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Sample records for assisted deposition ibad

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. Deposition studies and coordinated characterization of MOCVD YBCO films on IBAD-MgO templates

    International Nuclear Information System (INIS)

    A recently installed research-scale metal-organic chemical vapor deposition (MOCVD) system at Oak Ridge National Laboratory, provided by SuperPower, Inc., has been used to investigate processing variables for MOCVD YBCO precursors and trends in the resulting properties. Systematic studies of YBCO film growth on LaMnO3/IBAD-MgO templates were carried out by optimizing deposition temperature and oxygen flow rate. Microstructural and superconducting properties of the YBCO films were analyzed by x-ray diffraction, scanning electron microscopy and transport measurements. The identification of intermediate phases formed during the YBCO precursor transformation was investigated by coordinated reel-to-reel Raman microprobe analysis. With this combination of various characterization techniques, an improved understanding of the growth characteristics of MOCVD YBCO films was established. Finally, critical current densities greater than 2 MA cm-2 for film thicknesses of 0.8 μm were demonstrated.

  7. Optical properties of Fe2O3 deposited by IBAD and its usage in interference filters

    Czech Academy of Sciences Publication Activity Database

    Budasz, Jiří; Huťka, Jan; Václavík, Jan

    Vol. 9442. Bellingham: SPIE-INT SOC OPTICAL ENGINEERING, 2015 - (Kovačičinová, J.; Vít, T.), s. 944207-944207. (SPIE). ISBN 978-1-62841-557-5. ISSN 0277-786X. [Optics and Measurement Conference 2014 (OaM 2014). Liberec (CZ), 07.10.2014-10.10.2014] R&D Projects: GA MŠk(CZ) LO1206 Institutional support: RVO:61389021 Keywords : Thin film * Hematite * Fe2O3 * IBAD * evaporation Subject RIV: JJ - Other Materials http://spie.org/Publications/Proceedings/Paper/10.1117/12.2176920

  8. Pulsed laser deposition of YBCO thin films on IBAD-YSZ substrates

    International Nuclear Information System (INIS)

    High-quality YBa2Cu3O7-x (YBCO) films were fabricated on yttria-stabilized zirconia (YSZ)-buffered Hastelloy C276 substrates by pulsed laser deposition. YSZ was grown by ion-beam-assisted deposition. A thin (∼10 nm) CeO2 layer was deposited before the deposition of YBCO. The crystalline structure and biaxial texture of the YBCO film and the buffer layer were examined by x-ray diffraction 2θ-scan, φ-scan and pole-figure analysis. Epitaxial growth of the YBCO film on the buffer layer was observed. Full width at half maximum (FWHM) value of 7.4 deg. was measured from the φ-scan of YBCO(103). Raman spectroscopy showed compositional uniformity and phase integrity in the YBCO films. Surface morphologies of the YBCO films were examined by scanning electron microscopy. Comparative studies indicated that the CeO2 buffer layer significantly improves the structural alignment and superconducting properties of YBCO films. Tc = 90 K, with sharp transition, and transport Jc = 2.2 x 106 A cm-2 at 77 K in zero-external field were obtained on the 0.5 μm thick YBCO films. The dependence of Jc on the FWHM of the YBCO(103) φ-scan indicated that high Jc is associated with low FWHM

  9. Pulsed laser deposition of YBCO thin films on IBAD-YSZ substrates

    Science.gov (United States)

    Li, M.; Ma, B.; Koritala, R. E.; Fisher, B. L.; Venkataraman, K.; Balachandran, U.

    2003-01-01

    High-quality YBa2Cu3O7-x (YBCO) films were fabricated on yttria-stabilized zirconia (YSZ)-buffered Hastelloy C276 substrates by pulsed laser deposition. YSZ was grown by ion-beam-assisted deposition. A thin (approx10 nm) CeO2 layer was deposited before the deposition of YBCO. The crystalline structure and biaxial texture of the YBCO film and the buffer layer were examined by x-ray diffraction 2theta-scan, phi-scan and pole-figure analysis. Epitaxial growth of the YBCO film on the buffer layer was observed. Full width at half maximum (FWHM) value of 7.4° was measured from the phi-scan of YBCO(103). Raman spectroscopy showed compositional uniformity and phase integrity in the YBCO films. Surface morphologies of the YBCO films were examined by scanning electron microscopy. Comparative studies indicated that the CeO2 buffer layer significantly improves the structural alignment and superconducting properties of YBCO films. Tc = 90 K, with sharp transition, and transport Jc = 2.2 × 106 A cm-2 at 77 K in zero-external field were obtained on the 0.5 mum thick YBCO films. The dependence of Jc on the FWHM of the YBCO(103) phi-scan indicated that high Jc is associated with low FWHM.

  10. Pulsed laser deposition of YBCO thin films on IBAD-YSZ substrates

    Energy Technology Data Exchange (ETDEWEB)

    Li, M [Energy Technology Division, Argonne National Laboratory, Argonne, IL (United States); Ma, B [Energy Technology Division, Argonne National Laboratory, Argonne, IL (United States); Koritala, R E [Energy Technology Division, Argonne National Laboratory, Argonne, IL (United States); Fisher, B L [Energy Technology Division, Argonne National Laboratory, Argonne, IL (United States); Venkataraman, K [Chemical Technology Division, Argonne National Laboratory, Argonne, IL (United States); Balachandran, U [Energy Technology Division, Argonne National Laboratory, Argonne, IL (United States)

    2003-01-01

    High-quality YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) films were fabricated on yttria-stabilized zirconia (YSZ)-buffered Hastelloy C276 substrates by pulsed laser deposition. YSZ was grown by ion-beam-assisted deposition. A thin ({approx}10 nm) CeO{sub 2} layer was deposited before the deposition of YBCO. The crystalline structure and biaxial texture of the YBCO film and the buffer layer were examined by x-ray diffraction 2{theta}-scan, {phi}-scan and pole-figure analysis. Epitaxial growth of the YBCO film on the buffer layer was observed. Full width at half maximum (FWHM) value of 7.4 deg. was measured from the {phi}-scan of YBCO(103). Raman spectroscopy showed compositional uniformity and phase integrity in the YBCO films. Surface morphologies of the YBCO films were examined by scanning electron microscopy. Comparative studies indicated that the CeO{sub 2} buffer layer significantly improves the structural alignment and superconducting properties of YBCO films. T{sub c} = 90 K, with sharp transition, and transport J{sub c} = 2.2 x 10{sup 6} A cm{sup -2} at 77 K in zero-external field were obtained on the 0.5 {mu}m thick YBCO films. The dependence of J{sub c} on the FWHM of the YBCO(103) {phi}-scan indicated that high J{sub c} is associated with low FWHM.

  11. Creation of biomaterials using the dual beam IBAD methods

    International Nuclear Information System (INIS)

    The Dual Beam Ion Assisted Deposition technique (IBAD) application for creation of the hard, biocompatible coating layers has been presented and discussed. As substrate the stainless steel, Ti, special titanium alloys, the Al2O3 or other solid materials can be used. Presently, the biocompatible coating layers such as DLC (Diamond Like Coating), β-SiC, TiC, hydroxyapatite and thin coating layer based on Ca, P, O, H have been prepared and investigated

  12. 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.

  13. 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

  14. 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.

  15. Measuring the Process Parameters of the IBAD Method

    Directory of Open Access Journals (Sweden)

    M. Zoriy

    2003-01-01

    Full Text Available Chromium nitride films are known as good protective layers for against both corrosion and wear. These coatings have been studied in detail during recent years. Their protective capability strongly depends on the deposition conditions. A modern method for preparing chromium nitride is the IBAD (Ion Beam Assisted Deposition method. The main parameter determining the composition and properties of the films prepared by the IBAD method is the arrival ratio of impinging nitrogen ions to chromium atoms. In order to calibrate the ion beam XY-mechanical scanner with a Faraday cup, a detector was designed and constructed. By mathematical processing of the data, the flux of the nitrogen atoms was found. To obtain the flux of the chromium atoms the RBS and Talystep methods were used. Now, on the basis of this data, we can perform CrNx, coatings with controlled composition and properties.

  16. Fabrication of highly textured IBAD-MgO template by continuous reel-to-reel process and its characterization

    Science.gov (United States)

    Ko, K. P.; Ha, H. S.; Kim, H. K.; Yu, K. K.; Ko, R. K.; Moon, S. H.; Oh, S. S.; Park, C.; Yoo, S. I.

    2007-10-01

    Highly textured long-length MgO template was successfully deposited on a polycrystalline metal tape using ion-beam-assisted deposition (IBAD). To increase the speed of the IBAD processing, tape moving system was modified from a single-turn to multi-turn system with 14-pass and five heating zones, which leads to larger deposition area. The overall process consists of reel-to-reel electro-polishing of a Hastelloy C276 tape, deposition of Al2O3 diffusion layer and Y2O3 seed layer, deposition of IBAD-MgO and homo-epi MgO layer, and deposition of LaMnO3 (LMO) buffer layer and YBa2Cu3O7-δ (YBCO) superconducting layer using pulsed laser deposition (PLD). Recently, 100 m long IBAD-MgO tape with in-plane texture of Δϕ < 7° has been successfully fabricated. Critical current density (Jc) of 0.94 MA/cm2 at 77 K in self field was obtained from the YBCO coated conductor grown on 20 cm long LMO-buffered IBAD-MgO template by the PLD process.

  17. Fabrication of highly textured IBAD-MgO template by continuous reel-to-reel process and its characterization

    Energy Technology Data Exchange (ETDEWEB)

    Ko, K.P. [Department of Materials Science and Engineering, College of Engineering, Seoul National University, Shillim-Dong, Gwanak-ku, Seoul 151-744 (Korea, Republic of); Ha, H.S. [Superconducting Material Research Group, Korea Electrotechnology Research Institute, Changwon, Kyungnam (Korea, Republic of); Kim, H.K.; Yu, K.K. [Superconductor, Nano and Advanced Materials Corporation, Anyang (Korea, Republic of); Ko, R.K. [Superconducting Material Research Group, Korea Electrotechnology Research Institute, Changwon, Kyungnam (Korea, Republic of); Moon, S.H. [Superconductor, Nano and Advanced Materials Corporation, Anyang (Korea, Republic of); Oh, S.S. [Superconducting Material Research Group, Korea Electrotechnology Research Institute, Changwon, Kyungnam (Korea, Republic of); Park, C. [Department of Materials Science and Engineering, College of Engineering, Seoul National University, Shillim-Dong, Gwanak-ku, Seoul 151-744 (Korea, Republic of); Yoo, S.I. [Department of Materials Science and Engineering, College of Engineering, Seoul National University, Shillim-Dong, Gwanak-ku, Seoul 151-744 (Korea, Republic of)], E-mail: siyoo@snu.ac.kr

    2007-10-01

    Highly textured long-length MgO template was successfully deposited on a polycrystalline metal tape using ion-beam-assisted deposition (IBAD). To increase the speed of the IBAD processing, tape moving system was modified from a single-turn to multi-turn system with 14-pass and five heating zones, which leads to larger deposition area. The overall process consists of reel-to-reel electro-polishing of a Hastelloy C276 tape, deposition of Al{sub 2}O{sub 3} diffusion layer and Y{sub 2}O{sub 3} seed layer, deposition of IBAD-MgO and homo-epi MgO layer, and deposition of LaMnO{sub 3} (LMO) buffer layer and YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) superconducting layer using pulsed laser deposition (PLD). Recently, 100 m long IBAD-MgO tape with in-plane texture of {delta}{phi} < 7{sup o} has been successfully fabricated. Critical current density (J{sub c}) of 0.94 MA/cm{sup 2} at 77 K in self field was obtained from the YBCO coated conductor grown on 20 cm long LMO-buffered IBAD-MgO template by the PLD process.

  18. Fabrication of highly textured IBAD-MgO template by continuous reel-to-reel process and its characterization

    International Nuclear Information System (INIS)

    Highly textured long-length MgO template was successfully deposited on a polycrystalline metal tape using ion-beam-assisted deposition (IBAD). To increase the speed of the IBAD processing, tape moving system was modified from a single-turn to multi-turn system with 14-pass and five heating zones, which leads to larger deposition area. The overall process consists of reel-to-reel electro-polishing of a Hastelloy C276 tape, deposition of Al2O3 diffusion layer and Y2O3 seed layer, deposition of IBAD-MgO and homo-epi MgO layer, and deposition of LaMnO3 (LMO) buffer layer and YBa2Cu3O7-δ (YBCO) superconducting layer using pulsed laser deposition (PLD). Recently, 100 m long IBAD-MgO tape with in-plane texture of Δφ o has been successfully fabricated. Critical current density (Jc) of 0.94 MA/cm2 at 77 K in self field was obtained from the YBCO coated conductor grown on 20 cm long LMO-buffered IBAD-MgO template by the PLD process

  19. 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

  20. 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}.

  1. 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.

  2. Biaxially aligned YSZ and CeO2 buffer layers on hastelloy prepared by magnetron IBAD

    International Nuclear Information System (INIS)

    Full text: The development of high-current, flexible superconducting YBCO tapes is based on a metal substrates overcoated with a biaxially aligned oxide buffer layer to serve as a template for the epitaxial growth of c-axis oriented Yba2Cu3O7 thin films. A secondary function of the buffer is to act as a diffusion barrier to metal species to prevent them from poisoning the superconducting film. Widely studied oxide buffer layers include yttria-stabilised zirconia (YSZ) and cerium oxide (CeO2) produced by ion-beam-assisted deposition (IBAD). We have combined IBAD with magnetron sputtering to deposit biaxially aligned YSZ and CeO2 on Hastelloy C276 substrates held at room temperature. The ion beam is directed at 55deg to the normal of the film plane. In addition, we achieved room temperature epitaxial growth of CeO2 films on IBAD YSZ films by bias sputtering to form biaxially aligned CeO2/YSZ bilayers. The crystalline quality and inplane orientation of the films (200 nm thick) were investigated by x-ray diffraction techniques including ω and φ scans and pole figures. The IBAD YSZ and CeO2 films have a (111) pole in the ion beam direction with a full width at half maximum, FWHM = 24 - 30 deg; the CeO2/YSZ bilayer is similarly aligned with FWHM = 32 deg

  3. All-chemical YBa2Cu3O7 coated conductors on IBAD-YSZ stainless steel substrates

    International Nuclear Information System (INIS)

    We report on the fabrication of all-chemical YBa2Cu3O7 coated conductors on IBAD-YSZ (IBAD stands for ion beam assisted deposition; YSZ is yttrium stabilized zirconia) stainless steel substrates. YBCO films were grown by the trifluoroacetates route on top of CeO2 buffer layers made by metal-organic decomposition. The achievement of atomically flat CeO2 surfaces is found to be a key factor for obtaining clean interfaces with YBCO and high performance. Coated conductors with percolative critical currents of JcGB(65 K) = 1.8 MA cm-2 were achieved. The determination of the intra-grain critical current JcG from inductive measurements suggests that the limiting factor for JcGB is the YBCO in-plane texture, which is already of higher quality than that of the IBAD-YSZ cap layer. (rapid communication)

  4. 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.

  5. 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.

  6. YBCO films grown by reactive co-evaporation on simplified IBAD-MgO coated conductor templates

    International Nuclear Information System (INIS)

    We demonstrate coated conductors fabricated by reactive co-evaporation of YBa2Cu3Oy (YBCO) by cyclic deposition and reaction (RCE-CDR) on ion-beam-assisted-deposition- (IBAD-) textured templates simplified by the elimination of the epitaxial buffer layer. Hastelloy substrates, both polished and unpolished, were used as a starting material for the IBAD templates. Y2O3 bed layers were then deposited followed by IBAD-textured MgO and a thin homoepitaxial MgO layer. The MgO-terminated templates were used for direct deposition of YBCO by RCE-CDR. Critical current densities obtained for the undoped YBCO material are comparable to the best values measured previously with the use of LaMnO3 or SrTiO3 epitaxial buffer layers and state-of-the-art coated conductor results. The structural characterization data indicate a well oriented YBCO film with a robust template. Electrical measurements also indicate no weak links and a typical magnetic field behavior of undoped YBCO, characterized by a low density of naturally occurring strong pinning centers and correlations along the ab direction.

  7. 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.

  8. 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

  9. Substrate surface treatment and YSZ buffer layers by IBAD method for coated conductors

    International Nuclear Information System (INIS)

    In this work, an Ion Beam Assisted Deposition (IBAD) system was utilized to fabricate Yttria-Stabilized Zirconia (YSZ) template films for coated conductors. The surface of the Hastelloy C276 substrate was modified by rolling and electropolishing. The effect of the electropolishing parameters of the substrate on the texture of the YSZ buffer layers was studied. The electropolishing current and time were optimized for short samples of 1 cmx1 cm square shape as 1 A and 60 s, respectively. And the relationship between the roughness of the substrate surface and the texture of the YSZ layer is discussed. Reel-to-reel metal tape moving apparatus was installed and used to produce meter-long buffer layer for coated conductors. The YSZ template film was deposited by IBAD method on meter-long Hastelloy tape with tape shifting speed of 15-20 m/h, and the thickness of the buffer layer was up to about 1.7 μm. The Hastelloy substrate surface was measured by Atomic Force Microscope. The thickness of the YSZ films over length was measured by Thermal Field Emission Scan Electronic Microscopy. X Ray Diffraction Ω-scan and φ-scan measurements were performed in order to examine the out-of-plane and in-plane texture of the YSZ buffer layers, respectively.

  10. Substrate surface treatment and YSZ buffer layers by IBAD method for coated conductors

    Science.gov (United States)

    Feng, F.; Liu, R.; Chen, H.; Shi, K.; Wang, Z.; Wu, W.; Han, Z.

    2009-10-01

    In this work, an Ion Beam Assisted Deposition (IBAD) system was utilized to fabricate Yttria-Stabilized Zirconia (YSZ) template films for coated conductors. The surface of the Hastelloy C276 substrate was modified by rolling and electropolishing. The effect of the electropolishing parameters of the substrate on the texture of the YSZ buffer layers was studied. The electropolishing current and time were optimized for short samples of 1 cm×1 cm square shape as 1 A and 60 s, respectively. And the relationship between the roughness of the substrate surface and the texture of the YSZ layer is discussed. Reel-to-reel metal tape moving apparatus was installed and used to produce meter-long buffer layer for coated conductors. The YSZ template film was deposited by IBAD method on meter-long Hastelloy tape with tape shifting speed of 15-20 m/h, and the thickness of the buffer layer was up to about 1.7 μm. The Hastelloy substrate surface was measured by Atomic Force Microscope. The thickness of the YSZ films over length was measured by Thermal Field Emission Scan Electronic Microscopy. X Ray Diffraction Ω-scan and ϕ-scan measurements were performed in order to examine the out-of-plane and in-plane texture of the YSZ buffer layers, respectively.

  11. Substrate surface treatment and YSZ buffer layers by IBAD method for coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Feng, F. [Department of Physics, Tsinghua University, Beijing 100084 (China); Liu, R. [Innova Superconductor Technology Co., Ltd., 7 Rongchang Dongjie, Longsheng Industrial Park, Beijing Economic and Technological Developemnt Area, Beijing 100176 (China); Chen, H. [Department of Physics, Tsinghua University, Beijing 100084 (China); Shi, K., E-mail: shikai@tsinghua.edu.c [Department of Physics, Tsinghua University, Beijing 100084 (China); Wang, Z. [Department of Physics, School of Science, Beijing Institute of Technology, Beijing 100081 (China); Wu, W.; Han, Z. [Department of Physics, Tsinghua University, Beijing 100084 (China)

    2009-10-15

    In this work, an Ion Beam Assisted Deposition (IBAD) system was utilized to fabricate Yttria-Stabilized Zirconia (YSZ) template films for coated conductors. The surface of the Hastelloy C276 substrate was modified by rolling and electropolishing. The effect of the electropolishing parameters of the substrate on the texture of the YSZ buffer layers was studied. The electropolishing current and time were optimized for short samples of 1 cmx1 cm square shape as 1 A and 60 s, respectively. And the relationship between the roughness of the substrate surface and the texture of the YSZ layer is discussed. Reel-to-reel metal tape moving apparatus was installed and used to produce meter-long buffer layer for coated conductors. The YSZ template film was deposited by IBAD method on meter-long Hastelloy tape with tape shifting speed of 15-20 m/h, and the thickness of the buffer layer was up to about 1.7 mum. The Hastelloy substrate surface was measured by Atomic Force Microscope. The thickness of the YSZ films over length was measured by Thermal Field Emission Scan Electronic Microscopy. X Ray Diffraction OMEGA-scan and phi-scan measurements were performed in order to examine the out-of-plane and in-plane texture of the YSZ buffer layers, respectively.

  12. 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.

  13. 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.

  14. Creation of the SiCx layers as interface of hard wear protective coatings by dual beam IBAD method

    International Nuclear Information System (INIS)

    The paper presents the current status of research connected with forming one- and multi-layer, anti wear, microcrystalline and amorphous coatings, one-element (e.g. Diamond Like carbon coatings) (DLC) and multi-element (e. g. SiC) at the application of dual beam IBAD (Ion Beam Assisted Deposition) method. This method features high technological flexibility, consisting in the possibility of composing layers with desired properties with the coating's good adhesion to the substrate. In the research on the formed coatings, the method of detecting backscattered charged particles (RBS - Rutherford Backscattering Spectroscopy) and for specifying tribological features set of mechanical methods were used. (author)

  15. 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

  16. 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)

  17. 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)

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  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. Development of the IBAD MgO process for HTS coated conductors

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-01-01

    We discuss our progress toward depositing IBAD MgO as a template for subsequent deposition of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) high temperature superconductors on metallic substrates. We have refined the process by improving substrate preparation and by using reflected high-energy electron diffraction (RHEED) to monitor the growth of IBAD MgO films. Here we present results on our work to optimize the IBAD MgO process for continuous processing of meter lengths. High quality IBAD MgO has been deposited on moving metal tape for use in coated conductor fabrication. By incorporating optimized processing parameters, we have been able to deposit films on moving metallic substrates with in-plane mosaic spreads near 8{sup o}. The subsequent pulsed laser deposition (PLD) of 1.5 {micro}m thick YBCO films has resulted in superconducting transport critical current densities >1MA/cm{sup 2} (75K,SF) on small area samples.

  6. YBCO superconducting tapes by magnetron IBAD

    International Nuclear Information System (INIS)

    Full text: Large-scale commercial applications of high-temperature superconductors in power devices and systems operating at liquid nitrogen temperatures (77 K) require flexible wire or tape with high critical current density, Jc = 104 - 106 A cm-2, that can be sustained in moderate to high magnetic field, ie. ≤ 0.2 T for transmission cables, 2 - 4 T for motors and transformers, 2 - 10 T for energy storage devices and superconducting magnets. These requirements cannot be met with the silver-sheathed Bi-2223/Ag composite tapes because of inherent materials constraints (eg. low flux pinning, granularity) and various processing difficulties. Recent efforts to produce high-current YBCO superconducting tapes (YBa2Cu3O7/buffer/metal) based on high quality epitaxial c-axis YBa2Cu3O7 thin films deposited on buffered Ni-based alloy substrates have demonstrated Jc = 105 - 106 A cm-2 and unsurpassed magnetic field performance at 77 K. From an existing platform in ion beam and thin film technologies we are developing in situ processes to address scale-up issues to produce YBCO tape. Here we discuss the deposition by magnetron IBAD and the properties of YBCO tapes. Biaxially aligned YSZ and CeO2 buffer layers are deposited at room temperature on polished Hastelloy substrates. Epitaxial YBa2Cu3O7 thin films, 200 - 400 nm thick, are deposited at 750 deg C by sputtering a stoichiometric YBa2Cu3O7 ceramic target in an argon/oxygen plasma. X-ray θ-2θ diffraction, rocking curves (ω scans), φ scans and pole figures are used to determine the crystalline quality and biaxial alignment of films. Typical YSZ and CeO2 buffer layers have (111) poles in the direction of the ion beam (55 deg) and full width at half maximum FWHM = 24 - 30 deg. The YBCO tapes have (103) pole FWHM = 24 deg, Δω = 2 deg and Jc ∼ 3x105 A cm-2 at 77 K Similar YBa2Cu3O7 films deposited on MgO (100) substrates have Jc = (1 - 4)x106 A cm-2

  7. Current progress in YBCO coated conductors using IBAD MgO template layers

    Energy Technology Data Exchange (ETDEWEB)

    Groves, J. R. (James R.); Arendt, P. N. (Paul N.); Foltyn, S. R. (Stephen R.); Jia, Quanxi; Holesinger, T. G. (Terry G.); Emmert, L. A. (Luke A.); DePaula, R. F. (Raymond Felix); Dowden, P. C. (Paul C.); Stan, L. (Liliana); Brewer, R. T. (Rhett T.); Atwater, H. A. (Harry A.)

    2002-01-01

    We present key improvements to growing high quality ({approx}7 degrees {Delta}{phi}) magnesium oxide (MgO) The use of a new layer for IBAD MgO nucleation and reduction in surface roughness of substrates have resulted in better in-plane texture. The processing window for obtaining optimum template texture is very narrow ({approx}10 seconds) using Si,N,. This has been ameliorated by use of an alternate amorphous nucleation layer. The substrate surface roughness has a significant effect on the initial nucleation texture of IBAD MgO films. A surface roughness of -1 nm has resulted in better in-plane texture for IBAD MgO films deposited on metal substrates. We have also implemented a method to quantify IBAD MgO texture using reflected high-energy electron diffraction (RHEED). Utilizing this in situ tool, we have been able to refine deposition parameters to routinely grow films in batch mode that have a {Delta}{phi} of {approx} 7 degrees. Deposited meter lengths have had {Delta}{phi} values from 7-9 degrees with 10% uniformity. One to two micrometer thick YBCO films on these templates have had critical current densities in excess of 1 MA/cm2 at 75 K, in self field.

  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. 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

  10. Chemical solution derived planarization layers for highly aligned IBAD-MgO templates

    International Nuclear Information System (INIS)

    The main goal of this research is to develop a chemical solution derived planarization layer to fabricate highly aligned IBAD-MgO templates for the development of high temperature superconductor (HTS) based coated conductors. The standard IBAD-MgO template needs an additional electrochemical polishing step of the mechanically polished 50 μm-thick Hastelloy C-276 substrates to ensure a flat and smooth surface for subsequent growth of multi-layer buffer architectures, which include: sputtered 80 nm Al2O3; sputtered 7 nm Y2O3; IBAD 10 nm MgO; sputtered 30 nm homo-epi MgO; and sputtered 30 nm LaMnO3 (LMO) layers. We have successfully developed a solution planarization layer that removes the electrochemical polishing step and also acts as a barrier layer. Crack-free, smooth Al2O3 layers were prepared on mechanically polished Hastelloy substrates using a chemical solution process. The average surface roughness value, Ra, for a starting substrate was 9–10 nm. After eight coatings of Al2O3 layer, the Ra was reduced to 2 nm. Highly aligned IBAD-MgO layers with out-of-plane and in-plane textures comparable to the standard IBAD-MgO layers were successfully deposited on top of the solution planarization Al2O3 layers with an Y2O3 nucleation layer using a reel-to-reel ion-beam sputtering system. Both homo-epi MgO and LMO layers were subsequently deposited on the IBAD-MgO layers using RF sputtering to complete the buffer stack required for the growth of HTS films. YBa2Cu3O7−δ (YBCO) films with a thickness of 0.8 μm deposited on these IBAD-MgO templates by pulsed laser deposition showed a high self-field critical current density, Jc, of 3.04 MA cm−2 at 77 K and 6.05 MA cm−2 at 65 K. These results demonstrate that a low-cost chemical-solution-based, high-throughput Al2O3 planarization layer can remove the electro-polishing step and replace sputtered Al2O3 layers for the production of high Jc YBCO-coated conductors. (fast track communication)

  11. In-field critical current property of IBAD/PLD coated conductors

    International Nuclear Information System (INIS)

    REBa2Cu3Oy, (RE : rare earth elements, RE123) coated conductors are expected to show high performance in superconducting applications, due to their high mechanical strength and high current density in magnetic fields. Fujikura has developed ion-beam-assisted-deposition (IBAD) and pulsed-laser-deposition (PLD) technique, and today we routinely manufacture coated conductors with length over 500 m and Ic over 500 A/cm-width at 77 K, self field. We have also been able to fabricate long conductors with higher Ic by thickening RE123 layer. Although Ic performances at 77 K, self field are important, but performances in magnetic fields at lower temperatures below 77 K are more important for coil applications. In this work, we evaluated coated conductors with thick RE123 layer in magnetic fields at low temperatures. All samples are fabricated with long length. We measured samples by four-probe transport method at wide temperature range from 77 K to 10 K by using cryo-cooled cryostat. A conductor with 5.5 μm thick RE123 exhibits high Ic values of 937 A/cm-width at 77 K, self field, 637 A/cm-width at 50 K, 5 T and 976 A/cm-width at 40 K, 5 T.

  12. 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.

  13. 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.

  14. 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

  15. Polymer-assisted deposition of films

    Science.gov (United States)

    McCleskey,Thomas M.; Burrell,Anthony K.; Jia,Quanxi; Lin,Yuan

    2012-02-28

    A polymer assisted deposition process for deposition of metal nitride films and the like is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures under a suitable atmosphere to yield metal nitride films and the like. Such films can be conformal on a variety of substrates including non-planar substrates. In some instances, the films can be epitaxial in structure and can be of optical quality. The process can be organic solvent-free.

  16. 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.

  17. 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.)

  18. Thickness dependence of Ic and Jc of LTG-SmBCO coated-conductor on IBAD-MgO tapes

    International Nuclear Information System (INIS)

    We have reported SmBa2Cu3Oy (SmBCO) films on single crystalline substrates prepared by low-temperature growth (LTG) technique. The LTG-SmBCO films showed high critical current densities in magnetic fields compared with conventional SmBCO films prepared by pulsed laser deposition (PLD) method. In this study, to enhance critical current (Ic) in magnetic field, we fabricated thick LTG-SmBCO films on metal substrates with ion-beam assisted deposition (IBAD)-MgO buffer and estimated the Ic and Jc in magnetic fields. All the SmBCO films showed c-axis orientation and cube-on-cube in-plane texture. Tc of the LTG-SmBCO films were 93.1-93.4 K. Jc and Ic of a 0.5 μm-thick SmBCO film were 3.0 MA/cm2 and 150 A/cm-width at 77 K in self-field, respectively. Those of a 2.0 μm-thick film were 1.6 MA/cm2 and 284 A/cm-width respectively. Although Ic increased with the film thickness increasing up to 2 μm, the Ic tended to be saturated in 300 A/cm-width. From a cross sectional TEM image of the SmBCO film, we recognized a-axis oriented grains and 45o grains and Cu-O precipitates. Because these undesired grains form dead layers, Ic saturated above a certain thickness. We achieved that Ic in magnetic fields of the LTG-SmBCO films with a thickness of 2.0 μm were 88 A/cm-width at 1 T and 28 A/cm-width at 3 T.

  19. Adhesion strength study of IBAD-MOCVD-based 2G HTS wire using a peel test

    International Nuclear Information System (INIS)

    A peel test was used to study the adhesion strength of a commercial grade 2G HTS wire which features a characteristic multilayer structure with the rare earth-based MOCVD superconducting film deposited on an IBAD-MgO template. The peel test could be carried out at various peeling angles (from 90° to 180°) and the peel strength of a wire was defined as the steady-state peeling load determined from a load-displacement curve. The test results had good reproducibility and accuracy, making the test a reliable and useful method for studying the adhesion strength of the wire. By characterizing the peeled surfaces the weakest interface in a wire could be identified. The peel strength data of the wire was analyzed together with the performance of the experimental magnet coils fabricated using the wire. The effect of the silver contact layer annealing on the peel strength is discussed.

  20. Large area deposition of YBCO thick films for applications in resistive fault current limiting devices

    International Nuclear Information System (INIS)

    The preparation of the switching element of a resistive superconducting fault current limiter requires the up-scaling of deposition techniques for thin YBa2Cu3O7-x (YBCO) films to large areas and high film thicknesses. For a projected 100 kVA limiter model an area of about 400 cm2 and a film thickness of up to 5 μm will be necessary, depending on the material properties like critical current density jc and normal state resistivity ρn. Within a joint project various deposition methods including pulsed laser deposition (PLD), magnetron sputtering (MS), thermal evaporation (TE) and plasma flash evaporation (PFE) are evaluated as possible candidates for the operation of deposition systems capable of coating 20 x 20 cm2 substrates. Both single crystalline wafers and polycrystalline ceramic plates are considered as substrates. To achieve high jc on polycrystalline substrate materials an additional zirconia buffer layer consisting of biaxially orientated crystallites has to be prepared by ion beam assisted deposition (IBAD). In small samples with IBAD buffer critical currents above 105 A cm-2 with a maximum of 1 x 106 A cm-2 have been achieved. The presently available sample sizes depend on the installed systems for YBCO and buffer deposition, respectively and on the commercial availability of the substrate material. The largest samples which have been prepared and characterised have sizes of 1 x 25 cm2 and 5 x 5 cm2 for PLD, 10 x 10 cm2 for TE and IBAD, 2 in. (1 in.=2.54 cm) diameter for MS, and 3 x 7 cm2 for PFE. The corresponding highest film thicknesses are 4.5 μm for PLD, 1.4 μm for TE, 1.6 μm for IBAD and 0.4 μm for MS. (orig.)

  1. Electrostatic force assisted deposition of graphene

    Science.gov (United States)

    Liang, Xiaogan

    2011-11-15

    An embodiment of a method of depositing graphene includes bringing a stamp into contact with a substrate over a contact area. The stamp has at least a few layers of the graphene covering the contact area. An electric field is developed over the contact area. The stamp is removed from the vicinity of the substrate which leaves at least a layer of the graphene substantially covering the contact area.

  2. Microreactor-Assisted Solution Deposition for Compound Semiconductor Thin Films

    Directory of Open Access Journals (Sweden)

    Chang-Ho Choi

    2014-05-01

    Full Text Available State-of-the-art techniques for the fabrication of compound semiconductors are mostly vacuum-based physical vapor or chemical vapor deposition processes. These vacuum-based techniques typically operate at high temperatures and normally require higher capital costs. Solution-based techniques offer opportunities to fabricate compound semiconductors at lower temperatures and lower capital costs. Among many solution-based deposition processes, chemical bath deposition is an attractive technique for depositing semiconductor films, owing to its low temperature, low cost and large area deposition capability. Chemical bath deposition processes are mainly performed using batch reactors, where all reactants are fed into the reactor simultaneously and products are removed after the processing is finished. Consequently, reaction selectivity is difficult, which can lead to unwanted secondary reactions. Microreactor-assisted solution deposition processes can overcome this limitation by producing short-life molecular intermediates used for heterogeneous thin film synthesis and quenching the reaction prior to homogeneous reactions. In this paper, we present progress in the synthesis and deposition of semiconductor thin films with a focus on CdS using microreactor-assisted solution deposition and provide an overview of its prospect for scale-up.

  3. Precursors for the polymer-assisted deposition of films

    Science.gov (United States)

    McCleskey, Thomas M.; Burrell, Anthony K.; Jia, Quanxi; Lin, Yuan

    2013-09-10

    A polymer assisted deposition process for deposition of metal oxide films is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures to yield metal oxide films. Such films can be epitaxial in structure and can be of optical quality. The process can be organic solvent-free.

  4. 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.

  5. Lipase biofilm deposited by Matrix Assisted Pulsed Laser Evaporation technique

    Energy Technology Data Exchange (ETDEWEB)

    Aronne, Antonio [Department of Chemical Engineering, Materials and Industrial Production, University of Naples “Federico II”, Napoli (Italy); Bloisi, Francesco, E-mail: bloisi@na.infn.it [SPIN – CNR, Naples (Italy); Department of Physics, University of Naples “Federico II”, Napoli (Italy); Calabria, Raffaela; Califano, Valeria [Istituto Motori – CNR, Naples (Italy); Depero, Laura E. [Department of Mechanical and Industrial Engineering, University of Brescia, Brescia (Italy); Fanelli, Esther [Department of Chemical Engineering, Materials and Industrial Production, University of Naples “Federico II”, Napoli (Italy); Federici, Stefania [Department of Mechanical and Industrial Engineering, University of Brescia, Brescia (Italy); Massoli, Patrizio [Istituto Motori – CNR, Naples (Italy); Vicari, Luciano R.M. [SPIN – CNR, Naples (Italy); Department of Physics, University of Naples “Federico II”, Napoli (Italy)

    2015-05-01

    Highlights: • A lipase film was deposited with Matrix Assisted Pulsed Laser Evaporation technique. • FTIR spectra show that laser irradiation do not damage lipase molecule. • Laser fluence controls the characteristics of complex structure generated by MAPLE. - Abstract: Lipase is an enzyme that finds application in biodiesel production and for detection of esters and triglycerides in biosensors. Matrix Assisted Pulsed Laser Evaporation (MAPLE), a technique derived from Pulsed Laser Deposition (PLD) for deposition of undamaged biomolecules or polymers, is characterized by the use of a frozen target obtained from a solution/suspension of the guest material (to be deposited) in a volatile matrix (solvent). The presence of the solvent avoids or at least reduces the potential damage of guest molecules by laser radiation but only the guest material reaches the substrate in an essentially solvent-free deposition. MAPLE can be used for enzymes immobilization, essential for industrial application, allowing the development of continuous processes, an easier separation of products, the reuse of the catalyst and, in some cases, enhancing enzyme properties (pH, temperature stability, etc.) and catalytic activity in non-aqueous media. Here we show that MAPLE technique can be used to deposit undamaged lipase and that the complex structure (due to droplets generated during extraction from target) of the deposited material can be controlled by changing the laser beam fluence.

  6. Lipase biofilm deposited by Matrix Assisted Pulsed Laser Evaporation technique

    International Nuclear Information System (INIS)

    Highlights: • A lipase film was deposited with Matrix Assisted Pulsed Laser Evaporation technique. • FTIR spectra show that laser irradiation do not damage lipase molecule. • Laser fluence controls the characteristics of complex structure generated by MAPLE. - Abstract: Lipase is an enzyme that finds application in biodiesel production and for detection of esters and triglycerides in biosensors. Matrix Assisted Pulsed Laser Evaporation (MAPLE), a technique derived from Pulsed Laser Deposition (PLD) for deposition of undamaged biomolecules or polymers, is characterized by the use of a frozen target obtained from a solution/suspension of the guest material (to be deposited) in a volatile matrix (solvent). The presence of the solvent avoids or at least reduces the potential damage of guest molecules by laser radiation but only the guest material reaches the substrate in an essentially solvent-free deposition. MAPLE can be used for enzymes immobilization, essential for industrial application, allowing the development of continuous processes, an easier separation of products, the reuse of the catalyst and, in some cases, enhancing enzyme properties (pH, temperature stability, etc.) and catalytic activity in non-aqueous media. Here we show that MAPLE technique can be used to deposit undamaged lipase and that the complex structure (due to droplets generated during extraction from target) of the deposited material can be controlled by changing the laser beam fluence

  7. Controllable deposition of gadolinium doped ceria electrolyte films by magnetic-field-assisted electrostatic spray deposition

    International Nuclear Information System (INIS)

    This paper describes a simple and low-temperature approach to fabrication of dense and crack-free gadolinium doped ceria (GDC) thin films with controllable deposition by a magnetic-field-assisted electrostatic spray deposition technique. The influences of external permanent magnets on the deposition of GDC films were investigated. The coating area deposited using two magnets with the same pole arrangement decreased in comparison with the case of no magnets, whereas the largest deposition area was obtained in the system of the opposite poles. Analysis of as-deposited films at 450 °C indicated the formation of uniform, smooth and dense thin films with a single-phase fluorite structure. The films produced in the system using same poles were thicker, smaller in crystallite size and smoother than those fabricated under other conditions. Additionally, the GDC film deposited using the same pole arrangement showed the maximum in electrical conductivity of about 2.5 × 10−2 S/cm at a low operating temperature of 500 °C. - Highlights: • Magnetic-field-assisted electrostatic spray allows a controllable coating. • Dense, crack-free thin films were obtained at low process temperature of 450 °C. • Control of deposition, thickness and uniformity is easy to achieve simultaneously. • Films from the same pole were thicker, smaller in crystal size and smoother. • The maximum conductivity of doped ceria film was 2.5 × 10−2 S/cm at 500 °C

  8. Lipase biofilm deposited by Matrix Assisted Pulsed Laser Evaporation technique

    Science.gov (United States)

    Aronne, Antonio; Bloisi, Francesco; Calabria, Raffaela; Califano, Valeria; Depero, Laura E.; Fanelli, Esther; Federici, Stefania; Massoli, Patrizio; Vicari, Luciano R. M.

    2015-05-01

    Lipase is an enzyme that finds application in biodiesel production and for detection of esters and triglycerides in biosensors. Matrix Assisted Pulsed Laser Evaporation (MAPLE), a technique derived from Pulsed Laser Deposition (PLD) for deposition of undamaged biomolecules or polymers, is characterized by the use of a frozen target obtained from a solution/suspension of the guest material (to be deposited) in a volatile matrix (solvent). The presence of the solvent avoids or at least reduces the potential damage of guest molecules by laser radiation but only the guest material reaches the substrate in an essentially solvent-free deposition. MAPLE can be used for enzymes immobilization, essential for industrial application, allowing the development of continuous processes, an easier separation of products, the reuse of the catalyst and, in some cases, enhancing enzyme properties (pH, temperature stability, etc.) and catalytic activity in non-aqueous media. Here we show that MAPLE technique can be used to deposit undamaged lipase and that the complex structure (due to droplets generated during extraction from target) of the deposited material can be controlled by changing the laser beam fluence.

  9. Electric field assisted aerosol assisted chemical vapour deposition of nanostructured metal oxide thin films

    International Nuclear Information System (INIS)

    Nanostructured thin films of tungsten, vanadium and titanium oxides were deposited on gas sensor substrates from the electric field assisted chemical vapour deposition reaction of tungsten hexaphenoxide, vanadyl acetylacetonate and titanium tetraisopropoxide respectively. The electric fields were generated by applying a potential difference between the inter-digitated electrodes of the gas sensor substrates during the deposition. The deposited films were characterised using scanning electron microscopy, X-ray diffraction and Raman spectroscopy. The application of an electric field, encouraged the formation of interesting and unusual nanostructured morphologies, with a change in scale length and island packing. It was also noted that crystallographic orientation of the films could be controlled as a function of electric field type and strength. The gas sensor properties of the films were also examined; it was found that a two to three fold enhancement in the gas response could be observed from sensors with enhanced morphologies compared to control sensors grown without application of an electric field. - Highlights: • Electric field assisted chemical vapour deposition method • Ability to create high surface area film architectures • Can produce enhanced sensor response • Good control over film properties

  10. Electric field assisted aerosol assisted chemical vapour deposition of nanostructured metal oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Naik, Anupriya J.T.; Bowman, Christopher; Panjwani, Naitik [Department of Chemistry, University College London, Christopher Ingold Laboratories, 20 Gordon Street, London WC1H OAJ (United Kingdom); Warwick, Michael E.A. [Department of Chemistry, University College London, Christopher Ingold Laboratories, 20 Gordon Street, London WC1H OAJ (United Kingdom); UCL Energy Institute, Central House, 14 Upper Woburn Place, London WC1H 0HY (United Kingdom); Binions, Russell, E-mail: r.binions@qmul.ac.uk [Department of Chemistry, University College London, Christopher Ingold Laboratories, 20 Gordon Street, London WC1H OAJ (United Kingdom); School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom)

    2013-10-01

    Nanostructured thin films of tungsten, vanadium and titanium oxides were deposited on gas sensor substrates from the electric field assisted chemical vapour deposition reaction of tungsten hexaphenoxide, vanadyl acetylacetonate and titanium tetraisopropoxide respectively. The electric fields were generated by applying a potential difference between the inter-digitated electrodes of the gas sensor substrates during the deposition. The deposited films were characterised using scanning electron microscopy, X-ray diffraction and Raman spectroscopy. The application of an electric field, encouraged the formation of interesting and unusual nanostructured morphologies, with a change in scale length and island packing. It was also noted that crystallographic orientation of the films could be controlled as a function of electric field type and strength. The gas sensor properties of the films were also examined; it was found that a two to three fold enhancement in the gas response could be observed from sensors with enhanced morphologies compared to control sensors grown without application of an electric field. - Highlights: • Electric field assisted chemical vapour deposition method • Ability to create high surface area film architectures • Can produce enhanced sensor response • Good control over film properties.

  11. Plasma assisted chemical vapour deposition for optical coatings

    International Nuclear Information System (INIS)

    Full text: Plasma assisted chemical vapour deposition (PECVD) is commonly used in semiconductor fabrication plants for depositing layers of dielectric materials. Reactive gasses are admitted to a chamber at low pressure and applying an electric field, usually a RF field, generates a plasma. The gasses react to form a solid material on the walls of the chamber and substrates. In this project we are exploring the possibility of applying this method to the growth of multilayer optical thin films. A small prototype system was constructed and optical multi layers of up to 24 layers were deposited over a diameter of 90 mm. The system uses 13.56 MHz RF to generate the plasma in a simple capacitive plate chamber. The gasses used were silane, oxygen and nitrogen. This allows SiO2 (RI 1.45) and Si3N4 (RI 1.93) to be deposited. Multilayer coatings were designed using these materials on TFCalc. The required thickness for the various layers were tabulated and fed into a computer controlling the gas flow during deposition. In this way the structures were deposited semi-automatically. The growing films were monitored using a spectrometer looking at light reflected from the growing film over a range from 400 - 800 nm simultaneously. This data was then used to reconstruct the deposition and analyze deviations from the design. An SEM micrograph of the cross-section of the multilayers was used to obtain relative thicknesses of the individual layers. Other structures deposited include rugate notch filters, coloured filters and broad band anti-reflection layers. Running the prototype has proved the concept and the project has moved to a scale up stage in which a larger version is being constructed at Avtronics Pty Ltd. This aims to coat uniformly over a diameter of 600 mm. Initially, the same materials will be used to produce coatings but fixture work will increase the refractive index range of materials which can be deposited and fully automate the coating process. (authors)

  12. Ion assisted methods of deposition of SiC

    International Nuclear Information System (INIS)

    This study describes attempts to synthesize thin SiC films by using a variety of ion beam processing routes at non-elevated temperature. SiC is one of the most widely investigated materials because it has many attractive properties. A main objective of this investigation was to compare and contrast different methods of ion assistance for deposition of SiC films and to attempt to grow functionally gradient films. Three approaches were employed. (1) Silicone oil vapour deposition under concurrent argon ion irradiation in which silicone vapour was decomposed and adsorbed on the substrate. (2) Dual ion beam deposition in which two argon ion beams were employed, with one sputtering a silicon target to provide a Si flux, and the other bombarding the substrate on which films grow. Methane and ethene gas were introduced into the system with a partial pressure up to 1.8 x 10-2Pa. The energy of the sputtering beam was around 1 keV, whilst the bombarding beam energies were altered from 0 to 500 eV. (3) Dual target sputtering in which the target consisted of carbon and silicon. The different area ratios of carbon and silicon targets were investigated. (Author)

  13. Plasma and Ion Assistance in Physical Vapor Deposition: AHistorical Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre

    2007-02-28

    Deposition of films using plasma or plasma-assist can betraced back surprisingly far, namely to the 18th century for arcs and tothe 19th century for sputtering. However, only since the 1960s thecoatings community considered other processes than evaporation for largescale commercial use. Ion Plating was perhaps the first importantprocess, introducing vapor ionization and substrate bias to generate abeam of ions arriving on the surface of the growing film. Ratherindependently, cathodic arc deposition was established as an energeticcondensation process, first in the former Soviet Union in the 1970s, andin the 1980s in the Western Hemisphere. About a dozen various ion-basedcoating technologies evolved in the last decades, all characterized byspecific plasma or ion generation processes. Gridded and gridless ionsources were taken from space propulsion and applied to thin filmdeposition. Modeling and simulation have helped to make plasma and ionseffects to be reasonably well understood. Yet--due to the complex, oftennon-linear and non-equilibrium nature of plasma and surfaceinteractions--there is still a place for the experience plasma"sourcerer."

  14. 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

  15. Thin-Film Deposition of Metal Oxides by Aerosol-Assisted Chemical Vapour Deposition: Evaluation of Film Crystallinity

    Science.gov (United States)

    Takeuchi, Masahiro; Maki, Kunisuke

    2007-12-01

    Sn-doped In2O3 (ITO) thin films are deposited on glass substrates using 0.2 M aqueous and methanol solutions of InCl3(4H2O) with 5 mol % SnCl2(2H2O) by aerosol-assisted chemical vapour deposition under positive and negative temperature gradient conditions. The film crystallinity is evaluated by determining the film thickness dependence of X-ray diffraction peak height. When using aqueous solution, the ITO films grow with the same crystallinity during the deposition, but when using methanol solution, the preferred orientation of ITO changes during the deposition.

  16. Structural and electrical properties of electric field assisted spray deposited pea structured ZnO film

    Science.gov (United States)

    Chaturvedi, Neha; Swami, Sanjay Kumar; Dutta, Viresh

    2016-05-01

    Spray deposition of ZnO film was carried out. The uneven growth of ZnO nanostructures is resulted for spray deposited ZnO film. Application of DC voltage (1000V) during spray deposition provides formation of pea like structures with uniform coverage over the substrate. Electric field assisted spray deposition provides increased crystallinity with reduced resistivity and improved mobility of the ZnO film as compared to spray deposited ZnO film without electric field. This with large area deposition makes the process more efficient than other techniques.

  17. CrN films deposited by ion source-assisted magnetron sputtering

    International Nuclear Information System (INIS)

    CrN coatings were deposited on Si (100) and piston rings by ion source assisted 40 kHz magnetron sputtering. Structure and composition of the coatings were characterized by X-ray diffraction, atomic force microscopy, scanning electron microscopy and transmission electron microscopy. Mechanical and tribological properties were assessed by microhardness and pin-on-disc testing. The ion source-assisted system has a deposition rate of 3.88 μm/h, against 2.2 μm/h without ion-source assistance. The CrN coatings prepared with ion source assistance exhibited an increase in microhardness (up to 16.3 GPa) and decrease in friction coefficient (down to 0.48) at the optimized cathode source-to-substrate distance. Under optimized conditions, CrN coatings were deposited on piston rings, with a thickness of 25 μm and hardness of 17.85 GPa. (authors)

  18. Laser-assisted deposition of thin C60 films

    DEFF Research Database (Denmark)

    Schou, Jørgen; Canulescu, Stela; Fæster, Søren

    Metal and metal oxide films with controlled thickness from a fraction of a monolayer up more than 1000 nm and known stoichiometry can be produced by pulsed laser deposition (PLD) relatively easily, and (PLD) is now a standard technique in all major research laboratories within materials science...

  19. Microwave assisted apatite coating deposition on Ti6Al4V implants

    International Nuclear Information System (INIS)

    In this work we report a novel microwave assisted technology to deposit a uniform, ultra-thin apatite coating without any cracks on titanium implants in minutes. This method comprises of conventional biomimetic coating in synergism with microwave irradiation to result in alkaline earth phosphate nucleation. The microwave assisted coating process mainly follows the initial stages of biomimetic coating until the step of the Ca-P nuclei formation. After that, due to microwave irradiation more Ca-P nuclei are formed to cover the whole surface of the implant instead of the growth of deposited Ca-P nuclei to Ca-P globules and coatings. It is interesting to note the doping of Mg2+ to Ca-P apatite coating can significantly change the properties and performances of as-deposited coatings. The hydrophilicity, physical properties, bioactivity, cell adhesion, and growth capability of as-deposited microwave assisted coatings were investigated. The study shows that this coating technology has great potential in biomedical applications. Additionally, since biomimetic coating can be applied to series of implant materials such as polymer, metals and glass, it is expected this microwave assisted coating technology can also be applied to these materials if they can remains stable at 100 °C, the boiling point of water. - Highlights: • A microwave assisted apatite coating process. • Apatite composition can be controlled by adjusting solution composition. • The deposited apatite coating is uniform, non-crack, and ultra-thin. • The coating process takes only a few minutes

  20. Light-assisted deposition of CdS thin films

    Science.gov (United States)

    Bacaksiz, E.; Novruzov, V.; Karal, H.; Yanmaz, E.; Altunbas, M.; Kopya, A. I.

    2001-11-01

    The effects of white light illumination during the deposition of CdS thin films in a quasi-closed volume on the structural, photoelectrical and optical properties are investigated. The films were highly c-axis oriented with an increasing intensity of (002) reflection as the illumination increases. The room temperature resistivity values of the CdS films decreased in the range of 107-104 Ω cm. The photosensitivity in the fundamental absorption region and the transparency in the transmission region considerably increased as the illumination increased. Under 100 mW cm-2 insolation, the efficiencies of the CdS/CdTe solar cells based on CdS window materials which were deposited: (1) in the dark; and (2) under an illumination of 150 mW cm-2 were found to be 1.8% and 7.3%, respectively.

  1. Solvent-assisted dewetting during chemical vapor deposition.

    Science.gov (United States)

    Chen, Xichong; Anthamatten, Mitchell

    2009-10-01

    This study examines the use of a nonreactive solvent vapor, tert-butanol, during initiated chemical vapor deposition (iCVD) to promote polymer film dewetting. iCVD is a solventless technique to grow polymer thin films directly from gas phase feeds. Using a custom-built axisymmetric hot-zone reactor, smooth poly(methyl methacrylate) films are grown from methyl methacrylate (MMA) and tert-butyl peroxide (TBPO). When solvent vapor is used, nonequilibrium dewetted structures comprising of randomly distributed polymer droplets are observed. The length scale of observed topographies, determined using power spectral density (PSD) analysis, ranges from 5 to 100 microm and is influenced by deposition conditions, especially the carrier gas and solvent vapor flow rates. The use of a carrier gas leads to faster deposition rates and suppresses thin film dewetting. The use of solvent vapor promotes dewetting and leads to larger length scales of the dewetted features. Control over lateral length scale is demonstrated by preparation of hierarchal "bump on bump" topographies. Vapor-induced dewetting is demonstrated on silicon wafer substrate with a native oxide layer and also on hydrophobically modified substrate prepared using silane coupling. Autophobic dewetting of PMMA from SiOx/Si during iCVD is attributed to a thin film instability driven by both long-range van der Waals forces and short-range polar interactions. PMID:19670895

  2. Photocatalytic activity of tin-doped TiO{sub 2} film deposited via aerosol assisted chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Chua, Chin Sheng, E-mail: cschua@simtech.a-star.edu.sg [School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, 638075 (Singapore); Tan, Ooi Kiang; Tse, Man Siu [School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Ding, Xingzhao [Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, 638075 (Singapore)

    2013-10-01

    Tin-doped TiO{sub 2} films are deposited via aerosol assisted chemical vapor deposition using a precursor mixture composing of titanium tetraisopropoxide and tetrabutyl tin. The amount of tin doping in the deposited films is controlled by the volume % concentration ratio of tetrabutyl tin over titanium tetraisopropoxide in the mixed precursor solution. X-ray diffraction analysis results reveal that the as-deposited films are composed of pure anatase TiO{sub 2} phase. Red-shift in the absorbance spectra is observed attributed to the introduction of Sn{sup 4+} band states below the conduction band of TiO{sub 2}. The effect of tin doping on the photocatalytic property of TiO{sub 2} films is studied through the degradation of stearic acid under UV light illumination. It is found that there is a 10% enhancement on the degradation rate of stearic acid for the film with 3.8% tin doping in comparison with pure TiO{sub 2} film. This improvement of photocatalytic performance with tin incorporation could be ascribed to the reduction of electron-hole recombination rate through charge separation and an increased amount of OH radicals which are crucial for the degradation of stearic acid. Further increase in tin doping results in the formation of recombination site and large anatase grains, which leads to a decrease in the degradation rate. - Highlights: ► Deposition of tin-doped TiO{sub 2} film via aerosol assisted chemical vapor depositionDeposited anatase films show red-shifted in UV–vis spectrum with tin-dopants. ► Photoactivity improves at low tin concentration but reduces at higher concentration. ► Improvement in photoactivity due to bandgap narrowing from Sn{sup 4+} band states ► Maximum photoactivity achieved occurs for films with 3.8% tin doping.

  3. In situ biaxial texture analysis of MGO films during growth on amorphous substrates by ion beam-assisted deposition

    Energy Technology Data Exchange (ETDEWEB)

    Brewer, R. T. (Rhett T.); Arendt, P. N. (Paul N.); Atwater, H. A. (Harry A.); Groves, J. R. (James R.)

    2001-01-01

    We used a previously reported kinematical electron scattering model to develop a RHEED based method for performing quantitative analysis of mosaic polycrystalline thin film in-plane and out-of-plain grain orientation distributions. RHEED based biaxial texture measurements are compared to X-Ray and transmission electron microscopy measurements to establish the validity of the RHEED analysis method. In situ RHEED analysis reveals that the out of plane orientation distribution starts out very broad, and then decreases during IBAD MgO growth. Other results included evidence that the in-plane orientation distribution narrows, the grain size increases, and the film roughens as film thickness increases during IBAD MgO growth. Homoepitaxy of MgO improves the biaxial texture of the IBAD layer, making X-ray measurements of IBAD films with an additional homoepitaxial layer not quantitatively representative of the IBAD layer. Systematic offsets between RHEED analysis and X-ray measurements of biaxial texture, coupled with evidence that biaxial texture improves with increasing film thickness, indicate that RHEED is a superior technique for probing surface biaxial texture.

  4. Superhydrophobic polymer films via aerosol assisted deposition - Taking a leaf out of nature's book

    International Nuclear Information System (INIS)

    Aerosol assisted deposition of three sets of polymer films based on commercially available resins was achieved on various substrates. The films were characterised using a range of methods, including water contact and slip angle to determine water repellent properties. The aerosol assisted deposition inside the chemical vapour deposition reactor was unique in generating a highly rough superhydrophobic surface with water contact angles up to 170o. During the deposition process, two of the polymers were cured resulting in the development of high surface morphology. It was observed that the polymer that did not cure did not develop such a rough surface resulting in a lower water contact angle (∼ 99o). The superhydrophobic films had a Cassie-Baxter type wetting with water failing to penetrate the surface porosity, water spraying on the surface would bounce off. These films had exceptionally low slide angles of ca 1-2o from the horizontal.

  5. Improvement of copper plating adhesion on silane modified PET film by ultrasonic-assisted electroless deposition

    International Nuclear Information System (INIS)

    Copper thin film on silane modified poly(ethylene terephthalate) (PET) substrate was fabricated by ultrasonic-assisted electroless deposition. The composition and topography of copper plating PET films were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. Peel adhesion strength, as high as 16.7 N/cm, was achieved for the planting copper layer to the modified PET substrate with ultrasonic-assisted deposition; however, a relative low value as 11.9 N/cm was obtained for the sample without ultrasonic vibration by the same measurement. The electrical conductivity of Cu film was changed from 7.9 x 104 to 2.1 x 105 S/cm by using ultrasonic technique. Ultrasonic operation has the significant merits of fast deposition and formation of good membranes for electroless deposition of Cu on PET film.

  6. 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)

  7. Functional porphyrin thin films deposited by matrix assisted pulsed laser evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Cristescu, R., E-mail: rodica.cristescu@inflpr.ro [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, P.O. Box MG-36, Atomistilor 409, Bucharest-Magurele (Romania); Popescu, C.; Popescu, A.C.; Mihailescu, I.N. [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, P.O. Box MG-36, Atomistilor 409, Bucharest-Magurele (Romania); Ciucu, A.A. [Univeristy of Bucharest, Chemistry Department, Bucharest (Romania); Andronie, A.; Iordache, S.; Stamatin, I. [University of Bucharest, 3 Nano-SAE Research Center, P.O. Box MG-38, Bucharest-Magurele (Romania); Fagadar-Cosma, E. [Institute of Chemistry Timisoara of Romanian Academy, Department of Organic Chemistry, 300223 Timisoara (Romania); Chrisey, D.B. [Rensselaer Polytechnic Institute, School of Engineering, Department of Materials Science and Engineering, Troy 12180-3590, NY (United States)

    2010-05-25

    We report the first successful deposition of functionalized and nanostructured Zn(II)- and Co(II)-metalloporphyrin thin films by matrix assisted pulsed laser evaporation onto silicon wafers, quartz plates and screen-printed electrodes. The deposited nanostructures have been characterized by Raman spectrometry and cyclic voltammetry. The novelty of our contribution consists of the evaluation of the sensitivity of the MAPLE-deposited Zn(II)- and Co(II)-metalloporphyrin thin films on screen-printed carbon nanotube electrodes when challenged with dopamine.

  8. Functional porphyrin thin films deposited by matrix assisted pulsed laser evaporation

    International Nuclear Information System (INIS)

    We report the first successful deposition of functionalized and nanostructured Zn(II)- and Co(II)-metalloporphyrin thin films by matrix assisted pulsed laser evaporation onto silicon wafers, quartz plates and screen-printed electrodes. The deposited nanostructures have been characterized by Raman spectrometry and cyclic voltammetry. The novelty of our contribution consists of the evaluation of the sensitivity of the MAPLE-deposited Zn(II)- and Co(II)-metalloporphyrin thin films on screen-printed carbon nanotube electrodes when challenged with dopamine.

  9. 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.

  10. UV and RIR matrix assisted pulsed laser deposition of organic MEH-PPV films

    International Nuclear Information System (INIS)

    A comparative study of thin film production based on gentle laser-ablation techniques has been carried out with the luminescent polymer poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene]. Using a free-electron laser films were made by resonant infrared pulsed laser deposition (RIR-PLD). For the first time resonant infrared matrix assisted pulsed laser evaporation (RIR-MAPLE) was successfully demonstrated on a luminescent polymer system. In addition to this, an excimer laser has been used for UV-MAPLE depositions at 193 and 248-nm irradiation. Films deposited onto NaCl and quartz substrates were analyzed by Fourier transform infrared spectroscopy, UV-visible absorbance and photoluminescence. Photoluminescent material was deposited by RIR-MAPLE and 248-nm MAPLE, while the RIR-PLD and 193-nm-MAPLE depositions displayed the smoothest surfaces but did not show photoluminescence

  11. 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...

  12. Study of electrospray assisted electrophoretic deposition of carbon nanotubes on insulator substrates

    Science.gov (United States)

    Kanakamedala, Kalyan; DeSoto, Jared; Sarkar, Anirban; Race, Theda Daniels

    2015-11-01

    In recent years, electrophoretic deposition (EPD) has been adopted as a cost-effective and reliable single-step solution-based room temperature coating method for carbon nanotubes (CNTs), predominantly on conducting surfaces. Contrary to this general pre-requisite of conductive target substrates, in this work we have explored a fabrication strategy for the scalable deposition of CNTs on insulating glass surfaces by the sequential combination of electrospraying and the EPD technique. This combined process flow has been referred to as "electrospray-assisted EPD", where an initial CNT coating on glass substrates is obtained by electrospraying which, in turn, further assists CNT film growth by EPD. The successful integration of the electrospray technique in the EPD process flow also eliminates the need for surface functionalization of the insulator substrates prior to the deposition step. Electrospray-assisted EPD has resulted in the successful fabrication of uniform, homogenous, and thick CNT deposits (˜4.5 - 5 μm) with precise thickness control. A detailed investigation of the effect of the initial electrosprayed coating on the final CNT film growth and thickness is also presented in this report. This research endeavor presents a significant opportunity for the integration of this deposition model into a wider platform of materials research and technology, chemical sensing, and applications based upon printable and flexible electronics. [Figure not available: see fulltext.

  13. Growth mechanism of planar or nanorod structured tungsten oxide thin films deposited via aerosol assisted chemical vapour deposition (AACVD)

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Min; Blackman, Chris [Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom)

    2015-07-15

    Aerosol assisted chemical vapour deposition (AACVD) is used to deposit tungsten oxide thin films from tungsten hexacarbonyl (W(CO){sub 6}) at 339 to 358 C on quartz substrate. The morphologies of as-deposited thin films, which are comprised of two phases (W{sub 25}O{sub 73} and W{sub 17}O{sub 47}), vary from planar to nanorod (NR) structures as the distance from the inlet towards the outlet of the reactor is traversed. This is related to variation of the actual temperature on the substrate surface (ΔT = 19 C), which result in a change in growth mode due to competition between growth rate (perpendicular to substrate) and nucleation rate (parallel to substrate). When the ratio of perpendicular growth rate to growth rate contributed by nucleation is higher than 7.1, the as-deposited tungsten oxide thin film forms as NR. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Carbon nitride deposition onto steel substrates by radio frequency plasma assisted pulsed laser deposition with substrate heating

    International Nuclear Information System (INIS)

    Carbon nitride (CNx) films are promising candidates for tribological application due to its low friction coefficient. However, the adhesion strength of the film on steel substrate was poor at elevated temperature during deposition. In this study, CNx film was fabricated on bearing steel (SUJ2) and austenitic stainless steel (AISI304) substrates with radio frequency (RF) plasma assisted pulsed laser deposition in nitrogen gas atmosphere. Adhesion strength of the film on the steel substrates was improved by blasting or polishing of the substrate surface before deposition. Thick CNx film was deposited on the steel substrates by substrate heating and substrate pretreatment. The atomic composition ratio of N/C and the bonding ratio of sp3 / (sp2 + sp3) increased with substrate temperature. Maximum atomic composition ratio of N/C was 0.155 on SUJ2 substrate and 0.171 on AISI304 substrate at 40 W of RF power and 673 K of substrate temperature. The maximum adhesion strength of 14.8 MPa was obtained at blasted SUJ2 substrate. The maximum knoop hardness of 8.94 GPa and the lowest friction coefficient of 0.072 were obtained on SUJ2 substrate with polished no. 150 at 40 W of RF power and 673 K of substrate temperature.

  15. Carbon nitride deposition onto steel substrates by radio frequency plasma assisted pulsed laser deposition with substrate heating

    Energy Technology Data Exchange (ETDEWEB)

    Yasui, Toshiaki, E-mail: yasui@me.tut.ac.jp [Department of Mechanical Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi, Aichi 441-8580 (Japan); Kimura, Shingo [Department of Production Systems Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi, Aichi 441-8580 (Japan); Nishikawa, Ryutaro; Fukumoto, Masahiro [Department of Mechanical Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi, Aichi 441-8580 (Japan)

    2012-11-15

    Carbon nitride (CNx) films are promising candidates for tribological application due to its low friction coefficient. However, the adhesion strength of the film on steel substrate was poor at elevated temperature during deposition. In this study, CNx film was fabricated on bearing steel (SUJ2) and austenitic stainless steel (AISI304) substrates with radio frequency (RF) plasma assisted pulsed laser deposition in nitrogen gas atmosphere. Adhesion strength of the film on the steel substrates was improved by blasting or polishing of the substrate surface before deposition. Thick CNx film was deposited on the steel substrates by substrate heating and substrate pretreatment. The atomic composition ratio of N/C and the bonding ratio of sp{sup 3} / (sp{sup 2} + sp{sup 3}) increased with substrate temperature. Maximum atomic composition ratio of N/C was 0.155 on SUJ2 substrate and 0.171 on AISI304 substrate at 40 W of RF power and 673 K of substrate temperature. The maximum adhesion strength of 14.8 MPa was obtained at blasted SUJ2 substrate. The maximum knoop hardness of 8.94 GPa and the lowest friction coefficient of 0.072 were obtained on SUJ2 substrate with polished no. 150 at 40 W of RF power and 673 K of substrate temperature.

  16. CdS thin films prepared by laser assisted chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, L.V.; Mendivil, M.I.; Garcia Guillen, G.; Aguilar Martinez, J.A. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Krishnan, B. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); CIIDIT – Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico); Avellaneda, D.; Castillo, G.A.; Das Roy, T.K. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); CIIDIT – Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)

    2015-05-01

    Highlights: • CdS thin films by conventional CBD and laser assisted CBD. • Characterized these films using XRD, XPS, AFM, optical and electrical measurements. • Accelerated growth was observed in the laser assisted CBD process. • Improved dark conductivity and good photocurrent response for the LACBD CdS. - Abstract: In this work, we report the preparation and characterization of CdS thin films by laser assisted chemical bath deposition (LACBD). CdS thin films were prepared from a chemical bath containing cadmium chloride, triethanolamine, ammonium hydroxide and thiourea under various deposition conditions. The thin films were deposited by in situ irradiation of the bath using a continuous laser of wavelength 532 nm, varying the power density. The thin films obtained during deposition of 10, 20 and 30 min were analyzed. The changes in morphology, structure, composition, optical and electrical properties of the CdS thin films due to in situ irradiation of the bath were analyzed by atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV–vis spectroscopy. The thin films obtained by LACBD were nanocrystalline, photoconductive and presented interesting morphologies. The results showed that LACBD is an effective synthesis technique to obtain nanocrystalline CdS thin films having good optoelectronic properties.

  17. CdS thin films prepared by laser assisted chemical bath deposition

    International Nuclear Information System (INIS)

    Highlights: • CdS thin films by conventional CBD and laser assisted CBD. • Characterized these films using XRD, XPS, AFM, optical and electrical measurements. • Accelerated growth was observed in the laser assisted CBD process. • Improved dark conductivity and good photocurrent response for the LACBD CdS. - Abstract: In this work, we report the preparation and characterization of CdS thin films by laser assisted chemical bath deposition (LACBD). CdS thin films were prepared from a chemical bath containing cadmium chloride, triethanolamine, ammonium hydroxide and thiourea under various deposition conditions. The thin films were deposited by in situ irradiation of the bath using a continuous laser of wavelength 532 nm, varying the power density. The thin films obtained during deposition of 10, 20 and 30 min were analyzed. The changes in morphology, structure, composition, optical and electrical properties of the CdS thin films due to in situ irradiation of the bath were analyzed by atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV–vis spectroscopy. The thin films obtained by LACBD were nanocrystalline, photoconductive and presented interesting morphologies. The results showed that LACBD is an effective synthesis technique to obtain nanocrystalline CdS thin films having good optoelectronic properties

  18. Plasma Assisted Chemical Vapour Deposition – Technological Design Of Functional Coatings

    Directory of Open Access Journals (Sweden)

    Januś M.

    2015-06-01

    Full Text Available Plasma Assisted Chemical Vapour Deposition (PA CVD method allows to deposit of homogeneous, well-adhesive coatings at lower temperature on different substrates. Plasmochemical treatment significantly impacts on physicochemical parameters of modified surfaces. In this study we present the overview of the possibilities of plasma processes for the deposition of diamond-like carbon coatings doped Si and/or N atoms on the Ti Grade2, aluminum-zinc alloy and polyetherketone substrate. Depending on the type of modified substrate had improved the corrosion properties including biocompatibility of titanium surface, increase of surface hardness with deposition of good adhesion and fine-grained coatings (in the case of Al-Zn alloy and improving of the wear resistance (in the case of PEEK substrate.

  19. Structural Evolution of SiC Films During Plasma-Assisted Chemical Vapour Deposition

    International Nuclear Information System (INIS)

    Evolution of chemical bonding configurations for the films deposited from hexamethyldisiloxane (HMDSO) diluted with H2 during plasma assisted chemical vapour deposition is investigated. In the experiment a small amount of CH4 was added to adjust the plasma environment and modify the structure of the deposited films. The measurements of Raman spectroscopy and X-ray diffraction (XRD) revealed the production of 6H-SiC embedded in the amorphous matrix without the input of CH4. As CH4 was introduced into the deposition reaction, the transition of 6H-SiC to cubic SiC in the films took place, and also the film surfaces changed from a structure of ellipsoids to cauliflower-like shapes. With a further increase of CH4 in the flow ratio, the obtained films varied from Si-C bonding dominant to a sp2/sp3 carbon-rich composition. (low temperature plasma)

  20. 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

  1. The minimum amount of "matrix " needed for matrix-assisted pulsed laser deposition of biomolecules

    DEFF Research Database (Denmark)

    Tabetah, Marshall; Matei, Andreea; Constantinescu, Catalin;

    2014-01-01

    The ability of matrix-assisted pulsed laser evaporation (MAPLE) technique to transfer and deposit high-quality thin organic, bioorganic, and composite films with minimum chemical modification of the target material has been utilized in numerous applications. One of the outstanding problems in MAPLE...... the ejection of intact lysozyme molecules from pressed lysozyme targets containing small amounts of residual water. The results of this study suggest a new approach for deposition of thin films of bioorganic molecules with minimum chemical modification of the molecular structure and minimum...... film deposition, however, is the presence of residual solvent (matrix) codeposited with the polymer material and adversely affecting the quality of the deposited films. In this work, we investigate the possibility of alleviating this problem by reducing the amount of matrix in the target. A series of...

  2. 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.

  3. Ion-Bombardment of X-Ray Multilayer Coatings - Comparison of Ion Etching and Ion Assisted Deposition

    NARCIS (Netherlands)

    Puik, E. J.; van der Wiel, M. J.; Zeijlemaker, H.; Verhoeven, J.

    1991-01-01

    The effects of two forms of ion bombardment treatment on the reflectivity of multilayer X-ray coatings were compared: ion etching of the metal layers, taking place after deposition, and ion bombardment during deposition, the so-called ion assisted deposition. The ion beam was an Ar+ beam of 200 eV,

  4. Ion assisted deposition of refractory oxide thin film coatings for improved optical and structural properties

    International Nuclear Information System (INIS)

    Ion assisted deposition technique (IAD) has emerged as a powerful tool to control the optical and structural properties of thin film coatings. Keeping in view the complexity of the interaction of ions with the films being deposited, sophisticated ion sources have been developed that cater to the need of modern optical coatings with stringent spectral and environmental specifications. In the present work, the results of ion assisted deposition (IAD) of two commonly used refractory oxides, namely TiO2 and ZrO2, using cold cathode ion source (CC-102R) are presented. Through successive feedback and calibration techniques, various ion beams as well as deposition parameters have been optimized to achieve the best optical and structural film properties in the prevalent deposition geometry of the coating system. It has been possible to eliminate the unwanted optical and structural inhomogeneities from these films using and optimized set of process parameters. Interference modulated spectrophotometric and phase modulated ellipsometric techniques have been very successfully utilized to analyze the optical and structural parameters of the films. Several precision multilayer coatings have been developed and are being used for laser and spectroscopic applications. (author)

  5. 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

  6. Gradient SiNx IBAD coating: preparation and measurement of concentration profile

    International Nuclear Information System (INIS)

    Preparation of gradient SiNx coating by the ion beam assisted deposition method with high ion energy is described. Special shape of the concentration of nitrogen in the coating was chosen and constructed. Concentration profile was constructed in three steps with different ratios of nitrogen and silicon atom fluxes. Ion energy was 90 keV. Concentration profile was measured by RBS (Rutherford Back Scattering) method. (author). 1 ref., 2 figs

  7. Plasma and Ion Assistance in Physical Vapor Deposition: A Historical Perspective

    OpenAIRE

    Anders, Andre

    2007-01-01

    Deposition of films using plasma or plasma-assist can be traced back surprisingly far, namely to the 18th century for arcs and to the 19th century for sputtering. However, only since the 1960s the coatings community considered other processes than evaporation for large scale commercial use. Ion Plating was perhaps the first important process, introducing vapor ionization and substrate bias to generate a beam of ions arriving on the surface of the growing film. Rather independently, catho...

  8. Laser-assisted chemical liquid-phase deposition of metals for micro- and optoelectronics

    OpenAIRE

    Kordás, K. (Krisztián)

    2002-01-01

    Abstract The demands toward the development of simple and cost-effective fabrication methods of metallic structures with high lateral resolution on different substrates - applied in many fields of technology, such as in microelectronics, optoelectronics, micromechanics as well as in sensor and actuator applications - gave the idea to perform this research. Due to its simplicity, laser-assisted chemical liquid-phase deposition (LCLD) has been investigated and applied for the metallization o...

  9. Mechanical and transport properties of IBAD/EDDC-SmBCO coated conductor tapes during fatigue loading

    Science.gov (United States)

    Shin, Hyung-Seop; Dedicatoria, Marlon J.

    2011-06-01

    In electrical devices like superconducting motor, generator and SMES, HTS coated conductor (CC) tapes will be subjected to alternating stress or strain during manufacturing and operation. The repeated loading will affect the mechanical integrity and eventually the electrical transport property of CC tapes. Therefore in such applications, electro-mechanical property of CC tapes should be evaluated. In this study, the endurance of an IBAD/EDDC-SmBCO CC tape under high-cycle fatigue loading has been evaluated. Applied maximum stress and fatigue life ( S-N) relation was obtained at 77 K. The mechanical properties and the critical current, I c, of the sample under fatigue loading were investigated at 77 K. Considering the practical operating environment, the effect of the stress ratio R, on the degradation behavior of I c under fatigue loading was also examined.

  10. 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.

  11. Aerosol assisted chemical vapor deposition using nanoparticle precursors: a route to nanocomposite thin films.

    Science.gov (United States)

    Palgrave, Robert G; Parkin, Ivan P

    2006-02-01

    Gold nanoparticle and gold/semiconductor nanocomposite thin films have been deposited using aerosol assisted chemical vapor deposition (CVD). A preformed gold colloid in toluene was used as a precursor to deposit gold films onto silica glass. These nanoparticle films showed the characteristic plasmon absorption of Au nanoparticles at 537 nm, and scanning electron microscopic (SEM) imaging confirmed the presence of individual gold particles. Nanocomposite films were deposited from the colloid concurrently with conventional CVD precursors. A film of gold particles in a host tungsten oxide matrix resulted from co-deposition with [W(OPh)(6)], while gold particles in a host titania matrix resulted from co-deposition with [Ti(O(i)Pr)(4)]. The density of Au nanoparticles within the film could be varied by changing the Au colloid concentration in the original precursor solution. Titania/gold composite films were intensely colored and showed dichromism: blue in transmitted light and red in reflected light. They showed metal-like reflection spectra and plasmon absorption. X-ray photoelectron spectroscopy and energy-dispersive X-ray analysis confirmed the presence of metallic gold, and SEM imaging showed individual Au nanoparticles embedded in the films. X-ray diffraction detected crystalline gold in the composite films. This CVD technique can be readily extended to produce other nanocomposite films by varying the colloids and precursors used, and it offers a rapid, convenient route to nanoparticle and nanocomposite thin films. PMID:16448130

  12. Aerosol-Assisted Chemical Vapor Deposited Thin Films for Space Photovoltaics

    Science.gov (United States)

    Hepp, Aloysius F.; McNatt, Jeremiah; Dickman, John E.; Jin, Michael H.-C.; Banger, Kulbinder K.; Kelly, Christopher V.; AquinoGonzalez, Angel R.; Rockett, Angus A.

    2006-01-01

    Copper indium disulfide thin films were deposited via aerosol-assisted chemical vapor deposition using single source precursors. Processing and post-processing parameters were varied in order to modify morphology, stoichiometry, crystallography, electrical properties, and optical properties in order to optimize device-quality material. Growth at atmospheric pressure in a horizontal hot-wall reactor at 395 C yielded best device films. Placing the susceptor closer to the evaporation zone and flowing a more precursor-rich carrier gas through the reactor yielded shinier, smoother, denser-looking films. Growth of (112)-oriented films yielded more Cu-rich films with fewer secondary phases than growth of (204)/(220)-oriented films. Post-deposition sulfur-vapor annealing enhanced stoichiometry and crystallinity of the films. Photoluminescence studies revealed four major emission bands (1.45, 1.43, 1.37, and 1.32 eV) and a broad band associated with deep defects. The highest device efficiency for an aerosol-assisted chemical vapor deposited cell was 1.03 percent.

  13. Radio-frequency assisted pulsed laser deposition of nanostructured WOx films

    International Nuclear Information System (INIS)

    The synthesis of tungsten oxide films with large surface area is promising for gas sensing applications. Thin WOx films were obtained by radio-frequency assisted pulsed laser deposition (RF-PLD). A tungsten target was ablated at 700 and 900 Pa in reactive oxygen, or in a 50% mixed oxygen-helium atmosphere at the same total pressure values. Corning glass was used as substrate, at temperatures including 673, 773 and 873 K. Other deposition parameters such as laser fluence (4.5 J cm-2), laser wavelength (355 nm), radiofrequency power (150 W), target to substrate distance (4 cm), laser spot area (0.7 mm2), and number of laser shots (12,000) were kept fixed. The sensitivity on the deposition conditions of morphology, nanostructure, bond coordination, and roughness of the obtained films were analyzed by scanning and transmission electron microscopy, micro-Raman spectroscopy, and atomic force microscopy.

  14. Ion assisted deposition of SiO2 film from silicon

    Science.gov (United States)

    Pham, Tuan. H.; Dang, Cu. X.

    2005-09-01

    Silicon dioxide, SiO2, is one of the preferred low index materials for optical thin film technology. It is often deposited by electron beam evaporation source with less porosity and scattering, relatively durable and can have a good laser damage threshold. Beside these advantages the deposition of critical optical thin film stacks with silicon dioxide from an E-gun was severely limited by the stability of the evaporation pattern or angular distribution of the material. The even surface of SiO2 granules in crucible will tend to develop into groove and become deeper with the evaporation process. As the results, angular distribution of the evaporation vapor changes in non-predicted manner. This report presents our experiments to apply Ion Assisted Deposition process to evaporate silicon in a molten liquid form. By choosing appropriate process parameters we can get SiO2 film with good and stable property.

  15. 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.

  16. 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.

  17. Growth Assisted by Glancing Angle Deposition: A New Technique to Fabricate Highly Porous Anisotropic Thin Films.

    Science.gov (United States)

    Sanchez-Valencia, Juan Ramon; Longtin, Remi; Rossell, Marta D; Gröning, Pierangelo

    2016-04-01

    We report a new methodology based on glancing angle deposition (GLAD) of an organic molecule in combination with perpendicular growth of a second inorganic material. The resulting thin films retain a very well-defined tilted columnar microstructure characteristic of GLAD with the inorganic material embedded inside the columns. We refer to this new methodology as growth assisted by glancing angle deposition or GAGLAD, since the material of interest (here, the inorganic) grows in the form of tilted columns, though it is deposited under a nonglancing configuration. As a "proof of concept", we have used silver and zinc oxide as the perpendicularly deposited material since they usually form ill-defined columnar microstructures at room temperature by GLAD. By means of our GAGLAD methodology, the typical tilted columnar microstructure can be developed for materials that otherwise do not form ordered structures under conventional GLAD. This simple methodology broadens significantly the range of materials where control of the microstructure can be achieved by tuning the geometrical deposition parameters. The two examples presented here, Ag/Alq3 and ZnO/Alq3, have been deposited by physical vapor deposition (PVD) and plasma enhanced chemical vapor deposition (PECVD), respectively: two different vacuum techniques that illustrate the generality of the proposed technique. The two type of hybrid samples present very interesting properties that demonstrate the potentiality of GAGLAD. On one hand, the Ag/Alq3 samples present highly optical anisotropic properties when they are analyzed with linearly polarized light. To our knowledge, these Ag/Alq3 samples present the highest angular selectivity reported in the visible range. On the other hand, ZnO/Alq3 samples are used to develop highly porous ZnO thin films by using Alq3 as sacrificial material. In this way, antireflective ZnO samples with very low refractive index and extinction coefficient have been obtained. PMID:26954074

  18. Aerosol assisted atmospheric pressure chemical vapor deposition of silicon thin films using liquid cyclic hydrosilanes

    International Nuclear Information System (INIS)

    Silicon (Si) thin films were produced using an aerosol assisted atmospheric pressure chemical vapor deposition technique with liquid hydrosilane precursors cyclopentasilane (CPS, Si5H10) and cyclohexasilane (CHS, Si6H12). Thin films were deposited at temperatures between 300 and 500 °C, with maximum observed deposition rates of 55 and 47 nm/s for CPS and CHS, respectively, at 500 °C. Atomic force microscopic analyses of the films depict smooth surfaces with roughness of 4–8 nm. Raman spectroscopic analysis indicates that the Si films deposited at 300 °C and 350 °C consist of a hydrogenated amorphous Si (a-Si:H) phase while the films deposited at 400, 450, and 500 °C are comprised predominantly of a hydrogenated nanocrystalline Si (nc-Si:H) phase. The wide optical bandgaps of 2–2.28 eV for films deposited at 350–400 °C and 1.7–1.8 eV for those deposited at 450–500 °C support the Raman data and depict a transition from a-Si:H to nc-Si:H. Films deposited at 450 oC possess the highest photosensitivity of 102–103 under AM 1.5G illumination. Based on the growth model developed for other silanes, we suggest a mechanism that governs the film growth using CPS and CHS. - Highlights: • Si films via AA-APCVD are realized using cyclopentasilane (CPS) and cyclohexasilane (CHS). • Low activation energies of CPS and CHS allow Si thin films at low temperatures (300 °C). • High growth rates of 47–55 nm/s were obtained at 500 °C • Near device quality Si thin films with 2–3 orders of photosensitivity • Si thin films via AA-APCVD are amenable to continuous roll-to-roll manufacturing

  19. Ion-assisted doping of 2-6 compounds during physical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Bube, R H [Stanford Univ., CA (USA). Dept. of Materials Science and Engineering

    1990-07-01

    This report describes a research program to (1) investigate ion-assisted doping during chemical vapor deposition of CdTe and (2) determine the influence of co-depositing ionized dopant atoms in the growth and structural and photoelectronic properties of the deposited films. In p-CdTe homo-epitaxial films, we controlled doping up to about 6 {times} 10{sup 16} cm{sup {minus}3} and 2 {times} 10{sup 17} cm{sub {minus}3} or ion-assisted depositions with As and P ions, respectively. At a growth rate of approximately 0.1 {mu}m/min, a substrate temperature of 400{degree}C, and ion energy of 60 eV, a maximum doping density was found near an ion current of 0.6{mu}A/cm{sup 2}. Related studies included elucidating the role of low-energy ion damage in the ion-assisted doping process, and investigating the decrease in carrier density near the surface of p-CdTe upon heating in vacuum, H{sub 2}, or Ar. We demonstrate the ability to make carrier density profiles and to grade junctions, and we present preliminary results from polycrystalline p-CdTe films grown on graphite and alumina substrates. We also present solar cells prepared using the p-CdTe as the collector area and n-CdS as the window layer, and we examine their photovoltaic parameters for different carrier densities and configurations in p-CdTe. 91 refs., 44 figs., 5 tabs.

  20. Aspects of the SrO-CuO-TiO2 Ternary System Related to the Deposition of SrTiO3 and Copper-Doped SrTiO3 Thin-Film Buffer Layers

    Energy Technology Data Exchange (ETDEWEB)

    A. Ayala

    2004-12-20

    YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) coated conductors are promising materials for large-scale superconductivity applications. One version of a YBCO coated conductor is based on ion beam assisted deposition (IBAD) of magnesium oxide (MgO) onto polycrystalline metal substrates. SrTiO{sub 3} (STO) is often deposited by physical vapor deposition (PVD) methods as a buffer layer between the YBCO and IBAD MgO due to its chemical stability and lattice mismatch of only {approx}1.5% with YBCO. In this work, some aspects of the stability of STO with respect to copper (Cu) and chemical solution deposition of STO on IBAD MgO templates were examined. Solubility limits of Cu in STO were established by processing Cu-doped STO powders by conventional bulk preparation techniques. The maximum solubility of Cu in STO was {approx}1% as determined by transmission electron microscopy (TEM) and Rietveld refinements of x-ray diffraction (XRD) data. XRD analysis, performed in collaboration with NIST, on powder compositions on the STO/SrCuO{sub 2} tie line did not identify any ternary phases. SrCu{sub 0.10}Ti{sub 0.90}O{sub y} buffer layers were prepared by pulsed laser deposition (PLD) and CSD on IBAD MgO flexible metallic textured tapes. TEM analysis of a {approx}100 nm thick SrCu{sub 0.10}Ti{sub 0.90}O{sub y} buffer layer deposited by PLD showed a smooth Cu-doped STO/MgO interface. A {approx}600 nm thick YBCO film, deposited onto the SrCu{sub 0.10}Ti{sub 0.90}O{sub y} buffer by PLD, exhibited a T{sub c} of 87 K and critical current density (J{sub c}) of {approx}1 MA/cm{sup 2}. STO and Cu-doped STO thin films by CSD were {approx}30 nm thick. The in plane alignment (FWHM) after deposition of the STO improved by {approx}1{sup o} while it degraded by {approx}2{sup o} with the SrCu{sub 0.05}TiO{sub y} buffer. YBCO was deposited by PLD on the STO and SrCu{sub 0.05}TiO{sub y} buffers. The in plane alignment (FWHM) of the YBCO with the STO buffer layer slightly improved while that of the

  1. Plasma-assisted deposition of lithium phosphorus oxynitride films: Substrate bias effects

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoon Gu; Wadley, H.N.G. [Department of Material Science and Engineering, University of Virginia, 395 McCormick Road, Charlottesville, VA 22904 (United States)

    2009-02-15

    Lithium phosphorus oxynitride (Lipon) films have been synthesized by a plasma-assisted directed vapor deposition (PA-DVD) approach. In this approach, a hollow cathode technique was used to create an argon plasma through which was propagated an electron-beam generated Li{sub 3}PO{sub 4} vapor entrained in a N{sub 2}-doped helium gas jet. Without plasma assistance, amorphous, mud cracked and highly porous Li{sub 3}PO{sub 4} films were formed. When plasma-assistance was used, nitrogen was incorporated creating a Lipon film whose composition, morphology, structure, and deposition rate could be manipulated by modifying the substrate bias. Films with spiral or very smooth surfaces could be made in this way. Fully amorphous films or films with locally crystallized regions in an amorphous matrix could be synthesized by varying the bias voltage. The presence of these local regions of crystallinity within a Lipon film decreased the Li-ion conductivities from the 10{sup -7} S cm{sup -1} to 10{sup -10} S cm{sup -1} range. (author)

  2. Ion assisted deposition with low-energy ions for applications in modern optics

    CERN Document Server

    Kennedy, M

    1999-01-01

    realised by a process adaptation with UV-absorbing films. A further focal point are antireflective coatings on alkali halides optics for high-power CO sub 2 -lasers. Ion assisted deposition of NaF-films at extremely low ion energies (E sub i sub o sub n approx 5 eV) qualifies antireflective coatings with minimal absorption (alpha approx 1.5 cm sup - sup 1), high short-pulse damage threshold (50%-LIDT approx 60J/cm sup 2) and improved degradational stability. Main objective of this work is the development of ion assisted deposition processes without additional substrate heating for applications in precision and laser optics. New low-energy ion sources with ion energies below 100 eV were employed for the research work. Starting point of the process development are basic investigations on the ion assisted evaporation of fluoride and oxide thin film materials. The optimisation of the coating processes is primary done with the help of optical characterisation methods (spectral photometry, laser calorimetry, measur...

  3. Plasma-assisted directed vapor deposition for synthesizing lithium phosphorus oxynitride thin films

    Science.gov (United States)

    Kim, Yoon Gu

    This dissertation explores a new vapor deposition route for synthesizing lithium phosphorus oxynitride (Lipon) thin-film electrolytes for rechargeable thin-film Li/Li-ion batteries. These batteries operate at a high voltage (around 4.0 V) and exhibit a long cyclic life (over 10,000 charge/discharge cycles). These features stem from the extremely low leakage current of the Lipon film electrolyte when in contact with a lithium anode, and its good Li-ion conductivity (in the 10-6-10-7 S/cm range). Lipon films have usually been synthesized by reactive RF-magnetron sputtering, which suffers from a very low deposition rate (˜2 nm/min). It therefore takes many hours to make the 1-2 mum thick films needed for battery applications. Other deposition approaches, such as Pulsed Laser Deposition, Ion Beam Assisted Deposition, and E-beam evaporation, have been investigated but resulted in unsatisfactory Lipon film performance. Here, a plasma-assisted directed vapor deposition (PA-DVD) approach has been explored to synthesize dense, amorphous Lipon films. Unlike conventional e-beam evaporation, the e-beam based DVD approach employs an annular nozzle to generate a rarefied supersonic inert gas jet around the periphery of an electron beam evaporated source material. The vapor is entrained in the jet and rapidly transferred to a substrate. Because the supersonic gas jet focuses the vapor (it impedes lateral spreading of the vapor flux), most of the evaporant reaches the substrate. As a result, the deposition rate of Lipon films can be potentially much higher than most other processes. The PA-DVD approach used here employs a hollow cathode to create low-energy plasma through which the vapor is propagated. This plasma ionized some of the evaporant and reactive gases (nitrogen) that were added to the jet. This increased their reactivity and atomic mobility on a substrate enabling the reactive synthesis of lithium phosphorus oxynitride from a lithium phosphate source. This dissertation

  4. Ion-assisted deposition of moisture-stable hafnium oxide films for ultraviolet applications

    International Nuclear Information System (INIS)

    A design-of-experiments statistical approach was taken to determine the optimum ion gun operating parameters for the deposition of moisture-stable, low-absorbing hafnium oxide films by ion-assisted electron-beam evaporation. Factors identified as affecting the quality of hafnia films were chamber pressure, deposition rate, ion gun source gas composition, and ion gun current. Both oxygen and argon were used as source gases. High and low levels of the factors were chosen on the basis of our experience with the operating range of the system, and we made a series of 24 runs with all possible combinations of these factors. From a statistical analysis of the data, we find that the best films are obtained with a 1:1 mixture of argon and oxygen, 3-3.5 x 10-4 Torr chamber pressure, 0.3-nm/s deposition rate, and 0.5-A ion gun current. X-ray diffraction measurements show that the ion-assisted films exhibit a partial monoclinic crystalline structure, whereas the unassisted films are amorphous

  5. Preparation of ZnO films with variable electric field-assisted atomic layer deposition technique

    International Nuclear Information System (INIS)

    The ZnO films have been prepared by a variable electric field-assisted atomic layer deposition method (ALD). By applying electric fields during the precursor pulses, we can modulate both the crystal orientation and structure of the obtained ZnO films. The ZnO films with c-axis preferred orientation and the least oxygen vacancy defect were obtained when the holder electric polarities were positive and negative during the DEZn and H2O pulse, respectively. It is supported that when electric field was applied in the chamber, the torque may lead to the precursor molecular alignments along the electric field direction, which could affect the film growth process and then influence their structures and properties. This variable electric field-assisted ALD approach would provide an efficient protocol for the growth of semiconductor films with designed properties.

  6. Scalable route to CH3NH3PbI3 perovskite thin films by aerosol assisted chemical vapour deposition

    OpenAIRE

    Bhachu, D. S.; Scanlon, D. O.; Saban, E. J.; Bronstein, H.; Parkin, I. P.; Carmalt, C. J.; Palgrave, R. G.

    2015-01-01

    Methyl-ammonium lead iodide is the archetypal perovskite solar cell material. Phase pure, compositionally uniform methyl-ammonium lead iodide thin films on large glass substrates were deposited using ambient pressure aerosol assisted chemical vapour deposition. This opens up a route to efficient scale up of hybrid perovskite film growth towards industrial deployment.

  7. Biomolecular papain thin films grown by matrix assisted and conventional pulsed laser deposition: A comparative study

    Science.gov (United States)

    György, E.; Pérez del Pino, A.; Sauthier, G.; Figueras, A.

    2009-12-01

    Biomolecular papain thin films were grown both by matrix assisted pulsed laser evaporation (MAPLE) and conventional pulsed laser deposition (PLD) techniques with the aid of an UV KrF∗ (λ =248 nm, τFWHM≅20 ns) excimer laser source. For the MAPLE experiments the targets submitted to laser radiation consisted on frozen composites obtained by dissolving the biomaterial powder in distilled water at 10 wt % concentration. Conventional pressed biomaterial powder targets were used in the PLD experiments. The surface morphology of the obtained thin films was studied by atomic force microscopy and their structure and composition were investigated by Fourier transform infrared spectroscopy. The possible physical mechanisms implied in the ablation processes of the two techniques, under comparable experimental conditions were identified. The results showed that the growth mode, surface morphology as well as structure of the deposited biomaterial thin films are determined both by the incident laser fluence value as well as target preparation procedure.

  8. Continuous Microreactor-Assisted Solution Deposition for Scalable Production of CdS Films

    Energy Technology Data Exchange (ETDEWEB)

    Ramprasad, Sudhir; Su, Yu-Wei; Chang, Chih-Hung; Paul, Brian; Palo, Daniel R.

    2013-06-13

    Solution deposition offers an attractive, low temperature option in the cost effective production of thin film solar cells. Continuous microreactor-assisted solution deposition (MASD) was used to produce nanocrystalline cadmium sulfide (CdS) films on fluorine doped tin oxide (FTO) coated glass substrates with excellent uniformity. We report a novel liquid coating technique using a ceramic rod to efficiently and uniformly apply reactive solution to large substrates (152 mm × 152 mm). This technique represents an inexpensive approach to utilize the MASD on the substrate for uniform growth of CdS films. Nano-crystalline CdS films have been produced from liquid phase at ~90°C, with average thicknesses of 70 nm to 230 nm and with a 5 to 12% thickness variation. The CdS films produced were characterized by UV-Vis spectroscopy, transmission electron microscopy, and X-Ray diffraction to demonstrate their suitability to thin-film solar technology.

  9. Electrochemically assisted deposition of strontium modified magnesium phosphate on titanium surfaces.

    Science.gov (United States)

    Meininger, M; Wolf-Brandstetter, C; Zerweck, J; Wenninger, F; Gbureck, U; Groll, J; Moseke, C

    2016-10-01

    Electrochemically assisted deposition was utilized to produce ceramic coatings on the basis of magnesium ammonium phosphate (struvite) on corundum-blasted titanium surfaces. By the addition of defined concentrations of strontium nitrate to the coating electrolyte Sr(2+) ions were successfully incorporated into the struvite matrix. By variation of deposition parameters it was possible to fabricate coatings with different kinetics of Sr(2+) into physiological media, whereas the release of therapeutically relevant strontium doses could be sustained over several weeks. Morphological and crystallographic examinations of the immersed coatings revealed that the degradation of struvite and the release of Sr(2+) ions were accompanied by a transformation of the coating to a calcium phosphate based phase similar to low-crystalline hydroxyapatite. These findings showed that strontium doped struvite coatings may provide a promising degradable coating system for the local application of strontium or other biologically active metal ions in the implant-bone interface. PMID:27287100

  10. Electron behaviour in CH4/H2 gas mixture in electron-assisted chemical vapour deposition

    Institute of Scientific and Technical Information of China (English)

    Dong Li-Fang; Ma Bo-Qin; Wang Zhi-Jun

    2004-01-01

    The behaviour of electrons in CH4/H2 gas mixture in electron-assisted chemical vapour deposition of diamond is investigated using Monte Carlo simulation. The electron drift velocity in gas mixture is obtained over a wide range of E/P (the ratio of the electric field to gas pressure) from 1500 to 300000 (V/m kPa-1). The electron energy distribution and average energy under different gas pressure (0.1-20kPa) and CH4 concentration (0.5%-10.0%) are calculated. Their effects on the diamond growth are also discussed. It is believed that these results will be helpful to the selection of optimum experimental conditions for high quality diamond film deposition.

  11. Oscillatory barrier-assisted Langmuir-Blodgett deposition of large-scale quantum dot monolayers

    Science.gov (United States)

    Xu, Shicheng; Dadlani, Anup L.; Acharya, Shinjita; Schindler, Peter; Prinz, Fritz B.

    2016-03-01

    Depositing continuous, large-scale quantum dot films with low pinhole density is an inevitable but nontrivial step for studying their properties for applications in catalysis, electronic devices, and optoelectronics. This rising interest in high-quality quantum dot films has provided research impetus to improve the deposition technique. We show that by incorporating oscillatory barriers in the commonly used Langmuir-Blodgett method, large-scale monolayers of quantum dots with full coverage up to several millimeters have been achieved. With assistance of perturbation provided by the oscillatory barriers, the film has been shown to relax towards thermal equilibrium, and this physical process has been supported by molecular dynamics simulation. In addition, time evolution of dilatational moduli has been shown to give a clear indication of the film morphology and its stability.

  12. Functionalized porphyrin conjugate thin films deposited by matrix assisted pulsed laser evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Iordache, S. [University of Bucharest, 3Nano-SAE Research Center, PO Box MG-38, Bucharest-Magurele (Romania); Cristescu, R., E-mail: rodica.cristescu@inflpr.ro [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, P.O. Box MG-36, Bucharest-Magurele (Romania); Popescu, A.C.; Popescu, C.E.; Dorcioman, G.; Mihailescu, I.N. [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, P.O. Box MG-36, Bucharest-Magurele (Romania); Ciucu, A.A. [University of Bucharest, Faculty of Chemistry, Bucharest (Romania); Balan, A.; Stamatin, I. [University of Bucharest, 3Nano-SAE Research Center, PO Box MG-38, Bucharest-Magurele (Romania); Fagadar-Cosma, E. [Institute of Chemistry Timisoara of Romanian Academy, M. Viteazul Ave. 24, 300223-Timisoara (Romania); Chrisey, D.B. [Tulane University, Departments of Physics and Biomedical Engineering, New Orleans, LA 70118 (United States)

    2013-08-01

    We report on the deposition of nanostructured porphyrin-base, 5(4-carboxyphenyl)-10,15,20-tris(4-phenoxyphenyl)-porphyrin thin films by matrix assisted pulsed laser evaporation onto silicon substrates with screen-printed electrodes. AFM investigations have shown that at 400 mJ/cm{sup 2} fluence a topographical transition takes place from the platelet-like stacking porphyrin-based nanostructures in a perpendicular arrangement to a quasi-parallel one both relative to the substrate surface. Raman spectroscopy has shown that the chemical structure of the deposited thin films is preserved for fluences within the range of 200–300 mJ/cm{sup 2}. Cyclic voltammograms have demonstrated that the free porphyrin is appropriate as a single mediator for glucose in a specific case of screen-printed electrodes, suggesting potential for designing a new class of biosensors.

  13. 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.

  14. Metal oxide targets produced by the polymer-assisted deposition method

    International Nuclear Information System (INIS)

    The polymer-assisted deposition (PAD) method was used to create crack-free homogenous metal oxide films for use as targets in nuclear science applications. Metal oxide films of europium, thulium, and hafnium were prepared as models for actinide oxides. Films produced by a single application of PAD were homogenous and uniform and ranged in thickness from 30 to 320 nm. Reapplication of the PAD method (six times) with a 10% by weight hafnium(IV) solution resulted in an equally homogeneous and uniform film with a total thickness of 600 nm.

  15. Metal oxide targets produced by the polymer-assisted deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Mitch A., E-mail: mitch@berkeley.ed [Department of Chemistry, Room 446 Latimer Hall, University of California Berkeley, Berkeley, CA 94720-1460 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Ali, Mazhar N.; Chang, Noel N.; Parsons-Moss, T. [Department of Chemistry, Room 446 Latimer Hall, University of California Berkeley, Berkeley, CA 94720-1460 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Ashby, Paul D. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Gates, Jacklyn M. [Department of Chemistry, Room 446 Latimer Hall, University of California Berkeley, Berkeley, CA 94720-1460 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Stavsetra, Liv [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Gregorich, Kenneth E.; Nitsche, Heino [Department of Chemistry, Room 446 Latimer Hall, University of California Berkeley, Berkeley, CA 94720-1460 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2010-02-11

    The polymer-assisted deposition (PAD) method was used to create crack-free homogenous metal oxide films for use as targets in nuclear science applications. Metal oxide films of europium, thulium, and hafnium were prepared as models for actinide oxides. Films produced by a single application of PAD were homogenous and uniform and ranged in thickness from 30 to 320 nm. Reapplication of the PAD method (six times) with a 10% by weight hafnium(IV) solution resulted in an equally homogeneous and uniform film with a total thickness of 600 nm.

  16. Gas phase chemistry during electron assisted chemical vapor deposition (EACVD) of diamond films

    International Nuclear Information System (INIS)

    Diamond films were deposited in electron assisted chemical vapor deposition (EACVD) reactor using two source mixtures of CH4-H2 and C2H5OH-H2, respectively. The plasma gas composition during diamond growing was investigated in situ using optical emission spectroscopy (OES). In two cases of C2H2OH-H2 and CH4-H2 plasma, it was shown that CH and CH+ were all important precursor species in the diamond deposition reaction while the yields of poor diamond films corresponded to the presence of the C2 emission line. The difference between these two cases was that some oxygen-containing species (CH2O, CHO and O2) were detected in the C2H5OH-H2 plasma. The presence of these products may maintain the quality of the deposited diamond films while increasing carbon source concentration, and the growth rate was thus enhanced. These results imply that the increase in the growth rate of diamond film using C2H5OH-H2 mixture is primarily due to a change in gas phase environment

  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. Lithium phosphorous oxynitride films synthesized by a plasma-assisted directed vapor deposition approach

    International Nuclear Information System (INIS)

    A plasma-assisted directed vapor deposition approach has been explored for the synthesis of lithium phosphorous oxynitride (Lipon) thin films. A Li3PO4 source was first evaporated using a high voltage electron beam and the resulting vapor entrained in a nitrogen-doped supersonic helium gas jet and deposited on a substrate at ambient temperature. This approach failed to incorporate significant concentrations of nitrogen in the films. A hollow cathode technique was then used to create an argon plasma that enabled partial ionization of both the Li3PO4 vapor and nitrogen gas just above the substrate surface. The plasma-enhanced deposition process greatly increased the gas phase and surface reactivity of the system and facilitated the synthesis and high rate deposition of amorphous Lipon films with the N/P ratios between 0.39 and 1.49. Manipulation of the plasma-enhanced process conditions also enabled control of the pore morphology and significantly affected the ionic transport properties of these films. This enabled the synthesis of electrolyte films with lithium ion conductivities in the 10-7-10-8 S/m range. They appear to be well suited for thin-film battery applications

  19. High fluence deposition of polyethylene glycol films at 1064 nm by matrix assisted pulsed laser evaporation (MAPLE)

    DEFF Research Database (Denmark)

    Purice, Andreea; Schou, Jørgen; Kingshott, P.; Pryds, Nini; Dinescu, M.

    2007-01-01

    microbalance. The laser fluence needed to produce PEG films turned out to be unexpectedly high with a threshold of 9 J/cm(2) and the deposition rate was much lower than that with laser light at 355 nm. Results from matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI......Matrix assisted pulsed laser evaporation (MAPLE) has been applied for deposition of thin polyethylene glycol (PEG) films with infrared laser light at 1064 nm. We have irradiated frozen targets (of 1 wt.% PEG dissolved in water) and measured the deposition rate in situ with a quartz crystal 2...

  20. 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

  1. 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.

  2. Fabrication and characterization of kesterite Cu2ZnSnS4 thin films deposited by electrostatic spray assisted vapour deposition method

    OpenAIRE

    J.P. Liu; Choy, Kwang-Leong; Placidi, M.; J. López-García; Saucedo, Edgardo; Colombara, Diego; Robert, Erika

    2014-01-01

    Most of the high efficiency kesterite solar cells are fabricated by vacuum or hydrazine-based solution methods which have drawbacks, such as high cost, high toxicity or explosivity. In our contribution, an alternative non-vacuum and environmental friendly deposition technology called electrostatic spray assisted vapour deposition (ESAVD) has been used for the cost-effective growth of Cu2ZnSnS4 (CZTS) thin films with well controlled structure and composition. CZTS films have been characterized...

  3. Graphene-assisted growth of high-quality AlN by metalorganic chemical vapor deposition

    Science.gov (United States)

    Zeng, Qing; Chen, Zhaolong; Zhao, Yun; Wei, Tongbo; Chen, Xiang; Zhang, Yun; Yuan, Guodong; Li, Jinmin

    2016-08-01

    High-quality AlN films were directly grown on graphene/sapphire substrates by metalorganic chemical vapor deposition (MOCVD). The graphene layers were directly grown on sapphire by atmospheric-pressure chemical vapor deposition (APCVD), a low-cost catalyst-free method. We analyzed the influence of the graphene layer on the nucleation of AlN at the initial stage of growth and found that sparse AlN grains on graphene grew and formed a continuous film via lateral coalescence. Graphene-assisted AlN films are smooth and continuous, and the full width at half maximum (FWHM) values for (0002) and (10\\bar{1}2) reflections are 360 and 622.2 arcsec, which are lower than that of the film directly grown on sapphire. The high-resolution TEM images near the AlN/sapphire interface for graphene-assisted AlN films clearly show the presence of graphene, which kept its original morphology after the 1200 °C growth of AlN.

  4. Surfactant-assisted electrochemical deposition of {alpha}-cobalt hydroxide for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Ting [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Jiang, Hao; Ma, Jan [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Temasek Laboratories, Nanyang Technological University, Singapore 637553 (Singapore)

    2011-01-15

    A N-methylpyrrolidone (NMP) assisted electrochemical deposition route has been developed to realize the synthesis of a dense {alpha}-Co(OH){sub 2} layered structure, which is composed of nanosheets, each with a thickness of 10 nm. The capacitive characteristics of the as-obtained {alpha}-Co(OH){sub 2} are investigated by means of cyclic voltammetry (CV), charge/discharge characterization, and electrochemical impedance spectroscopy (EIS), in 1 M KOH electrolyte. The results indicate that {alpha}-Co(OH){sub 2} prepared in the presence of 20 vol.% NMP has denser and thin layered structure which promotes an increased surface area and a shortened ion diffusion path. The as-prepared {alpha}-Co(OH){sub 2} shows better electrochemical performance with specific capacitance of 651 F g{sup -1} in a potential range of -0.1 to 0.45 V. These findings suggest that the surfactant-assisted electrochemical deposition is a promising process for building densely packed material systems with enhanced properties, for application in supercapacitors. (author)

  5. Surfactant-assisted electrochemical deposition of α-cobalt hydroxide for supercapacitors

    Science.gov (United States)

    Zhao, Ting; Jiang, Hao; Ma, Jan

    A N-methylpyrrolidone (NMP) assisted electrochemical deposition route has been developed to realize the synthesis of a dense α-Co(OH) 2 layered structure, which is composed of nanosheets, each with a thickness of 10 nm. The capacitive characteristics of the as-obtained α-Co(OH) 2 are investigated by means of cyclic voltammetry (CV), charge/discharge characterization, and electrochemical impedance spectroscopy (EIS), in 1 M KOH electrolyte. The results indicate that α-Co(OH) 2 prepared in the presence of 20 vol.% NMP has denser and thin layered structure which promotes an increased surface area and a shortened ion diffusion path. The as-prepared α-Co(OH) 2 shows better electrochemical performance with specific capacitance of 651 F g -1 in a potential range of -0.1 to 0.45 V. These findings suggest that the surfactant-assisted electrochemical deposition is a promising process for building densely packed material systems with enhanced properties, for application in supercapacitors.

  6. Aerosol assisted atmospheric pressure chemical vapor deposition of silicon thin films using liquid cyclic hydrosilanes

    Energy Technology Data Exchange (ETDEWEB)

    Guruvenket, Srinivasan, E-mail: guruvenket.srinivasan@ndsu.edu [Center for Nanoscale Energy Related Materials, 1715 NDSU Research Park Drive N, North Dakota State University, Fargo, ND 58102 (United States); Hoey, Justin M.; Anderson, Kenneth J.; Frohlich, Matthew T.; Sailer, Robert A. [Center for Nanoscale Energy Related Materials, 1715 NDSU Research Park Drive N, North Dakota State University, Fargo, ND 58102 (United States); Boudjouk, Philip [Center for Nanoscale Energy Related Materials, 1715 NDSU Research Park Drive N, North Dakota State University, Fargo, ND 58102 (United States); Department of Chemistry and Biochemistry, Ladd-Dunbar Hall, North Dakota State University, Fargo, ND 58102 (United States)

    2015-08-31

    Silicon (Si) thin films were produced using an aerosol assisted atmospheric pressure chemical vapor deposition technique with liquid hydrosilane precursors cyclopentasilane (CPS, Si{sub 5}H{sub 10}) and cyclohexasilane (CHS, Si{sub 6}H{sub 12}). Thin films were deposited at temperatures between 300 and 500 °C, with maximum observed deposition rates of 55 and 47 nm/s for CPS and CHS, respectively, at 500 °C. Atomic force microscopic analyses of the films depict smooth surfaces with roughness of 4–8 nm. Raman spectroscopic analysis indicates that the Si films deposited at 300 °C and 350 °C consist of a hydrogenated amorphous Si (a-Si:H) phase while the films deposited at 400, 450, and 500 °C are comprised predominantly of a hydrogenated nanocrystalline Si (nc-Si:H) phase. The wide optical bandgaps of 2–2.28 eV for films deposited at 350–400 °C and 1.7–1.8 eV for those deposited at 450–500 °C support the Raman data and depict a transition from a-Si:H to nc-Si:H. Films deposited at 450 {sup o}C possess the highest photosensitivity of 10{sup 2}–10{sup 3} under AM 1.5G illumination. Based on the growth model developed for other silanes, we suggest a mechanism that governs the film growth using CPS and CHS. - Highlights: • Si films via AA-APCVD are realized using cyclopentasilane (CPS) and cyclohexasilane (CHS). • Low activation energies of CPS and CHS allow Si thin films at low temperatures (300 °C). • High growth rates of 47–55 nm/s were obtained at 500 °C • Near device quality Si thin films with 2–3 orders of photosensitivity • Si thin films via AA-APCVD are amenable to continuous roll-to-roll manufacturing.

  7. High-speed deposition of titanium carbide coatings by laser-assisted metal–organic CVD

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Yansheng [Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Tu, Rong, E-mail: turong@whut.edu.cn [State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Goto, Takashi [Institute for Materials Research, Tohoku University, Aoba-ku, 2-1-1 Katahira, Sendai 980-8577 (Japan)

    2013-08-01

    Graphical abstract: - Highlights: • A semiconductor laser was first used to prepare wide-area LCVD-TiC{sub x} coatings. • The effect of laser power for the deposition of TiC{sub x} coatings was discussed. • TiC{sub x} coatings showed a columnar cross section and a dense surface texture. • TiC{sub x} coatings had a 1–4 order lower laser density than those of previous reports. • This study gives the possibility of LCVD applying on the preparation of TiC{sub x} coating. - Abstract: A semiconductor laser-assisted chemical vapor deposition (LCVD) of titanium carbide (TiC{sub x}) coatings on Al{sub 2}O{sub 3} substrate using tetrakis (diethylamido) titanium (TDEAT) and C{sub 2}H{sub 2} as source materials were investigated. The influences of laser power (P{sub L}) and pre-heating temperature (T{sub pre}) on the microstructure and deposition rate of TiC{sub x} coatings were examined. Single phase of TiC{sub x} coatings were obtained at P{sub L} = 100–200 W. TiC{sub x} coatings had a cauliflower-like surface and columnar cross section. TiC{sub x} coatings in the present study had the highest R{sub dep} (54 μm/h) at a relative low T{sub dep} than those of conventional CVD-TiC{sub x} coatings. The highest volume deposition rate (V{sub dep}) of TiC{sub x} coatings was about 4.7 × 10{sup −12} m{sup 3} s{sup −1}, which had 3–10{sup 5} times larger deposition area and 1–4 order lower laser density than those of previous LCVD using CO{sub 2}, Nd:YAG and argon ion laser.

  8. 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

  9. The Formation of Nanocrystalline Diamond Coating on WC Deposited by Microwave Assisted Plasma CVD

    Science.gov (United States)

    Toff, M. R. M.; Hamzah, E.; Purniawan, A.

    2010-03-01

    Diamond is one form of carbon structure. The extreme hardness and high chemical resistant of diamond coatings determined that many works on this area relate to coated materials for tribological applications in biomedicine, as mechanical seals or cutting tools for hard machining operations. In the work, nanocrystalline diamond (NCD) coated tungsten carbide (WC) have been deposited by microwave assisted plasma chemical vapor deposition (MAPCVD) from CH4/H2 mixtures. Morphology of NCD was investigated by using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The quality of NCD is defined as ratio between diamond and non diamond and also full width at half maximum (FWHM) was determined using Raman spectra. The result found that the NCD structure can be deposited on WC surface using CH4/H2 gas mixture with grain size ˜20 nm to 100 nm. Increase %CH4 concentration due to increase the nucleation of NCD whereas decrease the quality of diamond. Based on Raman spectra, the quality of NCD is in the range ˜98.82-99.01% and 99.56-99.75% for NCD and microcrystalline (MCD), respectively. In addition, FWHM of NCD is high than MCD in the range of 8.664-62.24 cm-1 and 4.24-5.05 cm-1 for NCD and MCD respectively that indicate the crystallineity of NCD is smaller than MCD.

  10. Nanocomposite Coatings Codeposited with Nanoparticles Using Aerosol-Assisted Chemical Vapour Deposition

    Directory of Open Access Journals (Sweden)

    Xianghui Hou

    2013-01-01

    Full Text Available Incorporating nanoscale materials into suitable matrices is an effective route to produce nanocomposites with unique properties for practical applications. Due to the flexibility in precursor atomization and delivery, aerosol-assisted chemical vapour deposition (AACVD process is a promising way to synthesize desired nanocomposite coatings incorporating with preformed nanoscale materials. The presence of nanoscale materials in AACVD process would significantly influence deposition mechanism and thus affect microstructure and properties of the nanocomposites. In the present work, inorganic fullerene-like tungsten disulfide (IF-WS2 has been codeposited with Cr2O3 coatings using AACVD. In order to understand the codeposition process for the nanocomposite coatings, chemical reactions of the precursor and the deposition mechanism have been studied. The correlation between microstructure of the nanocomposite coatings and the codeposition mechanism in the AACVD process has been investigated. The heterogeneous reaction on the surface of IF-WS2 nanoparticles, before reaching the substrate surface, is the key feature of the codeposition in the AACVD process. The agglomeration of nanoparticles in the nanocomposite coatings is also discussed.

  11. Self-heating technique of metallic substrate for reel-to-reel and double-sided deposition of YBa2Cu3O7- δ films

    Science.gov (United States)

    Zhang, Fei; Zhao, Ruipeng; Xue, Yan; Wang, Hui; He, Yuanying; Zhang, Pan; Tao, Bowan; Xiong, Jie; Li, Yanrong

    2016-02-01

    A new, simple, and highly efficient heating technology for metal tape substrates is proposed and applied to reel-to-reel and double-sided film deposition. In this technology, direct electrical current ( I DC) is conducted into the metal layer of oxide-buffered metal substrate to induce heat. Different substrate surface temperatures were achieved by varying I DC from 22 to 25 A. At these temperatures, a series of 1-μm-thick and 5-cm-long YBa2Cu3O7- δ (YBCO) films were fabricated on ion-beam-assisted deposition (IBAD) templates through metal organic chemical vapor deposition. X-ray diffraction analysis on the samples revealed that the YBCO film changed its growth mode from mixed a-axis and c-axis to purely c-axis with increasing I DC. The optimal out-of-plane and in-plane texture reached ~1.4° and 3.5°, respectively. A 30-m-long and 500-nm-thick single-sided YBCO-coated conductor was also prepared through reel-to-reel deposition using the proposed heating method. The fabricated conductor presented homogeneous crystallization and texture and exhibited a critical current density at self-field and 77 K ( J c 77K, 0T ) of 2.8-3.2 MA/cm2. Moreover, 500-nm-thick YBCO films were fabricated simultaneously on both sides of the double-sided IBAD template. The two sides of films demonstrated uniform texture and J c 77K, 0T of 3.2 MA/cm2. Results demonstrated that the proposed substrate heating technology can be used for reel-to-reel and double-sided deposition of YBCO-coated conductors.

  12. Microwave engineering of plasma-assisted CVD reactors for diamond deposition

    Science.gov (United States)

    Silva, F.; Hassouni, K.; Bonnin, X.; Gicquel, A.

    2009-09-01

    The unique properties of CVD diamond make it a compelling choice for high power electronics. In order to achieve industrial use of CVD diamond, one must simultaneously obtain an excellent control of the film purity, very low defect content and a sufficiently rapid growth rate. Currently, only microwave plasma-assisted chemical vapour deposition (MPACVD) processes making use of resonant cavity systems provide enough atomic hydrogen to satisfy these requirements. We show in this paper that the use of high microwave power density (MWPD) plasmas is necessary to promote atomic hydrogen concentrations that are high enough to ensure the deposition of high purity diamond films at large growth rates. Moreover, the deposition of homogeneous films on large surfaces calls for the production of plasma with appropriate shapes and large volumes. The production of such plasmas needs generating a fairly high electric field over extended regions and requires a careful design of the MW coupling system, especially the cavity. As far as MW coupling efficiency is concerned, the presence of a plasma load represents a mismatching perturbation to the cavity. This perturbation is especially important at high MWPD where the reflected fraction of the input power may be quite high. This mismatch can lead to a pronounced heating of the reactor walls. It must therefore be taken into account from the very beginning of the reactor design. This requires the implementation of plasma modelling tools coupled to detailed electromagnetic simulations. This is discussed in section 3. We also briefly discuss the operating principles of the main commercial plasma reactors before introducing the reactor design methodology we have developed. Modelling results for a new generation of reactors developed at LIMHP, working at very high power density, will be presented. Lastly, we show that scaling up this type of reactor to lower frequencies (915 MHz) can result in high density plasmas allowing for fast and

  13. 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.

  14. 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

  15. Quarterly Report: Microchannel-Assisted Nanomaterial Deposition Technology for Photovoltaic Material Production

    Energy Technology Data Exchange (ETDEWEB)

    Palo, Daniel R.

    2011-04-26

    Quarterly report to ITP for Nanomanufacturing program. Report covers FY11 Q2. The primary objective of this project is to develop a nanomanufacturing process which will reduce the manufacturing energy, environmental discharge, and production cost associated with current nano-scale thin-film photovoltaic (PV) manufacturing approaches. The secondary objective is to use a derivative of this nanomanufacturing process to enable greener, more efficient manufacturing of higher efficiency quantum dot-based photovoltaic cells now under development. The work is to develop and demonstrate a scalable (pilot) microreactor-assisted nanomaterial processing platform for the production, purification, functionalization, and solution deposition of nanomaterials for photovoltaic applications. The high level task duration is shown. Phase I consists of a pilot platform for Gen II PV films along with parallel efforts aimed at Gen III PV quantum dot materials. Status of each task is described.

  16. In situ doping of ZnO nanowires using aerosol-assisted chemical vapour deposition

    Energy Technology Data Exchange (ETDEWEB)

    Pung, Swee-Yong; Choy, Kwang-Leong; Hou Xianghui; Dinsdale, Keith, E-mail: Kwang-leong.Choy@nottingham.ac.uk [Faculty of Engineering, Energy and Sustainability Research Division, University of Nottingham, Nottingham NG7 2RD (United Kingdom)

    2010-08-27

    An in situ doping approach of producing Al-doped ZnO NWs was demonstrated using an aerosol-assisted chemical vapour deposition (AA-CVD) technique. In this technique, Zn precursor was kept in the middle of a horizontal tube furnace whereas the dopant solution was kept in an aerosol generator, which was located outside the furnace. The Al aerosol was flowed into the reactor during the growth of NWs in order to achieve in situ doping. Al-doped ZnO NWs were synthesized as verified by the combination of XRD, TEM/EDS and TOF-SIMS analysis. Highly (00.2) oriented ZnO seed layers were used to promote vertically aligned growth of Al-doped ZnO NWs. Lastly, a growth mechanism of vertically aligned Al-doped ZnO NWs was discussed.

  17. Synthesis of conductive semi-transparent silver films deposited by a Pneumatically-Assisted Ultrasonic Spray Pyrolysis Technique

    International Nuclear Information System (INIS)

    Highlights: • We deposited metallic silver films without post-deposition annealing. • The spray pyrolysis technique is of low cost and scalable for industrial applications. • We obtained deposition rate of 60 nm min−1 at 300 °C. • The average resistivity was 1E−7 Ω m. • Semi-transparent silver films were obtained at 350 °C and deposition time of 45 s. -- Abstract: The synthesis and characterization of nanostructured silver films deposited on corning glass by a deposition technique called Pneumatically-Assisted Ultrasonic Spray Pyrolysis are reported. Silver nitrate and triethanolamine were used as silver precursor and reducer agent, respectively. The substrate temperatures during deposition were in the range of 300–450 °C and the deposition times from 30 to 240 s. The deposited films are polycrystalline with cubic face-centered structure, and crystalline grain size less than 30 nm. Deposition rates up to 600 Å min−1 were obtained at substrate temperature as low as 300 °C. The electrical, optical, and morphological properties of these films are also reported. Semi-transparent conductive silver films were obtained at 350 °C with a deposition time of 45 s

  18. Synthesis of conductive semi-transparent silver films deposited by a Pneumatically-Assisted Ultrasonic Spray Pyrolysis Technique

    Energy Technology Data Exchange (ETDEWEB)

    Zaleta-Alejandre, E.; Balderas-Xicoténcatl, R. [Centro de Investigación y de Estudios Avanzados-IPN, Departamento de Física, , Apdo. Postal 14-470, Del, Gustavo A. Madero, C.P. 07000, México, D.F. (Mexico); Arrieta, M.L. Pérez [Universidad Autónoma de Zacatecas, Unidad Académica de Física, Calzada Solidaridad esq. Paseo, La Bufa s/n, C.P. 98060, Zacatecas, México (Mexico); Meza-Rocha, A.N.; Rivera-Álvarez, Z. [Centro de Investigación y de Estudios Avanzados-IPN, Departamento de Física, , Apdo. Postal 14-470, Del, Gustavo A. Madero, C.P. 07000, México, D.F. (Mexico); Falcony, C., E-mail: cfalcony@fis.cinvestav.mx [Centro de Investigación y de Estudios Avanzados-IPN, Departamento de Física, , Apdo. Postal 14-470, Del, Gustavo A. Madero, C.P. 07000, México, D.F. (Mexico)

    2013-10-01

    Highlights: • We deposited metallic silver films without post-deposition annealing. • The spray pyrolysis technique is of low cost and scalable for industrial applications. • We obtained deposition rate of 60 nm min{sup −1} at 300 °C. • The average resistivity was 1E−7 Ω m. • Semi-transparent silver films were obtained at 350 °C and deposition time of 45 s. -- Abstract: The synthesis and characterization of nanostructured silver films deposited on corning glass by a deposition technique called Pneumatically-Assisted Ultrasonic Spray Pyrolysis are reported. Silver nitrate and triethanolamine were used as silver precursor and reducer agent, respectively. The substrate temperatures during deposition were in the range of 300–450 °C and the deposition times from 30 to 240 s. The deposited films are polycrystalline with cubic face-centered structure, and crystalline grain size less than 30 nm. Deposition rates up to 600 Å min{sup −1} were obtained at substrate temperature as low as 300 °C. The electrical, optical, and morphological properties of these films are also reported. Semi-transparent conductive silver films were obtained at 350 °C with a deposition time of 45 s.

  19. Effects of precursor evaporation temperature on the properties of the yttrium oxide thin films deposited by microwave electron cyclotron resonance plasma assisted metal organic chemical vapor deposition

    International Nuclear Information System (INIS)

    Yttrium oxide thin films are deposited using indigenously developed metal organic precursor (2,2,6,6-tetra methyl-3,5-hepitane dionate) yttrium, commonly known as Y(thd)3 (synthesized by ultrasound method). Microwave electron cyclotron resonance plasma assisted metal organic chemical vapor deposition process was used for these depositions. Depositions were carried out at a substrate temperature of 350 oC with argon to oxygen gas flow rates fixed to 1 sccm and 10 sccm respectively throughout the experiments. The precursor evaporation temperature (precursor temperature) was varied over a range of 170-275 oC keeping all other parameters constant. The deposited coatings are characterized by X-ray photoelectron spectroscopy, glancing angle X-ray diffraction and infrared spectroscopy. Thickness and refractive index of the coatings are measured by the spectroscopic ellipsometry. Hardness and elastic modulus of the films are measured by load depth sensing nanoindentation technique. C-Y2O3 phase is deposited at lower precursor temperature (170 oC). At higher temperature (220 oC) cubic yttrium oxide is deposited with yttrium hydroxide carbonate as a minor phase. When the temperature of the precursor increased (275 oC) further, hexagonal Y2O3 with some multiphase structure including body centered cubic yttria and yttrium silicate is observed in the deposited film. The properties of the films drastically change with these structural transitions. These changes in the film properties are correlated here with the precursor evaporation characteristics obtained at low pressures.

  20. Hybrid chemical vapour and nanoceramic aerosol assisted deposition for multifunctional nanocomposite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Warwick, Michael E.A.; Dunnill, Charles W.; Goodall, Josie; Darr, Jawwad A.; Binions, Russell, E-mail: uccarbi@ucl.ac.uk

    2011-07-01

    Hybrid atmospheric pressure chemical vapour and aerosol assisted deposition via the reaction of vanadium acetylacetonate and a suspension of preformed titanium dioxide or cerium dioxide nanoparticles, led to the production of vanadium dioxide nanocomposite thin films on glass substrates. The preformed nanoparticle oxides used for the aerosol were synthesised using a continuous hydrothermal flow synthesis route involving the rapid reaction of a metal salt solution with a flow of supercritical water in a flow reactor. Multifunctional nanocomposite thin films from the hybrid deposition process were characterised using scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The functional properties of the films were evaluated using variable temperature optical measurements to assess thermochromic behaviour and methylene blue photodecolourisation experiments to assess photocatalytic activity. The tests show that the films are multifunctional in that they are thermochromic (having a large change in infra-red reflectivity upon exceeding the thermochromic transition temperature) and have significant photocatalytic activity under irradiation with 254 nm light.

  1. Chemical vapor deposition graphene transfer process to a polymeric substrate assisted by a spin coater

    Science.gov (United States)

    Kessler, Felipe; da Rocha, Caique O. C.; Medeiros, Gabriela S.; Fechine, Guilhermino J. M.

    2016-03-01

    A new method to transfer chemical vapor deposition graphene to polymeric substrates is demonstrated here, it is called direct dry transfer assisted by a spin coater (DDT-SC). Compared to the conventional method DDT, the improvement of the contact between graphene-polymer due to a very thin polymeric film deposited by spin coater before the transfer process prevented air bubbles and/or moisture and avoided molecular expansion on the graphene-polymer interface. An acrylonitrile-butadiene-styrene copolymer, a high impact polystyrene, polybutadiene adipate-co-terephthalate, polylactide acid, and a styrene-butadiene-styrene copolymer are the polymers used for the transfers since they did not work very well by using the DDT process. Raman spectroscopy and optical microscopy were used to identify, to quantify, and to qualify graphene transferred to the polymer substrates. The quantity of graphene transferred was substantially increased for all polymers by using the DDT-SC method when compared with the DDT standard method. After the transfer, the intensity of the D band remained low, indicating low defect density and good quality of the transfer. The DDT-SC transfer process expands the number of graphene applications since the polymer substrate candidates are increased.

  2. Self-heating technique of metallic substrate for reel-to-reel and double-sided deposition of YBa{sub 2}Cu{sub 3}O{sub 7-δ} films

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fei; Zhao, Ruipeng; Xue, Yan; He, Yuanying; Zhang, Pan; Tao, Bowan; Xiong, Jie; Li, Yanrong [University of Electronic Science and Technology of China, State Key Laboratory of Electronic Thin Film and Integrated Devices, Chengdu (China); Wang, Hui [Chinese Academy of Sciences, Applied Research Laboratory of Superconduction and New Material, Institute of Electrical Engineering, Beijing (China)

    2016-02-15

    A new, simple, and highly efficient heating technology for metal tape substrates is proposed and applied to reel-to-reel and double-sided film deposition. In this technology, direct electrical current (I{sub DC}) is conducted into the metal layer of oxide-buffered metal substrate to induce heat. Different substrate surface temperatures were achieved by varying I{sub DC} from 22 to 25 A. At these temperatures, a series of 1-μm-thick and 5-cm-long YBa{sub 2}Cu{sub 3}O{sub 7-δ} (YBCO) films were fabricated on ion-beam-assisted deposition (IBAD) templates through metal organic chemical vapor deposition. X-ray diffraction analysis on the samples revealed that the YBCO film changed its growth mode from mixed a-axis and c-axis to purely c-axis with increasing I{sub DC}. The optimal out-of-plane and in-plane texture reached ∝1.4 and 3.5 , respectively. A 30-m-long and 500-nm-thick single-sided YBCO-coated conductor was also prepared through reel-to-reel deposition using the proposed heating method. The fabricated conductor presented homogeneous crystallization and texture and exhibited a critical current density at self-field and 77 K (J{sub c} {sub 77K,} {sub 0T}) of 2.8-3.2 MA/cm{sup 2}. Moreover, 500-nm-thick YBCO films were fabricated simultaneously on both sides of the double-sided IBAD template. The two sides of films demonstrated uniform texture and J{sub c} {sub 77K,} {sub 0T} of 3.2 MA/cm{sup 2}. Results demonstrated that the proposed substrate heating technology can be used for reel-to-reel and double-sided deposition of YBCO-coated conductors. (orig.)

  3. Microstructure and texture evolution of CeO{sub 2} buffer layers prepared via dip-coating sol-gel method on IBAD-YSZ/Hastelloy substrates

    Energy Technology Data Exchange (ETDEWEB)

    Du, P. [Applied Superconductivity Research Center, Department of Physics, Tsinghua University, Beijing 100084 (China)], E-mail: honey00@mails.tsinghua.edu.cn; Wang, S.S.; Chen, H.; Wang, Z.; Sun, J.C.; Han, Z. [Applied Superconductivity Research Center, Department of Physics, Tsinghua University, Beijing 100084 (China); Schmidt, W.; Neumuller, H.W. [Siemens AG, CT PS 3, Erlangen 91052 (Germany)

    2007-10-01

    We have fabricated CeO{sub 2} buffer layers on IBAD-YSZ/Hastelloy substrates via dip-coating sol-gel method using inorganic salts as starting materials. X-ray diffraction (XRD), scanning electron microscopy (SEM) and scanning probe microscope (SPM) were applied to investigate the influential factors in film formation and texture evolution. Flat, crack-free CeO{sub 2} films with sharp (0 0 2) c-axis orientation and good texture were obtained by carefully controlling the precursor solution quality, dip-coating and heating process. Compared with IBAD-YSZ/Hastelloy substrates, textures of CeO{sub 2} films were effectively improved.

  4. Influence of travel speed on spray deposition uniformity from an air-assisted variable-rate sprayer

    Science.gov (United States)

    A newly developed LiDAR-guided air-assisted variable-rate sprayer for nursery and orchard applications was tested at various travel speeds to compare its spray deposition and coverage uniformity with constant-rate applications. Spray samplers, including nylon screens and water-sensitive papers (WSP)...

  5. Development of aerosol assisted chemical vapor deposition for thin film fabrication

    Science.gov (United States)

    Maulana, Dwindra Wilham; Marthatika, Dian; Panatarani, Camellia; Mindara, Jajat Yuda; Joni, I. Made

    2016-02-01

    Chemical vapor deposition (CVD) is widely used to grow a thin film applied in many industrial applications. This paper report the development of an aerosol assisted chemical vapor deposition (AACVD) which is one of the CVD methods. Newly developed AACVD system consists of a chamber of pyrex glass, two wire-heating elements placed to cover pyrex glass, a substrate holder, and an aerosol generator using an air brush sprayer. The temperature control system was developed to prevent condensation on the chamber walls. The control performances such as the overshoot and settling time were obtained from of the developed temperature controller. Wire-heating elements were controlled at certain setting value to heat the injected aerosol to form a thin film in the substrate. The performance of as-developed AACVD system tested to form a thin film where aerosol was sprayed into the chamber with a flow rate of 7 liters/minutes, and vary in temperatures and concentrations of precursor. The temperature control system have an overshoot around 25 °C from the desired set point temperature, very small temperature ripple 2 °C and a settling time of 20 minutes. As-developed AACVD successfully fabricated a ZnO thin film with thickness of below 1 µm. The performances of system on formation of thin films influenced by the generally controlled process such as values of setting temperature and concentration where the aerosol flow rate was fixed. Higher temperature was applied, the more uniform ZnO thin films were produced. In addition, temperature of the substrate also affected on surface roughness of the obtained films, while concentration of ZnO precursor determined the thickness of produce films. It is concluded that newly simple AACVD can be applied to produce a thin film.

  6. Ultralight boron nitride aerogels via template-assisted chemical vapor deposition

    Science.gov (United States)

    Song, Yangxi; Li, Bin; Yang, Siwei; Ding, Guqiao; Zhang, Changrui; Xie, Xiaoming

    2015-05-01

    Boron nitride (BN) aerogels are porous materials with a continuous three-dimensional network structure. They are attracting increasing attention for a wide range of applications. Here, we report the template-assisted synthesis of BN aerogels by catalyst-free, low-pressure chemical vapor deposition on graphene-carbon nanotube composite aerogels using borazine as the B and N sources with a relatively low temperature of 900 °C. The three-dimensional structure of the BN aerogels was achieved through the structural design of carbon aerogel templates. The BN aerogels have an ultrahigh specific surface area, ultralow density, excellent oil absorbing ability, and high temperature oxidation resistance. The specific surface area of BN aerogels can reach up to 1051 m2 g-1, 2-3 times larger than the reported BN aerogels. The mass density can be as low as 0.6 mg cm-3, much lower than that of air. The BN aerogels exhibit high hydrophobic properties and can absorb up to 160 times their weight in oil. This is much higher than porous BN nanosheets reported previously. The BN aerogels can be restored for reuse after oil absorption simply by burning them in air. This is because of their high temperature oxidation resistance and suggests broad utility as water treatment tools.

  7. Influence of APS bias voltage on properties of HfO2 and SiO2 single layer deposited by plasma ion-assisted deposition

    Institute of Scientific and Technical Information of China (English)

    Meiping Zhu; Kui Yi; Zhengxiu Fan; Jianda Shao

    2011-01-01

    @@ HfO2 and SiO2 single layer is deposited on glass substrate with plasma ion assistance provided by Leybold advanced plasma source (APS). The deposition is performed with a bias voltage in the range of 70-130 V for HfO2, and 70-170 V for SiO2. Optical, structural, mechanical properties, as well as absorption and laser induced damage threshold at 1064 nm of HfO2 and SiO2 single layer deposited with the plasma ion assistance are systematically investigated. With the increase of APS bias voltage, coatings with higher refractive index, reduced surface roughness, and higher laser-induced damage threshold (LIDT) are obtained, and no significant change of the absorption at 1064 nm is observed. For HfO2, a bias voltage can be identified to achieve coatings without any stress. However, too-high bias voltage can cause the increase of surface roughness and stress, and decrease the LIDT. The bias voltage can be properly identified to achieve coatings with desired properties.%HfO2 and SiO2 single layer is deposited on glass substrate with plasma ion assistance provided by Leybold advanced plasma source (APS). The deposition is performed with a bias voltage in the range of 70-130 V for HfO2, and 70-170 V for SiO2. Optical, structural, mechanical properties, as well as absorption and laser induced damage threshold at 1064 nm of HfO2 and SiO2 single layer deposited with the plasma ion assistance are systematically investigated. With the increase of APS bias voltage, coatings with higher refractive index, reduced surface roughness, and higher laser-induced damage threshold (LIDT) are obtained, and no significant change of the absorption at 1064 nm is observed. For HfO2, a bias voltage can be identified to achieve coatings without any stress. However, too-high bias voltage can cause the increase of surface roughness and stress, and decrease the LIDT. The bias voltage can be properly identified to achieve coatings with desired properties.

  8. 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%

  9. Reduced thermal budget processing of Y-Ba-Cu-O films by rapid isothermal processing assisted metalorganic chemical vapor deposition

    International Nuclear Information System (INIS)

    Metalorganic chemical vapor deposition (MOCVD) has the potential of emerging as a viable technique to fabricate ribbons, tapes, coated wires, and the deposition of films of high-temperature superconductors, and related materials. As a reduced thermal budget processing technique, rapid isothermal processing (RIP) based on incoherent radiation as the source of energy can be usefully coupled to conventional MOCVD. In this paper we report on the deposition and characterization of high quality superconducting thin films of Y-Ba-Cu-O (YBCO) on yttrium stabilized zirconia substrates by RIP assisted MOCVD. Using O2 gas as the source of oxygen, YBCO films deposited initially at 600 degree C for 1 min and at 745 degree C for 25 min followed by deposition at 780 degree C for 45 s are primarily c-axis oriented and zero resistance is observed at 89--90 K. The zero magnetic field current density at 53 and 77 K are 1.2x106 and 3x105 A/cm2, respectively. By using a mixture of N2O and O2 as the oxygen source substrate temperature was further reduced in the deposition of YBCO films. The films deposited initially at 600 degree C for 1 min and than at 720 degree C for 30 min are c-axis oriented and with zero resistance being observed at 91 K. The zero magnetic field current densities at 53 and 77 K are 3.4x106 and 1.2x106 A/cm2, respectively. To the best of our knowledge this is the highest value of critical current density, Jc for films deposited by MOCVD at a substrate temperature as low as 720 degree C. It is envisioned that high energy photons from the incoherent light source and the use of a mixture of N2O and O2 as the oxygen source, assist chemical reactions and lower overall thermal budget for processing of these films

  10. Formation of SiC Nanostruture Using Hexamethyldisiloxane During Plasma-Assisted Hot-Filament Chemical Vapor Deposition

    International Nuclear Information System (INIS)

    Growth of SiC nanowires in plasma-assisted hot filament chemical-vapor-deposition by using hexamethyldisiloxane (HMDSO) as the gas source is reported. The SiC nanowires (SiC-NWs) grew on Au-coated silicon substrate with core-shell structure, where the core consisted of polycrystalline SiC grains and the shell exhibited amorphous structure. The featured structures such as cones, polyhedrons, ball-liked particles were observed in the case without plasma assistance. The underlying mechanism for the growth of nanostructures was also discussed. The high chemical activity induced by the plasma process plays an important role in using monomer to generate nanostructure.

  11. Electron Cyclotron Resonance Plasma-Assisted Atomic Layer Deposition of Amorphous Al2O3 Thin Films

    International Nuclear Information System (INIS)

    Without extra heating, Al2O3 thin films were deposited on a hydrogen-terminated Si substrate etched in hydrofluoric acid by using a self-built electron cyclotron resonance (ECR) plasma-assisted atomic layer deposition (ALD) device with Al(CH3)3 (trimethylaluminum; TMA) and O2 used as precursor and oxidant, respectively. During the deposition process, Ar was introduced as a carrier and purging gas. The chemical composition and microstructure of the as-deposited Al2O3 films were characterized by using X-ray diffraction (XRD), an X-ray photoelectric spectroscope (XPS), a scanning electron microscope (SEM), an atomic force microscope (AFM) and a high-resolution transmission electron microscope (HRTEM). It achieved a growth rate of 0.24 nm/cycle, which is much higher than that deposited by thermal ALD. It was found that the smooth surface thin film was amorphous alumina, and an interfacial layer formed with a thickness of ca. 2 nm was observed between the Al2O3 film and substrate Si by HRTEM. We conclude that ECR plasma-assisted ALD can grow Al2O3 films with an excellent quality at a high growth rate at ambient temperature.

  12. Study on absorbance and laser damage threshold of HfO2 films prepared by ion-assisted reaction deposition

    Institute of Scientific and Technical Information of China (English)

    张大伟; 范树海; 高卫东; 贺洪波; 王英剑; 邵建达; 范正修; 孙浩杰

    2004-01-01

    Using a new kind of EH1000 ion source, hafnium dioxide (HfO2) films are deposited with different depo sition techniques and different conditions. The absorbance and the laser damage threshold of these films have been measured and studied. By comparing these characteristics, one can conclude that under right conditions, such as high partial pressure of oxygen and right kind of ion source, the ion-assisted reaction deposition can prepare HfO2 films with higher laser induced damage threshold.

  13. Nanoparticulate cerium dioxide and cerium dioxide-titanium dioxide composite thin films on glass by aerosol assisted chemical vapour deposition

    International Nuclear Information System (INIS)

    Two series of composite thin films were deposited on glass by aerosol assisted chemical vapour deposition (AACVD)-nanoparticulate cerium dioxide and nanoparticulate cerium dioxide embedded in a titanium dioxide matrix. The films were analysed by a range of techniques including UV-visible absorption spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive analysis by X-rays. The AACVD prepared films showed the functional properties of photocatalysis and super-hydrophilicity. The CeO2 nanoparticle thin films displaying photocatalysis and photo-induced hydrophilicity almost comparable to that of anatase titania.

  14. Development of a high magnetic field assisted pulsed laser deposition system

    Science.gov (United States)

    Zhang, Kejun; Dai, Jianming; Wu, Wenbin; Zhang, Peng; Zuo, Xuzhong; Zhou, Shu; Zhu, Xuebin; Sheng, Zhigao; Liang, Changhao; Sun, Yuping

    2015-09-01

    A high magnetic field assisted pulsed laser deposition (HMF-PLD) system has been developed to in situ grow thin films in a high magnetic field up to 10 T. In this system, a specially designed PLD cylindrical vacuum chamber is horizontally located in the bore configuration of a superconducting magnet with a bore diameter of 200 mm. To adjust the focused pulsed laser into the target in such a narrow PLD vacuum chamber, an ingeniously built-in laser leading-in chamber is employed, including a laser mirror with a reflection angle of 65° and a damage threshold up to 3.4 J/cm2. A laser alignment system consisting of a built-in video-unit leading-in chamber and a low-energy alignment laser is applied to monitor and align the pulsed laser propagation in the PLD vacuum chamber. We have grown La0.7Sr0.3MnO3 (LSMO) thin films on (LaAlO3)0.3(Sr2AlTaO6)0.7 (001) [LSAT (001)] substrates by HMF-PLD. The results show that the nanostructures of the LSMO films can be tuned from an epitaxially continuous film structure without field to a vertically aligned nanorod structure with an applied high magnetic field above 5 T, and the dimension size of the nanorods can be tuned by the strength of the magnetic field. The associated magnetic anisotropy is found to be highly dependent on the nanorod structures. We show how the HMF-PLD provides an effective route toward tuning the nanostructures and the physical properties of functional thin films, giving it an important role in development of nanodevices and their application.

  15. Nanoscale coatings of tungsten by radio frequency plasma assisted chemical vapor deposition on graphite

    International Nuclear Information System (INIS)

    Future thermonuclear fusion reactors including ITER are heading towards full scale operations with tungsten being the material for the divertor, limiter and probably the first wall too. Tungsten has several superior properties over its low Z competitors in terms of higher melting point, lower sputtering yield, low fuel retention (D - T) etc. So far, fusion experimentalists have gained enough experience and have rich databases with carbon as its first wall as well as target materials in tokamaks. However, database for tungsten line radiation in variety of plasmas i.e. basic laboratory scale to high density and high temperature plasmas is rare and this requires immediate attention to construct a database with experimental evidences. Such studies are not limited to only large scale fusion reactors but small and medium scale toroidally confined devices can be suitably utilized. Present day tokamaks are now switching to plasma facing components made up of tungsten. As the complete replacement of the wall and target materials from carbon to tungsten in existing tokamaks is challenging and time consuming exercise, tungsten coatings on selected target materials remains a very feasible option for the purpose. This paper will present the development of indigenous tungsten coating reactor which has successfully produced tungsten coated graphite tiles of sample dimensions. The tungsten coated graphite tiles are produced by RF plasma assisted chemical vapor deposition of tungsten on graphite substrates. The RF plasma is produced with 60 - 100 W power and tungsten nano ions are produced by dissociating the precursor gas tungsten hexa-fluoride (WF6) in sufficient hydrogen background. Further, challenges in handling WF6 plasma at high pressures and in-situ spectroscopy results during the coating process will be presented. (author)

  16. Fabrication of three-dimensional scaffolds using precision extrusion deposition with an assisted cooling device

    Energy Technology Data Exchange (ETDEWEB)

    Hamid, Q; Snyder, J; Wang, C; Guceri, S; Sun, W [Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA (United States); Timmer, M; Hammer, J, E-mail: sunwei@drexel.edu [Advanced Technologies and Regenerative Medicine, Somerville, NJ (United States)

    2011-09-15

    In the field of biofabrication, tissue engineering and regenerative medicine, there are many methodologies to fabricate a building block (scaffold) which is unique to the target tissue or organ that facilitates cell growth, attachment, proliferation and/or differentiation. Currently, there are many techniques that fabricate three-dimensional scaffolds; however, there are advantages, limitations and specific tissue focuses of each fabrication technique. The focus of this initiative is to utilize an existing technique and expand the library of biomaterials which can be utilized to fabricate three-dimensional scaffolds rather than focusing on a new fabrication technique. An expanded library of biomaterials will enable the precision extrusion deposition (PED) device to construct three-dimensional scaffolds with enhanced biological, chemical and mechanical cues that will benefit tissue generation. Computer-aided motion and extrusion drive the PED to precisely fabricate micro-scaled scaffolds with biologically inspired, porosity, interconnectivity and internal and external architectures. The high printing resolution, precision and controllability of the PED allow for closer mimicry of tissues and organs. The PED expands its library of biopolymers by introducing an assisting cooling (AC) device which increases the working extrusion temperature from 120 to 250 deg. C. This paper investigates the PED with the integrated AC's capabilities to fabricate three-dimensional scaffolds that support cell growth, attachment and proliferation. Studies carried out in this paper utilized a biopolymer whose melting point is established to be 200 deg. C. This polymer was selected to illustrate the newly developed device's ability to fabricate three-dimensional scaffolds from a new library of biopolymers. Three-dimensional scaffolds fabricated with the integrated AC device should illustrate structural integrity and ability to support cell attachment and proliferation.

  17. New Target Methodology: Polymer-Assisted Deposition and Its Applications on Gas-Phase Nuclear Chemistry with Rutherfordium

    OpenAIRE

    Garcia, Mitch Andre

    2009-01-01

    This work focuses on three research topics that were distinctly different but broadly centered around developing new methods to perform transactinide gas-phase chemistry. First, the application of a new materials science methodology, Polymer-Assisted Deposition (PAD), to target manufacturing is described. Second, the construction of a new experimental apparatus to conduct gas-phase chemistry and the design of circuits and electronics for the measurement of alpha-decay energy is discussed. Thi...

  18. Pitting resistance of TiN deposited on Inconel 600 by plasma-assisted chemical vapor deposition

    International Nuclear Information System (INIS)

    TiN films were deposited on Inconel 600 by PACVD using the gaseous mixture of TiCl4, N2, H2, and Ar in order to increase the pitting resistance of Inconel 600. The pitting resistance was examined using a potentiodynamic polarization technique with a chloride solution. The effect of chloride concentration in the electrolyte on the pitting potential was also investigated. Inconel 600 coated with TiN film shows a superior pitting resistance to that without TiN film in condition that the thickness of the film is greater than a certain critical value. As the deposition temperature as well as the RF power increases, the residual Cl concentration in the film decreases, resulting in the improvement of the pitting resistance. However, the TiN films deposited at too high RF powers, even though the Cl concentration in TiN film is very small, show inferior pitting resistance, which is due to the formation of the network type microvoids structure. ((orig.))

  19. Redeposition in plasma-assisted atomic layer deposition: Silicon nitride film quality ruled by the gas residence time

    International Nuclear Information System (INIS)

    The requirements on the material properties and growth control of silicon nitride (SiNx) spacer films in transistors are becoming ever more stringent as scaling of transistor structures continues. One method to deposit high-quality films with excellent control is atomic layer deposition (ALD). However, depositing SiNx by ALD has turned out to be very challenging. In this work, it is shown that the plasma gas residence time τ is a key parameter for the deposition of SiNx by plasma-assisted ALD and that this parameter can be linked to a so-called “redeposition effect”. This previously ignored effect, which takes place during the plasma step, is the dissociation of reaction products in the plasma and the subsequent redeposition of reaction-product fragments on the surface. For SiNx ALD using SiH2(NHtBu)2 as precursor and N2 plasma as reactant, the gas residence time τ was found to determine both SiNx film quality and the resulting growth per cycle. It is shown that redeposition can be minimized by using a short residence time resulting in high-quality films with a high wet-etch resistance (i.e., a wet-etch rate of 0.5 nm/min in buffered HF solution). Due to the fundamental nature of the redeposition effect, it is expected to play a role in many more plasma-assisted ALD processes

  20. Redeposition in plasma-assisted atomic layer deposition: Silicon nitride film quality ruled by the gas residence time

    Science.gov (United States)

    Knoops, Harm C. M.; de Peuter, K.; Kessels, W. M. M.

    2015-07-01

    The requirements on the material properties and growth control of silicon nitride (SiNx) spacer films in transistors are becoming ever more stringent as scaling of transistor structures continues. One method to deposit high-quality films with excellent control is atomic layer deposition (ALD). However, depositing SiNx by ALD has turned out to be very challenging. In this work, it is shown that the plasma gas residence time τ is a key parameter for the deposition of SiNx by plasma-assisted ALD and that this parameter can be linked to a so-called "redeposition effect". This previously ignored effect, which takes place during the plasma step, is the dissociation of reaction products in the plasma and the subsequent redeposition of reaction-product fragments on the surface. For SiNx ALD using SiH2(NHtBu)2 as precursor and N2 plasma as reactant, the gas residence time τ was found to determine both SiNx film quality and the resulting growth per cycle. It is shown that redeposition can be minimized by using a short residence time resulting in high-quality films with a high wet-etch resistance (i.e., a wet-etch rate of 0.5 nm/min in buffered HF solution). Due to the fundamental nature of the redeposition effect, it is expected to play a role in many more plasma-assisted ALD processes.

  1. Influence of Increasing Deposition Temperature on Electrical Properties of Amorphous Carbon Thin Film Prepared by Aerosol-Assisted Thermal CVD

    International Nuclear Information System (INIS)

    This paper reports on the successful deposition of p-type semiconducting amorphous carbon (paC) films fabricated onto the glass substrate by Aerosol-Assisted Thermal Chemical Vapor Deposition (CVD) using natural source of camphor oil as the precursor material. The analyze reveal that conductivity and resistivity shows some changes at different deposition temperature, that is the conductivity increase as temperature increase from 350 to 550 degree Celsius, but drop slightly at 550 degree Celsius. Other than that, optical and structural properties were also characterized by using UV-VIS-NIR system and Atomic Force Microscopy. The same trend of optical and electrical can be seen when the measurement from the Taucs plot expose a decreasing value of optical band gap as temperature increase, but slightly increase when temperature increase to 550 degree Celsius. (author)

  2. Aerosol assisted chemical vapour deposition of germanium thin films using organogermanium carboxylates as precursors and formation of germania films

    Indian Academy of Sciences (India)

    Alpa Y Shah; Amey Wadawale; Vijaykumar S Sagoria; Vimal K Jain; C A Betty; S Bhattacharya

    2012-06-01

    Diethyl germanium bis-picolinate, [Et2Ge(O2CC5H4N)2], and trimethyl germanium quinaldate, [Me3Ge(O2CC9H6N)], have been used as precursors for deposition of thin films of germanium by aerosol assisted chemical vapour deposition (AACVD). The thermogravimetric analysis revealed complete volatilization of complexes under nitrogen atmosphere. Germanium thin films were deposited on silicon wafers at 700°C employing AACVD method. These films on oxidation under an oxygen atmosphere at 600°C yield GeO2. Both Ge and GeO2 films were characterized by XRD, SEM and EDS measurements. Their electrical properties were assessed by current–voltage (–) characterization.

  3. Characteristics and properties of metal aluminum thin films prepared by electron cyclotron resonance plasma-assisted atomic layer deposition technology

    Institute of Scientific and Technical Information of China (English)

    Xiong Yu-Qing; Li Xing-Cun; Chen Qiang; Lei Wen-Wen; Zhao Qiao; Sang Li-Jun; Liu Zhong-Wei; Wang Zheng-Duo; Yang Li-Zhen

    2012-01-01

    Metal aluminum (Al) thin films are prepared by 2450 MHz electron cyclotron resonance plasma-assisted atomic layer deposition on glass and p-Si substrates using trimethylaluminum as the precursor and hydrogen as the reductive gas.We focus our attention on the plasma source for the thin-film preparation and annealing of the as-deposited films relative to the surface square resistivity.The square resistivity of as-deposited Al films is greatly reduced after annealing and almost reaches the value of bulk metal.Through chemical and structural analysis,we conclude that the square resistivity is determined by neither the contaminant concentration nor the surface morphology,but by both the crystallinity and crystal size in this process.

  4. 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

  5. XPS study of target poisoning during the plasma assisted deposition of a-C:H/Au thin films

    International Nuclear Information System (INIS)

    The X-ray photoelectron spectroscopic (XPS) study of the target poisoning during the deposition of a-C:H/Au using combined radio frequency (RF) powered magnetron sputtering at 100 W and plasma-assisted chemical vapor deposition (PACVD) with a mass flow ratio of 0.5 between CH4 and at is made by Gampp. In this paper we extend this study to both RF and bipolar pulsed (BPP) powered magnetron sputtering in gas mixtures of different values of CH4/Ar mass flow ratio. Elemental compositions of deposited a-C:H/Au layers have been determined by in situ X-ray photoelectron spectroscopy. To determine the elemental content of a sample, the integration over Au 4f7/2, C 1s and 0 1s core level signals (oxygen shows up as an impurity of max. 1 at.%) was used. One may generally conclude that the character of target poisoning process is steep and step-like in time regardless of the type of magnetron power supply, i.e. that it is inherent to the deposition of a-C:H/Au using present deposition setup. Therefore, in the attempts to obtain stable and reproducible deposition conditions and homogeneous coatings, the target had to be driven to the certain degree of poisoning. This is done by conditioning in pure CH4 (covering) and in pure Ar plasma (cleaning) subsequently and alternatively, until the desired Au content is reached. Then, for deposition purposes, a CH4/Ar gas mixture was selected so that steady state of target covering and cleaning is sustained

  6. Enhancing the thermal conductivity of polymer-assisted deposited Al2O3 film by nitrogen doping

    Institute of Scientific and Technical Information of China (English)

    Huang Jiang; Zhang Yin; Pan Tai-Song; Zeng Bo; Hu Guo-Hua; Lin Yuan

    2012-01-01

    Polymer-assisted deposition technique has been used to deposit Al2O3 and N-doped Al2O3 (AlON) thin films on Si(100) substrates.The chemical compositions,crystallinity,and thermal conductivity of the as-grown films have been characterized by X-ray photoelectron spectroscopy (XPS),X-ray diffraction (XRD),and 3-omega method,respectively.Amorphous and polycrystalline Al2O3 and AlON thin films have been formed at 700 ℃ and 1000 ℃.The thermal conductivity results indicated that the effect of nitrogen doping on the thermal conductivity is determined by the competition of the increase of Al-N bonding and the suppression of crystallinity.A 67% enhancement in thermal conductivity has been achieved for the samples grown at 700 ℃,demonstrating that the nitrogen doping is an effective way to improve the thermal performance of polymer-assisted-deposited Al2O3 thin films at a relatively low growth temperature.

  7. 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.)

  8. Spatio-selective surface modification of glass assisted by laser-induced deposition of gold nanoparticles

    International Nuclear Information System (INIS)

    Using pulsed laser irradiation (532 nm), dodecanethiol-capped gold nanoparticles (DT-Au) were deposited on the laser-irradiated region of a hydrophobic glass substrate modified with dimethyloctadecylchlorosilane (DMOS). After removal of deposited DT-Au, the laser-deposited region on the substrate was hydrophilic, as verified by static water contact angles. X-ray photoelectron spectroscopy suggested that the naked glass surface was not exposed at the hydrophilic region. Immersion of the substrate into gold nanorod (NR) solution selectively immobilized NRs on the hydrophilic surface via electrostatic interactions, indicating that the hydrophilic region was an anionic surface. From these results, it is expected that some immobilized DMOS groups on the laser-irradiated region of the substrate were oxidized during DT-Au deposition and fragmentation of the deposited DT-Au

  9. Surface chemistry of plasma-assisted atomic layer deposition of Al2O3 studied by infrared spectroscopy

    International Nuclear Information System (INIS)

    The surface groups created during plasma-assisted atomic layer deposition (ALD) of Al2O3 were studied by infrared spectroscopy. For temperatures in the range of 25-150 deg. C, -CH3 and -OH were unveiled as dominant surface groups after the Al(CH3)3 precursor and O2 plasma half-cycles, respectively. At lower temperatures more -OH and C-related impurities were found to be incorporated in the Al2O3 film, but the impurity level could be reduced by prolonging the plasma exposure. The results demonstrate that -OH surface groups rule the surface chemistry of the Al2O3 process and likely that of plasma-assisted ALD of metal oxides from organometallic precursors in general

  10. 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

  11. UV and RIR matrix assisted pulsed laser deposition of organic MEH-PPV films

    DEFF Research Database (Denmark)

    Christensen, Bo Toftmann; Papantonalis, M.R.; Auyeung, R.C.Y.;

    2004-01-01

    A comparative study of thin film production based on gentle laser-ablation techniques has been carried out with the luminescent polymer poly [2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene]. Using a free-electron laser films were made by resonant infrared pulsed laser deposition (RIR-PLD...... substrates were analyzed by Fourier transform infrared spectroscopy, UV-visible absorbance and photoluminescence. Photoluminescent material was deposited by RIR-MAPLE and 248-nm MAPLE, while the RIR-PLD and 193-nm-MAPLE depositions displayed the smoothest surfaces but did not show photoluminescence. (C) 2003...

  12. 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.

  13. Sapphire substrate-induced effects in VO2 thin films grown by oxygen plasma-assisted pulsed laser deposition

    International Nuclear Information System (INIS)

    We investigate the structural and electronic properties of VO2 thin films on c-plane sapphire substrates with three different surface morphologies to control the strain at the substrate-film interface. Only non-annealed substrates with no discernible surface features (terraces) provided a suitable template for VO2 film growth with a semiconductor-metal transition (SMT), which was much lower than the bulk transition temperature. In addition to strain, oxygen vacancy concentration also affects the properties of VO2, which can be controlled through deposition conditions. Oxygen plasma-assisted pulsed laser deposition allows favorable conditions for VO2 film growth with SMTs that can be easily tailored for device applications

  14. 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

  15. 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.

  16. 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.

  17. Failure Strain and Strain-Stress Analysis in Titanium Nitride Coatings Deposited on Religa Heart Ext Ventricular Assist Device

    OpenAIRE

    Kopernik M.

    2015-01-01

    The Polish ventricular assist device is made of Bionate II with deposited TiN biocompatible nano-coating. The two scale finite element model is composed of a macro-model of blood chamber and a micro-model of the TiN/Bionate II. The numerical analysis of stress and strain states confirmed the possibility of fracture. Therefore, the identification of a fracture parameter considered as a failure strain is the purpose of the present work. The tensile test in a micro chamber of the SEM was perform...

  18. Redeposition in plasma-assisted atomic layer deposition: Silicon nitride film quality ruled by the gas residence time

    Energy Technology Data Exchange (ETDEWEB)

    Knoops, Harm C. M., E-mail: h.c.m.knoops@tue.nl, E-mail: w.m.m.kessels@tue.nl [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Oxford Instruments Plasma Technology, North End, Bristol BS49 4AP (United Kingdom); Peuter, K. de; Kessels, W. M. M., E-mail: h.c.m.knoops@tue.nl, E-mail: w.m.m.kessels@tue.nl [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

    2015-07-06

    The requirements on the material properties and growth control of silicon nitride (SiN{sub x}) spacer films in transistors are becoming ever more stringent as scaling of transistor structures continues. One method to deposit high-quality films with excellent control is atomic layer deposition (ALD). However, depositing SiN{sub x} by ALD has turned out to be very challenging. In this work, it is shown that the plasma gas residence time τ is a key parameter for the deposition of SiN{sub x} by plasma-assisted ALD and that this parameter can be linked to a so-called “redeposition effect”. This previously ignored effect, which takes place during the plasma step, is the dissociation of reaction products in the plasma and the subsequent redeposition of reaction-product fragments on the surface. For SiN{sub x} ALD using SiH{sub 2}(NH{sup t}Bu){sub 2} as precursor and N{sub 2} plasma as reactant, the gas residence time τ was found to determine both SiN{sub x} film quality and the resulting growth per cycle. It is shown that redeposition can be minimized by using a short residence time resulting in high-quality films with a high wet-etch resistance (i.e., a wet-etch rate of 0.5 nm/min in buffered HF solution). Due to the fundamental nature of the redeposition effect, it is expected to play a role in many more plasma-assisted ALD processes.

  19. Matrix-Assisted Pulsed Laser Thin Film Deposition by Using Nd:YAG Laser

    Directory of Open Access Journals (Sweden)

    Francesco Bloisi

    2012-01-01

    In this paper, the MAPLE technique is described in details, together with a survey of current and possible future applications for both organic and biomaterial deposition taking into account the advantages of using an Nd:YAG laser. Beside other results, we have experimental confirmation that MAPLE applications are not limited to transparent molecules highly soluble in light absorbing solvent, thus allowing deposition of poorly soluble light absorbing molecules suspended in a light transparent liquid.

  20. Pulse-reverse electrodeposition for mesoporous metal films: combination of hydrogen evolution assisted deposition and electrochemical dealloying.

    Science.gov (United States)

    Cherevko, Serhiy; Kulyk, Nadiia; Chung, Chan-Hwa

    2012-01-21

    Hydrogen evolution assisted electrodeposition is a new bottom-up technique allowing the fast and simple synthesis of nanometals. Electrochemical dealloying is a top-down approach with the same purpose. In this work, we show that a combination of these two methods in sequence by pulse-reverse electrodeposition can be used to prepare high-surface-area nanostructured metals. Highly porous adherent platinum is obtained by the deposition of CuPt alloy during the cathodic cycles and the selective dissolution of copper during the anodic cycles. The convection created by the movement of the hydrogen bubbles increases the deposition rate and removes the dissolved copper ions from the diffusion layer, which ensures the deposition of a film with the same stoichiometry throughout the whole process. Due to the relatively high ratio of copper atoms on the surface in the as-deposited layer, it is proposed that the dealloying kinetics is significantly higher than that usually observed during the dealloying process in a model system. The proposed approach has several advantages over other methods, such as a very high growth rate and needlessness of any post-treatment processes. A detailed analysis of the effect of pulse-reverse waveform parameters on the properties of the films is presented. Mesoporous platinum with pores and ligaments having characteristic sizes of less than 10 nm, an equivalent surface area of up to ca. 220 m(2) cm(-3), and a roughness factor of more than 1000 is fabricated. PMID:22139451

  1. Optical emission spectroscopy as a tool for studying, optimizing, and monitoring plasma-assisted atomic layer deposition processes

    International Nuclear Information System (INIS)

    In this note it is demonstrated that optical emission spectroscopy (OES) is an easy-to-implement and valuable tool to study, optimize, and monitor thin film growth by plasma-assisted atomic layer deposition (ALD). The species in the plasma can be identified through the analysis of the light emitted by the plasma. OES provides therefore information on the reactant species delivered to the surface by the plasma but it also yields unique insight into the surface reaction products and, as a consequence, on the reaction mechanisms of the deposition process. Time-resolved measurements reveal information about the amount of precursor dosing and length of plasma exposure needed to saturate the self-limiting half reactions, which is useful for the optimization of the ALD process. Furthermore, time-resolved OES can also be used as an easy-to-implement process monitoring tool for plasma-assisted ALD processes on production equipment; for example, to monitor reactor wall conditions or to detect process faults in real time.

  2. 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

  3. Improving flux pinning in YBa[sub 2]Cu[sub 3]O[sub 7] coated conductors by changing the buffer layer deposition conditions

    Energy Technology Data Exchange (ETDEWEB)

    Maiorov, B. A. (Boris Alfredo); Wang, H. (Haiyan); Foltyn, S. R. (Stephen R.); Arendt, P. N. (Paul N.); Civale, L. (Leonardo)

    2004-01-01

    We present a comparative study of the flux pinning properties of YBa{sub 2}Cu{sub 3}O{sub 7} films deposited by pulsed laser deposition on polycrystalline metal substrates with a biaxially oriented MgO template produced by ion-beam-assisted deposition (IBAD), varying the deposition temperature (T{sub STO}) for the SrTiO{sub 3} buffer layer. We find that when T{sub STO} = T*{sub STO} = 820 C, the critical current density at self-field (J{sub c}{sup sf}) is maximized and the surface roughness minimized. On the contrary, in-field critical current density (J{sub c}) measurements show that at high fields, samples with T{sub STO}

  4. UV and RIR matrix assisted pulsed laser deposition of organic MEH-PPV films

    DEFF Research Database (Denmark)

    Christensen, Bo Toftmann; Papantonalis, M.R.; Auyeung, R.C.Y.; Kim, W.; O'Malley, S.M.; Bubb, D.M.; Horwitz, J.S.; Schou, Jørgen; Johansen, P.M.; Haglund Jr., R.E.

    A comparative study of thin film production based on gentle laser-ablation techniques has been carried out with the luminescent polymer poly [2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene]. Using a free-electron laser films were made by resonant infrared pulsed laser deposition (RIR-PLD)....

  5. Surface-grafted polymer-assisted electroless deposition of metals for flexible and stretchable electronics.

    Science.gov (United States)

    Liu, Xuqing; Zhou, Xuechang; Li, Yi; Zheng, Zijian

    2012-05-01

    Surface-grafted polymers, that is, ultrathin layers of polymer coating covalently tethered to a surface, can serve as a particularly promising nanoplatform for electroless deposition (ELD) of metal thin films and patterned structures. Such polymers consist of a large number of well-defined binding sites for highly efficient and selective uptake of ELD catalysts. Moreover, the polymer chains provide flexible 3D network structures to trap the electrolessly deposited metal particles, leading to strong metal-substrate adhesion. In the past decade, surface-grafted polymers have been demonstrated as efficient nanoplatforms for fabricating durable and high-performance metal coatings by ELD on plastic substrates for applications in flexible and stretchable electronics. This focus review summarizes these recent advances, with a particular focus on applications in polymeric flexible and stretchable substrates. An outlook on the future challenges and opportunities in this field is given at the end of this paper. PMID:22392811

  6. 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.

  7. Pulse-reverse electrodeposition for mesoporous metal films: combination of hydrogen evolution assisted deposition and electrochemical dealloying

    Science.gov (United States)

    Cherevko, Serhiy; Kulyk, Nadiia; Chung, Chan-Hwa

    2012-01-01

    Hydrogen evolution assisted electrodeposition is a new bottom-up technique allowing the fast and simple synthesis of nanometals. Electrochemical dealloying is a top-down approach with the same purpose. In this work, we show that a combination of these two methods in sequence by pulse-reverse electrodeposition can be used to prepare high-surface-area nanostructured metals. Highly porous adherent platinum is obtained by the deposition of CuPt alloy during the cathodic cycles and the selective dissolution of copper during the anodic cycles. The convection created by the movement of the hydrogen bubbles increases the deposition rate and removes the dissolved copper ions from the diffusion layer, which ensures the deposition of a film with the same stoichiometry throughout the whole process. Due to the relatively high ratio of copper atoms on the surface in the as-deposited layer, it is proposed that the dealloying kinetics is significantly higher than that usually observed during the dealloying process in a model system. The proposed approach has several advantages over other methods, such as a very high growth rate and needlessness of any post-treatment processes. A detailed analysis of the effect of pulse-reverse waveform parameters on the properties of the films is presented. Mesoporous platinum with pores and ligaments having characteristic sizes of less than 10 nm, an equivalent surface area of up to ca. 220 m2 cm-3, and a roughness factor of more than 1000 is fabricated.Hydrogen evolution assisted electrodeposition is a new bottom-up technique allowing the fast and simple synthesis of nanometals. Electrochemical dealloying is a top-down approach with the same purpose. In this work, we show that a combination of these two methods in sequence by pulse-reverse electrodeposition can be used to prepare high-surface-area nanostructured metals. Highly porous adherent platinum is obtained by the deposition of CuPt alloy during the cathodic cycles and the selective

  8. Laser-assisted deposition and element analysis of nano-composite oxide thin films

    International Nuclear Information System (INIS)

    Functional oxide thin films are epitaxially grown by pulsed-laser deposition (PLD) method. High-Tc superconducting (HTS) films of enhanced critical current density Jc are deposited by laser ablation of YBa2Cu3O7 (Y-123) ceramics containing Y2Ba4CuMOx (M-2411, M=Ag,Nb,Ru,Zr) nano-particles. The Jc enhancement of nano-composite films depends on the secondary phase content of the ceramic targets. Piezoelectric oxides such as novel GaPO4 and ZnO doped with Lithium and Aluminum are grown as thin films and double-layers. The monitoring of deposition processes and the element analysis of layers and ceramics are performed by laser-induced break down spectroscopy (LIBS). The LIBS signals recorded in situ are stable for more than 10000 laser pulses employed for target ablation. The relative element concentration in thin films and ceramics is the same demonstrating stoichiometric ablation and transfer of the multi-component oxide materials

  9. Assisted deposition of nano-hydroxyapatite onto exfoliated carbon nanotube oxide scaffolds.

    Science.gov (United States)

    Zanin, H; Rosa, C M R; Eliaz, N; May, P W; Marciano, F R; Lobo, A O

    2015-06-14

    Electrodeposited nano-hydroxyapatite (nHAp) is more similar to biological apatite in terms of microstructure and dimension than apatites prepared by other processes. Reinforcement with carbon nanotubes (CNTs) enhances its mechanical properties and increases adhesion of osteoblasts. Here, we carefully studied nHAp deposited onto vertically aligned multi-walled CNT (VAMWCNT) scaffolds by electrodeposition and soaking in a simulated body fluid (SBF). VAMWCNTs are porous biocompatible scaffolds with nanometric porosity and exceptional mechanical and chemical properties. The VAMWCNT films were prepared on a Ti substrate by a microwave plasma chemical vapour deposition method, and then oxidized and exfoliated by oxygen plasma etching (OPE) to produce graphene oxide (GO) at the VAMWCNT tips. The attachment of oxygen functional groups was found to be crucial for nHAp nucleation during electrodeposition. A thin layer of plate-like and needle-like nHAp with high crystallinity was formed without any need for thermal treatment. This composite (henceforth referred to as nHAp-VAMWCNT-GO) served as the scaffold for in vitro biomineralization when soaked in the SBF, resulting in the formation of both carbonate-rich and carbonate-poor globular-like nHAp. Different steps in the deposition of biological apatite onto VAMWCNT-GO and during the short-term biomineralization process were analysed. Due to their unique structure and properties, such nano-bio-composites may become useful in accelerating in vivo bone regeneration processes. PMID:25990927

  10. Electroless deposition of metal nanoparticles on graphene with substrate-assisted techniques

    Science.gov (United States)

    Zaniewski, Anna M.; Trimble, Christie J.; Meeks, Veronica; Nemanich, Robert J.

    2015-03-01

    We present the electroless reduction of solution-based metal ions for nanoparticle deposition on a variety of substrates. The substrates include graphene-coated metals, insulators, doped semiconductors, and patterned ferroelectrics. We find that the metal ions are spontaneously reduced on a wide variety of graphene substrates, and the substrates play a large role in the nanoparticle coverage. For example, the reduction of gold chloride to gold nanoparticles on graphene/lithium niobate results in 3% nanoparticle coverage compared to 20% coverage on graphene/silicon and 60% on graphene/copper. Given that the work function of graphene is approximately 4.4eV, the Fermi level is -0.1 V vs the normal hydrogen electrode (NHE). Since the reduction potential of gold chloride is +1.002 V, the spontaneous transfer of electrons from the graphene to the metal ion is energetically favorable. However, we find substrates with similar work functions nevertheless result in varied deposition rates, which we attribute to electron availability. We also find that patterned ferrolectrics can be used as a template for patterned nanoparticle deposition, with and without graphene. This work is supported by the National Science Foundation under Grant # DMR-1206935.

  11. Assisted deposition of nano-hydroxyapatite onto exfoliated carbon nanotube oxide scaffolds

    Science.gov (United States)

    Zanin, H.; Rosa, C. M. R.; Eliaz, N.; May, P. W.; Marciano, F. R.; Lobo, A. O.

    2015-05-01

    Electrodeposited nano-hydroxyapatite (nHAp) is more similar to biological apatite in terms of microstructure and dimension than apatites prepared by other processes. Reinforcement with carbon nanotubes (CNTs) enhances its mechanical properties and increases adhesion of osteoblasts. Here, we carefully studied nHAp deposited onto vertically aligned multi-walled CNT (VAMWCNT) scaffolds by electrodeposition and soaking in a simulated body fluid (SBF). VAMWCNTs are porous biocompatible scaffolds with nanometric porosity and exceptional mechanical and chemical properties. The VAMWCNT films were prepared on a Ti substrate by a microwave plasma chemical vapour deposition method, and then oxidized and exfoliated by oxygen plasma etching (OPE) to produce graphene oxide (GO) at the VAMWCNT tips. The attachment of oxygen functional groups was found to be crucial for nHAp nucleation during electrodeposition. A thin layer of plate-like and needle-like nHAp with high crystallinity was formed without any need for thermal treatment. This composite (henceforth referred to as nHAp-VAMWCNT-GO) served as the scaffold for in vitro biomineralization when soaked in the SBF, resulting in the formation of both carbonate-rich and carbonate-poor globular-like nHAp. Different steps in the deposition of biological apatite onto VAMWCNT-GO and during the short-term biomineralization process were analysed. Due to their unique structure and properties, such nano-bio-composites may become useful in accelerating in vivo bone regeneration processes.

  12. Characterization of diamond thin films deposited by a CO2 laser-assisted combustion-flame method

    International Nuclear Information System (INIS)

    Diamond thin films were deposited by a CO2 laser-assisted O2/C2H2/C2H4 combustion-flame process. The effect of the deposition parameters, in particular the laser wavelength and power, on the film surface morphology, microstructure and phases present was the primary focus of the work. The laser power was set at 100, 400 and 800 W while the wavelength was varied and set at 10.591 μm in the untuned condition and set at 10.532 μm to resonantly match the CH2-wagging vibrational mode of the C2H4 molecule when in the tuned condition. When the laser was coupled to the combustion flame during deposition the diamond film growth was enhanced as the lateral grain size increased from 1 μm to greater than 5 μm. The greatest increase in grain size occurred when the wavelength was in the tuned condition. Scanning transmission electron microscopy images from focused-ion beam cross-sectioned samples revealed a sub-layer of smaller grains less than 1 μm in size near the substrate surface at the lower laser powers and untuned wavelength. X-ray diffraction results showed a more intense Diamond (111) peak as the laser power increased from 100 to 800 W for the films deposited with the tuned laser wavelength. Micro-Raman spectra showed a diamond peak nearly twice as intense from the films with the tuned laser wavelength.

  13. Electrostatic quadrupole plasma mass spectrometer measurements during thin film depositions using simultaneous matrix assisted pulsed laser evaporation and magnetron sputtering

    International Nuclear Information System (INIS)

    A hybrid plasma deposition process, combining matrix assisted pulsed laser evaporation (MAPLE) of carbon nanopearls (CNPs) with magnetron sputtering of gold was investigated for growth of composite films, where 100 nm sized CNPs were encapsulated into a gold matrix. Composition and morphology of such composite films was characterized with x-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy (TEM) analysis. Carbon deposits on a gold magnetron sputter target and carbon impurities in the gold matrices of deposited films were observed while codepositing from gold and frozen toluene-CNP MAPLE targets in pure argon. Electrostatic quadrupole plasma analysis was used to determine that a likely mechanism for generation of carbon impurities was a reaction between toluene vapor generated from the MAPLE target and the argon plasma originating from the magnetron sputtering process. Carbon impurities of codeposited films were significantly reduced by introducing argon-oxygen mixtures into the deposition chamber; reactive oxygen species such as O and O+ effectively removed carbon contamination of gold matrix during the codeposition processes. Increasing the oxygen to argon ratio decreased the magnetron target sputter rate, and hence hybrid process optimization to prevent gold matrix contamination and maintain a high sputter yield is needed. High resolution TEM with energy dispersive spectrometry elemental mapping was used to study carbon distribution throughout the gold matrix as well as embedded CNP clusters. This research has demonstrated that a hybrid MAPLE and magnetron sputtering codeposition process is a viable means for synthesis of composite thin films from premanufactured nanoscale constituents, and that cross-process contaminations can be overcome with understanding of hybrid plasma process interaction mechanisms.

  14. Low temperature deposition of indium tin oxide films by plasma ion-assisted evaporation.

    Science.gov (United States)

    Füchsel, Kevin; Schulz, Ulrike; Kaiser, Norbert; Tünnermann, Andreas

    2008-05-01

    Coatings of transparent conductive oxides, especially indium tin oxide (ITO), are important in different fields. So far, application of these materials has been limited to substrates with high thermal stability. We describe an improved coating process for ITO based on plasma ion-assisted evaporation at a substrate temperature below 100 degrees C, which is suitable for organic substrates. In characterizing the thin films, we used the classical Drude theory to calculate the resistivity from optical film properties and compared the data with linear four-point measurements. X-ray diffraction spectroscopy was used to determine the structural properties of the thin films. PMID:18449263

  15. Growth of large size diamond single crystals by plasma assisted chemical vapour deposition: Recent achievements and remaining challenges

    Science.gov (United States)

    Tallaire, Alexandre; Achard, Jocelyn; Silva, François; Brinza, Ovidiu; Gicquel, Alix

    2013-02-01

    Diamond is a material with outstanding properties making it particularly suited for high added-value applications such as optical windows, power electronics, radiation detection, quantum information, bio-sensing and many others. Tremendous progresses in its synthesis by microwave plasma assisted chemical vapour deposition have allowed obtaining single crystal optical-grade material with thicknesses of up to a few millimetres. However the requirements in terms of size, purity and crystalline quality are getting more and more difficult to achieve with respect to the forecasted applications, thus pushing the synthesis method to its scientific and technological limits. In this paper, after a short description of the operating principles of the growth technique, the challenges of increasing crystal dimensions both laterally and vertically, decreasing and controlling point and extended defects as well as modulating crystal conductivity by an efficient doping will be detailed before offering some insights into ways to overcome them.

  16. Monte Carlo simulation of the behaviour of electrons during electron-assisted chemical vapour deposition of diamond

    Institute of Scientific and Technical Information of China (English)

    董丽芳; 陈俊英; 董国义; 尚勇

    2002-01-01

    The behaviour of electrons during electron-assisted chemical vapour deposition of diamond is investigated using Monte Carlo simulation. The electron energy distribution and velocity distribution are obtained over a wide range of reduced field E/N (the ratio of the electric field to gas molecule density) from 100 to 2000 in units of 1Td=10-17Vcm2.Their effects on the diamond growth are also discussed. Themain results obtained are as follows. (1) The velocity profile is asymmetric for the component parallel to the field.Ihe velocity distribution has a peak shift in the field direction. Most electrons possess non-zero velocity parallel to the substrate. (2) The number of atomic H is a function of E/N. (3) High-quality diamond can be obtained under the condition of E/N from 50 to 800Td due to sufficient atomic H and electron bombardment.

  17. Low temperature thin film transistors with hollow cathode plasma-assisted atomic layer deposition based GaN channels

    International Nuclear Information System (INIS)

    We report GaN thin film transistors (TFT) with a thermal budget below 250 °C. GaN thin films are grown at 200 °C by hollow cathode plasma-assisted atomic layer deposition (HCPA-ALD). HCPA-ALD-based GaN thin films are found to have a polycrystalline wurtzite structure with an average crystallite size of 9.3 nm. TFTs with bottom gate configuration are fabricated with HCPA-ALD grown GaN channel layers. Fabricated TFTs exhibit n-type field effect characteristics. N-channel GaN TFTs demonstrated on-to-off ratios (ION/IOFF) of 103 and sub-threshold swing of 3.3 V/decade. The entire TFT device fabrication process temperature is below 250 °C, which is the lowest process temperature reported for GaN based transistors, so far.

  18. Numerical And Experimental Analysis Of Fracture Of Athrombogenic Coatings Deposited On Ventricular Assist Device In Micro-Shear Test

    Directory of Open Access Journals (Sweden)

    Kopernik M.

    2015-06-01

    Full Text Available The Polish left ventricular assist device (LVAD – RELIGA_EXT will be made of thermoplastic polycarbonate-urethane (Bionate II with deposited athrombogenic nano-coatings: gold (Au and titanium nitride (TiN. Referring to the physical model, the two-scale model of LVAD developed in the previous works in the authors’ finite element code is composed of a macro-model of blood chamber and a micro-model of wall: TiN, Au and Bionate II. The numerical analysis of stress and strain states confirmed the possibility of fracture based on localization of zones of the biggest values of triaxiality factor. The introduction of Au interlayer between TiN and polymer improved the toughness of the connection, and increased the compressive residual stress in the coating what resulted in reduction of stress and strain close to the boundary between substrate and coating.

  19. Deposition of matrix-free fullerene films with improved morphology by matrix-assisted pulsed laser evaporation (MAPLE)

    DEFF Research Database (Denmark)

    Canulescu, Stela; Schou, Jørgen; Fæster, Søren;

    2013-01-01

    Thin films of C60 were deposited by matrix-assisted pulsed laser evaporation (MAPLE) from a frozen target of anisole with 0.67 wt% C60. Above a fluence of 1.5 J/cm2 the C60 films are strongly non-uniform and are resulting from transfer of matrix-droplets containing fullerenes. At low fluence the...... fullerene molecules in the films are intact, the surface morphology is substantially improved and there are no measurable traces of the matrix molecules in the film. This may indicate a regime of dominant evaporation at low fluence which merges into the MAPLE regime of liquid ejection of the host matrix at...

  20. Role of fluorine atoms in the oxidation-hydrolysis process of plasma assisted chemical vapor deposition fluorinated silicon nitride film

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, O.; Gomez-Aleixandre, C.; Palacio, C. (Universidad Autonoma de Madrid (Spain))

    The oxidation and/or hydrolysis of a plasma assisted chemical vapor deposition fluorinated silicon nitride film in a moisture atmosphere has been studied. The film presents fluorine atoms incorporated as -SiF, -SiF[sub 2], -SiF[sub 3], and [-SiF[sub 2]-][sub n] groups. The open structure of the film, due to the high fluorine content as [-SiF[sub 2]-][sub n], favors the penetration of oxygen and water molecules in the network. The evolution of the film has been explained by the different reactivity of the silicon atoms depending on their chemical environment. The role of fluorine atoms incorporated into the film has been established. 12 refs., 3 figs., 1 tab.

  1. Ion-assisted deposition of yttrium fluoride as a substitute for thorium fluoride: application to infrared antireflection coating on germanium

    Science.gov (United States)

    Robic, Jean-Yves; Rolland, Bernard; Deutsch, Jean-Claude; Gallais, Patrick

    1994-11-01

    Yttrium fluoride has been proposed as a substitute for thorium fluoride in anti-reflection coatings for the infrared range. We have studied the ion assisted deposition (IAD) of YF3 in order to obtain dense and low absorbency layers in the 8 to 12 mm spectral window. Refractive index and extinction coefficient of this fluoride were determined from spectrophotometry measurements. We have then associated the YF3 with ZnS and Ge layers so as to obtain four layer anti-reflection coatings on germanium. The stress induced by each layer in the coating was measured and the sum was shown to be equal to the stress of the total coating. Eventually, an industrial, high efficiency, both side anti-reflection coating on germanium was developed using IAD YF3 film.

  2. Properties of La and Nb-modified PZT thin films grown by radio frequency assisted pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Verardi, P. [CNR-Istituto di Acustica, Via del Fosso del Cavaliere 100, I-00133 Rome (Italy); Craciun, F. [CNR-Istituto dei Sistemi Complessi, Via del Fosso del Cavaliere 100, I-00133 Rome (Italy); Dinescu, M. [NILPRP, Bucharest, PO Box MG-16, RO-76900 (Romania)]. E-mail: dinescum@ifin.nipne.ro; Scarisoreanu, N. [NILPRP, Bucharest, PO Box MG-16, RO-76900 (Romania); Moldovan, A. [NILPRP, Bucharest, PO Box MG-16, RO-76900 (Romania); Purice, A. [NILPRP, Bucharest, PO Box MG-16, RO-76900 (Romania); Galassi, C. [CNR-ISTEC, Via Granarolo 64, I 48018 Faenza (Italy)

    2005-04-25

    Lead zirconate titanate ferroelectric thin films added with La and Nb has been grown by radio frequency assisted pulsed laser deposition on Pt/Si, starting from sintered targets. The dielectric properties were measured in a large frequency range and their dependence on the a.c. driving field amplitude has been investigated. A linear decreasing of the dielectric permittivity with frequency logarithm increasing has been evidenced. The most important factor for the driving field amplitude influence on the dielectric properties is the type of vacancies introduced by La and Nb substitutions, which indicates that the dynamics involved in a.c. field behavior is controlled by interaction mechanisms between ferroelectric domain or nanodomain walls and pinning (vacancies) centers.

  3. Polymer-assisted metal deposition (PAMD): a full-solution strategy for flexible, stretchable, compressible, and wearable metal conductors.

    Science.gov (United States)

    Yu, You; Yan, Casey; Zheng, Zijian

    2014-08-20

    Metal interconnects, contacts, and electrodes are indispensable elements for most applications of flexible, stretchable, and wearable electronics. Current fabrication methods for these metal conductors are mainly based on conventional microfabrication procedures that have been migrated from Si semiconductor industries, which face significant challenges for organic-based compliant substrates. This Research News highlights a recently developed full-solution processing strategy, polymer-assisted metal deposition (PAMD), which is particularly suitable for the roll-to-roll, low-cost fabrication of high-performance compliant metal conductors (Cu, Ni, Ag, and Au) on a wide variety of organic substrates including plastics, elastomers, papers, and textiles. This paper presents i) the principles of PAMD, and how to use it for making ii) flexible, stretchable, and wearable conductive metal electrodes, iii) patterned metal interconnects, and d) 3D stretchable and compressible metal sponges. A critical perspective on this emerging strategy is also provided. PMID:24458846

  4. Electronic and optical device applications of hollow cathode plasma assisted atomic layer deposition based GaN thin films

    International Nuclear Information System (INIS)

    Electronic and optoelectronic devices, namely, thin film transistors (TFTs) and metal–semiconductor–metal (MSM) photodetectors, based on GaN films grown by hollow cathode plasma-assisted atomic layer deposition (PA-ALD) are demonstrated. Resistivity of GaN thin films and metal-GaN contact resistance are investigated as a function of annealing temperature. Effect of the plasma gas and postmetallization annealing on the performances of the TFTs as well as the effect of the annealing on the performance of MSM photodetectors are studied. Dark current to voltage and responsivity behavior of MSM devices are investigated as well. TFTs with the N2/H2 PA-ALD based GaN channels are observed to have improved stability and transfer characteristics with respect to NH3 PA-ALD based transistors. Dark current of the MSM photodetectors is suppressed strongly after high-temperature annealing in N2:H2 ambient

  5. Properties of Erbium Doped Hydrogenated Amorphous Carbon Layers Fabricated by Sputtering and Plasma Assisted Chemical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    V. Prajzler

    2008-01-01

    Full Text Available We report about properties of carbon layers doped with Er3+ ions fabricated by Plasma Assisted Chemical Vapor Deposition (PACVD and by sputtering on silicon or glass substrates. The structure of the samples was characterized by X-ray diffraction and their composition was determined by Rutherford Backscattering Spectroscopy and Elastic Recoil Detection Analysis. The Absorbance spectrum was taken in the spectral range from 400 nm to 600 nm. Photoluminescence spectra were obtained using two types of Ar laser (λex=514.5 nm, lex=488 nm and also using a semiconductor laser (λex=980 nm. Samples fabricated by magnetron sputtering exhibited typical emission at 1530 nm when pumped at 514.5 nm. 

  6. Computer assisted in vivo measurements of internally deposited radionuclides using dual-crystal scintillation detectors

    International Nuclear Information System (INIS)

    This paper discusses a channel specific modification of the low energy photon spectrum from an in vivo measurement of internally deposited radionuclides to remove the influence of naturally occurring K-40 in the body. A method has been developed to take advantage of the CsI(Tl) crystal in the dual-crystal detector and use it to directly measure K-40 while the then NaI(Tl) crystal measures only the low energy photons. Live-time, interactive computer analysis is used to determine the channel specific percentage contribution to the low energy spectrum

  7. Surface hydrophobic modification of cellulose membranes by plasma-assisted deposition of hydrocarbon films

    Directory of Open Access Journals (Sweden)

    Mudtorlep Nisoa

    2010-03-01

    Full Text Available Surface modification by plasma polymerization is an efficient method to change the surface properties of a membrane. Desirable functionality such as hydrophobicity or hydrophilicity can be obtained, depending on plasma chemistry of gas precursors and discharge conditions. In this work, RF magnetron plasma is produced using acetylene and nitrogen as precursor gases. Variations of RF power, particle flux, deposited time and pressure of the precursor gases have been made to observe coating effects on the cellulose membranes. When appropriated conditions are used, a thin brownish film of hydrocarbon was formed on the membrane, and the water contact angle increased from 35 to 130 degrees.

  8. Spatially selective materials deposition by hydrogen-assisted laser-induced transfer

    International Nuclear Information System (INIS)

    Si and Al lines were deposited on glass substrates using a transfer technique based on the explosive release of hydrogen from a hydrogenated amorphous Si film melted by a laser pulse. The Si lines have a minimum width of 4.5 μm and are well defined, while the Al lines are wider and less uniform. Analysis of time-resolved infrared transmission signals reveals that the lines do not break into droplets upon ejection, in contrast to the behavior of unpatterned films. This difference is attributed to the escape of hydrogen through the sides of the molten lines into the adjacent material. (c) 2000 American Institute of Physics

  9. Ozone-assisted atomic layer deposited ZnO thin films for multifunctional device applications

    International Nuclear Information System (INIS)

    We demonstrate the growth temperature dependence of film thickness and surface roughness of ZnO films grown by atomic layer deposition using ozone as an oxidizer. The significantly low growth rate of the film using O3 precursor is attributed to the recombinative surface loss of O3. The variation of the spatial uniformity inferred from the surface roughness of the ZnO films and the O3 concentration was explained by a transition from reaction- to recombination-limited growth. We have fabricated a metal–oxide–semiconductor device, consisting of an insulating ZnO layer using an O3 source, between metallic and semiconducting Al : ZnO layers. The device demonstrates a remarkable resistive switching behaviour. The electrochemical migration of oxygen vacancies, which is created in the vicinity of the interface of ZnO semiconductor–ZnO insulator, drives the resistive switching behaviour. This significant result produced on the all-oxide-based device fabricated by atomic layer deposited ZnO can have significant impact for multifunctional applications. (paper)

  10. In-situ photo-assisted deposition of silver particles on hydrogel fibers for antibacterial applications

    International Nuclear Information System (INIS)

    Silver nanoparticles (AgNPs) have attracted intensive research interest and have been recently incorporated in polymers, medical devices, hydrogels and burn dressings to control the proliferation of microorganisms. In this study a novel silver antibacterial coating was deposited for the first time on hydrogel fibers through an in-situ photo-chemical reaction. Hydrogel blends obtained by mixing different percentages of silver-treated and untreated fibers were characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Four different fluids, such as phosphate buffered saline (PBS), simulated body fluid (SBF), chemical simulated wound fluid (cSWF), and deionized water (DI water), were used for evaluating the swelling properties. The results obtained confirmed that the presence of silver did not affect the properties of the hydrogel. Moreover, the results obtained through inductively coupled plasma mass spectrometry (ICP-MS) demonstrated very low silver release values, thus indicating the perfect adhesion of the silver coating to the substrate. Good antibacterial capabilities were demonstrated by any hydrogel blend on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) through agar diffusion tests and optical density readings. - Highlights: • An innovative nano-silver deposition technique was adopted on hydrogel fibers. • Antibacterial effects was verified by agar diffusion and optical density tests. • The swelling properties were investigated using 4 different fluids. • Hydrogel blends with different percentages of silver-treated fibers were compared

  11. Synthesis of CdS nanostructures using template-assisted ammonia-free chemical bath deposition

    Science.gov (United States)

    Preda, N.; Enculescu, M.; Gherendi, F.; Matei, E.; Toimil-Molares, M. E.; Enculescu, I.

    2012-09-01

    CdS micro- and nano-structures (micro/nanotubes and nanostructured films) were obtained by ammonia-free chemical bath deposition using polymer templates (ion track-etched polycarbonate membranes and poly(styrene-hydroxyethyl methacrylate) nanosphere arrays). The semiconductor structures were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), optical absorption, photoluminescence and electrical measurements. The diameters of CdS tubes are between 300 nm and few microns and the lengths are up to tens of micrometers. The SEM images prove that the CdS films are nanostructured due to the deposition on the polymer nanosphere arrays. For both CdS structures (tubes and films) the XRD patterns show a hexagonal phase. The optical studies reveal a band gap value of about 2.5-2.6 eV and a red luminescence at ˜1.77 eV. A higher increase of conductivity is observed for illuminating the CdS nanostructured film when compared to the simple semiconductor film. This is a consequence of the periodic patterning induced by the polymer nanosphere array.

  12. In-situ photo-assisted deposition of silver particles on hydrogel fibers for antibacterial applications

    Energy Technology Data Exchange (ETDEWEB)

    Raho, Riccardo [Department of Engineering for Innovation, University of Salento, Via per Monteroni, 73100 Lecce (Italy); CBN, Center for Biomolecular Nanotechnologies, Fondazione Istituto Italiano di Tecnologia, Via Barsanti, 73010 Arnesano, Lecce (Italy); Paladini, Federica; Lombardi, Fiorella Anna [Department of Engineering for Innovation, University of Salento, Via per Monteroni, 73100 Lecce (Italy); Boccarella, Sandro [Megatex S.p.A., Via Cima D' Aosta, 73040 Melissano, Lecce (Italy); Zunino, Benedetta [Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00198 Roma (Italy); Pollini, Mauro, E-mail: mauro.pollini@unisalento.it [Department of Engineering for Innovation, University of Salento, Via per Monteroni, 73100 Lecce (Italy); Silvertech Ltd., Via per Monteroni, 73100 Lecce (Italy)

    2015-10-01

    Silver nanoparticles (AgNPs) have attracted intensive research interest and have been recently incorporated in polymers, medical devices, hydrogels and burn dressings to control the proliferation of microorganisms. In this study a novel silver antibacterial coating was deposited for the first time on hydrogel fibers through an in-situ photo-chemical reaction. Hydrogel blends obtained by mixing different percentages of silver-treated and untreated fibers were characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Four different fluids, such as phosphate buffered saline (PBS), simulated body fluid (SBF), chemical simulated wound fluid (cSWF), and deionized water (DI water), were used for evaluating the swelling properties. The results obtained confirmed that the presence of silver did not affect the properties of the hydrogel. Moreover, the results obtained through inductively coupled plasma mass spectrometry (ICP-MS) demonstrated very low silver release values, thus indicating the perfect adhesion of the silver coating to the substrate. Good antibacterial capabilities were demonstrated by any hydrogel blend on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) through agar diffusion tests and optical density readings. - Highlights: • An innovative nano-silver deposition technique was adopted on hydrogel fibers. • Antibacterial effects was verified by agar diffusion and optical density tests. • The swelling properties were investigated using 4 different fluids. • Hydrogel blends with different percentages of silver-treated fibers were compared.

  13. 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.

  14. Fabrication and gas sensing properties of pure and au-functionalised W03 nanoneedle-like structures, synthesised via aerosol assisted chemical vapour deposition method

    OpenAIRE

    Stoycheva, Toni

    2011-01-01

    In this doctoral thesis, it has been investigated and developed the Aerosol Assisted Chemical Vapour Deposition (AACVD) method for direct in-situ growth of intrinsic and Au-functionalised nanostructured WO3, as well as SnO2-based devices for gas sensing applications. The nanostructured material synthesis, device fabrication and their gas sensing properties have been studied. AACVD method was used for synthesis and direct deposition of sensing films onto classical alumina and microhotplat...

  15. Direction-tunable nanotwins in copper nanowires by laser-assisted electrochemical deposition

    International Nuclear Information System (INIS)

    Nanotwins can improve mechanical strength and maintain high electrical conductivity in metallic nanowires. We demonstrated a method of pulsed-laser-assisted electrodeposition, which could form dense nanotwins with tunable directions in copper nanowires of uniform sizes. Transmission electron microscopy characterization showed with a growth potential of − 0.2 V, nanotwins tend to align along the longitudinal direction of the nanowires, whereas at a larger potential of − 0.8 V, nanotwins of {111}/〈112〉 type perpendicular to the longitudinal direction of the wire were formed. The two types of nanotwins were investigated by comparing the microstructures under different electrochemical conditions and laser irradiation energies. Two different mechanisms are proposed—annealing twins and growth twins. (paper)

  16. Characterization of tribo-layers on self-lubricating plasma-assisted chemical-vapor-deposited TiN coatings

    International Nuclear Information System (INIS)

    Recently, several new solid lubricants and modern lubrication concepts have been developed to achieve lower friction and wear and thus longer lifetime in severe tribological applications. The aim of this study is to characterize tribo-layers formed during ball-on-disc testing on low-friction, Cl-containing TiN coatings deposited by plasma assisted chemical vapor deposition and to clarify their formation mechanism. Characterization of the transfer layers was done by optical microscopy, optical profilometry, Raman spectroscopy, Auger electron spectroscopy and X-ray photoelectron spectroscopy. Differential scanning calorimetry was used to provide information on the chlorine-influenced chemical reactions of the coatings in ambient air. Iron oxide layers of a thickness in the nm-range have been found on low-chlorine containing TiN coatings (3 at.% Cl) rutile layers were preferably formed, resulting in friction coefficients below 0.2. This self-lubrication mechanism can be explained by the in-situ formation of easy-shearable titanium oxides in the contact zone in the presence of humidity and oxygen

  17. 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°.

  18. Failure Strain and Strain-Stress Analysis in Titanium Nitride Coatings Deposited on Religa Heart Ext Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Kopernik M.

    2015-04-01

    Full Text Available The Polish ventricular assist device is made of Bionate II with deposited TiN biocompatible nano-coating. The two scale finite element model is composed of a macro-model of blood chamber and a micro-model of the TiN/Bionate II. The numerical analysis of stress and strain states confirmed the possibility of fracture. Therefore, the identification of a fracture parameter considered as a failure strain is the purpose of the present work. The tensile test in a micro chamber of the SEM was performed to calibrate the fracture parameter of the material system TiN/Bionate II. The failure strain is a function of a temperature, a thickness of coating and parameters of surface's profile. The failure strain was calculated at the stage of the test, in which the initiation of fracture occurred. The finite element micro-model includes the surface roughness and the failure strain under tension condition for two thicknesses of coatings which will be deposited on the medical device.

  19. In Situ Nanocalorimetric Investigations of Plasma Assisted Deposited Poly(ethylene oxide)-like Films by Specific Heat Spectroscopy.

    Science.gov (United States)

    Madkou, Sherif; Melnichu, Iurii; Choukourov, Andrei; Krakovsky, Ivan; Biederman, Hynek; Schönhals, Andreas

    2016-04-28

    In recent years, highly cross-linked plasma polymers have started to unveil their potential in numerous biomedical applications in thin-film form. However, conventional diagnostic methods often fail due to their diverse molecular dynamics conformations. Here, glassy dynamics and the melting transition of thin PEO-like plasma assisted deposited (ppPEO) films (thickness 100 nm) were in situ studied by a combination of specific heat spectroscopy, utilizing a pJ/K sensitive ac-calorimeter chip, and composition analytical techniques. Different cross-linking densities were obtained by different plasma powers during the deposition of the films. Glassy dynamics were observed for all values of the plasma power. It was found that the glassy dynamics slows down with increasing the plasma power. Moreover, the underlying relaxation time spectra broaden indicating that the molecular motions become more heterogeneous with increasing plasma power. In a second set of the experiment, the melting behavior of the ppPEO films was studied. The melting temperature of ppPEO was found to decrease with increasing plasma power. This was explained by a decrease of the order in the crystals due to formation of chemical defects during the plasma process. PMID:27055060

  20. 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

  1. Polystyrene sphere monolayer assisted electrochemical deposition of ZnO nanorods with controlable surface density

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, D., E-mail: daniel.ramirez@ucv.c [Laboratorio de Electroquimica, Pontificia Universidad Catolica de Valparaiso, Valparaiso (Chile); Gomez, H. [Laboratorio de Electroquimica, Pontificia Universidad Catolica de Valparaiso, Valparaiso (Chile); Lincot, D. [Institute de Recherche et Developpement sur l' Energie Photovoltaique-IRDEP, 6 Quai Watier 78401, Chatou Cedex (France)

    2010-02-15

    In this paper we report the zinc oxide nanorods (ZnO NRs) growth by electrochemical deposition onto polycrystalline gold electrodes modified with assemblies of polystyrene sphere monolayers (PSSMs). Growth occurs through the interstitial spaces between the hexagonally close packed spheres. ZnO NRs nucleate in the region where three adjacent spheres leave a space, being able to grow and projected over the PSSMs. The nanorod surface density (N{sub NR}) shows a linear dependence with respect to a PS sphere diameter selected. XRD analysis shows these ZnO NRs are highly oriented along the (0 0 2) plane (c-axis). This open the possibility to have electronic devices with mechanically supported nanometric materials.

  2. Remote plasma-assisted deposition of metals onto the surface of nanocrystalline ZnO

    Science.gov (United States)

    Leal, Sergio A.; Nemashkalo, Anastasiia; Chapagain, Puskar; Pant, Shreedhar; Alarcon, Phillip; Strzhemechny, Yuri M.

    2011-10-01

    Controllable surface modification of nanoscale ZnO is crucial for many existing and future applications. We investigated the effectiveness of metal deposition using remote O2/He plasma passing through a metal mesh electrode onto the surface of ZnO nanopowders with an average grain size of 25 nm. Surface stoichiometry was monitored in situ with Auger electron spectroscopy, whereas surface optoelectronic properties were probed; also in situ, using surface photovoltage (SPV) spectroscopy. We observed a strong dependence of surface modification on the distance from the metal electrode. At short distances the metal coverage was reaching tens of percent of one monolayer. Simultaneously we observed a significant improvement of the SPV response pointing to metal-enhanced surface charge dynamics.

  3. Microstructural, chemical and textural characterization of ZnO nanorods synthesized by aerosol assisted chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Sáenz-Trevizo, A.; Amézaga-Madrid, P.; Fuentes-Cobas, L.; Pizá-Ruiz, P.; Antúnez-Flores, W.; Ornelas-Gutiérrez, C. [Centro de Investigación en Materiales Avanzados, S.C., Chihuahua, Chihuahua 31109 (Mexico); Pérez-García, S.A. [Centro de Investigación en Materiales Avanzados, S.C., Unidad Monterrey, Apodaca, Nuevo León 66600 (Mexico); Miki-Yoshida, M., E-mail: mario.miki@cimav.edu.mx [Centro de Investigación en Materiales Avanzados, S.C., Chihuahua, Chihuahua 31109 (Mexico)

    2014-12-15

    ZnO nanorods were synthesized by aerosol assisted chemical vapor deposition onto TiO{sub 2} covered borosilicate glass substrates. Deposition parameters were optimized and kept constant. Solely the effect of different nozzle velocities on the growth of ZnO nanorods was evaluated in order to develop a dense and uniform structure. The crystalline structure was characterized by conventional X-ray diffraction in grazing incidence and Bragg–Brentano configurations. In addition, two-dimensional grazing incidence synchrotron radiation diffraction was employed to determine the preferred growth direction of the nanorods. Morphology and growth characteristics analyzed by electron microscopy were correlated with diffraction outcomes. Chemical composition was established by X-ray photoelectron spectroscopy. X-ray diffraction results and X-ray photoelectron spectroscopy showed the presence of wurtzite ZnO and anatase TiO{sub 2} phases. Morphological changes noticed when the deposition velocity was lowered to the minimum, indicated the formation of relatively vertically oriented nanorods evenly distributed onto the TiO{sub 2} buffer film. By coupling two-dimensional X-ray diffraction and computational modeling with ANAELU it was proved that a successful texture determination was achieved and confirmed by scanning electron microscopy analysis. Texture analysis led to the conclusion of a preferred growth direction in [001] having a distribution width Ω = 20° ± 2°. - Highlights: • Uniform and pure single-crystal ZnO nanorods were obtained by AACVD technique. • Longitudinal and transversal axis parallel to the [001] and [110] directions, respectively. • Texture was determined by 2D synchrotron diffraction and electron microscopy analysis. • Nanorods have its [001] direction distributed close to the normal of the substrate. • Angular spread about the preferred orientation is 20° ± 2°.

  4. Nucleation and growth of cubic boron nitride films produced by ion-assisted pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Friedmann, T.A.; Medlin, D.L.; Mirkarimi, P.B.; McCarty, K.F.; Klaus, E.J.; Boehme, D.R.; Johnsen, H.A.; Mills, M.J.; Ottesen, D.K. [Sandia National Labs., Livermore, CA (United States)

    1993-12-31

    We are studying the boron nitride system using a pulsed excimer laser to ablate from hexagonal BN (cBN) targets to form cubic BN (cBN) films. We are depositing BN films on heated (25--800C) Si (100) surfaces and are using a broad-beam ion source operated with Ar and N{sub 2} source gases to produce BN films with a high percentage of sp{sup 3}-bonded cBN. In order to optimize growth and nucleation of cBN films, parametric studies of the growth parameters have been performed. The best films to date show >85% sp{sup 3}-bonded BN as determined from Fourier-transform infrared (FTIR) reflection spectroscopy. High resolution transmission electron microscopy (TEM) and selected area electron diffraction confirm the presence of cBN in these samples. The films are polycrystalline and show grain sizes up to 30--40 mn. We find from both the FTIR and TEM analyses that the cBN content in these films evolves with growth time. Initially, the films are deposited as hBN and the cBN nucleates on this hBN underlayer. Importantly, the position of the cBN IR phonon also changes with growth time. Initially this mode appears near 1130 cm{sup {minus}1} and the position decreases with growth time to a constant value of 1085 cm{sup {minus}1}. Since in bulk cBN this IR mode appears at 1065 cm{sup {minus}1}, a large compressive stress induced by the ion bombardment is suggested. In addition, we report on the variation in cBN percentage with temperature.

  5. UV assisted photoelectrocatalytic oxidation of phthalic acid using spray deposited Al doped zinc oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Mahadik, M.A.; Shinde, S.S.; Hunge, Y.M.; Mohite, V.S.; Kumbhar, S.S.; Moholkar, A.V.; Rajpure, K.Y.; Bhosale, C.H., E-mail: chbhosale@gmail.com

    2014-10-25

    Highlights: • Nanostructured undoped and AZO thin films prepared by chemical spray pyrolysis. • Effect of Al doping on the structural, morphological and photoluminance properties. • Photocatalytic degradation of phthalic acid under UV light illumination. • Reaction kinetics and mineralization of phthalic acid. - Abstract: Undoped and Al doped ZnO (AZO) thin films are successfully prepared by spray pyrolysis technique at optimised substrate temperature of 400 °C onto amorphous and F:SnO{sub 2} coated glass substrates. Effect of Al doping on structural, morphological and optical properties of ZnO thin films is studied. Deposited films are polycrystalline with a hexagonal (wurtzite) crystal structure having (0 0 2) preferred orientation. The PEC characterization shows that, short circuit current (I{sub sc}) and open circuit voltage (V{sub oc}) are (I{sub sc} = 0.38 mA and V{sub oc} = 421 mV) relatively higher at the 3 at.% Al doping. SEM images show deposited thin films are compact and uniform with seed like grains. All films exhibit average transmittance of about 82% in the visible region and a sharp absorption onset at 375 nm corresponding to 3.3 eV. The photocatalytic activities of the large surface area (64 cm{sup 2}) Al-doped ZnO photocatalyst samples were evaluated by photoelectrocatalytic degradation of phthalic acid under UV light irradiation. The results show that the 3 at.% AZO thin film photocatalyst exhibited degradation of phthalic acid up to about 45% within 3 h with significant reduction in COD and TOC values.

  6. Mesoscale elucidation of laser-assisted chemical deposition of Sn nanostructured electrodes

    International Nuclear Information System (INIS)

    Nanostructured tin (Sn) is a promising high-capacity electrode for improved performance in lithium-ion batteries for electric vehicles. In this work, Sn nanoisland growth for nanostructured electrodes assisted by the pulse laser irradiation has been investigated based on a mesoscale modeling formalism. The influence of pertinent processing conditions, such as pulse duration, heating/cooling rates, and atom flux, on the Sn nanostructure formation is specifically considered. The interaction between the adsorbed atom and the substrate, represented by the adatom diffusion barrier, is carefully studied. It is found that the diffusion barrier predominantly affects the distribution of Sn atoms. For both α-Sn and β-Sn, the averaged coordination number is larger than 3 when the diffusion barrier equals to 0.15 eV. The averaged coordination number decreases as the diffusion barrier increases. The substrate temperature, which is determined by heating/cooling rates and pulse duration, can also affect the formation of Sn nanoislands. For α-Sn, when applied low heating/cooling rates, nanoislands cannot form if the diffusion barrier is larger than 0.35 eV

  7. Photocatalytic zinc oxide thin films obtained by surfactant assisted spray pyrolysis deposition

    International Nuclear Information System (INIS)

    Zinc oxide thin films were obtained by spray pyrolysis deposition using three surfactants with linear C12 tails as soft templating agents: anionic sodium dodecylsulfate (SDS), cationic dodecyltrimethylammonium bromide (DTAB) and nonionic dodecanol (DD). The influence of the surfactants’ type and concentration (above and below critical micelle concentration in the precursor system) on the thin film formation was investigated and was correlated with their photocatalytic efficiency in methylorange removal, under visible and UV iradiation. The surfactants influence both the nucleation and growth stages, mainly through the Zn-surfactant interactions at the droplet border and/or on the micelles. In situ doping with Na+ (in SDS) improves the removal efficiency up to 19.88% under VIS irradiation, while the highest removal efficiencies in ZnO thin films obtained using DTAB and DD are 16.27% and 15.44%, respectively. Under UV irradiation the highest efficiencies are 45.28% (SDS), 51.59% (DTAB) and 49.43% (DD).

  8. In-situ monitoring of plasma ion assisted deposition (PIAD) processes

    Science.gov (United States)

    Harhausen, Jens; Foest, Rüdiger; Loffhagen, Detlef

    2015-09-01

    Present photonics applications depend on accurate production techniques. Plasma based processes might be termed the backbone of multilayer optical coatings which are the key components of dielectric mirrors, filters or antireflectives. However, the sector strongly relies on process recipies based on empirical optimization of thin film properties. Limitations in quality, repeatability and yield are faced. In this contribution results of efforts on plasma characterization of a beam source employed for PIAD are presented. Data on electron and ion kinetics as well as optical emission facilitated a comprehensive understanding of underlying physics of ion beam generation and propagation in an industrial type batch coater. In order to promote the development of next generation production plants, concepts for in-situ diagnostics are investigated. Results from monitoring of optical radiance of the plasma plume near the source and electron density near the substrates are discussed. The novel concept of the multipole resonance probe is applied during deposition in order to trace variations not only in magnitude of plasma density, but also its spatial distribution. Coating materials comprise TiO2, Ta2O5, Al2O3 and SiO2. Funded by the German Federal Ministry of Education and Research (BMBF) under Grant 13N13213).

  9. Synthesis and characterization of GaN nanowires by a catalyst assisted chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Wei Xiaofeng [College of Physics and Electronics, Shandong Normal University, Jinan, 250014 (China); Shi Feng, E-mail: sf751106@163.com [College of Physics and Electronics, Shandong Normal University, Jinan, 250014 (China)

    2011-09-15

    GaN nanowires have been fabricated on Si(1 1 1) substrates by chemical vapor deposition (CVD) method with NiCl{sub 2} as catalyst and their compositions, microstructures, morphologies and light emitting properties were characterized by X-ray diffraction (XRD), FT-IR spectrophotometer (FTIR), scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM), Raman spectroscopy and photoluminescence (PL). The results demonstrate that the nanowires are single-crystal GaN with hexagonal wurtzite structure and high crystalline quality, having the size of 20-50 nm in diameter and several tens of microns in length with some nano-droplets on their tips, which reveals that the growth mechanism of GaN nanowires agrees with vapor-liquid-solid (VLS) process. Five first-order Raman active phonon bands move to low shift and A{sub 1}(TO), E{sub 1}(TO), and E{sub 2} (high) bands are overlapped and broaden, which is caused by uncertainty in the phonon wave vector. Five non-first-order active Raman phonons also appear, which is caused by the small dimension and high surface disorder degree. A blue-shift of the band-gap emission occurs due to quantum confinement effect.

  10. 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.)

  11. 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.

  12. Analysis of copper (I) oxide thin films grown in a photo-assisted chemical vapor deposition reactor for photovoltaic applications

    Science.gov (United States)

    Mohiuddin, Omar H.

    Copper (I) oxide (Cu2O) has enormous potenetial for photovoltaic applications. Cu2O is a p-type semiconductor with a direct band gap of 2.2 eV. When grown on silicon, thin film Cu2O has the potential to increase photovoltaic eciency. Cu2O is a suitable photovoltaic material because it is inexpensive, non-toxic and abundant in the earth's crust. A model was developed based on a stagnation flow reactor with a reduction in activation energy for the precursor decomposition due to the light irradiation to model the light irradiation. The parameters that were tested were substrate temperature (200 to 700° C), gas temperature (100 and 150 °C) and carrier gas flow rate (25 to 100 sccm). The model was tested with a 480 nm and 172 nm light irradiation source and without any light irradiation source. This thesis utilizes a photo assisted chemical vapor deposition reactor to deposit films of Cu2O on silicon. The films were grown with a surface temperature of 700 °C, a gas temperature of 150 °C and an oxygen gas flow rate of 100 sccm. One deposition was done without the use of any light irradiation and another deposition was done with a 480 nm light irradiation source. X-ray diffraction, ellipsometry and transmission electron microscopy (TEM) were used to investigate the light irradiation eect on the lm growth and morphology. When grown with light irradiation, the ellipsometer showed that the film thickness increased to 98 +/- 6 nm from 74 +/- 10 nm, which shows that there is greater uniformity with a higher thickness when grown with light irradiation. The XRD results showed an increase in crystallinity in Cu2O grown with light irradiation, and the TEM results showed the grain sizes double when grown with light irradiation. The UV irradiation has been shown to increase the copper (I) oxide film quality and lm thickness. The model showed that the effect of the light irradiation was maximized at a surface temperature of 400 °C After this temperature the thermal eects become

  13. 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

  14. K and Au bicatalyst assisted growth of carbon nanocoils from acetylene: effect of deposition parameters on field emission properties.

    Science.gov (United States)

    Tsou, Tsung-Yu; Lee, Chi-Young; Chiu, Hsin-Tien

    2012-12-01

    We demonstrated the growth of carbon nanocoils (CNCs) via chemical vapor deposition (CVD) using Au and K metals as the catalysts to assist the thermal decomposition of C(2)H(2). Typical CNCs (wire diameter: 50-80 nm, coil diameter: 110-140 nm, pitch: 100-200 nm, tens of micrometers), identified as amorphous coiled carbon fibers by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), were grown at proper combinations of reaction parameters. Au nanoparticles (NPs), identified by energy dispersion X-ray spectroscopy (EDX) and electron diffraction (ED), were located at the tips of the CNCs. The observations suggested that a tip-growth mechanism involving the Au NPs as the nucleation sites was in operation. In the reaction, the liquid-phase K metal assisted the decomposition of C(2)H(2) by lowering the reaction temperature. We propose that acetylide and hydride intermediates were formed in the reaction. Further decomposition of the acetylide intermediates generated solid-phase carbon to grow the CNCs. Effects of varying the reaction conditions on the CNC growth were investigated. On the basis of the results, a Au and K bicatalyst enhanced tip-growth vapor-liquid-solid (VLS) mechanism was proposed to rationalize the CNC formation process. Electron field emission (EFE) characteristics of the CNCs were studied. The best EFE result showed a turn-on field (E(to)) of 3.78 V/μm and a field enhancement factor (β) of 1852. In addition, the current density (J) was as high as 43 mA/cm(2) at 6.87 V/μm. The data suggest that the CNCs could be employed for field emission device applications. PMID:23167627

  15. Shadow-casted ultrathin surface coatings of titanium and titanium/silicon oxide sol particles via ultrasound-assisted deposition.

    Science.gov (United States)

    Karahan, H Enis; Birer, Özgür; Karakuş, Kerem; Yıldırım, Cansu

    2016-07-01

    Ultrasound-assisted deposition (USAD) of sol nanoparticles enables the formation of uniform and inherently stable thin films. However, the technique still suffers in coating hard substrates and the use of fast-reacting sol-gel precursors still remains challenging. Here, we report on the deposition of ultrathin titanium and titanium/silicon hybrid oxide coatings using hydroxylated silicon wafers as a model hard substrate. We use acetic acid as the catalyst which also suppresses the reactivity of titanium tetraisopropoxide while increasing the reactivity of tetraethyl orthosilicate through chemical modifications. Taking the advantage of this peculiar behavior, we successfully prepared titanium and titanium/silicon hybrid oxide coatings by USAD. Varying the amount of acetic acid in the reaction media, we managed to modulate thickness and surface roughness of the coatings in nanoscale. Field-emission scanning electron microscopy and atomic force microscopy studies showed the formation of conformal coatings having nanoroughness. Quantitative chemical state maps obtained by x-ray photoelectron spectroscopy (XPS) suggested the formation of ultrathin (thickness measurements by rotating analyzer ellipsometry supported this observation. For the first time, XPS chemical maps revealed the transport effect of ultrasonic waves since coatings were directly cast on rectangular substrates as circular shadows of the horn with clear thickness gradient from the center to the edges. In addition to the progress made in coating hard substrates, employing fast-reacting precursors and achieving hybrid coatings; this report provides the first visual evidence on previously suggested "acceleration and smashing" mechanism as the main driving force of USAD. PMID:26964975

  16. Iron selenide films by aerosol assisted chemical vapor deposition from single source organometallic precursor in the presence of surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Raja Azadar [Department of Chemistry, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Badshah, Amin, E-mail: aminbadshah@yahoo.com [Department of Chemistry, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Younis, Adnan [School of Materials Science and Engineering, University of New South Wales, Sydney 2052, NSW (Australia); Khan, Malik Dilshad [Department of Chemistry, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Akhtar, Javeed [Department of Physics, COMSATS Institute of Information Technology, Park Road, Chak Shahzad, Islamabad (Pakistan)

    2014-09-30

    This article presents the synthesis and characterization (multinuclear nuclear magnetic resonance, Fourier transform infrared spectroscopy, carbon–hydrogen–nitrogen–sulfur analyzer, atomic absorption spectrometry and thermogravimetric analysis) of a single source organometallic precursor namely 1-acetyl-3-(4-ferrocenylphenyl)selenourea for the fabrication of iron selenide (FeSe) films on glass substrates using aerosol assisted chemical vapor deposition (AACVD). The changes in the morphologies of the films have been monitored by the use of two different surfactants i.e. triton X-100 and tetraoctylphosphonium bromide during AACVD. The role of surfactant has been evaluated by examining the interaction of the surfactants with the precursor by using UV–vis spectroscopy and cyclic voltammetry. The fabricated FeSe films have been characterized with powder X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. - Highlights: • Ferrocene incorporated selenourea (FIS) has been synthesized and characterized. • FeSe thin films have been fabricated from FIS. • Mechanism of film growth was studied with cyclic voltammetry and UV–vis spectroscopy.

  17. Electrochemically assisted deposition of sol-gel bio-composite with co-immobilized dehydrogenase and diaphorase

    Energy Technology Data Exchange (ETDEWEB)

    Wang Zhijie [LCPME, UMR 7564, CNRS-Nancy University, 405, rue de Vandoeuvre, 54600 Villers-les-Nancy (France); Etienne, Mathieu, E-mail: mathieu.etienne@lcpme.cnrs-nancy.fr [LCPME, UMR 7564, CNRS-Nancy University, 405, rue de Vandoeuvre, 54600 Villers-les-Nancy (France); Kohring, Gert-Wieland [Mikrobiologie, Universitaet des Saarlandes, Campus, Geb. A1.5, D-66123 Saarbruecken (Germany); Bon-Saint-Come, Yemima; Kuhn, Alexander [Universite Bordeaux, ISM, ENSCPB, 16 avenue Pey Berland, 33607 Pessac (France); Walcarius, Alain [LCPME, UMR 7564, CNRS-Nancy University, 405, rue de Vandoeuvre, 54600 Villers-les-Nancy (France)

    2011-10-30

    We report here that the electrochemically assisted deposition (EAD) of silica thin films can be a good strategy to co-encapsulate D-sorbitol dehydrogenase (DSDH) and diaphorase in an active form. This is achieved via the electrolysis of a hydrolyzed sol containing the biomolecules to initiate the poly-condensation of silica precursors upon electrochemically induced pH increase at the electrode/solution interface. DSDH was found to be very sensitive to the silica gel environment and the addition of a positively-charged polyelectrolyte was necessary to ensure effective operational behavior of the biomolecules. The composition of the sol and the conditions for electrolysis have been optimized with respect to the intensity of the electrochemical response to D-sorbitol oxidation. The K{sub m} of DSDH in the electrodeposited film was in the range of 3 mM, slightly better than the value determined biochemically in solution (6.5 mM). The co-immobilization of DSDH and diaphorase in this way led on the one hand to the possible reduction of NAD{sup +} to NADH (simultaneously to D-sorbitol oxidation) and on the other hand to the safe re-oxidation of the co-factor using a mediator (ferrocenedimethanol) as electron relay. The bioelectrocatalytic response looks promising for electro-enzymatic applications. To support this idea, the EAD of sol-gel bio-composite has been extended to macroporous electrodes displaying a much bigger electroactive surface area.

  18. Electronic and optical device applications of hollow cathode plasma assisted atomic layer deposition based GaN thin films

    Energy Technology Data Exchange (ETDEWEB)

    Bolat, Sami, E-mail: bolat@ee.bilkent.edu.tr; Tekcan, Burak [Department of Electrical and Electronics Engineering, Bilkent University, 06800, Ankara, Turkey and UNAM, National Nanotechnology Research Center, Bilkent University, 06800, Ankara (Turkey); Ozgit-Akgun, Cagla; Biyikli, Necmi [UNAM, National Nanotechnology Research Center, Bilkent University, 06800, Ankara, Turkey and Institute of Materials Science and Nanotechnology, Bilkent University, 06800, Ankara (Turkey); Okyay, Ali Kemal, E-mail: aokyay@ee.bilkent.edu.tr [Department of Electrical and Electronics Engineering, Bilkent University, 06800, Ankara (Turkey); UNAM, National Nanotechnology Research Center, Bilkent University, 06800, Ankara (Turkey); Institute of Materials Science and Nanotechnology, Bilkent University, 06800, Ankara (Turkey)

    2015-01-15

    Electronic and optoelectronic devices, namely, thin film transistors (TFTs) and metal–semiconductor–metal (MSM) photodetectors, based on GaN films grown by hollow cathode plasma-assisted atomic layer deposition (PA-ALD) are demonstrated. Resistivity of GaN thin films and metal-GaN contact resistance are investigated as a function of annealing temperature. Effect of the plasma gas and postmetallization annealing on the performances of the TFTs as well as the effect of the annealing on the performance of MSM photodetectors are studied. Dark current to voltage and responsivity behavior of MSM devices are investigated as well. TFTs with the N{sub 2}/H{sub 2} PA-ALD based GaN channels are observed to have improved stability and transfer characteristics with respect to NH{sub 3} PA-ALD based transistors. Dark current of the MSM photodetectors is suppressed strongly after high-temperature annealing in N{sub 2}:H{sub 2} ambient.

  19. Iron selenide films by aerosol assisted chemical vapor deposition from single source organometallic precursor in the presence of surfactants

    International Nuclear Information System (INIS)

    This article presents the synthesis and characterization (multinuclear nuclear magnetic resonance, Fourier transform infrared spectroscopy, carbon–hydrogen–nitrogen–sulfur analyzer, atomic absorption spectrometry and thermogravimetric analysis) of a single source organometallic precursor namely 1-acetyl-3-(4-ferrocenylphenyl)selenourea for the fabrication of iron selenide (FeSe) films on glass substrates using aerosol assisted chemical vapor deposition (AACVD). The changes in the morphologies of the films have been monitored by the use of two different surfactants i.e. triton X-100 and tetraoctylphosphonium bromide during AACVD. The role of surfactant has been evaluated by examining the interaction of the surfactants with the precursor by using UV–vis spectroscopy and cyclic voltammetry. The fabricated FeSe films have been characterized with powder X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. - Highlights: • Ferrocene incorporated selenourea (FIS) has been synthesized and characterized. • FeSe thin films have been fabricated from FIS. • Mechanism of film growth was studied with cyclic voltammetry and UV–vis spectroscopy

  20. Mechanical and electrochemical properties of ultrasonic-assisted electroless deposition of Ni–B–TiO2 composite coatings

    International Nuclear Information System (INIS)

    Highlights: • Ni–B–TiO2 coatings developed by ultrasonic-assisted electroless method. • Titania improves corrosion resistance and hardness of the Ni–B as-plated coatings. • Titania increases the surface film resistance of the Ni–B as-plated coatings. - Abstract: Nickel–Boron–Titania (Ni–B–TiO2) composite coatings were successfully obtained on mild steel (St-37) by simultaneous electroless deposition. TiO2 particles were dispersed in a suspension by ultrasonic irradiation. The surface morphology, particle size, elemental composition and phase analysis of the coatings were characterized by scanning electron microscopy (SEM), inductively coupled plasma (ICP) and X-ray diffraction (XRD). The hardness and friction coefficient of as- plated and heat treated Ni–B and Ni–B–TiO2 composite coatings were determined by Vickers diamond indentation and indentation scratch tests and compared with Ni–B coatings. As a result, the hardness (1263 HV) of the as-plated Ni–B–TiO2 coatings was improved significantly. In addition, the corrosion resistance behavior of the as-plated and heat treated Ni–B and Ni–B–TiO2 coatings were analyzed by anodic polarization and electrochemical impedance spectroscopic (EIS) studies in a 3.5 wt.% NaCl solution. The as-plated composite coatings (Ni–B–TiO2) exhibited enhanced corrosion resistance (0.2 μA/cm2) property over Ni–B coatings

  1. Isotopic enrichment of diamond using microwave plasma-assisted chemical vapor deposition with high carbon conversion efficiency

    International Nuclear Information System (INIS)

    Isotopically-controlled diamond crystals were grown using microwave plasma-assisted chemical vapor deposition. First, the highest carbon isotopic enrichment and their controllability were examined. Although the highest 12C isotopic ratio of 99.998% was achieved using methane with an isotopic ratio of 99.999%, the memory effect of an unintended carbon isotope was found to be considerable when the carbon isotopic ratio of feeding methane was tuned for isotopic multilayer formation. Secondly, a unique gas feeding sequence was proposed for increasing the carbon conversion efficiency from methane to diamond. Increasing the conversion efficiency is done by finding a suitable balance between the methane feeding rate and the carbon consumption rate for diamond growth. A high conversion efficiency of 70% was obtained for a polycrystalline diamond with a high 12C isotopic ratio of 99.997%. - Highlights: • Isotopic control of diamond films was investigated. • A high microwave power density condition was applied for diamond growth. • The controllable range of the carbon isotopic ratio was demonstrated. • Diamond films having the highest 12C carbon isotopic enrichment were grown. • High carbon conversion efficiency of 70% was achieved

  2. In situ photo-assisted deposition and photocatalysis of ZnIn2S4/transition metal chalcogenides for enhanced degradation and hydrogen evolution under visible light.

    Science.gov (United States)

    Lim, Wei Yang; Hong, Minghui; Ho, Ghim Wei

    2016-01-14

    The effective immobilization of a transition chalcogenide co-catalyst via an in situ aqueous photo-assisted deposition technique has shown great accessibility to complex ZnIn2S4 host hierarchical nanostructured materials with homogeneous distribution. The complementary photo-assisted deposition readily deposits finely-dispersed co-catalyst particles and simultaneously generates photocatalytic hydrogen. Another added advantage is that the photo-assisted deposition of the co-catalyst does not compromise the crystal structure or the integrity of the host photocatalyst, hence offering a better alternative to the doping technique. A systematic study of various transition metal chalcogenide co-catalysts and optimization of wt% MoS2, CuS and Ag2S loadings were demonstrated. Among them, the ZnIn2S4/MoS2 composite exhibits exceptional photocatalytic hydrogen production and stability as well as superior MO degradation under visible light irradiation. The present methodology is expected to be extendable to various transition metal oxides/chalcogenides since ionic derivatives exhibit high affinity to a variety of materials under photoirradiation. PMID:26605503

  3. Growth and characterization of large, high quality single crystal diamond substrates via microwave plasma assisted chemical vapor deposition

    Science.gov (United States)

    Nad, Shreya

    Single crystal diamond (SCD) substrates can be utilized in a wide range of applications. Important issues in the chemical vapor deposition (CVD) of such substrates include: shrinking of the SCD substrate area, stress and cracking, high defect density and hence low electronic quality and low optical quality due to high nitrogen impurities. The primary objective of this thesis is to begin to address these issues and to find possible solutions for enhancing the substrate dimensions and simultaneously improving the quality of the grown substrates. The deposition of SCD substrates is carried out in a microwave cavity plasma reactor via the microwave plasma assisted chemical vapor deposition technique. The operation of the reactor was first optimized to determine the safe and efficient operating regime. By adjusting the matching of the reactor cavity with the help of four internal tuning length variables, the system was further matched to operate at a maximum overall microwave coupling efficiency of ˜ 98%. Even with adjustments in the substrate holder position, the reactor remains well matched with a coupling efficiency of ˜ 95% indicating good experimental performance over a wide range of operating conditions. SCD substrates were synthesized at a high pressure of 240 Torr and with a high absorbed power density of 500 W/cm3. To counter the issue of shrinking substrate size during growth, the effect of different substrate holder designs was studied. An increase in the substrate dimensions (1.23 -- 2.5 times) after growth was achieved when the sides of the seeds were shielded from the intense microwave electromagnetic fields in a pocket holder design. Using such pocket holders, high growth rates of 16 -- 32 mum/hr were obtained for growth times of 8 -- 72 hours. The polycrystalline diamond rim deposition was minimized/eliminated from these growth runs, hence successfully enlarging the substrate size. Several synthesized CVD SCD substrates were laser cut and separated

  4. Physical and tribological properties of a-Si1-xCx:H coatings prepared by r.f. plama-assisted chemical vapour deposition

    International Nuclear Information System (INIS)

    A-Si1-xCx:H films deposited by r.f. plasma-assisted chemical vapour deposition were studied as a function of their composition. The friction and wear properties were investigated with the help of a conventional ball-on-disc apparatus. These results are correlated with chemical (Si/C atomic ratio) and structural (Raman and infrared spectroscopy) properties. The friction coefficient in a humid ambient atmosphere changes markedly with the carbon fraction and reaches a value as low as 0.05 for coatings with 70 to 90 at.% C. The carbon-rich films consist of diamond-like carbon with silicon. (orig.)

  5. High-Jc YBa2Cu3O7-δ superconducting film grown by laser-assisted chemical vapor deposition using a single liquid source and its microstructure

    Science.gov (United States)

    Zhao, Pei; Ito, Akihiko; Kato, Takeharu; Yokoe, Daisaku; Hirayama, Tsukasa; Goto, Takashi

    2013-09-01

    A YBa2Cu3O7-δ (YBCO) film was prepared on a multilayer-coated Hastelloy C276 substrate by laser-assisted metalorganic chemical vapor deposition using a single liquid source precursor. A c-axis-oriented YBCO film was grown epitaxially on a (100) CeO2 layer at a deposition rate of 11 μm h-1. A screw dislocation and stacking faults were observed in the cross-section of the YBCO film. The critical current density of the YBCO film reached 2.7 MA cm-2.

  6. On the influence of DC electric fields on the aerosol assisted chemical vapor deposition growth of photoactive titanium dioxide thin films.

    Science.gov (United States)

    Romero, Luz; Binions, Russell

    2013-11-01

    Titanium dioxide thin films were deposited on fluorine doped tin oxide glass substrate from the electric field assisted aerosol chemical vapor deposition (EACVD) reaction of titanium isopropoxide (TTIP, Ti(OC3H7)4) in toluene on glass substrates at a temperature of 450 °C. DC electric fields were generated by applying a potential difference between the electrodes of the transparent coated oxide coated glass substrates during the deposition. The deposited films were characterized using scanning electron microscopy, X-ray diffraction, atomic force microscopy, Raman spectroscopy, and UV-vis spectroscopy. The photoactivity and hydrophilicity of the deposited films were also analyzed using a dye-ink test and water-contact angle measurements. The characterization work revealed that the incorporation of DC electric fields produced significant reproducible changes in the film microstructure, preferred crystallographic orientation, roughness, and film thickness. Photocatalytic activity was calculated from the half-time (t1/2) or time taken to degrade 50% of the initial resazurin dye concentration. A large improvement in photocatalytic activity was observed for films deposited using an electric field with a strong orientation in the (004) direction (t1/2 17 min) as compared to a film deposited with no electric field (t1/2 40 min). PMID:24160408

  7. Characterization of amorphous yttria layers deposited by aqueous solutions of Y-chelate alkoxides complex

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young-Soon, E-mail: kyscjb@i-sunam.com; Lee, Yu-Ri; Kim, Byeong-Joo; Lee, Jae-Hun; Moon, Seung-Hyun; Lee, Hunju

    2015-01-15

    Highlights: • Economical method for crack-free amorphous yttria layer deposition by dip coating. • Simpler process for planar yttria film as a diffusion barrier and nucleation layer. • Easy control over the film properties with better characteristics. • Easy control over the thickness of the deposited films. • A feasible process that can be easily adopted by HTSCC industries. - Abstract: Crack-free amorphous yttria layers were deposited by dip coating in solutions of different Y-chelate alkoxides complex. Three Y-chelate solutions of different concentrations were prepared using yttrium acetate tetrahydrate, yttrium stearic acid as Y source materials. PEG, diethanolamine were used as chelating agents, while ethanol, methanol and tetradecane were used as solvent. Three different combinations of chelating and solvents were used to prepare solutions for Y{sub 2}O{sub 3} dip coating on SUS, electropolished and non-electropolished Hastelloy C-276 substrates. The thickness of the films was varied by changing the number of dipping cycles. At an optimized condition, the substrate surface roughness (rms) value was reduced from ∼50 nm to ∼1 nm over a 10 × 10 μm{sup 2} area. After Y{sub 2}O{sub 3} deposition, MgO was deposited using ion-beam assisted deposition (IBAD), then LaMnO{sub 3} (LMO) was deposited using sputtering and GdBCO was deposited using reactive co-evaporation by deposition and reaction (RCE-DR). Detailed X-ray study indicates that LMO/MgO/Y{sub 2}O{sub 3} and GdBCO/LMO/MgO/Y{sub 2}O{sub 3} stack films have good out-of-plane and in-plane textures with strong c-axis alignment. The critical current (Ic) of GdBCO/LMO/MgO/Y{sub 2}O{sub 3} multilayer structure varied from 190 to 420 A/cm with different solutions, when measured at 77 K. These results demonstrated that amorphous yttria can be easily deposited by dip coating using Y-chelates complex as a diffusion barrier and nucleation layer.

  8. Electrochromic and colorimetric properties of nickel(II) oxide thin films prepared by aerosol-assisted chemical vapor deposition.

    Science.gov (United States)

    Sialvi, Muhammad Z; Mortimer, Roger J; Wilcox, Geoffrey D; Teridi, Asri Mat; Varley, Thomas S; Wijayantha, K G Upul; Kirk, Caroline A

    2013-06-26

    Aerosol-assisted chemical vapor deposition (AACVD) was used for the first time in the preparation of thin-film electrochromic nickel(II) oxide (NiO). The as-deposited films were cubic NiO, with an octahedral-like grain structure, and an optical band gap that decreased from 3.61 to 3.48 eV on increase in film thickness (in the range 500-1000 nm). On oxidative voltammetric cycling in aqueous KOH (0.1 mol dm(-3)) electrolyte, the morphology gradually changed to an open porous NiO structure. The electrochromic properties of the films were investigated as a function of film thickness, following 50, 100, and 500 conditioning oxidative voltammetric cycles in aqueous KOH (0.1 mol dm(-3)). Light modulation of the films increased with the number of conditioning cycles. The maximum coloration efficiency (CE) for the NiO (transmissive light green, the "bleached" state) to NiOOH (deep brown, the colored state) electrochromic process was found to be 56.3 cm(2) C(-1) (at 450 nm) for films prepared by AACVD for 15 min followed by 100 "bleached"-to-colored conditioning oxidative voltammetric cycles. Electrochromic response times were bleaching process. The films showed good stability when tested for up to 10 000 color/bleach cycles. Using the CIE (Commission Internationale de l'Eclairage) system of colorimetry the color stimuli of the electrochromic NiO films and the changes that take place on reversibly oxidatively switching to the NiOOH form were calculated from in situ visible spectra recorded under electrochemical control. Reversible changes in the hue and saturation occur on oxidation of the NiO (transmissive light green) form to the NiOOH (deep brown) form, as shown by the track of the CIE 1931 xy chromaticity coordinates. As the NiO film is oxidized, a sharp decrease in luminance was observed. CIELAB L*a*b* coordinates were also used to quantify the electrochromic color states. A combination of a low L* and positive a* and b* values quantified the perceived deep brown

  9. The Two-Beam-Line Ion Implanter and Review of its Application to Creation of Complex Layers by the IBAD Method

    International Nuclear Information System (INIS)

    The present status of the two-beam-line ion implanter its basic specifications after the upgrading and the possibilities of its application to ion engineering methods is presented. The examples of created layers (DLC, TiNx, SiCx) and research methods applied to find out the features of the ion beam assisted deposited coatings are presented in order to prove the suitability of the device to scientific studies

  10. The role of hydrogen in oxygen-assisted chemical vapor deposition growth of millimeter-sized graphene single crystals

    Science.gov (United States)

    Zhao, Pei; Cheng, Yu; Zhao, Dongchen; Yin, Kun; Zhang, Xuewei; Song, Meng; Yin, Shaoqian; Song, Yenan; Wang, Peng; Wang, Miao; Xia, Yang; Wang, Hongtao

    2016-03-01

    Involving oxygen in the traditional chemical vapor deposition (CVD) process has proven a promising approach to achieve large-scale graphene single crystals (GSCs), but its many relevant fundamental aspects are still not fully understood. Here we report a systematic study on the role of hydrogen in the growth of millimeter-sized GSCs using enclosure-like Cu structures via the oxygen-assisted CVD process. Results show that GSCs have different first layer growth behaviors on the inside and outside surfaces of a Cu enclosure when the H2 environment is varied, and these behaviors will consequently and strongly influence the adlayer formation in these GSCs, leading to two entirely different growth modes. Low H2 partial pressure (PH2) tends to result in fast growth of dendritically shaped GSCs with multiple small adlayers, but high PH2 can modify the GSC shape into hexagons with single large adlayer nuclei. This difference of adlayers is attributed to the different C diffusion paths determined by the shapes of their host GSCs. On the basis of these observations, we developed an isothermal two-step method to obtain GSCs with significantly improved growth rate and sample quality, in which low PH2 is first set to accelerate the growth rate followed by high PH2 to restrict the adlayer nuclei. Our results prove that the growth of GSCs can reach a reasonable optimization between their growth rates and sample quality by simply adjusting the CVD H2 environment, which we believe will lead to more improvements in graphene synthesis and fundamental insight into the related growth mechanisms.Involving oxygen in the traditional chemical vapor deposition (CVD) process has proven a promising approach to achieve large-scale graphene single crystals (GSCs), but its many relevant fundamental aspects are still not fully understood. Here we report a systematic study on the role of hydrogen in the growth of millimeter-sized GSCs using enclosure-like Cu structures via the oxygen-assisted CVD

  11. Dioxo-Fluoroalkoxide Tungsten(VI) Complexes for Growth of WOx Thin Films by Aerosol-Assisted Chemical Vapor Deposition.

    Science.gov (United States)

    Bonsu, Richard O; Kim, Hankook; O'Donohue, Christopher; Korotkov, Roman Y; Abboud, Khalil A; Anderson, Timothy J; McElwee-White, Lisa

    2015-08-01

    The soluble bis(fluoroalkoxide) dioxo tungsten(VI) complexes WO2(OR)2(DME) [1, R = C(CF3)2CH3; 2, R = C(CF3)3] have been synthesized by alkoxide-chloride metathesis and evaluated as precursors for aerosol-assisted chemical vapor deposition (AACVD) of WOx. The (1)H NMR and (19)F NMR spectra of 1 and 2 are consistent with an equilibrium between the dimethoxyethane (DME) complexes 1 and 2 and the solvato complexes WO2(OR)2(CD3CN)2 [1b, R = C(CF3)2CH3; 2b, R = C(CF3)3] in acetonitrile-d3 solution. Studies of the fragmentation of 1 and 2 by mass spectrometry and thermolysis resulted in observation of DME and the corresponding alcohols, with hexafluoroisobutylene also generated from 1. DFT calculations on possible decomposition mechanisms for 1 located pathways for hydrogen abstraction by a terminal oxo to form hexafluoroisobutylene, followed by dimerization of the resulting terminal hydroxide complex and dissociation of the alcohol. AACVD using 1 occurred between 100 and 550 °C and produced both substoichiometric amorphous WOx and a polycrystalline W18O49 monoclinic phase, which exhibits 1-D preferred growth in the [010] direction. The work function (4.9-5.6 eV), mean optical transmittance (39.1-91.1%), conductivity (0.4-2.3 S/cm), and surface roughness (3.4-7.9 nm) of the WOx films are suitable for charge injection layers in organic electronics. PMID:26172992

  12. Mechanical and electrochemical properties of ultrasonic-assisted electroless deposition of Ni–B–TiO{sub 2} composite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Niksefat, Vahid; Ghorbani, Mohammad, E-mail: ghorbani@sharif.edu

    2015-06-05

    Highlights: • Ni–B–TiO{sub 2} coatings developed by ultrasonic-assisted electroless method. • Titania improves corrosion resistance and hardness of the Ni–B as-plated coatings. • Titania increases the surface film resistance of the Ni–B as-plated coatings. - Abstract: Nickel–Boron–Titania (Ni–B–TiO{sub 2}) composite coatings were successfully obtained on mild steel (St-37) by simultaneous electroless deposition. TiO{sub 2} particles were dispersed in a suspension by ultrasonic irradiation. The surface morphology, particle size, elemental composition and phase analysis of the coatings were characterized by scanning electron microscopy (SEM), inductively coupled plasma (ICP) and X-ray diffraction (XRD). The hardness and friction coefficient of as- plated and heat treated Ni–B and Ni–B–TiO{sub 2} composite coatings were determined by Vickers diamond indentation and indentation scratch tests and compared with Ni–B coatings. As a result, the hardness (1263 HV) of the as-plated Ni–B–TiO{sub 2} coatings was improved significantly. In addition, the corrosion resistance behavior of the as-plated and heat treated Ni–B and Ni–B–TiO{sub 2} coatings were analyzed by anodic polarization and electrochemical impedance spectroscopic (EIS) studies in a 3.5 wt.% NaCl solution. The as-plated composite coatings (Ni–B–TiO{sub 2}) exhibited enhanced corrosion resistance (0.2 μA/cm{sup 2}) property over Ni–B coatings.

  13. Dense CdS thin films on fluorine-doped tin oxide coated glass by high-rate microreactor-assisted solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Su, Yu-Wei, E-mail: suyuweiwayne@gmail.com [School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR 97330 (United States); Microproducts Breakthrough Institute and Oregon Process Innovation Center, Corvallis, Oregon 97330 (United States); Ramprasad, Sudhir [Energy Processes and Materials Division, Pacific Northwest National Laboratory, Corvallis, OR 9730 (United States); Microproducts Breakthrough Institute and Oregon Process Innovation Center, Corvallis, Oregon 97330 (United States); Han, Seung-Yeol; Wang, Wei [School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR 97330 (United States); Microproducts Breakthrough Institute and Oregon Process Innovation Center, Corvallis, Oregon 97330 (United States); Ryu, Si-Ok [School of Display and Chemical Engineering, Yeungnam University, 214-1 Dae-dong, Gyeonsan, Gyeongbuk 712-749 (Korea, Republic of); Palo, Daniel R. [Barr Engineering Co., Hibbing, MN 55747 (United States); Paul, Brian K. [School of Mechanical, Industrial and Manufacturing Engineering, Oregon State University, Corvallis, OR 97330 (United States); Microproducts Breakthrough Institute and Oregon Process Innovation Center, Corvallis, Oregon 97330 (United States); Chang, Chih-hung [School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR 97330 (United States); Microproducts Breakthrough Institute and Oregon Process Innovation Center, Corvallis, Oregon 97330 (United States)

    2013-04-01

    Continuous microreactor-assisted solution deposition is demonstrated for the deposition of CdS thin films on fluorine-doped tin oxide (FTO) coated glass. The continuous flow system consists of a microscale T-junction micromixer with the co-axial water circulation heat exchanger to control the reacting chemical flux and optimize the heterogeneous surface reaction. Dense, high quality nanocrystallite CdS thin films were deposited at an average rate of 25.2 nm/min, which is significantly higher than the reported growth rate from typical batch chemical bath deposition process. Focused-ion-beam was used for transmission electron microscopy specimen preparation to characterize the interfacial microstructure of CdS and FTO layers. The band gap was determined at 2.44 eV by UV–vis absorption spectroscopy. X-ray photon spectroscopy shows the binding energies of Cd 3d{sub 3/2}, Cd 3d{sub 5/2}, S 2P{sub 3/2} and S 2P{sub 1/2} at 411.7 eV, 404.8 eV, 162.1 eV and 163.4 eV, respectively. - Highlights: ► CdS films deposited using continuous microreactor-assisted solution deposition (MASD) ► Dense nanocrystallite CdS films can be reached at a rate of 25.2 [nm/min]. ► MASD can approach higher film growth rate than conventional chemical bath deposition.

  14. Sonication-assisted sequential chemical bath deposition of CdS nanoparticles into TiO2 nanotube arrays for application in solar cells

    International Nuclear Information System (INIS)

    Highlights: ► CdS sensitized TNTAs photoanode were prepared by sonication-assisted CBD approach. ► Sonication-assisted CBD (SSCBD) prevents CdS aggregating at the top of TNTAs. ► SSCBD promote the deposition quantity of nanoparticles into the TNTAs effectively. ► Compared with classical CBD, S-CdS/TNTAs cells exhibit an increase of η by 65.8%. - Abstract: CdS nanoparticles sensitized TiO2 nanotube arrays photoanode for semiconductors sensitized solar cells (SSSCs) were prepared by sonication-assisted sequential chemical bath deposition (SSCBD) approach and labeled as S-CdS/TNTAs. The S-CdS/TNTAs solar cell was assembled into a typical sandwich structure with backside illumination. Short-circuit current density (Jsc), open circuit potential (Voc), fill factor (FF) and power conversion efficiency (PCE) of the cells under AM 1.5 irradiation were about 4.16 mA cm−2, 446 mV, 43.9% and 0.814%, respectively. Compared with classical sequential chemical bath deposition (SCBD), SSCBD process could effectively prevent CdS nanoparticles aggregating at the top surface of TNTAs and resulted in an increase of PCE by 65.8%. Increased performance of S-CdS/TNTAs solar cell may be attributed to the more efficient charge-transfer process and the lower charge recombination, as evidenced from FESEM and electrochemical impedance spectroscopy (EIS).

  15. Observation of low resistivity and high mobility in Ga doped ZnO thin films grown by buffer assisted pulsed laser deposition

    International Nuclear Information System (INIS)

    Highlights: • Ga doped ZnO thin films were grown using buffer assisted pulsed laser deposition. • Lowest resistivity ∼5.1 × 10−5 Ω cm with a mobility of ∼41.9 cm2/V s was observed. • Buffer assisted growth methodology maintains relatively good crystalline quality. • This plays a key role in decreasing the resistivity of to the aforementioned value. • This resistivity value, to the best of our knowledge is the lowest so far in ZnO. - Abstract: We have grown Ga doped ZnO (GZO) thin films at moderate temperatures with Ga concentrations in the range varying from 0.25 to 3 at.% on sapphire substrates using buffer assisted pulsed laser deposition. Room temperature resistivity measured was ∼5.1 × 10−5 Ω cm with a electron mobility of ∼41.9 cm2/V s for an optimum Ga concentration of ∼0.75 at.% in the GZO films. Buffer assisted growth methodology maintains relatively good crystalline quality of the GZO thin films, thereby improving the electron mobility even at high dopant concentrations. This plays a key role in decreasing the resistivity of GZO films to the aforementioned value, which to the best of our knowledge is the lowest so far. These highly conducting GZO thin films with good mobility are potential candidates for transparent conducting oxide (TCO) applications in various optoelectronic devices

  16. Performance Improvement of Microcrystalline p-SiC/i-Si/n-Si Thin Film Solar Cells by Using Laser-Assisted Plasma Enhanced Chemical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    Hsin-Ying Lee

    2014-01-01

    Full Text Available The microcrystalline p-SiC/i-Si/n-Si thin film solar cells treated with hydrogen plasma were fabricated at low temperature using a CO2 laser-assisted plasma enhanced chemical vapor deposition (LAPECVD system. According to the micro-Raman results, the i-Si films shifted from 482 cm−1 to 512 cm−1 as the assisting laser power increased from 0 W to 80 W, which indicated a gradual transformation from amorphous to crystalline Si. From X-ray diffraction (XRD results, the microcrystalline i-Si films with (111, (220, and (311 diffraction were obtained. Compared with the Si-based thin film solar cells deposited without laser assistance, the short-circuit current density and the power conversion efficiency of the solar cells with assisting laser power of 80 W were improved from 14.38 mA/cm2 to 18.16 mA/cm2 and from 6.89% to 8.58%, respectively.

  17. Observation of low resistivity and high mobility in Ga doped ZnO thin films grown by buffer assisted pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ajimsha, R.S., E-mail: ajimsha@gmail.com [Laser Material Processing Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India); Das, Amit K.; Misra, P.; Joshi, M.P.; Kukreja, L.M. [Laser Material Processing Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India); Kumar, R.; Sharma, T.K.; Oak, S.M. [Semiconductor Physics & Devices Lab., Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)

    2015-07-25

    Highlights: • Ga doped ZnO thin films were grown using buffer assisted pulsed laser deposition. • Lowest resistivity ∼5.1 × 10{sup −5} Ω cm with a mobility of ∼41.9 cm{sup 2}/V s was observed. • Buffer assisted growth methodology maintains relatively good crystalline quality. • This plays a key role in decreasing the resistivity of to the aforementioned value. • This resistivity value, to the best of our knowledge is the lowest so far in ZnO. - Abstract: We have grown Ga doped ZnO (GZO) thin films at moderate temperatures with Ga concentrations in the range varying from 0.25 to 3 at.% on sapphire substrates using buffer assisted pulsed laser deposition. Room temperature resistivity measured was ∼5.1 × 10{sup −5} Ω cm with a electron mobility of ∼41.9 cm{sup 2}/V s for an optimum Ga concentration of ∼0.75 at.% in the GZO films. Buffer assisted growth methodology maintains relatively good crystalline quality of the GZO thin films, thereby improving the electron mobility even at high dopant concentrations. This plays a key role in decreasing the resistivity of GZO films to the aforementioned value, which to the best of our knowledge is the lowest so far. These highly conducting GZO thin films with good mobility are potential candidates for transparent conducting oxide (TCO) applications in various optoelectronic devices.

  18. Electroless copper on refractory and noble metal substrates with an ultra-thin plasma-assisted atomic layer deposited palladium layer

    International Nuclear Information System (INIS)

    Electroless Cu was investigated on refractory metal, W and TaN X, and Ir noble metal substrates with a plasma-assisted atomic layer deposited palladium layer for the potential back-end-of-the-line (BEOL) metallization of advanced integrated devices. The sodium and potassium-free Cu electroless bath consisted of: ethylenediamine tetraacetic acid (EDTA) as a chelating agent, glyoxylic acid as a reducing agent, and additional chemicals such as polyethylene glycol, 2,2'-dipyridine and RE-610 as surfactant, stabilizer and wetting agent respectively. The growth and chemical characterization of the Cu films was carried out with a field emission scanning electron microscope (FE-SEM), X-ray photoelectron spectroscopy (XPS), and Rutherford backscattering spectrometry (RBS). Group VIII metals such as Pt, Pd, etc., are stable in the electroless bath and catalytic towards the oxidation of glyoxylic acid and therefore work well for the electroless deposition of Cu. From RBS analysis, the amount of carbon and oxygen in Cu films were less than 1-3%. The Cu films were electroless deposited at 45-50 deg. C on patterned tantalum nitride with plasma-assisted atomic layer deposited (PA-ALD) Pd as a catalytic layer. Electroless Cu trench fill was successful with ultrasonic vibration, RE-610, and lowering the temperature to 45-50 deg. C on TaN X with the PA-ALD Pd catalytic layer

  19. On titanium dioxide thin films growth from the direct current electric field assisted chemical vapour deposition of titanium (IV) chloride in toluene

    International Nuclear Information System (INIS)

    Titanium dioxide thin films were deposited from the aerosol assisted chemical vapour deposition reaction of titanium tetrachloride in toluene (1 M) at 600 °C and 5 L min−1. Direct current electric fields were applied and increased in a range of 0 to 30 V during the reaction. Changes in particle size, agglomeration and particle shape were observed. Raman spectroscopy analysis revealed different composition of anatase and rutile and crystal phase depending on the field strength applied. The photocatalytic activity was calculated from the half-life or time needed by the films to degrade 50% Resazurin dye-ink initial concentration. High photocatalytic performance with high anatase content (98.3%) was observed with half-life values of 3.9 min. Deposited films with pure content in rutile showed better photocatalytic performance than films with mix of crystal phases with anatase content below 40%. - Highlights: • Electric field assisted chemical vapour deposition used to synthesis titania thin films. • Significant alterations to crystallographic orientation and microstructure observed • Order of magnitude reduction in half life of dye degradation obtainable

  20. Thin films of tin(II) sulphide (SnS) by aerosol-assisted chemical vapour deposition (AACVD) using tin(II) dithiocarbamates as single-source precursors

    Science.gov (United States)

    Kevin, Punarja; Lewis, David J.; Raftery, James; Azad Malik, M.; O'Brien, Paul

    2015-04-01

    The synthesis of the asymmetric dithiocarbamates of tin(II) with the formula [Sn(S2CNRR')2] (where R=Et, R'=n-Bu (1); R=Me, R'=n-Bu (2); R=R'=Et (3)) and their use for the deposition of SnS thin films by aerosol-assisted chemical vapour deposition (AACVD) is described. The effects of temperature and the concentration of the precursors on deposition were investigated. The stoichiometry of SnS was best at higher concentrations of precursors (250 mM) and at 450 °C. The direct electronic band gap of the SnS produced by this method was estimated from optical absorbance measurements as 1.2 eV. The composition of films was confirmed by powder X-ray diffraction (p-XRD) and energy dispersive analysis of X-rays (EDAX) spectroscopy.

  1. Deposição e perdas da calda em feijoeiro em aplicação com assistência de ar na barra pulverizadora Spray deposition and spray loss using air-assistance boom on bean plants

    Directory of Open Access Journals (Sweden)

    Carlos Gilberto Raetano

    2004-01-01

    Full Text Available Com o objetivo de avaliar a influência da assistência de ar na deposição da calda de pulverização, em plantas de feijoeiro (Phaseolus vulgaris aos 26 dias após a emergência (DAE, com pontas de pulverização de jato cônico vazio (JA-0,5 e JA-1 e jato plano (AXI-110015, e volumes de calda, foi realizado um experimento em delineamento inteiramente casualizado, utilizando como traçador o íon cobre. Alvos coletores (papel de filtro com 3 x 3 cm foram afixados nas superfícies adaxial e abaxial de folíolos posicionados nas partes superior e inferior das plantas. Para aplicar a solução traçadora, utilizou-se pulverizador com barras de 14 metros, com e sem assistência de ar, volumes de 60 e 100 L.ha-1, e velocidade do ar correspondente a 50% da rotação máxima do ventilador. Após a aplicação, os coletores foram lavados individualmente em solução extratora de ácido nítrico a 1,0 mol.L-1, e a quantificação dos depósitos através de espectrofotometria. A assistência de ar não influenciou na deposição da calda tanto a 60 quanto a 100 L.ha-1. O maior volume proporcionou maiores depósitos, sendo constatadas elevadas perdas para o solo (mais de 60%.Aiming to evaluate the effect of air-assistance in spray deposition on bean plants (Phaseolus vulgaris with hollow nozzles (JA-0,5 and JA-1 and flat fan nozzle type (AXI-110015, and volume rates by air-assisted and non-assisted sprayers, a completely randomized experiment was carried out using copper ion as a tracer to the evaluation of the deposits. At 26 days after emergence, artificial targets were positioned on the upper and under-side of the leaflets, on the top and bottom parts of the same plants under spray boom. For the application of tracer solution it was used a fourteen meter boom sprayer with and without air-assistance at 60 and 100 L.ha-1 of volume rates. The air flow was 50% of the maximum fan rotation. After application, targets were individually washed with an

  2. Selective Deposition and Alignment of Single-Walled Carbon Nanotubes Assisted by Dielectrophoresis: From Thin Films to Individual Nanotubes

    OpenAIRE

    Li Pengfei; Xue Wei

    2010-01-01

    Abstract Dielectrophoresis has been used in the controlled deposition of single-walled carbon nanotubes (SWNTs) with the focus on the alignment of nanotube thin films and their applications in the last decade. In this paper, we extend the research from the selective deposition of SWNT thin films to the alignment of small nanotube bundles and individual nanotubes. Electrodes with “teeth”-like patterns are fabricated to study the influence of the electrode width on the deposition an...

  3. Influence of alkali metals (Na, Li, Rb) on the performance of electrostatic spray-assisted vapor deposited Cu2ZnSn(S,Se)4 solar cells

    Science.gov (United States)

    Altamura, Giovanni; Wang, Mingqing; Choy, Kwang-Leong

    2016-02-01

    Electrostatic Spray-Assisted Vapor Deposition (ESAVD) is a non-vacuum and cost-effective method to deposit metal oxide, various sulphide and chalcogenide at large scale. In this work, ESAVD was used to deposit Cu2ZnSn(S1-xSex)4 (CZTSSe) absorber. Different alkali metals like Na, Li and Rb were incorporated in CZTSSe compounds to further improve the photovoltaic performances of related devices. In addition, to the best of our knowledge, no experimental study has been carried out to test the effect of Li and Rb incorporation in CZTSSe solar cells. X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and glow discharge spectroscopy have been used to characterize the phase purity, morphology and composition of as-deposited CZTSSe thin films. Photovoltaic properties of the resulting devices were determined by completing the solar cells as follows: Mo/CZTSSe/CdS/i-ZnO/Al:ZnO/Ni/Al. The results showed that Li, Na and Rb incorporation can increase power conversion efficiency of CZTS devices up to 5.5%. The introduction of a thiourea treatment, has improved the quality of the absorber|buffer interface, pushed the device efficiency up to 6.3% which is at the moment the best reported result for ESAVD deposited CZTSSe solar cells.

  4. Microwave-assisted catalytic fast pyrolysis of biomass for bio-oil production using chemical vapor deposition modified HZSM-5 catalyst.

    Science.gov (United States)

    Zhang, Bo; Zhong, Zhaoping; Chen, Paul; Ruan, Roger

    2015-12-01

    Chemical vapor deposition with tetra-ethyl-orthosilicate as the modifier was applied to deposit the external acid sites of HZSM-5, and the modified HZSM-5 samples were used for the microwave-assisted catalytic fast pyrolysis (MACFP) of biomass for bio-oil production. The experimental results showed that the external acid sites of HZSM-5 decreased significantly when SiO2 deposited amount increased from 0% to 5.9%. For product distribution, the coke yield decreased, the oil fraction yield decreased at first and then increased, and the yields of water and gas first increased and then decreased over the range of SiO2 deposited amount studied. For chemical compositions in oil fraction, the relative contents of aliphatic hydrocarbons, aromatic hydrocarbons and oxygen-containing aromatic compounds first increased to maximum values and then decreased, while the relative content of oxygen-containing aliphatic compounds first decreased and then increased with increasing SiO2 deposited amount. PMID:26318925

  5. Influence of alkali metals (Na, Li, Rb) on the performance of electrostatic spray-assisted vapor deposited Cu2ZnSn(S,Se)4 solar cells.

    Science.gov (United States)

    Altamura, Giovanni; Wang, Mingqing; Choy, Kwang-Leong

    2016-01-01

    Electrostatic Spray-Assisted Vapor Deposition (ESAVD) is a non-vacuum and cost-effective method to deposit metal oxide, various sulphide and chalcogenide at large scale. In this work, ESAVD was used to deposit Cu2ZnSn(S1-xSex)4 (CZTSSe) absorber. Different alkali metals like Na, Li and Rb were incorporated in CZTSSe compounds to further improve the photovoltaic performances of related devices. In addition, to the best of our knowledge, no experimental study has been carried out to test the effect of Li and Rb incorporation in CZTSSe solar cells. X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and glow discharge spectroscopy have been used to characterize the phase purity, morphology and composition of as-deposited CZTSSe thin films. Photovoltaic properties of the resulting devices were determined by completing the solar cells as follows: Mo/CZTSSe/CdS/i-ZnO/Al:ZnO/Ni/Al. The results showed that Li, Na and Rb incorporation can increase power conversion efficiency of CZTS devices up to 5.5%. The introduction of a thiourea treatment, has improved the quality of the absorber(|)buffer interface, pushed the device efficiency up to 6.3% which is at the moment the best reported result for ESAVD deposited CZTSSe solar cells. PMID:26916212

  6. Ecofriendly and Nonvacuum Electrostatic Spray-Assisted Vapor Deposition of Cu(In,Ga)(S,Se)2 Thin Film Solar Cells.

    Science.gov (United States)

    Hossain, Md Anower; Wang, Mingqing; Choy, Kwang-Leong

    2015-10-14

    Chalcopyrite Cu(In,Ga)(S,Se)2 (CIGSSe) thin films have been deposited by a novel, nonvacuum, and cost-effective electrostatic spray-assisted vapor deposition (ESAVD) method. The generation of a fine aerosol of precursor solution, and their controlled deposition onto a molybdenum substrate, results in adherent, dense, and uniform Cu(In,Ga)S2 (CIGS) films. This is an essential tool to keep the interfacial area of thin film solar cells to a minimum value for efficient charge separation as it helps to achieve the desired surface smoothness uniformity for subsequent cadmium sulfide and window layer deposition. This nonvacuum aerosol based approach for making the CIGSSe film uses environmentally benign precursor solution, and it is cheaper for producing solar cells than that of the vacuum-based thin film solar technology. An optimized CIGSSe thin film solar cell with a device configuration of molybdenum-coated soda-lime glass substrate/CIGSSe/CdS/i-ZnO/AZO shows the photovoltaic (j-V) characteristics of Voc=0.518 V, jsc=28.79 mA cm(-2), fill factor=64.02%, and a promising power conversion efficiency of η=9.55% under simulated AM 1.5 100 mW cm(-2) illuminations, without the use of an antireflection layer. This demonstrates the potential of ESAVD deposition as a promising alternative approach for making thin film CIGSSe solar cells at a lower cost. PMID:26390182

  7. 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.

  8. 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)

  9. 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)

  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. Bioactivity and osteogenic cell response of TiO2 nanotubes coupled with nanoscale calcium phosphate via ultrasonification-assisted electrochemical deposition

    International Nuclear Information System (INIS)

    Ultrasonification-assisted electrochemical deposition was used to introduce nanoscale calcium phosphate (CaP) into well-ordered TiO2 nanotube arrays (NTA) fabricated by anodic oxidation. Field emission scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and a drop-shape analysis system were used to investigate the morphology, constituent components and hydrophilicity of the nanostructured CaP/NTA surface. Bioactivity and osteogenic cell response were also characterized by hydroxyapatite (HA) formation tests, protein adsorption tests, and in vitro preosteoblast culture experiments. Abundant acicular nanoscale calcium phosphate was successfully deposited on the inner and outer walls of the nanotubes. After immersion in simulated body fluid, increased hydroxyapatite formation was apparent on the surface of TiO2 nanotubes coupled with nanoscale CaP when compared to simple nanotube structures and polished titanium. The CaP/NTA surface also adsorbed a greater amount of protein after being exposed to bovine serum albumin solution. During cell culture experiments, the preosteoblasts exhibited enhanced cellular adhesion, proliferation, and differentiation on the CaP/NTA surfaces. The results demonstrate that the introduction of nanoscale calcium phosphate into self-organized TiO2 nanotubes via a straightforward ultrasonification-assisted deposition technique enhances the bioactivity and osteogenic cell response, owing to the combined effects of the nanostructured surface topography, chemical composition, and hydrophilicity.

  12. Preparation of ZnO/Al2O3 catalysts by using atomic layer deposition for plasma-assisted non-oxidative methane coupling

    Science.gov (United States)

    Jeong, Myung-Geun; Kim, Young Dok; Park, Sunyoung; Kasinathan, Palraj; Hwang, Young Kyu; Chang, Jong-San; Park, Yong-Ki

    2016-05-01

    We prepared a ZnO/mesoporous Al2O3-shell/core structure by using atomic layer deposition (ALD) of ZnO on commercially-available mesoporous Al2O3. We used various analysis techniques such as scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, inductively coupled plasma-atomic emission spectroscopy, and surface area and pore size analyses based on nitrogen isotherm data. A 200 nm-thick slab of mesoporous Al2O3 particles was decorated by ZnO upon ALD deposition, whereas the inner part of the Al2O3 particle was free of ZnO. We evaluated the catalytic activity of the bare and the ZnO-covered Al2O3 for plasma-assisted nonoxidative coupling of methane. The catalytic behavior was shown to be sensitive to the amount of ZnO deposited. Particularly, 40-cycled ZnO/Al2O3 showed an enhanced selectivity to the olefin product with almost the same CH4 conversion as that of bare Al2O3. Preparation of the shell/core structure by using ALD can be an interesting strategy for finding highly-efficient catalysts in a plasma-assisted catalytic reaction.

  13. Growth and electro-optical properties of Ga-doped ZnO films prepared by aerosol assisted chemical vapour deposition

    International Nuclear Information System (INIS)

    Transparent conductive Ga-doped ZnO thin films were deposited onto glass substrates by a low-cost aerosol assisted chemical vapour deposition technique and the effect of gallium content on the ZnO film growth behaviour and opto-electronic properties was systematically investigated. It is found that, upon increasing Ga addition, the ZnO film crystallinity exhibits a continuous reduction in quality associated with the preferential orientation transformed from (002) to (102). The (002) oriented samples had a microstructure of parallel columnar grains while the (102) oriented coating was thickened by overlapping particles. The ZnO:Ga coatings exhibit high carrier concentration (up to 4.1 × 1020 cm−3) but low carrier mobility (up to 0.8 cm2 V−1 s−1), resulting in a minimum resistivity value of 2.3 × 10−2 Ω cm. The inferior carrier mobility performance could result from a profound ionized and neutral impurity scattering effect. Good visible transmittance (≈ 70–80%) is observed in these ZnO:Ga films and samples with higher carrier density present better infrared reflection performance (up to 37.2% at 2500 nm). - Highlights: • Aerosol assisted chemical vapour deposition of doped zinc oxide thin films • Gallium doping and opto-electronic properties systemically investigated • Growth mechanism changed by % gallium incorporation

  14. Growth and electro-optical properties of Ga-doped ZnO films prepared by aerosol assisted chemical vapour deposition

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shuqun [School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Carraro, Giorgio [Department of Chemistry and INSTM, Padova University, Padova 35131 (Italy); Barreca, Davide [CNR-IENI and INSTM, Department of Chemistry, Padova University, Padova 35131 (Italy); Binions, Russell [School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom)

    2015-06-01

    Transparent conductive Ga-doped ZnO thin films were deposited onto glass substrates by a low-cost aerosol assisted chemical vapour deposition technique and the effect of gallium content on the ZnO film growth behaviour and opto-electronic properties was systematically investigated. It is found that, upon increasing Ga addition, the ZnO film crystallinity exhibits a continuous reduction in quality associated with the preferential orientation transformed from (002) to (102). The (002) oriented samples had a microstructure of parallel columnar grains while the (102) oriented coating was thickened by overlapping particles. The ZnO:Ga coatings exhibit high carrier concentration (up to 4.1 × 10{sup 20} cm{sup −3}) but low carrier mobility (up to 0.8 cm{sup 2} V{sup −1} s{sup −1}), resulting in a minimum resistivity value of 2.3 × 10{sup −2} Ω cm. The inferior carrier mobility performance could result from a profound ionized and neutral impurity scattering effect. Good visible transmittance (≈ 70–80%) is observed in these ZnO:Ga films and samples with higher carrier density present better infrared reflection performance (up to 37.2% at 2500 nm). - Highlights: • Aerosol assisted chemical vapour deposition of doped zinc oxide thin films • Gallium doping and opto-electronic properties systemically investigated • Growth mechanism changed by % gallium incorporation.

  15. Bioactivity and osteogenic cell response of TiO2 nanotubes coupled with nanoscale calcium phosphate via ultrasonification-assisted electrochemical deposition

    Science.gov (United States)

    Chen, Jianyu; Zhang, Zhiguang; Ouyang, Jianglin; Chen, Xianshuai; Xu, Zhewu; Sun, Xuetong

    2014-06-01

    Ultrasonification-assisted electrochemical deposition was used to introduce nanoscale calcium phosphate (CaP) into well-ordered TiO2 nanotube arrays (NTA) fabricated by anodic oxidation. Field emission scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and a drop-shape analysis system were used to investigate the morphology, constituent components and hydrophilicity of the nanostructured CaP/NTA surface. Bioactivity and osteogenic cell response were also characterized by hydroxyapatite (HA) formation tests, protein adsorption tests, and in vitro preosteoblast culture experiments. Abundant acicular nanoscale calcium phosphate was successfully deposited on the inner and outer walls of the nanotubes. After immersion in simulated body fluid, increased hydroxyapatite formation was apparent on the surface of TiO2 nanotubes coupled with nanoscale CaP when compared to simple nanotube structures and polished titanium. The CaP/NTA surface also adsorbed a greater amount of protein after being exposed to bovine serum albumin solution. During cell culture experiments, the preosteoblasts exhibited enhanced cellular adhesion, proliferation, and differentiation on the CaP/NTA surfaces. The results demonstrate that the introduction of nanoscale calcium phosphate into self-organized TiO2 nanotubes via a straightforward ultrasonification-assisted deposition technique enhances the bioactivity and osteogenic cell response, owing to the combined effects of the nanostructured surface topography, chemical composition, and hydrophilicity.

  16. Bioactivity and osteogenic cell response of TiO{sub 2} nanotubes coupled with nanoscale calcium phosphate via ultrasonification-assisted electrochemical deposition

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jianyu, E-mail: chenjianyu-b2@163.com [Guanghua School of Stomatology, Hospital of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Zhang, Zhiguang, E-mail: 13580393430@163.com [Guanghua School of Stomatology, Hospital of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Ouyang, Jianglin; Chen, Xianshuai [Guangzhou Institute of Advanced Technology, Chinese Academy of Science, Guangzhou 511458 (China); Xu, Zhewu [Guanghua School of Stomatology, Hospital of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Sun, Xuetong [Guangzhou Institute of Advanced Technology, Chinese Academy of Science, Guangzhou 511458 (China)

    2014-06-01

    Ultrasonification-assisted electrochemical deposition was used to introduce nanoscale calcium phosphate (CaP) into well-ordered TiO{sub 2} nanotube arrays (NTA) fabricated by anodic oxidation. Field emission scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and a drop-shape analysis system were used to investigate the morphology, constituent components and hydrophilicity of the nanostructured CaP/NTA surface. Bioactivity and osteogenic cell response were also characterized by hydroxyapatite (HA) formation tests, protein adsorption tests, and in vitro preosteoblast culture experiments. Abundant acicular nanoscale calcium phosphate was successfully deposited on the inner and outer walls of the nanotubes. After immersion in simulated body fluid, increased hydroxyapatite formation was apparent on the surface of TiO{sub 2} nanotubes coupled with nanoscale CaP when compared to simple nanotube structures and polished titanium. The CaP/NTA surface also adsorbed a greater amount of protein after being exposed to bovine serum albumin solution. During cell culture experiments, the preosteoblasts exhibited enhanced cellular adhesion, proliferation, and differentiation on the CaP/NTA surfaces. The results demonstrate that the introduction of nanoscale calcium phosphate into self-organized TiO{sub 2} nanotubes via a straightforward ultrasonification-assisted deposition technique enhances the bioactivity and osteogenic cell response, owing to the combined effects of the nanostructured surface topography, chemical composition, and hydrophilicity.

  17. Deposition of thin layers of boron nitrides and hydrogenated microcrystalline silicon assisted by high current direct current arc plasma

    International Nuclear Information System (INIS)

    In the frame of this thesis, a high current direct current arc (HCDCA) used for the industrial deposition of diamond, has been adapted to study the deposition of two types of coatings: a) boron nitride, whose cubic phase is similar to diamond, for tribological applications, b) hydrogenated microcrystalline silicon, for applications in the semiconductor fields (flat panel displays, solar cells,...). For the deposition of these coatings, the substrates were placed in the diffusion region of the arc. The substrate heating is mainly due to atomic species recombining on its surface. The deposition temperature, varying from 300 to 900 oC according to the films deposited, is determined by the substrate position, the arc power and the injected gas fluxes, without the use of any external heating or cooling system. Measurements performed on the arc plasma show that the electronic temperature is around 2 eV (23'000 K) while the gas temperature is lower than 5500 K. Typical electronic densities are in the range of 1012-101'3 cm-3. For the deposition of boron nitride films, different boron precursors were used and a wide parameter range was investigated. The extreme difficulty of synthesising cubic boron nitride films by chemical vapour deposition (CVD) did not allow to stabilize the cubic phase of boron nitride in HCDCA. Coatings resulted in hexagonal or amorphous boron nitride with a chemical composition close to stoichiometric. The presence of hydrogen leads to the deposition of rough and porous films. Negative biasing of the samples, for positive ion bombardment, is commonly used to stabilize the cubic phase. In HCDCA and in our biasing range, only a densification of the films could be observed. A boron nitride deposition plasma study by infrared absorption spectroscopy in a capacitive radio frequency reactor has demonstrated the usefulness of this diagnostic for the understanding of the various chemical reactions which occur in this kind of plasma. Diborane dissociation

  18. Fabrication of ceramic coatings on NIFS-HEAT by arc-source plasma-assisted deposition method for fusion blanket application

    International Nuclear Information System (INIS)

    Al2O3 coatings and AlN coatings were fabricated by filtered arc-source plasma assisted deposition method on a low activation vanadium alloy NIFS-HEAT-2' for self-cooled liquid blanket application. The AlN coating had a low electrical resistivity due to relatively large amount of Al deposited in the coatings than that of N. Al2O3 bulk specimens and the Al2O3 coating were sintered in Li20-Sn80 and Flibe. They showed a high compatibility in the Li20-Sn80 at 823 K for 1 day. In the Flibe at 823 K for 2 days, on the contrast, slight mass decreases of the bulk specimens were observed and the coatings disappeared. (author)

  19. Preparation of high-quality hydrogenated amorphous silicon film with a new microwave electron cyclotron resonance chemical vapour deposition system assisted with hot wire

    Institute of Scientific and Technical Information of China (English)

    Zhu Xiu-Hong; Chen Guang-Hua; Yin Sheng-Yi; Rong Yan-Dong; Zhang Wen-Li; Hu Yue-Hui

    2005-01-01

    The preparation of high-quality hydrogenated amorphous silicon (a-Si:H) film with a new microwave electron cyclotron resonance-chemical vapour deposition (MWECR-CVD) system assisted with hot wire is presented. In this system the hot wire plays an important role in perfecting the microstructure as well as improving the stability and the optoelectronic properties of the a-Si:H film. The experimental results indicate that in the microstructure of the a-Si:H film, the concentration of dihydride is decreased and a trace of microcrystalline occurs, which is useful to improve its stability, and that in the optoelectronic properties of the a-Si:H film, the deposition rate reaches above 2.0nm/s and the photosensitivity increases up to 4.71× 105.

  20. 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.

  1. Vertical La0.7Ca0.3MnO3 nanorods tailored by high magnetic field assisted pulsed laser deposition

    OpenAIRE

    Kejun Zhang; Jianming Dai; Xuebin Zhu; Xiaoguang Zhu; Xuzhong Zuo; Peng Zhang; Ling Hu; Wenjian Lu; Wenhai Song; Zhigao Sheng; Wenbin Wu; Yuping Sun; Youwei Du

    2016-01-01

    La0.7Ca0.3MnO3 (LCMO) thin films on (LaAlO3)0.3(Sr2AlTaO6)0.7 (001) [LSAT (001)] single crystal substrates have been prepared by high magnetic field assisted pulsed laser deposition (HMF-PLD) developed by ourselves. Uniformly sized and vertically aligned nanorod structures can be obtained under an applied high magnetic field above 5 T, and the dimension size of the nanorods can be manipulated by varying the applied magnetic field. It is found that the magnetic anisotropy is strongly correlate...

  2. Effect of surfactants on the morphology of FeSe films fabricated from a single source precursor by aerosol assisted chemical vapour deposition

    Indian Academy of Sciences (India)

    Raja Azadar Hussain; Amin Badshah; Naghma Haider; Malik Dilshad Khan; Bhajan Lal

    2015-03-01

    This article presents the fabrication of FeSe thin films from a single source precursor namely (1-(2-fluorobenzoyl)-3-(4-ferrocenyl-3-methylphenyl)selenourea (MeP2F)) by aerosol assisted chemical vapour deposition (AACVD). All the films were prepared via similar experimental conditions (temperature, flow rate, concentration, solvent system and reactor type) except the use of three different concentrations of two different surfactants i.e., triton and span. Seven thin films were characterized with PXRD, SEM, AFM, EDS and EDS mapping. The mechanism of the interaction of surfactant with MeP2F was determined with cyclic voltammetry (CV) and UV-Vis spectroscopy.

  3. Hydrogen plasma enhanced alignment on CNT-STM tips grown by liquid catalyst-assisted microwave plasma-enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    Carbon nanotubes are grown directly on a scanning tunneling microscopy tip by liquid catalyst-assisted microwave-enhanced chemical vapor deposition, and effects of hydrogen plasma treatment on the tip have been investigated in detail by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and Raman spectroscopy. The unaligned CNTs on the as-grown tip apex have been realigned and reshaped by subsequent hydrogen plasma treatment. The diameter of CNTs is enlarged mainly due to amorphous layers being re-sputtered over their outer shells

  4. Composition and properties of surface of Me/Si systems, prepared by deposition of Ti and Co thin films assisted by self-ion

    International Nuclear Information System (INIS)

    In this paper a composite structure, topography, wettability and nanohardness of a surface (100) Si modified by means of ion-assisted deposition of coatings in conditions of a self-irradiation are discussed. Rutherford backscattering of He+ ions and computer program RUMP were applied to investigate a composition of surface. It is established, that coatings include atoms of metal, hydrogen, carbon, oxygen, silicon. The nanoindentation data from coated systems were used for calculation of the hardness and elastic modulus using load and displacement sensing indentation experiments. Atomic Force Microscopy surface observations were used to investigate the topography of modified surfaces. Hydrophilicity was measured by means of the contact angle measurement technique. (authors)

  5. Air-assisted boom sprayer and spray deposition on bean plants Assistência de ar em barra de pulverização e a deposição da calda em feijoeiro

    Directory of Open Access Journals (Sweden)

    Fernando Cesar Bauer

    2003-01-01

    Full Text Available The development of safe pesticide application techniques with low volume rates, frequency and spray drift, along with the need to obtain better control level of crop pest control levels, justify the air-assistance in boom sprayers. The aim of this research was to evaluate the spray deposition on bean plants with different nozzles and volume rates by air-assisted and non-assisted sprayers. A completely randomized experiment was carried out using copper oxide as a tracer (50% metalic copper for deposit evaluation. The artificial targets were fixed on the upper and under-side of the leaflets, at the top and lower third of the same plants under the spray boom. After application, targets were washed individually with an extracting solution of nitric acid (1.0 mol L-1. The tracer deposition on the artificial targets was quantified by atomic absorption spectrofotometry. The effects of air-assisted spray were not significant in relation to spray deposition 48 days after emergence of the bean plants.A possibilidade do desenvolvimento de técnicas de aplicação de produtos fitossanitários mais seguras, com menores volumes de calda, número de aplicações e deriva, aliados à necessidade de se obter melhores níveis de controle dos agentes nocivos às plantas cultivadas, justificam o uso da assistência de ar junto à barra de pulverização. Com o objetivo de avaliar a deposição da pulverização na cultura do feijoeiro (Phaseolus vulgaris, em presença e ausência da assistência de ar junto à barra de pulverização, com diferentes pontas de pulverização e volumes de calda, foi conduzido um experimento em delineamento inteiramente casualizado, utilizando-se como traçador o óxido cuproso. Alvos artificiais (papel filtro com 3 x 3 cm foram afixados nas superfícies adaxial e abaxial de folíolos posicionados nos terços superior e inferior de plantas, selecionadas ao acaso, distribuídas perpendicularmente ao deslocamento do pulverizador. Ap

  6. 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

  7. Electrochemically assisted deposition of hydroxyapatite on Ti6Al4V substrates covered by CVD diamond films - Coating characterization and first cell biological results.

    Science.gov (United States)

    Strąkowska, Paulina; Beutner, René; Gnyba, Marcin; Zielinski, Andrzej; Scharnweber, Dieter

    2016-02-01

    Although titanium and its alloys are widely used as implant material for orthopedic and dental applications they show only limited corrosion stability and osseointegration in different cases. The aim of the presented research was to develop and characterize a novel surface modification system from a thin diamond base layer and a hydroxyapatite (HAp) top coating deposited on the alloy Ti6Al4V widely used for implants in contact with bone. This coating system is expected to improve both the long-term corrosion behavior and the biocompatibility and bioactivity of respective surfaces. The diamond base films were obtained by Microwave Plasma Assisted Chemical Vapor Deposition (MW-PACVD); the HAp coatings were formed in aqueous solutions by electrochemically assisted deposition (ECAD) at varying polarization parameters. Scanning electron microscopy (SEM), Raman microscopy, and electrical conductivity measurements were applied to characterize the generated surface states; the calcium phosphate coatings were additionally chemically analyzed for their composition. The biological properties of the coating system were assessed using hMSC cells analyzing for cell adhesion, proliferation, and osteogenic differentiation. Varying MW-PACVD process conditions resulted in composite coatings containing microcrystalline diamond (MCD/Ti-C), nanocrystalline diamond (NCD), and boron-doped nanocrystalline diamond (B-NCD) with the NCD coatings being dense and homogeneous and the B-NCD coatings showing increased electrical conductivity. The ECAD process resulted in calcium phosphate coatings from stoichiometric and non-stoichiometric HAp. The deposition of HAp on the B-NCD films run at lower cathodic potentials and resulted both in the highest coating mass and the most homogenous appearance. Initial cell biological investigations showed an improved cell adhesion in the order B-NCD>HAp/B-NCD>uncoated substrate. Cell proliferation was improved for both investigated coatings whereas ALP

  8. Comparison of tungsten films grown by CVD and hot-wire assisted atomic layer deposition in a cold-wall reactor

    International Nuclear Information System (INIS)

    In this work, the authors developed hot-wire assisted atomic layer deposition (HWALD) to deposit tungsten (W) with a tungsten filament heated up to 1700–2000 °C. Atomic hydrogen (at-H) was generated by dissociation of molecular hydrogen (H2), which reacted with WF6 at the substrate to deposit W. The growth behavior was monitored in real time by an in situ spectroscopic ellipsometer. In this work, the authors compare samples with tungsten grown by either HWALD or chemical vapor deposition (CVD) in terms of growth kinetics and properties. For CVD, the samples were made in a mixture of WF6 and molecular or atomic hydrogen. Resistivity of the WF6-H2 CVD layers was 20 μΩ·cm, whereas for the WF6-at-H-CVD layers, it was 28 μΩ·cm. Interestingly, the resistivity was as high as 100 μΩ·cm for the HWALD films, although the tungsten films were 99% pure according to x-ray photoelectron spectroscopy. X-ray diffraction reveals that the HWALD W was crystallized as β-W, whereas both CVD films were in the α-W phase

  9. Heterocyclic dithiocarbamato-iron(III) complexes: single-source precursors for aerosol-assisted chemical vapour deposition (AACVD) of iron sulfide thin films.

    Science.gov (United States)

    Mlowe, Sixberth; Lewis, David J; Malik, Mohammad Azad; Raftery, James; Mubofu, Egid B; O'Brien, Paul; Revaprasadu, Neerish

    2016-02-14

    Tris-(piperidinedithiocarbamato)iron(III) (1) and tris-(tetrahydroquinolinedithiocarbamato)iron(iii) (2) complexes have been synthesized and their single-crystal X-ray structures were determined. Thermogravimetric analysis (TGA) of the complexes showed decomposition to iron sulfide. Both complexes were then used as single-source precursors for the deposition of iron sulfide thin films by aerosol-assisted chemical vapour deposition (AACVD). Energy-dispersive X-ray (EDX) spectroscopy confirmed the formation of iron sulfide films. The addition of tert-butyl thiol almost doubled the sulfur content in the deposited films. Scanning electron microscopy (SEM) images of the iron sulfide films from both complexes showed flakes/leaves/sheets, spherical granules and nanofibres. The sizes and shapes of these crystallites depended on the nature of the precursor, temperature, solvent and the amount of tert-butyl thiol used. The observed optical properties are dependent upon the variation of reaction parameters such as temperature and solvent. Powder X-ray diffraction (p-XRD) studies revealed that pyrrhotite, hexagonal (Fe0.975S), marcasite and smythite (Fe3S4) phases were differently deposited. PMID:26732865

  10. Study of temperature dependence and angular distribution of poly(9,9-dioctylfluorene) polymer films deposited by matrix-assisted pulsed laser evaporation (MAPLE)

    International Nuclear Information System (INIS)

    Poly(9,9-dioctylfluorene) (PFO) polymer films were deposited by matrix-assisted pulsed laser evaporation (MAPLE) technique. The polymer was diluted (0.5 wt%) in tetrahydrofuran and, once cooled to liquid nitrogen temperature, it was irradiated with a KrF excimer laser. 10,000 laser pulses were used to deposit PFO films on Si substrates at different temperatures (-16, 30, 50 and 70 deg. C). One PFO film was deposited with 16,000 laser pulses at a substrate temperature of 50 deg. C. The morphology, optical and structural properties of the films were investigated by SEM, AFM, PL and FTIR spectroscopy. SEM inspection showed different characteristic features on the film surface, like deflated balloons, droplets and entangled polymer filaments. The roughness of the films was, at least partially, controlled by substrate heating, which however had the effect to reduce the deposition rate. The increase of the laser pulse number modified the target composition and increased the surface roughness. The angular distribution of the material ejected from the target confirmed the forward ejection of the target material. PFO films presented negligible modification of the chemical structure respect to the bulk material.

  11. Growth of thick La2Zr2O7 buffer layers for coated conductors by polymer-assisted chemical solution deposition

    International Nuclear Information System (INIS)

    Highlights: • We develops a low-cost and high-efficient technology of fabricating LZO buffer layers. • Sufficient thickness LZO buffer layers have been obtained on NiW (2 0 0) alloy substrate. • Highly biaxially textured YBCO thin film has been deposited on LZO/NiW. - Abstract: La2Zr2O7 (LZO) epitaxial films have been deposited on LaAlO3 (LAO) (1 0 0) single-crystal surface and bi-axially textured NiW (2 0 0) alloy substrate by polymer-assisted chemical solution deposition, and afterwards studied with XRD, SEM and AFM approaches. Highly in-plane and out-of-plane oriented, dense, smooth, crack free and with a sufficient thickness (>240 nm) LZO buffer layers have been obtained on LAO (1 0 0) single-crystal surface; The films deposited on NiW (2 0 0) alloy substrate are also found with high degree in-plane and out-of-plane texturing, good density with pin-hole-free, micro-crack-free nature and a thickness of 300 nm. Highly epitaxial 500 nm thick YBa2Cu3O7−x (YBCO) thin film exhibits the self-field critical current density (Jc) reached 1.3 MA/cm2 at 77 K .These results demonstrate the LZO epi-films obtained with current techniques have potential to be a buffer layer for REBCO coated conductors

  12. 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.

  13. The use of surface modification techniques for the corrosion protection of aluminum and aluminum alloys

    International Nuclear Information System (INIS)

    Surface modification techniques such as ion beam assisted deposition (IBAD) and radio frequency plasma enhanced chemical vapor deposition (PECVD) offer a means to produce surfaces with unique and improved properties. This paper reviews the advantages of the IBAD and PECVD processes and discusses the preparation and pitting corrosion behavior of IBAD modified aluminum surfaces and PECVD coatings on a 7075 aluminum alloy. Pitting potential values for the base materials and for the base materials with silicon nitride IBAD, tantalum oxide IBAD, or PECVD diamond-like carbon coatings were determined in deaerated 0.1M NaCl solutions. The thickness of the modified region ranged from 0.01 to 5.0 microm. All three coatings improved the resistance to pit initiation

  14. Properties of Ultrathin Al2O3-TiO2 Nanolaminate Films for Gate Dielectric Applications Deposited by Plasma-Assisted Atomic Layer Deposition

    Science.gov (United States)

    Garces, Nelson; Meyer, David; Nepal, Neeraj; Wheeler, Virginia; Eddy, Charles

    2012-02-01

    High permittivity dielectrics such as Al2O3, HfO2, Ta2O5, TiO2, etc., are an essential component of aggressively-scaled III-V and graphene field effect transistors (FETs) where insulators are necessary to reduce gate leakage current while maintaining high gate capacitance and charge control of the channel. Atomic layer deposition (ALD) has the capability to deposit hybrid films, or nanolaminates, of two or more dielectrics that have unique properties. Thin [Al2O3+TiO2] nanolaminates with varying TiO2 and Al2O3 content were deposited on n-Si substrates at ˜225-300 C using ALD. A nanolaminate is composed of bilayers, defined as the sum of (x)Al2O3 and (y)TiO2, where x, and y indicate the number of times a component monolayer is repeated. While the overall thickness of the dielectric was held at ˜ 17-20 nm, the relative ratio of Al2O3 to TiO2 in the bilayer stack was varied to evaluate changes in the material properties and electrical performance of the oxides. C-V and I-V measurements on various [(x)TiO2+(y)Al2O3] MOS capacitors were taken. The high-TiO2-content films show limited evidence of oxide charge trapping and relatively large dielectric constants (κ˜15), whereas the high-Al2O3-content films offer a larger optical bandgap and improved suppression of leakage current. We will discuss the properties of very thin nanolaminates and their possible use as gate oxides. Morphological, electrical, and XPS composition assessments will be presented.

  15. Surface morphological and photoelectrochemical studies of ZnS thin films developed from single source precursors by aerosol assisted chemical vapour deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ehsan, Muhammad Ali [Faculty of Science, Department of Chemistry, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Peiris, T.A. Nirmal; Wijayantha, K.G. Upul [Department of Chemistry, Loughborough University, Loughborough, LE11 3TU (United Kingdom); Khaledi, Hamid [Faculty of Science, Department of Chemistry, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Ming, Huang Nay [Faculty of Science, Department of Physics, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Misran, Misni; Arifin, Zainudin [Faculty of Science, Department of Chemistry, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Mazhar, Muhammad, E-mail: mazhar42pk@yahoo.com [Faculty of Science, Department of Chemistry, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia)

    2013-07-01

    Zinc sulphide (ZnS) thin films have been deposited on fluorine-doped tin oxide-coated conducting glass substrates at 375, 425 and 475 °C temperatures from single source adduct precursors [Zn(S{sub 2}CNCy{sub 2}){sub 2}(py)] (1) [where, Cy = cyclohexyl, py = pyridine] and [Zn{S_2CN(CH_2Ph)(Me)}{sub 2}(py)] (2) [where, Ph = Phenyl, Me = Methyl] using aerosol assisted chemical vapour deposition (AACVD). The precursor complexes have been characterized by microanalysis, infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, X-ray single crystal and thermogravimetric analysis. Thermal analysis showed that both precursors (1) and (2) undergo thermal decomposition at 375 °C to produce ZnS residues. The deposited ZnS films have been characterized by X-ray diffraction and energy dispersive X-ray spectroscopy. Scanning electron microscopic studies indicated that the surface morphology of ZnS films strongly depends on the nature of the precursor and the deposition temperature, regardless of marginal variation in thermal stability of the precursors. Direct band gap energies of 3.36 and 3.40 eV have been estimated from the ultraviolet–visible spectroscopy for the ZnS films fabricated from precursors (1) and (2), respectively. The current–voltage characteristics recorded under air mass 1.5 illumination confirmed that the deposited ZnS thin films are photoactive under anodic bias conditions. Furthermore, the photoelectrochemical (PEC) results indicate that these synthesised single source precursors are suitable for obtaining ZnS thin films by AACVD method. The ZnS thin film electrode prepared in this study are very promising for solar energy conversion and optoelectronic applications. The PEC properties of ZnS electrodes prepared from (2) are superior to that of the ZnS electrode prepared from precursor (1). - Highlights: • Synthesis and characterization of zinc dithiocarbamate pyridine adducts. • ZnS photo electrodes have been fabricated using aerosol-assisted

  16. Surface morphological and photoelectrochemical studies of ZnS thin films developed from single source precursors by aerosol assisted chemical vapour deposition

    International Nuclear Information System (INIS)

    Zinc sulphide (ZnS) thin films have been deposited on fluorine-doped tin oxide-coated conducting glass substrates at 375, 425 and 475 °C temperatures from single source adduct precursors [Zn(S2CNCy2)2(py)] (1) [where, Cy = cyclohexyl, py = pyridine] and [Zn{S2CN(CH2Ph)(Me)}2(py)] (2) [where, Ph = Phenyl, Me = Methyl] using aerosol assisted chemical vapour deposition (AACVD). The precursor complexes have been characterized by microanalysis, infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, X-ray single crystal and thermogravimetric analysis. Thermal analysis showed that both precursors (1) and (2) undergo thermal decomposition at 375 °C to produce ZnS residues. The deposited ZnS films have been characterized by X-ray diffraction and energy dispersive X-ray spectroscopy. Scanning electron microscopic studies indicated that the surface morphology of ZnS films strongly depends on the nature of the precursor and the deposition temperature, regardless of marginal variation in thermal stability of the precursors. Direct band gap energies of 3.36 and 3.40 eV have been estimated from the ultraviolet–visible spectroscopy for the ZnS films fabricated from precursors (1) and (2), respectively. The current–voltage characteristics recorded under air mass 1.5 illumination confirmed that the deposited ZnS thin films are photoactive under anodic bias conditions. Furthermore, the photoelectrochemical (PEC) results indicate that these synthesised single source precursors are suitable for obtaining ZnS thin films by AACVD method. The ZnS thin film electrode prepared in this study are very promising for solar energy conversion and optoelectronic applications. The PEC properties of ZnS electrodes prepared from (2) are superior to that of the ZnS electrode prepared from precursor (1). - Highlights: • Synthesis and characterization of zinc dithiocarbamate pyridine adducts. • ZnS photo electrodes have been fabricated using aerosol-assisted chemical vapor

  17. Graphene synthesis by laser-assisted chemical vapor deposition on Ni plate and the effect of process parameters on uniform graphene growth

    International Nuclear Information System (INIS)

    A fast, simple technique was developed to fabricate few-layer graphene films at ambient pressure and room temperature by laser-assisted chemical vapor deposition on polycrystalline Ni plates. Laser scanning speed was found as the most important factor in the production of few-layer graphene. The quality of graphene films was controlled by varying the laser power. Uniform graphene ribbons with a width of 1.5 mm and a length of 16 mm were obtained at a scanning speed of 1.3 mm/s and a laser power of 600 W. The developed technique provided a promising application of a high-power laser system to fabricate a graphene film. - Highlights: • Uniform few-layer graphene was fabricated at room temperature and ambient conditions. • Laser-assisted chemical vapor deposition was used to grow the layers in a few seconds. • The effect of process parameters on graphene growth was discussed. • This cost effective method could facilitate the integration of graphene in electronic devices

  18. Thin films of hydrogenated amorphous carbon (a-C:H) obtained through chemical vapor deposition assisted by plasma

    International Nuclear Information System (INIS)

    Films of hydrogenated amorphous carbon (a-C:H) were deposited using one source of microwave plasma with magnetic field (type ECR), using mixtures of H2/CH4 in relationship of 80/20 and 95/05 as precursory gases, with work pressures of 4X10-4 to 6x10-4 Torr and an incident power of the discharge of microwaves with a constant value of 400 W. It was analyzed the influence among the properties of the films, as the deposit rate, the composition and the bonding types, and the deposit conditions, such as the flow rates of the precursory gases and the polarization voltage of the sample holders. (Author)

  19. Investigations on the effects of plasma-assisted pre-treatment for plasma-assisted chemical vapour deposition TiN coatings on tool steel

    Energy Technology Data Exchange (ETDEWEB)

    Gammer, K.; Stoiber, M.; Wagner, J.; Hutter, H.; Kullmer, R.; Mitterer, C

    2004-08-16

    Different mixtures of hydrogen, nitrogen and argon were tested for the cleaning and nitriding of cold-working, high chromium tool steel, prior to TiN deposition with the aim of improving adhesion of the TiN layer. It is well known that the condition of the substrate surface and hardening of the substrate by nitriding have a large influence on the adhesion strength of films. Good adhesion was achieved when nitrogen-hydrogen atmosphere with 40%-80% nitrogen (and 20%-60% hydrogen, respectively) was used, the best adhesion quality values were achieved (HF 1-2) with 40% nitrogen. With higher or lower fractions of nitrogen in the pre-treatment gas, adhesion was reduced. Argon addition also had negative effects on the adhesion strength. The microstructure and chemical composition of the near-interface region of the differently pretreated samples were analysed using secondary ion mass spectrometry, X-ray diffraction and light optical microscopy.

  20. Investigations on the effects of plasma-assisted pre-treatment for plasma-assisted chemical vapour deposition TiN coatings on tool steel

    International Nuclear Information System (INIS)

    Different mixtures of hydrogen, nitrogen and argon were tested for the cleaning and nitriding of cold-working, high chromium tool steel, prior to TiN deposition with the aim of improving adhesion of the TiN layer. It is well known that the condition of the substrate surface and hardening of the substrate by nitriding have a large influence on the adhesion strength of films. Good adhesion was achieved when nitrogen-hydrogen atmosphere with 40%-80% nitrogen (and 20%-60% hydrogen, respectively) was used, the best adhesion quality values were achieved (HF 1-2) with 40% nitrogen. With higher or lower fractions of nitrogen in the pre-treatment gas, adhesion was reduced. Argon addition also had negative effects on the adhesion strength. The microstructure and chemical composition of the near-interface region of the differently pretreated samples were analysed using secondary ion mass spectrometry, X-ray diffraction and light optical microscopy

  1. 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)

  2. Carbon diffusion in uncoated and titanium nitride coated iron substrates during microwave plasma assisted chemical vapor deposition of diamond

    International Nuclear Information System (INIS)

    Auger Electron Spectroscopy has been employed to investigate the effectiveness of thin films of TiN as barriers to carbon diffusion during Chemical Vapor Deposition (CVD) of diamond onto Fe substrates. Auger Depth Profiling was used to monitor the C concentration in the TiN layer, through the interface and into the substrate both before and after CVD diamond deposition. The results show that a layer of TiN only 250 Angstroems thick is sufficient to inhibit soot formation on the Fe surface and C diffusion into the Fe bulk. 14 refs., 4 figs

  3. Development and characterization of a layer by layer ultrasound assisted spray deposition process for thin polymer films

    Science.gov (United States)

    Balakrishnan, Anandh

    An Ultrasound assisted Atomization (UA) system has been developed and investigated to synthesize ˜20microm polyurethane thin films with uniform, repeatable thickness and microstructure. The UA system comprised a 20 kHz atomizer probe mounted on 750 W/cm2 transducer, a heated glass chamber and a rotating substrate. The rationale for the work has been built through a careful Design of Experiments (DoE) that sought to answer questions regarding the process-microstructure relationships from both the spray and material points of view. The independent variables chosen were the polymer solution weight percentage (0.2%, 2%, and 4%), power amplitude (energy) percentage supplied to the nozzle (23%, 29%, 37%, and 46%),the temperature of deposition (45°C, 80°C) and flow rate (50microL/min, 150microL/min). The research questions focused on influence of the process parameters on the microstructure and properties of the film. One of the problems involved fixing the trajectory of the spray and also making use of the droplet surfaces created by the spray. To achieve this, a simple air-draft attachment was devised and the influence of the same was evaluated through process and film characterization experiments. A mechanism for the draft has been schematically provided. The use of such a draft to fabricate thin polymer films via ultrasound atomization has not been achieved before and represents a 'first step' in advancing this ultrasound technology. The primary findings of the work were that the film microstructure and properties were heavily influenced by the flow rate, energy of atomization, and test temperature. In addition, the droplet diameters seemed to be readily amenable to change for the 0.2 and 2% solutions and the use of the air-draft made the process feasible, repeatable and accurate. For the 4% solutions, viscosity seemed to stabilize the liquid solution film at the tip requiring larger energies of atomization. In all, relative to the 0.2% films the fracture strengths

  4. Bending strain effects on the critical current in Cu-stabilized IBAD/EDDC processed SmBCO coated conductor tape

    International Nuclear Information System (INIS)

    Influences of bending strain on the critical current, Ic, in Cu-stabilized IBAD/EDDC processed SmBCO coated conductor (CC) tapes were investigated at 77 K and self-field using a small-scale Goldacker type bending test rig. Considering the location of the superconducting layer against the neutral axis, tensile and compressive bending strains were applied to the SmBCO coating layer and the strain effect on Ic degradation was discussed. Under tensile bending strain, the Ic decreased monotonically but recovered reversibly up to the irreversible strain limit. Under compressive bending strain, however, the Ic increased but in some cases it suddenly dropped after straightening due to the delamination of the copper stabilizer. Also, repeated bending strains were applied to Cu-stabilized SmBCO CC samples in order to observe the behavior of Ic under cyclic loading. Ic Initially decreased with the application of 0.7% bending strain, but when the tape was subjected to repeated bending up to 100 cycles, no more degradation occurred. And finally, the Ic almost recovered to Ic0 when the tape was straightened

  5. Deposition of CeO 2/YSZ buffer layer on Hastelloy substrates for MOD process of YBa 2Cu 3O 7- x film

    Science.gov (United States)

    Fuji, Hiroshi; Honjo, Tetsuji; Nakamura, Yuichi; Izumi, Teruo; Takeshi, Araki; Hirabayashi, Izumi; Shiohara, Yuh; Iijima, Yasuhiro; Takeda, Kaoru

    2001-08-01

    Trifluoroacetate metalorganic deposition (TFA-MOD) process is expected as a low cost process for mass production of coated conductors because it is a non-vacuum process. In order to apply the technique to fabrication of coated conductors, suitable buffer layers have to be considered to achieve a high orientation of superconducting layer and prevention of the reaction with metal substrate. The combination of CeO 2 on IBAD-YSZ is considered as an effective buffer for TFA-MOD process expecting to satisfy a high acid resistivity and high crystal grain alignment. The CeO 2 buffer layer was deposited on IBAD-YSZ/Hastelloy substrates by RF magnetron sputtering. From XRD analysis, the CeO 2 buffer layer showed very good in-plane alignment on YSZ-IBAD buffer layer. In a holding time of 1 h, the suitable maximum heat treatment temperature was found to be from 750°C to 775°C for TFA-Y123 on metal substrate. The Jc- B property of Y123 on CeO 2/YSZ/Hastelloy shows the Jc values of 1.4 MA/cm 2 at 77.3 K, 0 T and more than 10 5 A/cm 2 at 77.3 K, 2 T. The high performance under high magnetic field was confirmed.

  6. Selective Deposition and Alignment of Single-Walled Carbon Nanotubes Assisted by Dielectrophoresis: From Thin Films to Individual Nanotubes

    Directory of Open Access Journals (Sweden)

    Li Pengfei

    2010-01-01

    Full Text Available Abstract Dielectrophoresis has been used in the controlled deposition of single-walled carbon nanotubes (SWNTs with the focus on the alignment of nanotube thin films and their applications in the last decade. In this paper, we extend the research from the selective deposition of SWNT thin films to the alignment of small nanotube bundles and individual nanotubes. Electrodes with “teeth”-like patterns are fabricated to study the influence of the electrode width on the deposition and alignment of SWNTs. The entire fabrication process is compatible with optical lithography-based techniques. Therefore, the fabrication cost is low, and the resulting devices are inexpensive. A series of SWNT solutions is prepared with concentrations ranging from 0.0125 to 0.2 mg/ml. The alignment of SWNT thin films, small bundles, and individual nanotubes is achieved under the optimized experimental conditions. The electrical properties of these samples are characterized; the linear current–voltage plots prove that the aligned SWNTs are mainly metallic nanotubes. The microscopy inspection of the samples demonstrates that the alignment of small nanotube bundles and individual nanotubes can only be achieved using narrow electrodes and low-concentration solutions. Our investigation shows that it is possible to deposit a controlled amount of SWNTs in desirable locations using dielectrophoresis.

  7. Carbon Nitride Thin Films Deposited by Plasma Assisted Nd∶YAG Laser Ablation of Graphite in N2+H2 Atmosphere

    Institute of Scientific and Technical Information of China (English)

    YU Wei; WANG Shufang; ZHANG Lianshui; LI Xiaowei; FU Guangsheng

    2001-01-01

    Carbon nitride thin films are deposited on silicon wafers by 532 nm Nd∶YAG laser ablation of graphite in the N2+H2 atmosphere assisted by a dc glow discharge plasma at a higher gas pressure of about 4.0 kPa. The properties of the thin films are investigated by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and X-ray diffraction (XRD). The results show that the deposited films are composed of α-C3N4, β-C3N4 phase and have the N/C atomic ratio of 2.01. The optical emission spectroscopy (OES) studies indicate that the introduction of a dc glow discharge and the adoption of a higher gas pressure during the film deposition are favorable to the net generation of the atomic N, CN radicals and N+2 in B2Σ+u excited state in the plasma, which are considered to play a major role in the synthesis of carbon nitride.

  8. Growth of thick La2Zr2O7 buffer layers for coated conductors by polymer-assisted chemical solution deposition

    Science.gov (United States)

    Zhang, Xin; Zhao, Yong; Xia, Yudong; Guo, Chunsheng; Cheng, C. H.; Zhang, Yong; Zhang, Han

    2015-06-01

    La2Zr2O7 (LZO) epitaxial films have been deposited on LaAlO3 (LAO) (1 0 0) single-crystal surface and bi-axially textured NiW (2 0 0) alloy substrate by polymer-assisted chemical solution deposition, and afterwards studied with XRD, SEM and AFM approaches. Highly in-plane and out-of-plane oriented, dense, smooth, crack free and with a sufficient thickness (>240 nm) LZO buffer layers have been obtained on LAO (1 0 0) single-crystal surface; The films deposited on NiW (2 0 0) alloy substrate are also found with high degree in-plane and out-of-plane texturing, good density with pin-hole-free, micro-crack-free nature and a thickness of 300 nm. Highly epitaxial 500 nm thick YBa2Cu3O7-x (YBCO) thin film exhibits the self-field critical current density (Jc) reached 1.3 MA/cm2 at 77 K .These results demonstrate the LZO epi-films obtained with current techniques have potential to be a buffer layer for REBCO coated conductors.

  9. The effects of the forward speed and air volume of an air-assisted sprayer on spray deposition in tendone trained vineyards

    Directory of Open Access Journals (Sweden)

    Simone Pascuzzi

    2013-12-01

    Full Text Available This paper reports the results of spray application trials in a tendone trained vineyard in order to evaluate the influence of forward speed and air volume on the foliar deposition of plant protection products (PPPs, maintaining roughly constant the volume applied. The trials used an air-assisted sprayer with a centrifugal fan and 4+4 adjustable fan-shaped diffusers, each with a nozzle-holder group. A full factorial experimental design was implemented, with three forward speeds and two airflow rates, organised with a randomised complete block design including three replicates. In order to consider the influence of canopy development, the tests (one spray application for each replicate of a mixture containing a water-soluble food dye as a tracer were replicated during two phenological stages: i the end of flowering; and ii berry touch. Leaves were picked at random from the canopy after each spray treatment, and foliar PPP deposition was evaluated using a spectrophotometer. This analysis of foliar deposition showed that the airflow rates produced by the fan were unsuitable for the dense canopy typical of this type of vineyard. However, the special shape of the diffusers may make this sprayer effective if the main objective of pesticide applications in tendone trained table grape vineyards is to control bunch diseases.

  10. 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

  11. Structural characteristics of copper/hydrogenated amorphous carbon composite films prepared by microwave plasma-assisted deposition processes from methane-argon and acetylene-argon gas mixtures

    International Nuclear Information System (INIS)

    Copper/hydrogenated amorphous carbon (Cu/a-C:H) composite films have been deposited on silicon substrates by a hybrid technique combining microwave plasma-assisted chemical vapor deposition and sputter-deposition from methane-argon and acetylene-argon gas mixtures. The major objective of this work was to investigate the effect of the carbon gas precursor on the structural characteristics of Cu/a-C:H composite films deposited at ambient temperature. The major characteristics of CH4-argon and C2H2-argon plasmas were analyzed by Langmuir probe measurements. The composition of films was determined by Rutherford backscattering spectroscopy, energy recoil detection analyses and nuclear reaction analyses. The carbon content in the films was observed to vary in the range 20-77 at.% and 7.5-99 at.% as the CH4 and C2H2 concentrations in the gas phase increased from 10 to 100%, respectively. The atom number ratio H/C in the films was scattered approximately 0.4 whatever the carbon gas precursor used. The crystallographic structure and the size of copper crystallites incorporated in the a-C were determined by X-ray diffraction techniques. The copper crystallite size decreased from 20 nm in pure copper films to less than 5 nm in Cu/a-C:H films containing more than 40 at.% of carbon. Grazing incidence small angle X-ray scattering measurements were performed to investigate the size distribution and distance of copper crystallites as functions of the deposition parameters. The structural characteristics of copper crystallites were dependent on the hydrocarbon gas precursor used. The crystallite size and the width of the size distribution were homogeneous in films deposited from CH4. Copper crystallites with an anisotropic shape were found in films deposited from C2H2. The major radicals formed in the plasma and condensed on the surface of growing films, namely CH and C2H radicals for films produced from CH4 and C2H2, respectively, play probably a crucial role in the growth

  12. 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

  13. Growth of thick La{sub 2}Zr{sub 2}O{sub 7} buffer layers for coated conductors by polymer-assisted chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xin, E-mail: xzhang@my.swjtu.edu.cn [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity and New Energy Center (SNEC), Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Electrical Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhao, Yong, E-mail: yzhao@swjtu.edu.cn [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity and New Energy Center (SNEC), Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Xia, Yudong [State Key Lab of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Guo, Chunsheng [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity and New Energy Center (SNEC), Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, C.H. [School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Zhang, Yong [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity and New Energy Center (SNEC), Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhang, Han [Department of Physics, Peking University, Beijing 100871 (China)

    2015-06-15

    Highlights: • We develops a low-cost and high-efficient technology of fabricating LZO buffer layers. • Sufficient thickness LZO buffer layers have been obtained on NiW (2 0 0) alloy substrate. • Highly biaxially textured YBCO thin film has been deposited on LZO/NiW. - Abstract: La{sub 2}Zr{sub 2}O{sub 7} (LZO) epitaxial films have been deposited on LaAlO{sub 3} (LAO) (1 0 0) single-crystal surface and bi-axially textured NiW (2 0 0) alloy substrate by polymer-assisted chemical solution deposition, and afterwards studied with XRD, SEM and AFM approaches. Highly in-plane and out-of-plane oriented, dense, smooth, crack free and with a sufficient thickness (>240 nm) LZO buffer layers have been obtained on LAO (1 0 0) single-crystal surface; The films deposited on NiW (2 0 0) alloy substrate are also found with high degree in-plane and out-of-plane texturing, good density with pin-hole-free, micro-crack-free nature and a thickness of 300 nm. Highly epitaxial 500 nm thick YBa{sub 2}Cu{sub 3}O{sub 7−x} (YBCO) thin film exhibits the self-field critical current density (Jc) reached 1.3 MA/cm{sup 2} at 77 K .These results demonstrate the LZO epi-films obtained with current techniques have potential to be a buffer layer for REBCO coated conductors.

  14. Surface analysis and osteoblasts response of a titanium oxi-carbide film deposited on titanium by ion plating plasma assisted (IPPA).

    Science.gov (United States)

    Mazzola, L; Bemporad, E; Misiano, C; Pepe, F; Santini, P; Scandurra, R

    2011-10-01

    Titanium is the most widely used material in orthopaedic and dental implantoprosthesis due to its superior physical properties and enhanced biocompatibility due to the spontaneous formation of a passivating layer of titanium oxides which, however, does not form good chemical bonds with bone and tends to brake exposing bulk titanium to harsh body fluids releasing titanium particles which may prime an inflammation response and a fibrotic tissue production. In order to avoid these possible problems and to enhance the biocompatibility of titanium implants, modifications of titanium surfaces by many different materials as hydroxyapatite, titanium nitride, titanium oxide and titanium carbide have been proposed. The latter is shown to be an efficient protection for the titanium implant in the harsh conditions of biological tissues and, compared to untreated titanium, acting like an osteoblast stimulation factor increasing in vitro production of proteins involved in osteogenesis. These results were confirmed by in vivo experiments in rabbits: implants covered by the titanium carbide (TiC) layer were faster and better osseointegrated than untreated titanium implants. The TiC layer was deposited by a Pulsed Laser Deposition (PLD) device which allowed only one deposition per cycle, shown to be unsuitable for industrial applications. Therefore the main objective of the present work was to replace PLD process with an Ion Plating Plasma Assisted (IPPA) deposition process, which is suitable for industrial upgrading. By this technique, nanostructured TiOx-TiCy-C has been deposited on titanium after sandblasting with 120 micron zirconia spheres. XPS analyses revealed the presence of about 33% carbon (50% of which is present as free carbon), 39% oxygen and 28% titanium (37% of which is bound to carbon to form TiC and 63% is bound to oxygen to form non stoichiometric oxides). Surface mechanical response of as-deposited coatings has been performed by nanoindentation techniques

  15. Solid-State Spun Fibers from 1 mm Long Carbon Nanotube Forests Synthesized by Water-Assisted Chemical Vapor Deposition

    Science.gov (United States)

    Zhang, Shanju; Zhu, Lingbo; Minus, Marilyn L.; Chae, han Gi; Jagannathan, Sudhakar; Wong, Ching-Ping; Kowalik, Janusz; Roberson, Luke B.; Kumar, Satish

    2007-01-01

    In this work, we report continuous carbon nanotube fibers dry-drawn directly from water-assisted CVD grown forests with millimeter scale length. As-drawn nanotube fibers exist as aerogel and can be transformed into more compact fibers through twisting or densification with a volatile liquid. Nanotube fibers are characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Raman microscopy and wide-angle X-ray diffraction (WAXD). Mechanical behavior and electrical conductivity of the post-treated nanotube fibers are investigated.

  16. Substrate temperature influence on the properties of GaN thin films grown by hollow-cathode plasma-assisted atomic layer deposition

    International Nuclear Information System (INIS)

    Gallium nitride films were grown by hollow cathode plasma-assisted atomic layer deposition using triethylgallium and N2/H2 plasma. An optimized recipe for GaN film was developed, and the effect of substrate temperature was studied in both self-limiting growth window and thermal decomposition-limited growth region. With increased substrate temperature, film crystallinity improved, and the optical band edge decreased from 3.60 to 3.52 eV. The refractive index and reflectivity in Reststrahlen band increased with the substrate temperature. Compressive strain is observed for both samples, and the surface roughness is observed to increase with the substrate temperature. Despite these temperature dependent material properties, the chemical composition, E1(TO), phonon position, and crystalline phases present in the GaN film were relatively independent from growth temperature

  17. Substrate temperature influence on the properties of GaN thin films grown by hollow-cathode plasma-assisted atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Alevli, Mustafa, E-mail: mustafaalevli@marmara.edu.tr; Gungor, Neşe [Department of Physics, Faculty of Arts and Sciences, Marmara University, Goztepe, 34722 Istanbul (Turkey); Haider, Ali; Kizir, Seda; Leghari, Shahid A.; Biyikli, Necmi, E-mail: biyikli@unam.bilkent.edu.tr [Institute of Materials Science and Nanotechnology, Bilkent University, Bilkent, 06800 Ankara, Turkey and National Nanotechnology Research Center (UNAM), Bilkent University, Bilkent, 06800 Ankara (Turkey)

    2016-01-15

    Gallium nitride films were grown by hollow cathode plasma-assisted atomic layer deposition using triethylgallium and N{sub 2}/H{sub 2} plasma. An optimized recipe for GaN film was developed, and the effect of substrate temperature was studied in both self-limiting growth window and thermal decomposition-limited growth region. With increased substrate temperature, film crystallinity improved, and the optical band edge decreased from 3.60 to 3.52 eV. The refractive index and reflectivity in Reststrahlen band increased with the substrate temperature. Compressive strain is observed for both samples, and the surface roughness is observed to increase with the substrate temperature. Despite these temperature dependent material properties, the chemical composition, E{sub 1}(TO), phonon position, and crystalline phases present in the GaN film were relatively independent from growth temperature.

  18. Synthesis, structural characterization and optical properties of multilayered Yttria-stabilized ZrO2 thin films obtained by aerosol assisted chemical vapour deposition

    International Nuclear Information System (INIS)

    Multilayered Yttria-stabilized zirconium (YSZ) oxide thin films were synthesized by aerosol assisted chemical vapour deposition onto borosilicate glass substrate. The film consisted of a periodic stack of several YSZ layer pairs. Each pair was composed of layers, a few nanometers thick, of the same composition but different density. Optically the multilayered microstructure correspond to alternating layers of high (dense layer) and low (porous layer) refraction index. The microstructure was analysed by electron and atomic force microscopy. Optical properties were evaluated by reflectance spectroscopy, and associated with the cross sectional microstructure of the films. The measured effective refractive index of the films deviates from bulk value. The discrepancy can be explained by the multilayered structure of the film

  19. Direct synthesis of large area graphene on insulating substrate by gallium vapor-assisted chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Katsuhisa, E-mail: k.murakami@bk.tsukuba.ac.jp; Hiyama, Takaki; Kuwajima, Tomoya; Fujita, Jun-ichi [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8573 (Japan); Tsukuba Research Center for Interdisciplinary Materials Science, University of Tsukuba, Tsukuba 305-8573 (Japan); Tanaka, Shunsuke; Hirukawa, Ayaka [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8573 (Japan); Kano, Emi [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8573 (Japan); National Institute for Materials Science, Tsukuba 305-0047 (Japan); Takeguchi, Masaki [National Institute for Materials Science, Tsukuba 305-0047 (Japan)

    2015-03-02

    A single layer of graphene with dimensions of 20 mm × 20 mm was grown directly on an insulating substrate by chemical vapor deposition using Ga vapor catalysts. The graphene layer showed highly homogeneous crystal quality over a large area on the insulating substrate. The crystal quality of the graphene was measured by Raman spectroscopy and was found to improve with increasing Ga vapor density on the reaction area. High-resolution transmission electron microscopy observations showed that the synthesized graphene had a perfect atomic-scale crystal structure within its grains, which ranged in size from 50 nm to 200 nm.

  20. Direct synthesis of large area graphene on insulating substrate by gallium vapor-assisted chemical vapor deposition

    International Nuclear Information System (INIS)

    A single layer of graphene with dimensions of 20 mm × 20 mm was grown directly on an insulating substrate by chemical vapor deposition using Ga vapor catalysts. The graphene layer showed highly homogeneous crystal quality over a large area on the insulating substrate. The crystal quality of the graphene was measured by Raman spectroscopy and was found to improve with increasing Ga vapor density on the reaction area. High-resolution transmission electron microscopy observations showed that the synthesized graphene had a perfect atomic-scale crystal structure within its grains, which ranged in size from 50 nm to 200 nm

  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. The influence of substrate orientation and annealing condition on the properties of LaMnO3 thin films grown by polymer-assisted deposition

    International Nuclear Information System (INIS)

    Highlights: • LaMnO3 thin films were grown by a simple polymer-assisted deposition method. • Increasing the annealing temperature, the TIM of LaMnO3 shifts to high temperature. • Changing the substrate orientation from (1 1 1) to (1 0 0), the TIM of LaMnO3 increases. • It is showed that magnetic order correlates well with an insulator to metal behavior. - Abstract: The epitaxial films of LaMnO3 were fabricated via a simple polymer-assisted deposition method. The effects of substrate orientation and annealing condition on the structure and properties of LaMnO3 films have been investigated. It is found by X-ray diffraction and Raman spectroscopy that increase in the oxygen content results in a decrease in unit cell volume along with a reduction in Jahn–Teller distortion. Besides, with increase in annealing temperature, the resistivity of the film decreases and the insulator–metal transition temperature TIM shifts to higher temperature. The maximum of the resistivity is highly substrate-orientation dependent in the ascending order of (1 0 0) < (1 1 0) < (1 1 1). Furthermore, the TIM of LaMnO3 film increases with the substrate orientation changing from (1 1 1) to (1 0 0). It is shown that magnetic order correlates well with an insulator to metal behavior. All results reveal that the lattice distortion of MnO6 octahedron can be tuned by different annealing condition and the substrate orientation, which can be effective methods to adjust the structure, electrical and magnetic properties of LaMnO3 films

  3. The influence of substrate orientation and annealing condition on the properties of LaMnO{sub 3} thin films grown by polymer-assisted deposition

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Changzheng; Shi, Lei, E-mail: shil@ustc.edu.cn; Zhao, Jiyin; Li, Yang; Zhou, Shiming; Yao, Dan

    2015-10-01

    Highlights: • LaMnO{sub 3} thin films were grown by a simple polymer-assisted deposition method. • Increasing the annealing temperature, the T{sub IM} of LaMnO{sub 3} shifts to high temperature. • Changing the substrate orientation from (1 1 1) to (1 0 0), the T{sub IM} of LaMnO{sub 3} increases. • It is showed that magnetic order correlates well with an insulator to metal behavior. - Abstract: The epitaxial films of LaMnO{sub 3} were fabricated via a simple polymer-assisted deposition method. The effects of substrate orientation and annealing condition on the structure and properties of LaMnO{sub 3} films have been investigated. It is found by X-ray diffraction and Raman spectroscopy that increase in the oxygen content results in a decrease in unit cell volume along with a reduction in Jahn–Teller distortion. Besides, with increase in annealing temperature, the resistivity of the film decreases and the insulator–metal transition temperature T{sub IM} shifts to higher temperature. The maximum of the resistivity is highly substrate-orientation dependent in the ascending order of (1 0 0) < (1 1 0) < (1 1 1). Furthermore, the T{sub IM} of LaMnO{sub 3} film increases with the substrate orientation changing from (1 1 1) to (1 0 0). It is shown that magnetic order correlates well with an insulator to metal behavior. All results reveal that the lattice distortion of MnO{sub 6} octahedron can be tuned by different annealing condition and the substrate orientation, which can be effective methods to adjust the structure, electrical and magnetic properties of LaMnO{sub 3} films.

  4. Pulsed laser deposition assisted fabrication and characterization of Fe–Co nanoparticles embedded in TiN thin film matrix

    International Nuclear Information System (INIS)

    The FeCo material was synthesized in nanoparticle form in a TiN/FeCo/TiN sandwich structure using a pulsed laser deposition (PLD) method. FeCo is significantly cheaper than noble metal based bimetallic materials such as Fe–Pt, Ni–Pd, etc. A Fe0.5 Co0.5 composition was chosen in this study which is based on the local spin-density electronic-structure calculations. The advantage of this structure is in-situ passivation of FeCo nanoparticles by TiN thin films which is highly stable against atmospheric ambient conditions. TiN/FeCo/TiN samples with variable FeCo nanoparticle size were made by changing the number of laser pulses impinging on a chemically synthesized composite FeCo target. By controlling the particle size in the confined layers, it was possible to tune the magnetic properties from superparamagnetic to ferromagnetic in a controlled way. Magnetic hysteresis characteristics below the blocking temperature are consistent with single-domain behavior. - Highlights: ► TiN/FeCo/TiN structure using FeCo nanoparticles (NP) made by pulsed laser deposition ► In-situ passivation of FeCo NP is highly stable against atmospheric conditions. ► FeCo NP size controlled by number of laser pulses impinging on composite FeCo target ► Magnetic properties controlled by particle size in the confined layers

  5. Role of the substrate on the magnetic anisotropy of magnetite thin films grown by ion-assisted deposition

    Science.gov (United States)

    Prieto, Pilar; Prieto, José Emilio; Gargallo-Caballero, Raquel; Marco, José Francisco; de la Figuera, Juan

    2015-12-01

    Magnetite (Fe3O4) thin films were deposited on MgO (0 0 1), SrTiO3 (0 0 1), LaAlO3 (0 0 1) single crystal substrates as well on as silicon and amorphous glass in order to study the effect of the substrate on their magnetic properties, mainly the magnetic anisotropy. We have performed a structural, morphological and compositional characterization by X-ray diffraction, atomic force microscopy and Rutherford backscattering ion channeling in oxygen resonance mode. The magnetic anisotropy has been investigated by vectorial magneto-optical Kerr effect. The results indicate that the magnetic anisotropy is especially influenced by the substrate-induced microstructure. In-plane isotropy and uniaxial anisotropy behavior have been observed on silicon and glass substrates, respectively. The transition between both behaviors depends on grain size. For LaAlO3 substrates, in which the lattice mismatch between the Fe3O4 films and the substrate is significant, a weak in-plane fourfold magnetic anisotropy is induced. However when magnetite is deposited on MgO (0 0 1) and SrTiO3 (0 0 1) substrates, a well-defined fourfold in-plane magnetic anisotropy is observed with easy axes along [1 0 0] and [0 1 0] directions. The magnetic properties on these two latter substrates are similar in terms of magnetic anisotropy and coercive fields.

  6. Vertical La0.7Ca0.3MnO3 nanorods tailored by high magnetic field assisted pulsed laser deposition

    Science.gov (United States)

    Zhang, Kejun; Dai, Jianming; Zhu, Xuebin; Zhu, Xiaoguang; Zuo, Xuzhong; Zhang, Peng; Hu, Ling; Lu, Wenjian; Song, Wenhai; Sheng, Zhigao; Wu, Wenbin; Sun, Yuping; Du, Youwei

    2016-01-01

    La0.7Ca0.3MnO3 (LCMO) thin films on (LaAlO3)0.3(Sr2AlTaO6)0.7 (001) [LSAT (001)] single crystal substrates have been prepared by high magnetic field assisted pulsed laser deposition (HMF-PLD) developed by ourselves. Uniformly sized and vertically aligned nanorod structures can be obtained under an applied high magnetic field above 5 T, and the dimension size of the nanorods can be manipulated by varying the applied magnetic field. It is found that the magnetic anisotropy is strongly correlated to the dimension size of the nanorods. A significantly enhanced low-field magnetoresistance (LFMR) of -36% under 0.5 T at 100 K can be obtained due to the enhanced carrier scattering at the vertical grain boundaries between the nanorods for the LCMO films. The growth mechanism of the nanorods has been also discussed, which can be attributed to the variation of deposition rate, adatom surface diffusion, and nucleation induced by the application of a high magnetic field in the film processing. The successful achievements of such vertical nanorod structures will provide an instructive route to investigate the physical nature of these nanostructures and achieve nanodevice manipulation.

  7. Effect of doping on the Structural and Optical Properties of SnO2 Thin Films fabricated by Aerosol Assisted Chemical Vapor Deposition

    International Nuclear Information System (INIS)

    In order to achieve high conductivity and transmittance of transparent conducting oxide (TCO), we attempted to fabricate Mg doped SnO2 (MgxSn1−xO2) thin films and characterized them for their structural and optical properties. The MgxSn1−xO2 thin films have been deposited on glass substrate by using aero-sole assisted chemical vapor deposition (AACVD). The molar concentration of Mg concentration was changed from 0 to 8%. The confirmation of tetragonal structure and particle size (32 to 87nm) has been calculated of thin films by XRD. The surface roughness is decreased with the increase of the dopant concentration, which has been investigated by atomic force microscopy (AFM). The optical transmission has increased from 54 to 78% and the band gape of pure SnO2 has been found to be in the range of 3.76eV and it is shifted to 3.69eV for 6Wt % Mg doping and then increase on further increasing the Mg doping.

  8. Electrical conduction and dielectric relaxation properties of AlN thin films grown by hollow-cathode plasma-assisted atomic layer deposition

    Science.gov (United States)

    Altuntas, Halit; Bayrak, Turkan; Kizir, Seda; Haider, Ali; Biyikli, Necmi

    2016-07-01

    In this study, aluminum nitride (AlN) thin films were deposited at 200 °C, on p-type silicon substrates utilizing a capacitively coupled hollow-cathode plasma source integrated atomic layer deposition (ALD) reactor. The structural properties of AlN were characterized by grazing incidence x-ray diffraction, by which we confirmed the hexagonal wurtzite single-phase crystalline structure. The films exhibited an optical band edge around ∼5.7 eV. The refractive index and extinction coefficient of the AlN films were measured via a spectroscopic ellipsometer. In addition, to investigate the electrical conduction mechanisms and dielectric properties, Al/AlN/p-Si metal-insulator-semiconductor capacitor structures were fabricated, and current density–voltage and frequency dependent (7 kHz–5 MHz) dielectric constant measurements (within the strong accumulation region) were performed. A peak of dielectric loss was observed at a frequency of 3 MHz and the Cole–Davidson empirical formula was used to determine the relaxation time. It was concluded that the native point defects such as nitrogen vacancies and DX centers formed with the involvement of Si atoms into the AlN layers might have influenced the electrical conduction and dielectric relaxation properties of the plasma-assisted ALD grown AlN films.

  9. Influence of WC-Co substrate pretreatment on diamond film deposition by laser-assisted combustion synthesis.

    Science.gov (United States)

    Veillère, Amélie; Guillemet, Thomas; Xie, Zhi Qiang; Zuhlke, Craig A; Alexander, Dennis R; Silvain, Jean-François; Heintz, Jean-Marc; Chandra, Namas; Lu, Yong Feng

    2011-04-01

    The quality of diamond films deposited on cemented tungsten carbide substrates (WC-Co) is limited by the presence of the cobalt binder. The cobalt in the WC-Co substrates enhances the formation of nondiamond carbon on the substrate surface, resulting in a poor film adhesion and a low diamond quality. In this study, we investigated pretreatments of WC-Co substrates in three different approaches, namely, chemical etching, laser etching, and laser etching followed by acid treatment. The laser produces a periodic surface pattern, thus increasing the roughness and releasing the stress at the interfaces between the substrate and the grown diamond film. Effects of these pretreatments have been analyzed in terms of microstructure and cobalt content. Raman spectroscopy was conducted to characterize both the diamond quality and compressive residual stress in the films. PMID:21462974

  10. Nano-Borides and Silicide Dispersed Composite Coating on AISI 304 Stainless Steel by Laser-Assisted HVOF Spray Deposition

    Science.gov (United States)

    Sharma, Prashant; Majumdar, Jyotsna Dutta

    2014-10-01

    The study concerned a detailed microstructural investigation of nano-borides (Cr2B and Ni3B) and nano-silicide (Ni2Si) dispersed γ-nickel composite coating on AISI 304 stainless steel by HVOF spray deposition of the NiCrBSi precursor powder and subsequent laser surface melting. A continuous wave diode laser with an applied power of 3 kW and scan speed of 20 mm/s in argon shroud was employed. The characterization of the surface in terms of microstructure, microtexture, phases, and composition were carried out and compared with the as-coated (high-velocity oxy-fuel sprayed) surface. Laser surface melting led to homogenization and refinement of microstructures with the formation of few nano-silicides of nickel along with nano-borides of nickel and chromium (Ni3B, Cr2B, and Cr2B3). A detailed microtexture analysis showed the presence of no specific texture in the as-sprayed and laser-melted surface of Cr2B and Ni3B phases. The average microhardness was improved to 750-900 VHN as compared to 250 VHN of the as-received substrate. Laser surface melting improved the microhardness further to as high as 1400 VHN due to refinement of microstructure and the presence of silicides.

  11. 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.

  12. Wide band gap semiconductor templates

    Energy Technology Data Exchange (ETDEWEB)

    Arendt, Paul N. (Los Alamos, NM); Stan, Liliana (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM); DePaula, Raymond F. (Santa Fe, NM); Usov, Igor O. (Los Alamos, NM)

    2010-12-14

    The present invention relates to a thin film structure based on an epitaxial (111)-oriented rare earth-Group IVB oxide on the cubic (001) MgO terminated surface and the ion-beam-assisted deposition ("IBAD") techniques that are amendable to be over coated by semiconductors with hexagonal crystal structures. The IBAD magnesium oxide ("MgO") technology, in conjunction with certain template materials, is used to fabricate the desired thin film array. Similarly, IBAD MgO with appropriate template layers can be used for semiconductors with cubic type crystal structures.

  13. Selective synthesis of large diameter, highly conductive and high density single-walled carbon nanotubes by a thiophene-assisted chemical vapor deposition method on transparent substrates

    Science.gov (United States)

    Li, Jinghua; Otsuka, Keigo; Zhang, Xiao; Maruyama, Shigeo; Liu, Jie

    2016-07-01

    Selective synthesis of single-walled carbon nanotubes (SWNTs) with controlled properties is an important research topic for SWNT studies. Here we report a thiophene-assisted chemical vapor deposition (CVD) method to directly grow highly conductive SWNT thin films on substrates, including transparent ones. By adding low concentration thiophene into the carbon feedstock (ethanol), the as-prepared carbon nanotubes demonstrate an obvious up-shift in the diameter distribution while the single-walled structure is still retained. In the proposed mechanism, the change in the diameter is sourced from the increase in the carbon yield induced by the sulfur-containing compound. Such SWNTs are found to possess high conductivity with 95% SWNTs demonstrating on/off ratios lower than 100 in transistors. More importantly, it is further demonstrated that this method can be used to directly synthesize dense SWNT networks on transparent substrates which can be utilized as transparent conductive films (TCFs) with very high transparency. Such TCFs can be applied to fabricate a light modulating window as a proof-of-concept. The present work provides important insights into the growth mechanism of SWNTs and great potential for the preparation of TCFs with high scalability, easy operation and low cost.Selective synthesis of single-walled carbon nanotubes (SWNTs) with controlled properties is an important research topic for SWNT studies. Here we report a thiophene-assisted chemical vapor deposition (CVD) method to directly grow highly conductive SWNT thin films on substrates, including transparent ones. By adding low concentration thiophene into the carbon feedstock (ethanol), the as-prepared carbon nanotubes demonstrate an obvious up-shift in the diameter distribution while the single-walled structure is still retained. In the proposed mechanism, the change in the diameter is sourced from the increase in the carbon yield induced by the sulfur-containing compound. Such SWNTs are found to

  14. Process diagnostics and monitoring using the multipole resonance probe in an inhomogeneous plasma for ion-assisted deposition of optical coatings

    International Nuclear Information System (INIS)

    The application of a multipole resonance probe (MRP) for diagnostic and monitoring purposes in a plasma ion-assisted deposition (PIAD) process is reported. Recently, the MRP was proposed as an economical and industry compatible plasma diagnostic device (Lapke et al 2011 Plasma Sources Sci. Technol. 20 042001). The major advantages of the MRP are its robustness against dielectric coating and its high sensitivity to measure the electron density. The PIAD process investigated is driven by the advanced plasma source (APS), which generates an ion beam in the deposition chamber for the production of high performance optical coatings. With a background neutral pressure of p0 ∼ 20 mPa the plasma expands from the source region into the recipient, leading to an inhomogeneous spatial distribution. Electron density and electron temperature vary over the distance from substrate (ne ∼ 109 cm−3 and Te,eff ∼ 2 eV) to the APS (ne ≳ 1012 cm−3 and Te,eff ∼ 20 eV) (Harhausen et al 2012 Plasma Sources Sci. Technol. 21 035012). This huge variation of the plasma parameters represents a big challenge for plasma diagnostics to operate precisely for all plasma conditions. The results obtained by the MRP are compared to those from a Langmuir probe chosen as reference diagnostics. It is demonstrated that the MRP is suited for the characterization of the PIAD plasma as well as for electron density monitoring. The latter aspect offers the possibility to develop new control schemes for complex industrial plasma environments. (paper)

  15. Effects of SiO_2 and TiO_2 on resistance stabilities of flexible indium-tin-oxide films prepared by ion assisted deposition

    Institute of Scientific and Technical Information of China (English)

    LI Yuqiong; YU Zhinong; WANG Wuyu; FAN Yuejiang; DING Zhao; XUE Wei

    2009-01-01

    Inorganic buffer layers such as SiO_2 or TiO_2 and transparent conductive indium-tin-oxide (ITO) films were prepared on polyethylene terephthalate (PET) substrates by ion assisted deposition (LAD) at room temperature, and the effects of SiO_2 and TiO_2 on the bending resis-tance performance of flexible ITO films were investigated. The results show that ITO films with SiO_2 or TiO_2 buffer layer have better resis-tance stabihties compared to ones without the buffer layer when the ITO films are inwards bent at a bending radius more than 1.2 cm and when the ITO films are outwards bent at a bending radius from 0.8 cm to 1.2 cm. ITO films with SiO_2 buffer layer have better resistance sta-bilities compared to ones with TiO_2 buffer layer after the ITO Films are bent several hundreds of cycles at the same bending radius, for the adhesion of SiO_2 is stronger than that of TiO_2. The compressive stress resulted from inward bending leads to the formation of more defects in the ITO films compared with the tensile stress arising from outward bending. SiO_2 and TiO_2 buffer layers can effectively improve the crystal-linity of ITO films in (400), (440) directions.

  16. Microstructural and optical properties of transparent conductive ZnO : Al : Mo films deposited by template-assisted sol–gel method

    Indian Academy of Sciences (India)

    H-Y He; J-F Huang; Z He; J Lu; Q Shen

    2014-05-01

    Transparent conductive ZnO : Al : Mo films with a molar ratio of Zn : Al : Mo = 99 : 0.99 : 0.01 were deposited on quartz glass substrate by a template-assisted sol-gel process and characterized by X-ray diffraction, atomic force microscopy, scanning electron microscopy, and UV–Vis and luminescent spectrophotometries. The four types of organic template have induced nanowire morphology with varying aspect ratio. Dip coating in one constant positive and reverse direction causes the parallel array of ZnO : Al : Mo nanowires on the quartz glass substrate. Long and parallel arrayed nanowire films show obviously blue shifts and enhanced transmittances in the UV-Vis light range. The PEG-1000 and PEG-2000 have optimal effects among four templates as constant weight content is used. The films show strong ultraviolet, violet and bluish violet emissions. The templates also lead to overall thicker film and more native defect and thereby remarkably enhancing photoluminescence of the films. Long chain organic template can be used to optimize the optical properties of the doped ZnO film.

  17. Aligned synthesis of multi-walled carbon nanotubes with high purity by aerosol assisted chemical vapor deposition: Effect of water vapor

    International Nuclear Information System (INIS)

    Aligned multi-walled carbon nanotubes (MWCNTs) with high purity and bulk yield were achieved on a silicon substrate by an aerosol-assisted chemical vapor deposition. The introduction of specific amounts of water vapor played a key role in in situ controlling the purity and surface defects of the nanotubes. The morphology, surface quality and structure of MWCNTs were characterized by secondary and backscattered electron imaging in a field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM). Crystallinity and defects of the MWCNTs' were investigated by high-resolution transmission electron microscopy (HRTEM) and Raman spectroscopy. In this work, water vapor was found to provide a weak oxidative environment, which enhanced and purified the MWCNTs' growth. However, excessive water vapor would inhibit the MWCNTs growth with a poor surface quality. In addition, it has been found that the surface morphology of the CNTs can be modified intentionally through producing some surface defects by tuning the amount of the water vapor, which may offer more nucleation sites on the chemically inert CNT surface for various applications such as catalyst support.

  18. Nano-sized Fe-metal catalyst on ZnO-SiO2: (photo-assisted deposition and impregnation) Synthesis routes and nanostructure characterization

    International Nuclear Information System (INIS)

    Highlights: → We prepared Fe/ZnO-SiO2 by two methods. → We tested photocatalytic activity for degradation of methylene blue dye. → We controlled band gap and size. → We found activity of Fe/ZnO-SiO2 prepared by PAD is hightest photocatalytic activity. - Abstract: A nano-sized Fe metal on ZnO-SiO2 was synthesized using the photo-assisted deposition (PAD) and impregnation routes. The obtained samples were characterized by a series of techniques including X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy, N2 adsorption, extended X-ray absorption fine structure (EXAFS), and transmission electron microscopy (TEM). Photocatalytic reactivity using Fe-ZnO-SiO2 catalysts under visible-light condition on the degradation of methylene blue dye was evaluated. The results of characterization reveal, a notable photocatalytic activity of PAD:Fe-ZnO-SiO2 which was about 9 and 12 times higher than that of Img:Fe-ZnO-SiO2 and ZnO-SiO2, respectively.

  19. Array of Cu2O nano-columns fabricated by oblique angle sputter deposition and their application in photo-assisted proton reduction

    International Nuclear Information System (INIS)

    Nano-columnar arrays of Cu2O were grown by the oblique angle sputter deposition technique based on the self-shadowing principle. The as-grown nano-columnar samples are oriented along (111) direction, and they are highly transmitting in the visible range with a low reflectance. In this work, we show the photo-electrochemical activity of nano-columnar array of Cu2O, which shows a higher (∼25%) photocurrent density and a two-fold enhancement in the incident-to-photon conversion efficiency as compared to continuous thin film of Cu2O in photo-assisted proton reduction type reaction. The improvement in electrochemical activity of nano-columnar Cu2O photocathode can be attributed to the change in morphology, crystal structure, as well as electrical property, which shows a higher degree of band bending, increased donor carrier (e−) density and lower width of space charge region as revealed by capacitance measurements and Mott-Schottky analysis

  20. 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

  1. 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

  2. Nonlinear optical studies on 4-(ferrocenylmethylimino)-2-hydroxy-benzoic acid thin films deposited by matrix-assisted pulsed laser evaporation (MAPLE)

    Science.gov (United States)

    Matei, Andreea; Marinescu, Maria; Constantinescu, Catalin; Ion, Valentin; Mitu, Bogdana; Ionita, Iulian; Dinescu, Maria; Emandi, Ana

    2016-06-01

    We present results on a new, laboratory synthesized ferrocene-derivative, i.e. 4-(ferrocenylmethylimino)-2-hydroxy-benzoic acid. Thin films with controlled thickness are deposited by matrix-assisted pulsed laser evaporation (MAPLE), on quartz and silicon substrates, with the aim of evaluating the nonlinear optical properties for potential optoelectronic applications. Dimethyl sulfoxide was used as matrix, with 1% wt. concentration of the guest compound. The frozen target is irradiated by using a Nd:YAG laser (4ω/266 nm, 7 ns pulse duration, 10 Hz repetition rate), at low fluences ranging from 0.1 to 1 J/cm2. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) are used to probe the surface morphology of the films. Fourier transform infrared (FTIR) and Raman spectroscopy reveal similar structure of the thin film material when compared to the starting material. The optical properties of the thin films are investigated by spectroscopic-ellipsometry (SE), and the refractive index dependence with respect to temperature is studied. The second harmonic generation (SHG) potential is assessed by using a femtosecond Ti:sapphire laser (800 nm, 60-100 fs pulse duration, 80 MHz repetition rate), at 200 mW maximum output power, revealing that the SHG signal intensity is strongly influenced by the films' thickness.

  3. Transport properties and microstructure of La0.7Sr0.3MnO3 nanocrystalline thin films grown by polymer-assisted chemical solution deposition

    Institute of Scientific and Technical Information of China (English)

    Min Zhang; Li Lv; Zhantao Wei; Xinsheng Yang; Xin Zhang

    2014-01-01

    Perovskite-based materials can be widely used in the aerospace and transportation field. Perovskite man-ganese oxides La0.7Sr0.3MnO3 (LSMO) thin films were grown on LaAlO3 (100) and Si (100) single crystal sub-strates by the polymer-assisted chemical solution deposi-tion (PACSD) method. Electronic transport behavior, microstructure, and magnetoresistance (MR) of LSMO thin films on different substrates were investigated. The resis-tance of LSMO films fabricated on LaAlO3 substrates is smaller than that on the Si substrates. The magnetic field reduces resistance of LSMO films both on Si and LAO in the wide temperature region, when the insulator-metal transition temperature shifts to higher temperature. The low-field magnetoresistance of LSMO films on Si in low temperature range at 1 T is larger than that of LSMO films on LAO. However, the MR of LSMO film on LAO films at room-temperature is about 5.17%. The thin films are smooth and dense with uniform nanocrystal size grain. These results demonstrate that PACSD is an effective technique for producing high quality LSMO films, which is significant to improve the magnetic properties and the application of automotive sensor.

  4. High-Jc YBa2Cu3O7−δ superconducting film grown by laser-assisted chemical vapor deposition using a single liquid source and its microstructure

    International Nuclear Information System (INIS)

    A YBa2Cu3O7-δ (YBCO) film was prepared on a multilayer-coated Hastelloy C276 substrate by laser-assisted metalorganic chemical vapor deposition using a single liquid source precursor. A c-axis-oriented YBCO film was grown epitaxially on a (100) CeO2 layer at a deposition rate of 11 μm h−1. A screw dislocation and stacking faults were observed in the cross-section of the YBCO film. The critical current density of the YBCO film reached 2.7 MA cm−2. (paper)

  5. Preparation of highly photocatalytic active CdS/TiO2 nanocomposites by combining chemical bath deposition and microwave-assisted hydrothermal synthesis

    International Nuclear Information System (INIS)

    CdS/TiO2 nanocomposites were prepared from Cd and Ti (1:1 M ratio) using cetyltrimethylammonium bromide by a two-step chemical bath deposition (CBD) and microwave-assisted hydrothermal synthesis (MAHS) method. A series of nanocomposites with different morphologies and activities were prepared by varying the reaction time in the MAHS (2, 4, and 6 h). The crystal structure, morphology, and surface physicochemical properties of the nanocomposites were characterized by X-ray diffraction, UV–visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and N2 adsorption–desorption measurements. The results show that the CdS/TiO2 nanocomposites were composed of anatase TiO2 and hexagonal CdS phases with strong absorption in the visible region. The surface morphologies changed slightly with increasing microwave irradiation time, while the Brunauer–Emmett–Teller surface area increased remarkably. The photocatalytic degradation of methyl orange (MO) was investigated under UV light and simulated sunlight irradiation. The photocatalytic activity of the CdS/TiO2 (6 h) composites prepared by the MAHS method was higher than those of CdS, P25, and other CdS/TiO2 nanocomposites. The CdS/TiO2 (6 h) nanocomposites significantly affected the UV and microwave-assisted photocatalytic degradation of different dyes. To elucidate the photocatalytic reaction mechanism for the CdS/TiO2 nanocomposites, controlled experiments were performed by adding different radical scavengers. - Graphical abstract: CdS/TiO2 nanocomposites were prepared using CTAB by CBD combined with MAHS method. In addition, with increasing microwave irradiation time, the morphology of CdS/TiO2 changed from popcorn-like to wedge-like structure. - Highlights: • The CdS/TiO2 was prepared by CBD combined with MAHS two-step method under CTAB. • The morphologies of as-samples were different with the time of microwave increased. • Compared with TiO2, as-samples show

  6. Preparation of highly photocatalytic active CdS/TiO{sub 2} nanocomposites by combining chemical bath deposition and microwave-assisted hydrothermal synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Li, Li, E-mail: qqhrll@163.com [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Key Laboratory of Composite Modified Material of Colleges in Heilongjiang Province, Qiqihar 161006 (China); Wang, Lili [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Hu, Tianyu [College of Environment and Resources, Jilin University, Changchun 130024 (China); Zhang, Wenzhi; Zhang, Xiuli; Chen, Xi [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China)

    2014-10-15

    CdS/TiO{sub 2} nanocomposites were prepared from Cd and Ti (1:1 M ratio) using cetyltrimethylammonium bromide by a two-step chemical bath deposition (CBD) and microwave-assisted hydrothermal synthesis (MAHS) method. A series of nanocomposites with different morphologies and activities were prepared by varying the reaction time in the MAHS (2, 4, and 6 h). The crystal structure, morphology, and surface physicochemical properties of the nanocomposites were characterized by X-ray diffraction, UV–visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and N{sub 2} adsorption–desorption measurements. The results show that the CdS/TiO{sub 2} nanocomposites were composed of anatase TiO{sub 2} and hexagonal CdS phases with strong absorption in the visible region. The surface morphologies changed slightly with increasing microwave irradiation time, while the Brunauer–Emmett–Teller surface area increased remarkably. The photocatalytic degradation of methyl orange (MO) was investigated under UV light and simulated sunlight irradiation. The photocatalytic activity of the CdS/TiO{sub 2} (6 h) composites prepared by the MAHS method was higher than those of CdS, P25, and other CdS/TiO{sub 2} nanocomposites. The CdS/TiO{sub 2} (6 h) nanocomposites significantly affected the UV and microwave-assisted photocatalytic degradation of different dyes. To elucidate the photocatalytic reaction mechanism for the CdS/TiO{sub 2} nanocomposites, controlled experiments were performed by adding different radical scavengers. - Graphical abstract: CdS/TiO{sub 2} nanocomposites were prepared using CTAB by CBD combined with MAHS method. In addition, with increasing microwave irradiation time, the morphology of CdS/TiO{sub 2} changed from popcorn-like to wedge-like structure. - Highlights: • The CdS/TiO{sub 2} was prepared by CBD combined with MAHS two-step method under CTAB. • The morphologies of as-samples were different with the time of

  7. Single and multi-layered core-shell structures based on ZnO nanorods obtained by aerosol assisted chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Sáenz-Trevizo, A.; Amézaga-Madrid, P.; Pizá-Ruiz, P.; Antúnez-Flores, W.; Ornelas-Gutiérrez, C.; Miki-Yoshida, M., E-mail: mario.miki@cimav.edu.mx

    2015-07-15

    Core–shell nanorod structures were prepared by a sequential synthesis using an aerosol assisted chemical vapor deposition technique. Several samples consisting of ZnO nanorods were initially grown over TiO{sub 2} film-coated borosilicate glass substrates, following the synthesis conditions reported elsewhere. Later on, a uniform layer consisting of individual Al, Ni, Ti or Fe oxides was grown onto ZnO nanorod samples forming the so-called single MO{sub x}/ZnO nanorod core–shell structures, where MO{sub x} was the metal oxide shell. Additionally, a three-layer core–shell sample was developed by growing Fe, Ti and Fe oxides alternately, onto the ZnO nanorods. The microstructure of the core–shell materials was characterized by grazing incidence X-ray diffraction, scanning and transmission electron microscopy. Energy dispersive X-ray spectroscopy was employed to corroborate the formation of different metal oxides. X-ray diffraction outcomes for single core–shell structures showed solely the presence of ZnO as wurtzite and TiO{sub 2} as anatase. For the multi-layered shell sample, the existence of Fe{sub 2}O{sub 3} as hematite was also detected. Morphological observations suggested the existence of an outer material grown onto the nanorods and further microstructural analysis by HR-STEM confirmed the development of core–shell structures in all cases. These studies also showed that the individual Al, Fe, Ni and Ti oxide layers are amorphous; an observation that matched with X-ray diffraction analysis where no apparent extra oxides were detected. For the multi-layered sample, the development of a shell consisting of three different oxide layers onto the nanorods was found. Overall results showed that no alteration in the primary ZnO core was produced during the growth of the shells, indicating that the deposition technique used herein was and it is suitable for the synthesis of homogeneous and complex nanomaterials high in quality and purity. In addition

  8. Single and multi-layered core-shell structures based on ZnO nanorods obtained by aerosol assisted chemical vapor deposition

    International Nuclear Information System (INIS)

    Core–shell nanorod structures were prepared by a sequential synthesis using an aerosol assisted chemical vapor deposition technique. Several samples consisting of ZnO nanorods were initially grown over TiO2 film-coated borosilicate glass substrates, following the synthesis conditions reported elsewhere. Later on, a uniform layer consisting of individual Al, Ni, Ti or Fe oxides was grown onto ZnO nanorod samples forming the so-called single MOx/ZnO nanorod core–shell structures, where MOx was the metal oxide shell. Additionally, a three-layer core–shell sample was developed by growing Fe, Ti and Fe oxides alternately, onto the ZnO nanorods. The microstructure of the core–shell materials was characterized by grazing incidence X-ray diffraction, scanning and transmission electron microscopy. Energy dispersive X-ray spectroscopy was employed to corroborate the formation of different metal oxides. X-ray diffraction outcomes for single core–shell structures showed solely the presence of ZnO as wurtzite and TiO2 as anatase. For the multi-layered shell sample, the existence of Fe2O3 as hematite was also detected. Morphological observations suggested the existence of an outer material grown onto the nanorods and further microstructural analysis by HR-STEM confirmed the development of core–shell structures in all cases. These studies also showed that the individual Al, Fe, Ni and Ti oxide layers are amorphous; an observation that matched with X-ray diffraction analysis where no apparent extra oxides were detected. For the multi-layered sample, the development of a shell consisting of three different oxide layers onto the nanorods was found. Overall results showed that no alteration in the primary ZnO core was produced during the growth of the shells, indicating that the deposition technique used herein was and it is suitable for the synthesis of homogeneous and complex nanomaterials high in quality and purity. In addition, materials absorptance determined from

  9. Fabrication of Y1-xRE xBa2Cu3O y films on single crystalline substrates and IBAD buffered metallic tapes by advanced TFA-MOD process

    International Nuclear Information System (INIS)

    We fabricated Y1-xSm xBa2Cu3O y and YSm xBa2Cu3O y (YSmBCO) films on SrTiO3 (STO) single crystalline substrates and IBAD buffered metallic tapes (PLD-CeO2/IBAD-GZO/Hastelloy) by the advanced TFA-MOD process by mixing TFA salts of Y, Sm, Ba and Cu naphthenate, and tried to improve the superconductivity properties compared with those of the pure YBa2Cu3O7-δ (YBCO). As a result, J c values of Y1-xSm xBa2Cu3O y films with x = 0.05 or 0.3, which were fabricated on STO substrates, were improved under the high magnetic fields compared with those of the YBCO without substitution. However, Sm segregation was detected near the STO substrate which was obtained by the TEM-EDS (transmission electron microscopy-energy-dispersive X-ray spectroscopy) analysis. On the other hand, Y1-xSm xBa2Cu3O y films with x = 0.05 and YSm xBa2Cu3O y films with x = 0.3, which were fabricated on IBAD buffered metallic substrates, also improved I c value under the high magnetic fields compared with those of the YBCO without substitution. Moreover, from the TEM-EDS analysis, Y or Sm segregation was not found. The difference in the Sm segregation behavior between the film on STO and CeO2 buffered substrates could be explained by the difference in the ratios of the misfit parameters between YBCO/substrate and SmBCO/substrate. Additionally, it was considered that the above phenomenon might be unique in the MOD system and could not be observed in the PLD system, because of the difference in the crystal growth mechanism. In the film of YSm0.3Ba2Cu3O y, we observed the grains of (Y, Sm)2O3 and (Y, Sm)2Cu2O5 by TEM observation. We will further investigate the origin of pinning centers

  10. Tuning the metal-insulator transition via epitaxial strain and Co doping in NdNiO{sub 3} thin films grown by polymer-assisted deposition

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Dan; Shi, Lei, E-mail: shil@ustc.edu.cn; Zhou, Shiming; Liu, Haifeng; Zhao, Jiyin; Li, Yang [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Wang, Yang [Instrumental Analysis Center, Hefei University of Technology, Hefei, Anhui 230009 (China)

    2016-01-21

    The epitaxial NdNi{sub 1-x}Co{sub x}O{sub 3} (0 ≤ x ≤ 0.10) thin films on (001) LaAlO{sub 3} and (001) SrTiO{sub 3} substrates were grown by a simple polymer-assisted deposition technique. The co-function of the epitaxial strain and Co doping on the metal-insulator transition in perovskite nickelate NdNiO{sub 3} thin films is investigated. X-ray diffraction and scanning electron microscopy reveal that the as-prepared thin films exhibit good crystallinity and heteroepitaxy. The temperature dependent resistivities of the thin films indicate that both the epitaxial strain and Co doping lower the metal-insulator (MI) transition temperature, which can be treated as a way to tune the MI transition. Furthermore, under the investigated Co-doping levels, the MI transition temperature (T{sub MI}) shifts to low temperatures with Co content increasing under both compressive and tensile strain, and the more distinction is in the former situation. When x is increased up to 0.10, the insulating phase is completely suppressed under the compressive strain. With the strain increases from compression to tension, the resistivities are enhanced both in the metal and insulating regions. However, the Co-doping effect on the resistivity shows a more complex situation. As Co content x increases from zero to 0.10, the resistivities are reduced both in the metal and insulating regions under the tensile strain, whereas they are enhanced in the high-temperature metal region under the compressive strain. Based on the temperature dependent resistivity in the metal regions, it is suggested that the electron-phonon coupling in the films becomes weaker with the increase of both the strain and Co-doping.

  11. Effect of O2 gas partial pressure on mechanical properties of Al2O3 films deposited by inductively coupled plasma-assisted radio frequency magnetron sputtering

    International Nuclear Information System (INIS)

    The effect of O2 partial pressure on the mechanical properties of Al2O3 films is studied. Using films prepared by inductively coupled plasma-assisted radio frequency magnetron sputtering, the deposition rate of Al2O3 decreases rapidly when oxygen is added to the argon sputtering gas. The internal stresses in the films are compressive, with magnitude decreasing steeply from 1.6 GPa for films sputtered in pure argon gas to 0.5 GPa for films sputtered in argon gas at an O2 partial pressure of 0.89 × 10−2 Pa. Stress increases gradually with increasing O2 partial pressure. Using a nanoindentation tester with a Berkovich indenter, film hardness was measured to be about 14 GPa for films sputtered in pure argon gas. Hardness decreases rapidly on the addition of O2 gas, but increases when the O2 partial pressure is increased. Adhesion, measured using a Vickers microhardness tester, increases with increasing O2 partial pressure. Electron probe microanalyzer measurements reveal that the argon content of films decreases with increasing O2 partial pressure, whereas the O to Al composition ratio increases from 1.15 for films sputtered in pure argon gas to 1.5 for films sputtered in argon gas at O2 partial pressures over 2.4 × 10−2 Pa. X-ray diffraction measurements reveal that films sputtered in pure argon gas have an amorphous crystal structure, whereas γ-Al2O3 is produced for films sputtered in argon gas with added O2 gas. Atomic force microscopy observations reveal that the surface topography of sputtered Al2O3 films changes from spherical to needlelike as O2 partial pressure is increased. Fracture cross sections of the films observed by scanning electron microscopy reveal that the film morphology exhibits no discernible features at all O2 partial pressures.

  12. Nanodots and microwires of ZrO2 grown on LaAlO3 by photo-assisted metal-organic chemical vapor deposition

    Science.gov (United States)

    Feng, Guo; Xin-Sheng, Wang; Shi-Wei, Zhuang; Guo-Xing, Li; Bao-Lin, Zhang; Pen-Chu, Chou

    2016-02-01

    ZrO2 nanodots are successfully prepared on LaAlO3 (LAO) (100) substrates by photo-assisted metal-organic chemical vapor deposition (MOCVD). It is indicated that the sizes and densities of ZrO2 nanodots are controllable by modulating the growth temperature, oxygen partial pressure, and growth time. Meanwhile, the microwires are observed on the surfaces of substrates. It is found that there is an obvious competitive relationship between the nanodots and the microwires. In a growth temperature range from 500 °C to 660 °C, the microwires turn longest and widest at 600 °C, but in contrast, the nanodots grow into the smallest diameter at 600 °C. This phenomenon could be illustrated by the energy barrier, decomposition rate of Zr(tmhd)4, and mobility of atoms. In addition, growth time or oxygen partial pressure also affects the competitive relationship between the nanodots and the microwires. With increasing oxygen partial pressure from 451 Pa to 752 Pa, the microwires gradually grow larger while the nanodots become smaller. To further achieve the controllable growth, the coarsening effect of ZrO2 is modified by varying the growth time, and the experimental results show that the coarsening effect of microwires is higher than that of nanodots by increasing the growth time to quickly minimize ZrO2 energy density. Project supported by the National Natural Science Foundation of China (Grant No. 51002063) and the International Science and Technology Cooperation Program of Science and Technology Bureau of Changchun City, China (Grant No. 12ZX68).

  13. Tuning the metal-insulator transition via epitaxial strain and Co doping in NdNiO3 thin films grown by polymer-assisted deposition

    International Nuclear Information System (INIS)

    The epitaxial NdNi1-xCoxO3 (0 ≤ x ≤ 0.10) thin films on (001) LaAlO3 and (001) SrTiO3 substrates were grown by a simple polymer-assisted deposition technique. The co-function of the epitaxial strain and Co doping on the metal-insulator transition in perovskite nickelate NdNiO3 thin films is investigated. X-ray diffraction and scanning electron microscopy reveal that the as-prepared thin films exhibit good crystallinity and heteroepitaxy. The temperature dependent resistivities of the thin films indicate that both the epitaxial strain and Co doping lower the metal-insulator (MI) transition temperature, which can be treated as a way to tune the MI transition. Furthermore, under the investigated Co-doping levels, the MI transition temperature (TMI) shifts to low temperatures with Co content increasing under both compressive and tensile strain, and the more distinction is in the former situation. When x is increased up to 0.10, the insulating phase is completely suppressed under the compressive strain. With the strain increases from compression to tension, the resistivities are enhanced both in the metal and insulating regions. However, the Co-doping effect on the resistivity shows a more complex situation. As Co content x increases from zero to 0.10, the resistivities are reduced both in the metal and insulating regions under the tensile strain, whereas they are enhanced in the high-temperature metal region under the compressive strain. Based on the temperature dependent resistivity in the metal regions, it is suggested that the electron-phonon coupling in the films becomes weaker with the increase of both the strain and Co-doping

  14. Friction and Wear Properties of Selected Solid Lubricating Films. Part 3; Magnetron-Sputtered and Plasma-Assisted, Chemical-Vapor-Deposited Diamondlike Carbon Films

    Science.gov (United States)

    Miyoshi, Kazuhisa; Iwaki, Masanori; Gotoh, Kenichi; Obara, Shingo; Imagawa, Kichiro

    2000-01-01

    To evaluate commercially developed dry solid film lubricants for aerospace bearing applications, an investigation was conducted to examine the friction and wear behavior of magnetron-sputtered diamondlike carbon (MS DLC) and plasma-assisted, chemical-vapor-deposited diamondlike carbon (PACVD DLC) films in sliding contact with 6-mm-diameter American Iron and Steel Institute (AISI) 440C stainless steel balls. Unidirectional sliding friction experiments were conducted with a load of 5.9 N (600 g), a mean Hertzian contact pressure of 0.79 GPa (maximum Hertzian contact pressure of L-2 GPa), and a sliding velocity of 0.2 m/s. The experiments were conducted at room temperature in three environments: ultrahigh vacuum (vacuum pressure, 7x10(exp -7) Pa), humid air (relative humidity, approx.20 percent), and dry nitrogen (relative humidity, films were characterized by scanning electron microscopy, energy-dispersive x-ray spectroscopy, and surface profilometry. Marked differences in the friction and wear of the DLC films investigated herein resulted from the environmental conditions. The main criteria for judging the performance of the DLC films were coefficient of friction and wear rate, which had to be less than 0.3 and on the order of 10(exp -6) cu mm/N-m or less, respectively. MS DLC films and PACVD DLC films met the criteria in humid air and dry nitrogen but failed in ultrahigh vacuum, where the coefficients of friction were greater than the criterion, 0.3. In sliding contact with 440C stainless steel balls in all three environments the PACVD DLC films exhibited better tribological performance (i.e., lower friction and wear) than the MS DLC films. All sliding involved adhesive transfer of wear materials: transfer of DLC wear debris to the counterpart 440C stainless steel and transfer of 440C stainless steel wear debris to the counterpart DLC film.

  15. Design and fabrication of a computer-controlled rapid-isothermal-processing-assisted metalorganic chemical-vapor-deposition system for high-temperature superconducting thin films and related materials

    International Nuclear Information System (INIS)

    Metalorganic chemical vapor deposition (MOCVD) is an ideal technique for the development of several high-temperature superconducting products. For the development of certain electronic products, reduced thermal budget (product of processing time and temperature) processing is a necessity. Rapid isothermal processing (RIP) based on incoherent light as the source of energy is emerging as a key reduced thermal budget processing technique. Driven by potential applications a RIP-assisted MOCVD system has been designed and fabricated for the deposition of high-temperature superconducting thin films and related materials. Experimental details of the RIP-assisted MOCVD system are described. The results of Y-Ba-Cu-O (YBCO) films deposited on yttrium-stabilized zirconia, SrTiO3, and MgO substrates are also presented. In the case of SrTiO3 substrates, YBCO films were deposited at a substrate temperature of 640 degree C. The onset temperature is 91 K and the transition temperature Tc is observed at 89 K. The value of zero-magnetic-field current density Jc at 77 K is 1.5x106 A/cm2. The results presented represent the best values of transition temperature Tc, c-axis orientation, and zero magnetic-field critical current density Jc values for the thermal budget used in the growth of the superconducting thin films by MOCVD

  16. Assistência de ar e volumes de aplicação na deposição de calda e no controle do arroz vermelho (Oryza sativa L. Air assistance and volume of application in spray deposition and in red rice control (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Leopoldo L. S. Vigano

    2007-12-01

    Full Text Available O trabalho teve como objetivo avaliar o efeito da assistência de ar junto à barra pulverizadora e de três volumes de pulverização na dessecação e deposição da calda em arroz vermelho, sob cultivo de nabo forrageiro, em áreas de recuperação de várzeas, utilizando o herbicida paraquat e o corante Azul Brilhante, respectivamente. Os volumes de pulverização foram 100; 200 e 300 L ha-1 da solução aquosa, contendo corante alimentício (1.500 mg L-1. Com ou sem a assistência de ar junto à barra, foram utilizadas pontas de pulverização de jato plano tipo AXI 110015 à pressão de 117,3 kPa, AXI 11002 e AXI 11003 a 276 kPa. A avaliação da deposição da pulverização deu-se em folhas de plantas de arroz vermelho. Os maiores volumes (200 e 300 L ha-1 pulverizados com a assistência de ar junto à barra pulverizadora proporcionaram maiores depósitos do corante em relação ao volume de 100 L ha-1. Não foram constatadas diferenças na deposição do corante para os volumes pulverizados, sem a assistência de ar junto à barra, tampouco entre os volumes de 200 e 300 L ha-1 com a assistência de ar junto à barra. As maiores percentagens de controle do arroz vermelho foram obtidas com a assistência de ar junto à barra, independentemente do volume pulverizado, equivalendo-se ao controle obtido com 300 L ha-1, sem o uso dessa tecnologia.The aim of this research was to evaluate the effect of air-assistance on spraying at three volumes in spray deposition and control of red rice under fodder radish cultivation. To evaluate the control of this weed and spray deposition were used paraquat herbicide and a Brilliant Blue dye, respectively. The three spraying volumes were 100, 200 and 300 L ha-1, using a tracer dye at 1,500 mg L-1. Both solutions and volumes were sprayed with flat fan nozzles AXI 110015 at 117.3 kPa, AXI 11002 and AXI 11003 at 276 kPa, respectively, with and without air-assistance on the boom. The evaluation of deposition

  17. Comparison of trimethylgallium and triethylgallium as “Ga” source materials for the growth of ultrathin GaN films on Si (100) substrates via hollow-cathode plasma-assisted atomic layer deposition

    International Nuclear Information System (INIS)

    GaN films grown by hollow cathode plasma-assisted atomic layer deposition using trimethylgallium (TMG) and triethylgallium (TEG) as gallium precursors are compared. Optimized and saturated TMG/TEG pulse widths were used in order to study the effect of group-III precursors. The films were characterized by grazing incidence x-ray diffraction, atomic force microscopy, x-ray photoelectron spectroscopy, and spectroscopic ellipsometry. Refractive index follows the same trend of crystalline quality, mean grain, and crystallite sizes. GaN layers grown using TMG precursor exhibited improved structural and optical properties when compared to GaN films grown with TEG precursor

  18. Comparison of trimethylgallium and triethylgallium as “Ga” source materials for the growth of ultrathin GaN films on Si (100) substrates via hollow-cathode plasma-assisted atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Alevli, Mustafa, E-mail: mustafaalevli@marmara.edu.tr [Department of Physics, Marmara University, Göztepe Kadıköy, 34722 İstanbul (Turkey); Haider, Ali; Kizir, Seda; Leghari, Shahid A.; Biyikli, Necmi, E-mail: biyikli@unam.bilkent.edu.tr [Institute of Materials Science and Nanotechnology, Bilkent University, Bilkent, 06800 Ankara, Turkey and National Nanotechnology Research Center (UNAM), Bilkent University, Bilkent, 06800 Ankara (Turkey)

    2016-01-15

    GaN films grown by hollow cathode plasma-assisted atomic layer deposition using trimethylgallium (TMG) and triethylgallium (TEG) as gallium precursors are compared. Optimized and saturated TMG/TEG pulse widths were used in order to study the effect of group-III precursors. The films were characterized by grazing incidence x-ray diffraction, atomic force microscopy, x-ray photoelectron spectroscopy, and spectroscopic ellipsometry. Refractive index follows the same trend of crystalline quality, mean grain, and crystallite sizes. GaN layers grown using TMG precursor exhibited improved structural and optical properties when compared to GaN films grown with TEG precursor.

  19. Deposition of NiO onto MoO3/gamma-Al2O3 Extrudates by Water-Assisted Spreading Method

    Czech Academy of Sciences Publication Activity Database

    Kaluža, Luděk; Zdražil, Miroslav; Vít, Zdeněk

    Prague : J. Heyrovský Institute of Physical Chemistry of the ASCR, v.v.i, 2009, S.70-71. ISBN 978-80-87351-04-8. [Symposium on Catalysis /41./. Prague (CZ), 02.11.2009-03.11.2009] R&D Projects: GA ČR GA104/09/0751 Institutional research plan: CEZ:AV0Z40720504 Keywords : hydrodesulfurization * NiMo * water-assisted spreading Subject RIV: CF - Physical ; Theoretical Chemistry

  20. 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.

  1. The electronic structure of tungsten oxide thin films prepared by pulsed cathodic arc deposition and plasma-assisted pulsed magnetron sputtering

    International Nuclear Information System (INIS)

    Pulsed cathodic arc and pulsed magnetron sputtered WO3 thin films were investigated using electron microscopy. It was found that the cathodic arc deposited material consisted of the α-WO3 phase with a high degree of crystallinity. In contrast, the magnetron sputtered material was highly disordered making it difficult to determine its phase. Electron energy-loss spectroscopy was used to study the oxygen K edge of the films and it was found that the near-edge fine structures of films produced by the two deposition methods differed. The oxygen K-edge near-edge structures for various phases of WO3 were calculated using two different self-consistent methods. Each phase was found to exhibit a unique oxygen K edge, which would allow different phases of WO3 to be identified using x-ray absorption spectroscopy or electron energy-loss spectroscopy. Both calculation methods predicted an oxygen K edge for the γ-WO3 phase which compared well to previous x-ray absorption spectra. In addition, a close match was found between the oxygen K edges obtained experimentally from the cathodic arc deposited material and that calculated for the α-WO3 phase

  2. Enhanced Photoluminescence and Raman Properties of Al-Doped ZnO Nanostructures Prepared Using Thermal Chemical Vapor Deposition of Methanol Assisted with Heated Brass

    OpenAIRE

    Thandavan, Tamil Many K.; Gani, Siti Meriam Abdul; San Wong, Chiow; Md. Nor, Roslan

    2015-01-01

    Vapor phase transport (VPT) assisted by mixture of methanol and acetone via thermal evaporation of brass (CuZn) was used to prepare un-doped and Al-doped zinc oxide (ZnO) nanostructures (NSs). The structure and morphology were characterized by field emission scanning electron microscopy (FESEM) and x-ray diffraction (XRD). Photoluminescence (PL) properties of un-doped and Al-doped ZnO showed significant changes in the optical properties providing evidence for several types of defects such as ...

  3. Mathematical modeling for the composition prediction of compound films grown by ion-assisted deposition technique and its application to TiN x film

    Science.gov (United States)

    Kim, Jae-Keun; Colligon, J. S.; Jeong, Sang-Hun

    2004-10-01

    A simple general model has been formulated to explain the composition of compound films during growth simultaneous with ion bombardment. The variables in this model are (a) the sticking probability of the background residual reactive gas in the film, (b) an ion-enhanced sticking probability of these reactive gases arising from ion-enhanced adsorption and mixing and (c) ion implantation of the energetic ions impinging on the growing film. Preferential sputtering of various components in the film is also taken into account. The model is shown to be successful in explaining the experimental variations in the composition of TiN x films produced by ion-assisted growth.

  4. Significant improvements of the high-field properties of carbon-doped MgB2 films by hot-filament-assisted hybrid physical-chemical vapor deposition using methane as the doping source

    International Nuclear Information System (INIS)

    We report a significant enhancement in upper critical field Hc2 and irreversibility field Hirr in carbon-doped MgB2 films fabricated by hot-filament-assisted hybrid physical-chemical vapor deposition (HFA-HPCVD) using methane as the doping source. For the parallel field, a very large temperature derivative -dHc2parallelab/dT value of 3 T K-1 near Tc was achieved in a heavily doped film with Tc near 28 K. Carbon doping also enhanced flux pinning, resulting in a much higher critical current density in a magnetic field Jc(H) than in undoped samples. The result suggests a more effective doping of carbon into the MgB2 structure and a better connectivity between the carbon-doped MgB2 grains than in previous reports. A clear correlation between the decrease in grain size and the enhancement of Hc2 was observed. (rapid communication)

  5. Screw-Dislocation-Driven Growth of Two-Dimensional Few-Layer and Pyramid-Like WSe2 by Sulfur-Assisted Chemical Vapor Deposition

    OpenAIRE

    Chen, Liang; Liu, Bilu; Abbas, Ahmad N.; Ma, Yuqiang; Fang, Xin; Liu, Yihang; Zhou, Chongwu

    2014-01-01

    Two-dimensional (2D) layered tungsten diselenides (WSe2) material has recently drawn a lot of attention due to its unique optoelectronic properties and ambipolar transport behavior. However, direct chemical vapor deposition (CVD) synthesis of 2D WSe2 is not as straightforward as other 2D materials due to the low reactivity between reactants in WSe2 synthesis. In addition, the growth mechanism of WSe2 in such CVD process remains unclear. Here we report the observation of a screw-dislocation-dr...

  6. Effect of nitrogen surrounding gas and plasma assistance on nitrogen incorporation in a-C:N films by femtosecond pulsed laser deposition

    Science.gov (United States)

    Bourquard, F.; Maddi, C.; Donnet, C.; Loir, A.-S.; Barnier, V.; Wolski, K.; Garrelie, F.

    2016-06-01

    In the context of nitrogen-rich amorphous carbon thin films ultrafast pulsed laser deposition from graphite targets in inert nitrogen or nitrogen plasma ambient, this study assesses the correlation between the ablation plume composition and dynamics and the thin films contents and structures. The use of both optical emission spectroscopy and spectrally resolved 2D imaging, coupled with intensified CCD temporal resolution, allows to precisely follow such species of the plume as CN and C2 molecules, from their apparition to their deposition on the substrate. The results show that carbon-nitrogen bonding arises at the early time of expansion with little changes in quantity thereafter. The key role of the DC-bias is in lowering the molecular weight of the ambient gas, thus easing molecules way toward the target and interfering with the chemical reaction for CN generation. Depending on the ambient pressure, these processes will have drastically different effects on the thin films properties and contents. This work thus explains the origin of high nitrogen contents in a-C:N thin films obtained using DC-bias, and proposes an easy in situ optical observation-based way to predict and look for the best conditions to maximize those contents in future work.

  7. Chemistry, phase formation, and catalytic activity of thin palladium-containing oxide films synthesized by plasma-assisted physical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre

    2010-11-26

    The chemistry, microstructure, and catalytic activity of thin films incorporating palladium were studied using scanning and transmission electron microscopies, X-ray diffraction, spectrophotometry, 4-point probe and catalytic tests. The films were synthesized using pulsed filtered cathodic arc and magnetron sputter deposition, i.e. techniques far from thermodynamic equilibrium. Catalytic particles were formed by thermally cycling thin films of the Pd-Pt-O system. The evolution and phase formation in such films as a function of temperature were discussed in terms of the stability of PdO and PtO2 in air. The catalytic efficiency was found to be strongly affected by the chemical composition, with oxidized palladium definitely playing a major role in the combustion of methane. Reactive sputter deposition of thin films in the Pd-Zr-Y-O system allowed us forming microstructures ranging from nanocrystalline zirconia to palladium nanoparticles embedded in a (Zr,Y)4Pd2O matrix. The sequence of phase formation is put in relation to simple thermodynamic considerations.

  8. Theoretical modeling of temperature dependent catalyst-assisted growth of conical carbon nanotube tip by plasma enhanced chemical vapor deposition process

    Energy Technology Data Exchange (ETDEWEB)

    Tewari, Aarti; Sharma, Suresh C. [Department of Applied Physics, Delhi Technological University (DTU), Shahbad Daulatpur, Bawana Road, Delhi 110 042 (India)

    2015-02-15

    A theoretical model has been developed to examine the effect of substrate temperature on the growth of the conical carbon nanotube (CNT) tip assisted by the catalyst in a reactive plasma. The growth rate of the CNT with conical tip because of diffusion and accretion of ions on catalyst nanoparticle including the charging rate of the CNT, kinetics of plasma species, and the evolution of the substrate temperature in reactive plasma has been taken into account. The effect of substrate temperature for different ion densities and temperatures on the growth of the conical CNT tip has been investigated for typical glow discharge plasma parameters. The results of the present model can serve as a major tool in better understanding of plasma heating effects on the growth of CNTs.

  9. A comparison of the wear and fatigue properties of plasma-assisted physical vapour deposition TiN, CrN and duplex coatings on Ti-6Al-4V

    International Nuclear Information System (INIS)

    The study sets out to establish a comparison between duplex systems of plasma nitriding followed by plasma-assisted physical vapour deposition (PAPVD) of TiN deposited on Ti-6Al-4V, compared with PAPVD of TiN and CrN alone. The fatigue resistance has also been examined since conventional surface modifications can often impair fatigue resistance. A rubber-wheel-type abrasion tester and pin-on-disc sliding wear tester were used to examine the wear resistance of the coatings and the load-bearing capacity of the substrate respectively. A Wohler-type rotating tester was used to study the fatigue properties. Using smooth rotating-bending fatigue specimens tested in air at 5700 rev min-1 for 106 cycles or until failure it was found that TiN, CrN and the duplex coating did not impair fatigue resistance but actually improved the S-N curves and increased the endurance limit. From the wear results it was found that, although TiN and CrN do improve the wear resistance of Ti-6Al-4V significantly, it is the duplex coating that has much the greater load-bearing capacity on the titanium substrate and gives a significant improvement on PAPVD TiN or CrN coatings in sliding and abrasive wear conditions. (orig.)

  10. 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.

  11. Enhanced photoluminescence and Raman properties of Al-Doped ZnO nanostructures prepared using thermal chemical vapor deposition of methanol assisted with heated brass.

    Directory of Open Access Journals (Sweden)

    Tamil Many K Thandavan

    Full Text Available Vapor phase transport (VPT assisted by mixture of methanol and acetone via thermal evaporation of brass (CuZn was used to prepare un-doped and Al-doped zinc oxide (ZnO nanostructures (NSs. The structure and morphology were characterized by field emission scanning electron microscopy (FESEM and x-ray diffraction (XRD. Photoluminescence (PL properties of un-doped and Al-doped ZnO showed significant changes in the optical properties providing evidence for several types of defects such as zinc interstitials (Zni, oxygen interstitials (Oi, zinc vacancy (Vzn, singly charged zinc vacancy (VZn-, oxygen vacancy (Vo, singly charged oxygen vacancy (Vo+ and oxygen anti-site defects (OZn in the grown NSs. The Al-doped ZnO NSs have exhibited shifted PL peaks at near band edge (NBE and red luminescence compared to the un-doped ZnO. The Raman scattering results provided evidence of Al doping into the ZnO NSs due to peak shift from 145 cm-1 to an anomalous peak at 138 cm-1. Presence of enhanced Raman signal at around 274 and 743 cm-1 further confirmed Al in ZnO NSs. The enhanced D and G band in all Al-doped ZnO NSs shows possible functionalization and doping process in ZnO NSs.

  12. Enhanced photoluminescence and Raman properties of Al-Doped ZnO nanostructures prepared using thermal chemical vapor deposition of methanol assisted with heated brass.

    Science.gov (United States)

    Thandavan, Tamil Many K; Gani, Siti Meriam Abdul; San Wong, Chiow; Md Nor, Roslan

    2015-01-01

    Vapor phase transport (VPT) assisted by mixture of methanol and acetone via thermal evaporation of brass (CuZn) was used to prepare un-doped and Al-doped zinc oxide (ZnO) nanostructures (NSs). The structure and morphology were characterized by field emission scanning electron microscopy (FESEM) and x-ray diffraction (XRD). Photoluminescence (PL) properties of un-doped and Al-doped ZnO showed significant changes in the optical properties providing evidence for several types of defects such as zinc interstitials (Zni), oxygen interstitials (Oi), zinc vacancy (Vzn), singly charged zinc vacancy (VZn-), oxygen vacancy (Vo), singly charged oxygen vacancy (Vo+) and oxygen anti-site defects (OZn) in the grown NSs. The Al-doped ZnO NSs have exhibited shifted PL peaks at near band edge (NBE) and red luminescence compared to the un-doped ZnO. The Raman scattering results provided evidence of Al doping into the ZnO NSs due to peak shift from 145 cm-1 to an anomalous peak at 138 cm-1. Presence of enhanced Raman signal at around 274 and 743 cm-1 further confirmed Al in ZnO NSs. The enhanced D and G band in all Al-doped ZnO NSs shows possible functionalization and doping process in ZnO NSs. PMID:25756598

  13. Determining the microwave coupling and operational efficiencies of a microwave plasma assisted chemical vapor deposition reactor under high pressure diamond synthesis operating conditions

    International Nuclear Information System (INIS)

    The microwave coupling efficiency of the 2.45 GHz, microwave plasma assisted diamond synthesis process is investigated by experimentally measuring the performance of a specific single mode excited, internally tuned microwave plasma reactor. Plasma reactor coupling efficiencies (η) > 90% are achieved over the entire 100–260 Torr pressure range and 1.5–2.4 kW input power diamond synthesis regime. When operating at a specific experimental operating condition, small additional internal tuning adjustments can be made to achieve η > 98%. When the plasma reactor has low empty cavity losses, i.e., the empty cavity quality factor is >1500, then overall microwave discharge coupling efficiencies (ηcoup) of >94% can be achieved. A large, safe, and efficient experimental operating regime is identified. Both substrate hot spots and the formation of microwave plasmoids are eliminated when operating within this regime. This investigation suggests that both the reactor design and the reactor process operation must be considered when attempting to lower diamond synthesis electrical energy costs while still enabling a very versatile and flexible operation performance

  14. Determining the microwave coupling and operational efficiencies of a microwave plasma assisted chemical vapor deposition reactor under high pressure diamond synthesis operating conditions

    Science.gov (United States)

    Nad, Shreya; Gu, Yajun; Asmussen, Jes

    2015-07-01

    The microwave coupling efficiency of the 2.45 GHz, microwave plasma assisted diamond synthesis process is investigated by experimentally measuring the performance of a specific single mode excited, internally tuned microwave plasma reactor. Plasma reactor coupling efficiencies (η) > 90% are achieved over the entire 100-260 Torr pressure range and 1.5-2.4 kW input power diamond synthesis regime. When operating at a specific experimental operating condition, small additional internal tuning adjustments can be made to achieve η > 98%. When the plasma reactor has low empty cavity losses, i.e., the empty cavity quality factor is >1500, then overall microwave discharge coupling efficiencies (ηcoup) of >94% can be achieved. A large, safe, and efficient experimental operating regime is identified. Both substrate hot spots and the formation of microwave plasmoids are eliminated when operating within this regime. This investigation suggests that both the reactor design and the reactor process operation must be considered when attempting to lower diamond synthesis electrical energy costs while still enabling a very versatile and flexible operation performance.

  15. Self-archiving to Institutional Repositories Is Improved by Assisted and Mandated Deposit; Disciplinary Culture is not a Factor. A Review of: Xia, Jingfeng. “Assessment of Self-Archiving in Institutional Repositories: Across Disciplines.” The Journal of Academic Librarianship 33.6 (Dec. 2007: 647-54.

    Directory of Open Access Journals (Sweden)

    Gaby Haddow

    2008-06-01

    subjected to further analysis. Using an “average publications per year” calculation for each discipline (from a 1977 paper, a final weighted rate of depositing was calculated for the four disciplines in the seven IRs. Main Results – Without weighting for faculty size, deposit rates vary greatly between disciplines. In most institutions, deposit rates for chemistry and sociology were higher than rates for physics and economics. When faculty size is controlled for, the highest deposit rates in five IRs were for chemistry and sociology. Only two IRs were found to have the highest deposit rates for physics and economics. These results did not change overall when the weighting for publishing productivity was applied: the same five IRs had highest deposit rates for chemistry and sociology. Exceptions to these findings were the IRs at University of Melbourne and University of Queensland, where the highest deposit rates were for economics and physics. On examination of depositor information, it was found that only 2.3% of economics deposits in the Melbourne IR were self-archived. Administrative assistants and other staffwere responsible for depositing 97.7% of the IR’s economics holdings. Self-archiving of physics items to the Melbourne IR was 90%; however, these deposits comprised student theses and dissertations only. Self-archiving practices were examined for:chemistry, physics and economics deposits at the University of Melbourne; chemistry and economics at the University of Queensland; and chemistry, physics and sociology at Queensland University ofTechnology (the only IR in the sample with a mandatory deposit policy. Like Melbourne, self-archiving of economics deposits at the University of Queensland was also low, at 17%. Of the remaining economics deposits, a librarian was responsible for depositing 68%. Chemistry deposits at both Melbourne and Queensland had much higher self-archiving rates, 76.2% and 100% respectively, than those found for physics and economics. At

  16. Depósito e perdas de calda em sistema de pulverização com turboatomizador em videira Deposition and spray losses in an air-assisted sprayer system in grapevine

    Directory of Open Access Journals (Sweden)

    Marcelo G. Balan

    2006-08-01

    Full Text Available Grande parte dos viticultores da região Norte do Paraná pratica a condução da videira em caramanchão, com mais de 50 aplicações fitossanitárias em um único ciclo. O objetivo deste trabalho foi avaliar essas aplicações com turboatomizador assistido de ar no sistema de pulverização, por meio do depósito de calda nas folhas e perdas. O trabalho foi desenvolvido utilizando-se de cinco condições de aplicação, variando-se tamanho de gotas e volume de aplicação, com quatro repetições, em blocos casualizados. A avaliação do sistema foi feita com a aplicação de uma calda de cloreto de potássio (5%, sendo o depósito nas folhas medido pela condutividade elétrica, e as perdas, pela comparação entre volumes aplicado e recuperado nas folhas. Para todas as condições, as perdas foram superiores a 48%. Os maiores volumes aplicados apresentaram as maiores deposições, e gotas maiores apresentaram maior depósito e mesma perda em relação a gotas menores. Os menores volumes não diferiram com relação à deposição, destacando-se as condições gotas maiores a volume baixo e a testemunha utilizada pelo viticultor, que apresentaram as menores perdas. Os resultados demonstram que o turboatomizador é uma importante ferramenta para maximizar as operações de pulverização em uva, e as alterações na configuração das pontas de pulverização devem ser mais estudadas.Winegrowers in the north of Paraná State carry on grapevines in arbour and pesticide applications could overcome more than fifty times in a cycle. The aim of this study was to evaluate the features of the air assisted sprayer application system by spray volume deposition and losses. Five treatments and four randomized blocks were used. The treatments varied the droplet size and application volume. The evaluation of the system was done with a 5% spray solution containing KCl being the leaves spray deposit measured through electric conductivity and the losses by the

  17. Fabrication of carbon nanofiber-reinforced aluminum matrix composites assisted by aluminum coating formed on nanofiber surface by in situ chemical vapor deposition

    International Nuclear Information System (INIS)

    The van der Waals agglomeration of carbon nanofibers (CNFs) and the weight difference and poor wettability between CNFs and aluminum hinder the fabrication of dense CNF-reinforced aluminum matrix composites with superior properties. In this study, to improve this situation, CNFs were coated with aluminum by a simple and low-cost in situ chemical vapor deposition (in situ CVD). Iodine was used to accelerate the transport of aluminum atoms. The coating layer formed by the in situ CVD was characterized using scanning electron microscopy, transmission electron microscopy, x-ray diffraction, Fourier transform-infrared spectroscopy, and x-ray photoelectron spectroscopy. The results confirmed that the CNFs were successfully coated with aluminum. The composites were fabricated to investigate the effect of the aluminum coating formed on the CNFs. The dispersion of CNFs, density, Vickers micro-hardness and thermal conductivity of the composites fabricated by powder metallurgy were improved. Pressure-less infiltration experiments were conducted to fabricate composites by casting. The results demonstrated that the wettability and infiltration were dramatically improved by the aluminum coating layer on CNFs. The aluminum coating formed by the in situ CVD technique was proved to be effective for the fabrication of CNF-reinforced aluminum matrix composites. (paper)

  18. Fabrication of carbon nanofiber-reinforced aluminum matrix composites assisted by aluminum coating formed on nanofiber surface by in situ chemical vapor deposition

    Science.gov (United States)

    Ogawa, Fumio; Masuda, Chitoshi

    2015-01-01

    The van der Waals agglomeration of carbon nanofibers (CNFs) and the weight difference and poor wettability between CNFs and aluminum hinder the fabrication of dense CNF-reinforced aluminum matrix composites with superior properties. In this study, to improve this situation, CNFs were coated with aluminum by a simple and low-cost in situ chemical vapor deposition (in situ CVD). Iodine was used to accelerate the transport of aluminum atoms. The coating layer formed by the in situ CVD was characterized using scanning electron microscopy, transmission electron microscopy, x-ray diffraction, Fourier transform-infrared spectroscopy, and x-ray photoelectron spectroscopy. The results confirmed that the CNFs were successfully coated with aluminum. The composites were fabricated to investigate the effect of the aluminum coating formed on the CNFs. The dispersion of CNFs, density, Vickers micro-hardness and thermal conductivity of the composites fabricated by powder metallurgy were improved. Pressure-less infiltration experiments were conducted to fabricate composites by casting. The results demonstrated that the wettability and infiltration were dramatically improved by the aluminum coating layer on CNFs. The aluminum coating formed by the in situ CVD technique was proved to be effective for the fabrication of CNF-reinforced aluminum matrix composites.

  19. Effects of N{sub 2}O gas addition on the properties of ZnO films grown by catalytic reaction-assisted chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Yasui, Kanji, E-mail: kyasui@vos.nagaokaut.ac.jp; Morioka, Makoto; Kanauchi, Shingo; Ohashi, Yuki; Kato, Takahiro; Tamayama, Yasuhiro [Department of Electrical, Electronic, and Information Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 (Japan)

    2015-11-15

    The influence of N{sub 2}O gas addition on the properties of zinc oxide (ZnO) films grown on a-plane (11–20) sapphire (a-Al{sub 2}O{sub 3}) substrates was investigated, using a chemical vapor deposition method based on the reaction between dimethylzinc and high-temperature H{sub 2}O produced by a catalytic H{sub 2}-O{sub 2} reaction on platinum (Pt) nanoparticles. The addition of N{sub 2}O was found to increase the size of the crystalline facets and to improve the crystal orientation along the c-axis. The electron mobility at 290 K was also increased to 234 cm{sup 2}/Vs following the addition of N{sub 2}O gas at a pressure of 3.2 × 10{sup −3 }Pa. In addition, the minimum full width at half maximum of the most intense photoluminescence peak derived from neutral donor bound excitons at 10 K decreased to 0.6 meV by the addition of N{sub 2}O gas at a pressure of 3.1 × 10{sup −2 }Pa.

  20. Titania nanocoating on MnCO3 microspheres via liquid-phase deposition for fabrication of template-assisted core-shell- and hollow-structured composites.

    Science.gov (United States)

    Lee, Hack-Keun; Sakemi, Daisuke; Selyanchyn, Roman; Lee, Cheal-Gyu; Lee, Seung-Woo

    2014-01-01

    A novel class of core-shell- and hollow-structured MnCO3/TiO2 composites was synthesized by titania nanocoating on MnCO3 microspheres via two-step liquid-phase deposition at room temperature. Morphological change from core-shell to hollow microparticles was possible in the prepared samples by controlling prereaction time of MnCO3 and [NH4]2TiF6. Upon the prereaction process, the core of the core-shell MnCO3/TiO2 became highly porous, and a honeycomb-like surface that resembled the orientation of self-assembled MnCO3 nanocrystals was developed. The MnCO3 core was completely removed after 6 h prereaction. Calcination at 600 °C resulted in the transformation of both core-shell- and hollow-structured composites to Mn2O3/TiO2 anatase microspheres that retained their original morphologies. X-ray diffraction, field-emission scanning electron microscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, and electron probe microanalysis were employed for microsphere characterization. As the first trial for application of the synthesized materials, solid-extraction of organics from aqueous media was examined using methylene blue (MB). Both types of Mn2O3/TiO2 composites showed very fast adsorption of MB with high extraction values of 5.2 and 6.4 μmol g(-1) for the core-shell and hollow structures, respectively. Current work provides a new approach for facile fabrication of titania-metal oxide nanocomposites with unique morphological features and promising application possibilities. PMID:24320871

  1. MAPLE deposition of nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Caricato, A.P., E-mail: annapaola.caricato@le.infn.it [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Arima, V.; Catalano, M. [National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Cesaria, M. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Cozzoli, P.D. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Martino, M. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Taurino, A.; Rella, R. [Institute for Microelectronics and Microsystems, IMM-CNR, Via Monteroni, I-73100 Lecce (Italy); Scarfiello, R. [National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Tunno, T. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Zacheo, A. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy)

    2014-05-01

    The matrix-assisted pulsed laser evaporation (MAPLE) has been recently exploited for depositing films of nanomaterials by combining the advantages of colloidal inorganic nanoparticles and laser-based techniques. MAPLE-deposition of nanomaterials meeting applicative purposes demands their peculiar properties to be taken into account while planning depositions to guarantee a congruent transfer (in terms of crystal structure and geometric features) and explain the deposition outcome. In particular, since nanofluids can enhance thermal conductivity with respect to conventional fluids, laser-induced heating can induce different ablation thermal regimes as compared to the MAPLE-treatment of soft materials. Moreover, nanoparticles exhibit lower melting temperatures and can experience pre-melting phenomena as compared to their bulk counterparts, which could easily induce shape and or crystal phase modification of the material to be deposited even at very low fluences. In this complex scenario, this review paper focuses on examples of MAPLE-depositions of size and shape controlled nanoparticles for different applications highlights advantages and challenges of the MAPLE-technique. The influence of the deposition parameters on the physical mechanisms which govern the deposition process is discussed.

  2. Surgical Assisting

    Science.gov (United States)

    ... specific training over and above a degree in science, nursing, physician assisting, or another health profession. Prerequisites . Recommended eligibility requirements for admission into a surgical assisting program are: Bachelor of Science degree (or higher) Associate degree in an allied ...

  3. Assistive Technology

    Science.gov (United States)

    ... Page Resize Text Printer Friendly Online Chat Assistive Technology Assistive technology (AT) is any service or tool that helps ... be difficult or impossible. For older adults, such technology may be a walker to improve mobility or ...

  4. Assisted Living

    Science.gov (United States)

    ... overwhelming majority of residents are female. Assisted Living Philosophy The philosophy of assisted living is to provide personalized, resident ... loved ones to learn about the care provider philosophy . Freedom of Choice The most progressive state regulations ...

  5. Advanced thermally assisted surface engineering processes

    CERN Document Server

    Chattopadhyay, Ramnarayan

    2007-01-01

    Preface. Acknowledgements. 1: Wear, Surface Heat and Surface Engineering. 2: Plasma Assisted Thermal Processes. 3: Ion Beam Processes. 4: Electron Beam Processes. 5: Microwave Assisted Surface Modification Processes. 6: Laser Assisted Surface Engineering Processes. 7: Solar Energy for Surface Modifications. 8: Combustion Processes for Surface Modification. 9: Friction Weld Surfacing. 10: Induction Surface Modification Processes. 11: Surfacing by Spark Deposition Processes. 12: Arc Assisted Advanced Surface Engineering Processes. 13: Hot Isostatic Press. 14: Fluid Bed Processes. 15: P

  6. United Nations programme for the assistance in Uruguay mining exploration

    International Nuclear Information System (INIS)

    The Uruguay government asked for the United Nations for the development of technical assistance programme in geological considerations of the Valentines iron deposits. This agreement was signed as Mining prospect ion assistance in Uruguay.

  7. Assisted Ventilation.

    Science.gov (United States)

    Dries, David J

    2016-01-01

    Controlled Mechanical Ventilation may be essential in the setting of severe respiratory failure but consequences to the patient including increased use of sedation and neuromuscular blockade may contribute to delirium, atelectasis, and diaphragm dysfunction. Assisted ventilation allows spontaneous breathing activity to restore physiological displacement of the diaphragm and recruit better perfused lung regions. Pressure Support Ventilation is the most frequently used mode of assisted mechanical ventilation. However, this mode continues to provide a monotonous pattern of support for respiration which is normally a dynamic process. Noisy Pressure Support Ventilation where tidal volume is varied randomly by the ventilator may improve ventilation and perfusion matching but the degree of support is still determined by the ventilator. Two more recent modes of ventilation, Proportional Assist Ventilation and Neurally Adjusted Ventilatory Assist (NAVA), allow patient determination of the pattern and depth of ventilation. Proposed advantages of Proportional Assist Ventilation and NAVA include decrease in patient ventilator asynchrony and improved adaptation of ventilator support to changing patient demand. Work of breathing can be normalized with these modes as well. To date, however, a clear pattern of clinical benefit has not been demonstrated. Existing challenges for both of the newer assist modes include monitoring patients with dynamic hyperinflation (auto-positive end expiratory pressure), obstructive lung disease, and air leaks in the ventilator system. NAVA is dependent on consistent transduction of diaphragm activity by an electrode system placed in the esophagus. Longevity of effective support with this technique is unclear. PMID:25501776

  8. 24 CFR 891.775 - Security deposits.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Security deposits. 891.775 Section 891.775 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... Individuals-Section 162 Assistance § 891.775 Security deposits. The general requirements for security...

  9. Hearing Assistive Technology

    Science.gov (United States)

    ... for the Public / Hearing and Balance Hearing Assistive Technology Hearing Assistive Technology: FM Systems | Infrared Systems | Induction ... Assistive Technology Systems Solutions What are hearing assistive technology systems (HATS)? Hearing assistive technology systems (HATS) are ...

  10. Fabrication of Eu{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7−δ}+BaHfO{sub 3} coated conductors with 141 A/cm-w under 3 T at 77 K using the IBAD/PLD process

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, T., E-mail: tomo.yoshida@istec.or.jp; Ibi, A.; Takahashi, T.; Yoshizumi, M.; Izumi, T.; Shiohara, Y.

    2014-09-15

    Highlights: • A new combination of EuBCO + BHO system was investigated by the IBAD/PLD process. • A EuBCO + BHO film showed extremely high property of 141 A/cm-w at 77 K, 3 T. • A 200 m long EuBCO + BHO CC with 55.5 A/cm-w at 77 K, 3 T was fabricated. • A 93.7 m long EuBCO + BHO CC with 108 A/cm-w at 77 K, 3 T was fabricated. - Abstract: Introduction of artificial pinning centers such as BaZrO{sub 3} (BZO), BaSnO{sub 3} (BSO), BaHfO{sub 3} (BHO) nano-rods is effective to improve in-field critical currents (I{sub c}). In particular, the BHO doping into Gd{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7−δ} had been found to exhibit high in-field I{sub c} under wide ranges of temperatures and magnetic fields. Furthermore, a long coated conductor (CC) with high in-field properties and high uniformity was successfully fabricated by means of BHO doping. However, increase of the I{sub c} values exhibited somewhat in a saturated manner with thickening the superconducting films above 3 μm. In this work, a new combination of Eu{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7−δ} (EuBCO) + BHO system was investigated using the IBAD/PLD process to improve in-field performance especially in thick films. As a result, it was found that a EuBCO + BHO film with 3.6 μm in thickness showed extremely high property of 141 A/cm-w measured at 77 K, 3 T. This high in-field I{sub c} value was tentatively explained due to suppression of a-axis oriented grains even in thick films. A 200 m long EuBCO + BHO CC with 55.5 A/cm-w and a 93.7 m long CC with 108 A/cm-w measured at 77 K, 3 T were successfully fabricated.

  11. Deposited radionuclides

    International Nuclear Information System (INIS)

    The results presented are from the nationwide programme to survey the fall-out levels of radionuclides in Finland. This programme includes results from the vicinities of the nuclear power plants at Loviisa and Olkiluoto. Analysis of deposition samples for their 3H, 89Sr and 90Sr, as well as 137Cs and other gamma radionuclide contents was continued. The results are given as a follow-up to the previous results. The cumulative deposition of long-lived radionuclides retained in soil was measured near the Finnish nuclear power stations. The 90Sr and 137Cs levels in deposition in 1979 were lower than in the previous two years, and no 89Sr was detected. The trend to slightly increasing 3H concentrations of previous years was reversed in 1979. The mean annual deposition of tritium at different sampling stations varied from 85 nCi/m2 (3.1 kBq/m2) to 180 nCi/m2 (6.7 kBq/m2). The total annual deposits of various fission product radionuclides have decreased continuously since the maximum in 1977. No short-lived radionuclides originating from either nuclear explosions or nuclear power plants were observed in 1979. (author)

  12. Deposited radionuclides

    International Nuclear Information System (INIS)

    The measurements presented here were carried out for determination of the fallout levels of radionuclides throughout the country, including the areas surrounding the nuclear power plants at Loviisa and Olkiluoto. The 90Sr, 137Cs and 3H contents of deposition were determined and the results are given as a follow-up to the previous results. 89Sr and other gammaradionuclides in addition to 137Cs were measured from wet and dry deposition. Also 89-90Sr, 239-240Pu, 137Cs and other gammaradionuclides deposited in soil were measured. The radiochemical separation technique was used to determine 89Sr, 90Sr, 137Cs and 239-240Pu. Tritium contents were determined by liquid scintillation counting after electrolytic enrichment. Gammaradionuclides were measured by Ge(Li) spectrometry. In 1977 the contents of the long-lived radionuclides 90Sr and 137Cs in deposition increased to almost the same level as in the early '70s. This is due to the high-yield atmospheric nuclear weapon tests carried out by China. A slight increase in 3H deposition can also be noticed in 1977. The results of soil sample measurements indicate that practically all the activity is found in the top 20 cm layer. (author)

  13. Deposited radionuclides

    International Nuclear Information System (INIS)

    Measurements were carried out to determine the fall-out levels of radionuclides in Finland including those from the surroundings of the nuclear power plants at Loviisa and Olkiluoto. Deposition samples were analysed for their 3H, 89Sr and 90Sr as well as 137Cs and other gamma radionuclide contents. 90Sr, 239,240Pu, as well as 137Cs and other gamma radionuclides deposited in soil were also measured. The 90Sr and 137Cs levels in deposition in 1978 remained at almost the same level as in 1977. The slightly increasing trend in 3H concentrations continued in 1978. The mean annual deposition of tritium at different sampling stations varied from 120 nCi/m2 (4.4 kBq/m2) to 200 nCi/m2 (7.4 kBq/m2). The total annual deposits of various fission product radionuclides during 1978 were smaller than during 1977. No increase in radioactivity originating from nuclear power plants could be observed. (author)

  14. Thin films of hydrogenated amorphous carbon (a-C:H) obtained through chemical vapor deposition assisted by plasma; Peliculas delgadas de carbono amorfo hidrogenado (a-C:H) obtenidas mediante deposito quimico de vapores asistido por plasma

    Energy Technology Data Exchange (ETDEWEB)

    Mejia H, J.A.; Camps C, E.E.; Escobar A, L.; Romero H, S.; Chirino O, S. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Muhl S, S. [IIM-UNAM, 04510 Mexico D.F. (Mexico)

    2004-07-01

    Films of hydrogenated amorphous carbon (a-C:H) were deposited using one source of microwave plasma with magnetic field (type ECR), using mixtures of H{sub 2}/CH{sub 4} in relationship of 80/20 and 95/05 as precursory gases, with work pressures of 4X10{sup -4} to 6x10{sup -4} Torr and an incident power of the discharge of microwaves with a constant value of 400 W. It was analyzed the influence among the properties of the films, as the deposit rate, the composition and the bonding types, and the deposit conditions, such as the flow rates of the precursory gases and the polarization voltage of the sample holders. (Author)

  15. Enhancement of Low-field Magnetoresistance in Self-Assembled Epitaxial La0.67Ca0.33MnO3:NiO and La0.67Ca0.33MnO3:Co3O4 Composite Films via Polymer-Assisted Deposition.

    Science.gov (United States)

    Zhou, Meng; Li, Yuling; Jeon, Il; Yi, Qinghua; Zhu, Xuebin; Tang, Xianwu; Wang, Haiyan; Fei, Ling; Sun, Yuping; Deng, Shuguang; Matsuo, Yutaka; Luo, Hongmei; Zou, Guifu

    2016-01-01

    Polymer-assisted deposition method has been used to fabricate self-assembled epitaxial La0.67Ca0.33MnO3:NiO and La0.67Ca0.33MnO3:Co3O4 films on LaAlO3 substrates. Compared to pulsed-laser deposition method, polymer-assisted deposition provides a simpler and lower-cost approach to self-assembled composite films with enhanced low-field magnetoresistance effect. After the addition of NiO or Co3O4, triangular NiO and tetrahedral Co3O4 nanoparticles remain on the surface of La0.67Ca0.33MnO3 films. This results in a dramatic increase in resistivity of the films from 0.0061 Ω•cm to 0.59 Ω•cm and 1.07 Ω•cm, and a decrease in metal-insulator transition temperature from 270 K to 180 K and 172 K by the addition of 10%-NiO and 10%-Co3O4, respectively. Accordingly, the maximum absolute magnetoresistance value is improved from -44.6% to -59.1% and -52.7% by the addition of 10%-NiO and 10%-Co3O4, respectively. The enhanced low-field magnetoresistance property is ascribed to the introduced insulating phase at the grain boundaries. The magnetism is found to be more suppressed for the La0.67Ca0.33MnO3:Co3O4 composite films than the La0.67Ca0.33MnO3:NiO films, which can be attributed to the antiferromagnetic properties of the Co3O4 phase. The solution-processed composite films show enhanced low-field magnetoresistance effect which are crucial in practical applications. We expect our polymer-assisted deposited films paving the pathway in the field of hole-doped perovskites with their intrinsic colossal magnetoresistance. PMID:27381661

  16. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20111705 An Junbo(Team 603,Bureau of Nonferrous Metals Geological Exploration of Jilin Province,Hunchun 133300,China);Xu Renjie Geological Features and Ore Genesis of Baishilazi Scheelite Deposit in Yanbian Area(Jilin Geology,ISSN1001-2427,CN22-1099/P,29(3),2010,p.39-43,2 illus.,2 tables,7 refs.)Key words:tungsten ores,Jilin ProvinceThe Baishilazi scheelite deposit is located in contacting zone between the marble of the Late Palaeozoic Qinglongcun Group and the Hercynian biotite granite.The vein and lenticular major ore body is obviously controlled by NE-extending faults and con

  17. Thin Film Deposition Using Energetic Ions

    Directory of Open Access Journals (Sweden)

    Stephan Mändl

    2010-07-01

    Full Text Available One important recent trend in deposition technology is the continuous expansion of available processes towards higher ion assistance with the subsequent beneficial effects to film properties. Nowadays, a multitude of processes, including laser ablation and deposition, vacuum arc deposition, ion assisted deposition, high power impulse magnetron sputtering and plasma immersion ion implantation, are available. However, there are obstacles to overcome in all technologies, including line-of-sight processes, particle contaminations and low growth rates, which lead to ongoing process refinements and development of new methods. Concerning the deposited thin films, control of energetic ion bombardment leads to improved adhesion, reduced substrate temperatures, control of intrinsic stress within the films as well as adjustment of surface texture, phase formation and nanotopography. This review illustrates recent trends for both areas; plasma process and solid state surface processes.

  18. Foreign assistance

    International Nuclear Information System (INIS)

    This paper reports that providing energy assistance to developing countries remains a relatively low priority of the Agency for International Development. AID is helping some developing countries meet their energy needs, but this assistance varies substantially because of the agency's decentralized structure. Most AID energy funding has gone to a handful of countries-primarily Egypt and Pakistan. With limited funding in most other countries, AID concentrates on providing technical expertise and promoting energy policy reforms that will encourage both energy efficiency and leverage investment by the private sector and other donors. Although a 1989 congressional directive to pursue a global warming initiative has had a marginal impact on the agency's energy programming, many AID energy programs, including those directed at energy conservation, help address global warming concerns

  19. Deposition of thin layers of boron nitrides and hydrogenated microcrystalline silicon assisted by high current direct current arc plasma; Deposition assistee par un plasma a arc a haut courant continu de couches minces de Nitrure de Bore et de Silicium microcristallin hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    Franz, D. [Ecole Polytechnique Federale de Lausanne, Centre de Recherches en Physique des Plasmas (CRPP), CH-1015 Lausanne (Switzerland)

    1999-09-01

    In the frame of this thesis, a high current direct current arc (HCDCA) used for the industrial deposition of diamond, has been adapted to study the deposition of two types of coatings: a) boron nitride, whose cubic phase is similar to diamond, for tribological applications, b) hydrogenated microcrystalline silicon, for applications in the semiconductor fields (flat panel displays, solar cells,...). For the deposition of these coatings, the substrates were placed in the diffusion region of the arc. The substrate heating is mainly due to atomic species recombining on its surface. The deposition temperature, varying from 300 to 900 {sup o}C according to the films deposited, is determined by the substrate position, the arc power and the injected gas fluxes, without the use of any external heating or cooling system. Measurements performed on the arc plasma show that the electronic temperature is around 2 eV (23'000 K) while the gas temperature is lower than 5500 K. Typical electronic densities are in the range of 10{sup 12}-10{sup 1'}3 cm{sup -3}. For the deposition of boron nitride films, different boron precursors were used and a wide parameter range was investigated. The extreme difficulty of synthesising cubic boron nitride films by chemical vapour deposition (CVD) did not allow to stabilize the cubic phase of boron nitride in HCDCA. Coatings resulted in hexagonal or amorphous boron nitride with a chemical composition close to stoichiometric. The presence of hydrogen leads to the deposition of rough and porous films. Negative biasing of the samples, for positive ion bombardment, is commonly used to stabilize the cubic phase. In HCDCA and in our biasing range, only a densification of the films could be observed. A boron nitride deposition plasma study by infrared absorption spectroscopy in a capacitive radio frequency reactor has demonstrated the usefulness of this diagnostic for the understanding of the various chemical reactions which occur in this kind

  20. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    20150904An Fang(State Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi’an 710069,China);Wang Juli Skarn Mineral Assemblage in Representative Ore Districts of Sayak Copper Orefield,Kazakhstan,and Its Genetic Implications(Mineral Deposits,ISSN0258-7106,CN11-1965/P,33(3),2014,p.521-540,

  1. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20131601 Gao Junbo(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550003,China);Yang Ruidong Hydrothermal Venting-Flowing Sedimentation Characteristics of Devonian Barite Deposits from Leji,Zhenning County,Guizhou Province(Acta Sedimentologica Sinica,ISSN1000-0550,CN62-1038/P,30(3),

  2. Structural characterization of MAPLE deposited lipase biofilm

    Energy Technology Data Exchange (ETDEWEB)

    Aronne, Antonio [Department of Chemical Engineering, Materials and Industrial Production, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Ausanio, Giovanni; Bloisi, Francesco [CNR-SPIN and Department of Physics, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Calabria, Raffaela [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Califano, Valeria, E-mail: v.califano@im.cnr.it [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Fanelli, Esther [Department of Chemical Engineering, Materials and Industrial Production, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Massoli, Patrizio [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Vicari, Luciano R.M. [CNR-SPIN and Department of Physics, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy)

    2014-11-30

    Highlights: • Lipase from Candida Rugosa was deposited by Matrix Assisted Pulsed Laser Evaporation (MAPLE) on KBr pellets, mica and glass substrate. • The deposited film was characterized morphologically and structurally by optical microscopy, SEM and FTIR analysis. • Results of characterization underlined a phenomenon of aggregation taking place. • The aggregation phenomenon was reversible since lipase showed activity in the transesterification reaction between soybean oil and isopropyl alcohol once detached from the substrate. - Abstract: Lipases (triacylglycerol ester hydrolases) are enzymes used in several industrial applications. Enzymes immobilization can be used to address key issues limiting widespread application at industrial level. Immobilization efficiency is related to the ability to preserve the native conformation of the enzyme. MAPLE (Matrix Assisted Pulsed Laser Evaporation) technique, a laser deposition procedure for treating organic/polymeric/biomaterials, was applied for the deposition of lipase enzyme in an ice matrix, using near infrared laser radiation. Microscopy analysis showed that the deposition occurred in micrometric and submicrometric clusters with a wide size distribution. AFM imaging showed that inter-cluster regions are uniformly covered with smaller aggregates of nanometric size. Fourier transform infrared spectroscopy was used for both recognizing the deposited material and analyzing its secondary structure. Results showed that the protein underwent reversible self-association during the deposition process. Actually, preliminary tests of MAPLE deposited lipase used for soybean oil transesterification with isopropyl alcohol followed by gas chromatography–mass spectrometry gave results consistent with undamaged deposition of lipase.

  3. Structural characterization of MAPLE deposited lipase biofilm

    International Nuclear Information System (INIS)

    Highlights: • Lipase from Candida Rugosa was deposited by Matrix Assisted Pulsed Laser Evaporation (MAPLE) on KBr pellets, mica and glass substrate. • The deposited film was characterized morphologically and structurally by optical microscopy, SEM and FTIR analysis. • Results of characterization underlined a phenomenon of aggregation taking place. • The aggregation phenomenon was reversible since lipase showed activity in the transesterification reaction between soybean oil and isopropyl alcohol once detached from the substrate. - Abstract: Lipases (triacylglycerol ester hydrolases) are enzymes used in several industrial applications. Enzymes immobilization can be used to address key issues limiting widespread application at industrial level. Immobilization efficiency is related to the ability to preserve the native conformation of the enzyme. MAPLE (Matrix Assisted Pulsed Laser Evaporation) technique, a laser deposition procedure for treating organic/polymeric/biomaterials, was applied for the deposition of lipase enzyme in an ice matrix, using near infrared laser radiation. Microscopy analysis showed that the deposition occurred in micrometric and submicrometric clusters with a wide size distribution. AFM imaging showed that inter-cluster regions are uniformly covered with smaller aggregates of nanometric size. Fourier transform infrared spectroscopy was used for both recognizing the deposited material and analyzing its secondary structure. Results showed that the protein underwent reversible self-association during the deposition process. Actually, preliminary tests of MAPLE deposited lipase used for soybean oil transesterification with isopropyl alcohol followed by gas chromatography–mass spectrometry gave results consistent with undamaged deposition of lipase

  4. Deposit insurance and international bank deposits

    OpenAIRE

    Harry Huizinga; Gaëtan Nicodème

    2003-01-01

    This paper examines how international depositors respond to national deposit insurance policies. Countries with explicit deposit insurance are found to be relatively attractive to international non-bank depositors. Deposit schemes characterized by co-insurance, a private administration, and a low deposit insurance premium appear to be particularly favored by these depositors. The sensitivity of non-bank deposits to deposit insurance policies opens up the possibility of international regulator...

  5. Tool steel ion beam assisted nitrocarburization

    Energy Technology Data Exchange (ETDEWEB)

    Zagonel, L.F. [Instituto de Fisica ' Gleb Wataghin' , Universidade Estadual de Campinas, Unicamp, 13083-970 Campinas, Sao Paulo (Brazil)], E-mail: zagonel@ifi.unicamp.br; Alvarez, F. [Instituto de Fisica ' Gleb Wataghin' , Universidade Estadual de Campinas, Unicamp, 13083-970 Campinas, Sao Paulo (Brazil)

    2007-09-15

    The nitrocarburization of the AISI-H13 tool steel by ion beam assisted deposition is reported. In this technique, a carbon film is continuously deposited over the sample by the ion beam sputtering of a carbon target while a second ion source is used to bombard the sample with low energy nitrogen ions. The results show that the presence of carbon has an important impact on the crystalline and microstructural properties of the material without modification of the case depth.

  6. Tool steel ion beam assisted nitrocarburization

    International Nuclear Information System (INIS)

    The nitrocarburization of the AISI-H13 tool steel by ion beam assisted deposition is reported. In this technique, a carbon film is continuously deposited over the sample by the ion beam sputtering of a carbon target while a second ion source is used to bombard the sample with low energy nitrogen ions. The results show that the presence of carbon has an important impact on the crystalline and microstructural properties of the material without modification of the case depth

  7. Template-assisted synthesis of III-nitride and metal-oxide nano-heterostructures using low-temperature atomic layer deposition for energy, sensing, and catalysis applications (Presentation Recording)

    Science.gov (United States)

    Biyikli, Necmi; Ozgit-Akgun, Cagla; Eren, Hamit; Haider, Ali; Uyar, Tamer; Kayaci, Fatma; Guler, Mustafa Ozgur; Garifullin, Ruslan; Okyay, Ali K.; Ulusoy, Gamze M.; Goldenberg, Eda

    2015-08-01

    Recent experimental research efforts on developing functional nanostructured III-nitride and metal-oxide materials via low-temperature atomic layer deposition (ALD) will be reviewed. Ultimate conformality, a unique propoerty of ALD process, is utilized to fabricate core-shell and hollow tubular nanostructures on various nano-templates including electrospun nanofibrous polymers, self-assembled peptide nanofibers, metallic nanowires, and multi-wall carbon nanotubes (MWCNTs). III-nitride and metal-oxide coatings were deposited on these nano-templates via thermal and plasma-enhanced ALD processes with thickness values ranging from a few mono-layers to 40 nm. Metal-oxide materials studied include ZnO, TiO2, HfO2, ZrO2, and Al2O3. Standard ALD growth recipes were modified so that precursor molecules have enough time to diffuse and penetrate within the layers/pores of the nano-template material. As a result, uniform and conformal coatings on high-surface area nano-templates were demonstrated. Substrate temperatures were kept below 200C and within the self-limiting ALD window, so that temperature-sensitive template materials preserved their integrity III-nitride coatings were applied to similar nano-templates via plasma-enhanced ALD (PEALD) technique. AlN, GaN, and InN thin-film coating recipes were optimized to achieve self-limiting growth with deposition temperatures as low as 100C. BN growth took place only for >350C, in which precursor decomposition occured and therefore growth proceeded in CVD regime. III-nitride core-shell and hollow tubular single and multi-layered nanostructures were fabricated. The resulting metal-oxide and III-nitride core-shell and hollow nano-tubular structures were used for photocatalysis, dye sensitized solar cell (DSSC), energy storage and chemical sensing applications. Significantly enhanced catalysis, solar efficiency, charge capacity and sensitivity performance are reported. Moreover, core-shell metal-oxide and III-nitride materials

  8. Microstructure and Electrical Properties of PMN-PT Thin Films Prepared by Oxygen Plasma Assisted Pulsed Laser Deposition%氧等离子体辅助脉冲激光沉积法制备PMN-PT薄膜的微观结构和电学性能

    Institute of Scientific and Technical Information of China (English)

    何邕; 李效民; 高相东; 冷雪; 王炜

    2011-01-01

    Lead magnesium niobate-lead titanate (PMN-PT) ferroelectric thin films with composition near the morphotropic phase boundary (MPB) were deposited on Si substrate by oxygen plasma assisted pulsed laser deposition (PLD).Highly (001)-oriented PMN-PT thin films with lower oxygen defect and higher crystalline property were obtained.The results show that the microstructure and electrical properties of PMN-PT thin films strongly depend on the partial pressure and the activity of oxygen in the deposition process.With the use of oxygen plasma,the dielectric constant of the PMN-PT thin film is increased from 1484 to 3012,the remnant polarization (2Pr) changes from 18μC/cm2 to 38 μC/cm2.%采用氧等离子体辅助脉冲激光沉积方法(PLD)在硅衬底上,制备出高度(001)取向的钙钛矿相结构钛铌镁酸铅(PMN-PT)薄膜.研究了氧等离子体辅助对PMN-PT薄膜相结构、微观形貌和电学性能的影响.结果表明,通过在薄膜沉积过程中引入高活性的氧等离子,可以有效地提高PMN-PT薄膜的结晶质量和微观结构.未采用氧等离子体辅助PLD方法制备PMN-PT薄膜的介电常数(10 kHz)和剩余极化(2Pr)分别为1484和18 μC/cm2,通过采用氧等离子体辅助,其介电常数和剩余极化分别提高至3012和38 μC/cm2.

  9. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20111761 Chen Hua(115 Geological Party,Guizhou Bureau of Geology and Mineral Exploration & Development,Guiyang 551400,China);Deng Chao Analysis on the Metallogenic Environment of Maochang Bauxite in Guizhou Province(Guizhou Geology,ISSN1000-5943,CN52-1059/P,27(3),2010,p.198-201,2 illus.,1 table,8 refs.)Key words:bauxite deposit,Guizhou Province By long time physical and chemical process,the carbonate rock after Central Guizhou uplidft,becomes red clay,after further weathering,the red clay decomposed into the oxide,hydroxide of Al and Fe,in the dissolution hole and depression,it concentrates primary fragmentary tight and earthy karst bauxite ore.Because the variation of landform,it decomposes and cracks again,affords the material source

  10. Physician-assisted death.

    OpenAIRE

    Senn, John S.

    1995-01-01

    Physician-assisted death includes both euthanasia and assistance in suicide. The CMA urges its members to adhere to the principles of palliative care. It does not support euthanasia and assisted suicide. The following policy summary includes definitions of euthanasia and assisted suicide, background information, basic ethical principles and physician concerns about legalization of physician-assisted death.

  11. Biaxially aligned buffer layers of cerium oxide, yttria stabilized zirconia, and their bilayers

    International Nuclear Information System (INIS)

    Biaxially aligned cerium oxide (CeO2) and yttria stabilized zirconia (YSZ) films were deposited on Ni-based metal (Hastelloy C276) substrates held at room temperature using ion beam assisted (IBAD) magnetron deposition with the ion beam directed at 55 degree to the normal of the film plane. In addition, we achieved, room-temperature epitaxial growth of CeO2 by bias sputtering to form biaxially aligned CeO2/YSZ bilayers. The crystalline structure and in-plane orientation of films was investigated by x-ray diffraction techniques. Both the IBAD CeO2 and YSZ films, and the CeO2/YSZ bilayers have a (111) pole in the ion beam direction. copyright 1997 American Institute of Physics

  12. Biaxially aligned buffer layers of cerium oxide, yttria stabilized zirconia, and their bilayers

    Science.gov (United States)

    Gnanarajan, S.; Katsaros, A.; Savvides, N.

    1997-05-01

    Biaxially aligned cerium oxide (CeO2) and yttria stabilized zirconia (YSZ) films were deposited on Ni-based metal (Hastelloy C276) substrates held at room temperature using ion beam assisted (IBAD) magnetron deposition with the ion beam directed at 55° to the normal of the film plane. In addition, we achieved, room-temperature epitaxial growth of CeO2 by bias sputtering to form biaxially aligned CeO2/YSZ bilayers. The crystalline structure and in-plane orientation of films was investigated by x-ray diffraction techniques. Both the IBAD CeO2 and YSZ films, and the CeO2/YSZ bilayers have a (111) pole in the ion beam direction.

  13. Electron transfer with self-assembled copper ions at Au-deposited biomimetic films: mechanistic ‘anomalies’ disclosed by temperature- and pressure-assisted fast-scan voltammetry

    International Nuclear Information System (INIS)

    It has been suggested that electron transfer (ET) processes occurring in complex environments capable of glass transitions, specifically in biomolecules, under certain conditions may experience the medium’s nonlinear response and nonergodic kinetic patterns. The interiors of self-assembled organic films (SAMs) deposited on solid conducting platforms (electrodes) are known to undergo glassy dynamics as well, hence they may also exhibit the abovementioned ‘irregularities’. We took advantage of Cu2+ ions as redox-active probes trapped in the Au-deposited  −COOH-terminated SAMs, either L-cysteine, or 3-mercaptopropionic acid diluted by the inert 2-mercaptoethanol, to systematically study the impact of glassy dynamics on ET using the fast-scan voltammetry technique and its temperature and high-pressure extensions. We found that respective kinetic data can be rationalized within the extended Marcus theory, taking into account the frictionally controlled (adiabatic) mechanism for short-range ET, and complications due to the medium’s nonlinear response and broken ergodicity. This combination shows up in essential deviations from the conventional energy gap (overpotential) dependence and in essentially nonlinear temperature (Arrhenius) and high-pressure patterns, respectively. Biomimetic aspects for these systems are also discussed in the context of recently published results for interfacial ET involving self-assembled blue copper protein (azurin) placed in contact with a glassy environment. (paper)

  14. Direct formation of a current collector layer on a partially reduced graphite oxide film using sputter-assisted metal deposition to fabricate high-power micro-supercapacitor electrodes

    Science.gov (United States)

    Byun, Segi; Yu, Jin

    2016-03-01

    When a reduced graphite oxide (RGO) freestanding film is fabricated on a supercapacitor cell via compression onto a current collector, there are gaps between the film and the current collector, even if the cell is carefully assembled. These gaps can induce increases in the electrical series resistance (ESR) of the cell, resulting in degradation of the cell's electrochemical performance. Here, to effectively reduce the ESR of the supercapacitor, metal sputtering deposition is introduced. This enables the direct formation of the current collector layer on a partially reduced GO (pRGO) film, the model system. Using metal sputtering, a nickel (Ni) layer with a thickness <1 μm can be created easily on one side of the pRGO film. Good electrical interconnection between the pRGO film and the current collector can be obtained using a Ni layer formed on the pRGO film. The pRGO film sustains its film form with high packing density (∼1.31 g cm-3). Furthermore, the Ni-sputtered pRGO film with optimized Ni thickness exhibits remarkable enhancement of its electrochemical performance. This includes a superior rate capability and semi-permanent cycle life compared with the untreated pRGO film. This is due to the significant decrease in the ESR of the film.

  15. Effect of ECR-assisted microwave plasma nitriding treatment on the microstructure characteristics of FCVA deposited ultra-thin ta-C films for high-density magnetic storage applications

    International Nuclear Information System (INIS)

    There are higher technical requirements for protecting layer of magnetic heads and disks used in future high-density storage fields. In this paper, ultra-thin (2 nm thickness) tetrahedral amorphous carbon (ta-C) films were firstly prepared by filtered cathodic vacuum arc (FCVA) method, then a series of nitriding treatments were performed with nitrogen plasma generated using electron cyclotron resonance (ECR) microwave source. Here it highlighted the influence of nitrogen flow and applied substrate bias voltage on the structural characteristics of ta-C films during the plasma nitriding process. The chemical compositions, element depth distribution profiles, physical structures and bonding configurations of plasma-nitrided ta-C films were investigated by X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and UV-vis Raman spectroscopy. The experimental results show that the carbon nitride compounds (CNx) are formed in nitrogenated ta-C films in which the N content and its depth distribution depends on bias voltage to large extent rather than N2 flow. The N content of nitrogenated ta-C films can reach 16 at.% for a substrate bias of -300 V and a N2 flow of 90 sccm. With increasing nitrogen content, there is less G peak dispersion and more ordering of structure. Furthermore, appropriate nitriding treatment (substrate bias: -100 V, N2 flow: 150 sccm) can greatly increase the fraction of sp3 and sp3C-N bonds, but the values begin to fall when the N content is above 9.8 at.%. All these indicate that suitable ECR-assisted microwave plasma nitriding is a potential modification method to obtain ultra-thin ta-C films with higher sp3 and sp3C-N fractions for high-density magnetic storage applications.

  16. Biosensor Applications of MAPLE Deposited Lipase

    Directory of Open Access Journals (Sweden)

    Valeria Califano

    2014-10-01

    Full Text Available Matrix Assisted Pulsed Laser Evaporation (MAPLE is a thin film deposition technique derived from Pulsed Laser Deposition (PLD for deposition of delicate (polymers, complex biological molecules, etc. materials in undamaged form. The main difference of MAPLE technique with respect to PLD is the target: it is a frozen solution or suspension of the (guest molecules to be deposited in a volatile substance (matrix. Since laser beam energy is mainly absorbed by the matrix, damages to the delicate guest molecules are avoided, or at least reduced. Lipase, an enzyme catalyzing reactions borne by triglycerides, has been used in biosensors for detection of β-hydroxyacid esters and triglycerides in blood serum. Enzymes immobilization on a substrate is therefore required. In this paper we show that it is possible, using MAPLE technique, to deposit lipase on a substrate, as shown by AFM observation, preserving its conformational structure, as shown by FTIR analysis.

  17. Fundamentals of laser-assisted fabrication of inorganic and organic films

    DEFF Research Database (Denmark)

    Schou, Jørgen

    2008-01-01

    The standard method for producing films by laser-assisted methods, Pulsed Laser Deposition (PLD) will be reviewed. The films considered are usually inorganic films, but also films of organic materials have been produced. Also the deposition of organic films by MAPLE (Matrix Assisted Pulsed Laser...

  18. Microstructural development and control in YBa[sub 2]Cu[sub 3]O[sub y

    Energy Technology Data Exchange (ETDEWEB)

    Holesinger, T. G. (Terry G.); Gibbons, B. J. (Brady J.); Foltyn, S. R. (Stephen R.); Arendt, P. N. (Paul N.); Groves, J. R. (James R.); Coulter, J. Y. (James Y.)

    2001-01-01

    A study of some defect structures in Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} (Y-123)coated conductors based on ion-beam -assisted-deposition (IBAD) of yttria-stabilized zirconia (YSZ) on nickel alloy substrates is presented. Defect structures can originate anywhere in the coated conductor architecture. Defects can be additive and propagate through the entire film structure to affect the growth, orientation, arid properties of the superconducting film. Interfacial Ieactions between Y- 123 and the underlying buffer layer and the corresponding effects on the transport properticis of the films can be controlled with the thickness of the underlying buffer layer. With a 9Ow ceria buffer layer on an IBAD YSZ coated metal substrate, a J, value of 1.7 MA/cm{sup 2} (self-field, 75K) was obtained in a 1.5{micro}m thick Y-123 film.

  19. Fe Spin Reorientation across the Metamagnetic Transition in Strained FeRh Thin Films

    Science.gov (United States)

    Bordel, C.; Juraszek, J.; Cooke, David W.; Baldasseroni, C.; Mankovsky, S.; Minár, J.; Ebert, H.; Moyerman, S.; Fullerton, E. E.; Hellman, F.

    2012-09-01

    A spin reorientation accompanying the temperature-induced antiferromagnetic (AFM) to ferromagnetic (FM) phase transition is reported in strained epitaxial FeRh thin films. Fe57 conversion electron Mössbauer spectrometry showed that the Fe moments have different orientations in FeRh grown on thick single-crystalline MgO and in FeRh grown on ion-beam-assist-deposited (IBAD) MgO. It was also observed, in both samples, that the Fe moments switch orientations at the AFM to FM phase transition. Perpendicular anisotropy was evidenced in the AFM phase of the film grown on IBAD MgO and in the FM phase of that grown on regular MgO. Density-functional theory calculations enabled this spin-reorientation transition to be accurately reproduced for both FeRh films across the AFM-FM phase transition and show that these results are due to differences in strain.

  20. Ion beam induced adhesion improvement of metal layers - a comparative study on composite layers

    International Nuclear Information System (INIS)

    The adhesion of thin layers of metals like Al, Cu, Cr, Ti etc. on polymer, ceramic or composite substrates is of great importance for microelectronics (printed circuits, packaging), and materials science. Therefore investigations on the adhesion improvement of copper on high temperature thermoplasts, carbon fibre reinforced polymers (CFK) and pure carbon by ion bombardment were undertaken. Ion beam mixing as well as ion beam assisted deposition (IBAD) was applied. It was shown that the electronic stopping power is the most important parameter for adhesion in the case of ion beam mixing by non-reactive ions. Reactive ions, especially metals, add an important chemical effect when stopped near the interface. IBAD Cu-layers have only good adhesion properties when prepared by low energy ion bombardment or with reactive intermediate layers. ((orig.))

  1. DLC films deposited by DC PACVD method

    International Nuclear Information System (INIS)

    In this paper the deposition of DLC coating by direct current PACVD (DC PACVD) is presented. DLC films were deposited on silicon (111) and steel substrates. The steel substrate consists of 0.9 % - C, 4.14% - Cr, 6.1% - W, 5% - Mo, 2.02% - V. These samples were polished up to a mirror finish using series of standard metallurgical polishing steps. The apparatus for plasma assisted chemical vapor deposition consisted of vacuum chamber, diffusion pump, two parallel electrodes and generator of DC discharge plasma. We deposited DLC films on our substrates with the same parameters, but one, which was changed. The microhardness of the coated materials is higher than the base material about 13 GPa at the load 50 mN and bias voltage -900 V. (Authors)

  2. Assisted Living Community Profile

    Science.gov (United States)

    ... for the Seniors Housing & Care Industry, reflects NCAL's philosophy of assisted living. 2 Data also from the ... Assisted Living Studies Clinical Practice Guidelines Health Information Technology In-Service Training Tools Periodicals State Regulatory Review ...

  3. Assisted Vaginal Delivery

    Science.gov (United States)

    ... having a repeat assisted vaginal delivery in a future pregnancy? If you have had one assisted vaginal ... Education Green Journal Practice Management Coding Health Info Technology Professional Liability Managing Your Practice Patient Safety & Quality ...

  4. ForeignAssistance.gov

    Data.gov (United States)

    US Agency for International Development — ForeignAssistance.gov provides a view of U.S. Government foreign assistance funds across agencies and enables users to explore, analyze, and review aid investments...

  5. Assisted Reproductive Technology (ART)

    Science.gov (United States)

    ... Information Clinical Trials Resources and Publications Assisted Reproductive Technology (ART) Skip sharing on social media links Share ... American Society for Reproductive Medicine. (2012). Assisted reproductive technologies: A guide for patients . Retrieved June 11, 2012, ...

  6. Antireflection coatings on plastics deposited by plasma polymerization process

    Indian Academy of Sciences (India)

    K M K Srivatsa; M Bera; A Basu; T K Bhattacharya

    2008-08-01

    Antireflection coatings (ARCs) are deposited on the surfaces of optical elements like spectacle lenses to increase light transmission and improve their performance. In the ophthalmic industry, plastic lenses are rapidly displacing glass lenses due to several advantageous features. However, the deposition of ARCs on plastic lenses is a challenging task, because the plastic surface needs treatment for adhesion improvement and surface hardening before depositing the ARC. This surface treatment is usually done in a multi-stage process—exposure to energetic radiations, followed by deposition of a carbonyl hard coating by spin or dip coating processes, UV curing, etc. However, this treatment can also be done by plasma processes. Moreover, the plasma polymerization process allows deposition of optical films at room temperature, essential for plastics. The energetic ions in plasma processes provide similar effects as in ion assisted physical deposition processes to produce hard coatings, without requiring sophisticated ion sources. The plasma polymerization process is more economical than ion-assisted physical vapour deposition processes as regards equipment and source materials and is more cost-effective, enabling the surface treatment and deposition of the ARC in the same deposition system in a single run by varying the system parameters at each step. Since published results of the plasma polymerization processes developed abroad are rather sketchy and the techniques are mostly veiled in commercial secrecy, innovative and indigenous plasma-based techniques have been developed in this work for depositing the complete ARCs on plastic substrates.

  7. VIDEO ASSISTED THYROIDECTOMY

    OpenAIRE

    C. Bradea

    2009-01-01

    Video assisted techniques were documented by M.Gagner (1996 – video assisted parathyroidectomy), Henry (1999), Shimizu (1999), Ohgami (2000), Miccoli (2000 – video assisted parathyroidectomy and thyroidectomy). The advantage of this kind of surgery: aesthetics i.e. trying to make only small scars on the neck. Our first case of video assisted thyroidectomy was a female 50 years of age, with multinodular goiter, nodules of 2-3 cm in each lobe, admitted in our clinic in December 2008. History of...

  8. Diamond deposition on siliconized stainless steel

    International Nuclear Information System (INIS)

    Silicon diffusion layers in AISI 304 and AISI 316 type stainless steels were investigated as an alternative to surface barrier coatings for diamond film growth. Uniform 2 μm thick silicon rich interlayers were obtained by coating the surface of the steels with silicon and performing diffusion treatments at 800 deg. C. Adherent diamond films with low sp2 carbon content were deposited on the diffused silicon layers by a modified hot filament assisted chemical vapor deposition (HFCVD) method. Characterization of as-siliconized layers and diamond coatings was performed by energy dispersive X-ray analysis, scanning electron microscopy, X-ray diffraction and Raman spectroscopy.

  9. Structural characterization of MAPLE deposited lipase biofilm

    Science.gov (United States)

    Aronne, Antonio; Ausanio, Giovanni; Bloisi, Francesco; Calabria, Raffaela; Califano, Valeria; Fanelli, Esther; Massoli, Patrizio; Vicari, Luciano R. M.

    2014-11-01

    Lipases (triacylglycerol ester hydrolases) are enzymes used in several industrial applications. Enzymes immobilization can be used to address key issues limiting widespread application at industrial level. Immobilization efficiency is related to the ability to preserve the native conformation of the enzyme. MAPLE (Matrix Assisted Pulsed Laser Evaporation) technique, a laser deposition procedure for treating organic/polymeric/biomaterials, was applied for the deposition of lipase enzyme in an ice matrix, using near infrared laser radiation. Microscopy analysis showed that the deposition occurred in micrometric and submicrometric clusters with a wide size distribution. AFM imaging showed that inter-cluster regions are uniformly covered with smaller aggregates of nanometric size. Fourier transform infrared spectroscopy was used for both recognizing the deposited material and analyzing its secondary structure. Results showed that the protein underwent reversible self-association during the deposition process. Actually, preliminary tests of MAPLE deposited lipase used for soybean oil transesterification with isopropyl alcohol followed by gas chromatography-mass spectrometry gave results consistent with undamaged deposition of lipase.

  10. Efeito da velocidade do ar em barra de pulverização na deposição de produtos fitossanitários em feijoeiro Efect of the air speed in air-assisted sprayer on bean crop pesticide spray deposition

    Directory of Open Access Journals (Sweden)

    Carlos Gilberto Raetano

    2003-01-01

    Full Text Available Com o objetivo de avaliar o efeito da variação da velocidade do ar em barra de pulverização na deposição da calda na cultura do feijoeiro (Phaseolus vulgaris, realizou-se o experimento em 9 e 10 de outubro de 2000, no Centro de Pesquisas Agronômicas - Cyanamid, em Iracemápolis (SP, em delineamento inteiramente casualizado, aos 48 dias após a emergência (DAE. Para isso, convencionou-se que a rotação máxima do ventilador, medida com o auxílio de fototacômetro, possibilitou a obtenção da velocidade máxima do ar na barra de pulverização e, a partir daí, níveis de 50% e 75% da velocidade máxima do ar. Alvos artificiais foram fixados na superfície adaxial e na abaxial de folíolos posicionados, nos terços superior e inferior das plantas selecionadas, ao acaso, e distribuídas perpendicularmente ao deslocamento do pulverizador. O óxido cuproso (50% de cobre metálico foi o traçador utilizado em pulverização e a determinação quantitativa dos depósitos feita com o uso da espectrofotometria de absorção atômica. Os resultados sugerem que a variação da velocidade do ar na barra pulverizadora não influenciou sobre os níveis de depósitos no feijoeiro, aos 48 DAE, nas condições do presente trabalho.The aim of this research was to evaluate the effects of air speed in air-assisted sprayer on bean crop (Phaseolus vulgaris spray deposition. The experiment was carried out at 48 days after crop emergence and the experimental design was randomized. The maximum air speed in spray boom was obtained with the maximum of the fan rotation by a phototachometer. The middle and third air speed were obtained with lower fan rotation. The tracer used in the spray solution was copper oxid (50% of the metalic copper. It was measured by atomic spectrophotometry absorption equipment. The targets were fixed on the under and upper-side of the leaves, in the top and lower third of the same plant under the spray boom. The effects of variation

  11. 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.

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

    Institute of Scientific and Technical Information of China (English)

    LI; Dejun

    2001-01-01

    [1]Gallagher, J. J., Simpson, J. A., Search for trapped electrons and a magnetic moment at Mars by Mariner IV, Science, 1965, 149: 1233—1239.[2]Russell, C. T., The magnetic field of Mars: Mars 3 evidence reexamined, Geophys. Res. Lett., 1978, 5: 81—86.[3]Riedler, W., Schwingenschun, K., Lichtenegger, H. et al., Interaction of solar wind with the planet Mars: Phobos 2 magnetic field observations, Planet. Space Sci., 1991, 39: 75—81.[4]Gringauz, K. I., What was known about the Martian magnetosphere before Phobos-2 mission, Planet. Space Sci., 1991, 39: 73—74.[5]Acuna, M. H., Connerney, J. E. P., Wasilewski, P. et al., Magnetic field and plasma observations at Mars: Initial results of the Mars global surveyor mission, Science, 1998, 279: 1676—1680.[6]Mohlmann, D., Riedler. W., Rustenbuch, J. et al., The question of an internal Martian magnetic field, Planet. Space Sci., 1991, 39: 83—88.[7]Shi, J. K., Liu, Z. X., Zhang, T. L., A theoretical study on the O+ ions of the Martian magnetosphere, Chin Astron Astrophys., 1999, 23: 377—383.[8]Rosenbauer, H., Shutte, N., Apathy, I. et al., Ions of Martian origin and plasma sheet in the Martian magnetotail: Initial results of TAUS experiment, Nature, 1989, 341: 612—614.[9]Lundin, R., Zakharov, A., Pelinen, R. et al., ASPERA/Phobos measurements of the ion outflow from the Martian ionosphere, Geophy. Res. Lett., 1990, 17: 873—876.[10]Verigin, M. I., Shutte, N. M., Galeev, A. A. et al., Ions of planetary origin in the Martian magnetosphere (Phobos 2 / TAUS experiment), Planet. Space Sci., 1991, 39: 131—137.[11]Lundin, R., Zakharov, A., Pelinen, R. et al., First measurements of the ionospheric plasma escape from Mars, Nature, 1989, 341: 609—612.[12]Lammer, H., Bauer, S. J., Nonthermal atmospheric escape from Mars and Titan, J. Geophys. Res., 1991, 96: 1819—1826.[13]Haider, S. A., O+ escape in the polar ion exosphere of Mars, Adv. Space Res., 1995, 16: 49—55.[14]Shi. J. K., Liu, Z. X., Zhang, T. L. et al., The influence of the intrinsic magnetic field on the distribution of O+ in Martian magnetosphere, Chinese Science Bulletin (in Chinese), 1997, 42(23): 1898—1901.[15]Luhmann, J. G., Brace, L. H., Near-Mars space, Rev. Geophys., 1991, 29: 121—140.[16]Luhmann, J. G., Schwingenschuh, K., A model of the magnetic ion environment of Mars, J. Geophys. Res., 1990, 95: 939—945.[17]Slavin, J. A., Schwingenschuh, K., Reidler, W. et al., The solar wind interaction with Mars: Mariner-4, Mars-2,3,5, and Phobos-2 observation of bow shock position and shape, J. Geophys. Res., 1991, 96: 11235—11241.[18]Eviater, A., Lencheek, A. M., Singer, S. F., Distribution of density in an ion-exosphere of a nonrotating planet, Phys. Fluids, 1964, 7: 1775—1779.

  13. Microstructural and Tribological Characterization of Duplex Coatings with Additional Ion Bombardment

    Institute of Scientific and Technical Information of China (English)

    B.Skorie; D.Kakas; M.akita

    2004-01-01

    A duplex surface treatment involves the sequential application of two surface technologies to produce a surface composition with combined properties. A typical duplex process involves plasma nitriding and the PVD coating treatment of steels. In the paper are presented characteristics of hard coatings, type TiN, produced by classic technology PVD (physical vapour deposition) and IBAD (ion beam assisted deposition). Subsequent ion implantation was provided with N5+ ions. The dependence of friction coefficient was investigated by means of tribometer (pin-on-ring). The sliding pair was TiN thin coating on steel pin combined with steel ring without coating. The ring was produced from hardenable steel.

  14. Microstructural and Tribological Characterization of Duplex Coatings with Additional Ion Bombardment

    Institute of Scientific and Technical Information of China (English)

    B.(S)kori(c); D.Kaka(s); M.Rakita

    2004-01-01

    A duplex surface treatment involves the sequential application of two surface technologies to produce a surface composition with combined properties. A typical duplex process involves plasma nitriding and the PVD coating treatment of steels. In the paper are presented characteristics of hard coatings, type TiN, produced by classic technology PVD (physical vapour deposition) and IBAD (ion beam assisted deposition). Subsequent ion implantation was provided with N5+ions. The dependence of friction coefficient was investigated by means of tribometer (pin-on-ring). The sliding pair was TiN thin coating on steel pin combined with steel ring without coating. The ring was produced from hardenable steel.

  15. Electro-Deposition Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The electro-deposition laboratory can electro-deposit various coatings onto small test samples and bench level prototypes. This facility provides the foundation for...

  16. Calcium Pyrophosphate Deposition (CPPD)

    Science.gov (United States)

    ... Patient / Caregiver Diseases & Conditions Calcium Pyrophosphate Deposition (CPPD) Calcium Pyrophosphate Deposition (CPPD) Fast Facts The risk of ... young people, too. Proper diagnosis depends on detecting calcium pyrophosphate crystals in the fluid of an affected ...

  17. Physical vapor deposition of cubic boron nitride thin films

    International Nuclear Information System (INIS)

    Cubic boron nitride was successfully deposited using physical vapor-deposition methods. RF-sputtering, magnetron sputtering, dual-ion-beam deposition, and ion-beam-assisted evaporation were all used. The ion-assisted evaporation, using boron evaporation and bombardment by nitrogen and argon ions, led to successful cubic boron nitride growth over the widest and most controllable range of conditions. It was found that two factors were important for c-BN growth: bombardment of the growing film and the presence of argon. A systematic study of the deposition conditions was carried out. It was found that the value of momentum transferred into the growing from by the bombarding ions was critical. There was a very narrow transition range in which mixed cubic and hexagonal phase films were prepared. Momentum-per-atom value took into account all the variables involved in ion-assisted deposition: deposition rate, ion energy, ion flux, and ion species. No other factor led to the same control of the process. The role of temperature was also studied; it was found that at low temperatures only mixed cubic and hexagonal material are deposited

  18. Research on Advanced Thin Film Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Goldner, Ronald B. [Tufts Univ., Medford, MA (United States)

    2003-11-24

    During the past 7 years, the Tufts group has been carrying out research on advanced thin film batteries composed of a thin film LiCo02 cathode (positive electrode), a thin film LiPON (lithium phosphorous oxynitride) solid electrolyte, and a thin film graphitic carbon anode (negative electrode), under grant DE FG02-95ER14578. Prior to 1997, the research had been using an rfsputter deposition process for LiCoOi and LiPON and an electron beam evaporation or a controlled anode arc evaporation method for depositing the carbon layer. The pre-1997 work led to the deposition of a single layer cell that was successfully cycled for more than 400 times [1,2] and the research also led to the deposition of a monolithic double-cell 7 volt battery that was cycled for more than 15 times [3]. Since 1997, the research has been concerned primarily with developing a research-worthy and, possibly, a production-worthy, thin film deposition process, termed IBAD (ion beam assisted deposition) for depositing each ofthe electrodes and the electrolyte of a completely inorganic solid thin film battery. The main focus has been on depositing three materials - graphitic carbon as the negative electrode (anode), lithium cobalt oxide (nominally LiCoCb) as the positive electrode (cathode), and lithium phosphorus oxynitride (LiPON) as the electrolyte. Since 1998, carbon, LiCoOa, and LiPON films have been deposited using the IBAD process with the following results.

  19. Selection of bentonite deposits

    International Nuclear Information System (INIS)

    The selection of bentonite deposits is to offer a supply base of backfill/buffer materials for high-level radioactive waste repository in China. In this paper the comprehensive evaluation criteria were discussed first, then a comprehensive comment on bentonite deposits in China was given. The properties of geographic distribution, origin, reserves and ore quality of bentonite deposits were also discussed. The comprehensive comparison studies on 12 large-sized bentonite deposits was presented. Based on the results obtained Gaomiaozi bentonite deposit, Inner Mongolia, was recommended as the first choice of backfill/buffer materials for repository in China. (author)

  20. Assistance Focus: Africa (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2014-12-01

    The Clean Energy Solutions Center Ask an Expert service connects governments seeking policy information and advice with one of more than 30 global policy experts who can provide reliable and unbiased quick-response advice and information. The service is available at no cost to government agency representatives from any country and the technical institutes assisting them. This publication presents summaries of assistance provided to African governments, including the benefits of that assistance.

  1. Acid Deposition Phenomena

    International Nuclear Information System (INIS)

    Acid deposition, commonly known as acid rain, occurs when emissions from the combustion of fossil fuels and other industrial processes undergo complex chemical reactions in the atmosphere and fall to the earth as wet deposition (rain, snow, cloud, fog) or dry deposition (dry particles, gas). Rain and snow are already naturally acidic, but are only considered problematic when less than a ph of 5.0 The main chemical precursors leading to acidic conditions are atmospheric concentrations of sulfur dioxide (SO2) and nitrogen oxides (NOx). When these two compounds react with water, oxygen, and sunlight in the atmosphere, the result is sulfuric (H2SO4) and nitric acids (HNO3), the primary agents of acid deposition which mainly produced from the combustion of fossil fuel and from petroleum refinery. Airborne chemicals can travel long distances from their sources and can therefore affect ecosystems over broad regional scales and in locations far from the sources of emissions. According to the concern of petroleum ministry with the environment and occupational health, in this paper we will discussed the acid deposition phenomena through the following: Types of acidic deposition and its components in the atmosphere Natural and man-made sources of compounds causing the acidic deposition. Chemical reactions causing the acidic deposition phenomenon in the atmosphere. Factors affecting level of acidic deposition in the atmosphere. Impact of acid deposition. Procedures for acidic deposition control in petroleum industry

  2. HT deposition to snow

    International Nuclear Information System (INIS)

    A series of exposure chamber measurements of the deposition of HT to snow were conducted at a field site. These experiments indicate that deposition velocities for conversion of HT to HTO are likely 10-6 m s-1 or less, which is approximately two to three orders of magnitude slower than deposition to soils under growing season conditions. Previous measurements of deposition to soil under freezing or near-freezing conditions also indicated very low deposition velocities. Deposition under winder conditions is thus likely to be much slower than deposition to soil under growing season conditions. It is concluded that exposure to HTO formed by the conversion of HT to HTO during a winter release of HT over snow or frozen ground is likely to be small compared to the dose from the HT plume itself. (4 tabs., 5 figs., 14 refs.)

  3. Turning assistive machines into assistive robots

    Science.gov (United States)

    Argall, Brenna D.

    2015-01-01

    For decades, the potential for automation in particular, in the form of smart wheelchairs to aid those with motor, or cognitive, impairments has been recognized. It is a paradox that often the more severe a person's motor impairment, the more challenging it is for them to operate the very assistive machines which might enhance their quality of life. A primary aim of my lab is to address this confound by incorporating robotics autonomy and intelligence into assistive machines turning the machine into a kind of robot, and offloading some of the control burden from the user. Robots already synthetically sense, act in and reason about the world, and these technologies can be leveraged to help bridge the gap left by sensory, motor or cognitive impairments in the users of assistive machines. This paper overviews some of the ongoing projects in my lab, which strives to advance human ability through robotics autonomy.

  4. Airfoil deposition model

    Science.gov (United States)

    Kohl, F. J.

    1982-01-01

    The methodology to predict deposit evolution (deposition rate and subsequent flow of liquid deposits) as a function of fuel and air impurity content and relevant aerodynamic parameters for turbine airfoils is developed in this research. The spectrum of deposition conditions encountered in gas turbine operations includes the mechanisms of vapor deposition, small particle deposition with thermophoresis, and larger particle deposition with inertial effects. The focus is on using a simplified version of the comprehensive multicomponent vapor diffusion formalism to make deposition predictions for: (1) simple geometry collectors; and (2) gas turbine blade shapes, including both developing laminar and turbulent boundary layers. For the gas turbine blade the insights developed in previous programs are being combined with heat and mass transfer coefficient calculations using the STAN 5 boundary layer code to predict vapor deposition rates and corresponding liquid layer thicknesses on turbine blades. A computer program is being written which utilizes the local values of the calculated deposition rate and skin friction to calculate the increment in liquid condensate layer growth along a collector surface.

  5. Service water assistance program

    Energy Technology Data Exchange (ETDEWEB)

    Munchausen, J.H. [EPRI Plant Support Engineering, Charlotte, NC (United States)

    1995-09-01

    The Service Water Assistance Program was developed to provide utility service water system engineers with a mechanism to quickly and efficiently address service water issues. Since its inception, its ability to assist utilities has resulted in a reduction in the operations and maintenance costs associated with service water systems and has provided a medium for EPRI awareness of industry service water issues.

  6. Service water assistance program

    International Nuclear Information System (INIS)

    The Service Water Assistance Program was developed to provide utility service water system engineers with a mechanism to quickly and efficiently address service water issues. Since its inception, its ability to assist utilities has resulted in a reduction in the operations and maintenance costs associated with service water systems and has provided a medium for EPRI awareness of industry service water issues

  7. Egress door opening assister

    Energy Technology Data Exchange (ETDEWEB)

    Allison, Thomas L.

    2015-10-06

    A door opening spring assistance apparatus is set forth that will automatically apply a door opening assistance force using a combination of rods and coil springs. The release of the rods by the coil springs reduces the force required to set the door in motion.

  8. Shedding of ash deposits

    DEFF Research Database (Denmark)

    Zbogar, Ana; Frandsen, Flemming; Jensen, Peter Arendt;

    2009-01-01

    Ash deposits formed during fuel thermal conversion and located on furnace walls and on convective pass tubes, may seriously inhibit the transfer of heat to the working fluid and hence reduce the overall process efficiency. Combustion of biomass causes formation of large quantities of troublesome...... ash deposits which contain significant concentrations of alkali, and earth-alkali metals. The specific composition of biomass deposits give different characteristics as compared to coal ash deposits, i.e. different physical significance of the deposition mechanisms, lower melting temperatures, etc....... Low melting temperatures make straw ashes especially troublesome, since their stickiness is higher at lower temperatures, compared to coal ashes. Increased stickiness will eventually lead to a higher collection efficiency of incoming ash particles, meaning that the deposit may grow even faster...

  9. Designing Real Time Assistive Technologies

    DEFF Research Database (Denmark)

    Sonne, Tobias; Obel, Carsten; Grønbæk, Kaj

    2015-01-01

    design criteria in relation to three core components (sensing, recognizing, and assisting) for designing real time assistive technologies for children with ADHD. Based on these design criteria, we designed the Child Activity Sensing and Training Tool (CASTT), a real time assistive prototype that captures......) real time assistive technologies have potential to assist children with ADHD in regaining attention in critical school situations....

  10. The Imouraren deposit, Niger

    International Nuclear Information System (INIS)

    Imouraren deposit has been discovered in the late sixties. It is located South of Arlit where two mines are mined, one open pit and one underground. The grades of reduced Imouraren Uranium ore are lesser than these of Arlit and Akouta. Imouraren deposit is owned by COGEMA (France): 70% and ONAREM (Niger): 30%. The concession area is about 45 square kilometers. The thickness of the deposit is between 50 and 60 meters and its depth reaches 110 to 170 meters. (author)

  11. Deposits and relationship lending

    OpenAIRE

    Mitchell Berlin; Mester, Loretta J.

    1998-01-01

    The authors empirically examine the hypothesis that access to deposits with inelastic rates (core deposits) permits a bank to make contractual agreements with borrowers that are infeasible if the bank must pay market rates for its funds. Access to core deposits insulates a bank's costs of funds from exogenous shocks, allowing the bank to insulate its borrowers against exogenous credit shocks. Using a large sample of loans from the Survey of the Terms of Bank Lending, the authors find that whe...

  12. Uraniferous surficial deposits

    International Nuclear Information System (INIS)

    As a result of the discovery of uranium in surficial deposits of Tertiary to Recent age, in Australia and Southern Africa, increasing attention is being paid to the location and understanding of the genesis of these deposits. The paper discusses the definitions and terminology currently in use and a classification of these deposits is presented. It is concluded that in order to obtain a measure of clarity, the terms calcrete, gypcrete and dolocrete should not be used to describe the uraniferous valley-fill deposits of Southern Africa and Australia

  13. Fundamentals of laser-assisted fabrication of inorganic and organic films

    DEFF Research Database (Denmark)

    Schou, Jørgen

    The standard method for producing films by laser-assisted methods, Pulsed Laser Deposition (PLD) will be reviewed. The films considered are usually inorganic films, but also films of organic materials have been produced. Also the deposition of organic films by MAPLE (Matrix Assisted Pulsed Laser...... Evaporation), in which the target is replaced by a frozen matrix containing a few per cent film material, will be reviewed....

  14. Microstructure of vapor deposited coatings on curved substrates

    International Nuclear Information System (INIS)

    Thermal barrier coating systems consisting of a metallic bond coat and ceramic over layer are widely used to extend the life of gas turbine engine components. They are applied using either high-vacuum physical vapor deposition techniques in which vapor atoms rarely experience scattering collisions during propagation to a substrate, or by gas jet assisted (low-vacuum) vapor deposition techniques that utilize scattering from streamlines to enable non-line-of-sight deposition. Both approaches require substrate motion to coat a substrate of complex shape. Here, direct simulation Monte Carlo and kinetic Monte Carlo simulation methods are combined to simulate the deposition of a nickel coating over the concave and convex surfaces of a model airfoil, and the simulation results are compared with those from experimental depositions. The simulation method successfully predicted variations in coating thickness, columnar growth angle, and porosity during both stationary and substrate rotated deposition. It was then used to investigate a wide range of vapor deposition conditions spanning high-vacuum physical vapor deposition to low-vacuum gas jet assisted vapor deposition. The average coating thickness was found to increase initially with gas pressure reaching a maximum at a chamber pressure of 8–10 Pa, but the best coating thickness uniformity was achieved under high vacuum deposition conditions. However, high vacuum conditions increased the variation in the coatings pore volume fraction over the surface of the airfoil. The simulation approach was combined with an optimization algorithm and used to investigate novel deposition concepts to tailor the local coating thickness

  15. Microstructure of vapor deposited coatings on curved substrates

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, Theron M.; Zhao, Hengbei; Wadley, Haydn N. G., E-mail: haydn@virginia.edu [Department of Materials Science and Engineering, University of Virginia, 395 McCormick Rd., P.O. Box 400745, Charlottesville, Virginia 22904 (United States)

    2015-09-15

    Thermal barrier coating systems consisting of a metallic bond coat and ceramic over layer are widely used to extend the life of gas turbine engine components. They are applied using either high-vacuum physical vapor deposition techniques in which vapor atoms rarely experience scattering collisions during propagation to a substrate, or by gas jet assisted (low-vacuum) vapor deposition techniques that utilize scattering from streamlines to enable non-line-of-sight deposition. Both approaches require substrate motion to coat a substrate of complex shape. Here, direct simulation Monte Carlo and kinetic Monte Carlo simulation methods are combined to simulate the deposition of a nickel coating over the concave and convex surfaces of a model airfoil, and the simulation results are compared with those from experimental depositions. The simulation method successfully predicted variations in coating thickness, columnar growth angle, and porosity during both stationary and substrate rotated deposition. It was then used to investigate a wide range of vapor deposition conditions spanning high-vacuum physical vapor deposition to low-vacuum gas jet assisted vapor deposition. The average coating thickness was found to increase initially with gas pressure reaching a maximum at a chamber pressure of 8–10 Pa, but the best coating thickness uniformity was achieved under high vacuum deposition conditions. However, high vacuum conditions increased the variation in the coatings pore volume fraction over the surface of the airfoil. The simulation approach was combined with an optimization algorithm and used to investigate novel deposition concepts to tailor the local coating thickness.

  16. Weatherization Assistance Program Technical Assistance Center

    Energy Technology Data Exchange (ETDEWEB)

    Robert Adams

    2009-01-07

    The following is a synopsis of the major achievements attributed to the operation of the Weatherization Assistance Program Technical Assistance Center (WAPTAC) by the National Association for State Community Services Programs (NASCSP). During the past five years, the WAPTAC has developed into the premier source for information related to operating the Weatherization Assistance Program (WAP) at the state and local levels. The services provide through WAPTAC include both virtual technical support as well as hands-on training and instruction in classroom and in the field. The WAPTAC achieved several important milestones during its operation including the establishment of a national Weatherization Day now celebrated in most states, the implementation of a comprehensive Public Information Campaign (PIC) to raise the awareness of the Program among policy makers and the public, the training of more than 150 new state managers and staff as they assume their duties in state offices around the country, and the creation and support of a major virtual information source on the Internet being accessed by thousands of staff each month. The Weatherization Assistance Program Technical Assistance Center serves the Department of Energy's (DOE) Office of Weatherization and Intergovernmental Program as a valuable training and technical assistance resource for the network of 54 direct state grantees (50 states, District of Columbia and three Native American tribes) and the network of 900 local subgrantees (comprised of community action agencies, units of local government, and other non-profit organizations). The services provided through WAPTAC focus on standardizing and improving the daily management of the WAP. Staff continually identify policies changes and best practices to help the network improve its effectiveness and enhance the benefits of the Program for the customers who receive service and the federal and private investors. The operations of WAPTAC are separated into

  17. FEMA Hazard Mitigation Assistance Flood Mitigation Assistance (FMA) Data

    Data.gov (United States)

    Department of Homeland Security — This dataset contains closed and obligated projects funded under the following Hazard Mitigation Assistance (HMA) grant programs: Flood Mitigation Assistance (FMA)....

  18. Social and Human Service Assistants

    Science.gov (United States)

    ... Similar Occupations More Info Summary Social and human service assistants help clients to identify and obtain benefits and services. Quick ... and Human Service Assistants Do Social and human service assistants provide client services, including support for families, in a wide ...

  19. Robotic assisted laparoscopic colectomy.

    LENUS (Irish Health Repository)

    Pandalai, S

    2010-06-01

    Robotic surgery has evolved over the last decade to compensate for limitations in human dexterity. It avoids the need for a trained assistant while decreasing error rates such as perforations. The nature of the robotic assistance varies from voice activated camera control to more elaborate telerobotic systems such as the Zeus and the Da Vinci where the surgeon controls the robotic arms using a console. Herein, we report the first series of robotic assisted colectomies in Ireland using a voice activated camera control system.

  20. Deposition patterns with Turbuhaler.

    Science.gov (United States)

    Borgström, L

    1994-01-01

    The degree of lung deposition is an important factor in the evaluation of different inhalation flow driven dry powder inhalers. A number of studies using radioactive and non-radioactive methods have been performed with Turbuhaler to assess lung deposition under different conditions. Mean total lung deposition of terbutaline sulfate or budesonide via Turbuhaler in healthy volunteers ranged from 21-32% of the dose when a normal inhalation flow (60L/min) was used. At a low flow (30L/min) a mean 15% of the dose was deposited in the lungs, a similar value as for a well-performed inhalation via a pressurized metered dose inhaler. Regional deposition of inhaled drug can be expressed as the ratio between the amount of drug deposited in the more peripheral parts of the lung relative to the more central parts. In a comparative study, budesonide and terbutaline sulfate were given by inhalation via Turbuhaler to healthy volunteers. The ratio of peripheral to central deposition was 2.03 for terbutaline and 1.72 for budesonide. Thus, both the water-soluble terbutaline sulfate and the non-water soluble budesonide seemed to behave in the same way when inhaled via Turbuhaler. In conclusion, Turbuhaler delivers over 20% of a metered dose to the lungs when inhaled at a normal inhalation flow rate. The regional deposition pattern in the lungs was the same for terbutaline sulfate and budesonide, in spite of differences in water solubility. PMID:10147081

  1. Biomimetic thin film deposition

    Energy Technology Data Exchange (ETDEWEB)

    Rieke, P.R.; Graff, G.E.; Campbell, A.A.; Bunker, B.C.; Baskaran, S.; Song, L.; Tarasevich, B.J.; Fryxell, G.E.

    1995-09-01

    Biological mineral deposition for the formation of bone, mollusk shell and other hard tissues provides materials scientists with illustrative materials processing strategies. This presentation will review the key features of biomineralization and how these features can be of technical importance. We have adapted existing knowledge of biomineralization to develop a unique method of depositing inorganic thin films and coating. Our approach to thin film deposition is to modify substrate surfaces to imitate the proteins found in nature that are responsible for controlling mineral deposition. These biomimetic surfaces control the nucleation and growth of the mineral from a supersaturated aqueous solution. This has many processing advantages including simple processing equipment, environmentally benign reagents, uniform coating of highly complex shapes, and enhanced adherence of coating. Many different types of metal oxide, hydroxide, sulfide and phosphate materials with useful mechanical, optical, electronic and biomedical properties can be deposited.

  2. Robot-Assisted Prostatectomy

    Medline Plus

    Full Text Available ... this da Vinci assisted laparoscopic radical prostatectomy. Our scrub, which is Alex Santander, our nurse anesthetist back ... Okay, Dr. Pinon, you’re going to come scrub in? Yes, I will, yes. Dr. Pinon is ...

  3. Robot-Assisted Prostatectomy

    Medline Plus

    Full Text Available ... joysticks and his feet pressing on pedals to control these robotic instruments. There’s almost always an assistant ... Sure. To help divide the tissue and to control bleeding. Right now I’m going to clean ...

  4. Superfund Technical Assistance Grants

    Data.gov (United States)

    U.S. Environmental Protection Agency — This asset includes data related to the Superfund Technical Assistance Grant program, including grant number, award amounts, award dates, period of performance,...

  5. Financial Assistance Information

    Science.gov (United States)

    ... Other Sites: Genetic and Rare Diseases Information Center Financial Assistance Information The National Institutes of Health (NIH) ... area call 900-638-0742. Top of page Financial Aid for Medical Treatments Information on financial aid ...

  6. Robot-Assisted Prostatectomy

    Medline Plus

    Full Text Available ... Robotic Surgery. My name is Dr. Andy Pinon. This is my partner, Dr. Darren Bruck. He’s going ... at the very beginning, helping us navigate through this da Vinci assisted laparoscopic radical prostatectomy. Our scrub, ...

  7. Robot-Assisted Prostatectomy

    Medline Plus

    Full Text Available Watch South Miami Hospital Surgeons Perform Robot-Assisted Prostatectomy South Miami Hospital Miami, FL January 19, 2010 Good afternoon. Welcome to the South Miami Hospital operating room, the Center ...

  8. Computer assisted radiology

    International Nuclear Information System (INIS)

    The proceedings of the CAR'93 symposium present the 126 oral papers and the 58 posters contributed to the four Technical Sessions entitled: (1) Image Management, (2) Medical Workstations, (3) Digital Image Generation - DIG, and (4) Application Systems - AS. Topics discussed in Session (1) are: picture archiving and communication systems, teleradiology, hospital information systems and radiological information systems, technology assessment and implications, standards, and data bases. Session (2) deals with computer vision, computer graphics, design and application, man computer interaction. Session (3) goes into the details of the diagnostic examination methods such as digital radiography, MRI, CT, nuclear medicine, ultrasound, digital angiography, and multimodality imaging. Session (4) is devoted to computer-assisted techniques, as there are: computer assisted radiological diagnosis, knowledge based systems, computer assisted radiation therapy and computer assisted surgical planning. (UWA). 266 figs

  9. Homelessness Assistance and Resources

    Science.gov (United States)

    ... Performance Measure Resources View videos, programming specifications, an introductory guide, and more on how CoCs can measure ... a Program Affordable Housing Community Development Consolidated Planning Economic Development Environmental Review Financial Management Homelessness Assistance Rural ...

  10. Assisted Reproductive Technology

    Science.gov (United States)

    Assisted reproductive technology (ART) is used to treat infertility. It includes fertility treatments that handle both a woman's egg ... back in the woman's body. In vitro fertilization (IVF) is the most common and effective type of ...

  11. Robot-Assisted Prostatectomy

    Medline Plus

    Full Text Available ... prostatic fossa. Okay. This is where the prostate sat. If you look at the bottom of the ... as assistant, and I am waiting for the new instruments to be inserted so we can perform ...

  12. Concepts in Assisted Circulation

    OpenAIRE

    Lefemine, Armand A.; Dunbar, Jacob; DeLucia, Anthony

    1986-01-01

    Assisted circulation by extracorporeal and extracardiac bypass techniques must be based on the requirements of the heart and of the total body, though these may differ. The cardiac problem in cardiogenic shock is more likely to be a biventricular problem demanding decompression of both sides. Extra pulmonary oxygenation should be avoided because of complexity in long-term use. Principles of assisted circulation may be applied in an extra-thoracic temporary manner or as an intracorporeal long-...

  13. Heteronuclear proton assisted recoupling

    OpenAIRE

    De Paëpe, Gaël; Lewandowski, Józef R.; Loquet, Antoine; Eddy, Matt; Megy, Simon; Böckmann, Anja; Griffin, Robert G.

    2011-01-01

    We describe a theoretical framework for understanding the heteronuclear version of the third spin assisted recoupling polarization transfer mechanism and demonstrate its potential for detecting long-distance intramolecular and intermolecular 15N–13C contacts in biomolecular systems. The pulse sequence, proton assisted insensitive nuclei cross polarization (PAIN-CP) relies on a cross term between 1H–15N and 1H–13C dipolar couplings to mediate zero- and/or double-quantum 15N–13C recoupling. In ...

  14. Mechanical Circulatory Assist Devices

    OpenAIRE

    Park, Sang B.; Magovern, George J.; Christlieb, Ignacio Y.; Kao, Race L.

    1987-01-01

    Cardiogenic shock occurs in about 10% of the 1.5 million patients who suffer myocardial infarction and in approximately 1% of the 200,000 patients who undergo open-heart surgery each year. The ventricular assist device decreases the workload of the failing ventricles and increases the blood flow through the coronary system. Recovery of failing myocardium after mechanical circulatory assistance has been well documented; however, the mechanisms that contribute to the recovery of a failing heart...

  15. Processing of C60 thin films by Matrix-Assisted Pulsed Laser Evaporation (MAPLE)

    DEFF Research Database (Denmark)

    Canulescu, Stela; Schou, Jørgen; Fæster, Søren

    2011-01-01

    Thin films of fullerenes (C60) were deposited onto silicon using matrix-assisted pulsed laser evaporation (MAPLE). The deposition was carried out from a frozen homogeneous dilute solution of C60 in anisole (0.67 wt%), and over a broad range of laser fluences, from 0.15 J/cm2 up to 3.9 J/cm2. MAPL...

  16. CANDU energy for steam assisted gravity drainage

    International Nuclear Information System (INIS)

    Traditional open-pit mining has been used by industry for many years to remove oil sands from shallow deposits. To increase production capacity, the industry is looking for new technology to exploit bitumen from deep deposits. Among them, SAGD (Steam-Assisted Gravity Drainage) appears to be the most promising approach. It uses steam to remove bitumen from underground reservoirs. Recently, the SAGD recovery process has been put into commercial operation by major oil companies.Atomic Energy Canada Limited has assessed the use of the ACR-1000 as a source of heat and electricity for oil sand extraction and processing. The ACR-1000 design is an evolutionary development of the familiar CANDU technology, adding innovations to enhance economics, operations, and safety margins. The net electrical output from a standard ACR-1000 will be close to 1100 MWe, depending on local cooling water temperature

  17. Multiphoton polymerization using optical trap assisted nanopatterning

    Science.gov (United States)

    Leitz, Karl-Heinz; Tsai, Yu-Cheng; Flad, Florian; Schäffer, Eike; Quentin, Ulf; Alexeev, Ilya; Fardel, Romain; Arnold, Craig B.; Schmidt, Michael

    2013-06-01

    In this letter, we show the combination of multiphoton polymerization and optical trap assisted nanopatterning (OTAN) for the additive manufacturing of structures with nanometer resolution. User-defined patterns of polymer nanostructures are deposited on a glass substrate by a 3.5 μm polystyrene sphere focusing IR femtosecond laser pulses, showing minimum feature sizes of λ/10. Feature size depends on the applied laser fluence and the bead surface spacing. A finite element model describes the intensity enhancement in the microbead focus. The results presented suggest that OTAN in combination with multiphoton processing is a viable technique for additive nanomanufacturing with sub-diffraction-limited resolution.

  18. Ion implantation inhibits cell attachment to glassy polymeric carbon

    International Nuclear Information System (INIS)

    Implantation of MeV gold, oxygen, carbon ions into GPC alters the surface topography of GPC and enhances the already strong tendency for cells to attach to GPC. We have shown that implantation of silver ions near the surface strongly inhibits cell growth on GPC. Both enhanced adhesion of and inhibition of cell growth are desirable improvements on cardiac implants that have long been successfully fabricated from biocompatible glassy polymeric carbon (GPC). In vitro biocompatibility tests have been carried out with model cell lines to demonstrate that ion beam assisted deposition (IBAD) of silver, as well as silver ion bombardment, can favorably influence the surface of GPC for biomedical applications

  19. {sup 14}N depth profiles in Ti and Ti6Al4V nitrided by various methods, measured by nuclear reaction analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vickridge, I.; Trompetter, B. [Institute of Geological and Nuclear Sciences Ltd., Lower Hutt (New Zealand); Brown, I. [Industrial Research Ltd, Lower Hutt (New Zealand)

    1993-12-31

    Titanium alloys have desirable mechanical properties for applications in many areas, but their surface properties, such as friction coefficient, hardness, and wear and corrosion resistance often need to be enhanced. This may be accomplished by forming a thin layer of titanium nitride on the surface, by such methods as thermal nitriding, Ion Beam Assisted Deposition (IBAD), sol-gel technology, or ion implantation. Ion Beam Analysis is assuming an increasing importance for characterising the composition of the outer few microns since it is the only technique that can rapidly yield quantitative concentration depth profiles of {sup 14}N with minimal disruption of the analysed region. 8 refs., 7 figs.

  20. Structural and mechanical properties of nano-crystal TiN coatings

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chenhui; PAN Guoshun; LUO Jianbin; LI Wenzhi; CHEN Darong

    2004-01-01

    The structural and mechanical properties of TiN coatings prepared by ion beam assisted deposition (IBAD) were studied. The coatings have a polycrystal structure with grain size of ~10 nm or less. The hardness of the coatings increases with increasing grain size of TiN crystallites. The coating with grain size of 10.3 nm even has a superhardness of 44.7GPa. The relationship between the hardness and the grain size in the nano-crystalline coatings was discussed on the basis of grain-boundary triple junctions.