WorldWideScience

Sample records for carbon films deposited

  1. Deposition of diamondlike carbon films

    Science.gov (United States)

    Mirtich, M. J.; Sovey, J. S.; Banks, B. A. (Inventor)

    1984-01-01

    A diamondlike carbon film is deposited in the surface of a substrate by exposing the surface to an argon ion beam containing a hydrocarbon. The current density in the ion beam is low during initial deposition of the film. Subsequent to this initial low current condition, the ion beam is increased to full power. At the same time, a second argon ion beam is directed toward the surface of the substrate. The second ion beam has an energy level much greater than that of the ion beam containing the hydrocarbon. This addition of energy to the system increases mobility of the condensing atoms and serves to remove lesser bound atoms.

  2. Source Molecular Effect on Amorphous Carbon Film Deposition

    OpenAIRE

    Kawazoe, Hiroki; Inayoshi, Takanori; Shinohara, Masanori; Matsuda, Yoshinobu; Fujiyama, Hiroshi; Nitta, Yuki; Nakatani, Tatsuyuki

    2009-01-01

    We investigated deposition process of amorphous carbon films using acetylene and methane as a source molecule, by using infrared spectroscopy in multiple internal reflection geometry (MIR-IRAS). We found that deposited film structures were different due to source molecules.

  3. Hard carbon films: Deposition and diagnostics

    OpenAIRE

    Frgala Zdeněk; Kudrle Vít; Janča Jan; Meško Marcel; Eliáš Marek; Buršík Jiří

    2003-01-01

    We studied the growth of microcrystalline diamond films on pre-treated Si and WC-Co substrates by microwave plasma chemical vapour deposition (MPCVD). The pre-treatment was varied and its effect on diamond film was studied.

  4. Coaxial carbon plasma gun deposition of amorphous carbon films

    International Nuclear Information System (INIS)

    A unique plasma gun employing coaxial carbon electrodes was used in an attempt to deposit thin films of amorphous diamond-like carbon. A number of different structural, compositional, and electrical characterization techniques were used to characterize these films. These included scanning electron microscopy, scanning transmission electron microscopy, X ray diffraction and absorption, spectrographic analysis, energy dispersive spectroscopy, and selected area electron diffraction. Optical absorption and electrical resistivity measurements were also performed. The films were determined to be primarily amorphous, with poor adhesion to fused silica substrates. Many inclusions of particulates were found to be present as well. Analysis of these particulates revealed the presence of trace impurities, such as Fe and Cu, which were also found in the graphite electrode material. The electrodes were the source of these impurities. No evidence of diamond-like crystallite structure was found in any of the film samples. Details of the apparatus, experimental procedure, and film characteristics are presented

  5. Coaxial carbon plasma gun deposition of amorphous carbon films

    Science.gov (United States)

    Sater, D. M.; Gulino, D. A.; Rutledge, S. K.

    1984-01-01

    A unique plasma gun employing coaxial carbon electrodes was used in an attempt to deposit thin films of amorphous diamond-like carbon. A number of different structural, compositional, and electrical characterization techniques were used to characterize these films. These included scanning electron microscopy, scanning transmission electron microscopy, X ray diffraction and absorption, spectrographic analysis, energy dispersive spectroscopy, and selected area electron diffraction. Optical absorption and electrical resistivity measurements were also performed. The films were determined to be primarily amorphous, with poor adhesion to fused silica substrates. Many inclusions of particulates were found to be present as well. Analysis of these particulates revealed the presence of trace impurities, such as Fe and Cu, which were also found in the graphite electrode material. The electrodes were the source of these impurities. No evidence of diamond-like crystallite structure was found in any of the film samples. Details of the apparatus, experimental procedure, and film characteristics are presented.

  6. Physical properties of chemical vapour deposited nanostructured carbon thin films

    Energy Technology Data Exchange (ETDEWEB)

    Mahadik, D.B.; Shinde, S.S.; Bhosale, C.H. [Electrochemical Materials Laboratory, Department of Physics, Shivaji University, Kolhapur, Maharashtra 416004 (India); Rajpure, K.Y., E-mail: rajpure@yahoo.com [Electrochemical Materials Laboratory, Department of Physics, Shivaji University, Kolhapur, Maharashtra 416004 (India)

    2011-02-03

    Research highlights: In the present paper, nanostructured carbon films are grown using a natural precursor 'turpentine oil (C{sub 10}H{sub 16})' as a carbon source in the simple thermal chemical vapour deposition method. The influence of substrate surface topography (viz. stainless steel, fluorine doped tin oxide coated quartz) and temperature on the evolution of carbon allotropes surfaces topography/microstructural and structural properties are investigated and discussed. - Abstract: A simple thermal chemical vapour deposition technique is employed for the deposition of carbon films by pyrolysing the natural precursor 'turpentine oil' on to the stainless steel (SS) and FTO coated quartz substrates at higher temperatures (700-1100 deg. C). In this work, we have studied the influence of substrate and deposition temperature on the evolution of structural and morphological properties of nanostructured carbon films. The films were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), contact angle measurements, Fourier transform infrared (FTIR) and Raman spectroscopy techniques. XRD study reveals that the films are polycrystalline exhibiting hexagonal and face-centered cubic structures on SS and FTO coated glass substrates respectively. SEM images show the porous and agglomerated surface of the films. Deposited carbon films show the hydrophobic nature. FTIR study displays C-H and O-H stretching vibration modes in the films. Raman analysis shows that, high ID/IG for FTO substrate confirms the dominance of sp{sup 3} bonds with diamond phase and less for SS shows graphitization effect with dominant sp{sup 2} bonds. It reveals the difference in local microstructure of carbon deposits leading to variation in contact angle and hardness, which is ascribed to difference in the packing density of carbon films, as observed also by Raman.

  7. Properties of electrophoretically deposited single wall carbon nanotube films

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Junyoung; Jalali, Maryam; Campbell, Stephen A., E-mail: campb001@umn.edu

    2015-08-31

    This paper describes techniques for rapidly producing a carbon nanotube thin film by electrophoretic deposition at room temperature and determines the film mass density and electrical/mechanical properties of such films. The mechanism of electrophoretic deposition of thin layers is explained with experimental data. Also, film thickness is measured as a function of time, electrical field and suspension concentration. We use Rutherford backscattering spectroscopy to determine the film mass density. Films created in this manner have a resistivity of 2.14 × 10{sup −3} Ω·cm, a mass density that varies with thickness from 0.12 to 0.54 g/cm{sup 3}, and a Young's modulus between 4.72 and 5.67 GPa. The latter was found to be independent of thickness from 77 to 134 nm. We also report on fabricating free-standing films by removing the metal seed layer under the CNT film, and selectively etching a sacrificial layer. This method could be extended to flexible photovoltaic devices or high frequency RF MEMS devices. - Highlights: • We explain the electrophoretic deposition process and mechanism of thin SWCNT film deposition. • Characterization of the SWCNT film properties including density, resistivity, transmittance, and Young's modulus. • The film density and resistivity are found to be a function of the film thickness. • Techniques developed to create free standing layers of SW-CNTs for flexible electronics and mechanical actuators.

  8. Properties of electrophoretically deposited single wall carbon nanotube films

    International Nuclear Information System (INIS)

    This paper describes techniques for rapidly producing a carbon nanotube thin film by electrophoretic deposition at room temperature and determines the film mass density and electrical/mechanical properties of such films. The mechanism of electrophoretic deposition of thin layers is explained with experimental data. Also, film thickness is measured as a function of time, electrical field and suspension concentration. We use Rutherford backscattering spectroscopy to determine the film mass density. Films created in this manner have a resistivity of 2.14 × 10−3 Ω·cm, a mass density that varies with thickness from 0.12 to 0.54 g/cm3, and a Young's modulus between 4.72 and 5.67 GPa. The latter was found to be independent of thickness from 77 to 134 nm. We also report on fabricating free-standing films by removing the metal seed layer under the CNT film, and selectively etching a sacrificial layer. This method could be extended to flexible photovoltaic devices or high frequency RF MEMS devices. - Highlights: • We explain the electrophoretic deposition process and mechanism of thin SWCNT film deposition. • Characterization of the SWCNT film properties including density, resistivity, transmittance, and Young's modulus. • The film density and resistivity are found to be a function of the film thickness. • Techniques developed to create free standing layers of SW-CNTs for flexible electronics and mechanical actuators

  9. Deposition And Characterization Of Ultra Thin Diamond Like Carbon Films

    Science.gov (United States)

    Tomcik, B.

    2010-07-01

    Amorphous hydrogenated and/or nitrogenated carbon films, a-C:H/a-C:N, in overall thickness up to 2 nm are materials of choice as a mechanical and corrosion protection layer of the magnetic media in modern hard disk drive disks. In order to obtain high density and void-free films the sputtering technology has been replaced by different plasma and ion beam deposition techniques. Hydrocarbon gas precursors, like C2H2 or CH4 with H2 and N2 as reactive gases are commonly used in Kaufman DC ion and RF plasma beam sources. Optimum incident energy of carbon ions, C+, is up to 100 eV while the typical ion current densities during the film formation are in the mA/cm2 range. Other carbon deposition techniques, like filtered cathodic arc, still suffer from co-deposition of fine nanosized carbon clusters (nano dust) and their improvements are moving toward arc excitation in the kHz and MHz frequency range. Non-destructive film analysis like μ-Raman optical spectroscopy, spectroscopic ellipsometry, FTIR and optical surface analysis are mainly used in the carbon film characterization. Due to extreme low film thicknesses the surface enhanced Raman spectroscopy (SERS) with pre-deposited layer of Au can reduce the signal collection time and minimize photon-induced damage during the spectra acquisition. Standard approach in the μ-Raman film evaluation is the measurement of the position (shift) and area of D and G-peaks under the deconvoluted overall carbon spectrum. Also, a slope of the carbon spectrum in the 1000-2000 cm-1 wavenumber range is used as a measure of the hydrogen intake within a film. Diamond like carbon (DLC) film should possess elasticity and self-healing properties during the occasional crash of the read-write head flying only couple of nanometers above the spinning film. Film corrosion protection capabilities are mostly evaluated by electrochemical tests, potentio-dynamic and linear polarization method and by business environmental method. Corrosion mechanism

  10. Deuterium trapping in carbon films formed in different deposition conditions

    International Nuclear Information System (INIS)

    The paper presents the results of investigations on hydrogen trapping in the carbon films deposited in the plasma of four experimental devices (two laboratory stands, plasma accelerator QSPA-T and tokamak Tore Supra) covering a wide range of deposition conditions. The features of hydrogen trapping common for these devices are evaluated. It is shown that the trapping in the films of the certain device increases with the decrease of the deposition rate. Hydrogen from residual gas constitutes nearly half, or bigger part of the whole retention in the deposited films. It is trapped through inelastic interaction of the particles with the surface (“potential” mechanism of trapping). Ion irradiation and oxygen impurities activate the “potential” trapping. In conclusion some implications from the presented data are drawn

  11. Plasma-enhanced Deposition of Nano-Structured Carbon Films

    Institute of Scientific and Technical Information of China (English)

    Yang Qiaoqin (杨巧勤); Xiao Chijin (肖持进); A. Hirose

    2005-01-01

    By pre-treating substrate with different methods and patterning the catalyst, selective and patterned growth of diamond and graphitic nano-structured carbon films have been realized through DC Plasma-Enhanced Hot Filament Chemical Vapor Deposition (PE-HFCVD).Through two-step processing in an HFCVD reactor, novel nano-structured composite diamond films containing a nanocrystalline diamond layer on the top of a nanocone diamond layer have been synthesized. Well-aligned carbon nanotubes, diamond and graphitic carbon nanocones with controllable alignment orientations have been synthesized by using PE-HFCVD. The orientation of the nanostructures can be controlled by adjusting the working pressure. In a Microwave Plasma Enhanced Chemical Vapor Deposition (MW-PECVD) reactor, high-quality diamond films have been synthesized at low temperatures (310 ℃~550 ℃) without adding oxygen or halogen gas in a newly developed processing technique. In this process, carbon source originates from graphite etching, instead of hydrocarbon. The lowest growth temperature for the growth of nanocrystalline diamond films with a reasonable growth rate without addition of oxygen or halogen is 260 ℃.

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

    Science.gov (United States)

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

    1984-01-01

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

  13. Methods of Boron-carbon Deposited Film Removal

    Science.gov (United States)

    Airapetov, A.; Terentiev, V.; Voituk, A.; Zakharov, A.

    Boron carbide was proposed as a material for in-situ renewable protecting coating for tungsten tiles of the ITER divertor. It is necessary to develop a method of gasification of boron-carbon film which deposits during B4C sputtering. In this paper the results of the first stage investigation of gasification methods of boron-carbon films are presented. Two gasification methods of films are investigated: interaction with the ozone-oxygen mixture and irradiation in plasma with the working gas composed of oxygen, ethanol, and, in some cases, helium. The gasification rate in the ozone-oxygen mixture at 250 °C for B/C films with different B/C ratio and carbon fiber composite (CFC), was measured. For B/C films the gasification rate decreased with increasing B/C ratio (from 45 nm/h at B/C=0.7 to 4 nm/h at B/C=2.1; for CFC - 15 μm/h). Films gasification rates were measured under ion irradiation from ethanol-oxygen-helium plasma at different temperatures, with different ion energies and different gas mixtures. The maximum obtained removal rate was near 230 nm/h in case of ethanol-oxygen plasma and at 150°C of the sample temperature.

  14. Argon-hydrogen rf plasma study for carbon film deposition

    International Nuclear Information System (INIS)

    In this work the effect of hydrogen addition on the physical properties and the sputtering efficiency of an radio-frequency (rf) (13.56 MHz) Ar plasma was investigated. The discharges in Ar-H2 were used to sputter-deposit carbon films from a graphite cathode, with a hydrogen concentration in the feed gas ranging from 0 to 100% (the useful range for film growth was however limited to 0-85%). The physical plasma parameters were determined using a Langmuir probe, which, coupled with a chemical modelling of the ion-molecule and electron-molecule reactions in gas phase, enabled us to define the energy flux conditions at the cathode. The results show that hydrogen exerts a positive effect on the film deposition rate at the lowest end of the hydrogen concentration range, an enhancing deposition effect correlated with a high density of ArH+ ions in the plasma and a high energy flux carried by the ions to the cathode. Nonetheless, an analysis of the processes at the cathode indicates that the sputtering mechanism was essentially physical in the low [H2] range (3-20%) but that a chemical assistance of the process should be considered too for the remaining [H2] range. Besides, even in the physical sputtering regime, the target material removal occurred with a reactive sputtering mechanism, which implies a chemical modification of the target surface layers and surface binding energy

  15. Argon-hydrogen rf plasma study for carbon film deposition

    Energy Technology Data Exchange (ETDEWEB)

    Laidani, N [ITC-Irst, Divisione Fisica-Chimica delle Superfici ed Interfacce, Via Sommarive 18, Povo 38050, Trento (Italy); Bartali, R [ITC-Irst, Divisione Fisica-Chimica delle Superfici ed Interfacce, Via Sommarive 18, Povo 38050, Trento (Italy); Tosi, P [Dipartimento di Fisica, Laboratorio Fasci Molecolari, Universita degli Studi di Trento, Via Sommarive 15, Povo 38050, Trento (Italy); Anderle, M [ITC-Irst, Divisione Fisica-Chimica delle Superfici ed Interfacce, Via Sommarive 18, Povo 38050, Trento (Italy)

    2004-09-21

    In this work the effect of hydrogen addition on the physical properties and the sputtering efficiency of an radio-frequency (rf) (13.56 MHz) Ar plasma was investigated. The discharges in Ar-H{sub 2} were used to sputter-deposit carbon films from a graphite cathode, with a hydrogen concentration in the feed gas ranging from 0 to 100% (the useful range for film growth was however limited to 0-85%). The physical plasma parameters were determined using a Langmuir probe, which, coupled with a chemical modelling of the ion-molecule and electron-molecule reactions in gas phase, enabled us to define the energy flux conditions at the cathode. The results show that hydrogen exerts a positive effect on the film deposition rate at the lowest end of the hydrogen concentration range, an enhancing deposition effect correlated with a high density of ArH{sup +} ions in the plasma and a high energy flux carried by the ions to the cathode. Nonetheless, an analysis of the processes at the cathode indicates that the sputtering mechanism was essentially physical in the low [H{sub 2}] range (3-20%) but that a chemical assistance of the process should be considered too for the remaining [H{sub 2}] range. Besides, even in the physical sputtering regime, the target material removal occurred with a reactive sputtering mechanism, which implies a chemical modification of the target surface layers and surface binding energy.

  16. Cross-sectional STEM study of cathodic arc deposited amorphous carbon and carbon-nitride films

    International Nuclear Information System (INIS)

    Full text: The VG601 high resolution dedicated Scanning Transmission Electron Microscope (STEM) located at the University of Sydney has the capability of providing structural information with a spatial resolution of less than one nanometre. Compositional information can be obtained using either Energy Dispersive Spectroscopy (EDS) or Electron Energy Loss Spectroscopy. Each characteristic absorption edge in EELS also exhibits structure which provides information on the atomic environment of the absorbing atom. The combination of EELS and STEM therefore provides a powerful tool for analysing structure at the nanometre scale. In this work we investigate the structure of cathodic arc deposited carbon and carbon-nitride films using this EELS/STEM combination. By preparing the films in cross-section and collecting a number of spectra in a line through the film thickness (line profile), it is possible to investigate the deposition process in great detail since variations in structure with depth in the film provide information on the 'history' of film growth. In the case of carbon based materials, this technique provides a direct measure of the variations in both density and proportion of diamond-like bonding. These measurements will be used to help understand the mechanisms of film growth by cathodic arc deposition

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

    Science.gov (United States)

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

    1982-01-01

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

  18. Crystal structure of diamondlike carbon films prepared by ionized deposition from methane gas

    International Nuclear Information System (INIS)

    Diamondlike carbon films have been prepared by ionized deposition from methane gas. The film structures were examined by transmission electron microscopy, electron diffraction, and electron spectroscopy for chemical analysis techniques. It was found that the structure of the carbon films could be classified into three types: (i) amorphous, (ii) graphite, and (iii) cubic. These types depended mainly on the deposition conditions. Usually crystalline carbon films were diamond mixed with graphite showing an average grain size of several hundred angstroms. Very hard films were composed of diamond crystallites distributed in amorphous matrix

  19. Opto-electrical properties of amorphous carbon thin film deposited from natural precursor camphor

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, Debabrata [Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400 076 (India)]. E-mail: dpradhan@sciborg.uwaterloo.ca; Sharon, Maheshwar [Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400 076 (India)

    2007-06-30

    A simple thermal chemical vapor deposition technique is employed for the pyrolysis of a natural precursor 'camphor' and deposition of carbon films on alumina substrate at higher temperatures (600-900 deg. C). X-ray diffraction measurement reveals the amorphous structure of these films. The carbon films properties are found to significantly vary with the deposition temperatures. At higher deposition temperature, films have shown predominately sp{sup 2}-bonded carbon and therefore, higher conductivity and lower optical band gap (Tauc gap). These amorphous carbon (a-C) films are also characterized with Raman and X-ray photoelectron spectroscopy. In addition, electrical and optical properties are measured. The thermoelectric measurement shows these as-grown a-C films are p-type in nature.

  20. Fast deposition of diamond-like carbon films by radio frequency hollow cathode method

    International Nuclear Information System (INIS)

    Diamond-like carbon (DLC) thin films were deposited on p-type Si (100) substrates by RF hollow cathode method under different RF power and pressure, using ethane as the precursor gas. The deposition rate of 45 nm/min was achieved, almost 4 times higher than by conventional radio frequency plasma enhanced chemical vapor deposition. The mechanism of fast DLC films deposition is attributed to high plasma density in RF hollow cathode method, discussed in this paper. Scanning electron microscopy and Raman spectroscopy were used to investigate the microstructure of DLC films. The film hardness and Young's modulus were measured by nanoindentation. - Highlights: • Diamond-like carbon thin films were deposited by RF hollow cathode method. • The deposition rate of 45 nm/min was achieved. • A higher plasma density results in a higher deposition rate

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

    Science.gov (United States)

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

    1993-01-01

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

  2. Field Emission from Amorphous carbon Nitride Films Deposited on silicon Tip Arrays

    Institute of Scientific and Technical Information of China (English)

    李俊杰; 郑伟涛; 孙龙; 卞海蛟; 金曾孙; 赵海峰; 宋航; 孟松鹤; 赫晓东; 韩杰才

    2003-01-01

    Amorphous carbon nitride films (a-CNx) were deposited on silicon tip arrays by rf magnetron sputtering in pure nitrogen atmosphere. The field emission property of carbon nitride films on Si tips was compared with that of carbon nitride on silicon wafer. The results show that field emission property of carbon nitride films deposited on silicon tips can be improved significantly in contrast with that on wafer. It can be explained that field emission is sensitive to the local curvature and geometry, thus silicon tips can effectively promote field emission property of a-CNx films. In addition, the films deposited on silicon tips have a smaller effective work function ( F = 0.024 eV)of electron field emission than that on silicon wafer ( F = 0.060 e V), which indicates a significant enhancement of the ability of electron field emission from a-CNx films.

  3. Structure and composition of plasma deposited boron-containing carbon films

    International Nuclear Information System (INIS)

    Deposition of boron-carbon films on silicon, nickel, graphite, Kh18N10T steel from gas discharge plasma, the film chemical composition and erosion resistance to ion-plasma effects are studied. Conclusion is made on possibility of such film application as well coating for discharge chambers of thermonuclear facilities. Method of deposition from plasma makes it possible to avoid application of the previously used high-toxic and dangerously explosive B2H6

  4. Nanostructured Diamond-Like Carbon Films Grown by Off-Axis Pulsed Laser Deposition

    OpenAIRE

    Seong Shan Yap; Chen Hon Nee; Seong Ling Yap; Teck Yong Tou

    2015-01-01

    Nanostructured diamond-like carbon (DLC) films instead of the ultrasmooth film were obtained by pulsed laser ablation of pyrolytic graphite. Deposition was performed at room temperature in vacuum with substrates placed at off-axis position. The configuration utilized high density plasma plume arriving at low effective angle for the formation of nanostructured DLC. Nanostructures with maximum size of 50 nm were deposited as compared to the ultrasmooth DLC films obtained in a conventional depos...

  5. Amorphous carbon thin films deposited on Si and PET: Study of interface states

    International Nuclear Information System (INIS)

    Thin carbon films with various thickness, deposited on different substrates (Si and poly-ethylene-terephthalate) at the same operating conditions in a ratio frequency plasma enhanced chemical vapor deposition system were characterized by Doppler broadening spectroscopy. The films and the substrates were depth profiled by a slow positron beam. The aim od these measurements was to study the open volume structure and the interface of the films. It was found that, independently from the substrate, the films were homogeneous and exhibited to some open volume distribution. On the contrary, the effective positron diffusion length in the Si substrate was found to change with the thickness of the carbon films. This behaviour was found to change with the thickness of the carbon films. This behaviour was interpreted as a change in the electric field at the carbon/silicon interface. (author)

  6. Hydorgen sputtering of carbon thin films deposited on platinum

    International Nuclear Information System (INIS)

    Carbon has been suggested as a suitable low Z element for the lining of the first walls of controlled thermonuclear reactors in order to reduce radiative plasma losses due to sputtering. In this paper the measurement of sputtering of carbon thin films by protons in the energy range 0.6-10.0 keV, is described. H2+ or H3+ ions were used as bombarding ions to obtain equivalent H+ sputtering yields at energies below that at which the ion source provides sufficient proton current. The sputter yield was found to range from 7x10-3-1.5x10-2 atoms/proton with a broad maximum in the 2.0 keV region with the carbon film kept near ambient temperature. (B.D.)

  7. Amorphous carbon film deposition on inner surface of tubes using atmospheric pressure pulsed filamentary plasma source

    OpenAIRE

    Pothiraja, Ramasamy; Bibinov, Nikita; Awakowicz, Peter

    2011-01-01

    Uniform amorphous carbon film is deposited on the inner surface of quartz tube having the inner diameter of 6 mm and the outer diameter of 8 mm. A pulsed filamentary plasma source is used for the deposition. Long plasma filaments (~ 140 mm) as a positive discharge are generated inside the tube in argon with methane admixture. FTIR-ATR, XRD, SEM, LSM and XPS analyses give the conclusion that deposited film is amorphous composed of non-hydrogenated sp2 carbon and hydrogenated sp3 carbon. Plasma...

  8. Carbon film deposition from high velocity rarefied flow

    International Nuclear Information System (INIS)

    The presented study is based on the idea of the activation of a gas-precursor high velocity flow by hot wire. The wire forms the channel for flow before expansion to substrate. The construction allows change of the specific flow rate, velocity, composition and temperature of a gas mixture by studying the film synthesis in conditions from free molecular to continuum flow at velocities from hundreds to thousands of m/s. At a high pressure, the film has typical and unusual hexagonal incorporations for diamond tetragonal particles. Raman spectrum with the pronounced diamond peak is typical for diamond-like film. X-ray diffraction points in the presence of lonsdaleite. Conditions of deposition were simulated by Monte Carlo method. Collisions with hot surfaces and chemical transformations were taken into consideration as well

  9. Nanostructured Diamond-Like Carbon Films Grown by Off-Axis Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Seong Shan Yap

    2015-01-01

    Full Text Available Nanostructured diamond-like carbon (DLC films instead of the ultrasmooth film were obtained by pulsed laser ablation of pyrolytic graphite. Deposition was performed at room temperature in vacuum with substrates placed at off-axis position. The configuration utilized high density plasma plume arriving at low effective angle for the formation of nanostructured DLC. Nanostructures with maximum size of 50 nm were deposited as compared to the ultrasmooth DLC films obtained in a conventional deposition. The Raman spectra of the films confirmed that the films were diamond-like/amorphous in nature. Although grown at an angle, ion energy of >35 eV was obtained at the off-axis position. This was proposed to be responsible for subplantation growth of sp3 hybridized carbon. The condensation of energetic clusters and oblique angle deposition correspondingly gave rise to the formation of nanostructured DLC in this study.

  10. Interposition fixing structure of TiO2 film deposited on activated carbon fibers

    Institute of Scientific and Technical Information of China (English)

    FU Ping-feng; LUAN Yong; DAI Xue-gang

    2006-01-01

    The immobilized photocatalyst, TiO2 film supported on activated carbon fibers (TiO2/ACFs) prepared with molecular adsorption-deposition (MAD), exhibits high stability in cyclic photodegradation runs. The interposition fixing structure between TiO2 film and carbon fiber was investigated by means of SEM-EDX, XRD, XPS and FTIR, and a model was proposed to explain this structure. With SEM examination of carbon fiber surface after removing the deposited TiO2 film, a residual TiO2 super-thin film was found to exist still. By determining surface groups on ACFs, titanium sulfate (Ti2(SO4)3) in burnt remainders of the TiO2/ACFs was thought to be formed with an interfacial reaction between TiO2 film and carbon fibers. These provide some evidence of firm attachment of TiO2 film to carbon fiber surface. In the consideration of characteristics of the MAD, the deposition mechanism of TiO2 film on ACFs was proposed, and the interposition fixing structure was inferred to intercrossedly form between TiO2 film and ACFs' surface. This structure leaded to firm attachment and high stability of the TiO2 film.

  11. Hydrogenated diamond-like carbon film deposited on UHMWPE by RF-PECVD

    International Nuclear Information System (INIS)

    In this work, investigations were conducted to analyze the properties of diamond-like carbon (DLC) film deposited on ultra-high molecular weight polyethylene (UHMWPE) by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) at a low temperature of 50 deg. C. Composition and structure of the films were characterized by scanning electron microscopy (SEM) and Raman spectroscopy. Hardness and wettability of the film were tested. Tribological characterizations were carried out on a universal micro-tribometer, and reciprocating friction against ZrO2 ball was adopted with 25% bovine serum as lubrication. Results show that DLC film was successfully deposited on UHMWPE surface by RF-PECVD and the sp3 content was about 20% in the film. The film increased the macrohardness of the substrate by about 42% and the wettability was improved too. Tribology test showed a higher friction coefficient but a much smaller wear volume after the deposition due to the surface roughening and strengthening.

  12. Metal-doped diamond-like carbon films synthesized by filter-arc deposition

    International Nuclear Information System (INIS)

    Diamond-like carbon (DLC) thin films are extensively utilized in the semiconductor, electric and cutting machine industries owing to their high hardness, high elastic modulus, low friction coefficients and high chemical stability. DLC films are prepared by ion beam-assisted deposition (BAD), sputter deposition, plasma-enhanced chemical vapor deposition (PECVD), cathodic arc evaporation (CAE), and filter arc deposition (FAD). The major drawbacks of these methods are the degraded hardness associated with the low sp3/sp2 bonding ratio, the rough surface and poor adhesion caused by the presence of particles. In this study, a self-developed filter arc deposition (FAD) system was employed to prepare metal-containing DLC films with a low particle density. The relationships between the DLC film properties, such as film structure, surface morphology and mechanical behavior, with variation of substrate bias and target current, are examined. Experimental results demonstrate that FAD-DLC films have a lower ratio, suggesting that FAD-DLC films have a greater sp3 bonding than the CAE-DLC films. FAD-DLC films also exhibit a low friction coefficient of 0.14 and half of the number of surface particles as in the CAE-DLC films. Introducing a CrN interfacial layer between the substrate and the DLC films enables the magnetic field strength of the filter to be controlled to improve the adhesion and effectively eliminate the contaminating particles. Accordingly, the FAD system improves the tribological properties of the DLC films

  13. Deuterium retention and desorption behavior of co-deposited carbon film produced in gap

    International Nuclear Information System (INIS)

    Co-deposition of deuterium with carbon in an opening on a plasma-facing surface, a so-called 'gap', was simulated by using a deuterium arc discharge with carbon electrodes. The carbon deposition distribution and deuterium retention/desorption behavior of the carbon film were investigated. The amount of deposited carbon decreased exponentially with an increase of the distance from the gap entrance and more rapidly decreased with an increase in discharge gas pressure. The deuterium concentration in the carbon film increased with discharge gas pressure. At a high discharge gas pressure of 36 Pa, the atomic ratio of D/C in the carbon film reached as high as 0.9. Deuterium retained in the film desorbed mainly in the forms of D2, HD, CD4 and C2D4. The desorption behavior of retained deuterium depended on D/C. In a film with a high D/C ratio, desorption of D2 started at lower temperatures. The amount of desorbed hydrocarbons (CD4 and C2D4) increased with D/C. Carbon film with high D/C tended to contain a polymer-like structure, which could be related to the desorption behavior of the retained deuterium. (author)

  14. The Effect of Deposition Rate on Morphology and Structural Properties of Carbon-Nickel Composite Films

    OpenAIRE

    Smohammad Elahi; Vali Dalouji; Shahoo Valedbagi

    2013-01-01

    Carbon-nickel films were grown by radio frequency magnetron cosputtering on glass substrates. The films were deposited under different deposition times, from 50 to 600 sec, at room temperature. We noticed that up to 180 sec the sputtering occurs in more metal content mode and in greater than 180 sec it occurs in more nonmetal content mode. It is shown that the structural and morphological properties of carbon-nickel films were strongly influenced by this behavior.

  15. Amorphous carbon film deposition on inner surface of tubes using atmospheric pressure pulsed filamentary plasma source

    CERN Document Server

    Pothiraja, Ramasamy; Awakowicz, Peter

    2011-01-01

    Uniform amorphous carbon film is deposited on the inner surface of quartz tube having the inner diameter of 6 mm and the outer diameter of 8 mm. A pulsed filamentary plasma source is used for the deposition. Long plasma filaments (~ 140 mm) as a positive discharge are generated inside the tube in argon with methane admixture. FTIR-ATR, XRD, SEM, LSM and XPS analyses give the conclusion that deposited film is amorphous composed of non-hydrogenated sp2 carbon and hydrogenated sp3 carbon. Plasma is characterized using optical emission spectroscopy, voltage-current measurement, microphotography and numerical simulation. On the basis of observed plasma parameters, the kinetics of the film deposition process is discussed.

  16. Synthesis and tribological properties of diamond-like carbon films by electrochemical anode deposition

    Science.gov (United States)

    Li, Yang; Zhang, GuiFeng; Hou, XiaoDuo; Deng, DeWei

    2012-06-01

    Diamond-like carbon films (DLC) are deposited on Ti substrate by electrochemical anodic deposition at room temperature in pure methanol solution using a pulsed DC voltage at a range from 200 V to 2000 V. Raman spectroscopy analysis of the films reveals two broaden characteristic absorption peaks centred at ˜1350 cm-1 and 1580 cm-1, relating to D- and G-band of typical DLC films, respectively. A broad peak centred at 1325-1330 cm-1 is observed when an applied potential is 1200 V, which can confirm that the deposited films contained diamond structure phase. Tribological properties of the coated Ti substrates have been measured by means of a ball-on-plate wear test machine. A related growth mechanism of DLC films by the anodic deposition mode has also been discussed.

  17. Synthesis and characterization of thin films of nitrided amorphous carbon deposited by laser ablation

    International Nuclear Information System (INIS)

    The objective of this work is the synthesis and characterization of thin films of amorphous carbon (a-C) and thin films of nitrided amorphous carbon (a-C-N) using the laser ablation technique for their deposit. For this purpose, the physical properties of the obtained films were studied as function of diverse parameters of deposit such as: nitrogen pressure, power density, substrate temperature and substrate-target distance. For the characterization of the properties of the deposited thin films the following techniques were used: a) Raman spectroscopy which has demonstrated being a sensitive technique to the sp2 and sp3 bonds content, b) Energy Dispersive Spectroscopy which allows to know semi-quantitatively way the presence of the elements which make up the deposited films, c) Spectrophotometry, for obtaining the absorption spectra and subsequently the optical energy gap of the deposited material, d) Ellipsometry for determining the refraction index, e) Scanning Electron Microscopy for studying the surface morphology of thin films and, f) Profilemetry, which allows the determination the thickness of the deposited thin films. (Author)

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

    Institute of Scientific and Technical Information of China (English)

    JIANG Jin-qiu; Chen Zhu-ping

    2001-01-01

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

  19. Metalorganic Chemical Vapor Deposition of Ruthenium-Doped Diamond like Carbon Films

    Science.gov (United States)

    Sunkara, M. K.; Ueno, M.; Lian, G.; Dickey, E. C.

    2001-01-01

    We investigated metalorganic precursor deposition using a Microwave Electron Cyclotron Resonance (ECR) plasma for depositing metal-doped diamondlike carbon films. Specifically, the deposition of ruthenium doped diamondlike carbon films was investigated using the decomposition of a novel ruthenium precursor, Bis(ethylcyclopentadienyl)-ruthenium (Ru(C5H4C2H5)2). The ruthenium precursor was introduced close to the substrate stage. The substrate was independently biased using an applied RF power. Films were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Four Point Probe. The conductivity of the films deposited using ruthenium precursor showed strong dependency on the deposition parameters such as pressure. Ruthenium doped sample showed the presence of diamond crystallites with an average size of approx. 3 nm while un-doped diamondlike carbon sample showed the presence of diamond crystallites with an average size of 11 nm. TEM results showed that ruthenium was atomically dispersed within the amorphous carbon network in the films.

  20. Molecular dynamics simulation of the deposition process of hydrogenated diamond-like carbon (DLC) films

    Institute of Scientific and Technical Information of China (English)

    ZHANG YuJun; DONG GuangNeng; MAO JunHong; XIE YouBai

    2008-01-01

    The deposition process of hydrogenated diamond-like carbon (DLC) film greatly affects its frictional properties. In this study, CH3 radicals are selected as source species to deposit hydrogenated DLC films for molecular dynamics simulation. The growth and structural properties of hydrogenated DLC films are investigated and elucidated in detail. By comparison and statistical analysis, the authors find that the ratio of carbon to hydrogen in the films generally shows a monotonously increasing trend with the increase of impact energy. Carbon atoms are more reactive during deposition and more liable to bond with substrate atoms than hydrogen atoms. In addition, there exists a peak value of the number of hydrogen atoms deposited in hydrogenated DLC films. The trends of the variation are opposite on the two sides of this peak point, and itbecomes stable when impact energy is greater than 80 eV. The average relative density also indicates a rising trend along with the increment of impact energy, while it does not reach the saturation value until impact energy comes to 50 eV. The hydrogen content in source species is a key factor to determine the hydrogen content in hydrogenated DLC films. When the hydrogen content in source species is high, the hydrogen content in hydrogenated DLC films is accordingly high.

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

    International Nuclear Information System (INIS)

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

  2. Structural changes of hydrogenated amorphous carbon films deposited on steel rods

    Science.gov (United States)

    Choi, Junho; Hatta, Tetsuya

    2015-12-01

    In this study, hydrogenated amorphous carbon (a-C:H) films were deposited on steel rods of various radii by using bipolar-type plasma based ion implantation and deposition, and the film structure and mechanical properties have been investigated. Furthermore, the behavior of plasma surrounding the steel rods (i.e., flux and energy of incident ions and electrons) was investigated using the particle-in-cell Monte Carlo collision (PIC-MCC) method to examine the mechanism behind the structural changes of the a-C:H films. Three kinds of amorphous carbon films with different microstructures were prepared by changing the negative pulse voltages from -1 kV to -5 kV: one polymer-like carbon film and two diamond-like carbon films that possess the maximum FWHM(G) (full width at half maximum of Raman G-peak) and maximum hardness. The structure of the a-C:H films was evaluated through Raman spectroscopy, and the hardness of the films was measured using nanoindentation. It was found that the structures of a-C:H films deposited on the steel-rod surfaces are quite different from those on flat surfaces, and the film structures are directly affected by the curvature of the rod. It was also determined from the plasma simulation that the incident electron flux and ion flux become more intense as the curvature increases, resulting in the structural changes of the a-C:H films due to hydrogen evolution and thermal relaxation in the films.

  3. 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.

  4. Pyrolyzed thin film carbon

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Liger, Matthieu (Inventor); Harder, Theodore (Inventor); Konishi, Satoshi (Inventor); Miserendino, Scott (Inventor)

    2010-01-01

    A method of making carbon thin films comprises depositing a catalyst on a substrate, depositing a hydrocarbon in contact with the catalyst and pyrolyzing the hydrocarbon. A method of controlling a carbon thin film density comprises etching a cavity into a substrate, depositing a hydrocarbon into the cavity, and pyrolyzing the hydrocarbon while in the cavity to form a carbon thin film. Controlling a carbon thin film density is achieved by changing the volume of the cavity. Methods of making carbon containing patterned structures are also provided. Carbon thin films and carbon containing patterned structures can be used in NEMS, MEMS, liquid chromatography, and sensor devices.

  5. Chemical vapor deposition of high quality graphene films from carbon dioxide atmospheres.

    Science.gov (United States)

    Strudwick, Andrew James; Weber, Nils Eike; Schwab, Matthias Georg; Kettner, Michel; Weitz, R Thomas; Wünsch, Josef R; Müllen, Klaus; Sachdev, Hermann

    2015-01-27

    The realization of graphene-based, next-generation electronic applications essentially depends on a reproducible, large-scale production of graphene films via chemical vapor deposition (CVD). We demonstrate how key challenges such as uniformity and homogeneity of the copper metal substrate as well as the growth chemistry can be improved by the use of carbon dioxide and carbon dioxide enriched gas atmospheres. Our approach enables graphene film production protocols free of elemental hydrogen and provides graphene layers of superior quality compared to samples produced by conventional hydrogen/methane based CVD processes. The substrates and resulting graphene films were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Raman microscopy, sheet resistance and transport measurements. The superior quality of the as-grown graphene films on copper is indicated by Raman maps revealing average G band widths as low as 18 ± 8 cm(-1) at 514.5 nm excitation. In addition, high charge carrier mobilities of up to 1975 cm(2)/(V s) were observed for electrons in transferred films obtained from a carbon dioxide based growth protocol. The enhanced graphene film quality can be explained by the mild oxidation properties of carbon dioxide, which at high temperatures enables an uniform conditioning of the substrates by an efficient removal of pre-existing and emerging carbon impurities and a continuous suppression and in situ etching of carbon of lesser quality being co-deposited during the CVD growth. PMID:25398132

  6. Deposit of thin films of nitrided amorphous carbon using the laser ablation technique

    International Nuclear Information System (INIS)

    It is reported the synthesis and characterization of thin films of amorphous carbon (a-C) nitrided, deposited by laser ablation in a nitrogen atmosphere at pressures which are from 4.5 x 10 -4 Torr until 7.5 x 10 -2 Torr. The structural properties of the films are studied by Raman spectroscopy obtaining similar spectra at the reported for carbon films type diamond. The study of behavior of the energy gap and the ratio nitrogen/carbon (N/C) in the films, shows that the energy gap is reduced when the nitrogen incorporation is increased. It is showed that the refraction index of the thin films diminish as nitrogen pressure is increased, indicating the formation of graphitic material. (Author)

  7. Physical vapor deposition synthesis of tungsten monocarbide (WC) thin films on different carbon substrates

    International Nuclear Information System (INIS)

    The synthesis of tungsten monocarbide (WC) thin films has been performed by physical vapor deposition on various substrates including glassy carbon, carbon fiber sheet, carbon foam, and carbon cloth. The WC and W2C phase contents of these films have been evaluated with bulk and surface analysis techniques such as x-ray diffraction, x-ray photoelectron spectroscopy, and scanning electron microscopy. These characterization techniques were also used to determine the effects of synthesis by nonreactive and reactive sputtering. The synthesis of WC particles supported on the carbon fiber substrate has also been accomplished using the temperature programmed reaction method. Overall, the results demonstrate that the phase purity of tungsten carbides can be controlled by the deposition environment and annealing temperatures

  8. Characterization of hydrogenated diamond-like carbon films electrochemically deposited on a silicon substrate

    International Nuclear Information System (INIS)

    Diamond-like carbon (DLC) films were deposited on a Si substrate by electrolysis in a methanol solution at ambient pressure and low temperature. The morphology and microstructure of the resulting DLC films were analysed using atomic force microscopy, Raman spectroscopy, Fourier transformation infrared spectrometry, x-ray photoelectron spectroscopy (XPS), and x-ray excited Auger electron spectroscopy (XAES). The surface energy and mechanical properties of the DLC films were examined, and the growth mechanism of the DLC films in liquid phase electro-deposition is discussed as well. The results of the study show that the hydrogenated diamond-like carbon films are smooth and compact. The percentage of sp3 carbon in the DLC films is determined as 55-60%, based on the corresponding XPS and first-derivative XAES spectra of graphite, diamond, and the tested films. The DLC films show low surface free energy, good mechanical properties, excellent friction-reduction and wear-resistance. It is suggested that methanol dissociates to generate the active species of CH3+ and C2H4 at high voltage applied to the electrode, followed by the generation of the alkyl chain [-CH2-CH2-]n whose C-C and C-H bond lengths and C-C-C and H-C-H bond angles are close to that of diamond. Subsequently, a diamond-like structure was formed by the ordered dehydrogenation of a short-chain [-CH2-CH2-]n in the electrolysis process

  9. Silicon carbon alloy thin film depositions using electron cyclotron resonance microwave plasmas

    Science.gov (United States)

    Shing, Y. H.; Pool, F. S.

    1990-01-01

    Amorphous and microcrystalline silicon carbon films (a-SiC:H, micro-c-SiC:H) have been deposited using SiH4, CH4 and H2 mixed gas ECR (electron cyclotron resonance) plasmas. The optical bandgap of a-SiC:H films is not dependent on the hydrogen dilution in the ECR plasma. The deposition rate of a-SiC:H films is found to be strongly dependent on the ECR magnetic field and the hydrogen dilution. The hydrogen dilution effect on the deposition rate indicates that the etching in ECR hydrogen plasmas plays an important role in the deposition of a-SiC:H films. The optical constants n and k of ECR-deposited a-SiC:H films in the wavelength region of 0.4 to 1.0 micron are determined to be 2.03-1.90 and 0.04-0.00, respectively. The microstructures of ECR-deposited micro-c-SiC:H films are shown by X-ray diffraction and SEM (scanning electron microscopy) to be composed of 1000-A alpha-SiC microcrystallites and amorphous network structures.

  10. Optical and mechanical properties of diamond like carbon films deposited by microwave ECR plasma CVD

    Indian Academy of Sciences (India)

    S B Singh; M Pandey; N Chand; A Biswas; D Bhattacharya; S Dash; A K Tyagi; R M Dey; S K Kulkarni; D S Patil

    2008-10-01

    Diamond like carbon (DLC) films were deposited on Si (111) substrates by microwave electron cyclotron resonance (ECR) plasma chemical vapour deposition (CVD) process using plasma of argon and methane gases. During deposition, a d.c. self-bias was applied to the substrates by application of 13.56 MHz rf power. DLC films deposited at three different bias voltages (–60 V, –100 V and –150 V) were characterized by FTIR, Raman spectroscopy and spectroscopic ellipsometry to study the variation in the bonding and optical properties of the deposited coatings with process parameters. The mechanical properties such as hardness and elastic modulus were measured by load depth sensing indentation technique. The DLC film deposited at –100 V bias exhibit high hardness (∼ 19 GPa), high elastic modulus (∼ 160 GPa) and high refractive index (∼ 2.16–2.26) as compared to films deposited at –60 V and –150 V substrate bias. This study clearly shows the significance of substrate bias in controlling the optical and mechanical properties of DLC films.

  11. Incorporation of nitrogen into amorphous carbon films produced by surface-wave plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    In order to study the influence of nitrogen incorporated into amorphous carbon films, nitrogenated amorphous carbon films have been deposited by using surface wave plasma chemical vapor deposition under various ratios of N2/CH4 gas flow. Optical emission spectroscopy has been used to monitor plasma features near the deposition zone. After deposition, the samples are checked by Raman spectroscopy and x-ray photo spectroscopy (XPS). Optical emission intensities of CH and N atom in the plasma are found to be enhanced with the increase in the N2/CH4 gas flow ratio, and then reach their maximums when the N2/CH4 gas flow ratio is 5%. A contrary variation is found in Raman spectra of deposited films. The intensity ratio of the D band to the G band (ID/IG) and the peak positions of the G and D bands all reach their minimums when the N2/CH4 gas flow ratio is 5%. These show that the structure of amorphous carbon films has been significantly modified by introduction of nitrogen

  12. Electronic state modification in laser deposited amorphous carbon films by the inclusion of nitrogen

    OpenAIRE

    Y. Miyajima; Adamopoulos, G; Henley, SJ; V.Stolojan; Tison, Y; Garcia-Caurel, E; Drevillon, B.; Shannon, JM; Silva, SRP

    2008-01-01

    In this study, we investigate the effect of the inclusion of nitrogen in amorphous carbon thin films deposited by pulsed laser deposition, which results in stress induced modifications to the band structure and the concomitant changes to the electronic transport properties. The microstructural changes due to nitrogen incorporation were examined using electron energy-loss spectroscopy and Raman scattering. The band structure was investigated using spectroscopic ellipsometry data in the range o...

  13. Deposition, characterization, and tribological applications of near-frictionless carbon films on glass and ceramic substrates

    International Nuclear Information System (INIS)

    As an element, carbon is rather unique and offers a range of rare opportunities for the design and fabrication of zero-, one-, two-, and three-dimensional nanostructured novel materials and coatings such as fullerenes, nanotubes, thin films, and free-standing nano-to-macroscale structures. Among these, carbon-based two-dimensional thin films (such as diamond and diamond-like carbon (DLC)) have attracted an overwhelming interest in recent years, mainly because of their exceptional physical, chemical, mechanical, electrical, and tribological properties. In particular, certain DLC films were found to provide extremely low friction and wear coefficients to sliding metallic and ceramic surfaces. Since the early 1990s, carbon has been used at Argonne National Laboratory to synthesize a class of novel DLC films that now provide friction and wear coefficients as low as 0.001 and 10-11-10-10 mm3 N-1 m-1, respectively, when tested in inert or vacuum test environments. Over the years, we have optimized these films and applied them successfully to all kinds of metallic and ceramic substrates and evaluated their friction and wear properties under a wide range of sliding conditions. In this paper, we will provide details of our recent work on the deposition, characterization, and tribological applications of near-frictionless carbon films on glass and ceramic substrates. We will also provide chemical and structural information about these films and describe the fundamental tribological mechanisms that control their unusual friction and wear behaviour

  14. 'Diamondlike' carbon films - Optical absorption, dielectric properties, and hardness dependence on deposition parameters

    Science.gov (United States)

    Natarajan, V.; Lamb, J. D.; Woollam, J. A.; Liu, D. C.; Gulino, D. A.

    1985-01-01

    An RF plasma deposition system was used to prepare amorphous 'diamondlike' carbon films. The source gases for the RF system include methane, ethylene, propane, and propylene, and the parameters varied were power, dc substrate bias, and postdeposition anneal temperature. Films were deposited on various substrates. The main diagnostics were optical absorption in the visible and in the infrared, admittance as a function of frequency, hardness, and Auger and ESCA spectroscopy. Band gap is found to depend strongly on RF power level and band gaps up to 2.7 eV and hardness up to 7 Mohs were found. There appears to be an inverse relationship between hardness and optical band gap.

  15. Nanocomposite metal amorphous-carbon thin films deposited by hybrid PVD and PECVD technique.

    Science.gov (United States)

    Teixeira, V; Soares, P; Martins, A J; Carneiro, J; Cerqueira, F

    2009-07-01

    Carbon based films can combine the properties of solid lubricating graphite structure and hard diamond crystal structure, i.e., high hardness, chemical inertness, high thermal conductivity and optical transparency without the crystalline structure of diamond. Issues of fundamental importance associated with nanocarbon coatings are reducing stress, improving adhesion and compatibility with substrates. In this work new nanocomposite coatings with improved toughness based in nanocrystalline phases of metals and ceramics embedded in amorphous carbon matrix are being developed within the frame of a research project: nc-MeNxCy/a-C(Me) with Me = Mo, Si, Al, Ti, etc. Carbide forming metal/carbon (Me/C) composite films with Me = Mo, W or Ti possess appropriate properties to overcome the limitation of pure DLC films. These novel coating architectures will be adopted with the objective to decrease residual stress, improve adherence and fracture toughness, obtain low friction coefficient and high wear-resistance. Nanocomposite DLC's films were deposited by hybrid technique using a PVD-Physically Vapor Deposition (magnetron sputtering) and Plasma Enhanced Chemical Vapor Deposition (PECVD), by the use of CH4 gas. The parameters varied were: deposition time, substrate temperature (180 degrees C) and dopant (Si + Mo) of the amorphous carbon matrix. All the depositions were made on silicon wafers and steel substrates precoated with a silicon inter-layer. The characterisation of the film's physico-mechanical properties will be presented in order to understand the influence of the deposition parameters and metal content used within the a-C matrix in the thin film properties. Film microstructure and film hybridization state was characterized by Raman Spectroscopy. In order to characterize morphology SEM and AFM will be used. Film composition was measured by Energy-Dispersive X-ray analysis (EDS) and by X-ray photoelectron spectroscopy (XPS). The contact angle for the produced DLC's on

  16. Influence of thin film nickel pretreatment on catalytic thermal chemical vapor deposition of carbon nanofibers

    International Nuclear Information System (INIS)

    Nickel and other metal nanoparticles are known to be active as catalysts in the synthesis of carbon nanofibers. In this paper we investigate how dewetting and break-up of nickel thin films depends on film thickness, film–substrate interaction and pretreatment conditions. This is evaluated for films evaporated on oxidized silicon and fused silica substrates with or without tantalum coating, which were subsequently exposed to different pretreatment atmospheres (vacuum, nitrogen, air and hydrogen; 1 h, 650 °C). Atomic force microscopy, scanning electron microscopy and energy dispersive X-ray analysis were used to characterize the films. Pretreated Ni films were subjected to a thermal catalytic chemical vapor deposition procedure with brief ethylene exposures (0.5–3 min, 635 °C). It was found that only on the spherical nanoparticles originating from a hydrogen pretreatment of a Ni film with Ta adhesion layer, homogeneously distributed, randomly-oriented, well-attached, and semi-crystalline carbon nanofibers be synthesized. - Highlights: • On the formation of nanoparticles required for carbon nanofiber (CNF) synthesis • Various evaporated thin films on oxidized silicon and fused silica: Ni and Ni/Ta • Pretreatment of nickel-based thin films in vacuum, nitrogen, air and hydrogen • Only on reduced Ni/Ta fast – within 3 min – initiation of CNF nucleation and growth

  17. Hydrogenated diamond-like carbon film deposited on UHMWPE by RF-PECVD

    Energy Technology Data Exchange (ETDEWEB)

    Shi Xingling, E-mail: shixingling1985@hotmail.com [School of Materials Science and Engineering, China University of Mining and Technology, South Road of Third Cycle, Xuzhou, 221116 (China); Wang Qingliang; Xu Lingli; Ge Shirong [School of Materials Science and Engineering, China University of Mining and Technology, South Road of Third Cycle, Xuzhou, 221116 (China); Wang Chao [Test and Analysis Center of China University of Mining and Technology, Xuzhou, 221116 (China)

    2009-07-15

    In this work, investigations were conducted to analyze the properties of diamond-like carbon (DLC) film deposited on ultra-high molecular weight polyethylene (UHMWPE) by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) at a low temperature of 50 deg. C. Composition and structure of the films were characterized by scanning electron microscopy (SEM) and Raman spectroscopy. Hardness and wettability of the film were tested. Tribological characterizations were carried out on a universal micro-tribometer, and reciprocating friction against ZrO{sub 2} ball was adopted with 25% bovine serum as lubrication. Results show that DLC film was successfully deposited on UHMWPE surface by RF-PECVD and the sp{sup 3} content was about 20% in the film. The film increased the macrohardness of the substrate by about 42% and the wettability was improved too. Tribology test showed a higher friction coefficient but a much smaller wear volume after the deposition due to the surface roughening and strengthening.

  18. Structure and mechanical properties of diamondlike carbon films produced by hollow-cathode plasma deposition

    International Nuclear Information System (INIS)

    Diamondlike carbon (DLC) films are deposited on AISI 304 stainless-steel substrates using hollow-cathode chemical vapor deposition. The effects of the substrate bias on the structural and mechanical properties of the films are studied. X-ray photoelectron spectroscopy reveals the existence of C=C (sp2) and C-C (sp3) functional groups in the films, and Raman spectra show that the ratio of the G (graphite) peak to the D (disorder) peak depends on the sample bias. The DLC film deposited at -50 V bias has the highest sp3 content, and this is consistent with the G-band position and D-band full width at half maximum as a result of substrate biasing. The sample bias also has a critical influence on the thickness and hardness of the deposited films. The largest thickness (1700 nm) and highest hardness (HV1099) are achieved at a bias voltage of -50 V. All the films show low friction coefficients, and the sample treated at -200 V gives rise to the lowest friction coefficient

  19. Multi-Directional Growth of Aligned Carbon Nanotubes Over Catalyst Film Prepared by Atomic Layer Deposition

    Directory of Open Access Journals (Sweden)

    Zhou Kai

    2010-01-01

    Full Text Available Abstract The structure of vertically aligned carbon nanotubes (CNTs severely depends on the properties of pre-prepared catalyst films. Aiming for the preparation of precisely controlled catalyst film, atomic layer deposition (ALD was employed to deposit uniform Fe2O3 film for the growth of CNT arrays on planar substrate surfaces as well as the curved ones. Iron acetylacetonate and ozone were introduced into the reactor alternately as precursors to realize the formation of catalyst films. By varying the deposition cycles, uniform and smooth Fe2O3 catalyst films with different thicknesses were obtained on Si/SiO2 substrate, which supported the growth of highly oriented few-walled CNT arrays. Utilizing the advantage of ALD process in coating non-planar surfaces, uniform catalyst films can also be successfully deposited onto quartz fibers. Aligned few-walled CNTs can be grafted on the quartz fibers, and they self-organized into a leaf-shaped structure due to the curved surface morphology. The growth of aligned CNTs on non-planar surfaces holds promise in constructing hierarchical CNT architectures in future.

  20. RIR MAPLE procedure for deposition of carbon rich Si/C/H films

    International Nuclear Information System (INIS)

    We applied the resonant infrared matrix assisted pulsed laser evaporation (RIR MAPLE) technique to demonstrate a new approach to a controlled deposition of carbon rich amorphous Si/C/H film. In absence of radicals and accelerated species commonly generated in PECVD and sputtering setups, the RIR MAPLE method does not decompose precursor molecules. Moreover, unlike the standard MAPLE procedure, in which solvent molecules absorb laser energy from excimer or near infrared lasers, we applied the pulsed TEA CO2 laser to excite the dendrimer precursor molecules in a frozen target. In this manner we achieved just cross-linking of the starting precursor on substrates and the deposition of carbon rich Si/C/H film. The film was analyzed by Fourier Transformed Infrared (FTIR), UV/VIS, Raman and X-ray Photoelectron (XPS) spectroscopy and Atomic Force Microscopy (AFM) technique. According to analyses the film retained the precursor elemental composition free of graphitic (sp2) clusters. In course of reaction only the peripheral allyl groups containing C=C bonds were opened to achieve cross-linking. Whereas annealing to 300 °C was necessary for the elimination of =C–H1, 2 bonds in the films prepared at 200 °C, those bonds vanished completely for the films prepared at substrate temperature 255 °C. The film posseses a smooth surface with root mean square (RMS) parameter up to 10 nm within scanned distance 2.5 μm.

  1. Physical properties of nitrogen-doped diamond-like amorphous carbon films deposited by supermagnetron plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Diamond-like amorphous carbon films doped with nitrogen (DAC:N) were deposited on Si and glass wafers intermittently using i-C4H10/N2 repetitive supermagnetron plasma chemical vapor deposition. Deposition duration, which is equal to a plasma heating time of wafer, was selected to be 40 or 60 s, and several layers were deposited repetitively to form one thick film. DAC:N films were deposited at a lower-electrode temperature of 100 deg. C as a function of upper- and lower-electrode rf powers (200 W/200 W-1 kW/1 kW) and N2 concentration (0%-80%). With an increase in N2 concentration and rf power, the resistivity and the optical band gap decreased monotonously. With increase of the deposition duration from 40 to 60 s, resistivity decreased to 0.03Ω cm and optical band gap decreased to 0.02 eV (substantially equal to 0 eV within the range of experimental error), at an N2 concentration of 80% and rf power of 1 kW(/1 kW)

  2. Chromium-doped diamond-like carbon films deposited by dual-pulsed laser deposition

    Czech Academy of Sciences Publication Activity Database

    Písařík, Petr; Jelínek, Miroslav; Kocourek, Tomáš; Zezulová, M.; Remsa, Jan; Jurek, Karel

    2014-01-01

    Roč. 117, č. 1 (2014), s. 83-88. ISSN 0947-8396 R&D Projects: GA MŠk LD12069 Institutional support: RVO:68378271 Keywords : diamond like carbon * chromium * contact angle * surface free energy * dual laser deposition * zeta potential Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.704, year: 2014

  3. Pulsed laser deposition of thin carbon films in a neutral gas background

    International Nuclear Information System (INIS)

    We studied carbon film deposition using a laser-produced plasma, in argon and helium background gas, at pressures between 0.5 and 700 mTorr. A Nd : YAG, 370 mJ, 3.5 ns, at 1.06 µm, operating at 10 Hz, with a fluence of 6.7 J cm−2 was used. The laser plasma was characterized using space resolved OES and a fast response Faraday cup. The resulting carbon films were analysed using AFM, Raman spectroscopy, XPS and SIMS. The structural properties of the carbon films were found to be strongly correlated with the laser carbon plasma composition. Films with a relatively high content of sp3, characteristic of DLC, were obtained at pressures below 200 mTorr. For these conditions the characteristic carbon ion energies in the expanding laser plasma were of the order of 100 eV. At higher pressures sp2 bonds, associated with amorphous carbon, were dominant, which coincides with a high content of C2 molecules in the laser plasma, and a characteristic carbon ion energy around 20 eV. (paper)

  4. Diamondlike carbon deposition on plastic films by plasma source ion implantation

    International Nuclear Information System (INIS)

    Application of pulsed high negative voltage (∼10 μs pulse width, 300-900 pulses per second) to a substrate is found to induce discharge, thereby increasing ion current with an inductively coupled plasma source. This plasma source ion beam implantation (PSII) technique is investigated for the pretreatment and deposition of diamond-like carbon (DLC) thin layer on polyethylene terepthalate (PET) film. Pretreatment of PET with N2 and Ar plasma is expected to provide added barrier effects when coupled with DLC deposition, with possible application to fabrication of PET beverage bottles. PSII treatment using N2 and Ar in separate stages is found to change the color of the PET film, effectively increasing near-ultraviolet absorption. The effects of this pretreatment on the chemical bonding of C, H, and O are examined by x-ray photoelectron spectroscopy (XPS). DLC thin film was successfully deposited on the PET film. The surface of the DLC thin layer is observed to be smooth by scanning electron microscopy, and its structure characteristics are examined by XPS and laser Raman spectroscopy. Subsequent processing using acetylene or acetylene and Ar (20%) produced thin carbon layers that are confirmed to be graphite-dominated DLC. Also, this PSII method is employed in order to deposit the DLC layer on the inside surface of the PET bottle and to reduce oxygen permeation rate by 40%

  5. Diamondlike carbon deposition on plastic films by plasma source ion implantation

    Science.gov (United States)

    Tanaka, T.; Yoshida, M.; Shinohara, M.; Takagi, T.

    2002-05-01

    Application of pulsed high negative voltage (~10 μs pulse width, 300-900 pulses per second) to a substrate is found to induce discharge, thereby increasing ion current with an inductively coupled plasma source. This plasma source ion beam implantation (PSII) technique is investigated for the pretreatment and deposition of diamond-like carbon (DLC) thin layer on polyethylene terepthalate (PET) film. Pretreatment of PET with N2 and Ar plasma is expected to provide added barrier effects when coupled with DLC deposition, with possible application to fabrication of PET beverage bottles. PSII treatment using N2 and Ar in separate stages is found to change the color of the PET film, effectively increasing near-ultraviolet absorption. The effects of this pretreatment on the chemical bonding of C, H, and O are examined by x-ray photoelectron spectroscopy (XPS). DLC thin film was successfully deposited on the PET film. The surface of the DLC thin layer is observed to be smooth by scanning electron microscopy, and its structure characteristics are examined by XPS and laser Raman spectroscopy. Subsequent processing using acetylene or acetylene and Ar (20%) produced thin carbon layers that are confirmed to be graphite-dominated DLC. Also, this PSII method is employed in order to deposit the DLC layer on the inside surface of the PET bottle and to reduce oxygen permeation rate by 40%.

  6. Electrospray deposition of carbon nanotube thin films for flexible transparent electrodes.

    Science.gov (United States)

    Meng, Yinan; Xin, Guoqing; Nam, Jaewook; Cho, Sung Min; Chae, Heeyeop

    2013-09-01

    Flexible transparent carbon nanotube (CNT) electrodes were fabricated by electrospray deposition, a large-area scalable and cost-effective process. The carbon nanotubes were dispersed in N,N-dimethylformamide (DMF) and deposited on polyethylene terephthalate (PET) substrates by electrospray deposition process at room temperature and atmospheric pressure. Major process variables were characterized and optimized for the electrospray process development such as electric field between nozzle and substrates, CNT solution flowrate, gap between nozzle and substrates, solution concentration, solvent properties and surface temperature. The sheet resistance of the electrospray deposited CNT films were reduced by HNO3 doping process. 169 Omega/sq sheet resistance and 86% optical transmittance was achieved with low surface roughness of 1.2 nm. The films showed high flexibility and transparency, making them potential replacements of ITO or ZnO in such as solid state lighting, touch panels, and solar cells. Electrospray process is a scalable process and we believe that this process can be applied for large area carbon nanotube film formation. PMID:24205613

  7. Crystalline and amorphous carbon nitride films produced by high-energy shock plasma deposition

    International Nuclear Information System (INIS)

    High-energy shock plasma deposition techniques are used to produce carbon-nitride films containing both crystalline and amorphous components. The structures are examined by high-resolution transmission electron microscopy, parallel-electron-energy loss spectroscopy and electron diffraction. The crystalline phase appears to be face-centered cubic with unit cell parameter approx. a=0.63nm and it may be stabilized by calcium and oxygen at about 1-2 at % levels. The carbon atoms appear to have both trigonal and tetrahedral bonding for the crystalline phase. There is PEELS evidence that a significant fraction of the nitrogen atoms have sp2 trigonal bonds in the crystalline phase. The amorphous carbon-nitride film component varies from essentially graphite, containing virtually no nitrogen, to amorphous carbon-nitride containing up to 10 at % N, where the fraction of sp3 bonds is significant. 15 refs., 5 figs

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

    Science.gov (United States)

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

    1985-01-01

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

  9. Synthesis and Characteristics of Diamond-like Carbon Films Deposited on Quartz Substrate

    Institute of Scientific and Technical Information of China (English)

    黄卫东; 丁鼎; 詹如娟

    2004-01-01

    Diamond-like carbon (DLC) films are deposited on quartz substrate using pure CH4 in the surface wave plasma equipment. A direct current negative bias up to -90 V is applied to the substrate to investigate the bias effect on the film characteristics. Deposited films are characterized by Raman spectroscopy, infrared (IR) and ultraviolet-visible absorption techniques.There are two broad Raman peaks around 1340 cm-1 and 1600 cm-1 and the first one has a greater sp3 component with an increased bias. Infrared spectroscopy has three sp3 C-H modes at 2852 cm-1, 2926 cm- 1 and 2962 cm-1, respectively and also shows an intensity increase with the negative bias. Optical band gap is calculated from the ultraviolet-visible absorption spectroscopy and the increased values with negative bias and deposition time are obtained. After a thermal anneal at about 500 ℃ for an hour to the film deposited under the bias of-90 V, we get an almost unchanged Raman spectrum and a peak intensity-reduced IR signal, which indicates a reduced H-content in the film. Meanwhile the optical band gap changed from 0.85 eV to 1.5 eV.

  10. Field Emission Properties of Ball-Like Nano-Carbon Thin Films Deposited on Mo Films with Accidented Topography

    International Nuclear Information System (INIS)

    Ball-like nano-carhon thin films (BNCTs) are grown on Mo layers by microwave plasma chemical vapour deposition (MPCVD) system. The Mo layers are deposited on ceramic substrates by electron beam deposition method and are pretreated by ultrasonically scratching. The optimization effects of ultrasonically scratching pretreat-ment on the surface micro-structures of carbon films are studied. It is found from field-emission scanning electron microscope (FE-SEM) images and Raman spectra that the surface structures of the carbon films deposited on Mo pretreated are improved, which are composed of highly uniform nano-structured carbon balls with considerable disorder structures. Field emission (FE) measurements are carried out using a diode structure. The experimental results indicate that the BNCTs exhibit good FE properties, which have the turn on field of 1.56 V/μm, and the current density of 1.0mA/cm2 at electric field of 4.0 V/μm, the uniformly distributed emission site density from a broad well-proportioned emission area of 4 cm2 are also obtained. Linearity is observed in Fowler–Nordheim (F–N) plots in higher Geld region, and the possible emission mechanism of BNCTs is discussed. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  11. Diamond-Like Carbon Film Deposition Using DC Ion Source with Cold Hollow Cathode

    Directory of Open Access Journals (Sweden)

    E. F. Shevchenko

    2014-01-01

    Full Text Available Carbon diamond-like thin films on a silicon substrate were deposited by direct reactive ion beam method with an ion source based on Penning direct-current discharge system with cold hollow cathode. Deposition was performed under various conditions. The pressure (12–200 mPa and the plasma-forming gas composition consisting of different organic compounds and hydrogen (C3H8, CH4, Si(CH32Cl2, H2, the voltage of accelerating gap in the range 0.5–5 kV, and the substrate temperature in the range 20–850°C were varied. Synthesized films were researched using nanoindentation, Raman, and FTIR spectroscopy methods. Analysis of the experimental results was made in accordance with a developed model describing processes of growth of the amorphous and crystalline carbon materials.

  12. Raman spectroscopic studies of thin film carbon nanostructures deposited using electro deposition technique

    Science.gov (United States)

    Dayal, Saurabh; Sasi, Arshali; Jhariya, Sapna; Sasikumar, C.

    2016-05-01

    In the present work our focus is to synthesize carbon nanostructures (CNS) by electro deposition technique without using any surface pretreatment or catalyst preparation before CNS formation. The process were carried out at significantly low voltage and at low temperature as reported elsewhere. Further the samples were characterized using different characterization tools such as SEM and Raman spectroscopy. The SEM results showed the fibres or tubular like morphology. Raman spectra shows strong finger print at 1600 cm-1 (G peak), 1350 cm-1 (D peak) along with the radial breathing mode (RBM) between 150cm-1 to 300 cm-1. This confirms the formation of tubular carbon nanostructures.

  13. Microstructure and tribological performance of diamond-like carbon films deposited on hydrogenated rubber

    International Nuclear Information System (INIS)

    In this paper, the microstructure and tribological performance of diamond-like carbon (DLC) films prepared by plasma chemical vapor deposition on hydrogenated nitrile butadiene rubbers (HNBR) are studied. Different negative variations of temperature during film growth were selected by proper changes of the bias voltage. Raman measurements show a similar bonding regardless of the voltages used. A columnar growth and a tile-like microstructure of the DLC films were identified by scanning electron microscopy. Patch sizes can be correlated with the deposition conditions. The coefficient of friction (CoF) of DLC film coated HNBR was found to be much lower than that of the unprotected rubber, and more reduced for the DLC films with smaller patch sizes, which is explained by a better flexibility and conformity of the film during testing. In one of the samples, unexpected low CoF was observed, which was attributed to a modification of the mechanical properties of the rubber during the plasma treatment at high voltage. This issue was confirmed by X-ray photoelectron spectroscopy, which indicated a modification of the cross linking in the rubber. - Highlights: ► Bias voltage does not vary the chemical bonding and surface morphology of films. ► Film structure is patched, whose size depends on the etching and deposition voltages. ► The frictional behavior can be correlated with the patch size of the films. ► Surface analysis showed that rubber x-linking is modified by etching at high voltage. ► Modification of rubber x-linking leads to a different frictional behavior.

  14. Deposition of Fluorinated Diamond-Like-Carbon Films by Exposure of Electrothermal Pulsed Plasmas

    Science.gov (United States)

    Kimura, Takashi; Iida, Masayasu

    2011-08-01

    Thin amorphous carbon films are deposited on silicon substrates by exposure to pulsed plasmas where the feed gas is mainly generated from the ablation of an insulator. An electrothermal pulsed plasma thruster with a discharge room in an insulator rod is used as the pulsed plasma for the ablation of the insulator, and the material of the insulator rod is poly(tetrafluoroethylene) (PTFE). The pulsed plasma, in which the estimated electron density is on the order of 1022-1023 m-3, is generated by the stored energy in the capacitor. The deposition rate, which depends on the stored energy, is lower than 1 nm per pulse in our experiment. The maximum hardness measured using a nanoindenter is about 7 GPa at a stored energy of about 2.7 J, beyond which the hardness of the films decreases with the increase in stored energy. Raman spectroscopy is also carried out to examine the formation of fluorinated diamond-like carbon films. In addition, the influence of dilution gas on the properties of the deposited films is also investigated.

  15. Mechanical and tribological properties of amorphous carbon films deposited on implanted steel substrates

    International Nuclear Information System (INIS)

    Hydrogen-free amorphous carbon (a-C) films were deposited using unbalanced magnetron sputtering technique from graphite targets on AISI 440C steel substrates implanted with (1) carbon (C), (2) titanium (Ti), and (3) titanium followed by carbon (Ti+C), respectively. After deposition, the adhesion strength of the films was examined by scratch test and Rockwell-C indentation test. The tribological performance of the films was evaluated by a typical ball-on-disk tribometer and a reciprocating wear tester. A dynamic impact tester was also carried out to study the fatigue strength of the films. In order to study the effect of the pre-treatment of steel substrates by means of ion implantation on the actual performance of a-C films, the implanted substrates were investigated by using X-ray photoelectron spectroscopy and nano-indentation, from which the composition depth profile as well as the hardness (H) and elastic modulus (E) depth profiles could be accurately obtained. As a result, due to higher contents of carbide bonds appeared at the outmost surface of the C and Ti+C implanted substrates, a critical load over 65 N was obtained, indicating good scratch resistance of the films. The combination of high interfacial strength and high plastic deformation resistance (H3/E2) of the Ti+C implanted substrates led to a higher load-carrying capacity and longer duration lifetime in the sliding wear test. In the dynamic impact test, the good adhesion strength and high toughness of C and Ti+C implanted substrates improved the impact resistance of the films

  16. Hydrogen concentration of co-deposited carbon films produced in the vicinity of local island divertor in Large Helical Device

    International Nuclear Information System (INIS)

    It is quite important to evaluate hydrogen concentration of co-deposited carbon film/dust to estimate in-vessel tritium inventory in ITER. The co-deposited carbon films were prepared at the wall of pumping duct in Local Island Divertor experiments of LHD. The hydrogen concentration of the co-deposited carbon film at the wall not facing to the plasma with a low temperature was extremely high, 1.3 in the atomic ratio of H/C. This value is triple times higher than the previous value obtained by hydrogen ion irradiation to graphite. The crystal structure of the co-deposited carbon film observed by Raman spectroscopy showed very unique structure (polymeric a-C:H), which is well consistent with the high hydrogen concentration. The accumulation of in-vessel tritium inventory is also discussed. (author)

  17. Deodorisation effect of diamond-like carbon/titanium dioxide multilayer thin films deposited onto polypropylene

    Science.gov (United States)

    Ozeki, K.; Hirakuri, K. K.; Masuzawa, T.

    2011-04-01

    Many types of plastic containers have been used for the storage of food. In the present study, diamond-like carbon (DLC)/titanium oxide (TiO2) multilayer thin films were deposited on polypropylene (PP) to prevent flavour retention and to remove flavour in plastic containers. For the flavour removal test, two types of multilayer films were prepared, DLC/TiO2 films and DLC/TiO2/DLC films. The residual gas concentration of acetaldehyde, ethylene, and turmeric compounds in bottle including the DLC/TiO2-coated and the DLC/TiO2/DLC-coated PP plates were measured after UV radiation, and the amount of adsorbed compounds to the plates was determined. The percentages of residual gas for acetaldehyde, ethylene, and turmeric with the DLC/TiO2 coated plates were 0.8%, 65.2% and 75.0% after 40 h of UV radiation, respectively. For the DLC/TiO2/DLC film, the percentages of residual gas for acetaldehyde, ethylene and turmeric decreased to 34.9%, 76.0% and 85.3% after 40 h of UV radiation, respectively. The DLC/TiO2/DLC film had a photocatalytic effect even though the TiO2 film was covered with the DLC film.

  18. Deodorisation effect of diamond-like carbon/titanium dioxide multilayer thin films deposited onto polypropylene

    International Nuclear Information System (INIS)

    Many types of plastic containers have been used for the storage of food. In the present study, diamond-like carbon (DLC)/titanium oxide (TiO2) multilayer thin films were deposited on polypropylene (PP) to prevent flavour retention and to remove flavour in plastic containers. For the flavour removal test, two types of multilayer films were prepared, DLC/TiO2 films and DLC/TiO2/DLC films. The residual gas concentration of acetaldehyde, ethylene, and turmeric compounds in bottle including the DLC/TiO2-coated and the DLC/TiO2/DLC-coated PP plates were measured after UV radiation, and the amount of adsorbed compounds to the plates was determined. The percentages of residual gas for acetaldehyde, ethylene, and turmeric with the DLC/TiO2 coated plates were 0.8%, 65.2% and 75.0% after 40 h of UV radiation, respectively. For the DLC/TiO2/DLC film, the percentages of residual gas for acetaldehyde, ethylene and turmeric decreased to 34.9%, 76.0% and 85.3% after 40 h of UV radiation, respectively. The DLC/TiO2/DLC film had a photocatalytic effect even though the TiO2 film was covered with the DLC film.

  19. Deodorisation effect of diamond-like carbon/titanium dioxide multilayer thin films deposited onto polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Ozeki, K., E-mail: ozeki@mx.ibaraki.ac.jp [Department of Mechanical Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan); Frontier Research Center for Applied Atomic Sciences, 162-1 Shirakata, Toukai, Ibaraki 319-1106 (Japan); Hirakuri, K.K. [Applied Systems Engineering, Graduate School of Science and Engineering, Tokyo Denki University, Ishizaka, Hatoyama, Hiki, Saitama 350-0394 (Japan); Masuzawa, T. [Department of Mechanical Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan)

    2011-04-15

    Many types of plastic containers have been used for the storage of food. In the present study, diamond-like carbon (DLC)/titanium oxide (TiO{sub 2}) multilayer thin films were deposited on polypropylene (PP) to prevent flavour retention and to remove flavour in plastic containers. For the flavour removal test, two types of multilayer films were prepared, DLC/TiO{sub 2} films and DLC/TiO{sub 2}/DLC films. The residual gas concentration of acetaldehyde, ethylene, and turmeric compounds in bottle including the DLC/TiO{sub 2}-coated and the DLC/TiO{sub 2}/DLC-coated PP plates were measured after UV radiation, and the amount of adsorbed compounds to the plates was determined. The percentages of residual gas for acetaldehyde, ethylene, and turmeric with the DLC/TiO{sub 2} coated plates were 0.8%, 65.2% and 75.0% after 40 h of UV radiation, respectively. For the DLC/TiO{sub 2}/DLC film, the percentages of residual gas for acetaldehyde, ethylene and turmeric decreased to 34.9%, 76.0% and 85.3% after 40 h of UV radiation, respectively. The DLC/TiO{sub 2}/DLC film had a photocatalytic effect even though the TiO{sub 2} film was covered with the DLC film.

  20. Diamond-like carbon films deposited on three-dimensional shape substrate model by liquid electrochemical technique

    Energy Technology Data Exchange (ETDEWEB)

    He, Y.Y. [Institute of Nano-photonics, School of Physics and Materials Engineering, Dalian Nationalities University, 116600 Dalian (China); Zhang, G.F. [School of Materials Science and Engineering, Dalian University of Technology, 116024, Dalian China (China); Zhao, Y.; Liu, D.D. [Institute of Nano-photonics, School of Physics and Materials Engineering, Dalian Nationalities University, 116600 Dalian (China); Cong, Y., E-mail: congyan@ciomp.ac.cn [Institute of Nano-photonics, School of Physics and Materials Engineering, Dalian Nationalities University, 116600 Dalian (China); Buck, V. [Thin Film Technology Group, Faculty of Physics, University Duisburg-Essen and CeNIDE, 47057 Duisburg (Germany)

    2015-09-01

    Diamond-like carbon (DLC) films were deposited on three-dimensional (3D) shape substrate model by electrolysis of 2-propanol solution at low temperature (60 °C). This 3D shape model was composed of a horizontally aligned stainless steel wafer and vertically aligned stainless steel rods. Morphology and microstructure of the films were analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy, respectively. The results suggested there were only differences in film uniformity and thickness for two kinds of samples. The hydrogenated amorphous carbon films deposited on horizontally aligned substrate were smooth and homogeneous. And the film thickness of DLC films gained on the vertical substrates decreased along vertical direction. It is believed that bubble formation could enhance nucleation on the wetted capillary area. This experiment shows that deposition of DLC films by liquid phase deposition on 3D shape conductive substrates is possible. - Highlights: • DLC film is expected to be deposited on complex surface/shape substrate. • DLC film is deposited on 3D shape substrate by liquid electrochemical method. • Horizontal substrate is covered by smooth and homogeneous DLC films. • Film thickness decreases along vertical direction due to boiling effect.

  1. ERDA characterization of carbon nitride films deposited by hollow cathode discharge process

    International Nuclear Information System (INIS)

    The interest in carbon nitride (CN) thin films stems from the theoretical work of Liu and Cohen predicting the extreme hardness of this material, comparable to or greater than that of diamond. The growth of CN thin films employing various deposition techniques such as plasma chemical vapor deposition, sputtering, laser ablation, ion assisted dynamic mixing and low energy ion implantation has been reported. This contribution presents some results about the characterization of CNx films using elastic recoil detection analysis (ERDA) technique. CN films were deposited on silicon substrates by electron beam evaporation of pure graphite in a nitrogen environment. A hollow cathode discharge in arc regime was used both for evaporating a graphite target and for generating a high density plasma in the vicinity of the substrate. The main deposition parameters were as follows: gas (N2) pressure, 10-2 - 5.10-2 mbar; hollow cathode discharge power, 2.5 - 5 kW; substrate negative bias voltage, 0-150 V; graphite evaporation rate, 0.08 - 0.2 g/min; deposition duration, 15-60 min. The ERDA measurements were carried out at the Tandem accelerator of IFIN-HH using a 63Cu10+ beam at 80 MeV. The samples were mounted in a scattering target chamber with a vacuum higher than 5 x 10-5 Torr. The detector consisted in a compact ΔE(gas)-E(solid) telescope, placed at 30 angle with respect to the beam. The elements of the main interests were C and N. The measured Δ E -E spectra for two samples prepared in different conditions are presented. A quantitative analysis of the C and N energy spectra using our program SURFAN have been carried out for the these samples. It shows that the nitrogen to carbon atomic concentration ratio is close to 0.3. The nitrogen content is lower than that expected for the ideal β - C3N4 solid. (authors)

  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. Friction properties of amorphous carbon ultrathin films deposited by filtered cathodic vacuum arc and radio-frequency sputtering

    International Nuclear Information System (INIS)

    The friction properties of ultrathin films of amorphous carbon (a-C) deposited on Si(100) substrates by filtered cathodic vacuum arc and radio-frequency sputtering were investigated by surface force microscopy. Deposition parameters yielding a-C films with high sp3 content were used to deposit films of thickness between 5 and 35 nm. The coefficient of friction of both types of a-C films was measured with a 1-μm-radius conical diamond tip and normal loads in the range of 20–640 μN. The results show a strong dependence of the friction properties on the surface roughness, thickness, and structure of the a-C films, which are influenced by the intricacies of the deposition method. The dependence of the coefficient of friction on normal load and the dominance of adhesion and plowing friction mechanisms are interpreted in terms of the through-thickness variation of carbon atom hybridization of the a-C films. - Highlights: • Comparison of nanoscale friction properties of ultrathin amorphous carbon films. • Friction dependence on film roughness, thickness, and structure (hybridization). • Effect of through-thickness changes in carbon atom hybridization on film friction. • Explanation of film friction trends in terms of competing friction mechanisms

  4. Friction properties of amorphous carbon ultrathin films deposited by filtered cathodic vacuum arc and radio-frequency sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Matlak, J.; Komvopoulos, K., E-mail: kyriakos@me.berkeley.edu

    2015-03-31

    The friction properties of ultrathin films of amorphous carbon (a-C) deposited on Si(100) substrates by filtered cathodic vacuum arc and radio-frequency sputtering were investigated by surface force microscopy. Deposition parameters yielding a-C films with high sp{sup 3} content were used to deposit films of thickness between 5 and 35 nm. The coefficient of friction of both types of a-C films was measured with a 1-μm-radius conical diamond tip and normal loads in the range of 20–640 μN. The results show a strong dependence of the friction properties on the surface roughness, thickness, and structure of the a-C films, which are influenced by the intricacies of the deposition method. The dependence of the coefficient of friction on normal load and the dominance of adhesion and plowing friction mechanisms are interpreted in terms of the through-thickness variation of carbon atom hybridization of the a-C films. - Highlights: • Comparison of nanoscale friction properties of ultrathin amorphous carbon films. • Friction dependence on film roughness, thickness, and structure (hybridization). • Effect of through-thickness changes in carbon atom hybridization on film friction. • Explanation of film friction trends in terms of competing friction mechanisms.

  5. Controlled fluoridation of amorphous carbon films deposited at reactive plasma conditions

    Directory of Open Access Journals (Sweden)

    Yoffe Alexander

    2015-09-01

    Full Text Available A study of the correlations between plasma parameters, gas ratios, and deposited amorphous carbon film properties is presented. The injection of a C4F8/Ar/N2 mixture of gases was successfully used in an inductively coupled plasma system for the preparation of amorphous carbon films with different fluoride doping at room-temperature, using silicon as a substrate. This coating was formed at low-pressure and low-energy using an inductively coupled plasma process. A strong dependence between the ratios of gases during deposition and the composition of the substrate compounds was shown. The values of ratios between Ar (or Ar+N2 and C4F8 - 1:1 and between N2 and Ar - 1:2 in the N2/Ar/C4F8 mixture were found as the best for low fluoridated coatings. In addition, an example of improving the etch-passivation in the Bosch procedure was described. Scanning electron microscopy with energy dispersive spectroscopy options, X-ray diffraction, and X-ray reflectivity were used for quantitative analysis of the deposited films.

  6. Interface study between nanostructured tantalum nitride films and carbon nanotubes grown by chemical vapour deposition

    International Nuclear Information System (INIS)

    Highlights: • Our paper deals with the understanding of the carbon nanotubes growth parameters following the use of specific thin nitride buffer films. • For a large choice of buffer, we use ultra thin films elaborated by the very new method: high power pulsed magnetron sputtering; it allows a larger nitrogen incorporation in the films and lead to out of equilibrium phase formation. • Then by a multiscale investigation, developing a structural, a chemical and a morphology approach, we lead to some conclusion on the correlation between the phase transition for the buffer and morphology transition for the CNTs. • That is a new and deep approach. - Abstract: We present the role of nitrogen content in tantalum nitride ultra-thin buffers, on the carbon nanotubes (CNTs) growth by chemical vapour deposition at 850 °C, assisted by ferrocene as catalyst source. Tantalum nitride (TaNx) films with a very large range of concentration x = [0, 1.8] and various nanostructures, from amorphous Ta(N) to Ta3N5, were deposited by Highly Pulsed Plasma Magnetron Sputtering. The buffer films are characterized after heat treatment at 850 °C, and after the CNT growth, by wide angle X-ray scattering in grazing incidence and scanning electron microscopy. The CNT diameter explored by transition electron microscopy shows an all-out value for under stoichiometric thin films (Ta1-N1−δ, Ta3-N5−δ) and a minimum value just above the stoichiometric phases (Ta1-N1+δ, Ta3-N5+δ). Firstly one shows that the buffer films under the heat treatment present surface modification highly dependent on their initial state, which influences the catalyst particles diffusion. Secondly at the stoichiometric TaN phase we show that a specific ternary phase FeTa2O6 is formed at the interface CNT/buffer, not present in the other cases, leading to a special CNT growth condition

  7. Diamondlike carbon deposition on plastic films by plasma source ion implantation

    CERN Document Server

    Tanaka, T; Shinohara, M; Takagi, T

    2002-01-01

    Application of pulsed high negative voltage (approx 10 mu s pulse width, 300-900 pulses per second) to a substrate is found to induce discharge, thereby increasing ion current with an inductively coupled plasma source. This plasma source ion beam implantation (PSII) technique is investigated for the pretreatment and deposition of diamond-like carbon (DLC) thin layer on polyethylene terepthalate (PET) film. Pretreatment of PET with N sub 2 and Ar plasma is expected to provide added barrier effects when coupled with DLC deposition, with possible application to fabrication of PET beverage bottles. PSII treatment using N sub 2 and Ar in separate stages is found to change the color of the PET film, effectively increasing near-ultraviolet absorption. The effects of this pretreatment on the chemical bonding of C, H, and O are examined by x-ray photoelectron spectroscopy (XPS). DLC thin film was successfully deposited on the PET film. The surface of the DLC thin layer is observed to be smooth by scanning electron mic...

  8. The multilayered structure of ultrathin amorphous carbon films synthesized by filtered cathodic vacuum arc deposition

    KAUST Repository

    Wang, Na

    2013-08-01

    The structure of ultrathin amorphous carbon (a-C) films synthesized by filtered cathodic vacuum arc (FCVA) deposition was investigated by high-resolution transmission electron microscopy, electron energy loss spectroscopy, and x-ray photoelectron spectroscopy. Results of the plasmon excitation energy shift and through-thickness elemental concentration show a multilayered a-C film structure comprising an interface layer consisting of C, Si, and, possibly, SiC, a buffer layer with continuously increasing sp 3 fraction, a relatively thicker layer (bulk film) of constant sp 3 content, and an ultrathin surface layer rich in sp 2 hybridization. A detailed study of the C K-edge spectrum indicates that the buffer layer between the interface layer and the bulk film is due to the partial backscattering of C+ ions interacting with the heavy atoms of the silicon substrate. The results of this study provide insight into the minimum thickness of a-C films deposited by FCVA under optimum substrate bias conditions. Copyright © 2013 Materials Research Society.

  9. Protolytic carbon film technology

    Energy Technology Data Exchange (ETDEWEB)

    Renschler, C.L.; White, C.A.

    1996-04-01

    This paper presents a technique for the deposition of polyacrylonitrile (PAN) on virtually any surface allowing carbon film formation with only the caveat that the substrate must withstand carbonization temperatures of at least 600 degrees centigrade. The influence of processing conditions upon the structure and properties of the carbonized film is discussed. Electrical conductivity, microstructure, and morphology control are also described.

  10. Incidence Angle Effect of Energetic Carbon Ions on Deposition Rate, Topography, and Structure of Ultrathin Amorphous Carbon Films Deposited by Filtered Cathodic Vacuum Arc

    KAUST Repository

    Wang, N.

    2012-07-01

    The effect of the incidence angle of energetic carbon ions on the thickness, topography, and structure of ultrathin amorphous carbon (a-C) films synthesized by filtered cathodic vacuum arc (FCVA) was examined in the context of numerical and experimental results. The thickness of a-C films deposited at different incidence angles was investigated in the light of Monte Carlo simulations, and the calculated depth profiles were compared with those obtained from high-resolution transmission electron microscopy (TEM). The topography and structure of the a-C films were studied by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), respectively. The film thickness decreased with the increase of the incidence angle, while the surface roughness increased and the content of tetrahedral carbon hybridization (sp 3) decreased significantly with the increase of the incidence angle above 45° , measured from the surface normal. TEM, AFM, and XPS results indicate that the smoothest and thinnest a-C films with the highest content of sp 3 carbon bonding were produced for an incidence angle of 45°. The findings of this study have direct implications in ultrahigh-density magnetic recording, where ultrathin and smooth a-C films with high sp 3 contents are of critical importance. © 2012 IEEE.

  11. Co-sputter deposited nickel-copper bimetallic nanoalloy embedded carbon films for electrocatalytic biomarker detection

    Science.gov (United States)

    Shiba, Shunsuke; Kato, Dai; Kamata, Tomoyuki; Niwa, Osamu

    2016-06-01

    -mannitol, which should be detected with a low detection limit in urine samples for the diagnosis of severe intestinal diseases. With a Ni/Cu ratio of around 64/36, the electrocatalytic current per metal area was 3.4 times larger than that of an alloy film electrode with a similar composition (~70/30). This improved electrocatalytic activity realized higher stability (n = 60, relative standard deviation (RSD): 4.6%) than the alloy film (RSD: 32.2%) as demonstrated by continuous measurements of d-mannitol. Electronic supplementary information (ESI) available: The concept of UBM co-sputtering for fabricating nanoalloy embedded carbon films. HRTEM images of the NiNP and Ni32Cu68 nanoalloy embedded carbon films. The experimental conditions for sputter deposition, HRTEM, HAADF-STEM, STEM-EDS measurements and continuous flow injection analysis. XPS analysis of the nanoalloy embedded carbon film. Repeated CVs of both the nanoalloy embedded carbon film and the alloy film. Amperometric detection of d-mannitol in the presence of chloride ions. See DOI: 10.1039/c6nr02287a

  12. Deposition and characterization of carbon nanotubes (CNTS) based films for sensing applications

    Science.gov (United States)

    Dissanayake, Amila C.

    The advent of carbon nanotubes (CNTs) has opened up lot of novel applications because of their unique electrical and mechanical properties. CNTs are well known material for its exceptional electrical, mechanical, optical, thermal and chemical properties. A single-wall nanotube (SWNT) can be either semiconducting, metallic or semi-metallic, based on its chirality and diameter. SWNTs can be used in transistor device as active channels due to high electron mobility (~10000 cm2/(V s), electrical interconnects, nano-scale circuits, field-emission displays, light-emitting devices and thermal heat sinks due to low resistivity, high current density (~109A cm-2 ) and high thermal conductivity (~3500 W m-1). Further, their high Young's modulus and fracture stress is suitable for various sensing applications such as strain/pressure and use in chemical/biological sensors. This work mainly involves the deposition of CNT-based films following two different methods via a conventional microwave chemical vapor deposition (MWCVD) and spinning CNT-composites, and explored the possibility of using CNT-based films in strain gauge applications. Deposited films are characterized and analyzed for their structure, microstructure, composition and electrical properties. Rutherford Backscattering Spectrometry (RBS), X-ray Reflectivity (XRR), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM) and electrical impedance measurement techniques are used to characterize the films prepared by both the above mentioned methods. The synthesis/deposition process is improved based on the observed films properties. A carbon nanotube forest grown on the Si (100) substrate with Ni as a catalyst using CVD system shows an amorphous nature due to loss of catalytic activity of Ni nano-islands. XPS and RBS data show Ni nano-particles diffused into the Si substrate and surface layer of Ni particles turns out to nickel silicide. The

  13. Synthesis of Ag-doped hydrogenated carbon thin films by a hybrid PVD–PECVD deposition process

    Indian Academy of Sciences (India)

    Majji Venkatesh; Sukru Taktak; Efstathios I Meletis

    2014-12-01

    Silver-doped hydrogenated amorphous carbon (Ag-DLC) films were deposited on Si substrates using a hybrid plasma vapour deposition–plasma enhanced chemical vapour deposition (PVD–PECVD) process combining Ag target magnetron sputtering and PECVD in an Ar–CH4 plasma. Processing parameters (working pressure, CH4/Ar ratio and magnetron current) were varied to obtain good deposition rate and a wide variety of Ag films. Structure and bonding environment of the films were obtained from transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and Fourier transform infrared (FTIR) spectroscopy studies. Variation of processing parameters was found to produce Ag-doped amorphous carbon or diamond-like carbon (DLC) films with a range of characteristics with CH4/Ar ratio exercising a dominant effect. It was pointed out that Ag concentration and deposition rate of the film increased with the increase in d.c. magnetron current. At higher Ar concentration in plasma, Ag content increased whereas deposition rate of the film decreased. FTIR study showed that the films contained a significant amount of hydrogen and, as a result of an increase in the Ag content in the hydrogenated DLC film, $sp^{2}$ bond content also increased. The TEM cross sectional studies revealed that crystalline Ag particles were formed with a size in the range of 2–4 nm throughout an amorphous DLC matrix.

  14. Mechanical properties of amorphous hydrogenated carbon films fabricated on polyethylene terephthalate foils by plasma immersion ion implantation and deposition

    International Nuclear Information System (INIS)

    Amorphous hydrogenated carbon (a-C:H) films have been deposited on polyethylene terephthalate by plasma immersion ion implantation and deposition. The influence of deposition parameters such as gas pressure, bias voltage, and nitrogen incorporation on the mechanical properties of the a-C:H films are investigated. X-ray photoelectron spectroscopy reveals that the ratio of sp3 to sp2 is 0.24 indicating that the film is mainly composed of graphitelike carbon. Nanoindentation tests disclose enhanced surface hardness of ∼6 GPa. The friction coefficient of the film deposited at higher gas pressure, for instance, 2.0 Pa, is lower than that of the film deposited at a lower pressure such as 0.5 Pa. The films deposited using a low bias voltage tend to fail easily in the friction tests and nitrogen incorporation into the a-C:H films decreases the friction coefficient. Mechanical folding tests show that deformation failure is worse on a thinner a-C:H film

  15. Characterization of amorphous hydrogenated carbon films deposited by MFPUMST at different ratios of mixed gases

    Indian Academy of Sciences (India)

    Haiyang Dai; Changyong Zhan; Hui Jiang; Ningkang Huang

    2012-12-01

    Amorphous hydrogenated carbon films (-C:H) on -type (100) silicon wafers were prepared with a middle frequency pulsed unbalanced magnetron sputtering technique (MFPUMST) at different ratios of methane–argon gases. The band characteristics, mechanical properties as well as refractive index were measured by Raman spectra, X-ray photoelectron spectroscopy (XPS), nano-indentation tests and spectroscopic ellipsometry. It is found that the 3 fraction increases with increasing Ar concentration in the range of 17–50%, and then decreases when Ar concentration exceeds 50%. The nano-indentation tests reveal that nano-hardness and elastic modulus of the films increase with increasing Ar concentration in the range of 17–50%, while decreases with increasing Ar concentration from 50% to 86%. The variations in the nano-hardness and the elastic modulus could be interpreted due to different 3 fractions in the prepared -C:H films. The variation of refractive index with wavelength have the same tendency for the -C:H films prepared at different Ar concentrations, they decrease with increasing wavelength from 600 to 1700 nm. For certain wavelengths within 600–1700 nm, refractive index has the highest value at the Ar concentration of 50%, and it is smaller at the Ar concentration of 86% than at 17%. The results given above indicate that ratio of mixed gases has a strong influence on bonding configuration and properties of -C:H films during deposition. The related mechanism is discussed in this paper.

  16. Deposition of calcium carbonate films by a polymer-induced liquid-precursor (PILP) process

    Science.gov (United States)

    Gower, Laurie B.; Odom, Damian J.

    2000-03-01

    A polypeptide additive has been used to transform the solution crystallization of calcium carbonate to a solidification process of a liquid-phase mineral precursor. In situ observations reveal that polyaspartate induces liquid-liquid phase separation of droplets of a mineral precursor. The droplets deposit on the substrate and coalesce to form a coating, which then solidifies into calcitic tablets and films. Transition bars form during the amorphous to crystalline transition, leading to sectorization of calcite tablets, and the defect textures and crystal morphologies are atypical of solution grown crystals. The formation of nonequilibrium crystal morphologies using an acidic polypeptide may have implications in the field of biomineralization, and the environmentally friendly aspects of this polymer-induced liquid-precursor (PILP) process may offer new techniques for aqueous-based processing of ceramic films, coatings, and particulates.

  17. Control of carbon content in amorphous GeTe films deposited by plasma enhanced chemical vapor deposition (PE-MOCVD) for phase-change random access memory applications

    International Nuclear Information System (INIS)

    Amorphous and smooth GeTe thin films are deposited on 200 mm silicon substrates by plasma enhanced—metal organic chemical vapor deposition (PE–MOCVD) using the commercial organometallic precursors TDMAGe and DIPTe as Ge and Te precursors, respectively. X-ray photoelectron spectroscopy (XPS) measurements show a stoichiometric composition of the deposited GeTe films but with high carbon contamination. Using information collected by Optical Emission Spectroscopy (OES) and XPS, the origin of carbon contamination is determined and the dissociation mechanisms of Ge and Te precursors in H2 + Ar plasma are proposed. As a result, carbon level is properly controlled by varying operating parameters such as plasma radio frequency power, pressure and H2 rate. Finally, GeTe films with carbon level as low as 5 at. % are obtained. (paper)

  18. Control of carbon content in amorphous GeTe films deposited by plasma enhanced chemical vapor deposition (PE-MOCVD) for phase-change random access memory applications

    Science.gov (United States)

    Aoukar, M.; Szkutnik, P. D.; Jourde, D.; Pelissier, B.; Michallon, P.; Noé, P.; Vallée, C.

    2015-07-01

    Amorphous and smooth GeTe thin films are deposited on 200 mm silicon substrates by plasma enhanced—metal organic chemical vapor deposition (PE-MOCVD) using the commercial organometallic precursors TDMAGe and DIPTe as Ge and Te precursors, respectively. X-ray photoelectron spectroscopy (XPS) measurements show a stoichiometric composition of the deposited GeTe films but with high carbon contamination. Using information collected by Optical Emission Spectroscopy (OES) and XPS, the origin of carbon contamination is determined and the dissociation mechanisms of Ge and Te precursors in H2 + Ar plasma are proposed. As a result, carbon level is properly controlled by varying operating parameters such as plasma radio frequency power, pressure and H2 rate. Finally, GeTe films with carbon level as low as 5 at. % are obtained.

  19. Effect of pressure on the deposition of hydrogen-free amorphous carbon and carbon nitride films by the pulsed cathodic arc discharge method

    International Nuclear Information System (INIS)

    Hydrogen-free amorphous carbon (a-C) and carbon nitride (a-C:N) films were deposited using the pulsed cathodic arc discharge at different argon and nitrogen pressures. The surface and mechanical properties of these films were found to strongly depend on the gas pressure. The tetrahedral amorphous carbon and hard a-C:N films with smooth surfaces (rms roughness: 0.15 nm) were prepared at lower gas pressures (-2 Pa). Incorporation of an increasing amount of nitrogen in a-C:N films caused a decrease in film hardness. All the films were covered with the thin (0.3-2 nm) graphite-like surface layers. The film hardness was correlated to the soft surface layer thickness, and the films with thinner surface layers exhibit higher hardness. The mean energies of pulsed plasma beams were measured as the functions of argon and nitrogen pressures. The mean energies of plasma beams decrease in an exponential fashion with increasing gas pressure due to the carbon ion collisions with the neutral gas species. The effects of mean energies of deposited species on the film deposition were explained in terms of the thermal spike migration of surface atoms. The formation of graphite-like surface layers is associated with the low-energy deposition process. The low-energy (10 eV) species may produce the strong thermal spike at film surface, and contribute to the formation of sp3 bonded structure at a sp3 bonded matrix

  20. Characteristics of Diamond-Like Carbon Films Deposited on Polymer Dental Materials

    Science.gov (United States)

    Ohtake, Naoto; Uchi, Tomio; Yasuhara, Toshiyuki; Takashima, Mai

    2012-09-01

    Characterizations of diamond-like carbon (DLC) deposited on a polymer artificial tooth were performed. DLC films were deposited on dental parts made of poly(methyl methacrylate) (PMMA) resin by dc-pulse plasma chemical vapor deposition (CVD) from methane. Wear resistance test results revealed that a DLC-coated resin tooth has a very high wear resistance against tooth brushing, and endures 24 h brushing without a marked weight decrease. Cell cultivation test results show that DLC plays an important role in preventing cell death. Moreover, a biocompatibility test using a rabbit revealed that a connective tissue in the vicinity of DLC-coated PMMA is significantly thinner than that of noncoated PMMA. The numbers of inflammatory cells in the vicinity of DLC-coated and noncoated surfaces are 0 and 508 cells/mm2, respectively. These results led us to conclude that DLC films are an excellent material for use as the coating of a polymer artificial tooth in terms of not only high wear resistance but also biocompatibility.

  1. Spray deposition of steam treated and functionalized single-walled and multi-walled carbon nanotube films for supercapacitors

    International Nuclear Information System (INIS)

    Steam purified, carboxylic and ester functionalized single-walled carbon nanotube (SWNT) and multi-walled carbon nanotube (MWNT) films with homogeneous distribution and flexible control of thickness and area were fabricated on polymeric and metallic substrates using a modified spray deposition technique. By employing a pre-sprayed polyelectrolyte, the adhesion of the carbon nanotube (CNT) films to the substrates was significantly enhanced by electrostatic interaction. Carboxylic and ester functionalization improved electrochemical performance when immersed in 0.1 M H2SO4 and the specific capacitance reached 155 and 77 F g-1 for carboxylic functionalized SWNT and MWNT films respectively. Compared with existing techniques such as hot pressing, vacuum filtration and dip coating, the ambient pressure spray deposition technique is suggested as particularly well suited for preparing CNT films at large scale for applications including providing electrodes for electrochemical supercapacitors and paper batteries.

  2. Defect effect on tribological behavior of diamond-like carbon films deposited with hydrogen diluted benzene gas in aqueous environment

    Science.gov (United States)

    Yi, Jin Woo; Park, Se Jun; Moon, Myoung-Woon; Lee, Kwang-Ryeol; Kim, Seock-Sam

    2009-05-01

    This study examined the friction and wear behavior of diamond-like carbon (DLC) films deposited from a radio frequency glow discharge using a hydrogen diluted benzene gas mixture. The DLC films were deposited on Si (1 0 0) and polished stainless steel substrates by radio frequency plasma-assisted chemical vapor deposition (r.f.-PACVD) at hydrogen to benzene ratios, or the hydrogen dilution ratio, ranging from 0 to 2.0. The wear test was carried out in both ambient and aqueous environments using a homemade ball-on-disk type wear rig. The stability of the DLC coating in an aqueous environment was improved by diluting the benzene precursor gas with hydrogen, suggesting that hydrogen dilution during the deposition of DLC films suppressed the initiation of defects in the film and improved the adhesion of the coating to the interface.

  3. Production and characterization of hydrogenated amorphous carbon thin films deposited in methane plasmas diluted by noble gases

    International Nuclear Information System (INIS)

    The dilution effects of the precursor methane atmosphere by three noble gases (Ar, Ne and He) on the mechanical properties and the microstructure of hydrogenated amorphous carbon films deposited by rf-PECVD were studied. The chemical composition and atomic density of the films were determined by ion beam analysis. The film microstructure was probed by means of Raman spectroscopy. The internal stress was determined through the measurement of the changing of the substrate curvature by a profilometer, while nanoindentation experiments provided the film hardness. The results show that the precursor atmosphere dilution by different noble gases did not induce substantial modifications in the microstructure or in the mechanical properties of the films. On the other hand, the composition, the microstructure and the mechanical properties of the films are strongly dependent on the self-bias voltage. The results confirm the importance of the ion bombardment during film growth on the mechanical properties of the films

  4. Electrochemical deposition of carbon films on titanium in molten LiCl-KCl-K{sub 2}CO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Song, Qiushi; Xu, Qian, E-mail: Qianxu201@mail.neu.edu.cn; Wang, Yang; Shang, Xujing; Li, Zaiyuan

    2012-09-30

    Electrodeposition of carbon films on the oxide-scale-coated titanium has been performed in a LiCl-KCl-K{sub 2}CO{sub 3} melt, which are characterized by scanning electron microscopy, Raman spectroscopy and X-ray diffraction analysis. The electrochemical process of carbon deposition is investigated by cyclic voltammetry on the graphite, titanium and oxide-scale-coated titanium electrodes. The particle-size-gradient carbon films over the oxide-scale-coated titanium can be achieved by electrodeposition under the controlled potentials for avoiding codeposition of lithium carbide. The deposited carbon films are comprised of micron-sized 'quasi-spherical' carbon particles with graphitized and amorphous phases. The cyclic voltammetry behavior on the graphite, titanium and oxide-scale-coated titanium electrodes shows that CO{sub 3}{sup 2-} ions are reduced most favorably on the graphite for the three electrodes. Lithium ions can discharge under the less negative potential on the electrode containing carbon compared with titanium electrode because of the formation of lithium carbide from the reaction between lithium and carbon. - Highlights: Black-Right-Pointing-Pointer Carbon films are prepared on oxide-scale-coated titanium in a LiCl-KCl-K{sub 2}CO{sub 3} melt. Black-Right-Pointing-Pointer The films comprise micron-size 'quasi-spherical' carbon particles. Black-Right-Pointing-Pointer The films present particle-size-gradient. Black-Right-Pointing-Pointer The particles contain graphitized and amorphous phases. Black-Right-Pointing-Pointer The prepared carbon films are more electrochemically active than graphite.

  5. Effect of nitrogen pressure on optical properties and microstructure of diamond-like carbon films grown by pulsed laser deposition

    Institute of Scientific and Technical Information of China (English)

    DING Xu-Li; LI Qing-Shan; KONG Xiang-he

    2009-01-01

    The effect of nitrogen pressure on optical properties of hydrogen-free diamond-like carbon (DLC) films deposited by pulsed laser ablation graphite in different background pressures of nitrogen is reported. By varying nitrogen pressures from 0.05 to 15.00 Pa, the photoluminescence is gradually increased and optical transmittance is gradually decreased. Atomic force microscopy (AFM) is used to observe the surface morphology of the DLC films. The results indicate that the surface becomes unsmoothed and there are some globose particles on the films surface with the rise of nitrogen pressures. The microstructure of the films is characterized using Raman spectroscopy.

  6. Carbon thin film thermometry

    Science.gov (United States)

    Collier, R. S.; Sparks, L. L.; Strobridge, T. R.

    1973-01-01

    The work concerning carbon thin film thermometry is reported. Optimum film deposition parameters were sought on an empirical basis for maximum stability of the films. One hundred films were fabricated for use at the Marshall Space Flight Center; 10 of these films were given a precise quasi-continuous calibration of temperature vs. resistance with 22 intervals between 5 and 80 K using primary platinum and germanium thermometers. Sensitivity curves were established and the remaining 90 films were given a three point calibration and fitted to the established sensitivity curves. Hydrogen gas-liquid discrimination set points are given for each film.

  7. Influence of thin film nickel pretreatment on catalytic thermal chemical vapor deposition of carbon nanofibers

    NARCIS (Netherlands)

    Tiggelaar, R.M.; Thakur, D.B.; Nair, H.; Lefferts, L.; Seshan, K.; Gardeniers, J.G.E.

    2013-01-01

    Nickel and other metal nanoparticles are known to be active as catalysts in the synthesis of carbon nanofibers. In this paper we investigate how dewetting and break-up of nickel thin films depends on film thickness, film–substrate interaction and pretreatment conditions. This is evaluated for films

  8. Electron emission from nano-structured carbon films fabricated by hot-filament chemical-vapor deposition and microwave plasma-enhanced chemical vapor deposition

    CERN Document Server

    Park, K H; Lee, K M; Oh, S G; Lee, S I; Koh, K H

    2000-01-01

    The electron-emission characteristics of nano-structured carbon films fabricated by using the HFCVD (hot- filament chemical-vapor deposition) and the MPECVD (microwave plasma-enhanced chemical-vapor deposition) methods with a metal catalyst are presented. According to our observation, neither the formation nor the alignment of nano tubes is absolutely necessary to realize carbon-based electron emitters. However, utilization of chrome as an interlayer between Si substrates and metal catalyst particles results in a great improvement in the emission characteristics and the mechanical stability. Also, fabrication of good electron-emitting carbon films on glass substrates, with sputter-deposited chrome electrodes,at a nominal temperature approx 615 .deg. C was demonstrated.

  9. Investigation on single walled carbon nanotube thin films deposited by Langmuir Blodgett method

    International Nuclear Information System (INIS)

    Langmuir Blodgett is a technique to deposit a homogeneous film with a fine control over thickness and molecular organization. Thin films of functionalized SWCNTs have been prepared by Langmuir Blodgett method. The good surface spreading properties of SWCNTs at air/water interface are indicated by surface pressure-area isotherm and the monolayer formed on water surface is transferred onto the quartz substrate by vertical dipping. A multilayer film is thus obtained in a layer by layer manner. The film is characterized by Atomic Force Microscope (AFM), UV-Vis-NIR spectroscopy and FTIR.AFM shows the surface morphology of the deposited film. UV-Vis-NIR spectroscopy shows the characteristic peaks of semiconducting SWCNTs. The uniformity of LB film can be used further in understanding the optical and electrical behavior of these materials

  10. Investigation on single walled carbon nanotube thin films deposited by Langmuir Blodgett method

    Energy Technology Data Exchange (ETDEWEB)

    Vishalli,, E-mail: vishalli-2008@yahoo.com; Dharamvir, Keya [Department of Physics, Panjab University, Chandigarh (India); Kaur, Ramneek; Raina, K. K. [Materials Research Laboratory, School of Physics and Materials Science, Thapar University, Patiala (India)

    2015-05-15

    Langmuir Blodgett is a technique to deposit a homogeneous film with a fine control over thickness and molecular organization. Thin films of functionalized SWCNTs have been prepared by Langmuir Blodgett method. The good surface spreading properties of SWCNTs at air/water interface are indicated by surface pressure-area isotherm and the monolayer formed on water surface is transferred onto the quartz substrate by vertical dipping. A multilayer film is thus obtained in a layer by layer manner. The film is characterized by Atomic Force Microscope (AFM), UV-Vis-NIR spectroscopy and FTIR.AFM shows the surface morphology of the deposited film. UV-Vis-NIR spectroscopy shows the characteristic peaks of semiconducting SWCNTs. The uniformity of LB film can be used further in understanding the optical and electrical behavior of these materials.

  11. Plasma deposition of amorphous hydrogenated carbon films on III-V semiconductors

    Science.gov (United States)

    Pouch, John J.; Warner, Joseph D.; Liu, David C.; Alterovitz, Samuel A.

    1988-01-01

    Amorphous hydrogenated carbon films were grown on GaAs, InP and fused silica substrates using plasmas generated from hydrocarbon gases. Methane and n-butane sources were utilized. The effects of flow rate and power density on film growth were investigated. Carbon was the major constituent in the films. The degree of asymmetry at the carbon-semiconductor interface was approximately independent of the power density. Different H-C bonding configurations were detected by the technique of secondary-ion mass spectrometry. Band gaps up to 3 eV were obtained from optical absorption studies. Breakdown strengths as high as 600 MV/m were measured.

  12. Synthesis of thin films in boron-carbon-nitrogen ternary system by microwave plasma enhanced chemical vapor deposition

    Science.gov (United States)

    Kukreja, Ratandeep Singh

    The Boron Carbon Nitorgen (B-C-N) ternary system includes materials with exceptional properties such as wide band gap, excellent thermal conductivity, high bulk modulus, extreme hardness and transparency in the optical and UV range that find application in most fields ranging from micro-electronics, bio-sensors, and cutting tools to materials for space age technology. Interesting materials that belong to the B-C-N ternary system include Carbon nano-tubes, Boron Carbide, Boron Carbon Nitride (B-CN), hexagonal Boron Nitride ( h-BN), cubic Boron Nitride (c-BN), Diamond and beta Carbon Nitride (beta-C3N4). Synthesis of these materials requires precisely controlled and energetically favorable conditions. Chemical vapor deposition is widely used technique for deposition of thin films of ceramics, metals and metal-organic compounds. Microwave plasma enhanced chemical vapor deposition (MPECVD) is especially interesting because of its ability to deposit materials that are meta-stable under the deposition conditions, for e.g. diamond. In the present study, attempt has been made to synthesize beta-carbon nitride (beta-C3N4) and cubic-Boron Nitride (c-BN) thin films by MPECVD. Also included is the investigation of dependence of residual stress and thermal conductivity of the diamond thin films, deposited by MPECVD, on substrate pre-treatment and deposition temperature. Si incorporated CNx thin films are synthesized and characterized while attempting to deposit beta-C3N4 thin films on Si substrates using Methane (CH4), Nitrogen (N2), and Hydrogen (H2). It is shown that the composition and morphology of Si incorporated CNx thin film can be tailored by controlling the sequence of introduction of the precursor gases in the plasma chamber. Greater than 100mum size hexagonal crystals of N-Si-C are deposited when Nitrogen precursor is introduced first while agglomerates of nano-meter range graphitic needles of C-Si-N are deposited when Carbon precursor is introduced first in the

  13. The effect of substrate bias on titanium carbide/amorphous carbon nanocomposite films deposited by filtered cathodic vacuum arc

    International Nuclear Information System (INIS)

    The titanium carbide/amorphous carbon nanocomposite films have been deposited on silicon substrate by filtered cathodic vacuum arc (FCVA) technology, the effects of substrate bias on composition, structures and mechanical properties of the films are studied by scanning electron spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy and nano-indentation. The results show that the Ti content, deposition rate and hardness at first increase and then decrease with increasing the substrate bias. Maximum hardness of the titanium carbide/amorphous carbon nanocomposite film is 51 Gpa prepared at −400 V. The hardness enhancement may be attributed to the compressive stress and the fraction of crystalline TiC phase due to ion bombardment

  14. Thermal effects on structure and photoluminescence properties of diamond-like carbon films prepared by pulsed laser deposition

    Institute of Scientific and Technical Information of China (English)

    CHEN Da; LI Qing-shan; WANG Jing-jing; ZHENG Xue-gang

    2006-01-01

    Un-hydrogenated Diamond-like Carbon (DLC) films were prepared by pulsed laser deposition technique at different substrate temperature.The Raman spectra,the absorption and the photoluminescence spectra were measured.The dependence of structure and photoluminescence properties on deposition temperature were studied in detail.The experimental results indicate that the sp2 sites form small clusters that consist of both olefinic chains and aromatic ring groups within the sp3 matrix.With raising deposition temperature,the optical band gaps increase from 1.87 to 2.85 eV.The main band of photoluminescence centered at around 700nm shifts to short wavelength,and the intensity of this band increases.The photoluminescence can be attributed to carrier localization within an increasing sp2 clusters.It was clarified that the DLC films are ordered with increasing deposition temperature.

  15. Uniform deposition of ternary chalcogenide nanoparticles onto mesoporous TiO2 film using liquid carbon dioxide-based coating

    International Nuclear Information System (INIS)

    We report the simultaneous deposition of two different metal precursors dissolved in liquid carbon dioxide (l-CO2), aiming to the synthesis of ternary chalcopyrite (e.g. CuInS2) nanoparticles on a mesoporous TiO2 film. The l-CO2-based deposition of Cu and In precursors and subsequent reaction with a dilute H2S gas resulted in CuxInySz nanoparticles uniformly deposited across the entire thickness of a mesoporous TiO2 film. Further heat treatment (air annealing and sulfurization) led to the formation of more stoichiometric CuInS2 nanoparticles. The formation of CuInS2 on TiO2 was confirmed by scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. The crystal growth of CuInS2 was also found to be controllable by adjusting the number of coating cycles of the l-CO2-based deposition. - Highlights: • Simultaneous deposition of two different metal precursors dissolved in l-CO2. • Uniform deposition of CuInS2 nanoparticles across mesoporous TiO2 film. • Highly crystalline CuInS2 formed on mesoporous TiO2 film. • Nearly stoichiometric ratio of Cu:In:S was obtained

  16. Amorphous silicon carbon films prepared by hybrid plasma enhanced chemical vapor/sputtering deposition system: Effects of r.f. power

    International Nuclear Information System (INIS)

    Silicon carbon films were deposited using a hybrid radio frequency (r.f.) plasma enhanced chemical vapor deposition (PECVD)/sputtering deposition system at different r.f. powers. This deposition system combines the advantages of r.f. PECVD and sputtering techniques for the deposition of silicon carbon films with the added advantage of eliminating the use of highly toxic silane gas in the deposition process. Silicon (Si) atoms were sputtered from a pure amorphous silicon (a-Si) target by argon (Ar) ions and carbon (C) atoms were incorporated into the film from C based growth radicals generated through the discharge of methane (CH4) gas. The effects of r.f. powers of 60, 80, 100, 120 and 150 W applied during the deposition process on the structural and optical properties of the films were investigated. Raman spectroscopic studies showed that the silicon carbon films contain amorphous silicon carbide (SiC) and amorphous carbon (a-C) phases. The r.f. power showed significant influence on the C incorporation in the film structure. The a-C phases became more ordered in films with high C incorporation in the film structure. These films also produced high photoluminescence emission intensity at around 600 nm wavelength as a result of quantum confinement effects from the presence of sp2 C clusters embedded in the a-SiC and a-C phases in the films. - Highlights: ► Effects of radio frequency (r.f.) power on silicon carbon (SiC) films were studied. ► Hybrid plasma enhanced chemical vapor deposition/sputtering technique was used. ► r.f. power influences C incorporation in the film structure. ► High C incorporation results in higher ordering of the amorphous C phase. ► These films produced high photoluminescence emission intensity

  17. Study of Cu diffusion behavior in carbon rich SiCN:H films deposited from trimethylphenylsilane

    Energy Technology Data Exchange (ETDEWEB)

    Ermakova, E. [Nikolaev Institute of Inorganic Chemistry SB RAS, 630090 Novosibirsk (Russian Federation); Mogilnikov, K. [Rzhanov Institute of Semiconductor Physics SB RAS, 630090 Novosibirsk (Russian Federation); Rumyantsev, Yu.; Kichay, V.; Maximovskii, E. [Nikolaev Institute of Inorganic Chemistry SB RAS, 630090 Novosibirsk (Russian Federation); Semenova, O. [Rzhanov Institute of Semiconductor Physics SB RAS, 630090 Novosibirsk (Russian Federation); Kosinova, M., E-mail: marina@niic.nsc.ru [Nikolaev Institute of Inorganic Chemistry SB RAS, 630090 Novosibirsk (Russian Federation)

    2015-08-03

    Amorphous SiC{sub x}:H and SiC{sub x}N{sub y}:H films were grown on Si (100) substrates by plasma enhanced chemical vapor deposition using trimethylphenylsilane as a precursor. Detailed studies including Fourier transformed infra-red spectrometry, elemental analysis, transmission electron microscopy, dielectric constant and porosity investigations, and preliminary Cu diffusion experiments were performed. It was shown that the films contained pores connected by narrow channels with a diameter of 5 Å, and the total porosity did not exceed 1.5%. The film with both low dielectric constant and low porosity was chosen for Cu diffusion barrier experiments. Si/SiC{sub x}:H/Cu structure was created and then annealed. The investigation of cross-sectional cut suggested that the film had good barrier properties against copper diffusion. - Highlights: • SiC:H and SiCN:H films were prepared by plasma enhanced chemical vapor deposition. • Trimethylphenylsilane in a mixture with helium and ammonia was used as a precursor. • The deposited films have dielectric constant close to 3.5. • The films had a nanoporous structure; the total porosity did not exceed 1.5%.

  18. Studies of diamond-like carbon (DLC) films deposited on stainless steel substrate with Si/SiC intermediate layers

    Institute of Scientific and Technical Information of China (English)

    Wang Jing; Liu Gui-Chang; Wang Li-Da; Deng Xin-Lü; Xu Jun

    2008-01-01

    In this work, diamond-like carbon (DLC) films were deposited on stainless steel substrates with Si/SiC intermediate layers by combining plasma enhanced sputtering physical vapour deposition (PEUMS-PVD) and microwave electron cyclotron resonance plasma enhanced chemical vapour deposition (MW-ECRPECVD) techniques. The influence of substrate negative self-bias voltage and Si target power on the structure and nano-mechanical behaviour of the DLC films were investigated by Raman spectroscopy, nano-indentation, and the film structural morphology by atomic force microscopy (AFM). With the increase of deposition bias voltage, the G band shifted to higher wave-number and the integrated intensity ratio ID/IG increased. We considered these as evidences for the development of graphitization in the films. As the substrate negative self-bias voltage increased, particle bombardment function was enhanced and thesp3-bond carbon density reducing, resulted in the peak values of hardness (H) and elastic modulus (E). Silicon addition promoted the formation of sp3 bonding and reduced the hardness. The incorporated Si atoms substituted sp2- bond carbon atoms in ring structures, which promoted the formation of sp3-bond. The structural transition from C-C to C-Si bonds resulted in relaxation of the residual stress which led to the decrease of internal stress and hardness. The results of AFM indicated that the films was dense and homogeneous, the roughness of the films was decreased due to the increase of substrate negative self-bias voltage and the Si target power.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-11-30

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

  1. Deposition and field-emission characterization of electrically conductive nitrogen-doped diamond-like amorphous carbon films

    International Nuclear Information System (INIS)

    For the fabrication of high performance field emitters, diamond-like amorphous carbon films doped with nitrogen (DAC:N) were formed using an intermittent supermagnetron plasma chemical vapor deposition technique. DAC:N films were deposited using isobutane plasma to investigate the influence of discharge-off time and electrode spacing on the physical properties of the films at upper- and lower-electrode radio frequency (rf) powers (LORF) of 800 W/50-800 W. At LORF of 100 W, a discharge-on time of 1 min, and a discharge-off time (cooling time) of 30 s-10 min, resistivity was decreased with a decrease of the cooling time. By reducing the electrode spacing from 60 to 20 mm at a LORF of 50 and 800 W, the optical band gap of DAC:N film was decreased from 0.85 and 0.23 eV to 0.6 and 0 eV, respectively. A flat DAC:N film of 700 A thickness was deposited on a n-Si wafer at rf powers of 800 W/800 W. Using this flat DAC:N film, a threshold electric field of 18 V/μm was observed and maximum field-emission current density of 2.2 mA/cm2 was observed at the electric field of 32 V/μm

  2. Tritium retention properties of tungsten, graphite and co-deposited carbon film

    International Nuclear Information System (INIS)

    DT+ ion irradiation was performed on polycrystalline tungsten, graphite and carbon film and both the amount of retained tritium and the reduction of retained tritium after preservation in vacuum were investigated using an IP technique and BIXS. In addition, the relationship between the retention properties of tritium and the microstructure of graphite and carbon film were studied with Raman spectroscopy. The amount of retained tritium in tungsten was smaller than in both graphite and carbon film. After 1 keV of DT+ irradiation, graphite showed no reduction of the amount of retained tritium after six months preservation while that of carbon film decreased by approximately 20% after 40 days preservation. It was suggested that this difference might be associated with differences in the microstructure between graphite and carbon film. In tungsten, the amount of retained tritium decreased to approximately half after 18 days preservation. As the incident energy of implanted tritium to tungsten increased, the decrease in tritium retention during preservation became slower. Tungsten's properties of releasing tritium while preserved in vacuum would be a useful tool for the reduction/removal of retained tritium

  3. Structure evolution from nanocolumns to nanoporous of nitrogen doped amorphous carbon films deposited by magnetron sputtering

    International Nuclear Information System (INIS)

    Different nitrogen doped amorphous carbon (CNx) films were obtained by magnetron sputtering of carbon target in argon and nitrogen atmosphere at the increasing negative bias voltages from 0 to 150 V. The films structures have experienced great change, from the novel column to nanoporous structure at the bias voltage of 0 V to the porous structure at 150 V. The proposed growth process was that the CNx nuclei grew at 0 V acted as the 'seeds' for the growth of the nanocolumns, and ion etching effects at 150 V induced the formation of nanoporous structures. Furthermore, a comparison study showed that the field emission properties of the CNx films were related with the introduction of the nitrogen atoms, the size and concentration of sp2 C clusters and the surface roughness. The films with rougher surface have lower threshold field.

  4. 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)

  5. Deposition of hard and adherent diamond-like carbon films inside steel tubes using a pulsed-DC discharge.

    Science.gov (United States)

    Trava-Airoldi, Vladimir Jesus; Capote, Gil; Bonetti, Luís Francisco; Fernandes, Jesum; Blando, Eduardo; Hübler, Roberto; Radi, Polyana Alves; Santos, Lúcia Vieira; Corat, Evaldo José

    2009-06-01

    A new, low cost, pulsed-DC plasma-enhanced chemical vapor deposition system that uses a bipolar, pulsed power supply was designed and tested to evaluate its capacity to produce quality diamond-like carbon films on the inner surface of steel tubes. The main focus of the study was to attain films with low friction coefficients, low total stress, a high degree of hardness, and very good adherence to the inner surface of long metallic tubes at a reasonable growth rate. In order to enhance the diamond-like carbon coating adhesion to metallic surfaces, four steps were used: (1) argon ion sputtering; (2) plasma nitriding; (3) a thin amorphous silicon interlayer deposition, using silane as the precursor gas; and (4) diamond-like carbon film deposition using methane atmosphere. This paper presents various test results as functions of the methane gas pressure and of the coaxial metal anode diameter, where the pulsed-DC voltage constant is kept constant. The influence of the coaxial metal anode diameter and of the methane gas pressure is also demonstrated. The results obtained showed the possibilities of using these DLC coatings for reduced friction and to harden inner surface of the steel tubes. PMID:19504937

  6. Comparative Study on Hydrogenated and Deuterated Amorphous Carbon Films Deposited by RF PECVD

    Czech Academy of Sciences Publication Activity Database

    Buršíková, V.; Stoica, A.; Peřina, Vratislav; Mikšová, Romana; Slavíček, P.; Mocanu, V.

    Innsbruck: Innsbruck univesity press, 2012, s. 242-246. ISBN 978-3-902719-52-2. [XVIIIth Symposium on Atomic, cluster and Surface Physics 2012 (SAPS 2012). Alpe d´Huez (FR), 22.01.2012-27.01.2012] R&D Projects: GA ČR GA202/07/1669 Institutional support: RVO:61389005 Keywords : hydrogenated carbon thin films * deuterated carbon thin films * PECVD * RBS * ERDA * OES * coating properties Subject RIV: BL - Plasma and Gas Discharge Physics http://www.uibk.ac.at/iup/buch_pdfs/it_sasp_2012sw_131211.pdf

  7. Immobilization of carbon nanotubes on functionalized graphene film grown by chemical vapor deposition and characterization of the hybrid material

    Directory of Open Access Journals (Sweden)

    Prashanta Dhoj Adhikari

    2014-01-01

    Full Text Available We report the surface functionalization of graphene films grown by chemical vapor deposition and fabrication of a hybrid material combining multi-walled carbon nanotubes and graphene (CNT–G. Amine-terminated self-assembled monolayers were prepared on graphene by the UV-modification of oxidized groups introduced onto the film surface. Amine-termination led to effective interaction with functionalized CNTs to assemble a CNT–G hybrid through covalent bonding. Characterization clearly showed no defects of the graphene film after the immobilization reaction with CNT. In addition, the hybrid graphene material revealed a distinctive CNT–G structure and p–n type electrical properties. The introduction of functional groups on the graphene film surface and fabrication of CNT–G hybrids with the present technique could provide an efficient, novel route to device fabrication.

  8. Immobilization of carbon nanotubes on functionalized graphene film grown by chemical vapor deposition and characterization of the hybrid material

    International Nuclear Information System (INIS)

    We report the surface functionalization of graphene films grown by chemical vapor deposition and fabrication of a hybrid material combining multi-walled carbon nanotubes and graphene (CNT–G). Amine-terminated self-assembled monolayers were prepared on graphene by the UV-modification of oxidized groups introduced onto the film surface. Amine-termination led to effective interaction with functionalized CNTs to assemble a CNT–G hybrid through covalent bonding. Characterization clearly showed no defects of the graphene film after the immobilization reaction with CNT. In addition, the hybrid graphene material revealed a distinctive CNT–G structure and p–n type electrical properties. The introduction of functional groups on the graphene film surface and fabrication of CNT–G hybrids with the present technique could provide an efficient, novel route to device fabrication. (paper)

  9. Gas barrier properties of hydrogenated amorphous carbon films coated on polymers by surface-wave plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Gas barrier characteristics of hydrogenated amorphous carbon (a-C:H) thin films coated on polymer sheets using the large-area surface-wave plasma (SWP) were studied. With SWP in He and CH4 gas mixture, a-C:H films were deposited over about 100 mm in diameter on high density polyethylene or polyethylene terephthalate (PET) sheets at temperature less than 70 deg. C. Experimental results show that gas permeation in the case of a-C:H film coating on PET sheet was reduced by a factor of more than 150 (0.27 cm3/m2 day atm), compared with that before coating. Plasma characteristics of SWP, such as electron density and electron energy distribution functions, and other film characteristics measured with Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy and atomic force microscope are presented and discussed

  10. Enhanced field emission characteristics of nitrogen-doped carbon nanotube films grown by microwave plasma enhanced chemical vapor deposition process

    International Nuclear Information System (INIS)

    Nitrogen-doped carbon nanotube (CNT) films have been synthesized by simple microwave plasma enhanced chemical vapor deposition technique. The morphology and structures were investigated by scanning electron microscopy and high resolution transmission electron microscopy. Morphology of the films was found to be greatly affected by the nature of the substrates. Vertically aligned CNTs were observed on mirror polished Si substrates. On the other hand, randomly oriented flower like morphology of CNTs was found on mechanically polished ones. All the CNTs were found to have bamboo structure with very sharp tips. These films showed very good field emission characteristics with threshold field in the range of 2.65-3.55 V/μm. CNT film with flower like morphology showed lower threshold field as compared to vertically aligned structures. Open graphite edges on the side surface of the bamboo-shaped CNT are suggested to enhance the field emission characteristics which may act as additional emission sites

  11. Fluorine and boron co-doped diamond-like carbon films deposited by pulsed glow discharge plasma immersion ion processing

    CERN Document Server

    He, X M; Peters, A M; Taylor, B; Nastasi, M

    2002-01-01

    Fluorine (F) and boron (B) co-doped diamond-like carbon (FB-DLC) films were prepared on different substrates by the plasma immersion ion processing (PIIP) technique. A pulse glow discharge plasma was used for the PIIP deposition and was produced at a pressure of 1.33 Pa from acetylene (C sub 2 H sub 2), diborane (B sub 2 H sub 6), and hexafluoroethane (C sub 2 F sub 6) gas. Films of FB-DLC were deposited with different chemical compositions by varying the flow ratios of the C sub 2 H sub 2 , B sub 2 H sub 6 , and C sub 2 F sub 6 source gases. The incorporation of B sub 2 H sub 6 and C sub 2 F sub 6 into PIIP deposited DLC resulted in the formation of F-C and B-C hybridized bonding structures. The levels of the F and B concentrations effected the chemical bonding and the physical properties as was evident from the changes observed in density, hardness, stress, friction coefficient, and contact angle of water on films. Compared to B-doped or F-doped DLC films, the F and B co-doping of DLC during PIIP deposition...

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

    International Nuclear Information System (INIS)

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

  13. CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES: Field Emission Properties of Ball-Like Nano-Carbon Thin Films Deposited on Mo Films with Accidented Topography

    Science.gov (United States)

    Wang, Long-Yang; Wang, Xiao-Ping; Wang, Li-Jun; Zhang, Lei

    2008-11-01

    Ball-like nano-carhon thin films (BNCTs) are grown on Mo layers by microwave plasma chemical vapour deposition (MPCVD) system. The Mo layers are deposited on ceramic substrates by electron beam deposition method and are pretreated by ultrasonically scratching. The optimization effects of ultrasonically scratching pretreat-ment on the surface micro-structures of carbon films are studied. It is found from field-emission scanning electron microscope (FE-SEM) images and Raman spectra that the surface structures of the carbon films deposited on Mo pretreated are improved, which are composed of highly uniform nano-structured carbon balls with considerable disorder structures. Field emission (FE) measurements are carried out using a diode structure. The experimental results indicate that the BNCTs exhibit good FE properties, which have the turn on field of 1.56 V/μm, and the current density of 1.0mA/cm2 at electric field of 4.0 V/μm, the uniformly distributed emission site density from a broad well-proportioned emission area of 4 cm2 are also obtained. Linearity is observed in Fowler-Nordheim (F-N) plots in higher Geld region, and the possible emission mechanism of BNCTs is discussed.

  14. Effect of acetic acid on electrochemical deposition of carbon-nitride thin film

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Electrochemical deposition method was employed to prepare CNx thin film from methanol-urea solution,and it was shown that adding a little acetic acid in the solution significantly affected the deposition process.After optimizing the experiment conditions,we obtained polycrystalline grains with sizes of about 3―7μm on the faces of single crystal silicon.X-ray diffraction spectrua indicate that the grains are mainly composed of cubic phase mixed with a small amount of β and α phases.

  15. Study on pulsed excimer laser deposited films

    CERN Document Server

    Liu Jing Ru; Li Tie Jun; Yao Dong Sheng; Wang Li Ge; Yuan Xiao; Wang Sheng; Ye Xi Sheng

    2002-01-01

    Pulsed lasers of two different durations (30 ns, 500 fs) are used to deposit Hydrogen-free Diamond Like Carbon (DLC) films over large areas. Analysis of DLC films shows remarkable mechanical, optical, electrical, and chemical properties that are close to those of diamond. By optical emission spectroscopy and ion probe, the effects of plasma characteristic on DLC film are on experimentally studied. Amorphous silicon films deposited by PLD are also experimentally studied

  16. Stress relief patterns of hydrogenated amorphous carbon films grown by dc-pulse plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Hydrogenated amorphous carbon films were prepared on Si (1 0 0) substrates by dc-pulse plasma chemical vapor deposition. The nature of the deposited films was characterized by Raman spectra and the stress relief patterns were observed by scanning electron microscope. Besides the well-known sinusoidal type and flower type patterns, etc., two different stress relief patterns, ring type and peg-top shape with exiguous tine on the top, were observed. The ring type in this paper was a clear ridge-cracked buckle and unusual. Two competing buckle delamination morphologies ring and sinusoidal buckling coexist. The ridge-cracked buckle in ring type was narrower than the sinusoidal buckling. Meanwhile peg-top shape with exiguous tine on the top in this paper was unusual. These different patterns supported the approach in which the stress relief forms have been analyzed using the theory of plate buckling.

  17. 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.

  18. Structural properties and surface wettability of Cu-containing diamond-like carbon films prepared by a hybrid linear ion beam deposition technique

    International Nuclear Information System (INIS)

    Cu-containing diamond-like carbon (Cu-DLC) films were deposited on Si/glass substrate by a hybrid ion beam deposition system. The Cu concentration (0.1–39.7 at.%) in the film was controlled by varying the sputtering current. The microstructure and composition of Cu-DLC films were investigated systematically. The surface topography, roughness and surface wettability of the films were also studied. Results indicated that with increasing the Cu concentration, the water contact angle of the films changed from 66.8° for pure carbon film to more than 104.4° for Cu-DLC films with Cu concentration larger than 24.4 at.%. In the hydrophilic region, the polar surface energy decreased from 30.54 mJ/m2 for pure carbon film to 2.48 mJ/m2 for the film with Cu 7.0 at.%. - Highlights: • Cu-containing diamond-like carbon (DLC) films were deposited by a hybrid ion beam system. • Cu-containing DLC films exhibited a wide range of water contact angle. • The water contact angles vary with the surface energies and surface roughness

  19. Suppression of hydrogenated carbon film deposition and hydrogen isotope retention by nitrogen addition into cold remote H/D and CH4 mixture plasmas

    International Nuclear Information System (INIS)

    Control of tritium retention and its removal from the first wall of future fusion devices are one of the most crucial issues for safety and effective use for fuel. Nitrogen addition into remote edge plasmas has been considered and tested as an effective method for suppression of carbon film deposition and reduction of hydrogen isotope absorption in the deposited films. In this paper we have investigated the scavenger effects of nitrogen injected into low temperature D2/CH4 plasmas on hydrogenated carbon film growth using a small helical device. The result of the deposition shows that the key reactive particles with CN and ND(H) bonds to suppression of hydrogenated carbon film growth and hydrogen isotope absorption are much slowly generated compared with hydrocarbon particles such as CD(H)x and C2D(H)x. This may be due to the slow atomic nitrogen diffusion into hydrogenated carbon layer and the chemical equilibrium between nitrogen absorption

  20. Suppression of hydrogenated carbon film deposition and hydrogen isotope retention by nitrogen addition into cold remote H/D and CH4 mixture plasmas

    Science.gov (United States)

    Iida, K.; Notani, M.; Uesugi, Y.; Tanaka, Y.; Ishijima, T.

    2015-08-01

    Control of tritium retention and its removal from the first wall of future fusion devices are one of the most crucial issues for safety and effective use for fuel. Nitrogen addition into remote edge plasmas has been considered and tested as an effective method for suppression of carbon film deposition and reduction of hydrogen isotope absorption in the deposited films. In this paper we have investigated the scavenger effects of nitrogen injected into low temperature D2/CH4 plasmas on hydrogenated carbon film growth using a small helical device. The result of the deposition shows that the key reactive particles with CN and ND(H) bonds to suppression of hydrogenated carbon film growth and hydrogen isotope absorption are much slowly generated compared with hydrocarbon particles such as CD(H)x and C2D(H)x. This may be due to the slow atomic nitrogen diffusion into hydrogenated carbon layer and the chemical equilibrium between nitrogen absorption.

  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. Time-Resolved Observation of Deposition Process of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films in Pulsed Laser Deposition

    OpenAIRE

    Kunihito Nagayama; Tsuyoshi Yoshitake; Takashi Nishiyama; Kenji Hanada

    2009-01-01

    Optical emission spectroscopy was used to study pulsed laser ablation of graphite in a hydrogen atmosphere wherein ultrananocrystalline diamond (UNCD)/hydrogenated amorphous carbon (a-C:H) composite films were grown on heated substrates. Time-resolved photographs of a plume that expanded from a laser-irradiation spot toward a substrate were taken using a high-speed ICCD camera equipped with narrow-bandpass filters. While the emissions from C atoms and C2 dimers lasted above the laser-irradi...

  3. 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.

  4. 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.

  5. Debris reduction for copper and diamond-like carbon thin films produced by magnetically guided pulsed laser deposition

    CERN Document Server

    Tsui, Y Y; Vick, D; Fedosejevs, R

    2002-01-01

    The effectiveness of debris reduction using magnetically guided pulsed laser deposition (MGPLD) is reported here. KrF laser pulses (248 nm) of 100 mJ energy were focused to intensities of 6x10 sup 9 W/cm sup 2 onto the surface of a copper or a carbon source target and a magnetic field of 0.3 T as used to steer the plasma around a curved arc of 0.5 m length to the deposition substrate. Debris counts were compared for films produced by the MGPLD and conventional PLD (nonguided) techniques. A significant reduction in particulates of size greater than 0.1 mu m was achieved using MGPLD. For the copper films, particulate count was reduced from 150 000 particles/cm sup 2 /nm to 50 particulates/cm sup 2 /nm and for diamond-like carbon thin films particulate count was reduced from 25 000 particles/cm sup 2 /nm to 1200 particles/cm sup 2 /nm.

  6. Electrochemical Behaviour of Sputtering Deposited DLC Films

    Institute of Scientific and Technical Information of China (English)

    LIU Erjia; ZENG A,LIU L X

    2003-01-01

    Diamondlike carbon (DLC) films were deposited via magnetron sputtering process. The energetic ion bombardment on the surface of growing film is one of the major parameters that control the atom mobility on the film surface and further the physical and chemical characteristics of the films. In this study, the energy of carbon ions was monitored by changing sputtering power density, and its effect on the electrochemical performance of the films was investigated. For the deposition at a higher sputtering power density, a higher sp3 content in the DLC films was achieved with denser structure and increased film-substrate adhesion. The impedance at the interface of Si substrate/sulfuric acid solution was significantly enhanced, and at the same time higher film resistance, lower capacitance, higher breakdown potential and longer breakdown time were observed, which were related to the significant sp3 content of the DLC films.

  7. Ion-implanted Mechanism of the Deposition Process for Diamond-Like Carbon Films

    Institute of Scientific and Technical Information of China (English)

    WANG Xue-Min; WU Wei-Dong; WANG Yu-Ying; WANG Hai-Ping; GE Fang-Fang; TANG Yong-Jian; JU Xin

    2011-01-01

    Due to the local densification, high-energy C and doped ions can greatly affect the bonding configurations of diamond-like carbon films. We investigate the corresponding affection of different incident ions with energy from WeV to 600eV by Monte Carlo methods. The ion-implanted mechanism called the subplantation (for C, N, O, W, Y, etc.) is confirmed. Obvious thermal effect could be induced by the subplantation of the incident ions. Further, the subplantation of C ions is proved by in situ reflection high energy electron diffraction (RHEED). The observation from an atomic force microscope (AFM) indicates that the initial implantation of C ions might result in the final primitive-cell-like morphology of the smooth film (in an area of 1.2 mm × 0.9 mm, rms roughness smaller than 20 nm by Wyko).

  8. Synthesis and characterization of thin films of nitrided amorphous carbon deposited by laser ablation; Sintesis y caracterizacion de peliculas delgadas de carbono amorfo nitrurado, depositadas por ablacion laser

    Energy Technology Data Exchange (ETDEWEB)

    Rebollo P, B

    2001-07-01

    The objective of this work is the synthesis and characterization of thin films of amorphous carbon (a-C) and thin films of nitrided amorphous carbon (a-C-N) using the laser ablation technique for their deposit. For this purpose, the physical properties of the obtained films were studied as function of diverse parameters of deposit such as: nitrogen pressure, power density, substrate temperature and substrate-target distance. For the characterization of the properties of the deposited thin films the following techniques were used: a) Raman spectroscopy which has demonstrated being a sensitive technique to the sp{sup 2} and sp{sup 3} bonds content, b) Energy Dispersive Spectroscopy which allows to know semi-quantitatively way the presence of the elements which make up the deposited films, c) Spectrophotometry, for obtaining the absorption spectra and subsequently the optical energy gap of the deposited material, d) Ellipsometry for determining the refraction index, e) Scanning Electron Microscopy for studying the surface morphology of thin films and, f) Profilemetry, which allows the determination the thickness of the deposited thin films. (Author)

  9. The fabrication of a carbon nanotube transparent conductive film by electrophoretic deposition and hot-pressing transfer

    International Nuclear Information System (INIS)

    A super-flexible single-walled carbon nanotube (SWCNT) transparent conductive film (TCF) was produced based on a combination of electrophoretic deposition (EPD) and hot-pressing transfer. EPD was performed in a diluted SWCNT suspension with high zeta potential prepared by a pre-dispersion-then-dilution procedure using sodium dodecyl sulfate as the surfactant and negative charge supplier. A SWCNT film was deposited on a stainless steel anode surface by direct current electrophoresis and then transferred to a poly(ethylene terephthalate) substrate by hot-pressing to achieve a flexible SWCNT TCF. The SWCNT TCF obtained by this technique can achieve a sheet resistance of 220 Ω/sq with 81% transparency at 550 nm wavelength and a strong adhesion to the substrate. More importantly, no decrease in the conductivity of the SWCNT TCF was detected after 10 000 cycles of repeated bending. The result indicates that the EPD and hot-pressing transfer technique is an effective approach for fabricating a carbon nanotube TCF with excellent flexibility.

  10. Electrochemical Behaviour of Sputtering Deposited DLC Films

    Institute of Scientific and Technical Information of China (English)

    LIUErjia; ZENGA; LIULX

    2003-01-01

    Diamondlike carbon (DLC) films were deposited via magnetron sputtering process. The energetic ion hombardment on the surface of growing film is one of the major parameters that control the atom mobility on the flirt1 surface and further the physical and chemical characteristics of the films. In this study, the energy of carbon ions was monitored by changing sputtering powerdensity, and its effect on the electrochemical performance of the films was investigated. For the deposition at a higher sputtering power density, a higher sp3 content in the DLC films was achieved with denser structure and increased film-substrate adhesion. The impedance at the interface of Si substrate/sulfufic acid solution was significantly enhanced, and at the same time higher film resistance, lower capacitance, higher breakdown potential and longer breakdown time were observed, which were related to the significant sp3 content of the DLC films.

  11. Optimized pulsed laser deposition by wavelength and static electric field control: The case of tetrahedral amorphous carbon films

    Science.gov (United States)

    Patsalas, P.; Kaziannis, S.; Kosmidis, C.; Papadimitriou, D.; Abadias, G.; Evangelakis, G. A.

    2007-06-01

    We report on the application of a static (dc) electric field in the plume region during the pulsed Nd doped yttrium aluminum garnet laser deposition (PLD) of tetrahedral amorphous carbon (ta-C) films in vacuum ambient (pressure=10-4-10-3Pa), where the working pressure is exclusively due to ablation vapor. This approach is strikingly different from the plasma- or ion-beam-assisted PLD because the mean free path at this pressure is by far longer than the target to substrate distance. Thus, the electric field interacts with individual ionized species invoking ion acceleration and gas-phase reactions among different ionized species. These phenomena are clearly dependent on the laser wavelength (first, second, or third harmonic, λ =1064, 532, and 355nm, respectively) used for the ablation. We found that the application of the electric field causes surface smoothing (the roughness decreases from about 1to0.4nm) and faster deposition rate (from about 2to7nm/min) for the second and third harmonics. In addition, the phenomena are less intense in the case of the first harmonic due to the low concentration of ionized species in the plume. In addition, in the case of PLD using λ =532nm, the electric field improves the film's density (from 2.60to2.95g/cm3). The correlations found are discussed in terms of the ablated species and the deposition mechanisms of the ta-C.

  12. Thin Film Deposition of Conducting Polymers and Carbon Allotropes via Interfacial Solution Processing and Evaporative Vapor Phase Polymerization

    OpenAIRE

    D'Arcy, Julio Marcelo

    2012-01-01

    A new solution processing technique is developed for depositing continuously conductive transparent thin films comprised of conducting polymer nanostructures. The deposition mechanism is driven by interfacial surface tension gradients leading to rapid directional fluid flow known as the Marangoni effect. This technique is a universal solution to thin film deposition for coating any type of substrate at ambient conditions within seconds. The versatility of this method of deposition is further ...

  13. Structure and gas-barrier properties of amorphous hydrogenated carbon films deposited on inner walls of cylindrical polyethylene terephthalate by plasma-enhanced chemical vapor deposition

    Science.gov (United States)

    Li, Jing; Gong, Chunzhi; Tian, Xiubo; Yang, Shiqin; Fu, Ricky K. Y.; Chu, Paul K.

    2009-01-01

    The influence of radio-frequency (RF) power on the structure and gas permeation through amorphous hydrogenated carbon films deposited on cylindrical polyethylene terephthalate (PET) samples is investigated. The results show that a higher radio-frequency power leads to a smaller sp 3/sp 2 value but produces fewer defects with smaller size. The permeability of PET samples decreases significantly after a-C:H deposition and the RF only exerts a small influence. However, the coating uniformity, color, and wettability of the surface are affected by the RF power. A higher RF power results in to better uniformity and it may be attributed to the combination of the high-density plasma and sample heating.

  14. Structure and gas-barrier properties of amorphous hydrogenated carbon films deposited on inner walls of cylindrical polyethylene terephthalate by plasma-enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    The influence of radio-frequency (RF) power on the structure and gas permeation through amorphous hydrogenated carbon films deposited on cylindrical polyethylene terephthalate (PET) samples is investigated. The results show that a higher radio-frequency power leads to a smaller sp3/sp2 value but produces fewer defects with smaller size. The permeability of PET samples decreases significantly after a-C:H deposition and the RF only exerts a small influence. However, the coating uniformity, color, and wettability of the surface are affected by the RF power. A higher RF power results in to better uniformity and it may be attributed to the combination of the high-density plasma and sample heating.

  15. Carbon film and its applications

    International Nuclear Information System (INIS)

    Diamond like carbon was prepared by the decomposition of methane in a microwave discharge. The effect of dilution gases, such as hydrogen, argon and helium, on the deposition was examined in the light of the identification of the deposits and the results of plasma diagnostics. When hydrogen was added, diamond like particles including large amounts of hydrogen were obtained. Diamond like films including graphitic carbon and a smaller amount of hydrogen were deposited from the methane-argon plasma. The correlation between the deposit and species present in the plasma is discussed. The deposition of diamond like carbon not including graphitic carbon from the methane-hydrogen plasma was succeeded because of the formation of CH3 radicals having sp3 hybrid orbital of carbon for diamond formation from the plasma and a removal of graphitic carbon from the deposit by sputtering. (author)

  16. A low-temperature synthesis of electrochemical active Pt nanoparticles and thin films by atomic layer deposition on Si(111) and glassy carbon surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Rui [Joint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, CA 91125 (United States); Han, Lihao [Joint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, CA 91125 (United States); Photovoltaic Materials and Devices (PVMD) Laboratory, Delft University of Technology, P.O. Box 5031, GA Delft 2600 (Netherlands); Huang, Zhuangqun; Ferrer, Ivonne M. [Joint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, CA 91125 (United States); Division of Chemistry and Chemical Engineering, California Institute of Technology, 210 Noyes Laboratory 127-72, Pasadena, CA 91125 (United States); Smets, Arno H.M.; Zeman, Miro [Photovoltaic Materials and Devices (PVMD) Laboratory, Delft University of Technology, P.O. Box 5031, GA Delft 2600 (Netherlands); Brunschwig, Bruce S., E-mail: bsb@caltech.edu [Beckman Institute, California Institute of Technology, Pasadena, CA 91125 (United States); Lewis, Nathan S., E-mail: nslewis@caltech.edu [Joint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, CA 91125 (United States); Beckman Institute, California Institute of Technology, Pasadena, CA 91125 (United States); Division of Chemistry and Chemical Engineering, California Institute of Technology, 210 Noyes Laboratory 127-72, Pasadena, CA 91125 (United States); Kavli Nanoscience Institute, California Institute of Technology, Pasadena, CA 91125 (United States)

    2015-07-01

    Atomic layer deposition (ALD) was used to deposit nanoparticles and thin films of Pt onto etched p-type Si(111) wafers and glassy carbon discs. Using precursors of MeCpPtMe{sub 3} and ozone and a temperature window of 200–300 °C, the growth rate was 80–110 pm/cycle. X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscopy (SEM) were used to analyze the composition, structure, morphology, and thickness of the ALD-grown Pt nanoparticle films. The catalytic activity of the ALD-grown Pt for the hydrogen evolution reaction was shown to be equivalent to that of e-beam evaporated Pt on glassy carbon electrode. - Highlights: • Pure Pt films were grown by atomic layer deposition (ALD) using MeCpPtMe3 and ozone. • ALD-grown Pt thin films had high growth rates of 110 pm/cycle. • ALD-grown Pt films were electrocatalytic for hydrogen evolution from water. • Electrocatalytic activity of the ALD Pt films was equivalent to e-beam deposited Pt. • No carbon species were detected in the ALD-grown Pt films.

  17. A low-temperature synthesis of electrochemical active Pt nanoparticles and thin films by atomic layer deposition on Si(111) and glassy carbon surfaces

    International Nuclear Information System (INIS)

    Atomic layer deposition (ALD) was used to deposit nanoparticles and thin films of Pt onto etched p-type Si(111) wafers and glassy carbon discs. Using precursors of MeCpPtMe3 and ozone and a temperature window of 200–300 °C, the growth rate was 80–110 pm/cycle. X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscopy (SEM) were used to analyze the composition, structure, morphology, and thickness of the ALD-grown Pt nanoparticle films. The catalytic activity of the ALD-grown Pt for the hydrogen evolution reaction was shown to be equivalent to that of e-beam evaporated Pt on glassy carbon electrode. - Highlights: • Pure Pt films were grown by atomic layer deposition (ALD) using MeCpPtMe3 and ozone. • ALD-grown Pt thin films had high growth rates of 110 pm/cycle. • ALD-grown Pt films were electrocatalytic for hydrogen evolution from water. • Electrocatalytic activity of the ALD Pt films was equivalent to e-beam deposited Pt. • No carbon species were detected in the ALD-grown Pt films

  18. Effects of frequency of pulsed substrate bias on structure and properties of silicon-doped diamond-like carbon films by plasma deposition

    International Nuclear Information System (INIS)

    We have investigated the effects of the frequency of pulsed substrate bias on the structure and properties of Si-doped diamond-like carbon (Si-DLC) films deposited by radio-frequency plasma-enhanced chemical vapor deposition using CH4, Ar, and monomethylsilane (CH3SiH3) as the Si source. The Si/(Si + C) ratios in the Si-DLC films deposited using pulsed bias were higher than that of the dc-biased Si-DLC film, and the Si fraction increased with decreasing frequency. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses revealed that Si–C, Si–Hn, and C–Hn bonds in the Si-DLC films increased with decreasing frequency. The internal stress decreased as the frequency decreased, which is probably due to the increase in Si–C, Si–Hn, and C–Hn bonds in the films. It was found that the wear rate of the pulse-biased Si-DLC film deposited at the highest frequency in this study is comparable to that of the dc-biased, undoped DLC film. Furthermore, the friction coefficient of the former is about one third of that of the latter. - Highlights: • The tribological properties of Si-doped films were improved at higher frequencies. • The internal stress of Si-doped films was lowered at lower frequencies. • The adhesion of pulse-biased films was improved at lower frequencies

  19. Fretting wear and fretting fatigue behaviors of diamond-like carbon and graphite-like carbon films deposited on Ti-6Al-4V alloy

    International Nuclear Information System (INIS)

    Highlights: • The effect of DLC and GLC films on the FW and FF resistance was investigated. • The bonding strength and toughness were investigated by home-made device. • The FW and FF resistance was improved significantly by DLC and GLC films. • The effect of bonding strength and toughness is more important than that of friction factor in improving the FW and FF resistance. - Abstract: To investigate their effect on the fretting wear (FW) and fretting fatigue (FF) resistance of a Ti6Al4V alloy, the diamond-like carbon (DLC) and graphite-like carbon (GLC) films were deposited on a Ti6Al4V alloy substrate using closed field unbalanced magnetron sputtering. The basic film properties, such as surface morphology, micro-structure, micro-hardness, bonding strength, and toughness were investigated by atomic force microscopy, X-ray photoelecton spectroscopy, nano-hardness testing, scratch testing and by a home-made repeated press-press test system, respectively. The FW and FF resistance was studied using home-made devices. The results show that DLC and GLC films can reduce the friction factor while the FW and FF resistance of the titanium alloy were improved significantly. However, the FW and FF resistance of the DLC film on the titanium alloy was better than that of the GLC film. This was attributed to the excellent properties of bonding strength and toughness of the DLC film. Moreover, the effect of bonding strength and toughness is more important than that of friction factor in improving the FW and FF resistance

  20. A Novel Reactive Gas Source and Its Application to Carbon Nanotube Film Deposition

    Institute of Scientific and Technical Information of China (English)

    JIANG Nan; CHEN Han-Yuan; QIAN Sheng-Fa

    2005-01-01

    @@ Generally, gaseous discharge at pressure higher than 10 kPa will collapse to filamentary form or streamer, which will produce a non-uniform treatment on the sample surface. Thus, atmospheric pressure glow discharge (APGD) is developed. However the realization of the APGD is not obvious, it needs special conditions. We propose a new concept to solve the non-uniformity problem. By using a grid electrode and putting the sample downstream of the discharge plasma, the streamers, instead of striking on sample surface, will strike on the grid, and the neutral active species produced in the discharge diffuse out to reach the sample surface uniformly. Finally, a carbon nanotube (CNT) film was produced to test this new concept.

  1. Intermittent chemical vapor deposition of thick electrically conductive diamond-like amorphous carbon films using i-C4H10/N2 supermagnetron plasma

    International Nuclear Information System (INIS)

    Electrically conductive diamond-like amorphous carbon (DAC) films with nitrogen (DAC:N) were deposited on Si and SiO2 wafers using the i-C4H10/N2 supermagnetron plasma chemical vapor deposition (CVD) method. Resistivity and hardness decreased with increase of upper electrode rf power (UPRF) under constant lower electrode rf power (LORF). Film thickness increased linearly to over 0.3 μm with deposition time via intermittent deposition. The film exhibited good adhesion to the substrate. Low-resistance thick films were deposited using alternating multilayer CVD at UPRF/LORFs of 1 kW/1 kW and 300 W/300 W. In the deposited alternating multiple layers, resistivity significantly decreased with the increase of H layer (1 kW/1 kW) thickness, and film thickness significantly increased with the increase of L layer (300 W/300 W) thickness. By the deposition of H/L multiple layers, a film of 2.1 μm thickness and 0.14 Ω cm resistivity was obtained

  2. Deposit of thin films of nitrided amorphous carbon using the laser ablation technique; Deposito de peliculas delgadas de carbono amorfo nitrurado utilizando la tecnica de ablacion laser

    Energy Technology Data Exchange (ETDEWEB)

    Rebollo, P.B.; Escobar A, L.; Camps C, E. [Departamento de Fisica, Instituto Nacional de Investigaciones Nucleares, C.P. 52045 Salazar, Estado de Mexico (Mexico); Haro P, E.; Camacho L, M.A. [Departamento de Fisica, Universidad Autonoma Metropolitana Iztapalapa (Mexico); Muhl S, S. [Instituto de Investigacion en Materiales, UNAM (Mexico)

    2000-07-01

    It is reported the synthesis and characterization of thin films of amorphous carbon (a-C) nitrided, deposited by laser ablation in a nitrogen atmosphere at pressures which are from 4.5 x 10 {sup -4} Torr until 7.5 x 10 {sup -2} Torr. The structural properties of the films are studied by Raman spectroscopy obtaining similar spectra at the reported for carbon films type diamond. The study of behavior of the energy gap and the ratio nitrogen/carbon (N/C) in the films, shows that the energy gap is reduced when the nitrogen incorporation is increased. It is showed that the refraction index of the thin films diminish as nitrogen pressure is increased, indicating the formation of graphitic material. (Author)

  3. 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

  4. The effect of deposition energy of energetic atoms on the growth and structure of ultrathin amorphous carbon films studied by molecular dynamics simulations

    KAUST Repository

    Wang, N

    2014-05-16

    The growth and structure of ultrathin amorphous carbon films was investigated by molecular dynamics simulations. The second-generation reactive-empirical-bond-order potential was used to model atomic interactions. Films with different structures were simulated by varying the deposition energy of carbon atoms in the range of 1-120 eV. Intrinsic film characteristics (e.g. density and internal stress) were determined after the system reached equilibrium. Short- and intermediate-range carbon atom ordering is examined in the context of atomic hybridization and ring connectivity simulation results. It is shown that relatively high deposition energy (i.e., 80 eV) yields a multilayer film structure consisting of an intermixing layer, bulk film and surface layer, consistent with the classical subplantation model. The highest film density (3.3 g cm-3), sp3 fraction (∼43%), and intermediate-range carbon atom ordering correspond to a deposition energy of ∼80 eV, which is in good agreement with experimental findings. © 2014 IOP Publishing Ltd.

  5. Influence of duty ratio of pulsed bias on structure and properties of silicon-doped diamond-like carbon films by plasma deposition

    International Nuclear Information System (INIS)

    We have investigated the influence of the duty ratio of pulsed substrate bias on the structure and properties of Si-doped diamond-like carbon (Si-DLC) films deposited by radio frequency plasma-enhanced chemical vapor deposition using CH4, Ar, and monomethylsilane (CH3SiH3) as the Si source. The Si/(Si + C) ratios in the Si-DLC films deposited using pulsed bias were higher than that of the dc-biased Si-DLC film, and the Si fraction increased with decreasing pulse duty ratio. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses revealed that Si-C, Si-Hn, and C-Hn bonds in the Si-DLC films increased with decreasing duty ratio. The internal stress decreased as the duty ratio decreased, which is probably due to the increase in Si-C, Si-Hn, and C-Hn bonds in the films. The Si-DLC films deposited using pulsed bias had higher adhesion strength than the dc-biased Si-DLC film because of the further reduction of internal stress. At higher duty ratios, although the Si fractions of the pulse-biased Si-DLC films were higher than that of the dc-biased Si-DLC film, the wear rates of the former were less than that of the latter. - Highlights: • The internal stress of Si-doped films was lowered at lower duty ratios. • The adhesion of pulse-biased films was improved compared with that of dc films. • The tribological properties of Si-doped films were improved by the use of pulse bias

  6. Influence of Fe-doped on structural, electronic structural and optical properties of hydrogenated amorphous carbon films prepared by plasma enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    Fe-doped hydrogenated amorphous carbon (a-C:H:Fe) films were deposited from an isobutene/ferrocene/H2 gas mixture by plasma enhanced chemical metal organic vapor deposition. Raman spectra were used to characterize the bonding structure of the a-C:H:Fe films and hydrogenated amorphous carbon (a-C:H) films. Optical properties were investigated by the UV-vis spectroscopy and the photoluminescence spectra. The number of six-numbered rings of the a-C:H films increases and sp2 clustering of the films decreases after Fe-doping. The Tauc optical gap of the a-C:H:Fe films becomes narrower by 0.15-0.23 eV relative to the value of the a-C:H films. The narrowing of the optical gap after doping is attributed primarily to the extended state around the Fe deep level in the band gap and the narrowing of the π and π* band edge states because of the increase of the number of six-numbered rings in the a-C:H films. Fe deep level defects of the a-C:H:Fe films contribute chiefly to non-radiative recombination.

  7. Morphological and Chemical Evolution of Gradually Deposited Diamond-Like Carbon Films on Polyethylene Terephthalate: From Subplantation Processes to Structural Reorganization by Intrinsic Stress Release Phenomena.

    Science.gov (United States)

    Catena, Alberto; Guo, Qiaochu; Kunze, Michael R; Agnello, Simonpietro; Gelardi, Franco M; Wehner, Stefan; Fischer, Christian B

    2016-04-27

    Diamond-like carbon (DLC) films on polyethylene terephthalate (PET) are nowadays intensively studied composites due to their excellent gas barrier properties and biocompatibility. Despite their applicative features being highly explored, the interface properties and structural film evolution of DLC coatings on PET during deposition processes are still sparsely investigated. In this study two different types of DLC films were gradually deposited on PET by radio frequency plasma-enhanced chemical vapor deposition (RF-PECVD) using acetylene plasma. The surface morphology of the deposited samples has been analyzed by atomic force microscopy (AFM). Their chemical composition was investigated by diffusive reflectance infrared Fourier transform (DRIFT) and Raman spectroscopy analysis and the surface wettability by contact angle measurements. Subplantation processes and interface effects are revealed through the morphological and chemical analysis of both types. During plasma deposition processes the increasing carbon load causes the rise of intrinsic film stress. It is proven that stress release phenomena cause the transition between polymer-like to a more cross-linked DLC network by folding dehydrogenated chains into closed 6-fold rings. These findings significantly lead to an enhanced understanding in DLC film growth mechanism by RF-PECVD processes. PMID:27058762

  8. The Role of Ambient Gas and Pressure on the Structuring of Hard Diamond-Like Carbon Films Synthesized by Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Andrei C. Popescu

    2015-06-01

    Full Text Available Hard carbon thin films were synthesized on Si (100 and quartz substrates by the Pulsed Laser Deposition (PLD technique in vacuum or methane ambient to study their suitability for applications requiring high mechanical resistance. The deposited films’ surface morphology was investigated by scanning electron microscopy, crystalline status by X-ray diffraction, packing and density by X-ray reflectivity, chemical bonding by Raman and X-ray photoelectron spectroscopy, adherence by “pull-out” measurements and mechanical properties by nanoindentation tests. Films synthesized in vacuum were a-C DLC type, while films synthesized in methane were categorized as a-C:H. The majority of PLD films consisted of two layers: one low density layer towards the surface and a higher density layer in contact with the substrate. The deposition gas pressure played a crucial role on films thickness, component layers thickness ratio, structure and mechanical properties. The films were smooth, amorphous and composed of a mixture of sp3-sp2 carbon, with sp3 content ranging between 50% and 90%. The thickness and density of the two constituent layers of a film directly determined its mechanical properties.

  9. Improved adhesion and tribological properties of fast-deposited hard graphite-like hydrogenated amorphous carbon films

    NARCIS (Netherlands)

    Zaharia, T.; Kudlacek, P.; Creatore, M.; Groenen, R.; Persoone, P.; M. C. M. van de Sanden,

    2011-01-01

    Graphite-like hard hydrogenated amorphous carbon (a-C:H) was deposited using an Ar-C(2)H(2) expanding thermal plasma chemical vapour deposition (ETP-CVD) process. The relatively high hardness of the fast deposited a-C:H material leads to high compressive stress resulting in poor adhesion between the

  10. Pyrolyzed carbon film diodes.

    Science.gov (United States)

    Morton, Kirstin C; Tokuhisa, Hideo; Baker, Lane A

    2013-11-13

    We have previously reported pyrolyzed parylene C (PPC) as a conductive carbon electrode material for use with micropipets, atomic force microscopy probes, and planar electrodes. Advantages of carbon electrode fabrication from PPC include conformal coating of high-aspect ratio micro/nanoscale features and the benefits afforded by chemical vapor deposition of carbon polymers. In this work, we demonstrate chemical surface doping of PPC through the use of previously reported methods. Chemically treated PPC films are characterized by multiple spectroscopic and electronic measurements. Pyrolyzed parylene C and doped PPC are used to construct diodes that are examined as both p-n heterojunction and Schottky barrier diodes. Half-wave rectification is achieved with PPC diodes and demonstrates the applicability of PPC as a conductive and semiconductive material in device fabrication. PMID:24090451

  11. Near-Edge X-Ray Absorption Fine Structure of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Films Prepared by Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Shinya Ohmagari

    2009-01-01

    Full Text Available The atomic bonding configuration of ultrananocrystalline diamond (UNCD/hydrogenated amorphous carbon (a-C:H films prepared by pulsed laser ablation of graphite in a hydrogen atmosphere was examined by near-edge X-ray absorption fine structure spectroscopy. The measured spectra were decomposed with simple component spectra, and they were analyzed in detail. As compared to the a-C:H films deposited at room substrate-temperature, the UNCD/a-C:H and nonhydrogenated amorphous carbon (a-C films deposited at a substrate-temperature of 550∘C exhibited enhanced π∗ and σ∗C≡C peaks. At the elevated substrate-temperature, the π∗ and σ∗C≡C bonds formation is enhanced while the σ∗C–H and σ∗C–C bonds formation is suppressed. The UNCD/a-C:H film showed a larger σ∗C–C peak than the a-C film deposited at the same elevated substrate-temperature in vacuum. We believe that the intense σ∗C–C peak is evidently responsible for UNCD crystallites existence in the film.

  12. Synthesis, structural and field emission properties of multiwall carbon nanotube-graphene-like nanocarbon hybrid films grown by microwave plasma enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    Multiwall carbon nanotube (MWCNT)-graphene-like nanocarbon hybrid films were directly deposited on nickel substrate without any pre-treatment in a single-step by microwave plasma enhanced chemical vapor deposition (MW PECVD) technique at 600 °C. The effects of hydrogen partial pressure on the growth of MWCNT-graphene-like nanocarbon hybrid films and their structural, morphological and field emission properties were investigated. High resolution scanning electron microscope revealed MWCNT structure. High resolution transmission electron microscope images and Raman spectra revealed graphene-like nanocarbon film. Raman spectra showed 2D, G, D and D + G peaks at approximately 2690, 1590, 1350 and 2930 cm−1, respectively. The minimum threshold field for electron emission was found to be 3.6 V/μm corresponding to 1 μA/cm2 current density for the MWCNT-graphene-like nanocarbon hybrid film deposited at 20 Torr pressure whereas the maximum current density of 0.12 mA/cm2 and field enhancement factor of ∼3356 was obtained for the sample deposited at 5 Torr pressure. - Highlights: • MWCNT-graphene-like nanocarbon hybrid films were synthesized by MWPECVD technique. • Effect of pressure on the structural and field emission properties has been studied. • FESEM revealed MWCNT and HRTEM revealed graphene-like nanocarbon film structure. • Minimum ET = 3.6 V/μm with β = 3164 has been obtained in the film deposited at 20 Torr. • Maximum J = 0.12 mA/cm2 with β = 3356 has been obtained in the film deposited at 5 Torr

  13. Uniform deposition of ternary chalcogenide nanoparticles onto mesoporous TiO{sub 2} film using liquid carbon dioxide-based coating

    Energy Technology Data Exchange (ETDEWEB)

    Nursanto, Eduardus Budi [Clean Energy Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136–791 (Korea, Republic of); Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology,217, Gajeong-ro, Yuseong-gu, Daejeon 305–333 (Korea, Republic of); Park, Se Jin [Clean Energy Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136–791 (Korea, Republic of); Jeon, Hyo Sang; Hwang, Yun Jeong [Clean Energy Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136–791 (Korea, Republic of); Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology,217, Gajeong-ro, Yuseong-gu, Daejeon 305–333 (Korea, Republic of); Kim, Jaehoon, E-mail: jaehoonkim@skku.edu [School of Mechanical Engineering, Sungkyunkwan University, 2066, Seobu-Ro, Jangan-Gu, Suwon, GyeongGi-Do 440–746 (Korea, Republic of); SKKU Advanced Institute of Nano Technology (SAINT), 2066, Seobu-Ro, Jangan-Gu, Suwon, GyeongGi-Do 440–746 (Korea, Republic of); Min, Byoung Koun, E-mail: bkmin@kist.re.kr [Clean Energy Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136–791 (Korea, Republic of); Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology,217, Gajeong-ro, Yuseong-gu, Daejeon 305–333 (Korea, Republic of); Green School, Korea University, 145,Anam-ro, Seongbuk-gu, Seoul 136–713 (Korea, Republic of)

    2014-08-28

    We report the simultaneous deposition of two different metal precursors dissolved in liquid carbon dioxide (l-CO{sub 2}), aiming to the synthesis of ternary chalcopyrite (e.g. CuInS{sub 2}) nanoparticles on a mesoporous TiO{sub 2} film. The l-CO{sub 2}-based deposition of Cu and In precursors and subsequent reaction with a dilute H{sub 2}S gas resulted in Cu{sub x}In{sub y}S{sub z} nanoparticles uniformly deposited across the entire thickness of a mesoporous TiO{sub 2} film. Further heat treatment (air annealing and sulfurization) led to the formation of more stoichiometric CuInS{sub 2} nanoparticles. The formation of CuInS{sub 2} on TiO{sub 2} was confirmed by scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. The crystal growth of CuInS{sub 2} was also found to be controllable by adjusting the number of coating cycles of the l-CO{sub 2}-based deposition. - Highlights: • Simultaneous deposition of two different metal precursors dissolved in l-CO{sub 2}. • Uniform deposition of CuInS{sub 2} nanoparticles across mesoporous TiO{sub 2} film. • Highly crystalline CuInS{sub 2} formed on mesoporous TiO{sub 2} film. • Nearly stoichiometric ratio of Cu:In:S was obtained.

  14. The effect of electrochemical phenomena on the deposition of carbon containing inorganic thin films from supersonic expansion of aqueous supercritical solutions

    Science.gov (United States)

    Sezer, Ali Osman

    The supersonic expansion of dilute aqueous solutions for the synthesis of new materials is a complex flow system. Flow prediction and modeling are, therefore, quite challenging. Electrokinetic streaming potentials generated during the supersonic nozzle expansion further complicate the nature of these flow processes. Flow-generated potentials are believed to significantly affect the electrochemical environment of the flow, and therefore, may influence the properties of the product. This dissertation research was an attempt to experimentally and theoretically investigate the significance of flow-generated electrochemical phenomena and their possible effect on the deposited thin carbon films. Brand's computer model was used to predict the physical properties of the expanding jet at the nozzle. The sensitivity of the predicted flow parameters to operating conditions was then analyzed. The results of this parametric flow modeling were used to identify deposition regions of flow space that have less sensitivity to fluctuations in process temperatures and pressures. Streaming currents were predicted from measured nozzle currents. The first high-temperature-pressure Pourbaix diagrams were constructed for the carbon-water system. Equilibrium Pourbaix diagrams together with predicted streaming currents suggested a possible CVD-like mechanism for the deposition of thin carbon films. Deposited carbon films were analyzed for morphology, composition and structure by vibrational spectroscopy and electron microscopy. IR and Raman analysis of carbon samples were not conclusive in revealing any measurable differences in samples. Although Raman spectra showed considerable shifts in peak positions, the lack of internal standard in the spectra made it difficult to draw any reliable conclusions. Significant variations in surface morphology were found for samples grown under different substrate bias. Electron diffraction analysis conclusively showed the presence of a cubic diamond and

  15. 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

  16. Study of Fluorine Addition Influence in the Dielectric Constant of Diamond-Like Carbon Thin Film Deposited by Reactive Sputtering

    Science.gov (United States)

    Trippe, S. C.; Mansano, R. D.

    The hydrogenated amorphous carbon films (a-C:H) or DLC (Diamond-Like Carbon) films are well known for exhibiting high electrical resistivity, low dielectric constant, high mechanical hardness, low friction coefficient, low superficial roughness and also for being inert. In this paper, we produced fluorinated DLC films (a-C:F), and studied the effect of adding CF4 on the above-mentioned properties of DLC films. These films were produced by a reactive RF magnetron sputtering system using a target of pure carbon in stable graphite allotrope. We performed measurements of electrical characteristic curves of capacitance as a function of applied tension (C-V) and current as a function of the applied tension (I-V). We showed the dielectric constant (k) and the resistivity (ρ) as functions of the CF4 concentration. On films with 65% CF4, we found that k = 2.7, and on films with 70% CF4, ρ = 12.3 × 1011 Ω cm. The value of the electrical breakdown field to films with 70% CF4 is 5.3 × 106 V/cm.

  17. Carbon thin films deposited by the magnetron sputtering technique using cobalt, copper and nickel as buffer-layers; Filmes finos de carbono depositados por meio da tecnica de magnetron sputtering usando cobalto, cobre e niquel como buffer-layers

    Energy Technology Data Exchange (ETDEWEB)

    Costa e Silva, Danilo Lopes

    2015-11-01

    In this work, carbon thin films were produced by the magnetron sputtering technique using single crystal substrates of alumina c-plane (0001) and Si (111) and Si (100) substrates, employing Co, Ni and Cu as intermediate films (buffer-layers). The depositions were conducted in three stages, first with cobalt buffer-layers where only after the production of a large number of samples, the depositions using cooper buffer-layers were carried out on Si substrates. Then, depositions were performed with nickel buffer layers using single-crystal alumina substrates. The crystallinity of the carbon films was evaluated by using the technique of Raman spectroscopy and, then, by X-ray diffraction (XRD). The morphological characterization of the films was performed by scanning electron microscopy (SEM and FEG-SEM) and high-resolution transmission electron microscopy (HRTEM). The XRD peaks related to the carbon films were observed only in the results of the samples with cobalt and nickel buffer-layers. The Raman spectroscopy showed that the carbon films with the best degree of crystallinity were the ones produced with Si (111) substrates, for the Cu buffers, and sapphire substrates for the Ni and Co buffers, where the latter resulted in a sample with the best crystallinity of all the ones produced in this work. It was observed that the cobalt has low recovering over the alumina substrates when compared to the nickel. Sorption tests of Ce ions by the carbon films were conducted in two samples and it was observed that the sorption did not occur probably because of the low crystallinity of the carbon films in both samples. (author)

  18. Effects of radio-frequency power on the properties of carbon thin films prepared by thermal chemical vapor deposition enhanced with remote inductively-coupled-plasma using acetylene/nitrogen mixtures

    International Nuclear Information System (INIS)

    The effects of radio-frequency (rf) power on the properties of carbon thin films prepared by thermal chemical vapor deposition (CVD) enhanced with remote inductively-coupled-plasma (ICP) are investigated. Acetylene and nitrogen were used as the precursor gases, and rf-powers of ICP were set as 0, 100, 200, 300, and 400 W. The deposition temperature, working pressure, and deposition time were set as 1248 K, 4 kPa, and 2 h, respectively. The residual gases, film thicknesses, microstructures, chemical characteristics, mechanical properties, and electrical properties of carbon thin films were investigated by residual gas analyzer (RGA), field emission scanning electron microscopy, X-ray diffractometer (and Raman scattering spectrometer), X-ray photoelectron spectrometer, nanoindenter, and four point probe, respectively. RGA results reveal that the main species in the gas phase contain H2, C2H, C2H2, HCN (or C2H3), and N2 (or C2H4). Moreover, C2H, C2H2, and C2H4 can be speculated as the main species for carbon thin film deposition. As the rf-power increases from 0 to 400 W, the deposition rate of carbon thin films decreases from 204 to 36.0 nm/h. The crystallinity and ordering degree of carbon thin films increase with increasing rf-power from 0 to 400 W, but the ratio of sp2 carbon sites in carbon thin films decreases from 95 to 75%. The Young's modulus, hardness, and electrical resistivity of carbon thin films increase with increasing rf-power. Furthermore, the effects of rf-power on the deposition rates of carbon thin films prepared by thermal CVD enhanced with remote ICP using C2H2/N2 and CH4/N2 mixtures are compared. - Highlights: • Carbon films are prepared by TCVD enhanced with remote ICP using C2H2/N2 mixtures. • The deposition rate of carbon thin films decreases with increasing the rf-power. • C2H, C2H2, and C2H4 are speculated as the main species for carbon film deposition. • The sp2 sites in carbon thin films decrease with increasing rf-power.

  19. Study on glow discharge effects on catalyst films for growing aligned carbon nanofibers in negative bias-enhanced hot filament chemical vapor deposition system

    International Nuclear Information System (INIS)

    Aligned carbon nanofibers (ACNFs) were grown on silicon substrates coated with NiFe catalyst films by negative bias-enhanced hot filament chemical vapor deposition (CVD). The growth and structure of the aligned carbon nanofibers were investigated by scanning electron microscopy (SEM). The results indicate that the aligned carbon nanofibers could be synthesized after the glow discharge appears when the negative bias is higher than a certain value, while they are bent if the glow discharge does not appear. Furthermore, the diameters of the aligned carbon nanofibers are reduced and their lengths are increased with increasing the negative bias. It is shown that the glow discharge resulting from the negative bias plays an important role in the growth of aligned carbon nanofibers. Here, the effects of the glow discharge on the growth and structure of the aligned carbon nanofibers are discussed

  20. Laser deposition of HTSC films

    International Nuclear Information System (INIS)

    Studies of the high-temperature superconducting (HTSC) films fabrication by the laser deposition are reviewed. Physical and chemical processes taking place during laser deposition are considered, such as the target evaporation, the material transport from the target to the substrate, the film growth on the substrate, thermochemical reactions and mass transfer within the HTSC films and their stability. The experimental results on the laser deposition of different HTSC ceramics and their properties investigations are given. The major technological issues are discussed including the deposition schemes, the oxygen supply, the target compositions and structure, the substrates and interface layers selection, the deposition regimes and their impact on the HTSC films properties. 169 refs.; 6 figs.; 2 tabs

  1. Spray deposition of LiMn{sub 2}O{sub 4} nanoparticle-decorated multiwalled carbon nanotube films as cathode material for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Hong, H.P. [Department of Control and Instrumentation Engineering, Korea University, Jochiwon, 339-700 (Korea, Republic of); Kim, M.S. [Department of Advanced Materials Chemistry, BK21 Research Team, Korea University, Jochiwon, 339-700 (Korea, Republic of); Lee, Y.H. [Department of Biomicrosystem Technology, Korea University, Seoul, 136-701 (Korea, Republic of); Yu, J.S. [Department of Advanced Materials Chemistry, BK21 Research Team, Korea University, Jochiwon, 339-700 (Korea, Republic of); Lee, C.J. [School of Electrical Engineering, Korea University, Seoul, 136-710 (Korea, Republic of); Min, N.K., E-mail: nkmin@korea.ac.kr [Department of Control and Instrumentation Engineering, Korea University, Jochiwon, 339-700 (Korea, Republic of)

    2013-11-29

    We prepared LiMn{sub 2}O{sub 4} nanoparticle-decorated multiwalled carbon nanotube (MWCNT) films as a cathode electrode for lithium-ion batteries using a spray-deposition method. The surface morphologies and structures of the films were characterized using scanning electron microscopy and X-ray diffraction analysis. The results revealed that fairly homogeneous spinel LiMn{sub 2}O{sub 4} nanopowder-based films with the grain size of 20–50 nm were successfully formed on the surface of the MWCNTs. Cyclic voltammetry confirmed the presence of typical spinel LiMn{sub 2}O{sub 4} structure on the MWCNTs with showing stronger oxidative peaks of better reversibility as compared to a pure LiMn{sub 2}O{sub 4} electrode. The spray-deposited LiMn{sub 2}O{sub 4}-decorated MWCNT film was also found to have a higher discharge capacity (97.2 mAh/g) than the as-deposited LiMn{sub 2}O{sub 4} film (75.2 mAh/g) as well as excellent cycling stability. These characteristics are due to the fact that MWCNTs provide the cathode with multiple electron tunneling pathways and a mechanically strong framework. - Highlights: • This study discusses LiMn{sub 2}O{sub 4}(LM)-coated multiwalled carbon nanotube film (MWCNT) • LM-coated MWCNT electrodes are deposited using spray-coating methods. • LM-coated MWCNT electrodes show high discharge capacity. • LM-coated MWCNT electrodes show cycle stability. • MWCNT framework maintains the structure of LM during the electrochemical reaction.

  2. Spray deposition of LiMn2O4 nanoparticle-decorated multiwalled carbon nanotube films as cathode material for lithium-ion batteries

    International Nuclear Information System (INIS)

    We prepared LiMn2O4 nanoparticle-decorated multiwalled carbon nanotube (MWCNT) films as a cathode electrode for lithium-ion batteries using a spray-deposition method. The surface morphologies and structures of the films were characterized using scanning electron microscopy and X-ray diffraction analysis. The results revealed that fairly homogeneous spinel LiMn2O4 nanopowder-based films with the grain size of 20–50 nm were successfully formed on the surface of the MWCNTs. Cyclic voltammetry confirmed the presence of typical spinel LiMn2O4 structure on the MWCNTs with showing stronger oxidative peaks of better reversibility as compared to a pure LiMn2O4 electrode. The spray-deposited LiMn2O4-decorated MWCNT film was also found to have a higher discharge capacity (97.2 mAh/g) than the as-deposited LiMn2O4 film (75.2 mAh/g) as well as excellent cycling stability. These characteristics are due to the fact that MWCNTs provide the cathode with multiple electron tunneling pathways and a mechanically strong framework. - Highlights: • This study discusses LiMn2O4(LM)-coated multiwalled carbon nanotube film (MWCNT) • LM-coated MWCNT electrodes are deposited using spray-coating methods. • LM-coated MWCNT electrodes show high discharge capacity. • LM-coated MWCNT electrodes show cycle stability. • MWCNT framework maintains the structure of LM during the electrochemical reaction

  3. 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.

  4. Improvement in the degradation resistance of silicon nanostructures by the deposition of diamond-like carbon films

    Energy Technology Data Exchange (ETDEWEB)

    Klyui, N. I., E-mail: klyui@isp.kiev.ua; Semenenko, M. A.; Khatsevich, I. M.; Makarov, A. V.; Kabaldin, A. N. [National Academy of Sciences of Ukraine, Lashkarev Institute of Semiconductor Physics (Ukraine); Fomovskii, F. V. [Kremenchug National University (Ukraine); Han, Wei [Jilin University, College of Physics (China)

    2015-08-15

    It is established that the deposition of a diamond-like film onto a structure with silicon nanoclusters in a silicon dioxide matrix yields an increase in the long-wavelength photoluminescence intensity of silicon nanoclusters due to the passivation of active-recombination centers with hydrogen and a shift of the photoluminescence peak to the region of higher photosensitivity of silicon-based solar cells. It is also shown that, due to the deposited diamond-like film, the resistance of such a structure to degradation upon exposure to γ radiation is improved, which is also defined by the effect of the passivation of radiation-induced activerecombination centers by hydrogen that is released from the films during treatment.

  5. Improvement in the degradation resistance of silicon nanostructures by the deposition of diamond-like carbon films

    International Nuclear Information System (INIS)

    It is established that the deposition of a diamond-like film onto a structure with silicon nanoclusters in a silicon dioxide matrix yields an increase in the long-wavelength photoluminescence intensity of silicon nanoclusters due to the passivation of active-recombination centers with hydrogen and a shift of the photoluminescence peak to the region of higher photosensitivity of silicon-based solar cells. It is also shown that, due to the deposited diamond-like film, the resistance of such a structure to degradation upon exposure to γ radiation is improved, which is also defined by the effect of the passivation of radiation-induced activerecombination centers by hydrogen that is released from the films during treatment

  6. Deposition of carbon dioxide

    International Nuclear Information System (INIS)

    In Norway, there is currently a debate about whether or not to build gas power stations. To meet the possibility of reduced emission quotas for carbon dioxide in the future, current interest focuses on the incorporation of large-scale separation and deposition of carbon dioxide when such plants are planned. A group of experts concludes that this technology will become self-financing by means of environmental taxes. From the environmental point of view, taxes upon production are to be preferred over taxes on consumption

  7. Hydrogenation effects on carrier transport in boron-doped ultrananocrystalline diamond/amorphous carbon films prepared by coaxial arc plasma deposition

    International Nuclear Information System (INIS)

    Boron-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films were deposited by coaxial arc plasma deposition with a boron-blended graphite target at a base pressure of <10−3 Pa and at hydrogen pressures of ≤53.3 Pa. The hydrogenation effects on the electrical properties of the films were investigated in terms of chemical bonding. Hydrogen-scattering spectrometry showed that the maximum hydrogen content was 35 at. % for the film produced at 53.3-Pa hydrogen pressure. The Fourier-transform infrared spectra showed strong absorptions by sp3 C–H bonds, which were specific to the UNCD/a-C:H, and can be attributed to hydrogen atoms terminating the dangling bonds at ultrananocrystalline diamond grain boundaries. Temperature-dependence of the electrical conductivity showed that the films changed from semimetallic to semiconducting with increasing hydrogen pressure, i.e., with enhanced hydrogenation, probably due to hydrogenation suppressing the formation of graphitic bonds, which are a source of carriers. Carrier transport in semiconducting hydrogenated films can be explained by a variable-range hopping model. The rectifying action of heterojunctions comprising the hydrogenated films and n-type Si substrates implies carrier transport in tunneling

  8. Structure, mechanical, and frictional properties of hydrogenated fullerene-like amorphous carbon film prepared by direct current plasma enhanced chemical vapor deposition

    Science.gov (United States)

    Wang, Yongfu; Gao, Kaixiong; Zhang, Junyan

    2016-07-01

    In this study, fullerene like carbon (FL-C) is introduced in hydrogenated amorphous carbon (a-C:H) film by employing a direct current plasma enhanced chemical vapor deposition. The film has a low friction and wear, such as 0.011 and 2.3 × 10-9mm3/N m in the N2, and 0.014 and 8.4 × 10-8mm3/N m in the humid air, and high hardness and elasticity (25.8 GPa and 83.1%), to make further engineering applications in practice. It has several nanometers ordered domains consisting of less frequently cross-linked graphitic sheet stacks. We provide new evidences for understanding the reported Raman fit model involving four vibrational frequencies from five, six, and seven C-atom rings of FL-C structures, and discuss the structure evolution before or after friction according to the change in the 1200 cm-1 Raman band intensity caused by five- and seven-carbon rings. Friction inevitably facilitates the transformation of carbon into FL-C nanostructures, namely, the ultra low friction comes from both such structures within the carbon film and the sliding induced at friction interface.

  9. Preparation and bioactive properties of nanocrystalline hydroxyapatite thin films obtained by conversion of atomic layer deposited calcium carbonate.

    Science.gov (United States)

    Holopainen, Jani; Kauppinen, Kyösti; Mizohata, Kenichiro; Santala, Eero; Mikkola, Esa; Heikkilä, Mikko; Kokkonen, Hanna; Leskelä, Markku; Lehenkari, Petri; Tuukkanen, Juha; Ritala, Mikko

    2014-09-01

    Nanocrystalline hydroxyapatite thin films were fabricated on silicon and titanium by atomic layer deposition (ALD) of CaCO3 and its subsequent conversion to hydroxyapatite by diammonium hydrogen phosphate (DAP) solution. The effects of conversion process parameters to crystallinity and morphology of the films were examined. DAP concentration was found to be critical in controlling the crystal size and homogeneity of the films. The hydroxyapatite phase was identified by XRD. ToF-elastic recoil detection analysis studies revealed that the films are calcium deficient in relation to hydroxyapatite with a Ca/P ratio of 1.39 for films converted with 0.2 M DAP at 95 °C. The coatings prepared on titanium conformally follow the rough surface topography of the substrate, verifying that the good step coverage of the ALD method was maintained in the conversion process. The dissolution tests revealed that the coating was nondissolvable in the cell culture medium. Annealing the coated sample at 700 °C for 1 h seemed to enhance its bonding properties to the substrate. Also, the biocompatibility of the coatings was confirmed by human bone marrow derived cells in vitro. The developed method provides a new possibility to produce thin film coatings on titanium implants with bone-type hydroxyapatite that is biocompatible with human osteoblasts and osteoclasts. PMID:25280849

  10. Nanofriction properties of molecular deposition films

    Institute of Scientific and Technical Information of China (English)

    王强斌; 高芒来; 张嗣伟

    2000-01-01

    The nanofriction properties of Au substrate and monolayer molecular deposition film and multilayer molecular deposition films on Au substrate and the molecular deposition films modified with alkyl-terminal molecule have been investigated by using an atomic force microscope. It is concluded that ( i ) the deposition of molecular deposition films on Au substrate and the modification of alkyl-terminal molecule to the molecular deposition films can reduce the frictional force; (ii) the molecular deposition films with the same terminal exhibit similar nanofriction properties, which has nothing to do with the molecular chain-length and the layer number; (iii) the unstable nanofriction properties of molecular deposition films are contributed to the active terminal of the molecular deposition film, which can be eliminated by decorating the active molecular deposition film with alkyl-terminal molecule, moreover, the decoration of alkyl-terminal molecule can lower the frictional force conspicuously; (iv) the relat

  11. Structural and Physical Characteristics of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Deposited Using a Coaxial Arc Plasma Gun

    Science.gov (United States)

    Yoshitake, Tsuyoshi; Nakagawa, You; Nagano, Akira; Ohtani, Ryota; Setoyama, Hiroyuki; Kobayashi, Eiichi; Sumitani, Kazushi; Agawa, Yoshiaki; Nagayama, Kunihito

    2010-01-01

    Ultrananocrystalline diamond (UNCD)/hydrogenated amorphous carbon (a-C:H) films were formed without initial nucleation using a coaxial arc plasma gun. The UNCD crystallite diameters estimated from the X-ray diffraction peaks were approximately 2 nm. The Fourier transform infrared absorption spectrum exhibited an intense sp3-CH peak that might originate from the grain boundaries between UNCD crystallites whose dangling bonds are terminated with hydrogen atoms. A narrow sp3 peak in the photoemission spectrum implied that the film comprises a large number of UNCD crystallites. Large optical absorption coefficients at photon energies larger than 3 eV that might be due to the grain boundaries are specific to the UNCD/a-C:H films.

  12. Immobilization and stretching of 5'-pyrene-terminated DNA on carbon film deposited on electron microscope grid.

    Science.gov (United States)

    Loukanov, Alexandre; Filipov, Chavdar; Lecheva, Marta; Emin, Saim

    2015-11-01

    The immobilization and stretching of randomly coiled DNA molecules on hydrophobic carbon film is a challenging microscopic technique, which possess various applications, especially for genome sequencing. In this report the pyrenyl nucleus is used as an anchor moiety to acquire higher affinity of double stranded DNA to the graphite surface. DNA and pyrene are joined through a linker composed of four aliphatic methylene groups. For the preparation of pyrene-terminated DNA a multifunctional phosphoramidite monomer compound was designed. It contains pyrenylbutoxy group as an anchor moiety for π-stacking attachment to the carbon film, 2-cyanoethyloxy, and diisopropylamino as coupling groups for conjugation to activated oligonucleotide chain or DNA molecule. This monomer derivative was suitable for incorporation into automated solid-phase DNA synthesis and was attached to the 5' terminus of the DNA chain through a phosphodiester linkage. The successful immobilization and stretching of pyrene-terminated DNA was demonstrated by conventional 100 kV transmission electron microscope. The microscopic analysis confirmed the stretched shape of the negatively charged nucleic acid pieces on the hydrophobic carbon film. PMID:26303786

  13. Structural and electrical properties and current–voltage characteristics of nitrogen-doped diamond-like carbon films on Si substrates by plasma-enhanced chemical vapor deposition

    Science.gov (United States)

    Tsuchiya, Masato; Murakami, Kazuki; Magara, Kohei; Nakamura, Kazuki; Ohashi, Haruka; Tokuda, Kengo; Takami, Takahiro; Ogasawara, Haruka; Enta, Yoshiharu; Suzuki, Yushi; Ando, Satoshi; Nakazawa, Hideki

    2016-06-01

    We have deposited nitrogen-doped diamond-like carbon (N-DLC) films by plasma-enhanced chemical vapor deposition using CH4, N2, and Ar, and investigated the effects of N doping on the structure and the electrical, mechanical, and optical properties of the N-DLC films. We fabricated undoped DLC/p-type Si and N-DLC/p-type Si heterojunctions and examined the current–voltage characteristics of the heterojunctions. When the N2 flow ratio was increased from 0 to 3.64%, the resistivity markedly decreased from the order of 105 Ω·cm to that of 10‑2 Ω·cm and the internal stress also decreased. The resistivity gradually increased with increasing N2 flow ratio from 3.64 to 13.6%, and then it decreased at a N2 flow ratio of 13.6%. These behaviors can be explained in terms of the clustering of sp2 carbons and the formation of sp3C–N, sp2C=N, sp1C≡N, and C–H n bonds. The rectification ratio of the heterojunction using the N-DLC film prepared at 3.64% was 35.8 at ±0.5 V.

  14. Intrinsic stress analysis of sputtered carbon film

    Institute of Scientific and Technical Information of China (English)

    Liqin Liu; Zhanshan Wang; Jingtao Zhu; Zhong Zhang; Moyan Tan; Qiushi Huang; Rui Chen; Jing Xu; Lingyan Chen

    2008-01-01

    Intrinsic stresses of carbon films deposited by direct current (DC) magnetron sputtering were investigated.The bombardments of energetic particles during the growth of films were considered to be the main reason for compressive intrinsic stresses.The values of intrinsic stresses were determined by measuring the radius of curvature of substrates before and after film deposition.By varying argon pressure and target-substrate distance,energies of neutral carbon atoms impinging on the growing films were optimized to control the intrinsic stresses level.The stress evolution in carbon films as a function of film thickness was investigated and a void-related stress relief mechanism was proposed to interpret this evolution.

  15. Nanostructured carbon films with oriented graphitic planes

    International Nuclear Information System (INIS)

    Nanostructured carbon films with oriented graphitic planes can be deposited by applying energetic carbon bombardment. The present work shows the possibility of structuring graphitic planes perpendicular to the substrate in following two distinct ways: (i) applying sufficiently large carbon energies for deposition at room temperature (E>10 keV), (ii) utilizing much lower energies for deposition at elevated substrate temperatures (T>200 deg. C). High resolution transmission electron microscopy is used to probe the graphitic planes. The alignment achieved at elevated temperatures does not depend on the deposition angle. The data provides insight into the mechanisms leading to the growth of oriented graphitic planes under different conditions.

  16. Growth of carbon nanofiber coatings on nickel thin films on fused silica by catalytic thermal chemical vapor deposition: On the use of titanium, titanium–tungsten and tantalum as adhesion layers

    NARCIS (Netherlands)

    Thakur, D.B.; Tiggelaar, R.M.; Gardeniers, J.G.E.; Lefferts, L.; Seshan, K.

    2009-01-01

    Coatings of carbon nanofiber (CNF) layers were synthesized on fused silica substrates using a catalytic thermal chemical vapor deposition process (C-TCVD). The effects of various adhesion layers–titanium, titanium–tungsten and tantalum–under the nickel thin film on the attachment of carbon nanofiber

  17. Investigation of copper and silver nanoparticles deposited on a nitrogen-doped diamond-like carbon (N-DLC) film electrode for bio-sensing

    International Nuclear Information System (INIS)

    An electrochemical method has been employed in this work to deposit copper and silver nanoparticles onto chemical-vapor-deposited nitrogen doped hydrogen amorphous diamond-like carbon (N-DLC) film electrodes. The electrochemical behaviors of the metal-nanoparticle-modified N-DLC electrodes have been characterized in the presence of glucose and hydrogen peroxide in the electrolyte. The copper and the silver nanoparticles possess high catalytic function for the oxidation of glucose and the reduction of hydro peroxide, respectively. The well-defined reduction responses of the reduction or hydrogen peroxide give the silver-nanoparticle-modified N-DLC electrodes high potential for application in hydrogen-peroxide sensing without a label.

  18. Atomic layer deposition and characterization of biocompatible hydroxyapatite thin films

    International Nuclear Information System (INIS)

    Atomic layer deposition (ALD) was used to produce hydroxyapatite from Ca(thd)2 (thd = 2,2,6,6-tetramethyl-3,5-heptanedionato) and (CH3O)3PO onto Si(100) and Corning (0211). Film crystallinity, stoichiometry, possible impurities and surface morphology were determined. The as-deposited films contained significant amounts of carbonate impurities however, annealing at moist N2 flow reduced the carbonate content even at 400 oC. The as-deposited Ca-P-O films were amorphous but rapid thermal annealing promoted the formation of the hydroxyapatite phase. Mouse MC 3T3-E1 cells were used for the cell culture experiments. According to the bioactivity studies cell proliferation was enhanced on as-deposited ALD-grown Ca-P-O films and greatly enhanced on films annealed at 500 oC in comparison with reference cells on borosilicate glass or cell culture polystyrene.

  19. Time-Resolved Spectroscopic Observation of Deposition Processes of Ultrananocrystalline Diamond/Amorphous Carbon Composite Films by Using a Coaxial Arc Plasma Gun

    Science.gov (United States)

    Hanada, Kenji; Yoshitake, Tsuyoshi; Nishiyama, Takashi; Nagayama, Kunihito

    2010-08-01

    The deposition of ultrananocrystalline diamond (UNCD)/amorphous carbon composite films using a coaxial arc plasma gun in vacuum and, for comparison, in a 53.3 Pa hydrogen atmosphere was spectroscopically observed using a high-speed camera equipped with narrow-band-pass filters. UNCD crystallites with diameters of approximately 1.6 nm were formed even in vacuum. These extremely small crystallites imply that the formation is predominantly due to nucleation without the subsequent growth. Even in vacuum, emissions from C+ ions, C atoms, and C2 dimers lasted for approximately 100 µs, although the emission lifetimes of these species are generally 10 ns. We consider that the nucleation is due to the supersaturated environment containing excited carbon species with large number densities.

  20. Piezoresistive effect in carbon nanotube films

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The piezoresistive effect of the pristine carbon nanotube (CNT) films has been studied. Carbon nanotubes were synthesized by hot filament chemical vapor deposition. The piezoresistive effect in the pristine CNT films was studied by a three-point bending test. The gauge factor for the pristine CNT films under 500 microstrains was found to be at least 65 at room temperature, and increased with temperature, exceeding that of polycrystalline silicon (30) at 35℃. The origin of the piezoresistivity in CNT films may be ascribed to a pressure-induced change in the band gap and the defects.

  1. Effects of radio-frequency power on the properties of carbon thin films prepared by thermal chemical vapor deposition enhanced with remote inductively-coupled-plasma using acetylene/nitrogen mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Liang-Hsun; Wu, Kuan-Chang; Shiue, Sham-Tsong, E-mail: stshiue@dragon.nchu.edu.tw

    2014-11-03

    The effects of radio-frequency (rf) power on the properties of carbon thin films prepared by thermal chemical vapor deposition (CVD) enhanced with remote inductively-coupled-plasma (ICP) are investigated. Acetylene and nitrogen were used as the precursor gases, and rf-powers of ICP were set as 0, 100, 200, 300, and 400 W. The deposition temperature, working pressure, and deposition time were set as 1248 K, 4 kPa, and 2 h, respectively. The residual gases, film thicknesses, microstructures, chemical characteristics, mechanical properties, and electrical properties of carbon thin films were investigated by residual gas analyzer (RGA), field emission scanning electron microscopy, X-ray diffractometer (and Raman scattering spectrometer), X-ray photoelectron spectrometer, nanoindenter, and four point probe, respectively. RGA results reveal that the main species in the gas phase contain H{sub 2}, C{sub 2}H, C{sub 2}H{sub 2}, HCN (or C{sub 2}H{sub 3}), and N{sub 2} (or C{sub 2}H{sub 4}). Moreover, C{sub 2}H, C{sub 2}H{sub 2}, and C{sub 2}H{sub 4} can be speculated as the main species for carbon thin film deposition. As the rf-power increases from 0 to 400 W, the deposition rate of carbon thin films decreases from 204 to 36.0 nm/h. The crystallinity and ordering degree of carbon thin films increase with increasing rf-power from 0 to 400 W, but the ratio of sp{sup 2} carbon sites in carbon thin films decreases from 95 to 75%. The Young's modulus, hardness, and electrical resistivity of carbon thin films increase with increasing rf-power. Furthermore, the effects of rf-power on the deposition rates of carbon thin films prepared by thermal CVD enhanced with remote ICP using C{sub 2}H{sub 2}/N{sub 2} and CH{sub 4}/N{sub 2} mixtures are compared. - Highlights: • Carbon films are prepared by TCVD enhanced with remote ICP using C{sub 2}H{sub 2}/N{sub 2} mixtures. • The deposition rate of carbon thin films decreases with increasing the rf-power. • C{sub 2}H, C{sub 2}H

  2. Low temperature laser physical vapor deposition of multilayered thin films

    International Nuclear Information System (INIS)

    The authors have investigated the formation of various multilayer thin films by the laser physical vapor deposition technique. A multi stage target holder was constructed to perform all process steps in-situ; target/substrate cleaning, deposition, and annealing. The laser physical vapor deposition technique offers many advantages over conventional physical vapor techniques, such as, lower substrate temperature, microstructural control, and very low contamination levels. Film thickness can be controlled from near atomic to micron dimensions. A layer-by-layer (two dimensional) growth can be achieved, resulting in nonequilibrium structures. The films were analyzed using cross-section and high resolution transmission electron microscopy (TEM). The significant reduction in substrate temperature for the formation of high quality multilayer and epitaxial films opens up many new areas of applications requiring reduced thermal-budget processing. The authors present results of sequential deposition of multilayered thin films of carbon and tungsten, titanium nitride and carbide, and high Tc superconductor compounds

  3. Electrochemical atomic layer deposition of a CuInSe2 thin film on flexible multi-walled carbon nanotubes/polyimide nanocomposite membrane: Structural and photoelectrical characterizations

    International Nuclear Information System (INIS)

    Highlights: → CuInSe2 thin film has been successfully synthesized on CNT/PI membrane. → Optical band gap measurements give a band gap of 1.05 eV. → OCP and I-V studies show that the sample is beneficial to photoelectric applications. - Abstract: This study describes a method for the fabrication of an electrochemical atomic layer deposition (EC-ALD) used to fabricate the ternary, semiconducting compound, CuInSe2 (CISe), onto a flexible, carboxyl-functionalized multi-walled carbon nanotube/polyimide (COOH-MWCNT/PI) nanocomposite membrane. The elements were deposited using amperometric methods (I-t) in the following sequence: Se/Cu/Se/In/Se/Cu/Se/In and so on, in which the optimum deposition potential for each element was obtained via a cyclic voltammetry (CV) technique. Field emission scanning electron microscopy (FE-SEM) showed that the deposits consisted of many spherical nanoparticles, and energy dispersive spectroscopy (EDS) analysis indicated that the atomic ratio of the deposits (CuInSe) was 1.14 1.00 2.18, similar to the stoichiometric value of the compound. Near Fourier transform infrared spectroscopy (FT-IR) transmission measurements provided a band gap of 1.05 eV, which was confirmed by the absorption spectrum. Open-circuit potential (OCP) and current-voltage (I-V) measurements showed the resulting composite had a good p-type property. CISe spherical NPs electrodeposited on the CNTs/PI membrane may have promising applications in optoelectronic nanodevices and nanotechnologies; in addition, the CNTs/PI membrane could be used as raw material for manufacturing solar cells.

  4. Minerals deposited as thin films

    International Nuclear Information System (INIS)

    Free matrix effects are due to thin film deposits. Thus, it was decided to investigate this technique as a possibility to use pure oxide of the desired element, extrapolating its concentration from analytical curves made with avoiding, at the same time, mathematical corrections. The proposed method was employed to determine iron and titanium concentrations in geological samples. The range studied was 0.1-5%m/m for titanium and 5-20%m/m for iron. For both elements the reproducibility was about 7% and differences between this method and other chemical determinations were 15% for titanium and 7% for iron. (Author)

  5. Magnetron sputter deposition of low-stress, carbon-containing cubic boron nitride films using Ar-N2-CH4 gas mixtures

    International Nuclear Information System (INIS)

    Cubic boron nitride (c-BN) films produced by PVD and plasma-assisted CVD techniques typically exhibit undesired high compressive stresses. One of the effective and feasible methods to reduce stress and hence improve film adhesion has been a controlled addition of a third element into the film during deposition. In the present study, BN films were grown on to silicon substrates using reactive magnetron sputtering with a hexagonal BN target. An auxiliary flow of methane was mixed into argon and nitrogen as the working gas. The deposition was conducted at various methane flow rates at 400 oC substrate temperature, 0.2 Pa total working pressure, and - 250 V r.f. substrate bias. The microstructure of the deposited films was then examined in dependence of the methane flow rate. With increasing methane flow rate from 0 to approx. 2.0 sccm, the fraction of the cubic BN phase in the deposited films decreased gradually down to approx. 75 vol.%, whereas the film stress was reduced much more rapidly and almost linearly in relation to the methane flow rate. At 2.1 sccm methane, the stress became approx. 3 times reduced. Owing to the significantly decreased film stress, adherent, micrometer thick, cubic-phase dominant films can be allowed to form on silicon substrate. The microstructure of the films will be illustrated through FTIR and XRR.

  6. Depositing Adherent Ag Films On Ti Films On Alumina

    Science.gov (United States)

    Honecy, Frank S.

    1995-01-01

    Report discusses cleaning of ceramic (principally, alumina) substrates in preparation for sputter deposition of titanium intermediate films on substrates followed by sputter deposition of outer silver films. Principal intended application, substrates sliding parts in advanced high-temperature heat engines, and outer silver films serve as solid lubricants: lubricating properties described in "Solid Lubricant for Alumina" (LEW-15495).

  7. Nanofriction properties of molecular deposition films

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The nanofriction properties of Au substrate and monolayer molecular deposition film and multilayer molecular deposition films on Au substrate and the molecular deposition films modified with alkyl-terminal molecule have been investigated by using an atomic force microscope. It is concluded that (ⅰ) the deposition of molecular deposition films on Au substrate and the modification of alkyl-terminal molecule to the molecular deposition films can reduce the frictional force; (ⅱ) the molecular deposition films with the same terminal exhibit similar nanofriction properties, which has nothing to do with the molecular chain-length and the layer number; (ⅲ) the unstable nanofriction properties of molecular deposition films are contributed to the active terminal of the molecular deposition film, which can be eliminated by decorating the active molecular deposition film with alkyl-terminal molecule, moreover, the decoration of alkyl-terminal molecule can lower the frictional force conspicuously; (ⅳ) the relative humidity affects the frictional force; the higher the RH, the lower the frictional force.

  8. Piezoresistive Sensors Based on Carbon Nanotube Films

    Institute of Scientific and Technical Information of China (English)

    L(U) Jian-wei; WANG Wan-lu; LIAO Ke-jun; WANG Yong-tian; LIU CHang-lin; Zeng Qing-gao

    2005-01-01

    Piezoresistive effect of carbon nanotube films was investigated by a three-point bending test.Carbon nanotubes were synthesized by hot filament chemical vapor deposition.The experimental results showed that the carbon nanotubes have a striking piezoresistive effect.The relative resistance was changed from 0 to 10.5×10-2 and 3.25×10-2 for doped and undoped films respectively at room temperature when the microstrain under stress from 0 to 500. The gauge factors for doped and undoped carbon nanotube films under 500 microstrain were about 220 and 67 at room temperature, respectively, exceeding that of polycrystalline silicon (30) at 35℃.The origin of the resistance changes in the films may be attributed to a strain-induced change in the band gap for the doped tubes and the defects for the undoped tubes.

  9. A Comparative Study of Three Different Chemical Vapor Deposition Techniques of Carbon Nanotube Growth on Diamond Films

    Directory of Open Access Journals (Sweden)

    Betty T. Quinton

    2013-01-01

    Full Text Available This paper compares between the methods of growing carbon nanotubes (CNTs on diamond substrates and evaluates the quality of the CNTs and the interfacial strength. One potential application for these materials is a heat sink/spreader for high-power electronic devices. The CNTs and diamond substrates have a significantly higher specific thermal conductivity than traditional heat sink/spreader materials making them good replacement candidates. Only limited research has been performed on these CNT/diamond structures and their suitability of different growth methods. This study investigates three potential chemical vapor deposition (CVD techniques for growing CNTs on diamond: thermal CVD (T-CVD, microwave plasma-enhanced CVD (MPE-CVD, and floating catalyst thermal CVD (FCT-CVD. Scanning electron microscopy (SEM and high-resolution transmission electron microscopy (TEM were used to analyze the morphology and topology of the CNTs. Raman spectroscopy was used to assess the quality of the CNTs by determining the ID/IG peak intensity ratios. Additionally, the CNT/diamond samples were sonicated for qualitative comparisons of the durability of the CNT forests. T-CVD provided the largest diameter tubes, with catalysts residing mainly at the CNT/diamond interface. The MPE-CVD process yielded non uniform defective CNTs, and FCT-CVD resulted in the smallest diameter CNTs with catalyst particles imbedded throughout the length of the nanotubes.

  10. Deposition of silicon oxide like films from HMDSO by means of atmospheric pressure microplasma jets: Study of deposition mechanisms

    CERN Document Server

    Reuter, R; Ellerweg, D; Arcos, T de los; von Keudell, A; Benedikt, J

    2011-01-01

    The deposition of thin SiOxCyH or SiOxHy films by means of atmospheric pressure microplasma jets with Helium / Hexamethyldisiloxane (HMDSO / O2) mixtures and the role of surface reactions for the film growth have been investigated. The growth rate and the carbon-content in the film are measured as a function of the O2 and HMDSO mixture in the gas flow. Two types of microplasma jets, one with a planar and one with a coaxial geometry, are used to study the deposition process. The very localised deposition on and treatment of the surface gives the opportunity to separate deposition and treatment processes by applying two jets on a rotating substrate. The etching of carbon at the surface and the increasing HMDSO depletion leading to an increasing deposition rate are both induced by admixing oxygen. Carbon free films can be deposited, even without addition of oxygen, and the main loss channels for carbon are surface reactions.

  11. Pulsed laser deposition of anatase thin films on textile substrates

    Science.gov (United States)

    Krämer, André; Kunz, Clemens; Gräf, Stephan; Müller, Frank A.

    2015-10-01

    Pulsed laser deposition (PLD) is a highly versatile tool to prepare functional thin film coatings. In our study we utilised a Q-switched CO2 laser with a pulse duration τ ≈ 300 ns, a laser wavelength λ = 10.59 μm, a repetition frequency frep = 800 Hz and a peak power Ppeak = 15 kW to deposit crystalline anatase thin films on carbon fibre fabrics. For this purpose, preparatory experiments were performed on silicon substrates to optimise the anatase deposition conditions including the influence of different substrate temperatures and oxygen partial pressures. Processing parameters were then transferred to deposit anatase on carbon fibres. Scanning electron microscopy, X-ray diffraction analyses, Raman spectroscopy and tactile profilometry were used to characterise the samples and to reveal the formation of phase pure anatase without the occurrence of a secondary rutile phase. Methanol conversion test were used to prove the photocatalytic activity of the coated carbon fibres.

  12. Energetic deposition of thin metal films

    CERN Document Server

    Al-Busaidy, M S K

    2001-01-01

    deposited films. The primary aim of this thesis was to study the physical effect of energetic deposition metal thin films. The secondary aim is to enhance the quality of the films produced to a desired quality. Grazing incidence X-ray reflectivity (GIXR) measurements from a high-energy synchrotron radiation source were carried out to study and characterise the samples. Optical Profilers Interferometery, Atomic Force Microscope (AFM), Auger electron spectroscopy (AES), Medium energy ion spectroscopy (MEIS), and the Electron microscope studies were the other main structural characterisation tools used. AI/Fe trilayers, as well as multilayers were deposited using a Nordico planar D.C. magnetron deposition system at different voltage biases and pressures. The films were calibrated and investigated. The relation between energetic deposition variation and structural properties was intensely researched. Energetic deposition refers to the method in which the deposited species possess higher kinetic energy and impact ...

  13. Deposition and characterization of Ru thin films prepared by metallorganic chemical vapor deposition

    CERN Document Server

    Kang, S Y; Lee, S K; Hwang, C S; Kim, H J

    2000-01-01

    Ru thin films were deposited at 300 approx 400 .deg. C by using Ru(C sub 5 H sub 4 C sub 2 H sub 5) sub 2 (Ru(EtCp) sub 2) as a precursor and low-pressure metalorganic chemical vapor deposition. The addition of O sub 2 gas was essential to form Ru thin films. The deposition rates of the films were about 200 A/min. For low oxygen addition and high substrate temperature, RuO sub 2 phases were formed. Also, thermodynamic calculations showed that all the supplied oxygen was consumed to oxidize carbon and hydrogen, cracked from the precursor ligand, rather than Ru. Thus, metal films could be obtained There was an optimum oxygen to precursor ratio at which the pure Ru phase could be obtained with minimum generation of carbon and RuO sub 2

  14. Properties of nitrogen containing diamond-like carbon films

    International Nuclear Information System (INIS)

    Optical and mechanical properties of nitrogen containing diamond- like carbon (NC-DLC) films deposited by RF plasma decomposition of CH4:H2:N2 gas mixture were investigated. Nitrogen was incorporated into DLC films both during film growth and after deposition of film by implantation of nitrogen ions. It was shown that both optical and mechanical properties of the films strongly depend on nitrogen content in the films. In some cases the mechanical properties of nitrogen implanted films were improved in comparison with unimplanted samples. (author). 7 refs., 2 figs

  15. Chromium carbide thin films deposited by ultra-short pulse laser deposition

    International Nuclear Information System (INIS)

    Pulsed laser deposition performed by a laser with a pulse duration of 250 fs has been used to deposit films from a Cr3C2 target. Due to the different processes involved in the laser ablation when it is performed by an ultra-short pulse source instead of a conventional short pulse one, it has been possible to obtain in vacuum films containing only one type of carbide, Cr3C2, as shown by X-ray photoelectron spectroscopy. On the other hand, Cr3C2 is not the only component of the films, since a large amount of amorphous carbon is also present. The films, deposited at room temperature, are amorphous and seem to be formed by the coalescence of a large number of particles with nanometric size. The film composition can be explained in terms of thermal evaporation from particles ejected from the target.

  16. Superconductive niobium films coating carbon nanotube fibers

    Science.gov (United States)

    Salvato, M.; Lucci, M.; Ottaviani, I.; Cirillo, M.; Behabtu, N.; Young, C. C.; Pasquali, M.; Vecchione, A.; Fittipaldi, R.; Corato, V.

    2014-11-01

    Superconducting niobium (Nb) has been successfully obtained by sputter deposition on carbon nanotube fibers. The transport properties of the niobium coating the fibers are compared to those of niobium thin films deposited on oxidized Si substrates during the same deposition run. For niobium films with thicknesses above 300 nm, the niobium coating the fibers and the thin films show similar normal state and superconducting properties with critical current density, measured at T = 4.2 K, of the order of 105 A cm-2. Thinner niobium layers coating the fibers also show the onset of the superconducting transition in the resistivity versus temperature dependence, but zero resistance is not observed down to T = 1 K. We evidence by scanning electron microscopy (SEM) and current-voltage measurements that the granular structure of the samples is the main reason for the lack of true global superconductivity for thicknesses below 300 nm.

  17. Superconductive niobium films coating carbon nanotube fibers

    International Nuclear Information System (INIS)

    Superconducting niobium (Nb) has been successfully obtained by sputter deposition on carbon nanotube fibers. The transport properties of the niobium coating the fibers are compared to those of niobium thin films deposited on oxidized Si substrates during the same deposition run. For niobium films with thicknesses above 300 nm, the niobium coating the fibers and the thin films show similar normal state and superconducting properties with critical current density, measured at T = 4.2 K, of the order of 105 A cm−2. Thinner niobium layers coating the fibers also show the onset of the superconducting transition in the resistivity versus temperature dependence, but zero resistance is not observed down to T = 1 K. We evidence by scanning electron microscopy (SEM) and current-voltage measurements that the granular structure of the samples is the main reason for the lack of true global superconductivity for thicknesses below 300 nm. (paper)

  18. Cathodoluminescence in Quaternary carbonate deposits

    Science.gov (United States)

    Braithwaite, Colin J. R.

    2016-05-01

    The cathodoluminescent oscillatory and sectoral growth zones common in crystals formed in ancient limestone successions in a variety of putative environments appear to be rare or absent from Recent and Pleistocene marine carbonate sequences. The factors controlling cathodoluminescence and reasons for this disparity are examined. The cathodoluminescent zones in the cements of ancient rocks have been interpreted as responses to variations in the redox potential of formative pore waters during crystal growth; although similar cathodoluminescent behaviour is recorded from some deposits, including travertines and Quaternary speleothems, formed in what are thought to have been strongly oxidizing environments. The apparent absence of cathodoluminescence in the most Recent and Pleistocene marine deposits, that presumably reflect deposition and diagenesis in environments that are also characteristically oxidized, therefore seems anomalous. The controlling influences on cathodoluminescence are reviewed, together with evidence relating to observations of Pleistocene marine deposits and likely conditions of formation but, where it is present, the mechanism(s) for its development remain elusive.

  19. Protective film formation of carbon steel surfaces for corrosion and deposit control in Heavy Water Plant, Manuguru (Paper No. 1.1)

    International Nuclear Information System (INIS)

    Heavy Water Plant, Manuguru based on H2S-H2O bi-thermal chemical exchange process employs carbon steel as major material of construction for towers and piping. Several different phases of iron sulphide form as a result of interaction between aqueous H2S and carbon steel. Development of a procedure for formation of stable film on carbon steel as a preconditioning step was carried out based on work done by Heavy Water Division and the experiences of HWP, Kota. Heavy Water Plant, Manuguru was designed for carrying protective film formation of entire exchange unit including vessels, tanks, pipings etc. under dynamic conditions. This paper describes the procedure followed for the protective film formation of carbon steel surfaces at HWP, Manuguru. (author). 2 refs., 3 tabs., 2 figs

  20. 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)

  1. Thin film deposition on powder surfaces using atmospheric pressure discharge

    International Nuclear Information System (INIS)

    The deposition of SiOx containing films on NaCl and KBr particles in dielectric barrier discharge under atmospheric pressure was investigated. As precursor hexamethyldisiloxane (HMDSO) and tetraethoxysilane (TEOS) in argon-oxygen gas mixtures were used. The deposited layers were studied by means of light microscopy, SEM and XPS investigations. The particles could be completely covered by SiOx. With increasing oxygen content in the coating the carbon content decreases

  2. Deposition of thin films of multicomponent materials

    Science.gov (United States)

    Thakoor, Sarita (Inventor)

    1993-01-01

    Composite films of multicomponent materials, such as oxides and nitrides, e.g., lead zirconate titanate, are deposited by dc magnetron sputtering, employing a rotating substrate holder, which rotates relative to a plurality of targets, one target for each metal element of the multicomponent material. The sputtering is carried out in a reactive atmosphere. The substrates on which the layers are deposited are at ambient temperature. Following deposition of the composite film, the film is heated to a temperature sufficient to initiate a solid state reaction and form the final product, which is substantially single phase and substantially homogeneous.

  3. 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.

  4. Dry-transfer of chemical vapour deposited nanocarbon thin films

    OpenAIRE

    Cole, Matthew Thomas

    2012-01-01

    This thesis presents the development of chemical vapour deposited (CVD) graphene and multi-walled carbon nanotubes (MWCNTs) as enabling technologies for flexible transparent conductors offering enhanced functionality. The technologies developed could be employed as thin film field emission sources, optical sensors and substrate-free wideband optical polarisers. Detailed studies were performed on CVD Fe and Ni catalysed carbon nanotubes and nanofibres on indium tin oxide, alu...

  5. Carbonate Deposition on Antarctic Shelves

    Science.gov (United States)

    Frank, T. D.; James, N. P.; Malcolm, I.

    2011-12-01

    Limestones associated with glaciomarine deposits occur throughout the geologic record but remain poorly understood. The best-described examples formed during major ice ages of the Neoproterozoic and Late Paleozoic. Quaternary analogs on Antarctic shelves have received comparatively little study. Here, we report on the composition, spatial distribution, and stratigraphic context of carbonate sediments contained in piston cores from the Ross Sea. The goals of this work are to (1) document the nature and distribution of carbonate sediments on the Ross Sea continental shelf and (2) examine temporal relationships to Quaternary glaciation. Results will be used to develop criteria that will improve understanding of analogous deposits in the ancient record. All carbonate-rich intervals in piston cores from the Ross Rea, now housed at the Antarctic Marine Geology Research Facility at Florida State University, were examined and described in detail. Sediment samples were disaggregated and sieved into size fractions before description with paleontological analysis carried out on the coarsest size fraction (>250 microns). Carbonate-rich sediments are concentrated in the northwestern Ross Sea, along the distal margins of Mawson and Pennell Banks. Calcareous facies include a spectrum of lithologies that range from fossiliferous mud, sand, and gravel to skeletal floatstone-rudstone and bafflestone. Floatstone-rudstone and bafflestone is most abundant along western-facing slopes in areas protected from the Antarctic Coastal Current. Sand-prone facies dominate the tops of banks and mud-prone, often spicultic, facies occur in deeper areas. The carbonate factory is characterized by a low-diversity, heterozoan assemblage that is dominated by stylasterine hydrocorals, barnacles, and bryozoans. Molluscs and echinoids are present but not abundant. Planktic and benthic foraminifera are ubiquitous components of the sediment matrix, which is locally very rich in sponge spicules. Biota rarely

  6. Ferroelectric thin films deposited by pulsed laser deposition

    Science.gov (United States)

    Dinu, Raluca; Vrejoiu, I.; Verardi, P.; Craciun, F.; Dinescu, Maria

    2001-06-01

    Influence of substrate and electrode on the properties of PbZr0.53Ti0.47O3 (PZT) thin films grown by pulsed laser deposition technique (1060 nm wavelength Nd:YAG laser light, 10 ns pulse duration, 10 Hz repetition rate, 0.35 J/pulse, 25 J/cm2 laser fluence, deposition rate about 1 angstrom/pulse) was studied. The substrate temperatures were in the range 380 degree(s)C-400 degree(s)C. Oriented crystalline PZT layers with 1-3 micrometers thickness were deposited on glass substrates plated with Au/Pt/NiCr electrodes, from a PZT commercial target in oxygen reactive atmosphere. The deposited PZT films with perovskite structure were preferentially oriented along the (111) direction as revealed from XRD spectra. Piezoelectric d33 coefficients up to 30 pC/N were obtained on as deposited films. Ferroelectric hysteresis loops at 100 Hz revealed a remanent polarization of 15 (mu) C/cm2 and a coercive field of 100 kV/cm. A comparison with properties of PZT films deposited using a KrF laser and with SrBi2Ta2O9 (SBT) films is reported.

  7. Antimicrobial Properties of Diamond-Like Carbon/Silver Nanocomposite Thin Films Deposited on Textiles: Towards Smart Bandages

    OpenAIRE

    Tadas Juknius; Modestas Ružauskas; Tomas Tamulevičius; Rita Šiugždinienė; Indrė Juknienė; Andrius Vasiliauskas; Aušrinė Jurkevičiūtė; Sigitas Tamulevičius

    2016-01-01

    In the current work, a new antibacterial bandage was proposed where diamond-like carbon with silver nanoparticle (DLC:Ag)-coated synthetic silk tissue was used as a building block. The DLC:Ag structure, the dimensions of nanoparticles, the silver concentration and the silver ion release were studied systematically employing scanning electron microscopy, energy dispersive X-ray spectroscopy and atomic absorption spectroscopy, respectively. Antimicrobial properties were investigated using micro...

  8. 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)

  9. Optical and mechanical characterization of zirconia-carbon nanocomposite films

    International Nuclear Information System (INIS)

    The focus of the present work is the study of carbon co-deposition effect on the optical and mechanical properties of zirconia films. Optical and dielectric constant, band gap and transition lifetime of such composite systems were determined, as well as their elasticity properties. The thin ZrO2-x-C films were sputter-deposited on silicon and polycarbonate, from a pure ZrO2 and graphite targets in a radio-frequency argon plasma. Besides the zirconia phase and crystalline parameter changes induced by carbon addition, the electronic properties to the films were significantly modified: a drastical optical gap lowering was observed along an increased electronic dielectric constant and refractive index. The invariance of the film elasticity modulus and the similarity of the optical transition lifetime values with those of pure amorphous carbon films indicate an immiscibility of the ceramic and carbon components of the film structure

  10. Optical and mechanical characterization of zirconia-carbon nanocomposite films

    Energy Technology Data Exchange (ETDEWEB)

    Laidani, N. [ITC-IRST, Divisione Fisica-Chimica delle Superfici ed Interfacce, Via Sommarive 18, 38050 Povo (Trento) (Italy)], E-mail: laidani@itc.it; Micheli, V.; Bartali, R.; Gottardi, G.; Anderle, M. [ITC-IRST, Divisione Fisica-Chimica delle Superfici ed Interfacce, Via Sommarive 18, 38050 Povo (Trento) (Italy)

    2008-02-15

    The focus of the present work is the study of carbon co-deposition effect on the optical and mechanical properties of zirconia films. Optical and dielectric constant, band gap and transition lifetime of such composite systems were determined, as well as their elasticity properties. The thin ZrO{sub 2-x}-C films were sputter-deposited on silicon and polycarbonate, from a pure ZrO{sub 2} and graphite targets in a radio-frequency argon plasma. Besides the zirconia phase and crystalline parameter changes induced by carbon addition, the electronic properties to the films were significantly modified: a drastical optical gap lowering was observed along an increased electronic dielectric constant and refractive index. The invariance of the film elasticity modulus and the similarity of the optical transition lifetime values with those of pure amorphous carbon films indicate an immiscibility of the ceramic and carbon components of the film structure.

  11. A comparison study between atomic and ionic nitrogen doped carbon films prepared by ion beam assisted cathode arc deposition at various pulse frequencies

    International Nuclear Information System (INIS)

    A comparison study of microstructure and bonds composition of carbon nitride (CNx) films fabricated at atomic and ionic nitrogen source by pulse cathode arc method was presented. The relative fractions of CN/CC bonds, N-sp3C/N-sp2C and graphite-like/pyridine-like N bonding configurations in the CN films were evaluated by combining C1s and N1s X-ray photoelectron spectroscopy with the hardness and optical band gap measurement. The dependence of microstructure (quantity, size and disordering degree of Csp2 clusters) of CNx films on the nitrogen source and pulse frequency was determined by Raman spectroscopy. Films with high atomic ratio of nitrogen/carbon (0.17) and high hardness were produced at ionic nitrogen source and low pulse frequency. The results showed that ionic nitrogen source facilitated the formation of CN bonds and N-sp2C bonding configurations (mainly in graphite-like N form). Moreover presenting an optimum pulse frequency (∼10 Hz) leaded to the most nitrogen coordinated with sp3-C and the highest ratio of CN/CC bonds in the CNx films. An equilibrium action mechanism might exist between the quantity and energy of carbon and nitrogen ions/atoms, giving more nitrogen-incorporated carbon materials. These allow us to obtain the high content of N-Csp3 bonding and expected bonding structure by optimizing pulse frequency and nitrogen source.

  12. Electrophoretic deposition of tannic acid-polypyrrolidone films and composites.

    Science.gov (United States)

    Luo, Dan; Zhang, Tianshi; Zhitomirsky, Igor

    2016-05-01

    Thin films of polyvinylpyrrolidone (PVP)-tannic acid (TA) complexes were prepared by a conceptually new strategy, based on electrophoretic deposition (EPD). Proof of concept investigations involved the analysis of the deposition yield, FTIR and UV-vis spectroscopy of the deposited material, and electron microscopy studies. The analysis of the deposition mechanism indicated that the limitations of the EPD in the deposition of small phenolic molecules, such as TA, and electrically neutral polymers, similar to PVP, containing hydrogen-accepting carbonyl groups, can be avoided. The remarkable adsorption properties of TA and film forming properties of the PVP-TA complexes allowed for the EPD of materials of different types, such as huntite mineral platelets and hydrotalcite clay particles, TiO2 and MnO2 oxide nanoparticles, multiwalled carbon nanotubes, TiN and Pd nanoparticles. Moreover, PVP-TA complexes were used for the co-deposition of different materials and formation of composite films. In another approach, TA was used as a capping agent for the hydrothermal synthesis of ZnO nanorods, which were then deposited by EPD using PVP-TA complexes. The fundamental adsorption and interaction mechanisms of TA involved chelation of metal atoms on particle surfaces with galloyl groups, π-π interactions and hydrogen bonding. The films prepared by EPD can be used for various applications, utilizing functional properties of TA, PVP, inorganic and organic materials of different types and their composites. PMID:26878711

  13. Perovskite Thin Films via Atomic Layer Deposition

    KAUST Repository

    Sutherland, Brandon R.

    2014-10-30

    © 2014 Wiley-VCH Verlag GmbH & Co. KGaA. (Graph Presented) A new method to deposit perovskite thin films that benefit from the thickness control and conformality of atomic layer deposition (ALD) is detailed. A seed layer of ALD PbS is place-exchanged with PbI2 and subsequently CH3NH3PbI3 perovskite. These films show promising optical properties, with gain coefficients of 3200 ± 830 cm-1.

  14. Thin film deposition with time varying temperature

    OpenAIRE

    de Assis, T. A.; Reis, F. D. A. A.

    2013-01-01

    We study the effects of time-dependent substrate/film temperature in the deposition of a mesoscopically thick film using a statistical model that accounts for diffusion of adatoms without lateral neighbors whose coefficients depend on an activation energy and temperature. Dynamic scaling with fixed temperature is extended to predict conditions in which the temperature variation significantly affects surface roughness scaling. It agrees with computer simulation results for deposition of up to ...

  15. Characterization of Thin Films Deposited with Precursor Ferrocene by Plasma Enhanced Chemical Vapour Deposition

    Institute of Scientific and Technical Information of China (English)

    YAO Kailun; ZHENG Jianwan; LIU Zuli; JIA Lihui

    2007-01-01

    In this paper,the characterization of thin films,deposited with the precursor ferrocene(FcH)by the plasma enhanced chemical vapour deposition(PECVD)technique,was investigated.The films were measured by Scanning Electronic Microscopy(SEM),Atomic Force Microscopy(AFM),Electron Spectroscopy for Chemical Analysis(ESCA),and superconducting Quantum Interference Device(SQUID).It was observed that the film's layer is homogeneous in thickness and has a dense morphology without cracks.The surface roughness is about 36 nm.From the results of ESCA,it can be inferred that the film mainly contains the compound FeOOH,and carbon is combined with oxygen in different forms under different supply-powers.The hysteresis loops indicate that the film is of soft magnetism.

  16. Impact wear resistance of silicon, oxygen and nitrogen containing amorphous carbon films deposited on steel substrates using PECVD

    Czech Academy of Sciences Publication Activity Database

    Fořt, Tomáš; Sobota, Jaroslav; Grossman, Jan; Bursíková, V.; Dupák, Libor; Peřina, Vratislav; Klapetek, P.; Buršík, Jiří

    Cancún : ICPIG2009 Local Organizing Committee, 2009 - (de Urquijo, J.), PB13-13:1-4 ISBN 978-1-61567-694-1. [International Conference on Phenomena in Ionized Gases (ICPIG) /29./. Cancun (MX), 12.07.2009-17.07.2009] R&D Projects: GA ČR GA202/07/1669; GA AV ČR KAN311610701 Institutional research plan: CEZ:AV0Z20650511; CEZ:AV0Z10480505; CEZ:AV0Z20410507 Keywords : PECVD * diamond-like carbon coatings Subject RIV: BL - Plasma and Gas Discharge Physics http://www.icpig2009.unam.mx/pdf/PB13-13.pdf

  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. Structural morphology of amorphous conducting carbon film

    Indian Academy of Sciences (India)

    P N Vishwakarma; V Prasad; S V Subramanyam; V Ganesan

    2005-10-01

    Amorphous conducting carbon films deposited over quartz substrates were analysed using X-ray diffraction and AFM technique. X-ray diffraction data reveal disorder and roughness in the plane of graphene sheet as compared to that of graphite. This roughness increases with decrease in preparation temperature. The AFM data shows surface roughness of carbon films depending on preparation temperatures. The surface roughness increases with decrease in preparation temperature. Also some nucleating islands were seen on the samples prepared at 900°C, which are not present on the films prepared at 700°C. Detailed analysis of these islands reveals distorted graphitic lattice arrangement. So we believe these islands to be nucleating graphitic. Power spectrum density (PSD) analysis of the carbon surface indicates a transition from the nonlinear growth mode to linear surface-diffusion dominated growth mode resulting in a relatively smoother surface as one moves from low preparation temperature to high preparation temperature. The amorphous carbon films deposited over a rough quartz substrate reveal nucleating diamond like structures. The density of these nucleating diamond like structures was found to be independent of substrate temperature (700–900°C).

  19. CVD growth and field emission properties of nanostructured carbon films

    International Nuclear Information System (INIS)

    An investigation of the growth mechanisms, electronical and structural properties, and field emissions of carbon films obtained by chemical vapour deposition showed that field emissions from films composed of spatially oriented carbon nanotubes and plate-like graphite nanocrystals exhibit non-metallic behaviour. The experimental evidence of work function local reduction for carbon film materials is reported here. A model of the emission site is proposed and the mechanism of field emission from nanostructured carbon materials is described. In agreement with the model proposed here, the electron emission in different carbon materials results from sp3-like defects in an sp2 network of their graphite-like component. (author)

  20. Post deposition purification of PTCDA thin films

    International Nuclear Information System (INIS)

    The decomposition of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) molecules during evaporation of unpurified raw material in ultra high vacuum was studied. The fragments were identified by mass spectrometry and the influence of these fragments and further contaminations of the raw material on the electronic structure of PTCDA thin films was measured by photoemission spectroscopy. Annealing of contaminated PTCDA films was tested as cheap and easy to perform method for (partial) post deposition purification of the contaminated films

  1. Ultraviolet laser deposition of graphene thin films without catalytic layers

    KAUST Repository

    Sarath Kumar, S. R.

    2013-01-09

    In this letter, the formation of nanostructured graphene by ultraviolet laser ablation of a highly ordered pyrolytic graphite target under optimized conditions is demonstrated, without a catalytic layer, and a model for the growth process is proposed. Previously, graphene film deposition by low-energy laser (2.3 eV) was explained by photo-thermal models, which implied that graphene films cannot be deposited by laser energies higher than the C-C bond energy in highly ordered pyrolytic graphite (3.7 eV). Here, we show that nanostructured graphene films can in fact be deposited using ultraviolet laser (5 eV) directly over different substrates, without a catalytic layer. The formation of graphene is explained by bond-breaking assisted by photoelectronic excitation leading to formation of carbon clusters at the target and annealing out of defects at the substrate.

  2. Ion plating technique improves thin film deposition

    Science.gov (United States)

    Mattox, D. M.

    1968-01-01

    Ion plating technique keeps the substrate surface clean until the film is deposited, allows extensive diffusion and chemical reaction, and joins insoluble or incompatible materials. The technique involves the deposition of ions on the substrate surface while it is being bombarded with inert gas ions.

  3. Microwave-enhanced thin-film deposition

    Science.gov (United States)

    Chitre, S.

    1984-01-01

    The deposition of semiconducting and insulating thin films at low temperatures using microwave technology was explored. The method of plasma formations, selection of a power source, the design of the microwave plasma cavity, the microwave circuitry, impedance matching, plasma diagnostics, the deposition chamber and the vacuum system were studied.

  4. Characterization of titanium oxynitride films deposited by low pressure chemical vapor deposition using amide Ti precursor

    Energy Technology Data Exchange (ETDEWEB)

    Song Xuemei; Gopireddy, Deepthi [Department of Chemical Engineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States); Takoudis, Christos G. [Department of Chemical Engineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States); Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States)], E-mail: takoudis@uic.edu

    2008-07-31

    In this study, we investigate the use of an amide-based Ti-containing precursor, namely tetrakis(diethylamido)titanium (TDEAT), for TiN{sub x}O{sub y} film deposition at low temperature. Traditionally, alkoxide-based Ti-containing precursor, such as titanium tetra-isopropoxide (TTIP), along with NH{sub 3} is used for titanium oxynitride (TiN{sub x}O{sub y}) film deposition. When TTIP is used, at low temperatures it is difficult to form TiN{sub x}O{sub y} films with high N/O ratios. In this study, by using TDEAT, TiN{sub x}O{sub y} films are deposited on H-passivated Si (100) substrates in a cold wall reactor at 300 {sup o}C and 106 Pa. Rutherford backscattering spectroscopy analysis shows nitrogen incorporation in the TiN{sub x}O{sub y} films to be as high as 28 at.%. X-ray photoelectron spectroscopy analysis of as-deposited films confirms the formation of{sub .} TiN{sub x}O{sub y}, while Fourier transform infrared and Raman spectra indicate that the films have amorphous structure. Moreover, there is no detectable bulk carbon impurity and no SiO{sub 2} formation at the TiN{sub x}O{sub y}/Si interface. Upon annealing the as-deposited films in air at 750 deg. C for 30 min, they oxidize to TiO{sub 2} and crystallize to form a rutile structure with a small amount of anatase phase. Based on these results, TDEAT appears to be a promising precursor for both TiN{sub x}O{sub y} and TiO{sub 2} film deposition.

  5. Antimicrobial Properties of Diamond-Like Carbon/Silver Nanocomposite Thin Films Deposited on Textiles: Towards Smart Bandages

    Directory of Open Access Journals (Sweden)

    Tadas Juknius

    2016-05-01

    Full Text Available In the current work, a new antibacterial bandage was proposed where diamond-like carbon with silver nanoparticle (DLC:Ag-coated synthetic silk tissue was used as a building block. The DLC:Ag structure, the dimensions of nanoparticles, the silver concentration and the silver ion release were studied systematically employing scanning electron microscopy, energy dispersive X-ray spectroscopy and atomic absorption spectroscopy, respectively. Antimicrobial properties were investigated using microbiological tests (disk diffusion method and spread-plate technique. The DLC:Ag layer was stabilized on the surface of the bandage using a thin layer of medical grade gelatin and cellulose. Four different strains of Staphylococcus aureus extracted from humans’ and animals’ infected wounds were used. It is demonstrated that the efficiency of the Ag+ ion release to the aqueous media can be increased by further RF oxygen plasma etching of the nanocomposite. It was obtained that the best antibacterial properties were demonstrated by the plasma-processed DLC:Ag layer having a 3.12 at % Ag surface concentration with the dominating linear dimensions of nanoparticles being 23.7 nm. An extra protective layer made from cellulose and gelatin with agar contributed to the accumulation and efficient release of silver ions to the aqueous media, increasing bandage antimicrobial efficiency up to 50% as compared to the single DLC:Ag layer on textile.

  6. Multiwalled carbon nanotube film for strain sensing

    International Nuclear Information System (INIS)

    We have studied the possibility of using multiwalled carbon nanotube (MWCNT) films as strain sensors. The MWCNT films were prepared by a solution/filtration method and were bonded directly onto specimens by a nonconductive adhesive. For comparison, conventional foil strain gages were also bonded to the structure on the opposite side. The specimens then underwent a uniaxial tensile load-unload cycle to evaluate them as strain sensors. To ensure good electrical contact between carbon nanotube film and the wires, a thin layer of copper was thermally deposited on both ends of the film as electrodes, and the wires were connected to the electrodes by silver ink. Wheatstone bridges were used to convert the resistance changes of the MWCNTs to voltage output. Results indicated that the output voltages were proportional to the strain readings from the stain indicator. The effect of temperature on the resistance was measured and the MWCNT film resistance was found to be independent of temperature over the range 273-363 K. The optimal film dimension for strain sensing was evaluated as well. Dynamic tests suggest that the MWCNTs were able to extract the structural signature. Our results indicate that MWCNT film is potentially useful for structural health monitoring and vibration control applications

  7. Tribological studies of amorphous hydrogenated carbon films in a vacuum, spacelike environment

    Science.gov (United States)

    Miyoshi, Kazuhisa

    1991-01-01

    Recent work on the adhesion and friction properties of plasma-deposited amorphous hydrogenated carbon films and their dependence on preparation conditions are reviewed. The results of the study indicate that plasma deposition enables one to deposit a variety of amorphous hydrogenated carbon (a-C:H) exhibiting diamondlike friction behavior. The plasma-deposited a-C:H films can be effectively used as hard lubricating films on ceramic materials such as silicon nitride in vacuum.

  8. Growth of graphene films from non-gaseous carbon sources

    Science.gov (United States)

    Tour, James; Sun, Zhengzong; Yan, Zheng; Ruan, Gedeng; Peng, Zhiwei

    2015-08-04

    In various embodiments, the present disclosure provides methods of forming graphene films by: (1) depositing a non-gaseous carbon source onto a catalyst surface; (2) exposing the non-gaseous carbon source to at least one gas with a flow rate; and (3) initiating the conversion of the non-gaseous carbon source to the graphene film, where the thickness of the graphene film is controllable by the gas flow rate. Additional embodiments of the present disclosure pertain to graphene films made in accordance with the methods of the present disclosure.

  9. Large-Scale Graphene Film Deposition for Monolithic Device Fabrication

    Science.gov (United States)

    Al-shurman, Khaled

    and on the silicon-based substrate. Large- area bilayer graphene film was formed on silicon based platform. COMSOL Multiphysics was used to investigate the CVD graphene growth on Ni films. Factors affecting CVD graphene synthesis include carbon solubility in Ni, growth time, growth temperature, as well as Ni film thickness. COMSOL model uses transport of diluted species, heat transfer in Ni thin film as well as deformed geometry module. In this particular research, the number of simulated graphene layers on Ni film was compared with experimental data. Also, the effect of many CVD parameters on graphene film fabrication is stated. In conclusion, a novel method for direct large-scale graphene film fabrication on silicon based platform at low temperature was achieved using hot-filament chemical vapor deposition.

  10. Preparation and analysis of amorphous carbon films deposited from (C6H12)/Ar/He chemistry for application as the dry etch hard mask in the semiconductor manufacturing process

    International Nuclear Information System (INIS)

    Amorphous carbon layers (ACL) were deposited on Si (100) wafers by plasma enhanced chemical vapor deposition (PECVD) by using 1-hexene (C6H12) as a carbon source for dry etch hard mask of semiconductor devices manufacturing process. The deposition characteristics and film properties were investigated by means of ellipsometry, Raman spectroscopy, X-ray photo electron spectroscopy (XPS) and stress analysis. Hardness, Young's modulus, and surface roughness of ACL deposited at 550 deg. C were investigated by using nano-indentation and AFM. The deposition rate was decreased from 5050 A/min to 2160 A/min, and dry etch rate was decreased from 2090 A/min to 1770 A/min, and extinction coefficient was increased from 0.1 to 0.5. Raman analysis revealed a higher shift of the G-peak and a lower shift of the D-peak and the increase of I(D)/I(G) ratio as the deposition temperature was increased from 350 deg. C to 550 deg. C. XPS results of ACL deposited at 550 deg. C revealed a carbon 1s binding energy of 284.4 eV. The compressive film stress was decreased from 2.95 GPa to 1.28 GPa with increasing deposition temperature. The hardness and Young's modulus of ACL deposited at 550 deg. C were 5.8 GPa and 48.7 GPa respectively. The surface roughness RMS of ACL deposited at 550 deg. C was 2.24 A, and that after cleaning in diluted HF solution (H2O:HF = 200:1), SC1 (NH4OH:H2O2:H2O = 1:4:20) solution, and sulfuric acid solution (H2SO4:H2O2 = 6:1) was 2.28 A, 2.30 A and 7.34 A, respectively. The removal amount of ACL deposited at 550 deg. C in diluted HF solution, SC1 solution and sulfuric acid solution was 6 A, 36 A and 110 A, respectively. These results demonstrated the viability of ACL deposited by PECVD from C6H12 at 550 deg. C for application as the dry etch hard mask in fabrication of semiconductor devices.

  11. Preparation and analysis of amorphous carbon films deposited from (C{sub 6}H{sub 12})/Ar/He chemistry for application as the dry etch hard mask in the semiconductor manufacturing process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seungmoo [Department of Materials Science and Engineering, Korea University, Seoul, 136-701 (Korea, Republic of); TC Technology Team, Samsung Electronics Co. Ltd., Gyeounggi-Do, 446-711 (Korea, Republic of); Won, Jaihyung; Choi, Jongsik [TC Technology Team, Samsung Electronics Co. Ltd., Gyeounggi-Do, 446-711 (Korea, Republic of); Jang, Samseok [Department of Materials Science and Engineering, Korea University, Seoul, 136-701 (Korea, Republic of); Jee, Yeonhong; Lee, Hyeondeok [TC Technology Team, Samsung Electronics Co. Ltd., Gyeounggi-Do, 446-711 (Korea, Republic of); Byun, Dongjin, E-mail: dbyun@korea.ac.kr [Department of Materials Science and Engineering, Korea University, Seoul, 136-701 (Korea, Republic of)

    2011-08-01

    Amorphous carbon layers (ACL) were deposited on Si (100) wafers by plasma enhanced chemical vapor deposition (PECVD) by using 1-hexene (C{sub 6}H{sub 12}) as a carbon source for dry etch hard mask of semiconductor devices manufacturing process. The deposition characteristics and film properties were investigated by means of ellipsometry, Raman spectroscopy, X-ray photo electron spectroscopy (XPS) and stress analysis. Hardness, Young's modulus, and surface roughness of ACL deposited at 550 deg. C were investigated by using nano-indentation and AFM. The deposition rate was decreased from 5050 A/min to 2160 A/min, and dry etch rate was decreased from 2090 A/min to 1770 A/min, and extinction coefficient was increased from 0.1 to 0.5. Raman analysis revealed a higher shift of the G-peak and a lower shift of the D-peak and the increase of I(D)/I(G) ratio as the deposition temperature was increased from 350 deg. C to 550 deg. C. XPS results of ACL deposited at 550 deg. C revealed a carbon 1s binding energy of 284.4 eV. The compressive film stress was decreased from 2.95 GPa to 1.28 GPa with increasing deposition temperature. The hardness and Young's modulus of ACL deposited at 550 deg. C were 5.8 GPa and 48.7 GPa respectively. The surface roughness RMS of ACL deposited at 550 deg. C was 2.24 A, and that after cleaning in diluted HF solution (H{sub 2}O:HF = 200:1), SC1 (NH{sub 4}OH:H{sub 2}O{sub 2}:H{sub 2}O = 1:4:20) solution, and sulfuric acid solution (H{sub 2}SO{sub 4}:H{sub 2}O{sub 2} = 6:1) was 2.28 A, 2.30 A and 7.34 A, respectively. The removal amount of ACL deposited at 550 deg. C in diluted HF solution, SC1 solution and sulfuric acid solution was 6 A, 36 A and 110 A, respectively. These results demonstrated the viability of ACL deposited by PECVD from C{sub 6}H{sub 12} at 550 deg. C for application as the dry etch hard mask in fabrication of semiconductor devices.

  12. Novel doped hydroxyapatite thin films obtained by pulsed laser deposition

    International Nuclear Information System (INIS)

    Highlights: ► HA coatings synthesized by pulsed laser deposition. ► Comparative study of commercial vs. animal origin materials. ► HA coatings of animal origin were rougher and more adherent to substrates. ► Animal origin films can be considered as promising candidates for implant coatings. - Abstract: We report on the synthesis of novel ovine and bovine derived hydroxyapatite thin films on titanium substrates by pulsed laser deposition for a new generation of implants. The calcination treatment applied to produce the hydroxyapatite powders from ovine/bovine bones was intended to induce crystallization and to prohibit the transmission of diseases. The deposited films were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy. Pull-off adherence and profilometry measurements were also carried out. X-ray diffraction ascertained the polycrystalline hydroxyapatite nature of the powders and films. Fourier transform infrared spectroscopy evidenced the vibrational bands characteristic to a hydroxyapatite material slightly carbonated. The micrographs of the films showed a uniform distribution of spheroidal particulates with a mean diameter of ∼2 μm. Pull-off measurements demonstrated excellent bonding strength values between the hydroxyapatite films and the titanium substrates. Because of their physical–chemical properties and low cost fabrication from renewable resources, we think that these new coating materials could be considered as a prospective competitor to synthetic hydroxyapatite used for implantology applications.

  13. Deposition of SiC thin films by PECVD

    CERN Document Server

    Cho, N I; Kim, C K

    1999-01-01

    The SiC films were deposited on Si substrate by the decomposition of CH sub 3 SiCl sub 3 (methylthrichlorosilane) molecules in a high frequency discharge field. From the Raman spectra, it is conjectured that the deposited film are formed into the polycrystalline structure. The photon absorption measurement reveal that the band gap of the electron energy state are to be 2.4 eV for SiC, and 2.6 eV for Si sub 0 sub . sub 4 C sub 0 sub . sub 6 , respectively. In the high power density regime, methyl-radicals decompose easily and increases the carbon concentration in plasma and result in the growing films.

  14. 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)

  15. Field Emission Properties of Nitrogen-doped Amorphous Carbon Films

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Nitrogen-doped amorphous carbon thin films are deposited on the ceramic substrates coated with Ti film by using direct current magnetron sputtering technique at N2 and Ar gas mixture atmosphere during deposition. The field emission properties of the deposited films have been investigated. The threshold field as low as 5.93V/μm is obtained and the maximum current density increases from 4μA/cm2 to 20.67μA/cm2 at 10.67V/μm comparing with undoped amorphous film. The results show that nitrogen doping plays an important role in field emission of amorphous carbon thin films.

  16. Low temperature CVD growth of ultrathin carbon films

    Science.gov (United States)

    Yang, Chao; Wu, Peng; Gan, Wei; Habib, Muhammad; Xu, Weiyu; Fang, Qi; Song, Li

    2016-05-01

    We demonstrate the low temperature, large area growth of ultrathin carbon films by chemical vapor deposition under atmospheric pressure on various substrates. In particularly, uniform and continuous carbon films with the thickness of 2-5 nm were successfully grown at a temperature as low as 500 oC on copper foils, as well as glass substrates coated with a 100 nm thick copper layer. The characterizations revealed that the low-temperature-grown carbon films consist on few short, curved graphene layers and thin amorphous carbon films. Particularly, the low-temperature grown samples exhibited over 90% transmittance at a wavelength range of 400-750 nm and comparable sheet resistance in contrast with the 1000oC-grown one. This low-temperature growth method may offer a facile way to directly prepare visible ultrathin carbon films on various substrate surfaces that are compatible with temperatures (500-600oC) used in several device processing technologies.

  17. Deposition and microstructure of pyrolytic carbon

    International Nuclear Information System (INIS)

    Two kinds of experiment concerning pyrolytic carbon deposition have been carried out. In one experiment, an attempt was made to coat alumina particles as well as buffer-coated UO2 particle with pyrolytic carbon of laminar structure by means of a fluidized bed technique. Benzene was used as the carbon source and the temperature was 10000C. In the other experiment, carbon deposition was made on graphite surface. Possibility was tested to obtain uniform coating along the direction of gas stream. Carbon source, in this case, was mainly n-hexane and the temperature ranged 750 -- 8500C. Microstructure of the deposit was studied in both experiments. (author)

  18. Growth processes and surface properties of diamondlike carbon films

    International Nuclear Information System (INIS)

    In this study, we compare the deposition processes and surface properties of tetrahedral amorphous carbon (ta-C) films from filtered pulsed cathodic arc discharge (PCAD) and hydrogenated amorphous carbon (a-C:H) films from electron cyclotron resonance (ECR)-plasma source ion implantation. The ion energy distributions (IEDs) of filtered-PCAD at various filter inductances and Ar gas pressures were measured using an ion energy analyzer. The IEDs of the carbon species in the absence of background gas and at low gas pressures are well fitted by shifted Maxwellian distributions. Film hardness and surface properties show a clear dependence on the IEDs. ta-C films with surface roughness at an atomic level and thin (0.3-0.9 nm) graphitelike layers at the film surfaces were deposited at various filter inductances in the highly ionized plasmas with the full width at half maximum ion energy distributions of 9-16 eV. The a-C:H films deposited at higher H/C ratios of reactive gases were covered with hydrogen and sp3 bonded carbon-enriched layers due to the simultaneous interaction of hydrocarbon species and atomic hydrogen. The effects of deposited species and ion energies on film surface properties were analyzed. Some carbon species have insufficient energies to break the delocalized π(nC) bonds at the graphitelike film surface, and they can govern film formation via surface diffusion and coalescence of nuclei. Dangling bonds created by atomic hydrogen lead to uniform chemisorption of hydrocarbon species from the ECR plasmas. The deposition processes of ta-C and a-C:H films are discussed on the basis of the experimental results

  19. Plasma enhanced chemical vapor deposition of zirconium nitride thin films

    International Nuclear Information System (INIS)

    Depositions of high quality zirconium nitride, (Zr3N4), films using the metal-organic precursor Zr(NEt2)4 were carried out in a microwave argon/ammonia plasma (2.45 GHz). The films were deposited on crystalline silicon wafers and quartz substrates at temperatures of 200--400 C. The transparent yellow films have resistivity values greater than MΩ cm. The stoichiometry is N/Zr = 1.3, with less than 5 atom % carbon and little or no oxygen. The hydrogen content is less than 9 atom %, and it does not vary with deposition temperature. The growth rates range from 600 to 1,200 angstrom/min, depending on the flow rates and precursor bubbler temperature. X-ray diffraction studies show a Zr3N4 film deposited at 400 C is polycrystalline with some (220) orientation. The crystallite size is approximately 30 angstrom. The band gap, as estimated from transmission spectra, is 3.1 eV

  20. Effect of the pulsed laser deposition conditions on the tribological properties of thin-film nanostructured coatings based on molybdenum diselenide and carbon

    Science.gov (United States)

    Fominskii, V. Yu.; Grigor'ev, S. N.; Romanov, R. I.; Nevolin, V. N.

    2012-04-01

    The structural state and tribological properties of gradient and composite antifriction coatings produced by pulsed laser codeposition from MoSe2(Ni) and graphite targets are studied. The coatings are deposited onto steel substrates in vacuum and an inert gas, and an antidrop shield is used to prevent the deposition of micron-size particles from a laser jet onto the coating. The deposition of a laser jet from the graphite target and the application of a negative potential to the substrate ensure additional high-energy atom bombardment of growing coatings. Comparative tribological tests performed at a relative air humidity of ˜50% demonstrate that the "drop-free" deposition of a laser-induced atomic flux in the shield shadow significantly improves the antifriction properties of MoSe x coatings, decreasing the friction coefficient from 0.07 to 0.04. The best tribological properties, which combine a low friction coefficient and high wear resistance, are detected in drop-free MoSe x coatings additionally alloyed with carbon (up to ˜55 at %) and subjected to effective bombardment by high-energy atoms during growth. Under these conditions, a dense nanocomposite structure containing the self-lubricating MoSe2 phase and an amorphous carbon phase with a rather high concentration of diamond bonds forms.

  1. Atomic layer deposition of Al{sub 2}O{sub 3} and Al{sub x}Ti{sub 1-x}O{sub y} thin films on N{sub 2}O plasma pretreated carbon materials

    Energy Technology Data Exchange (ETDEWEB)

    Markeev, Andrey M.; Chernikova, Anna G.; Chouprik, Anastasya A.; Zaitsev, Sergey A.; Ovchinnikov, Dmitry V.; Althues, Holger; Doerfler, Susanne [Moscow Institute of Physics and Technology, Institutskii per. 9, Dolgoprudny, Moscow Region 141700 (Russian Federation); Fraunhofer Institute for Material and Beam Technology (IWS) of Dresden, Winterbergstr. 28, Dresden 01277 (Germany)

    2013-01-15

    A mild N{sub 2}O plasma treatment technique (low power and low substrate temperature) for carbon materials' (including graphite and carbon nanotubes) functionalization followed by subsequent high-k dielectric atomic layer deposition (ALD) was developed. It was shown that N{sub 2}O plasma carbon functionalization leads to the formation of epoxide and carboxylic groups on the carbon surface which act as active centers for ALD and, as a result, conformal and uniform Al{sub 2}O{sub 3} and Ti{sub x}Al{sub 1-x}O{sub y} films' growth occurred on the carbon surfaces. It was shown that the electrical properties of multinary Ti{sub x}Al{sub 1-x}O{sub y} oxides are more promising in comparison to single Al{sub 2}O{sub 3} oxide. Some electrical properties of the Ti{sub x}Al{sub 1-x}O{sub y} films observed were a high dielectric constant {approx}19, low leakage current density (<3 Multiplication-Sign 10{sup -5} A/cm{sup 2} at 1 MV/cm), and high breakdown field ({approx}5.5 MV/cm).

  2. Processing of diamondlike carbon using plasma immersion ion deposition

    International Nuclear Information System (INIS)

    Plasma immersion ion deposition (PIID) has been used to synthesize hard amorphous hydrogenated carbon or diamondlike carbon (DLC) thin films on Si substrates with rf inductive plasmas of various Ar and C2H2 gas mixtures. The surface hardness and stress of the films were highly dependent on the magnitude of the total rf power and the pulse-bias duty factor. The ratios of the ion flux and the film deposition flux, Ji/Jd, were estimated and correlated with DLC film stress, hardness, and the amount of argon and hydrogen content retained. The DLC properties (hardness and film stress) were maximal when the Ji/Jd value ranged between 0.6 and 0.8. The balance between ion-energy transfer and relaxation in the surface and subsurface carbon atoms may explain the DLC growth in this work. The role of ion-current flux in the PIID process was found to be as important as it is in conventional ion beam assisted deposition processing. copyright 1999 American Vacuum Society

  3. The effect of humidity on the tribological behavior of diamond-like carbon (DLC) film coated on WC-Co by physical vapor deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Oezmen, Y.; Tanaka, A. [AIST, Tsukuba (Japan). Mech. Eng. Lab.; Sumiya, T. [Nanotec Co., Kasinoha, 277-0882, Kashiwa (Japan)

    2000-11-01

    DLC films have been coated by PVD on WC-Co substrate with and without Si interface. They have been tested under low ({proportional_to}20%) and high ({proportional_to}80%) humidity conditions by reciprocating friction and wear apparatus. For ascertaining the wear mechanism from the topographies of DLC films, optical and SEM images of wear tracks have been taken. Wear debris particles behave as an abrasive agent, depositing into the film and causing the start of failure. There are multiple wear mechanisms, such as fatigue, abrasion, etc., existing simultaneously in the wear of DLC film in both cases. Wear rate decreases as the total wear way increases. For the case of DLC coating without Si interface there is a good correlation between wear rate and friction coefficient. However, this harmony disappears for DLC/Si coating. A chemically activated process may be assumed as the controlling step in the micro crack propagation during the generation of a wear debris particle. The different tribological behaviors of the DLC coatings under different environmental conditions are explained. (orig.)

  4. Deposition of biopolymer films on micromechanical sensors

    DEFF Research Database (Denmark)

    Keller, Stephan Sylvest; Gammelgaard, Lene; Jensen, Marie P.;

    2011-01-01

    The influence of various parameters on the spray-coating of thin films of poly(l-lactide) (PLLA) was investigated. The optimized processing conditions were used for deposition of the biodegradable polymer on arrays of SU-8 microcantilevers. The resonance frequency of the cantilevers before and af...

  5. Uniform reflective films deposited on large surfaces

    Science.gov (United States)

    1966-01-01

    Specially designed baffle which intercepts varying amounts of the vapor stream from an evaporant source, vacuum deposits films of uniform thickness on large substrates, using a single small area evaporation source. A mirror coated by this method will have a reflectance as high as 82 percent at 1216 angstroms with a variation of only plus/minus 2 percent over the surface.

  6. Intrinsic graphene field effect transistor on amorphous carbon films

    OpenAIRE

    Tinchev, Savcho

    2013-01-01

    Fabrication of graphene field effect transistor is described which uses an intrinsic graphene on the surface of as deposited hydrogenated amorphous carbon films. Ambipolar characteristic has been demonstrated typical for graphene devices, which changes to unipolar characteristic if the surface graphene was etched in oxygen plasma. Because amorphous carbon films can be growth easily, with unlimited dimensions and no transfer of graphene is necessary, this can open new perspective for graphene ...

  7. A versatile new method for synthesis and deposition of doped, visible light-activated TiO2 thin films

    DEFF Research Database (Denmark)

    In, Su-il; Kean, A.H.; Orlov, A.; Tikhov, M.S.; Lambert, R.M.

    2009-01-01

    A flexible and widely applicable method allows the deposition of carbon-doped visible light-activated photocatalytic TiO2 thin films on a variety of substrates.......A flexible and widely applicable method allows the deposition of carbon-doped visible light-activated photocatalytic TiO2 thin films on a variety of substrates....

  8. Photoluminescence and Raman Spectroscopy Studies of Carbon Nitride Films

    OpenAIRE

    Hernández-Torres, J.; Gutierrez-Franco, A.; P. G. González; L. García-González; Hernandez-Quiroz, T.; Zamora-Peredo, L.; V.H. Méndez-García; A. Cisneros-de la Rosa

    2016-01-01

    Amorphous carbon nitride films with N/C ratios ranging from 2.24 to 3.26 were deposited by reactive sputtering at room temperature on corning glass, silicon, and quartz as substrates. The average chemical composition of the films was obtained from the semiquantitative energy dispersive spectroscopy analysis. Photoluminescence measurements were performed to determine the optical band gap of the films. The photoluminescence spectra displayed two peaks: one associated with the substrate and the ...

  9. Coadsorption of nitric oxide and carbon monoxide on the nickel clusters deposited onto MgO(111) film formed on Mo(110)

    Science.gov (United States)

    Magkoev, Tamerlan T.

    2004-10-01

    Coadsorption of NO and CO molecules on the Ni clusters deposited on MgO(111) film formed on a Mo(110) crystal has been studied by reflection-absorption infrared spectroscopy (RAIRS) and temperature programmed desorption (TPD). It is found that adsorption of NO molecules strongly affects the state of CO molecules, which were initially adsorbed on the Ni clusters. The observed features in RAIRS and TPD spectra are attributed to the change of the CO adsorption site and geometry, which is induced by NO adsorption.

  10. Carbon Doped MgB2 Thin Films using TMB

    Science.gov (United States)

    Wilke, R. H. T.; Li, Qi; Xi, X. X.; Lamborn, D. R.; Redwing, J.

    2007-03-01

    The most effective method to enhance the upper critical field in MgB2 is through carbon doping. In the case of thin films, ``alloying'' with carbon has resulted in enhanced Hc2 values estimated to be as high as 70 T for H parallel to ab and 40 T for H perpendicular ab [1]. ``Alloying'' refers to the in-situ Hybrid Physical-Chemical Vapor Deposition (HPCVD) of carbon containing MgB2 films using (C5H5)2Mg as the carbon source. While these films exhibit enhanced Hc2 values, there are amorphous boron- carbon phases in the grain boundaries that reduce the cross section area for superconducting current. We present here the results of our attempts to make more homogeneously carbon doped thin films using gaseuous trimethyl-boron (TMB) as the carbon source. Initial results indicate different behavior upon carbon doping using TMB from carbon-alloying. The microstructures and upper critical fields of the carbon doped films using TMB and carbon alloyed films will be compared. [1] V. Braccini et al., Phys. Rev. B 71 (2005) 012504. [2] A.V. Pogrebnyakov et al., Appl. Phys. Lett 85 (2004) 2017.

  11. Influence of the diameter of single-walled carbon nanotube bundles on the optoelectronic performance of dry-deposited thin films

    Directory of Open Access Journals (Sweden)

    Kimmo Mustonen

    2012-10-01

    Full Text Available The optoelectronic performance of thin films of single-walled carbon nanotubes (SWCNTs was studied with respect to the properties of both individual nanotubes and their bundles. The SWCNTs were synthesized in a hot wire generator aerosol reactor, collected by gas filtration and dry-transferred onto various substrates. By thus completely avoiding liquid dispersion steps, we were able to avoid any artifacts from residual surfactants or sonication. We found that bundle lengths determined the thin-film performance, as would be expected for highly resistive bundle–bundle junctions. However, we found no evidence that contact resistances were affected by the bundle diameters, although they did play a secondary role by simply affecting the absorption. The individual SWCNT diameters and their graphitization level as gauged by the Raman D band intensity did not show any clear correlation with the overall performance.

  12. Measurement of 5-eV atomic oxygen using carbon-based films: preliminary results

    OpenAIRE

    White, C de B; Roberts, G. T.; Chambers, A.R.

    2005-01-01

    Carbon-based sensors have been developed to measure the atmospheric neutral atomic oxygen (AO) flux experienced by spacecraft in low Earth orbit. Thin- and thick-film carbon sensor elements were deposited onto an alumina substrate between thick-film gold tracks and silver palladium solder pads. AO flux is deduced by measuring resistance changes as the carbon film erodes and applying a simple theory. A wide range of responses were observed that are dependent on the deposition process and post ...

  13. Magnetic properties of LCMO deposited films

    Science.gov (United States)

    Park, Seung-Iel; Jeong, Kwang Ho; Cho, Young Suk; Kim, Chul Sung

    2002-04-01

    La-Ca-Mn-O films were deposited with various thickness (500, 1000 and 1500°C) by RF-magnetron sputtering at 700°C and by the spin coating of sol-gel method at 400°C on LaAlO 3(1 0 0) and Si(1 0 0) single-crystal substrates. The crystal structure and chemical composition of the film grown by RF sputtering method were orthorhombic and La 0.89Ca 0.11MnO 3, respectively, while the film prepared by sol-gel spin coating was cubic with La 0.7Ca 0.3MnO 3. The temperature dependence of the resistance for the film grown by RF sputtering method with the thickness of 1000°C shows that a semiconductor-metal transition occurs at 242 K. The relative maximum magnetoresistance is about 273% at 226 K.

  14. Laser annealing of amorphous carbon films

    International Nuclear Information System (INIS)

    Amorphous (a-C) Carbon thin films were deposited, using pulsed laser deposition (PLD) with a Nd:YAG laser (1064 nm, 7 ns), from a pyrolytic graphite target, on silicon and refractory metal (Mo) substrates to a film thickness of 55, 400 and 500 nm. Samples were grown at RT and then annealed by a laser annealing technique, to reduce residual stress and induce a locally confined 'graphitization' process. The films were exposed to irradiation, in vacuum, by a Nd:YAG pulsed laser, operating at different wavelengths (VIS, N-UV) and increasing values of energy from 6-100 mJ/pulse. The thinner films were completely destroyed by N-UV laser treatment also at lower energies, owing to the almost direct propagation of heat to the Si substrate with melting and ruinous blistering effects. For thicker films the Raman micro-analysis evidenced the influence of laser treatments on the sp3/sp2 content evolution, and established the formation of aromatic nano-structures of average dimension 4.1-4.7 nm (derived from the ID/IG peak ratio), at fluence values round 50 mJ/cm2 for N-UV and 165 mJ/cm2 for VIS laser irradiation. Higher fluences were not suitable for a-Carbon 'graphitization', since a strong ablation process was the prominent effect of irradiation. Grazing incidence XRD (GI-XRD) used to evaluate the dimension and texturing of nano-particles confirmed the findings of Raman analysis. The effects of irradiation on surface morphology were studied by SEM analysis

  15. Nitrogen doping in camphoric carbon films and its application to photovoltaic cell

    Energy Technology Data Exchange (ETDEWEB)

    Mominuzzaman, Sharif M. [Department of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology, Dhaka 1000 (Bangladesh); Rusop, Mohamad; Soga, Tetsuo; Jimbo, Takashi [Department of Environmental Technology and Urban Planning, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Umeno, Masayoshi [Department of Electronic Engineering, Chubu University, Kasugai 487-8501 (Japan)

    2006-11-23

    Carbon films have been deposited on quartz and single-crystal silicon substrates by pulsed laser deposition technique. The soot for the target was obtained from burning camphor, a natural source. The effect of nitrogen (N) incorporation in camphoric carbon film is investigated. Optical gap for the undoped film is about 0.95eV. The optical gap remains unchanged for low N content and decreases to about 0.7eV. With higher N content the optical gap increases. The resistivity of the carbon film is increased with N content initially and decreases with higher N content till the film is deposited at 30mTorr. The results indicate successful doping for the film deposited at low nitrogen content. The J-V characteristics of N-incorporated carbon/silicon photovoltaic cell under illumination are observed to improve upon N-incorporation in carbon layer. (author)

  16. Pulsed laser deposition of pepsin thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kecskemeti, G. [Department of Optics and Quantum Electronics, University of Szeged, H-6720 Szeged, Dom ter 9 (Hungary)]. E-mail: kega@physx.u-szeged.hu; Kresz, N. [Department of Optics and Quantum Electronics, University of Szeged, H-6720 Szeged, Dom ter 9 (Hungary); Smausz, T. [Hungarian Academy of Sciences and University of Szeged, Research Group on Laser Physics, H-6720 Szeged, Dom ter 9 (Hungary); Hopp, B. [Hungarian Academy of Sciences and University of Szeged, Research Group on Laser Physics, H-6720 Szeged, Dom ter 9 (Hungary); Nogradi, A. [Department of Ophthalmology, University of Szeged, H-6720, Szeged, Koranyi fasor 10-11 (Hungary)

    2005-07-15

    Pulsed laser deposition (PLD) of organic and biological thin films has been extensively studied due to its importance in medical applications among others. Our investigations and results on PLD of a digestion catalyzing enzyme, pepsin, are presented. Targets pressed from pepsin powder were ablated with pulses of an ArF excimer laser ({lambda} = 193 nm, FWHM = 30 ns), the applied fluence was varied between 0.24 and 5.1 J/cm{sup 2}. The pressure in the PLD chamber was 2.7 x 10{sup -3} Pa. The thin layers were deposited onto glass and KBr substrates. Our IR spectroscopic measurements proved that the chemical composition of deposited thin films is similar to that of the target material deposited at 0.5 and 1.3 J/cm{sup 2}. The protein digesting capacity of the transferred pepsin was tested by adapting a modified 'protein cube' method. Dissolution of the ovalbumin sections proved that the deposited layers consisted of catalytically active pepsin.

  17. Carbon nanotube forests growth using catalysts from atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Bingan; Zhang, Can; Esconjauregui, Santiago; Xie, Rongsi; Zhong, Guofang; Robertson, John [Department of Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom); Bhardwaj, Sunil [Istituto Officina dei Materiali-CNR Laboratorio TASC, s.s. 14, km 163.4, I-34012 Trieste (Italy); Sincrotone Trieste S.C.p.A., s.s. 14, km 163.4, I-34149 Trieste (Italy); Cepek, Cinzia [Istituto Officina dei Materiali-CNR Laboratorio TASC, s.s. 14, km 163.4, I-34012 Trieste (Italy)

    2014-04-14

    We have grown carbon nanotubes using Fe and Ni catalyst films deposited by atomic layer deposition. Both metals lead to catalytically active nanoparticles for growing vertically aligned nanotube forests or carbon fibres, depending on the growth conditions and whether the substrate is alumina or silica. The resulting nanotubes have narrow diameter and wall number distributions that are as narrow as those grown from sputtered catalysts. The state of the catalyst is studied by in-situ and ex-situ X-ray photoemission spectroscopy. We demonstrate multi-directional nanotube growth on a porous alumina foam coated with Fe prepared by atomic layer deposition. This deposition technique can be useful for nanotube applications in microelectronics, filter technology, and energy storage.

  18. Novel doped hydroxyapatite thin films obtained by pulsed laser deposition

    Science.gov (United States)

    Duta, L.; Oktar, F. N.; Stan, G. E.; Popescu-Pelin, G.; Serban, N.; Luculescu, C.; Mihailescu, I. N.

    2013-01-01

    We report on the synthesis of novel ovine and bovine derived hydroxyapatite thin films on titanium substrates by pulsed laser deposition for a new generation of implants. The calcination treatment applied to produce the hydroxyapatite powders from ovine/bovine bones was intended to induce crystallization and to prohibit the transmission of diseases. The deposited films were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy. Pull-off adherence and profilometry measurements were also carried out. X-ray diffraction ascertained the polycrystalline hydroxyapatite nature of the powders and films. Fourier transform infrared spectroscopy evidenced the vibrational bands characteristic to a hydroxyapatite material slightly carbonated. The micrographs of the films showed a uniform distribution of spheroidal particulates with a mean diameter of ∼2 μm. Pull-off measurements demonstrated excellent bonding strength values between the hydroxyapatite films and the titanium substrates. Because of their physical-chemical properties and low cost fabrication from renewable resources, we think that these new coating materials could be considered as a prospective competitor to synthetic hydroxyapatite used for implantology applications.

  19. Transparent ultrathin conducting carbon films

    International Nuclear Information System (INIS)

    Ultrathin conductive carbon layers (UCCLs) were created by spin coating resists and subsequently converting them to conductive films by pyrolysis. Homogeneous layers as thin as 3 nm with nearly atomically smooth surfaces could be obtained. Layer characterization was carried out with the help of atomic force microscopy, profilometry, four-point probe measurements, Raman spectroscopy and ultraviolet-visible spectroscopy. The Raman spectra and high-resolution transmission electron microscopy image indicated that a glassy carbon like material was obtained after pyrolysis. The electrical properties of the UCCL could be controlled over a wide range by varying the pyrolysis temperature. Variation in transmittance with conductivity was investigated for applications as transparent conducting films. It was observed that the layers are continuous down to a thickness below 10 nm, with conductivities of 1.6 x 104 S/m, matching the best values observed for pyrolyzed carbon films. Further, the chemical stability of the films and their utilization as transparent electrochemical electrodes has been investigated using cyclic voltammetry and electrochemical impedance spectroscopy.

  20. Deposit of thin films for Tokamaks conditioning

    International Nuclear Information System (INIS)

    discharge plasma, created in a calibrated mixture of methane-hydrogen during the hydrogenated amorphous carbon film deposit on the vessel wall of Novillo tokamak, were determined by mass spectrometry. By way of measuring the emission lines of the carbon and oxygen impurities in intense discharges, the time required by the plasma to interact with the wall was estimated. In addition to it, the temporal conduct of the emission line intensity of these impurities was observed by means of an intensified CCD detector. Once an ∼ 10 % of helium was introduced in the operating gas of the tokamak discharges, a 25-42 eV time variation of the electron temperature was measured using the intensity ratio technique. (Author)

  1. Engineering properties of superhard films with ion energy and post-deposition processing

    International Nuclear Information System (INIS)

    Recent developments in plasma synthesis of hard materials using energetic ions are described. Metal Plasma Immersion Ion Implantation and Deposition (MePIIID) has been used to prepare several hard films: from diamondlike carbon (DLC) to carbides, from nitrides to oxides. The energy of the depositing species is controlled to maximize adhesion as well as to change the physical and chemical properties of the films. Adhesion is promoted by the creation of a graded interface between the film and the substrate. The energy of the depositing ions is also used to modify and control the intrinsic stresses and the microstructure of the films. The deposition is carried out at room temperature, which is important for temperature sensitive substrates. A correlation between intrinsic stresses and the energetics of the deposition is presented for the case of DLC films, and means to reduce stress levels are discussed

  2. Study on re-sputtering during CNx film deposition through spectroscopic diagnostics of plasma

    International Nuclear Information System (INIS)

    A nitrogen-carbon plasma was generated during the deposition of carbon nitride (CNx) thin films by pulsed laser ablation of a graphite target in a discharge nitrogen plasma, and the optical emission of the generated nitrogen-carbon plasma was measured for the diagnostics of the plasma and the characterization of the process of CNx film deposition. The nitrogen-carbon plasma was recognized to contain various species including nitrogen molecules and molecular ions excited in the ambient N2 gas, carbon atoms and atomic ions ablated from the graphite target and CN radicals. The temporal evolution and spatial distribution of the CN emission and their dependence on the substrate bias voltage show two groups of CN radicals flying in opposite directions. One represents the CN radicals formed as the products of the reactions occurring in the nitrogen-carbon plasma, revealing the reactive deposition of CNx film due to the reactive expansion of the ablation carbon plasma in the discharge nitrogen plasma and the effective formation of gaseous CN radicals as precursors for CNx film growth. The other one represents the CN radicals re-sputtered from the growing CNx film by energetic plasma species, evidencing the re-sputtering of the growing film accompanying film growth. And, the re-sputtering presents ion-induced sputtering features

  3. Carbon-atom wires produced by nanosecond pulsed laser deposition in a background gas

    OpenAIRE

    Casari, C. S.; Giannuzzi, C. S.; V. Russo

    2016-01-01

    Wires of sp-hybridized carbon atoms are attracting interest for both fundamental aspects of carbon science and for their appealing functional properties. The synthesis by physical vapor deposition has been reported to provide sp-rich carbon films but still needs to be further developed and understood in detail. Here the synthesis of carbon-atom wires (CAWs) has been achieved by nanosecond pulsed laser deposition (PLD) expoliting the strong out-of-equilibrium conditions occurring when the abla...

  4. Synthesis of Aligned Carbon Nanotubes by Thermal Chemical Vapor Deposition

    Institute of Scientific and Technical Information of China (English)

    LI Gang; ZHOU Ming; MA Weiwei; CAI Lan

    2009-01-01

    Single crystal silicon was found to be very beneficial to the growth of aligned carbon nanotubes by chemical vapor deposition with C2H2 as carbon source. A thin film of Ni served as catalyst was deposited on the Si substrate by the K575X Peltier Cooled High Resolution Sputter Coater before growth. The growth properties of carbon nanotubes were studied as a function of the Ni catalyst layer thickness. The diameter, growth rate and areal density of the carbon nanotubes were controlled by the initial thickness of the catalyst layer. Steric hindrance between nanotubes forces them to grow in well-aligned manner at an initial stage of growth. Transmission electron microscope analysis revealed that nanotubes grew by a tip growth mechanism.

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

    Science.gov (United States)

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

    1996-01-01

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

  6. ENHANCING ADHESION OF TETRAHEDRAL AMORPHOUS CARBON FILMS

    Institute of Scientific and Technical Information of China (English)

    Zhao Yuqing; Lin Yi; Wang Xiaoyan; Wang Yanwu; Wei Xinyu

    2005-01-01

    Objective The high energy ion bombardment technique is applied to enhancing the adhesion of the tetrahedral amorphous carbon (TAC) films deposited by the filtered cathode vacuum arc (FCVA). Methods The abrasion method, scratch method, heating and shaking method as well as boiling salt solution method is used to test the adhesion of the TAC films on various material substrates. Results The test results show that the adhesion is increased as the ion bombardment energy increases. However, if the bombardment energy were over the corresponding optimum value, the adhesion would be enhanced very slowly for the harder material substrates and drops quickly, for the softer ones. Conclusion The optimum values of the ion bombardment energy are larger for the harder materials than that for the softer ones.

  7. Effect of protic solvents on CdS thin films prepared by chemical bath deposition

    International Nuclear Information System (INIS)

    In this study, cadmium sulfide (CdS) thin films are grown on glass substrates by chemical bath deposition (CBD) in an aqueous bath containing 10–20 vol.% alcohol. The roles of ethanol as a protic solvent that substantially improves the quality of films are explored extensively. The deposited films in an alcohol bath are found to be more compact and smoother with smaller CdS grains. The X-ray diffractograms of the samples confirm that all films were polycrystalline with mixed wurtzite (hexagonal) and zinkblende (cubic) phases. Raman spectra indicate that, for a film deposited in an alcohol bath, the position of 1LO is closer to the value for single crystal CdS, indicating that these films have a high degree of crystallinity. The as-deposited CdS thin films in a 10 vol.% alcohol bath were found to have the highest visible transmittance of 81.9%. XPS analysis reveals a stronger signal of C1s for samples deposited in the alcohol baths, indicating that there are more carbonaceous residues on the films with protic solvent than on the films with water. A higher XPS S/Cd atomic ratio for films deposited in an alcohol bath indicates that undesirable surface reactions (leading to sulfur containing compounds other than CdS) occur less frequently over the substrates. - Highlights: • Study of CBD-CdS films grown in an alcohol-containing aqueous bath is reported. • The deposited films in an alcohol bath are more compact with smaller CdS grains. • Raman spectra show that in an alcohol bath, the CdS film has a better crystallinity. • XPS reveals more carbon residues remain on the films deposited using alcohol bath. • In an alcohol bath, the undesirable surface reactions with Cd ions were hindered

  8. Piezoresistive Effect of Doped carbon Nanotube/Cellulose Films

    Institute of Scientific and Technical Information of China (English)

    王万录; 廖克俊; 李勇; 王永田

    2003-01-01

    The strain-induced resistance changes in iodine-doped and undoped carbon nanotube films were investigated by a three-point bending test. Carbon nanotubes were fabricated by hot filament chemical vapour deposition. The experimental results showed that there has a striking piezoresistive effect in carbon nanotube films. The gauge factor for I-doped and undoped carbon nanotube films under 500 microstrain was about 125 and 65 respectively at room temperature, exceeding that of polycrystalline silicon (30) at 35℃. The origin of the piezoresistivity in the films may be ascribed to a strain-induced change in the band gap for the doped tubes and to the intertube contact resistance for the undoped tubes.

  9. Morphology of CdSe films prepared by chemical bath deposition: The role of substrate

    Energy Technology Data Exchange (ETDEWEB)

    Simurda, M. [Charles University in Prague, Faculty of Mathematics and Physics, Ke Karlovu 3, 121 16 Prague 2 (Czech Republic); Nemec, P. [Charles University in Prague, Faculty of Mathematics and Physics, Ke Karlovu 3, 121 16 Prague 2 (Czech Republic)]. E-mail: nemec@karlov.mff.cuni.cz; Formanek, P. [Institut fuer Strukturphysik, Technische Universitaet Dresden, Zellescher Weg 16, D-01062 Dresden (Germany); Nemec, I. [Charles University in Prague, Faculty of Science, Albertov 6, 128 43 Prague 2 (Czech Republic); Nemcova, Y. [Charles University in Prague, Faculty of Science, Albertov 6, 128 43 Prague 2 (Czech Republic); Maly, P. [Charles University in Prague, Faculty of Mathematics and Physics, Ke Karlovu 3, 121 16 Prague 2 (Czech Republic)

    2006-07-26

    We combine optical spectroscopy and transmission electron microscopy to study the growth and the structural morphology of CdSe films prepared by chemical bath deposition (CBD) on two considerably different substrates. The films grown on glass are compact and strongly adherent to the substrate. On the contrary, the films deposited on carbon-coated glass (with approx. 20 nm thick amorphous carbon layer) are only loosely adherent to the substrate. Using transmission electron microscopy we revealed that even though the films grown on both substrates are assembled from closely spaced nanocrystals with diameter of about 5 nm, the films morphology on the sub-micrometer scale is considerably different in the two cases. While the films deposited on glass are rather compact, the films prepared on carbon layer have high porosity and are formed by interconnected spheres which size is dependent on the duration of deposition (e.g. 155 nm for 6 h and 350 nm for 24 h). This shows that the choice of the substrate for CBD has a stronger influence on the sub-micrometer film morphology than on the properties of individual nanocrystals forming the film.

  10. Morphology of CdSe films prepared by chemical bath deposition: The role of substrate

    International Nuclear Information System (INIS)

    We combine optical spectroscopy and transmission electron microscopy to study the growth and the structural morphology of CdSe films prepared by chemical bath deposition (CBD) on two considerably different substrates. The films grown on glass are compact and strongly adherent to the substrate. On the contrary, the films deposited on carbon-coated glass (with approx. 20 nm thick amorphous carbon layer) are only loosely adherent to the substrate. Using transmission electron microscopy we revealed that even though the films grown on both substrates are assembled from closely spaced nanocrystals with diameter of about 5 nm, the films morphology on the sub-micrometer scale is considerably different in the two cases. While the films deposited on glass are rather compact, the films prepared on carbon layer have high porosity and are formed by interconnected spheres which size is dependent on the duration of deposition (e.g. 155 nm for 6 h and 350 nm for 24 h). This shows that the choice of the substrate for CBD has a stronger influence on the sub-micrometer film morphology than on the properties of individual nanocrystals forming the film

  11. Deposition and Tribological Properties of Sulfur-Doped DLC Films Deposited by PBII Method

    Directory of Open Access Journals (Sweden)

    Nutthanun Moolsradoo

    2010-01-01

    Full Text Available Sulfur-doped diamond-like carbon films (S-DLC fabricated from C2H2 and SF6 mixtures were used to study the effects of sulfur content and negative pulse bias voltage on the deposition and tribological properties of films prepared by plasma-based ion implantation (PBII. The structure and relative concentration of the films were analyzed by Raman spectroscopy and Auger electron spectroscopy. Hardness and elastic modulus of films were measured by nanoindentation hardness testing. Tribological characteristics of films were performed using a ball-on-disk friction tester. The results indicate that with the increasing sulfur content, the hardness and elastic modulus decrease. Additionally, by changing the negative pulse bias voltage from 0 kV to −5 kV, the hardness and elastic modulus increase, while the friction coefficient and specific wear rate tends to decrease. Moreover, at a negative pulse bias voltage of −5 kV and flow-rate ratio of 1 : 2, there is considerable improvement in friction coefficient of 0.05 under ambient air is due to the formation of a transfer films on the interface. The decrease in the friction coefficient of films doped with 4.9 at.% sulfur is greater under high vacuum (0.03 than under ambient air (>0.1.

  12. Synthesis and characterization of carbon/silica superhydrophobic multi-layer films

    International Nuclear Information System (INIS)

    C/SiO2 multi-layer films (3-layer films and 5-layer films) were obtained by sol-gel method and physical deposition on glass plates, and then heated at 500 oC for 1 h under a nitrogen atmosphere. The mechanical adhesive force with the substrate of the multi-layer films was sharply enhanced compared to the as-deposited amorphous carbon film. An absorption layer was formed on heat treated C/SiO2 multi-layer films by modification of the surface with trimethylchlorosilane, and the wettability of the films changed from hydrophilic to super-hydrophobic. The structures of the physically deposited carbon and the multi-layer films were analyzed by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. The experimental results showed that the 5-layer films had a concentric ring structure that caused the film to be superhydrophobic.

  13. Optical properties and morphology of PECVD deposited titanium dioxide films

    Directory of Open Access Journals (Sweden)

    J. Kowalski

    2009-12-01

    Full Text Available Purpose: The purpose of the present work is to compare the structure and optical properties, with respect to their potential optical applications, of titanium dioxide films synthesized with the PECVD method from two different precursor materials, namely titanium tetrachloride and titanium tetraethoxide (TEOT.Design/methodology/approach: Optical properties as well as thickness of the films were analyzed by means of Variable Angle Spectroscopic Ellipsometry (VASE. Morphology studies were carried out by Scanning Electron Microscopy (SEM and chemical composition characterisation was performed with the help of Energy Dispersive Spectroscopy (EDS unit coupled with the electron microscope.Findings: Optical parameters approaching those of titanium dioxide were achieved for both precursors. Studies of morphology show that the films produced from TEOT have favourable, smooth surface in contradiction to broccoli-like structure obtained for the chloride precursor. The type of substance used for titanium oxides synthesis determined chemical composition of the films resulting in their enrichment with either chlorine or carbon, depending on the precursor composition.Practical implications: The optical quality of the films is good enough to suggest their applications in stack multilayer interference filters. The refractive index values of these films advocate their use as high refractive index materials while their low extinction coefficients assure the devices transparency.Originality/value: The work presents deposition rates as well as the films optical properties, chemical composition and morphology in relation to operational parameters of their synthesis. It also provides a comparison of these characteristics for two competitive precursor compounds. Finally, it presents the capability of PECVD method for the deposition of optical coatings onto polymer substrates.

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

    International Nuclear Information System (INIS)

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

  15. Substrate heating measurements in pulsed ion beam film deposition

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-05-01

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

  16. Beam-Induced Deposition of Thin Metallic Films.

    Science.gov (United States)

    Funsten, Herbert Oliver, III

    1990-01-01

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

  17. Tribological behavior and film formation mechanisms of carbon nanopearls

    Science.gov (United States)

    Hunter, Chad Nicholas

    Carbon nanopearls (CNPs) are amorphous carbon spheres that contain concentrically-oriented nanometer-sized graphitic flakes. Because of their spherical shape, size (˜150 nm), and structure consisting of concentrically oriented nano-sized sp2 flakes, CNPs are of interest for tribological applications, in particular for use in solid lubricant coatings. These studies were focused on investigating mechanisms of CNP lubrication, development of methods to deposit CNP onto substrates, synthesizing CNP-gold hybrid films using Matrix Assisted Pulsed Laser Evaporation (MAPLE) and magnetron sputtering, and studying plasmas and other species present during film deposition using an Electrostatic Quadrupole Plasma (EQP) analyzer. CNPs deposited onto silicon using drop casting with methanol showed good lubricating properties in sliding contacts under dry conditions, where a transfer film was created in which morphology changed from nano-sized spheres to micron-sized agglomerates consisting of many highly deformed CNPs in which the nano-sized graphene flakes are sheared from the wrapped layer structure of the CNPs. The morphology of carbon nanopearl films deposited using a MAPLE system equipped with a 248 nm KrF excimer laser source was found to be influenced by multiple factors, including composition of the matrix solvent, laser energy and repetition rate, background pressure, and substrate temperature. The best parameters for depositing CNP films that are disperse, droplet-free and have the maximum amount of material deposited are as follows: toluene matrix, 700 mJ, 1 Hz, 100°C substrate temperature, and unregulated vacuum pressure. During depositions using MAPLE and sputtering in argon, electron ionization of toluene vapor generated from the MAPLE target and charge exchange reactions between toluene vapor and the argon plasma generated by the magnetron caused carbon to be deposited onto the gold sputter target. Thin films deposited under these conditions contained high

  18. AFM Study on Reliability of Nanoscale DLC Films Deposited by ECR-MPCVD

    Institute of Scientific and Technical Information of China (English)

    ZHUShou-xing; ZHUShi-gen; DINGJian-ning

    2004-01-01

    Nanoindentation, scratch and wear tests based on an atomic force microscope (AFM) were carried out to study the reliability of diamond-like carbon (DLC) films, deposited by electron cyclotron resonance microwave plasma chemical vapor deposition (ECR-MPCVD). The predictors for film reliability were given to investigate the resistance of DLC films to indent, scratch, and wear. Experimental results showed that the films at 64.9nm and 12.07nm exhibited better reliability than thin one at 2.78nm, 4.48nm. In addition, the reliability strength of films above 12.07nm went stable, and the films showed good performance of anti-indentation, anti-scratch and anti-wear. Finally, size effect of nanoscale monolayer film was introduced to explain the reliability of nanoscale DLC films.

  19. TFA-MOD (Metal Organic Deposition Using Trifluoroacetates) Films with Thickness Greater Than 1 Micron by a Single Deposition

    Science.gov (United States)

    Araki, Takeshi; Hayashi, Mariko; Fuke, Hiroyuki

    The key to obtaining films with thickness greater than 1 micron by a single TFA-MOD deposition is a crack-preventing material. The ratio of fluorine atoms to total fluorine and hydrogen atoms (RF) of the chemical is important for forming excellent superconducting films. Although hydrogen atoms lead to carbon residue, which fatally deteriorates superconducting properties of the resulting film, hydrogen atoms form strong hydrogen bonds with trifluoroacetates and have an excellent crack-prevention effect. The RF range from 0.75 to 0.96 is effective for obtaining single-coated, thick, high-critical-current-density superconducting films.

  20. Understanding the deposition mechanism of pulsed laser deposited B-C films using dual-targets

    International Nuclear Information System (INIS)

    Boron carbide thin films with stoichiometry (boron-carbon atomic ratio) range of 0.1 ∼ 8.9 were fabricated via pulsed laser deposition by using boron-carbon dual-targets. However, this experimental data on stoichiometry were smaller than the computer simulation values. The discrepancy was investigated by studies on composition and microstructure of the thin films and targets by scanning electron microscopy, excitation laser Raman spectroscopy, and X-ray photoelectron spectroscopy. The results indicate that the boron liquid droplets were formed by phase explosion after laser irradiation on boron sector. Part of the boron droplets would be lost via ejection in the direction of laser beam, which is tilted 45° to the surface of substrate

  1. Nanomechanical characterization of amorphous hydrogenated carbon thin films

    International Nuclear Information System (INIS)

    Amorphous hydrogenated carbon (a-C:H) thin films deposited on a silicon substrate under various mixtures of methane-hydrogen gas by electron cyclotron resonance microwave plasma chemical vapor deposition (ECR-MPCVD) was investigated. Microstructure, surface morphology and mechanical characterizations of the a-C:H films were analyzed using Raman spectroscopy, atomic force microscopy (AFM) and nanoindentation technique, respectively. The results indicated there was an increase of the hydrogen content, the ratio of the D-peak to the G-peak (I D/I G) increased but the surface roughness of the films was reduced. Both hardness and Young's modulus increased as the hydrogen content was increased. In addition, the contact stress-strain analysis is reported. The results confirmed that the mechanical properties of the amorphous hydrogenated carbon thin films improved using a higher H2 content in the source gas

  2. Low-temperature deposition of ZrC thin films from a single source precursor

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.C.; Healy, M.D.; Springer, R.W. (Los Alamos National Lab., NM (United States)); Rubiano, R.R. (Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Nuclear Engineering)

    1992-01-01

    Stable zirconium carbide thin films have been deposited from a single source organometallic precursor, tetraneopentyl zirconium, at substrate temperatures above 500C. Materials deposited above this temperature are crystalline by X-ray diffraction. A metal to carbon ratio of 1:2 is observed by Auger electron spectroscopy depth profiling. X-ray photoelectron spectroscopy indicates the zirconium is single phase. The observed spectra correspond well to spectra for zirconium carbide standards. Carbon XPS reveals carbidic and graphitic or hydrocarbon species with a third unknown carbon species. Elastic recoil detection finds a large, up to 16%, hydrogen content in the thin film.

  3. Low-temperature deposition of ZrC thin films from a single source precursor

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.C.; Healy, M.D.; Springer, R.W. [Los Alamos National Lab., NM (United States); Rubiano, R.R. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Nuclear Engineering

    1992-12-31

    Stable zirconium carbide thin films have been deposited from a single source organometallic precursor, tetraneopentyl zirconium, at substrate temperatures above 500C. Materials deposited above this temperature are crystalline by X-ray diffraction. A metal to carbon ratio of 1:2 is observed by Auger electron spectroscopy depth profiling. X-ray photoelectron spectroscopy indicates the zirconium is single phase. The observed spectra correspond well to spectra for zirconium carbide standards. Carbon XPS reveals carbidic and graphitic or hydrocarbon species with a third unknown carbon species. Elastic recoil detection finds a large, up to 16%, hydrogen content in the thin film.

  4. Electrochemical sensor for nitric oxide using layered films composed of a polycationic dendrimer and nickel(II) phthalocyaninetetrasulfonate deposited on a carbon fiber electrode

    International Nuclear Information System (INIS)

    We have developed an electrochemical sensor for nitric oxide that is based on multi-layers of nickel(II) phthalocyaninetetrasulfonate and a polyamidoamine dendrimer assembled on the surface of a carbon-fiber microelectrode. This sensor responds to nitric oxide at a working potential of 800 mV with a sensitivity of 5.54 pA∙μM-1 which, however, depends on the dendrimer layer position deposited on the microelectrode. The limit of detection is as low as 5.5 μM at a signal-to-noise ratio of 3. The electrode exhibits good selectivity for nitric oxide over common interferents including dopamine, nitrite, hydrogen peroxide, norepinephrine, epinephrine and ascorbic acid. (author)

  5. Effect of ambient gaseous environment on the properties of amorphous carbon thin films

    International Nuclear Information System (INIS)

    Amorphous carbon films have been deposited by filtered cathodic jet carbon arc technique under different gaseous environments. Scanning electron microscope and atomic force microscope studies have been performed on the deposited films for the surface morphological studies. The morphology of the deposited film changes with the change in gas environment. X-ray photoelectron spectroscopic (XPS) and Raman studies have been carried out on the deposited samples for the evaluation of the chemical bonding of carbon atoms with the ambient gas atoms. The sp3 and sp2 contents have been evaluated from the XPS studies and found to be dependent on the gaseous environment. The film deposited under hydrogen environment has the highest value of the sp3 content (54.6 at.%) whereas the film deposited under helium environment has the lowest value of sp3 content (37 at.%). For the evaluation of the electrical and mechanical properties of the deposited films, the electrical conductivity and nanoindentation measurements have been performed on the deposited films. It has been observed that the film deposited under helium environment has the highest electrical conductivity and the lowest hardness (∼15 GPa) value whereas film deposited under hydrogen environment has the highest hardness (∼21 GPa) and the lowest conductivity.

  6. Influence of dc bias on amorphous carbon deposited by pulse laser ablation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Amorphous carbon films were deposited on single-crystalline silicon and K9 glass by pulse laser ablation using different negative substrate bias. Scanning electron microscope (SEM) was used to observe morphology of the surface. Thickness and refractive index of the film deposited on K9 glass were measured by ellipsometry. Micro-hardness of films was measured relatively to single crystal silicon. All films deposited on silicon were analyzed by Raman spectra. All spectra were deconvoluted to three peaks. Line-width ratios varied similarly with bias voltage when the laser energy was kept invariant.

  7. Electromagnetic interference shielding effectiveness of nanoreinforced polymer composites deposited with conductive metallic thin films

    International Nuclear Information System (INIS)

    The effect of using conductive metallic thin films deposited on high density polyethylene (HDPE) and styrene butadiene copolymer (SBC) in conjunction with carbon nanofiber (CNF) reinforcement of HDPE and SBC was investigated in order to improve the electromagnetic interference shielding effectiveness (EMI SE) of the structures. Thin films of copper, silver and aluminum were deposited by thermal evaporation onto the polymeric matrices and its composites (0–20 wt.% of CNFs). Results show a synergistic effect of the two approaches (metallic coating and CNF reinforcement) toward improving the EMI SE. The chemical composition, surface morphology, carbon nanofiber distribution, thickness and microstructure of metallic coated polymers are examined using X-Ray Diffraction and Scanning Electron Microscopy. - Highlights: ► Metallic thin films were evaporated on carbon nanofiber reinforced polymers. ► The electromagnetic shielding effectiveness of the structures was evaluated. ► Thin films and carbon nanofibers synergistically improved the shielding effectiveness.

  8. Electromagnetic interference shielding effectiveness of nanoreinforced polymer composites deposited with conductive metallic thin films

    Energy Technology Data Exchange (ETDEWEB)

    Mihut, D.M., E-mail: dorinamm@yahoo.com [Department of Mechanical Engineering, The University of Texas Pan American, 1201 W University Drive, Edinburg, TX (United States); Lozano, K. [Department of Mechanical Engineering, The University of Texas Pan American, 1201 W University Drive, Edinburg, TX (United States); Tidrow, S.C. [Department of Physics and Geology, The University of Texas Pan American, 1201 W University Drive, Edinburg, TX (United States); Garcia, H. [Department of Mechanical Engineering, The University of Texas Pan American, 1201 W University Drive, Edinburg, TX (United States)

    2012-08-31

    The effect of using conductive metallic thin films deposited on high density polyethylene (HDPE) and styrene butadiene copolymer (SBC) in conjunction with carbon nanofiber (CNF) reinforcement of HDPE and SBC was investigated in order to improve the electromagnetic interference shielding effectiveness (EMI SE) of the structures. Thin films of copper, silver and aluminum were deposited by thermal evaporation onto the polymeric matrices and its composites (0-20 wt.% of CNFs). Results show a synergistic effect of the two approaches (metallic coating and CNF reinforcement) toward improving the EMI SE. The chemical composition, surface morphology, carbon nanofiber distribution, thickness and microstructure of metallic coated polymers are examined using X-Ray Diffraction and Scanning Electron Microscopy. - Highlights: Black-Right-Pointing-Pointer Metallic thin films were evaporated on carbon nanofiber reinforced polymers. Black-Right-Pointing-Pointer The electromagnetic shielding effectiveness of the structures was evaluated. Black-Right-Pointing-Pointer Thin films and carbon nanofibers synergistically improved the shielding effectiveness.

  9. Characterization of chemical vapour deposited diamond films: correlation between hydrogen incorporation and film morphology and quality

    International Nuclear Information System (INIS)

    In order to tailor diamond synthesized through chemical vapour deposition (CVD) for different applications, many diamond films of different colours and variable quality were deposited by a 5 kW microwave plasma CVD reactor under different growth conditions. The morphology, quality and hydrogen incorporation of these films were characterized using scanning electron microscopy (SEM), Raman and Fourier-transform infrared (FTIR) spectroscopy, respectively. From this study, a general trend between hydrogen incorporation and film colour, morphology and quality was found. That is, as the films sorted by colour gradually become darker, ranging from white through grey to black, high magnification SEM images illustrate that the smoothness of the well defined crystalline facet gradually decreases and second nucleation starts to appear on it, indicating gradual degradation of the crystalline quality. Correspondingly, Raman spectra evidence that the diamond Raman peak at 1332 cm-1 becomes broader and the non-diamond carbon band around 1500 cm-1 starts to appear and becomes stronger, confirming increase of the non-diamond component and decrease of the phase purity of the film, while FTIR spectra show that the CH stretching band and the two CVD diamond specific peaks around 2830 cm-1 rise rapidly, and this indicates that the total amount of hydrogen incorporated into the film increases significantly

  10. 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)

  11. Resonant infrared pulsed laser deposition of thin biodegradable polymer films

    DEFF Research Database (Denmark)

    Bubb, D.M.; Toftmann, B.; Haglund Jr., R.F.;

    2002-01-01

    Thin films of the biodegradable polymer poly(DL-lactide-co-glycolide) (PLGA) were deposited using resonant infrared pulsed laser deposition (RIR-PLD). The output of a free-electron laser was focused onto a solid target of the polymer, and the films were deposited using 2.90 (resonant with O...

  12. Structural anisotropy of magnetically aligned single wall carbon nanotube films

    International Nuclear Information System (INIS)

    Thick films of aligned single wall carbon nanotubes and ropes have been produced by filtration/deposition from suspension in strong magnetic fields. We measured mosaic distributions of rope orientations in the film plane, for samples of different thicknesses. For an ∼1 μm film the full width at half maximum (FWHM) derived from electron diffraction is 25 degree sign -28 degree sign . The FWHM of a thicker film (∼7 μm) measured by x-ray diffraction is slightly broader, 35±3 degree sign . Aligned films are denser than ordinary filter-deposited ones, and much denser than as-grown material. Optimization of the process is expected to yield smaller FWHMs and higher densities. (c) 2000 American Institute of Physics

  13. Electrophoretically-deposited solid film lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Dugger, M.T.; Panitz, J.K.J.; Vanecek, C.W.

    1995-04-01

    An aqueous-based process that uses electrophoresis to attract powdered lubricant in suspension to a charged target was developed. The deposition process yields coatings with low friction, complies with environmental safety regulations, requires minimal equipment, and has several advantages over processes involving organic binders or vacuum techniques. This work focuses on development of the deposition process, includes an analysis of the friction coefficient of the material in sliding contact with stainless steel under a range of conditions, and a functional evaluation of coating performance in a precision mechanical device application. Results show that solid lubricant films with friction coefficients as low as 0.03 can be produced. A 0.03 friction coefficient is superior to solid lubricants with binder systems and is comparable to friction coefficients generated with more costly vacuum techniques.

  14. Low temperature temporal and spatial atomic layer deposition of TiO{sub 2} films

    Energy Technology Data Exchange (ETDEWEB)

    Aghaee, Morteza, E-mail: m.aghaee@tue.nl; Maydannik, Philipp S. [ASTRaL Group, Laboratory of Green Chemistry, Lappeenranta University of Technology, Sammonkatu 12, 50130 Mikkeli (Finland); Johansson, Petri; Kuusipalo, Jurkka [Paper Converting and Packaging Technology, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere (Finland); Creatore, Mariadriana [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Homola, Tomáš; Cameron, David C. [R& D Center for Low-Cost Plasma and Nanotechnology Surface Modification, Masaryk University, Kotlářská 2, 611 37 Brno (Czech Republic)

    2015-07-15

    Titanium dioxide films were grown by atomic layer deposition (ALD) using titanium tetraisopropoxide as a titanium precursor and water, ozone, or oxygen plasma as coreactants. Low temperatures (80–120 °C) were used to grow moisture barrier TiO{sub 2} films on polyethylene naphthalate. The maximum growth per cycle for water, ozone, and oxygen plasma processes were 0.33, 0.12, and 0.56 Å/cycle, respectively. X-ray photoelectron spectrometry was used to evaluate the chemical composition of the layers and the origin of the carbon contamination was studied by deconvoluting carbon C1s peaks. In plasma-assisted ALD, the film properties were dependent on the energy dose supplied by the plasma. TiO{sub 2} films were also successfully deposited by using a spatial ALD (SALD) system based on the results from the temporal ALD. Similar properties were measured compared to the temporal ALD deposited TiO{sub 2}, but the deposition time could be reduced using SALD. The TiO{sub 2} films deposited by plasma-assisted ALD showed better moisture barrier properties than the layers deposited by thermal processes. Water vapor transmission rate values lower than 5 × 10{sup −4} g day{sup −1} m{sup −2} (38 °C and 90% RH) was measured for 20 nm of TiO{sub 2} film deposited by plasma-assisted ALD.

  15. CdTe Films Deposited by Closed-space Sublimation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    CdTe films are prepared by closed-space sublimation technology. Dependence of film crystalline on substrate materials and substrate temperature is investigated. It is found that films exhibit higher crystallinity at substrate temperature higher than 400℃. And the CdTe films deposited on CdS films with higher crystallinity have bigger crystallite and higher uniformity. Treatment with CdCl2 methanol solution promotes the crystallite growth of CdTe films during annealing.

  16. Optical detection of carbon dioxide adsorption on epitaxial CuFe1 -xGaxO2 Delafossite film grown by pulse laser deposition

    Science.gov (United States)

    Rojas, S.; Joshi, T.; Wheatley, R. A.; Sarabia, M.; Borisov, P.; Lederman, D.; Cabrera, A. L.

    2016-06-01

    A highly epitaxial delafossite CuFe1 -xGaxO2 film was made with pulse laser deposition in high vacuum. The sample thickness was around 48 nm and it was terminated with CuFeO2. This delafossite sample was exposed to a CO2 atmosphere under controlled conditions and chemisorption of CO2 on the surface was observed. Transmittance and reflectance spectroscopies were recorded for the sample post surface heat treatment held in a vacuum chamber (0.05 Kpa) and after exposure to CO2. Both spectra were recorded over a wavelength range of 350-1100 nm. Chemisorption of CO2 was correlated with an increase in transmittance and decrease in reflectance in the pressure range 0-60 kPa. These observations were confirmed with X-ray photoelectron spectroscopy and thermal programmed desorption data obtained in an independent experiment. The CO2 is bound to the surface forming a carboxylate structure via coordination of a bent CO2- δ molecule to a Cu center.

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

    International Nuclear Information System (INIS)

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

  18. Liquid-phase-deposited barium titanate thin films on silicon

    International Nuclear Information System (INIS)

    Using a mixture of hexafluorotitanic acid, barium nitrate and boric acid, high refractive index (1.54) barium titanate films can be deposited on silicon substrates. The deposited barium titanate films have featureless surfaces. The deposition temperature is near room temperature (800C). However, there are many fluorine and silicon incorporations in the films. The refractive index of the as-deposited film is 1.54. By current-voltage measurement, the leakage current of the as-deposited film with a thickness of 1000 A is about 9.48x10-7 A cm-2 at the electrical field intensity of 0.3 MV cm-1. By capacitance-voltage measurement, the effective oxide charge of the liquid-phase-deposited barium titanate film is 3.06x1011 cm-2 and the static dielectric constant is about 22. (author)

  19. Turbostratic-like carbon nitride coatings deposited by industrial-scale direct current magnetron sputtering

    International Nuclear Information System (INIS)

    Carbon nitride thin films were deposited by direct current magnetron sputtering in an industrial-scale equipment at different deposition temperatures and substrate bias voltages. The films had N/(N + C) atomic fractions between 0.2 and 0.3 as determined by X-ray photoelectron spectroscopy (XPS). Raman spectroscopy provided insight into the ordering and extension of the graphite-like clusters, whereas nanoindentation revealed information on the mechanical properties of the films. The internal compressive film stress was evaluated from the substrate bending method. At low deposition temperatures the films were amorphous, whereas the film deposited at approximately 380 °C had a turbostratic-like structure as confirmed by high-resolution transmission electron microscopy images. The turbostratic-like film had a highly elastic response when subjected to nanoindentation. When a CrN interlayer was deposited between the film and the substrate, XPS and Raman spectroscopy indicated that the turbostratic-like structure was maintained. However, it was inconclusive whether the film still exhibited an extraordinary elastic recovery. An increased substrate bias voltage, without additional heating and without deposition of an interlayer, resulted in a structural ordering, although not to the extent of a turbostratic-like structure. - Highlights: • Carbon nitride films were deposited by industrial-scale magnetron sputtering. • The deposition temperature and the substrate bias voltage were varied. • A turbostratic-like structure was obtained at an elevated deposition temperature. • The turbostratic-like film exhibited a very high elastic recovery. • The influence of a CrN interlayer on the film properties was investigated

  20. MgB{sub 2} thin films by hybrid physical-chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Xi, X.X. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States)]|[Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States)]. E-mail: xxx4@psu.edu; Pogrebnyakov, A.V. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States)]|[Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Xu, S.Y.; Chen, K.; Cui, Y.; Maertz, E.C. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Zhuang, C.G. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States)]|[Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States)]|[Department of Physics, Peking University, Beijing 100871 (China); Li, Qi [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Lamborn, D.R. [Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Redwing, J.M. [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States)]|[Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Liu, Z.K.; Soukiassian, A.; Schlom, D.G.; Weng, X.J.; Dickey, E.C. [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Chen, Y.B.; Tian, W.; Pan, X.Q. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Cybart, S.A. [Department of Physics, University of California, Berkeley, CA 94720 (United States); Dynes, R.C. [Department of Physics, University of California, Berkeley, CA 94720 (United States)

    2007-06-01

    Hybrid physical-chemical vapor deposition (HPCVD) has been the most effective technique for depositing MgB{sub 2} thin films. It generates high magnesium vapor pressures and provides a clean environment for the growth of high purity MgB{sub 2} films. The epitaxial pure MgB{sub 2} films grown by HPCVD show higher-than-bulk T {sub c} due to tensile strain in the films. The HPCVD films are the cleanest MgB{sub 2} materials reported, allowing basic research, such as on magnetoresistance, that reveals the two-band nature of MgB{sub 2}. The carbon-alloyed HPCVD films demonstrate record-high H {sub c2} values promising for high magnetic field applications. The HPCVD films and multilayers have enabled the fabrication of high quality MgB{sub 2} Josephson junctions.

  1. MgB 2 thin films by hybrid physical-chemical vapor deposition

    Science.gov (United States)

    Xi, X. X.; Pogrebnyakov, A. V.; Xu, S. Y.; Chen, K.; Cui, Y.; Maertz, E. C.; Zhuang, C. G.; Li, Qi; Lamborn, D. R.; Redwing, J. M.; Liu, Z. K.; Soukiassian, A.; Schlom, D. G.; Weng, X. J.; Dickey, E. C.; Chen, Y. B.; Tian, W.; Pan, X. Q.; Cybart, S. A.; Dynes, R. C.

    2007-06-01

    Hybrid physical-chemical vapor deposition (HPCVD) has been the most effective technique for depositing MgB 2 thin films. It generates high magnesium vapor pressures and provides a clean environment for the growth of high purity MgB 2 films. The epitaxial pure MgB 2 films grown by HPCVD show higher-than-bulk Tc due to tensile strain in the films. The HPCVD films are the cleanest MgB 2 materials reported, allowing basic research, such as on magnetoresistance, that reveals the two-band nature of MgB 2. The carbon-alloyed HPCVD films demonstrate record-high Hc2 values promising for high magnetic field applications. The HPCVD films and multilayers have enabled the fabrication of high quality MgB 2 Josephson junctions.

  2. MgB2 thin films by hybrid physical-chemical vapor deposition

    International Nuclear Information System (INIS)

    Hybrid physical-chemical vapor deposition (HPCVD) has been the most effective technique for depositing MgB2 thin films. It generates high magnesium vapor pressures and provides a clean environment for the growth of high purity MgB2 films. The epitaxial pure MgB2 films grown by HPCVD show higher-than-bulk T c due to tensile strain in the films. The HPCVD films are the cleanest MgB2 materials reported, allowing basic research, such as on magnetoresistance, that reveals the two-band nature of MgB2. The carbon-alloyed HPCVD films demonstrate record-high H c2 values promising for high magnetic field applications. The HPCVD films and multilayers have enabled the fabrication of high quality MgB2 Josephson junctions

  3. Self-organized formation of metal-carbon nanostructures by hyperthermal ion deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hannstein, I.K.

    2006-04-26

    The quasi-simultaneous deposition of mass-selected hyperthermal carbon and metal ions results in a variety of interesting film morphologies, depending on the metal used and the deposition conditions. The observed features are of the order of a few nanometres and are therefore interesting for future potential applications in the various fields of nanotechnology. The present study focuses on the structural analysis of amorphous carbon films containing either copper, silver, gold, or iron using amongst others Rutherford Backscattering Spectroscopy, High Resolution Transmission Electron Microscopy, and Energy Dispersive X-Ray Spectroscopy. The film morphologies found are as follows: copper-containing films consist of copper nanoclusters with sizes ranging from about 3 to 9 nm uniformly distributed throughout the amorphous carbon matrix. The cluster size hereby rises with the copper content of the films. The silver containing films decompose into a pure amorphous carbon film with silver agglomerates at the surface. Both, the gold- and the iron-containing films show a multilayer structure of metal-rich layers with higher cluster density separated by metal-depleted amorphous carbon layers. The layer distances are of the order of up to 15 nm in the case of gold-carbon films and 7 nm in the case of iron-carbon films. The formation of theses different structures cannot be treated in the context of conventional self-organization mechanisms basing upon thermal diffusion and equilibrium thermodynamics. Instead, an ion-induced atomic transport, sputtering effects, and the stability of small metal clusters were taken into account in order to model the structure formation processes. A similar multilayer morphology was recently also reported in the literature for metal-carbon films grown by magnetron sputtering techniques. In order to investigate, whether the mechanisms are the same as in the case of the ion beam deposited films described above, first experiments were conducted

  4. Electrochemical atomic layer deposition of a CuInSe{sub 2} thin film on flexible multi-walled carbon nanotubes/polyimide nanocomposite membrane: Structural and photoelectrical characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Kou Huanhuan; Zhang Xin; Jiang Yimin; Li Jiajia; Yu Shengjiao; Zheng Zhixiang [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Wang Chunming, E-mail: wangcm@lzu.edu.cn [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China)

    2011-06-30

    Highlights: > CuInSe{sub 2} thin film has been successfully synthesized on CNT/PI membrane. > Optical band gap measurements give a band gap of 1.05 eV. > OCP and I-V studies show that the sample is beneficial to photoelectric applications. - Abstract: This study describes a method for the fabrication of an electrochemical atomic layer deposition (EC-ALD) used to fabricate the ternary, semiconducting compound, CuInSe{sub 2} (CISe), onto a flexible, carboxyl-functionalized multi-walled carbon nanotube/polyimide (COOH-MWCNT/PI) nanocomposite membrane. The elements were deposited using amperometric methods (I-t) in the following sequence: Se/Cu/Se/In/Se/Cu/Se/In and so on, in which the optimum deposition potential for each element was obtained via a cyclic voltammetry (CV) technique. Field emission scanning electron microscopy (FE-SEM) showed that the deposits consisted of many spherical nanoparticles, and energy dispersive spectroscopy (EDS) analysis indicated that the atomic ratio of the deposits (CuInSe) was 1.14 1.00 2.18, similar to the stoichiometric value of the compound. Near Fourier transform infrared spectroscopy (FT-IR) transmission measurements provided a band gap of 1.05 eV, which was confirmed by the absorption spectrum. Open-circuit potential (OCP) and current-voltage (I-V) measurements showed the resulting composite had a good p-type property. CISe spherical NPs electrodeposited on the CNTs/PI membrane may have promising applications in optoelectronic nanodevices and nanotechnologies; in addition, the CNTs/PI membrane could be used as raw material for manufacturing solar cells.

  5. Conductive porous carbon film as a lithium metal storage medium

    International Nuclear Information System (INIS)

    Highlights: • Conductive porous carbon films were prepared by distributing amorphous carbon nanoparticles. • The porous film provides enough conductive surfaces and reduces the effective current density. • By using the film, dendritic Li growth can be effectively prevented. • The use of the porous framework can be extended for use in other 3D structured materials for efficient Li metal storage. - Abstract: The Li metal anode boasts attractive electrochemical characteristics for use in rechargeable Li batteries, such as a high theoretical capacity and a low redox potential. However, poor cycle efficiency and safety problems relating to dendritic Li growth during cycling should be addressed. Here we propose a strategy to increase the coulombic efficiency of the Li metal electrode. Conductive porous carbon films (CPCFs) were prepared by distributing amorphous carbon nanoparticles within a polymer binder. This porous structure is able to provide enough conductive surfaces for Li deposition and dissolution, which reduce the effective current density. Moreover, the pores in these films enable the electrolyte to easily penetrate into the empty space, and Li can be densely deposited between the carbon particles. As a result, dendritic Li growth can be effectively prevented. Electrochemical tests demonstrate that the coulombic efficiency of the porous electrode can be greatly improved compared to that of the pure Cu electrode. By allowing for the development of robust Li metal electrodes, this approach provides key insight into the design of high-capacity anodes for Li metal batteries, such as Li-air and Li-S systems

  6. Chemical Liquid Phase Deposition of Thin Aluminum Oxide Films

    OpenAIRE

    Sun, Jie; Sun, Yingchun

    2007-01-01

    Thin aluminum oxide films were deposited by a new and simple physicochemical method called chemical liquid phase deposition (CLD) on semiconductor materials. Aluminum sulfate with crystallized water and sodium bicarbonate were used as precursors for film growth, and the control of the system pH value played an important role in this experiment. The growth rate is 12 nm/h at room temperature. Post-growth annealing not only densifies and purifies the films, but results in film crystallization a...

  7. Energetic Deposition of Niobium Thin Film in Vacuum

    OpenAIRE

    Wu, Genfa

    2002-01-01

    Niobium thin films are expected to be free of solid inclusions commonly seen in solid niobium. For particle accelerators, niobium thin film has the potential to replace the solid niobium in the making of the accelerating structures. In order to understand and improve the superconducting performance of niobium thin films at cryogenic temperature, an energetic vacuum deposition system has been developed to study deposition energy effects on the properties of niobium thin films on various substr...

  8. Pulsed laser deposition and characterization of Alnico5 magnetic films

    International Nuclear Information System (INIS)

    Alnico5 films were deposited by pulsed laser deposition on glass substrate at room temperature under a vacuum ∼10−3 Torr in the absence and in the presence of 500 Oe external transverse magnetic field applied on the plasma plume during film deposition. For this purpose, Nd:YAG laser was employed to ablate the Alnico5 target. The ablated material was deposited on glass substrate placed at a distance of 2 cm from the target. The structural and magnetic properties of the film were analyzed by X-ray diffraction, atomic force microscope, and vibrating sample magnetometer. X-ray diffraction patterns showed that the Alnico5 films were amorphous in nature. Atomic force microscopy revealed that the Alnico5 film deposited in absence of external magnetic field has larger root-mean-square roughness value (60.2 nm) than the magnetically deposited film (42.9 nm). Vibrating sample magnetometer measurements showed that the in-plane saturation magnetization of Alnico5 film deposited in the presence of external magnetic field increases by 32% as compared to that for the film deposited in the absence of external magnetic field. However, the out-of-plane saturation magnetization was almost independent of the external magnetic field. In magnetically deposited film, there is in-plane anisotropy parallel to the applied external magnetic field.

  9. Cuprous oxide thin films grown by hydrothermal electrochemical deposition technique

    International Nuclear Information System (INIS)

    Semiconducting cuprous oxide films were grown by a hydrothermal electro-deposition technique on metal (Cu) and glass (ITO) substrates between 60 °C and 100 °C. X-ray diffraction studies reveal the formation of cubic cuprous oxide films in different preferred orientations depending upon the deposition technique used. Film growth, uniformity, grain size, optical band gap and photoelectrochemical response were found to improve in the hydrothermal electrochemical deposition technique. - Highlights: • Cu2O thin films were grown on Cu and glass substrates. • Conventional and hydrothermal electrochemical deposition techniques were used. • Hydrothermal electrochemical growth showed improved morphology, thickness and optical band gap

  10. Real-Time Deposition Monitor for Ultrathin Conductive Films

    Science.gov (United States)

    Hines, Jacqueline

    2011-01-01

    A device has been developed that can be used for the real-time monitoring of ultrathin (2 or more) conductive films. The device responds in less than two microseconds, and can be used to monitor film depositions up to about 60 thick. Actual thickness monitoring capability will vary based on properties of the film being deposited. This is a single-use device, which, due to the very low device cost, can be disposable. Conventional quartz/crystal microbalance devices have proven inadequate to monitor the thickness of Pd films during deposition of ultrathin films for hydrogen sensor devices. When the deposited film is less than 100 , the QCM measurements are inadequate to allow monitoring of the ultrathin films being developed. Thus, an improved, high-sensitivity, real-time deposition monitor was needed to continue Pd film deposition development. The new deposition monitor utilizes a surface acoustic wave (SAW) device in a differential delay-line configuration to produce both a reference response and a response for the portion of the device on which the film is being deposited. Both responses are monitored simultaneously during deposition. The reference response remains unchanged, while the attenuation of the sensing path (where the film is being deposited) varies as the film thickness increases. This device utilizes the fact that on high-coupling piezoelectric substrates, the attenuation of an SAW undergoes a transition from low to very high, and back to low as the conductivity of a film on the device surface goes from nonconductive to highly conductive. Thus, the sensing path response starts with a low insertion loss, and as a conductive film is deposited, the film conductivity increases, causing the device insertion loss to increase dramatically (by up to 80 dB or more), and then with continued film thickness increases (and the corresponding conductivity increases), the device insertion loss goes back down to the low level at which it started. This provides a

  11. Optical Properties of a-SiC:H Films Deposited by Glowdischarge Methods

    Directory of Open Access Journals (Sweden)

    Lusitra Munisa

    2003-12-01

    Full Text Available he optical properties of amorphous silicon carbon films deposited by glowdischarge method have been studied using ultra violet-visible (uv-vis spectroscopy. The refractive index was calculated by Swanepoel’s formula using transmission data then followed by numerical simulation. The films density tends to decrease with increasing carbon content. The widening of the optical gap by increasing carbon content indicates the enhancement of film’s transparence. Both real and imaginary parts of the dielectric constant show variation in magnitude as the carbon content increase.

  12. Effects of methane in the deposition of superconducting niobium nitride thin films at ambient substrate temperature

    International Nuclear Information System (INIS)

    Thin films of the niobium-carbon-nitrogen system have been prepared at ambient substrate temperature by rf diode reactive sputtering in an argon-nitrogen atmosphere with controlled amounts of methane added to the sputter gas. Superconducting transition temperatures ranged from approximately 11 to 15.85 0K. Auger and x-ray diffraction analysis indicate that all films were of the single phase B1 structure with a small amount of ν-phase hexagonal structure in the very low carbon containing films. A correlation of the superconducting properties, room temperature sheet resistance, preferred crystallite orientation, and film composition was observed. The results of this investigation show that high T/sub c/ niobium nitride/niobium carbonitride thin films can be prepared at ambient substrate temperatures with the proper amount of nitrogen and methane partial pressures during film deposition. These films have potential application for the fabrication of high T/sub c/ Josephson tunnel junctions

  13. Microstructural and optical properties of nanocrystalline ZnO deposited onto vertically aligned carbon nanotubes by physical vapor deposition

    International Nuclear Information System (INIS)

    Nanocrystalline ZnO films with thicknesses of 5 nm, 10 nm, 20 nm, and 50 nm were deposited via magnetron sputtering onto the surface of vertically aligned multi-walled carbon nanotubes (MWCNTs). The ZnO/CNTs heterostructures were characterized by scanning electron microscopy, high resolution transmission electron microscopy, and X-ray diffraction studies. No structural degradation of the CNTs was observed and photoluminescence (PL) measurements of the nanostructured ZnO layers show that the optical properties of these films are typical of ZnO deposited at low temperatures. The results indicate that magnetron sputtering is a viable technique for growing heterostructures and depositing functional layers onto CNTs.

  14. Room-Temperature Deposition of NbN Superconducting Films

    Science.gov (United States)

    Thakoor, S.; Lamb, J. L.; Thakoor, A. P.; Khanna, S. K.

    1986-01-01

    Films with high superconducting transition temperatures deposited by reactive magnetron sputtering. Since deposition process does not involve significantly high substrate temperatures, employed to deposit counter electrode in superconductor/insulator/superconductor junction without causing any thermal or mechanical degradation of underlying delicate tunneling barrier. Substrates for room-temperature deposition of NbN polymeric or coated with photoresist, making films accessible to conventional lithographic patterning techniques. Further refinements in deposition technique yield films with smaller transition widths, Tc of which might approach predicted value of 18 K.

  15. Carbon nanotube film anodes for flexible lithium ion batteries

    Science.gov (United States)

    Yoon, Sora; Lee, Sehyun; Kim, Soyoung; Park, Kyung-Won; Cho, Daehwan; Jeong, Youngjin

    2015-04-01

    In this study, carbon nanotube (CNT) film anodes are prepared for use in flexible lithium ion batteries, and the electrochemical performance of the CNT film anodes is evaluated. The CNT films are synthesized via chemical vapor deposition and direct spinning. The films are heat-treated under a nitrogen atmosphere at a high temperature to study the effects of heat treatment on the battery performance. The electrodes made with the CNT films are characterized via charge-discharge test, cyclic voltammetry, and impedance measurement. The results indicate that batteries with films heat-treated under a nitrogen atmosphere show a higher capacity, which can be a result of their high crystalline perfection. The impedance analysis shows that a lower resistance at the interface can be obtained by using heat-treated films. The charge-discharge tests are carried out by adjusting the rate from C/2 to 10C, and when the rate slows from 10C to 1C, the capacity of the samples largely recovers. The nitrogen/heat-treated CNT film electrodes present a capacity that is twice as high, such as 2C, 5C, and 10C, than untreated CNT film electrodes. These results indicate that the carbon nanotube film anodes have high potential for use in portable and wearable computers due to their flexibility.

  16. Catalytic carbon deposition on 3-dimensional carbon fibre supports

    OpenAIRE

    Thornton, Matthew James

    2005-01-01

    Catalytic carbon deposition reactions, using methane, ethane or synthetic natural gas (1.8 vol. % propane, 6.7 vol. % ethane and balance methane) as the carbon-containing gas feedstock with or without the addition of hydrogen, have been investigated over nickel, cobalt and iron catalysts supported on 3-dimensional carbon fibre supports, using both a horizontal tube furnace and an isothermal, isobaric induction furnace. The transition metal catalysts were prepared by impregnating 3-dimens...

  17. SnS2 Thin Film Deposition by Spray Pyrolysis

    Science.gov (United States)

    Yahia Jaber, Abdallah; Noaiman Alamri, Saleh; Salah Aida, Mohammed

    2012-06-01

    Tin disulfide (SnS2) thin films have been synthesized using a simplified spray pyrolysis technique using a perfume atomizer. The films were deposited using two different solutions prepared by the dilution of SnCl2 and thiourea in distilled water and in methanol. The obtained films have a microcrystalline structure. The film deposited using methanol as the solvent is nearly stochiometric SnS2 with a spinel phase having a (001) preferential orientation. The film prepared with an aqueous solution is Sn-rich. Scanning electronic microscopy (SEM) images reveal that the film deposited with the aqueous solution is rough and is formed with large wires. However, the film deposited with methanol is dense and smooth. Conductivity measurements indicate that the aqueous solution leads to an n-type semiconductor, while methanol leads to a p-type semiconductor.

  18. 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.

  19. Photoelectrochemical activity of liquid phase deposited TiO2 film for degradation of benzotriazole

    International Nuclear Information System (INIS)

    TiO2 film deposited on glassy carbon electrode surface was prepared via the liquid phase deposition (LPD). The deposited TiO2 film before and after calcination was characterized with scanning electron microscopy (SEM) and X-ray diffraction (XRD). Based on the high photoelectrochemical activity of calcined LPD TiO2 film, the photoelectrocatalytic degradation of benzotriazole (BTA) was investigated. Compared with the electrochemical oxidation process, direct photolysis or photocatalysis for treatment of BTA, a synergetic photoelectrocatalytic degradation effect was observed using the LPD TiO2 film-coated electrode. Various factors influencing the photoelectrocatalytic degradation of BTA such as film calcination, applied bias potential, pH value, supporting electrolyte concentration and initial concentration of BTA were investigated. The COD removal for BTA solution was analyzed to evaluate the mineralization of the PEC process. Based on the degradation experimental results, a possible photoelectrocatalytic degradation mechanism for BTA was proposed.

  20. Dielectric properties of 'diamondlike' carbon prepared by RF plasma deposition

    Science.gov (United States)

    Lamb, J. D.; Woollam, J. A.

    1985-01-01

    Metal-carbon-metal structures were fabricated using either gold or aluminum evaporated electrodes and RF plasma (methane) deposited 'diamondlike' carbon films. Alternating-current conductance and capacitance versus voltage and frequency (10 Hz to 13 MHz) data were taken to determine the dielectric properties of these films. Conductance versus frequency data fit a generalized power law, consistent with both dc and hopping conduction components. The capacitance versus frequency data are well matched to the conductance versus frequency data, as predicted by a Kramers-Kronig analysis. The dielectric loss tangent is nearly constant at 0.5 to 1.0 percent over the frequency range from 1 to 100 kHz. The dc resistivity is above 10 to the 13th ohm cm, and the dc breakdown strength is above 8 x 10 to the 6th V/cm is properly prepared samples.

  1. Synthesis and characterization of boron incorporated diamond-like carbon thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, L.L. [Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9 (Canada); Yang, Q., E-mail: qiaoqin.yang@usask.ca [Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9 (Canada); Tang, Y.; Yang, L.; Zhang, C. [Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9 (Canada); Hu, Y.; Cui, X. [Canadian Light Source Inc., 101 Perimeter Road, Saskatoon, SK S7N 0X4 (Canada)

    2015-08-31

    Boron incorporated diamond-like carbon (B-DLC) (up to 8 wt.% boron) thin films were synthesized on silicon wafers using biased target ion beam deposition technique, where diamond-like carbon (DLC) was deposited by ion beam deposition and boron (B) was simultaneously incorporated by biased target sputtering of a boron carbide (B{sub 4}C) target under different conditions. Pure DLC films and B–C films were also synthesized by ion beam deposition and biased target sputtering of B{sub 4}C under similar conditions, respectively, as reference samples. The microstructure and mechanical properties of the synthesized films have been characterized by various technologies. It has been found that B exists in different states in B-DLC, including carbon-rich and B-rich boron carbides, boron suboxide and boron oxide, and the oxidation of B probably occurs during the film deposition. The incorporation of B into DLC leads to the increase of sp{sup 3} bonded carbon in the films, the increase of both film hardness and elastic modulus, and the decrease of both surface roughness and friction coefficient. Furthermore, the content of sp{sup 3} bonded carbon, film hardness and elastic modulus increase, and the film surface roughness and friction coefficient decrease with the increase of B-rich carbide in the B-DLC films. - Highlights: • Biased target ion beam deposition technique is promising to produce high quality DLC based thin films; • Boron exists in different states in B-DLC thin films; • The incorporation of B to DLC with different levels leads to improved film properties; • The fraction of sp{sup 3} bonded C in B-DLC thin films increase with the increase of B-rich carbide content in the films.

  2. Synthesis and characterization of boron incorporated diamond-like carbon thin films

    International Nuclear Information System (INIS)

    Boron incorporated diamond-like carbon (B-DLC) (up to 8 wt.% boron) thin films were synthesized on silicon wafers using biased target ion beam deposition technique, where diamond-like carbon (DLC) was deposited by ion beam deposition and boron (B) was simultaneously incorporated by biased target sputtering of a boron carbide (B4C) target under different conditions. Pure DLC films and B–C films were also synthesized by ion beam deposition and biased target sputtering of B4C under similar conditions, respectively, as reference samples. The microstructure and mechanical properties of the synthesized films have been characterized by various technologies. It has been found that B exists in different states in B-DLC, including carbon-rich and B-rich boron carbides, boron suboxide and boron oxide, and the oxidation of B probably occurs during the film deposition. The incorporation of B into DLC leads to the increase of sp3 bonded carbon in the films, the increase of both film hardness and elastic modulus, and the decrease of both surface roughness and friction coefficient. Furthermore, the content of sp3 bonded carbon, film hardness and elastic modulus increase, and the film surface roughness and friction coefficient decrease with the increase of B-rich carbide in the B-DLC films. - Highlights: • Biased target ion beam deposition technique is promising to produce high quality DLC based thin films; • Boron exists in different states in B-DLC thin films; • The incorporation of B to DLC with different levels leads to improved film properties; • The fraction of sp3 bonded C in B-DLC thin films increase with the increase of B-rich carbide content in the films

  3. Controlled Deposition and Alignment of Carbon Nanotubes

    Science.gov (United States)

    Smits, Jan M. (Inventor); Wincheski, Russell A. (Inventor); Patry, JoAnne L. (Inventor); Watkins, Anthony Neal (Inventor); Jordan, Jeffrey D. (Inventor)

    2012-01-01

    A carbon nanotube (CNT) attraction material is deposited on a substrate in the gap region between two electrodes on the substrate. An electric potential is applied to the two electrodes. The CNT attraction material is wetted with a solution defined by a carrier liquid having carbon nanotubes (CNTs) suspended therein. A portion of the CNTs align with the electric field and adhere to the CNT attraction material. The carrier liquid and any CNTs not adhered to the CNT attraction material are then removed.

  4. X-ray scattering of calcite thin films deposited by atomic layer deposition: Studies in air and in calcite saturated water solution

    International Nuclear Information System (INIS)

    Carbonates are one of the most abundant groups of minerals in earth systems and are important in many geological settings and industrial processes. Calcite (CaCO3) thin films produced by atomic layer deposition offer a method to evaluate the surficial properties of carbonates as well as interactions at the carbonate–fluid interface. Using synchrotron X-ray reflectivity and X-ray diffraction, these films are observed to be porous, polycrystalline, and have crystallites oriented with the major (104) calcite cleavage plane parallel to the surface of the z-cut single crystal quartz substrate. An Al2O3 buffer layer, present between quartz and the calcite film, does not affect the as-deposited film, but does influence how the films reorganize in contact with fluid. Without a buffer layer, calcite reorients its crystallites to have populations of (006) and (030) parallel to the substrate, while those with an Al2O3 buffer layer become more amorphous. Amorphous films may represent an analog to amorphous calcium carbonate and provide insights into that material's thermophysical behavior. Due to a higher percentage of pore spaces available for fluid infiltration, films deposited at higher temperature make the calcite thin films more susceptible to amorphization. These films are chemically similar, but structurally dissimilar to bulk natural calcite. Nevertheless, they can be a complementary system to traditional single crystal X-ray surface scattering studies on carbonates, particularly for important but less common minerals, to evaluate mineral–fluid interfacial interactions. - Highlights: • Atomic layer deposition (ALD) used to produce calcite films. • Calcite film orientation and crystallinity depend on ALD parameters. • ALD calcite films can be both crystalline and amorphous. • Interaction of water with films can re-orient or amorphize the films. • ALD calcite films may be useful to study carbonate–fluid interfacial interactions

  5. Friction and wear of plasma-deposited amorphous hydrogenated films on silicon nitride

    Science.gov (United States)

    Miyoshi, Kazuhisa

    1991-01-01

    An investigation was conducted to examine the friction and wear behavior of amorphous hydrogenated carbon (a-C:H) films in sliding contact with silicon nitride pins in both dry nitrogen and humid air environments. Amorphous hydrogenated carbon films approximately 0.06 micron thick were deposited on silicon nitride flat substrates by using the 30 kHz ac glow discharge of a planar plasma reactor. The results indicate that an increase in plasma deposition power gives an increase in film density and hardness. The high-density a-C:H films deposited behaved tribologically much like bulk diamond. In the dry nitrogen environment, a tribochemical reaction produced a substance, probably a hydrocarbon-rich layer, that decreased the coefficient of friction. In the humid air environment, tribochemical interactions drastically reduced the wear life of a-C:H films and water vapor greatly increased the friction. Even in humid air, effective lubrication is possible with vacuum-annealed a-C:H films. The vacuum-annealed high-density a-C:H film formed an outermost superficial graphitic layer, which behaved like graphite, on the bulk a-C:H film. Like graphite, the annealed a-C:H film with the superficial graphitic layer showed low friction when adsorbed water vapor was present.

  6. In situ electron spectroscopic identification of carbon species deposited by laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Samano, E.C.; Gamietea, A.; Cota, L. [IFUNAM, Ensenada (Mexico). Lab. de Ensenada; Soto, G. [IFUNAM, Ensenada (Mexico). Lab. de Ensenada]|[Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (Mexico). Programa de Posgrado en Fisica de Materiales

    1997-05-01

    Thin carbon films were grown on Si (111) substrates by ablating a graphite target utilizing an excimer pulsed laser in a UHV Riber {copyright} LDM-32 system. Two kinds of films were produced, a highly oriented pyrolytic graphite (HOPG) type and a diamond-like carbon (DLC) type. A relationship of the films microstructure with laser power density and substrate conditions was observed. The HOPG films were homogeneous but the DLC films were heterogeneous, as shown by micrographs. The thin films are monitored and analyzed in situ during the first stages of the deposition process. The monitoring was done by RHEED and the characterization by several surface spectroscopic techniques, AES, XPS and EELS. The formation of a SiC interface was observed for both films due to the reaction of the first carbon species with the substrate surface.

  7. Evaluation of neodymium doped fluoride glass films deposited by pulsed laser deposition

    OpenAIRE

    Harwood, D.W.J.; Eason, R. W.; Taylor, E. R.

    1997-01-01

    Pulsed laser deposition (PLD) has been evaluated as a technique for the realisation of neodymium doped fluoride glass waveguides. In contrast to other high energy techniques such as sputtering and molecular beam epitaxy, pulsed laser deposition appears to reliably reproduce the bulk stoichiometry of the doped glass in thin film form. However, characteristically for this deposition technique, the film topography is dominated by micron size particulates generated during fabrication. Film unifor...

  8. Microwave plasma CVD technology of carbon and carbon-nitrogen films

    International Nuclear Information System (INIS)

    Carbon and carbon-nitrogen films have been deposited by Microwave Plasma Chemical Vapor Deposition at 2.45 GHz. During the process methane-argon-hydrogen-nitrogen atmospheres were used. The films were grown in a wide temperature range from the room temperature up to 950oC in total gas pressure from 0.1 to 0.5 Tr. The materials were examined by means of FTIR and optical spectroscopy. The authors investigated the influence of technological conditions on composition, structure and optical properties. The chemical composition of films depended on the substrate temperature and plasma content. The carbon hydrogen bonds intensity decreased strongly at elevated temperature.The process of degradation of mechanical properties was also observed. The results indicate that there is a possibility of mechanical and electronic applications of these materials. (author)

  9. 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.

  10. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-02-15

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

  12. AlN thin films prepared by DC arc deposition

    Science.gov (United States)

    Liang, Hai-feng; Yan, Yi-xin; Miao, Shu-fan

    2006-02-01

    Many researchers are interested in AlN films because of their novel thermal, chemical, mechanical, acoustic, and optical properties. Many methodsincluding such as DC/RF sputtering, chemical vapor deposition (CVD), laser chemical vapor deposition(LCVD), molecular beam epitaxy (MBE), thermal vapor deposition, can be used to prepare AlN films. In this paper, a new method, DC arc deposition, is used to deposite AlN films. It is an anti-reflective, protective film on optical elements. FTIR are used to determine the ALN structure and measure the transmittance spectrum. Ellipsometry is used to determine the films' refractive index, extinction index and thickness. The films' anti-wear properties are tested by pin-on-disc way and the anti-corrosion(anti-acid, anti-alkali, anti-salt) properties are also tested. The results show that the films is AlN films by the 670cm -1 typical peak, the films' extinction index is near to zero in the range of visible and infrared waveband, the films' refractive index is varied from 1.7 to 2.1 at range of visible and infrared waveband. The films have better anti-wear, anti-acid and anti-alkali properties, but their anti-salt properties are not good.

  13. Impact of laser power density on tribological properties of Pulsed Laser Deposited DLC films

    International Nuclear Information System (INIS)

    Fabrication of wear resistant and low friction carbon films on the engineered substrates is considered as a challenging task for expanding the applications of diamond-like carbon (DLC) films. In this paper, pulsed laser deposition (PLD) technique is used to deposit DLC films on two different types of technologically important class of substrates such as silicon and AISI 304 stainless steel. Laser power density is one of the important parameter used to tailor the fraction of sp2 bonded amorphous carbon (a-C) and tetrahedral amorphous carbon (ta-C) made by sp3 domain in the DLC film. The I(D)/I(G) ratio decreases with the increasing laser power density which is associated with decrease in fraction of a-C/ta-C ratio. The fraction of these chemical components is quantitatively analyzed by EELS which is well supported to the data obtained from the Raman spectroscopy. Tribological properties of the DLC are associated with chemical structure of the film. However, the super low value of friction coefficient 0.003 is obtained when the film is predominantly constituted by a-C and sp2 fraction which is embedded within the clusters of ta-C. Such a particular film with super low friction coefficient is measured while it was deposited on steel at low laser power density of 2 GW/cm2. The super low friction mechanism is explained by low sliding resistance of a-C/sp2 and ta-C clusters. Combination of excellent physical and mechanical properties of wear resistance and super low friction coefficient of DLC films is desirable for engineering applications. Moreover, the high friction coefficient of DLC films deposited at 9GW/cm2 is related to widening of the intergrain distance caused by transformation from sp2 to sp3 hybridized structure

  14. Impact of laser power density on tribological properties of Pulsed Laser Deposited DLC films

    Directory of Open Access Journals (Sweden)

    S. Gayathri

    2013-12-01

    Full Text Available Fabrication of wear resistant and low friction carbon films on the engineered substrates is considered as a challenging task for expanding the applications of diamond-like carbon (DLC films. In this paper, pulsed laser deposition (PLD technique is used to deposit DLC films on two different types of technologically important class of substrates such as silicon and AISI 304 stainless steel. Laser power density is one of the important parameter used to tailor the fraction of sp2 bonded amorphous carbon (a-C and tetrahedral amorphous carbon (ta-C made by sp3 domain in the DLC film. The I(D/I(G ratio decreases with the increasing laser power density which is associated with decrease in fraction of a-C/ta-C ratio. The fraction of these chemical components is quantitatively analyzed by EELS which is well supported to the data obtained from the Raman spectroscopy. Tribological properties of the DLC are associated with chemical structure of the film. However, the super low value of friction coefficient 0.003 is obtained when the film is predominantly constituted by a-C and sp2 fraction which is embedded within the clusters of ta-C. Such a particular film with super low friction coefficient is measured while it was deposited on steel at low laser power density of 2 GW/cm2. The super low friction mechanism is explained by low sliding resistance of a-C/sp2 and ta-C clusters. Combination of excellent physical and mechanical properties of wear resistance and super low friction coefficient of DLC films is desirable for engineering applications. Moreover, the high friction coefficient of DLC films deposited at 9GW/cm2 is related to widening of the intergrain distance caused by transformation from sp2 to sp3 hybridized structure.

  15. Deposition and characterization of organosilicon thin films from TEOS+O2 gas mixture

    International Nuclear Information System (INIS)

    SixOyCz films were prepared by rf plasma deposition using a non-conventional self-biased barrel system. The deposited films were highly transparent in the optical region and relatively hard. The hardness increased with the increasing negative self-bias potential across the substrate during deposition. The amount of carbon atoms incorporated in the layer increased with increasing self-bias but the atomic composition substantially depended on the tetraethoxysilane and O2 partial pressures during deposition. The hydrogen content of the films reached 30 to 60 atomic % and decreased with the increasing oxygen partial pressure during deposition. The optical constants of deposited thin films were very similar to those of SiO2. In thermal annealing of thin films deposited on Si substrates a change of internal stress from compressive stress to tensile stress was observed at 400 to 500oC; a remarkable thermal hysteresis of the measured stress during the first post-deposition annealing, however, was also observed. (J.B.) 1 tab., 8 figs., 21 refs

  16. Optical circular dichroism of vacuum-deposited film stacks

    Science.gov (United States)

    Fan, B.; Vithana, H. K. M.; Kralik, J. C.; Faris, S. M.

    1998-02-01

    We report on optical circular dichroism of chiral multilayer SiO x films obtained by a novel vacuum deposition technique. The film layers were deposited at an oblique incidence angle to render them optically anisotropic, and were stacked such that the optic axes of the layers spiral in a helical fashion about the substrate normal. The resulting film stacks display both wavelength and polarization selectivity, in analogy with organic cholesteric liquid crystals aligned in the planar texture. Reflectance spectra of two films of opposite chirality are presented. Both film stacks are tuned to reflect in the visible and were prepared using obliquely deposited SiO x. Calculated spectra using a Berreman's 4×4 matrix approach agree well with the experimental findings. It is concluded that vacuum-deposited chiral film stacks hold promise for use as high-efficiency polarizers and other novel optical components.

  17. Atomic Layer Deposition of Zirconium Oxide on Carbon Nanoparticles

    International Nuclear Information System (INIS)

    In this report we describe preparation of structures containing carbon nanoparticles for potential applications in nonvolatile memories. The carbon nanoparticles were synthesized from 5-methylresorcinol and formaldehyde via base catalysed polycondensation reaction, and were distributed over substrates by dip-coating the substrates into an organic solution. Before deposition of nanoparticles the substrates were covered with 2 nm thick Al2O3 layer grown by atomic layer deposition (ALD) from Al(CH3)3 and O3. After deposition of nanoparticles the samples were coated with ZrO2 films grown from C5H5Zr[N(CH3)2]3 and H2O. Both dielectrics were grown in two-temperature ALD processes starting deposition of Al2O3 at 25 °C and ZrO2 at 200 °C, thereafter completing both processes at a substrate temperature of 300 °C. Deposition of ZrO2 changed the structure of C-nanoparticles, which still remained in a Si/Al2O3/C/ZrO2 structure as a separate layer. Electrical characterization of nanostructures containing Al2O3 as tunnel oxide, C-nanoparticles as charge traps and ZrO2 as control oxide showed hysteretic flat-band voltage shift of about 1V

  18. Improvement of orthodontic friction by coating archwire with carbon nitride film

    Energy Technology Data Exchange (ETDEWEB)

    Wei Songbo [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Shao Tianmin, E-mail: shaotm@mail.tsinghua.edu.cn [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Ding Peng [Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing 100081 (China)

    2011-10-01

    In order to reduce frictional resistance between archwire and bracket during orthodontic tooth movement, carbon nitride (CNx) thin films were deposited on the surface of archwires with ion beam assisted deposition (IBAD). The energy-dispersive X-ray spectrometer (EDS) analysis showed that the CNx film was successfully deposited on the surface of the orthodontic wires. X-ray photoelectron spectroscopy (XPS) analysis suggested that the deposited CNx film was sp{sup 2} carbon dominated structures, and diversiform bonds (N-C, N{identical_to}C, et al.) coexisted in the film. The friction tests indicated that the CNx film significantly reduced the wire-bracket friction both in ambient air and in artificial saliva. The sp{sup 2}C rich structure of the CNx film as well as its protection function for the archwire was responsible for the low friction of the wire-bracket sliding system.

  19. Improvement of orthodontic friction by coating archwire with carbon nitride film

    International Nuclear Information System (INIS)

    In order to reduce frictional resistance between archwire and bracket during orthodontic tooth movement, carbon nitride (CNx) thin films were deposited on the surface of archwires with ion beam assisted deposition (IBAD). The energy-dispersive X-ray spectrometer (EDS) analysis showed that the CNx film was successfully deposited on the surface of the orthodontic wires. X-ray photoelectron spectroscopy (XPS) analysis suggested that the deposited CNx film was sp2 carbon dominated structures, and diversiform bonds (N-C, N≡C, et al.) coexisted in the film. The friction tests indicated that the CNx film significantly reduced the wire-bracket friction both in ambient air and in artificial saliva. The sp2C rich structure of the CNx film as well as its protection function for the archwire was responsible for the low friction of the wire-bracket sliding system.

  20. Influence of deposition time on the properties of chemical bath deposited manganese sulfide thin films

    Directory of Open Access Journals (Sweden)

    Anuar Kassim

    2010-12-01

    Full Text Available Manganese sulfide thin films were chemically deposited from an aqueous solution containing manganese sulfate, sodium thiosulfate and sodium tartrate. The influence of deposition time (2, 3, 6 and 8 days on the properties of thin films was investigated. The structure and surface morphology of the thin films were studied by X-ray diffraction and atomic force microscopy, respectively. In addition, in order to investigate the optical properties of the thin films, the UV-visible spectrophotometry was used. The XRD results indicated that the deposited MnS2 thin films exhibited a polycrystalline cubic structure. The number of MnS2 peaks on the XRD patterns initially increased from three to six peaks and then decreased to five peaks, as the deposition time was increased from 2 to 8 days. From the AFM measurements, the film thickness and surface roughness were found to be dependent on the deposition time.

  1. 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.

  2. Preparation and optical properties of sol-gel-deposited electrochromic iron oxide films

    Science.gov (United States)

    Ozer, Nilgun; Tepehan, Fatma; Tepehan, Galip

    1997-10-01

    The preparation and optical properties of sol-gel deposited iron oxide films are investigated in this study. The films are deposited on glass by spin-coating from polymeric sol-gel solutions. The coating solutions were prepared from Fe(OCH3H7)3 and isopropanol. Fe2O3 films were obtained at a firing temperature 180 degrees Celsius. The films were characterized by x-ray diffractometry (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), cyclic voltammetry (CV) and UV-Vis spectroscopy. The electrochemical properties of the films were studied in 0.5 M LiClO4/propylene carbonate (PC) solution. The CV results showed reversibility of the Li+/e- insertion/extraction process in the Fe2O3 films up to 200 cycles. Reduction and oxidation of the amorphous films in 0.5 M LiClO4-PC solution caused noticeable changes in optical absorption. XRD of the films showed that they had an amorphous structure. Fourier transform infrared spectroscopy (FTIR) measurements showed that the composition of the film is Fe2O3. In-situ spectrophotometric measurements indicated that these films show weak electrochromism in the spectral range of 350 - 800 nm. The optical band gap is estimated to be 1.92 eV for the amorphous film. The spectroelectrochemical properties clearly indicated that cyclic stability of the iron oxide films deteriorated above 200 cycles.

  3. 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

  4. Rate and pressure dependence of contaminants in vacuum-deposited aluminum films

    International Nuclear Information System (INIS)

    Experiments have been conducted to measure the quantity of trapped impurities in electron-beam-deposited aluminum films. The depositions were conducted at the 1.3 x 10-4--1.3 x 10-2 Pa pressure range with rates varying from a few tenths to 7.0 nm/s. An RGA was used to record the residual gas spectrum before and during all runs. The films were analyzed by sputter profiling and Auger electron spectroscopy. The chief contaminants found were carbon and oxygen. The carbon contaminant tracked the gauge pressure over two orders of magnitude ranging from a few atomic percent to the 500--1000 ppm range. The partial pressures of H2O, O2, and other gases were varied during deposition to determine their individual roles in contaminating the films. As a result, a relationship between the residual gas spectrum, and chemical analysis was found

  5. Facile fabrication of boron nitride nanosheets-amorphous carbon hybrid film for optoelectronic applications

    KAUST Repository

    Wan, Shanhong

    2015-01-01

    A novel boron nitride nanosheets (BNNSs)-amorphous carbon (a-C) hybrid film has been deposited successfully on silicon substrates by simultaneous electrochemical deposition, and showed a good integrity of this B-C-N composite film by the interfacial bonding. This synthesis can potentially provide the facile control of the B-C-N composite film for the potential optoelectronic devices. This journal is

  6. Low temperature CVD growth of ultrathin carbon films

    Directory of Open Access Journals (Sweden)

    Chao Yang

    2016-05-01

    Full Text Available We demonstrate the low temperature, large area growth of ultrathin carbon films by chemical vapor deposition under atmospheric pressure on various substrates. In particularly, uniform and continuous carbon films with the thickness of 2-5 nm were successfully grown at a temperature as low as 500 oC on copper foils, as well as glass substrates coated with a 100 nm thick copper layer. The characterizations revealed that the low-temperature-grown carbon films consist on few short, curved graphene layers and thin amorphous carbon films. Particularly, the low-temperature grown samples exhibited over 90% transmittance at a wavelength range of 400-750 nm and comparable sheet resistance in contrast with the 1000oC-grown one. This low-temperature growth method may offer a facile way to directly prepare visible ultrathin carbon films on various substrate surfaces that are compatible with temperatures (500-600oC used in several device processing technologies.

  7. Synthesis of carbo-nitride films using high-energy shock plasma deposition

    International Nuclear Information System (INIS)

    Recent investigations shows that an enhanced nitrogen content of carbo-nitride films improves wear resistance, hardness, tribological and other properties of these films. The present work reports on the properties of nitrogen rich carbon films produced by an intense gas discharge between carbon electrodes in a nitrogen atmosphere. The energy of the discharge, initial nitrogen pressure, number of discharges and geometry are varied to establish their effect on the nitrogen content and the mechanical, structural and morphological characteristics of the deposited carbon-nitride films. The structural diagnostics include optical and scanning electron microscopy, as well as Auger and Raman Spectroscopes and Rutherford Backscattering. The C-N films formed fell into two categories, differing in morphology and mechanical properties. Type I are C-N films, containing up to 35 at. % nitrogen, and which have an amorphous structure. These films are formed at relatively low plasma shock pressure and exhibit relatively low microhardness, ∼ 2 GPa. In a relatively narrow range of the plasma shock pressure and temperature the second type of C-N deposition is observed consisting of high density, closely-packed crystal-like grains growing perpendicular to the substrate surface and displaying a cauliflower-like morphology. The microhardness of these films reaches 15 GPa, as measured by the Vickers method. 14 refs., 7 figs

  8. Electrophoretic Deposition of Carbon Nanotubes on 3-Amino-Propyl-Triethoxysilane (APTES) Surface Functionalized Silicon Substrates

    OpenAIRE

    Theda Daniels-Race; Anirban Sarkar

    2013-01-01

    Fabrication of uniform thin coatings of multi-walled carbon nanotubes (MWCNTs) by electrophoretic deposition (EPD) on semiconductor (silicon) substrates with 3-aminopropyl-triethoxysilane (APTES) surface functionalization has been studied extensively in this report. The gradual deposition and eventual film formation of the carbon nanotubes (CNTs) is greatly assisted by the Coulombic force of attraction existing between the positively charged –NH2 surface groups of APTES and the acid treated, ...

  9. Study on the preparation of high barrier hydrogenated carbon film and its properties

    International Nuclear Information System (INIS)

    Hydrogenated carbon thin films were fabricated on the surface of polyethylene terephthalate (PET) by radio frequency plasma enhanced chemical vapor deposition (r.f. PECVD). The film structure properties were studied by means of atomic force microscope (AFM), x-ray photo-electron (XPS), laser Raman spectroscopy, Fourier-transform infrared spectra (FTIR), etc. The barrier property of the film was conducted on the water vapor permeation instrument. The results show that nano-hydrogenated carbon films have been deposited on PET surface and they are mainly composed of sp2 and sp3 hybridized hydrogenated carbon compounds. Plasma parameters influence the films' growth rate and structure characteristics. The film reduces the water vapor permeation ratio of the PET by 7 times at a film thickness of only 900 nm. (authors)

  10. Effects of deposition time in chemically deposited ZnS films in acidic solution

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, H.; Chelouche, A., E-mail: azeddinechelouche@gmail.com; Talantikite, D.; Merzouk, H.; Boudjouan, F.; Djouadi, D.

    2015-08-31

    We report an experimental study on the synthesis and characterization of zinc sulfide (ZnS) single layer thin films deposited on glass substrates by chemical bath deposition technique in acidic solution. The effect of deposition time on the microstructure, surface morphology, optical absorption, transmittance, and photoluminescence (PL) was investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), UV-Vis–NIR spectrophotometry and photoluminescence (PL) spectroscopy. The results showed that the samples exhibit wurtzite structure and their crystal quality is improved by increasing deposition time. The latter, was found to affect the morphology of the thin films as showed by SEM micrographs. The optical measurements revealed a high transparency in the visible range and a dependence of absorption edge and band gap on deposition time. The room temperature PL spectra indicated that all ZnS grown thin films emit a UV and blue light, while the band intensities are found to be dependent on deposition times. - Highlights: • Single layer ZnS thin films were deposited by CBD in acidic solution at 95 °C. • The effect of deposition time was investigated. • Coexistence of ZnS and ZnO hexagonal structures for time deposition below 2 h • Thicker ZnS films were achieved after monolayer deposition for 5 h. • The highest UV-blue emission observed in thin film deposited at 5 h.

  11. Effects of deposition time in chemically deposited ZnS films in acidic solution

    International Nuclear Information System (INIS)

    We report an experimental study on the synthesis and characterization of zinc sulfide (ZnS) single layer thin films deposited on glass substrates by chemical bath deposition technique in acidic solution. The effect of deposition time on the microstructure, surface morphology, optical absorption, transmittance, and photoluminescence (PL) was investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), UV-Vis–NIR spectrophotometry and photoluminescence (PL) spectroscopy. The results showed that the samples exhibit wurtzite structure and their crystal quality is improved by increasing deposition time. The latter, was found to affect the morphology of the thin films as showed by SEM micrographs. The optical measurements revealed a high transparency in the visible range and a dependence of absorption edge and band gap on deposition time. The room temperature PL spectra indicated that all ZnS grown thin films emit a UV and blue light, while the band intensities are found to be dependent on deposition times. - Highlights: • Single layer ZnS thin films were deposited by CBD in acidic solution at 95 °C. • The effect of deposition time was investigated. • Coexistence of ZnS and ZnO hexagonal structures for time deposition below 2 h • Thicker ZnS films were achieved after monolayer deposition for 5 h. • The highest UV-blue emission observed in thin film deposited at 5 h

  12. Gas barrier properties of titanium oxynitride films deposited on polyethylene terephthalate substrates by reactive magnetron sputtering

    International Nuclear Information System (INIS)

    Titanium oxynitride (TiNxOy) films were deposited on polyethylene terephthalate (PET) substrates by means of a reactive radio frequency (RF) magnetron sputtering system in which the power density and substrate bias were the varied parameters. Experimental results show that the deposited TiNxOy films exhibited an amorphous or a columnar structure with fine crystalline dependent on power density. The deposition rate increases significantly in conjunction as the power density increases from 2 W/cm2 to 7 W/cm2. The maximum deposition rate occurs, as the substrate bias is -40 V at a certain power densities chosen in this study. The film's roughness slightly decreases with increasing substrate bias. The TiNxOy films deposited at power densities above 4 W/cm2 show a steady Ti:N:O ratio of about 1:1:0.8. The water vapor and oxygen transmission rates of the TiNxOy films reach values as low as 0.98 g/m2-day-atm and 0.60 cm3/m2-day-atm which are about 6 and 47 times lower than those of the uncoated PET substrate, respectively. These transmission rates are comparable to those of DLC, carbon-based and Al2O3 barrier films. Therefore, TiNxOy films are potential candidates to be used as a gas permeation barrier for PET substrate

  13. Characterization of transparent silica films deposited on polymeric materials

    International Nuclear Information System (INIS)

    Silica films were synthesized by capacitively coupled RF PECVD using mixtures of organo-silane and oxygen as a source. The chemical bonding states and compositions of the films deposited were evaluated with FTIR and XPS. Film surfaces and cross-sections were observed by SEM. Oxygen transmission rates (OTR) of the films coated on polyethylene terephthalate (PET) substrates were measured by an isopiestic method. (Authors)

  14. Deposition and investigation of lanthanum cerium hexaboride thin films

    Science.gov (United States)

    Kuzanyan, A. S.; Harutyunyan, S. R.; Vardanyan, V. O.; Badalyan, G. R.; Petrosyan, V. A.; Kuzanyan, V. S.; Petrosyan, S. I.; Karapetyan, V. E.; Wood, K. S.; Wu, H.-D.; Gulian, A. M.

    2006-09-01

    Thin films of lanthanum-cerium hexaboride, the promising thermoelectric material for low-temperature applications, are deposited on various substrates by the electron-beam evaporation, pulsed laser deposition and magnetron sputtering. The influence of the deposition conditions on the films X-ray characteristics, composition, microstructure and physical properties, such as the resistivity and Seebeck coefficient, is studied. The preferred (100) orientation of all films is obtained from XRD traces. In the range of 780-800 °C deposition temperature the highest intensity of diffractions peaks and the highest degree of the preferred orientation are observed. The temperature dependence of the resistivity and the Seebeck coefficient of films are investigated in the temperature range of 4-300 K. The features appropriate to Kondo effect in the dependences ρ( T) and S( T) are detected at temperatures below 20 K. Interplay between the value of the Seebeck coefficient, metallic parameters and Kondo scattering of investigated films is discussed.

  15. Graphene diamond-like carbon films heterostructure

    Science.gov (United States)

    Zhao, Fang; Afandi, Abdulkareem; Jackman, Richard B.

    2015-03-01

    A limitation to the potential use of graphene as an electronic material is the lack of control over the 2D materials properties once it is deposited on a supporting substrate. Here, the use of Diamond-like Carbon (DLC) interlayers between the substrate and the graphene is shown to offer the prospect of overcoming this problem. The DLC films used here, more properly known as a-C:H with ˜25% hydrogen content, have been terminated with N or F moieties prior to graphene deposition. It is found that nitrogen terminations lead to an optical band gap shrinkage in the DLC, whilst fluorine groups reduce the DLC's surface energy. CVD monolayer graphene subsequently transferred to DLC, N terminated DLC, and F terminated DLC has then been studied with AFM, Raman and XPS analysis, and correlated with Hall effect measurements that give an insight into the heterostructures electrical properties. The results show that different terminations strongly affect the electronic properties of the graphene heterostructures. G-F-DLC samples were p-type and displayed considerably higher mobility than the other heterostructures, whilst G-N-DLC samples supported higher carrier densities, being almost metallic in character. Since it would be possible to locally pattern the distribution of these differing surface terminations, this work offers the prospect for 2D lateral control of the electronic properties of graphene layers for device applications.

  16. Graphene diamond-like carbon films heterostructure

    International Nuclear Information System (INIS)

    A limitation to the potential use of graphene as an electronic material is the lack of control over the 2D materials properties once it is deposited on a supporting substrate. Here, the use of Diamond-like Carbon (DLC) interlayers between the substrate and the graphene is shown to offer the prospect of overcoming this problem. The DLC films used here, more properly known as a-C:H with ∼25% hydrogen content, have been terminated with N or F moieties prior to graphene deposition. It is found that nitrogen terminations lead to an optical band gap shrinkage in the DLC, whilst fluorine groups reduce the DLC's surface energy. CVD monolayer graphene subsequently transferred to DLC, N terminated DLC, and F terminated DLC has then been studied with AFM, Raman and XPS analysis, and correlated with Hall effect measurements that give an insight into the heterostructures electrical properties. The results show that different terminations strongly affect the electronic properties of the graphene heterostructures. G-F-DLC samples were p-type and displayed considerably higher mobility than the other heterostructures, whilst G-N-DLC samples supported higher carrier densities, being almost metallic in character. Since it would be possible to locally pattern the distribution of these differing surface terminations, this work offers the prospect for 2D lateral control of the electronic properties of graphene layers for device applications

  17. Graphene diamond-like carbon films heterostructure

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Fang; Afandi, Abdulkareem; Jackman, Richard B., E-mail: r.jackman@ucl.ac.uk [London Centre for Nanotechnology, Electronic and Electrical Engineering Department, University College London, 17-19 Gordon Street, London WC1H 0AH (United Kingdom)

    2015-03-09

    A limitation to the potential use of graphene as an electronic material is the lack of control over the 2D materials properties once it is deposited on a supporting substrate. Here, the use of Diamond-like Carbon (DLC) interlayers between the substrate and the graphene is shown to offer the prospect of overcoming this problem. The DLC films used here, more properly known as a-C:H with ∼25% hydrogen content, have been terminated with N or F moieties prior to graphene deposition. It is found that nitrogen terminations lead to an optical band gap shrinkage in the DLC, whilst fluorine groups reduce the DLC's surface energy. CVD monolayer graphene subsequently transferred to DLC, N terminated DLC, and F terminated DLC has then been studied with AFM, Raman and XPS analysis, and correlated with Hall effect measurements that give an insight into the heterostructures electrical properties. The results show that different terminations strongly affect the electronic properties of the graphene heterostructures. G-F-DLC samples were p-type and displayed considerably higher mobility than the other heterostructures, whilst G-N-DLC samples supported higher carrier densities, being almost metallic in character. Since it would be possible to locally pattern the distribution of these differing surface terminations, this work offers the prospect for 2D lateral control of the electronic properties of graphene layers for device applications.

  18. Synthesis of tungsten oxide thin film by liquid phase deposition

    International Nuclear Information System (INIS)

    High purity and well crystallized tungsten acid hydrates (H2WO4.H2O) thin films were prepared from H2WO4-HF(aq.) and H3BO3 as precursors by the liquid phase deposition method. The crystal structure was indexed as monoclinic with unit cell lattice constants a = 7.517 A, b = 6.907 A, c = 3.694 A and β = 89.58 deg. The monoclinic phase was transformed into orthorhombic WO3.H2O after heating at 100 deg. C. Further heating from 300 to 500 deg. C resulted in an anhydrous monoclinic WO3 films. The effects of the composition and the reaction time on the deposition and the microstructures of the deposited films were studied by the means of scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The film formation showed strong dependence upon the composition, whereas the amount of deposition, the shape and the films thickness could be controlled by the reaction time. Cross-sectional TEM image of WO3 film deposited on Au wire indicated that the epitaxial growth of the film was maintained after calcination at 500 deg. C. XPS analysis also revealed the existence of W6+ ions in both the deposited and calcined films.

  19. Low temperature deposition of silver sulfide thin films by AACVD for gas sensor application

    International Nuclear Information System (INIS)

    Highlights: ► Silver sulfide thin films were deposited by aerosol assisted chemical vapor deposition from a single source precursor [Ag(S2CN (C2H5)2)3]2 (1). ► The precursor (1), prepared in high yield by simple reported chemical procedure, was characterized and undergoes facile decomposition at 400 °C. ► The deposited thin films were characterized by SEM, EDX and XRD which suggests the formation of impurity-free mesoporous Ag2S, with well defined particles evenly distributed in the range of 0.3–0.5 μm. ► The optical bandgap energy of the thin film was estimated, and it is about 1.33 eV. ► The thin films were investigated for the gas sensor applications. - Abstract: Crack free Ag2S thin films were deposited on glass substrates by aerosol assisted chemical vapor deposition (AACVD) using [Ag(S2CN (C2H5)2)3]2 (1) as a precursor. Thin films were deposited from solution of methanol at 400 °C and characterized by X-ray diffraction (XRD), UV–vis spectroscopy, scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) analysis. SEM image of thin film showed well-defined and porous surface morphology with an average particle size of 0.3–0.5 μm. Optical band gaps energy of 1.33 eV was estimated for Ag2S thin film, by extrapolating the linear part of the Tauc plot recorded at room temperature. The gas sensing characteristics of the novel gas sensors based on Ag2S were investigated for the detection carbon monoxide. The effect of operating temperature and change in gas concentration on the performance of carbon monoxide were investigated. The sensing mechanism of sensor was discussed.

  20. Crystalline Indium Sulphide thin film by photo accelerated deposition technique

    Science.gov (United States)

    Dhanya, A. C.; Preetha, K. C.; Deepa, K.; Remadevi, T. L.

    2015-02-01

    Indium sulfide thin films deserve special attention because of its potential application as buffer layers in CIGS based solar cells. Highly transparent indium sulfide (InS) thin films were prepared using a novel method called photo accelerated chemical deposition (PCD). Ultraviolet source of 150 W was used to irradiate the solution. Compared to all other chemical methods, PCD scores its advantage for its low cost, flexible substrate and capable of large area of deposition. Reports on deposition of high quality InS thin films at room temperature are very rare in literature. The precursor solution was initially heated to 90°C for ten minutes and then deposition was carried out at room temperature for two hours. The appearance of the film changed from lemon yellow to bright yellow as the deposition time increased. The sample was characterized for its structural and optical properties. XRD profile showed the polycrystalline behavior of the film with mixed phases having crystallite size of 17 nm. The surface morphology of the films exhibited uniformly distributed honey comb like structures. The film appeared to be smooth and the value of extinction coefficient was negligible. Optical measurements showed that the film has more than 80% transmission in the visible region. The direct band gap energy was 2.47eV. This method is highly suitable for the synthesis of crystalline and transparent indium sulfide thin films and can be used for various photo voltaic applications.

  1. Resonant infrared pulsed laser deposition of thin biodegradable polymer films

    International Nuclear Information System (INIS)

    Thin films of the biodegradable polymer poly(DL-lactide-co-glycolide) (PLGA) were deposited using resonant infrared pulsed laser deposition (RIR-PLD). The output of a free-electron laser was focused onto a solid target of the polymer, and the films were deposited using 2.90 (resonant with O-H stretch) and 3.40 (C-H) μm light at macropulse fluences of 7.8 and 6.7 J/cm2, respectively. Under these conditions, a 0.5-μm thick film can be grown in less than 5 min. Film structure was determined from infrared absorbance measurements and gel permeation chromatography (GPC). While the infrared absorbance spectrum of the films is nearly identical with that of the native polymer, the average molecular weight of the films is a little less than half that of the starting material. Potential strategies for defeating this mass change are discussed. (orig.)

  2. Self-assembled mesoporous carbon films for platinum metal catalyst loading

    International Nuclear Information System (INIS)

    This work demonstrates the use of self-assembled carbon films in designing fuel cell electrode. Well-dispersed mesoporous carbon particles were prepared based on the spontaneous and strong chemisorption of polyoxometalate (POM) solution on carbon surface. Electrostatically self-assembled films of the POM stabilized carbon interlaced with cationic polyelectrolyte binding layer were useful for confining electrodeposition of platinum (Pt) catalyst. The structure and morphology of the resulting films were characterized by X-ray diffraction and scanning electron microscopy respectively. The electrocatalytic activities of Pt deposited on the self-assembled carbon films toward the degradation of small organic molecules are largely dependent on the quantity of Pt and carbon. This work represents a simply controlled test-bed for fundamental studies on loading metal catalysts on ordered mesoporous carbon films for catalysis.

  3. Atomic layer deposition and post-deposition annealing of PbTiO3 thin films

    International Nuclear Information System (INIS)

    Lead titanate thin films were deposited by atomic layer deposition on Si(100) using Ph4Pb and Ti(O-i-Pr)4 as metal precursors and O3 and H2O as oxygen sources. The influence of the Ti : Pb precursor pulsing ratio on the film growth, stoichiometry and quality was studied at two different temperatures, i.e. 250 and 300 deg. C. Uniform and stoichiometric films were obtained using a Ti : Pb precursor pulsing ratio of 1 : 10 at 250 deg. C or 1 : 28 at 300 deg. C. The as-deposited films were amorphous but the crystalline PbTiO3 phase was obtained by rapid thermal annealing at 600-900 deg. C both in N2 and O2 ambient. Thin PbTiO3 films were visually uniform and roughness values for as-deposited and annealed films were observed by atomic force microscopy

  4. Effect of deposition pressure and post deposition annealing on SmCo thin film properties

    International Nuclear Information System (INIS)

    In this article we report on the effect of the deposition pressure and the post deposition annealing conditions on the structural and magnetic properties of SmCo thin films deposited on Si(100) wafers employing Ta buffer and capping layers. The films were deposited by DC magnetron sputtering and annealed in vacuum at various temperatures. The films under investigation were isotropic with high remanence magnetization, maximum coercive field of 8 kOe and a squareness ratio of coercivity higher than 0.9. It was found that the Ar pressure during the deposition is a key factor in controlling the stoichiometry and the structural and magnetic properties of the SmCo films, while the effect of the annealing temperature is crucial in optimizing the magnetic properties of the films. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Superconducting niobium nitride thin films by reactive pulsed laser deposition

    International Nuclear Information System (INIS)

    The structural, electronic, and nanomechanical properties of cubic niobium nitride thin films were investigated. The films were deposited on Si(100) under different background nitrogen gas pressures (26.7-66.7 Pa) at constant substrate temperature of 800 °C by reactive pulsed laser deposition. Our results reveal that the NbNx films exhibit a cubic δ-NbN with strong (111) orientation and highly-oriented textured structures. We find nitrogen background pressure to be an important factor in determining the structure of the NbNx films. The dependence of the electronic structure as well as that of the superconducting transition temperature (Tc) on the nitrogen gas background pressure is studied. A correlation between surface morphology, electronic and superconducting properties is found for the deposited NbNx thin films. The highly-textured δ-NbN films have a Tc up to 15.07 K. Nanoindentation with continuous stiffness method is used to evaluate the hardness and modulus of the NbNx thin films as a function of depth. The film deposited at nitrogen background pressure of 66.7 Pa exhibits improved superconducting properties and shows higher hardness values as compared to films deposited at lower nitrogen pressures. - Highlights: • NbN thin films were deposited on Si(100) using reactive pulse laser deposition. • Different nitrogen background pressures were used. • Increasing nitrogen gas pressure impacts the phase and superconducting properties. • Thin NbN films with superconducting phase showed transition temperature up to 15.07 K

  6. Deposition of metal oxide films and nanostructures by methods derived from photochemical metal organic deposition

    OpenAIRE

    Xin ZHANG

    2009-01-01

    In this research, methods for the deposition of patterned films and nanostructures were developed from photochemical metal organic deposition (PMOD). Positive lithographic PMOD was demonstrated with films of titanium (IV) di-n-butoxide bis(2-ethylhexanoate) (Ti(OBun)2(eh)2), titanium (IV) diisopropoxide bis(2,4-pentanedionate), and zirconium (IV) di-n-butoxide bis(2,4-pentanedionate). The photochemistry of these complexes in films was studied by FTIR, AES, and XRD. Photo-induced reactivity an...

  7. As-grown magnesium diboride superconducting thin films deposited by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Grassano, G.; Ramadan, W.; Ferrando, V.; Bellingeri, E.; Marre, D.; Ferdeghini, C.; Grasso, G.; Putti, M.; Chincarini, A. [INFM, Dipartimento di Fisica, Genoa (Italy); Manfrinetti, P.; Palenzona, A. [INFM, Dipartimento di Chimica e Chimica Industriale, Genoa (Italy)

    2001-09-01

    As-grown superconducting MgB{sub 2} thin films were deposited by pulsed laser deposition on magnesium oxide and sapphire substrates. Starting from a non-stoichiometric, Mg and B mixed-powder target, we were able to grow the superconducting phase during the film deposition, without any further annealing process. So far, samples grown in the temperature range of 400-450 deg. C, and at an argon buffer pressure of the order of 10{sup -2} mbar turned out to be superconducting with an onset temperature of the resistive transition at about 25 K. Even if the deposition process still needs to be fully optimized, we have demonstrated that this method allows us to achieve in situ deposition of as-grown superconducting thin films. This procedure could therefore be promising for the deposition of high-quality epitaxial MgB{sub 2} thin films. (author)

  8. Local deposition and patterning of catalytic thin films in microsystems

    International Nuclear Information System (INIS)

    The local deposition of catalysts is desired in a wide range of catalytic microsystems (microreactors and sensors). In this study, we investigate technologies enabling deposition and patterning of catalyst thin films in a manner compatible with standard micromachining processes. We evaluate and compare deposition techniques based on a combination of a self-assembly, soft-lithography and conventional micromachining. Platinum (Pt) and palladium (Pd) were used as model catalysts, both as a sputtered thin film and as nanoparticles supported on γ-alumina. The thin films were characterized and tested in terms of their catalytic activity based on CO chemisorption measurements, stability and reproducibility. (paper)

  9. Physical vapor deposition and patterning of calcium fluoride films

    International Nuclear Information System (INIS)

    Physical vapor deposition of calcium fluoride (CaF2) thin films was performed via electron beam evaporation, resistive/thermal evaporation, and nonreactive radio frequency sputtering. Patterning of the resultant ''usable'' thin films was then also attempted in several ways, including by shadow mask deposition, liftoff, and direct chemical etching. Resistive evaporation produced the most stable films, having polycrystalline morphology with a moderately strong preference to the 331 orientation. The cleanest patterning results were obtained via a polymer/metal liftoff. The results and implications of each of the various deposition and patterning techniques are discussed.

  10. Pulsed laser deposition of amorphous carbon/silver nanocomposites

    International Nuclear Information System (INIS)

    Metal/amorphous carbon (a-C:M) composite films are emerging as a category of very important engineering materials for surface protection. We implement pulsed laser deposition (PLD) to grow pure a-C and a-C:Ag nanocomposites. Our PLD process is assisted by a static electric field. We investigate the structural features of the a-C:Ag nanocomposites and the bonding configuration of the a-C matrix with respect to the electric field and the composition of the PLD target. For this study we use Auger electron spectroscopy (AES), electron energy loss spectroscopy (EELS) and X-ray diffraction (XRD). We show that the Ag mean grain size and the sp2 content of the a-C matrix are increasing with increasing Ag content in the films

  11. Pulsed laser deposition of amorphous carbon/silver nanocomposites

    Science.gov (United States)

    Matenoglou, G.; Evangelakis, G. A.; Kosmidis, C.; Foulias, S.; Papadimitriou, D.; Patsalas, P.

    2007-07-01

    Metal/amorphous carbon (a-C:M) composite films are emerging as a category of very important engineering materials for surface protection. We implement pulsed laser deposition (PLD) to grow pure a-C and a-C:Ag nanocomposites. Our PLD process is assisted by a static electric field. We investigate the structural features of the a-C:Ag nanocomposites and the bonding configuration of the a-C matrix with respect to the electric field and the composition of the PLD target. For this study we use Auger electron spectroscopy (AES), electron energy loss spectroscopy (EELS) and X-ray diffraction (XRD). We show that the Ag mean grain size and the sp 2 content of the a-C matrix are increasing with increasing Ag content in the films.

  12. Pulsed laser deposition of amorphous carbon/silver nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Matenoglou, G. [University of Ioannina, Department of Materials Science and Engineering, GR-45110 Ioannina (Greece); Evangelakis, G.A. [University of Ioannina, Department of Physics, GR-45110 Ioannina (Greece); Kosmidis, C. [University of Ioannina, Department of Physics, GR-45110 Ioannina (Greece); Foulias, S. [University of Ioannina, Department of Physics, GR-45110 Ioannina (Greece); Papadimitriou, D. [University of Ioannina, Department of Physics, GR-45110 Ioannina (Greece); Patsalas, P. [University of Ioannina, Department of Materials Science and Engineering, GR-45110 Ioannina (Greece)]. E-mail: ppats@cc.uoi.gr

    2007-07-31

    Metal/amorphous carbon (a-C:M) composite films are emerging as a category of very important engineering materials for surface protection. We implement pulsed laser deposition (PLD) to grow pure a-C and a-C:Ag nanocomposites. Our PLD process is assisted by a static electric field. We investigate the structural features of the a-C:Ag nanocomposites and the bonding configuration of the a-C matrix with respect to the electric field and the composition of the PLD target. For this study we use Auger electron spectroscopy (AES), electron energy loss spectroscopy (EELS) and X-ray diffraction (XRD). We show that the Ag mean grain size and the sp{sup 2} content of the a-C matrix are increasing with increasing Ag content in the films.

  13. Homogeneous nanocrystalline cubic silicon carbide films prepared by inductively coupled plasma chemical vapor deposition.

    Science.gov (United States)

    Cheng, Qijin; Xu, S; Long, Jidong; Huang, Shiyong; Guo, Jun

    2007-11-21

    Silicon carbide films with different carbon concentrations x(C) have been synthesized by inductively coupled plasma chemical vapor deposition from a SiH(4)/CH(4)/H(2) gas mixture at a low substrate temperature of 500 °C. The characteristics of the films were studied by x-ray photoelectron spectroscopy, x-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, Fourier transform infrared absorption spectroscopy, and Raman spectroscopy. Our experimental results show that, at x(C) = 49 at.%, the film is made up of homogeneous nanocrystalline cubic silicon carbide without any phase of silicon, graphite, or diamond crystallites/clusters. The average size of SiC crystallites is approximately 6 nm. At a lower value of x(C), polycrystalline silicon and amorphous silicon carbide coexist in the films. At a higher value of x(C), amorphous carbon and silicon carbide coexist in the films. PMID:21730481

  14. Filling performance and electrical characteristics of Al2O3 films deposited by atomic layer deposition for through-silicon via applications

    International Nuclear Information System (INIS)

    We have evaluated the conformality and electrical properties of Al2O3 films deposited by atomic layer deposition at temperatures below 300 °C for through-silicon via (TSV) applications. Al2O3 films were able to be conformally deposited on the scallops of 50-μm-wide, 100-μm-deep TSV at the temperature range between 200 and 300 °C. The median breakdown fields of the metal–insulator–metal device with 30-nm-thick Al2O3 layer were above 6 MV/cm for the films deposited at 250 and 300 °C, while that at 200 °C was inferior due to residual carbon impurities in the oxide layer. - Highlights: • Filling performance and electrical properties of Al2O3 films were evaluated. • Al2O3 films were conformally deposited on the scallops of through-silicon via holes. • The median breakdown field of 30-nm-thick Al2O3 layer was above 6 MV/cm. • The Al2O3 film deposited at 200 °C was inferior due to the residual carbon impurities. • Al2O3 films showed a promise as the dielectric for through-silicon via application

  15. Nanoindentation and AFM studies of PECVD DLC and reactively sputtered Ti containing carbon films

    Indian Academy of Sciences (India)

    A Pauschitz; J Schalko; T Koch; C Eisenmenger-Sittner; S Kvasnica; Manish Roy

    2003-10-01

    Amorphous carbon film, also known as DLC film, is a promising material for tribological application. It is noted that properties relevant to tribological application change significantly depending on the method of preparation of these films. These properties are also altered by the composition of the films. In view of this, the objective of the present work is to compare the nanoindentation and atomic force microscopy (AFM) study of diamond like carbon (DLC) film obtained by plasma enhanced chemical vapour deposition (PECVD) with the Ti containing amorphous carbon (Ti/-C : H) film obtained by unbalanced magnetron sputter deposition (UMSD). Towards that purpose, DLC and Ti/-C : H films are deposited on silicon substrate by PECVD and UMSD processes, respectively. The microstructural features and the mechanical properties of these films are evaluated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nanoindentation and by AFM. The results show that the PECVD DLC film has a higher elastic modulus, hardness and roughness than the UMSD Ti/-C : H film. It also has a lower pull off force than Ti containing amorphous carbon film.

  16. Preparation of composite electroheat carbon film

    Institute of Scientific and Technical Information of China (English)

    XIA Jin-tong; TU Chuan-jun; LI Yan; HU Li-min; DENG Jiu-hua

    2005-01-01

    A kind of conductive and heating unit, which can reach a high surface electroheat temperature at a low voltage, was developed in view of the traditional electroheat coating which has a low surface electroheat temperature and an insufficient heat resistance of its binder. The coating molded electroheat carbon film(CMECF) was prepared by carbonizing the coating which was prepared by adding modified resin into flake graphite and carbon fiber, coating molded onto the surface of the heat resisting matrix after dried, while the hot pressing molded electroheat thick carbon film(HPMETCF) was prepared by carbonizing the bodies whose powders were hot pressing molded directly.The surface and inner microstructure of the carbon film was characterized and analyzed by SEM and DSC/TG, while electroheat property was tested by voltage-current volume resistivity tester and electrical parameter tester. The results show that, close-packed carbon network configuration is formed within the composite electroheat carbon film film after anti-oxidizable treatment reaches a higher surface electroheat temperature than that of the existing electroheat coatings at a low voltage, and has excellent electroheat property, high thermal efficiency as well as stable physicochemical property. It is found that, at room temperature(19± 2 ℃) and 22 V for 5 min, the surface electroheat temperature of the self-produced CMECF (mfiller/mresin = 1. 8/1) reaches 112 ℃ while HPMETCF (mfiller/mresin = 3. 6/1) reaches 265 ℃.

  17. Coloration efficiency of chemically deposited electrochromic thin films

    International Nuclear Information System (INIS)

    Transparent nickel oxide and copper oxide thin films were produced by very simple and economic method of chemical deposition. Those films were deposited onto fluorine doped tin oxide (FTO) coated glass substrates. Electrochromic test device (ECTD) was constructed by using these films as working electrodes, together with the FTO as a counter electrode in alkaline environment (0,1 M NaOH aqueous solution). All the obtained films exhibited electrochromic behavior. Nichel oxide films were transparent for visible light in the reduced state, and displayed a dark brown color in the oxidised state and displayed a very dark brown color in the reduced state. The coloration efficiency (CE) at wavelength λ=670 nm was estimated from the slope of the graphical presentation of the optical density as a function of the charge density, during the charge extraction (nickel oxide films) and charge insertion (copper oxide films). (Author)

  18. Synthesis and characterization of carbon nanotube reinforced copper thin films

    OpenAIRE

    Otto, Cornelia

    2006-01-01

    Two model composites of copper and carbon nanotubes were fabricated by very different deposition methods. Copper electrodeposition in a plating bath containing nanotubes created a 3D matrix of randomly oriented CNTs within a thick, 20 micron Cu film. In contrast, sandwiching a layer of well-separated nanotubes between two sub-micron sputtered Cu layers produced a 2D-composite with nanotubes lying parallel to the substrate surface. These composites, which were mechanically tested using var...

  19. A glucose biosensor using methyl viologen redox mediator on carbon film electrodes

    OpenAIRE

    Ghica, Mariana Emilia; Christopher M. A. Brett

    2005-01-01

    A new methyl viologen-mediated amperometric enzyme electrode sensitive to glucose has been developed using carbon film electrode substrates. Carbon film electrodes from resistors fabricated by pyrolytic deposition of carbon were modified by immobilization of glucose oxidase through cross-linking with glutaraldehyde in the presence of bovine serum albumin. The mediator, methyl viologen, was directly immobilised with the enzyme together with Nafion cation-exchange polymer. The electrochemistry ...

  20. Deposition, Characterization, And Simulation Of Thin Films With Form Birefringence

    Science.gov (United States)

    Jacobson, M. R.; Horowitz, F.; Liao, Bangjun

    1984-12-01

    Birefringence in optical thin films due to structure on a scale large compared to atoms but small compared to optical wavelengths, known as form birefringence (FB), was observed almost a century ago. More recently, studies of obliquely deposited metal films stimulated new interest in birefringent films. The link between structure, which is predominantly columnar in evaporated thin films, and birefringence has been conclusively demonstrated through ellipsometric measurement and modeling. Direct measurements of form birefringence are especially tedious in tilted films, since essentially four quantities must be derived: three indices of refraction and the film thickness. Clearly, four measurements are required; Horowitz' used an ellipsometric method to perform such measurements on a zirconium oxide (Zr02) film. Later, a 4.6-μm-thick film of Zr02 was obliquely deposited; spectrophotometric measurements revealed its utility as a half-wave plate. A parallel effort directed at understanding FB films through computer simulations has been undertaken by Sikkens and Liao. These simulations can be specialized to include defects, epitaxy, and anisotropic surface mobility. Applications of obliquely deposited FB films of familiar thin film materials can be anticipated if their structure and performance can be more thoroughly understood.

  1. Study on re-sputtering during CN{sub x} film deposition through spectroscopic diagnostics of plasma

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Peipei; Yang, Xu; Li, Hui; Cai, Hua [Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); Sun, Jian; Xu, Ning [Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University, Shanghai 200433 (China); Wu, Jiada, E-mail: jdwu@fudan.edu.cn [Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University, Shanghai 200433 (China); Engineering Research Center of Advanced Lighting Technology, Ministry of Education, Fudan University, Shanghai 200433 (China)

    2015-10-15

    A nitrogen-carbon plasma was generated during the deposition of carbon nitride (CN{sub x}) thin films by pulsed laser ablation of a graphite target in a discharge nitrogen plasma, and the optical emission of the generated nitrogen-carbon plasma was measured for the diagnostics of the plasma and the characterization of the process of CN{sub x} film deposition. The nitrogen-carbon plasma was recognized to contain various species including nitrogen molecules and molecular ions excited in the ambient N{sub 2} gas, carbon atoms and atomic ions ablated from the graphite target and CN radicals. The temporal evolution and spatial distribution of the CN emission and their dependence on the substrate bias voltage show two groups of CN radicals flying in opposite directions. One represents the CN radicals formed as the products of the reactions occurring in the nitrogen-carbon plasma, revealing the reactive deposition of CN{sub x} film due to the reactive expansion of the ablation carbon plasma in the discharge nitrogen plasma and the effective formation of gaseous CN radicals as precursors for CN{sub x} film growth. The other one represents the CN radicals re-sputtered from the growing CN{sub x} film by energetic plasma species, evidencing the re-sputtering of the growing film accompanying film growth. And, the re-sputtering presents ion-induced sputtering features.

  2. Rocky Mountain Carbonate Spring Deposit development

    Science.gov (United States)

    Rainey, Dustin Kyle

    Relict Holocene carbonate spring deposits containing diverse biotic and abiotic depositional textures are present at Fall Creek cold sulphur springs, Alberta, Fairmont Hot Springs, British Columbia, and Hot Creek cold springs, British Columbia. The relict deposits are formed mainly of low-magnesium crystalline calcite contained in laterally continuous strata. Paleo-flow regimes were characterized by extensive sheet flow that increased the surface area of spring water exposed to the atmosphere. Calcite precipitated inorganically from spring water that attained CaCO3 supersaturation through agitation-induced CO2 degassing that was facilitated by elevated flow rates and a large surface area as spring water flowed down-slope. Thus, the deposits contain only minor amounts of detrital, mechanically deposited, and biogenic carbonate. Evaporation was only a minor contributor to CaCO3 supersaturation, mainly in quiescent environments. Photosynthetic CO2 removal did not measurably contribute to CaCO3 supersaturation. Calcite crystals precipitated in biotic facies formed from low to moderately supersaturated spring water, whereas abiotic dendrite crystals formed rapidly from highly supersaturated spring water. Calcite passively nucleated on cyanobacteria, bryophytes and macrophytes, and was probably facilitated by cyanobacterial extracellular polymeric substances. Cyanobacterial filaments and stromatolites are integral parts of all three deposits, whereas bryophytes were restricted to the Fall Creek and Hot Creek deposits. Diagenetic microbial degradation of crystalline calcite was common to all three deposits, but recrystallization was limited to the Fall Creek deposit. The amount and location of calcite precipitation relative to the vents was controlled by the concentrations of Ca2+ and HCO3- in solution, and discharge volume fluctuations. Spring water with high [Ca2+] and [HCO 3-] precipitated large amounts of calcite proximal to the vents (e.g. Fairmont), whereas spring

  3. Plasma sputtering system for deposition of thin film combinatorial libraries

    Science.gov (United States)

    Cooper, James S.; Zhang, Guanghai; McGinn, Paul J.

    2005-06-01

    The design of a plasma sputtering system for the deposition of combinatorial libraries is described. A rotating carousel is used to position shadow masks between the targets and the substrate. Multilayer films are built up by depositing sequentially through various masks. Postdeposition annealing is used to promote interdiffusion of the layered structures. Either discrete or compositional gradient libraries can be deposited in this system. Samples appropriate for characterization with a scanning electrochemical microscope or a multichannel microelectrode array system can be produced. The properties of some deposited Pt-Ru films for fuel cell applications are described.

  4. Method and apparatus for making diamond-like carbon films

    Science.gov (United States)

    Pern, Fu-Jann; Touryan, Kenell J.; Panosyan, Zhozef Retevos; Gippius, Aleksey Alekseyevich

    2008-12-02

    Ion-assisted plasma enhanced deposition of diamond-like carbon (DLC) films on the surface of photovoltaic solar cells is accomplished with a method and apparatus for controlling ion energy. The quality of DLC layers is fine-tuned by a properly biased system of special electrodes and by exact control of the feed gas mixture compositions. Uniform (with degree of non-uniformity of optical parameters less than 5%) large area (more than 110 cm.sup.2) DLC films with optical parameters varied within the given range and with stability against harmful effects of the environment are achieved.

  5. Superconductivity in Sulfur-Doped Amorphous Carbon Films

    OpenAIRE

    Felner, I.; Wolf, O; Millo, O.

    2013-01-01

    Following our previous investigations on superconductivity in amorphous carbon (aC) based systems; we have prepared thin composite aC-W films using electron-beam induced deposition. The films did not show any sign for superconductivity above 5 K. However, local, non-percolative, superconductivity emerged at Tc = 34.4 K after treatment with sulfur at 250 C for 24 hours. The superconducting features in the magnetization curves were by far sharper compared to our previous results, and the shield...

  6. Atomic layer deposition of cobalt carbide films and their magnetic properties using propanol as a reducing agent

    Science.gov (United States)

    Sarr, Mouhamadou; Bahlawane, Naoufal; Arl, Didier; Dossot, Manuel; McRae, Edward; Lenoble, Damien

    2016-08-01

    The investigation of highly conformal thin films using Atomic Layer Deposition (ALD) is driven by a variety of applications in modern technologies. In particular, the emergence of 3D memory device architectures requires conformal materials with tuneable magnetic properties. Here, nanocomposites of carbon, cobalt and cobalt carbide are deposited by ALD using cobalt acetylacetonate with propanol as a reducing agent. Films were grown by varying the ALD deposition parameters including deposition temperature and propanol exposure time. The morphology, the chemical composition and the crystalline structure of the cobalt carbide film were investigated. Vibrating Sample Magnetometer (VSM) measurements revealed magnetic hysteresis loops with a coercivity reaching 500 Oe and a maximal saturation magnetization of 0.9 T with a grain size less than 15 nm. Magnetic properties are shown to be tuneable by adjusting the deposition parameters that significantly affect the microstructure and the composition of the deposited films.

  7. Structure and photoluminescence of films composed of carbon nanoflakes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yi, E-mail: wangyi@cqut.edu.cn [College of Mechanical Engineering, Chongqing University of Technology, 69 Hongguang Rd, Lijiatuo, Banan District, Chongqing 400054, P R China (China); Li, Lin [College of Chemistry, Chongqing Normal University, Chongqing 401331, P R China (China); Cheng, Qijin [School of Energy Research, Xiamen University, Xiamen 361005, P R China (China); He, Chunlin [Liaoning Provincial Key Laboratory of Advanced Materials, Shenyang University, Shenyang 110044, P R China (China)

    2015-05-15

    Carbon nanoflake films (CNFFs) were directly synthesized by plasma-enhanced hot filament chemical vapor deposition. The results of field emission scanning electron microscope, transmission electron microscope, micro-Raman spectroscope, X-ray photoelectron spectroscope and Fourier transform infrared spectroscope indicate that the CNFFs are composed of bending carbon nanoflakes with the hydrocarbon and hydroxyl functional groups, and the carbon nanoflakes become thin in a long deposition time. The structural change of carbon nanoflakes is related to the formation of structural units and the aggregation of hydrocarbon radicals near the carbon nanoflakes. Moreover, the photoluminescence (PL) properties of CNFFs were studied in a Ramalog system and a PL spectroscope. The PL results indicate that the PL intensity of CNFFs is lowered with the increase of thickness of CNFFs. The lowering of PL intensity for the thick CNFFs originates from the effect of more dangling bonds in the CNFFs. In addition, we studied the structural difference of carbon nanoflakes grown by different CVD systems and the PL difference of carbon nanoflakes in different measurement systems. The results achieved here are important to control the growth and structure of graphene-based materials and fabricate the optoelectronic devices related to carbon-based materials. - Highlights: • Carbon nanoflake films (CNFFs) were synthesized by PEHFCVD. • The structure of CNFFs is related to the aggregation of carbon hydrocarbon radicals. • The PL intensity of CNFFs is lowered with the thickness increase of CNFFs. • The change of PL intensity of CNFFs is due to the dangling bonds in CNFFs. • The widening of PL bands of CNFFs results from the diversity of carbon nanofalkes.

  8. Structure and photoluminescence of films composed of carbon nanoflakes

    International Nuclear Information System (INIS)

    Carbon nanoflake films (CNFFs) were directly synthesized by plasma-enhanced hot filament chemical vapor deposition. The results of field emission scanning electron microscope, transmission electron microscope, micro-Raman spectroscope, X-ray photoelectron spectroscope and Fourier transform infrared spectroscope indicate that the CNFFs are composed of bending carbon nanoflakes with the hydrocarbon and hydroxyl functional groups, and the carbon nanoflakes become thin in a long deposition time. The structural change of carbon nanoflakes is related to the formation of structural units and the aggregation of hydrocarbon radicals near the carbon nanoflakes. Moreover, the photoluminescence (PL) properties of CNFFs were studied in a Ramalog system and a PL spectroscope. The PL results indicate that the PL intensity of CNFFs is lowered with the increase of thickness of CNFFs. The lowering of PL intensity for the thick CNFFs originates from the effect of more dangling bonds in the CNFFs. In addition, we studied the structural difference of carbon nanoflakes grown by different CVD systems and the PL difference of carbon nanoflakes in different measurement systems. The results achieved here are important to control the growth and structure of graphene-based materials and fabricate the optoelectronic devices related to carbon-based materials. - Highlights: • Carbon nanoflake films (CNFFs) were synthesized by PEHFCVD. • The structure of CNFFs is related to the aggregation of carbon hydrocarbon radicals. • The PL intensity of CNFFs is lowered with the thickness increase of CNFFs. • The change of PL intensity of CNFFs is due to the dangling bonds in CNFFs. • The widening of PL bands of CNFFs results from the diversity of carbon nanofalkes

  9. ZnSe thin films by chemical bath deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Lokhande, C.D.; Patil, P.S.; Tributsch, H. [Hahn-Meitner-Institute, Bereich Physikalische Chemie, Abt. CS, Glienicker Strasse-100, D-14109 Berlin (Germany); Ennaoui, A. [Hahn-Meitner-Institute, Bereich Physikalische Chemie, Abt. CG, Glienicker Strasse-100, D-14109 Berlin (Germany)

    1998-09-04

    The ZnSe thin films have been deposited onto glass substrates by the simple chemical bath deposition method using selenourea as a selenide ion source from an aqueous alkaline medium. The effect of Zn ion concentration, bath temperature and deposition time period on the quality and thickness of ZnSe films has been studied. The ZnSe films have been characterized by XRD, TEM, EDAX, TRMC (time-resolved microwave conductivity), optical absorbance and RBS techniques for their structural, compositional, electronic and optical properties. The as-deposited ZnSe films are found to be amorphous, Zn rich with optical band gap, Eg, equal to 2.9 eV

  10. Sputter deposition of BSCCO films from a hollow cathode

    International Nuclear Information System (INIS)

    High-Tc superconducting thin films were deposited onto MgO single crystal substrates from a hollow cathode onto ceramic targets with the nominal composition of Bi2Sr2CaCu2Ox. Films similar in composition to those used for the targets were deposited on MgO substrates by rf sputtering. The effects of sputtering time, rf power, and post-annealing on film microstructure and properties were studied in detail. Substrate temperature was found to have a significant influence on the film characteristics. Initial results show that deposition rates from a hollow cathode are an order of magnitude higher than those of a planar magnetron source at equivalent power levels. Large deposition rates allow for the coating of long lengths of wire

  11. Magnetron deposition of TCO films using ion beam

    Science.gov (United States)

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

    2015-11-01

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

  12. Chemical Liquid Phase Deposition of Thin Aluminum Oxide Films

    Institute of Scientific and Technical Information of China (English)

    SUN,Jie(孙捷); SUN,Ying-Chun(孙迎春)

    2004-01-01

    Thin aluminum oxide films were deposited by a new and simple physicochemical method called chemical liquid phase deposition (CLD) on semiconductor materials. Aluminum sulfate with crystallized water and sodium bicarbonate were used as precursors for film growth, and the control of the system's pH value played an important role in this experiment. The growth rate is 12 nm/h with the deposition at [Al2(SO4)3]=0.0837 mol·L-1, [NaHCO3]=0.214 mol·L-1, 15 ℃. Post-growth annealing not only densifies and purifies the films, but results in film crystallization as well, Excellent quality of A12O3 films in this work is supported by electron dispersion spectroscopy,Fourier transform infrared spectrum, X-ray diffraction spectrum and scanning electron microscopy photograph.

  13. Nitrogen incorporation in sputter deposited molybdenum nitride thin films

    International Nuclear Information System (INIS)

    In this paper, the authors report on the high temperature performance of sputter deposited molybdenum (Mo) and molybdenum nitride (Mo2N) thin films. Various argon and nitrogen gas compositions are applied for thin film synthetization, and the amount of nitrogen incorporation is determined by Auger measurements. Furthermore, effusion measurements identifying the binding conditions of the nitrogen in the thin film are performed up to 1000 °C. These results are in excellent agreement with film stress and scanning electron microscope analyses, both indicating stable film properties up to annealing temperatures of 500 °C

  14. Nitrogen incorporation in sputter deposited molybdenum nitride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Stöber, Laura, E-mail: laura.stoeber@tuwien.ac.at; Patocka, Florian, E-mail: florian.patocka@tuwien.ac.at; Schneider, Michael, E-mail: michael.schneider@tuwien.ac.at; Schmid, Ulrich, E-mail: ulrich.e366.schmid@tuwien.ac.at [Institute of Sensor and Actuator Systems, TU Wien, Gußhausstraße 27-29, A-1040 Vienna (Austria); Konrath, Jens Peter, E-mail: jenspeter.konrath@infineon.com; Haberl, Verena, E-mail: verena.haberl@infineon.com [Infineon Technologies Austria AG, Siemensstraße 2, 9500 Villach (Austria)

    2016-03-15

    In this paper, the authors report on the high temperature performance of sputter deposited molybdenum (Mo) and molybdenum nitride (Mo{sub 2}N) thin films. Various argon and nitrogen gas compositions are applied for thin film synthetization, and the amount of nitrogen incorporation is determined by Auger measurements. Furthermore, effusion measurements identifying the binding conditions of the nitrogen in the thin film are performed up to 1000 °C. These results are in excellent agreement with film stress and scanning electron microscope analyses, both indicating stable film properties up to annealing temperatures of 500 °C.

  15. Growth of superconducting tantalum films by pulsed laser deposition

    International Nuclear Information System (INIS)

    Pulsed laser deposition (PLD) was used to grow superconducting Ta-films with critical temperatures close to bulk values (4.5 K) on sapphire substrates. Results are compared with films grown by e-beam evaporation. The PLD method allows the growth of superconducting Ta-films on substrates kept at ambient temperature but film surfaces are plagued by sub-micron particles. On the other hand, e-beam evaporation results in smooth surfaces but requires a substrate temperature of the order of 400 C for producing high-quality superconducting films. Critical temperatures, residual resistance ratios, and crystal structure are presented. (orig.)

  16. Plasma deposition of polymer composite films incorporating nanocellulose whiskers

    OpenAIRE

    Samyn, P; Airoudj, A.; Laborie, M.-P.; Mathew, A. P.; Roucoules, V.

    2011-01-01

    Abstract In a trend for sustainable engineering and functionalization of surfaces, we explore the possibilities of gas phase processes to deposit nanocomposite films. From an analysis of pulsed plasma polymerization of maleic anhydride in the presence of nanocellulose whiskers, it seems that thin nanocomposite films can be deposited with various patterns. By specifically modifying plasma parameters such as total power, duty cycle, and monomer gas pressure, the nanocellulose whisker...

  17. ZnS thin film deposited with chemical bath deposition process directed by different stirring speeds

    International Nuclear Information System (INIS)

    In this combined film thickness, scanning electron microscopy (SEM), X-ray diffraction and optical properties study, we explore the effects of different stirring speeds on the growth and optical properties of ZnS film deposited by CBD method. From the disclosed changes of thickness of ZnS film, we conclude that film thickness is independent of the stirring speeds in the heterogeneous process (deposition time less than 40 min), but increases with the stirring speeds and/or deposition time increasing in the homogeneous process. Grazing incident X-ray diffraction (GIXRD) and the study of optical properties disclosed that the ZnS films grown with different stirring speeds show partially crystallized film and exhibit good transmittance (70-88% in the visible region), but the stirring speeds cannot give much effects on the structure and optical properties in the homogeneous process.

  18. Tribological property enhancement of CrN films by metal vapor vacuum arc implantation of Vanadium and Carbon ions

    International Nuclear Information System (INIS)

    CrN films have been extensively used in precision forming and molding applications because of their excellent tribological properties and oxidation-resisting characteristics. Vanadium and carbon ions are introduced into the near surface layer of deposited CrN films via metal vapor vacuum arc implantation to improve the wear performance of CrN films. Dense and smooth CrN film was deposited using a filtered arc deposition system, which provides fully ionized Cr plasma on the substrate surface. Subsequently, surface bombardment of the deposited CrN film with vanadium and carbon ions densifies the film and forms an alloy near the surface. These CrN-based films were characterized by X-ray photoelectron electron and Auger electron spectroscopies. Examinations of the tribological and mechanical film properties, including wear resistance, corrosion resistance and fracture toughness were performed and correlated with respect to the implantation parameters

  19. Spray pyrolysis deposited tin selenide thin films for thermoelectric applications

    International Nuclear Information System (INIS)

    Tin selenide thin films were prepared by spray pyrolysis technique using tin (II) chloride and selenourea as a precursor compounds using Se:Sn atomic ratio of 1:1 in the starting solution onto glass substrates. Deposition process was carried out in the substrate temperature range of 250 °C–400 °C using 1 ml/min flow rate. The films were investigated using X-ray diffraction, field emission scanning electron microscopy, Raman spectroscopy, optical absorption and thermoelectric studies. The X-ray diffraction patterns suggest that the major phase is hexagonal-SnSe2 was present when the deposition was carried out in 275–375 °C temperature range, while for the films deposited in the below and above to this range, Sn and Se precipitates into some impure and mixed phase. Raman scattering analysis allowed the assignment of peaks at ∼180 cm−1 to the hexagonal-SnSe2 phase. The optical absorption study shows that the direct band gap of the film decreases with increase in substrate temperature and increasing crystallite size. The thermo-electrical measurements have shown n-type conductivity in as deposited films and the magnitude of thermo EMF for films has been found to be increasing with increasing deposition temperature, except for 350 °C sample. 350 °C deposited samples shows enhance thermoelectric value as compared to other samples. Thermoelectric study reveal that although sample deposited between 275 °C and 375 °C are structurally same but 350 °C sample is thermoelectrically best. - Highlights: • Influence of substrate temperature on the deposition of SnSe has been shown. • Seebeck measurements at 275°C–375 °C confirms n-type conductivity. • Higher seebeck coefficient has been observed at 350 °C deposited film. • Decrease in band gap was observed on increasing Tsub and size of the crystallites

  20. Atomic oxygen resistant behaviors of Mo/diamond-like carbon nanocomposite lubricating films

    International Nuclear Information System (INIS)

    Mo doped diamond-like carbon (Mo/DLC) films were deposited on Si substrates via unbalanced magnetron sputtering of molybdenum combined with plasma chemical vapor deposition of CH4/Ar. The microstructure of the films, characterized by transmission electron microscopy and selected area electron diffraction, was considered as a nanocomposite with nano-sized MoC particles uniformly embedded in the amorphous carbon matrix. The structure, morphology, surface composition and tribological properties of the Mo/DLC films before and after the atomic oxygen (AO) irradiation were investigated and a comparison made with the DLC films. The Mo/DLC films exhibited more excellent degradation resistant behaviors in AO environment than the DLC films, and the MoC nanoparticles were proved to play a critical role of preventing the incursion of AO and maintaining the intrinsic structure and excellent tribological properties of DLC films.

  1. Preparation of thin carbon films (1963)

    International Nuclear Information System (INIS)

    Carbon deposits have been prepared on silica glass supports in order to determine more accurately than by weighing the losses liable to occur during oxidation, for example under irradiation in the presence of CO2. Several processes have been studied with a view to obtaining deposits for which the variation in optical density as a function of carbon departure shall be reproducible for each sample. Among the methods used, the most satisfactory is that in which the pyrolytic carbon deposited on a carbon filament is evaporated; however only the samples prepared simultaneously exhibit the required identical behaviour. The carbonaceous deposits have been studied by micro-electronic diffraction. An examination of the photographs shows the presence of graphite monocrystals of about (30 μ)2. (author)

  2. Electrochromism of the electroless deposited cuprous oxide films

    International Nuclear Information System (INIS)

    Thin cuprous oxide films were prepared by a low cost, chemical deposition (electroless) method onto glass substrates pre-coated with fluorine doped tin oxide. The X-ray diffraction pattern confirmed the Cu2O composition of the films. Visible transmittance spectra of the cuprous oxide films were studied for the as-prepared, colored and bleached films. The cyclic voltammetry study showed that those films exhibited cathode coloring electrochromism, i.e. the films showed change of color from yellowish to black upon application of an electric field. The transmittance across the films for laser light of 670 nm was found to change due to the voltage change for about 50%. The coloration memory of those films was also studied during 6 h, ex-situ. The coloration efficiency at 670 nm was calculated to be 37 cm2/C

  3. Electrochromism of the electroless deposited cuprous oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Neskovska, R. [Faculty of Technical Sciences, University ' St. Clement Ohridski' , Bitola (Macedonia, The Former Yugoslav Republic of); Ristova, M. [Faculty of Natural Sciences and Mathematics, Institute of Physics, P.O. Box 162, Skopje (Macedonia, The Former Yugoslav Republic of)]. E-mail: mristova@iunona.pmf.ukim.edu.mk; Velevska, J. [Faculty of Natural Sciences and Mathematics, Institute of Physics, P.O. Box 162, Skopje (Macedonia, The Former Yugoslav Republic of); Ristov, M. [Macedonian Academy of Sciences and Arts, Skopje, Bul. Krste Misirkov bb, Skopje (Macedonia, The Former Yugoslav Republic of)

    2007-04-09

    Thin cuprous oxide films were prepared by a low cost, chemical deposition (electroless) method onto glass substrates pre-coated with fluorine doped tin oxide. The X-ray diffraction pattern confirmed the Cu{sub 2}O composition of the films. Visible transmittance spectra of the cuprous oxide films were studied for the as-prepared, colored and bleached films. The cyclic voltammetry study showed that those films exhibited cathode coloring electrochromism, i.e. the films showed change of color from yellowish to black upon application of an electric field. The transmittance across the films for laser light of 670 nm was found to change due to the voltage change for about 50%. The coloration memory of those films was also studied during 6 h, ex-situ. The coloration efficiency at 670 nm was calculated to be 37 cm{sup 2}/C.

  4. Characterization of polymer thin films obtained by pulsed laser deposition

    International Nuclear Information System (INIS)

    The development of laser techniques for the deposition of polymer and biomaterial thin films on solid surfaces in a controlled manner has attracted great attention during the last few years. Here we report the deposition of thin polymer films, namely Polyepichlorhydrin by pulsed laser deposition. Polyepichlorhydrin polymer was deposited on flat substrate (i.e. silicon) using an NdYAG laser (266 nm, 5 ns pulse duration and 10 Hz repetition rate). The obtained thin films have been characterized by atomic force microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy and spectroscopic ellipsometry. It was found that for laser fluences up to 1.5 J/cm2 the chemical structure of the deposited polyepichlorhydrin polymer thin layers resembles to the native polymer, whilst by increasing the laser fluence above 1.5 J/cm2 the polyepichlorohydrin films present deviations from the bulk polymer. Morphological investigations (atomic force microscopy and scanning electron microscopy) reveal continuous polyepichlorhydrin thin films for a relatively narrow range of fluences (1-1.5 J/cm2). The wavelength dependence of the refractive index and extinction coefficient was determined by ellipsometry studies which lead to new insights about the material. The obtained results indicate that pulsed laser deposition method is potentially useful for the fabrication of polymer thin films to be used in applications including electronics, microsensor or bioengineering industries.

  5. Pulsed laser deposition of the yttria-stabilized zirconia films

    International Nuclear Information System (INIS)

    Yttria-stabilized zirconia (YSZ) films are of considerable interest in optical, electronic and aerospace community and multitude of fabrication techniques are reported in the literature. This paper reports the characteristics of the YSZ films produced by pulsed laser deposition technique using a KrF excimer laser with yttria-stabilized zirconia targets. Morphological characteristics of the YSZ films were investigated by atomic force microscope (AFM) and scanning electron microscope. Distinct peak and valley structures with height differences in the range of 10-30 nm were observed in AFM images of the YSZ film surfaces, and measured roughness was 3.5-6.5 nm. A nanoindenter was used to investigate mechanical properties of the films deposited at different chamber pressure. Measured hardness and Young's modulus were about 10-11 GPa and 86-95 GPa respectively. Elemental composition and structural characteristics of the YSZ films were analyzed by electron prove micro-analyzer and X-ray diffraction, respectively

  6. Plasma deposition of fluorocarbon thin films from c-C4F8 using pulsed and continuous rf excitation

    International Nuclear Information System (INIS)

    Fluorocarbon films of varying composition have been deposited from pulsed and continuous plasmas of octafluorocyclobutane (c-C4F8) and c-C4F8/Ar. Continuous plasma deposition rates are a very weak function of applied rf power (may be within experimental error). Pulsed plasma deposition rates are significantly lower than continuous plasma rates at the same average power. The pulsed plasma deposition rates can be attributed almost entirely to the plasma on time during the pulse, but there is a slight dependence on pulse off time. Ar addition affects the deposition rates through a residence time effect, but also affects the deposition chemistry by reducing the degree of C4F8 dissociation, resulting in more fluorinated films. Refractive indices for all films increase approximately linearly with applied rf power, with the pulsed plasma-deposited films falling on the same curve. Carbon 1s x-ray photoelectron spectroscopy shows that the continuous plasma-deposited films become increasingly fluorinated as the rf power is decreased. Pulsed plasma films are more fluorinated than similar average power continuous plasma films: 44% CF2 for 10/50 (400 W on time, 67 W average power) versus 37% for 50 W continuous. Literature and preliminary gas-phase measurements suggest that the C4F8 is not fully dissociated in either plasma system and that larger species in the gas phase may play a significant role in the deposition mechanisms

  7. Photoluminescence properties of poly (p-phenylene vinylene) films deposited by chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Gedelian, Cynthia A. [Department of Physics, Applied Physics, and Astronomy, Center for Integrated Electronics, Rensselaer Polytechnic Institute, Troy 12180-3590, NY (United States); Rajanna, K.C., E-mail: kcrajannaou@yahoo.com [Department of Chemistry, Osmania University, Hyderabad 500007, Andhra Pradesh (India); Premerlani, Brian; Lu, Toh-Ming [Department of Physics, Applied Physics, and Astronomy, Center for Integrated Electronics, Rensselaer Polytechnic Institute, Troy 12180-3590, NY (United States)

    2014-01-15

    Photoluminescence spectra of PPV at varying thicknesses and temperatures have been studied. A study of the quenching of the polymer film using a modified version of fluorescence spectroscopy reveals interface effects dominating at thicknesses below about 600 Å, while bulk effects dominate at higher thicknesses. The application of the Stern–Volmer equation to solid film is discussed. Stern–Volmer plots were nonlinear with downward deviations at higher thickness of the film which was explained due to self-quenching in films and larger conformational change and increased restriction from change in electron density due to electron transition during excitation in bulk polymer films over 60 nm thick. PPV deposited into porous (∼4 nm in diameter) nanostructured substrate shows a larger 0–0 than 0–1 transition peak intensity and decreased disorder in the films due to structure imposed by substrate matrix. Temperature dependent effects are measured for a film at 500 Å, right on the border between the two areas. PPV films deposited on porous methyl silsesquioxane (MSQ) were also examined in order to compare the flat film to a substrate that allows for the domination of interface effects. The enthalpies of the first two peaks are very similar, but the third peak demonstrates a lower enthalpy and a larger wavelength shift with temperature. Films deposited inside pores show a smaller amount of disorder than flat films. Calculation of the Huang–Rhys factor at varying temperatures for the flat film and film in porous MSQ shows large temperature dependence for the flat film but a smaller amount of disorder in the nanostructured film. -- Highlights: • Poly (p-phenylene vinylene) films deposited by chemical vapor deposition exhibited photoluminescence properties. • Fluorescence spectra of the polymer films revealed interface effects dominating at thicknesses below about 600 Å, while bulk effects dominate at higher thicknesses. • Stern–Volmer plots were

  8. Photoluminescence properties of poly (p-phenylene vinylene) films deposited by chemical vapor deposition

    International Nuclear Information System (INIS)

    Photoluminescence spectra of PPV at varying thicknesses and temperatures have been studied. A study of the quenching of the polymer film using a modified version of fluorescence spectroscopy reveals interface effects dominating at thicknesses below about 600 Å, while bulk effects dominate at higher thicknesses. The application of the Stern–Volmer equation to solid film is discussed. Stern–Volmer plots were nonlinear with downward deviations at higher thickness of the film which was explained due to self-quenching in films and larger conformational change and increased restriction from change in electron density due to electron transition during excitation in bulk polymer films over 60 nm thick. PPV deposited into porous (∼4 nm in diameter) nanostructured substrate shows a larger 0–0 than 0–1 transition peak intensity and decreased disorder in the films due to structure imposed by substrate matrix. Temperature dependent effects are measured for a film at 500 Å, right on the border between the two areas. PPV films deposited on porous methyl silsesquioxane (MSQ) were also examined in order to compare the flat film to a substrate that allows for the domination of interface effects. The enthalpies of the first two peaks are very similar, but the third peak demonstrates a lower enthalpy and a larger wavelength shift with temperature. Films deposited inside pores show a smaller amount of disorder than flat films. Calculation of the Huang–Rhys factor at varying temperatures for the flat film and film in porous MSQ shows large temperature dependence for the flat film but a smaller amount of disorder in the nanostructured film. -- Highlights: • Poly (p-phenylene vinylene) films deposited by chemical vapor deposition exhibited photoluminescence properties. • Fluorescence spectra of the polymer films revealed interface effects dominating at thicknesses below about 600 Å, while bulk effects dominate at higher thicknesses. • Stern–Volmer plots were

  9. Friction of diamond-like carbon films in different atmospheres

    International Nuclear Information System (INIS)

    Diamond-like carbon (DLC) films constitute a class of new materials with a wide range of compositions, properties, and performance. In particular, the tribological properties of these films are rather intriguing and can be strongly influenced by the test conditions and environment. In this paper, we performed a series of model experiments in high vacuum and with various added gases to elucidate the influence of different test environments on the tribological behavior of three DLC films. Specifically, we studied the behavior of a hydrogen-free film produced by a cathodic arc process and two highly hydrogenated films produced by plasma-enhanced chemical-vapor deposition. Flats and balls used in our experiments were coated with DLC and tested in a pin-on-disc machine under a load of 1 N and at constant rotational frequency. With a low background pressure, in the 10(sup -6) Pa range, the highly hydrogenated films exhibited a friction coefficient of less than 0.01, whereas the hydrogen-free film gave a friction coefficient of approximately 0.6. Adding oxygen or hydrogen to the experimental environment changed the friction to some extent. However, admission of water vapor into the test chamber caused large changes: the friction coefficient decreased drastically for the hydrogen-free DLC film whereas it increased a bit for one of the highly hydrogenated films. These results indicate that water molecules play a prominent role in the frictional behavior of DLC films-most notably for hydrogen-free films but also for highly hydrogenated films

  10. Deposition technology and properties of diamond-like carbon thin film on tappet%发动机挺柱沉积类金刚石薄膜的工艺及性能

    Institute of Scientific and Technical Information of China (English)

    黄平; 张营营; 张斌; 范梅梅; 李兴杰; 强力

    2013-01-01

    采用磁控溅射法,以Cr、Ti和石墨为靶材,Ar、N2和CH4为溅射气体,在材料为20CrMo的发动机挺柱上利用多层梯度复合技术沉积了低摩擦类金刚石(DLC)薄膜复合层CrTi/CrTiN/CrTiC/DLC.该薄膜复合层的纳米压痕硬度高达13 GPa,结合力为50 N,表面粗糙度为0.398 nm.在SRV-IV微动摩擦磨损试验机上进行耐磨损试验后,DLC复合薄膜挺柱的磨损率为渗碳挺柱的1/6.该研究技术具有自主知识产权,实现了挺柱批量化覆膜加工,并有望在发动机主要摩擦副上推广应用.%A low-friction multilayered diamond-like carbon (DLC) film with gradient structure of CrTi/CrTiN/CrTiC/DLC was deposited on tappet made of 20CrMo by magnetron sputtering of Cr,Ti,and graphite targets in Ar/N2/CH4 atmosphere.The composite thin film features hardness up to 13 GPa,bonding strength 50 N,and surface roughness 0.398 nm.The wear rate of the sputtered tappet is 1/6 of that of a carburized one after testing by SRV-IV fretting tribometer.The bulk thin film processing of tappets by using the technology with independent intellectual property rights has been realized,showing a promising use in manufacturing main friction couples of engines.

  11. Pulsed laser deposition and characterisation of thin superconducting films

    Energy Technology Data Exchange (ETDEWEB)

    Morone, A. [CNR, zona industriale di Tito Scalo, Potenza (Italy). Istituto per i Materiali Speciali

    1996-09-01

    Same concepts on pulsed laser deposition of thin films will be discussed and same examples of high transition temperature (HTc) BiSrCaCuO (BISCO) and low transition temperature NbN/MgO/NbN multilayers will be presented. X-ray and others characterizations of these films will be reported and discussed. Electrical properties of superconducting thin films will be realized as a function of structural and morphological aspect.

  12. Ag films grown by remote plasma enhanced atomic layer deposition on different substrates

    Energy Technology Data Exchange (ETDEWEB)

    Amusan, Akinwumi A., E-mail: akinwumi.amusan@ovgu.de; Kalkofen, Bodo; Burte, Edmund P. [Institute of Micro and Sensor Systems, Otto-von-Guericke University, Universitätsplatz 2, 39106 Magdeburg (Germany); Gargouri, Hassan; Wandel, Klaus; Pinnow, Cay [SENTECH Instruments GmbH, Schwarzschildstraße 2, 12489 Berlin (Germany); Lisker, Marco [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany)

    2016-01-15

    Silver (Ag) layers were deposited by remote plasma enhanced atomic layer deposition (PALD) using Ag(fod)(PEt{sub 3}) (fod = 2,2-dimethyl-6,6,7,7,8,8,8-heptafluorooctane-3,5-dionato) as precursor and hydrogen plasma on silicon substrate covered with thin films of SiO{sub 2}, TiN, Ti/TiN, Co, Ni, and W at different deposition temperatures from 70  to 200 °C. The deposited silver films were analyzed by x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) with energy dispersive x-ray spectroscopy, four point probe measurement, ellipsometric measurement, x-ray fluorescence (XRF), and x-ray diffraction (XRD). XPS revealed pure Ag with carbon and oxygen contamination close to the detection limit after 30 s argon sputtering for depositions made at 120 and 200 °C substrate temperatures. However, an oxygen contamination was detected in the Ag film deposited at 70 °C after 12 s argon sputtering. A resistivity of 5.7 × 10{sup −6} Ω cm was obtained for approximately 97 nm Ag film on SiO{sub 2}/Si substrate. The thickness was determined from the SEM cross section on the SiO{sub 2}/Si substrate and also compared with XRF measurements. Polycrystalline cubic Ag reflections were identified from XRD for PALD Ag films deposited at 120 and 200 °C. Compared to W surface, where poor adhesion of the films was found, Co, Ni, TiN, Ti/TiN and SiO{sub 2} surfaces had better adhesion for silver films as revealed by SEM, TEM, and AFM images.

  13. Ag films grown by remote plasma enhanced atomic layer deposition on different substrates

    International Nuclear Information System (INIS)

    Silver (Ag) layers were deposited by remote plasma enhanced atomic layer deposition (PALD) using Ag(fod)(PEt3) (fod = 2,2-dimethyl-6,6,7,7,8,8,8-heptafluorooctane-3,5-dionato) as precursor and hydrogen plasma on silicon substrate covered with thin films of SiO2, TiN, Ti/TiN, Co, Ni, and W at different deposition temperatures from 70  to 200 °C. The deposited silver films were analyzed by x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) with energy dispersive x-ray spectroscopy, four point probe measurement, ellipsometric measurement, x-ray fluorescence (XRF), and x-ray diffraction (XRD). XPS revealed pure Ag with carbon and oxygen contamination close to the detection limit after 30 s argon sputtering for depositions made at 120 and 200 °C substrate temperatures. However, an oxygen contamination was detected in the Ag film deposited at 70 °C after 12 s argon sputtering. A resistivity of 5.7 × 10−6 Ω cm was obtained for approximately 97 nm Ag film on SiO2/Si substrate. The thickness was determined from the SEM cross section on the SiO2/Si substrate and also compared with XRF measurements. Polycrystalline cubic Ag reflections were identified from XRD for PALD Ag films deposited at 120 and 200 °C. Compared to W surface, where poor adhesion of the films was found, Co, Ni, TiN, Ti/TiN and SiO2 surfaces had better adhesion for silver films as revealed by SEM, TEM, and AFM images

  14. Characterization of CdTe Films Deposited at Various Bath Temperatures and Concentrations Using Electrophoretic Deposition

    Directory of Open Access Journals (Sweden)

    Zulkarnain Zainal

    2012-05-01

    Full Text Available CdTe film was deposited using the electrophoretic deposition technique onto an ITO glass at various bath temperatures. Four batch film compositions were used by mixing 1 to 4 wt% concentration of CdTe powder with 10 mL of a solution of methanol and toluene. X-ray Diffraction analysis showed that the films exhibited polycrystalline nature of zinc-blende structure with the (111 orientation as the most prominent peak. From the Atomic Force Microscopy, the thickness and surface roughness of the CdTe film increased with the increase of CdTe concentration. The optical energy band gap of film decreased with the increase of CdTe concentration, and with the increase of isothermal bath temperature. The film thickness increased with respect to the increase of CdTe concentration and bath temperature, and following, the numerical expression for the film thickness with respect to these two variables has been established.

  15. Properties of a-C:H:O plasma polymer films deposited from acetone vapors

    Energy Technology Data Exchange (ETDEWEB)

    Drabik, M., E-mail: martin.drabik@gmail.com [Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen (Switzerland); Celma, C. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen (Switzerland); Kousal, J.; Biederman, H. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holešovičkách 2, 180 00 Prague 8 (Czech Republic); Hegemann, D. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen (Switzerland)

    2014-12-31

    To gain insight into the deposition and stability of oxygen-containing plasma polymer films, the properties of amorphous oxygenated hydrocarbon (a-C:H:O) plasma polymer coatings deposited from acetone vapors under various experimental conditions are investigated. Apart from the discharge power, the influence of the reactive carbon dioxide (CO{sub 2}) gas on the structure of the resulting films is studied. It is found by characterization using X-ray Photoelectron Spectroscopy and Fourier-Transform Infrared Spectroscopy that the experimental conditions particularly influence the amount of oxygen in the deposited a-C:H:O plasma polymer films. The O/C elemental ratio increases with increasing amount of CO{sub 2} in the working gas mixture (up to 0.2 for 24 sccm of CO{sub 2} at 30 W) and decreases with increasing RF discharge power (down to 0.17 for 50 W). Furthermore, the nature of bonds between the oxygen and carbon atoms has been examined. Only low amounts of double and triple bonded carbon are observed. This has a particular influence on the aging of the plasma polymer films which is studied both in ambient air and in distilled water for up to 4 months. Overall, stable a-C:H:O plasma polymer films are deposited comprising low amounts (up to about 5%) of ester/carboxyl groups. - Highlights: • Hydrocarbon plasma polymer films with variable oxygen content can be prepared. • Stable oxygenated hydrocarbon plasma polymers contain max 5% of ester/carboxyl groups. • Acetone-derived plasma polymer films can be used as permanent hydrophilic surfaces.

  16. Properties of a-C:H:O plasma polymer films deposited from acetone vapors

    International Nuclear Information System (INIS)

    To gain insight into the deposition and stability of oxygen-containing plasma polymer films, the properties of amorphous oxygenated hydrocarbon (a-C:H:O) plasma polymer coatings deposited from acetone vapors under various experimental conditions are investigated. Apart from the discharge power, the influence of the reactive carbon dioxide (CO2) gas on the structure of the resulting films is studied. It is found by characterization using X-ray Photoelectron Spectroscopy and Fourier-Transform Infrared Spectroscopy that the experimental conditions particularly influence the amount of oxygen in the deposited a-C:H:O plasma polymer films. The O/C elemental ratio increases with increasing amount of CO2 in the working gas mixture (up to 0.2 for 24 sccm of CO2 at 30 W) and decreases with increasing RF discharge power (down to 0.17 for 50 W). Furthermore, the nature of bonds between the oxygen and carbon atoms has been examined. Only low amounts of double and triple bonded carbon are observed. This has a particular influence on the aging of the plasma polymer films which is studied both in ambient air and in distilled water for up to 4 months. Overall, stable a-C:H:O plasma polymer films are deposited comprising low amounts (up to about 5%) of ester/carboxyl groups. - Highlights: • Hydrocarbon plasma polymer films with variable oxygen content can be prepared. • Stable oxygenated hydrocarbon plasma polymers contain max 5% of ester/carboxyl groups. • Acetone-derived plasma polymer films can be used as permanent hydrophilic surfaces

  17. The role of oxygen and surface reactions in the deposition of silicon oxide like films from HMDSO at atmospheric pressure

    OpenAIRE

    Reuter, R; Rügner, K.; Ellerweg, D.; Arcos, T. de los; von Keudell, A.; Benedikt, J

    2011-01-01

    The deposition of thin SiO$_x$C$_y$H$_z$ or SiO$_x$H$_y$ films by means of atmospheric pressure microplasma jets with admixture of Hexamethyldisiloxane (HMDSO) and oxygen and the role of surface reactions in film growth are investigated. Two types of microplasma jets, one with a planar electrodes and operated in helium gas and the other one with a coaxial geometry operated in argon, are used to study the deposition process. The growth rate of the film and the carbon-content in the film are me...

  18. Deposition of SiOx barrier films by O2/TMDSO RF-PECVD

    Institute of Scientific and Technical Information of China (English)

    Zhou Mei-Li; Fu Ya-Bo; Chen Qiang; Ge Yuan-Jing

    2007-01-01

    This paper reports that the SiOx barrier films are deposited on polyethylene terephthalate substrate by plasmaenhanced chemical vapour deposition (PECVD) for the application of transparent barrier packaging. The variations of O2/Tetramethyldisiloxane (TMDSO) ratio and input power in radio frequency (RF) plasma are carried out to optimize barrier properties of the SiOx coated film. The properties of the coatings are characterized by Fourier transform infrared,water wpour transmission rate (WVTR), oxygen transmission rate (OTR), and atomic force microscopy analysers. It is found that the O2/TMDSO ratio exceeding 2:1 and the input power over 200 W yield SiOx films with low carbon contents which can be good to the barrier (WVTR and OTR) properties of the SiOx coatings. Also, the film properties not only depend on oxygen concentration of the inlet gas mixtures and input power, but also relate to the surface morphology of the coating.

  19. Fabrication and Cytocompatibility of In Situ Crosslinked Carbon Nanomaterial Films

    Science.gov (United States)

    Patel, Sunny C.; Lalwani, Gaurav; Grover, Kartikey; Qin, Yi-Xian; Sitharaman, Balaji

    2015-05-01

    Assembly of carbon nanomaterials into two-dimensional (2D) coatings and films that harness their unique physiochemical properties may lead to high impact energy capture/storage, sensors, and biomedical applications. For potential biomedical applications, the suitability of current techniques such as chemical vapor deposition, spray and dip coating, and vacuum filtration, employed to fabricate macroscopic 2D all carbon coatings or films still requires thorough examination. Each of these methods presents challenges with regards to scalability, suitability for a large variety of substrates, mechanical stability of coatings or films, or biocompatibility. Herein we report a coating process that allow for rapid, in situ chemical crosslinking of multi-walled carbon nanotubes (MWCNTs) into macroscopic all carbon coatings. The resultant coatings were found to be continuous, electrically conductive, significantly more robust, and cytocompatible to human adipose derived stem cells. The results lay groundwork for 3D layer-on-layer nanomaterial assemblies (including various forms of graphene) and also opens avenues to further explore the potential of MWCNT films as a novel class of nano-fibrous mats for tissue engineering and regenerative medicine.

  20. Strontium-Doped Lanthanum Manganite Films Prepared by Magnetic Deposition

    DEFF Research Database (Denmark)

    Menon, Mohan; Larsen, Casper; Andersen, Kjeld Bøhm

    2009-01-01

    with the concentration of the suspension. Deposition phenomena were explained by modeling the magnetic flux in the deposition cell. Particles aligned with the flux lines, forming chains of LSM particles that, upon sintering, resulted in the formation of porous films with long chains of LSM grains....

  1. Resonant infrared pulsed laser deposition of cyclic olefin copolymer films

    Energy Technology Data Exchange (ETDEWEB)

    Singaravelu, Senthil R. [ODU, JLAB; Klopf, John M. [JLAB; Schriver, Kenneth E. [Vanderbilt; Park, HyeKyoung [JLAB; Kelley, Michael J. [JLAB; Haglund, Jr., Richard F. [Vanderbilt

    2013-08-01

    Barrier materials on thin-film organic optoelectronic devices inhibit the uptake of water, oxygen, or environmental contaminants, and fabricating them is a major challenge. By definition, these barrier layers must be insoluble, so the usual routes to polymer- or organic-film deposition by spin coating are not problematic. In this paper, we report comparative studies of pulsed laser deposition of cyclic olefin copolymer (COC), an excellent moisture barrier and a model system for a larger class of protective materials that are potentially useful in organic electronic devices, such as organic light-emitting diodes (OLEDs). Thin films of COC were deposited by resonant and nonresonant infrared pulsed laser ablation of solid COC targets, using a free-electron laser tuned to the 3.43 μm C–H stretch of the COC, and a high-intensity nanosecond Q-switched laser operated at 1064 nm. The ablation craters and deposited films were characterized by scanning-electron microscopy, Fourier-transform infrared spectrometry, atomic-force microscopy, high-resolution optical microscopy, and surface profilometry. Thermal-diffusion calculations were performed to determine the temperature rise induced in the film at the C–H resonant wavelength. The results show that resonant infrared pulsed laser deposition (RIR-PLD) is an effective, low-temperature thin-film deposition technique that leads to evaporation and deposition of intact molecules in homogeneous, smooth films. Nonresonant PLD, on the other hand, leads to photothermal damage, degradation of the COC polymers, and to the deposition only of particulates.

  2. The effects of gamma-irradiation on DLC thin film-deposited polycarbonate

    International Nuclear Information System (INIS)

    DLC(Diamond-like carbon) thin film-deposition polycarbonate specimens were irradiated by high level gamma-ray and made observation of their irradiation effects. In order to do that, diamond-like carbon thin films were deposited on polycarbonate specimens by plasma-enhanced chemical vapor deposition system, and then those specimens are irradiated in the high level irradiation facility in KAERI at the same dose rate of 106 rad. Relative concentration of free radicals generated during irraiation of the DLC-deposited and undeposited specimens was determined by the analysis of EPR(electron paramagnetic resonance) spectrum at the elapsed time of 4 hours and 2 months after irradiation of those specimens. As a result of the analysis, it was found that the radical concentration in the DLC-undeposited specimen at the elapsed time of 2 months reduced rapidly in 4 % compared with that at the elapsed time of 4 hours, whereas the concentration in the DLC-deposited specimens decreased slowly in the vicinity of 60 %. Consequently, DLC thin film-deposition polycarbonate specimens resulted in the increase of radiation-oxidation resistance

  3. Characterization of Si:O:C:H films fabricated using electron emission enhanced chemical vapour deposition

    International Nuclear Information System (INIS)

    Silicon-based polymers and oxides may be formed when vapours of oxygen-containing organosilicone compounds are exposed to energetic electrons drawn from a hot filament by a bias potential applied to a second electrode in a controlled atmosphere in a vacuum chamber. As little deposition occurs in the absence of the bias potential, electron impact fragmentation is the key mechanism in film fabrication using electron-emission enhanced chemical vapour deposition (EEECVD). The feasibility of depositing amorphous hydrogenated carbon films also containing silicon from plasmas of tetramethylsilane or hexamethyldisiloxane has already been shown. In this work, we report the deposition of diverse films from plasmas of tetraethoxysilane (TEOS)-argon mixtures and the characterization of the materials obtained. The effects of changes in the substrate holder bias (VS) and of the proportion of TEOS in the mixture (XT) on the chemical structure of the films are examined by infrared-reflection absorption spectroscopy (IRRAS) at near-normal and oblique incidence using unpolarised and p-polarised, light, respectively. The latter is particularly useful in detecting vibrational modes not observed when using conventional near-normal incidence. Elemental analyses of the film were carried out by X-ray photoelectron spectroscopy (XPS), which was also useful in complementary structural investigations. In addition, the dependencies of the deposition rate on VS and XT are presented

  4. Anomalous hysteresis properties of iron films deposited on liquid surfaces

    Science.gov (United States)

    Ye, Quan-Lin; Feng, Chun-Mu; Xu, Xiao-Jun; Jin, Jin-Sheng; Xia, A.-Gen; Ye, Gao-Xiang

    2005-07-01

    A nearly free sustained iron film system, deposited on silicone oil surfaces by vapor-phase deposition method, has been fabricated and its crystal structure as well as magnetic properties has been studied. Both the temperature-dependent coercivity Hc(T) and exchange anisotropy field HE(T) of the iron films possess a maximum peak around the critical temperature Tcrit=10-15 and 4K, respectively. Our experimental results show that the anomalous hysteresis properties mainly result from the oxide surfaces of the films with spin-glass-like phase below freezing temperature Tf=30-50K.

  5. Thin-film organic photonics molecular layer deposition and applications

    CERN Document Server

    Yoshimura, Tetsuzo

    2011-01-01

    Among the many atomic/molecular assembling techniques used to develop artificial materials, molecular layer deposition (MLD) continues to receive special attention as the next-generation growth technique for organic thin-film materials used in photonics and electronics. Thin-Film Organic Photonics: Molecular Layer Deposition and Applications describes how photonic/electronic properties of thin films can be improved through MLD, which enables precise control of atomic and molecular arrangements to construct a wire network that achieves ""three-dimensional growth"". MLD facilitates dot-by-dot--o

  6. Deuterium retention in the carbon co-deposition layers deposited by magnetron sputtering in D2/He atmosphere

    International Nuclear Information System (INIS)

    Carbon was deposited on Si and W substrates using a D2/He plasma in a radio frequency magnetron sputtering system. The deposited layers were examined with ion beam analysis (IBA), Raman spectra analysis (RS) and scanning electron microscopy (SEM). The growth rate of the layers deposited at 2.5 Pa total pressure and 300 K decreased with increasing He fraction in the D2/He gas mixture. The deuterium concentration in the layers deposited on the Si substrate increased from 14% to 28% when the flow rate of the He gas relative to the D2 gas was varied from 0.125 to 0.5, but the deuterium concentration in the layers on a W substrate decreased from 24% to 14%. Deuterium or helium retention and the layer thickness all significantly decreased when the substrate temperature was increased from 423 K to 773 K. Raman analysis showed that the deposited layers were amorphous deuterated-carbon layers (named a-C: D layer) and the extent of bond disorder increased dramatically with the increasing helium content in the film. Blisters and bubbles occurred in the films for high helium content in the films, and surface cracking and exfoliation were also observed

  7. Properties of a-C:H:Si thin films deposited by middle-frequency magnetron sputtering

    Science.gov (United States)

    Jiang, Jinlong; Wang, Yubao; Du, Jinfang; Yang, Hua; Hao, Junying

    2016-08-01

    The silicon doped hydrogenated amorphous carbon (a-C:H:Si) films were prepared on silicon substrates by middle-frequency magnetron sputtering silicon target in an argon and methane gas mixture atmosphere. The deposition rate, chemical composition, structure, surface properties, stress, hardness and tribological properties in the ambient air of the films were systemically investigated using X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), atomic force microscopy (AFM), nanoindentation and tribological tester. The results show that doped silicon content in the films is controlled in the wide range from 39.7 at.% to 0.2 at.% by various methane gas flow rate, and methane flow rate affects not only the silicon content but also its chemical bonding structure in the films due to the transformation of sputtering modes. Meanwhile, the sp3 carbon component in the films linearly increases with increasing of methane flow rate. The film deposited at moderate methane flow rate of 40-60 sccm exhibits the very smooth surface (RMS roughness 0.4 nm), low stress (0.42 GPa), high hardness (21.1 GPa), as well as low friction coefficient (0.038) and wear rate (1.6 × 10-7 mm3/Nm). The superior tribological performance of the films could be attributed to the formation and integral covering of the transfer materials on the sliding surface and their high hardness.

  8. Carbon films produced from ionic liquid carbon precursors

    Science.gov (United States)

    Dai, Sheng; Luo, Huimin; Lee, Je Seung

    2013-11-05

    The invention is directed to a method for producing a film of porous carbon, the method comprising carbonizing a film of an ionic liquid, wherein the ionic liquid has the general formula (X.sup.+a).sub.x(Y.sup.-b).sub.y, wherein the variables a and b are, independently, non-zero integers, and the subscript variables x and y are, independently, non-zero integers, such that ax=by, and at least one of X.sup.+ and Y.sup.- possesses at least one carbon-nitrogen unsaturated bond. The invention is also directed to a composition comprising a porous carbon film possessing a nitrogen content of at least 10 atom %.

  9. Measuring Thicknesses Of Vacuum-Deposited Organic Thin Films

    Science.gov (United States)

    David, Carey E.

    1996-01-01

    Method of measuring thickness of thin organic liquid film deposited in vacuum involves use of quartz-crystal monitor (QCM) calibrated by use of witness plate that has, in turn, calibrated by measurement of absorption of infrared light in deposited material. Present procedure somewhat tedious, but once calibration accomplished, thicknesses of organic liquid deposits monitored in real time and in situ by use of QCM.

  10. Holmium titanium oxide thin films grown by atomic layer deposition

    International Nuclear Information System (INIS)

    Thin solid holmium titanium oxide films were grown by atomic layer deposition at 300 °C on silicon substrates. The precursors used were Ho(thd)3, Ti(OCH(CH3)2)4 and O3. The composition of the films was varied via changing the holmium–titanium ratio by variation of relative amounts of the sequential deposition cycles of constituent oxides, i.e. Ho2O3 and TiO2. The constituent oxides alone were crystallized in as-deposited states. After mixing the Ho2O3 or TiO2 layers the films were amorphous but were crystallized after annealing at 800–1000 °C, mostly transforming into the Ho2Ti2O7 phase. The stoichiometric ratio of 1:1 between Ti and Ho contents was achieved by application of at least twice as many Ho2O3 deposition cycles as TiO2 cycles. Magnetometry revealed that saturation magnetization could be observed in the films containing lower amounts of holmium compared to titanium. - Highlights: • Holmium-doped TiO2 and holmium titanates were deposited by ALD. • Crystallization temperature increased with the Ho:Ti ratio. • Holmium titanate films possessed pyrochlore phase. • The films could demonstrate saturative magnetization

  11. 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.

  12. 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.

  13. Tungsten trioxide thin films prepared by electrostatic spray deposition technique

    International Nuclear Information System (INIS)

    Tungsten trioxide (WO3) thin films deposited on a Pt-coated alumina substrate using the electrostatic spray deposition (ESD) technique is reported in this paper. As precursor solution, tungsten (VI) ethoxide in ethanol was used. The morphology and the microstructure of the films were studied using scanning electron microscopy coupled with energy dispersive X-ray analysis, transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. Dense to porous morphologies were obtained by tuning the deposition temperature. Impedance spectroscopy and current-voltage measurements were used to study the electrical behaviour of the films in air, in temperature range 300-500 deg. C. The activation energy was estimated from Arrhenius plots. Considering the obtained results, the ESD technique proved to be an effective technique for the fabrication of porous tungsten trioxide thin films

  14. Plasma deposition of polymer composite films incorporating nanocellulose whiskers

    Science.gov (United States)

    Samyn, P.; Airoudj, A.; Laborie, M.-P.; Mathew, A. P.; Roucoules, V.

    2011-11-01

    In a trend for sustainable engineering and functionalization of surfaces, we explore the possibilities of gas phase processes to deposit nanocomposite films. From an analysis of pulsed plasma polymerization of maleic anhydride in the presence of nanocellulose whiskers, it seems that thin nanocomposite films can be deposited with various patterns. By specifically modifying plasma parameters such as total power, duty cycle, and monomer gas pressure, the nanocellulose whiskers are either incorporated into a buckled polymer film or single nanocellulose whiskers are deposited on top of a polymeric film. The density of the latter can be controlled by modifying the exact positioning of the substrate in the reactor. The resulting morphologies are evaluated by optical microscopy, AFM, contact angle measurements and ellipsometry.

  15. Deposition of pure gold thin films from organometallic precursors

    Science.gov (United States)

    Parkhomenko, Roman G.; Trubin, Sergey V.; Turgambaeva, Asiya E.; Igumenov, Igor К.

    2015-03-01

    Using metallorganic chemical vapor deposition, pure gold thin films have been obtained from a number of volatile dimethylgold(III) complexes with different types of chelating organic ligands. Deposition was performed in argon (10 Torr) with and without hydrogen and oxygen as reactant gases and with additional VUV (vacuum ultraviolet) stimulation. According to the XRD phase analysis, gold films grow mainly in [111] direction. The influence of precursor structure on the morphology of the deposited layers was demonstrated. It was established that presence of H2 raises the growth rate and porosity of the films significantly with decreased amount of any impurities. With the VUV stimulation, the gold content in the films amounts to >99 at%.

  16. Aerosol deposition of (Cu,Ti) substituted bismuth vanadate films

    International Nuclear Information System (INIS)

    Bismuth vanadate, Bi4V2O11, and related compounds with various metal (Me) substitutions, Bi4(MexV1−x)2O11−δ, show some of the highest ionic conductivities among the known solid oxide electrolytes. Films of Cu and Ti substituted bismuth vanadate were prepared by an aerosol deposition method, a spray coating process also described as room temperature impact consolidation. Resultant films, several microns in thickness, were dense with good adhesion to the substrate. Scanning electron microscopy and high temperature X-ray diffraction were used to monitor the effects of temperature on the structure and microstructure of the film. The particle size remained nano-scale while microstrain decreased rapidly up to 500 °C, above which coarsening and texturing increased rapidly. Impedance measurements of films deposited on inter-digital electrodes revealed an annealing effect on the ionic conductivity, with the conductivity exceeding that of a screen printed film, and approaching that of bulk ceramic. - Highlights: • Cu and Ti doped bismuth vanadate films were prepared by aerosol deposition (AD). • Dense 3–5 μm thick films were deposited on alumina, silicon and gold electrodes. • Annealing of the AD-layer increases the conductivity by 1.5 orders of magnitude. • Effect of temperature on structure and microstructure was investigated

  17. Deposition and investigation of lanthanum-cerium hexaboride thin films

    International Nuclear Information System (INIS)

    Thin films of lanthanum-cerium hexaboride, the promising thermoelectric material for low-temperature applications, are deposited on various substrates by the electron-beam evaporation, pulsed laser deposition and magnetron sputtering. The influence of the deposition conditions on the films X-ray characteristics, composition, microstructure and physical properties, such as the resistivity and Seebeck coefficient, is studied. The preferred (100) orientation of all films is obtained from XRD traces. In the range of 780-800 deg. C deposition temperature the highest intensity of diffractions peaks and the highest degree of the preferred orientation are observed. The temperature dependence of the resistivity and the Seebeck coefficient of films are investigated in the temperature range of 4-300 K. The features appropriate to Kondo effect in the dependences ρ(T) and S(T) are detected at temperatures below 20 K. Interplay between the value of the Seebeck coefficient, metallic parameters and Kondo scattering of investigated films is discussed. - Graphical abstract: Kondo scattering in (La,Ce)B6 films: temperature dependence of the resistivity of (La,Ce)B6 films on various substrates and the ceramics La0.99Ce0.01B6

  18. Aerosol deposition of (Cu,Ti) substituted bismuth vanadate films

    Energy Technology Data Exchange (ETDEWEB)

    Exner, Jörg, E-mail: Functional.Materials@Uni-Bayreuth.de [University of Bayreuth, Department of Functional Materials, Universitätsstraße 30, 95440 Bayreuth (Germany); Fuierer, Paul [Materials and Metallurgical Engineering Department, New Mexico Institute of Mining and Technology, Socorro, NM 87801 (United States); Moos, Ralf [University of Bayreuth, Department of Functional Materials, Universitätsstraße 30, 95440 Bayreuth (Germany)

    2014-12-31

    Bismuth vanadate, Bi{sub 4}V{sub 2}O{sub 11}, and related compounds with various metal (Me) substitutions, Bi{sub 4}(Me{sub x}V{sub 1−x}){sub 2}O{sub 11−δ}, show some of the highest ionic conductivities among the known solid oxide electrolytes. Films of Cu and Ti substituted bismuth vanadate were prepared by an aerosol deposition method, a spray coating process also described as room temperature impact consolidation. Resultant films, several microns in thickness, were dense with good adhesion to the substrate. Scanning electron microscopy and high temperature X-ray diffraction were used to monitor the effects of temperature on the structure and microstructure of the film. The particle size remained nano-scale while microstrain decreased rapidly up to 500 °C, above which coarsening and texturing increased rapidly. Impedance measurements of films deposited on inter-digital electrodes revealed an annealing effect on the ionic conductivity, with the conductivity exceeding that of a screen printed film, and approaching that of bulk ceramic. - Highlights: • Cu and Ti doped bismuth vanadate films were prepared by aerosol deposition (AD). • Dense 3–5 μm thick films were deposited on alumina, silicon and gold electrodes. • Annealing of the AD-layer increases the conductivity by 1.5 orders of magnitude. • Effect of temperature on structure and microstructure was investigated.

  19. Electrochemical and Antimicrobial Properties of Diamondlike Carbon-Metal Composite Films

    Energy Technology Data Exchange (ETDEWEB)

    MORRISON, M. L.; BUCHANAN, R. A.; LIAW, P. K.; BERRY, C. J.; BRIGMON, R.; RIESTER, L.; JIN, C.; NARAYAN, R. J.

    2005-05-11

    Implants containing antimicrobial metals may reduce morbidity, mortality, and healthcare costs associated with medical device-related infections. We have deposited diamondlike carbon-silver (DLC-Ag), diamondlike carbon-platinum (DLC-Pt), and diamondlike carbon-silver-platinum (DLC-AgPt) thin films using a multicomponent target pulsed laser deposition process. Transmission electron microscopy of the DLC-silver and DLC-platinum composite films revealed that the silver and platinum self-assemble into nanoparticle arrays within the diamondlike carbon matrix. The diamondlike carbon-silver film possesses hardness and Young's modulus values of 37 GPa and 331 GPa, respectively. The diamondlike carbon-metal composite films exhibited passive behavior at open-circuit potentials. Low corrosion rates were observed during testing in a phosphate-buffered saline (PBS) electrolyte. In addition, the diamondlike carbon-metal composite films were found to be immune to localized corrosion below 1000 mV (SCE). DLC-silver-platinum films demonstrated exceptional antimicrobial properties against Staphylococcus bacteria. It is believed that a galvanic couple forms between platinum and silver, which accelerates silver ion release and provides more robust antimicrobial activity. Diamondlike carbon-silver-platinum films may provide unique biological functionalities and improved lifetimes for cardiovascular, orthopaedic, biosensor, and implantable microelectromechanical systems.

  20. Electrochemical and Antimicrobial Properties of Diamondlike Carbon-Metal Composite Films

    International Nuclear Information System (INIS)

    Implants containing antimicrobial metals may reduce morbidity, mortality, and healthcare costs associated with medical device-related infections. We have deposited diamondlike carbon-silver (DLC-Ag), diamondlike carbon-platinum (DLC-Pt), and diamondlike carbon-silver-platinum (DLC-AgPt) thin films using a multicomponent target pulsed laser deposition process. Transmission electron microscopy of the DLC-silver and DLC-platinum composite films revealed that the silver and platinum self-assemble into nanoparticle arrays within the diamondlike carbon matrix. The diamondlike carbon-silver film possesses hardness and Young's modulus values of 37 GPa and 331 GPa, respectively. The diamondlike carbon-metal composite films exhibited passive behavior at open-circuit potentials. Low corrosion rates were observed during testing in a phosphate-buffered saline (PBS) electrolyte. In addition, the diamondlike carbon-metal composite films were found to be immune to localized corrosion below 1000 mV (SCE). DLC-silver-platinum films demonstrated exceptional antimicrobial properties against Staphylococcus bacteria. It is believed that a galvanic couple forms between platinum and silver, which accelerates silver ion release and provides more robust antimicrobial activity. Diamondlike carbon-silver-platinum films may provide unique biological functionalities and improved lifetimes for cardiovascular, orthopaedic, biosensor, and implantable microelectromechanical systems

  1. UV laser deposition of metal films by photogenerated free radicals

    Science.gov (United States)

    Montgomery, R. K.; Mantei, T. D.

    1986-01-01

    A novel photochemical method for liquid-phase deposition of metal films is described. In the liquid phase deposition scheme, a metal containing compound and a metal-metal bonded carbonyl complex are dissolved together in a polar solvent and the mixture is irradiated using a UV laser. The optical arrangement consists of a HeCd laser which provides 7 mW of power at a wavelength of 325 nm in the TEM(OO) mode. The beam is attenuated and may be expanded to a diameter of 5-20 mm. Experiments with photochemical deposition of silver films onto glass and quartz substrates are described in detail. Mass spectrometric analysis of deposited silver films indicated a deposition rate of about 1 A/s at incident power levels of 0.01 W/sq cm. UV laser-induced copper and palladium films have also been obtained. A black and white photograph showing the silver Van Der Pauw pattern of a solution-deposited film is provided.

  2. Deposition of antimony telluride thin film by ECALE

    Institute of Scientific and Technical Information of China (English)

    GAO Xianhui; YANG Junyou; ZHU Wen; HOU Jie; BAO Siqian; FAN Xi'an; DUAN Xingkai

    2006-01-01

    The process of Sb2Te3 thin film growth on the Pt substrate by electrochemical atomic layer epitaxy (ECALE) was studied. Cyclic voltammetric scanning was performed to analyze the electrochemical behavior of Te and Sb on the Pt substrate. Sb2Te3 film was formed using an automated flow deposition system by alternately depositing Te and Sb atomic layers for 400 circles. The deposited Sb2Te3 films were characterized by XRD, EDX, FTIR and FESEM observation. Sb2Te3 compound structure was confirmed by XRD pattern and agreed well with the results of EDX quantitative analysis and coulometric analysis. FESEM micrographs showed that the deposit was composed of fine nano particles with size of about 20 nm. FESEM image of the cross section showed that the deposited films were very smooth and dense with thickness of about 190 nm. The optical band gap of the deposited Sb2Te3 film was determined as 0.42 eV by FTIR spectroscopy, and it was blue shifted in comparison with that of the bulk Sb2Te3 single crystal due to its nanocrystalline microstructure.

  3. Methane Flow Rate Effects On The Optical Properties of Amorphous Silicon Carbon (a-SiC:H Films Deposited By DC Sputtering Methods

    Directory of Open Access Journals (Sweden)

    Rosari Saleh

    2002-04-01

    Full Text Available We have investigated the refractive index (n and the optical absorption coeffi cient (α from refl ection and transmission measurements on hydrogenated amorphous silicon carbon (a-SiC:H fi lms. The a-SiC:H fi lms were prepared by dc sputtering method using silicon target in argon and methane gas mixtures. The refractive index (n decreases as the methane fl ow rate increase. The optical absorption coeffi cient (α shifts to higher energy with increasing methane fl ow rate. At higher methane fl ow rate, the fi lms tend to be more disorder and have wider optical gap. The relation of the optical properties and the disorder amorphous network with the compositional properties will be discussed.

  4. Nanodiamond films deposited at moderate temperature on pure titanium substrate pretreated by ultrasonic scratching in diamond powder suspension

    Institute of Scientific and Technical Information of China (English)

    Syed Jawid Askari; Fanxiu Lv; Akhtar Farid; Fengying Wang; Qi He; Zuyuan Zhou

    2006-01-01

    Nanocrystalline diamond (NCD) film deposition on pure titanium and Ti alloys is extraordinarily difficult because of the high diffusion coefficient of carbon in Ti, the large mismatch in their thermal expansion coefficients, the complex nature of the interlayer formed during diamond deposition, and the difficulty to achieve very high nucleation density. In this investigation, NCD films were successfully deposited on pure Ti substrate by using a novel substrate pretreatment of ultrasonic scratching in a diamond powder-ethanol suspension and by a two-step process at moderate temperature. It was shown that by scratching with a 30-μm diamond suspension for 1 h, followed by a 10-h diamond deposition, a continuous NCD film was obtained with an average grain size of about 200 nm. Detailed experimental results on the preparation, characterization, and successful deposition of the NCD films on Ti were discussed.

  5. Influence of the argon flow on the DLC films morphology deposited on Si

    International Nuclear Information System (INIS)

    Full text: Amorphous hydrogenated carbon a-c: H film (dlc type) were deposited on Si wafer using Micro Wave Electron Ciclotron Resonance/PACVD method which made it possible to use high-density plasma at low pressure, with C6H6/Ar gaseous, negatively bias (-200 v), at 350 oC and 250 oC deposition temperatures and 10-4 - 15.10-4 mbar pressure range. It was found a strong dependence of the surface morphology, roughness, and friction coefficient as function of the argon flow rate changing in the range 5-35 sccm when the benzen flow was kept constant 7 sccm. All produced films under the used deposition conditions are with an absence of O2, and with Ar contamination. Fig1 (a,b,c,) shows clearly that the dissociation of C6H6 by Ar atoms in different flow rate influences strongly the surface morphology of the carbon films. When the Ar flow decrease, films with same thickness and fabricated under the same others conditions reveal an increased number of particles. With higher Ar flow 35 sccm, the film was uniform, with an absence of particulates and smooth: the roughness Ra was 0.03μm. Fig.1b shows the film morphology produced with Ar flow 15 sccm. We can see aome particles with nearly globular form, clusters and pores. Ra was 0.16 μm. From EDAX and WDX analysis, the particles are with the same nature than the films. Wtih lower Ar flow 5 sccm, the bulk of the deposited films becomes completely with a presence of furrow and without particles. In this case, Ra was 1.65 μm. The similar particles are also observed with Pulsed laser-deposition (PLD) technique in the work of Oshok Kumar and co. who reported that the film deposited at the lower energy density (5 Jcm-2) was quite smooth with an absence of particulates and teh films deposited at higher energy density (10 Jcm-2) contained small scattered particulates. In teh case of Pulsed Laser- Arc source deposition technique the particles seems to be dependent on the length of the arc pulses. The results of indicated that the

  6. 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.

  7. Sheet Resistance and Gas-Sensing Properties of Tin Oxide Thin Films by Plasma Enhanced Chemical Vapor Deposition

    Institute of Scientific and Technical Information of China (English)

    刘彭义; 陈俊芳; 孙汪典

    2004-01-01

    Tin oxide (SnO2) thin films are prepared at different temperatures by plasmaenhanced chemical vapor deposition (PECVD). The structural characterizations of the films are investigated by various analysis techniques. X-ray diffraction patterns (XRD) show that the phase of SnO2 films are different at different deposition temperatures. The sheet resistance of the films decreases with increase of deposition temperature. X-ray photoelectron spectroscopy (XPS) shows that the SnO2 thin film is non-stoichiometric. The sheet resistance increases with increase in oxygen flow. Sb-doped SnO2 thin films are more sensitive to alcohol than carbon monoxide, and its maximum sensitivity is about 220%.

  8. Wet deposition of elemental carbon and sulfate in Sweden

    OpenAIRE

    Ogren, J.A.; R. J. Charlson

    2011-01-01

    Elemental carbon and sulfate were measured in monthly precipitation samples at 12 rural sites inSweden from April to August, 1981. Wet deposition of excess sulfate was significantly correlatedwith elemental carbon deposition, and no systematic spatial or temporal variations in the ratio ofexcess sulfate to elemental carbon were observed. Comparision of these results with sulfur andelemental carbon emissions in Western Europe suggests that elemental carbon is removed at aslower rate than sulfu...

  9. Chemical vapour deposition of zeolitic imidazolate framework thin films

    Science.gov (United States)

    Stassen, Ivo; Styles, Mark; Grenci, Gianluca; Gorp, Hans Van; Vanderlinden, Willem; Feyter, Steven De; Falcaro, Paolo; Vos, Dirk De; Vereecken, Philippe; Ameloot, Rob

    2016-03-01

    Integrating metal-organic frameworks (MOFs) in microelectronics has disruptive potential because of the unique properties of these microporous crystalline materials. Suitable film deposition methods are crucial to leverage MOFs in this field. Conventional solvent-based procedures, typically adapted from powder preparation routes, are incompatible with nanofabrication because of corrosion and contamination risks. We demonstrate a chemical vapour deposition process (MOF-CVD) that enables high-quality films of ZIF-8, a prototypical MOF material, with a uniform and controlled thickness, even on high-aspect-ratio features. Furthermore, we demonstrate how MOF-CVD enables previously inaccessible routes such as lift-off patterning and depositing MOF films on fragile features. The compatibility of MOF-CVD with existing infrastructure, both in research and production facilities, will greatly facilitate MOF integration in microelectronics. MOF-CVD is the first vapour-phase deposition method for any type of microporous crystalline network solid and marks a milestone in processing such materials.

  10. Structural Characterization of Carbon Nanomaterial Film In Situ Synthesized on Various Bulk Metals

    Directory of Open Access Journals (Sweden)

    J. Y. Xu

    2014-01-01

    Full Text Available Carbon nanofiber films were prepared via a simple chemical vapor deposition (CVD method on various bulk metal substrates including bulk 316 L stainless steel, pure cobalt, and pure nickel treated by surface mechanical attrition treatment (SMAT. The microstructures of the carbon nanomaterial film were studied by SEM, TEM, XRD, and Raman spectroscopy. In this paper, bulk metallic materials treated by SMAT served as substrates as well as catalysts for carbon nanomaterial film formation. The results indicate that the carbon nanofiber films are formed concerning the catalytic effects of the refined metallic particles during CVD on the surface of SMAT-treated bulk metal substrates. However, distinguished morphologies of carbon nanomaterial film are displayed in the case of the diverse bulk metal substrates.

  11. Effect of Different Catalyst Deposition Technique on Aligned Multiwalled Carbon Nanotubes Grown by Thermal Chemical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    Mohamed Shuaib Mohamed Saheed

    2014-01-01

    Full Text Available The paper reported the investigation of the substrate preparation technique involving deposition of iron catalyst by electron beam evaporation and ferrocene vaporization in order to produce vertically aligned multiwalled carbon nanotubes array needed for fabrication of tailored devices. Prior to the growth at 700°C in ethylene, silicon dioxide coated silicon substrate was prepared by depositing alumina followed by iron using two different methods as described earlier. Characterization analysis revealed that aligned multiwalled carbon nanotubes array of 107.9 µm thickness grown by thermal chemical vapor deposition technique can only be achieved for the sample with iron deposited using ferrocene vaporization. The thick layer of partially oxidized iron film can prevent the deactivation of catalyst and thus is able to sustain the growth. It also increases the rate of permeation of the hydrocarbon gas into the catalyst particles and prevents agglomeration at the growth temperature. Combination of alumina-iron layer provides an efficient growth of high density multiwalled carbon nanotubes array with the steady growth rate of 3.6 µm per minute for the first 12 minutes and dropped by half after 40 minutes. Thicker and uniform iron catalyst film obtained from ferrocene vaporization is attributed to the multidirectional deposition of particles in the gaseous form.

  12. Formation and electron field emission of graphene films grown by hot filament chemical vapor deposition

    International Nuclear Information System (INIS)

    Graphene films with different structures were catalytically grown on the silicon substrate pre-deposited with a gold film by hot filament chemical vapor deposition under different conditions, where methane, hydrogen and nitrogen were used as the reactive gases. The morphological and compositional properties of graphene films were studied using advanced instruments including field emission scanning electron microscopy, micro-Raman spectroscopy and X-ray photoelectron spectroscopy. The results indicate that the structure and composition of graphene films are changed with the variation of the growth conditions. According to the theory related to thermodynamics, the formation of graphene films was theoretically analyzed and the results indicate that the formation of graphene films is related to the fast incorporation and precipitation of carbon. The electron field emission (EFE) properties of graphene films were studied in a high vacuum system of ∼10−6 Pa and the EFE results show that the turn-on field is in a range of 5.2–5.64 V μm−1 and the maximum current density is about 63 μ A cm−2 at the field of 7.7 V μm−1. These results are important to control the structure of graphene films and have the potential applications of graphene in various nanodevices. - Highlights: • Graphene films are grown on gold films by hot filament chemical vapor deposition. • Hierarchical nanoflower structures made of graphene flakes are demonstrated. • The size of gold nanodroplets plays an important role in graphene flake formation. • The films show competitive electron field emission properties

  13. Sputter deposited Terfenol-D thin films for multiferroic applications

    Directory of Open Access Journals (Sweden)

    K. P. Mohanchandra

    2015-09-01

    Full Text Available In this paper, we study the sputter deposition and crystallization process to produce high quality Terfenol-D thin film (100 nm with surface roughness below 1.5 nm. The Terfenol-D thin film was produced using DC magnetron sputtering technique with various sputtering parameters and two different crystallization methods, i.e. substrate heating and post-annealing. Several characterization techniques including WDS, XRD, TEM, AFM, SQUID and MOKE were used to determine the physical and magnetic properties of the Terfenol-D films. TEM studies reveal that the film deposited on the heated substrate has large grains grown along the film thickness producing undesirable surface roughness while the film crystallized by post-annealing method shows uniformly distributed small grains producing a smooth surface. The Terfenol-D film was also deposited onto (011 cut PMN-PT single crystal substrate. With the application of an electric field the film exhibited a 1553 Oe change in coercivity with an estimated saturation magnetostriction of λs = 910 x 10−6.

  14. Sputter deposited Terfenol-D thin films for multiferroic applications

    Science.gov (United States)

    Mohanchandra, K. P.; Prikhodko, S. V.; Wetzlar, K. P.; Sun, W. Y.; Nordeen, P.; Carman, G. P.

    2015-09-01

    In this paper, we study the sputter deposition and crystallization process to produce high quality Terfenol-D thin film (100 nm) with surface roughness below 1.5 nm. The Terfenol-D thin film was produced using DC magnetron sputtering technique with various sputtering parameters and two different crystallization methods, i.e. substrate heating and post-annealing. Several characterization techniques including WDS, XRD, TEM, AFM, SQUID and MOKE were used to determine the physical and magnetic properties of the Terfenol-D films. TEM studies reveal that the film deposited on the heated substrate has large grains grown along the film thickness producing undesirable surface roughness while the film crystallized by post-annealing method shows uniformly distributed small grains producing a smooth surface. The Terfenol-D film was also deposited onto (011) cut PMN-PT single crystal substrate. With the application of an electric field the film exhibited a 1553 Oe change in coercivity with an estimated saturation magnetostriction of λs = 910 x 10-6.

  15. Electrostatic spray deposited zinc oxide films for gas sensor applications

    International Nuclear Information System (INIS)

    In this work, thin films of zinc oxide (ZnO) for gas-sensor applications were deposited on platinum coated alumina substrate, using electrostatic spray deposition (ESD) technique. As precursor solution zinc acetate in ethanol was used. Scanning electron microscopy (SEM) evaluation showed a porous and homogeneous film morphology and the energy dispersive X-ray analysis (EDX) confirmed the composition of the films with no presence of other impurities. The microstructure studied with X-ray diffraction (XRD) and Raman spectroscopy indicated that the ZnO oxide films are crystallized in a hexagonal wurtzite phase. The films showed good sensitivity to 1 ppm nitrogen dioxide (NO2) at 300 oC while a much lower sensitivity to 12 ppm hydrogen sulphide (H2S)

  16. Deposition of the platinum crystals on the carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new technique and the affecting factors for depositing platinum on the carbon nanotubes were investigated. The results show that the deposited platinum crystals in the atmosphere of hydrogen or nitrogen have a small size and a homogeneous distribution on the surface of the carbon nanotubes. The pretreatment would decrease the platinum particles on the carbon nanotubes significantly.

  17. Photoluminescence of amorphous carbon films fabricated by layer-by-layer hydrogen plasma chemical annealing method

    Institute of Scientific and Technical Information of China (English)

    徐骏; 黄晓辉; 李伟; 王立; 陈坤基

    2002-01-01

    A method in which nanometre-thick film deposition was alternated with hydrogen plasma annealing (layer-by-layermethod) was applied to fabricate hydrogenated amorphous carbon films in a conventional plasma-enhanced chemicalvapour deposition system. It was found that the hydrogen plasma treatment could decrease the hydrogen concentrationin the films and change the sp2/sp3 ratio to some extent by chemical etching. Blue photoluminescence was observed atroom temperature, as a result of the reduction of sp2 clusters in the films.

  18. Defect control in room temperature deposited cadmium sulfide thin films by pulsed laser deposition

    International Nuclear Information System (INIS)

    The control of defects in cadmium sulfide thin films and its impact on the resulting CdS optical and electrical characteristics are studied. Sulfur vacancies and cadmium interstitial concentrations in the CdS films are controlled using the ambient pressure during pulsed laser deposition. CdS film resistivities ranging from 10−1 to 104 Ω-cm are achieved. Hall Effect measurements show that the carrier concentration ranges from 1019 to 1013 cm−3 and is responsible for the observed resistivity variation. Hall mobility varies from 2 to 12 cm2/V-s for the same pressure regime. Although the energy bandgap remains unaffected (∼ 2.42 eV), the optical transmittance is reduced due to the increase of defects in the CdS films. Rutherford back scattering spectroscopy shows the dependence of the CdS films stoichiometry with deposition pressure. The presence of CdS defects is attributed to more energetic species reaching the substrate, inducing surface damage in the CdS films during pulsed laser deposition. - Highlights: • CdS thin films deposited by pulsed laser deposition at room temperature. • The optical, electrical and structural properties were evaluated. • Carrier concentration ranged from 1019 to 1013 cm−3. • The chemical composition was studied by Rutherford back scattering. • The density of sulfur vacancies and cadmium interstitial was varied

  19. The electrolytic deposition of carbon from molten Li2CO3

    International Nuclear Information System (INIS)

    Electrodeposition of carbon on an nickel electrode in molten salt has been investigated with the aid of scanning electron microscopy (SEM) and cyclic voltammetry, using molten LiCl, as a base electrolyte with adding of 1 and 5 % of Li2CO3. Commercial nickel wire was used as a cathode and graphite crucible as the anode electrode. A cyclic voltammograms for an nickel electrode indicates that the deposition or discharge of carbon at the cathode occurs at potential range of - 0.8 to -1.7 V. Further, SEM observations showed that morphology of the carbon at the cathode is in the form of a fairly hard black deposit. It was found that the quality of the deposit depends by the cathode surface, applied overpotential, content of lithium carbonate and the thickness of the carbon film. (Original)

  20. Nanotribological performance of fullerene-like carbon nitride films

    Energy Technology Data Exchange (ETDEWEB)

    Flores-Ruiz, Francisco Javier; Enriquez-Flores, Christian Ivan [Centro de Investigación y Estudios Avanzados (CINVESTAV) IPN, Unidad Querétaro, Lib. Norponiente 2000, Real de Juriquilla, C.P. 76230, Querétaro, Qro., México (Mexico); Chiñas-Castillo, Fernando, E-mail: fernandochinas@gmail.com [Department of Mechanical Engineering, Instituto Tecnológico de Oaxaca, Oaxaca, Oax. Calz. Tecnológico No. 125, CP. 68030, Oaxaca, Oax. (Mexico); Espinoza-Beltrán, Francisco Javier [Centro de Investigación y Estudios Avanzados (CINVESTAV) IPN, Unidad Querétaro, Lib. Norponiente 2000, Real de Juriquilla, C.P. 76230, Querétaro, Qro., México (Mexico)

    2014-09-30

    Highlights: • Fullerene-like CNx samples show an elastic recovery of 92.5% and 94.5% while amorphous CNx samples had only 75% elastic recovery. • Fullerene-like CNx films show an increment of 34.86% and 50.57% in fractions of C 1s and N 1s. • Fullerene-like CNx samples show a lower friction coefficient compared to amorphous CNx samples. • Friction reduction characteristics of fullerene-like CNx films are strongly related to the increase of sp{sup 3} CN bonds. - Abstract: Fullerene-like carbon nitride films exhibit high elastic modulus and low friction coefficient. In this study, thin CNx films were deposited on silicon substrate by DC magnetron sputtering and the tribological behavior at nanoscale was evaluated using an atomic force microscope. Results show that CNx films with fullerene-like structure have a friction coefficient (CoF ∼ 0.009–0.022) that is lower than amorphous CNx films (CoF ∼ 0.028–0.032). Analysis of specimens characterized by X-ray photoelectron spectroscopy shows that films with fullerene-like structure have a higher number of sp{sup 3} CN bonds and exhibit the best mechanical properties with high values of elastic modulus (E > 180 GPa) and hardness (H > 20 GPa). The elastic recovery determined on specimens with a fullerene-like CNx structure was of 95% while specimens of amorphous CNx structure had only 75% elastic recovery.

  1. High-quality AlN films grown on chemical vapor-deposited graphene films

    OpenAIRE

    Chen Bin-Hao; Hsu Hsiu-Hao; Lin David T.W.

    2016-01-01

    We report the growth of high-quality AlN films on graphene. The graphene films were synthesized by CVD and then transferred onto silicon substrates. Epitaxial aluminum nitride films were deposited by DC magnetron sputtering on both graphene as an intermediate layer and silicon as a substrate. The structural characteristics of the AlN films and graphene were investigated. Highly c-axis-oriented AlN crystal structures are investigated based on the XRDpatterns observations.

  2. High-quality AlN films grown on chemical vapor-deposited graphene films

    Directory of Open Access Journals (Sweden)

    Chen Bin-Hao

    2016-01-01

    Full Text Available We report the growth of high-quality AlN films on graphene. The graphene films were synthesized by CVD and then transferred onto silicon substrates. Epitaxial aluminum nitride films were deposited by DC magnetron sputtering on both graphene as an intermediate layer and silicon as a substrate. The structural characteristics of the AlN films and graphene were investigated. Highly c-axis-oriented AlN crystal structures are investigated based on the XRDpatterns observations.

  3. Plasma modification of medical implants by carbon coatings depositions

    Directory of Open Access Journals (Sweden)

    J. Grabarczyk

    2009-12-01

    Full Text Available Purpose: The main goal was to work out the technology of deposition of carbon layers onto surface of medical implants made of the AISI316L medical steel. So far the results of carried investigations have proved that layers synthesized in RF PACVD process noticeably improve the biotolerance of the medical steel. Positive experimental results concerning the implementation of carbon layers conducted in the Institute of Materials Science and Engineering of the Technical University of Lodz were the basis for attempt of industrial application of the worked out technology.Design/methodology/approach: Carbon layers were manufactured using radio frequency plasma RF PACVD method. The technology was worked out for the surfaces of the intramedullary nails. The investigations were carried out in order to compare obtained synthesis results with the layers deposited under the laboratory conditions. In this work the following are presented: the surface topography investigation, results of nanohardness and adhesion measurements as well as the raman spectra. Medical examination results were presented in our earlier publications. In the description of obtained investigation results are also presented the preliminary results of the medical treatment effects with the use of intramedullary nails covered with the carbon layer.Findings: Carbon layers manufactured onto intramedullary nails presented good mechanical properties. Applied synthesis parameters made it possible to manufacture uniform film onto whole implant surface. Thickness of the layer was varied in the range of 200 – 400 nm, however total modification area contained 3.5 micrometers. Nails covered with the carbon layer positively passed the tests and were admitted into medical trade turnover. Positive medical treatment results were observed especially in case of patients with affirmed allergies onto alloying components contained in medical steels like chromium and nickel.Research limitations

  4. 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.

  5. Structural and optical properties of tellurite thin film glasses deposited by pulsed laser deposition

    International Nuclear Information System (INIS)

    Tellurite (TeO2-TiO2-Nb2O5) thin film glasses have been produced by pulsed laser deposition at room temperature at laser energy densities in the range of 0.8-1.5 J/cm2 and oxygen pressures in the range of 3-11 Pa. The oxygen concentration in the films increases with laser energy density to reach values very close to that of the bulk glass at 1.5 J/cm2, while films prepared at 1.5 J/cm2 and pressures above 5 Pa show oxygen concentration in excess of 10% comparing to the glass. X-ray photoelectron spectroscopy shows the presence of elementary Te in films deposited at O2 pressures ≤ 5 Pa that is not detected at higher pressures, while analysis of Raman spectra of the samples suggests a progressive substitution of TeO3 trigonal pyramids by TeO4 trigonal bipyramids in the films when increasing their oxygen content. Spectroscopic ellipsometry analysis combined with Cauchy and effective medium modeling demonstrates the influence of these compositional and structural modifications on the optical response of the films. Since the oxygen content determines their optical response through the structural modifications induced in the films, those can be effectively controlled by tuning the deposition conditions, and films having large n (2.08) and reduced k (-4) at 1.5 μm have been produced using the optimum deposition conditions.

  6. Silicon and aluminum doping effects on the microstructure and properties of polymeric amorphous carbon films

    Science.gov (United States)

    Liu, Xiaoqiang; Hao, Junying; Xie, Yuntao

    2016-08-01

    Polymeric amorphous carbon films were prepared by radio frequency (R.F. 13.56 MHz) magnetron sputtering deposition. The microstructure evolution of the deposited polymeric films induced by silicon (Si) and aluminum(Al) doping were scrutinized through infrared spectroscopy, multi-wavelength Raman spectroscopy, scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). The comparative results show that Si doping can enhance polymerization and Al doping results in an increase in the ordered carbon clusters. Si and Al co-doping into polymeric films leads to the formation of an unusual dual nanostructure consisting of cross-linked polymer-like hydrocarbon chains and fullerene-like carbon clusters. The super-high elasticity and super-low friction coefficients (amorphous carbon films with different elements doping are also discussed in detail.

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

    Science.gov (United States)

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

    1983-01-01

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

  8. Investigation of thin film deposition on stainless steel 304 substrates under different operating conditions

    Science.gov (United States)

    Chowdhury, M. A.; Nuruzzaman, D. M.

    2016-02-01

    In recent times, friction and wear in relation to the deposited carbon films on the steel substrates are important issues for industrial applications. In this research study, solid thin films were deposited on the stainless steel 304 (SS 304) substrates under different operating conditions. In the experiments, natural gas (97.14% methane) was used as a precursor gas in a hot filament thermal chemical vapor deposition (CVD) reactor. Deposition rates on SS 304 substrates were investigated under gas flow rates 0.5 - 3.0 l/min, pressure 20 - 50 torr, gap between activation heater and substrate 3.0 - 6.0 mm and deposition duration 30 - 120 minutes. The obtained results show that there are significant effects of these parameters on the deposition rates on SS 304 within the observed range. Friction coefficient of SS 304 sliding against SS 314 was also investigated under normal loads 5 - 10 N and sliding velocities 0.5 - m/s before and after deposition. The experimental results reveal that in general, frictional values are lower after deposition than that of before deposition.

  9. Current understanding of the growth of carbon nanotubes in catalytic chemical vapour deposition

    OpenAIRE

    Jourdain, Vincent; Bichara, Christophe

    2013-01-01

    Due to its higher degree of control and its scalability, catalytic chemical vapour deposition is now the prevailing synthesis method of carbon nanotubes. Catalytic chemical vapour deposition implies the catalytic conversion of a gaseous precursor into a solid material at the surface of reactive particles or of a continuous catalyst film acting as a template for the growing material. Significant progress has been made in the field of nanotube synthesis by this method although nanotube samples ...

  10. Nanostructured zinc oxide films synthesized by successive chemical solution deposition for gas sensor applications

    International Nuclear Information System (INIS)

    Nanostructured ZnO thin films have been deposited using a successive chemical solution deposition method. The structural, morphological, electrical and sensing properties of the films were studied for different concentrations of Al-dopant and were analyzed as a function of rapid photothermal processing temperatures. The films were investigated by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron and micro-Raman spectroscopy. Electrical and gas sensitivity measurements were conducted as well. The average grain size is 240 and 224 A for undoped ZnO and Al-doped ZnO films, respectively. We demonstrate that rapid photothermal processing is an efficient method for improving the quality of nanostructured ZnO films. Nanostructured ZnO films doped with Al showed a higher sensitivity to carbon dioxide than undoped ZnO films. The correlations between material compositions, microstructures of the films and the properties of the gas sensors are discussed

  11. Reactive DC Magnetron Sputtering Deposition of Copper Nitride Thin Film

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Copper nitride thin film was deposited on glass substrates by reactive DC (direct current) magnetron sputtering at a 0.5 Pa N2 partial pressure and different substrate temperatures. The as-prepared film, characterized with X-Ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy measurements, showed a composed structure of Cu3N crystallites with anti-ReO3 structure and a slight oxidation of the resulted film.The crystal structure and growth rate of Cu3N films were affected strongly by substrate temperature. The preferred crystalline orientation of Cu3N films were (111) and (200) at RT, 100℃. These peaks decayed at 200℃ and 300℃ only Cu (111) peak was noticed. Growth of Cu3N films at 100℃ is the optimum substrate temperature for producing high-quality (111) Cu3N films. The deposition rate of Cu3N films estimated to be in range of 18-30 nm/min increased while the resistivity and the microhardness of Cu3N films decreased when the temperature of glass substrate increased.

  12. Electron bombardment of certain thin films during deposition

    International Nuclear Information System (INIS)

    The performance of multilayer thin film optical filters was studied. In 1947, R.M. Rice established the technique of bombarding the substrate with electrons of several kilovolts as the films were being deposited. This process improved the durability of zinc sulfide films dramatically. An electron source filament was installed inside the coating chamber and electrically isolated the substrate holder, which was connected to a positive high voltage supply. An accelerating loop placed just above the filament enchanced its efficiency. The source was calibrated by measuring the current through the substrate holder. Single layer films of five different materials were deposited, each at its own set of electron bombardment parameters. The microstructure was analyzed. Antimony trioxide films showed a shift in lattice orientation, but this did not affect columnar structure or macroscopic quantities. Potassium hexafluorozirconate films showed elimination of both crystal structure and columnar growth, resulting in slightly reduced durability and some absorption. Silicon monoxide films suffered no change in structure or properties. Zinc sulfide films demonstrated the change in crystal structure, which was quantified and shown to improve moisture resistance. Optical properties were unaffected. Magnesium fluoride films showed a slight increase in crystallinity with only subtle changes in durability and optical properties. Generally, electron bombardment reduced or rearranged crystal structure

  13. Multiwalled Carbon Nanotube Deposition on Model Environmental Surfaces

    Science.gov (United States)

    Deposition of multiwalled carbon nanotubes (MWNTs) on model environmental surfaces was investigated using a quartz crystal microbalance with dissipation monitoring (QCM-D). Deposition behaviors of MWNTs on positively and negatively charged surfaces were in good agreement with Der...

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

    International Nuclear Information System (INIS)

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

  15. Pulsed laser deposition of niobium nitride thin films

    International Nuclear Information System (INIS)

    Niobium nitride (NbNx) films were grown on Nb and Si(100) substrates using pulsed laser deposition. NbNx films were deposited on Nb substrates using PLD with a Q-switched Nd:YAG laser (λ = 1064 nm, ∼40 ns pulse width, and 10 Hz repetition rate) at different laser fluences, nitrogen background pressures and deposition substrate temperatures. When all the fabrication parameters are fixed, except for the laser fluence, the surface roughness, nitrogen content, and grain size increase with increasing laser fluence. Increasing nitrogen background pressure leads to a change in the phase structure of the NbNx films from mixed β-Nb2N and cubic δ-NbN phases to single hexagonal β-Nb2N. The substrate temperature affects the preferred orientation of the crystal structure. The structural and electronic, properties of NbNx deposited on Si(100) were also investigated. The NbNx films exhibited a cubic δ-NbN with a strong (111) orientation. A correlation between surface morphology, electronic, and superconducting properties was found. The observations establish guidelines for adjusting the deposition parameters to achieve the desired NbNx film morphology and phase

  16. Pulsed laser deposition of niobium nitride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Farha, Ashraf Hassan, E-mail: ahass006@odu.edu; Elsayed-Ali, Hani E., E-mail: helsayed@odu.edu [Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA 23529 (United States); Applied Research Center, Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Department of Physics, Faculty of Science, Ain Shams University, Cairo 11566 (Egypt); Ufuktepe, Yüksel, E-mail: ufuk@cu.edu.tr [Department of Physics, University of Cukurova, 01330 Adana (Turkey); Myneni, Ganapati, E-mail: rao@jlab.org [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)

    2015-12-04

    Niobium nitride (NbN{sub x}) films were grown on Nb and Si(100) substrates using pulsed laser deposition. NbN{sub x} films were deposited on Nb substrates using PLD with a Q-switched Nd:YAG laser (λ = 1064 nm, ∼40 ns pulse width, and 10 Hz repetition rate) at different laser fluences, nitrogen background pressures and deposition substrate temperatures. When all the fabrication parameters are fixed, except for the laser fluence, the surface roughness, nitrogen content, and grain size increase with increasing laser fluence. Increasing nitrogen background pressure leads to a change in the phase structure of the NbN{sub x} films from mixed β-Nb{sub 2}N and cubic δ-NbN phases to single hexagonal β-Nb{sub 2}N. The substrate temperature affects the preferred orientation of the crystal structure. The structural and electronic, properties of NbN{sub x} deposited on Si(100) were also investigated. The NbN{sub x} films exhibited a cubic δ-NbN with a strong (111) orientation. A correlation between surface morphology, electronic, and superconducting properties was found. The observations establish guidelines for adjusting the deposition parameters to achieve the desired NbN{sub x} film morphology and phase.

  17. Rhodium thin film-carbon nanotube nanostructures: Synthesis, characterization and electron transfer properties

    International Nuclear Information System (INIS)

    Rh thin films have been synthesized onto carbon nanotubes by pulsed laser deposition under vacuum and under 266 Pa of helium background pressure. Field emission scanning electron microscopy revealed two types of Rh films: (i) Rh film fabricated under vacuum was smooth and of closed structure and (ii) Rh prepared at 266 Pa of He was porous. Transmission electron microscopy showed that the smooth Rh film was made of highly interconnected particles of 2 nm diameter, whereas the porous film had a morphology of particles arranged into columns with particles having an average diameter of 5 nm. In addition, using high resolution transmission electron microscopy images, the Rh film thickness could be estimated to be about 20 nm. X-ray diffraction pattern showed well-crystallized thin films with a (111) intense orientation. X-ray photoelectron spectroscopy confirmed the presence of metallic Rh at the surface of the carbon nanotubes. Preliminary evaluation of the electron transfer properties showed that porous Rh-carbon nanotubes exhibited reduced oxophilicity than smooth Rh. In addition, the porous Rh film offered larger electrochemical stability window between the onset of hydrogen adsorption and Rh oxide formation. Such interesting properties have important implications in many electroanalytical applications. - Highlights: • Pulsed laser synthesis used to deposit rhodium thin films onto carbon nanotubes. • Smooth and porous rhodium films verified by electron microscopy analyses • Electron transfer properties studied in sulfuric acid solution

  18. Electromagnetic characteristics of carbon nanotube film materials

    Directory of Open Access Journals (Sweden)

    Zhang Wei

    2015-08-01

    Full Text Available Carbon nanotube (CNT possesses remarkable electrical conductivity, which shows great potential for the application as electromagnetic shielding material. This paper aims to characterize the electromagnetic parameters of a high CNT loading film by using waveguide method. The effects of layer number of CNT laminate, CNT alignment and resin impregnation on the electromagnetic characteristics were analyzed. It is shown that CNT film exhibits anisotropic electromagnetic characteristic. Pristine CNT film shows higher real part of complex permittivity, conductivity and shielding effectiveness when the polarized direction of incident wave is perpendicular to the winding direction of CNT film. For the CNT film laminates, complex permittivity increases with increasing layer number, and correspondingly, shielding effectiveness decreases. The five-layer CNT film shows extraordinary shielding performance with shielding effectiveness ranging from 67 dB to 78 dB in X-band. Stretching process induces the alignment of CNTs. When aligned direction of CNTs is parallel to the electric field, CNT film shows negative permittivity and higher conductivity. Moreover, resin impregnation into CNT film leads to the decrease of conductivity and shielding effectiveness. This research will contribute to the structural design for the application of CNT film as electromagnetic shielding materials.

  19. Deposition of Thin Film Electrolyte by Pulsed Laser Deposition (PLD) for micro-SOFC Development

    OpenAIRE

    Krogstad, Hedda Nordby

    2012-01-01

    Optimalization of PLD deposition of YSZ for micr-SOFC electrolyte applications by varying deposition pressure and target-substrate distance.Substrate used was Si-based chips and wafers (large area PLD), and the substrate temperature was held at 600. Dense films were obtained at 20 mTorr.

  20. Chemical vapor deposition and characterization of titanium dioxide thin films

    Science.gov (United States)

    Gilmer, David Christopher

    1998-12-01

    The continued drive to decrease the size and increase the speed of micro-electronic Metal-Oxide-Semiconductor (MOS) devices is hampered by some of the properties of the SiOsb2 gate dielectric. This research has focused on the CVD of TiOsb2 thin films to replace SiOsb2 as the gate dielectric in MOS capacitors and transistors. The relationship of CVD parameters and post-deposition anneal treatments to the physical and electrical properties of thin films of TiOsb2 has been studied. Structural and electrical characterization of TiOsb2 films grown from the CVD precursors tetraisopropoxotitanium (IV) (TTIP) and TTIP plus Hsb2O is described in Chapter 3. Both types of deposition produced stoichiometric TiOsb2 films comprised of polycrystalline anatase, but the interface properties were dramatically degraded when water vapor was added. Films grown with TTIP in the presence of Hsb2O contained greater than 50% more hydrogen than films grown using only TTIP and the hydrogen content of films deposited in both wet and dry TTIP environments decreased sharply with a post deposition Osb2 anneal. A significant thickness variation of the dielectric constant was observed which could be explained by an interfacial oxide and the finite accumulation thickness. Fabricated TiOsb2 capacitors exhibited electrically equivalent SiOsb2 gate dielectric thicknesses and leakage current densities as low as 38, and 1×10sp{-8} Amp/cmsp2 respectively. Chapter 4 discusses the low temperature CVD of crystalline TiOsb2 thin films deposited using the precursor tetranitratotitanium (IV), TNT, which produces crystalline TiOsb2 films of the anatase phase in UHV-CVD at temperatures as low as 184sp°C. Fabricated TiOsb2 capacitors exhibited electrically equivalent SiOsb2 gate dielectric thicknesses and leakage current densities as low as 17, and 1×10sp{-8} Amp/cmsp2 respectively. Chapter 5 describes the results of a comparison of physical and electrical properties between TiOsb2 films grown via LPCVD using