission electron microscopy and nano-indentation. It was found that the Ti content in Ti-DLC films gets increased with increasing target bias voltage. At about 4.2 at.% of Ti, uniform sized well dispersed nanocrystals were seen in the DLC matrix. Using FFT analysis, a facility available in the TEM, it was found that the nanocrystals are in cubic TiC phase. Though at the core, the incorporated Ti atoms react with carbon to form cubic TiC; most of the surface exposed Ti atoms were found to react with the atmospheric oxygen to form weakly bonded Ti-O. The presence of TiC nanocrystals greatly modified the sp 3/sp 2 hybridized bonding ratio and is reflected in mechanical hardness of Ti-DLC films. These films were then tested for their biocompatibility by an invitro cell culturing test. Morphological observation and the cell proliferation test have demonstrated that the human osteoblast cells well attach and proliferate on the surface of Ti incorporated DLC films, suggesting possible applications in bone related implant coatings.

  2. Effect of titanium incorporation on the structural, mechanical and biocompatible properties of DLC thin films prepared by reactive-biased target ion beam deposition method

    International Nuclear Information System (INIS)

    Amorphous diamond like carbon (DLC) and titanium incorporated diamond like carbon (Ti-DLC) thin films were deposited by using reactive-biased target ion beam deposition method. The effects of Ti incorporation and target bias voltage on the microstructure and mechanical properties of the as-deposited films were investigated by means of X-ray photoelectron spectroscopy, Raman spectroscopy, transmission electron microscopy and nano-indentation. It was found that the Ti content in Ti-DLC films gets increased with increasing target bias voltage. At about 4.2 at.% of Ti, uniform sized well dispersed nanocrystals were seen in the DLC matrix. Using FFT analysis, a facility available in the TEM, it was found that the nanocrystals are in cubic TiC phase. Though at the core, the incorporated Ti atoms react with carbon to form cubic TiC; most of the surface exposed Ti atoms were found to react with the atmospheric oxygen to form weakly bonded Ti-O. The presence of TiC nanocrystals greatly modified the sp3/sp2 hybridized bonding ratio and is reflected in mechanical hardness of Ti-DLC films. These films were then tested for their biocompatibility by an invitro cell culturing test. Morphological observation and the cell proliferation test have demonstrated that the human osteoblast cells well attach and proliferate on the surface of Ti incorporated DLC films, suggesting possible applications in bone related implant coatings.

  3. Hopping of electron transport in granular Cu{sub x}(SiO{sub 2}){sub 1–x} nanocomposite films deposited by ion-beam sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Svito, I.; Fedotov, A.K. [Belarusian State University, 220030 Minsk (Belarus); Koltunowicz, T.N., E-mail: t.koltunowicz@pollub.pl [Lublin University of Technology, 20-618 Lublin (Poland); Zukowski, P. [Lublin University of Technology, 20-618 Lublin (Poland); Kalinin, Y.; Sitnikov, A. [Voronezh State Technical University, 250770 Voronezh (Russian Federation); Czarnacka, K. [Lublin University of Technology, 20-618 Lublin (Poland); Saad, A. [Al Balqa Applied University, Physics Department, P.O. Box 4545, Amman 11953 (Jordan)

    2014-12-05

    Highlights: • Nanocomposites deposited in the argon ambient. • Cu{sub x}(SiO{sub 2}){sub 1–x} nanocomposite films (0.36 < x < 0.73, 3–5 μm thickness). • Formation of the “shells” is probably due to the partial oxidation of Cu nanoparticles. - Abstract: The paper presents investigation into the Cu{sub x}(SiO{sub 2}){sub 1–x} nanocomposite films (0.36 < x < 0.73, 3–5 μm thick) deposited by ion-beam sputtering of the compound Cu/SiO{sub 2} target in argon ambient. It has been shown that at x < 0.68 the studied samples displayed a hopping mechanism of electron transport, whereas beyond this concentration a metallic-like character of σ(T) along the percolation net of Cu nanoparticles in the silica matrix was observed. Taking into account that at x = 0.68 associated with a much higher percolation threshold relevant to 3D metal–insulator composites (∼0.50), such a behavior can be attributed to the formation of the CuO{sub 2}-based “shells” around the Cu “cores” observed by Raman spectroscopy. The formation of the “shells” is probably due to partial oxidation of Cu nanoparticles during the deposition procedure, resulting from the residual oxygen in a vacuum chamber after its filling with Ar gas.

  4. Silicon-substituted hydroxyapatite coating with Si content on the nanotube-formed Ti–Nb–Zr alloy using electron beam-physical vapor deposition

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate the electrochemical characteristics of silicon-substituted hydroxyapatite coatings on the nanotube-formed Ti–35Nb–10Zr alloy. The silicon-substituted hydroxyapatite (Si–HA) coatings on the nanotube structure were deposited by electron beam-physical vapor deposition and anodization methods, and biodegradation properties were analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy measurement. The surface characteristics were analyzed by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD). The Si–HA layers were deposited with rough features having highly ordered nanotube structures on the titanium alloy substrate. The thickness of the Si–HA coating was less than that of the HA coating. The XRD results confirmed that the Si–HA coating on the nanotube structure consisted of TiO2 anatase, TiO2 rutile, hydroxyapatite, and calcium phosphate silicate. The Si–HA coating surface exhibited lower Icorr than the HA coating, and the polarization resistance was increased by substitution of silicon in hydroxyapatite. - Highlights: • Silicon substituted hydroxyapatite (Si–HA) was coated on nanotubular titanium alloy. • The Si–HA coating thickness was less than single hydroxyapatite (HA) coating. • Si–HA coatings consisted of TiO2, HA, and Ca5(PO4)2SiO4. • Polarization resistance of the coating was increased by Si substitution in HA

  5. Characterisation of Pristine and Recoated electron beam evaporation plasma-assisted physical vapour deposition Cr-N coatings on AISI M2 steel and WC-Co substrates

    International Nuclear Information System (INIS)

    This paper is focussed on the characterisation of electron beam evaporation plasma-assisted physical vapour deposition Cr-N coatings deposited on AISI M2 steel and hardmetal (K10) substrates in two different conditions: Pristine (i.e., coated) and Recoated (i.e., stripped and recoated). Analytical methods, including X-ray diffraction (XRD), scanning electron microscopy, scratch adhesion and pin-on-disc tests were used to evaluate several coating properties. XRD analyses indicated that both Pristine and Recoated coatings consisted of a mixture of hexagonal Cr2N and cubic CrN, regardless of substrate type. For the M2 steel substrate, only small differences were found in terms of coating phases, microstructure, adhesion, friction and wear coefficients between Pristine and Recoated. Recoated on WC-Co (K10) exhibited a less dense microstructure and significant inferior adhesion compared to Pristine on WC-Co (K10). The wear coefficient of Recoated on WC-Co was 100 times higher than those exhibited by all other specimens. The results obtained confirm that the stripping process did not adversely affect the Cr-N properties when this coating was deposited onto M2 steel substrates, but it is clear from the unsatisfactory tribological performance of Recoated on WC-Co that the stripping process is unsuitable for hardmetal substrates

  6. African swine fever virus Georgia isolate harboring deletions of 9GL and MGF360/505 genes is highly attenuated in swine but does not confer protection against parental virus challenge.

    Science.gov (United States)

    O'Donnell, Vivian; Holinka, Lauren G; Sanford, Brenton; Krug, Peter W; Carlson, Jolene; Pacheco, Juan M; Reese, Bo; Risatti, Guillermo R; Gladue, Douglas P; Borca, Manuel V

    2016-08-01

    African swine fever virus (ASFV) produces a contagious disease of domestic pigs that results in severe economic consequences to the swine industry. Control of the disease has been hampered by the unavailability of vaccines. We recently reported the development of two experimental vaccine strains (ASFV-G-Δ9GL and ASFV-G-ΔMGF) based on the attenuation of the highly virulent and epidemiologically relevant Georgia2007 isolate. Deletion of the 9GL gene or six genes of the MGF360/505 group produced two attenuated ASFV strains which were able to confer protection to animals when challenged with the virulent parental virus. Both viruses, although efficient in inducing protection, present concerns regarding their safety. In an attempt to solve this problem we developed a novel virus strain, ASFV-G-Δ9GL/ΔMGF, based on the deletion of all genes deleted in ASFV-G-Δ9GL and ASFV-G-ΔMGF. ASFV-G-Δ9GL/ΔMGF is the first derivative of a highly virulent ASFV field strain subjected to a double round of recombination events seeking to sequentially delete specific genes. ASFV-G-Δ9GL/ΔMGF showed a decreased ability to replicate in primary swine macrophage cultures relative to that of ASFV-G and ASFV-G-ΔMGF but similar to that of ASFV-G-Δ9GL. ASFV-G-Δ9GL/ΔMGF was attenuated when intramuscularly inoculated into swine, even at doses as high as 10(6) HAD50. Animals infected with doses ranging from 10(2) to 10(6) HAD50 did not present detectable levels of virus in blood at any time post-infection and they did not develop detectable levels of anti-ASFV antibodies. Importantly, ASFV-G-Δ9GL/ΔMGF does not induce protection against challenge with the virulent parental ASFV-G isolate. Results presented here suggest caution towards approaches involving genomic manipulations when developing rationally designed ASFV vaccine strains. PMID:27182007

  7. Interface controlled growth of nanostructures in discontinuous Ag and Au thin films fabricated by ion beam sputter deposition for plasmonic applications

    Indian Academy of Sciences (India)

    R Brahma; M Ghanashyam Krishna

    2012-08-01

    The growth of discontinuous thin films of Ag and Au by low energy ion beam sputter deposition is reported. The study focuses on the role of the film–substrate in determining the shape and size of nanostructures achieved in such films. Ag films were deposited using Ar ion energy of 150 eV while the Au films were deposited with Ar ion energies of 250–450 eV. Three types of interfaces were investigated in this study. The first set of film–substrate interfaces consisted of Ag and Au films grown on borosilicate glass and carbon coated Cu grids used as substrates. The second set of films was metallic bilayers in which one of the metals (Ag or Au) was grown on a continuous film of the other metal (Au or Ag). The third set of interfaces comprised of discontinuous Ag and Au films deposited on different dielectrics such as SiO2, TiO2 and ZrO2. In each case, a rich variety of nanostructures including self organized arrays of nanoparticles, nanoclusters and nanoneedles have been achieved. The role of the film–substrate interface is discussed within the framework of existing theories of thin film nucleation and growth. Interfacial nanostructuring of thin films is demonstrated to be a viable technique to realize a variety of nanostructures. The use of interfacial nanostructuring for plasmonic applications is demonstrated. It is shown that the surface Plasmon resonance of the metal nanostructures can be tuned over a wide range of wavelengths from 400 to 700 nm by controlling the film–substrate interface.

  8. Stoichiometry and characterization of aluminum oxynitride thin films grown by ion-beam-assisted pulsed laser deposition

    International Nuclear Information System (INIS)

    Oxides are inherently stable in air at elevated temperatures and may serve as wear resistant matrices for solid lubricants. Aluminum oxide is a particularly good candidate for a matrix because it has good diffusion barrier properties and modest hardness. Most thin film deposition techniques that are used to grow alumina require high temperatures to impart crystallinity. Crystalline films are about twice as hard as amorphous ones. Unfortunately, the mechanical properties of most engineering steels are degraded at temperatures above 250-350 deg. C. This work is focused on using energetic reactive ion bombardment during simultaneous pulsed laser deposition to enhance film crystallization at low temperatures. Alumina films were grown at several background gas pressures and temperatures, with and without Ar ion bombardment. The films were nearly stoichiometric except for depositions in vacuum. Using nitrogen ion bombardment, nitrogen was incorporated into the films and formed the Al-O-N matrix. Nitrogen concentration could be controlled through selection of gas pressure and ion energy. Crystalline Al-O-N films were grown at 330 deg. C with a negative bias voltage to the substrate, and showed improved hardness in comparison to amorphous films

  9. 力影响下的IGF-1剪切变体——力生长因子(MGF)研究进展%Study on Splice Variant of Insulin-like Growth Factor-1:Mechano Growth Factor(MGF)under Influence of Force

    Institute of Scientific and Technical Information of China (English)

    王峰; 赵建芳; 王宝珍; 王贵平

    2011-01-01

    The mechano growth factor (MGF) as an splice variant of the insulin-like growth factor-1, which can respond to the stimulation of force signal and adjust expression of itself, and then influence local mass and structure changes, for instance muscle hypertrophy, strength skeleton etc.Studies have shown that the MGF can activate satellite cells and enhancement multiplication of stem cells.It plays an important role on cure sarcopenia, prevent myocardial damage and apoptosis, repair of nerve injury and the treatment of bone defects ect.Therefore, making an intensive study of MGF will be widely used in treat disease and repair tissue engineering.%力生长因子(MGF)作为IGF-1的一个剪切变构体,能够响应力信号刺激而调节自身的表达,进而影响局部组织和结构变化,如肌肉肥大、骨骼强壮等.研究表明,MGF能够激活卫星细胞、促进干细胞增殖,在治疗肌肉丢失、预防心肌损伤、防止细胞凋亡和修复神经损伤以及治疗骨缺陷等方面具有重要的作用,因此对MGF深入研究,期望在疾病治疗和组织工程修复领域取得广泛的应用.

  10. Charge recombination reduction in dye-sensitized solar cells by means of an electron beam-deposited TiO2 buffer layer between conductive glass and photoelectrode

    International Nuclear Information System (INIS)

    A thin anatase titanium dioxide compact film was deposited by electron beam evaporation as buffer layer between the conductive transparent electrode and the porous TiO2-based photoelectrode in dye-sensitized solar cells. The effect of such a buffer layer on the back transfer reaction of electrons to tri-iodide ions in liquid electrolyte-based cells has been studied by means of both electrochemical impedance spectroscopy and open circuit photovoltage decay analysis. The influence of the thickness has been also investigated and an increment in overall quantum conversion efficiency η as high as + 31% with respect to the standard cell - fabricated onto an uncoated conductive glass - has been revealed in the case of a 120 nm thick buffer layer.

  11. Effects of calcium phosphate coating to SLA surface implants by the ion-beam-assisted deposition method on self-contained coronal defect healing in dogs

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate the healing of self-contained coronal defects on a sand-blasted, large-grit, acid-etched (SLA) surface implant, which had a calcium phosphate (CaP) coating applied by ion-beam-assisted deposition (IBAD). We also evaluated the effect of heating the coating to different temperatures. The CaP-coated SLA implants exhibited a slightly larger bone healing capacity in the self-contained coronal defect than SLA implants, indicating that combining SLA surface implants and a CaP coating by the IBAD method had synergistic effects on bone healing. There was no difference in the healing capacity between 350 deg. C and 450 deg. C heat treatment of the coating layer.

  12. Effects of calcium phosphate coating to SLA surface implants by the ion-beam-assisted deposition method on self-contained coronal defect healing in dogs

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Heun-Joo; Song, Ji-Eun; Um, Yoo-Jung; Chae, Gyung Joon; Jung, Ui-Won; Kim, Chang-Sung; Choi, Seong-Ho [Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, 134 Shinchon-Dong, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Chung, Sung-Min [Dentium Co., Seoul (Korea, Republic of); Lee, In-Seop, E-mail: shchoi726@yuhs.a [Institute of Physics and Applied Physics, Atomic-scale Surface Science Research Center, Yonsei University, Seoul (Korea, Republic of)

    2009-08-15

    The aim of this study was to evaluate the healing of self-contained coronal defects on a sand-blasted, large-grit, acid-etched (SLA) surface implant, which had a calcium phosphate (CaP) coating applied by ion-beam-assisted deposition (IBAD). We also evaluated the effect of heating the coating to different temperatures. The CaP-coated SLA implants exhibited a slightly larger bone healing capacity in the self-contained coronal defect than SLA implants, indicating that combining SLA surface implants and a CaP coating by the IBAD method had synergistic effects on bone healing. There was no difference in the healing capacity between 350 deg. C and 450 deg. C heat treatment of the coating layer.

  13. Superconducting YBa sub 2 Cu sub 3 O sub 7 thin films grown in-situ by ion beam CO-deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kellett, B.K.; James, J.H.; Gauzzi, A.; Dwir, B.; Pavuna, D. (Inst. of Micro and Optoelectronics, Dept. of Physics, Federal Inst. of Tech., Lausanne (Switzerland))

    1989-12-01

    Superconducting YBCO thin films have been grown in-situ by three ion beam co-deposition sputtering. Both metal and oxide targets of Cu and Y and BaF{sub 2} and BaCO{sub 3} targets have been investigated. Film composition was determined by RBS and AES analysis. Films grown using BaF{sub 2} show fluorine contamination, whereas the carbon concentration in films grown using BaCO{sub 3} is beneath the Auger detection limit. Superconducting films have been grown on SrTiO{sub 3} (T{sub co}=78K) and on Si with SiO{sub 2} or Y{sub 2}O{sub 3} buffer layers (T{sub co}=35K). (orig.).

  14. 200 MeV Ag15+ ion beam irradiation effects on spray deposited 5 wt% `Li' doped V2O5 thin film

    Science.gov (United States)

    Kovendhan, M.; Joseph, D. Paul; Manimuthu, P.; Sendilkumar, A.; Asokan, K.; Venkateswaran, C.; Mohan, R.

    2016-05-01

    Lithium 5 wt% doped V2O5 thin film was deposited onto ITO substrate by spray pyrolysis technique. The substrate temperature was kept at 450 °C. 200 MeV Ag15+ ion beams at a fluence of 5×1012 ions/cm2 was irradiated on 5 wt% `Li' doped V2O5 film of thickness 1367 nm. The XRD pattern confirms that the pristine film is non stoichiometry with orthorhombic structure and upon irradiation the crystallinity decreased and an obvious textured growth along (020) plane is induced. Raman peak observed at 917 cm-1 is due to oxygen deficiency. Upon irradiation, the optical transparency and band gap of the film decreased. Electrical transport property study shows that the resistivity increased by one order for the irradiated film.

  15. Effect of MgF_2-H_3BO_3 flux on the properties of(Ce,Tb)MgAl_(11)O_(19) phosphor

    Institute of Scientific and Technical Information of China (English)

    冯宗玉; 庄卫东; 黄小卫; 温晓帆; 胡运生

    2010-01-01

    The green-emitting(Ce,Tb)MgAl11O19(CTMA) phosphor was prepared by the conventional high temperature solid-state reaction method.The effect of fluxes on the crystal structure,particle morphology,size distribution and photoluminescence properties of CTMA phosphor was investigated by means of the X-ray powder diffraction,scanning electron microscopy and photoluminescence spectrum.The results showed that the addition of appropriate amount of MgF2-H3BO3 flux improved the phase purity of CTMA phosphor,and influen...

  16. The development of laser chemical vapor deposition and focused ion beam methods for prototype integrated circuit modification

    OpenAIRE

    Remes, J. (Jukka)

    2006-01-01

    Abstract In this work the LCVD of copper and nickel from the precursor gases Cu(hfac)tmvs and Ni(CO)4 has been investigated. The in-house constructed LCVD system and processes and the practical utilisation of these in prototype integrated circuit edit work are described. The investigated process parameters include laser power, laser scan speed, precursor partial pressure and the effect of H2 and He carrier gases. The deposited metal conductor lines have been examined by LIMA, AFM, FIB seco...

  17. Estimation of the dose deposited by electron beams in radiotherapy in voxelised phantoms using the Monte Carlo simulation platform GATE based on GEANT4 in a grid environment

    International Nuclear Information System (INIS)

    Radiation therapy treatment planning requires accurate determination of absorbed dose in the patient. Monte Carlo simulation is the most accurate method for solving the transport problem of particles in matter. This thesis is the first study dealing with the validation of the Monte Carlo simulation platform GATE (GEANT4 Application for Tomographic Emission), based on GEANT4 (Geometry And Tracking) libraries, for the computation of absorbed dose deposited by electron beams. This thesis aims at demonstrating that GATE/GEANT4 calculations are able to reach treatment planning requirements in situations where analytical algorithms are not satisfactory. The goal is to prove that GATE/GEANT4 is useful for treatment planning using electrons and competes with well validated Monte Carlo codes. This is demonstrated by the simulations with GATE/GEANT4 of realistic electron beams and electron sources used for external radiation therapy or targeted radiation therapy. The computed absorbed dose distributions are in agreement with experimental measurements and/or calculations from other Monte Carlo codes. Furthermore, guidelines are proposed to fix the physics parameters of the GATE/GEANT4 simulations in order to ensure the accuracy of absorbed dose calculations according to radiation therapy requirements. (author)

  18. Amorphous silicon carbonitride diaphragm for environmental-cell transmission electron microscope fabricated by low-energy ion beam induced chemical vapor deposition

    Science.gov (United States)

    Matsutani, Takaomi; Yamasaki, Kayo; Imaeda, Norihiro; Kawasaki, Tadahiro

    2015-12-01

    An amorphous silicon carbonitride (a-SiCN) diaphragm for an environmental-cell transmission electron microscope (E-TEM) was fabricated by low-energy ion beam induced chemical vapor deposition (LEIBICVD) with hexamethyldisilazane (HMDSN). The films were prepared by using gaseous HMDSN and N2+ ions with energies ranging from 300 to 600 eV. The diaphragms were applied to Si (1 0 0) and a Cu grid with 100-μm-diameter holes. With increasing ion energy, these diaphragms became perfectly smooth surfaces (RMS = 0.43 nm at 600 eV), as confirmed by atomic force microscopy and TEM. The diaphragms were amorphous and transparent to 200 kV electrons, and no charge-up was observed. Fourier transform infrared spectra and X-ray photoelectron spectra revealed that the elimination of organic compounds and formation of Si-N and C-N bonds can be promoted in diaphragms by increasing the ion impact energy. The resistance to electron beams and reaction gases in the E-cell was improved when the diaphragm was formed with high ion energy.

  19. Effects of N{sup +}{sub 2} ion irradiation during AlN film growth by dual ion-beam deposition

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Sang Hun; Kim, Jae Keun; Lee, Byung Teak [Chonnam National Univ., Kwangju (Korea, Republic of)

    2003-02-01

    We report on the composition, chemical state, and structure of the AlN films grown with concurrent N{sub 2}{sup +} ion bombardment during film growth using a dual ion-beam deposition system. The AlN films prepared at various bombarding ion-beam conditions were characterized by RBS, XPS, and TEM. The analytical results of RBS spectra performed using rump code represented that the composition ratio (N/Al) of the AlN films grown with concurrent N{sub 2}{sup +} ion bombardment could be controlled from N/Al < 1 to N/Al >1, depending on both the energy and the flux of N{sup +}{sub 2} ions incident on the growing film, and the value of N/Al ratio reached to 1.6 at higher energy and flux. XPS analysis also showed a good agreement with these RBS results. TEM diffraction patterns indicated that film orientation varied from a c-axis normal to the film surface to a c-axis parallel to the film surface as the energy of the irradiated N{sup +}{sub 2} ion increased from 200 eV to 500 eV. This preferential growth was explained in terms of ion channeling.

  20. Effects of Defects in SiO2 Thin Films Prepared on Polyethylene Terephthalate by High-Temperature E-beam Deposition

    Science.gov (United States)

    Han, Jin‑Woo; Kang, Hee‑Jin; Kim, Jong‑Hwan; Seo, Dae‑Shik

    2006-08-01

    In this study, we characterized silicon oxide (SiO2) thin film prepared on polyethylene terephthalate (PET) substrates by electron-beam (e-beam) deposition for transparent barrier application. As the chamber temperature is increased from 30 to 110 °C, the roughness increases while water vapor transmission rate (WVTR) decreases. Under these conditions, WVTR of PET can be reduced from a level of 0.57 g/m2/day (bare subtrate) to 0.05 g/m2/day after application of a 200-nm-thick SiO2 coating at 110 °C. A more efficient way to improve permeation of PET was carried out by using a double sided coating of a 5-μm-thick parylene film. It was found that WVTR for PET substrates can be reduced to a level of -0.2 g/m2/day. The double-sided parylene coating on PET could contribute in lowering the stress of oxide film, which greatly improves the WVTR data. These results indicate that the SiO2/parylene/PET barrier coatings have a high potential for flexible organic light-emitting diode (OLED) applications.

  1. On the mechanisms of the formation of nanocrystalline Cr-N and V-N coatings upon ion-beam-assisted deposition

    Science.gov (United States)

    Guglya, A. G.

    2010-01-01

    The paper generalizes the results of investigations performed at the Kharkov Institute of Physics and Technology, National Scientific Center, aimed at the development and analysis of nanocrystalline Cr-N and V-N coatings produced by the method of ion-beam-assisted deposition (IBAD method). The effect of temperature of the process and the ratio between its ionic and atomic components (N+/Cr, V) on the resistivity of the coatings has been studied. It has been found that the ion-assisted irradiation leads to the formation of nanocrystalline nitride structures, whose phase composition depends not only on the concentration of nitrogen implanted by the ion beam, but also on the amount of the physical adsorption of nitrogen, including its adsorption from the residual atmosphere. It has been shown that the IBAD method can be used for both production of dense nanocrystalline composites and creation of nanoporous structures. It has been found that the grain size, the internal porosity, and the electrophysical characteristics of the coatings are intimately connected with the Gibbs energy of the nitride phases. The mechanisms responsible for the formation of such coatings have been discussed in terms of the thermodynamics of the nitride-formation process.

  2. Smooth e-beam-deposited tin-doped indium oxide for III-nitride vertical-cavity surface-emitting laser intracavity contacts

    Science.gov (United States)

    Leonard, J. T.; Cohen, D. A.; Yonkee, B. P.; Farrell, R. M.; DenBaars, S. P.; Speck, J. S.; Nakamura, S.

    2015-10-01

    We carried out a series of simulations analyzing the dependence of mirror reflectance, threshold current density, and differential efficiency on the scattering loss caused by the roughness of tin-doped indium oxide (ITO) intracavity contacts for 405 nm flip-chip III-nitride vertical-cavity surface-emitting lasers (VCSELs). From these results, we determined that the ITO root-mean-square (RMS) roughness should be Motivated by this requirement, we investigated the surface morphology and optoelectronic properties of electron-beam (e-beam) evaporated ITO films, as a function of substrate temperature and oxygen flow and pressure. The transparency and conductivity were seen to increase with increasing temperature. Decreasing the oxygen flow and pressure resulted in an increase in the transparency and resistivity. Neither the temperature, nor oxygen flow and pressure series on single-layer ITO films resulted in highly transparent and conductive films with <1 nm RMS roughness. To achieve <1 nm RMS roughness with good optoelectronic properties, a multi-layer ITO film was developed, utilizing a two-step temperature scheme. The optimized multi-layer ITO films had an RMS roughness of <1 nm, along with a high transparency (˜90% at 405 nm) and low resistivity (˜2 × 10-4 Ω-cm). This multi-layer ITO e-beam deposition technique is expected to prevent p-GaN plasma damage, typically observed in sputtered ITO films on p-GaN, while simultaneously reducing the threshold current density and increasing the differential efficiency of III-nitride VCSELs.

  3. Greatly improved interfacial passivation of in-situ high κ dielectric deposition on freshly grown molecule beam epitaxy Ge epitaxial layer on Ge(100)

    Energy Technology Data Exchange (ETDEWEB)

    Chu, R. L. [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Liu, Y. C.; Lee, W. C.; Huang, M. L.; Kwo, J., E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Lin, T. D.; Hong, M., E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw [Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Pi, T. W. [National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan (China)

    2014-05-19

    A high-quality high-κ/Ge interface has been achieved by combining molecule beam epitaxy grown Ge epitaxial layer and in-situ deposited high κ dielectric. The employment of Ge epitaxial layer has sucessfully buried and/or removed the residue of unfavorable carbon and native oxides on the chemically cleaned and ultra-high vacuum annealed Ge(100) wafer surface, as studied using angle-resolved x-ray photoelectron spectroscopy. Moreover, the scanning tunneling microscopy analyses showed the significant improvements in Ge surface roughness from 3.5 Å to 1 Å with the epi-layer growth. Thus, chemically cleaner, atomically more ordered, and morphologically smoother Ge surfaces were obtained for the subsquent deposition of high κ dielectrics, comparing with those substrates without Ge epi-layer. The capacitance-voltage (C-V) characteristics and low extracted interfacial trap density (D{sub it}) reveal the improved high-κ/Ge interface using the Ge epi-layer approach.

  4. Study on copper phthalocyanine and perylene-based ambipolar organic light-emitting field-effect transistors produced using neutral beam deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae-Kyu; Oh, Jeong-Do; Shin, Eun-Sol; Seo, Hoon-Seok; Choi, Jong-Ho, E-mail: jhc@korea.ac.kr [Department of Chemistry, Research Institute for Natural Sciences, Korea University, Anam-Dong, Seoul 136-701 (Korea, Republic of)

    2014-04-28

    The neutral cluster beam deposition (NCBD) method has been applied to the production and characterization of ambipolar, heterojunction-based organic light-emitting field-effect transistors (OLEFETs) with a top-contact, multi-digitated, long-channel geometry. Organic thin films of n-type N,N′-ditridecylperylene-3,4,9,10-tetracarboxylic diimide and p-type copper phthalocyanine were successively deposited on the hydroxyl-free polymethyl-methacrylate (PMMA)-coated SiO{sub 2} dielectrics using the NCBD method. Characterization of the morphological and structural properties of the organic active layers was performed using atomic force microscopy and X-ray diffraction. Various device parameters such as hole- and electron-carrier mobilities, threshold voltages, and electroluminescence (EL) were derived from the fits of the observed current-voltage and current-voltage-light emission characteristics of OLEFETs. The OLEFETs demonstrated good field-effect characteristics, well-balanced ambipolarity, and substantial EL under ambient conditions. The device performance, which is strongly correlated with the surface morphology and the structural properties of the organic active layers, is discussed along with the operating conduction mechanism.

  5. Study on copper phthalocyanine and perylene-based ambipolar organic light-emitting field-effect transistors produced using neutral beam deposition method

    International Nuclear Information System (INIS)

    The neutral cluster beam deposition (NCBD) method has been applied to the production and characterization of ambipolar, heterojunction-based organic light-emitting field-effect transistors (OLEFETs) with a top-contact, multi-digitated, long-channel geometry. Organic thin films of n-type N,N′-ditridecylperylene-3,4,9,10-tetracarboxylic diimide and p-type copper phthalocyanine were successively deposited on the hydroxyl-free polymethyl-methacrylate (PMMA)-coated SiO2 dielectrics using the NCBD method. Characterization of the morphological and structural properties of the organic active layers was performed using atomic force microscopy and X-ray diffraction. Various device parameters such as hole- and electron-carrier mobilities, threshold voltages, and electroluminescence (EL) were derived from the fits of the observed current-voltage and current-voltage-light emission characteristics of OLEFETs. The OLEFETs demonstrated good field-effect characteristics, well-balanced ambipolarity, and substantial EL under ambient conditions. The device performance, which is strongly correlated with the surface morphology and the structural properties of the organic active layers, is discussed along with the operating conduction mechanism

  6. Simulation of dose deposition in heterogeneities in the human body, using the Penelope code for photons beams of energies of a linear accelerator

    International Nuclear Information System (INIS)

    The progress in cancer treatment systems in heterogeneities of human body has had obstacles by the lack of a suitable experimental model test. The only option is to develop simulated theoretical models that have the same properties in interfaces similar to human tissues, to know the radiation behavior in the interaction with these materials. In this paper we used the Monte Carlo method by Penelope code based solely on studies for the cancer treatment as well as for the calibration of beams and their various interactions in mannequins. This paper also aims the construction, simulation and characterization of an equivalent object to the tissues of the human body with various heterogeneities, we will later use to control and plan experientially doses supplied in treating tumors in radiotherapy. To fulfill the objective we study the ionizing radiation and the various processes occurring in the interaction with matter; understanding that to calculate the dose deposited in tissues interfaces (percentage depth dose) must be taken into consideration aspects such as the deposited energy, irradiation fields, density, thickness, tissue sensitivity and other items. (Author)

  7. Quantitative plasma-fuel and impurity profiling in thick plasma-deposited layers by means of micro ion beam analysis and SIMS

    International Nuclear Information System (INIS)

    The operation of the Joint European Torus (JET) with full-carbon wall during the last decades has proven the importance of material re-deposition processes in remote areas of the tokamak. The thickness of the deposits in shadowed areas can reach 1 mm. The main constituent is carbon, with little inclusion of Inconel components. Atomic fractions Be/C and D/C can locally reach 1. Three methods were used to study thick deposits on JET divertor surfaces: (i) NRA analysis with a 15 μm wide, 3 MeV 3He ion microbeam on a polished cross section of the layer to determine the concentration distribution of D, Be and C and the distribution of Ni by particle induced X-ray emission; (ii) elastic proton scattering (EPS) from the top of the layers with a broad proton beam at 3.5 and 4.6 MeV. These methods were absolutely calibrated using thick elemental targets. (iii) Depth profiling of D, Be and Ni was done with secondary ion mass spectrometry (SIMS), sputtering the layers from the surface. The three methods are complementary. The thickest layers are accessible only by microbeam mapping of the cross sections, albeit with limited spatial resolution. The SIMS has the best depth resolution, but is difficult for absolute quantification and is limited in accessible depth. The probed depth with proton backscattering is limited to about 30 μm. The combination of all three methods provided a coherent picture of the layer composition. It was possible to correlate the SIMS profiling results to quantitative data obtained by the microbeam method

  8. Silicon-substituted hydroxyapatite coating with Si content on the nanotube-formed Ti–Nb–Zr alloy using electron beam-physical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Yong-Hoon [Division of Restorative, Prosthetic and Primary Care Dentistry, College of Dentistry, The Ohio State University, 305 W. 12th Ave., Columbus, OH (United States); Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, and Research Center for Oral Disease Regulation of the Aged, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, and Research Center for Oral Disease Regulation of the Aged, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Brantley, William A. [Division of Restorative, Prosthetic and Primary Care Dentistry, College of Dentistry, The Ohio State University, 305 W. 12th Ave., Columbus, OH (United States)

    2013-11-01

    The purpose of this study was to investigate the electrochemical characteristics of silicon-substituted hydroxyapatite coatings on the nanotube-formed Ti–35Nb–10Zr alloy. The silicon-substituted hydroxyapatite (Si–HA) coatings on the nanotube structure were deposited by electron beam-physical vapor deposition and anodization methods, and biodegradation properties were analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy measurement. The surface characteristics were analyzed by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD). The Si–HA layers were deposited with rough features having highly ordered nanotube structures on the titanium alloy substrate. The thickness of the Si–HA coating was less than that of the HA coating. The XRD results confirmed that the Si–HA coating on the nanotube structure consisted of TiO{sub 2} anatase, TiO{sub 2} rutile, hydroxyapatite, and calcium phosphate silicate. The Si–HA coating surface exhibited lower I{sub corr} than the HA coating, and the polarization resistance was increased by substitution of silicon in hydroxyapatite. - Highlights: • Silicon substituted hydroxyapatite (Si–HA) was coated on nanotubular titanium alloy. • The Si–HA coating thickness was less than single hydroxyapatite (HA) coating. • Si–HA coatings consisted of TiO{sub 2}, HA, and Ca{sub 5}(PO{sub 4}){sub 2}SiO{sub 4}. • Polarization resistance of the coating was increased by Si substitution in HA.

  9. Quantitative plasma-fuel and impurity profiling in thick plasma-deposited layers by means of micro ion beam analysis and SIMS

    Energy Technology Data Exchange (ETDEWEB)

    Bykov, Igor, E-mail: igor.bykov@ee.kth.se [Fusion Pasma Physics, Royal Institute of Technology (KTH), Teknikringen 31, Stockholm 10044 (Sweden); Bergsåker, Henric; Petersson, Per [Fusion Pasma Physics, Royal Institute of Technology (KTH), Teknikringen 31, Stockholm 10044 (Sweden); Likonen, Jari [VTT, Association EURATOM-TEKES, P.O. Box 1000, Otaniemi 02044 (Finland); Possnert, Göran [Tandem Laboratory (Association EURATOM-VR), Uppsala Universitet, Box 256, Uppsala 75105 (Sweden)

    2014-08-01

    The operation of the Joint European Torus (JET) with full-carbon wall during the last decades has proven the importance of material re-deposition processes in remote areas of the tokamak. The thickness of the deposits in shadowed areas can reach 1 mm. The main constituent is carbon, with little inclusion of Inconel components. Atomic fractions Be/C and D/C can locally reach 1. Three methods were used to study thick deposits on JET divertor surfaces: (i) NRA analysis with a 15 μm wide, 3 MeV {sup 3}He ion microbeam on a polished cross section of the layer to determine the concentration distribution of D, Be and C and the distribution of Ni by particle induced X-ray emission; (ii) elastic proton scattering (EPS) from the top of the layers with a broad proton beam at 3.5 and 4.6 MeV. These methods were absolutely calibrated using thick elemental targets. (iii) Depth profiling of D, Be and Ni was done with secondary ion mass spectrometry (SIMS), sputtering the layers from the surface. The three methods are complementary. The thickest layers are accessible only by microbeam mapping of the cross sections, albeit with limited spatial resolution. The SIMS has the best depth resolution, but is difficult for absolute quantification and is limited in accessible depth. The probed depth with proton backscattering is limited to about 30 μm. The combination of all three methods provided a coherent picture of the layer composition. It was possible to correlate the SIMS profiling results to quantitative data obtained by the microbeam method.

  10. Characteristics of ZnS and PbF2 thin films deposited by ionized cluster beam

    International Nuclear Information System (INIS)

    By using the Ion Cluster Beam method high transmission property films with high adhesive strength have been developed for use as anti-reflection coatings for optical transmission windows. It has been demonstrated that the acceleration voltage plays a very important role in producing high quality optical films. The transmission windows details are as follows; (1) the Ge coated with ZnS film obtained at 3 kV acceleration voltage had a transmittance of 96% and the adhesive strength of the film obtained was over 430 kg/cm2. (2) the ZnS coated with PbF2 film obtained by the control of acceleration voltages above 0.5 kV had transmittance of 95% and the adhesive strength of the film was 240 kg/cm2. (author)

  11. On Generation and Propagation of the Plasma Ion Beam for Plasma Ion Assisted Deposition (PIAD) of Optical Coatings

    Science.gov (United States)

    Harhausen, J.; Brinkmann, R. P.; Foest, R.; Ohl, A.; Schröder, B.

    2011-10-01

    PIAD is a technique employed for the production of high performance optical coatings. Here, the plasma source is a hot cathode direct current discharge with an auxiliary magnetic field (APS). Its specific design together with a low chamber pressure of p ~ 2 .10-4mbar results in the generation of energetic ions (typ. Ei = 50 . . 150eV) impinging onto the substrates. Until today, data on the plasma parameters in the coating chamber is sparse. This contribution presents details on the energy distribution functions (EDF) of electrons and ions in the strongly inhomogeneous APS plume using Langmuir probe and retarding field energy analyzer diagnostics. The IEDF is characterized by two separate populations of low and high energy. An analytical model for the evolution of the ion beam reveals that the slow ion component is due to charge exchange of fast ions with the background neutral gas. This model is indispensable for the estimation of the NEDF. Funded by the German Ministry for Education and Research (BMBF, Fkz. 13N10462).

  12. Thermal stability studies of ion beam sputter deposited C/B4C X-ray multilayer mirror

    International Nuclear Information System (INIS)

    We report the results of thermal stability study carried out on C/B4C multilayer structure. We have analyzed the structure of as-deposited and vacuum annealed C/B4C multilayer film by soft X-ray reflectivity measurements. We observed that multilayer period expansion continues till 600 °C and slight contraction at higher annealing temperature. The results show that the multilayer structure is stable even after 700 °C annealing. Raman spectroscopy indicates graphitization of carbon layer with increasing annealing temperature. Graphitization of carbon results in increases of layer thickness and decreases in density as also observed by soft X-ray reflectivity. We observed reduction in measured soft X-ray reflectivity at 6.56 and 4.39 nm wavelengths after 800 °C annealing. C/B4C multilayer structure has been tested over a period of one year to investigate its temporal stability. - Highlights: ► We reported the experimental results on thermal stability of C/B4C combination. ► Multilayer structure is stable even after 700 °C annealing. ► C/B4C can be used as a stable multilayer mirror both in soft and hard X-ray regions. ► C/B4C multilayer structure has shown good temporal stability

  13. Transparent conductive indium oxide film deposited on low temperature substrates by activated reactive evaporation.

    Science.gov (United States)

    Marcovitch, O; Klein, Z; Lubezky, I

    1989-07-15

    High quality conductive coatings for the visible region were prepared on low temperature glass substrates. The conductive layer was an indium oxide film deposited by the activated reactive evaporation technique using a glow discharge hollow cathode ion gun. An antireflective layer of MgF(2) was deposited over the conductive layer. The average transmission in the visible region of the coated glass with sheet resistance of coating was durable and passed a series of environmental tests according to MIL-C-675C. PMID:20555600

  14. Composite films prepared by plasma ion-assisted deposition (IAD) for design and fabrication of antireflection coatings in visible and near-infrared spectral regions

    Science.gov (United States)

    Tsai, Rung-Ywan; Ho, Fang C.

    1994-11-01

    Ion-assisted deposition (IAD) processes configured with a well-controlled plasma source at the center base of a vacuum chamber, which accommodates two independent e-gun sources, is used to deposition TiO2MgF2 and TiO2-SiO2 composite films of selected component ratios. Films prepared by this technology are found durable, uniform, and nonabsorbing in visible and near-IR regions. Single- and multilayer antireflection coatings with refractive index from 1.38 to 2.36 at (lambda) equals 550 nm are presented. Methods of enhancement in optical performance of these coatings are studied. The advantages of AR coatings formed by TiO2-MgF2 composite films over those similar systems consisting of TiO2-SiO2 composite films in both visible and near-IR regions are also presented.

  15. Core and grain boundary sensitivity of tungsten-oxide sensor devices by molecular beam assisted particle deposition

    Science.gov (United States)

    Huelser, T. P.; Lorke, A.; Ifeacho, P.; Wiggers, H.; Schulz, C.

    2007-12-01

    In this study, we investigate the synthesis of WO3 and WOx (2.6≥x≤2.8) by adding different concentrations of tungsten hexafluoride (WF6) into a H2/O2/Ar premixed flame within a low-pressure reactor equipped with a particle-mass spectrometer (PMS). The PMS results show that mean particle diameters dp between 5 and 9 nm of the as-synthesized metal-oxides can be obtained by varying the residence time and precursor concentration in the reactor. This result is further validated by N2 adsorption measurements on the particle surface, which yielded a 91 m2/g surface area, corresponding to a spherical particle diameter of 9 nm (Brunauer-Emmett-Teller technique). H2/O2 ratios of 1.6 and 0.63 are selected to influence the stoichiometry of the powders, resulting in blue-colored WOx and white WO3 respectively. X-ray diffraction (XRD) analysis of the as-synthesized materials indicates that the powders are mostly amorphous, and the observed broad reflexes can be attributed to the orthorhombic structure of β-WO3. Thermal annealing at 973 K for 3 h in air resulted in crystalline WO3 comprised of both monoclinic and orthorhombic phases. The transmission electron microscope micrograph analysis shows that the particles exhibit spherical morphology with some degree of agglomeration. Impedance spectroscopy is used for the electrical characterization of tungsten-oxide thin films with a thickness of 50 nm. Furthermore, the temperature-dependent gas-sensing properties of the material deposited on interdigital capacitors are investigated. Sensitivity experiments reveal two contributions to the overall sensitivity, which result from the surface and the core of each particle.

  16. Epitaxial Bi3Fe5O12(001) films grown by pulsed laser deposition and reactive ion beam sputtering techniques

    Science.gov (United States)

    Adachi, N.; Denysenkov, V. P.; Khartsev, S. I.; Grishin, A. M.; Okuda, T.

    2000-09-01

    We report on processing and comparative characterization of epitaxial Bi3Fe5O12 (BIG) films grown onto Gd3(ScGa)5O12[GSGG,(001)] single crystal using pulsed laser deposition (PLD) and reactive ion beam sputtering (RIBS) techniques. A very high deposition rate of about 0.8 μm/h has been achieved in the PLD process. Comprehensive x-ray diffraction analyses reveal epitaxial quality both of the films: they are single phase, exclusively (001) oriented, the full width at half maximum of the rocking curve of (004) Bragg reflection is 0.06 deg for PLD and 0.05 deg for RIBS film, strongly in-plane textured with cube-on-cube film-to-substrate epitaxial relationship. Saturation magnetization 4πMs and Faraday rotation at 635 nm were found to be 1400 Gs and -7.8 deg/μm in PLD-BIG, and 1200 Gs and -6.9 deg/μm in RIBS-BIG. Ferromagnetic resonance (FMR) measurements performed at 9.25 GHz yielded the gyromagnetic ratio γ=1.797×107l/s Oe, 1.826×107 l/s Oe; the constants of uniaxial magnetic anisotropy were Ku*=-8.66×104erg/cm3, -8.60×104 erg/cm3; the cubic magnetic anisotropy K1=-2.7×103 erg/cm3,-3.8×103 erg/cm3; and the FMR linewidth ΔH=25 and 34 Oe for PLD and RIBS films correspondingly. High Faraday rotation, low microwave loss, and low coercive field ⩽40 Oe of BIG/GSGG(001) films promise their use in integrated magneto-optic applications.

  17. Morphological evolution of self-assembled SiGe islands based on a mixed-phase pre-SiGe island layer grown by ion beam sputtering deposition

    International Nuclear Information System (INIS)

    Highlights: • The economical ion beam sputtering deposition technique was employed in this work. • A mixed-phase pre-SiGe island sub-layer was inserted and its effects were identified. • An evolution model of regeneration and secondary growth of islands was proposed. • A new mechanism called “lateral atomic migration” in mixed-phase layer was proposed. • An overlap behavior which was different from the coarsening mechanism was observed. - Abstract: We present a study of the evolution of self-assembled SiGe islands grown on a microcrystalline Si (μc-Si)-based mixed-phase pre-SiGe island layer. Using atomic force microscopy, lots of new short islands with smaller diameters, high islands with transition dome (TD) shape, and super islands with ∼20 nm in height are observed after the Ge layer deposition. This anomalous experimental finding is well clarified by a model of regeneration and secondary growth. It is found that the density of the super islands increases rapidly at the initial stage when the Ge coverage exceeds ∼1.2 nm. This is essentially the result of the selective aggregation of Ge adatoms on the pre-SiGe island layer. The Ge content and stored strain in SiGe islands calculated based on Raman spectra decrease with the increase of the Ge coverage. It is demonstrated that the chemical potential difference-induced lateral atomic migration (LAM) from amorphous SiGe alloy into SiGe islands can be responsible for this phenomenon. The LAM also leads to the formation of very large dome islands. Finally, the overlap behavior of neighbor islands in the sample with 2.2 nm-thick Ge layer is explained by the combined action of denser nucleation centers, faster growth rates of super islands in lateral direction, and coarsening of neighbor small islands

  18. Optical and structural properties of microcrystalline GaN on an amorphous substrate prepared by a combination of molecular beam epitaxy and metal–organic chemical vapor deposition

    Science.gov (United States)

    Min, Jung-Wook; Hwang, Hyeong-Yong; Kang, Eun-Kyu; Park, Kwangwook; Kim, Ci-Hyun; Lee, Dong-Seon; Jho, Young-Dahl; Bae, Si-Young; Lee, Yong-Tak

    2016-05-01

    Microscale platelet-shaped GaN grains were grown on amorphous substrates by a combined epitaxial growth method of molecular beam epitaxy (MBE) and metal–organic chemical vapor deposition (MOCVD). First, MBE GaN was grown on an amorphous substrate as a pre-orienting layer and its structural properties were investigated. Second, MOCVD grown GaN samples using the different growth techniques of planar and selective area growth (SAG) were comparatively investigated by transmission electron microscopy (TEM), cathodoluminescence (CL), and photoluminescence (PL). In MOCVD planar GaN, strong bound exciton peaks dominated despite the high density of the threading dislocations (TDs). In MOCVD SAG GaN, on the other hand, TDs were clearly reduced with bending, but basal stacking fault (BSF) PL peaks were observed at 3.42 eV. The combined epitaxial method not only provides a deep understanding of the growth behavior but also suggests an alternative approach for the growth of GaN on amorphous substances.

  19. Enhanced threshold voltage of Zn-doped Ge2Sb2Te5 phase-change memory deposited by electron-beam evaporation

    International Nuclear Information System (INIS)

    Zn-doped Ge2Sb2Te5 (GST) thin films are deposited on glass substrates by an electron-beam evaporation technique in an ultra-high vacuum. GST mixed with 5%, 10%, 20% Zn is used. Through in situ resistance measurements, an increase of crystalline temperature in Zn-doped GST was observed. From absorption spectra, the optical bandgap values of 10% Zn-doped GST in different structures are estimated to be 1.1, 0.9, and 0.7 eV, respectively, which are slightly wider than that of pure GST. A prototype phase-change memory (PCM) device using GST thin film doped with Zn was fabricated. The current-voltage test results of the devices show better switching performances in both SET and RESET processes than that of the device using pure GST film. The threshold voltage is greatly increased with the adding of Zn atom with fixed proportion, which can weaken the interaction during the read and write operation of PCM. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Optical constants of e-beam-deposited zirconium dioxide measured in the 55-150 Å wavelength region using the reflectivity technique.

    Science.gov (United States)

    Singh, Amol; Sinha, Mangalika; Gupta, R K; Modi, Mohammed H

    2016-04-20

    In the present study, optical constants of e-beam-deposited zirconium dioxide (ZrO2) thin film are determined in the 55-150 Å soft x-ray wavelength region using the angle-dependent reflectivity technique. Soft x-ray reflectivity measurements are carried out using the reflectivity beamline at the Indus-1 synchrotron radiation source. Derived optical constants (δ and β) are compared with the tabulated values of Henke et al. [http://henke.lbl.gov/optical_constants/asf.html]. It is found that the measured δ values are consistently lower than the tabulated bulk values in the 70-150 Å wavelength region. In this region, the delta values are lower by 19%-24% from the tabulated data. Below the Zr M4 edge (66.3 Å), a deviation in delta values is found as ∼2%-21%. These changes are attributed to growth-related defects (oxygen and voids) and variation in film stoichiometry. To the best of our knowledge, the present study gives the first reported experimental values of optical constants for ZrO2 in the 55-150 Å wavelength region. PMID:27140084

  1. The effect of substrate bias voltages on impact resistance of CrAlN coatings deposited by modified ion beam enhanced magnetron sputtering

    International Nuclear Information System (INIS)

    CrAlN coatings were deposited on silicon and AISI H13 steel substrates using a modified ion beam enhanced magnetron sputtering system. The effect of substrate negative bias voltages on the impact property of the CrAlN coatings was studied. The X-ray diffraction (XRD) data show that all CrAlN coatings were crystallized in the cubic NaCl B1 structure, with the (1 1 1), (2 0 0) (2 2 0) and (2 2 2) diffraction peaks observed. Two-dimensional surface morphologies of CrAlN coatings were investigated by atomic force microscope (AFM). The results show that with increasing substrate bias voltage the coatings became more compact and denser, and the microhardness and fracture toughness of the coatings increased correspondingly. In the dynamic impact resistance tests, the CrAlN coatings displayed better impact resistance with the increase of bias voltage, due to the reduced emergence and propagation of the cracks in coatings with a very dense structure and the increase of hardness and fracture toughness in coatings.

  2. Networks of ultra-fine Ag nanocrystals in a Teflon AF (registered) matrix by vapour phase e-beam-assisted deposition

    International Nuclear Information System (INIS)

    We have fabricated nanocomposite thin films comprising silver (Ag) nanoparticles dispersed in a Teflon AF (registered) polymer matrix using electron-beam-assisted physical vapour deposition. Four different Ag nanoparticle volume fillings (20%, 35%, 70% and 75%) were achieved by varying the relative metal-polymer evaporation rates with the formation of highly crystalline Ag nanoparticles regardless of the filling ratio. The present fabrication technique allowed full control over dispersion uniformity of nanoparticles in the polymer network. At 20% and 35% metal volume fillings, the nanocomposite film morphology consists of a uniformly dispersed assembly of equiaxed isolated Ag nanoparticles. At higher metal volume fractions the nanocomposite structures displayed two different and unique Ag nanoparticle arrangements within the polymer matrix. In particular, at 70% metal filling, the formation of irregularly shaped clusters of individually assembled nanocrystals was observed. At a slightly higher volume filling (75%), larger irregularly shaped Ag nanocrystals that appeared to be the result of coalescence and grain growth were observed. Finally, a composite theory developed by Tandon and Weng was used to estimate various elastic properties of the nanocomposite films. At high metal filling, the reinforcing effect of the Ag nanoparticles was reflected as approximately a sixfold increase in the elastic modulus compared to the virgin polymer film. Possible applications of such ultra-fine metal nanoparticles networks are discussed

  3. Characterization of high-κ LaLuO3 thin film grown on AlGaN/GaN heterostructure by molecular beam deposition

    International Nuclear Information System (INIS)

    We report the study of high-dielectric-constant (high-κ) dielectric LaLuO3 (LLO) thin film that is grown on AlGaN/GaN heterostructure by molecular beam deposition (MBD). The physical properties of LLO on AlGaN/GaN heterostrucure have been investigated with atomic force microscopy, x-ray photoelectron spectroscopy, and TEM. It is revealed that the MBD-grown 16 nm-thick LLO film is polycrystalline with a thin (∼2 nm) amorphous transition layer at the LLO/GaN interface. The bandgap of LLO is derived as 5.3 ± 0.04 eV from O1s energy loss spectrum. Capacitance-voltage (C-V) characteristics of a Ni-Au/LLO/III-nitride metal-insulator-semiconductor diode exhibit small frequency dispersion (<2%) and reveal a high effective dielectric constant of ∼28 for the LLO film. The LLO layer is shown to be effective in suppressing the reverse and forward leakage current in the MIS diode. In particular, the MIS diode forward current is reduced by 7 orders of magnitude at a forward bias of 1 V compared to a conventional Ni-Au/III-nitride Schottky diode.

  4. 1.5-nm-thick silicon oxide gate films grown at 150 deg. C using modified reactive ion beam deposition with pyrolytic-gas passivation

    International Nuclear Information System (INIS)

    Low-temperature ultrathin silicon oxide gate film growth using modified reactive ion beam deposition (RIBD) with an in situ pyrolytic-gas passivation (PGP) method is described. RIBD uses low-energy-controlled reactive and ionized species and potentializes low-temperature film growth. By combining RIBD with PGP using N2O and NF3, 1.5-nm-thick silicon oxide gate films with high-potential barrier height energy, 3.51 eV, and low-leakage current, less than about 10-5 A/cm2 at 2 MV/cm, can be obtained at a growth temperature of 150 deg. C. From an evaluation of number densities of N, F, and O atoms near the 1.5-5.0-nm-thick RIBD-with-PGP silicon oxide films/Si(100) interfaces, it is believed that interfacial N and F atoms contribute to improve the electrical characteristics and F effectively compensates the residual inconsistent-state bonding sites after the N passivation

  5. A photoluminescence comparison of CdTe thin films grown by molecular-beam epitaxy, metalorganic chemical vapor deposition, and sputtering in ultrahigh vacuum

    Science.gov (United States)

    Feng, Z. C.; Bevan, M. J.; Krishnaswamy, S. V.; Choyke, W. J.

    1988-09-01

    High perfection CdTe thin films have been grown on (001) InSb and CdTe substrates by molecular-beam epitaxy, metalorganic chemical vapor deposition (MOCVD), and sputtering in ultrahigh vacuum techniques. The quality of the as-grown CdTe films are characterized by 2-K photoluminescence. The spectra show strong and sharp exciton transitions and weak 1.40-1.50-eV defect-related bands. Radiative defect densities of lower than 0.002 are realized. High-resolution spectroscopy shows that the full width at half maximum of the principal bound exciton lines is about 0.1 meV. Such small ρ values and narrow photoluminescence lines have not been previously reported. The largest luminescence efficiency is observed for MOCVD-CdTe films grown on CdTe substrates. A variety of impurities appear to be responsible for the observed radiative transitions in these three kinds of CdTe films. We attempt to assign the observed impurity related lines by a comparison with ``known'' impurities in bulk CdTe spectra given in the literature.

  6. Effects of a high magnetic field on structure evolution and properties of the molecular beam vapor deposited Fe60Ni40 nanoparticles thin films

    International Nuclear Information System (INIS)

    The Fe60Ni40 (in atomic %) nanoparticles (NPs) thin films with 90 nm thickness were prepared on 25 and 400 °C quartz substrates by using the molecular beam vapor deposition (MBVD) method under a 6 T high magnetic field (HMF). The effects of a HMF on the structure evolution and properties of Fe–Ni thin films were studied by using X-ray diffraction, atomic force microscopy, transmission electron microscopy, vibrating sample magnetometer and four-point probe method. The results show that the crystallinity of thin films is enhanced by a 6 T HMF, and a 6 T HMF changes phase composition of thin films on 25 °C substrate. It is found that the nanoparticle size decreases; the nanoparticle size distribution becomes narrow, and the root mean square (rms) roughness of thin films decreases under a 6 T HMF relative to that without HMF. These lead to the decrease of coercive force, and the increase of in-plane remanence ratio under a 6 T HMF

  7. Influence of the shape and surface oxidation in the magnetization reversal of thin iron nanowires grown by focused electron beam induced deposition

    Directory of Open Access Journals (Sweden)

    Luis A. Rodríguez

    2015-06-01

    Full Text Available Iron nanostructures grown by focused electron beam induced deposition (FEBID are promising for applications in magnetic sensing, storage and logic. Such applications require a precise design and determination of the coercive field (HC, which depends on the shape of the nanostructure. In the present work, we have used the Fe2(CO9 precursor to grow iron nanowires by FEBID in the thickness range from 10 to 45 nm and width range from 50 to 500 nm. These nanowires exhibit an Fe content between 80 and 85%, thus giving a high ferromagnetic signal. Magneto-optical Kerr characterization indicates that HC decreases for increasing thickness and width, providing a route to control the magnetization reversal field through the modification of the nanowire dimensions. Transmission electron microscopy experiments indicate that these wires have a bell-type shape with a surface oxide layer of about 5 nm. Such features are decisive in the actual value of HC as micromagnetic simulations demonstrate. These results will help to make appropriate designs of magnetic nanowires grown by FEBID.

  8. Influences of oxygen partial pressure on structure and related properties of ZrO2 thin films prepared by electron beam evaporation deposition

    International Nuclear Information System (INIS)

    ZrO2 thin films were prepared by electron beam evaporation at different oxygen partial pressures. The influences of oxygen partial pressure on structure and related properties of ZrO2 thin films were studied. Transmittance, thermal absorption, structure and residual stress of ZrO2 thin films were measured by spectrophotometer, surface thermal lensing technique (STL), X-ray diffraction and optical interferometer, respectively. The results showed that the structure and related properties varied progressively with the increase of oxygen partial pressure. The refractive indices and the packing densities of the thin films decreased when the oxygen partial pressure increased. The tetragonal phase fraction in the thin films decreased gradually as oxygen partial pressure increased. The residual stress of film deposited at base pressure was high compressive stress, the value decreased with the increase of oxygen partial pressure, and the residual stress became tensile with the further increase of oxygen pressure, which was corresponding to the evolution of packing densities and variation of interplanar distances

  9. Effect of discharge current and deposition temperature on roughness and density of NbC films fabricated by ion beam sputtering technique

    Energy Technology Data Exchange (ETDEWEB)

    Dhawan, Rajnish, E-mail: rajnish@rrcat.gov.in; Rai, Sanjay, E-mail: rajnish@rrcat.gov.in; Lodha, G. S., E-mail: rajnish@rrcat.gov.in [X-ray optics Section, Indus Synchrotron Utilization Division, Raja Ramanna Center for Advanced Technology, Indore-452013 (India)

    2014-04-24

    NbC films were prepared using Ion beam sputtering system at various discharges current from 0.4 amps to 1.2 amps at room temperature. Effect of temperature on NbC films were also studied by depositing NbC films at various temperatures from room temperature to 200,300,400 and 600°C. X-ray reflectivity (XRR) study shows that surface roughness of the film decreases with decrease in discharge current. The optimum lowest roughness 3.2Å having density 92% of bulk was achieved at discharge current 0.6 amps at 3.0 cm{sup 3}/min Ar gas flow. X-ray study also shows that film roughness decreases with increase in temperature of the film and after a certain temperature it increases with increase in temperature. The lowest surface roughness 2.1Å was achieved at 300°C with density 83% of bulk NbC at constant discharge current 0.6 amps.

  10. Effect of temperature on residual stress and mechanical properties of Ti films prepared by both ion implantation and ion beam assisted deposition

    International Nuclear Information System (INIS)

    Ti films with a thickness of 1.6 μm (group A) and 4.6 μm (group B) were prepared on surface of silicon crystal by metal vapor vacuum arc (MEVVA) ion implantation combined with ion beam assisted deposition (IBAD). Different anneal temperatures ranging from 100 to 500 deg. C were used to investigate effect of temperature on residual stress and mechanical properties of the Ti films. X-ray diffraction (XRD) was used to measure residual stress of the Ti films. The morphology, depth profile, roughness, nanohardness, and modulus of the Ti films were measured by scanning electron microscopy (SEM), scanning Auger nanoprobe (SAN), atomic force microscopy (AFM), and nanoindentation, respectively. The experimental results suggest that residual stress was sensitive to film thickness and anneal temperature. The critical temperatures of the sample groups A and B that residual stress changed from compressive to tensile were 404 and 428 deg. C, respectively. The mean surface roughness and grain size of the annealed Ti films increased with increasing anneal temperature. The values of nanohardness and modulus of the Ti films reached their maximum values near the surface, then, reached corresponding values with increasing depth of the indentation. The mechanism of stress relaxation of the Ti films is discussed in terms of re-crystallization and difference of coefficient of thermal expansion between Ti film and Si substrate.

  11. Optical and Structural Properties of Microcrystalline GaN on an Amorphous Substrate Prepared by a Combination of Molecular Beam Epitaxy and Metal-Organic Chemical Vapor Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Min, Jung-Wook; Hwang, Hyeong-Yong; Kang, Eun-Kyu; Park, Kwangwook; Kim, Ci-Hyun; Lee, Dong-Seon; Jho, Young-Dahl; Bae, Si-Young; Lee, Yong-Tak

    2016-05-01

    Microscale platelet-shaped GaN grains were grown on amorphous substrates by a combined epitaxial growth method of molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD). First, MBE GaN was grown on an amorphous substrate as a pre-orienting layer and its structural properties were investigated. Second, MOCVD grown GaN samples using the different growth techniques of planar and selective area growth (SAG) were comparatively investigated by transmission electron microscopy (TEM), cathodoluminescence (CL), and photoluminescence (PL). In MOCVD planar GaN, strong bound exciton peaks dominated despite the high density of the threading dislocations (TDs). In MOCVD SAG GaN, on the other hand, TDs were clearly reduced with bending, but basal stacking fault (BSF) PL peaks were observed at 3.42 eV. The combined epitaxial method not only provides a deep understanding of the growth behavior but also suggests an alternative approach for the growth of GaN on amorphous substances.

  12. Electrical characteristics of mixed Zr-Si oxide thin films prepared by ion beam induced chemical vapor deposition at room temperature

    International Nuclear Information System (INIS)

    Mixed Zr-Si oxide thin films have been prepared at room temperature by ion beam decomposition of organometallic volatile precursors. The films were flat and amorphous. They did not present phase segregation of the pure single oxides. A significant amount of impurities (-C-, -CHx, -OH, and other radicals coming from partially decomposed precursors) remained incorporated in the films after the deposition process. This effect is minimized if the Ar content in the O2/Ar bombarding gas is maximized. Static permittivity and breakdown electrical field of the films were determined by capacitance-voltage and current-voltage electrical measurements. It is found that the static permittivity increases non-linearly from ∼ 4 for pure SiO2 to ∼ 15 for pure ZrO2. Most of the dielectric failures in the films were due to extrinsic breakdown failures. The maximum breakdown electrical field decreases from ∼ 10.5 MV/cm for pure SiO2 to ∼ 45 MV/cm for pure ZrO2. These characteristics are justified by high impurity content of the thin films. In addition, the analysis of the conduction mechanisms in the formed dielectrics is consistent to Schottky and Poole-Frenkel emission for low and high electric fields applied, respectively.

  13. Optimization of TiO2/Cu/TiO2 multilayers as a transparent composite electrode deposited by electron-beam evaporation at room temperature

    Institute of Scientific and Technical Information of China (English)

    孙洪涛; 王小平; 寇志起; 王丽军; 王金烨; 孙义清

    2015-01-01

    Highly transparent indium-free composite electrodes of TiO2/Cu/TiO2 are deposited by electron-beam evaporation at room temperature. The effects of Cu thickness and annealing temperature on the electrical and optical properties of the multilayer film are investigated. The critical thickness of Cu mid-layer to form a continuous conducting layer is found to be 11 nm. The multilayer with a mid-Cu thickness of 11 nm is optimized to obtain a resistivity of 7.4×10−5 Ω·cm and an average optical transmittance of 86%in the visible spectral range. The figure of merit of the TiO2/Cu(11 nm)/TiO2 multilayer annealed at 150 ◦C reaches a minimum resistivity of 5.9×10−5 Ω·cm and an average optical transmittance of 88%in the visible spectral range. The experimental results indicate that TiO2/Cu/TiO2 multilayers can be used as a transparent electrode for solar cell and other display applications.

  14. Atomic Diffusion in Cu/Si (111) and Cu/SiO2/Si (111) Systems by Neutral Cluster Beam Deposition

    Institute of Scientific and Technical Information of China (English)

    CAO Bo; LI Gong-Ping; CHEN Xi-Meng; CHO Seong-Jin; KIM Hee

    2008-01-01

    @@ The Cu films are deposited on two kinds of p-type Si (111) substrates by ionized cluster beam (ICB) technique.The interface reaction and atomic diffusion of Cu/Si (111) and Cu/SiO2/Si (111) systems are studied at different annealing temperatures by x-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS). Some significant results are obtained: For the Cu/Si (111) samples prepared by neutral clusters, the interdiffusion of Cu and Si atoms occurs when annealed at 230℃. The diffusion coefficients of the samples annealed at 230℃and 500℃ are 8.5 × 10-15 cm2.s-1 and 3.0 × 10-14 cm2.s-1, respectively. The formation of the copper-silicide phase is observed by XRD, and its intensity becomes stronger with the increase of annealing temperature. For the Cu/SiO2/Si (111) samples prepared by neutral clusters, the interdiffusion of Cu and Si atoms occurs and copper silicides are formed when annealed at 450℃. The diffusion coefficients of Cu in Si are calculated to be 6.0 × 10-16 cm2.s-1 at 450℃, due to the fact that the existence of the SiO2 layer suppresses the interdiffusion of Cu and Si.

  15. 镁合金化学镀镍层的生长过程%Deposition process of electroless nickel plating on magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    邵忠财; 李建中; 康凤娣; 田彦文

    2005-01-01

    The initial nickel deposition for the direct electroless nickel plating on non-catalytically active magnesium alloy is critical. The surface morphology and composition of the initial nickel plating coating are obtained by means of the scanning electron microscopy (SEM) and the energy dispersive X-ray (EDS). In addition, the mass gain/loss in the initial nickel deposition process was measured by using the electrobalance. The results showed that the MgO coating was gradually corroded by the plating solution, at the same time, MgF2 produced by F , H+ and MgO was deposited on the substrate during the initial electroless plating process. The nickel of the initial electroless plating was mostly growing on the boundary between the MgF2 coating and the MgO coating of the activation substrate, and then came to two sides. After that, the Ni-P coating growth rate to cover with the MgF2 coating was prior to the MgO coating. The electroless plating was in company with the substrate corrosion, but the electroless plating rate catalyzed by the exchanged nickel was more than the substrate corrosion rate.

  16. Correlations between deposition parameters and structural and electrical properties of YBa2Cu3O7–delta thin films grown in situ by sequential ion beam sputtering

    OpenAIRE

    Kittl, J. A.; Nieh, C. W.; Lee, D.S.; Johnson, W. L.

    1990-01-01

    We have studied the correlations between deposition parameters and structural and electrical properties of YBa2Cu3O7–delta thin films grown in situ by sequential ion beam sputtering. Epitaxial, c-axis oriented YBa2Cu3O7–delta films were grown both on (100) SrTiO3 and on (100) MgO substrates following the stacking sequence of the ``123'' compound, with deposited layer thicknesses nominally equal to 1 monolayer. The c-axis lattice parameters obtained were larger than the corresponding lattice p...

  17. Beam-Beam Effects

    OpenAIRE

    Herr, W; Pieloni, T.

    2016-01-01

    One of the most severe limitations in high-intensity particle colliders is the beam-beam interaction, i.e. the perturbation of the beams as they cross the opposing beams. This introduction to beam-beam effects concentrates on a description of the phenomena that are present in modern colliding beam facilities.

  18. Beam-Beam Effects

    CERN Document Server

    Herr, W

    2014-01-01

    One of the most severe limitations in high-intensity particle colliders is the beam-beam interaction, i.e. the perturbation of the beams as they cross the opposing beams. This introduction to beam-beam effects concentrates on a description of the phenomena that are present in modern colliding beam facilities.

  19. Effect of deposition distance on thickness and microstructure of silicon thin film produced by electron beam evaporation; Efeito da distancia de deposicao na espessura e microestrutura de filme fino obtido por evaporacao por feixe de eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Toledo, T.F.; Ramanery, F.P.; Branco, J.R.T. [Fundacao Centro Tecnologico de Minas Gerais, Belo Horizonte, MG (Brazil)], e-mail: thalitaqui@yahoo.com.br; Cunha, M.A. [Acos Especiais Itabira S.A. (Acesita), Belo Horizonte, MG (Brazil)

    2006-07-01

    The interest for materials with new characteristics and properties made thin films an area of highest research interest. Silicon thin films have been widely used in solar cells, being the main active layer. In this work, the effect of deposition distance on thickness and microstructure of silicon films was investigated. The electron beam evaporation technique with argon plasma assistance was used to obtain films on stainless steel 304, Fe-Si alloy and soda lime glass. The experiments were made varying electron beam current and deposition pressure. The results are discussed based on Hertz-Knudsen's law and thin films microstructure evolution models. The samples were characterized by scanning electron microscopy, atomic force microscopy, X-ray diffraction and profilometer. (author)

  20. Ion-beam technologies

    Energy Technology Data Exchange (ETDEWEB)

    Fenske, G.R. [Argonne National Lab., IL (United States)

    1993-01-01

    This compilation of figures and diagrams reviews processes for depositing diamond/diamond-like carbon films. Processes addressed are chemical vapor deposition (HFCVD, PACVD, etc.), plasma vapor deposition (plasma sputtering, ion beam sputtering, evaporation, etc.), low-energy ion implantation, and hybrid processes (biased sputtering, IBAD, biased HFCVD, etc.). The tribological performance of coatings produced by different means is discussed.

  1. The Research of UV-Responsive Sensitivity Enhancement of Fluorescent Coating Films by MgF2 Layer%MgF2薄膜对荧光薄膜紫外响应灵敏度的增强特性研究

    Institute of Scientific and Technical Information of China (English)

    卢忠荣; 倪争技; 陶春先; 洪瑞金; 张大伟; 黄元申

    2014-01-01

    在光敏面上镀制荧光薄膜将紫外光转变为可见光,是提高CCD和CMOS图像传感器紫外响应灵敏度的一种有效方法。针对荧光薄膜入射界面的散射和反射损耗降低荧光发光强度的分析,研究在荧光薄膜上镀制增透膜和阻隔膜的灵敏度增强特性。采用真空热阻蒸发的镀膜方法分别制备了单层Lumogen荧光薄膜和MgF2/Lumogen复合膜。利用原子力显微镜,紫外可见近红外分光光度计,荧光光谱仪对两种样品的表面粗糙度,漫反射和透射光谱以及荧光发光光谱分别进行对比测试分析。结果表明:M g F2保护层降低了表面粗糙度,减小了入射界面的漫反射损耗,对500~700 nm的可见波段具有明显增透作用,也增强了Lumogen薄膜对紫外波段受激发射的荧光强度;同时,MgF2薄膜的抗损伤及水汽隔离性能对荧光薄膜紫外响应能力具有保护作用,为延长紫外CCD薄膜及器件的工作寿命提供了有效手段。%A low cost and less complicated expansion approach of wavelength responses with a Lumogen phosphor coating was adopted ,as they increased the quantum efficiency of CCD and CMOS detectors in ultra-violet by absorbing UV light and then re-emitting visible light .In this paper ,the sensitivity enhancement of fluorescence coatings was studied by adding an anti-reflection film or barrier film to reduce the loss of the scattering and reflection on the incident interface .The Lumogen and MgF2/Lumogen film were deposited on quartz glasses by physical vacuum deposition .The surface morphology ,transmittance spectrum ,reflec-tance spectrum and fluorescence emission spectrum were obtained by atomic force microscope (AFM ) ,spectrophotometer and fluorescence spectrometer ,respectively .The results indicated that MgF2 film had obvious positive effect on reducing scattering and reflection loss in 500~700 nm ,and enhancing the absorption of Lumogen coating in ultraviolet

  2. Efficient focusing of 8 keV X-rays with multilayer Fresnel zone plates fabricated by atomic layer deposition and focused ion beam milling

    International Nuclear Information System (INIS)

    The fabrication and performance of multilayer Al2O3/Ta2O5 Fresnel zone plates in the hard X-ray range and a discussion of possible future developments considering available materials are reported. Fresnel zone plates (FZPs) recently showed significant improvement by focusing soft X-rays down to ∼10 nm. In contrast to soft X-rays, generally a very high aspect ratio FZP is needed for efficient focusing of hard X-rays. Therefore, FZPs had limited success in the hard X-ray range owing to difficulties of manufacturing high-aspect-ratio zone plates using conventional techniques. Here, employing a method of fabrication based on atomic layer deposition (ALD) and focused ion beam (FIB) milling, FZPs with very high aspect ratios were prepared. Such multilayer FZPs with outermost zone widths of 10 and 35 nm and aspect ratios of up to 243 were tested for their focusing properties at 8 keV and shown to focus hard X-rays efficiently. This success was enabled by the outstanding layer quality thanks to ALD. Via the use of FIB for slicing the multilayer structures, desired aspect ratios could be obtained by precisely controlling the thickness. Experimental diffraction efficiencies of multilayer FZPs fabricated via this combination reached up to 15.58% at 8 keV. In addition, scanning transmission X-ray microscopy experiments at 1.5 keV were carried out using one of the multilayer FZPs and resolved a 60 nm feature size. Finally, the prospective of different material combinations with various outermost zone widths at 8 and 17 keV is discussed in the light of the coupled wave theory and the thin-grating approximation. Al2O3/Ir is outlined as a promising future material candidate for extremely high resolution with a theoretical efficiency of more than 20% for as small an outermost zone width as 10 nm at 17 keV

  3. Optical and structural properties of SiO{sub x} films grown by molecular beam deposition: Effect of the Si concentration and annealing temperature

    Energy Technology Data Exchange (ETDEWEB)

    Nikitin, Timur; Raesaenen, Markku; Khriachtchev, Leonid [Department of Chemistry, University of Helsinki, P. O. Box 55, Helsinki FI-00014 (Finland); Velagapudi, Rama; Sainio, Jani; Lahtinen, Jouko [Department of Applied Physics, Aalto University, P.O. Box 11100, FI-00076 Aalto (Finland); Novikov, Sergei [Department of Micro and Nanosciences, Aalto University, P.O. Box 13500, FI-02150, Aalto (Finland)

    2012-11-01

    We study the properties of Si-rich silicon oxide SiO{sub x} (x < 2) films grown on silica substrates by molecular beam deposition, in a wide range of Si content and annealing temperatures. The measured refractive index and absorption coefficient are successfully described using the effective medium approximation and the chemical compositions measured by x-ray photoelectron spectroscopy (XPS). The Si-SiO{sub 2} phase separation and the degree of Si crystallization increase with the annealing temperature; however, even after annealing at 1200 Degree-Sign C, the samples contain a large proportion of suboxides and partially disordered Si. The Si Raman signal and the absorption coefficient are nearly proportional to the amount of elemental Si provided by XPS. On the other hand, the Si Raman signal is much weaker than it is expected from the amount of elemental Si, which can be explained by the presence of ultra-small Si nanocrystals (diameters < 2 nm) and/or by the difference in the properties of bulk and nanoscale Si. The 1.5-eV photoluminescence (PL) intensity is the highest for annealing at 1100-1150 Degree-Sign C and x = 1.8-1.9. In contrast, the PL quantum yield steadily increases when the intensity of the Si Raman signal decreases. This observation suggests that the Si nanocrystals observed in the Raman spectra are not direct light-emitting centers. The temperatures induced by laser light in these films are surprisingly high, especially at the highest Si content (x {approx} 1.3). The laser-induced temperature (up to {approx}350 Degree-Sign C) substantially down-shifts the Raman band of Si nanocrystals (in our experiments from {approx}518 to {approx}512 cm{sup -1}) and increases the absorption coefficient (by a factor of {approx}1.4).

  4. Efficient focusing of 8 keV X-rays with multilayer Fresnel zone plates fabricated by atomic layer deposition and focused ion beam milling.

    Science.gov (United States)

    Mayer, Marcel; Keskinbora, Kahraman; Grévent, Corinne; Szeghalmi, Adriana; Knez, Mato; Weigand, Markus; Snigirev, Anatoly; Snigireva, Irina; Schütz, Gisela

    2013-05-01

    Fresnel zone plates (FZPs) recently showed significant improvement by focusing soft X-rays down to ~10 nm. In contrast to soft X-rays, generally a very high aspect ratio FZP is needed for efficient focusing of hard X-rays. Therefore, FZPs had limited success in the hard X-ray range owing to difficulties of manufacturing high-aspect-ratio zone plates using conventional techniques. Here, employing a method of fabrication based on atomic layer deposition (ALD) and focused ion beam (FIB) milling, FZPs with very high aspect ratios were prepared. Such multilayer FZPs with outermost zone widths of 10 and 35 nm and aspect ratios of up to 243 were tested for their focusing properties at 8 keV and shown to focus hard X-rays efficiently. This success was enabled by the outstanding layer quality thanks to ALD. Via the use of FIB for slicing the multilayer structures, desired aspect ratios could be obtained by precisely controlling the thickness. Experimental diffraction efficiencies of multilayer FZPs fabricated via this combination reached up to 15.58% at 8 keV. In addition, scanning transmission X-ray microscopy experiments at 1.5 keV were carried out using one of the multilayer FZPs and resolved a 60 nm feature size. Finally, the prospective of different material combinations with various outermost zone widths at 8 and 17 keV is discussed in the light of the coupled wave theory and the thin-grating approximation. Al2O3/Ir is outlined as a promising future material candidate for extremely high resolution with a theoretical efficiency of more than 20% for as small an outermost zone width as 10 nm at 17 keV. PMID:23592622

  5. LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Anisotropic laser mirrors based on obliquely deposited metal films

    Science.gov (United States)

    Troitskii, Yu V.; Troshin, B. I.

    1998-01-01

    A method is proposed for producing dielectric — metal polarising mirrors for normal light incidence. The anisotropic properties of the mirrors are imposed by an obliquely deposited metal film. The subsequent deposition of isotropic dielectric coatings ensures a high reflectance of visible light. Experiments were carried out on nickel and aluminium in combination with MgF2 and ZnS. At the 0.63 μm wavelength the reflectance was 98% and 95.5% for two linear polarisations of light incident on a mirror with a six-layer dielectric coating on an aluminium film.

  6. Deposition of diamondlike carbon films

    Science.gov (United States)

    Mirtich, M. J.; Sovey, J. S.; Banks, B. A. (Inventor)

    1984-01-01

    A diamondlike carbon film is deposited in the surface of a substrate by exposing the surface to an argon ion beam containing a hydrocarbon. The current density in the ion beam is low during initial deposition of the film. Subsequent to this initial low current condition, the ion beam is increased to full power. At the same time, a second argon ion beam is directed toward the surface of the substrate. The second ion beam has an energy level much greater than that of the ion beam containing the hydrocarbon. This addition of energy to the system increases mobility of the condensing atoms and serves to remove lesser bound atoms.

  7. Efficient focusing of 8 keV X-rays with multilayer Fresnel zone plates fabricated by atomic layer deposition and focused ion beam milling

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Marcel; Keskinbora, Kahraman; Grévent, Corinne, E-mail: grevent@is.mpg.de [Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, D-70569 Stuttgart (Germany); Szeghalmi, Adriana [Friedrich-Schiller-Universität Jena, Albert-Einstein-Strasse 15, D-07745 Jena (Germany); Knez, Mato [CIC nanoGUNE Consolider, Tolosa Hiribidea 76, E-20018 Donostia-San Sebastian (Spain); Basque Foundation for Science, Alameda Urquijo 36-5, E-48011 Bilbao (Spain); Weigand, Markus [Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, D-70569 Stuttgart (Germany); Snigirev, Anatoly; Snigireva, Irina [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, BP 220, F-38043 Grenoble (France); Schütz, Gisela [Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, D-70569 Stuttgart (Germany)

    2013-05-01

    The fabrication and performance of multilayer Al{sub 2}O{sub 3}/Ta{sub 2}O{sub 5} Fresnel zone plates in the hard X-ray range and a discussion of possible future developments considering available materials are reported. Fresnel zone plates (FZPs) recently showed significant improvement by focusing soft X-rays down to ∼10 nm. In contrast to soft X-rays, generally a very high aspect ratio FZP is needed for efficient focusing of hard X-rays. Therefore, FZPs had limited success in the hard X-ray range owing to difficulties of manufacturing high-aspect-ratio zone plates using conventional techniques. Here, employing a method of fabrication based on atomic layer deposition (ALD) and focused ion beam (FIB) milling, FZPs with very high aspect ratios were prepared. Such multilayer FZPs with outermost zone widths of 10 and 35 nm and aspect ratios of up to 243 were tested for their focusing properties at 8 keV and shown to focus hard X-rays efficiently. This success was enabled by the outstanding layer quality thanks to ALD. Via the use of FIB for slicing the multilayer structures, desired aspect ratios could be obtained by precisely controlling the thickness. Experimental diffraction efficiencies of multilayer FZPs fabricated via this combination reached up to 15.58% at 8 keV. In addition, scanning transmission X-ray microscopy experiments at 1.5 keV were carried out using one of the multilayer FZPs and resolved a 60 nm feature size. Finally, the prospective of different material combinations with various outermost zone widths at 8 and 17 keV is discussed in the light of the coupled wave theory and the thin-grating approximation. Al{sub 2}O{sub 3}/Ir is outlined as a promising future material candidate for extremely high resolution with a theoretical efficiency of more than 20% for as small an outermost zone width as 10 nm at 17 keV.

  8. On the ground-state splitting, fine structure of multiplets and EPR spectrum of Ni2+ doped in MgF2 crystal with orthorhombic site symmetry

    International Nuclear Information System (INIS)

    The 45×45 complete energy matrix for 3d8 ion at D2h site symmetry is used to calculate and assign the ground-state splitting and the fine structure of the multiplets of Ni2+(3d8) doped in MgF2 crystal with rutile type structure by the complete diagonalizaton method (CDM) in the frame of semi-empirical molecular orbital (MO) scheme in the strong crystal field (CF) approximation. In the calculation, all the configuration interactions though the cubic CF part, low-symmetry component (tetragonal and orthorhombic parts), Coulomb interaction and the spin–orbit coupling (SOC) interaction (both of the central ion and the liangds) are taken into account completely. The calculated results are in good agreement with the experimental data. In addition, the ground-state splitting is also calculated by the high-order perturbation method (PTM), together with the electron paramagnetic resonance (EPR) parameters D, E and g-factors (gx, gy and gz). The results of the spin–orbit splitting of the ground state calculated by CDM and PTM are not only close to each other, but also in good agreement with the observed data. The relationship between crystalline parameters and the fine structure of multiplets and EPR spectrum is established and the local defect structure is determined.

  9. Cluster ion beam facilities

    International Nuclear Information System (INIS)

    A brief state-of-the-art review in the field of cluster-surface interactions is presented. Ionised cluster beams could become a powerful and versatile tool for the modification and processing of surfaces as an alternative to ion implantation and ion assisted deposition. The main effects of cluster-surface collisions and possible applications of cluster ion beams are discussed. The outlooks of the Cluster Implantation and Deposition Apparatus (CIDA) being developed in Guteborg University are shown

  10. Comparison of the dose deposited between the OBI system and the Varian TrueBeam Imaging system; Comparacion de la dosis depositada entre el sistem OBI y el truebeam Imaging system de Varian

    Energy Technology Data Exchange (ETDEWEB)

    Pino, F.; Navarro, D.; Sancho, I.; Lizuain, M. C.

    2011-07-01

    The use of imaging systems for positioning kilovoltage radiotherapy treatments has experienced a peak in recent years. Techniques such as IMRT, these systems are applied to a large number of sessions to ensure accurate positioning. This makes it increased the interest to know the dose deposited in the patient. Companies involved in developing new designs focus their efforts on reducing the dose due to these positioning systems. The aim of this study is to compare the dose delivered by the OBI image guidance system with the new system image TrueBeam, both of Varian, both planar imaging as CT (CBCT).

  11. Beam-beam effects

    Energy Technology Data Exchange (ETDEWEB)

    Zholents, A.

    1994-12-01

    The term beam-beam effects is usually used to designate different phenomena associated with interactions of counter-rotating beams in storage rings. Typically, the authors speak about beam-beam effects when such interactions lead to an increase of the beam core size or to a reduction of the beam lifetime or to a growth of particle`s population in the beam halo and a correspondent increase of the background. Although observations of beam-beam effects are very similar in most storage rings, it is very likely that every particular case is largely unique and machine-dependent. This constitutes one of the problems in studying the beam-beam effects, because the experimental results are often obtained without characterizing a machine at the time of the experiment. Such machine parameters as a dynamic aperture, tune dependencies on amplitude of particle oscillations and energy, betatron phase advance between the interaction points and some others are not well known, thus making later analysis uncertain. The authors begin their discussion with demonstrations that beam-beam effects are closely related to non linear resonances. Then, they will show that a non linearity of the space charge field is responsible for the excitation of these resonances. After that, they will consider how beam-beam effects could be intensified by machine imperfections. Then, they will discuss a leading mechanism for the formation of the beam halo and will describe a new technique for beam tails and lifetime simulations. They will finish with a brief discussion of the coherent beam-beam effects.

  12. Calculation of energy deposited and stopping range through deuterium ignition beam and dynamical studies on the energy gain in D-3He mixtures

    OpenAIRE

    Hosseinimotlagh, S. N.; Jahedi, M.; Kianafraz, S.; Ghaderi, Sakineh

    2015-01-01

    The fast ignition approach to ICF consists in first compressing the fuel to high density by a suitable driver and then creating the hot spot required for ignition by means of a second external pulse. If the ignition beam is composed of deuterons, an additional energy is delivered to the target with increased energy gain. Therefore ,in this innovative suggestion ,we consider deuterium  beams for fast ignition in D+3He mixture and solve the dynamical  balance equations under the available  physi...

  13. Fluorescence and optical properties of Er.sup.3+./sup. doped LaF.sub.3./sub. films fabricated by Electron Beam Evaporation and Pulsed Laser Deposition

    Czech Academy of Sciences Publication Activity Database

    Lančok, Ján; Novotný, Michal; Bulíř, Jiří; Fitl, Přemysl; Pokorný, Petr; Bočan, Jiří; Munoz, D.; Gonzalo, J.; Afonso, C.N.; Moine, B.

    Strasbourg: EMRS, 2010. 3 16/1. [E- MRS - Strasbourg - 2010 K: Rare earth doped materials for optical based technologies. 07.06.2010-11.06.2010, Strasbourg] R&D Projects: GA AV ČR IAA100100729 Institutional research plan: CEZ:AV0Z10100522 Keywords : Electron Beam Evaporation * Fluoride LaF 3 * fluorescence Subject RIV: BH - Optics, Masers, Lasers

  14. Production and characterization of LiYF.sub.4./sub. oxifluoride glass ceramics prepared by electron beam evaporation and pulsed laser deposition

    Czech Academy of Sciences Publication Activity Database

    Bočan, Jiří; Lančok, Ján; Bulíř, Jiří; Fitl, Přemysl; Novotný, Michal

    Singapore : National University of Singapore, 2009 - (Luk´yanchuk, B.). s. 250-250 [International Conference on Laser Ablation /10./. 22.11.2009-27.11.2009, Singapore] R&D Projects: GA ČR GA106/07/0949; GA AV ČR KAN400100653 Institutional research plan: CEZ:AV0Z10100522 Keywords : oxifluoride glass ceramics * rare-earth doping * e-beam evaporation * PLD Subject RIV: BM - Solid Matter Physics ; Magnetism

  15. Denton E-beam Evaporator #1

    Data.gov (United States)

    Federal Laboratory Consortium — Description: CORAL Name: E-Beam Evap 1 This is a dual e-beam/thermal evaporator for the deposition of metal and dielectric thin films. Materials available are: Ag,...

  16. SEDIMENTARY FEATURES OF TSUNAMI BACKWASH DEPOSITS AS ASSESSED BY MICRO-BEAM SYNCHROTRON X-RAY FLUORESCENCE (μ-SXRF AT THE SIAM PHOTON LABORATORY

    Directory of Open Access Journals (Sweden)

    Siwatt Pongpiachan

    2013-01-01

    Full Text Available Over the past few years, several attempts have been performed to find alternative “chemical proxies” in order to discriminate “tsunami backwash deposits” from “typical marine sediments”. A wide range of statistical tools has been selected in order to investigate the sediments and/or terrestrial soils transportation mechanism during the tsunami inundation period by using several types of chemical tracers. To relate the physical and chemical characteristics of Typical Marine Sediments (TMS,Tsunami Backwash Deposits (TBD, Onshore Tsunami Deposits (OTD and Coastal Zone Soils (CZS with their synchrotron radiation based micro-X-ray Fluorescence (μ-SXRF spectra, the μ- SXRF spectra were built in the appropriate selected spectra range from 3,000 eV to 8,000 eV. Further challenges were considered by using the first-order derivative μ-SXRF spectra coupled with Probability Distribution Function (PDF, Hierarchical Cluster Analysis (HCA and Principal Component Analysis (PCA in order to investigate the elemental distribution characteristics in various types of terrestrial soils and marine sediments. Dendrographic classifications and multi-dimensional plots of principal components (i.e. bi-polar and three dimensional plots could indicate the impacts of terrestrial soils and/or marine sediments transport on onshore and/or offshore during the tsunami inundation period. Obviously, these advanced statistical analyses are quite useful and provide valuable information and thus shed new light on the study of paleotsunami.

  17. Estimation of the spatial energy deposition in CA1 pyramidal neurons under exposure to 12C and 56Fe ion beams

    Directory of Open Access Journals (Sweden)

    Munkhbaatar Batmunkh

    2015-10-01

    Full Text Available The exposure to heavy charged particles represents a significant risk to the central nervous system. In experiments with rodents, the irradiation with heavy ions induces a prolonged deficit in hippocampus-dependent learning and memory. The exact nature of these violations remains mostly unclear. In this regard, the estimation of radiation effects at the level of single neurons is of our special interest. The present study demonstrates the results of comparative calculations that are performed to clarify the early physical events in single neurons under the exposure to accelerated 12C and 56Fe ions with different parameters. Using the Geant4-based Monte Carlo simulations, the radiation effects are considered in terms of energy and dose deposition. The spatial patterns of energy and dose depositions within a single neural cell are produced. As additional characteristics, the spectra of the specific energy and energy imparted are estimated. Our results show that the cell morphology is an important factor determining the accumulation of radiation dose in neurons under the exposure to heavy ions. The data obtained suggest a possibility of radiation damage to synapses that are considered to play an important role in radiation-induced violations of hippocampus-dependent learning and memory.

  18. Friction and wear study of diamond-like carbon gradient coatings on Ti6Al4V substrate prepared by plasma source ion implant-ion beam enhanced deposition

    International Nuclear Information System (INIS)

    DLC gradient coatings had been deposited on Ti6Al4V alloy substrate by plasma source ion implantation-ion beam enhanced deposition method and their friction and wear behavior sliding against ultra high molecular weight polyethylene counterpart were investigated. The results showed that DLC gradient coated Ti6Al4V had low friction coefficient, which reduced 24, 14 and 10% compared with non-coated Ti6Al4V alloy under dry sliding, lubrication of bovine serum and 0.9% NaCl solution, respectively. DLC gradient coated Ti6Al4V showed significantly improved wear resistance, the wear rate was about half of non-coated Ti6Al4V alloy. The wear of ultra high molecular weight polyethylene counterpart was also reduced. High adhesion to Ti6Al4V substrate of DLC gradient coatings and surface structure played important roles in improved tribological performance, serious oxidative wear was eliminated when DLC gradient coating was applied to the Ti6Al4V alloy

  19. Correlations between deposition parameters and structural and electrical properties of YBa sub 2 Cu sub 3 O sub 7 minus. delta. thin films grown in situ by sequential ion beam sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Kittl, J.A.; Nieh, C.W.; Lee, D.S.; Johnson, W.L. (W. M. Keck Laboratory of Engineering Materials, California Institute of Technology, Pasadena, California 91125 (US))

    1990-06-11

    We have studied the correlations between deposition parameters and structural and electrical properties of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} thin films grown {ital in} {ital situ} by sequential ion beam sputtering. Epitaxial, {ital c}-axis oriented YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} films were grown both on (100) SrTiO{sub 3} and on (100) MgO substrates following the stacking sequence of the 123'' compound, with deposited layer thicknesses nominally equal to 1 monolayer. The {ital c}-axis lattice parameters obtained were larger than the corresponding lattice parameter in bulk samples, even after low-temperature anneals in O{sub 2}. The transition temperatures were found to decrease with the enlargement of the {ital c}-axis lattice parameter. A clear correlation between growth temperature and the value of the {ital c}-axis lattice parameter was observed. The {ital c}-axis lattice parameter and the x-ray linewidth of Bragg reflections with the {bold G} vector along the {ital c}-axis were also found to be correlated. This suggests a relationship between the {ital c}-axis lattice parameter and the structural coherence of the epitaxial films.

  20. Friction and wear study of diamond-like carbon gradient coatings on Ti6Al4V substrate prepared by plasma source ion implant-ion beam enhanced deposition

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Shuwen; Jiang Bin; Li Yan; Li Yanrong; Yin Guangfu; Zheng Changqiong

    2004-09-15

    DLC gradient coatings had been deposited on Ti6Al4V alloy substrate by plasma source ion implantation-ion beam enhanced deposition method and their friction and wear behavior sliding against ultra high molecular weight polyethylene counterpart were investigated. The results showed that DLC gradient coated Ti6Al4V had low friction coefficient, which reduced 24, 14 and 10% compared with non-coated Ti6Al4V alloy under dry sliding, lubrication of bovine serum and 0.9% NaCl solution, respectively. DLC gradient coated Ti6Al4V showed significantly improved wear resistance, the wear rate was about half of non-coated Ti6Al4V alloy. The wear of ultra high molecular weight polyethylene counterpart was also reduced. High adhesion to Ti6Al4V substrate of DLC gradient coatings and surface structure played important roles in improved tribological performance, serious oxidative wear was eliminated when DLC gradient coating was applied to the Ti6Al4V alloy.

  1. The Effects of Annealing and Discharging on the Characteristics of MgO Thin Films Prepared by Ion Beam-Assisted Deposition as a Protective Layer of AC-PDP

    Institute of Scientific and Technical Information of China (English)

    YU Zhinong; SUN Jian; XUE Wei; ZHENG Dexiu

    2007-01-01

    This study investigated the effects of annealing and discharging on the characteristics of MgO thin films prepared by ion beam-assisted deposition as a protective layer of AC-PDP. By an annealing process at a temperature of 450 °C for more than three hours, the crystallinity of the deposited MgO films was improved, but the surface of the (200)-oriented MgO thin films in the vicinity of the discharge electrodes, especially on the inner sides of the electrodes, was subjected to crack formation. The failure mechanism of the (200)-oriented MgO films was due to the compressive stress of MgO films plus the additional compressive stress induced by the differences in the coefficient of thermal expansion between the electrode and the dielectric layer. In the discharging process, all MgO films were eroded unevenly, and the serious erosion occurred near the edges of the discharge electrodes. ATM(atomic force microscopy) images show that the eroded surface of the (200)-oriented MgO thin film is smoother than that of the (lll)-oriented film. Also, the (200)-oriented MgO thin film shows an improved ability to resist ion erosion compared to the (lll)-oriented film.

  2. Enhancement of negative capacitance effect in (CoFeZr)x(CaF2)(100−x) nanocomposite films deposited by ion beam sputtering in argon and oxygen atmosphere

    International Nuclear Information System (INIS)

    Highlights: • (FeCoZr)x(CaF2)(100−x) nanomaterals deposited in oxygen-containing atmosphere (Ar + O2). • FeCoZr “cores” covered with FeCo-oxide “shells” embedded into nonoxygen dielectric matrix. • On σ(Tp) are two minima related to the crossing zero line values of Θ1 = 90° and of Θ2 = −90°. - Abstract: The paper presents frequency f and temperature Tp dependences of phase shift angle Θ, admittance σ and capacitance Cp for the as-deposited and annealed (CoFeZr)x(CaF2)(100−x) nanocomposite films deposited by ion-beam sputtering of a compound target in a mixed argon–oxygen gas atmosphere in vacuum chamber. The studied films presented metallic FeCoZr “cores” covered with FeCo-based oxide “shells” embedded into oxygen-free dielectric matrix (fluorite). It was found for the metallic phase content within the range of 52.2 at.% ⩽ x ⩽ 84.3 at.% in low-f region that Θ values were negative, while in the high-f region we observed the Θ < 0o. It was obtained that the f-dependences of capacitance module displayed minimum at the corresponding frequency when the Θ(f) crossed its zero line Θ = 0o. It was also observed that the σ(Tp) dependence displayed the occurrence of two minima that were related to the values of Θ1 = 90° (the first minimum) and of Θ2 = −90° (the second one). Some possible reasons of such behavior of (CoFeZr)x(CaF2)(100−x) nanocomposite films are discussed

  3. Secondary growth mechanism of SiGe islands deposited on a mixed-phase microcrystalline Si by ion beam co-sputtering

    Science.gov (United States)

    Ke, S. Y.; Yang, J.; Qiu, F.; Wang, Z. Q.; Wang, C.; Yang, Y.

    2015-11-01

    We discuss the SiGe island co-sputtering deposition on a microcrystalline silicon (μc-Si) buffer layer and the secondary island growth based on this pre-SiGe island layer. The growth phenomenon of SiGe islands on crystalline silicon (c-Si) is also investigated for comparison. The pre-SiGe layer grown on μc-Si exhibits a mixed-phase structure, including SiGe islands and amorphous SiGe (a-SiGe) alloy, while the layer deposited on c-Si shows a single-phase island structure. The preferential growth and Ostwald ripening growth are shown to be the secondary growth mechanism of SiGe islands on μc-Si and c-Si, respectively. This difference may result from the effect of amorphous phase Si (AP-Si) in μc-Si on the island growth. In addition, the Si-Ge intermixing behavior of the secondary-grown islands on μc-Si is interpreted by constructing the model of lateral atomic migration, while this behavior on c-Si is ascribed to traditional uphill atomic diffusion. It is found that the aspect ratios of the preferential-grown super islands are higher than those of the Ostwald-ripening ones. The lower lateral growth rate of super islands due to the lower surface energy of AP-Si on the μc-Si buffer layer for the non-wetting of Ge at 700 °C and the stronger Si-Ge intermixing effect at 730 °C may be responsible for this aspect ratio difference.

  4. Numerical calculation of energy deposition by high-energy electron beams: II-B. Improvements to the 6D phase space evolution model

    International Nuclear Information System (INIS)

    The phase space evolution model of Huizenga and Storchi, Morawska-Kaczynska and Huizenga and Janssen et al has been modified to (i) allow application on currently available computer equipment with limited memory (128 Megabytes) and (ii) allow 3D dose calculations based on 3D computer tomographic patient data. This is a further development aimed at the use of the phase space evolution model in radiotherapy electron beam treatment planning. The first modification regards the application of depth evolution of the phase space state combined with an alternative method to transport back-scattered electrons. This depth evolution method requires of the order of 15 times less computer memory than the energy evolution method. Results of previous and new electron transport methods are compared and show that the new electron transport method for back-scattered electrons hardly affects the accuracy of the calculated dose distributions. The second modification regards the simulation of electron transport through tissues with varying densities by applying distributed electron transport through similarly composed media with a limited number of fixed densities. Results of on-distributed and distributed electron transport are compared and show that the distributed electron transport method hardly affects the accuracy of the calculated dose distributions. It is also shown that the results of the new dose distribution calculations are still in good agreement with and require significantly less computation time than results obtained with the EGS4 Monte Carlo method. (author)

  5. Atomic scale modelling of nanosize Ni sub 3 Al cluster beam deposition on Al, Ni and Ni sub 3 Al (1 1 1) surfaces

    CERN Document Server

    Kharlamov, V S; Hou, M

    2002-01-01

    The slowing down of Ni sub 3 Al clusters on a Al, Ni and Ni sub 3 Al (1 1 1) surfaces is studied by atomic scale modelling. The semi-grand canonical metropolis Monte Carlo is used for the preparation of isolated clusters at thermodynamic equilibrium. The cluster deposition on the surface is studied in detail by classical Molecular Dynamics simulations that include a model to account for electron-phonon coupling. Long- and short-range orders in the cluster are evaluated as functions of temperature in an impact energy range between 0 and 1.5 eV/atom. The interaction between the Ni sub 3 Al cluster and an Al surface is characterised low short range (chemical) disorder. No sizeable epitaxy is found, subsequent to the impact. In contrast, in the case of Ni and Ni sub 3 Al substrates, which are harder materials than aluminium, the chemical disorder is higher and epitaxial accommodation is possible. With these substrates, chemical disorder in the cluster is an increasing function of the impact energy, as well as of ...

  6. Atomic scale modelling of nanosize Ni3Al cluster beam deposition on Al, Ni and Ni3Al (1 1 1) surfaces

    International Nuclear Information System (INIS)

    The slowing down of Ni3Al clusters on a Al, Ni and Ni3Al (1 1 1) surfaces is studied by atomic scale modelling. The semi-grand canonical metropolis Monte Carlo is used for the preparation of isolated clusters at thermodynamic equilibrium. The cluster deposition on the surface is studied in detail by classical Molecular Dynamics simulations that include a model to account for electron-phonon coupling. Long- and short-range orders in the cluster are evaluated as functions of temperature in an impact energy range between 0 and 1.5 eV/atom. The interaction between the Ni3Al cluster and an Al surface is characterised low short range (chemical) disorder. No sizeable epitaxy is found, subsequent to the impact. In contrast, in the case of Ni and Ni3Al substrates, which are harder materials than aluminium, the chemical disorder is higher and epitaxial accommodation is possible. With these substrates, chemical disorder in the cluster is an increasing function of the impact energy, as well as of temperature when the impact energy is low enough. The cluster epitaxy is enhanced by both the temperature and the impact energy. A direct correlation between epitaxy and chemical disordering is found during the accommodation of the cluster with the surface

  7. Nonlinear beam-beam resonances

    International Nuclear Information System (INIS)

    Head-on collisions of bunched beams are considered, assuming the two colliding beams have opposite charges. A few experimental observations are described. The single resonance analysis is developed that is applicable to the strong-weak case of the beam-beam interaction. In this case, the strong beam is unperturbed by the beam-beam interaction; motions of the weak beam particles are then analyzed in the presence of the nonlinear electromagnetic force produced by the strong beam at the collision points. The coherent motions of the two coupled strong beams are shown to exhibit distinct nonlinear resonance behavior. 16 refs., 22 figs

  8. Enhancement of negative capacitance effect in (CoFeZr){sub x}(CaF{sub 2}){sub (100−x)} nanocomposite films deposited by ion beam sputtering in argon and oxygen atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Koltunowicz, T.N., E-mail: t.koltunowicz@pollub.pl [Lublin University of Technology, 20-618 Lublin (Poland); Zhukowski, P., E-mail: p.zhukowski@pollub.pl [Lublin University of Technology, 20-618 Lublin (Poland); Bondariev, V. [Lublin University of Technology, 20-618 Lublin (Poland); Saad, A. [Al Balqa Applied University, Physics Department, P.O. Box 4545, Amman 11953 (Jordan); Fedotova, J.A. [National Center for Particles and High Energy Physics of Belarusian State University, 220040 Minsk (Belarus); Fedotov, A.K. [Belarusian State University, 220030 Minsk (Belarus); Milosavljević, M. [VINČA Institute of Nuclear Sciences, Belgrade University, P.O. Box 522, 11001 Belgrade (Serbia); Kasiuk, J.V. [National Center for Particles and High Energy Physics of Belarusian State University, 220040 Minsk (Belarus)

    2014-12-05

    Highlights: • (FeCoZr){sub x}(CaF{sub 2}){sub (100−x)} nanomaterals deposited in oxygen-containing atmosphere (Ar + O{sub 2}). • FeCoZr “cores” covered with FeCo-oxide “shells” embedded into nonoxygen dielectric matrix. • On σ(T{sub p}) are two minima related to the crossing zero line values of Θ{sub 1} = 90° and of Θ{sub 2} = −90°. - Abstract: The paper presents frequency f and temperature T{sub p} dependences of phase shift angle Θ, admittance σ and capacitance C{sub p} for the as-deposited and annealed (CoFeZr){sub x}(CaF{sub 2}){sub (100−x)} nanocomposite films deposited by ion-beam sputtering of a compound target in a mixed argon–oxygen gas atmosphere in vacuum chamber. The studied films presented metallic FeCoZr “cores” covered with FeCo-based oxide “shells” embedded into oxygen-free dielectric matrix (fluorite). It was found for the metallic phase content within the range of 52.2 at.% ⩽ x ⩽ 84.3 at.% in low-f region that Θ values were negative, while in the high-f region we observed the Θ < 0{sup o}. It was obtained that the f-dependences of capacitance module displayed minimum at the corresponding frequency when the Θ(f) crossed its zero line Θ = 0{sup o}. It was also observed that the σ(T{sub p}) dependence displayed the occurrence of two minima that were related to the values of Θ{sub 1} = 90° (the first minimum) and of Θ{sub 2} = −90° (the second one). Some possible reasons of such behavior of (CoFeZr){sub x}(CaF{sub 2}){sub (100−x)} nanocomposite films are discussed.

  9. The Changes in Skeletal Muscle Ultrasructure and MGF during and after Exhaustive Exercise in Rat%大负荷运动及其恢复期间大鼠骨骼肌超微结构及MGF的变化

    Institute of Scientific and Technical Information of China (English)

    潘同斌; 王晓雪; 唐芳; 左伟; 刘跃兵; 温慧霞

    2012-01-01

    Objective The purpose of this paper was to study the changes in skeletal muscle ultrasructure and mechano growth factors (MGF) during and after exhaustive exercise in rat. Methods Thirty six 8-week-old healthy male SD rats were randomly and equally divided into following 6 groups: sedentary control group (C);immediately after exhaustive exercise group(E0);12 hours after exhaustive exercise group (E12);24 hours after exhaustive exercise (E24);48 hours after exhaustive exercise group (E48);and 72 hours after exhaustive exercise group (E72). Rats in all exhaustive exercise groups underwent tail-loaded(3% of body weight) swimming once a day for seven days. Rats in respective groups were killed immediately,and at 12,24,48 and 72 hours after the last exhaustive exercise. The protein expression of MGF in gastrocnemius and serum was measured by ELISA, and the ultrastructural changes in rat rectus femoris were observed by electron microscopy. Results After a week of heavy-load swimming , (1 )widened muscle gap, slight deformation of endoplasmic reticulum and mitochondria, loose and thin myofibrils, and distorted Z lines revealed in all exhaustive exercise groups, especially in groups EO and E24; (2)the MGF increased significantly in all exhaustive exercise groups,especially in group E24 (P < 0.01) ;and MGF in group EO was significantly different from group C (P < 0.01). Conclusion Exhaustive swimming could cause micro-injury of skeletal muscles to a certain extent, and the increased MGF in skeletal muscle and serum after the exercise probably related to the repair process of the micro-injury.%目的:观察大负荷运动及其恢复期间大鼠骨骼肌超微结构及机械生长因子(MGF)的变化.方法:36只8周龄健康雄性SD大鼠随机分为6组,每组6只:安静对照组(C组)和力竭运动后即刻组(E0组)、12h组(E12组)、24h组(E24组)、48h组(E48组)、72h组(E72组).各力竭运动组尾部负重为3%体重,进行1周负

  10. Enhanced threshold voltage of Zn-doped Ge{sub 2}Sb{sub 2}Te{sub 5} phase-change memory deposited by electron-beam evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Rui [National Laboratory of Solid State Microstructures and School of Electronic Science and Engineering, Nanjing University, Nanjing (China); College of Electronic Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing (China); Jiang, Yifan; Xu, Ling; Ma, Zhongyuan; Yang, Fei; Xu, Jun [National Laboratory of Solid State Microstructures and School of Electronic Science and Engineering, Nanjing University, Nanjing (China); Su, Weining [National Laboratory of Solid State Microstructures, Department of Physics, Nanjing University, Nanjing (China)

    2013-12-15

    Zn-doped Ge{sub 2}Sb{sub 2}Te{sub 5} (GST) thin films are deposited on glass substrates by an electron-beam evaporation technique in an ultra-high vacuum. GST mixed with 5%, 10%, 20% Zn is used. Through in situ resistance measurements, an increase of crystalline temperature in Zn-doped GST was observed. From absorption spectra, the optical bandgap values of 10% Zn-doped GST in different structures are estimated to be 1.1, 0.9, and 0.7 eV, respectively, which are slightly wider than that of pure GST. A prototype phase-change memory (PCM) device using GST thin film doped with Zn was fabricated. The current-voltage test results of the devices show better switching performances in both SET and RESET processes than that of the device using pure GST film. The threshold voltage is greatly increased with the adding of Zn atom with fixed proportion, which can weaken the interaction during the read and write operation of PCM. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. High-permitivity cerium oxide prepared by molecular beam deposition as gate dielectric and passivation layer and applied to AlGaN/GaN power high electron mobility transistor devices

    Science.gov (United States)

    Chiu, Yu Sheng; Liao, Jen Ting; Lin, Yueh Chin; Chien Liu, Shin; Lin, Tai Ming; Iwai, Hiroshi; Kakushima, Kuniyuki; Chang, Edward Yi

    2016-05-01

    High-κ cerium oxide (CeO2) was applied to AlGaN/GaN high-electron-mobility transistors (HEMTs) as a gate insulator and a passivation layer by molecular beam deposition (MBD) for high-power applications. From capacitance–voltage (C–V) measurement results, the dielectric constant of the CeO2 film was 25.2. The C–V curves showed clear accumulation and depletion behaviors with a small hysteresis (20 mV). Moreover, the interface trap density (D it) was calculated to be 5.5 × 1011 eV‑1 cm‑2 at 150 °C. A CeO2 MOS-HEMT was fabricated and demonstrated a low subthreshold swing (SS) of 87 mV/decade, a high ON/OFF drain current ratio (I ON/I OFF) of 1.14 × 109, and a low gate leakage current density (J leakage) of 2.85 × 10‑9 A cm‑2 with an improved dynamic ON-resistance (R ON), which is about one order of magnitude lower than that of a conventional HEMT.

  12. Ion Beam Analysis, structure and corrosion studies of nc-TiN/a-Si{sub 3}N{sub 4} nanocomposite coatings deposited by sputtering on AISI 316L

    Energy Technology Data Exchange (ETDEWEB)

    García, J. [Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara, J. Guadalupe Zuno 48, Los Belenes, Zapopan, Jal. 45101 (Mexico); Canto, C.E. [Instituto de Física, UNAM, Avenida de la Investigación S/N, Coyoacán, México, D.F. 04510 (Mexico); Flores, M. [Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara, J. Guadalupe Zuno 48, Los Belenes, Zapopan, Jal. 45101 (Mexico); Andrade, E., E-mail: andrade@fisica.unam.mx [Instituto de Física, UNAM, Avenida de la Investigación S/N, Coyoacán, México, D.F. 04510 (Mexico); Rodríguez, E.; Jiménez, O. [Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara, J. Guadalupe Zuno 48, Los Belenes, Zapopan, Jal. 45101 (Mexico); Solis, C.; Lucio, O.G. de [Instituto de Física, UNAM, Avenida de la Investigación S/N, Coyoacán, México, D.F. 04510 (Mexico); Rocha, M.F. [ESIME-Z, Instituto Politécnico Nacional, ALM Zacatenco, México, D.F. 07738 (Mexico)

    2014-07-15

    In this work, nanocomposite coatings of nc-TiN/a-Si{sub 3}N{sub 4}, were deposited on AISI 316L stainless steel substrate by a DC and RF reactive magnetron co-sputtering technique using an Ar–N{sub 2} plasma. The structure of the coatings was characterized by means of XRD (X-ray Diffraction). The substrate and coating corrosion resistance were evaluated by potentiodynamic polarization using a Ringer solution as electrolyte. Corrosion tests were conducted with the purpose to evaluate the potential of this coating to be used on biomedical alloys. IBA (Ion Beam Analysis) techniques were applied to measure the elemental composition profiles of the films and, XPS (X-ray Photoelectron Spectroscopy) were used as a complementary technique to obtain information about the compounds present in the films. The nanocomposite coatings of nc-TiN/a-Si{sub 3}N{sub 4} show crystalline (TiN) and amorphous (Si{sub 3}N{sub 4}) phases which confer a better protection against the corrosion effects compared with that of the AISI 316L.

  13. Bessel Beams

    OpenAIRE

    McDonald, Kirk T

    2000-01-01

    Scalar Bessel beams are derived both via the wave equation and via diffraction theory. While such beams have a group velocity that exceeds the speed of light, this is a manifestation of the "scissors paradox" of special relativty. The signal velocity of a modulated Bessel beam is less than the speed of light. Forms of Bessel beams that satisfy Maxwell's equations are also given.

  14. 补充谷氨酰胺对过度训练大鼠腹膜巨噬细胞IGF-1和MGF基因表达的影响%Supplementing Glutamine Affects the IGF-1 and MGF mRNA Levels in Peritoneal Macrophages of Overtrained Rats

    Institute of Scientific and Technical Information of China (English)

    肖卫华; 陈佩杰

    2011-01-01

    目的:了解补充谷氨酰胺对过度训练大鼠腹膜巨噬细胞胰岛素样生长因子1(IGF-1)和机械生长因子(MGF)基因表达的影响.方法:8周龄健康雄性Wistar大鼠40K,随机分为安静对照组(C)、过度训练组(E)、过度训练补充谷氨酰胺组(EG).后两组根据取材时间不同分为2组:运动后36 h取材组(E1、EG1),运动后7天取材组(E2、EG2).总计5组,每组8只,除C组外,其他4组进行ll周递增负荷跑台训练.EG组从第5周开始至第8周灌胃补充谷氨酰胺(0.8 g/kg/d),以后几周加至饮用水补充,剂量逐周加大到1.1 g/kg/d.断头处死大鼠并分离纯化腹膜巨噬细胞,采用荧光定量PCR技术测定IGF-1和MGF基因表达.结果:安静状态下巨噬细胞即可表达IGF-1和MGF.11周过度训练后36 h,巨噬细胞IGF-1、MGF表达量显著增加,分别约为安静对照组的2l倍和92倍(P<0.01).EG1组IGF-1、MGF表达显著增加,分别约为安静对照组的10倍和37倍(P<0.01),但显著低于E1组(P<0.01).停训后恢复7天,E2组、EG2组IGF-1、MGF表达量分别与E1组、EG1组相比均显著下降(P<0.01),但与C组相比差异无统计学意义.结论:静息态巨噬细胞可表达IGF-1和MGF:过度训练可增强巨噬细胞IGF-1和MGF表达,MGF表达对运动应激更敏感;补充谷氨酰胺可部分抑制巨噬细胞IGF-1和MGF对过度训练的应答.%Objective To investigate the effect of supplementation of glutamine (Gln) on the IGF-1 and MGF mRNA levels in peritoneal macrophages of rats with overtraining. Methods Forty male Wistar rats were randomly divided into following groups: sedentary group (C, n = 8) , overtraining group (E) , overtraining and supplementation of Gln group (EG) . The groups E and EG were respectively subdivided into two groups which were sacrificed 36 hours (E1, EG1, n = 8) and 7 days (E2,EG2, n = 8) after the last training. All groups except the C underwent standard treadmill training with an increasing load for 11 weeks. And group EG

  15. Effects of high magnetic field on the structure evolution, magnetic and electrical properties of the molecular beam vapor deposited FexNi1−x (0.3≤x<0.8) thin films

    International Nuclear Information System (INIS)

    Nanocrystalline FexNi1−x (in at%, x=0.74, 0.6, 0.55, and 0.3) thin films were prepared on a 25 °C quartz substrate by using a molecular beam vapor deposition method with and without a 6 T magnetic field. The microstructure of the thin films was characterized by energy dispersive x-ray spectroscopy, x-ray diffractometry and transmission electron microscopy. The magnetic and electrical properties of the thin films were examined by a vibrating sample magnetometer and four-point probe method. Results show that the thicknesses of these films with different compositions are 50, 90, 80, and 150 nm, correspondingly. The crystallinity of FexNi1−x (x=0.74 and 0.6) thin films is enhanced, and the γ 〈111〉 orientation degree of the FexNi1−x (x=0.55 and 0.3) thin films increases under a 6 T magnetic field. The grain refinement and defect decrease under 6 T magnetic field are affirmed by TEM. A 6 T magnetic field can help the thin films transform from anisotropy to isotropy. The soft magnetic properties of the FexNi1−x (x=0.74, 0.6, 0.55, and 0.3) thin films are enhanced, and their resistivities decrease under a 6 T magnetic field. - Highlights: ► Crystallinity of thin films increases under a 6 T magnetic field. ► Defects of thin films reduce under 6 T magnetic field. ► Grains are refined and size distribution is narrow under 6 T magnetic field. ► 6 T magnetic field helps thin films transform from anisotropy to isotropy. ► Soft magnetic properties of films are improved under 6 T magnetic field

  16. Large area ion and plasma beam sources

    International Nuclear Information System (INIS)

    In the past a number of ion beam sources utilizing different methods for plasma excitation have been developed. Nevertheless, a widespread use in industrial applications has not happened, since the sources were often not able to fulfill specific demands like: broad homogeneous ion beams, compatibility with reactive gases, low ion energies at high ion current densities or electrical neutrality of the beam. Our contribution wants to demonstrate technical capabilities of rf ion and plasma beam sources, which can overcome the above mentioned disadvantages. The physical principles and features of respective sources are presented. We report on effective low pressure plasma excitation by electron cyclotron wave resonance (ECWR) for the generation of dense homogeneous plasmas and the rf plasma beam extraction method for the generation of broad low energy plasma beams. Some applications like direct plasma beam deposition of a-C:H and ion beam assisted deposition of Al and Cu with tailored thin film properties are discussed. (orig.)

  17. Opal neutron beams shutters

    International Nuclear Information System (INIS)

    Full text: The Opal Reactor has five beam tubes for neutron beams. Of these 5 tubes, two come from a cold neutron source, another two from thermal sources, and a fifth is ready for a future hot neutron source. Neutron guides come from the cold and thermal beam tubes. Neutron beams are enabled/disabled through shutters located inside the reactor pool's radial shield. These shutters were specially designed by INVAP for the OPAL reactor. They comprise fixed and movable shields. The movable part allows neutron beam enabling or disabling. The design of these shutters demanded the construction of prototypes that were further submitted to comprehensive tests to be qualified in light of the strict movement precision and high reliability requirements involved. The shielding material - a plastic and steel mix - was also specifically designed for this facility. The design required great efforts as to shield calculation and energy deposition. A heat removal system was designed to dissipate the energy absorbed by the shields. The cold and thermal beam shutters are built following a single vertical axis design. The hot shutter, due to different requirements, was designed with a horizontal axis

  18. Pulsed laser deposition of fluoride glass thin films

    International Nuclear Information System (INIS)

    The development of integrated waveguide lasers for different applications such as marking, illumination or medical technology has become highly desirable. Diode pumped planar waveguide lasers emitting in the green visible spectral range, e.g. thin films from praseodymium doped fluorozirconate glass matrix (called ZBLAN, owing to the main components ZrF4, BaF2, LaF3, AlF3 and NaF) as the active material pumped by a blue laser diode, have aroused great interest. In this work we have investigated the deposition of Pr:ZBLAN thin films using pulsed laser radiation of λ = 193 and λ = 248 nm. The deposition has been carried out on MgF2 single crystal substrates in a vacuum chamber by varying both processing gas pressure and energy fluence. The existence of an absorption line at 210 nm in Pr:ZBLAN leads to absorption and radiative relaxation of the absorbed laser energy of λ = 193 nm preventing the evaporation of target material. The deposited thin films consist of solidified and molten droplets and irregular particulates only. Furthermore, X-ray radiation has been applied to fluoride glass targets to enhance the absorption in the UV spectral region and to investigate the deposition of X-ray treated targets applying laser radiation of λ 248 nm. It has been shown that induced F-centres near the target surface are not thermally stable and can be easily ablated. Therefore, λ = 248 nm is not suitable for evaporation of Pr:ZBLAN.

  19. Advanced zirconia-coated carbonyl-iron particles for acidic magnetorheological finishing of chemical-vapor-deposited ZnS and other IR materials

    Science.gov (United States)

    Salzman, S.; Giannechini, L. J.; Romanofsky, H. J.; Golini, N.; Taylor, B.; Jacobs, S. D.; Lambropoulos, J. C.

    2015-10-01

    We present a modified version of zirconia-coated carbonyl-iron (CI) particles that were invented at the University of Rochester in 2008. The amount of zirconia on the coating is increased to further protect the iron particles from corrosion when introduced to an acidic environment. Five low-pH, magnetorheological (MR) fluids were made with five acids: acetic, hydrochloric, nitric, phosphoric, and hydrofluoric. All fluids were based on the modified zirconia-coated CI particles. Off-line viscosity and pH stability were measured for all acidic MR fluids to determine the ideal fluid composition for acidic MR finishing of chemical-vapor-deposited (CVD) zinc sulfide (ZnS) and other infrared (IR) optical materials, such as hot-isostatic-pressed (HIP) ZnS, CVD zinc selenide (ZnSe), and magnesium fluoride (MgF2). Results show significant reduction in surface artifacts (millimeter-size, pebble-like structures on the finished surface) for several standard-grade CVD ZnS substrates and good surface roughness for the non-CVD MgF2 substrate when MR finished with our advanced acidic MR fluid.

  20. Influence of Al3+doping on the energy levels and thermal property of the 3.5MgO·0.5MgF2·GeO2:Mn4+ red-emitting phosphor

    Science.gov (United States)

    Yuan, Lin-lin; Zhang, Xiao-Song; Xu, Jian-Ping; Sun, Jian; Jin, Han; Liu, Xiao-Juan; Li, Lin-Lin; Li, Lan

    2015-08-01

    A series of Al3+ -doped 3.5MgO·0.5MgF2·GeO2:Mn4+ red-emitting phosphors is synthesized by high temperature solid-state reaction. The broad excitation band at 300 nm-380 nm, resulting from the 4A2 → 4T1 transition of Mn4+, exhibits a blue shift with the increase of Al2O3 content. The observation of the decreased Mn4+O2 - distance is explained by the crystal field theory. The temperature-dependent photoluminescence spectra with various amounts of Al2O3 content are comparatively measured and the calculation shows that the activation energy increases up to 0.41 eV at the Al2O3 content of 0.1 mol. The maximum phonon densities of state for these samples are calculated from Raman spectra and they are correlated with the thermal properties. Project supported by the National High Technology Research and Development Program of China (Grant No. 2013AA014201), the Natural Science Foundation of Tianjin City, China (Grant Nos. 11JCYBJC00300 and 14JCZDJC31200), and the National Key Foundation for Exploring Scientific Instrument of China (Grant No. 2014YQ120351).