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1

Protective Thin Film Coating for Metals.  

National Technical Information Service (NTIS)

The patent application concerns amino compounds which are applied to steel and aluminum by direct application and also from solution, and then subjected to ultraviolet radiation to produce photo-oxidative polymerization of the coating on the surface of th...

C. V. Brouillette H. Hockman

1973-01-01

2

Thin Film Metal Coated Fiber Optic Hydrophone Probe  

PubMed Central

The purpose of this work was to improve on sensitivity performance of fiber sensor employed as Fiber Optic Hydrophone Probe (FOHP) by nano-scale thin film gold coating. The fiber is designed to provide a uniform and spatial averaging free response up to 100 MHz by etching down to an active diameter of about 9 ?m. The sensitivity performance of straight cleaved (i.e. full size core and cladding) uncoated, tapered uncoated and tapered thin film gold coated fiber sensors were compared in the frequency range of 1.5 MHz to 20 MHz in the presence of acoustic pressure amplitude levels of up to 6 MPa. An unprecedented voltage sensitivity of ?245 dB re 1V/uPa (560 mV/ MPa) was measured for thin film gold coated FOHP by optimizing the gold coating thickness.

Gopinath, R.; Arora, P.; Gandhi, G.; Daryoush, A.S.; El-Sherif, M.; Lewin, P.A.

2010-01-01

3

Ideal laminate theory for water transport analysis of metal-coated polymer films  

Microsoft Academic Search

We propose and validate a diffusion model, based on the ideal laminate theory (ILT), to describe water transport through metal-coated polymer films for barrier applications. The physical properties required for numerical implementation are studied. The analysis reveals that the solubility of the metallic coating is not required for an accurate water transport analysis, which makes the ILT-based model practical. The

Changsoo Jang; Young-Rae Cho; Bongtae Han

2008-01-01

4

Ideal laminate theory for water transport analysis of metal-coated polymer films  

NASA Astrophysics Data System (ADS)

We propose and validate a diffusion model, based on the ideal laminate theory (ILT), to describe water transport through metal-coated polymer films for barrier applications. The physical properties required for numerical implementation are studied. The analysis reveals that the solubility of the metallic coating is not required for an accurate water transport analysis, which makes the ILT-based model practical. The model is implemented numerically and the results are compared with the experimentally measured transient water weight gain of PET films with Al and Cr coatings to corroborate the validity of the model.

Jang, Changsoo; Cho, Young-Rae; Han, Bongtae

2008-09-01

5

Diamond Composite Films for Protective Coatings on Metals and Method of Formation  

NASA Technical Reports Server (NTRS)

Composite films consisting of diamond crystallites and hard amorphous films such as diamond-like carbon, titanium nitride, and titanium oxide are provided as protective coatings for metal substrates against extremely harsh environments. A composite layer having diamond crystallites and a hard amorphous film is affixed to a metal substrate via an interlayer including a bottom metal silicide film and a top silicon carbide film. The interlayer is formed either by depositing metal silicide and silicon carbide directly onto the metal substrate, or by first depositing an amorphous silicon film, then allowing top and bottom portions of the amorphous silicon to react during deposition of the diamond crystallites, to yield the desired interlayer structure.

Ong, Tiong P. (Inventor); Shing, Yuh-Han (Inventor)

1997-01-01

6

Preparation of metal oxide thin films using coating photolysis process with ArF excimer laser  

NASA Astrophysics Data System (ADS)

The preparation of metal oxide thin films have been developed using the metalorganic (MO) compounds coating photolysis process with ArF excimer laser irradiation at room temperature. The effect of the starting materials and irradiation method on the product films was investigated by FT-IR, UV, XRD and SEM. It was found that metal acetylacetonates or metal 2-ethylhexanoate was effective as the starting materials. When using metal acetylacetonates as the starting materials, crystallized TiO2, In2O3 and ZrO2 were obtained with ArF laser irradiation at 50 mJ/cm2 at a repetition rate of 5 Hz for 5 min. When using An-acac, Fe, Sn, or In 2-ethylhexanoate as the starting material, a two-step process consisting of both preliminary weak (10mJ/cm2) and sufficiently strong irradiation (50mJ/cm2) was found to be effective for obtaining crystallized ZnO, Fe2O3, SnO2 and In2O3 films. In addition, crystallized complex oxide thin films such as ITO, PbTo3 and PbZrO3 were successfully obtained from the metal acetylacetonates or metal 2-ethylhexanoate using MO coating photolysis process. Patterned metal oxide thin films were also obtained by the ArF laser irradiation through the photomask, followed by leaching with solvents. The crystallization mechanism was discussed from the point of view of the photochemical reaction and photothermal reaction.

Tsuchiya, Tetsuo; Watanabe, Akio; Imai, Yoji; Niino, Hiroyuki; Yabe, Akira; Yamaguchi, Iwao; Manabe, Takaaki; Kumagai, Toshiya; Mizuta, Susumu

2000-11-01

7

Coated Aluminized Film Resists Corrosion  

NASA Technical Reports Server (NTRS)

Commercially available corrosion-protection coating allows less costly metals - aluminum in particular used in heat-reflecting films for thermal barriers. Previously, such films had to incorporate gold as reflective layer to withstand humidity, moisture, and salt spray without corroding. This protective coating prevents corrosion of metalized films during evironmental exposure yet remains flexible, thermally stable and clear.

Rockoff, H. J.

1982-01-01

8

Microwave bonding of thin film metal coated substrates  

NASA Technical Reports Server (NTRS)

Bonding of materials such as MEMS materials is carried out using microwaves. High microwave absorbing films are placed within a microwave cavity containing other less microwave absorbing materials, and excited to cause selective heating in the skin depth of the films. This causes heating in one place more than another. This thereby minimizes unwanted heating effects during the microwave bonding process.

Barmatz, Martin B. (Inventor); Mai, John D. (Inventor); Jackson, Henry W. (Inventor); Budraa, Nasser K. (Inventor); Pike, William T. (Inventor)

2004-01-01

9

Stabilization of metal nanoparticle films on glass surfaces using ultrathin silica coating.  

PubMed

Metal nanoparticle (NP) films, prepared by adsorption of NPs from a colloidal solution onto a preconditioned solid substrate, usually form well-dispersed random NP monolayers on the surface. For certain metals (e.g., Au, Ag, Cu), the NP films display a characteristic localized surface plasmon resonance (LSPR) extinction band, conveniently measured using transmission or reflection ultraviolet-visible light (UV-vis) spectroscopy. The surface plasmon band wavelength, intensity, and shape are affected by (among other parameters) the NP spatial distribution on the surface and the effective refractive index (RI) of the surrounding medium. A major concern in the formation of such NP assemblies on surfaces is a commonly observed instability, i.e., a strong tendency of the NPs to undergo aggregation upon removal from the solution and drying, expressed as a drastic change in the LSPR band. Since various imaging modes and applications require dried NP films, preservation of the film initial (wet) morphology and optical properties upon drying are highly desirable. The latter is achieved in the present work by introducing a convenient and generally applicable method for preventing NP aggregation upon drying while preserving the original film morphology and optical response. Stabilization of Au and Ag NP monolayers toward drying is accomplished by coating the immobilized NPs with an ultrathin (3.0-3.5 nm) silica layer, deposited using a sol-gel reaction performed on an intermediate self-assembled aminosilane layer. The thin silica coating prevents NP aggregation and maintains the initial NP film morphology and LSPR response during several cycles of drying and immersion in water. It is shown that the silica-coated NP films retain their properties as effective LSPR transducers. PMID:24107238

Chaikin, Yulia; Kedem, Ofer; Raz, Jennifer; Vaskevich, Alexander; Rubinstein, Israel

2013-11-01

10

Morphology and Optical Properties of Zinc Oxide Films Grown on Metal Coated Glass Substrates by Aqueous Chemical Growth  

NASA Astrophysics Data System (ADS)

Zinc oxide films were deposited on three different metal coated substrates (gold, nickel and platinum) by aqueous chemical growth method. This paper discusses the effect of metal coated substrates on the morphology and optical properties of grown ZnO films. X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM) and UV-visible spectroscopy (UV-vis) were employed to characterize the samples. All the as-deposited ZnO films exhibit crystalline hexagonal wurzite structure. The crystallite size of the ZnO films were in the range of 29 to 32 nm. FESEM micrographs revealed hexagonal rod, oval-like and flower-like ZnO structures formed on all metal coated substrates. The Pt coated film contains higher density hexagonal rod as compared to others metal coated substrate. Most probably the Pt lattice parameter is the nearest to ZnO compared to nickel and gold. The optical band gap energy, Eg of ZnO films were estimated to be 3.30 eV which is near to bulk Eg, 3.37 eV. This indicates that the ZnO grown by aqueous chemical growth is able to produce similar quality properties to other conventional method either films or bulk size.

Bakar, M. A.; Hamid, M. A. A.; Jalar, A.; Shamsudin, R.

2013-04-01

11

Thin-film metal coated insulation barrier in a Josephson tunnel junction. [Patent application  

Microsoft Academic Search

A highly stable, durable, and reproducible Josephson tunnel junction consists of a thin-film electrode of a hard superconductor, a thin oxide insulation layer over the electrode constituting a Josephson tunnel junction barrier, a thin-film layer of stabilizing metal over the barrier, and a second thin-film hard superconductive electrode over the stabilizing film. The thin stabilizing metal film is made only

G. A. Hawkins; J. Clarke

1975-01-01

12

Characteristics of surface photorefractive waves in a nonlinear SBN-75 crystal coated with a metal film  

SciTech Connect

Based on the calculation of the electrostatic field potential of space charges, we have analysed the characteristic features of light-induced scattering of extraordinary polarised light in photorefractive (PR) crystals (for example, an SBN-75 crystal). Using the method of images, the electrostatic field is analysed for surface (aperiodic) waves along the crystal - dielectric (air) interface. It is shown that the field distributions satisfying the boundary conditions can emerge only upon accumulation of a screening electric charge in a narrow transition layer of thickness {approx}1 mm, the sign of the charge being opposite that of the space charge in the illuminated region of the crystal. A model is proposed to explain the observed features of the surface PR waves in a metal-film coated PR crystal. In considering the contact potential difference at the PR crystal - film interface it is shown that in the crystal layer (adjacent to the film) enriched with charge carriers, i.e., electrons, the refractive index can be significantly reduced. In the case of small excitation angles (0 - 1.5deg ), this layer can act as an optical barrier, the reflection from which can result in near-surface waves; a characteristic difference from the previously observed oscillatory surface waves is the presence of a broadened intensity distribution shifted inside the crystal. (nonlinear optical phenomena)

Nurligareev, D Kh; Usievich, B A; Sychugov, V A; Ivleva, Lyudmila I [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2013-01-31

13

Silane coating of metal substrates: Complementary use of electrochemical, optical and thermal analysis for the evaluation of film properties  

Microsoft Academic Search

Silane coating is a metal surface pre-treatment introduced as a replacement for chromium treatments. It is supposed to be suited for various metals, including aluminium, steel and galvanised steel. Good corrosion performance has been assigned to these hybrid organic–inorganic thin film deposition systems. The silane molecules contain SiOCnH(2n+1) groups, which after hydrolysis into reactive silanol groups SiOH form a covalent

I. De Graeve; J. Vereecken; A. Franquet; T. Van Schaftinghen; H. Terryn

2007-01-01

14

Analysis of metal temperature and coolant flow with a thermal-barrier coating on a full-coverage-film-cooled turbine vane  

NASA Technical Reports Server (NTRS)

The potential benefits of combining full-coverage film cooling with a thermal-barrier coating were investigated analytically for sections on the suction and pressure sides a high-temperature, high-pressure turbine vane. Metal and ceramic coating temperatures were calculated as a function of coating thickness and coolant flow. With a thermal-barrier coating, the coolant flows required for the chosen sections were half those of an uncoated design, and the metal outer temperatures were simultaneously reduced by over 111 K (200 F). For comparison, transpiration cooling was also investigated. Full-coverage film cooling of a coated vane required more coolant flow than did transpiration cooling.

Meitner, P. L.

1978-01-01

15

Water Vapor Permeation of Metal Oxide/Polymer Coated Plastic Films  

NASA Astrophysics Data System (ADS)

Barrier performance to water vapor permeation of ceramic coated layers deposited on flexible polymer films is of great interest to food packaging, medical device packaging and flat panel display industries. In this study, a new type film in which a ceramic layer is deposited on a polymer coated film was proposed for lower water vapor permeation. It is important how to control interfacial properties between each layer and film for good barrier performance. Several kinds of polymer coated materials were prepared for changing surface free energy of the films before and after depositing the ceramic layer. The ceramic layer, which is composed of mixed material of SiO2 and Al2O3, was adopted under the same conditions. The following results were obtained; 1) Water vapor permeation is not related to the surface energy of polymer coated films, 2) After depositing the ceramic layer, however, a strong correlation is observed between the water vapor permeation and surface free energy. 3) The phenomenon is considered that the polarity of the polymer layers plays a key role in changing the structure of ceramic coated layers.

Numata, Yukihiro; Oya, Toshiyuki; Kuwahara, Mitsuru; Ito, Katsuya

16

Direct Conversion of Metal Acetylacetonates and Metal Organic Acid Salts into Metal Oxides Thin Films Using Coating Photolysis Process with An ArF Excimer Laser  

NASA Astrophysics Data System (ADS)

Metal oxide films of TiO2, In2O3, ZrO2, ZnO, SnO2 and Fe2O3 have been successfully prepared by the coating photolysis process using ArF excimer laser irradiation at room temperature. When using metal acetylacetonates (acac) as the starting material, TiO2, In2O3 and ZrO2 were obtained with ArF laser irradiation at 50 mJ/cm2 at a repetition rate of 5 Hz for 5 min. When using Zn-acac, Fe, Sn, or In 2-ethylhexanoate as the starting material, a two-step process consisting of preliminary weak and sufficiently strong irradiation was found to be effective for obtaining ZnO, Fe2O3, SnO2 and In2O3 films.

Tsuchiya, Tetsuo; Watanabe, Akio; Imai, Yoji; Niino, Hiroyuki; Yamaguchi, Iwao; Manabe, Takaaki; Kumagai, Toshiya; Mizuta, Susumu

1999-10-01

17

Metallic and metalloceramic coating by thermal decomposition  

NASA Technical Reports Server (NTRS)

Metallic and metalloceramic coatings were prepared by thermal decomposition of a number of inorganic and metallo-organic compounds. The compounds were applied by spraying and by immersion, especially on ceramic fibers and fiber forms, which are easily coated by this procedure. Penetration of low-density ceramics is examined, and procedures are described that were used for converting the deposited materials to metals, oxides, or metal oxide films. Multiple-component films were also prepared. Photomicrographs illustrate the structure of these films.

Hendricks, R. C.; Mcdonald, G.

1985-01-01

18

Terahertz surface plasmons excitation by nonlinear mixing of lasers in over ultrathin metal film coated dielectric  

NASA Astrophysics Data System (ADS)

An ultrathin metal film deposited on dielectric plate supports low loss THz surface plasma wave (SPW). The SPW field falls off away from the metal film both inside the dielectric as well as in free space. Two lasers normally incident, from free space on the planar structure, exert a difference frequency ponderomotive force on the free electrons of the film and resonantly excite THz SPW. The ratio of SPW amplitude to lasers is 10-3 at laser intensity of 3 × 1012 W/cm2 at 1 ? m wavelength. The growth rate falls monotonically because at higher frequency the coupling of SPW is weak.

Kumar, Pawan; Tripathi, V. K.

2013-08-01

19

Protective Coatings for Metals  

NASA Technical Reports Server (NTRS)

Report evaluates protective coatings for metal structures in seashore and acid-cloud environments. Evaluation result of study of coating application characteristics, repair techniques, and field performance. Products from variety of manufacturers included in study. Also factory-coated panels and industrial galvanized panels with and without topcoats.

Ruggieri, D. J.; Rowe, A. P.

1986-01-01

20

On calculating the energy characteristics of a metal film with a dielectric coating  

NASA Astrophysics Data System (ADS)

A method for calculating the characteristics of a metal film in a dielectric surroundings is suggested. The most interesting case of asymmetric metal-dielectric sandwiches, in which the dielectrics on both sides of the film are different, is considered in the context of the Kohn-Sham modified method. The spectrum, the electron work function, and the surface energy of polycrystalline and single-crystal films placed into passive insulators are calculated for the first time. In general, the dielectric surroundings leads to a negative change in the electron work function and the surface energy. In addition to size-effect-related changes, the shift of the work function is determined by the arithmetic mean of the dielectric constants of the surrounding media. Calculations have been performed for Na, Al, and Pb.

Babich, A. V.

2014-02-01

21

Optimization of plasma parameters for high rate deposition of titanium nitride films as protective coating on bell-metal by reactive sputtering in cylindrical magnetron device  

NASA Astrophysics Data System (ADS)

Nano-structured titanium nitride (TiN) thin film coating is deposited by reactive sputtering in cylindrical magnetron device in argon and nitrogen gas mixtures at low temperature. This method of deposition using DC cylindrical magnetron configuration provides high uniform yield of film coating over large substrate area of different shapes desirous for various technological applications. The influence of nitrogen gas on the properties of TiN thin film as suitable surface protective coating on bell-metal has been studied. Structural morphological study of the deposited thin film carried out by employing X-ray diffraction exhibits a strong (2 0 0) lattice texture corresponding to TiN in single phase. The surface morphology of the film coating is studied using scanning electron microscope and atomic force microscope techniques. The optimized condition for the deposition of good quality TiN film coating is found to be at Ar:N 2 gas partial pressure ratio of 1:1. This coating of TiN serves a dual purpose of providing an anti-corrosive and hard protective layer over the bell-metal surface which is used for various commercial applications. The TiN film's radiant golden colour at proper deposition condition makes it a very suitable candidate for decorative applications.

Borah, Sankar Moni; Pal, Arup Ratan; Bailung, Heremba; Chutia, Joyanti

2008-07-01

22

Scanning electron microscopy at macromolecular resolution in low energy mode on biological specimens coated with ultra thin metal films.  

PubMed

In this report, conditions for attaining high resolution in scanning electron microscopy with soft biological specimens are described using the currently available high resolution scanning electron microscopes in emission mode of low energy electrons (secondary and charging electrons). Retinal rod outer segments, red blood cells, intestinal mucosa, and ferritin molecules were all used as biological test specimens. From uncoated specimens a new source of signal, referred to as a discharge signal, can provide a high yield of low energy electrons from an excitation area approximately the size of the beam's cross section. Additionally, under these conditions sufficient topographic contrast can be achieved by applying ultra thin metal coatins. A 0.5 nm thick gold film is found sufficient for generating the total signal, whereas increased coating thickness causes additional topographic background signal. However, a 2.0 nm film is needed for imaging surface details with the present instrument. Ultra thin, even, and grainless tantalum films have been found effective in eliminating the charging artifacts caused by external fields, and the decoration artifacts caused by crystal growth as seen in gold films. To improve, in high magnification work on ultra thin coated specimen, signal-to-noise ratio, methods for obtaining saturation of the signal with discharge electrons are shown. The necessity of confirming the information obtained in SEM by independent techniques (TEM of stereo-replicas or ultra thin sections) is discussed. PMID:392703

Peters, K R

1979-01-01

23

Direct excitation of the Tamm plasmon-polaritons on a dielectric Bragg reflector coated with a metal film  

NASA Astrophysics Data System (ADS)

Tamm plasmon-polariton is a surface state or surface wave formed at the boundary between a metal and a dielectric Bragg reflector. In order to directly excite the Tamm plasmon-polaritons with unit transmission, we design a structure of Bragg reflector coated with a metal film. Through the Bloch theorem of periodic structures and transfer matrix method, we deduce the existence conditions of the Tamm plasmon-polaritons. For a a finite structure, the Tamm plasmon-polaritons can be excited, which is dependent on the thickness of metal, the period number of the Bragg reflector, the incident direction and frequency. On proper conditions, a perfect transmission for the Tamm plasmon-polariton mode can be achieved without the use of attenuated total reflection prism coupling or diffraction grating.

Zhu, Y.-G.; Hu, W.-L.; Fang, Y.-T.

2013-09-01

24

Coating of plasma polymerized film  

NASA Technical Reports Server (NTRS)

Plasma polymerized thin film coating and the use of other coatings is suggested for passivation film, thin film used for conducting light, and solid body lubrication film of dielectrics of ultra insulators for electrical conduction, electron accessories, etc. The special features of flow discharge development and the polymerized film growth mechanism are discussed.

Morita, S.; Ishibashi, S.

1980-01-01

25

Method of forming graded polymeric coatings or films  

DOEpatents

Very smooth polymeric coatings or films graded in atomic number and density can readily be formed by first preparing the coating or film from the desired monomeric material and then contacting it with a fluid containing a metal or a mixture of metals for a time sufficient for such metal or metals to sorb and diffuse into the coating or film. Metal resinate solutions are particularly advantageous for this purpose. A metallic coating can in turn be produced on the metal-loaded film or coating by exposing it to a low pressure plasma of air, oxygen, or nitrous oxide. The process permits a metallic coating to be formed on a heat sensitive substrate without the use of elevated temperatures.

Liepins, Raimond (Los Alamos, NM)

1983-01-01

26

Method of forming metallic coatings on polymeric substrates  

DOEpatents

Very smooth polymeric coatings or films graded in atomic number and density an readily be formed by first preparing the coating or film from the desired monomeric material and then contacting it with a fluid containing a metal or a mixture of metals for a time sufficient for such metal or metals to sorb and diffuse into the coating or film. Metal resinate solutions are particularly advantageous for this purpose. A metallic coating can in turn be produced on the metal-loaded film or coating by exposing it to a low pressure plasma of air, oxygen, or nitrous oxide. The process permits a metallic coating to be formed on a heat sensitive substrate without the use of elevated temperatures.

Liepins, Raimond (Los Alamos, NM)

1984-01-01

27

Effect of thin condensate films of a metal working fluid of an electric propulsion engine on the integral optical coefficients of a spacecraft's thermal control coating  

NASA Astrophysics Data System (ADS)

Materials on experimental studies to determine the effect of thin condensate films of cesium (used as a model working medium for electric propulsion engines and some spacecraft power sources) on integral optical coefficients of spacecraft thermal control coatings are presented. A technique modified by the author and employing the regular thermal regime of a thin metal plate is used. Measurement results demonstrate that films with thicknesses of 100-1000 Å can seriously degrade the integral optical coefficients of thermal control coatings and thus disturb the heat balance of some spacecraft systems.

Chirov, A. A.

2014-05-01

28

Method of forming metal hydride films  

NASA Technical Reports Server (NTRS)

The substrate to be coated (which may be of metal, glass or the like) is cleaned, both chemically and by off-sputtering in a vacuum chamber. In an ultra-high vacuum system, vapor deposition by a sublimator or vaporizer coats a cooled shroud disposed around the substrate with a thin film of hydride forming metal which getters any contaminant gas molecules. A shutter is then opened to allow hydride forming metal to be deposited as a film or coating on the substrate. After the hydride forming metal coating is formed, deuterium or other hydrogen isotopes are bled into the vacuum system and diffused into the metal film or coating to form a hydride of metal film. Higher substrate temperatures and pressures may be used if various parameters are appropriately adjusted.

Steinberg, R.; Alger, D. L.; Cooper, D. W. (inventors)

1977-01-01

29

Influence of Coating Solution Composition on REBa2Cu3Oy (RE=Gd and Sm, Eu, Gd) Films Fabricated by Fluorine-Free Metal-Organic Deposition  

NASA Astrophysics Data System (ADS)

GdBa2Cu3Oy (GdBCO) and Sm0.33Eu0.33Gd0.33Ba2Cu3Oy (SEG) films were prepared by metal-organic deposition (MOD) using two fluorine-free solutions: a metal 2-ethylhexanate (2-EH) and a complex solution (CS) consisting of metal 2-EH and metal-naphthenate. We investigated the effects of these new fluorine-free solutions, and their potential use in the fabrication of several REBCO (RE: rare earth) materials. The crystal growth, surface morphology, and superconducting properties of films prepared on single-crystal LaAlO3 substrates at low oxygen partial pressure strongly depended upon the coating solution used. Films prepared using 2-EH exhibited improved thermal stability of the superconducting phase during heat treatment. On the other hand, films prepared by CS had a flat superconducting matrix, with a roughness of several tens of nm and large precipitates 2-3 ?m in diameter. In addition, the CS films had a higher critical temperature (91.2 K) than the 2-EH film. The zero-field critical current density at 77.3 K was 0.19 MA/cm2 for 2-EH films, and 0.61 MA/cm2 for CS films.

Nakamura, T.; Kita, R.; Kawabata, S.; Miura, O.; Ichinose, A.; Matsumoto, K.; Yoshida, Y.; Mukaida, M.; Horii, S.

30

Carbonaceous film coating  

DOEpatents

A method of making a carbonaceous film comprising heating tris(1,3,2-benzodiazaborolo)borazine or dodecahydro tris(1,3,2)diazaborine(1,2-a:1'2'-c:1''2''-e)borazine in an inert atmosphere in the presence of a substrate to a temperature at which the borazine compound decomposes, and the decomposition products deposit onto the substrate to form a thin, tenacious, highly reflective conductive coating having a narrow band gap which is susceptible of modification and a relatively low coefficient of friction.

Maya, L.

1988-04-27

31

Reflective and Electrically Conductive Surface Silvered Polyimide Films and Coatings Prepared via Unusual Single-Stage Self-Metallization Techniques  

NASA Technical Reports Server (NTRS)

Highly reflective and/or surface conductive flexible polyimide films can be prepared by the incorporation of positive valent silver compounds into solutions of poly(amic acid)s formed from a variety of dianhydrides and diamines. Thermal curing of selected silver(I)-containing poly(amic acid)s leads to cycloimidization of the polyimide precursor with concomitant silver(I) reduction and surface aggregation of the metal yielding a reflective and/or conductive silver surface similar to that of the native metal. However, not all silver(I) precursors are effective surface metallization agents and not all poly(amic acid)s metallize with equal facility. Ligand/anion and polyimide structural effects on film metallization efficacy and on physical properties on metallized films are reviewed.

Southward, Robin E.; Stoakley, Diane M.

2001-01-01

32

Morphogenesis of nanostructures in glancing angle deposition of metal thin film coatings  

NASA Astrophysics Data System (ADS)

Atomic vapors condensed onto solid surfaces form a remarkable category of condensed matter materials, the so-called thin films, with a myriad of compositions, morphological structures, and properties. The dynamic process of atomic condensation exhibits self-assembled pattern formation, producing morphologies with atomic-scale three- dimensional structures of seemingly limitless variety. This study attempts to shed new light on the dynamical growth processes of thin film deposition by analyzing in detail a previously unreported specific distinct emergent structure, a crystalline triangular-shaped spike that grows within copper and silver thin films. I explored the deposition parameters that lead to the growth of these unique structures, referred to as "nanospikes", fabricating approximately 55 thin films and used scanning electron microscopy and x-ray diffraction analysis. The variation of parameters include: vapor incidence angle, film thickness, substrate temperature, deposition rate, deposition material, substrate, and source-to-substrate distance. Microscopy analysis reveals that the silver and copper films deposited at glancing vapor incidence angles, 80 degrees and greater, have a high degree of branching interconnectivity between adjacent inclined nanorods. Diffraction analysis reveals that the vapor incidence angle influences the sub-populations of crystallites in the films, producing two different [110] crystal texture orientations. I hypothesize that the growth of nanospikes from nanorods is initiated by the stochastic arrival of vapor atoms and photons emitted from the deposition source at small diameter nanorods, and then driven by localized heating from vapor condensation and photon absorption. Restricted heat flow due to nanoscale thermal conduction maintains an elevated local temperature at the nanorod, enhancing adatom diffusion and enabling fast epitaxial crystal growth, leading to the formation and growth of nanospikes. Electron microscopy and x-ray diffraction analysis, and comparisons to related scientific literature, support this hypothesis. I also designed a highly modular ultrahigh vacuum deposition chamber, capable of concurrently mounting several different pieces of deposition equipment, that allows for a high degree of control of the growth dynamics of deposited thin films. I used the newly designed chamber to fabricate tailor-made nanostructured tantalum films for use in ultracapacitors, for the Cabot Corporation.

Brown, Timothy James

33

Metal oxide films on metal  

DOEpatents

A structure including a thin film of a conductive alkaline earth metal oxide selected from the group consisting of strontium ruthenium trioxide, calcium ruthenium trioxide, barium ruthenium trioxide, lanthanum-strontium cobalt oxide or mixed alkaline earth ruthenium trioxides thereof upon a thin film of a noble metal such as platinum is provided.

Wu, Xin D. (Los Alamos, NM); Tiwari, Prabhat (Los Alamos, NM)

1995-01-01

34

Components distribution in Cu(In,Ga)Se-2 films prepared by selenization of evaporated metallic precursors on bare and ITO-coated glass substrates  

NASA Astrophysics Data System (ADS)

Cu(In,Ga)Se-2 thin films have been prepared by selenization of the evaporated metallic precursors on transparent and conductive ITO-coated as well as uncoated glass substrates, by starting from slightly Cu-rich or Cu-poor overall metallic proportions. The objective is to determine the influence of the Cu availability on the constituents distribution achieved after selenization, by means of data obtained at several film depths by grazing incidence X-ray diffraction and X-ray photoelectron spectroscopy that have been related to the overall optical and structural characteristics of the material. This study points out the possibility of achieving homogeneous or graded absorber layers, showing for homogeneous samples an ITO/Cu(In,Ga)Se-2 interface with ohmic electrical characteristics suitable to act as back contact for semitransparent photovoltaic devices.

Guillén, C.; Herrero, J.

2012-02-01

35

Barrier Coatings for Refractory Metals and Superalloys  

SciTech Connect

In the closed working fluid loop of the proposed Prometheus space nuclear power plant (SNPP), there is the potential for reaction of core and plant structural materials with gas phase impurities and gas phase transport of interstitial elements between superalloy and refractory metal alloy components during service. Primary concerns are surface oxidation, interstitial embrittlement of refractory metals and decarburization of superalloys. In parallel with kinetic investigations, this letter evaluates the ability of potential coatings to prevent or impede communication between reactor and plant components. Key coating requirements are identified and current technology coating materials are reviewed relative to these requirements. Candidate coatings are identified for future evaluation based on current knowledge of design parameters and anticipated environment. Coatings were identified for superalloys and refractory metals to provide diffusion barriers to interstitial transport and act as reactive barriers to potential oxidation. Due to their high stability at low oxygen potential, alumina formers are most promising for oxidation protection given the anticipated coolant gas chemistry. A sublayer of iridium is recommended to provide inherent diffusion resistance to interstitials. Based on specific base metal selection, a thin film substrate--coating interdiffusion barrier layer may be necessary to meet mission life.

SM Sabol; BT Randall; JD Edington; CJ Larkin; BJ Close

2006-02-23

36

Protective Coatings of Metal Surfaces by Cold Plasma Treatment.  

National Technical Information Service (NTIS)

The cold plasma techniques for deposition of various types of protective coatings are reviewed. The main advantage of these techniques for deposition of ceramic films is the lower process temperature, which enables heat treating of the metal prior to depo...

R. Manory A. Grill

1985-01-01

37

Third-order optical nonlinearities of sol-gel silica coating films containing metal porphyrin derivatives measured by resonant femtosecond degenerate four-wave mixing technique  

NASA Astrophysics Data System (ADS)

Third-order optical nonlinearities of sol-gel silica coating films containing metal porphyrin derivatives were measured under resonant conditions by the femtosecond degenerate four-wave mixing (DFWM) technique. Temporal profiles of the DFWM signal were measured with a time resolution of 0.3 ps, and were found to consist of two components, the coherent instantaneous nonlinear response and the delayed response with a decay time constant of several to several hundred ps. The latter can be attributed to population grating of an excited state, and contribution of slow component was very little for a zinc porphyrin derivative. The values of electronic component of the optical nonlinear susceptibility, ?(3) xxxx, for these films were ca. 2 x 10-10 esu.

Kasatani, Kazuo; Okamoto, Hiroaki; Takenaka, Shunsuke

2003-11-01

38

Study of the resonant frequencies of silicon microcantilevers coated with vanadium dioxide films during the insulator-to-metal transition  

NASA Astrophysics Data System (ADS)

Vanadium dioxide (VO2) thin films were grown on silicon microcantilevers and companion test substrates by pulsed laser deposition followed by in situ annealing in an oxidizing atmosphere, with annealing times used to control crystallite sizes. Annealing times of 18 min produced VO2 films with average crystallite sizes of ~10 nm or less, while those annealed for 35 min had crystallites of average size ~90 nm, comparable to sample thickness. X-ray diffraction and x-ray photoelectron spectroscopy studies of the samples showed that films with crystallite sizes ~40 nm or greater consisted of substoichiometric VO2 in its monoclinic phase, with preferential orientation with (011) planes parallel to the sample surface, while finer structured samples had a substantially similar composition, but showed no clear evidence of preferential orientation and were probably partially amorphous. Forced vibration experiments were performed with the cantilevers as they were thermally cycled through the VO2 insulator-to-metal transition (IMT). Very large reversible changes in the resonant frequencies of up to 5% (3.6 kHz) as well as hysteretic behavior were observed, which depend strongly on film crystallite size. The average value of Young's modulus for VO2 films with crystallite sizes of ~90 nm was estimated from the mechanical resonance data at room temperature to be ~120 GPa, but the large tensile stresses which develop between film and substrate through the IMT impede a similar determination for the VO2 tetragonal phase, since the commonly used relationships for cantilever frequencies derived from elasticity theory are not applicable for strongly curved composite beams. The results presented show that VO2 thin films can be useful in novel microscale and nanoscale electromechanical resonators in which effective stiffness can be tuned thermally or optically. This response can provide additional functionality to VO2-based devices which take advantage of other property changes through the IMT.

Rúa, Armando; Fernández, Félix E.; Hines, Melissa A.; Sepúlveda, Nelson

2010-03-01

39

Bulk metallic glass coating of polymer substrates  

Microsoft Academic Search

Bulk Metallic Glass (BMG) alloy with the composition of Zr55Cu30Al10Ni5 was deposited by sputtering as thin films on several different engineering polymers and polymer composites. Polycarbonate, polymethyl methacrylate, polyamide 12, polyarylamide (50GF=50 % glass fibers), polyphenylene sulfide (30GF) and polybutylene terephthalate (30GF) were used as substrates. The microstructure of the deposited BMG coatings was studied by X-ray diffraction (XRD) and

Erno Soinila; Parmanand Sharma; Markku Heino; Kaj Pischow; Akihisa Inoue; Hannu Hänninen

2009-01-01

40

Optimization of plasma parameters for high rate deposition of titanium nitride films as protective coating on bell-metal by reactive sputtering in cylindrical magnetron device  

Microsoft Academic Search

Nano-structured titanium nitride (TiN) thin film coating is deposited by reactive sputtering in cylindrical magnetron device in argon and nitrogen gas mixtures at low temperature. This method of deposition using DC cylindrical magnetron configuration provides high uniform yield of film coating over large substrate area of different shapes desirous for various technological applications. The influence of nitrogen gas on the

Sankar Moni Borah; Arup Ratan Pal; Heremba Bailung; Joyanti Chutia

2008-01-01

41

Metal-Coated Optical Fibers for High Temperature Applications  

NASA Technical Reports Server (NTRS)

A DC magnetron sputtering system has been used to actively coat optical fibers with hermetic metal coatings during the fiber draw process. Thin films of Inconel 625 have been deposited on optical fibers and annealed in air at 2000 F. Scanning electron microscopy and Auger electron microscopy have been used to investigate the morphology and composition of the films prior to and following thermal cycling. Issues to be addressed include film adhesion, other coating materials, and a discussion of additional applications for this novel technology.

Zeakes, Jason; Murphy, Kent; Claus, Richard; Greene, Jonathan; Tran, Tuan

1996-01-01

42

Method of measuring metal coating adhesion  

DOEpatents

A method for measuring metal coating adhesion to a substrate material comprising the steps of preparing a test coupon of substrate material having the metal coating applied to one surface thereof, applying a second metal coating of gold or silver to opposite surfaces of the test coupon by hot hollow cathode process, applying a coating to one end of each of two pulling rod members, joining the coated ends of the pulling rod members to said opposite coated surfaces of the test coupon by a solid state bonding technique and finally applying instrumented static tensile loading to the pulling rod members until fracture of the metal coating adhesion to the substrate material occurs.

Roper, John R. (Northglenn, CO)

1985-01-01

43

Electrolytic Metallic Coatings for Carbon Fibers  

Microsoft Academic Search

This paper concerns electrolytic metallic coatings for carbon fibers and the related processes. Plating bath design, electrolyte selection and other aspects were investigated. Experimental results especially in copper electroplating show that the uniformity of metallic coatings on carbon fibers can be improved by the modification of plating bath and the selection of electrolytes. Thus continuous and uniform metallic coatings can

Y. X. Gan

1994-01-01

44

Thin film-coated polymer webs  

DOEpatents

The present invention relates to thin film-coated polymer webs, and more particularly to thin film electronic devices supported upon a polymer web, wherein the polymer web is treated with a purifying amount of electron beam radiation.

Wenz, Robert P. (Cottage Grove, MN); Weber, Michael F. (Shoreview, MN); Arudi, Ravindra L. (Woodbury, MN)

1992-02-04

45

Method of coating metal surfaces to form protective metal coating thereon  

DOEpatents

A process is disclosed for forming a protective metal coating on a metal surface using a flux consisting of an alkali metal fluoride, an alkaline earth metal fluoride, an alkali metal fluoaluminate, an alkali metal fluosilicate, and mixtures thereof. The flux, in particulate form, is mixed with particles of a metal coating material which may comprise aluminum, chromium, mixtures thereof, and alloys containing at least 50 wt. % aluminum and the particulate mixture is applied to the metal surface in a single step, followed by heating the coated metal surface to a temperature sufficient to cause the metal coating material to react with the metal surface to form a protective reaction product in the form of a metal coating bonded to the metal surface. The metal surface which reacts with the metal coating material to form the protective coating may comprise Fe, Co, Ni, Ti, V, Cr, Mn, Zr, Nb, Mo, Tc, Hf, Ta, W, Re and alloys thereof.

Krikorian, Oscar H. (Danville, CA); Curtis, Paul G. (Tracy, CA)

1992-01-01

46

Coated metal articles and method of making  

DOEpatents

The method of protectively coating metallic uranium which comprises dipping the metallic uranium in a molten alloy comprising about 20-75% of copper and about 80-25% of tin, dipping the coated uranium promptly into molten tin, withdrawing it from the molten tin and removing excess molten metal, thereupon dipping it into a molten metal bath comprising aluminum until it is coated with this metal, then promptly withdrawing it from the bath.

Boller, Ernest R. (Van Buren Township, IN); Eubank, Lowell D. (Wilmington, DE)

2004-07-06

47

Coated Metal Articles and Method of Making  

DOEpatents

The method of protectively coating metallic uranium which comprises dipping the metallic uranium in a molten alloy comprising about 20-75% of copper and about 80-25% of tin, dipping the coated uranium promptly into molten tin, withdrawing it from the molten tin and removing excess molten metal, thereupon dipping it into a molten metal bath comprising aluminum until it is coated with this metal, then promptly withdrawing it from the bath.

Boller, Ernest R.; Eubank, Lowell D.

2004-07-06

48

Use of Viscoelastic Properties of Metal Alkoxide Sols to Control the Microstructure and Quality of Spin-coated Sol-gel Thin-films  

Microsoft Academic Search

The sol-gel spin-coating technique is increasingly being used for the fabrication of thin-films with diverse applications in areas that include advanced optics, microelectronics and sensors. The performance quality of the thin film devices is affected by the thickness and homogenity of the film, which are in turn controlled by parameters such as substrate surface quality, viscoelastic properties of the sol,

Lam T. Nguyen; Pandiyan Murugaraj; Colin Rix; David Mainwaring

2002-01-01

49

Corrosion protective coating for metallic materials  

DOEpatents

Corrosion protective coatings for metallic materials, particularly aluminum and aluminum alloys, produced with simple, low-cost equipment and materials other than toxic metals or metal salts, or metal cyanides is disclosed. The metallic material is cleaned, degreased, and deoxidized, the surface is converted to a substantially alkaline condition, and the surface is chemically sealed with inorganic metal compounds. 1 fig.

Buchheit, R.G.; Martinez, M.A.

1998-05-26

50

Bulk metallic glass coating of polymer substrates  

NASA Astrophysics Data System (ADS)

Bulk Metallic Glass (BMG) alloy with the composition of Zr55Cu30Al10Ni5 was deposited by sputtering as thin films on several different engineering polymers and polymer composites. Polycarbonate, polymethyl methacrylate, polyamide 12, polyarylamide (50GF=50 % glass fibers), polyphenylene sulfide (30GF) and polybutylene terephthalate (30GF) were used as substrates. The microstructure of the deposited BMG coatings was studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results of XRD and SEM studies were consistent with amorphous microstructure. Elemental compositions of the coatings were verified by energy dispersive spectroscopy (EDS). Mechanical properties of the coatings were compared to copper mould cast BMG using nano- indentation tests with similar results. According to the cross-cut tape tests good adhesion was achieved between the studied BMG alloy and all other polymer substrates except polycarbonate. Nano-indentation results showed similar mechanical properties for coating and cast BMG. The results of this study look promising as they open new opportunities for BMG- polymer composite applications.

Soinila, Erno; Sharma, Parmanand; Heino, Markku; Pischow, Kaj; Inoue, Akihisa; Hänninen, Hannu

2009-01-01

51

High Critical Current in Metal Organic Derived YBCO Films.  

National Technical Information Service (NTIS)

The Phase II STTR Project focused on optimization of the Metal Organic Deposition (MOD) process for deposition thick, high critical current YBCO films for use in the Second Generation (2G) YBCO coated conductor wires. The project successfully extended the...

X. Li

2010-01-01

52

Dip coated 12CaO·7Al 2O 3 thin films through sol–gel process using metal alkoxide  

Microsoft Academic Search

Transparent nanostructured 12CaO·7Al2O3 thin films with cubic structure have been prepared on soda lime glass substrates via the sol–gel dip coating using the precursor sol solution at low temperature. The structural, compositional, morphological and optical properties of the 12CaO·7Al2O3 films and powder were studied using X-ray diffractometry (XRD), X-ray photoelectron spectroscopy, scanning electron microscopy (SEM) and atomic force microscopy. Optical

P. M. Chavhan; Anubha Sharma; R. K. Sharma; Gurmeet Singh; N. K. Kaushik

2010-01-01

53

Thermal and thermo-oxidative aging effects on the dielectric properties of thin polyimide films coated on metal substrate  

Microsoft Academic Search

Nowadays, polyimides (PIs) are widely used in electronic applications where high temperature operating devices are needed. In order to validate the use of PI as insulating layer in above 200 °C applications, the thermal (in inert atmosphere) and thermo-oxidative (in oxidant atmosphere) degradation at high temperature of PI thin films were investigated. The PI films (from 1.5 to 8.6 ?m),

R. Khazaka; S. Diaham; M. L. Locatelli; C. Trupin; B. Schlegel

2011-01-01

54

RF-PACVD of water repellent and protective HMDSO coatings on bell metal surfaces: Correlation between discharge parameters and film properties  

Microsoft Academic Search

Hexamethyldisiloxane (HMDSO) films have been deposited on bell metal using radiofrequency plasma assisted chemical vapor deposition (RF-PACVD) technique. The protective performances of the HMDSO films and their water repellency have been investigated as a function of DC self-bias voltage on the substrates during deposition. Plasma potential measurements during film deposition process are carried out by self-compensated emissive probe. Optical emission

A. J. Choudhury; S. A. Barve; Joyanti Chutia; A. R. Pal; R. Kishore; Jagannath; M. Pande; D. S. Patil

2011-01-01

55

UV curable polyurethane acrylate coatings for metal surfaces  

Microsoft Academic Search

Purpose – The purpose of this paper is to synthesise environment friendly UV curable polyurethane acrylate resins for various industrial applications and study the performance properties of the cured coating films applied over metal surfaces. Design\\/methodology\\/approach – The polyurethane acrylate resin was synthesised using polyester polyol (synthesised using ethylene glycol, adipic acid and 1,6 hexane diol), isophorone diisocynate (IPDI) and

A. Srivastava; D. Agarwal; S. Mistry; J. Singh

2008-01-01

56

Analysis of Hard Thin Film Coating  

NASA Technical Reports Server (NTRS)

Marshall Space Flight Center (MSFC) is interested in developing hard thin film coating for bearings. The wearing of the bearing is an important problem for space flight engine. Hard thin film coating can drastically improve the surface of the bearing and improve the wear-endurance of the bearing. However, many fundamental problems in surface physics, plasma deposition, etc, need further research. The approach is using Electron Cyclotron Resonance Chemical Vapor Deposition (ECRCVD) to deposit hard thin film on stainless steel bearing. The thin films in consideration include SiC, SiN and other materials. An ECRCVD deposition system is being assembled at MSFC.

Shen, Dashen

1998-01-01

57

Analysis of Hard Thin Film Coating  

NASA Technical Reports Server (NTRS)

MSFC is interested in developing hard thin film coating for bearings. The wearing of the bearing is an important problem for space flight engine. Hard thin film coating can drastically improve the surface of the bearing and improve the wear-endurance of the bearing. However, many fundamental problems in surface physics, plasma deposition, etc, need further research. The approach is using electron cyclotron resonance chemical vapor deposition (ECRCVD) to deposit hard thin film an stainless steel bearing. The thin films in consideration include SiC, SiN and other materials. An ECRCVD deposition system is being assembled at MSFC.

Shen, Dashen

1998-01-01

58

Improved performance of thin film broadband antireflective coatings  

NASA Astrophysics Data System (ADS)

Antireflective coatings are useful for a range of applications, from minimizing the radar cross-section of stealth aircraft, to maximizing the efficiency of solar energy panels. New low-index nanorod thin films promise broadband, broad angle performance for such coatings. We demonstrate that a bandwidth increase from 38.5% to 113% is possible by using a simple evolutionary strategy to optimize the thin film material parameters. A two dimensional FDTD planewave periodic scattering approach is used to demonstrate additional performance increase by adding losses to a single layer. The same technique may be used for antireflective coatings for which no analytical solution exists, as is the case with dispersive, non-linear materials, special geometries, and coatings with metallic or ferromagnetic inclusions. A procedure is outlined for using the FDTD approach to obtain a map of reflection coefficients with respect to wavelength and incidence angle.

Mishrikey, Matthew; Fallahi, Arya; Hafner, Christian; Vahldieck, Rüdiger

2007-10-01

59

Method of producing adherent metal oxide coatings on metallic surfaces  

DOEpatents

Provided is a process of producing an adherent synthetic corrosion product (sludge) coating on metallic surfaces. The method involves a chemical reaction between a dry solid powder mixture of at least one reactive metal oxide with orthophosphoric acid to produce a coating in which the particles are bound together and the matrix is adherent to the metallic surface.

Lane, Michael H. (Clifton Park, NY); Varrin, Jr., Robert D. (McLean, VA)

2001-01-01

60

Bi-metal coated aperture SNOM probes  

NASA Astrophysics Data System (ADS)

Aperture probes of scanning near-field optical microscopes (SNOM) offer resolution which is limited by a sum of the aperture diameter at the tip of a tapered waveguide probe and twice the skin depth in metal used for coating. An increase of resolution requires a decrease of the aperture diameter. However, due to low energy throughput of such probes aperture diameters usually are larger than 50 nm. A groove structure at fiber core-metal coating interface for photon-to-plasmon conversion enhances the energy throughput 5-fold for Al coated probes and 30-fold for Au coated probes due to lower losses in the metal. However, gold coated probes have lower resolution, first due to light coupling from the core to plasmons at the outside of the metal coating, and second due to the skin depth being larger than for Al. Here we report on the impact of a metal bilayer of constant thickness for coating aperture SNOM probes. The purpose of the bilayer of two metals of which the outer one is aluminum and the inner is a noble metal is to assure low losses, hence larger transmission. Using body-of-revolution finite-difference time-domain simulations we analyze properties of probes without corrugations to measure the impact of using a metal bilayer and choose an optimum bi-metal configuration. Additionally we investigate how this type of metalization works in the case of grooved probes.

Antosiewicz, Tomasz J.; Wróbel, Piotr; Szoplik, Tomasz

2011-05-01

61

Density-related properties of metal oxide films  

NASA Astrophysics Data System (ADS)

The density of the material in a deposited film determines many important film properties, for example hardness and abrasions resistance, adherence to the substrate, refractive index, film stress, flatness and film permeation. Chemical compound films like metal oxides, some nitrides and oxynitrides are mainly produced by reactive PVD processes. The energy input into the growing film strongly influence the density of the resulting film. High energetic coating conditions result e.g. in a high refractive index, but often also in relatively high residual optical absorption and high compressive film stress. In order to obtain films with improved properties immediately after deposition without time consuming post-deposition heat treatments, depositions of RLVIP-Ta2O5 films were carried out under relatively high oxygen pressures and under special rate conditions. The achieved reproducible film properties can practically be accepted for many low loss optical film applications.

Pulker, Hans K.; Schlichtherle, Stefan S.

2004-02-01

62

Measuring Thicknesses of Coatings on Metals  

NASA Technical Reports Server (NTRS)

Digital light sensor and eddy-current sensor measure thickness without contact. Surface of Coating reflects laser beam to optical sensor. Position of reflected spot on sensor used by microcomputer to calculate coating thickness. Eddy-current sensor maintains constant distance between optical sensor and metal substrate. When capabilities of available components fully exploited, instrument measures coatings from 0.001 to 6 in. (0.0025 to 15 cm) thick with accuracy of 1 part in 4,000. Instrument readily incorporated in automatic production and inspection systems. Used to inspect thermal-insulation layers, paint, and protective coatings. Also used to control application of coatings to preset thicknesses.

Cotty, Glenn M., Jr.

1986-01-01

63

Plasma-Spray Metal Coating On Foam  

NASA Technical Reports Server (NTRS)

Molds, forms, and other substrates made of foams coated with metals by plasma spraying. Foam might be ceramic, carbon, metallic, organic, or inorganic. After coat applied by plasma spraying, foam left intact or removed by acid leaching, conventional machining, water-jet cutting, or another suitable technique. Cores or vessels made of various foam materials plasma-coated with metals according to method useful as thermally insulating containers for foods, liquids, or gases, or as mandrels for making composite-material (matrix/fiber) parts, or making thermally insulating firewalls in automobiles.

Cranston, J.

1994-01-01

64

Flexible thin metal film thermal sensing system  

NASA Technical Reports Server (NTRS)

A flexible thin metal film thermal sensing system is provided. A self-metallized polymeric film has a polymeric film region and a metal surface disposed thereon. A layer of electrically-conductive metal is deposited directly onto the self-metallized polymeric film's metal surface. Coupled to at least one of the metal surface and the layer of electrically-conductive metal is a device/system for measuring an electrical characteristic associated therewith as an indication of temperature.

Thomsen, Donald L. (Inventor)

2010-01-01

65

Impact of patterned anti-reflection coating on the performance of Broadband Blackbody Absorber Based on Dielectric-Thin Metal Film Multilayers  

NASA Astrophysics Data System (ADS)

We present results from measurements on double period structures of alternating dielectric and thin metal layer coated with micro-patterned anti-reflection layer to improve absorption in mid-infrared range. We examine the effect on performance of patterns' period and the correlation with the effective medium theory. We find that the numerical results agree with the measured absorption spectra. We also investigate the limit of pattern feature size to achieve performance suggested by effective medium theory.

Guo, Shyhauh; Sushkov, Andrei; Drew, Dennis; Phaneuf, Raymond

2013-03-01

66

Systematic Evaluation of Jc Decrease in Thick Film Coated Conductors  

SciTech Connect

Address both thickness dependence of Jc, in thick film YBCO coated conductors through an application of a suite of new measurement techniques to thick film wire samples produced by commercially viable coated conductor technologies.

Alex Ignatiev; Dr. Amit Goyal

2006-05-10

67

Systematic Evaluation of Jc Decrease in Thick Film Coated Conductors  

Microsoft Academic Search

Address both thickness dependence of Jc, in thick film YBCO coated conductors through an application of a suite of new measurement techniques to thick film wire samples produced by commercially viable coated conductor technologies.

Alex Ignatiev; Amit Goyal

2006-01-01

68

Protective Coatings on Metals. Volume 6.  

National Technical Information Service (NTIS)

The book contains review articles and brief communications devoted to the theory and practice of the formation of protective diffusion coatings on metals and alloys. The book offers valuable information on different processes used in powder metallurgy, su...

G. V. Samsonov

1984-01-01

69

Remotely measuring a thin dielectric coating on a metallic cylinder.  

PubMed

A laser optical metrology system is described that remotely measures at high rate the presence and thickness of a thin-film lubricant on metallic cylinders with diameters on the order of 0.5 mm. Applications include remote measurement of hypodermic needle dielectric coating thickness in a clean room environment. High accuracy computer simulation of the electric field scattered from a coated cylinder by an incident laser beam is demonstrated using the condition numbers of the matrices defined by the boundary value matching equations derived from the eigenfunction expansion of the exact solution to Maxwell's equations. Dielectric coatings from 1 ?m to 50 ?m are seen to be readily observed and accurately measured using a remotely placed CMOS array. Distinctive signatures are shown for film thicknesses in the range from 0 to 10 ?m, and an appropriate location for CMOS detector placement is determined from the scattering patterns. PMID:22274253

George, Nicholas; Zavattero, Paul

2011-12-19

70

Structured Metal Coatings for Distributed Fiber Sensors  

Microsoft Academic Search

A transducer continuum is integrated to the fiber coating by means of a sequence of on-line sputtering, electro-plating, photolithography and periodical etching processes. Applications to the distributed sensing of temperature, strain and pressure are reported. 1. INTRODUCTION The present paper describes a technology whereby the organic coating of standard fibers is overcoated by a thin metal single- or multilayer. This

L. Falco; O. Parriaux

1992-01-01

71

Salt Spray Testing of Metallic - Ceramic Coatings.  

National Technical Information Service (NTIS)

Fifteen metallic-ceramic coatings consisting of aluminum or aluminum-magnesium pigment suspended in an inorganic binder were applied to steel panels and tested for corrosion resistance in SO2-salt fog and 5% salt fog, respectively. Four coatings offered b...

E. J. Jankowsky

1980-01-01

72

Eddy Current Assessment of Duplex Metallic Coatings  

NASA Astrophysics Data System (ADS)

EPRI is involved in a multi-year program with the Department of Energy to test, evaluate, and develop a field-deployable eddy current NDE system for life assessment of blade coatings for advanced gas turbines. The coatings evaluated from these advanced GE engines include CoCrAlY (GT 29) and NiCoCrAlY (GT 33) bond coats followed by top aluminide overlay coatings. These duplex metallic coatings commonly referred to as GT 29+ and GT 33+ coatings, respectively. In general, during cycling and continuous operation at higher operating temperature, coatings fail due to spallation of protective oxide layers, leading to consumption of protective coating by oxidation and to eventual failure of blades. To extend service life of these critical rotating components, an inspection-based condition assessment program has been initiated to help establish more optimum inspection intervals that are not dependent on time-in-service maintenance approach. This paper summarizes the latest results obtained to date using the state-of-the-art frequency-scanning eddy current tester with a built-in three-layer inversion analysis algorithm. Significant progress has been made in assessing and discriminating the duplex metallic coatings as normal, degraded, and/or cracked. In addition, quantitative assessment was conducted by estimating various coating and substrate conductivity values.

Krzywosz, K. J.

2004-02-01

73

Comparison of different strategies to realize highly reflective thin film coatings at 1064 nm  

Microsoft Academic Search

This paper addresses approaches to achieve highly reflective thin film coatings at 1064nm in the near infrared (NIR) spectral region. Different strategies, i.e. metal mirrors, homogeneous dielectric multilayer and hybrid multilayer (metal layer with multilayer enhancement) are suggested. These coatings are deposited with different techniques, and their optical and mechanical performances are analyzed and concluded. Compared to all-dielectric multilayer, metal-enhanced

Minghong Yang; Ciming Zhou; Desheng Jiang

2008-01-01

74

Molecular Level Coating of Metal Oxide Particles  

NASA Technical Reports Server (NTRS)

Polymer encapsulated metal oxide particles are prepared by combining a polyamide acid in a polar osmotic solvent with a metal alkoxide solution. The polymer was imidized and the metal oxide formed simultaneously in a refluxing organic solvent. The resulting polymer-metal oxide is an intimately mixed commingled blend, possessing, synergistic properties of both the polymer and preceramic metal oxide. The encapsulated metal oxide particles have multiple uses including, being useful in the production of skin lubricating creams, weather resistant paints, as a filler for paper. making ultraviolet light stable filled printing ink, being extruded into fibers or ribbons, and coatings for fibers used in the production of composite structural panels.

McDaniel, Patricia R. (Inventor); St.Clair, Terry L. (Inventor)

2002-01-01

75

Molecular Level Coating for Metal Oxide Particles  

NASA Technical Reports Server (NTRS)

Polymer encapsulated metal oxide particles are prepared by combining a polyamide acid in a polar aprotic solvent with a metal alkoxide solution. The polymer was imidized and the metal oxide formed simultaneously in a refluxing organic solvent. The resulting polymer-metal oxide is an intimately mixed commingled blend, possessing synergistic properties of both the polymer and preceramic metal oxide. The encapsulated metal oxide particles have multiple uses including, being useful in the production of skin lubricating creams, weather resistant paints, as a filler for paper, making ultraviolet light stable filled printing ink, being extruded into fibers or ribbons, and coatings for fibers used in the production of composite structural panels.

McDaniel, Patricia R. (Inventor); Saint Clair, Terry L. (Inventor)

2000-01-01

76

Polyvinyl acetate-based film coatings.  

PubMed

Polyvinyl acetate-based colloidal aqueous polymer dispersion Kollicoat(®) SR 30 D results in coatings characterized by moderate swelling behaviour, lipophilicity, pH-independent permeability for actives and high flexibility to withstand mechanical stress and is therefore used for controlled release coating. The colloidal aqueous polymer dispersion of Kollicoat(®) SR 30 D can be easily processed due to an optimal low minimum film forming temperature (MFT) of 18 °C without plasticizer addition and a thermal after-treatment (curing) of coated pellets. The drug release from Kollicoat(®) SR 30 D coated pellets was almost pH independent. Drug release could be easily adjusted by coating level or addition of soluble pore forming polymers. Physically stable Kollicoat(®) SR 30 D dispersions were obtained with the water-soluble polymers Kollidon(®) 30 and Kollicoat(®) IR up to 50% w/w. The addition of only 10% w/w triethyl citrate as plasticizer improved the flexibility of the films significantly and allowed compaction of the pellets. The drug release was almost independent of the compression force and the pellet content of the tablets. The inclusion of various tableting excipients slightly affected the drug release, primarily because of a different disintegration rate of the tablets. A combination of Kollicoat(®) SR 30 D and Kollicoat(®) IR with higher coating levels>10 mg/cm(2) is a relatively new alternative to OROS system which does not require drilling. PMID:24076229

Kolter, K; Dashevsky, A; Irfan, Muhamad; Bodmeier, R

2013-12-01

77

Cold Spray Formation of Thin Metal Coatings.  

National Technical Information Service (NTIS)

The invention relates to an adaptation of the cold spray process to provide a method of coating fine metal particles, including aluminum and copper, onto a work piece. In one embodiment, the invention is a metal agglomerated hard sphere composition capabl...

J. Liu

2004-01-01

78

Fiber metal interlayer improves ceramic coating performance  

SciTech Connect

This article is a review of the use of a compliant fiber metal inner layer between a ceramic coating and metal. The material used is Zirconia with phase stabilizers of magnesium oxide, calcium oxide, and yttrium oxide. Design, fabrication, and testing of the stabilized zirconia is discussed.

Jarrabet, G.P.

1994-11-01

79

Protective lithium ion conducting ceramic coating for lithium metal anodes and associate method  

Microsoft Academic Search

A battery structure including a cathode, a lithium metal anode and an electrolyte disposed between the lithium anode and the cathode utilizes a thin-film layer of lithium phosphorus oxynitride overlying so as to coat the lithium anode and thereby separate the lithium anode from the electrolyte. If desired, a preliminary layer of lithium nitride may be coated upon the lithium

John B

1994-01-01

80

Coating metals on micropowders by magnetron sputtering  

Microsoft Academic Search

Magnetron sputtering was used to coat various metals on micropowder surfaces. By using this method, the fine particles are better dispersed and can therefore be coated more homogeneously. The micro-powders used include cenospheres from fly ash of coal-burning electric power plants (diameter 40–200?m and particle density 0.7±0.1g\\/cm3), as well as carborundum particles of different sizes. Aluminum, silver, copper, cobalt and

Zheng Xu; Xiaozheng Yu; Zhigang Shen

2007-01-01

81

Covering solid, film cooled surfaces with a duplex thermal barrier coating  

NASA Astrophysics Data System (ADS)

Thermal barrier coating systems were applied to hardware having passageways in the walls connecting apertures in the surface to a gas supply for film cooling. An inert gas, such as argon, is discharged through the apertures during the application of the thermal barrier coating system by plasma spraying. This flow of inert gas reduces both blocking of the holes and base metal oxidation during the coating operation.

Liebert, C. H.

1983-09-01

82

Covering solid, film cooled surfaces with a duplex thermal barrier coating  

NASA Technical Reports Server (NTRS)

Thermal barrier coating systems were applied to hardware having passageways in the walls connecting apertures in the surface to a gas supply for film cooling. An inert gas, such as argon, is discharged through the apertures during the application of the thermal barrier coating system by plasma spraying. This flow of inert gas reduces both blocking of the holes and base metal oxidation during the coating operation.

Liebert, C. H. (inventor)

1983-01-01

83

Metallic seal for thermal barrier coating systems  

NASA Technical Reports Server (NTRS)

The invention is particularly concerned with sealing thermal barrier coating systems of the type in use and being contemplated for use in diesel and other internal combustion engines. The invention also would find application in moderately high temperature regions of gas turbine engines and any other application employing a thermal barrier coating at moderate temperatures. Ni-35Cr-6Al-1Y, Ni-35Cr-6Al-1Yb, or other metallic alloy denoted as MCrAlx is applied over a zirconia-based thermal barrier overlayer. The close-out layer is glass-bead preened to densify its surface. This seals and protects the thermal barrier coating system.

Miller, Robert A. (inventor)

1990-01-01

84

Rapidly solidified metal coatings by peen plating  

NASA Technical Reports Server (NTRS)

Specimens of 7075-T6 aluminum alloy were peen plated with rapidly solidified tin-lead and aluminum powders, and the cross-sections of the coated specimens were examined by light and electron microscopy. The properties of the peen plated specimens were also compared with those of shot peened specimens without any coating. It is found that peen plating with rapidly solidified metals improves the fatigue properties of the coated samples to a greater extent than shot peening alone. Specimens of 7075-T6 alloy peen plated with rapidly solidified tin-lead and aluminum exhibited better fatigue resistance than shot peened specimens in both air and salt water.

Chu, H. P.

1987-01-01

85

Metal-coated colloidal particles  

Microsoft Academic Search

Procedures are described for coating of submicrometre ceramic powders with copper and nickel. The process required precoating of the core particles with a palladium catalyst. A precoating procedure was developed in which palladium chloride is reduced by sodium hypophosphite or stannous chloride on the powder surface in aqueous suspensions. Commercial electroless solutions were used to deposit copper and nickel on

A. K. Garg; L. C. De Jonghe

1993-01-01

86

Effects of sputtered metal oxide films on the ceramic-to-metal bond.  

PubMed

The application of a thin oxide film is seen as a method of improving the ceramic-to-metal bond. Using sputter coating to form oxide films allows control of its thickness. The thickness of the oxide layer can also be controlled by sputter coating. Films produced by sputtering, in themselves, have superior bond strengths in that the high-energy levels that are used in the technique drive the coating material into the atomic lattice of the substrate material (dental gold). Remaining to be determined are optimum film thickness and the oxide to be used. However, the present study opens a field of study showing promise of improving porcelain-to-metal bonding in dental restoration. PMID:3908655

Bullard, J T; Dill, R E; Marker, V A; Payne, E V

1985-12-01

87

Dielectric Coating For Hot-Film Flow Sensors  

NASA Technical Reports Server (NTRS)

Very-thin-film dielectric coating stable over range of temperatures developed. This dielectric coating, combination of fused silica and thermoplastic polymer, has sufficient stability to withstand stresses placed upon it by cycling to and from cryogenic temperatures. Coating tailored to meet almost any criterion of roughness height. Useful for research in application of hot-film sensors to airfoils.

Hopson, Purnell, Jr.; Tran, Sang Q.

1990-01-01

88

Polyenamines for Films, Coatings, and Adhesives  

NASA Technical Reports Server (NTRS)

Easy process makes polymers with good mechanical properties. Synthesis involves Michael-type addition polymerization of two diacetylenic diketones, with various aromatic diamines in m-cresol at 60 to 130 degrees C. Technique provides synthetic route to high-molecular-weight polyenamines with moderate thermal stability and good mechanical properties. Polyenamines produced exhibit potential for use as films, coatings, adhesives, molding compounds, and composite matrices.

Hergenrother, Paul M.; Bass, Robert G.; Sinsky, Mark S.; Connell, John W.

1987-01-01

89

Coated metal fiber coalescing cell  

Microsoft Academic Search

A cell is described for coalescing oil droplets dispersed in a water emulsion including an elongated perforated tube core into which the emulsion is injected, layers of oleophilic plastic covered metal mat wound about the core through which the emulsion is forced to pass, the fibers of the metal mat being covered by oleophilic plastic such as vinyl, acrylic, polypropylene,

W. D. Rutz; R. J. Swain

1980-01-01

90

Comparison of different strategies to realize highly reflective thin film coatings at 1064 nm  

NASA Astrophysics Data System (ADS)

This paper addresses approaches to achieve highly reflective thin film coatings at 1064 nm in the near infrared (NIR) spectral region. Different strategies, i.e. metal mirrors, homogeneous dielectric multilayer and hybrid multilayer (metal layer with multilayer enhancement) are suggested. These coatings are deposited with different techniques, and their optical and mechanical performances are analyzed and concluded. Compared to all-dielectric multilayer, metal-enhanced coatings show lower thickness and lower stress load, and therefore are very promising in substrate-sensitive applications.

Yang, Minghong; Zhou, Ciming; Jiang, Desheng

2008-10-01

91

Aerosol chemical vapor deposition of metal oxide films  

DOEpatents

A process of preparing a film of a multicomponent metal oxide including: forming an aerosol from a solution comprised of a suitable solvent and at least two precursor compounds capable of volatilizing at temperatures lower than the decomposition temperature of said precursor compounds; passing said aerosol in combination with a suitable oxygen-containing carrier gas into a heated zone, said heated zone having a temperature sufficient to evaporate the solvent and volatilize said precursor compounds; and passing said volatilized precursor compounds against the surface of a substrate, said substrate having a sufficient temperature to decompose said volatilized precursor compounds whereby metal atoms contained within said volatilized precursor compounds are deposited as a metal oxide film upon the substrate is disclosed. In addition, a coated article comprising a multicomponent metal oxide film conforming to the surface of a substrate selected from the group consisting of silicon, magnesium oxide, yttrium-stabilized zirconium oxide, sapphire, or lanthanum gallate, said multicomponent metal oxide film characterized as having a substantially uniform thickness upon said FIELD OF THE INVENTION The present invention relates to the field of film coating deposition techniques, and more particularly to the deposition of multicomponent metal oxide films by aerosol chemical vapor deposition. This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).

Ott, Kevin C. (4745 Trinity Dr., Los Alamos, NM 87544); Kodas, Toivo T. (5200 Noreen Dr. NE., Albuquerque, NM 87111)

1994-01-01

92

Self-adaptive low friction coatings based on transition metal dichalcogenides  

Microsoft Academic Search

This paper deals with three fundamentally different concepts of self-lubricant coatings based on the transition metal dichalcogenides (TMD) and deposited by magnetron sputtering. The first two designs could be considered as traditional: the TMD films doped by carbon or nitrogen. The main attention is aimed at qualitative description of surface and sub-surface modification of the films as the result of

Tomas Polcar; Albano Cavaleiro

2011-01-01

93

Drying dip-coated colloidal films.  

PubMed

We present the results from a small-angle X-ray scattering (SAXS) study of lateral drying in thin films. The films, initially 10 ?m thick, are cast by dip-coating a mica sheet in an aqueous silica dispersion (particle radius 8 nm, volume fraction ?(s) = 0.14). During evaporation, a drying front sweeps across the film. An X-ray beam is focused on a selected spot of the film, and SAXS patterns are recorded at regular time intervals. As the film evaporates, SAXS spectra measure the ordering of particles, their volume fraction, the film thickness, and the water content, and a video camera images the solid regions of the film, recognized through their scattering of light. We find that the colloidal dispersion is first concentrated to ?(s) = 0.3, where the silica particles begin to jam under the effect of their repulsive interactions. Then the particles aggregate until they form a cohesive wet solid at ?(s) = 0.68 ± 0.02. Further evaporation from the wet solid leads to evacuation of water from pores of the film but leaves a residual water fraction ?(w) = 0.16. The whole drying process is completed within 3 min. An important finding is that, in any spot (away from boundaries), the number of particles is conserved throughout this drying process, leading to the formation of a homogeneous deposit. This implies that no flow of particles occurs in our films during drying, a behavior distinct to that encountered in the iconic coffee-stain drying. It is argued that this type of evolution is associated with the formation of a transition region that propagates ahead of the drying front. In this region the gradient of osmotic pressure balances the drag force exerted on the particles by capillary flow toward the liquid-solid front. PMID:22053849

Li, Joaquim; Cabane, Bernard; Sztucki, Michael; Gummel, Jérémie; Goehring, Lucas

2012-01-10

94

Study of two different thin film coating methods in transmission laser micro-joining of thin Ti-film coated glass and polyimide for biomedical applications.  

PubMed

Biomedical devices and implants require precision joining for hermetic sealing which can be achieved with low power lasers. The effect of two different thin metal film coating methods was studied in transmission laser micro-joints of titanium-coated glass and polyimide. The coating methods were cathodic arc physical vapor deposition (CA-PVD) and electron beam evaporation (EB-PVD). Titanium-coated glass joined to polyimide film can have neural electrode application. The improvement of the joint quality will be essential for robust performance of the device. Low power fiber laser (wave length = 1100 nm) was used for transmission laser micro-joining of thin titanium (Ti) film (approximately 200 nm) coated Pyrex borosilicate 7740 glass wafer (0.5 mm thick) and polyimide (Imidex) film (0.2 mm thick). Ti film acts as the coupling agent in the joining process. The Ti film deposition rate in the CA-PVD was 5-10 A/s and in the EB-PVD 1.5 A/s. The laser joint strength was measured by a lap shear test, the Ti film surfaces were analyzed by atomic force microscopy (AFM) and the lap shear tested joints were analyzed by optical microscopy and scanning electron microscopy (SEM). The film properties and the failure modes of the joints were correlated to joint strength. The CA-PVD produced around 4 times stronger laser joints than EB-PVD. The adhesion of the Ti film on glass by CA-PVD is better than that of the EB-PVD method. This is likely to be due to a higher film deposition rate and consequently higher adhesion or sticking coefficient for the CA-PVD particles arriving on the substrate compared to that of the EB-PVD film. EB-PVD shows poor laser bonding properties due to the development of thermal hotspots which occurs from film decohesion. PMID:19627828

Sultana, T; Georgiev, G L; Baird, R J; Auner, G W; Newaz, G; Patwa, R; Herfurth, H J

2009-07-01

95

UV dichroic coatings on metallic reflectors  

NASA Astrophysics Data System (ADS)

The work presented here explains the design and deposition process of dichroic coating on metallic reflectors developed for UV curing systems. Special designs are adopted to achieve the spectral band and optimized to suit to the requirements. A mirror, which reflects the UV radiation (220 - 400 nm) and absorbs visible and infrared radiation (400 - 2000nm), is described in detail.

Raghunath, C.; Babu, N. J.; chandran, K. M.

2008-05-01

96

Broadband Dielectric Resonator Antenna With Metal Coating  

Microsoft Academic Search

A broadband dielectric resonator (DR) antenna is proposed, which consists of a rectangular DR coated with metal on three sides and placed on a ground plane. The structure is analyzed by modelling the dielectric-air interface as perfect magnetic conductor (PMC). A coplanar waveguide (CPW) with terminating slots is used to feed the antenna. Measurement results exhibit a wide bandwidth of

Tze-Hsuan Chang; Jean-Fu Kiang

2007-01-01

97

Designs for thin-film-coated semiconductor thermal neutron detectors  

Microsoft Academic Search

Thin film coated semiconductor detectors have been studied and used as neutron detectors for decades. Unfortunately, with front-irradiated devices, the basic design limits the thermal neutron detection efficiency to only 3.95% for 10B-coated devices and only 4.3% for 6LiF-coated devices. Presented in the following work are several straightforward methods to increase the thermal neutron detection efficiency for thin-film-coated semiconductor thermal

Douglas S. McGregor; Raymond T. Klann; Holly K. Gersch; Jeffrey D. Sanders

2001-01-01

98

Peroxotungstic Acid Coated Films for Electrochromic Display Devices  

Microsoft Academic Search

Peroxotungstic acid coated films were investigated for applications to electrochromic display devices. Films coated with peroxotungstic acid aqueous solutions exhibited electrochromism in non-aqueous electrolyte solutions containing Li-salts. A good reversibility for the electrochromic reaction was attained after several writing-erasing cycles involving linear sweeps when the films had been heat-treated at about 120°C for 1 h. Cathodic polarization of the coated

Kazusuke Yamanaka; Hiroshi Oakamoto; Hirokazu Kidou; Tetsuichi Kudo

1986-01-01

99

Channel cracks in atomic-layer and molecular-layer deposited multilayer thin film coatings  

NASA Astrophysics Data System (ADS)

Metal oxide thin film coatings produced by atomic layer deposition have been shown to be an effective permeation barrier. The primary failure mode of such coatings under tensile loads is the propagation of channel cracks that penetrate vertically into the coating films. Recently, multi-layer structures that combine the metal oxide material with relatively soft polymeric layers produced by molecular layer deposition have been proposed to create composite thin films with desired properties, including potentially enhanced resistance to fracture. In this paper, we study the effects of layer geometry and material properties on the critical strain for channel crack propagation in the multi-layer composite films. Using finite element simulations and a thin-film fracture mechanics formalism, we show that if the fracture energy of the polymeric layer is lower than that of the metal oxide layer, the channel crack tends to penetrate through the entire composite film, and dividing the metal oxide and polymeric materials into thinner layers leads to a smaller critical strain. However, if the fracture energy of the polymeric material is high so that cracks only run through the metal oxide layers, more layers can result in a larger critical strain. For intermediate fracture energy of the polymer material, we developed a design map that identifies the optimal structure for given fracture energies and thicknesses of the metal oxide and polymeric layers. These results can facilitate the design of mechanically robust permeation barriers, an important component for the development of flexible electronics.

Long, Rong; Dunn, Martin L.

2014-06-01

100

Hydroxyapatite-coated metals: Interfacial reactions during sintering  

Microsoft Academic Search

Electrophoretic deposition (EPD) is a low cost flexible process for producing HA coatings on metal implants. Its main limitation is that it requires heating the coated implant in order to densify the HA. HA typically sinters at a temperature below 1150°C, but metal implants are degraded above 1000°C. Further, the metal induces the decomposition of the HA coating upon sintering.

M. We; A. J. Ruys; M. V. Swain; B. K. Milthorpe; C. C. Sorrell

2005-01-01

101

Sol-gel metal oxide and metal oxide/polymer multilayers applied by meniscus coating  

SciTech Connect

We are developing a meniscus coating process for manufacturing large-aperture dielectric multilayer high reflectors (HR`s) at ambient conditions from liquid suspensions. Using a lab-scale coater capable of coating 150 mm square substrates, we have produced several HR`s which give 99% + reflection with 24 layers and with edge effects confined to about 10 mm. In calendar 1993 we are taking delivery of an automated meniscus coating machine capable of coating substrates up to 400 mm wide and 600 mm long. The laser-damage threshold and failure stress of sol-gel thin films can be substantially increased through the use of soluble polymers which act as binders for the metal oxide particles comprising the deposited film. Refractive index control of the film is also possible through varying the polymer/oxide ratio. Much of our present effort present is in optimizing oxide particle/binder/solvent formulations for the high-index material. Films from colloidal zirconia strengthened with polyvinylpyrollidone (PVP) have given best results to date. An increase in the laser damage threshold (LDT) for single layers has been shown to significantly increase with increased polymer loading, but as yet the LDT for multilayer stacks remains low.

Britten, J.A.; Thomas, I.M.

1993-10-01

102

Protective coatings of metal surfaces by cold plasma treatment  

NASA Technical Reports Server (NTRS)

The cold plasma techniques for deposition of various types of protective coatings are reviewed. The main advantage of these techniques for deposition of ceramic films is the lower process temperature, which enables heat treating of the metal prior to deposition. In the field of surface hardening of steel, significant reduction of treatment time and energy consumption were obtained. A simple model for the plasma - surface reactions in a cold plasma system is presented, and the plasma deposition techniques are discussed in view of this model.

Manory, R.; Grill, A.

1985-01-01

103

Thin film coatings in solar-thermal power systems  

Microsoft Academic Search

The applications and requirements for thin film coatings in solar-thermal power systems are reviewed. The substantial impact of selective absorber coatings and antireflection coatings on both flat plate and concentrating type solar collectors is covered. The results of durability life tests on a high-temperature stable, vacuum-evaporated absorber coating consisting of layers of Al2O3-Mo-Al2O3 are reported. This coating was unaffected by

R. E. Peterson; J. W. Ramsey

1975-01-01

104

21 CFR 175.360 - Vinylidene chloride copolymer coatings for nylon film.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Vinylidene chloride copolymer coatings for nylon film. ...of Coatings § 175.360 Vinylidene chloride copolymer coatings for nylon film. Vinylidene chloride copolymer coatings identified in...

2013-04-01

105

Under-film corrosion of epoxy-coated galvanised steel  

Microsoft Academic Search

In most metallic systems that are protected by organic coatings, the absolute performance depends not so much on the quality of the coating but more on the response of the coating to defects that are either initially present, or that arise in the course of service. Here we study inhibition at a controlled through-thickness defect in organic-coated galvanised steel thus

I. M. Zin; S. B. Lyon; A. Hussain

2005-01-01

106

Thin films of metal-organic frameworks.  

PubMed

The fabrication of thin film coatings of metal-organic frameworks (MOFs) on various substrates is discussed in this critical review. Interestingly, the relatively few studies on MOF films that have appeared in the literature are limited to the following cases: [Zn4O(bdc)3] (MOF-5; bdc=1,4-benzenedicarboxylate), [Cu3(btc)2] (HKUST-1; btc=1,3,5-benzenetricarboxylate), [Zn2(bdc)2(dabco)] (dabco=1,4-diazabicyclo[2.2.2]octane), [Mn(HCOO)], [Cu2(pzdc)2(pyz)] (CPL-1; pzdc=pyrazine-2,3-dicarboxylate, pyz=pyrazine), [Fe(OH)(bdc)] (MIL-53(Fe)) and [Fe3O(bdc)3(Ac)] (MIL-88B; Ac=CH3COO-). Various substrates and support materials have been used, including silica, porous alumina, graphite and organic surfaces, i.e. self-assembled monolayers (SAMs) on gold, as well as silica surfaces. Most of the MOF films were grown by immersion of the selected substrates into specifically pre-treated solvothermal mother liquors of the particular MOF material. This results in more or less densely packed films of intergrown primary crystallites of sizes ranging up to several microm, leading to corresponding film thicknesses. Alternatively, almost atomically flat and very homogenous films, with thicknesses of up to ca. 100 nm, were grown in a novel stepwise layer-by-layer method. The individual growth steps are separated by removing unreacted components via rinsing the substrate with the solvent. The layer-by-layer method offers the possibility to study the kinetics of film formation in more detail using surface plasmon resonance. In some cases, particularly on SAM-modified substrates, a highly oriented growth was observed, and in the case of the MIL-53/MIL-88B system, a phase selective deposition of MIL-88B, rather than MIL-53(Fe), was reported. The growth of MOF thin films is important for smart membranes, catalytic coatings, chemical sensors and related nanodevices (63 references). PMID:19384445

Zacher, Denise; Shekhah, Osama; Wöll, Christof; Fischer, Roland A

2009-05-01

107

Characteristics and cytocompatibility of biodegradable polymer film on magnesium by spin coating.  

PubMed

In recent years, magnesium and its alloys have been investigated as biodegradable metallic materials in cardiovascular stents and bone implants. However, rapid corrosion rate in the early stage of the degradation process greatly influences the cytocompatibility and hinters their application. In this research, biodegradable polymer films are prepared under same coating condition by spin coating in order to improve the early corrosion resistance and cytocompatibility of Mg. The results present that uniform, nonporous, amorphous PLLA and semi-crystalline PCL films are coated on Mg. PLLA film shows better adhesion strength to Mg substrate than that of PCL film. For both PLLA and PCL, low molecular weight (LMW) film is thinner and exhibits better adhesion strength than high molecular weight (HMW) one. SaOS-2 cells show significantly good attachment and high growth on the polymer-coated Mg, demonstrating that all the polymer films can significantly improve the cytocompatibility in the 7-day incubation. The pH measurement of the immersion medium and the quantification of released Mg(2+) during the cell culture clearly indicate that the corrosion resistance of Mg substrate is improved by the polymer films to different extents. It can be concluded that both PLLA and PCL films are promising protective coatings for improving the initial corrosion resistance and cytocompatibility. PMID:22225942

Xu, Liping; Yamamoto, Akiko

2012-05-01

108

Bioactive glass coatings for orthopedic metallic implants  

SciTech Connect

The objective of this work is to develop bioactive glass coatings for metallic orthopedic implants. A new family of glasses in the SiO2-Na2O-K2O-CaO-MgO-P2O5 system has been synthesized and characterized. The glass properties (thermal expansion, softening and transformation temperatures, density and hardness) are in line with the predictions of established empirical models. The optimized firing conditions to fabricate coatings on Ti-based and Co-Cr alloys have been determined and related to the glass properties and the interfacial reactions. Excellent adhesion to alloys has been achieved through the formation of 100-200 nm thick interfacial layers (Ti5Si3 on Ti-based alloys and CrOx on Co-Cr). Finally, glass coatings, approximately 100 mu m thick, have been fabricated onto commercial Ti alloy-based dental implants.

Lopez-Esteban, Sonia; Saiz, Eduardo; Fujino, Sigheru; Oku, Takeo; Suganuma, Katsuaki; Tomsia, Antoni P.

2003-06-30

109

Indium doped zinc oxide nanowire thin films for antireflection and solar absorber coating applications  

NASA Astrophysics Data System (ADS)

Indium doped ZnO nanowire thin films were prepared by thermal oxidation of Zn-In metal bilayer films at 500°C. The ZnO:In nanowires are 20-100 nm in diameter and several tens of microns long. X-ray diffraction patterns confirm the formation of oxide and indicate that the films are polycrystalline, both in the as deposited and annealed states. The transmission which is <2% for the as deposited Zn-In films increases to >90% for the ZnO:In nanowire films. Significantly, the reflectance for the as deposited films is < 10% in the region between 200 to 1500 nm and < 2% for the nanowire films. Thus, the as deposited films can be used solar absorber coatings while the nanowire films are useful for antireflection applications. The growth of nanowires by this technique is attractive since it does not involve very high temperatures and the use of catalysts.

Shaik, Ummar Pasha; Krishna, M. Ghanashyam

2014-04-01

110

Size quantization in metal films  

NASA Astrophysics Data System (ADS)

The quantum size effect, predicted by I. M. Lifshits and A. M. Kosevich [Izv. Akad. Nauk SSSR Ser. Fiz. 19, 395 (1955)] has been investigated in many studies. The underlying basis of the analysis of quantum size oscillations of thermodynamics and kinetic characteristics of metal films is the quasiclassical quantization of the momentum component for isotropy model and quantization {S. S. Nedorezov, Zh. Éksp. Teor. Fiz. 51, 868 (1966) [Sov. Phys. JETP 24, 578 (1967)]} of a chord of the constant-energy surface in the case of anisotropy of the energy spectrum. In the given work the research of quantum size levels of energy of electrons in metal films is carried out by the method of J. M. Luttinger and W. Kohn. The exact conditions of size quantization are obtained.

Nedorezov, S. S.

2007-09-01

111

Thin Film Heater for Removable Volatile Protecting Coatings  

PubMed Central

Freshly coated aluminum mirrors have excellent reflectivity at far ultraviolet wavelengths. However, reflectivity rapidly degrades when the mirror surfaces are exposed to atmosphere. In order to avoid this problem, freshly coated aluminum surface can be protected by over-coating of a removable volatile protecting coating. This protecting coating can be re-evaporated by controlled heating or by some other methods when required. This type of removable coating has immediate application in UV space astronomy. The purpose of this paper is to demonstrate the feasibility of re-evaporation of removable volatile Zn protecting coating using a NiCr thin film heater without affecting the reflection properties of Al mirror surfaces.

Karim, Abid

2013-01-01

112

Liquid Galvanic Coatings for Protection of Imbedded Metals  

NASA Technical Reports Server (NTRS)

Coating compositions and methods of their use are described herein for the reduction of corrosion in imbedded metal structures. The coatings are applied as liquids to an external surface of a substrate in which the metal structures are imbedded. The coatings are subsequently allowed to dry. The liquid applied coatings provide galvanic protection to the imbedded metal structures. Continued protection can be maintained with periodic reapplication of the coating compositions, as necessary, to maintain electrical continuity. Because the coatings may be applied using methods similar to standard paints, and because the coatings are applied to external surfaces of the substrates in which the metal structures are imbedded, the corresponding corrosion protection may be easily maintained. The coating compositions are particularly useful in the protection of metal-reinforced concrete.

MacDowell, Louis G. (Inventor); Curran, Joseph J. (Inventor)

2003-01-01

113

Surface studies of novel oxide-free biocompatible coatings on metals  

NASA Astrophysics Data System (ADS)

The valence band and core-level X-ray Photoelectron Spectroscopy (XPS) was used to probe biocompatible films formed on the surface of metals. The key to the successful adhesion of these biocompatible films is shown to be the initial formation of a thin, oxide free, etidronate film on the metal. It was not found possible to prepare the biocompatible films directly on the metal surfaces. These films formed on metals may find application in medical implants. The biocompatible films were exposed to air, water and sodium chloride for corrosion studies. The thin hydroxyapatite and etidronate film on the metal show differential charging effects that caused a doubling of the peaks in some core level spectra. This shows the coating has some electric properties such as dielectric or piezoelectric characters. This coating may have application in the insulating materials of electronic circuits or dielectric/ piezoelectric layer in bio-sensors. Experiment and calculation method of X-ray Photoelectron Spectroscopy is one powerful technology in surface and interface analysis. The valence band spectra proved especially valuable in the identification of the surface chemistry of the films, and these spectra were interpreted by comparing the experimental spectra with spectra calculated using band structure calculations which showed good agreement with experiment. The calculated spectrum could also be used to compare with the difference of experiment spectra for the investigation of the interface layers.

GAO, FENG

114

Optical modeling of nanostructured films for selective coatings  

NASA Astrophysics Data System (ADS)

To improve the efficiency of solar thermal collectors, selective coatings need to be maximally transparent to sunlight (up to 2500 nm wavelength) and maximally reflective to heat radiation. One way to improve the transparency for sunlight without compromising the reflective properties at longer wavelengths is structuring thin metal films with holes. The purpose of this paper is to develop computer model capabilities to predict the optical properties of such structures by solving the Maxwell and materials equations using the finite element method in three dimensions. Coupling both sets of equations enables us to incorporate the full dispersion of metals, including their negative real part of permittivity. The finite element model is validated in two ways: firstly, by simulations of structured films using the FDTD method in the range of positive permittivity; and secondly, by the transmission and the ellipsometric measurement of homogeneous films. The simulations predict that holes with a diameter between 300 and 500 nm - and aligned in arrays with a mutual distance between 500 and 800 nm - significantly improve the performance of selective layers used for solar thermal collectors.

Altermatt, Pietro P.; Yang, Yang; Wang, Jun; Reineke-Koch, Rolf; Giovannetti, Federico

2008-08-01

115

Peroxotungstic Acid Coated Films for Electrochromic Display Devices  

NASA Astrophysics Data System (ADS)

Peroxotungstic acid coated films were investigated for applications to electrochromic display devices. Films coated with peroxotungstic acid aqueous solutions exhibited electrochromism in non-aqueous electrolyte solutions containing Li-salts. A good reversibility for the electrochromic reaction was attained after several writing-erasing cycles involving linear sweeps when the films had been heat-treated at about 120°C for 1 h. Cathodic polarization of the coated films irreversibly reduced the peroxotungstic acid to tungsten trioxide in the electrolyte. This resulted in the devices having poor initial response characteristics. After several aging cycles, however, the coloring efficiency and response rate of the coated films were favorable and comparable to those of tungsten trioxide evaporated films.

Yamanaka, Kazusuke; Oakamoto, Hiroshi; Kidou, Hirokazu; Kudo, Tetsuichi

1986-09-01

116

Optoacoustic method for determination of submicron metal coating properties: Theoretical consideration  

SciTech Connect

The goal of this work is theoretical consideration of the optoacoustic (OA) conversion in the system consisting of a metal film deposited on a transparent dielectric substrate and covered by a transparent liquid. This consideration implies a method for nondestructive evaluation of submicron metal coatings. The main principle of the method is the following. Irradiation of the metal film by a nanosecond laser pulse leads to transient heating and expansion of the film that in turn results in the generation of an acoustic signal. The waveform of the signal results from two contributions: the 'primary' signal from the thermal expansion of the metal film, which repeats the temporal profile of the laser pulse envelope, and the 'secondary' signal, which originates from the thermal expansion of the adjacent liquid layer. Due to low thermal conductivity of liquid compared to metal, the liquid accumulates heat that is released in metal and produces that secondary contribution into the OA conversion. This contribution is very sensitive to the properties of the film. The influence of the film thickness and its thermophysical parameters on the frequency-dependent efficiency of OA conversion and on the temporal profile of excited OA signals is discussed in detail. Based on these results, the method for nondestructive evaluation of submicron metal coatings properties is proposed.

Pelivanov, Ivan M.; Kopylova, Daria S.; Podymova, Natalia B.; Karabutov, Alexander A. [International Laser Center, M. V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation)

2009-07-01

117

Wear Resistance of Coating Films on Hob Teeth  

NASA Astrophysics Data System (ADS)

The wear resistance of coating films on hob teeth is investigated through the simulated hobbing tests with a flytool. The coating films on hob teeth are titanium family ceramics such as TiN, TiCN, TiSiN and TiAlN and aluminum chromium family ceramics such as AlCrN and AlCrSiN. The wear of coated tools is shown about film thickness, film materials, ingredient ratio in a film component and the oxidization of coating films. The oxidization is clarified from a result of the influence on the crater wear progress through wear cutting tests in atmosphere of nitrogen gas or oxygen gas. The oxidization of TiAlN coating films produces oxide products on the tool rake face, and this oxidation relates to the amount of crater wear. The increase of aluminum concentration in the TiAlN film improves the crater wear resistance in air atmosphere, while it has a reverse effect in nitrogen gases. The AlCrSiN film has effective wear resistance against the abrasive wear and/or oxidization wear. The oxidation film formed on the AlCrSiN film is very firm and this suppresses the oxidation wear on the rake face and works against the abrasive wear advantageously.

Umezaki, Yoji; Funaki, Yoshiyuki; Kurokawa, Syuhei; Ohnishi, Osamu; Doi, Toshiro

118

Nanostructured gold films as broadband terahertz antireflection coatings  

Microsoft Academic Search

The potential of nanometer-thick, randomly nanostructured gold films as broadband wave impedance-matching coatings for nondispersive substrates in the terahertz frequency range is demonstrated. Based on a wave impedance approach and the specific non-Drude conductivity of our films, we model the reflectivity at the coated interface between silicon and air and show that nanostructured films offer a considerably better broadband performance

Andreas Thoman; Andreas Kern; Hanspeter Helm; Markus Walther

2008-01-01

119

Thin film hydrous metal oxide catalysts  

DOEpatents

Thin film (<100 nm) hydrous metal oxide catalysts are prepared by 1) synthesis of a hydrous metal oxide, 2) deposition of the hydrous metal oxide upon an inert support surface, 3) ion exchange with catalytically active metals, and 4) activating the hydrous metal oxide catalysts.

Dosch, Robert G. (Albuquerque, NM); Stephens, Howard P. (Albuquerque, NM)

1995-01-01

120

Development of an all-metal thick film cost affective metallization system for solar cells  

NASA Technical Reports Server (NTRS)

An economical thick film solar cell contact for high volume production of low cost silicon solar array modules was investigated. All metal screenable pastes using base metals were studied. Solar cells with junction depths varying by a factor of 3.3, with and without a deposited oxide coating were used. Cells were screened and fired by a two step firing process. Adhesion and metallurgical results are unsatisfactory. No electrical information is obtained due to inadequate contact adhesion.

Ross, B.

1981-01-01

121

One-step graphene coating of heteroepitaxial GaN films.  

PubMed

Today, state-of-the-art III-Ns technology has been focused on the growth of c-plane nitrides by metal-organic chemical vapor deposition (MOCVD) using a conventional two-step growth process. Here we show that the use of graphene as a coating layer allows the one-step growth of heteroepitaxial GaN films on sapphire in a MOCVD reactor, simplifying the GaN growth process. It is found that the graphene coating improves the wetting between GaN and sapphire, and, with as little as ~0.6 nm of graphene coating, the overgrown GaN layer on sapphire becomes continuous and flat. With increasing thickness of the graphene coating, the structural and optical properties of one-step grown GaN films gradually transition towards those of GaN films grown by a conventional two-step growth method. The InGaN/GaN multiple quantum well structure grown on a GaN/graphene/sapphire heterosystem shows a high internal quantum efficiency, allowing the use of one-step grown GaN films as 'pseudo-substrates' in optoelectronic devices. The introduction of graphene as a coating layer provides an atomic playground for metal adatoms and simplifies the III-Ns growth process, making it potentially very useful as a means to grow other heteroepitaxial films on arbitrary substrates with lattice and thermal mismatch. PMID:23059535

Choi, Jae-Kyung; Huh, Jae-Hoon; Kim, Sung-Dae; Moon, Daeyoung; Yoon, Duhee; Joo, Kisu; Kwak, Jinsung; Chu, Jae Hwan; Kim, Sung Youb; Park, Kibog; Kim, Young-Woon; Yoon, Euijoon; Cheong, Hyeonsik; Kwon, Soon-Yong

2012-11-01

122

Polymer-assisted conformal coating of TiO2 thin films  

NASA Astrophysics Data System (ADS)

Conformal coating of nanofabricated structures with a high-index dielectric material is a common problem for a diverse set of integrated photonic and plasmonic devices such as planar waveguides, on-chip spectrometers, gratings, flat panel displays, optical sensors, and integrated optical devices. In this paper we were recently able to demonstrate an alternate method for conformally coating photonic nanostructures using a low cost, polymer-assisted deposition (PAD) process for the metal-oxide TiO2. In a PAD process a thermally curable, hybrid high refractive index polymer solution is spin-coated onto a substrate. The polymer controls the viscosity and binds the metal ions, resulting in a homogeneous distribution of the precursor in solution. When cured at elevated temperature, the hybrid polymer coating decomposes to form a metal oxide-rich film that has a high refractive index that conformally fills the voids in nanofabricated structures. The resulting films have refractive indices higher than 1.83 in the visible region and film thicknesses between 250-500 nm depending on the level of metal-oxide loading, cure temperature, and number of coatings.

Gillman, E. S.; Costello, D.; Moreno, M.; Raspopin, A.; Kasica, R.; Chen, L.

2010-08-01

123

Development of alloy-film coated dispenser cathode for terahertz vacuum electron devices application  

NASA Astrophysics Data System (ADS)

High power terahertz vacuum electron devices demand high current density and uniform emission dispenser cathode. It was found that the coating of noble metals e.g., Os, Ir, and Re on the surface of tungsten dispenser cathodes enhances the emission capabilities and uniformity. Hence metal coated cathode might be the best candidate for terahertz devices applications. In this study, ternary-alloy-film cathode (2Os:2Re:1 W) and Os coated cathode have been developed and the results are presented. The cathodes made out of this alloy coating showed 1.5 times higher emission and 0.02 eV emission uniformity as compared to those of simply Os coated cathodes which can be used in terahertz devices application.

Barik, R. K.; Bera, A.; Raju, R. S.; Tanwar, A. K.; Baek, I. K.; Min, S. H.; Kwon, O. J.; Sattorov, M. A.; Lee, K. W.; Park, G.-S.

2013-07-01

124

Evaluation of a non-catalytic coating for metallic TPS  

NASA Technical Reports Server (NTRS)

A commercially available ceramic coating was evaluated for application to metallic heat shields for Shuttle-type entry vehicles. Coated Inconel 617 specimens were subjected to thermal shock cycles, surface emittances were measured, and surface equilibrium temperatures were measured for coated and oxidized specimens exposed to an arc-tunnel environment. The coating adhered very well to the metal and appeared to be very non-catalytic.

Pittman, C. M.; Brown, R. D.; Shideler, J. L.

1984-01-01

125

Preparation of gold microcrystal-doped oxide optical coatings through adsorption of tetrachloroaurate ions on gel films  

Microsoft Academic Search

Transparent oxide films containing gold microcrystals for non-linear optics are prepared by a new sol—gel process, in which dip-coated gel films prepared from metal alkoxide solutions are immersed in NaAuCl4 · 2H2O aqueous solution and subsequently heat-treated. AuCl4? ions can be incorporated in alumina and titania gel films and thus gold crystals in the films can be formed. On the

Jun Matsuoka; Ryoko Naruse; Hiroyuki Nasu; Kanichi Kamiya

1997-01-01

126

Characterization of half-metallic CrO2-coated cantilevers  

Microsoft Academic Search

We report the characteristics of half-metallic CrO2-coated cantilevers for multi-applications of atomic force microscopes (AFMs), conducting AFMs (CAFMs), and magnetic force microscopes (MFMs). The half-metallic ferromagnetism of the half-metallic CrO2-coated cantilever was tested by simultaneous measurements of noncontact AFM images and MFM images of the (111) CrO2 thin film on the (200) Pt\\/Ti\\/SiO2\\/Si substrate. To test the conducting properties of

J Y Son; J H Cho

2007-01-01

127

Sputtered metallic coatings for optical fibers used in high-temperature environments  

NASA Astrophysics Data System (ADS)

Rf and dc planar magnetron sputtering systems were used to deposit high-temperature nickel- based super alloys, INCONEL 617, 625, Haynes 214, and thin films of palladium, as coatings on optical fibers for use in temperatures approaching 1000 degree(s)C. The nickel-based alloy coatings were applied on-line as the optical fiber was drawn, minimizing the exposure of the fiber to the deleterious effects of humidity. The thin film coatings of pure metals were sputtered using a new rf magnetron sputtering system custom designed and built for the Fiber and Electro Optics Research Center. The resulting coatings were analyzed using scanning electron microscopy, Auger electron microscopy, and energy dispersive x-ray spectroscopy. The coated fibers exhibit promise for embedded sensors in high temperature, high load composites used for advanced aerospace and energy applications.

Gunther, Michael F.; Zeakes, Jason S.; Lieber, Donald E.; May, Russell G.; Claus, Richard O.

1994-05-01

128

Metal-coated carbon nanotube tips for scanning probe microscopy  

NASA Astrophysics Data System (ADS)

Metal coating has been introduced in order to improve the resolution and capabilities of carbon nanotube scanning probe microscopy tips. We demonstrate magnetic force microscopy of magnetic recording tracks using Co coated nanotube tips. The resolution achieved is better than 20 nanometers. We also use Au coated nanotube tips to perform electrostatic force microscopy of a cut single nanotube with a narrow gap. The metal coating on nanotubes is found to enable the use of micrometers long nanotubes as scanning probes for topographic imaging of high aspect ratio structures. The metal-coated nanotube tips are shown to significantly decrease the convolution effects from the pyramidal silicon tip in these force microscopy techniques.

Yenilmez, Erhan

2005-03-01

129

Novel hydroxyapatite\\/tantalum surface coating for metallic dental implant  

Microsoft Academic Search

The aim of this study was to design and produce a novel surface composite coating on metallic substrate in order to improve the biocompatibility of metallic dental implant and the bone osteointegration simultaneously.Stainless steel 316L (SS) was used as a metallic substrate and a novel double-layer hydroxyapatite\\/tantalum (HA\\/Ta) coating was prepared on it. Tantalum coating was made using physical vapor

M. H. Fathi; F. Azam

2007-01-01

130

Electrophoretic Deposition of Hydroxyapatite Coatings on Metal Substrates: A Nanoparticulate Dual-Coating Approach  

Microsoft Academic Search

Hydroxyapatite coatings can be readily deposited on metal substrates by electrophoretic deposition. However, subsequent sintering is highly problematic owing to the fact that temperatures in excess of 1100°C are required for commercial hydroxyapatite powders to achieve high density. Such temperatures damage the metal and induce metal-catalysed decomposition of the hydroxyapatite. Furthermore, the firing shrinkage of the hydroxyapatite coating on a

M. Wei; A. J. Ruys; B. K. Milthorpe; C. C. Sorrell; J. H. Evans

2001-01-01

131

Abrasion resistance of biaxially oriented polypropylene films coated with nanocomposite hard coatings  

NASA Astrophysics Data System (ADS)

KMnO4-treated, functionalized, biaxially oriented polypropylene (BOPP) films coated with nano-silica hybrid material were synthesized. The abrasion resistance of the films was examined using a reciprocating fabric abrasion tester. Functional groups were confirmed by Fourier-transform infrared spectroscopy. Contact angle measurements were performed on the BOPP film surface to quantify the effectiveness of the functionalization. Results indicate that the abrasion resistance and roughness of the composite film were significantly affected by the modification of the BOPP film. Water surface contact angle of the modified BOPP films decreased from 90.1° to 71.4°,when KMnO4 concentration increased from 0 M to 0.25 M. Wettability of the BOPP films clearly improved after KMnO4 treatment. Abrasion resistance of the functionalized films coated with hybrid materials improved by 27.4% compared with that of the original film.

Wang, Jing; Zhu, Yaofeng; Fu, Yaqin

2013-11-01

132

Optical properties of granular Sn films with coating Al  

NASA Astrophysics Data System (ADS)

Optical properties of the granular Sn films with coating Al films are studied. The experimental results indicate that the Al coating strongly affects the optical properties of the granular Sn- films, the spectral selectivity of the solar energy in the visible region and the reflectance in the near IR region are enhanced. The filling factor Z of granular Sn films obviously influences the optical properties of the film system. Based on the installed structural model and Maxwell- Garnett theory, the reflective spectra are calculated and the theoretical results fit the experimental ones very well. It's show that the granular Sn films coated with Al have some kind of reflective color, it may be used as decorative mirrors for many purposes.

Wu, Guangming; Qian, Zheng X.

1991-11-01

133

Production of MgB 2 superconducting coatings by electrophoresis on metal substrates  

Microsoft Academic Search

Production of MgB2 coatings on various metallic substrates was achieved by means of the direct electrophoretic deposition technique. An inexpensive simple heat treatment in evacuated quartz tubes was developed as an alternative to inert gas flow during the process. The films were characterized by XRD, SEM and SQUID. It resulted that the procedure led to the production of uniform, dense

R. Argyropoulou; M. Ochsenkühn-Petropoulou

2009-01-01

134

Electrochromic properties of spin-coated thin films from peroxo-polymolybdovanadate solutions  

Microsoft Academic Search

A now mixed metal peroxo-polyacid based on Mo and V is formed by the direct reaction of a mixture of metallic Mo and V with hydrogen peroxide solution. A homogeneous amorphous thin film about 0.4 μm is fabricated on an indium tin oxide (ITO) glass substrate by a spin-coating technique using this peroxo-polymolybdovanadate solution. After heat-treatment from 80 to 120

Yong-ming Li; Tetsuichi Kudo

1995-01-01

135

Improvement of corrosion resistance of transparent conductive multilayer coating consisting of silver layers and transparent metal oxide layers  

SciTech Connect

An optical filter for plasma display panel (PDP) requires an electromagnetic shield with very high ability. The authors investigated a transparent conductive multilayer coating consisting of silver (Ag) layers and transparent metal oxide layers. The durability of the multilayer sputter coating, including the silver layer, is very sensitive to the surrounding atmosphere. For example, after an exposure test they found discolored points on the multilayer sputter coatings, possibly caused by migration of silver atoms in the silver layers. In their investigation, they modified the top surface of the multilayer sputter coatings with transition metals to improve the corrosion resistance of the multilayer coating. Specifically, they deposited transition metals 0.5-2 nm thick on the top surface of the multilayer coatings by sputtering. They chose indium tin oxide (ITO) as the transparent metal oxide. They applied the multilayer sputter coatings of seven layers to a polyethylene terephthalate (PET) film substrate. A cross-sectional structure of the film with the multilayer coatings is PET film/ITO/Ag/ITO/Ag/ITO/Ag/ITO. They evaluated the corrosion resistance of the films by a salt-water immersion test. In the test, they immersed the film with multilayer coatings into salt water, and then evaluated the appearance, transmittance, and electrical resistance of the multilayer coatings. They investigated several transition metals as the modifying material, and found that titanium and tantalum drastically improved the resistance of the multilayer coatings to the salt-water exposure without a significant decline in transmittance. They also investigated the relation between elapsed time after deposition of the modifying materials and resistance to the salt water. Furthermore, they investigated the effects of a heat treatment and an oxide plasma treatment on resistance to the salt water.

Koike, Katsuhiko; Yamazaki, Fumiharu; Okamura, Tomoyuki; Fukuda, Shin [Mitsui Chemicals, Inc., Sodegaura, Chiba 299-0265 (Japan)

2007-05-15

136

Lithographic deposition of patterned metal-organic framework coatings using a photobase generator.  

PubMed

A photobase generator was used to induce metal-organic framework (MOF) nucleation upon UV irradiation. This method was further developed into a simple, one-step method for depositing patterned MOF films. Furthermore, the ability of our method to coat a single substrate with MOF films having different chemical compositions is illustrated. The method is an important step towards integrating MOF deposition with existing lithographic techniques and the incorporation of these materials into sensors and other electronic devices. PMID:24719391

Keitz, Benjamin K; Yu, Chung Jui; Long, Jeffrey R; Ameloot, Rob

2014-05-26

137

Electrochemical behaviour of spin-coated films of vanadium pentoxide xerogel in aqueous electrolyte. Electron transfer between vanadium centres in the gel layers and intercalated tris (2,2?-bipyridyl) metal cations  

Microsoft Academic Search

The cyclic voltammogram of spin-coated films of vanadium pentoxide xerogel (V2O5 · nH2O) in aqueous electrolyte was found to depend on the potential range. When a freshly prepared film was cycled between 1.5 and 0.1 V vs. SCE a large broad oxidation peak at 0.55 V was observed. When the potential was swept down to ?0.6 V irreversible reduction of

Kevin Whalen; Gilles Villemure

1996-01-01

138

Experimental and Analytical Studies on the High Cycle Fatigue of Thin Film Metal on PET Substrate for Flexible Electronics Applications  

Microsoft Academic Search

This paper addresses the behavior of thin-film metal coated flexible substrates under high cyclic bending fatigue loading. Polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) are widely used substrates in the fabrication of microelectronic devices. Factors affecting the fatigue life of thin-film coated on a flexible PET substrates were studied, in- cluding thin-film thickness, film material, bending radius, temper- ature, and

Khalid Alzoubi; Susan Lu; Bahgat Sammakia; Mark Poliks

2011-01-01

139

New dielectric thin film coatings for silver and copper coated hollow infrared waveguides  

Microsoft Academic Search

Hollow waveguides have been developed for many years but their losses are still much greater than those for solid-core fiber optics. The primary emphasis in this work is the development of new metallic and dielectric coatings which may be used as coatings for lower loss hollow waveguides. Much of the work involves the use of polymer tubing coated with Ag

Roshan J. George

2004-01-01

140

Water soluble cellulose acetate: a versatile polymer for film coating.  

PubMed

The objective of this study was to investigate the use of water soluble cellulose acetate (WSCA) as a film coating material for tablets. Aspirin (ASA) tablets were prepared by direct compression and coated with either WSCA or HPMC (hydroxypropyl methylcellulose) dispersions. Coatings of 1-3%, depending on the intended application, were applied to the model drug (ASA) tablets employing a side-vented coating pan. Free films of WSCA, prepared by cast method, are crystal clear and, depending on the viscosity grade, are flexible, strong and durable. WSCA has the capability of forming free films without plasticizers and the films dry at room temperature. Glass transition temperature, Tg, was determined by differential scanning calorimetry. The Tg of WSCA is significantly higher relative to HPMC. Inclusion of plasticizer lowers the Tg of WSCA and effective plasticizers were PEG 400 and glycerin. Low viscosity WSCA was more soluble in water (25-30%) relative to medium viscosity WSCA (10-15%). WSCA solutions exhibited no increase in viscosity with an increase in temperature. Samples of coated (WSCA and HPMC) tablets and uncoated ASA cores were packaged for stability studies at room and elevated temperature storage. Physical stability of ASA tablets coated with 2:1 LV: MV (low viscosity: medium viscosity) WSCA formulations was better when compared to tablets coated with HPMC. Dissolution stability of WSCA coated ASA was similar to the physical stability results. After three months at elevated temperature (35 and 45 degrees C), the WSCA coated tablets complied with USP dissolution requirements for ASA, while the HPMC coated tablets did not. There was no difference in moisture (weight) gain of ASA tablets coated with either WSCA or HPMC. The WSCA coated tablets were not sticky or tacky, while the HPMC coated tablets were tacky and stuck together. PMID:17454061

Wheatley, Thomas A

2007-03-01

141

Hydrogen transport behavior of metal coatings for plasma facing components.  

National Technical Information Service (NTIS)

Plasma-facing components for experimental and commercial fusion reactor studies may include cladding or coatings of refractory metals like tungsten on metallic structural substrates such as copper, vanadium alloys and austenitic stainless steel. Issues of...

R. A. Anderl D. F. Holland G. R. Longhurst

1990-01-01

142

Obliquely deposited metal films for polarizers  

Microsoft Academic Search

The performance of obliquely deposited metal films as polarizers, which can be used for normally incident light, was improved. The relation between microscopic columnar structures and dichroism of the films was investigated by depositing various kinds of metals with changing deposition angles. The influence of substrate materials was also examined. It was revealed that enlargement of the spacing between the

Yasuhiko Takeda; Norihito Takeuchi; Tatsuo Fukano; Tomoyoshi Motohiro

2005-01-01

143

21 CFR 175.360 - Vinylidene chloride copolymer coatings for nylon film.  

Code of Federal Regulations, 2010 CFR

...Vinylidene chloride copolymer coatings for nylon film. 175.360 Section 175.360...Vinylidene chloride copolymer coatings for nylon film. Vinylidene chloride copolymer...identified in this section and applied on nylon film may be safely used as...

2009-04-01

144

21 CFR 175.360 - Vinylidene chloride copolymer coatings for nylon film.  

Code of Federal Regulations, 2010 CFR

...Vinylidene chloride copolymer coatings for nylon film. 175.360 Section 175.360...Vinylidene chloride copolymer coatings for nylon film. Vinylidene chloride copolymer...identified in this section and applied on nylon film may be safely used as...

2010-01-01

145

Delamination cracking in functionally graded coating\\/metal substrate systems  

Microsoft Academic Search

A micromechanics analysis is carried out for delamination cracking in functionally graded coating\\/substrate systems. The FGM coating is taken to be a ceramic\\/metal composite with its thermomechanical properties changing with position in the coating along the thickness direction. Based on a linear fracture mechanics analysis, the energy release rate of the delamination crack is determined as a function of the

G. Bao; H. Cai

1997-01-01

146

Birefringence in spin-coated films containing cellulose nanocrystals  

Microsoft Academic Search

Layer-by-layer (LbL) self-assembled polyelectrolyte multilayer films containing cellulose nanocrystals and poly(allylamine hydrochloride) were prepared by spin-coating. From 6 to 25 bilayers were deposited on a silicon substrate. The films displayed birefringence as a result of the intrinsic shape and optical anisotropy of rod-like cellulose nanocrystals which were oriented by the spin-coating process. The birefringence varied with thickness and with location

Emily D. Cranston; Derek G. Gray

2008-01-01

147

Flexible Thin Metal Film Thermal Sensing System  

NASA Technical Reports Server (NTRS)

A flexible thin metal film thermal sensing system is provided. A thermally-conductive film made from a thermally-insulating material is doped with thermally-conductive material. At least one layer of electrically-conductive metal is deposited directly onto a surface of the thermally-conductive film. One or more devices are coupled to the layer(s) to measure an electrical characteristic associated therewith as an indication of temperature.

Thomsen, Donald Laurence (Inventor)

2012-01-01

148

Ceramic coating on ceramic with metallic bond coating  

Microsoft Academic Search

The change in structure and adhesion strength of the interface by heating in air has been investigated for a plasma- sprayed\\u000a alumina coating on a ceramic substrate with a 50Ni- 50Cr alloy bond coating. A veined structure composed of NiO, NiCr\\u000a 2O4, and NiAl2O4 oxides grew from the bond coating into cracks or pores in the top coating and the

K. Kishitake; H. Era; F. Otsubo; T. Sonoda

1997-01-01

149

Ion-beam-assisted deposition of biaxially aligned yttria-stabilized zirconia template films on metallic substrates for YBCO-coated conductors  

NASA Astrophysics Data System (ADS)

Biaxially textured yttria-stabilized zirconia (YSZ) films were grown on mechanically polished Hastelloy C276 (HC) substrates by ion-beam-assisted deposition and electron-beam evaporation. The surface root-mean-square (RMS) roughness of the polished HC substrates was ?3 nm, as measured by atomic force microscopy (AFM). A water-cooled sample stage was used to hold the substrate temperature below 100 °C during deposition. RMS roughness of ?3.3 nm was measured on the deposited YSZ films by AFM. X-ray pole figures were conducted for texture analysis; in-plane texture measured from YSZ (111) ?-scan FWHM was 13.2° and out-of-plane texture from the YSZ (002) ?-scan FWHM was 7.7°. An ?10 nm thick CeO2 buffer layer was deposited on the YSZ film at 800 °C before YBCO films were ablated by pulsed laser deposition at 780 °C in a 250 mTorr flowing oxygen environment. Good in-plane texture with FWHM ? 7° was observed in YBCO films. Tc = 90 K, with sharp transition, and transport Jc of ?2.2 × 106 A cm-2 were observed in a 0.5 ?m thick, 5 mm wide, and 1 cm long sample at 77 K in self-field.

Ma, B.; Li, M.; Fisher, B. L.; Balachandran, U.

2002-07-01

150

Investigation of metal coatings for the free electron laser  

SciTech Connect

We are investigating the deposition and characteristics of metal coatings for use in environments such as the Free Electron Laser where the radiation resistance of metal coatings could prove to be of great benefit. We have concentrated our initial efforts on silver laminate coatings due to the high reflectance of silver at 1 micron wavelength. Our initial laminate coatings have utilized thin layers of titanium oxide to break up the columnar structure of the silver during electron-beam deposition on fused silica substrates. Our initial results on equal coating thickness samples indicate an improvement in damage threshold that ranges from 1.07 to 1.71 at 351 nm.

Scott, M.L.; Arendt, P.N.; Springer, R.W.; Cordi, R.C.; McCreary, W.J.

1985-01-01

151

Polarization Properties Of Fully Metal Coated Scanning Near-Field Optical Microscopy Probes  

Microsoft Academic Search

Cantilever based, fully metal coated near-field optical probes have been studied theoretically and experimentally. It is shown that these probe structures allow light transmission, even if the tip is entirely covered with a 60nm thick metallic film. The calculated far-field intensity patterns correspond to those of the experimental measurements. Furthermore, when the injected light is radially polarized, the calculations predict

Laure Aeschimann; Luciana Vaccaro; Terunobu Akiyama; Urs Staufer; Nicolaas F. de Rooij; Rolf Eckert; Harry Heinzelmann

2003-01-01

152

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

NASA Technical Reports Server (NTRS)

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

Mirtich, M. J.

1980-01-01

153

Protective Coatings on Metals. Volume 8.  

National Technical Information Service (NTIS)

The volume includes papers on different topics such as the laws of formation of different types of coatings, new applications and compositions of coatings, and the study of properties and practical application of diffusion-coated machine parts in various ...

G. V. Samsonov

1986-01-01

154

Ceramic coating on ceramic with metallic bond coating  

NASA Astrophysics Data System (ADS)

The change in structure and adhesion strength of the interface by heating in air has been investigated for a plasma- sprayed alumina coating on a ceramic substrate with a 50Ni- 50Cr alloy bond coating. A veined structure composed of NiO, NiCr 2O4, and NiAl2O4 oxides grew from the bond coating into cracks or pores in the top coating and the alumina substrate after heating at 1273 K for 20 h in air. The NiAl2O4 spinel may have formed by the oxidization of nickel, which subsequently reacted with the alumina coating or the substrate. The mechanism of the penetration of the spinel oxides into the cracks or pores is not clear. The adhesion strength of the coating is increased to about 15 MPa after heating at 1273 K for 20 h in air, compared to an as- sprayed coating strength of only 1.5 MPa.

Kishitake, K.; Era, H.; Otsubo, F.; Sonoda, T.

1997-09-01

155

21 CFR 888.3565 - Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis.  

Code of Federal Regulations, 2010 CFR

...joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis. 888...joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis. (a...joint patellofemorotibial metal/polymer porous-coated uncemented...

2010-04-01

156

Process for forming a metal compound coating on a substrate  

DOEpatents

A method of coating a substrate with a thin layer of a metal compound by forming a dispersion of an electrophoretically active organic colloid and a precursor of the metal compound in an electrolytic cell in which the substrate is an electrode. Upon application of an electric potential, the electrode is coated with a mixture of the organic colloid and the precursor to the metal compound, and the coated substrate is then heated in the presence of an atmosphere or vacuum to decompose the organic colloid and form a coating of either a combination of metal compound and carbon, or optionally forming a porous metal compound coating by heating to a temperature high enough to chemically react the carbon.

Sharp, D.J.; Vernon, M.E.; Wright, S.A.

1988-06-29

157

Process for forming a metal compound coating on a substrate  

DOEpatents

A method of coating a substrate with a thin layer of a metal compound by forming a dispersion of an electrophoretically active organic colloid and a precursor of the metal compound in an electrolytic cell in which the substrate is an electrode. Upon application of an electric potential, the electrode is coated with a mixture of the organic colloid and the precursor to the metal compound, and the coated substrate is then heated in the presence of an atmosphere or vacuum to decompose the organic colloid and form a coating of either a combination of metal compound and carbon, or optionally forming a porous metal compound coating by heating to a temperature high enough to chemically react the carbon.

Sharp, Donald J. (Albuquerque, NM); Vernon, Milton E. (Albuquerque, NM); Wright, Steven A. (Albuquerque, NM)

1991-01-01

158

Laser patterning of transparent conductive metal nanowire coatings: simulation and experiment  

NASA Astrophysics Data System (ADS)

Transparent and electrically conductive metal nanowire networks are possible replacements for costly indium tin oxide (ITO) films in many optoelectronic devices. ITO films are regularly patterned using pulsed lasers so similar technologies could be used for nanowire coatings to define electrode structures. Here, the effects of laser irradiation on conducting silver nanowire coatings are simulated and then investigated experimentally for networks formed by spray deposition onto transparent substrates. The ablation threshold fluence is found experimentally for such nanowire networks and is then related to film thickness. An effective model using finite-element heat transfer analysis is examined to look at energy dissipation through these nanowire networks and used to understand mechanisms at play in the laser-material interactions. It is demonstrated that the three-dimensional nature of these coatings and the relative ratios of the rates of lateral to vertical heat diffusion are important controlling parameter affecting the ablation threshold.

Henley, Simon J.; Cann, Maria; Jurewicz, Izabela; Dalton, Alan; Milne, David

2013-12-01

159

Laser patterning of transparent conductive metal nanowire coatings: simulation and experiment.  

PubMed

Transparent and electrically conductive metal nanowire networks are possible replacements for costly indium tin oxide (ITO) films in many optoelectronic devices. ITO films are regularly patterned using pulsed lasers so similar technologies could be used for nanowire coatings to define electrode structures. Here, the effects of laser irradiation on conducting silver nanowire coatings are simulated and then investigated experimentally for networks formed by spray deposition onto transparent substrates. The ablation threshold fluence is found experimentally for such nanowire networks and is then related to film thickness. An effective model using finite-element heat transfer analysis is examined to look at energy dissipation through these nanowire networks and used to understand mechanisms at play in the laser-material interactions. It is demonstrated that the three-dimensional nature of these coatings and the relative ratios of the rates of lateral to vertical heat diffusion are important controlling parameter affecting the ablation threshold. PMID:24287486

Henley, Simon J; Cann, Maria; Jurewicz, Izabela; Dalton, Alan; Milne, David

2014-01-21

160

Aerosol chemical vapor deposition of metal oxide films  

SciTech Connect

A process of preparing a film of a multicomponent metal oxide including: forming an aerosol from a solution comprised of a suitable solvent and at least two precursor compounds capable of volatilizing at temperatures lower than the decomposition temperature of said precursor compounds; passing said aerosol in combination with a suitable oxygen-containing carrier gas into a heated zone, said heated zone having a temperature sufficient to evaporate the solvent and volatilize said precursor compounds; and passing said volatilized precursor compounds against the surface of a substrate, said substrate having a sufficient temperature to decompose said volatilized precursor compounds whereby metal atoms contained within said volatilized precursor compounds are deposited as a metal oxide film upon the substrate is disclosed. In addition, a coated article comprising a multicomponent metal oxide film conforming to the surface of a substrate selected from the group consisting of silicon, magnesium oxide, yttrium-stabilized zirconium oxide, sapphire, or lanthanum gallate, said multicomponent metal oxide film characterized as having a substantially uniform thickness upon said substrate, and as having a crystalline orientation defined as predominantly C-axis oriented by x-ray diffraction is disclosed.

Ott, K.C.; Kodas, T.T.

1990-04-16

161

Recent Results From Thin-Film-Coated Semiconductor Neutron Detectors  

Microsoft Academic Search

Semiconductor based thermal neutron detectors provide a compact technology for neutron detection and imaging. Such devices can be produced by externally coating semiconductor charged particle detectors with neutron reactive films that convert free neutrons into charged-particle reaction products. Commonly used films for such devices utilize the 10 B(n,? ) 7 Li 3 H reaction, which are attractive due to the

D. S. McGregor; R. T. Klannb; J. D. Sandersc; K. J. Lindene; H. K. Gerschf; Elsa Ariesantia

162

Thin film coatings for space electrical power system applications  

NASA Technical Reports Server (NTRS)

This paper examines some of the ways in which thin film coatings can play a role in aerospace applications. Space systems discussed include photovoltaic and solar dynamic electric power generation systems, including applications in environmental protection, thermal energy storage, and radiator emittance enhancement. Potential applications of diamondlike films to both atmospheric and space based systems are examined. Also, potential uses of thin films of the recently discovered high-temperature superconductive materials are discussed.

Gulino, Daniel A.

1988-01-01

163

New criterion of thin film failure of different organic coatings by shearography  

NASA Astrophysics Data System (ADS)

In the present work, the temperature versus thermal deformation (strain) with respect to time, of different coating films were studied by a nondestructive technique (NDT) known as shearography. An organic coating, i.e., ACE Premium Enamel, on a metallic alloy, i.e., a carbon steel, was investigated at a temperature range simulating the severe weather temperatures in Kuwait especially between the daylight and the night time temperatures, 20-60 °C. The investigation focused on determining the in-plane displacement of the coating, which amounts to the thermal deformation (strain) with respect to the applied temperature range. Furthermore, the investigation focused on determining the thermal expansion coefficients of coatings, the slope of the plot of the thermal deformation (strain) versus the applied temperature range. In other words, one could determine, from the decreasing value of the thermal expansion coefficients of coatings, a critical (steady state) value of the thermal expansion coefficients of coatings, in which the integrity of the coatings can be assessed with respect to time. In fact, determination of critical (steady state) value of the thermal expansion coefficients of coatings could be accomplished independent of parameters, i.e., UV exposure, Humidity, exposure to chemical species, and so on, normally are considered in conventional methods of the assessment of the integrity of coatings. In other words, with the technique of shearography, one would need only to determine the critical (steady state) value of the thermal expansion coefficients of coatings, regardless of the history of the coating, in order to assess the integrity of coatings. Furthermore, results of shearography indicate that the technique is very useful NDT method not only for determining the critical value of the thermal expansion coefficients of different coatings, but also the technique can be used as a 2D microscope for monitoring the deformation of the coatings in real-time at a submicroscopic scale.

Habib, K.

2007-06-01

164

Solid-gel precursor solutions and methods for the fabrication of polymetallicsiloxane coating films  

DOEpatents

Solutions and preparation methods necessary for the fabrication of metal oxide cross-linked polysiloxane coating films are disclosed. The films are useful in provide heat resistance against oxidation, wear resistance, thermal insulation, and corrosion resistance of substrates. The sol-gel precursor solution comprises a mixture of a monomeric organoalkoxysilane, a metal alkoxide M(OR)[sub n] (wherein M is Ti, Zr, Ge or Al; R is CH[sub 3], C[sub 2]H[sub 5] or C[sub 3]H[sub 7]; and n is 3 or 4), methanol, water, HCl and NaOH. The invention provides a sol-gel solution, and a method of use thereof, which can be applied and processed at low temperatures (i.e., < 1,000 C.). The substrate can be coated by immersing it in the above mentioned solution at ambient temperature. The substrate is then withdrawn from the solution. Next, the coated substrate is heated for a time sufficient and at a temperature sufficient to yield a solid coating. The coated substrate is then heated for a time sufficient, and temperature sufficient to produce a polymetallicsiloxane coating.

Toshifumi Sugama.

1993-04-06

165

Hydroxyapatite-coated metals: interfacial reactions during sintering.  

PubMed

Electrophoretic deposition (EPD) is a low cost flexible process for producing HA coatings on metal implants. Its main limitation is that it requires heating the coated implant in order to densify the HA. HA typically sinters at a temperature below 1150 degrees C, but metal implants are degraded above 1000 degrees C. Further, the metal induces the decomposition of the HA coating upon sintering. Recent developments have enabled EPD of metathesis-synthesised uncalcined HA which sinters at approximately 1000 degrees C. The effects of temperature on HA-coated Ti, Ti6Al4V, and 316L stainless steel were investigated for dual coatings of metathesis HA sintered at 1000 degrees C. The use of dual HA coatings (coat, sinter, coat, sinter) enabled decomposition to be confined to the "undercoat" (HA layer 1), with the surface coating decomposition free. The tensile strength of the three metals was not significantly affected by the high sintering temperatures (925 degrees C < T < 1000 degrees C). XRD/SEM/EDS analyses of the interfacial zones revealed that 316L had a negligible HA:metal interfacial zone (approximately 1 microm) while HA:Ti and HA:Ti6Al4V had large interfacial zones (>10 microm) comprising a TiO2 oxidation zone and a CaTiO2 reaction zone. PMID:15744597

Wei, M; Ruys, A J; Swain, M V; Milthorpe, B K; Sorrell, C C

2005-02-01

166

Hot-melt coating: water sorption behavior of excipient films.  

PubMed

Hot-melt coating allows encapsulation of water-labile, drug-laden substrates to form a barrier that resists moisture ingress. To understand the interaction of water with excipients that can form moisture-protective coatings, sorption behavior of films of lipidic (glyceryl behenate) and polymeric (polyvinyl alcohol) coating excipients was investigated. A simple and rapid method using a new, fully automated instrumental technique to investigate the sorption/desorption behavior of excipient films is reported. Further, the influence of temperature and film thickness on the sorption behavior of films is examined. Both excipient films displayed sorption isotherms that were classified as type III and demonstrated hysteresis during desorption. The sorption data for both films did not follow the Langmuir model, and the BET model could only be used restrictively. The GAB model fitted the sorption data at all conditions and over the entire range of water activity studied. The ability of the Young and Nelson model to explain the hysteresis behavior, from analytical and mechanistic perspectives, is evaluated. Temperature and film thickness were found to profoundly influence the nature of moisture interaction and distribution of moisture in the excipient films. An Arrhenius-type relationship was observed between equilibrium moisture content of excipient films and temperature at constant water activity. PMID:11291204

Achanta, A S; Adusumilli, P S; James, K W; Rhodes, C T

2001-01-01

167

Characterization of half-metallic CrO2-coated cantilevers  

NASA Astrophysics Data System (ADS)

We report the characteristics of half-metallic CrO2-coated cantilevers for multi-applications of atomic force microscopes (AFMs), conducting AFMs (CAFMs), and magnetic force microscopes (MFMs). The half-metallic ferromagnetism of the half-metallic CrO2-coated cantilever was tested by simultaneous measurements of noncontact AFM images and MFM images of the (111) CrO2 thin film on the (200) Pt/Ti/SiO2/Si substrate. To test the conducting properties of the CrO2 cantilever, we also simultaneously measured the contact AFM image and the CAFM image of the (111) Pt thin film on the TiO2/SiO2/Si substrate.

Son, J. Y.; Cho, J. H.

2007-04-01

168

Terahertz surface plasmon excitation via nonlinear mixing of lasers in a metal-coated optical fiber.  

PubMed

Terahertz (THz) surface plasmon generation via nonlinear mixing of laser eigenmodes in an optical fiber coated with ultrathin metal foil and possessing a dielectric constant ripple of wave number q is investigated. The fiber supports THz surface plasma wave (SPW) with plasmon resonance in the THz domain and is controllable by film thickness. The lasers exert a difference frequency ponderomotive force on the electrons of the metal film. The ponderomotive force induces a nonlinear current driving the difference frequency THz SPW. THz amplitude to laser amplitude ratio of the order ?10(-2) can be achieved by CO2 laser in megawatt range. PMID:24104791

Kumar, Pawan; Tripathi, V K

2013-09-15

169

An Improved Tribological Polymer-Coating System for Metal Surfaces  

Microsoft Academic Search

Aromatic thermosetting polyester (ATSP)- and polytetrafluoroethylene (PTFE)-blended composites have been shown to exhibit\\u000a improved tribological performance with low wear and low friction. In this article, pure ATSP films were coated on aluminum\\u000a substrates and tested as a potential protective tribological coating. The tribological performance of this coating was tested\\u000a against steel, using pure sliding sphere-on-disk experiments. A fluoroadditive powder (solid

Jing Zhang; Andreas A. Polycarpou; James Economy

2010-01-01

170

Aging in Thin Metallic Films.  

National Technical Information Service (NTIS)

Low magnetostriction NiFe and NiFe based ternary films 220A and 340A thick were prepared by thermal evaporation and bias sputtering. A few evaporated films were sputter etched. The films were aged in air with a magnetic bias in the plane of the film and p...

H. R. Irons W. E. Anderson L. J. Schwee

1978-01-01

171

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

NASA Technical Reports Server (NTRS)

An electron bombardment argon ion source sputter deposited 17 metals and metal oxides on H-13 steel. The films ranged 1 to 8 micrometers in thickness and their adherence was generally greater than the capacity of the measuring device; adherence quality depended on proper precleaning of the substrate before deposition. N2 or air was introduced for correct stoichiometry in metallic compounds. Au, Ag, MgO, and Ta5Si3 films 8 microns thick have bond strength equal to 1 micron coatings; the bond strength of pure metallic films up to 5 microns thick was greater than the epoxy to film bond (8000 psi). The results of exposures of coated material to temperatures up to 700 C are presented.

Mirtich, M. J.

1980-01-01

172

Biofouling of Cr-Nickel Spray Coated Films on Steel Surfaces  

NASA Astrophysics Data System (ADS)

Nowadays, corrosion of metals brings us serious economic loss and it often reaches several percentage of GNP. Particularly the marine corrosion was serious and the counter measure was very hard to be established, since the number of factors is huge and complicated. One of the complicated factors in marine corrosion is biofouling. Biofouling was classified into two main categories, microfouling and macrofouling. The former is composed of biofilm formation mainly. Marine bacteria are attached to material surfaces, seeking for nutrition in oligotrophic environment and they excrete polysaccharide to form biofilm on metal surfaces. Then larger living matters are attached on the biofilms to develop biofouling on metal surfaces, which often lead loss and failures of metals in marine environments. From the viewpoint of corrosion protection and maintenance of marine structures, biofouling should be mitigated as much as possible. In this study, we applied spray coating to steels and investigated if chromium-nickel spray coating could mitigate the biofouling, being compared with the conventional aluminium-zinc spray coating in marine environments. The specimens used for this investigation are aluminium, zinc, aluminium-zinc, stacked chromium/nickel and those films were formed on carbon steel (JIS SS400). And the pores formed by spray coating were sealed by a commercial reagent for some specimens. All of those specimens were immersed into sea water located at Marina Kawage (854-3, Chisato, Tsu, Mie Prefecture) in Ise Bay for two weeks. The depth of the specimen was two meter from sea water surface and the distance was always kept constant, since they were suspended from the floating pier. The temperature in sea water changed from 10 to 15 degrees Celsius during the immersion test. The biofouling behavior was investigated by low vacuum SEM (Hitachi Miniscope TM1000) and X-ray fluorescent analysis. When the spray coated specimens with and without sealing agents were compared, the former showed higher antifouling properties generally. Aluminium-zinc alloy spray coated films had higher antifouling property. And the anti-property decreased in this order: Al-Zn alloy spray coating > Zinc spray coating > Aluminium spray coating > Stacked chromium/nickel spray coating. Aluminium and zinc spray coating has been evaluated high conventionally for anti-biofouling in marine environment. However, the Cr/Ni spray coating showed pretty high anti-fouling property.

Yoshida, Kento; Kanematsu, Hideyuki; Kuroda, Daisuke; Ikigai, Hajime; Kogo, Takeshi; Yokoyama, Seiji

2012-03-01

173

Ellipsometric study of oxide films formed on LDEF metal samples  

NASA Technical Reports Server (NTRS)

The optical constants of samples of six different metals (Al, Cu, Ni, Ta, W, and Zr) exposed to space on the Long Duration Exposure Facility (LDEF) were studied by variable angle spectroscopic ellipsometry. Measurements were also carried out on portions of each sample which were shielded from direct exposure by a metal bar. A least-squares fit of the data using an effective medium approximation was then carried out, with thickness and composition of surface films formed on the metal substrates as variable parameters. The analysis revealed that exposed portions of the Cu, Ni, Ta, and Zr samples are covered with porous oxide films ranging in thickness from 500 to 1000 A. The 410 A thick film of Al2O3 on the exposed Al sample is practically free of voids. Except for Cu, the shielded portions of these metals are covered by thin non-porous oxide films characteristic of exposure to air. The shielded part of the Cu sample has a much thicker porous coating of Cu2O. The tungsten data could not be analyzed.

Franzen, W.; Brodkin, J. S.; Sengupta, L. C.; Sagalyn, P. L.

1992-01-01

174

Metal multi-dielectric mirror coatings for Cherenkov detectors  

NASA Astrophysics Data System (ADS)

Application-specific reflective coatings have been developed and are being implemented in LHC experiments currently under construction. The broadband reflective coating consists of an aluminum film combined with one or two pairs of low- and high-index dielectric layers. The layer stacks are designed and optimized using commercial thin film software and verified on small mirror samples. The wavelength of peak reflectivity is tuned to maximize the light yield, taking into account the emission spectrum (e.g., Cherenkov) and the photosensor characteristics. We report about coatings of Mylar foil-based light guides for the Hadronic Forward calorimeter of CMS and spherical mirrors for the RICH2 counter of LHCb.

Braem, A.; David, C.; Joram, C.

2005-11-01

175

Molecular structure and optical properties of PTFE-based nanocomposite polymer-metal coatings  

NASA Astrophysics Data System (ADS)

The molecular organization of polytetrafluoroethylene (PTFE) thin coatings with incorporated Ag, Cu, and Mo nanoparticles that are deposited from an active gas component has been studied. Polyethylene terephtalate film coated by aluminium served as a substrate. The active gas component was produced by electron beam dispersion of original components in vacuum. The effect of metal particle size and its nature on the molecular structure of coatings have been investigated. Dichroism of thin nanocomposite coatings has been examined by polarized Fourier transform infrared spectroscopy using an attenuated total reflection unit. The morphology of the coatings has been analyzed by transmission (TEM), atomic-force (AFM), and scanning electron (SEM) microscopy. It is found that introduction of a metal (Ag or Cu) yields oriented layers at a lesser efficient thickness of a coating. The surface plasmon resonance of such structures was studied by measuring optical absorption of the coatings in the ultraviolet and visible ranges. The results show that the composite coatings containing Ag clusters are diameter less than 30 nm and absorb within the short-wave range from 400 to 550 nm.

Rahachou, A. V.; Rogachev, A. A.; Yarmolenko, M. A.; Xiao-Hong, Jiang; Bo, Liu Zhu

2012-01-01

176

Metal films on the surfaces and within diamond crystals from Arkhangelskaya and Yakutian diamond provinces  

NASA Astrophysics Data System (ADS)

Representative samples of diamonds from five kimberlite pipes (Lomonosovskaya, Archangel'sk, Snegurochka, XXIII Congress of the Communist Party of the Soviet Union (CPSU), and Internationalnaya) of the Arkhangelskaya and Yakutian diamond provinces in Russia have been studied. Thirty-three varieties of metal films have been identified as syngenetic associated minerals. The films consist of 15 chemical elements that occur in the form of native metals and their natural alloys. Remnants of metal films were detected within diamond crystals. The metal films coating diamonds are a worldwide phenomenon. To date, these films have been described from Europe, Asia, South America, and Africa. Native metals, their alloys, and intermetallides are actual companion minerals of diamond.

Makeev, A. B.; Kriulina, G. Yu.

2012-12-01

177

Electrodeposition of composite coatings containing nanoparticles in a metal deposit  

Microsoft Academic Search

Recent literature on the electrodeposition of metallic coatings containing nanosized particles is surveyed. The nanosized particles, suspended in the electrolyte by agitation and\\/or use of surfactants, can be codeposited with the metal. The inclusion of nanosized particles can give (i) an increased microhardness and corrosion resistance, (ii) modified growth to form a nanocrystalline metal deposit and (iii) a shift in

C. T. J. Low; R. G. A. Wills; F. C. Walsh

2006-01-01

178

Method of Coating Graphite Tubes With Refractory Metal Carbides.  

National Technical Information Service (NTIS)

The patent describes a method of coating graphite tubes with a refractory metal carbide. An alkali halide is reacted with a metallic oxide, said metallic portion being selected from the IVth or Vth group of the Periodic Table, the resulting salt reacting ...

C. Wohlberg

1973-01-01

179

Recycling light metals: Optimal thermal de-coating  

NASA Astrophysics Data System (ADS)

Thermal de-coating of painted and lacquered scrap is one of the new innovations developed for aluminum recycling. If implemented in all recycling and optimized as suggested in this article, recovery would be improved with considerable economic impact. Generally, contaminated scrap is difficult to recycle. Direct re-melting of coated scrap results in the generation of gaseous emissions, with increased metal oxidation, contamination, and salt flux usage. By thermal de-coating of the scrap these problems are avoided. Thermal de-coating followed by remelting of aluminum scrap is now common practice, while painted magnesium scrap is not currently de-coated and recycled. This article presents observations during heating of the contaminated light metals together with the mass loss, evolved gases, and residue after de-coating in order to give a general description of the de-coating process. It is argued that the main behavior during de-coating may be described as two distinct regimes—scission and combustion—regardless of metal substrate and coating. Monitoring the combustion regime should assure optimum de-coating.

Kvithyld, Anne; Meskers, C. E. M.; Gaal, Sean; Reuter, Markus; Engh, Thorvald Abel

2008-08-01

180

Experiment and theory of 'transparent' metal films  

Microsoft Academic Search

The optical properties of near-transparent porous platinum films supported on p-type indium phosphide (p-In-P) are reported. Both experimental and theoretical evidence is presented which shows that the previously reported effects on the photoelectrochemical solar-to-hydrogen conversion efficiency of catalytically active metals deposited on p-InP can be understood in terms of microstructure. When the metal films are sufficiently porous and built up

J. D. Porter; A. Heller; D. E. Aspnes

1985-01-01

181

Metal current collect protected by oxide film  

DOEpatents

Provided are low-cost, mechanically strong, highly electronically conductive current collects and associated structures for solid-state electrochemical devices, techniques for forming these structures, and devices incorporating the structures. The invention provides solid state electrochemical devices having as current interconnects a ferritic steel felt or screen coated with a protective oxide film.

Jacobson, Craig P. (Lafayette, CA); Visco, Steven J. (Berkeley, CA); DeJonghe, Lutgard C. (Lafayette, CA)

2004-05-25

182

Study on corrosion protection of organic coatings using electrochemical techniques: Thermal property characterization, film thickness investigation, and coating performance evaluation  

NASA Astrophysics Data System (ADS)

As an initial effort to establish a rapid, accurate, and comprehensive testing protocol for performance evaluation and lifetime prediction of corrosion protective coatings, the effects of coating thermal characteristics, coating application parameters, and coating formulation variations on corrosion protection have been explored. The study has been accomplished primarily through modern electrochemical techniques, such as Electrochemical Noise Methods (ENM) and Electrochemical Impedance Spectroscopy (EIS), with the aid of traditional thermal analysis, surface characterization, and appearance inspection. The employed electrochemical techniques have exhibited usefulness as powerful testing tools that have provided valuable results in good agreement with field observations and other measures by traditional methods. Thermal property characterization on fusion bonded epoxy (FBE) pipeline coatings has shown that coating electrical resistances decreased as temperature rose with a distinct thermal transition point corresponding to glass transition temperature (Tg) of the immersed coatings. The change in coating capacitance with temperature revealed the irreversible process of water ingress and the effects of electrolyte plasticization in the coating films. Film thickness investigation on marine coating systems has demonstrated that film thickness has significant influences on coating corrosion protection. Better performance is expected for a coating system with thicker film thickness as well as with more coating layers when applied at a constant film thickness. The results indicate that there was a possible critical minimum film thickness above which coating protective performance was greatly enhanced and that there was also a maximum limiting film thickness above which increasing film thickness made little contribution to corrosion protection. Coating performance evaluation on aircraft coating systems has offered accurate performance ranking and reasonable lifetime prediction for high-quality, anticorrosive coatings. The mechanisms of corrosion protection by several coating systems with various types of polymers and pigment volume concentrations (PVC) have been discovered. Future work will consider a broader selection of materials, different test conditions, and a greater variety of characterization techniques. More sophisticated data analysis methods also need to be developed.

Li, Junping

2002-08-01

183

Plasma-sprayed ceramic coatings for molten metal environments.  

SciTech Connect

Coating porosity is an important parameter to optimize for plasma-sprayed ceramics which are intended for service in molten metal environments. Too much porosity and the coatings may be infiltrated by the molten metal causing corrosive attack of the substrate or destruction of the coating upon solidification of the metal. Too little porosity and the coating may fail due to its inability to absorb thermal strains. This study describes the testing and analysis of tungsten rods coated with aluminum oxide, yttria-stabilized zirconia, yttrium oxide, and erbium oxide deposited by atmospheric plasma spraying. The samples were immersed in molten aluminum and analyzed after immersion. One of the ceramic materials used, yttrium oxide, was heat treated at 1000 C and 2000 C and analyzed by X-ray diffractography and mercury intrusion porosimetry. Slight changes in crysl nl structure and significant changes in porosity were observed after heat treatments.

Hollis, K. J. (Kendall J.); Peters, M. I. (Maria I.); Bartram, B. D. (Brian D.)

2002-01-01

184

Humidity Sensing of Ordered Macroporous Silicon With Thin-Film Surface Coating  

Microsoft Academic Search

Porous silicon (PS), as a gas\\/chemical sensing material, has been widely investigated. In this paper, the humidity sensing characteristics of n-type macroporous silicon with ordered structure and metal oxide thin-film coating is studied. The ordered PS has uniform pore size, pore shape and distribution. All pores are aligned vertically and open to the environment. The PS heterostructure (PS\\/Si substrate) and

Yun Wang; John T. W. Yeow

2009-01-01

185

Thin film coatings of WO 3 by cold gas dynamic spray: A technical note  

Microsoft Academic Search

Dense and adhesive WO3 films were prepared on a silicon substrate by the cold gas dynamic spray process (or cold spray). In contrast to standard\\u000a metallic coatings, there was no sizable crater formation and plastic deformation. However, the aggregation of raw powder particles\\u000a of a relatively large size was found to be destroyed upon impact on the substrate, forming a

Ha Yong Lee; Young Ho Yu; Young Cheol Lee; Young Pyo Hong; Kyung Hyun Ko

2005-01-01

186

Corrosion protection by sonoelectrodeposited organic films on zinc coated steel.  

PubMed

A variety of coatings based on electrosynthesized polypyrrole were deposited on zinc coated steel in presence or absence of ultrasound, and studied in terms of corrosion protection. Cr III and Cr VI commercial passivation were used as references. Depth profiling showed a homogeneous deposit for Cr III, while SEM imaging revealed good surface homogeneity for Cr VI layers. These chromium-based passivations ensured good protection against corrosion. Polypyrrole (PPy) was also electrochemically deposited on zinc coated steel with and without high frequency ultrasound irradiation in aqueous sodium tartrate-molybdate solution. Such PPy coatings act as a physical barrier against corrosive species. PPy electrosynthesized in silent conditions exhibits similar properties to Cr VI passivation with respect to corrosion protection. Ultrasound leads to more compact and more homogeneous surface structures for PPy, as well as to more homogeneous distribution of doping molybdate anions within the film. Far better corrosion protection is exhibited for such sonicated films. PMID:22516111

Et Taouil, Abdeslam; Mahmoud, Mahmoud Mourad; Lallemand, Fabrice; Lallemand, Séverine; Gigandet, Marie-Pierre; Hihn, Jean-Yves

2012-11-01

187

Interactions Between Glass-Ceramic Coatings and Metals.  

NASA Astrophysics Data System (ADS)

Available from UMI in association with The British Library. Requires signed TDF. A study of glass-ceramic coatings on metal substrates was carried out on a lithium-silicate glass-ceramic coating on Ni/Cr/Co alloy and a lithium-aluminosilicate glass-ceramic coating on titanium metal. In the Ni/Cr/Co case, Cr from the substrate tends to diffuse into the coating very rapidly at the firing temperature which results in saturation of Cr^ {+++} ions in the glass coating. The second oxidation step proceeds more rapidly at the coating surface and LiCr(SiO_3)_2 crystals start to precipitate on the surface of the coating. Mismatch of thermal expansion coefficient between LiCr(SiO _3)_2 and the coating causes severe disruption. Some components in the coating, for instance P_2O_5, react with Cr to form Cr_{12}P _7. As a result consumption of the intended nucleating agent P_2O _5<=ads to a poorly crystallized structure affecting coating properties. In the titanium system, the major problem is the reactivity of titanium and silica, which gives Ti _5 Si_3 as an interfacial layer. The gaseous O_2 produced may disrupt the molten glass structure during firing. Other interactions such as Ti/P_2O _5 can also proceed to give other damaging effects. The coating on titanium after firing is usually very porous if these interactions are not prevented. Preoxidation of Ni/Cr/Co alloy created an adherent Cr_2O_3 layer on the alloy surface, and this layer is very stable in the coating glass. This layer prevented direct contact of alloy and coating at the firing temperature, minimizing interfacial reactions and leading to the desired coating structure. Preoxidation of titanium metal can create a barrier of TiO_2 between the coating and metal to hinder the formation of Ti_5Si _3. The poor bonding strength of this layer meant that it was ineffective in forming a transition layer between the metal and coating. Furthermore, the TiO_2 can be readily dissolved by the coating glass during firing. Addition of an adherence oxide, CoO, was successful in (1) producing TiO _2 in situ at the interfacial area and Co/Ti dendrites; (2) diverting and hence minimizing the damaging direct reaction between Ti and SiO_2. (Abstract shortened by UMI.).

Hong, Feng

188

The role of electroplated coatings in metal joining  

SciTech Connect

Electroplated and electroless coatings often play an important role in soldering, brazing, and welding operations. Thin deposits applied to critical surfaces before the joining operations can provide the difference between success and failure. Diffusion welding applications sometimes require coatings to help promote joining. For some applications, electroplating by itself can be used to join metals that cannot be welded or brazed because of metallurgical incompatibility. The use of electroplated coatings for these various joining applications is reviewed here.

Dini, J.W. [Lawrence Livermore National Lab., CA (United States)

1996-05-01

189

Adhesion of coatings to sheet metal under plastic deformation  

Microsoft Academic Search

This study presents a new technique to evaluate adhesion of coatings to sheet metal under plastic deformation. Based on the concept of the forming limit diagram (FLD), the present work evaluates coating performance with the notch-coating adhesion test, the cross-hatch tape test (ASTM D3359), accelerated conditioning, the uniaxial tensile test, and the rectangular stretch bend test. Experiments were conducted on

Ravi Vayeda; Jyhwen Wang

2007-01-01

190

Deposition and Characterization of Thin Films on Metallic Substrates  

NASA Technical Reports Server (NTRS)

A CVD method was successfully developed to produce conversion coatings on aluminum alloys surfaces with reproducible results with a variety of precursors. A well defined protocol to prepare the precursor solutions formulated in a previous research was extended to other additives. It was demonstrated that solutions prepared following such a protocol could be used to systematically generate protective coatings onto aluminum surfaces. Experiments with a variety of formulations revealed that a refined deposition protocol yields reproducible conversion coatings of controlled composition. A preliminary correlation between solution formulations and successful precursors was derived. Coatings were tested for adhesion properties enhancement for commercial paints. A standard testing method was followed and clear trends were identified. Only one precursors was tested systematically. Anticipated work on other precursors should allow a better characterization of the effect of intermetallics on the production of conversion/protective coatings on metals and ceramics. The significance of this work was the practical demonstration that chemical vapor deposition (CVD) techniques can be used to systematically generate protective/conversion coating on non-ferrous surfaces. In order to become an effective approach to replace chromate-based pre- treatment processes, namely in the aerospace or automobile industry, the process parameters must be defined more precisely. Moreover, the feasibility of scale-up designs necessitates a more comprehensive characterization of the fluid flow, transport phenomena, and chemical kinetics interacting in the process. Kinetic characterization showed a significantly different effect of magnesium-based precursors when compared to iron-based precursors. Future work will concentrate on refining the process through computer simulations and further experimental studies on the effect of other transition metals to induce deposition of conversion/protective films on aluminum and other metallic substrates.

Gatica, Jorge E.

2005-01-01

191

Improved performance of thin film broadband antireflective coatings  

Microsoft Academic Search

Antireflective coatings are useful for a range of applications, from minimizing the radar cross-section of stealth aircraft, to maximizing the efficiency of solar energy panels. New low-index nanorod thin films promise broadband, broad angle performance for such coatings. We demonstrate that a bandwidth increase from 38.5% to 113% is possible by using a simple evolutionary strategy to optimize the thin

Matthew Mishrikey; Arya Fallahi; Christian Hafner; Rüdiger Vahldieck

2007-01-01

192

Effect of metallic coating properties on the tribology of oil- lubricated coated-ceramics  

SciTech Connect

The friction and wear behavior of zirconia ceramics lubricated with solid coatings (AG, Au, and Nb), deposited by ion-beam-assisted-deposition (IBAD) techniques, and a polyol-ester-based synthetic oil are presented. These results demonstrate that, although the simultaneous use of soft (e.g. Ag and Au) solid lubricants in conjunction with the synthetic lubricant significantly reduces the friction and wear under boundary lubrication at temperatures up to 250{degree}C, the durability of the soft films was poor. In contrast, durability of Nb coating (in terms of chemical reactivity and adhesion during the tribo-tests) was better than that of the Ag or Au films. However, the friction and wear behavior of the Nb-coated films was poorer than that of the ceramics coated with Ag or Au.

Ajayi, O.O.; Fenske, G.R.; Erdemir, A.; Erck, R.A.; Hsieh, J.H.; Nichols, F.A.

1992-01-01

193

Effect of metallic coating properties on the tribology of oil- lubricated coated-ceramics  

SciTech Connect

The friction and wear behavior of zirconia ceramics lubricated with solid coatings (AG, Au, and Nb), deposited by ion-beam-assisted-deposition (IBAD) techniques, and a polyol-ester-based synthetic oil are presented. These results demonstrate that, although the simultaneous use of soft (e.g. Ag and Au) solid lubricants in conjunction with the synthetic lubricant significantly reduces the friction and wear under boundary lubrication at temperatures up to 250{degree}C, the durability of the soft films was poor. In contrast, durability of Nb coating (in terms of chemical reactivity and adhesion during the tribo-tests) was better than that of the Ag or Au films. However, the friction and wear behavior of the Nb-coated films was poorer than that of the ceramics coated with Ag or Au.

Ajayi, O.O.; Fenske, G.R.; Erdemir, A.; Erck, R.A.; Hsieh, J.H.; Nichols, F.A.

1992-04-01

194

Metal flame spray coating protects electrical cables in extreme environment  

NASA Technical Reports Server (NTRS)

Metal flame spray coating prevents EMF measurement error in sheathed instrumentation cables which are externally attached to cylinders which were cooled on the inside, but exposed to gamma radiation on the outside. The coating provides a thermoconductive path for radiation induced high temperatures within the cables.

Brady, R. D.; Fox, H. A.

1967-01-01

195

Thin films of mixed metal compounds  

DOEpatents

Disclosed is a thin film heterojunction solar cell, said heterojunction comprising a p-type I-III-IV[sub 2] chalcopyrite substrate and an overlying layer of an n-type ternary mixed metal compound wherein said ternary mixed metal compound is applied to said substrate by introducing the vapor of a first metal compound to a vessel containing said substrate from a first vapor source while simultaneously introducing a vapor of a second metal compound from a second vapor source of said vessel, said first and second metals comprising the metal components of said mixed metal compound; independently controlling the vaporization rate of said first and second vapor sources; reducing the mean free path between vapor particles in said vessel, said gas being present in an amount sufficient to induce homogeneity of said vapor mixture; and depositing said mixed metal compound on said substrate in the form of a uniform composition polycrystalline mixed metal compound. 5 figs.

Mickelsen, R.A.; Chen, W.S.

1985-06-11

196

Durable silver thin film coating for diffraction gratings  

DOEpatents

A durable silver film thin film coated non-planar optical element has been developed to replace Gold as a material for fabricating such devices. Such a coating and resultant optical element has an increased efficiency and is resistant to tarnishing, can be easily stripped and re-deposited without modifying underlying grating structure, improves the throughput and power loading of short pulse compressor designs for ultra-fast laser systems, and can be utilized in variety of optical and spectrophotometric systems, particularly high-end spectrometers that require maximized efficiency.

Wolfe, Jesse D. (Discovery Bay, CA); Britten, Jerald A. (Oakley, CA); Komashko, Aleksey M. (San Diego, CA)

2006-05-30

197

Microtribological Performance of Metal-doped Molybdenum Disulfide Coatings  

NASA Astrophysics Data System (ADS)

The mechanical and tribological properties of pure MoS2, pure Au, Au-MoS2 and Ti-MoS2 coatings were evaluated and examined at a microscopic scale. The metal doped MoS2 coatings had varying metal content, 5-10at% for Ti and 10-90% for Au. Reciprocating sliding wear tests were performed with a range of initial Hertzian contact pressures from 0.41 to 3.5 GPa and in air at two humidity levels (i.e. "low" being 3-5%RH and "high" being 30-40%RH). Titanium and gold were chosen for this study as metal additives due to their positive influence on the mechanical properties of the coating. The friction and wear behavior at the micro-scale were directly compared to tribological properties at the macro-scale, which were performed using an in situ tribometer. Reciprocating micro- and macro- wear tests were performed with spherical diamond tip (with 10 and 50 mum radii) and a sapphire tip (with a radius of 3.175 mm), respectively. The range of initial Hertzian contact pressures for macro-scale (i.e. between 0.41GPa and 1.2GPa) overlapped with that for micro-scale. However, the initial Hertzian contact diameters (2*a) were very different (i.e. 0.8-2.3 mum for micro-scale and 60-180 mum for macro-scale). It was observed that the small addition of Ti or Au to MoS2 improved the microtribological properties (i.e. lower friction and less wear) compared to pure MoS2 coatings. The improved microtribological properties with metal additions were attributed to an increase in the mechanical properties, decrease in adhesion, and a decrease in the interfacial shear strength. In terms of the different length scales, lower steady state friction was observed for macrotribology compared to microtribology. The higher friction at the micro- scale was explained by the greater adhesion effects and additional velocity accommodation modes (e.g. microplowing or plowing). The microplowing or plowing at the microscopic scale was attributed to the tip roughness and the inability to sustain a stable transferfilm throughout the tests at high humidity. In addition, using in situ and ex situ techniques, three different stages for solid lubrication were identified based on differences in contact area, tip shapes, and environmental conditions. The first stage has been previously observed with macrotribology on MoS 2 coatings at low humidity levels. The second stage, on the other hand, was observed for micro-tribology where the contact size is significantly smaller compared to stage one. The main wear mechanism is still adhesion, but there is also some micro-plowing. The final stage was observed for humid sliding in microtribology, where no transfer films were observed and therefore the main wear mechanism was plowing.

Stoyanov, Pantcho

198

Sputtered YBCO films on metal substrates  

SciTech Connect

Magnetron sputtering was used to deposit superconducting YBCO thin films on four polycrystalline metal substrates. Yttrium-stabilized zirconia (YSZ) and silver were used as buffer layers. The thermal expansion coefficient of the substrate was apparently correlated to the properties of the superconductor. Auger depth profiles showed that the YSZ buffer blocked diffusion of most metal elements from the substrate. Nevertheless, contamination of the films depressed {ital T}{sub {ital c}} to 81 K on Hastelloy X from 87 K on single-crystal strontium titanate. The films on metal substrates were c-axis oriented, but with random rotation in the a-b plane and smaller grain size than epitaxial films on single crystals. The weak links from these factors restrict {ital J}{sub {ital c}} to 10{sup 4} A/cm{sup 2} at 40 K.

Yin, E.; Rubin, M.; Dixon, M. (Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720 (United States))

1992-07-01

199

Polyaniline films with nanostructure used as neural probe coating surfaces  

NASA Astrophysics Data System (ADS)

Polyaniline (PANi) films with high conductivity and nanostructure were prepared by a modified dipping method using four acids on a polytetrafluoroethylene (PTFE) substrate. The "doping-dedoping-redoping" process was carried out to investigate whether the electrical and surface properties of PANi coating could be changed. We found that the conductivity decreased with prolonged immersing time in both water and DMEM, until the PANi films were almost non-conductive. The as-prepared PANi films were hydrophilic, and the immersing treatment with DMEM made them hydrophobic. Moreover, they recovered their hydrophilicity following the redoping treatment. The morphologies of the PANi films became heterogeneous after the immersing-redoping treatment. These results provide a good reference for the use of conducting polymers as a neural probe coating.

Li, Da-Feng; Wang, Wei; Wang, Hua-Jie; Jia, Xue-Shun; Wang, Jin-Ye

2008-11-01

200

Coatings and Biodegradable and Bioabsorbable Films.  

National Technical Information Service (NTIS)

Research and development activities focused on environmentally friendly monomer, polymer and composite materials for Navy coating and packaging needs. Specifically focusing on the plasticizing effects of vegetable oil macromonomers as incorporated into em...

J. W. Rawlins S. F. Thames

2006-01-01

201

Ion beam sputter-deposited thin film coatings for protection of spacecraft polymers in low Earth orbit  

NASA Technical Reports Server (NTRS)

Ion beam sputter-deposited thin films of Al2O3, SiO2, and a codeposited mixture of predominantly SiO2 with small amounts of a fluoropolymer were evaluated both in laboratory plasma ashing tests and in space on board shuttle flight STS-8 for effectiveness in preventing oxidation of polyimide Kapton. Measurements of mass loss and optical performance of coated and uncoated polyimide samples exposed to the low Earth orbital environment are presented. Optical techniques were used to measure loss rates of protective films exposed to atomic oxygen. Results of the analysis of the space flight exposed samples indicate that thin film metal oxide coatings are very effective in protecting the polyimide. Metal oxide coatings with a small amount of fluoropolymer codeposited have the additional benefit of great flexibility.

Banks, B. A.; Mirtich, M. J.; Rutledge, S. K.; Swec, D. M.; Nahra, H. K.

1985-01-01

202

Film coatings for oral pulsatile release.  

PubMed

Pulsatile delivery is generally intended as a release of the active ingredient that is delayed for a programmable period of time to meet particular chronotherapeutic needs and, in the case of oral administration, also target distal intestinal regions, such as the colon. Most oral pulsatile delivery platforms consist in coated formulations wherein the applied polymer serves as the release-controlling agent. When exposed to aqueous media, the coating initially performs as a protective barrier and, subsequently, undergoes a timely failure based on diverse mechanisms depending on its physico-chemical and formulation characteristics. Indeed, it may be ruptured because of the gradual expansion of the core, swell and/or erode due to the glassy-rubbery polymer transition or become permeable thus allowing the drug molecules to diffuse outwards. Otherwise, when the coating is a semipermeable membrane provided with one or more orifices, the drug is released through the latter as a result of an osmotic water influx. The vast majority of pulsatile delivery systems described so far have been prepared by spray-coating, which offers important versatility and feasibility advantages over other techniques such as press- and dip-coating. In the present article, the design, manufacturing and performance of spray-coated pulsatile delivery platforms is thus reviewed. PMID:23506956

Maroni, Alessandra; Zema, Lucia; Loreti, Giulia; Palugan, Luca; Gazzaniga, Andrea

2013-12-01

203

Method for improving the oxidation-resistance of metal substrates coated with thermal barrier coatings  

DOEpatents

A method for providing a protective coating on a metal-based substrate is disclosed. The method involves the application of an aluminum-rich mixture to the substrate to form a discontinuous layer of aluminum-rich particles, followed by the application of a second coating over the discontinuous layer of aluminum-rich particles. Aluminum diffuses from the aluminum-rich layer into the substrate, and into any bond coat layer which is subsequently applied. Related articles are also described.

Thompson, Anthony Mark (Niskayuna, NY) [Niskayuna, NY; Gray, Dennis Michael (Delanson, NY) [Delanson, NY; Jackson, Melvin Robert (Niskayuna, NY) [Niskayuna, NY

2002-01-01

204

Interfacial electron transfer on cytochrome-c sensitised conformally coated mesoporous TiO2 films.  

PubMed

Hybrid protein films incorporating Cyt-c immobilized on TiO(2) films were prepared and characterised optically with UV-visible spectroscopy and electrochemically with cyclic voltammetry, and their conductivity properties were studied in detail. In addition the effects of a thin overlayer coating of a second metal oxide such as SiO(2), Al(2)O(3), ZrO(2) and MgO(2) were studied and the effects over the electrochemical properties of the hybrid working electrodes were discussed. PMID:18644749

Topoglidis, Emmanuel; Lutz, Thierry; Durrant, James R; Palomares, Emilio

2008-11-01

205

Superhydrophobic ceramic coatings enabled by phase-separated nanostructured composite TiO2–Cu2O thin films  

NASA Astrophysics Data System (ADS)

By exploiting phase-separation in oxide materials, we present a simple and potentially low-cost approach to create exceptional superhydrophobicity in thin-film based coatings. By selecting the TiO2–Cu2O system and depositing through magnetron sputtering onto single crystal and metal templates, we demonstrate growth of nanostructured, chemically phase-segregated composite films. These coatings, after appropriate chemical surface modification, demonstrate a robust, non-wetting Cassie–Baxter state and yield an exceptional superhydrophobic performance, with water droplet contact angles reaching to ?172° and sliding angles <1°. As an added benefit, despite the photo-active nature of TiO2, the chemically coated composite film surfaces display UV stability and retain superhydrophobic attributes even after exposure to UV (275 nm) radiation for an extended period of time. The present approach could benefit a variety of outdoor applications of superhydrophobic coatings, especially for those where exposure to extreme atmospheric conditions is required.

Aytug, Tolga; Bogorin, Daniela F.; Paranthaman, Parans M.; Mathis, John E.; Simpson, John T.; Christen, David K.

2014-06-01

206

Simple push coating of polymer thin-film transistors  

PubMed Central

Solution processibility is a unique advantage of organic semiconductors, permitting the low-cost production of flexible electronics under ambient conditions. However, the solution affinity to substrate surfaces remains a serious dilemma; liquid manipulation is more difficult on highly hydrophobic surfaces, but the use of such surfaces is indispensable for improving device characteristics. Here we demonstrate a simple technique, which we call ‘push coating’, to produce uniform large-area semiconducting polymer films over a hydrophobic surface with eliminating material loss. We utilize a poly(dimethylsiloxane)-based trilayer stamp whose conformal contact with the substrate enables capillarity-induced wetting of the surface. Films are formed through solvent sorption and retention in the stamp, allowing the stamp to be peeled perfectly from the film. The planar film formation on hydrophobic surfaces also enables subsequent fine film patterning. The technique improves the crystallinity and field-effect mobility of stamped semiconductor films, constituting a major step towards flexible electronics production.

Ikawa, Mitsuhiro; Yamada, Toshikazu; Matsui, Hiroyuki; Minemawari, Hiromi; Tsutsumi, Jun'ya; Horii, Yoshinori; Chikamatsu, Masayuki; Azumi, Reiko; Kumai, Reiji; Hasegawa, Tatsuo

2012-01-01

207

Evaluation of colorless polyimide film for thermal control coating applications  

NASA Technical Reports Server (NTRS)

A series of essentially colorless aromatic polyimide films was synthesized and characterized with the objective of obtaining maximum optical transparency for applications in space. Optical transparency is a requirement for high performance polymeric films used in second surface mirror coatings on thermal control systems. The intensity in color of aromatic polyimide films was lowered by reducing the electronic interaction between chromophoric centers in the polymer molecular structure and by using highly purified monomers. The resulting lightly colored to colorless polyimide films were characterized by UV-visible and infrared spectroscopy before and after exposure to 300 equivalent solar hours UV irradiation and varying doses of 1 MeV electron irradiation. After irradiation, the films were found to be 2 to 2.5 times more transparent than commercial polyimide film of the same thickness.

St.clair, A. K.; Slemp, W. S.

1985-01-01

208

Evaluation of colorless polyimide film for thermal control coating applications  

NASA Technical Reports Server (NTRS)

A series of essentially colorless aromatic polyimide films has been synthesized and characterized with the objective of obtaining maximum optical transparency for applications in space. Optical transparency is a requirement for high performance polymeric films used in second surface mirror coatings on thermal control systems. The intensity in color of aromatic polyimide films was lowered by reducing the electronic interaction between chromophoric centers in the polymer molecular structure and by using highly purified monomers. The resulting lightly colored to colorless polyimide films have been characterized by UV-visible and infrared spectroscopy before and after exposure to 300 equivalent solar hours UV irradiation and varying doses of 1 MeV electron irradiation. After irradiation, the films were found to be 2 to 2.5 times more transparent than commercial polyimide film of the same thickness.

St. Clair, A. K.; Slemp, W. S.

1985-01-01

209

Graphene film growth on polycrystalline metals.  

PubMed

Graphene, a true wonder material, is the newest member of the nanocarbon family. The continuous network of hexagonally arranged carbon atoms gives rise to exceptional electronic, mechanical, and thermal properties, which could result in the application of graphene in next generation electronic components, energy-storage materials such as capacitors and batteries, polymer nanocomposites, transparent conducting electrodes, and mechanical resonators. With one particularly attractive application, optically transparent conducting electrodes or films, graphene has the potential to rival indium tin oxide (ITO) and become a material for producing next generation displays, solar cells, and sensors. Typically, graphene has been produced from graphite using a variety of methods, but these techniques are not suitable for growing large-area graphene films. Therefore researchers have focused much effort on the development of methodology to grow graphene films across extended surfaces. This Account describes current progress in the formation and control of graphene films on polycrystalline metal surfaces. Researchers can grow graphene films on a variety of polycrystalline metal substrates using a range of experimental conditions. In particular, group 8 metals (iron and ruthenium), group 9 metals (cobalt, rhodium, and iridium), group 10 metals (nickel and platinum), and group 11 metals (copper and gold) can support the growth of these films. Stainless steel and other commercial copper-nickel alloys can also serve as substrates for graphene film growth. The use of copper and nickel currently predominates, and these metals produce large-area films that have been efficiently transferred and tested in many electronic devices. Researchers have grown graphene sheets more than 30 in. wide and transferred them onto display plastic ready for incorporation into next generation displays. The further development of graphene films in commercial applications will require high-quality, reproducible growth at ambient pressure and low temperature from cheap, readily available carbon sources. The growth of graphene on metal surfaces has drawbacks: researchers must transfer the graphene from the metal substrate or remove the metal by etching. Further research is needed to overcome these transfer and removal challenges. PMID:22891883

Edwards, Rebecca S; Coleman, Karl S

2013-01-15

210

Low Temperature Growth of Nanostructured Diamond Films on Metals  

NASA Technical Reports Server (NTRS)

The field of nanocrystalline diamond and tetrahedral amorphous carbon films has been the focus of intense experimental activity in the last few years for applications in field emission display devices, optical windows, and tribological coatings, The choice of substrate used in most studies has typically been silicon. For metals, however, the thermal expansion mismatch between the diamond film and substrate gives rise to thermal stress that often results in delamination of the film. To avoid this problem in conventional CVD deposition low substrate temperatures (less than 700 C) have been used, often with the incorporation of oxygen or carbon monoxide to the feedgas mixture. Conventionally grown CVD diamond films are also rough and would require post-deposition polishing for most applications. Therefore, there is an obvious need to develop techniques for deposition of well-adhered, smooth nano-structured diamond films on metals for various tribological applications. In our work, nanostructured diamond films are grown on a titanium alloy substrate using a two-step deposition process. The first step is performed at elevated temperature (820 C) for 30 minutes using a H2/CH4/N2 gas mixture in order to grow a thin (approx. 600 nm) nanostructured diamond layer and improve film adhesion. The remainder of the deposition involves growth at low temperature (less than 600 C) in a H2/CH4/O2 gas mixture. Laser reflectance Interferometry (LRI) pattern during growth of a nanostructured diamond film on Ti-6Al-4V alloy. The first 30 minutes are at a high temperature of 820 C and the rest of the film is grown at a low temperature of 580 T. The fringe pattern is observed till the very end due to extremely low surface roughness of 40 nm. The continuation of the smooth nanostructured diamond film growth during low temperature deposition is confirmed by in-situ laser reflectance interferometry and by post-deposition micro-Raman spectroscopy and surface profilometry. Similar experiments performed without the starting nanostructured diamond layer resulted in poorly adhered films with a more crystalline appearance and a higher surface roughness. This low temperature deposition of nanostructured diamond films on metals offers advantages in cases where high residual thermal stress leads to delamination at high temperatures.

Baker, Paul A.; Catledge, Shane A.; Vohra, Yogesh K.

2001-01-01

211

Predicted and measured EMI shielding effectiveness of a metallic mesh coating on a sapphire window over a broad frequency range  

NASA Astrophysics Data System (ADS)

Metallic mesh thin film coatings have been used for many years to provide electromagnetic interference (EMI) shielding on infrared windows and domes. The level of EMI shielding effectiveness (SE) of metallic mesh coatings when used in a high frequency application is understood and characterized. Conversely, the level of SE of these metallic mesh coatings when used in a low frequency application has been called into question. In a recent study, we applied an appropriately designed metallic mesh coating to a sapphire window, mounted that window in a fixture, and tested the SE of the window assembly over a frequency range that envelopes the various military platforms covered in MIL-STD-461 (10 kHz to 18 GHz) for a radiated emissions test. The test plan was devised in such a way as to independently assess the individual contributions of the aperture, the mounting, and the metallic mesh coating to the total shielding. The results of our testing will be described in this paper. Additionally, the test results will be compared to the predicted SE for both the aperture and the metallic mesh coated window in order to validate the predictive model. Finally, an assessment of the appropriateness of the use of metallic mesh coatings for EMI shielding in a low and/or broad range frequency application will be made.

Jacoby, Keith T.; Pieratt, Matthew W.; Halman, Jennifer I.; Ramsey, Keith A.

2009-05-01

212

Modification of optical properties of metal island films by electric field-assisted dissolution of clusters  

NASA Astrophysics Data System (ADS)

Metal island films show unique optical properties owing to the local surface plasmon resonance of islands free electrons. In the present study, the electric field assisted dissolution of clusters in metal island films is reported. Island films of Au, Ag, and Cu are deposited under different conditions by thermal evaporation and coated with thin dielectric layers. The samples are treated with the simultaneous application of an intense electric field and temperature, leading to the sample partial or total bleaching due to the dissolution of metal clusters in the films. Owing the facility of production of metal island films and the inexpensive technical requirements of the dissolution process, this approach suggests a novel path for the production of low-cost photonic structures.

Sancho-Parramon, J.; Janicki, V.; Zorc, H.; Lon?ari?, M.

2008-09-01

213

Process optimization of ultrasonic spray coating of polymer films.  

PubMed

In this work we have performed a detailed study of the influence of various parameters on spray coating of polymer films. Our aim is to produce polymer films of uniform thickness (500 nm to 1 ?m) and low roughness compared to the film thickness. The coatings are characterized with respect to thickness, roughness (profilometer), and morphology (optical microscopy). Polyvinylpyrrolidone (PVP) is used to do a full factorial design of experiments with selected process parameters such as temperature, distance between spray nozzle and substrate, and speed of the spray nozzle. A mathematical model is developed for statistical analysis which identifies the distance between nozzle and substrate as the most significant parameter. Depending on the drying of the sprayed droplets on the substrate, we define two broad regimes, "dry" and "wet". The optimum condition of spraying lies in a narrow window between these two regimes, where we obtain a film of desired quality. Both with increasing nozzle-substrate distance and temperature, the deposition moves from a wet state to a dry regime. Similar results are also achieved for solvents with low boiling points. Finally, we study film formation during spray coating with poly (D,L-lactide) (PDLLA). The results confirm the processing knowledge obtained with PVP and indicate that the observed trends are identical for spraying of other polymer films. PMID:23631433

Bose, Sanjukta; Keller, Stephan S; Alstrøm, Tommy S; Boisen, Anja; Almdal, Kristoffer

2013-06-11

214

Protective lithium ion conducting ceramic coating for lithium metal anodes and associate method  

DOEpatents

A battery structure including a cathode, a lithium metal anode and an electrolyte disposed between the lithium anode and the cathode utilizes a thin-film layer of lithium phosphorus oxynitride overlying so as to coat the lithium anode and thereby separate the lithium anode from the electrolyte. If desired, a preliminary layer of lithium nitride may be coated upon the lithium anode before the lithium phosphorous oxynitride is, in turn, coated upon the lithium anode so that the separation of the anode and the electrolyte is further enhanced. By coating the lithium anode with this material lay-up, the life of the battery is lengthened and the performance of the battery is enhanced.

Bates, John B. (Oak Ridge, TN)

1994-01-01

215

Practical antireflection coatings for metal-semiconductor solar cells  

NASA Technical Reports Server (NTRS)

The metal-semiconductor solar cell is a potential candidate for converting solar energy to electrical energy for space and terrestrial application. In this paper, a method for obtaining parameters of practical antireflection (AR) coatings for the metal-semiconductor solar cells is given. This method utilizes the measured equivalent index of refraction obtained from ellipsometry, since the surface to be AR coated has a multilayer structure. Both the experimental results and theoretical calculations of optical parameters for Ta2O5 AR coatings on Au-GaAs and Au-GaAs(0.78)P(0.22) solar cells are presented for comparison.

Yeh, Y. C. M.; Ernest, F. P.; Stirn, R. J.

1976-01-01

216

Practical anti-reflection coating for metal semiconductor solar cells  

NASA Technical Reports Server (NTRS)

The metal-semiconductor solar cell is a possible candidate for converting solar to electrical energy for terrestrial application. A method is given for obtaining optical parameters of practical antireflection coatings for the metal-semiconductor solar cell. This method utilizes the measured refractive index obtained from ellipsometry since the surface to be AR coated has a multilayer structure. Both the experimental results and theoretical calculation of optical parameters for Ta2O5 antireflection coatings on Au-GaAs and Au-GaAs(0.78)P(0.22) solar cells are presented for comparison.

Yeh, Y.-C. M.; Stirn, R. J.

1975-01-01

217

Application of terahertz pulsed imaging to analyse film coating characteristics of sustained-release coated pellets.  

PubMed

Terahertz pulsed imaging (TPI) was employed to explore its suitability for detecting differences in the film coating thickness and drug layer uniformity of multilayered, sustained-release coated, standard size pellets (approximately 1mm in diameter). Pellets consisting of a sugar starter core and a metoprolol succinate layer were coated with a Kollicoat(®) SR:Kollicoat(®) IR polymer blend for different times giving three groups of pellets (batches I, II and III), each with a different coating thickness according to weight gain. Ten pellets from each batch were mapped individually to evaluate the coating thickness and drug layer thickness between batches, between pellets within each batch, and across individual pellets (uniformity). From the terahertz waveform the terahertz electric field peak strength (TEFPS) was used to define a circular area (approximately 0.13 mm(2)) in the TPI maps, where no signal distortion was found due to pellet curvature in the measurement set-up used. The average coating thicknesses were 46 ?m, 71 ?m and 114 ?m, for batches I, II and III respectively, whilst no drug layer thickness difference between batches was observed. No statistically significant differences in the average coating thickness and drug layer thickness within batches (between pellets) but high thickness variability across individual pellets was observed. These results were confirmed by scanning electron microscopy (SEM). The coating thickness results correlated with the subsequent drug release behaviour. The fastest drug release was obtained from batch I with the lowest coating thickness and the slowest from batch III with the highest coating thickness. In conclusion, TPI is suitable for detailed, non-destructive evaluation of film coating and drug layer thicknesses in multilayered standard size pellets. PMID:23721891

Haaser, M; Karrout, Y; Velghe, C; Cuppok, Y; Gordon, K C; Pepper, M; Siepmann, J; Rades, T; Taday, P F; Strachan, C J

2013-12-01

218

Effect of Doping on beta-Tricalcium Phosphate Bioresorbable Bulk Material and Thin Film Coatings  

NASA Astrophysics Data System (ADS)

Magnesium has emerged as a revolutionary biodegradable metal for use as an orthopedic material, it has several advantages over the current metallic materials in use, including eliminating the effects of stress shielding, improving biocompatibility and inhibiting degradation rates, thus removing the requirement of a second surgery for implant removal. Due to the rapid degradation of magnesium, it is necessary to control the corrosion rates of the materials to match the rates of bone healing. This dissertation reports on the effect of doping on the properties of beta-tricalcium phosphate (beta-TCP). It also reports on its application as a thin film coating on magnesium alloys for implant applications. Adding various dopants to beta-TCP significantly influences critical properties. In this study, discs were fabricated in two compositions: (i) undoped beta-TCP, (ii) beta-TCP doped with 1.0 wt % MgO, 0.5 wt % ZnO, and 1.0 wt % TiO2. Films were fabricated from these compositions using the pulsed laser deposition (PLD) technique. These coatings were then characterized for corrosive, hardness, and cytocompatibility. The XRD patterns of the coating confirm the amorphous nature of the films. The presence of the metal oxides in beta-TCP improved ceramic densification. The application of these doped coatings was also found to increase the hardness by 88 %, the modulus of elasticity by 66 %, and improve corrosion resistance of the magnesium alloy substrate; with a 2.4 % improvement in Ecorr and 95 % decrease in icorr. Cell viability was studied using an osteoblast precursor cell line MC3T3-E1 to assure that the biocompatibility of these ceramics was not altered due to the dopants. Long-term biodegradation studies were conducted by measuring weight change and surface microstructure as a function of time in simulated body fluid. The results suggest that these coatings could be used for bioresorbable implants with improved corrosion resistance and increased hardness.

Abdalla, Suhaila

219

Self-bonding acrylic polymer overcoat for coated metal substrates  

US Patent & Trademark Office Database

An insulated heat bondable electrically conductive material includes an electrically conductive substrate, a base coat on the substrate of electrically insulating, heat resistant, cured resin, and an overcoat of heat curable acrylic polymer upon the base coat forming a heat bondable acrylic polymer coating thereon. The disclosure also includes: an insulated heat bondable magnet wire; a bondable enamel coated, insulated electrical conductor; an article; a dynamoelectric machine; a method of making an insulated, heat bondable metal substrate; and, a method of self-bonding a plurality of turns of a magnet wire.

1983-06-14

220

Electroless (autocatalytic) nickel-cobalt thin films as solar control coatings  

NASA Astrophysics Data System (ADS)

This paper describes the deposition of nickel-cobalt-phosphorous coatings by the electroless deposition technique for use as solar control coatings in architectural glazing of buildings. Electroless deposition is characterized by the autocatalytic deposition of a metal/alloy from an aqueous solution of its ions by interaction with a chemical reducing agent. The reducing agent provides electrons for the metal ions to be neutralized. The reduction is initiated by the catalyzed surface of the substrate and continued by the self catalytic activity of the deposited metal/alloy as long as the substrate is immersed in the electroless bath and operating conditions are maintained. Electroless nickel-cobalt-phosphorous thin films were deposited from a solution containing 15 g/l nickel sulphate, 5 g/l cobalt sulphate, 60 g.l ammonium citrate and 25 g/l sodium hypophosphite operating at 30 degree(s)C, at a pH of 9.5 for two minutes. Electroless nickel-cobalt-phosphorous coatings are found to satisfy the basic requirements of solar control coatings. Autocatalytic deposition technique offers the possibilities of producing large area coatings with low capital investment, stability and good adhesion to glass substrates.

John, S.; Srinivasan, K. N.; Selvam, M.; Anuradha, S.; Rajendran, S.

1994-09-01

221

Wear resistance of boron nitride coated metal  

Microsoft Academic Search

The wear resistance of boron nitride films was studied. The films of 1 mum thickness were prepared on the surface of a cutting tool by simultaneous nitrogen ion irradiation and vapor depositon of boron; the Vickers hardness of the films was between 3000 and 5000 kg\\/mm2. The test was performed by the cutting of steel. On the tool deposited directly,

Yasunori Andoh; Satoshi Nishiyama; Shigeki Sakai; Kiyoshi Ogata; Fuminori Fujimoto

1993-01-01

222

A comparison of boron-doped diamond thin-film and Hg-coated glassy carbon electrodes for anodic stripping voltammetric determination of heavy metal ions in aqueous media  

Microsoft Academic Search

The performance of boron-doped diamond (BDD) for the anodic stripping voltammetric (ASV) determination of heavy metal ions (Zn2+, Cd2+, Pb2+, Cu2+, Ag+) was compared with that of Hg-coated glassy carbon (Hg-GC). Hg has historically been the electrode of choice for ASV but there is an ongoing search for alternate electrodes and diamond is one of these. Despite the fundamentally different

Elizabeth A. McGaw; Greg M. Swain

2006-01-01

223

Interfacial bond strength of electrophoretically deposited hydroxyapatite coatings on metals.  

PubMed

Hydroxyapatite (HAp) coatings were deposited onto substrates of metal biomaterials (Ti, Ti6Al4V, and 316L stainless steel) by electrophoretic deposition (EPD). Only ultra-high surface area HAp powder, prepared by the metathesis method 10Ca(NO3)2 + 6(NH4)2HPO4 + 8NH4OH), could produce dense coatings when sintered at 875-1000degreesC. Single EPD coatings cracked during sintering owing to the 15-18% sintering shrinkage, but the HAp did not decompose. The use of dual coatings (coat, sinter, coat, sinter) resolved the cracking problem. Scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) inspection revealed that the second coating filled in the "valleys" in the cracks of the first coating. The interfacial shear strength of the dual coatings was found, by ASTM F1044-87, to be approximately 12 MPa on a titanium substrate and approximately 22 MPa on 316L stainless steel, comparing quite favorably with the 34 MPa benchmark (the shear strength of bovine cortical bone was found to be 34 MPa). Stainless steel gave the better result since -316L (20.5 microm mK(-1)) > alpha-HAp (approximately 14 microm mK(-1)), resulting in residual compressive stresses in the coating, whereas alpha-titanium (approximately 10.3 microm mK(-1)) < alpha-HAp, resulting in residual tensile stresses in the coating. PMID:15348125

Wei, M; Ruys, A J; Swain, M V; Kim, S H; Milthorpe, B K; Sorrell, C C

1999-07-01

224

Coatings Preserve Metal, Stone, Tile, and Concrete  

NASA Technical Reports Server (NTRS)

John B. Schutt, a chemist at Goddard Space Flight Center, created a coating for spacecraft that could resist corrosion and withstand high heat. After retiring from NASA, Schutt used his expertise to create new formulations for Daytona Beach, Florida-based Adsil Corporation, which now manufactures a family of coatings to preserve various surfaces. Adsil has created 150 jobs due to the products.

2014-01-01

225

Parametric Study of Metal/Polymer Multilayer Coatings for Temperature Wrinkling Prediction  

NASA Astrophysics Data System (ADS)

This article presents an analytic model for the prediction of wrinkling occurring in metal/polymer coatings under particular conditions. Owing to different thermal expansion coefficients (TECs) of the substrate and the different coating layers, temperature variation can induce a compressive stress in the coating. The wrinkling is the material response to the instability caused by this compressive stress. In this study, a reference case was selected: a 0.27-mm-thick steel sheet with a 5-?m-thick polymer layer and, on top of it, a thin aluminum film of 50 nm in thickness. For this reference case, it was observed and predicted by the model that an increase in temperature yielded to the wrinkling of the thin aluminum film. The geometry of the multilayer coating and the properties of the constituent materials are factors able to promote or prevent the wrinkle. To better understand and predict their effects, a sensitivity analysis was carried out with the proposed analytic model. A special attention was devoted to the temperature when wrinkling occurs. The key parameters having a significant influence on the wrinkling temperature were identified. It is concluded that the elastic modulus of the thin aluminum film and that of the polymer, the TEC of the thin film, and the initial stress induced during the processing of the multilayer system all had a significant influence on the wrinkling temperature.

Zhang, Lihong; Habraken, Anne Marie; Ben Bettaieb, Amine; Duchêne, Laurent

2013-09-01

226

Plasma-sprayed ceramic coatings for protection against molten metal.  

SciTech Connect

Molten metal environments pose a special demand on materials due to the high temperature corrosion effects and thermal expansion mismatch induced stress effects. A solution that has been successfully employed is the use of a base material for the mechanical strength and a coating material for the chemical compatibility with the molten metal. The work described here used such an approach coating tungsten rods with aluminum oxide, yttria-stabilized zirconia, yttrium oxide, and erbium oxide deposited by atmospheric plasma spraying. The ceramic materials were deposited under varying conditions to produce different structures. Measurement of particle characteristics was performed to correlate to material properties. The coatings were tested in a thermal cycling environment to simulate the metal melting cycle expected in service. Results of the testing indicate the effect of material composition and spray conditions on the thermal cycle crack resistance of the coatings.

Hollis, K. J. (Kendall J.); Peters, M. I. (Maria I.); Bartram, B. D. (Brian D.)

2002-01-01

227

In situ Raman spectroscopy of annealed diamondlike carbon metal composite films  

NASA Astrophysics Data System (ADS)

Diamondlike carbon films and diamondlike carbon-metal composite films may provide increased component reliability, decreased fuel consumption, decreased noise/vibration/harshness (NVH), and decreased lubricant use in next generation automotive components. Raman spectra were obtained for diamondlike carbon, diamondlike carbon-platinum composite films, and diamondlike carbon-gold composite films, which were annealed to a temperature of 523 °C. The Raman spectra for these films were fitted using a two-Gaussian function. The variation of the G-peak position, the D-peak position, and the ID/ IG ratio was examined as a function of temperature. The unalloyed diamondlike carbon film demonstrated greater thermal stability than the diamondlike carbon-noble metal composite films. These results suggest that the operating temperatures of the diamondlike carbon-coated automotive components must be kept under careful consideration.

Jin, C.; Zhou, H.; Graham, S.; Narayan, R. J.

2007-05-01

228

THE PENETRABILITY OF A THIN METALLIC FILM INSIDE THE RF FIELD.  

SciTech Connect

Thin metallic film was widely applied in various areas. Especially, recently we are planning to apply it in a ''Secondary emission enhanced photo-injector'', in which a diamond cathode is coated with a metallic film on its back to serve as a current path. The thickness of the film is originally considered to be in the order of 10 nm, which is much less than the skin depth, by a factor of almost 200. One would think intuitively that the RF filed would penetrate such a thin film. However, we found it is not true. The film will block most of the field. This paper addresses theoretical analysis as well as the experimental results, and demonstrates that the penetrability of a thin film is very poor. Consequently, most of the RF current will flow on the thin film causing a serious heating problem.

ZHAO, Y.; BEN-ZVI, I.; CHANG, X.; RAO, T.; CHEN, W.; DINARDO, R.; BEUTENMULLER, R.

2005-05-16

229

Metal coating on suspended carbon nanotubes and its implication to metal–tube interaction  

Microsoft Academic Search

Coating of various metals on suspended single-walled carbon nanotubes (SWNT) is carried out by electron-beam evaporation. Transmission electron microscopy studies reveal that Ti, Ni and Pd coatings on the suspended tubes are continuous and quasi-continuous, resulting in nanotube-supported metal nanowire structures. In strong contrast, Au, Al, and Fe coatings on the suspended SWNTs only form isolated discrete particles on the

Y. Zhang; Nathan W. Franklin; Robert J. Chen; Hongjie Dai

2000-01-01

230

A Investigation Into the Relaxation Behavior of Pharmaceutical Film Coatings  

Microsoft Academic Search

Polymeric materials utilized as film coatings exhibit many different time dependent relaxations which can yield relevant information regarding their use. In this dissertation research, the effect of additives on the primary relaxation behavior and the effect of physical aging, a relaxation to the lowest free energy state, on the physical properties of glassy polymeric materials was investigated. Glassy polymeric materials

Christopher Michael Sinko

1989-01-01

231

The drag-out problem in film coating theory  

Microsoft Academic Search

An important step towards the understanding of many industrial coating processes is a solution of the dragout problem, which is to determine the thickness of the film of liquid which clings to a plate when it is drawn steadily out of a bath of the liquid. An approximate solution, valid for small capillary numbers, was given by Landau and Levich,

S. D. R. Wilson

1982-01-01

232

Synergistic Fire Performance Between Metal or Metal Filled Organic Coatings and Engineering Plastics  

Microsoft Academic Search

Metal filled organic and EMI coatings affect the fire performance properties of engineering plastics. Zinc arc spray, zinc\\/epoxy, and zinc borate\\/epoxy coatings on modified-polyphenylene oxide (m-PPO) are particu larly effective. The results from non-flaming NBS smoke chamber tests show a dramatic reduction in smoke for zinc and zinc borate coatings, whereas a ZnO coating did not show the same effect.

Ramazan Benrashid; Gordon L. Nelson

1993-01-01

233

Nodular growth in thick-sputtered metallic coatings  

NASA Technical Reports Server (NTRS)

Thick-sputtered S-Monel, silver, and 304 stainless steel coatings were deposited on mica and metal substrates with various surface finishes to investigate the nodular growth in the coating by scanning electron microscopy. The geometry and the surface structure of the nodules are characterized. Compositional changes within the coating were analyzed by energy dispersive X-ray analysis. Defects in the surface finish (i.e., scratches, inclusions, etc.), act as preferential nucleation sites and form isolated and complex nodules and various surface overgrowths in the coating. The nodule boundaries are very vulnerable to chemical etching and these nodules do not disappear after full annealing. Further, they have undesirable effects on mechanical properties; cracks are initiated at the nodules when the coating is stressed by mechanical forces. These effects are illustrated by micrographs. Nodular growth within a coating can be minimized or eliminated by increasing the surface smoothness.

Spalvins, T.; Brainard, W. A.

1974-01-01

234

Magnetoelastic sensor for characterizing properties of thin-film/coatings  

NASA Technical Reports Server (NTRS)

An apparatus for determining elasticity characteristics of a thin-film layer. The apparatus comprises a sensor element having a base magnetostrictive element at least one surface of which is at least partially coated with the thin-film layer. The thin-film layer may be of a variety of materials (having a synthetic and/or bio-component) in a state or form capable of being deposited, manually or otherwise, on the base element surface, such as by way of eye-dropper, melting, dripping, brushing, sputtering, spraying, etching, evaporation, dip-coating, laminating, etc. Among suitable thin-film layers for the sensor element of the invention are fluent bio-substances, thin-film deposits used in manufacturing processes, polymeric coatings, paint, an adhesive, and so on. A receiver, preferably remotely located, is used to measure a plurality of values for magneto-elastic emission intensity of the sensor element in either characterization: (a) the measure of the plurality of values is used to identify a magneto-elastic resonant frequency value for the sensor element; and (b) the measure of the plurality of successive values is done at a preselected magneto-elastic frequency.

Bachas, Leonidas G. (Inventor); Barrett, Gary (Inventor); Grimes, Craig A. (Inventor); Kouzoudis, Dimitris (Inventor); Schmidt, Stefan (Inventor)

2004-01-01

235

Metal-doped magnetite thin films.  

PubMed

This paper investigates magnetite (Fe3O4) thin film containing a small amount of a metal element. The films are prepared by rf sputtering with a composite target of ceramic iron oxide with metal chips. Low-temperature magnetization of magnetite containing 5.3%Ge reveals that the film contains some magnetically weak coupling grains. The metal element Mg reduces both hematite (alpha-Fe2O3) and magnetite, resulting in single-phase wüstite (Fe1-xO). In contrast, adding Ge selectively reduces hematite, while magnetite remains unreactive. According to the free energy of reaction, the element Ge is able to reduce hematite only, whereas the element Mg is capable of reducing both hematite and magnetite. This property is in good agreement with the experiment results. PMID:22905582

Abe, Seishi; Ping, De Hai; Nakamura, Shintaro; Ohnuma, Masato; Ohnuma, Shigehiro

2012-06-01

236

A near-infrared reflectance analysis method for the noninvasive identification of film-coated and non-film-coated, blister-packed tablets  

Microsoft Academic Search

A non-invasive near-infrared reflectance analysis (NIRA) method has been developed to confirm the identity of blister-packed, film-coated and non film-coated tablets for clinical trial supplies. NIR spectra of the tablets were measured through the blister pack plastic using a fiber optic probe. The blister packs contained 18 cells which held pink, pentagonal tablets or film-coated, white, oblong tablets. The pink

Melissa A. Dempster; Brian F. MacDonald; Paul J. Gemperline; Nichole R. Boyer

1995-01-01

237

Novel microstructure in spin coated polyaniline thin films.  

PubMed

Polyaniline (Pani) thin films doped with camphor sulfonic acid (CSA) have been deposited on glass substrates using the spin coating technique. Pani is chemically synthesized by an oxidation method at ?0?°C. Pani-CSA films show a hexagonal structure in scanning electron micrographs, which occurs due to the crystalline growth of CSA. A dense hexagonal structure is visible for film deposited at 800 rpm, but it becomes sparser as the revolutions per minute are increased (1200, 1500 and 2000 rpm). Electronic transition of quinoid units cause an absorption shoulder at ?900 nm for films deposited at 1200, 1500 and 2000 rpm, which is not observed for film deposited at 800 rpm. PMID:21690993

Verma, Deepak; Dutta, V

2007-05-01

238

Density-related properties of metal oxide films  

Microsoft Academic Search

The density of the material in a deposited film determines many important film properties, for example hardness and abrasions resistance, adherence to the substrate, refractive index, film stress, flatness and film permeation. Chemical compound films like metal oxides, some nitrides and oxynitrides are mainly produced by reactive PVD processes. The energy input into the growing film strongly influence the density

Hans K. Pulker; Stefan S. Schlichtherle

2004-01-01

239

Size and rate dependent necking in thin metallic films  

NASA Astrophysics Data System (ADS)

The control of the ductility of thin metallic films is a major issue in a variety of technologies involving flexible electronics, MEMS and deformable coatings. An enhanced closed form 1D imperfection based localization analysis is developed in order to investigate the mechanics of diffuse necking in metallic films. The model relies on a description of the localization process in a finite length specimen using either a 2- or 3-zone model, under plane stress or plane strain tension conditions. A strain gradient plasticity contribution to the stabilization of the localization process is taken into account in the hardening response through a simple estimate of the deformation gradient inside the necking zone. The model, with gradient plasticity effects, is validated towards 2D finite element simulations. The response of the material involves both strain-hardening and rate sensitivity, as well as possible creep relaxation. The plastic flow parameters are related to the grain size and film thickness. The model shows, in agreement with experiments, that the ductility can either drop to small values for very small grain sizes and/or film thickness due to the high strength and to the presence of imperfections, or can remain constant or even increase owing to an increased rate sensitivity resulting from thermally activated mechanisms. This last stabilization effect can be reinforced by gradient plasticity effects if allowed by the dominant deformation mechanism.

Pardoen, T.

2014-01-01

240

Metallic and Ceramic Thin Film Thermocouples for Gas Turbine Engines  

PubMed Central

Temperatures of hot section components in today's gas turbine engines reach as high as 1,500 °C, making in situ monitoring of the severe temperature gradients within the engine rather difficult. Therefore, there is a need to develop instrumentation (i.e., thermocouples and strain gauges) for these turbine engines that can survive these harsh environments. Refractory metal and ceramic thin film thermocouples are well suited for this task since they have excellent chemical and electrical stability at high temperatures in oxidizing atmospheres, they are compatible with thermal barrier coatings commonly employed in today's engines, they have greater sensitivity than conventional wire thermocouples, and they are non-invasive to combustion aerodynamics in the engine. Thin film thermocouples based on platinum:palladium and indium oxynitride:indium tin oxynitride as well as their oxide counterparts have been developed for this purpose and have proven to be more stable than conventional type-S and type-K thin film thermocouples. The metallic and ceramic thin film thermocouples described within this paper exhibited remarkable stability and drift rates similar to bulk (wire) thermocouples.

Tougas, Ian M.; Amani, Matin; Gregory, Otto J.

2013-01-01

241

Evaluating the effect of coating equipment on tablet film quality using terahertz pulsed imaging.  

PubMed

In this study, terahertz pulsed imaging (TPI) was employed to investigate the effect of the coating equipment (fluid bed and drum coater) on the structure of the applied film coating and subsequent dissolution behaviour. Six tablets from every batch coated with the same delayed release coating formulation under recommended process conditions (provided by the coating polymer supplier) were mapped individually to evaluate the effect of coating device on critical coating characteristics (coating thickness, surface morphology and density). Although the traditional coating quality parameter (weight gain) indicated no differences between both batches, TPI analysis revealed a lower mean coating thickness (CT) for tablets coated in the drum coater compared to fluid bed coated tablets (p<0.05). Moreover, drum coated tablets showed a more pronounced CT variation between the two sides and the centre band of the biconvex tablets, with the CT around the centre band being 22.5% thinner than the top and bottom sides for the drum coated tablets and 12.5% thinner for fluid bed coated tablets. The TPI analysis suggested a denser coating for the drum coated tablets. Dissolution testing confirmed that the film coating density was the drug release governing factor, with faster drug release for tablets coated in the fluid bed coater (98 ± 4% after 6h) compared to drum coated tablets (72 ± 6% after 6h). Overall, TPI investigation revealed substantial differences in the applied film coating quality between tablets coated in the two coaters, which in turn correlated with the subsequent dissolution performance. PMID:23563103

Haaser, Miriam; Naelapää, Kaisa; Gordon, Keith C; Pepper, Michael; Rantanen, Jukka; Strachan, Clare J; Taday, Philip F; Zeitler, J Axel; Rades, Thomas

2013-11-01

242

Thin films by metal-organic precursor plasma spray  

SciTech Connect

While most plasma spray routes to coatings utilize solids as the precursor feedstock, metal-organic precursor plasma spray (MOPPS) is an area that the authors have investigated recently as a novel route to thin film materials. Very thin films are possible via MOPPS and the technology offers the possibility of forming graded structures by metering the liquid feed. The current work employs metal-organic compounds that are liquids at standard temperature-pressure conditions. In addition, these complexes contain chemical functionality that allows straightforward thermolytic transformation to targeted phases of interest. Toward that end, aluminum 3,5-heptanedionate (Al(hd){sub 3}), triethylsilane (HSi(C{sub 2}H{sub 5}){sub 3} or HSiEt{sub 3}), and titanium tetrakisdiethylamide (Ti(N(C{sub 2}H{sub 5}){sub 2}){sub 4} or Ti(NEt{sub 2}){sub 4}) were employed as precursors to aluminum oxide, silicon carbide, and titanium nitride, respectively. In all instances, the liquids contain metal-heteroatom bonds envisioned to provide atomic concentrations of the appropriate reagents at the film growth surface, thus promoting phase formation (e.g., Si-C bond in triethylsilane, Ti-N bond in titanium amide, etc.). Films were deposited using a Sulzer Metco TriplexPro-200 plasma spray system under various experimental conditions using design of experiment principles. Film compositions were analyzed by glazing incidence x-ray diffraction and elemental determination by x-ray spectroscopy. MOPPS films from HSiEt{sub 3} showed the formation of SiC phase but Al(hd){sub 3}-derived films were amorphous. The Ti(NEt{sub 2}){sub 4} precursor gave MOPPS films that appear to consist of nanosized splats of TiOCN with spheres of TiO{sub 2} anatase. While all films in this study suffered from poor adhesion, it is anticipated that the use of heated substrates will aid in the formation of dense, adherent films.

Schulz, Douglas L.; Sailer, Robert A.; Payne, Scott; Leach, James; Molz, Ronald J. [North Dakota State University, Fargo, North Dakota 58108-6050 (United States); Sulzer Metco (United States) Inc., Westbury, New York 11590-2724 (United States)

2009-07-15

243

Spray forming polymer membranes, coatings and films  

DOEpatents

A method is described for forming a polymer film having controlled physical and chemical characteristics, wherein a plume of nebulized droplets of a polymer or polymer precursor is directed toward a substrate from a converging/diverging nozzle having a throat at which the polymer or a precursor thereof is introduced and an exit from which the nebulized droplets of the polymer or precursor thereof leave entrained in a carrier gas. Relative movement between the nozzle and the substrate is provided to form a polymer film. Physical and chemical characteristics can be controlled by varying the deposition parameters and the gas and liquid chemistries. Semipermeable membranes of polyphosphazene films are disclosed, as are a variety of other polymer systems, both porous and non-porous. 4 figures.

McHugh, K.M.; Watson, L.D.; McAtee, R.E.; Ploger, S.A.

1993-10-12

244

Spray forming polymer membranes, coatings and films  

DOEpatents

A method of forming a polymer film having controlled physical and chemical characteristics, wherein a plume of nebulized droplets of a polymer or polymer precursor is directed toward a substrate from a converging/diverging nozzle having a throat at which the polymer or a precursor thereof is introduced and an exit from which the nebulized droplets of the polymer or precursor thereof leave entrained in a carrier gas. Relative movement between the nozzle and the substrate is provided to form a polymer film. Physical and chemical characteristics can be controlled by varying the deposition parameters and the gas and liquid chemistries. Semipermeable membranes of polyphosphazene films are disclosed, as are a variety of other polymer systems, both porous and non-porous.

McHugh, Kevin M. (Idaho Falls, ID); Watson, Lloyd D. (Rigby, ID); McAtee, Richard E. (Idaho Falls, ID); Ploger, Scott A. (Rigby, ID)

1993-01-01

245

Liquid metal film flow for fusion application  

SciTech Connect

Liquid metal film flow with a free surface is promising for application in Tokamak reactor diverter targets. Experiments with film flow of the eutectic alloy In-Ga-Sn on an inclined chute in a coplanar magnetic field have been conducted as a first step toward such target development. The chute width and length were, respective, 90 and 620 mm, the initial film thickness 4 mm, the mean velocity 0.18-1.25 m/s, and the magnetic field induction up to 0.6 T. The film mean thickness over the chute width and length was measured as well as the surface wave amplitude. The measured distribution of the film thickness over the length was compared with the calculated one based on one-and two-dimensional models. The correlation is satisfactory in the range of experimental characteristic parameters.

Baranov, V.V.; Kirillov, I.R.; Firsova, E.V. [I.I. Polzunov Central Boiler and Turbine Inst., St. Petersburg (Russian Federation)] [and others

1995-04-01

246

Immersion Deposition of Metal Films on Silicon and Germanium Substrates in Supercritical Carbon Dioxide  

SciTech Connect

A low temperature carbon dioxide based on immersion deposition technology (SFID) has been developed for producing palladium, copper, silver, and other metal films on silicon-based substrates in supercritical CO2. The reaction is initiated by oxidation of elemental silicon to SiF4 or H2SiF6 by HF with the release of electrons that cause the reduction of metal ions in an organometallic precursor to the metallic form on silicon surface in CO2. Only the substrate surfaces are coated with metals using this method. Based on surface analysis of the films and spectroscopic analysis of the reaction products, the mechanism of metal film deposition is discussed. The metal films (Pd, Cu, and Ag) formed on silicon surfaces by the SFID method exhibit good coverage, smooth and dense texture, high purity and a metallic behavior. Similarly, metal films can also be deposited onto geranium substrates using SFID. The gas-like properties and the high pressure of the supercritical fluids, combined with the low reaction temperature, make this SFID method potentially useful for depositing thin metal films in small features, which are difficult to accomplish by conventional CVD methods.

Ye, Xiang-Rong; Wai, Chien M.; Zhang, Daqing; Kranov, Yanko; Mcilroy, David; Lin, Yuehe; Engelhard, Mark H.

2003-01-29

247

New Synthetic Routes to Metal Boride Thin Films and Metallaboranes  

Microsoft Academic Search

This dissertation describes the investigation of the chemical vapor deposition of metal\\/metal boride thin films of transition and rare earth elements from metal halides and boron hydride precursors. Also reported are thermal routes to the synthesis of new metallaborane complexes. A systematic approach to the chemical vapor deposition of metal\\/metal boride thin films of the first row transition elements has

Shreyas Suresh Kher

1993-01-01

248

Wear resistance of boron nitride coated metal  

NASA Astrophysics Data System (ADS)

The wear resistance of boron nitride films was studied. The films of 1 ?m thickness were prepared on the surface of a cutting tool by simultaneous nitrogen ion irradiation and vapor depositon of boron; the Vickers hardness of the films was between 3000 and 5000 kg/mm 2. The test was performed by the cutting of steel. On the tool deposited directly, the wear of the surface is large and this could not be improved greatly. However, the tools prepared after nitridation of the surface layer by ion implantation and the one with another nitride layer in the interface showed decreasing wear, and the wear of the tool with an interlayer of silicon nitride could be decreased to about 15%. As a result, it became clear that boron nitride could be effectively used as a highly hard film by the optimization of the interface between the film and the matrix.

Andoh, Yasunori; Nishiyama, Satoshi; Sakai, Shigeki; Ogata, Kiyoshi; Fujimoto, Fuminori

1993-06-01

249

Micro-Scratch Study of a Magnetron-Sputtered Zr-Based Metallic-Glass Film  

SciTech Connect

Using the micro-scratch technique, the tribological behavior of ZrCuAlNi metallic-glass coatings on 316L stainless steel was studied. With the application of ramping normal loads, the critical normal loads of about 110 mN were determined, at which the coefficient of friction increased sharply and the indenter penetration depth exceeded the film thickness. No clear evidence of coating debonding has been found, which, together with the observation of multiple shear bands, indicates good adhesion and ductility of the metallic-glass coating. When subjected to constant normal loads, the coefficient of friction increased rapidly once the critical normal load was passed. The scratch results and the scanning-electron microscopy observations indicated good adhesion between the coating and the substrate, which may be due to the good interfacial bonding and low coating residual stress.

Liu, F. X. [University of Tennessee, Knoxville (UTK); Yang, F. Q. [University of Kentucky; Gao, Yanfei [ORNL; Jiang, W. H. [University of Tennessee, Knoxville (UTK); Guan, Y F [University of Tennessee, Knoxville (UTK); Rack, P. D. [University of Tennessee, Knoxville (UTK); Sergic, O. [CSM Instruments Inc.; Liaw, Peter K [University of Tennessee, Knoxville (UTK)

2009-01-01

250

Skylab D024 thermal control coatings and polymeric films experiment  

NASA Technical Reports Server (NTRS)

The Skylab D024 Thermal Control Coatings and Polymeric Films Experiment was designed to determine the effects of the external Skylab space environment on the performance and properties of a wide variety of selected thermal control coatings and polymeric films. Three duplicate sets of thermal control coatings and polymeric films were exposed to the Skylab space environment for varying periods of time during the mission. The specimens were retrieved by the astronauts during extravehicular activities (EVA) and placed in hermetically sealed return containers, recovered, and returned to the Wright Laboratory/Materials Laboratory/WPAFB, Ohio for analysis and evaluation. Postflight analysis of the three sets of recovered thermal control coatings indicated that measured changes in specimen thermo-optical properties were due to a combination of excessive contamination and solar degradation of the contaminant layer. The degree of degradation experienced over-rode, obscured, and compromised the measurement of the degradation of the substrate coatings themselves. Results of the analysis of the effects of exposure on the polymeric films and the contamination observed are also presented. The D024 results were used in the design of the LDEF M0003-5 Thermal Control Materials Experiment. The results are presented here to call to the attention of the many other LDEF experimenters the wealth of directly related, low earth orbit, space environmental exposure data that is available from the ten or more separate experiments that were conducted during the Skylab mission. Results of these experiments offer data on the results of low altitude space exposure on materials recovered from space with exposure longer than typical STS experiments for comparison with the LDEF results.

Lehn, William L.; Hurley, Charles J.

1992-01-01

251

Magnetic metal nanoparticles coated polyacrylonitrile textiles as microwave absorber  

NASA Astrophysics Data System (ADS)

Polyacrylonitrile (PAN) textiles with 2 mm thickness are coated with magnetic nanoparticles in coating baths with Ni, Co and their alloys via an electroless metal deposition method. The crystal structure, morphology and magnetic nature of composites are investigated by X-ray Powder diffraction, Scanning Electron Microscopy, and dc magnetization measurement techniques. The frequency dependent microwave absorption measurements have been carried out in the frequency range of 12.4-18 GHz (X and P bands). Diamagnetic and ferromagnetic properties are also investigated. Finally, the microwave absorption of composites is found strongly dependent on the coating time. One absorption peak is observed between 14.3 and 15.8 GHz with an efficient absorption bandwidth of 3.3-4.1 GHz (under -20 dB reflection loss limit). The Reflection loss (RL) can be achieved between -30 and -50 dB. It was found that the RL is decreasing and absorption bandwidth is decreasing with increasing coating time. While absorption peak moves to lower frequencies in Ni coated PAN textile, it goes higher frequencies in Co coated ones. The Ni-Co alloy coated composites have fluctuating curve of absorption frequency with respect to coating time. These results encourage further development of magnetic nanoparticle coated textile absorbers for broadband applications.

Akman, O.; Kavas, H.; Baykal, A.; Toprak, M. S.; Çoruh, Ali; Akta?, B.

2013-02-01

252

Tribology of metal-containing diamond-like carbon coatings  

Microsoft Academic Search

Ball-on-disk tests were run for several commercial and in-house metal-containing diamond-like carbon (Me:DLC) coatings on steel coupons. The balls, which were made from either WC?Co or 52100 steel, developed normal stresses between roughly 100 MPa and 1 GPa during the course of the experiments. The wear resistance of the Me:DLC coatings from the various sources (running against WC balls) differed

Stephen J. Harris; Anita M. Weiner; Wen-Jin Meng

1997-01-01

253

Indentation of Metallic and Cermet Thermal Spray Coatings  

NASA Astrophysics Data System (ADS)

Indentation methods are presented by which the elastic and inelastic stress-strain characteristics of metallic thermal spray (TS) coatings on substrates may be extracted. The methods are based on existing techniques for brittle solids, and adapted for the finite geometry associated with coatings. Basic assumptions and derivations are given, along with guidelines for experimental measurement. Using these, indentation inelastic stress-strain curves are generated for NiCrAlY and Ni-Al bondcoats, as well as WC-Co cermet coatings. Elastic moduli are extracted for CoNiCrAlY coatings. Results are briefly discussed in the context of the effect of feedstock material, process and post-process heat treatment on the intrinsic properties of splats as well as their in-coating cohesion. The methods presented are attractive, particularly for the TS industry, due to the minimal specimen preparation and lack of intricate equipment required for measurement.

Choi, W. B.; Prchlik, L.; Sampath, S.; Gouldstone, A.

2009-03-01

254

Bi-Sr-Ca-Cu-O superconducting films fabricated using metal alkoxides  

Microsoft Academic Search

Superconducting films in the Bi--Sr--Ca--Cu--O systems were made using metal alkoxides. To prepare a dip-coating solution using a mixed alkoxide solution, insoluble Cu and Bi alkoxides were dissolved by modification with 2-dimethylaminoethanol and formation of a double alkoxide, respectively. Formation of the double alkoxides of Bi with Ca or Sr was confirmed using FT-IR and ¹H-NMR. Bi--Sr--Ca--Cu--O films on yttria-stabilized

Shingo Katayama; Masahiro Sekine

1991-01-01

255

Transparent conductive ITO thin films through the sol-gel process using metal salts  

Microsoft Academic Search

The electrical and optical properties, structure and morphology of ITO thin films were investigated. Ten percent by weight Sn-doped indium oxide (ITO) films were prepared on soda-lime-silicate glass substrate by the sol-gel spin coating method using inorganic metal salts. All layers studied with a thickness range of 50–350 nm were polycrystalline with grain sizes in the range 20–30 nm depending

Seon-Soon Kim; Se-Young Choi; Chan-Gyung Park; Hyeon-Woo Jin

1999-01-01

256

The preparation and surface roughness of CeO 2–TiO 2 films by a sol–gel spin-coating process  

Microsoft Academic Search

Ultraviolet absorbing CeO2–TiO2 coatings were prepared by the sol–gel spin-coating process and heat treated at 500°C. The surface microstructure of the films was observed by SEM, and roughness and flatness were measured. We found a pattern on the surface of films. That pattern was similar to that of the metal vacuum chuck stage for fixing the substrate. The pattern on

Akio Makishima; Hiromichi Sakamoto; Jianbei Qiu

2004-01-01

257

Thermal fatigue testing of thin metal films  

Microsoft Academic Search

An experimental method is described for performing thermal fatigue testing of thin films and lines on substrates. The method uses Joule heating from alternating currents to generate temperature, strain, and stress cycles in the metal structures. The apparatus has been installed in a scanning electron microscope and allows in situ observations of the fatigue damage evolution. First observations on Cu

R. R. Keller; C. A. Volkert

2004-01-01

258

Interfacial bond strength of electrophoretically deposited hydroxyapatite coatings on metals  

Microsoft Academic Search

Hydroxyapatite (HAp) coatings were deposited onto substrates of metal biomaterials (Ti, Ti6Al4V, and 316L stainless steel) by electrophoretic deposition (EPD). Only ultra-high surface area HAp powder, prepared by the metathesis method 10Ca(NO3)2 + 6(NH4)2HPO4 + 8NH4OH), could produce dense coatings when sintered at 875–1000°C. Single EPD coatings cracked during sintering owing to the 15–18% sintering shrinkage, but the HAp did

M. Wei; A. J. Ruys; M. V. Swain; S. H. Kim; B. K. Milthorpe; C. C. Sorrell

1999-01-01

259

Continuously manufacturing of bulk metallic glass-coated wire composite  

Microsoft Academic Search

Continuously processing is developed for producing a novel bulk metallic glass (BMG)-coated wire composite. The process here yields wire composite coil with the wire diameter of several hundred microns. This paper shows Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 (VIT1) BMG-coated tungsten wire of 200?m and 250?m diameter as examples. The thickness of BMG coating is controllable from several to tens of microns. The amorphous structure

Xiaohua Chen; Baoyu Zhang; Guoliang Chen; Yong Zhang; Xidong Hui; Zhaoping Lu; Xiongjun Liu; Yong Xu; Xianran Xing

2010-01-01

260

Measurements and Diagnostics of Diamond Films and Coatings  

NASA Technical Reports Server (NTRS)

The commercial potential of chemical-vapor-deposited (CVD) diamond films has been established and a number of applications have been identified through university, industry, and government research studies. This paper discusses the methodologies used for property measurement and diagnostic of CVD diamond films and coatings. Measurement and diagnostic techniques studied include scanning electron microscopy, transmission electron microscopy, atomic force microscopy, stylus profilometry, x-ray diffraction, electron diffraction, Raman spectroscopy, Rutherford backscattering, elastic recoil spectroscopy, and friction examination. Each measurement and diagnostic technique provides unique information. A combination of techniques can provide the technical information required to understand the quality and properties of CVD diamond films, which are important to their application in specific component systems and environments. In this study the combination of measurement and diagnostic techniques was successfully applied to correlate deposition parameters and resultant diamond film composition, crystallinity, grain size, surface roughness, and coefficient of friction.

Miyoshi, Kazuhisa; Wu, Richard L. C.

1999-01-01

261

Self-healing of metallized polymer films of different nature  

Microsoft Academic Search

Self-healing is the spontaneous extinction of a local electrical arc due to the destruction of the electrodes during the process. It occurs in capacitors made of metallized films of plastics with a thin layer of metal. A theoretical model of the self-healing phenomenon has been elaborated from a previous investigation of aluminium metallized polypropylene films (PP films). To verify the

B. Walgenwitz; J.-H. Tortai; N. Bonifaci; A. Denat

2004-01-01

262

Quantum metal film in the dielectric environment  

NASA Astrophysics Data System (ADS)

A method has been proposed for self-consistent calculations of characteristics of a metal film in dielectrics. The most interesting (asymmetric) case of metal-dielectric sandwiches, where the dielectrics are different on both sides of the film, has been considered in terms of the modified Kohn-Sham method and the stabilized jellium model. The spectrum, electron work function, and surface energy of polycrystalline films placed in passive insulators have been calculated for the first time using Al and Na as an example. It has been found that the dielectric environment generally leads to a negative change in both the electron work function and the surface energy. In addition to the size changes, the shift of the work function is determined by the arithmetic mean of the dielectric constants of the surrounding media.

Babich, A. V.; Pogosov, V. V.

2013-01-01

263

Preparing oxidizer coated metal fuel particles  

NASA Technical Reports Server (NTRS)

A solid propellant composition of improved efficiency is described which includes an oxidizer containing ammonium perchlorate, and a powered metal fuel, preferably aluminum or beryllium, in the form of a composite. The metal fuel is contained in the crystalline lattice framework of the oxidizer, as well as within the oxidizer particles, and is disposed in the interstices between the oxidizer particles of the composition. The propellant composition is produced by a process comprising the crystallization of ammonium perchlorate in water, in the presence of finely divided aluminum or beryllium. A suitable binder is incorporated in the propellant composition to bind the individual particles of metal with the particles of oxidizer containing occluded metal.

Shafer, J. I.; Simmons, G. M. (inventors)

1974-01-01

264

Solar Selective Coatings Prepared From Thin-Film Molecular Mixtures and Evaluated  

NASA Technical Reports Server (NTRS)

Thin films composed of molecular mixtures of metal and dielectric are being considered for use as solar selective coatings for a variety of space power applications. By controlling molecular mixing during ion-beam sputter deposition, researchers can tailor the solar selective coatings to have the combined properties of high solar absorptance and low infrared emittance. On orbit, these combined properties simultaneously maximize the amount of solar energy captured by the coating and minimize the amount of thermal energy radiated. The solar selective coatings are envisioned for use on minisatellites, for applications where solar energy is used to power heat engines or to heat remote regions in the interior of the spacecraft. Such systems may be useful for various missions, particularly those to middle Earth orbit. Sunlight must be concentrated by a factor of 100 or more to achieve the desired heat inlet operating temperature. At lower concentration factors, the temperature of the heat inlet surface of the heat engine is too low for efficient operation, and at high concentration factors, cavity type heat receivers become attractive. The an artist's concept of a heat engine, with the annular heat absorbing surface near the focus of the concentrator coated with a solar selective coating is shown. In this artist's concept, the heat absorbing surface powers a small Stirling convertor. The astronaut's gloved hand is provided for scale. Several thin-film molecular mixtures have been prepared and evaluated to date, including mixtures of aluminum and aluminum oxide, nickel and aluminum oxide, titanium and aluminum oxide, and platinum and aluminum oxide. For example, a 2400- Angstrom thick mixture of titanium and aluminum oxide was found to have a solar absorptance of 0.93 and an infrared emittance of 0.06. On the basis of tests performed under flowing nitrogen at temperatures as high as 680 C, the coating appeared to be durable at elevated temperatures. Additional durability testing is planned, including exposure to atomic oxygen, vacuum ultraviolet radiation, and high-energy electrons.

Jaworske, Don A.

2003-01-01

265

Pentek metal coating removal system: Baseline report  

SciTech Connect

The Pentek coating removal technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The Pentek coating removal system consisted of the ROTO-PEEN Scaler, CORNER-CUTTER{reg_sign}, and VAC-PAC{reg_sign}. They are designed to remove coatings from steel, concrete, brick, and wood. The Scaler uses 3M Roto Peen tungsten carbide cutters while the CORNER-CUTTER{reg_sign} uses solid needles for descaling activities. These hand tools are used with the VAC-PAC{reg_sign} vacuum system to capture dust and debris as removal of the coating takes place. The safety and health evaluation during the testing demonstration focused on two main areas of exposure: dust and noise. Dust exposure minimal, but noise exposure was significant. Further testing for each exposure is recommended because of the environment where the testing demonstration took place. It is feasible that the dust and noise levels will be higher in an enclosed operating environment of different construction. In addition, other areas of concern found were arm-hand vibration, whole-body, ergonomics, heat stress, tripping hazards, electrical hazards, machine guarding, and lockout/tagout.

NONE

1997-07-31

266

Synthesis and characterization of sol-gel-derived nanomaterials and nanocrystalline electroless metal coatings  

NASA Astrophysics Data System (ADS)

CuS (minimum size of 2.5 nm), Ag2S (minimum and average size of 2.5 nm and 26 nm respectively), and Au (with minimum size of <10 nm) nanoparticles dispersed within the sol-gel derived hydroxypropyl cellulose (HPC)-silica films are synthesized using the gas diffusion technique. The effectiveness of HPC polymer, as a 'compatibilizer', to synthesize semiconductor and metal nanoparticles distributed uniformly within the silica film is demonstrated. The sol-gel derived HPC-silica films containing dispersed nanoparticles are characterized using x-ray photoelectron spectroscopy (XPS) to understand the mechanism of formation of nanoparticles within the film. The XPS core-level binding energies (B.E.) for the nanoparticles are observed to be sensitive to the variation in the chemical composition at the surface and their size. The 'cluster size effect' is shown to be useful in predicting the average nanoparticle size. Nanocrystalline ZrO2 particles are successfully synthesized using sol-gel technique utilizing HPC polymer as a 'steric barrier'. The use of HPC polymer is demonstrated to synthesize submicron-sized, non-agglomerated, and spherical as well as nanocrystalline ZrO2 particles by adjusting the sol-gel synthesis parameters. The effect of sol-gel synthesis parameters on ZrO2 nanocrystallite size, its distribution, and the phase evolution behavior of ZrO2 is studied. The optimum sol-gel synthesis parameters for synthesizing nanocrystalline ZrO2 with 100% tetragonal phase are identified. Cu/CuO-ZrO2 composite powder is synthesized using the electroless metal deposition technique. The mechanism of electroless deposition of Cu over ZrO2 particle surface is investigated using XPS. On the basis of 'cluster size effect', it is suggested that, the electroless metal deposition process activates the non-catalytic ceramic substrate surface by depositing metallic Pd0 clusters and not by the accepted Pd-Sn alloy catalyst. Fly ash cenosphere particle surface is also activated by metallic Pd0 clusters under similar coating conditions. The cenosphere particles are further coated with Ag using Pd-activation. The Cu and Ag-coated cenosphere particles find application in manufacturing conducting polymers used for electromagnetic interference (EMI) shielding application. The use of cost-effective activator (AgNO3) is demonstrated for coating the cenosphere particles with Cu for commercialization. The use of Focussed Ion Beam (FIB) microscopy technique is demonstrated to directly measure the coating-thickness.

Shukla, Satyajit Vishnu

267

Fabrication of Y123 coated conductors using metal organic decomposition process  

NASA Astrophysics Data System (ADS)

Recent trends in HTS research have been geared toward development of coated conductors. In these conductors, a flexible metallic substrate, typically a nickel alloy, is covered successively with one or more thin buffer layer such as YSZ, STO, MgO, etc., and a relatively thick film of Y123. To make the fabrication of such conductors scalable and cost effective, this paper demonstrates the application of metal organic decomposition techniques to deposit the buffer layers and the YBCO films. We present results obtained strontium titanate buffer layers. These buffer layers, processed on single crystal substrates using solution precursors and heat treated in a reducing atmosphere are highly textured and have a uniform smooth surface. YBCO films, 0.3-0.5?m thick, deposited on these buffered single crystals using the trifluoroacetate process shows good superconducting properties. YBCO films processed on strontium titanate buffered lanthanum aluminate substrates have transition temperatures of 90-91 K and critical current densities of the order of 10 5 A/cm 2 at 77K and self field. These processing techniques have been extended to textured nickel substrates. These results offer promise to the development of a scalable, solution based processing route to deposit buffer layers and YBCO films on flexible metallic textured tapes.

Sathyamurthy, S.; Salama, K.

268

Traction of Lubricated Rolling Contacts between Thin-Film Coatings and Steel  

Microsoft Academic Search

Tribological thin-film coatings can enhance the performance of mechanical components such as bearings and gears. Although a lubricant is present in most applications, the interactions of the lubricant with the coated surfaces are not always well understood. In the present study, Stribeck curves (i.e., traction coefficient vs. dimensionless film thickness ?) were generated for lubricated rolling contact between coated and

Ryan D. Evans; J. David Cogdell; Gerald A. Richter; Gary L. Doll

2008-01-01

269

Optimum antireflection coating for Antireflection-coated Metal-Oxide-Semiconductor /AMOS/ solar cells  

NASA Technical Reports Server (NTRS)

Consideration is given to the design of a single-layer optimum antireflection coating for AMOS (antireflection-coated metal-oxide-semiconductor) solar cells to match the entire sunlight spectrum. The energy conversion efficiency is maximized by maximizing the open-circuit voltage and the short-circuit current. The former is maximized by oxidation techniques and the latter is maximized by the light-coupling into the solar cell. With reference to the effective index of refraction as obtained by ellipsometry, examples of optimum antireflection coatings for 60-A Au-GaAs solar cells are presented.

Yeh, Y. C. M.; Ernest, F. P.; Stirn, R. J.

1977-01-01

270

Film coatings for taste masking and moisture protection.  

PubMed

Taste masking and moisture protection of oral dosage forms contribute significantly to the therapeutic effect of pharmaceutical and nutraceutical formulations either by ensuring patient compliance or by providing stability through shelf life of the dosage form. Among different types of taste, bitter taste is the most relevant for patient acceptance because of the extremely high sensitivity. As hydrolysis is the most common mode of degradation of an active ingredient, moisture protection plays a vital role in the stability of the active during manufacturing and storage. Optimized oral dosage forms need to reliably hinder the release of bitter drug molecules in the mouth or ensure stability of the active compound, while also ensuring fast drug release in the stomach to enable early therapeutic onset. Besides different formulation concepts, film coating is found to be the most effective and commonly used approach for taste masking and moisture protection. Film coating can be achieved through the use of water-soluble, cationic, anionic or neutral insoluble polymers from different chemical structures. Cationic polymers provide efficient moisture protection as well as taste masking without influencing the release of the drug in the gastric fluids. Polymers may be sprayed onto various types of cores from dispersions or solutions in organic, solvents or water in drum or fluidzed bed coaters. Applied quantities need insuring complete coating thickness ranging from 0.5 to 50 ?m or more finally. Insulating excipients, such as hydrophobic plasticizers, lipids, pigments or other insoluble substances will influence the functionality of films. Organoleptic tests are still common in testing the quality of taste-masked formulations. Recently, multi-channel taste sensors have been developed to quantify different types of taste. Dynamic vapor sorption technique and studies at elevated temperature provide effective concepts study the efficacy of the formulations. Efficient taste masking and reliable moisture protection of solid oral dosage forms can be achieved by film coating implementing the options of pharmaceutical polymers and processes. PMID:24148666

Joshi, S; Petereit, H-U

2013-12-01

271

Tantalum oxide thin films as protective coatings for sensors  

Microsoft Academic Search

Reactively sputtered tantalum oxide thin films have been investigated as protective coatings for aggressive media exposed sensors. Tantalum oxide is shown to be chemically very robust. The etch rate in aqueous potassium hydroxide with pH 11 at 140 is lower than 0.008 . Etching in liquids with pH values in the range from pH 2 to 11 have generally given

Carsten Christensen; Roger de Reus; Siebe Bouwstra

1999-01-01

272

Tantalum oxide thin films as protective coatings for sensors  

Microsoft Academic Search

Reactively sputtered tantalum oxide thin-films have been investigated as protective coating for aggressive media exposed sensors. Tantalum oxide is shown to be chemically very robust. The etch rate in aqueous potassium hydroxide with pH 11 at 140°C is lower than 0.008 Å\\/h. Etching in liquids with pH values in the range from pH 2-11 have generally given etch rates below

Carsten Christensen; Roger de Reus; S. Bouwstra

1999-01-01

273

Enhanced electrochemical properties of fluoride-coated LiCoO2 thin films  

PubMed Central

The electrochemical properties of fluoride-coated lithium cobalt oxide [LiCoO2] thin films were characterized. Aluminum fluoride [AlF3] and lanthanum fluoride [LaF3] coating layers were fabricated on a pristine LiCoO2 thin film by using a spin-coating process. The AlF3- and LaF3-coated films exhibited a higher rate capability, cyclic performance, and stability at high temperature than the pristine film. This indicates that the AlF3 and LaF3 layers effectively protected the surface of the pristine LiCoO2 film from the reactive electrolyte.

2012-01-01

274

Application of thick film and bulk coating technology to the Subterrene program  

SciTech Connect

From conference on structure-property relationships in thick film and bulk coatings; San Francisco, California, USA (28 Jan The Subterrene is a rock- melting earth-penetration system representing a significant advancement in excavation technology. Temperatures of 1700-2000 deg K are involved, and heated refractorymetal or alloy probes are used. Corrosion problems are severe on the exterior surfaces of the refractory metals used; bulk coatings having the required properties would be extremely desirable provided they could be deposited upon a substrate as a tenacious coating. Within the Subterrene, pyrographite radiant heaters are operating at temperatures to 2450 deg K. Graphite receptors added to improve the radiant heat transfer react with the Mo and W penetrator bodies to form carbides. A 30 mu m-thick CVD film of TaC may be applied to inhibit this reaction. The techniques of applying these fllms, their nature, and the results of their application, are discussed. The environment of an operating penetrator is described, and the requirements and properties of exterior coatings are outlined. (auth)

Stark, W.A. Jr.; Wallace, T.C.; Witteman, W.; Krupka, M.C.; David, W.R.; Radosevich, C.

1974-01-01

275

Metallic and nonmetallic coatings for ICF targets  

Microsoft Academic Search

Some fusion targets designed to be driven by 0.35 to 1 ..mu..m laser light are glass spheres coated with layers of various materials such as hydrocarbons, fluorocarbons, beryllium, copper, gold, platinum, etc. The glass shell, which is filled with gas, liquid or solid deuterium-tritium fuel, must have remarkably good surface and wall thickness uniformity. Methods for depositing the various materials

C. D. Hendricks; J. K. Crane; E. J. Hsieh; S. F. Meyer

1981-01-01

276

Laser surface modification of metal-coated ceramics  

Microsoft Academic Search

Pulsed excimer laser radiation has been successfully employed in the improvement (greater than 50 percent) of fracture strength of metal-coated ceramics. Thin metallic layers (about 500 A) of nickel were deposited on silicon nitride and silicon carbide substrates and further irradiated with pulsed excimer laser pulses. The laser energy density was varied from 0.4 to 2.0 J sq cm to

R. K. Singh; K. Jagannadham; J. Narayan

1988-01-01

277

Zinc oxide films prepared by sol-gel spin-coating  

Microsoft Academic Search

The d.c. electrical conductivity and optical properties of undoped zinc oxide films prepared by the sol-gel process using a spin-coating technique were investigated. The ZnO films were obtained by 10 cycle spin-coated and dried zinc acetate films followed by annealing in air at 500–575°C. The films deposited on the Pyrex glass substrate were polycrystalline and c-axis oriented. A minimum film

Y. Natsume; H Sakata

2000-01-01

278

Evaluation of Elastomers, Plastics, Coatings and Metals.  

National Technical Information Service (NTIS)

This report is divided into two sections, one covering the mechanical properties of metals and the other the evaluation of nonmetallic materials. The first section studies the fracture and crack growth properties of the primary structural materials, HP 9N...

D. A. Gerdeman W. E. Berner G. J. Petrak

1974-01-01

279

Conductive, Lusterless Coatings for Light Metals.  

National Technical Information Service (NTIS)

A metallic conductive, lusterless plating system with improved corrosion durability developed for aluminum was the basis for a program on the improvements of the corrosion durability of magnesium. A composite of electroplates containing either a fused tin...

C. H. Layer G. R. Schaer J. G. Beach W. H. Safranek

1972-01-01

280

Analysis of cermet films with large metal packing fractions  

NASA Astrophysics Data System (ADS)

Recently reported dielectric properties of deposited Rh films show anomalously small values of the real part of the dielectric function with respect to the imaginary part and also with respect to bulk values. This behavior is substantially different from that expected on the basis of standard isotropic effective-medium theories. Using a strong-coupling model that has an approximate analytic solution, I show that this behavior is consistent with a two-phase, microscopically inhomogeneous but macroscopically homogeneous physical mixture of metal and dielectric, where the dielectric (presumably a grain-boundary oxide or simply open spaces between grains) is restricted essentially to the boundaries of the metal particles and provides optical isolation between them (metal-rich cermet configuration.) The solution is of the Maxwell-Garnett type with the dielectric acting as host phase. Since this solution becomes exact in the limit of vanishing dielectric volume fraction, this model provides a striking demonstration that connectedness, not relative volume fraction, is the physical property determining the identity of the host species. The Rh-film data are best described by an analytic, two-parameter, two-phase effective-medium model that incorporates randomness as well as the coated-particle microstructure and was developed by Sen, Scala, and Cohen to describe the low-frequency conductance of sedimentary rocks.

Aspnes, D. E.

1986-01-01

281

Microstructure of a Base Metal Thick Film System.  

National Technical Information Service (NTIS)

A base metal thick film conductor system using glass frits with base metal oxide additions was investigated as metallization for hybrid microcircuits. Application of previous work on wetting and chemical bonding was made to this system. The observation of...

D. E. Mentley

1976-01-01

282

Intergranular metal phase increases thermal shock resistance of ceramic coating  

NASA Technical Reports Server (NTRS)

Dispersed copper phase increases the thermal shock resistance of a plasma-arc-sprayed coating of zirconia used as a heat barrier on a metal substrate. A small amount of copper is deposited on the granules of the zirconia powder before arc-spraying the resultant powder composite onto the substrate.

Carpenter, H. W.

1966-01-01

283

Metal coatings for laser fusion targets by electroplating  

Microsoft Academic Search

Metal coated laser fusion targets must be dense, uniform, spherically symmetric to within a few percent of their diameters, and smooth to better than a few tenths of a micron. Electroplating offers some unique advantages including low temperature deposition, a wide choice of elements, and substantial industrial plating technology. We have evaluated electroless and electroplating systems for gold and copper,

J. D. Illige; C. M. Yu; S. A. Letts

1981-01-01

284

Metal coatings for laser fusion targets by electroplating  

Microsoft Academic Search

Metal coated laser fusion targets must be dense, uniform spherically symmetric to within a few percent of their diameters and smooth to better than a few tenths of a micron. Electroplating offers some unique advantages including low temperature deposition, a wide choice of elements and substantial industrial plating technology. We have evaluatd electroless and electroplating systems for gold and copper,

J. D. Illige; C. M. Yu; S. A. Letts

1980-01-01

285

Coated metal sintering carriers for fuel cell electrodes  

DOEpatents

A carrier for conveying components of a fuel cell to be sintered through a sintering furnace. The carrier comprises a metal sheet coated with a water-based carbon paint, the water-based carbon paint comprising water, powdered graphite, an organic binder, a wetting agent, a dispersing agent and a defoaming agent.

Donelson, Richard (Glen Waverly, AU); Bryson, E. S. (Downers Grove, IL)

1998-01-01

286

Coated metal sintering carriers for fuel cell electrodes  

DOEpatents

A carrier is described for conveying components of a fuel cell to be sintered through a sintering furnace. The carrier comprises a metal sheet coated with a water-based carbon paint, the water-based carbon paint comprising water, powdered graphite, an organic binder, a wetting agent, a dispersing agent and a defoaming agent.

Donelson, R.; Bryson, E.S.

1998-11-10

287

Metallic biomaterials TiN-coated: corrosion analysis and biocompatibility.  

PubMed

Corrosion processes due to contact with the physiological environment should be avoided or minimized in orthopedic implants. Four metallic substrates frequently used as biomaterials: pure Ti, Ti-6Al-4V alloy, ASTM F138 stainless steel, and Co-Cr-Mo alloy, were coated with TiN using the physical vapor deposition (PVD) technique. These coatings have been screened by polarization curves in physiological solutions. TiN prepared by PVD is efficient as coating for stainless steel. On titanium and alloy there are no benefits concerning the corrosion resistance compared to the bare Ti-materials. TiN coatings have been screened according to ISO 10993 standard tests for biocompatibility and exhibited no cytotoxicity, dermal irritation, or acute systemic toxicity response. PMID:12752209

Paschoal, André Luís; Vanâncio, Everaldo Carlos; Canale, Lauralice de Campos Franceschini; da Silva, Orivaldo Lopes; Huerta-Vilca, Domingos; Motheo, Artur de Jesus

2003-05-01

288

Method For Improving The Oxidation Resistance Of Metal Substrates Coated With Thermal Barrier Coatings  

DOEpatents

A method for providing a protective coating on a metal-based substrate is disclosed. The method involves the application of an aluminum-rich mixture to the substrate to form a discontinuous layer of aluminum-rich particles, followed by the application of a second coating over the discontinuous layer of aluminum-rich particles. Aluminum diffuses from the aluminum-rich layer into the substrate, and into any bond coat layer which is subsequently applied. Related articles are also described. A method for providing a protective coating on a metal-based substrate is disclosed. The method involves the application of an aluminum-rich mixture to the substrate to form a discontinuous layer of aluminum-rich particles, followed by the application of a second coating over the discontinuous layer of aluminum-rich particles. Aluminum diffuses from the aluminum-rich layer into the substrate, and into any bond coat layer which is subsequently applied. Related articles are also described.

Thompson, Anthony Mark (Niskayuna, NY); Gray, Dennis Michael (Delanson, NY); Jackson, Melvin Robert (Niskayuna, NY)

2003-05-13

289

Silicon nitride films for the protective functional coating: blood compatibility and biomechanical property study.  

PubMed

Behaviors of silicon nitride films and their relation to blood compatibility and biomechanical have been interesting subjects to researchers. A systematic blood compatibility and biomechanical property investigation on the deposition of silicon-nitride films under varying N? and CF? flows was carried out by direct current unbalanced magnetron sputtering techniques. Significant role of surface property, chemical bonding state of silicon nitride film and blood compatibility, mechanical properties for the films were observed. The chemical bonding configurations, surface topography, contact angle and mechanical properties were characterized by means of X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and nano-indentation technique and CSEM pin-on-disk tribometer. Blood compatibility of the films was evaluated by platelet adhesion investigation. The results of the platelet adhesion tests shown that the effect of fluorine and nitrogen-doped revealed an intimate relationship between the ratio of polar component and dispersion component of the surface energy and its hemocompatibility. Si-N-O coating can be a great candidate for developing antithrombogenic surfaces in blood contacting materials. The chemical bonding state made an adjustment in microstructured surfaces, once in the totally wettable configuration, may improve the initial contact between platelet and biomedical materials, due to the appropriate ratio of dispersion component and polar component. To resist wear, biomedical components require coatings that are tough and hard, have low friction, and are bio-inert. The study suggests that by Si-N coating the metal surfaces could be a choice to prolong the life of the sliding pair Co-Cr-Mo alloy/UHMWPE implants. PMID:23137618

Shi, Zhifeng; Wang, Yingjun; Du, Chang; Huang, Nan; Wang, Lin; Ning, Chengyun

2012-12-01

290

Coloured paints based on coated flakes of metal as the pigment, for enhanced solar reflectance and cooler interiors: description and theory  

Microsoft Academic Search

Flakes of metal coated with thin dielectric films, when used as various coloured paint pigments, can reflect much more of the near infra red component of solar radiation than standard paints of equivalent colour, which makes them attractive for reducing cooling loads in cars and under metal roofs, while maintaining a wide range of decorative options. Spectral responses, solar absorptance

G. B. Smith; A. Gentle; P. Swift; A. Earp; N. Mronga

2003-01-01

291

Supercritical Fluid Immersion Deposition: A New Process for Selective Deposition of Metal Films on Silicon Substrates  

SciTech Connect

Supercritical CO2 is used as a new solvent for immersion deposition, a galvanic displacement process traditionally carried out in aqueous HF solutions containing metal ions, to selectively develop metal films on featured or non-featured silicon substrates. Components of supercritical fluid immersion deposition (SFID) solutions for fabricating Cu and Pd films on silicon substrates are described along with the corresponding experimental setup and procedure. Only silicon substrates exposed and reactive to SFID solutions can be coated. The highly pressurized and gas-like supercritical CO2, combined with the galvanic displacement property of immersion deposition, enables the SFID technique to selectively deposit metal films in small features. SFID may also provide a new method to fabricate palladium silicide in small features or to metallize porous silicon.

Ye, Xiangrong; Wai, Chien M.; Lin, Yuehe; Young, James S.; Engelhard, Mark H.

2005-01-01

292

Coatings for corrosion protection of metals and alloys  

Microsoft Academic Search

Thin films prepared by electrochemical and physical vapor deposition (PVD) methods were investigated for corrosion protection of metals and alloys. Various electrochemical methods were developed, such as electrophoretic deposition (EPD), electrolytic deposition (ELD) and combined methods. EPD method has been developed for the deposition of polymer films, including poly(2-vinylpyridine) (PVP) and co-polymer poly(4-vinylpyridine-co-butyl methacrylate) (PVPBM). The method involved the electrophoresis

Lijia Yang

2012-01-01

293

Structural and magnetic properties of ferromagnetic metal-oxide films grown by polymer assisted deposition  

NASA Astrophysics Data System (ADS)

Ferromagnetic metal-oxide films such as doped lanthanum manganites have been extensively investigated over the past decade due to their potential applications in different fields. To grow these oxide films, the most widely used approaches are physical vapor deposition, chemical vapor deposition, and chemical solution deposition techniques. One of the challenges in solution-based processes of such oxide films has been to produce high quality multilayer films and at the same time to control the stoichiometry. We describe a solution route called polymer-assisted deposition (PAD) to grow such oxide films. High quality epitaxial single layer and multilayer coated films of La0.67Sr0.33MnO3 (LSMO) and La0.67Ca0.33MnO3 (LCMO) have been grown by PAD. Multilayer is used to effectively take the advantages of both LSMO and LCMO with an aim to achieve large values of magnetoresistance (MR) near room temperature. An MR value as high as -66% at 5 T has been obtained at 295K for the multilayer-coated films with LSMO/LCMO volume ratio of 60/40. The successful growth of epitaxial doped lanthanum manganites with desired properties by PAD shows that PAD is a feasible alternative approach to the growth of high quality metal-oxide films.

Jain, M.; Shukla, P.; Hundley, M. F.; Burrell, A. K.; McCleskey, T. M.; Jia, Q. X.

2007-03-01

294

Metallic coating techniques for fiber Bragg grating sensors  

NASA Astrophysics Data System (ADS)

Fiber Bragg Grating sensors (FBG) have a great resistance to embedding processes. This property is very useful for monitoring parameters at inaccessible places. Embedded fiber optic sensors into composites have been studied for a long time, but embedding a fiber sensor into metallic structure is beginning to study. Recently, this has raised interest due to embedded FBG in the metallic structure provide capabilities for controlling parameters of the structural health status and also information about their own process of deterioration. The embedding process of the FBG sensors involves the fusion of structural metallic material. During this process, very high temperatures are achieved that could damage the Bragg grating or the silica fiber. To protect the sensor during the embedding process, a fiber coating is made with a metallic material with a high melting point. In this paper we study three different techniques for coating a FBG sensor: physical vapour deposition (PVD), electroless deposition and electroplating. This paper describes the experimental procedure for coating metallic fiber optic sensors and the optical characterization.

Grandal, T.; Piñeiro, E.; Asensio, A.; Rodriguez, F.

2013-11-01

295

Plasmon hybridzation in coated metallic nanosphere  

Microsoft Academic Search

The plasmon frequencies of a general core\\/double-shell structure are studied by plasmon hybridization method, and three distinct plasmon modes (?0, ?+, and ??) are found, in which the value of ?0 is always stable, and ?+ as well as ?? is variable with the radius ratios. The influences of dielectric effect and permittivity difference between metallic core and outer-shell are

Yao Zhang; Guang Tao Fei; Li De Zhang

2011-01-01

296

SILANE-BASED CONVERSION COATING FOR METALS  

EPA Science Inventory

For the past three years, a project to develop new pretreatment rinses for metals was carried out by the U.S. Environmental Protection Agency and the University of Cincinnati. The project involved optimization of laboratory rinses with dilute aqueous solutions organofunctional s...

297

Liquid metal embrittlement of steel with galvanized coatings  

NASA Astrophysics Data System (ADS)

Article presents the state of knowledge relating occurrences of liquid metals embrittlement. The results of experimental investigations of the LME phenomenon, reasons of its formation and influence of different parameters are described. Selected ideas of the applied research methods accessible in different works are presented. Samples made of C70D steel with tensions stretching (400-800 MPa) at different values and kinds of loading during the hot dip metallization were investigated. Coating processes in two bath: zinc and zinc with 2 % tin addition were made. The processes of hot dip metallization were done at 450 °C temperature and immersion time 180 s. Coated samples were investigated by light microscope to specify possibility appear of LME effect.

Mendala, J.

2012-05-01

298

The Electronic Structure of Transition Metal Coated Fullerenes  

NASA Astrophysics Data System (ADS)

Clusters composed of fullerene molecules with an outer shell of transition metal atoms in the composition C_60M_62 (M being a transition metal) have been produced with laser vaporisation techniques(F. Tast, N. Malinowski, S. Frank, M. Heinebrodt, I.M.L. Billas, and T. P. Martin, Z. Phys D 40), 351 (1997).. We have studied several of these very large systems with a parallel version of the all-electron NRLMOL cluster code. Optimized geometries of the metal encased fullerenes C_60Ti_62 and C_60V_62 are presented along with their HOMO-LUMO gaps, electron affinities, ionization energies, and cohesive energies. We compare the stability of these clusters to relaxed met-car structures (e.g. Ti_8C_12) and to relaxed rocksalt metal-carbide fragments (TiC)n with n=8 and 32. In addition to metal-coated fullerenes we consider the possibility of a trilayered structure consisting of a small shell of metal atoms enclosed by a metal coated fullerene. The nature of bonding in these systems is analyzed by studying the electronic charge distributions.

Patton, David C.; Pederson, Mark R.; Kaxiras, Efthimios

1998-03-01

299

Heterojunction thin films based on multifunctional metal oxides for photovoltaic application  

NASA Astrophysics Data System (ADS)

Metal oxides based multifunctional heterojunction thin films of ZnO/SnO2 and ZnO/SnO2/CuO QDs were prepared by spin-coating technique. The crystallographic properties and the surface morphologies of the films were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The optical absorption studies revealed that the film thickness has considerable effect on the band gap values and is found to be in the range of 3.73-3.48 eV. The photoluminescence spectra showed several weak visible emission peaks related to the deep level defects (450-575 nm). Finally, the current density-voltage (J-V) characteristic of ZnO/SnO2/CuO QDs (ZSCI) based heterojunction thin film coated on ITO is also reported.

Prabhu, M.; Marikkannan, M.; Mayandi, J.; Soundararajan, N.; Ramachandran, K.

2014-04-01

300

Fractional van der Waals interaction between thin metallic films  

Microsoft Academic Search

The van der Waals (vdW) interaction between thin metallic films varies with separation as the separation to a fractional power. This is in contrast to the usual integer-power separation dependence between objects such as atoms, dielectric films, or thick metallic films. We have calculated the free energy of attraction between sheets of gold, silver, copper, beryllium, and tungsten numerically using

M. Boström; Bo E. Sernelius

2000-01-01

301

Optical transmission through subwavelength hole arrays in ultrathin metal films  

Microsoft Academic Search

Contrary to thick opaque metal films, where an extraordinary high transmission of light is observed through subwavelength hole arrays, in ultrathin metal films perforation can lead to a suppressed or an enhanced transmission. Here we systematically investigate the optical transmission through semitransparent Au films structured with square arrays of subwavelength holes experimentally and theoretically. We measure the transmission at various

Julia Braun; Bruno Gompf; Thomas Weiss; Harald Giessen; Martin Dressel; Uwe Hübner

2011-01-01

302

Investigation of Cu coatings deposited by kinetic metallization  

SciTech Connect

Interfacial characterisation of Kinetic Metallization (KM) sprayed Cu coatings applied on metal substrates was performed using optical and electron microscopy, as well as microindentation hardness testing and microchemical analysis. The interfacial characterisation of KM coatings remains scarce to date. Cross sectional observations of KM coatings on light metal substrates revealed an undulating, patelliform profile with thin-lipped cusps at the interface. Pure Al and Mg substrates exhibited a mechanically impinged zone <{approx}5 {mu}m on the substrate material, approximately the size of deformed Cu powder particles. Examination of the Cu side of the interface indicated there was no long range interaction in the coating. On the substrate side of the interface, the KM process induced phase transformations (i.e. recrystallisation and an alloyed zone) in thin layers contiguous to the interface on pure Al and Mg substrates. Zones of elemental interdiffusion were identified at the interface upon Al and Mg substrates using scanning TEM. The width of intermixing zones was in the vicinity of < 1 {mu}m. This metallurgical interaction at the interface occurred on the length scales involving the initial single layer of Cu particles bonded on the substrate.

Han, Y.K. [ARC Centre of Excellence for Design in Light Metals (Australia); Department of Materials Engineering, Monash University, VIC 3800 (Australia); Birbilis, N., E-mail: nick.birbilis@eng.monash.edu.au [ARC Centre of Excellence for Design in Light Metals (Australia); Department of Materials Engineering, Monash University, VIC 3800 (Australia); Spencer, K.; Zhang, M.-X. [ARC Centre of Excellence for Design in Light Metals (Australia); School of Engineering, Division of Materials, University of Queensland, St Lucia, QLD 4072 (Australia); Muddle, B.C. [ARC Centre of Excellence for Design in Light Metals (Australia); Department of Materials Engineering, Monash University, VIC 3800 (Australia)

2010-11-15

303

Plasmon hybridzation in coated metallic nanosphere  

Microsoft Academic Search

The plasmon frequencies of a general core\\/double-shell structure are studied by plasmon hybridization method, and three distinct plasmon modes (omega0, omega+, and omega-) are found, in which the value of omega0 is always stable, and omega+ as well as omega- is variable with the radius ratios. The influences of dielectric effect and permittivity difference between metallic core and outer-shell are

Yao Zhang; Guang Tao; Li De Zhang

2011-01-01

304

Formation of molten metal films during metal-on-metal slip under extreme interfacial conditions  

Microsoft Academic Search

The present paper describes results of plate-impact pressure-shear friction experiments conducted to study time-resolved growth of molten metal films during dry metal-on-metal slip under extreme interfacial conditions. By employing tribo-pairs comprising hard tool-steel against relatively low melt-point metals such as 7075-T6 aluminum alloys, interfacial friction stress ranging from 100 to 400MPa and slip speeds of approximately 100m\\/s have been generated.

Nai-Shang Liou; Makoto Okada; Vikas Prakash

2004-01-01

305

[Dental implantations of ceramics-coated metals].  

PubMed

Recent studies and personal experience of the Authors in the field of dental implants have encountered the same fundamental problem which arises with orthopedic prosthesis procedures. The basic problem is that of adhesion between the bone tissue and the metal implant. Chrome-cobalt alloy, Tantalum and Titanium are the metals of most recent use. The Authors therefore proceeded to investigate the behaviour of alveolar bone tissue in the proximity of artificial teeth made of alloy (platinum-gold) covered with ceramic, as used in prosthetic dentistry. The experiment was carried out in a dog and a man. In the dog, two of its mandibular teeth were substituted with the same ceramic-gold implants: the first, a replica of natural tooth, was placed in the socket and held in place by metal splint and mandibular circumferential wirings. The other implant, without a replicated crown, was left free, within the alveolus, without contacting the near or opposing teeth. A solid smooth surfaced alumina device, shaped like a small cylinder, was implanted in the upper femoral epiphysis of the same animal. PMID:1105133

Cini, L; Gasparini, F; Michieli, S; Pizzoferrato, A; Sandrolini-Cortesi, S

1975-01-01

306

Method of producing solution-derived metal oxide thin films  

DOEpatents

A method of preparing metal oxide thin films by a solution method. A .beta.-metal .beta.-diketonate or carboxylate compound, where the metal is selected from groups 8, 9, 10, 11, and 12 of the Periodic Table, is solubilized in a strong Lewis base to form a homogeneous solution. This precursor solution forms within minutes and can be deposited on a substrate in a single layer or a multiple layers to form a metal oxide thin film. The substrate with the deposited thin film is heated to change the film from an amorphous phase to a ceramic metal oxide and cooled.

Boyle, Timothy J. (Albuquerque, NM); Ingersoll, David (Albuquerque, NM)

2000-01-01

307

Process for the preparation of metal-containing nanostructured films  

NASA Technical Reports Server (NTRS)

Metal-containing nanostructured films are prepared by electrodepositing a metal-containing composition within the pores of a mesoporous silica template to form a metal-containing silica nanocomposite. The nanocomposite is annealed to strengthen the deposited metal-containing composition. The silica is then removed from the nanocomposite, e.g., by dissolving the silica in an etching solution to provide a self-supporting metal-containing nanostructured film. The nanostructured films have a nanowire or nanomesh architecture depending on the pore structure of the mesoporous silica template used to prepare the films.

Lu, Yunfeng (Inventor); Wang, Donghai (Inventor)

2006-01-01

308

Coating geometries of metals on single-walled carbon nanotubes  

NASA Astrophysics Data System (ADS)

This paper studies the coating geometries of metals on single-walled carbon nanotubes (SWNTs) on the basis of the nucleation theory and wetting theory. The metal surface energy, cohesion energy, diffusion barrier, and metal-SWNT interfacial energy are calculated using first-principles calculation. Metals including Fe, Al, Au, Pd, Ni, and Ti are considered. For Ti, Ni, and Pd, low metal-SWNT interfacial energies and high diffusion barriers are responsible for forming continuous or quasicontinuous layers on the SWNT surface. In contrast, Al and Au have small diffusion barriers and poor SWNT surface wetting, thus they tend to aggregate and form large clusters. Although the binding energy between Fe and SWNTs is large, due to the large cohesion energy and poor wetting, Fe may form isolated clusters. All results are in good agreement with experimental observations.

He, Yu; Zhang, Jinyu; Wang, Yan; Yu, Zhiping

2010-02-01

309

Silicide coating on refractory metals in molten salt  

NASA Astrophysics Data System (ADS)

For better oxidation resistance of refractory metals in air, the electroless coating of silicide in the molten salt was developed in open air at 973 1173 K. The molten salt consists of NaCl, KCl, Na2SiF6 and Si powder, where the proportional reaction between Si and Si4+ ions forms Si2+ ions. Si2+ deposits on the metal substrate and forms the metal silicide. The deposited silicide layers were classified into two categories depending on the metal substrates: (1) Nb, Mo and Cr mainly formed silicon-rich disilicide (MSi2) layer. (2) Fe, Ni and Co formed silicon-poor silicide layer (MSin, n<2), such as Fe3Si. This difference was described by the diffusivity of Si through the silicide layer into the metal.

Tatemoto, K.; Ono, Y.; Suzuki, R. O.

2005-02-01

310

Refractive-index change caused by electrons in amorphous AsS and AsSe thin films doped with different metals by photodiffusion  

SciTech Connect

The refractive-index change caused by electrons was measured in amorphous AsS and AsSe thin films. Films were coated with different metals. Diffraction gratings were written by electron-beam lithography. The interactions of electrons in films with and without the photodiffusion of overcoated metal were compared. Incoming electrons caused metal atom and ion diffusion in both investigated cases. The metal diffusion was dependent on the metal and it was found to influence the refractive index. In some cases lateral diffusion of the metal was noticed. The conditions for applications were verified. {copyright} 2001 Optical Society of America

Nordman, Olli; Nordman, Nina; Pashkevich, Valfrid

2001-08-01

311

Rate-controlled synthesis of composition-modulated metal oxide thin films  

NASA Astrophysics Data System (ADS)

The development of advanced deposition technologies is continuously evolving for the synthesis of oxide coatings used in optical applications. Recent progress is made in the use of magnetron sputtering to reactively deposit metal-oxide thin films. The sputter deposition parameters are chosen with respect to the reaction kinetics of the metal-oxide system to enable a variation of composition along the film growth direction. The key process parameter to control is the sputtering rate of the target. The shape of the composition profile directly corresponds to the preselected variation of deposition rate. By simply varying the sputtering rate using a working gas that consists of an inert-oxygen mixture, structures are synthesized with composition profiles which can be either abrupt or graded in the growth direction. The result is a compositionally modulated structure of the metal-oxide system. This procedure for composition modulated synthesis is demonstrated for metals which are highly reactive with oxygen as well as for those metals which are not. The development of this deposition methodology will facilitate the design of metal oxide films for optical applications, as in gradient-index filters for example. Results are presented for the reactive sputter deposition of metal oxide coatings in the yttrium-oxide, molybdenum-oxide, and copper-oxide systems.

Jankowski, Alan F.

1994-09-01

312

A 15% efficient antireflection-coated metal-oxide-semiconductor solar cell  

NASA Technical Reports Server (NTRS)

A new effect is being developed which significantly improves the conversion efficiency of antireflection-coated metal-oxide-semiconductor (AMOS) solar cells. The effect, a marked increase in the open-circuit voltage, is produced by the addition of an oxide layer to the semiconductor. Cells using gold on n-type gallium arsenide have been made with efficiencies up to 15% in terrestrial sunlight. All processing steps are amenable to the use of low-cost polycrystalline films of GaAs in place of the single crystals now used.

Stirn, R. J.; Yeh, Y. C. M.

1975-01-01

313

Study of sensing properties and contrastive analysis of metal coating optical fiber grating  

NASA Astrophysics Data System (ADS)

Optical fiber grating (FBG) has been widely used in the measurement of parameters such as temperature and strain. However, FBG is too slim to broken, whose outside protective layer tends to shedding easily, and it is also hard to change the temperature and strain sensitivity. In order to overcome the above disadvantages and to further expand the application range of FBG, this paper improves the technology of fiber grating metal film plating process firstly. It adopts a compositive method including chemical plating and electroplating to gild FBG, copper FBG and galvanize FBG, which all get good metal coating. Then, the temperature and strain sensing properties of metalized FBG is studied in detail. Multiple metal coating FBGs were put in high-low temperature test-box together, and then the test-box worked continuously at the temperature range of 0°C?95°C. After several experiments, it concludes that metal plating enhances the temperature sensitivity of fiber grating, and the one with galvanization has the highest temperature sensitivity of 0.0235. At last, FBGs with various cladding were pasted on carbon fiber cantilever beam respectively and the pressure on the top of the cantilever increased gradually. The experimental results show that wavelength of fiber grating shift toward the long wavelength with the increase of the pressure, and the one with galvanization has the maximum strain sensitivity which has minimal impact on fiber properties.

Wang, Jing; Wang, Ning; Shi, Bin; Sui, Qingmei; Guan, Congsheng; Wei, Guangqing; Li, Shuhua

2014-02-01

314

Metal-AlN cermet solar selective coatings deposited by direct current magnetron sputtering technology  

NASA Astrophysics Data System (ADS)

A series of metal-aluminium nitride (M-AlN) cermet materials for solar selective coatings was deposited by a novel direct current (d.c.) magnetron sputtering technology. Aluminium nitride was used as the ceramic component in the cermets, and stainless steel (SS), nickel-based alloy 0022-3727/31/4/003/img1 (NiCr), molybdenum-based alloy 0022-3727/31/4/003/img2 (TZM) and tungsten were used as the metallic components. The aluminium nitride ceramic and metallic components of the cermets were deposited by simultaneously running both an aluminium target and another metallic target in a gas mixture of argon and nitrogen. The ceramic component was deposited by d.c. reactive sputtering and the metallic component by d.c. non-reactive sputtering. The total sputtering gas pressure was 0.8-1.0 Pa and the partial pressure of reactive nitrogen gas was set at 0.020-0.025 Pa which is sufficiently high to ensure that a nearly pure AlN ceramic sublayer was deposited by d.c. reactive sputtering. Because of the excellent nitriding resistance of stainless steel and the other alloys and metal, a nearly pure metallic sublayer was deposited by d.c. sputtering at this low nitrogen partial pressure. A multilayered system, consisting of alternating metallic and AlN ceramic sublayers, was deposited by substrate rotation. This multisublayer system can be considered as a macrohomogeneous cermet layer with metal volume fraction determined by controlling the thicknesses of metallic and ceramic sublayers. Following this procedure, M-AlN cermet solar selective coatings with a double cermet layer structure were deposited. The films of these selective surfaces have the following structure: a low metal volume fraction cermet layer is placed on a high metal volume fraction cermet layer which in turn is placed on an aluminium metal infrared reflection layer. The top surface layer consists of an aluminium nitride antireflection layer. A solar absorptance of 0.92-0.96 and a normal emittance of 0.03-0.05 at room temperature have been achieved for these M-AlN cermet solar selective coatings.

Zhang, Qi-Chu

1998-02-01

315

A Technique of Soldering to Thin Metal Films  

Microsoft Academic Search

In the past, soldering to thin metal films on glass or quartz substrates has normally been accomplished by suitably reinforcing the film at the soldering point with a thicker underlying film. This performance is necessary in order to prevent tin-lead solders and commonly used fluxes from destroying the film and to give better adhesion to the substrate. It has been

Richard B. Belser

1954-01-01

316

Thin film metallization for micro-bimetallic actuators  

Microsoft Academic Search

In this study, eleven different thin film metallization systems were evaluated for use in micro-bimetallic actuators for microelectromechanical structures. These films were evaporated or sputtered onto silicon wafers. The film stress and stress relaxation were determined by measuring changes in the wafer curvature. The phases and micro-structure of these films were evaluated with, scanning electron microscopy, transmission electron microscopy, Auger

Jonathan Frank Gorrell

1997-01-01

317

Metal matrix coated fiber composites and the methods of manufacturing such composites  

DOEpatents

A fiber coating which allows ceramic or metal fibers to be wetted by molten metals is disclosed. The coating inhibits degradation of the physical properties caused by chemical reaction between the fiber and the coating itself or between the fiber and the metal matrix. The fiber coating preferably includes at least a wetting layer, and in some applications, a wetting layer and a barrier layer between the fiber and the wetting layer. The wetting layer promotes fiber wetting by the metal matrix. The barrier layer inhibits fiber degradation. The fiber coating permits the fibers to be infiltrated with the metal matrix resulting in composites having unique properties not obtainable in pure materials.

Weeks, Jr., Joseph K. (Salt Lake City, UT); Gensse, Chantal (Salt Lake City, UT)

1993-01-01

318

Metallic glass coating on metals plate by adjusted explosive welding technique  

Microsoft Academic Search

Using an adjusted explosive welding technique, an aluminum plate has been coated by a Fe-based metallic glass foil in this work. Scanning electronic micrographs reveal a defect-free metallurgical bonding between the Fe-based metallic glass foil and the aluminum plate. Experimental evidence indicates that the Fe-based metallic glass foil almost retains its amorphous state and mechanical properties after the explosive welding

W. D. Liu; K. X. Liu; Q. Y. Chen; J. T. Wang; H. H. Yan; X. J. Li

2009-01-01

319

Inhibition of metal dusting using thermal spray coatings and laser treatment  

Microsoft Academic Search

Alloy 600 and Alloy 800H are susceptible to metal dusting. Both alloys were thermally sprayed with two different corrosion resistant coatings: Ni50Cr and Ni31Cr11Al0.6Y. Laser remelting was used to enhance further the effectiveness of these coatings to resist metal dusting by eliminating interconnected porosity and improving coating adhesion.Uncoated, coated and laser-treated coated samples of Alloy 600 and Alloy 800H were

K. T. Voisey; Z. Liu; F. H. Stott

2006-01-01

320

Water-resistant film from polyurethane/nitrocellulose coating to regenerated cellulose  

SciTech Connect

Water-resistant films were obtained from polyurethane (PU)/nitrocellulose coating to regenerated cellulose films, which were prepared by coagulating cellulose cuoxam solution. The PU/nitrocellulose coating layer was cured at 80 C for 2 min and formed semi-interpenetrating polymer networks (semi-IPNs) structure. The tensile strength ({sigma}{sub b}), water resistivity (R), water vapor permeability (P), and light transmittance of the coated films changed with nitrocellulose content in the coating, and the best values (such as {sigma}{sub b}, 679 kg/cm{sup 2}; R, 53%; P, 0.004 g/cm{sup 2}{center_dot}day) were attained at 33 wt % nitrocellulose. The TEM, EPMA, DTA, IR, and UV results showed that the coated films have strong interfacial bonding, which is caused by covalent and hydrogen bonds between the cellulose film and the semi-IPNs coating. The biodegradation half-life t{sub 1/2} of the coated films in soil at 20--30 c was given to be 58 days, and after about 6 months the coated films were almost completely decomposed by microorganisms. SEM and the kinetics of decay studied on the biodegradability were discussed. The water-resistant films coated with PU/nitrocellulose have promising application where biodegradation is important.

Zhang, L.; Zhou, Q. [Wuhan Univ. (China). Dept. of Chemistry] [Wuhan Univ. (China). Dept. of Chemistry

1997-07-01

321

Effectiveness and stability of plastic films coated with nisin for inhibition of Listeria monocytogenes.  

PubMed

Plastic films were coated with a cellulose-based carrier solution containing nisin, a natural antimicrobial peptide with the potential to inhibit growth of food spoilage and pathogenic microorganisms such as Listeria monocytogenes. Five commercial plastic films with different chemical compositions and surface properties were compared in this study: low-density polyethylene, ethylene-vinyl acetate copolymer, and three types of ethylene-methacrylic acid copolymers: Surlyn 1601, Nucrel 0403, and Nucrel 0903. The films were coated with nisin at a concentration of 1000 IU/cm2. Nisin-coated films were stored at room temperature (21 degrees C) and at 4 degrees C and analyzed weekly for 12 weeks. Antimicrobial activity of the different nisin-coated films against a nisin indicator strain, Lactococcus lactis subsp. cremoris ATCC 14365, and against L. monocytogenes ATCC 19115 was assessed using an inhibition zone assay. Nisin incorporated into the films was recovered by a boiling and extraction procedure, and its activity was quantified using an agar well diffusion assay. Film type did not have any significant effect on the antimicrobial activity of the nisin-coated films (P < 0.05); all five film types had comparable inhibition zones on both assays. The films maintained stable activity for the duration of the study, both at room temperature and refrigeration. The results of this study demonstrate that commercially available packaging films can be coated with nisin and the resulting antimicrobial films can be conveniently stored at room temperature with no adverse effect on nisin activity. PMID:17536692

Neetoo, Hudaa; Ye, Mu; Chen, Haiqiang

2007-05-01

322

Nanoscale Characterization of Thin Film Coatings Using Annular Dark Field Scanning Transmission Electron Microscopy  

Microsoft Academic Search

When considering the optical performance of thin films in the Extreme Ultraviolet (EUV), developing an accurate physical description of a thin film coating is necessary to be able to successfully model optical performance. With the short wavelengths of the EUV, film interfaces and sample roughness warrant special attention and care. The surfaces of thin film samples are routinely measured by

Guillermo Acosta; Richard Vanfleet; David D. Allred

323

Plasmonic enhancement of thin-film solar cells using gold-black coatings  

SciTech Connect

Coatings of conducting gold-black nano-structures on commercial thin-film amorphous-silicon solar cells enhance the short-circuit current by 20% over a broad spectrum from 400 to 800 nm wavelength. The efficiency, i.e. the ratio of the maximum electrical output power to the incident solar power, is found to increase 7% for initial un-optimized coatings. Metal blacks are produced cheaply and quickly in a low-vacuum process requiring no lithographic patterning. The inherently broad particle-size distribution is responsible for the broad spectrum enhancement in comparison to what has been reported for mono-disperse lithographically deposited or self-assembled metal nano-particles. Photoemission electron microscopy reveals the spatial-spectral distribution of hot-spots for plasmon resonances, where scattering of normally-incident solar flux into the plane increases the effective optical path in the thin film to enhance light harvesting. Efficiency enhancement is correlated with percent coverage and particle size distribution, which are determined from histogram and wavelet analysis of scanning electron microscopy images. Electrodynamic simulations reveal how the gold-black particles scatter the radiation and locally enhance the field strength.

Fredricksen, Christopher J.; Panjwani, D. R.; Arnold, J. P.; Figueiredo, P. N.; Rezaie, F. K.; Colwell, J. E.; Baillie, K.; Peppernick, Samuel J.; Joly, Alan G.; Beck, Kenneth M.; Hess, Wayne P.; Peale, Robert E.

2011-08-11

324

Plasmonic enhancement of thin-film solar cells using gold-black coatings  

NASA Astrophysics Data System (ADS)

Coatings of conducting gold-black nano-structures on commercial thin-film amorphous-silicon solar cells enhance the short-circuit current by 20% over a broad spectrum from 400 to 800 nm wavelength. The efficiency, i.e. the ratio of the maximum electrical output power to the incident solar power, is found to increase 7% for initial un-optimized coatings. Metal blacks are produced cheaply and quickly in a low-vacuum process requiring no lithographic patterning. The inherently broad particle-size distribution is responsible for the broad spectrum enhancement in comparison to what has been reported for mono-disperse lithographically deposited or self-assembled metal nano-particles. Photoemission electron microscopy reveals the spatial-spectral distribution of hot-spots for plasmon resonances, where scattering of normally-incident solar flux into the plane increases the effective optical path in the thin film to enhance light harvesting. Efficiency enhancement is correlated with percent coverage and particle size distribution, which are determined from histogram and wavelet analysis of scanning electron microscopy images. Electrodynamic simulations reveal how the gold-black particles scatter the radiation and locally enhance the field strength.

Fredricksen, C. J.; Panjwani, D. R.; Arnold, J. P.; Figueiredo, P. N.; Rezaie, F. K.; Colwell, J.; Baillie, K.; Peppernick, S. J.; Joly, A. G.; Beck, K. M.; Hess, W. P.; Peale, R. E.

2011-09-01

325

Investigation into the effects of metallic coating thickness on the corrosion properties of Zn–Al alloy galvanising coatings  

Microsoft Academic Search

Galvalloy (4.5% Al 95.5% Zn) coatings were produced on a continuous coil coating line at Corus Colors’ Shotton works with varying metallic coating thickness from 7.8?m (120gm?2) to 48?m (325gm?2) controlled using air knives. An overall decrease in aluminium content from 5.1% to 4.5wt% and a primary zinc volume fraction increase from 16.2% to 32.8% occurred as the coating thickness

David J. Penney; James H. Sullivan; David A. Worsley

2007-01-01

326

Frictional and morphological characteristics of ion plated soft, metallic films  

NASA Technical Reports Server (NTRS)

Ion plated metallic films in contrast to films applied by other deposition techniques offer a lower friction coefficient, longer endurance lives and exhibit a gradual increase in friction coefficient after the film has been worn off. The friction coefficients of metallic films are affected by the degree of adherence, thickness and nucleation and growth characteristics during ion plating lead to a fine, continuous crystalline structure, which contributes to a lower friction coefficient.

Spalvins, T.; Buzek, B.

1981-01-01

327

Quenched transmission of light through ultrathin metal films  

NASA Astrophysics Data System (ADS)

We discuss optical properties of ultrathin metal films, with particular attention to the phenomenon of quenched transmission. Transmission of light through an optically ultrathin metal film with a thickness comparable to its skin depth is significant. We demonstrate the quenched transmission through the ultrathin metal films when they are periodically modulated. We also discuss the physics behind it and explain how this abnormal phenomenon is ascribed to surface plasmon resonance effects.

Xiao, Sanshui; Mortensen, N. Asger

2011-09-01

328

Microwave absorbing properties of hollow microspheres plated with magnetic metal films  

NASA Astrophysics Data System (ADS)

Conductive and magnetic microspheres are fabricated through the electroless plating of Co, Co-10%Fe, Ni, and Ni-15%Fe films on hollow microspheres (cenospheres), and their high frequency electromagnetic and microwave absorbing properties are investigated in the composite specimens. The electroless plating of the metal films is conducted using a two-step process of surface sensitizing and metal plating. For the microspheres coated with the Co and Co-10%Fe films, impedance matching is not satisfied at all frequencies due to the small values of magnetic loss and dielectric constant. For the Ni-plated microsphere composites, the dielectric constant is too high to satisfy the impedance matching, which results in a small value of microwave absorbance. For the Ni-15%Fe thin film composite with appropriate magnetic permeability and dielectric permittivity, the impedance matching is satisfied in the GHz frequency and a lower value of reflection loss is predicted.

Kim, Sun-Tae; Kim, Sung-Soo

2014-05-01

329

The base metal of the oxide-coated cathode  

NASA Astrophysics Data System (ADS)

The oxide-coated cathode has been the most widely used electron emitter in vacuum electronic devices. From one manufacturing company to another the emissive oxide is either a double—Ba, Sr—or a triple—Ba, Sr, Ca—oxide, having always the same respective compositions. Conversely, the base metal composition is very often proprietary because of its importance in the cathode emission performances. The present paper aims at explaining the operation of the base metal through a review. After a brief introduction, the notion of activator is detailed along with their diffusivities and their associated interfacial compounds. Then, the different cathode life models are described prior to few comments on the composition choice of a base metal. Finally, the specificities of the RCA/Thomson "bimetal" base metal are presented with a discussion on the optimized composition choice illustrated by a long-term life-test of five different melts.

Poret, F.; Roquais, J. M.

2005-09-01

330

The role of size and coating in Au nanoparticles incorporated into bi-component polymeric thin-film transistors.  

PubMed

We describe the effect of blending poly(3-hexylthiophene) (P3HT) with Au nanoparticles (AuNPs) on the performance of organic thin-film transistors. To this end we have used AuNPs of two different sizes coated with chemisorbed SAMs of oligophenyl-thiols possessing increasing lengths. The electrical characteristics of the hybrid materials revealed changes in the field-effect mobility depending primarily on the AuNP size, as a result of the variable energy level of the coated metallic nanocluster and by the degree of modification of the P3HT crystalline structure. PMID:24604238

Mosciatti, Thomas; Orgiu, Emanuele; Raimondo, Corinna; Samorì, Paolo

2014-05-21

331

Graphene oxide thin film coated quartz crystal microbalance for humidity detection  

NASA Astrophysics Data System (ADS)

In this paper, we demonstrated that chemically derived graphene oxide (GO) thin film as a humidity sensitive coating deposited on quartz crystal microbalances (QCMs) for humidity detection. By exposing GO thin film coated QCMs to various relative humidity (RH) environments at room temperature, the humidity sensing characteristics of the QCMs such as sensitivity and linearity, response and recovery, humidity hysteresis were investigated. The experiment results show that GO thin film coated QCMs exhibit an excellent humidity sensing performance. Moreover, the possible humidity sensing mechanism of GO thin film coated QCMs was also investigated by monitoring the crystal's motional resistance change. It is suggested that the frequency response of the QCMs is dependent on water molecules adsorbed/desorbed masses on GO thin film in the low RH range, and on both water molecules adsorbed/desorbed masses on GO thin film and variations in interlayer expansion stress of GO thin film derived from swelling effect in the high RH range.

Yao, Yao; Chen, Xiangdong; Guo, Huihui; Wu, Zuquan

2011-06-01

332

Metallic oxide switches using thick film technology  

NASA Technical Reports Server (NTRS)

Metallic oxide thick film switches were processed on alumina substrates using thick film technology. Vanadium pentoxide in powder form was mixed with other oxides e.g., barium, strontium copper and glass frit, ground to a fine powder. Pastes and screen printable inks were made using commercial conductive vehicles and appropriate thinners. Some switching devices were processed by conventional screen printing and firing of the inks and commercial cermet conductor terminals on 96% alumina substrates while others were made by applying small beads or dots of the pastes between platinum wires. Static, and dynamic volt-ampere, and pulse tests indicate that the switching and self-oscillatory characteristics of these devices could make them useful in memory element, oscillator, and automatic control applications.

Patel, D. N.; Williams, L., Jr.

1974-01-01

333

Electron impinging on metallic thin film targets  

NASA Astrophysics Data System (ADS)

Based on the Vicanek and Urbassek theory [M. Vicanek, H.M. Urbassek, Phys. Rev. B 44 (1991) 7234] combined to a home-made Monte Carlo simulation, the present work deals with backscattering coefficients, mean penetration depths and stopping profiles for 1-4 keV electrons normally incident impinging on Al and Cu thin film targets. The cross-sections used to describe the electron transport are calculated via the appropriate analytical expression given by Jablonski [A. Jablonski, Phys. Rev. B 58 (1998) 16470] whose new improved version has been recently given [Z. Rouabah, N. Bouarissa, C. Champion, N. Bouaouadja, Appl. Surf. Sci. 255 (2009) 6217]. The behavior of the backscattering coefficient, mean penetration depth and stopping profiles versus the metallic film thickness at the nanometric scale and beyond is here analyzed and discussed.

Rouabah, Z.; Bouarissa, N.; Champion, C.

2010-03-01

334

Scratch resistance and adherence of novel organic–inorganic hybrid coatings on metallic and non-metallic substrates  

Microsoft Academic Search

Organic–inorganic hybrid coating material with a very high level of inorganic loading was prepared by a sol–gel process in which the initial hydrolysis and condensation steps of the inorganic precursors are separated. The coating solution was deposited onto various metallic and non-metallic substrates by a simple flow coating method. The coatings were then cured using UV radiation. The adherence of

Yung-Hoe Han; Alan Taylor; Kevin M. Knowles

2009-01-01

335

Quantitative Analysis of Electroplated Nickel Coating on Hard Metal  

PubMed Central

Electroplated nickel coating on cemented carbide is a potential pretreatment technique for providing an interlayer prior to diamond deposition on the hard metal substrate. The electroplated nickel coating is expected to be of high quality, for example, indicated by having adequate thickness and uniformity. Electroplating parameters should be set accordingly for this purpose. In this study, the gap distances between the electrodes and duration of electroplating process are the investigated variables. Their effect on the coating thickness and uniformity was analyzed and quantified using design of experiment. The nickel deposition was carried out by electroplating in a standard Watt's solution keeping other plating parameters (current: 0.1?Amp, electric potential: 1.0?V, and pH: 3.5) constant. The gap distance between anode and cathode varied at 5, 10, and 15?mm, while the plating time was 10, 20, and 30 minutes. Coating thickness was found to be proportional to the plating time and inversely proportional to the electrode gap distance, while the uniformity tends to improve at a large electrode gap. Empirical models of both coating thickness and uniformity were developed within the ranges of the gap distance and plating time settings, and an optimized solution was determined using these models.

Wahab, Hassan A.; Noordin, M. Y.; Izman, S.

2013-01-01

336

Quantitative analysis of electroplated nickel coating on hard metal.  

PubMed

Electroplated nickel coating on cemented carbide is a potential pretreatment technique for providing an interlayer prior to diamond deposition on the hard metal substrate. The electroplated nickel coating is expected to be of high quality, for example, indicated by having adequate thickness and uniformity. Electroplating parameters should be set accordingly for this purpose. In this study, the gap distances between the electrodes and duration of electroplating process are the investigated variables. Their effect on the coating thickness and uniformity was analyzed and quantified using design of experiment. The nickel deposition was carried out by electroplating in a standard Watt's solution keeping other plating parameters (current: 0.1?Amp, electric potential: 1.0?V, and pH: 3.5) constant. The gap distance between anode and cathode varied at 5, 10, and 15?mm, while the plating time was 10, 20, and 30 minutes. Coating thickness was found to be proportional to the plating time and inversely proportional to the electrode gap distance, while the uniformity tends to improve at a large electrode gap. Empirical models of both coating thickness and uniformity were developed within the ranges of the gap distance and plating time settings, and an optimized solution was determined using these models. PMID:23997678

Wahab, Hassan A; Noordin, M Y; Izman, S; Kurniawan, Denni

2013-01-01

337

Electrochromic properties of spin-coated thin films from peroxo-polymolybdovanadate solutions  

SciTech Connect

A now mixed metal peroxo-polyacid based on Mo and V is formed by the direct reaction of a mixture of metallic Mo and V with hydrogen peroxide solution. A homogeneous amorphous thin film about 0.4 {mu}m is fabricated on an indium tin oxide (ITO) glass substrate by a spin-coating technique using this peroxo-polymolybdovanadate solution. After heat-treatment from 80 to 120 C in air for 1 h, it shows reversible electrochromism in an organic LiClO{sub 4} electrolyte solution, and changes color from greenish yellow to grayish violet and violet, depending on the intercalation level of Li. Cyclic-voltammograms of the mixed Mo/V oxide film and those of the end members (MoO{sub 3} and V{sub 2}O{sub 5}) are quite different from one another, both in shape and peak-current potential, indicating that each film has distinctly different intercalation electrochemistry. The potential (E) vs. composition (x, Li content per mol Mo{sub 0.5}V{sub 0.5}O{sub 2.75}) diagram of the present film recorded in the intercalation process agrees with that of the deintercalation process in the range 0 < x < 1.5. The E-x relationship is approximated by two straight lines with different slopes, with a kink at x = 0.5. This suggests that in this film there are two kinds of sites with different site energies. The changes in electrochromic properties with heat-treatment are also discussed in relation to the microstructure of the film.

Li, Y.; Kudo, Tetsuichi [Univ. of Tokyo (Japan). Inst. of Industrial Science

1995-04-01

338

Study of coating distribution onto metallic hollow particles  

NASA Astrophysics Data System (ADS)

Porous lightweight materials have found increasing interest for various applications. Regular structured cellular materials might be accessible by sintering the hollow metallic particles. The properties of the final product depend to a large extent on the properties of original hollow metallic particles. Therefore, the preparation of reliable hollow spheres of defined parameters represents an important step towards the cellular solids production by means of powder metallurgy route. Electrochemical deposition of metallic coatings on the surface of hollow spherical particles facilitates the required modification of the surface corresponding to high mechanical quality. The copper hollow spheres were created on porous iron powder particles by electroless deposition. The suitable matrix for the preparation of relatively light but mechanically strong porous materials was obtained by electrochemical plating of copper hollow micro-particles by Ni layer. In this study ToF-SIMS depth profiling and SEM/EDX analysis with elements mapping are used to investigate the distribution of the coating components across the surface and subsurface layer of coated hollow particles.

Ori?áková, Renáta; Ori?ák, Andrej; Arlinghaus, Heinrich F.; Hellweg, Sebastian; Kupková, Miriam; Kabátová, Margita

2006-07-01

339

Metallic glass coating on metals plate by adjusted explosive welding technique  

NASA Astrophysics Data System (ADS)

Using an adjusted explosive welding technique, an aluminum plate has been coated by a Fe-based metallic glass foil in this work. Scanning electronic micrographs reveal a defect-free metallurgical bonding between the Fe-based metallic glass foil and the aluminum plate. Experimental evidence indicates that the Fe-based metallic glass foil almost retains its amorphous state and mechanical properties after the explosive welding process. Additionally, the detailed explosive welding process has been simulated by a self-developed hydro-code and the bonding mechanism has been investigated by numerical analysis. The successful welding between the Fe-based metallic glass foil and the aluminum plate provides a new way to obtain amorphous coating on general metal substrates.

Liu, W. D.; Liu, K. X.; Chen, Q. Y.; Wang, J. T.; Yan, H. H.; Li, X. J.

2009-09-01

340

Interaction of beam and coated metals at high power continuous irradiation  

NASA Astrophysics Data System (ADS)

The beam-matter interaction with various coating effects has received continued attention in the high power laser community. Previous works suggest that coatings promote target damage when compared to beaming on uncoated surface. Three types of paint coatings (acrylic urethane, silicone alkyd and stealth blend) and a water coat on metals (Al, Ti and STS) are irradiated with a CO 2 laser. Both strain and temperature measurements are provided for assessing the instantaneous response characteristics of each coating on different metals. A selective combination of surface coats with metals has been proven to be effective in either preventing or enhancing damage, both thermal and mechanical, associated with focused beaming on a target.

Kim, Yong Hyeon; Baek, Won-Kye; Yoh, Jack J.

2011-07-01

341

A microstructural study of transparent metal oxide gas barrier films  

Microsoft Academic Search

The relationship between the microstructure and the water vapour transmission rates of aluminium oxide and aluminium coatings deposited by magnetron sputtering on polyethylene terephthalate have been investigated. The gas barrier properties of the films have been measured as a function of temperature and a range of techniques used to characterize the coatings including atomic force microscopy, which also provided information

B. M Henry; F Dinelli; K.-Y Zhao; C. R. M Grovenor; O. V Kolosov; G. A. D Briggs; A. P Roberts; R. S Kumar; R. P Howson

1999-01-01

342

Thin Semiconductor/Metal Films For Infrared Devices  

NASA Technical Reports Server (NTRS)

Spectral responses of absorbers and reflectors tailored. Thin cermet films composites of metals and semiconductors undergoing development for use as broadband infrared reflectors and absorbers. Development extends concepts of semiconductor and dielectric films used as interference filters for infrared light and visible light. Composite films offer advantages over semiconductor films. Addition of metal particles contributes additional thermal conductivity, reducing thermal gradients and associated thermal stresses, with resultant enhancements of thermal stability. Because values of n in composite films made large, same optical effects achieved with lesser thicknesses. By decreasing thicknesses of films, one not only decreases weights but also contributes further to reductions of thermal stresses.

Lamb, James L.; Nagendra, Channamallappa L.

1995-01-01

343

Normal and interfacial stresses in thin-film coated optics: the case of diamond-coated zinc sulfide windows  

NASA Astrophysics Data System (ADS)

Optical components such as mirrors or windows consisting of a substrate and a coating made up of thin films created at elevated temperatures exhibit substantial residual stresses induced by growth strains and/or thermoelastic strains that develop during the cool-down phase. A comprehensive description of these stresses must include not only the normal stresses in the film layers and the substrate but also the interfacial shearing stresses, which may cause delamination to occur. We take advantage of recent progress in describing elastic interactions in multilayered laminates for obtaining conceptually correct formulas for the residual stresses and the substrate's curvature of thin-film coated optics. Available analytical solutions for the normal stresses of elastically isotropic structures make no assumptions regarding layer thicknesses, but disregard the potential impact of edge effects. For circular structures such as coated optics, we show that recent work by Suhir now allows us to describe the distribution of both normal and interfacial stresses as long as the thin-film conditions are satisfied. The task of evaluating the deflection turns out to be fairly straightforward, leading to the conclusion that edge effects do not alter the bow of large compliant structures. The case of diamond-coated ZnS windows illustrates how thermal expansion mismatches can give rise to compressive film stresses of gigapascal intensity, which cause substrate deformations that are unacceptable in terms of the optical performance. Since the deflection of a multilayer-coated substrate reflects the sum of the contributions (positive or negative) induced by each film, the deflection can be minimized by properly designing the film stack. For a diamond-coated ZnS window, this means that a suitable buffer must be in tension; in principle, a buffer made of calcium lanthanum sulfide, about 350 micrometers thick, can mitigate the bending force exerted by a 50 micrometers thick diamond film and suppress the shear at the substrate/coating interface, thus enhancing the adhesion.

Klein, Claude A.

2001-06-01

344

Fabrication of metal dielectric metal multilayer thin film: Color filter  

NASA Astrophysics Data System (ADS)

A highly efficient color filters based on a multilayer thin film Ag/MgF2/Ag were deposited on a glass substrate using thermal evaporation technique. They were designed by taking into account the influence of the dispersion characteristics and the thickness of silver (Ag) metal and magnesium fluoride (MgF2) dielectric layer. The cavity thickness for the blue, green and red color filter was 273, 334, and 170 nm respectively, while the metal layer was fixed at 32 nm. The center wavelength were found to be 460, 540, 620 nm for the blue, green and red devices and the corresponding peak transmission were 73.12%, 69.18% and 63.19%, respectively and provided a satisfactory color image. The spectral response of the device was also analyzed for the oblique light incidence as the tilt angle varied up to 70° and it was found to be angular dependent.

Kedawat, Garima; Jain, Vipin Kumar; Vijay, Y. K.

2014-04-01

345

Antimicrobial Edible Films and Coatings for Fresh and Minimally Processed Fruits and Vegetables: a Review  

Microsoft Academic Search

The use of edible films and coatings is an environmentally friendly technology that offers substantial advantages for shelf-life increase of many food products including fruits and vegetables. The development of new natural edible films and coatings with the addition of antimicrobial compounds to preserve fresh and minimally processed fruits and vegetables is a technological challenge for the industry and a

SILVIA A. VALENCIA-CHAMORRO; LLUÍS PALOU; MIGUEL A. DEL RÍO; MARÍA B. PÉREZ-GAGO

2011-01-01

346

Effect of Ceramic Particle Velocity on Cold Spray Deposition of MetalCeramic Coatings  

Microsoft Academic Search

In this paper, metal-ceramic coatings are cold sprayed taking into account the spray parameters of both metal and ceramic\\u000a particles. The effect of the ceramic particle velocity on the process of metal-ceramic coating formation and the coating properties\\u000a is analyzed. Copper and aluminum powders are used as metal components. Two fractions of aluminum oxide and silicon carbide\\u000a are sprayed in

A. Sova; V. F. Kosarev; A. Papyrin; I. Smurov

2011-01-01

347

Self-optimized metal coatings for fiber plasmonics by electroless deposition.  

PubMed

We present a novel method to prepare optimized metal coatings for infrared Surface Plasmon Resonance (SPR) sensors by electroless plating. We show that Tilted Fiber Bragg grating sensors can be used to monitor in real-time the growth of gold nano-films up to 70 nm in thickness and to stop the deposition of the gold at a thickness that maximizes the SPR (near 55 nm for sensors operating in the near infrared at wavelengths around 1550 nm). The deposited films are highly uniform around the fiber circumference and in spite of some nanoscale roughness (RMS surface roughness of 5.17 nm) the underlying gratings show high quality SPR responses in water. PMID:21996817

Bialiayeu, A; Caucheteur, C; Ahamad, N; Ianoul, A; Albert, J

2011-09-26

348

Interaction of beam and coated metals at high power continuous irradiation  

Microsoft Academic Search

The beam-matter interaction with various coating effects has received continued attention in the high power laser community. Previous works suggest that coatings promote target damage when compared to beaming on uncoated surface. Three types of paint coatings (acrylic urethane, silicone alkyd and stealth blend) and a water coat on metals (Al, Ti and STS) are irradiated with a CO2 laser.

Yong Hyeon Kim; Won-Kye Baek; Jack J. Yoh

2011-01-01

349

Corrosion behavior of rare earth metal (REM) conversion coatings on aluminum alloy LY12  

Microsoft Academic Search

The processes of the double layer rare earth metal (REM) conversion coating on aluminum alloy LY12 (2024) were introduced. The results of polarization tests showed that the corrosion resistance of the double layer REM conversion coating was superior to that of chromate conversion coating. The corrosion behavior of REM conversion coatings on LY12 alloy was studied with optical microscopy and

Yu Xingwen; Cao Chunan; Yao Zhiming; Zhou Derui; Yin Zhongda

2000-01-01

350

Method for nondestructive testing of the film coating behavior of surface acoustic wave (SAW) sensors  

NASA Astrophysics Data System (ADS)

This paper presents a practical non-destructive method for studying the film coating behavior of SAW devices by using a water soluble dielectric film (manitol) deposited on the SAW device surface by resistive evaporation. After measuring the electrical parameters of the film coated SAW device, the film can easily be removed from its surface by water rinsing without causing any damage to it. The SAW device can then be used over and over again in a large number of film depositions. The method was tested on a 1 GHz surface transverse wave (STW) resonator coated with manitol of varying thickness. After each coating and evaluation, the STW device was successfully recovered without significant performance degradation. Data is presented on the electrical changes of the STW device as a result of depositing manitol coatings of various thicknesses.

Taslakov, M. A.; Avramov, I. D.

2010-04-01

351

Noise in Half-Metallic Ferromagnetic Thin Films  

Microsoft Academic Search

Half metallic oxides are one of the most potential materials for the spintronics application, such as tunnel magnetoresistance. Among different half-metals CrO2 is the only binary oxide that is ferromagnetic metal and shows almost 100% spin polarization at the Fermi level. However, CrO2 films have higher low frequency noise, which is an order of magnitude more than the metal film

Siddhartha Ghosh; Guoxing Miao

2005-01-01

352

Thin film pc-Si by aluminium induced crystallization on metallic substrate  

NASA Astrophysics Data System (ADS)

Thin film polycrystalline silicon (pc-Si) on flexible metallic substrates is promising for low cost production of photovoltaic solar cells. One of the attractive methods to produce pc-Si solar cells consists in thickening a large-grained seed layer by epitaxy. In this work, the deposited seed layer is made by aluminium induced crystallization (AIC) of an amorphous silicon (a-Si) thin film on metallic substrates (Ni/Fe alloy) initially coated with a tantalum nitride (TaN) conductive diffusion barrier layer. Effect of the thermal budget on the AIC grown pc-Si seed layer was investigated in order to optimize the process (i.e. the quality of the pc-Si thin film). Structural and optical characterizations were carried out using optical microscopy, ?-Raman and Electron Backscatter Diffraction (EBSD). At optimal thermal annealing conditions, the continuous AIC grown pc-Si thin film showed an average grain size around 15 ?m. The grains were preferably (001) oriented which is favorable for its epitaxial thickening. This work proves the feasibility of the AIC method to grow large grains pc-Si seed layer on TaN coated metal substrates. These results are, in terms of grains size, the finest obtained by AIC on metallic substrates.

Delachat, F.; Antoni, F.; Prathap, P.; Slaoui, A.; Cayron, C.; Ducros, C.

2013-04-01

353

Flexible ceramic-reinforced polyurethane composite coatings on synthetic fibres: Process of continuous liquid film coating and its influence on the coating thickness  

Microsoft Academic Search

A concept for the realisation of composite layers on the surface of synthetic fibres by continuous liquid film coating of spread roving or monofilaments with a slurry containing ceramic particles and a polymeric binder is successfully demonstrated. Polyamide 6 monofilaments were coated with alumina particles and a polyurethane elastomer based binder system to achieve higher abrasion resistance. Under frictional load,

Felix A. Reifler; Felipe A. L. Sánchez; Frank J. Clemens; Ksenija Varga; Rudolf Hufenus

2010-01-01

354

Hydrophobic coating of solid materials by plasma-polymerized thin film using tetrafluoroethylene  

NASA Technical Reports Server (NTRS)

Glass slides were coated with plasma-polymerized tetrafluoroethylene films of different thickness using the glow discharge technique in a tube-shaped chamber, and the plasma conditions, film growth rates, light permeability of the polymer films, and particle bond strength in the polymer films were studied. Ashed sections of mouse organs and ashed bacillus spores were also coated to give them hydrophobic treatment without damaging their shapes or appearance. The hydrophobic coating of the specimens was successful, and the fine ash patterns were strongly fixed onto the glass slides, making permanent preparations.

Hozumi, K.; Kitamura, K.; Kitade, T.

1980-01-01

355

High Performance Polyamide 6 Fibers Using Polycarbonate Based Thermoplastic Polyurethane Thin Film Coatings a Novel Method  

Microsoft Academic Search

Polycarbonate based thermoplastic polyurethanes (CPU2) were prepared and coated onto polyamide 6 (PA 6) fibers. The CPU2 thin film coatings were prepared by dipping the PA 6 fibers into a viscous CPU2 adduct and cured at 100 °C for 12 h. Both the tensile strength and the elongation at break of the CPU2 thin film coated PA 6 fibers (CPU2-PA6)

Baiju John; Ken Kojio; Mutsuhisa Furukawa

2009-01-01

356

Tribology of a novel UHMWPE\\/PFPE dual-film coated onto Si surface  

Microsoft Academic Search

A novel wear resistant polymer composite layer is coated onto the Si surface. The first layer consists of ultra-high molecular weight polyethylene (UHMWPE) film and the second top layer is made of perfluoropolyether (PFPE). These two layers are coated onto Si using a simple dip-coating technique. This particular combination of dual-film has reduced the coefficient of friction by at least

N. Satyanarayana; Sujeet K. Sinha; Boon Hong Ong

2006-01-01

357

Fabrication of antiferroelectric PLZT films on metal foils.  

SciTech Connect

Fabrication of high-dielectric-strength antiferroelectric (AFE) films on metallic foils is technically important for advanced power electronics. To that end, we have deposited crack-free Pb{sub 0.92}La{sub 0.08}Zr{sub 0.95}Ti{sub 0.05}O{sub 3} (PLZT 8/95/5) films on nickel foils by chemical solution deposition. To eliminate the parasitic effect caused by the formation of a low-permittivity interfacial oxide, a conductive buffer layer of lanthanum nickel oxide (LNO) was coated by chemical solution deposition on the nickel foil before the deposition of PLZT. Use of the LNO buffer allowed high-quality film-on-foil capacitors to be processed in air. With the PLZT 8/95/5 deposited on LNO-buffered Ni foils, we observed field- and thermal-induced phase transformations of AFE to ferroelectric (FE). The AFE-to-FE phase transition field, E{sub AF} = 225 kV/cm, and the reverse phase transition field, E{sub FA} = 190 kV/cm, were measured at room temperature on a {approx}1.15 {micro}m-thick PLZT 8/95/5 film grown on LNO-buffered Ni foils. The relative permittivities of the AFE and FE states were {approx}600 and {approx}730, respectively, with dielectric loss {approx}0.04 at room temperature. The Curie temperature was {approx}210 C. The thermal-induced transition of AFE-to-FE phase occurred at {approx}175 C. Breakdown field strength of 1.2 MV/cm was measured at room temperature.

Ma, B.; Kwon, D.-K.; Narayanan, M.; Balachandran, U.; Energy Systems

2009-01-01

358

Fabrication of antiferroelectric PLZT films on metal foils  

SciTech Connect

Fabrication of high-dielectric-strength antiferroelectric (AFE) films on metallic foils is technically important for advanced power electronics. To that end, we have deposited crack-free Pb{sub 0.92}La{sub 0.08}Zr{sub 0.95}Ti{sub 0.05}O{sub 3} (PLZT 8/95/5) films on nickel foils by chemical solution deposition. To eliminate the parasitic effect caused by the formation of a low-permittivity interfacial oxide, a conductive buffer layer of lanthanum nickel oxide (LNO) was coated by chemical solution deposition on the nickel foil before the deposition of PLZT. Use of the LNO buffer allowed high-quality film-on-foil capacitors to be processed in air. With the PLZT 8/95/5 deposited on LNO-buffered Ni foils, we observed field- and thermal-induced phase transformations of AFE to ferroelectric (FE). The AFE-to-FE phase transition field, E{sub AF} = 225 kV/cm, and the reverse phase transition field, E{sub FA} = 190 kV/cm, were measured at room temperature on a {approx}1.15 {mu}m-thick PLZT 8/95/5 film grown on LNO-buffered Ni foils. The relative permittivities of the AFE and FE states were {approx}600 and {approx}730, respectively, with dielectric loss {approx}0.04 at room temperature. The Curie temperature was {approx}210 deg. C. The thermal-induced transition of AFE-to-FE phase occurred at {approx}175 deg. C. Breakdown field strength of 1.2 MV/cm was measured at room temperature.

Ma Beihai [Energy Systems Division, Argonne National Laboratory, Argonne, IL 60439 (United States)], E-mail: bma@anl.gov; Kwon, Do-Kyun; Narayanan, Manoj; Balachandran, U. [Energy Systems Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

2009-01-08

359

Formation of carbonated hydroxyapatite films on metallic surfaces using dihexadecyl phosphate-LB film as template.  

PubMed

Hydroxyapatite serves as a bioactive material for biomedical purposes, because it shares similarities with the inorganic part of the bone. However, how this material deposits on metallic surfaces using biomimetic matrices remains unclear. In this study, we deposited dihexadecyl phosphate, a phospholipid that bears a simple chemical structure, on stainless steel and titanium surfaces using the Langmuir-Blodgett (LB) technique; we employed the resulting matrix to grow carbonated hydroxyapatite. We obtained the calcium phosphate coating via a two-step process: we immersed the surfaces modified with the LB films into phosphate buffer, and then, we exposed the metal to a solution that simulated the concentration of ions in the human plasma. The latter step generated carbonated hydroxyapatite, the same mineral existing in the bone. The free energy related to the surface roughness and composition increased after we modified the supports. We investigated the film morphology by scanning electron and atomic force microscopies and determined surface composition by infrared spectroscopy and energy dispersive X-ray. We also studied the role of the surface roughness and the surface chemistry on cell viability. The surface-modified Ti significantly increased osteoblastic cells proliferation, supporting the potential use of these surfaces as osteogenic materials. PMID:24727116

de Souza, Israel D; Cruz, Marcos A E; de Faria, Amanda N; Zancanela, Daniela C; Simão, Ana M S; Ciancaglini, Pietro; Ramos, Ana P

2014-06-01

360

Control of Listeria monocytogenes on ham steaks by antimicrobials incorporated into chitosan-coated plastic films.  

PubMed

Contamination of ready-to-eat (RTE) meat products such as ham steaks with Listeria monocytogenes has been a concern for the meat processing industry. The objective of this study was to evaluate the antilisterial efficacy of chitosan-coated plastic films alone or incorporating five generally recognized as safe (GRAS) antimicrobials. Effect of chitosan-coated plastic film on the growth of L. monocytogenes was first investigated in an aqueous system of culture medium broth and chitosan-coated films were able to inhibit the growth of L. monocytogenes in a concentration-dependent manner. However, chitosan-coated plastic films were not able to control the growth of L. monocytogenes on ham steaks. Therefore, five GRAS antimicrobials were subsequently incorporated into chitosan-coated plastic films to enhance their antilisterial effectiveness. Ham steaks were surface-inoculated with a five-strain cocktail of L. monocytogenes and then packaged in chitosan-coated plastic films containing 500 IU/cm(2) of nisin, 0.01 g/cm(2) of sodium lactate (SL), 0.0025 g/cm(2) of sodium diacetate, 0.003 g/cm(2) of potassium sorbate (PB), or 0.001 g/cm(2) of sodium benzoate (SB). The samples were stored at room temperature (ca. 20 degrees C) for 10 days. Incorporating antimicrobials into chitosan-coated plastic films slowed down or inhibited the growth of L. monocytogenes. The chitosan-coated plastic film containing SL was the most effective antimicrobial film and its efficacy against L. monocytogenes on ham steaks was evaluated during 12-week storage at 4 degrees C. The film showed excellent long-term antilisterial effect with the counts of L. monocytogenes being slightly lower than the initial inoculum. Chitosan-coated plastic films containing 0.001 g/cm(2) of SL have a potential to be used on ham steaks to control L. monocytogenes. PMID:18206768

Ye, Mu; Neetoo, Hudaa; Chen, Haiqiang

2008-04-01

361

Characterization of a water-dispersible metal protective coating with Fourier transform infrared spectroscopy, modulated differential scanning calorimetry, and ellipsometry.  

PubMed

An ethylene-methacrylic acid copolymer, formulated by BASF as a waterborne suspension of its alkylammonium salt and used, among other applications, in art conservation as a temporary protective coating was characterized using Fourier transform infrared (FT-IR) spectroscopy aided by modulated differential scanning calorimetry (MDSC) and ellipsometry. The thermal conversion of thin copolymer films from the freshly applied state, where carboxylic acid and carboxylate ion functional groups co-exist, to a purely acidic working state was spectroscopically followed. Transmission mid-infrared data of the working state showed a 1 : 12 ratio of methacrylic acid towards ethylene units. The glass transition temperature (T(g)) in the same state was found at 45 °C. Copolymer films spin-coated on mechanically polished bronze and iron coupons were characterized with transflection infrared spectroscopy and compared to corresponding transmission mid-infrared spectra of copolymer films spin-coated on silicon wafers. In the case of bronze coupons, evidence for interaction of the carboxylate ion with the copper substrate was obtained. The chemical structure and the thermal behavior of the coating, as well as some implications on its protective capability towards iron and copper alloys, is discussed as this material has received considerable attention in the field of metal conservation and coatings. PMID:22524964

Boyatzis, Stamatis C; Douvas, Antonios M; Argyropoulos, Vassilike; Siatou, Amalia; Vlachopoulou, Marilena

2012-05-01

362

Metal and Molecular Films on COPPER(001)  

NASA Astrophysics Data System (ADS)

It is essential to understand the physical and chemical phenomena behind the growth of thin films in order to fabricate function-specific thin films, nanostructures and delta-doping layers. The present work reports on the study of metal and molecular films deposited on a metal surface using atomic beam scattering, Auger electron spectroscopy, low energy electron diffraction, photoemission and computer simulation. This study has focused on the characterization of growth of films under far-from-equilibrium conditions. The system chosen is Pb deposited on Cu, a system with a large lattice-mismatched interface. Growth modes of Pb multilayers can be manipulated by varying substrate temperature or by controlling the first layer structure. While the growth pattern, interface structure and surface morphology at the very early stage of growth at low temperature are strongly influenced by the Pb/Cu(100) interface, the interface roughens at later stages of growth and shows the characteristics of dynamical scaling. We have carried out computer simulations to study growth of islands. A simple but realistic model of energy barriers is developed for Monte Carlo simulation of the adatom diffusion and island growth of Cu growing on Cu(001). This simple model enables us to examine the microscopic processes, such as adatom diffusion, during growth. The scaling behavior observed experimentally by other groups has been confirmed by our simulation. The adsorption, bonding and ordering of orthocarborane (C_2B_{10}H_{12 }) molecular films on Cu(100) have been studied. Orthocarborane adsorbs molecularly on Cu(100) at 180K, with a preferential bonding orientation in which the two carbon atoms are involved in the bonding with the surface. Short range ordering of the overlayers are evident from the orthocarborane induced band structure effects. At room temperature, the adsorption of orthocarborane is dissociative. Photon induced selective dissociation is also observed. A time-of-flight (TOF) option was added to the existing elastic He beam scattering apparatus. It was then used to investigate the dynamical behavior of Hg c(2 x 2) overlayer on Cu(001). A dispersionless mode with energy of 4.3 meV has been found, showing weak chemisorption of Hg on Cu(100). The results correlate very well with the structural and dynamical properties previously studied.

Martel, Hong Zeng

363

Solgel derived tantalum pentoxide films as ultraviolet antireflective coatings for silicon.  

PubMed

A solgel process is described to produce Ta(2)O(5) films as short wavelength antireflective (AR) coatings for silicon. The AR coatings were optimized for 370 nm by controlling the acid catalyzed hydrolysis of Ta(OC(2)H(5))(5), the spin coating parameters, and the heat treatment process (rapid thermal processing (RTP) and muffle furnace). Film thickness uniformity across the wafer was better than 1%, and all the coatings tested passed the standard scotch tape test before and after heat treatment and exhibited no change in optical properties after submersion in liquid N(2). Several heat treatment protocols for densifying the films were studied. Spin coated films heat treated in a muffle furnace at 275 degrees C yielded Ta(2)O(5) AR coatings that reduced the reflectance losses from silicon at 370 nm by 86%, the reduction being within 1% of the theoretical value. Films subjected to RTP at temperatures ranging from 300 to 1000 degrees C reduced the reflectance loss in some cases by as much as 95%. The results demonstrate that spin coated solgel derived Ta(2)O(5) films subjected to a low temperature (<300 degrees C) heat treatment can form durable films suitable for near UV AR coatings for high index silicon devices, such as charge couple imagers and photovoltaic cells. PMID:20556030

Rehg, T J; Ochoa-Tapia, J A; Knoesen, A; Higgins, B G

1989-12-15

364

Theoretical characteristics of optical polarizing films using oblique metal island films  

NASA Astrophysics Data System (ADS)

An ultra-thin optical polarizing film using oblique metal island (OMI) film has been investigated theoretically. The polarizing film consists of a periodic multilayer of the OMI layers and glass layers. The OMI films are composed of prolate metal nanoclusters (I.E., islands) inclining to one side. The MOI films exhibit resonance-type absportion in visible and bear-infrared region and large optical anisotropy as the resonance wavelengths for the polarization along the shorter and longer axes of the prolate metal nanoclusters are different from each other. Therefore, the multilayer using the OMI films can be used as an optical polarizing film at the resonance wavelength. The resonance wavelength depends on the aspect ratio of the prolate islands, distance between the centers of the islands, and choice of the metal. The extinction ratio and insertion loss increase with the number of the OMI layer. In this paper we show the theoretical characteristics of the polarizing films composed of the OMI layers with idea and homogeneous film structure. We have successfully designed the optical polarizing film for the wavelength of 720 nm by choosing silver as metal. The extinction ration and insertion loss of the designed polarizing film are evaluated as 30 dB and 0.03 dB, respectively. The thickness of the polarizing film is calculated as 1800 nm. When aluminum is used as the metal, the polarizing films for the shorter wavelength can be designed.

Baba, Kazutaka

2006-03-01

365

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

PubMed

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 silicon substrates were also measured. Thin film adherence was studied by micro-scratch test. Residual stresses in the produced coatings will be analysed by bending technique. PMID:19916409

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

2009-07-01

366

Enhanced photocatalytic activity of metal coated ZnO nanowires.  

PubMed

A simple, facile and template free route has been described for the synthesis of ZnO nanowires. The morphology and structure of ZnO nanowires have been tuned by deposing silver and gold onto the surface of ZnO nanowire and this has been done by adding AgNO(3) and HAuCl(4) to aqueous suspension of ZnO. Our synthesized Ag and Au coated ZnO nanoparticles show different emissive property than the native ZnO nanowires. The photocatalytic degradation of Methylene Blue is also evaluated using ZnO and Ag and Au coated ZnO nanowires. It has been observed that Ag coated ZnO nano-needles exhibits significantly enhanced photocatalytic efficiency compare to ZnO nanowire and Au coated ZnO nano-leaves. Fluorescence spectra and surface structure of the samples with their photocatalytic activity indicates that surface deposited metal serves as an electron sinks to enhance the separation of photoinduced electrons from holes, leading to the formation of OH and it enhances their photocatalytic efficiency. PMID:22465775

Pyne, Santanu; Sahoo, Gobinda Prasad; Bhui, Dipak Kumar; Bar, Harekrishna; Sarkar, Priyanka; Samanta, Sadhan; Maity, Ashim; Misra, Ajay

2012-07-01

367

Cyclic nanoindentation studies on CrN thin films prepared by RF sputtering on Zr-based metallic glass  

NASA Astrophysics Data System (ADS)

Cyclic nanoindentation tests were carried out to study the influence of the chromium nitride thin films on the mechanical properties of Zr-based metallic glass. Chromium nitride thin coatings have been deposited on Zr50Cu40Al10 metallic glass substrate by RF sputtering. The deposition process was done at room temperature under nitrogen reactive gas using a metallic chromium target. The CrN films have a thickness of 300 nm. Several cyclic nanoindentation measurements were conducted on CrN films and Zr50Cu40Al10 metallic glass substrate samples at various loading rate values. We have found that the coated metallic glass sample shows high mechanical properties such as hardness and reduced elastic modulus. Cyclic nanoindentation results show a hardening behaviour for these CrN coatings. Moreover, the CrN coated on Zr-based metallic glass was found to have a high value of resistance to crack propagation, as being analysed through the SEM pictures of the residual Vickers indentation impressions.

Jellad, A.; Labdi, S.; Benameur, T.

2011-01-01

368

Amperometric Cholesterol Biosensor Using Layer-By-layer Adsorption Technique onto Polyaniline-Coated Polyester Films  

Microsoft Academic Search

An amperometric cholesterol biosensor was fabricated using polyaniline-coated polyester films. Polyaniline was dissolved in chloroform with camphorsulfonic acid, and polystyrene was added in this solution. Using this mixed solution, the coating was performed onto polyester films. Cholesterol oxidase was immobilized onto these films using an electrostatic layer-by-layer adsorption technique. Poly(diallyldimethylammonium chloride) was used as the counter ion source. The level

Min Jae Shin; Jin Gon Kim; Jae Sup Shin

2012-01-01

369

Fabrication of ceramic films for solid oxide fuel cells via slurry spin coating technique  

Microsoft Academic Search

Thin ceramic films of samaria-doped ceria (SDC) were deposited on green NiO–SDC substrate via a slurry spin coating technique followed by co-firing. The ceramic films as-prepared are homogenous and dense, without cracks and penetrating pinholes, as observed from cross-sectional SEM images. The thicknesses of the ceramic films for one coating run can be adjusted between 0.8 and 9?m by altering

Rob Hui; Zhenwei Wang; Sing Yick; Radenka Maric; Dave Ghosh

2007-01-01

370

Corrosion Control through a Better Understanding of the Metallic Substrate/Organic Coating/Interface.  

National Technical Information Service (NTIS)

Contents: Sensitive Test for Water under an Organic Coating; The Effect of Temperature and Alkali Metal Cation on the Cathodic Delamination of Polybutadiene from Steel; Acid Base Effects in Glass/Bead Phenoxy Model Coating Systems; Surface Acidity of Ferr...

H. Leidheiser E. M. Allen F. M. Fowkes R. D. Granata J. F. McIntyre

1986-01-01

371

Method of applying a bond coating and a thermal barrier coating on a metal substrate, and related articles  

DOEpatents

A method for applying at least one bond coating on a surface of a metal-based substrate is described. A foil of the bond coating material is first attached to the substrate surface and then fused thereto, e.g., by brazing. The foil is often initially prepared by thermally spraying the bond coating material onto a removable support sheet, and then detaching the support sheet. Optionally, the foil may also include a thermal barrier coating applied over the bond coating. The substrate can be a turbine engine component.

Hasz, Wayne Charles (Pownal, VT); Borom, Marcus Preston (Tucson, AZ)

2002-01-01

372

Discontinuous\\/continuous metal films grown on photosensitive glass  

Microsoft Academic Search

A new effect which allows direct formation of thin metal films of controlled morphology is described. Patterns of glass-ceramic opal are developed in photosensitive glass samples by UV irradiation and heat treatment. The samples are then ion exchanged in molten salt baths containing Ag+ or Cu+ ions. On subsequent firing in a hydrogen atmosphere, continuous films with typical thin metal

D. M. Trotter; D. W. Smith

1984-01-01

373

Surface enrichment in hot-dipped metallic coatings investigated by Auger electron spectroscopy  

NASA Astrophysics Data System (ADS)

The treatment, appearance, and corrosion resistance of metallic coatings are largely governed by the chemical composition of the surface. Auger electron spectroscopy shows that the surfaces of hot-dipped metallic coatings differ markedly from the bulk compositions of the coatings. For example, the surfaces of terne coatings, lead-tin alloys, contain little lead. The conventional galvanized coating, which is more than 99% zinc, has a predominantly aluminium oxide surface. Typical surface compositions of a range of hot-dipped metallic coatings are provided. A qualitative prediction of the dominant metallic species present on the surface of each of these coatings is presented in terms of the relative oxygen affinities of the metals. Theoretical equations for various mechanisms, such as atomic size mismatch, solubility, and oxidation, which could lead to surface segregation are considered, in order to place the experimental observations on a more quantitative basis.

Payling, R.; Mercer, P. D.

1985-05-01

374

Preparation and selective laser sintering of nylon-12 coated metal powders and post processing  

Microsoft Academic Search

A dissolution–precipitation process was successfully developed to prepare nylon-12 coated carbon steel powders. The SEM and laser diffraction particle size analysis results show that the metal particles are well coated by nylon-12 resin; therefore, an effective method for preparing nylon-12 coated metal powders is provided. Green parts were formed from the coated powders by selective laser sintering (SLS) process, and

Chunze Yan; Yusheng Shi; Jingsong Yang; Jinhui Liu

2009-01-01

375

Metal films on polymer substrates stretched beyond 50%  

Microsoft Academic Search

When a freestanding plastically deformable metal film is stretched, it ruptures by strain localization, and the elongation is less than a few percent. When the film is deposited on a polymer substrate, however, strain localization may be retarded by the substrate. This paper reports Cu films deposited on Kapton substrates and stretched up to the rupture of the substrates (at

Nanshu Lu; Xi Wang; Zhigang Suo; Joost Vlassak

2007-01-01

376

Integration of thin electroless copper films in copper interconnect metallization  

Microsoft Academic Search

Deposition of a thin electroless copper films on PVD copper seed layers in interconnect metallization was investigated for formation of a composite seed layer. Issues such as film stress, adhesion, electrical reliability, and hydrogen incorporation were addressed to determine feasibility of the process for the fabrication of real device structures. The formation of blisters between the copper films and underlying

E. Webb; C. Witt; T. Andryuschenko; J. Reid

2004-01-01

377

68 FR 64432 - National Emission Standards for Hazardous Air Pollutants: Surface Coating of Metal Cans  

Federal Register 2010, 2011, 2012, 2013

...protective layer for corrosion resistance. The emission limit...for surface coating of metal cans or ends (including...material that is applied to metal for the purpose of providing...the end for corrosion resistance. Research or laboratory...involves coating of flat metal sheets before they...

2003-11-13

378

Highly Conductive Group VI Transition Metal Dichalcogenide Films by Solution-Processed Deposition  

SciTech Connect

A new soluble synthetic route was developed to fabricate thin films of layered structure transition metal dichalcogendies, MoS{sub 2} and WS{sub 2}. High-quality thin films of the dichalcogenides were prepared using new soluble precursors, (CH{sub 3}NH{sub 3}){sub 2}MS{sub 4} (M = Mo, W). The precursors were dissolved in organic solvents and spun onto substrates via both single- and multistep spin coating procedures. The thin films were formed by the thermal decomposition of the coatings under inert atmosphere. Structural, electrical, optical absorption, thermal, and transport properties of the thin films were characterized. Surface morphology of the films was analyzed by atomic force microscopy and scanning electron microscopy. Highly conductive and textured n-type MoS{sub 2} films were obtained. The measured room temperature conductivity {approx}50 O-1 cm-1 is substantially higher than the previously reported values. The n-type WS{sub 2} films were prepared for the first time using solution-processed deposition. WS{sub 2} displays a conductivity of {approx}6.7 O-1 cm-1 at room temperature.

Ki, W.; Huang, X.; Li, J.; Young, D. L.; Zhang, Y.

2007-05-01

379

Shadowgraphic imaging of laser transfer driven by metal film blistering  

Microsoft Academic Search

A time-resolved shadowgraphic technique was used to investigate local transfer of diamond nanopowder from a thin titanium\\u000a film on a silica support under irradiation by 450-fs or 50-ps laser pulses. Clean powder ejection driven by blistering of\\u000a the metal film remaining on the target surface was found possible in a limited fluence range, but the metal film was removed\\u000a from

T. V. Kononenko; P. Alloncle; V. I. Konov; M. Sentis

2011-01-01

380

Angular dependence of thin-film dielectric coating damage thresholds  

SciTech Connect

Newman et al. reported experiments showing that the angular dependence of 351-nm laser damage thresholds in HfO{sub 2}/SiO{sub 2} multilayer dielectric reflectors was much weaker than even the 1/cos{theta} expected from simple geometric fluence dilution. Several plausible explanations were suggested, but none were convincing. We propose a simple geometric model based on a cylindrical form for the coating defect responsible for damage initiation. We have measured 248-nm damage thresholds for bare fused silica, evaporated aluminium films, and HfO{sub 2}/SiO{sub 2} and Al{sub 2}O{sub 3}/SiO{sub 2} dielectric reflectors at angles out to 85{degree}. The measured data agree well with our simple model.

Boyer, J.D.; Foltyn, S.R.; Mauro, B.R.; Sanders, V.E.

1989-01-01

381

The role of size and coating in Au nanoparticles incorporated into bi-component polymeric thin-film transistors  

NASA Astrophysics Data System (ADS)

We describe the effect of blending poly(3-hexylthiophene) (P3HT) with Au nanoparticles (AuNPs) on the performance of organic thin-film transistors. To this end we have used AuNPs of two different sizes coated with chemisorbed SAMs of oligophenyl-thiols possessing increasing lengths. The electrical characteristics of the hybrid materials revealed changes in the field-effect mobility depending primarily on the AuNP size, as a result of the variable energy level of the coated metallic nanocluster and by the degree of modification of the P3HT crystalline structure.We describe the effect of blending poly(3-hexylthiophene) (P3HT) with Au nanoparticles (AuNPs) on the performance of organic thin-film transistors. To this end we have used AuNPs of two different sizes coated with chemisorbed SAMs of oligophenyl-thiols possessing increasing lengths. The electrical characteristics of the hybrid materials revealed changes in the field-effect mobility depending primarily on the AuNP size, as a result of the variable energy level of the coated metallic nanocluster and by the degree of modification of the P3HT crystalline structure. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr00076e

Mosciatti, Thomas; Orgiu, Emanuele; Raimondo, Corinna; Samorì, Paolo

2014-04-01

382

Promising antimicrobial capability of thin film metallic glasses.  

PubMed

Thin film metallic glasses (TFMGs) are demonstrated to exhibit excellent surface flatness, high corrosion resistance and satisfactory hydrophobic properties. Moreover, the antimicrobial and biocompatibility abilities of TFMGs are examined and the results are compared with the behavior of pure Ag and 316L stainless steel. Three TFMGs, Al48Ag37Ti15, Zr54Ti35Si11, and Zr59Ti22Ag19, are prepared by sputtering to assess the antimicrobial performance against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, which are the most common nosocomial infection pathogens. Experimental results show that the antimicrobial effect of the Al- or Ag-containing AlAgTi and ZrTiAg TFMGs is similar to that of the pure Ag coating. The ZrTiSi TFMG with no Ag or Al shows poor antimicrobial capability. The physical properties of highly smooth surface and hydrophobic nature alone are not sufficient to result in promising antimicrobial ability. The chemical metal ion release still plays a major role, which should be born in mind in designing biomedical devices. PMID:24433907

Chu, Y Y; Lin, Y S; Chang, C M; Liu, J-K; Chen, C H; Huang, J C

2014-03-01

383

High-barrier coated bacterial cellulose nanowhiskers films with reduced moisture sensitivity.  

PubMed

This study reports on the development and characterization of bacterial cellulose (BCNW) films coated with hydrophobic layers, presenting enhanced barrier properties. Pure BCNW films showed good transparency and thermal stability, high rigidity and extremely low oxygen permeability at 0%RH. The dramatic increase in oxygen permeability at 80%RH, due to the hydrophilic character of BCNW, was counteracted through coating the films with annealed PLA electrospun nanostructured fibres or hydrophobic silanes. The use of electrospinning was crucial to attain a good adhesion between the hydrophilic BCNW and the hydrophobic PLA layer. After electrospinning, the fibres were homogenised by annealing, thus obtaining a uniform and continuous coating. Coated systems showed a hydrophobic surface and protected the BCNW from moisture, thus reducing ca. 70% the water permeability and up to 97% the oxygen permeability at 80%RH. Furthermore, this novel approach was seen to protect BCNW films from moisture more efficiently than coating with hydrophobic silanes. PMID:23987449

Martínez-Sanz, Marta; Lopez-Rubio, Amparo; Lagaron, Jose M

2013-10-15

384

In vitro study of drug loading on polymer-free oxide films of metallic implants.  

PubMed

Traditionally, a drug that is loaded onto a metallic surface has to use various polymer bondings as its platform. Unfortunately, polymer coatings on a metallic surface cause numerous problems after implantation, such as late thrombosis, inflammation, and restenosis. This research was conducted to investigate whether an oxide layer can be used as a polymer-free platform for drug loading, especially for cardiovascular stents. The interaction and loading of heparin onto different oxide films on 316LVM stainless steel wire was confirmed in vitro by experimental studies using linear voltammetry, electrochemical impedance spectroscopy, and electron spectroscopy for chemical analysis. The eluting of heparin from heparinized surface was studied by using high-performance liquid chromatography, and activated clotting time in addition to linear voltammetry and electron spectroscopy for chemical analysis analyses. Experimental results show that amorphous oxide could be a potential substitute for the polymer coating of drug-loaded stents for minimizing metallic corrosion, inflammation, late thrombosis, and restenosis. PMID:16082699

Shih, Chun-Ming; Shih, Chun-Che; Su, Yea-Yang; Chang, Nen-Chung; Lin, Shing-Jong

2005-12-01

385

Tribological performance of ceramic coatings deposited on metal surfaces for micro-bearing biomedical applications  

NASA Astrophysics Data System (ADS)

Modification of metal materials by means of ceramic coating deposition is an effective way of forming alternative bearing surfaces. Ceramic AlN, Al2O3 and nanocomposite oxynitride coatings are widely used as protective coatings against wear, diffusion and corrosion. The enhancement of the mechanical properties, such as hardness parameters, effective Young's modulus, toughness, elastic recovery and wear resistance of the coatings, is very important for the tribological performance of the next generation of ceramic-coated ball bearing devices.

Donkov, N.; Zykova, A.; Safonov, V.; Smolik, J.; Rogowska, R.; Luk'yanchenko, V.; Yakovin, S.

2014-05-01

386

Nanocrystalline spin coated sol-gel hydroxyapatite thin films on Ti substrate: Towards potential applications for implants  

NASA Astrophysics Data System (ADS)

Sol-gel spin coating is a promising process to obtain hydroxyapatite (HA) thin films. It is an alternative route to the hydroxyapatite deposition techniques usually employed to cover orthopaedic or dental titanium implant surfaces. The sol-gel (SG) parameters leading to a pure and crystalline HA coatings on Ti substrate were determined. They allow to reach a stoichiometric hydroxyapatite composition (ideal Ca/P atomic ratio 1.67) and a control of the growth of the crystalline phases. The samples, when observed by Scanning Electron Microscopy (SEM), exhibit grains of ca. 200 nm, well adapted for cell proliferation. The crystallisation of the HA films was thoroughly studied by X-Ray diffraction (XRD). The aim of this paper is to validate the sol-gel method as a processing method allowing the control of the mechanical state of the films and, in particular, of the residual stresses (RS) at metal-ceramic interfaces. These stresses were determined on titanium substrates. While the uncoated Ti substrates were in a compressive residual state, the coated ones were in a low tensile state. These results suggest that the sol-gel process is indeed a processing route to obtain HA coated Ti implants.

Carradò, Adele; Viart, Nathalie

2010-07-01

387

Superhydrophobic ceramic coatings enabled by phase-separated nanostructured composite TiO2-Cu2O thin films.  

PubMed

By exploiting phase-separation in oxide materials, we present a simple and potentially low-cost approach to create exceptional superhydrophobicity in thin-film based coatings. By selecting the TiO2-Cu2O system and depositing through magnetron sputtering onto single crystal and metal templates, we demonstrate growth of nanostructured, chemically phase-segregated composite films. These coatings, after appropriate chemical surface modification, demonstrate a robust, non-wetting Cassie-Baxter state and yield an exceptional superhydrophobic performance, with water droplet contact angles reaching to ?172° and sliding angles <1°. As an added benefit, despite the photo-active nature of TiO2, the chemically coated composite film surfaces display UV stability and retain superhydrophobic attributes even after exposure to UV (275 nm) radiation for an extended period of time. The present approach could benefit a variety of outdoor applications of superhydrophobic coatings, especially for those where exposure to extreme atmospheric conditions is required. PMID:24857856

Aytug, Tolga; Bogorin, Daniela F; Paranthaman, Parans M; Mathis, John E; Simpson, John T; Christen, David K

2014-06-20

388

The effects of sintering temperature on preparation, resistivity, and thermopower of c-axis oriented Ca 3Co 3.95Fe 0.05O 9 + ? films fabricated using sol–gel spin coating method  

Microsoft Academic Search

We report fabrication of the c-axis oriented Ca3Co3.95Fe0.05O9+? films by a simple sol–gel spin coating method. The films prepared in the temperature range of 650–700 °C show nonmetallic temperature dependence of resistivity in the whole investigated temperature range, whereas the films prepared in the temperature range of 750–775 °C show metallic temperature dependence in the high temperature regime. Sintering the films at

Chia-Jyi Liu; Pradipta K. Nayak; Zhi-Ru Lin; Kai-Yi Jeng

2008-01-01

389

Ethanol-resistant polymeric film coatings for controlled drug delivery.  

PubMed

The sensitivity of controlled release dosage forms to the presence of ethanol in the gastro intestinal tract is critical, if the incorporated drug is potent and exhibits severe side effects. This is for instance the case for most opioid drugs. The co-ingestion of alcoholic beverages can lead to dose dumping and potentially fatal consequences. For these reasons the marketing of hydromorphone HCl extended release capsules (Palladone) was suspended. The aim of this study was to develop a novel type of controlled release film coatings, which are ethanol-resistant: even the presence of high ethanol concentrations in the surrounding bulk fluid (e.g., up to 40%) should not affect the resulting drug release kinetics. Interestingly, blends of ethylcellulose and medium or high viscosity guar gums provide such ethanol resistance. Theophylline release from pellets coated with the aqueous ethylcellulose dispersion Aquacoat® ECD 30 containing 10 or 15% medium and high viscosity guar gum was virtually unaffected by the addition of 40% ethanol to the release medium. Furthermore, drug release was shown to be long term stable from this type of dosage forms under ambient and stress conditions (without packaging material), upon appropriate curing. PMID:23570984

Rosiaux, Y; Muschert, S; Chokshi, R; Leclercq, B; Siepmann, F; Siepmann, J

2013-07-10

390

Western blotting by thin-film direct coating.  

PubMed

A novel thin-film direct coating (TDC) technique was developed to markedly reduce the amount of antibody required for Western blotting (WB). Automatic application of the technique for a few seconds easily and homogeneously coats the specific primary antibody on the polyvinylidene fluoride (PVDF) membrane. While conventional WB requires 0.4 ?g of the primary antibody, the proposed technique only uses 4 × 10(-2) ?g, which can be reduced further to 4 × 10(-5) ?g by reducing the coater width. Moreover, the proposed process reduces antibody probing times from 60 to 10 min. The quantification capability of TDC WB showed high linearity within a 4-log2 dynamic range for detecting target antigen glutathione-S-transferase. Furthermore, TDC WB can specifically detect the extrinsic glutathione-S-transferase added in the Escherichia coli or 293T cell lysate with better staining sensitivity than conventional WB. TDC WB can also clearly probe the intrinsic ?-actin, ?-tubulin, and glyceraldehyde 3-phosphate dehydrogenase, which are usually used as control proteins in biological experiments. This novel technique has been shown to not only have valuable potential for increasing WB efficiency but also for providing significant material savings for future biomedical applications. PMID:24773468

Yen, Yi-Kuang; Jiang, Yi-Wei; Chang, Shih-Chung; Wang, An-Bang

2014-05-20

391

Metal-coated nanocylinder cavity for broadband nonclassical light emission.  

PubMed

A novel metal-coated nanocylinder-cavity architecture fully compatible with III-V GaInAs technology and benefiting from a broad spectral range enhancement of the local density of states is proposed as an integrated source of nonclassical light. Because of a judicious selection of the mode volume, the cavity combines good collection efficiency (?45%), large Purcell factors (?15) over a 80 nm spectral range, and a low sensitivity to inevitable spatial mismatches between the single emitter and the cavity mode. This represents a decisive step towards the implementation of reliable solid-state devices for the generation of entangled photon pairs at infrared wavelengths. PMID:21231093

Maksymov, I S; Besbes, M; Hugonin, J P; Yang, J; Beveratos, A; Sagnes, I; Robert-Philip, I; Lalanne, P

2010-10-29

392

Metal-Coated Nanocylinder Cavity for Broadband Nonclassical Light Emission  

NASA Astrophysics Data System (ADS)

A novel metal-coated nanocylinder-cavity architecture fully compatible with III-V GaInAs technology and benefiting from a broad spectral range enhancement of the local density of states is proposed as an integrated source of nonclassical light. Because of a judicious selection of the mode volume, the cavity combines good collection efficiency (?45%), large Purcell factors (?15) over a 80 nm spectral range, and a low sensitivity to inevitable spatial mismatches between the single emitter and the cavity mode. This represents a decisive step towards the implementation of reliable solid-state devices for the generation of entangled photon pairs at infrared wavelengths.

Maksymov, I. S.; Besbes, M.; Hugonin, J. P.; Yang, J.; Beveratos, A.; Sagnes, I.; Robert-Philip, I.; Lalanne, P.

2010-10-01

393

Heat Reflecting Window Coatings.  

National Technical Information Service (NTIS)

Heat loss caused by radiation through the window glass is significantly reduced by the use of coatings that reflect infrared radiation but are transparent to the visible light. This selectivity can be achieved by using metallic films with sufficiently low...

E. Koskiahde

1986-01-01

394

Preparation of chitosan-coated polyethylene packaging films by DBD plasma treatment.  

PubMed

Polyethylene (PE) packaging films were coated with chitosan in order to introduce the antibacterial activity to the films. To augment the interaction between the two polymers, we modified the surfaces of the PE films by dielectric barrier discharge (DBD) plasma before chitosan coating. After that the plasma-treated PE films were immersed in chitosan acetate solutions with different concentrations of chitosan. The optimum plasma treatment time was 10 s as determined from contact angle measurement. Effect of the plasma treatment on the surface roughness of the PE films was investigated by atomic force microscope (AFM) while the occurrence of polar functional groups was observed by X-ray photoelectron spectroscope (XPS) and Fourier transformed infrared spectroscope (FTIR). It was found that the surface roughness as well as the occurrence of oxygen-containing functional groups (i.e., C?O, C-O, and -OH) of the plasma-treated PE films increased from those of the untreated one, indicating that the DBD plasma enhanced hydrophilicity of the PE films. The amounts of chitosan coated on the PE films were determined after washing the coated films in water for several number of washing cycles prior to detection of the chitosan content by the Kjaldahl method. The amounts of chitosan coated on the PE films were constant after washing for three times and the chitosan-coated PE films exhibited appreciable antibacterial activity against Escherichia coli and Staphylococcus aureus. Hence, the obtained chitosan-coated PE films could be a promising candidate for antibacterial food packaging. PMID:22512401

Theapsak, Siriporn; Watthanaphanit, Anyarat; Rujiravanit, Ratana

2012-05-01

395

Metal-enhanced fluorescence: effect of surface coating  

NASA Astrophysics Data System (ADS)

Metal Enhanced Fluorescence (MEF), a phenomenon arising when a fluorophore is in closed proximity to a metallic structure such as metallic films or nanostructures, is seen as a way to increase the amount of reactive oxygen species produced by the irradiation of the protoporphyrin IX (PpIX), a photosensitizer commonly used in photodynamic therapy. Here, we show a study of the distance-dependent of MEF by applying multiple layers of polyelectrolyte (PE) on silver nanoparticles (AgNPs) to progressively increase the distance between AgNPs and PpIX, covalently bond to the last polyelectrolyte layer as well as exploring the use of AgNPs of different sizes ranging from 40 to 100 nm. Up to four fold increase of PpIX fluorescence was observed when this photosensitizing agent is bounded onto 100 nm sized Ag NPs. The effective corresponding distance between AgNPs and PpIX is three layers of PE.

Lismont, M.; François, A.; Dreesen, L.; Monro, T. M.

2014-03-01

396

Enhanced electrochemical properties of fluoride-coated LiCoO2 thin films.  

PubMed

The electrochemical properties of fluoride-coated lithium cobalt oxide [LiCoO2] thin films were characterized. Aluminum fluoride [AlF3] and lanthanum fluoride [LaF3] coating layers were fabricated on a pristine LiCoO2 thin film by using a spin-coating process. The AlF3- and LaF3-coated films exhibited a higher rate capability, cyclic performance, and stability at high temperature than the pristine film. This indicates that the AlF3 and LaF3 layers effectively protected the surface of the pristine LiCoO2 film from the reactive electrolyte. PMID:22221488

Lee, Hye Jin; Kim, Seuk Buom; Park, Yong Joon

2012-01-01

397

Metal-insulator phase transition in vanadium oxides films  

Microsoft Academic Search

Vanadium oxide films (VO2) are of a typical phase transition ranging between metal phase to a semi-conducting phase. The theoretical metamorphose temperature of VO2 is around 340K (67°C). This transition temperature is mostly governed by the deposition method in which the film was made, and the film's composition. Optical and electrical properties of VO2 films are dramatically changed during this

G. Golan; A. Axelevitch; B. Sigalov; B. Gorenstein

2003-01-01

398

Epitaxial Electrodeposition of Chiral Metal Oxide Films  

NASA Astrophysics Data System (ADS)

Chirality is ubiquitous in Nature. One enantiomer of a molecule is often physiologically active, while the other enantiomer may be either inactive or toxic. Chiral surfaces offer the possibility of developing heterogeneous enantiospecific catalysts that can more readily be separated from the products and reused. Chiral surfaces might also serve as electrochemical sensors for chiral molecules- perhaps even implantable chiral sensors that could be used to monitor drug levels in the body. Our trick to produce chiral surfaces is to electrodeposit low symmetry metal oxide films with chiral orientations on achiral substrates (see, Nature 425, 490, 2003). The relationship between three-dimensional and two-dimensional chirality will be discussed. Chiral surfaces lack mirror or glide plane symmetry. It is possible to produce chiral surfaces of materials which do not crystallize in chiral space groups. We have deposited chiral orientations of achiral CuO onto single-crystal Au and Cu using both tartaric acid and the amino acids alanine and valine to control the handedness of the electrodeposited films. We will present results on the chiral recognition of molecules such as tartaric or malic acid and L-dopa on the chiral electrodeposited CuO. Initial work on the electrochemical biomineralization of chiral nanostructures of calcite will also be discussed.

Switzer, Jay

2006-03-01

399

Sol-gel coating on acoustic wave devices: Thin film characterization and chemical sensor development  

SciTech Connect

We have investigated the use of porous oxide coatings, formed using sol-gel chemistry routes, as the discriminating elements of acoustic wave (AW) chemical sensors. These coatings provide several unique advantages: durability, high adsorption capacity based on large surface areas, and chemical selectivity based on both molecular size and chemical interactions. The porosity of these coatings is determined by performing nitrogen adsorption isotherms using the AW device response to mass changes to monitor the uptake of nitrogen at 77 K. These studies demonstrate how sol-gel chemistry and film-forming technique can be used to tailor the microstructure of thin coatings. The chemical sensitivity and selectivity obtained with this class of coatings will be demonstrated using several examples: hydrous titanate ion exchange coatings, zeolite/silicate microcomposite coatings, and surface-modified silicate films. 18 refs., 4 figs., 2 tabs.

Frye, G.G.; Brinker, C.J.; Ricco, A.J.; martin, S.J.; Hilliard, J.; Doughty, D.H.

1990-01-01

400

Metallic thin films for NEMS/MEMS: From fundamental behaviour to microstructural design and fabrication  

NASA Astrophysics Data System (ADS)

The main focus of this thesis is the study of thin metal films in microelectromechanical/ nanoelectromechanical systems (MEMS/NEMS), ranging from application to fundamental behaviour. The use of metallic structural components is desirable since they are electrically conductive, optically re ective and ductile. However, polycrystalline metallic thin films typically exhibit low strength and hardness, high surface roughness and significant incremental stress, making them unusable for NEMS/MEMS. By co-sputtering Ni-Mo thin films we are able to tailor the microstructure and surface morphology such that these limitations are overcome. As such, uncurled NEMS cantilevers possessing enhanced hardness, metallic conductivity and sub-nanometer roughness are fabricated with resonant frequencies in the MHz regime, and quality factors ranging from 200-900. Following this, the use and design of all-metal atomic force microscope (AFM) probes is investigated. This is motivated by the growing number of AFM applications which make use of metal-coated probes, and as a result of the metallization suffers from stress-induced cantilever bending, thermal expansion mismatch, increased tip radius and limited device lifetime due to coating wear. To this end, monostructural all-metal AFM probes having 1 ?m thickness, lengths of 100-400 ?m, and tip radii ranging from 10 to 40 nm are fabricated. This is accomplished through microstructural design of Cu-Hf thin films, where an optimal combination of resistivity (96 ??cm), hardness (5:2 GPa), ductility and incremental stress. Lastly, in many MEMS/NEMS applications the unique properties of nonmetallic components are required, but a metallization layer is still needed. As metallization layers become increasingly thinner, film stability can become problematic, due to the phenomenon of solid-state dewetting. The fundamental mechanisms of solid-state dewetting are investigated in Ni thin films on SiO2. This phenomenon is monitored in situ using time resolved differential reflectometry (TRDR) and ex situ using AFM. It is found that Ni dewetting on SiO2 occurs through the sequential processes of grain growth, grain boundary grooving, hole growth and particle coarsening. Kinetic analysis of the TRDR data revealed two rate-limiting processes, with activation energies of 0:31±0:04 and 0.59±00.6 eV. It is hypothesized that these kinetic pathways correspond to Ni grain growth and surface mass self-diffusion on the Ni(111) planes, respectively.

Luber, Erik

401

Evaluation of Adhesive Behaviors of Chromium Nitride Coating Films Produced by Arc Ion Plating Method  

NASA Astrophysics Data System (ADS)

Scratch tests and pin-on-disk wear tests were performed to clarify the cracking and delaminating behavior of CrN coatings. The CrN films were coated onto an aluminum alloy substrate, JIS A2024, by an arc ion plating method. Eight types of single-layered coating and multilayered coatings were prepared by changing the bias voltage during the deposition. LCI and LCII values were not improved by increasing the number of layers. The critical loads of the single-layered coatings decreased with increasing the bias voltage. It appears that, for the multilayered coatings, the combination of bias voltages influenced the critical loads. The critical loads strongly depended on dynamic hardness and Young’s modulus. In particular, the critical loads of the multilayered coatings were influenced by the properties of the intermediate and bottom layers as well as the surface roughness, hardness and Young’s modulus of the top layer. The large film delamination for single-layered coatings deposited using a high bias voltage occurred during pin-on-disk wear tests even though the critical loads of the single-layered coatings were higher than those of the multilayered coatings. If the brittle top layer could be broken and delaminated by the sliding contact, the ductile bottom layer coated under a bias voltage of 0V could endure the complete delamination of film.

Murakami, Ri-Ichi; Kim, Yun-Hae; Kimura, Kazushi; Yonekura, Daisuke; Shin, Do-Hoon

402

Friction resistance of buried pipeline coatings studied. [Comparative evaluation of coal tar felt and thin-film epoxy coatings  

Microsoft Academic Search

Static friction tests were conducted to find the coefficient of friction between coal tar felt and thin-film epoxy pipe coating and eight representative backfill soil samples from typical locations along a pipeline right-of-way. The results indicate that the friction coefficients are significantly higher than those previously extrapolated from the literature and that coal tar would be the preferable coating in

J. B. Ligon; G. R. Mayer

1975-01-01

403

Investigation of a methodology for in-film defects detection on film coated blank wafers  

NASA Astrophysics Data System (ADS)

Multi-patterning is one of the commonly used processes to shrink device node dimensions. With the miniaturization of the device node and the increasing number of coated layers and lithography processes, needs for defect reduction and control are getting stronger. Although there are needs for detecting in-film defects during the lithography process, it is difficult to verify in-film defects detected by an optical inspection tool because in-film defects usually appear as SEM Non-Visuals (SNV) during defect review using a scanning electron microscope (SEM). This makes the tuning of optical inspection tools difficult since these defects may be considered as noise. However, if these defects are "real defects", they will have a negative impact to manufacturing yield. In this paper, we investigate a new methodology to detect in-film defects with high sensitivity utilizing a broadband plasma inspection tool. This methodology is expected to allow the early detection of in-film defects before the pattern formation, hence improving device manufacturing yield.

Kiyotomi, Akiko; Dauendorffer, Arnaud; Shimura, Satoru; Miyazaki, Shinobu; Miyagi, Takemasa; Ota, Shigeru; Haneda, Koji; Baris, Oksen; Wei, Junwei

2014-04-01

404

A Investigation Into the Relaxation Behavior of Pharmaceutical Film Coatings.  

NASA Astrophysics Data System (ADS)

Polymeric materials utilized as film coatings exhibit many different time dependent relaxations which can yield relevant information regarding their use. In this dissertation research, the effect of additives on the primary relaxation behavior and the effect of physical aging, a relaxation to the lowest free energy state, on the physical properties of glassy polymeric materials was investigated. Glassy polymeric materials were chosen in this study since they are widely utilized in the pharmaceutical industry. The observation of the aging process using a creep compliance technique was confirmed with polystyrene, a material whose aging behavior has been well studied. Results from both hydroxypropyl methylcellulose phthalate, HP-55, and cellulose acetate indicate that these materials physically age in their sub-Tg temperature ranges. The mechanical data in both cases was successfully fit to a model which describes the relaxation behavior of condensed amorphous materials. The aging time and temperature dependence of key parameters from this model show that physical aging is thermally activated and thermoreversible. Aging time and temperature dependent reductions in the water permeability of cellulose acetate were observed. The reductions were correlated with calculations, based on the mechanical property changes, which describe the aging -induced relaxation of the glass. These results indicate that a structural change due to aging may be responsible for the observed reductions in water mobility in cellulose acetate. The dissolution rate of HP-55 was found to decrease to a limiting rate when physically aged. Mechanical measurements performed on film samples which were subjected to the same thermal history utilized in the dissolution experiments confirmed the observed aging effect. The effect of the addition of the plasticizers dibutyl phthalate and polyethylene glycol 200 on the primary relaxation behavior of Eudragit S100, an enteric coating, was also evaluated in this dissertation. Creep compliance measurements were performed on films in the glass transition region. Both plasticizers were found to increase the mechanical rate of response of the polymer. A free volume approach was used to describe plasticizing efficiency and it was found that dibutyl phthalate was more effective at changing the mechanical rate of response of Eudragit S100 than polyethylene glycol 200.

Sinko, Christopher Michael

405

Thickness dependent electronic structure and morphology of rubrene thin films on metal, semiconductor, and dielectric substrates  

NASA Astrophysics Data System (ADS)

The evolution of the electronic structure and morphology of rubrene thin films on noble-metal, semiconductor and dielectric substrates have been investigated as a function of thickness of deposited films by using photoelectron spectroscopy and atomic force microscopy. The clean polycrystalline Au and Ag were used as noble-metals, whereas, H passivated and SiO2 coated Si (100) were used as semiconductors and dielectric substrates. Discussion and comparison on interface dipole, energy level alignment, and surface morphology for the four cases are presented. The formation of dipole at metallic interfaces is found to occur due to push back effect. S parameter obtained from the variation of barrier height with the change of work function of the contacting metal indicates moderately weak interaction between rubrene and the metal substrates. The thickness dependent energy level alignment of the physisorbed rubrene films on different substrates is explained by a dielectric model in terms of electrostatic screening of photo-holes or photoemission final state relaxation energy. Films on all the substrates are found to grow following Stranski-Krastnov type growth mode and are more ordered at higher coverage.

Sinha, Sumona; Mukherjee, M.

2013-08-01

406

Proton Transport Through Atomic Layer Coated Thin-Films  

NASA Astrophysics Data System (ADS)

Prior research has concentrated on proton and electron transport in Pd-Ni thin films (500-2000Åunder unique conditions of an ultra high proton loading (proton/metal atom ratios of ˜0.9) with an applied electric field superimposed [1]. Simulations using WIEN2K, a Full-potential Linearized Augmented Plane Wave (FLAPW) package, showed a significant increase in the charged density build up around a proton located at edge site between Pd atoms, strongly affecting transport properties. Recently Iwamura, et al. [2], showed that mono-atomic layers of Cs or Sr on the surface of similar thin films undergo nuclear transmutations during deuterium flow through the films. This phenomenon is discussed here in terms of charged density build-up around these edge site atoms. In addition to configurational effects, their lower ionization potential significantly affects the charged density, increasing the collisional probability. [1] G. H. Miley, et al., Bult. Am. Phys. Soc., 47, No. 1, Pt. I, 368, (2002). [2] Y. Iwamura, et al., Jp. J. of Appl. Phys., 41, pt. 1, 7A, 4642, (2002).

Miley, George; Luo, Nie; Lipson, Andrei

2003-03-01

407

Growth, structure and properties of metal and metal oxide films  

NASA Astrophysics Data System (ADS)

Two systems, chromium and chromium oxide films on Pt(111), as well as rutile TiOsb2(110) surfaces, have been investigated using Low Energy Ion Scattering Spectroscopy (ISS), X-ray Photoelectron Spectroscopy (XPS), Low Energy Electron Diffraction (LEED), and Scanning Tunneling Microscopy (STM). The films of metal Cr and chromium oxide were grown by Cr vapor deposition in UHV and under an oxygen pressure of 2 x 10sp{-6} mbar, respectively. Both films grow in a step-flow mode. The Cr film is pseudomorphic to the Pt(111) substrate within the first two monolayers (ML). At higher coverages, the chromium overlayer adopts a bcc (110) surface structure and forms three-dimensional elongated islands oriented along the three close-packed directions of the Pt(111) surface. A self-organized Cr/Pt surface alloy is formed upon annealing 1.5-3 ML Cr/Pt(111) to 800 K. This alloy exhibits a highly-symmetric hexagonal network of one-atom-wide dislocation lines, with a unit cell dimension of 17.3 A. STM images reveal a strong variation of the local electronic structure due to the presence of a regular array of two-dimensional Cr clusters containing 10 atoms. For the chromium oxide, a well ordered p(2 x 2) structure is observed within the first 2 ML and attributed to the epitaxial growth of metastable Crsb3Osb4. At higher coverages, a (surd3 x surd3)R30sp° structure appears, due to formation of the stable Crsb2Osb3 phase. The influence of surface preparation procedures on the structure and appearance of TiOsb2(110) has been investigated. After initial cleaning and with increasing annealing temperature, the segregation of Ca impurity to the surfaces of fresh TiOsb2(110) single crystals has been observed. As revealed by LEED and STM, a ?ftlbrack {6enspace0atop 3enspace 1}rightrbrack structure is formed as an overlayer, with row-like features along the (001) direction. In line with the Ca 2psb{3/2} peak position of 347.4 eV, we propose formation of a CaTiOsb3-like compound, oriented with its (110) face parallel to the substrate. Upon annealing a sputtered rutile TiOsb2(110) surface and cooling it down in an oxygen background pressure, STM images show a highly-ordered (4 x 2) structure. We believe a new phase, anatase (110), is formed on the rutile TiOsb2(110) surface.

Zhang, Lanping

408

Deposition of alloy films. [on irregulary shaped metal object  

NASA Technical Reports Server (NTRS)

An invention is described which deposits metal alloy films on a metal object. A glow discharge is established by applying a high voltage between an anode and a cathode object disposed in an inert gas atmosphere. An alloy of two or more metals is vaporized and the vapor injected into the glow discharge causing the alloy to be plated onto the cathode object.

Spalvins, T. (inventor)

1973-01-01

409

Surface Chemistry of Nano-Structured Mixed Metal Oxide Films.  

National Technical Information Service (NTIS)

We have synthesizes and studied nano-structured porous mixed metal oxide thin films with high surface area and catalytic activity. By temporally controlling the deposition of two different metals in low-pressure oxygen we synthesized mixed metal oxide cat...

C. B. Mullins

2012-01-01

410

Ellipsometry study on gold-nanoparticle-coated gold thin film for biosensing application  

PubMed Central

The amplified plasmonic response from various distributions of gold nanoparticles (AuNPs) coated on top of gold thin film was studied via ellipsometry under total internal reflection mode. The surface plasmon resonance dip can be tuned from the visible to near infrared by simply varying the AuNP concentration. Theoretical modeling based on effective medium theory with a multi-slice model has been employed to fit the experimental results. Additionally, this experimental tool has been further extended to study bio-molecular interactions with metal surfaces as well as in studying protein-protein interaction without any labeling. Hence, this technique could provide a non-destructive way of designing tunable label-free optical biosensors with very high sensitivity.

Moirangthem, Rakesh Singh; Chang, Yia-Chung; Wei, Pei-Kuen

2011-01-01

411

Ellipsometry study on gold-nanoparticle-coated gold thin film for biosensing application.  

PubMed

The amplified plasmonic response from various distributions of gold nanoparticles (AuNPs) coated on top of gold thin film was studied via ellipsometry under total internal reflection mode. The surface plasmon resonance dip can be tuned from the visible to near infrared by simply varying the AuNP concentration. Theoretical modeling based on effective medium theory with a multi-slice model has been employed to fit the experimental results. Additionally, this experimental tool has been further extended to study bio-molecular interactions with metal surfaces as well as in studying protein-protein interaction without any labeling. Hence, this technique could provide a non-destructive way of designing tunable label-free optical biosensors with very high sensitivity. PMID:21991549

Moirangthem, Rakesh Singh; Chang, Yia-Chung; Wei, Pei-Kuen

2011-09-01

412

New synthetic routes to metal boride thin films and metallaboranes  

SciTech Connect

This dissertation describes the investigation of chemical vapor deposition of metal/metal boride thin films of transition and rare earth elements from metal halides and boron hydride precursors. Also reported are thermal routes to synthesis of new metallaborane complexes. An approach to the chemical vapor deposition of metal/metal boride thin films of the first row transition elements has been developed. Metal/metal boride thin films of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, and copper were prepared using metal halides, pentaborane (9) and decaborane (14) precursors. Mixed metal films were also deposited containing Fe-Co-B and Cu-Ni-B. The metal boride films were characterized by scanning electron microscopy (SEM), X-ray thin film diffraction (XRD), transmission electron diffraction (TED), atomic absorption spectrophotometry (AA), auger electron spectroscopy (AES), X-ray emission spectrometry (XES), Laser microprobe mass analysis (LAMMA), glow discharge mass spectrometry (GDMS) and elemental analysis. The chemical vapor deposition of rare earth boride films is presented. Thin films of LaB[sub 6], GdB[sub 6], and NdB[sub 6] were deposited from the corresponding metal chlorides, pentaborane(9) and decaborane(14) precursors. The rare earth boride films possessed unusual microstructures. Mixed metal films containing Co-Nd-B were also prepared. The films were characterized by scanning electron microscopy, X-ray thin film diffraction, reflection high energy electron diffraction, energy dispersive and wavelength dispersive X-ray emission spectrometry and glow discharge mass spectrometry. The reactions of the metal halide thermal dissociation species and neutral pentaborane(9) are described. [mu]-2,3,2',3'-Fe(B[sub 5]H[sub 8])[sub 2], 1, and [mu]-2,3,2',3'-Ti(B[sub 5]H[sub 8])[sub 2] 2, were synthesized. A thermal reaction of NiCl[sub 2] and B[sub 5]H[sub 9] produced compound 3 proposed as B[sub 10]H[sub 8]Ni[sub 2]Cl[sub 2].

Kher, S.S.

1993-01-01

413

Engineering the interface characteristics of ultrananocrystalline diamond films grown on Au-coated Si substrates.  

PubMed

Enhanced electron field emission (EFE) properties have been observed for ultrananocrystalline diamond (UNCD) films grown on Au-coated Si (UNCD/Au-Si) substrates. The EFE properties of UNCD/Au-Si could be turned on at a low field of 8.9 V/?m, attaining EFE current density of 4.5 mA/cm(2) at an applied field of 10.5 V/?m, which is superior to that of UNCD films grown on Si (UNCD/Si) substrates with the same chemical vapor deposition process. Moreover, a significant difference in current-voltage curves from scanning tunneling spectroscopic measurements at the grain and the grain boundary has been observed. From the variation of normalized conductance (dI/dV)/(I/V) versus V, bandgap of UNCD/Au-Si is measured to be 2.8 eV at the grain and nearly metallic at the grain boundary. Current imaging tunneling spectroscopy measurements show that the grain boundaries have higher electron field emission capacity than the grains. The diffusion of Au into the interface layer that results in the induction of graphite and converts the metal-to-Si interface from Schottky to Ohmic contact is believed to be the authentic factors, resulting in marvelous EFE properties of UNCD/Au-Si. PMID:22823911

Sankaran, Kamatchi Jothiramalingam; Panda, Kalpataru; Sundaravel, Balakrishnan; Chen, Huang-Chin; Lin, I-Nan; Lee, Chi-Young; Tai, Nyan-Hwa

2012-08-01

414

Bismuth film electrodes for heavy metals determination  

NASA Astrophysics Data System (ADS)

Bismuth film electrodes (BiFEs) have a potential to replace toxic mercury used most frequently for determination of heavy metals (Cd, Pb, Zn) by anodic stripping voltammetry. We prepared a graphite disc electrode (0.5 mm in diameter) from a pencil-lead rod and developed a nitrogen doped diamond-like carbon (NDLC) microelectrode array consisting of 50 625 microdiscs with 3 ?m in diameter and interelectrode distances of 20 ?m on a highly conductive silicon substrate as a support for BiFEs. The disc graphite BiFE was used for simultaneous determination of Pb(II), Cd(II) and Zn(II) by square wave voltammetry (SWV) in an aqueous solution. We found the optimum bismuth-to-metal concentration ratio in the solution to be 20. The dependence of the stripping responses on the concentration of target metals was linear in the range from 1×10 -8 to 1.2×10 -7 mol/L. Detection limits 2.4×10 -9 mol/L for Pb(II), 2.9×10 -9 mol/L for Cd(II) and 1.2×10 -8 mol/L for Zn(II) were estimated. A bismuth-plated NDLC microelectrode array was used for Pb(II) determination by differential pulse voltammetry (DPV) in an aqueous solution. We found that the stripping current for bismuth-plated NDLC array was linear in the concentration range of Pb(II) from 2×10 -8 to 1.2×10 -7 mol/L. The detection limit 2.2×10 -8 mol/L was estimated from a calibration plot.

Rehacek, Vlastimil; Hotovy, Ivan; Vojs, Marian; Mika, Fedor

2007-06-01

415

Sol-gel antireflective coating on plastics  

DOEpatents

An antireflection film made from reliquified sol-gel hydrolyzation, condensation polymeric reaction product of a silicon, alkoxides and/or metal alkoxides, or mixtures thereof. The film is particularly useful for coating plastics.

Ashley, C.S.; Reed, S.T.

1988-01-26

416

LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Anisotropic laser mirrors based on obliquely deposited metal films  

Microsoft Academic Search

A method is proposed for producing dielectric --- metal polarising mirrors for normal light incidence. The anisotropic properties of the mirrors are imposed by an obliquely deposited metal film. The subsequent deposition of isotropic dielectric coatings ensures a high reflectance of visible light. Experiments were carried out on nickel and aluminium in combination with MgF2 and ZnS. At the 0.63

Yu V. Troitskii; B. I. Troshin

1998-01-01

417

Oxide film on metal substrate reduced to form metal-oxide-metal layer structure  

NASA Technical Reports Server (NTRS)

Electrically conductive layer of zirconium on a zirconium-oxide film residing on a zirconium substrate is formed by reducing the oxide in a sodium-calcium solution. The reduced metal remains on the oxide surface as an adherent layer and seems to form a barrier that inhibits further reaction.

Youngdahl, C. A.

1967-01-01

418

Effect of metal film thickness on surface-atom coupling  

NASA Astrophysics Data System (ADS)

Metal film thickness is found to be an important parameter in the nonradiative coupling of atoms to metal surfaces. Silver, sodium, and potasium films in the thickness range 8-120 nm are evaporated onto a 40 K substrate in ultra high vacuum. At 11 K, layers of N 2 in the thickness range 3-300 nm are condensed onto the metal films. Low energy electrons excite the N, 2D? 4S (?) electronic transition. The lifetime of ? is measured as a function of nitrogen thickness and metal film thickness. Results are found to be in good agreement with classical theory based on nonradiative coupling of perpendicular dipoles to surface plasmons of the metal surface.

Adams, Arnold; Rendell, R. W.; Garnett, R. W.; Hansma, P. K.; Metiu, Horia

1980-09-01

419

Crystalline and electrical properties of (Bi,La)Ti O thin films coated on  

Microsoft Academic Search

Bi La Ti O (BLT, xs0.67-0.70) ferroelectric thin films were prepared on a single crystalline aluminum oxide film onto 4y xx 3.0 12 Si substrate (c-Al O ySi), and amorphous phase aluminum oxide film onto Si substrates (a-Al O ySi) by the sol-gel method. In 23 23 order for crystallization, the as-coated films were annealed at the temperature of 650

Ho Jung Chang; Sun Hwan Hwang; Hyeongtag Jeon; Yeong Cheol Kim; Kazuaki Sawada; Makoto Ishidad

420

Tin-doped indium oxide thin films deposited by sol–gel dip-coating technique  

Microsoft Academic Search

Indium tin oxide (ITO) thin films were prepared by the sol–gel dip-coating (SGDC) technique. The microstructure and electrical properties of ITO thin films crystallized using rapid thermal annealing (RTA) were compared with those of films prepared by classic thermal annealing (CTA). ITO thin films were successfully prepared by CTA at 500 °C for 30–60 min. At the same temperature of

K Daoudi; B Canut; M. G Blanchin; C. S Sandu; V. S Teodorescu; J. A Roger

2002-01-01

421

Quartz crystal microbalance sample stage for in situ characterization of thickness and surface morphology of spin coated polymer films  

SciTech Connect

A miniature spin coating stage is developed for in situ characterization of the thickness and the surface morphology of spin coated polymer films using quartz crystal microbalance (QCM) and atomic force microscopy. The spin coated polystyrene films deposited on gold surfaces from solutions using the stage were found to be uniform; the thickness of the films varied linearly with the polystyrene concentration in solution. The film thickness determined by the QCM agree with that from ellipsometry measurements.

Rao Nanxia; Xie Xin; Wielizcka, David; Zhu Daming [Department of Physics, University of Missouri-Kansas City, 5110 Rockhill Road, Kansas City, Missouri 64110 (United States)

2006-11-15

422

Synthesis and evaluation of rosin-based polymers as film coating materials.  

PubMed

Rosin-based polymers (R-1 and R-2) were synthesized and characterized for physicochemical properties, molecular weight (Mw), polydispersity (Mw/Mn), glass transition temperature (Tg), and thermogravimetry (TGA). Films of the polymers were cast on a mercury substrate by solvent evaporation technique. Free films were characterized for surface topography by scanning electron microscopy (SEM), water vapor transmission rate (WVTR), tensile strength, percentage elongation, and modulus of elasticity. The polymers were further evaluated as film coating materials by evaluating drug release from coated pellets with diclofenac sodium as a model drug. Drug was loaded on non-pareil seeds by a solution-layering technique and coated with varying concentrations of polymer solutions. Sustained release of the drug was observed from coated pellets. The newly synthesized rosin-based polymers promise considerable utility for pharmaceutical coating. PMID:12056531

Satturwar, P M; Mandaogade, P M; Fulzele, S V; Darwhekar, G N; Joshi, S B; Dorle, A K

2002-04-01

423

Solid film lubricants and thermal control coatings flown aboard the EOIM-3 MDA sub-experiment  

NASA Technical Reports Server (NTRS)

Additional experimental data were desired to support the selection of candidate thermal control coatings and solid film lubricants for the McDonnell Douglas Aerospace (MDA) Space Station hardware. The third Evaluation of Oxygen Interactions With Materials Mission (EOIM-3) flight experiment presented an opportunity to study the effects of the low Earth orbit environment on thermal control coatings and solid film lubricants. MDA provided five solid film lubricants and two anodic thermal control coatings for EOIM-3. The lubricant sample set consisted of three solid film lubricants with organic binders one solid film lubricant with an inorganic binder, and one solid film lubricant with no binder. The anodize coating sample set consisted of undyed sulfuric acid anodize and cobalt sulfide dyed sulfuric acid anodize, each on two different substrate aluminum alloys. The organic and inorganic binders in the solid film lubricants experienced erosion, and the lubricating pigments experienced oxidation. MDA is continuing to assess the effect of exposure to the low Earth orbit environment on the life and friction properties of the lubricants. Results to date support the design practice of shielding solid film lubricants from the low Earth orbit environment. Post-flight optical property analysis of the anodized specimens indicated that there were limited contamination effects and some atomic oxygen and ultraviolet radiation effects. These effects appeared to be within the values predicted by simulated ground testing and analysis of these materials, and they were different for each coating and substrate.

Murphy, Taylor J.; David, Kaia E.; Babel, Hank W.

1995-01-01

424

Study of double layer rare earth metal conversion coating on aluminum alloy LY12  

Microsoft Academic Search

The process of the double layer rare earth metal (REM) conversion coating on aluminum alloy LY12 (2024) was introduced in this paper. The corrosion resistance of REM conversion coating was examined by electrochemical impedance spectroscopy. The results showed that the coating increased the corrosion resistance (Rp) of the alloy surface, thus reducing the driving force of corrosion. The morphologies of

Yu Xingwen; Cao Chunan; Yao Zhiming; Zhou Derui; Yin Zhongda

2001-01-01

425

Apatite coating on ceramics, metals and polymers utilizing a biological process  

Microsoft Academic Search

A novel method of apatite coating is presented. The main characteristics of the method are that the apatite layer obtained consists of bone-like apatite and can be coated on various substrates including ceramics, metals and organic polymers. Coating is carried out in a simulated body fluid, the ion concentrations, temperature and pH of which are adjusted to almost equal to

Y. Abe; T. Kokubo; T. Yamamuro

1990-01-01

426

Insulator coating for high temperature alloys method for producing insulator coating for high temperature alloys  

DOEpatents

A method for fabricating an electrically insulating coating on a surface is disclosed comprising coating the surface with a metal, and reacting the metal coated surface with a nonmetal so as to create a film on the metal-coated surface. Alternatively, the invention provides for a method for producing a noncorrosive, electrically insulating coating on a surface saturated with a nonmetal comprising supplying a molten fluid, dissolving a metal in the molten fluid to create a mixture, and contacting the mixture with the saturated surface. Lastly, the invention provides an electrically insulative coating comprising an underlying structural substrate coated with an oxide or nitride compound. 2 figs.

Park, J.H.

1998-06-23

427

Tamarindus indica pectin blend film composition for coating tablets with enhanced adhesive force strength.  

PubMed

Tablet coating is the most useful method to improve tablet texture, odour and mask taste. Thus, the present investigation was aimed at developing an industrially acceptable aqueous tablet coating material. The physico-chemical, electrical and SEM investigations ensures that blending of Tamarindus indica (Linn.) pectin (TP) with chitosan gives water resistant film texture. Therefore, CH-TP (60:40) spray coated tablets were prepared. The evaluation of CH-TP coated tablets showed enhanced adhesive force strength (between tablet surface to coat) and negligible cohesive force strength (between two tablets) both evaluated using texture analyzer. The comparison of CH-TP coated tablets with Eudragit coated tablets further supported superiority of the former material. Thus, the findings pointed towards the potential of CH-TP for use as a tablet coating material in food as well as pharmaceutical industry. PMID:24507255

Khurana, Rajneet; Singh, Kuldeep; Sapra, Bharti; Tiwary, A K; Rana, Vikas

2014-02-15

428

Interface Thermal Conductance Between Metal Films and Copper  

NASA Astrophysics Data System (ADS)

Transient thermo-reflectance measurements were made on metals films deposited on Cu film. The Cu film was deposited on Si (001) and sapphire (0001) substrates. The metal films that were deposited include Al, Au, Sn, Zn, and In. The results were modeled using one-dimensional heat equation to determine thermal conductance of interfaces between the metal film and Cu (film/Cu) and Cu and Si (Cu/Si), or Cu and sapphire (Cu/sapphire) in each sample. The results were used to determine the importance of microstructural parameters such as surface roughness, lattice mismatch, solid solubility, and surface energy of the metal film on Cu. The experimental values of interface thermal conductance, although smaller in magnitude, were interpreted in terms of the predicted values by diffuse mismatch model after including the effect of the microstructural parameters. In particular, interface roughness, lattice mismatch, solid solubility, and wettability were found to be important parameters as these are responsible for good atomic level contact between the metal film and Cu.

Zheng, Hai; Jagannadham, K.

2014-05-01

429

Characterization of protective-layer-coated LiMn 2O 4 cathode thin films  

NASA Astrophysics Data System (ADS)

We introduced a post-annealing process for the preparation of spinel-phase LiMn 2O 4. The annealed films had proper crystallinity and surface roughness. In order to reduce the interface reaction during operation, we introduced a diamond-like carbon (DLC) film. The DLC films were deposited on LiMn 2O 4 films by using electron cyclotron resonance chemical vapor deposition (ECRCVD). A DLC-coated LiMn 2O 4 film was more stable during the charging-discharging reaction and showed higher discharge capacity over a wide voltage window than the uncoated LiMn 2O 4 film.

Moon, Hee-Soo; Lee, Seung Won; Lee, You-Kee; Park, Jong-Wan

430

Mixed polyvalent-monovalent metal coating for carbon-graphite fibers  

NASA Technical Reports Server (NTRS)

An improved coating of gasification catalyst for carbon-graphite fibers is provided comprising a mixture of a polyvalent metal such as calcium and a monovalent metal such as lithium. The addition of lithium provides a lighter coating and a more flexible coating when applied to a coating of a carboxyl containing resin such as polyacrylic acid since it reduces the crosslink density. Furthermore, the presence of lithium provides a glass-like substance during combustion which holds the fiber together resulting in slow, even combustion with much reduced evolution of conductive fragments. The coated fibers are utilized as fiber reinforcement for composites.

Harper-Tervet, J.; Tervet, F. W.; Humphrey, M. F. (inventors)

1982-01-01

431

Evaluation of an innovative use of removable thin film coating technology for the abatement of hazardous contaminants.  

PubMed

This study evaluates a new decontamination technique for the mitigation and abatement of hazardous particulates. The traditional decontamination methods used to clean facilities and equipment are time-consuming, prolonging workers' exposure time, may generate airborne hazards, and can be expensive. The use of removable thin film coating as a decontamination technique for surface contamination proved to be a more efficient method of decontamination. This method was tested at three different sites on different hazardous metals. One application of the coating reduced the levels of these metals 90% and had an average reduction of one magnitude. The paired t-tests that were performed for each metal demonstrated that there was a statistically significant reduction of the metal after the use of the coating: lead (p = 0.03), beryllium (p = 0.05), aluminum (p = 0.006), iron (p = 0.0001), and copper (p = 0.004). The Kendall tau-b correlation coefficient demonstrates that there was a positive correlation between the initial levels of contamination and the removal efficiency for all the samples taken from different locations on the floor for each of the three sites. This new decontamination technique worked efficiently, requiring only one application, which decreased exposure time and did not generate any airborne dust. PMID:19437305

Lumia, Margaret E; Gentile, Charles; Gochfeld, Michael; Efthimion, Philip; Robson, Mark

2009-08-01

432

Enhancing temperature sensing features of FBGs by use of thin film aluminium coating  

NASA Astrophysics Data System (ADS)

In this work we tested use of thin film aluminium coating to enhance the temperature sensing features of FBG sensors. Thin film coating was evaporated on the Bragg grating after removal of the original acrylate recoating, using a modified vacuum evaporation system that allows uniform radial deposition around the fibre. Results show that recoating thickness up to 0.5 ?m do not produce appreciable effects, whereas thickness of 2.3 ?m appreciably increases temperature sensitivity without increasing time response constant.

Caponero, Michele A.; Bonfigli, Francesca; Libera, Stefano; Polimadei, Andrea; Vincenti, Maria A.; Zini, Alessandro; Montereali, Rosa M.

2013-05-01

433

The Use of Electric Fields for Edible Coatings and Films Development and Production: A Review  

Microsoft Academic Search

Edible films and coatings can provide additional protection for food, while being a fully biodegradable, environmentally friendly\\u000a packaging system. A diversity of raw materials used to produce edible coatings and films are extracted from marine and agricultural\\u000a sources, including animals and plants. Electric fields processing holds advantage in producing safe, wholesome and nutritious\\u000a food. Recently, the presence of a moderate

Bartolomeu W. S. Souza; Miguel A. Cerqueira; José A. Teixeira; António A. Vicente

2010-01-01

434

Spectral identification of thin-film-coated and solid-form semiconductor neutron detectors  

Microsoft Academic Search

Semiconductor-based solid-state neutron detectors have received considerable attention in recent years. These devices can be categorized as either thin-film-coated diode detectors or solid-form bulk detectors. There have been many attempts to fabricate boron-based solid-form detectors utilizing processing techniques similar to those frequently used to fabricate thin-film-coated diodes. Consequently, results from attempts to fabricate boron-based semiconductor neutron detectors are often misinterpreted

Douglas S. McGregor; J. Kenneth Shultis

2004-01-01

435

Structural property of polycrystalline silicon films on aluminum-doped zinc oxide-coated glass  

Microsoft Academic Search

The structural properties of crystalline silicon (Si) films on bare and aluminum-doped zinc oxide (AZO)-coated glass substrates were comparatively investigated by X-ray diffractometer, Raman spectroscopy, and transmission electron microscope. It was observed that for the amorphous Si (a-Si) films on bare and AZO-coated glass substrates subjected to five-step rapid thermal annealing (RTA) at 750°C\\/60s, they were both polycrystalline in nature

Weiyan Wang; Jinhua Huang; Xianpeng Zhang; Ye Yang; Ruiqin Tan; Weijie Song

2011-01-01

436

Water vapor and oxygen-barrier performance of corn–zein coated polypropylene films  

Microsoft Academic Search

A novel corn–zein coating structure on polypropylene (PP) films was developed to examine its feasibility as an alternative water vapor and oxygen-barrier for flexible packaging industry. The barrier properties of the resulting films were evaluated as affected by coating formulation (solvent, corn–zein, plasticizer concentration and plasticizer type). Corn–zein with different amounts (5% and 15%) was dissolved in 70% and 95%

Funda Tihminlioglu; ?sa Do?an Atik; Banu Özen

2010-01-01

437

Thermal annealing effects on chemical states of deuterium implanted into boron coating film  

Microsoft Academic Search

To reveal interaction between boron coating film and energetic hydrogen isotopes, chemical states of deuterium implanted into the boron coating films deposited on graphite by using DC glow discharge in a diborane diluted helium have been studied. The XPS measurements showed the possibility of the formation of B–D and C–D bonds by D2+ ion implantation. The TDS experiments indicated that

H. Kodama; T. Sugiyama; Y. Morimoto; Y. Oya; K. Okuno; N. Inoue; A. Sagara; N. Noda

2003-01-01

438

The structure of ion plated films in relation to coating properties  

NASA Astrophysics Data System (ADS)

Ion plating is an ion assisted or glow discharge deposition technique, where ions or energetic atoms transfer energy, momentum and charge to the substrate and the growing film in a manner which can be controlled to favorably modify surface, subsurface chemistry, and microstructure. The glow discharge energizing effects from the initial nucleation stages to the final film growth are discussed. As a result, adherence, coherence, internal stresses, density and morphology of the coatings are significantly improved, over the conventional (nonion-assisted) techniques which in turn favorably affect the surface initiated failures caused by friction, wear, erosion, corrosion and fatigue. Ion plated films because of their graded coating/substrate interface, fine, uniform, densely packed film structure also induce a surface strengthening effect which improved the mechanical properties such as yield, tensile strength and fatigue life. Since a uniform, continuous film