Science.gov

Sample records for film materials processes

  1. Electronic processes in thin-film PV materials. Final report

    SciTech Connect

    Taylor, P.C.; Chen, D.; Chen, S.L.

    1998-07-01

    The electronic and optical processes in an important class of thin-film PV materials, hydrogenated amorphous silicon (a-Si:H) and related alloys, have been investigated using several experimental techniques designed for thin-film geometries. The experimental techniques include various magnetic resonance and optical spectroscopies and combinations of these two spectroscopies. Two-step optical excitation processes through the manifold of silicon dangling bond states have been identifies as important at low excitation energies. Local hydrogen motion has been studied using nuclear magnetic resonance techniques and found to be much more rapid than long range diffusion as measured by secondary ion mass spectroscopy. A new metastable effect has been found in a-Si:H films alloyed with sulfur. Spin-one optically excited states have been unambiguously identified using optically detected electron spin resonance. Local hydrogen bonding in microcrystalline silicon films has been studied using NMR.

  2. Thin film hydrogen sensors: A materials processing approach

    NASA Astrophysics Data System (ADS)

    Jayaraman, Raviprakash

    results. Also the geometry of the resistors did not have any effect on the sensor sensitivity or response. Mass spectroscopy and ion energy distribution function (IEDF) analysis are important tools for characterizing processing plasmas. In this work, the sputter discharges were studied using energy and quadrupole mass spectrometer from Hiden. The IEDF of pulsed DC sputter discharges indicated a higher energy peak (˜65eV) and a broad distribution in addition to the low energy peak (˜5eV). The high energy peak was absent from the DC sputter discharge. This high energy peak was correlated to the pulsing of the DC source and was found to be independent of the target material.

  3. Nonlinear Optical Properties of Organic and Polymeric Thin Film Materials of Potential for Microgravity Processing Studies

    NASA Technical Reports Server (NTRS)

    Abdeldayem, Hossin; Frazier, Donald O.; Paley, Mark S.; Penn, Benjamin; Witherow, William K.; Bank, Curtis; Shields, Angela; Hicks, Rosline; Ashley, Paul R.

    1996-01-01

    In this paper, we will take a closer look at the state of the art of polydiacetylene, and metal-free phthalocyanine films, in view of the microgravity impact on their optical properties, their nonlinear optical properties and their potential advantages for integrated optics. These materials have many attractive features with regard to their use in integrated optical circuits and optical switching. Thin films of these materials processed in microgravity environment show enhanced optical quality and better molecular alignment than those processed in unit gravity. Our studies of these materials indicate that microgravity can play a major role in integrated optics technology. Polydiacetylene films are produced by UV irradiation of monomer solution through an optical window. This novel technique of forming polydiacetylene thin films has been modified for constructing sophisticated micro-structure integrated optical patterns using a pre-programmed UV-Laser beam. Wave guiding through these thin films by the prism coupler technique has been demonstrated. The third order nonlinear parameters of these films have been evaluated. Metal-free phthalocyanine films of good optical quality are processed in our laboratories by vapor deposition technique. Initial studies on these films indicate that they have excellent chemical, laser, and environmental stability. They have large nonlinear optical parameters and show intrinsic optical bistability. This bistability is essential for optical logic gates and optical switching applications. Waveguiding and device making investigations of these materials are underway.

  4. Chemical-bath deposition of ZnSe thin films: Process and material characterization

    SciTech Connect

    Dona, J.M.; Herrero, J.

    1995-03-01

    Chemical-bath deposition of ZnSe thin films from NH{sub 3}/NH{sub 2}-NH{sub 2}/SeC(NH{sub 2}){sub 2}/Na{sub 2}SO{sub 3}/ZnSO{sub 4} solutions has been studied. The effect of various process parameters on the growth and the film quality is presented. A first approach to a mechanistic interpretation of the chemical process, based on the influence of the process parameters on the film growth rate, is reported. The structural, optical, chemical, and electrical properties of the ZnSe thin-films deposited by this method have been studied. The electron diffraction (EDS) analysis shows that the films are microcrystalline with mixed cubic and hexagonal structure. EDS analysis has demonstrated that the films are highly stoichiometric. Scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy studies of the ZnSe thin films deposited by this method show that the films are continuous and homogeneous. Optical measurements have allowed the authors to detect the presence of the spin-orbit splitting effect in this material. Electrical conductivity measurements have shown the highly resistive nature of these films ({rho} {approximately} 10{sup 9} {Omega} cm).

  5. A process to recycle thin film PV materials

    SciTech Connect

    Goozner, R.E.; Drinkard, W.F.; Long, M.O.; Byrd, C.M.

    1997-12-31

    The wide scale interest in the commercial potential of cadmium telluride (CdTe) and copper indium diselenide (CIS) photovoltaic modules is tempered by the use of toxic metals such as cadmium and selenium in their manufacture. Drinkard Metalox has adapted hydrometallurgical technology to recycle CdTe cells. The process will remove all the Cd and Te while, enabling reuse of substrates. Downstream processing recovers Te as metal from the lixivant, and removal of the lixivant leaves behind a pure Cd product. This process can also be utilized to process CIS cells. The lixivant will remove all the photoactive metals from the substrate of scrap CIS cells. A metallic stream of mixed Cu and Se metal is removed from the leachate by electrochemical methods. Subsequent processing will win purified Se.

  6. Composite film fabricated on biomedical material with corona streamer plasma processing to mitigate bacterial adhesion

    NASA Astrophysics Data System (ADS)

    Alhamarneh, Ibrahim; Pedrow, Patrick; Eskhan, Asma; Abu-Lail, Nehal

    2011-10-01

    Composite films might control bacterial adhesion and concomitant biofouling that afflicts biomedical materials. Different size molecules of polyethylene glycol (PEG) with nominal molecular weights 600, 2000, and 20000 g/mol were used to synthesize composite films with plasma processing and dip-coating procedures on surgical-grade 316L stainless steel. Before dip-coating, the substrate was pre-coated with plasma-polymerized di(ethylene glycol) vinyl ether (pp-EO2V) in an atmospheric pressure corona streamer plasma reactor. The PEG dip-coating step followed immediately in the same chamber due to the finite lifetime of radicals associated with freshly deposited pp-EO2V. Morphology of the composite film was investigated with an ESEM. FTIR confirmed incorporation of pp-EO2V and PEG species into the composite film. More investigations on the composite film were conducted by XPS measurements. Adhesion of the composite film was evaluated with a standard peel-off test. Stability of the composite film in buffer solution was evaluated by AFM. AFM was also used to measure the film roughness and thickness. Polar and non-polar contact angle measurements were included.

  7. Historical film processing

    NASA Astrophysics Data System (ADS)

    Wu, Yi; Suter, David

    1995-08-01

    This paper describes work using historical film material, including what is believed to be the world's first feature length film. The digital processing of historical film material permits many new facilities: digital restoration, electronic storage, automated indexing, and electronic delivery to name a few. Although the work aims ultimately to support all of the previously mentioned facilities, this paper concentrated upon automatic scene change detection, brightness correction, and frame registration. These processes are fundamental to a more complete and complex processing system, but, by themselves, could be immediately used in computer-assisted film cataloging.

  8. Modeling of plume dynamics in laser ablation processes for thin film deposition of materials

    SciTech Connect

    Leboeuf, J.N.; Chen, K.R.; Donato, J.M.; Geohegan, D.B.; Liu, C.L.; Puretzky, A.A.; Wood, R.F.

    1995-12-31

    The transport dynamics of laser-ablated neutral/plasma plumes are of significant interest for film growth by pulsed-laser deposition of materials since the magnitude and kinetic energy of the species arriving at the deposition substrate are key processing parameters. Dynamical calculations of plume propagation in vacuum and in background gas have been performed using particle-in-cell hydrodynamics, continuum gas dynamics, and scattering models. Results from these calculations are presented and compared with experimental observations.

  9. Thin films for material engineering

    NASA Astrophysics Data System (ADS)

    Wasa, Kiyotaka

    2016-07-01

    Thin films are defined as two-dimensional materials formed by condensing one by one atomic/molecular/ionic species of matter in contrast to bulk three-dimensional sintered ceramics. They are grown through atomic collisional chemical reaction on a substrate surface. Thin film growth processes are fascinating for developing innovative exotic materials. On the basis of my long research on sputtering deposition, this paper firstly describes the kinetic energy effect of sputtered adatoms on thin film growth and discusses on a possibility of room-temperature growth of cubic diamond crystallites and the perovskite thin films of binary compound PbTiO3. Secondly, high-performance sputtered ferroelectric thin films with extraordinary excellent crystallinity compatible with MBE deposited thin films are described in relation to a possible application for thin-film MEMS. Finally, the present thin-film technologies are discussed in terms of a future material science and engineering.

  10. Growth of thin films of organic nonlinear optical materials by vapor growth processes - An overview and examination of shortfalls

    NASA Technical Reports Server (NTRS)

    Frazier, D. O.; Penn, B. G.; Witherow, W. K.; Paley, M. S.

    1991-01-01

    Research on the growth of second- and third-order nonlinear optical (NLO) organic thin film by vapor deposition is reviewed. Particular attention is given to the experimental methods for growing thin films of p-chlorophenylurea, diacetylenes, and phthalocyanines; characteristics of the resulting films; and approaches for advancing thin film technology. It is concluded that the growth of NLO thin films by vapor processes is a promising method for the fabrication of planar waveguides for nonlinear optical devices. Two innovative approaches are proposed including a method of controlling the input beam frequency to maximize nonlinear effects in thin films and single crystals, and the alternate approach to the molecular design of organic NLO materials by increasing the transition dipole moment between ground and excited states of the molecule.

  11. Using iridium films to compensate for piezo-electric materials processing stresses in adjustable x-ray optics

    NASA Astrophysics Data System (ADS)

    Ames, A.; Bruni, R.; Cotroneo, V.; Johnson-Wilke, R.; Kester, T.; Reid, P.; Romaine, S.; Tolier-McKinstry, S.; Wilke, R. H. T.

    2015-09-01

    Adjustable X-ray optics represent a potential enabling technology for simultaneously achieving large effective area and high angular resolution for future X-ray Astronomy missions. The adjustable optics employ a bimorph mirror composed of a thin (1.5 μm) film of piezoelectric material deposited on the back of a 0.4 mm thick conical mirror segment. The application of localized electric fields in the piezoelectric material, normal to the mirror surface, result in localized deformations in mirror shape. Thus, mirror fabrication and mounting induced figure errors can be corrected, without the need for a massive reaction structure. With this approach, though, film stresses in the piezoelectric layer, resulting from deposition, crystallization, and differences in coefficient of thermal expansion, can distort the mirror. The large relative thickness of the piezoelectric material compared to the glass means that even 100MPa stresses can result in significant distortions. We have examined compensating for the piezoelectric processing related distortions by the deposition of controlled stress chromium/iridium films on the front surface of the mirror. We describe our experiments with tuning the product of the chromium/iridium film stress and film thickness to balance that resulting from the piezoelectric layer. We also evaluated the repeatability of this deposition process, and the robustness of the iridium coating.

  12. Analysis and assessment of film materials and associated manufacturing processes for a solar sail

    NASA Technical Reports Server (NTRS)

    Bradbury, E. J.; Jakobsen, R. J.; Sliemers, F. A.

    1978-01-01

    Candidate resin manufacturers and film producers were surveyed to determine the availability of key materials and to establish the capabilities of fabricators to prepare ultrathin films of these materials within the capacity/cost/time constraints of the Halley program. Infrared spectra of three candidate samples were obtained by pressing each sample against an internal reflection crystal with the polymer sandwiched between the crystal and the metal backing. The sample size was such that less than one-fourth of the surface of the crystal was covered with the sample. This resulted in weak spectra requiring a six-fold expansion. Internal reflection spectra of the three samples were obtained using both a KRS-5 and a Ge internal reflection crystal. Subtracted infrared spectra of the three samples are presented.

  13. Process for forming planarized films

    DOEpatents

    Pang, Stella W.; Horn, Mark W.

    1991-01-01

    A planarization process and apparatus which employs plasma-enhanced chemical vapor deposition (PECVD) to form plarnarization films of dielectric or conductive carbonaceous material on step-like substrates.

  14. First principles-based multiparadigm, multiscale strategy for simulating complex materials processes with applications to amorphous SiC films

    SciTech Connect

    Naserifar, Saber; Goddard, William A.; Tsotsis, Theodore T.; Sahimi, Muhammad

    2015-05-07

    Progress has recently been made in developing reactive force fields to describe chemical reactions in systems too large for quantum mechanical (QM) methods. In particular, ReaxFF, a force field with parameters that are obtained solely from fitting QM reaction data, has been used to predict structures and properties of many materials. Important applications require, however, determination of the final structures produced by such complex processes as chemical vapor deposition, atomic layer deposition, and formation of ceramic films by pyrolysis of polymers. This requires the force field to properly describe the formation of other products of the process, in addition to yielding the final structure of the material. We describe a strategy for accomplishing this and present an example of its use for forming amorphous SiC films that have a wide variety of applications. Extensive reactive molecular dynamics (MD) simulations have been carried out to simulate the pyrolysis of hydridopolycarbosilane. The reaction products all agree with the experimental data. After removing the reaction products, the system is cooled down to room temperature at which it produces amorphous SiC film, for which the computed radial distribution function, x-ray diffraction pattern, and the equation of state describing the three main SiC polytypes agree with the data and with the QM calculations. Extensive MD simulations have also been carried out to compute other structural properties, as well the effective diffusivities of light gases in the amorphous SiC film.

  15. Atomic layer epitaxy of group 4 materials: Surface processes, thin films, devices and their characterization

    NASA Astrophysics Data System (ADS)

    Davis, Robert F.; Bedair, S.; El-Masry, N. A.; Glass, J. T.; King, S.

    1994-12-01

    Residual surface contaminants were removed from vicinal 6H-SiC(0001) surfaces in UHV via high temperature annealing in SiH4. Characterization via AES, EELS, LEED, XPS, and UPS was conducted. At T greater than 850 C, the surface oxide was rapidly removed. Exposure to approx. 400 Langmuir (10(exp -6) Torr(dot)liter/s) of SiH4 resulted in complete surface oxide removal and a nearly stoichiometric (l x l) 6H-SiC surface suitable for ALE of SiC. Further exposure resulted in a (3 x 3)R30 deg Si-rich reconstructed surface. Subsequent annealing in UHV resulted in a (square root of 3 x square root of 3)R30 deg Si deficient/graphitic reconstructed surface. The first set of wafers containing HBT device structures were fabricated on SiC films grown via ALE. No transistor activity was detected. Electrical characterization and SEM showed the most likely fault to be inaccurate etching of the SiC emitter. Nucleation and growth of oriented diamond particles on seeded, group of zone axes (0001) oriented single crystal Co substrates was achieved via multi-step, hot-filament CVD process involving seeding, annealing, nucleation and growth. Diamond particles oriented group of zone axes (111) were obtained. Micro-Raman showed a FWHM of 4.3/cm. A very weak graphitic peak was observed on regions of the substrate not covered by the diamond particles. A nucleation model has been proposed. Initial results showed that CeO2 film grows epitaxially on (111) Si substrates. The CeO2 films had density of interfacial traps and fixed oxide charge values comparable to that of amorphous SiO2/Si.

  16. Processing Film, Processing Meaning

    ERIC Educational Resources Information Center

    Perkowski, Lisa M.

    2015-01-01

    Adolescents are at a ripe age to make meaning and think abstractly (Kerlavage, 1998); yet, they are not "born knowing how to get ideas into materials, or how materials can be manipulated to shape ideas and meaning" (Burton, 2012, p. 14). Adolescents need guidance in understanding abstract concepts, and art teachers play an important role…

  17. The materials processing research base of the Materials Processing Center

    NASA Technical Reports Server (NTRS)

    Flemings, M. C.; Bowen, H. K.; Kenney, G. B.

    1980-01-01

    The goals and activities of the center are discussed. The center activities encompass all engineering materials including metals, ceramics, polymers, electronic materials, composites, superconductors, and thin films. Processes include crystallization, solidification, nucleation, and polymer synthesis.

  18. MATERIAL AND PROCESS DEVELOPMENT LEADING TO ECONOMICAL HIGH-PERFORMANCE THIN-FILM SOLID OXIDE FUEL CELLS

    SciTech Connect

    Jie Guan; Nguyen Minh

    2003-12-01

    This report summarizes the results of the work conducted under the program: ''Material and Process Development Leading to Economical High-Performance Thin-Film Solid Oxide Fuel Cells'' under contract number DE-AC26-00NT40711. The program goal is to advance materials and processes that can be used to produce economical, high-performance solid oxide fuel cells (SOFC) capable of achieving extraordinary high power densities at reduced temperatures. Under this program, anode-supported thin electrolyte based on lanthanum gallate (LSMGF) has been developed using tape-calendering process. The fabrication parameters such as raw materials characteristics, tape formulations and sintering conditions have been evaluated. Dense anode supported LSGMF electrolytes with thickness range of 10-50 micron have been fabricated. High performance cathode based on Sr{sub 0.5}Sm{sub 0.5}CoO{sub 3} (SSC) has been developed. Polarization of {approx}0.23 ohm-cm{sup 2} has been achieved at 600 C with Sr{sub 0.5}Sm{sub 0.5}CoO{sub 3}cathode. The high-performance SSC cathode and thin gallate electrolyte have been integrated into single cells and cell performance has been characterized. Tested cells to date generally showed low performance because of low cell OCVs and material interactions between NiO in the anode and lanthanum gallate electrolyte.

  19. Micro-materials processing

    NASA Astrophysics Data System (ADS)

    Cohen, M. G.; Kaplan, R. A.; Arthurs, E. G.

    1982-06-01

    A model analysis of the absorption of laser energy in the millijoule range by a thin film on a substrate is presented to illustrate the underlying physical mechanism of laser micro-materials processing. The analysis is followed by a discussion of several applications from the electronics and semiconductor industries, including resistor trimming, laserscribing, laser damage gettering, laser marking, ablation of metal films, and mask repair. Finally, several uses of lasers in the diamond industry, such as removal of flaws from gemstone diamonds, diamond sawing, and diamond inscription, are briefly reviewed.

  20. FEASIBILITY OF MAGNETIC PARTICLE FILMS FOR CURIE TEMPERATURE-CONTROLLED PROCESSING OF COMPOSITE MATERIALS

    EPA Science Inventory

    The feasibility of using magnetic particulate susceptor materials for induction heating during bonding of polymer matrix composite materials is investigated. If properly designed, these systems should rapidly heat to the particulate material Curie temperature and dwell at that te...

  1. Superconducting materials processing

    NASA Technical Reports Server (NTRS)

    Hurley, John S.; Karikari, Emmanuel K.; Hiamang, S. O.; Danjaji, M.; Bassey, Affiong; Morgan, Andre

    1995-01-01

    The effects of materials processing on the properties and behavior of high temperature yttrium barium copper oxide (YBCO) superconductors were investigated. Electrical, magnetic, and structural characteristics of thin films (300 nm) YBA2CU3O(delta) structures grown by pulsed laser deposition on LaAlO3 and SrTiO3 substrates were used to evaluate processing. Pole projection and thin film diffraction measurements were used to establish grain orientation and verify structural integrity of the samples. Susceptibility magnetization, and transport measurements were used to evaluate the magnetic and electrical transport properties of the samples. Our results verified that an unfortunate consequence of processing is inherent changes to the internal structure of the material. This effect translates into modifications in the properties of the materials, and undesired feature that makes it very difficult to consistently predict material behavior. The results show that processing evaluation must incorporate a comprehensive understanding of the properties of the materials. Future studies will emphasize microstructural characteristics of the materials, in particular, those microscopic properties that map macroscopic behavior.

  2. An improved thick-film piezoelectric material by powder blending and enhanced processing parameters.

    PubMed

    Torah, Russel; Beeby, Steve P; White, Neil M

    2005-01-01

    This paper details improvements of the d33 co-efficient for thick-film lead zirconate titanate (PZT) layers. In particular, the effect of blending ball and attritor milled powders has been investigated. Mathematical modeling of the film structure has produced initial experimental values for powder combination percentages. A range of paste formulations between 8:1 and 2:1 ball to attritor milled PZT powders by weight have been mixed into a screen-printable paste. Each paste contains 10% by weight of lead borosilicate glass and an appropriate quantity of solvent to formulate a screen printable thixotropic paste. A d33 of 63.5 pC/N was obtained with a combination of 4:1 ball milled to attritor milled powder by weight. The improved paste combines the high d33 values of ball and the consistency of attritor milled powder. The measured d33 coefficient was further improved to 131 pC/N by increasing the furnace firing profile to 1000 degrees C, increasing the poling temperature to 200 degrees C, and using gold cermet and polymer electrodes that avoid silver migration effects and repeated firing of the PZT film. PMID:15742558

  3. Fluorination of amorphous thin-film materials with xenon fluoride

    DOEpatents

    Weil, R.B.

    1987-05-01

    A method is disclosed for producing fluorine-containing amorphous semiconductor material, preferably comprising amorphous silicon. The method includes depositing amorphous thin-film material onto a substrate while introducing xenon fluoride during the film deposition process.

  4. Fluorination of amorphous thin-film materials with xenon fluoride

    DOEpatents

    Weil, Raoul B.

    1988-01-01

    A method is disclosed for producing fluorine-containing amorphous semiconductor material, preferably comprising amorphous silicon. The method includes depositing amorphous thin-film material onto a substrate while introducing xenon fluoride during the film deposition process.

  5. Nanoscaled tin dioxide films processed from organotin-based hybrid materials: an organometallic route toward metal oxide gas sensors.

    PubMed

    Renard, Laetitia; Babot, Odile; Saadaoui, Hassan; Fuess, Hartmut; Brötz, Joachim; Gurlo, Aleksander; Arveux, Emmanuel; Klein, Andreas; Toupance, Thierry

    2012-11-01

    Nanocrystalline tin dioxide (SnO(2)) ultra-thin films were obtained employing a straightforward solution-based route that involves the calcination of bridged polystannoxane films processed by the sol-gel process from bis(triprop-1-ynylstannyl)alkylene and -arylene precursors. These films have been thoroughly characterized by FTIR, contact angle measurements, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force (AFM) and scanning electron (SEM) microscopies. Annealing at a high temperature gave 30-35 nm thick cassiterite SnO(2) films with a mean crystallite size ranging from 4 to 7 nm depending on the nature of the organic linker in the distannylated compound used as a precursor. In the presence of H(2) and CO gases, these layers led to highly sensitive, reversible and reproducible responses. The sensing properties were discussed in regard to the crystallinity and porosity of the sensing body that can be tuned by the nature of the precursor employed. Organometallic chemistry combined with the sol-gel process therefore offers new possibilities toward metal oxide nanostructures for the reproducible and sensitive detection of combustible and toxic gases. PMID:23011110

  6. Film stacking architecture for immersion lithography process

    NASA Astrophysics Data System (ADS)

    Goto, Tomohiro; Sanada, Masakazu; Miyagi, Tadashi; Shigemori, Kazuhito; Kanaoka, Masashi; Yasuda, Shuichi; Tamada, Osamu; Asai, Masaya

    2008-03-01

    In immersion lithography process, film stacking architecture will be necessary due to film peeling. However, the architecture will restrict lithographic area within a wafer due to top side EBR accuracy In this paper, we report an effective film stacking architecture that also allows maximum lithographic area. This study used a new bevel rinse system on RF3 for all materials to make suitable film stacking on the top side bevel. This evaluation showed that the new bevel rinse system allows the maximum lithographic area and a clean wafer edge. Patterning defects were improved with suitable film stacking.

  7. Telerobotic electronic materials processing experiment

    NASA Technical Reports Server (NTRS)

    Ollendorf, Stanford

    1991-01-01

    The Office of Commercial Programs (OCP), working in conjunction with NASA engineers at the Goddard Space Flight Center, is supporting research efforts in robot technology and microelectronics materials processing that will provide many spinoffs for science and industry. The Telerobotic Materials Processing Experiment (TRMPX) is a Shuttle-launched materials processing test payload using a Get Away Special can. The objectives of the project are to define, develop, and demonstrate an automated materials processing capability under realistic flight conditions. TRMPX will provide the capability to test the production processes that are dependent on microgravity. The processes proposed for testing include the annealing of amorphous silicon to increase grain size for more efficient solar cells, thin film deposition to demonstrate the potential of fabricating solar cells in orbit, and the annealing of radiation damaged solar cells.

  8. Process for producing dispersed particulate composite materials

    DOEpatents

    Henager, Jr., Charles H.; Hirth, John P.

    1995-01-01

    This invention is directed to a process for forming noninterwoven dispersed particulate composite products. In one case a composite multi-layer film product comprises a substantially noninterwoven multi-layer film having a plurality of discrete layers. This noninterwoven film comprises at least one discrete layer of a first material and at least one discrete layer of a second material. In another case the first and second materials are blended together with each other. In either case, the first material comprises a metalloid and the second material a metal compound. At least one component of a first material in one discrete layer undergoes a solid state displacement reaction with at least one component of a second material thereby producing the requisite noninterwoven composite film product. Preferably, the first material comprises silicon, the second material comprises Mo.sub.2 C, the third material comprises SiC and the fourth material comprises MoSi.sub.2.

  9. Plasma Processing of Advanced Materials

    SciTech Connect

    Heberlein, Joachim, V.R.; Pfender, Emil; Kortshagen, Uwe

    2005-02-28

    Plasma Processing of Advanced Materials The project had the overall objective of improving our understanding of the influences of process parameters on the properties of advanced superhard materials. The focus was on high rate deposition processes using thermal plasmas and atmospheric pressure glow discharges, and the emphasis on superhard materials was chosen because of the potential impact of such materials on industrial energy use and on the environment. In addition, the development of suitable diagnostic techniques was pursued. The project was divided into four tasks: (1) Deposition of superhard boron containing films using a supersonic plasma jet reactor (SPJR), and the characterization of the deposition process. (2) Deposition of superhard nanocomposite films in the silicon-nitrogen-carbon system using the triple torch plasma reactor (TTPR), and the characterization of the deposition process. (3) Deposition of films consisting of carbon nanotubes using an atmospheric pressure glow discharge reactor. (4) Adapting the Thomson scattering method for characterization of atmospheric pressure non-uniform plasmas with steep spatial gradients and temporal fluctuations. This report summarizes the results.

  10. Films and Film Sources for Materials Science and Engineering Courses

    ERIC Educational Resources Information Center

    Evans, Edward B.

    1972-01-01

    A selected list of films that are suitable for secondary schools through universities. They cover all phases of materials science and engineering. The films may be obtained, usually free of charge, for listed sources. (DF)

  11. Materials processing in space

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The feasibility and possible advantages of processing materials in a nongravitational field are considered. Areas of investigation include biomedical applications, the processing of inorganic materials, and flight programs and funding.

  12. Thin film phase transition materials development program

    NASA Astrophysics Data System (ADS)

    Case, W. E.

    1985-04-01

    A number of application concepts have emerged based on the idea that a phase transition thin film such as vanadium dioxide provides a high resolution, two-dimensional format for switching, recording, and processing optical signals. These applications range from high density optical disk recording systems and optical data processing to laser protection devices, infrared FLIRS and seekers, laser radar systems and IR scene simulators. All application candidates have a potential for providing either a totally new capability, an improved performance, a lower cost, or combinations of the three. Probably of greatest significance is the emergence of agile sensor concepts arising out of some of the film's special properties. These are represented by the above FLIRs, seekers and laser radar systems. A three year research program has been completed to advance the state-of-the-art in the preparation and characterization of selected thin film phase transition materials. The objectives of the program were: (1) to expand the data base and improve operational characteristics of Vought prepared vanadium dioxide thin films, (2) to evolve process chemistry and subsequently characterize several new program materials, including rare-earth chalcogenides, organic semiconductor charge complexes, alloys of transition metal oxides, and metal-insulator cermets, and (3) to spin-off new applications and concepts.

  13. Atomic layer epitaxy Group IV materials: Surface processes, thin films, devices and their characterization. Annual report, 1 January 1992-31 December 1992

    SciTech Connect

    Davis, R.F.; Bedair, S.; El-Masry, N.; Glass, J.T.

    1992-12-01

    An integrated growth and surface characterization system containing a hot filament reactor, sample transfer station, ESD and XPS has been established to investigate the ALE of diamond films. Complementary experiments concerned with the nucleation of diamond on molten surfaces, e. g., Al and Ge have also been conducted. Formation of GeO2 or an aluminum carbide and the degradation of the diamond by the molten material inhibited nucleation on the melted area. Monocrystalline thin films of Beta-SiC have been achieved in the temperature range of 850 deg -980 deg C by atomic layer-by-layer deposition of Si and C species via sequential exposures of Si(100) substrates to Si2H6 and C2H4. A UHV analytical system containing TPD, AES and XPS is being constructed in concert with the SiC ALE studies to determine the reaction chemistry important to this process. An eximer laser ablation system for the ALE of CeO2 has been completed and employed to successfully deposit films of this material on Si(100).... Atomic layer epitaxy(ALE), Diamond, Silicon carbide, Cerium dioxide.

  14. Materials processing in space

    NASA Technical Reports Server (NTRS)

    Waldron, R. D.; Criswell, D. R.

    1982-01-01

    Processing-refining of raw materials from extraterrestrial sources is detailed for a space materials handling facility. The discussion is constrained to those steps necessary to separate desired components from raw or altered input ores, semi-purified feedstocks, or process scrap and convert the material into elements, alloys, and consumables. The materials are regarded as originating from dead satellites and boosters, lunar materials, and asteroids. Strong attention will be given to recycling reagent substances to avoid the necessity of transporting replacements. It is assumed that since no aqueous processes exist on the moon, the distribution of minerals will be homogeneous. The processing-refining scenario will include hydrochemical, pyrochemical, electrochemical, and physical techniques selected for the output mass rate/unit plant mass ratio. Flow charts of the various materials processing operations which could be performed with lunar materials are provided, noting the necessity of delivering several alloying elements from the earth due to scarcities on the moon.

  15. Automated Composites Processing Technology: Film Module

    NASA Technical Reports Server (NTRS)

    Hulcher, A. Bruce

    2004-01-01

    NASA's Marshall Space Flight Center (MSFC) has developed a technology that combines a film/adhesive laydown module with fiber placement technology to enable the processing of composite prepreg tow/tape and films, foils or adhesives on the same placement machine. The development of this technology grew out of NASA's need for lightweight, permeation-resistant cryogenic propellant tanks. Autoclave processing of high performance composites results in thermally-induced stresses due to differences in the coefficients of thermal expansion of the fiber and matrix resin components. These stresses, together with the reduction in temperature due to cryogen storage, tend to initiate microcracking within the composite tank wall. One way in which to mitigate this problem is to introduce a thin, crack-resistant polymer film or foil into the tank wall. Investigation into methods to automate the processing of thin film or foil materials into composites led to the development of this technology. The concept employs an automated film supply and feed module that may be designed to fit existing fiber placement machines, or may be designed as integral equipment to new machines. This patent-pending technology can be designed such that both film and foil materials may be processed simultaneously, leading to a decrease in part build cycle time. The module may be designed having a compaction device independent of the host machine, or may utilize the host machine's compactor. The film module functions are controlled by a dedicated system independent of the fiber placement machine controls. The film, foil, or adhesive is processed via pre-existing placement machine run programs, further reducing operational expense.

  16. Attachment of lead wires to thin film thermocouples mounted on high temperature materials using the parallel gap welding process

    NASA Technical Reports Server (NTRS)

    Holanda, Raymond; Kim, Walter S.; Pencil, Eric; Groth, Mary; Danzey, Gerald A.

    1990-01-01

    Parallel gap resistance welding was used to attach lead wires to sputtered thin film sensors. Ranges of optimum welding parameters to produce an acceptable weld were determined. The thin film sensors were Pt13Rh/Pt thermocouples; they were mounted on substrates of MCrAlY-coated superalloys, aluminum oxide, silicon carbide and silicon nitride. The entire sensor system is designed to be used on aircraft engine parts. These sensor systems, including the thin-film-to-lead-wire connectors, were tested to 1000 C.

  17. Magnetic cassette for radiographic film material

    SciTech Connect

    Dallas, D.

    1985-03-26

    A radiographic film cassette having a plurality of magnet components integral with the cassette holder for adhering the cassette to ferrous material in X-raying for defects in welds or fissures in shipyards, pipe lines, or the like. What is provided is a substantially flexible cassette envelope comprising first and second layers of radiographic intensifying screens with a sheet of radiographic film positioned therebetween. The cassette would be a cassette envelope constructed of waterproof fabric or other suitable material providing a light-free environment, and having the ability to flex around the curvature of the surface of a pipe or the like to be x-rayed. There is further provided a plurality of magnet components, preferably situated in each corner of the cassette envelope and flexibly attached thereto for overall adherence of the envelope to the surface of the pipe or the like to be x-rayed during the process.

  18. Effect of Process Temperature and Reaction Cycle Number on Atomic Layer Deposition of TiO2 Thin Films Using TiCl4 and H2O Precursors: Correlation Between Material Properties and Process Environment

    NASA Astrophysics Data System (ADS)

    Chiappim, W.; Testoni, G. E.; de Lima, J. S. B.; Medeiros, H. S.; Pessoa, Rodrigo Sávio; Grigorov, K. G.; Vieira, L.; Maciel, H. S.

    2016-02-01

    The effect of process temperature and reaction cycle number on atomic layer-deposited TiO2 thin films onto Si(100) using TiCl4 and H2O precursors was investigated in order to discuss the correlation between the growth per cycle (GPC), film structure (crystallinity), and surface roughness as well as the dependence of some of these properties with gas phase environment such as HCl by-product. In this work, these correlations were studied for two conditions: (i) process temperatures in the range of 100-500 °C during 1000 reaction cycles and (ii) number of cycles in the range of 100-2000 for a fixed temperature of 250 °C. To investigate the material properties, Rutherford backscattering spectrometry (RBS), grazing incidence X-ray diffraction (GIXRD), and atomic force microscopy (AFM) techniques were used. Mass spectrometry technique was used to investigate the time evolution of gas phase species HCl and H2O during ALD process. Results indicate that the GPC does not correlate well with film crystallinity and surface roughness for the evaluated process parameters. Basically, the film crystallinity relies solely on grain growth kinetics of the material. This occurs due to higher HCl by-product content during each purge step. Furthermore, for films deposited at variable cycle number, the evolution of film thickness and elemental composition is altered from an initial amorphous structure to a near stoichiometric TiO2-x and, subsequently, becomes fully stoichiometric TiO2 at 400 cycles or above. At this cycle value, the GIXRD spectrum indicates the formation of (101) anatase orientation.

  19. Laser Processing Architecture for Improved Material Processing

    NASA Astrophysics Data System (ADS)

    Livingston, Frank E.; Helvajian, Henry

    This chapter presents a novel architecture and software-hardware design system for materials processing techniques that are widely applicable to laser direct-write patterning tools. This new laser material processing approach has been crafted by association with the genome and genotype concepts, where predetermined and prescribed laser pulse scripts are synchronously linked with the tool path geometry, and each concatenated pulse sequence is intended to induce a specific material transformation event and thereby express a particular material attribute. While the experimental approach depends on the delivery of discrete amplitude modulated laser pulses to each focused volume element with high fidelity, the architecture is highly versatile and capable of more advanced functionality. The capabilities of this novel architecture fall short of the coherent spatial control techniques that are now emerging, but can be readily applied to fundamental investigations of complex laser-material interaction phenomena, and easily integrated into commercial and industrial laser material processing applications. Section 9.1 provides a brief overview of laser-based machining and materials processing, with particular emphasis on the advantages of controlling energy deposition in light-matter interactions to subtly affect a material's thermodynamic properties. This section also includes a brief discussion of conventional approaches to photon modulation and process control. Section 9.2 comprehensively describes the development and capabilities of our novel laser genotype pulse modulation technique that facilitates the controlled and precise delivery of photons to a host material during direct-write patterning. This section also reviews the experimental design setup and synchronized photon control scheme, along with performance tests and diagnostic results. Section 9.3 discusses selected applications of the new laser genotype processing technique, including optical property variations

  20. LTCC Thick Film Process Characterization

    DOE PAGESBeta

    Girardi, M. A.; Peterson, K. A.; Vianco, P. T.

    2016-05-01

    Low temperature cofired ceramic (LTCC) technology has proven itself in military/space electronics, wireless communication, microsystems, medical and automotive electronics, and sensors. The use of LTCC for high frequency applications is appealing due to its low losses, design flexibility and packaging and integration capability. Moreover, we summarize the LTCC thick film process including some unconventional process steps such as feature machining in the unfired state and thin film definition of outer layer conductors. The LTCC thick film process was characterized to optimize process yields by focusing on these factors: 1) Print location, 2) Print thickness, 3) Drying of tapes and panels,more » 4) Shrinkage upon firing, and 5) Via topography. Statistical methods were used to analyze critical process and product characteristics in the determination towards that optimization goal.« less

  1. Material properties of novel polymeric films

    NASA Astrophysics Data System (ADS)

    Kim, Gene

    This dissertation will study the material properties of two types of novel polymer films (polyelectrolyte multilayer films and photolithographic polymer films). The formation of polylelectrolyte multilayer films onto functionalized aluminum oxide surfaces and functionalized poly(ethylene terephthaltate) (PET) were studied. Functionalization of the aluminum oxide surfaces was achieved via silane coupling. Functionalization of PET surfaces was achieved via hydrolysis and amidation. Surface characterization techniques such as X-ray photoelectron spectroscopy (XPS) and dynamic contact angle measurements were used to monitor the polyelectrolyte multilayer formation. Mechanical properties of the aluminum oxide supported polyelectrolyte multilayer films were tested using a simplified peel test. XPS was used to analyze the surfaces before and after peel. Single lap shear joint specimens were constructed to test the adhesive shear strength of the PET-supported polyelectrolyte multilayer film samples with the aid of a cyanoacrylate adhesive. The adhesive shear strength and its relation with the type of functionalization, number of polyelectrolyte layers, and the effect of polyelectrolyte conformation using added salt were explored. Also, characterization on the single lap joints after adhesive failure was carried out to determine the locus of failure within the multilayers by using XPS and SEM. Two types of photolithographic polymers were formulated and tested. These two polymers (photocrosslinkable polyacrylate (PUA), and a photocrosslinkable polyimide (HRP)) were used to investigate factors that would affect the structural integrity of these particular polymers under environmental variables such as processing (time, UV cure, pressure, and temperature) and ink exposure. Thermomechanical characterization was carried out to see the behavior of these two polymers under these environmental variables. Microscopic techniques were employed to study the morphological behavior of

  2. Polycrystalline thin film materials and devices

    SciTech Connect

    Baron, B.N.; Birkmire, R.W.; Phillips, J.E.; Shafarman, W.N.; Hegedus, S.S.; McCandless, B.E. . Inst. of Energy Conversion)

    1992-10-01

    Results of Phase II of a research program on polycrystalline thin film heterojunction solar cells are presented. Relations between processing, materials properties and device performance were studied. The analysis of these solar cells explains how minority carrier recombination at the interface and at grain boundaries can be reduced by doping of windows and absorber layers, such as in high efficiency CdTe and CuInSe{sub 2} based solar cells. The additional geometric dimension introduced by the polycrystallinity must be taken into consideration. The solar cells are limited by the diode current, caused by recombination in the space charge region. J-V characteristics of CuInSe{sub 2}/(CdZn)S cells were analyzed. Current-voltage and spectral response measurements were also made on high efficiency CdTe/CdS thin film solar cells prepared by vacuum evaporation. Cu-In bilayers were reacted with Se and H{sub 2}Se gas to form CuInSe{sub 2} films; the reaction pathways and the precursor were studied. Several approaches to fabrication of these thin film solar cells in a superstrate configuration were explored. A self-consistent picture of the effects of processing on the evolution of CdTe cells was developed.

  3. Femtosecond Laser Materials Processing

    SciTech Connect

    Banks, P.S.; Stuart, B.C.; Komashko, A.M.; Feit, M.D.; Rubenchik, A.M.; Perry, M.D.

    2000-03-06

    The use of femtosecond lasers allows materials processing of practically any material with extremely high precision and minimal collateral damage. Advantages over conventional laser machining (using pulses longer than a few tens of picoseconds) are realized by depositing the laser energy into the electrons of the material on a time scale short compared to the transfer time of this energy to the bulk of the material, resulting in increased ablation efficiency and negligible shock or thermal stress. The improvement in the morphology by using femtosecond pulses rather than nanosecond pulses has been studied in numerous materials from biologic materials to dielectrics to metals. During the drilling process, we have observed the onset of small channels which drill faster than the surrounding material.

  4. Femtosecond laser materials processing

    SciTech Connect

    Stuart, B. C., LLNL

    1998-06-02

    Femtosecond lasers enable materials processing of most any material with extremely high precision and negligible shock or thermal loading to the surrounding area Applications ranging from drilling teeth to cutting explosives to making high-aspect ratio cuts in metals with no heat-affected zone are made possible by this technology For material removal at reasonable rates, we developed a fully computer-controlled 15-Watt average power, 100-fs laser machining system.

  5. Preface: Thin films of molecular organic materials

    NASA Astrophysics Data System (ADS)

    Fraxedas, J.

    2008-03-01

    /substrate systems (also called heterostructures) based on the physical properties of the bulk materials, usually in the form of single crystals. However, in recent years the thin films community has been continually growing, helping the field to mature. In my opinion two main aspects have advanced the thin molecular films field. The first is the different applications with optical and electrical devices such as OFETs (organic field-effect transistors) and OLEDs (organic light emitting diodes), applications that could not have been achieved with single crystals because of limited size, difficult processability and mechanical fragility. The second is the involvement of the surface science community with their overwhelming arsenal of experimental techniques. From the synthesis point of view, the preparation of thin films is being regarded as a complementary synthesis route. The different externally accessible variables involved in the preparation process (temperature, pressure, molecular flux, distance, time, concentration, solvent, substrate, etc.), which define the so-called parameter hyperspace, can be so diverse when comparing competing synthesis routes (e.g. solution versus vapour growth) that we should not be surprised if different crystallographic phases with different morphologies are obtained, even if metastable. We should not forget here that the amazingly large number of available molecules is due to the longstanding and innovative work of synthesis chemists, a task that has not been sufficiently recognized (laymen in the domain of synthesis of organic molecules tend to believe that almost any molecule can be synthesized). In summary, one of the goals of this issue is to highlight the emerging importance of the field of thin molecular organic films by giving selected examples. It is clear that some important examples are missing, which are due in part to space limitation and to the understandable reluctance of highly-ranked specialists to contribute because of work overload

  6. Extraterrestrial materials processing

    NASA Technical Reports Server (NTRS)

    Steurer, W. H.

    1982-01-01

    The first year results of a multi-year study of processing extraterrestrial materials for use in space are summarized. Theoretically, there are potential major advantages to be derived from the use of such materials for future space endeavors. The types of known or postulated starting raw materials are described including silicate-rich mixed oxides on the Moon, some asteroids and Mars; free metals in some asteroids and in small quantities in the lunar soil; and probably volatiles like water and CO2 on Mars and some asteroids. Candidate processes for space materials are likely to be significantly different from their terrestrial counterparts largely because of: absence of atmosphere; lack of of readily available working fluids; low- or micro-gravity; no carbon-based fuels; readily available solar energy; and severe constraints on manned intervention. The extraction of metals and oxygen from lunar material by magma electrolysis or by vapor/ion phase separation appears practical.

  7. Ultrasonic Processing of Materials

    SciTech Connect

    Meek, Thomas T.; Han, Qingyou; Jian, Xiaogang; Xu, Hanbing

    2005-06-30

    The purpose of this project was to determine the impact of a new breakthrough technology, ultrasonic processing, on various industries, including steel, aluminum, metal casting, and forging. The specific goals of the project were to evaluate core principles and establish quantitative bases for the ultrasonc processing of materials, and to demonstrate key applications in the areas of grain refinement of alloys during solidification and degassing of alloy melts. This study focussed on two classes of materials - aluminum alloys and steels - and demonstrated the application of ultrasonic processing during ingot casting.

  8. Thin film dielectric composite materials

    DOEpatents

    Jia, Quanxi; Gibbons, Brady J.; Findikoglu, Alp T.; Park, Bae Ho

    2002-01-01

    A dielectric composite material comprising at least two crystal phases of different components with TiO.sub.2 as a first component and a material selected from the group consisting of Ba.sub.1-x Sr.sub.x TiO.sub.3 where x is from 0.3 to 0.7, Pb.sub.1-x Ca.sub.x TiO.sub.3 where x is from 0.4 to 0.7, Sr.sub.1-x Pb.sub.x TiO.sub.3 where x is from 0.2 to 0.4, Ba.sub.1-x Cd.sub.x TiO.sub.3 where x is from 0.02 to 0.1, BaTi.sub.1-x Zr.sub.x O.sub.3 where x is from 0.2 to 0.3, BaTi.sub.1-x Sn.sub.x O.sub.3 where x is from 0.15 to 0.3, BaTi.sub.1-x Hf.sub.x O.sub.3 where x is from 0.24 to 0.3, Pb.sub.1-1.3x La.sub.x TiO.sub.3+0.2x where x is from 0.23 to 0.3, (BaTiO.sub.3).sub.x (PbFeo.sub.0.5 Nb.sub.0.5 O.sub.3).sub.1-x where x is from 0.75 to 0.9, (PbTiO.sub.3).sub.- (PbCo.sub.0.5 W.sub.0.5 O.sub.3).sub.1-x where x is from 0.1 to 0.45, (PbTiO.sub.3).sub.x (PbMg.sub.0.5 W.sub.0.5 O.sub.3).sub.1-x where x is from 0.2 to 0.4, and (PbTiO.sub.3).sub.x (PbFe.sub.0.5 Ta.sub.0.5 O.sub.3).sub.1-x where x is from 0 to 0.2, as the second component is described. The dielectric composite material can be formed as a thin film upon suitable substrates.

  9. Laser processing for thin-film photovoltaics

    NASA Astrophysics Data System (ADS)

    Compaan, Alvin D.

    1995-04-01

    Over the past decade major advances have occurred in the field of thin- film photovoltaics (PV) with many of them a direct consequence of the application of laser processing. Improved cell efficiencies have been achieved in crystalline and polycrystalline Si, in hydrogenated amorphous silicon, and in two polycrystalline thin-film materials. The use of lasers in photovoltaics includes laser hole drilling for emitter wrap-through, laser trenching for buried bus lines, and laser texturing of crystalline and polycrystalline Si cells. In thin-film devices, laser scribing is gaining increased importance for module interconnects. Pulsed laser recrystallization of boron-doped hydrogenated amorphous silicon is used to form highly conductive p-layers in p-i-n amorphous silicon cells and in thin-film transistors. Optical beam melting appears to be an attractive method for forming metal semiconductor alloys for contact formation. Finally, pulsed lasers are used for deposition of the entire semiconductor absorber layer in two types of polycrystalline thin-film cells-those based on copper indium diselenide and those based on cadmium telluride. In our lab we have prepared and studied heavily doped polycrystalline silicon thin films and also have used laser physical vapor deposition (LPVD) to prepare 'all-LPVD' CdS/CdTe solar cells on glass with efficiencies tested at NREL at 10.5%. LPVD is highly flexible and ideally suited for prototyping PV cells using ternary or quaternary alloys and for exploring new dopant combinations.

  10. Ultrasonic Processing of Materials

    NASA Astrophysics Data System (ADS)

    Han, Qingyou

    2015-08-01

    Irradiation of high-energy ultrasonic vibration in metals and alloys generates oscillating strain and stress fields in solids, and introduces nonlinear effects such as cavitation, acoustic streaming, and radiation pressure in molten materials. These nonlinear effects can be utilized to assist conventional material processing processes. This article describes recent research at Oak Ridge National Labs and Purdue University on using high-intensity ultrasonic vibrations for degassing molten aluminum, processing particulate-reinforced metal matrix composites, refining metals and alloys during solidification process and welding, and producing bulk nanostructures in solid metals and alloys. Research results suggest that high-intensity ultrasonic vibration is capable of degassing and dispersing small particles in molten alloys, reducing grain size during alloy solidification, and inducing nanostructures in solid metals.

  11. Synthesis of ultra-nano-carbon composite materials with extremely high conductivity by plasma post-treatment process of ultrananocrystalline diamond films

    SciTech Connect

    Yeh, Chien-Jui; Leou, Keh-Chyang; Manoharan, Divinah; Chang, Hsin-Tzer; Lin, I-Nan

    2015-08-24

    Needle-like diamond grains encased in nano-graphitic layers are an ideal granular structure of diamond films to achieve high conductivity and superior electron field emission (EFE) properties. This paper describes the plasma post-treatment (ppt) of ultrananocrystalline diamond (UNCD) films at low substrate temperature to achieve such a unique granular structure. The CH{sub 4}/N{sub 2} plasma ppt-processed films exhibit high conductivity of σ = 1099 S/cm as well as excellent EFE properties with turn-on field of E{sub 0} = 2.48 V/μm (J{sub e} = 1.0 mA/cm{sup 2} at 6.5 V/μm). The ppt of UNCD film is simple and robust process that is especially useful for device applications.

  12. Processing of lunar materials

    NASA Astrophysics Data System (ADS)

    Poisl, W. Howard; Fabes, B. D.

    1994-07-01

    A variety of products made from lunar resources will be required for a lunar outpost. These products might be made by adapting existing processing techniques to the lunar environment, or by developing new techniques unique to the moon. In either case, processing techniques used on the moon will have to have a firm basis in basic principles of materials science and engineering, which can be used to understand the relationships between composition, processing, and properties of lunar-derived materials. These principles can also be used to optimize the properties of a product, once a more detailed knowledge of the lunar regolith is obtained. Using three types of ceramics (monolithic glasses, glass fibers, and glass-ceramics) produced from lunar simulants, we show that the application of materials science and engineering priciples is useful in understanding and optimizing the mechanical properties of ceramics on the moon. We also demonstrate that changes in composition and/or processing can have a significant effect on the strength of these materials.

  13. Processing Materials in Space

    NASA Technical Reports Server (NTRS)

    Zoller, L. K.

    1982-01-01

    Suggested program of material processing experiments in space described in 81 page report. For each experiment, report discusses influence of such gravitational effects as convection, buoyancy, sedimentation, and hydrostatic pressure. Report contains estimates of power and mission duration required for each experiment. Lists necessary equipment and appropriate spacecraft.

  14. Femtosecond laser materials processing

    SciTech Connect

    Stuart, B.C.

    1997-02-01

    The use femtosecond pulses for materials processing results in very precise cutting and drilling with high efficiency. Energy deposited in the electrons is not coupled into the bulk during the pulse, resulting in negligible shock or thermal loading to adjacent areas.

  15. Laser material processing system

    DOEpatents

    Dantus, Marcos

    2015-04-28

    A laser material processing system and method are provided. A further aspect of the present invention employs a laser for micromachining. In another aspect of the present invention, the system uses a hollow waveguide. In another aspect of the present invention, a laser beam pulse is given broad bandwidth for workpiece modification.

  16. Deposition of thin films of multicomponent materials

    NASA Technical Reports Server (NTRS)

    Thakoor, Sarita (Inventor)

    1993-01-01

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

  17. Film/Adhesive Processing Module for Fiber-Placement Processing of Composites

    NASA Technical Reports Server (NTRS)

    Hulcher, A. Bruce

    2007-01-01

    An automated apparatus has been designed and constructed that enables the automated lay-up of composite structures incorporating films, foils, and adhesives during the automated fiber-placement process. This apparatus, denoted a film module, could be used to deposit materials in film or thin sheet form either simultaneously when laying down the fiber composite article or in an independent step.

  18. Silicon film solar cell process

    NASA Technical Reports Server (NTRS)

    Hall, R. B.; Mcneely, J. B.; Barnett, A. M.

    1984-01-01

    The most promising way to reduce the cost of silicon in solar cells while still maintaining performance is to utilize thin films (10 to 20 microns thick) of crystalline silicon. The method of solution growth is being employed to grow thin polycrystalline films of silicon on dissimilar substrates. The initial results indicate that, using tin as the solvent, this growth process only requires operating temperatures in the range of 800 C to 1000 C. Growth rates in the range of 0.4 to 2.0 microns per minute and grain sizes in the range of 20 to 100 microns were achieved on both quartz and coated steel substrates. Typically, an aspect ratio of two to three between the width and the Si grain thickness is seen. Uniform coverage of Si growth on quartz over a 2.5 x 2.5 cm area was observed.

  19. Innovative industrial materials processes

    SciTech Connect

    Hane, G.; Abarcar, R.; Hauser, S.G.; Williams, T.A.

    1983-08-01

    This paper reviews innovative industrial materials processes that have the potential for significant improvements in energy use, yet require long-term research to achieve that potential. Potential revolutionary alternatives are reviewed for the following industries: iron and steel; aluminum; petroleum refining; paper and pulp; food and kindred products; stone, clay and glass; textiles; and chemicals. In total, 45 candidate processes were identified. Examples of these processes include direct steelmaking and ore-to-powder systems that potentially require 30% and 40% less energy, respectively, than conventional steelmaking systems; membrane separations and freeze crystallization that offer up to 90% reductions in energy use when compared with distillation; cold processing of cement that offers a 50% reduction in energy requirements; and dry forming of paper that offers a 25% reduction in the energy needed for papermaking.

  20. Surface engineering of glazing materials and structures using plasma processes

    SciTech Connect

    Anders, Andre; Monteiro, Othon R.

    2003-04-10

    A variety of coatings is commercially produced on a very large scale, including transparent conducting oxides and multi-layer silver-based low-emissivity and solar control coatings. A very brief review of materials and manufacturing process is presented and illustrated by ultrathin silver films and chevron copper films. Understanding the close relation between manufacturing processes and bulk and surface properties of materials is crucial for film growth and self-assembly processes.

  1. Lunar materials and processes

    NASA Technical Reports Server (NTRS)

    Burke, J. D.

    1986-01-01

    The paper surveys current information, describes some important unknowns about lunar materials, and discusses ways to gain more scientific and engineering knowledge concerning the industrial processes that could be used on the moon for the production of products useful in future enterprises in space. Lunar rocks and soils are rich in oxygen, but it is mostly chemically bound in silicates, so that chemical or thermal energy must be supplied to recover it. Iron and titanium are abundant and, in some of their known forms, readily recoverable; aluminum is plentiful but harder to extract. Methods for recovering lunar oxygen and metals fall into three classes: chemical, electrolytic, and dissociative, broadly characterized by their respective process temperatures. Examples of these methods are briefly discussed.

  2. Tungsten-doped thin film materials

    DOEpatents

    Xiang, Xiao-Dong; Chang, Hauyee; Gao, Chen; Takeuchi, Ichiro; Schultz, Peter G.

    2003-12-09

    A dielectric thin film material for high frequency use, including use as a capacitor, and having a low dielectric loss factor is provided, the film comprising a composition of tungsten-doped barium strontium titanate of the general formula (Ba.sub.x Sr.sub.1-x)TiO.sub.3, where X is between about 0.5 and about 1.0. Also provided is a method for making a dielectric thin film of the general formula (Ba.sub.x Sr.sub.1-x)TiO.sub.3 and doped with W, where X is between about 0.5 and about 1.0, a substrate is provided, TiO.sub.2, the W dopant, Ba, and optionally Sr are deposited on the substrate, and the substrate containing TiO.sub.2, the W dopant, Ba, and optionally Sr is heated to form a low loss dielectric thin film.

  3. Color Imaging management in film processing

    NASA Astrophysics Data System (ADS)

    Tremeau, Alain; Konik, Hubert; Colantoni, Philippe

    2003-12-01

    The latest research projects in the laboratory LIGIV concerns capture, processing, archiving and display of color images considering the trichromatic nature of the Human Vision System (HSV). Among these projects one addresses digital cinematographic film sequences of high resolution and dynamic range. This project aims to optimize the use of content for the post-production operators and for the end user. The studies presented in this paper address the use of metadata to optimise the consumption of video content on a device of user's choice independent of the nature of the equipment that captured the content. Optimising consumption includes enhancing the quality of image reconstruction on a display. Another part of this project addresses the content-based adaptation of image display. Main focus is on Regions of Interest (ROI) operations, based on the ROI concepts of MPEG-7. The aim of this second part is to characterize and ensure the conditions of display even if display device or display media changes. This requires firstly the definition of a reference color space and the definition of bi-directional color transformations for each peripheral device (camera, display, film recorder, etc.). The complicating factor is that different devices have different color gamuts, depending on the chromaticity of their primaries and the ambient illumination under which they are viewed. To match the displayed image to the aimed appearance, all kind of production metadata (camera specification, camera colour primaries, lighting conditions) should be associated to the film material. Metadata and content build together rich content. The author is assumed to specify conditions as known from digital graphics arts. To control image pre-processing and image post-processing, these specifications should be contained in the film's metadata. The specifications are related to the ICC profiles but need additionally consider mesopic viewing conditions.

  4. Process to form mesostructured films

    DOEpatents

    Brinker, C. Jeffrey; Anderson, Mark T.; Ganguli, Rahul; Lu, Yunfeng

    1999-01-01

    This invention comprises a method to form a family of supported films film with pore size in the approximate range 0.8-20 nm exhibiting highly ordered microstructures and porosity derived from an ordered micellar or liquid-crystalline organic-inorganic precursor structure that forms during film deposition. Optically transparent, 100-500-nm thick films exhibiting a unique range of microstructures and uni-modal pore sizes are formed in seconds in a continuous coating operation. Applications of these films include sensors, membranes, low dielectric constant interlayers, anti-reflective coatings, and optical hosts.

  5. Chemical processing of lunar materials

    NASA Technical Reports Server (NTRS)

    Criswell, D. R.; Waldron, R. D.

    1979-01-01

    The paper highlights recent work on the general problem of processing lunar materials. The discussion covers lunar source materials, refined products, motivations for using lunar materials, and general considerations for a lunar or space processing plant. Attention is given to chemical processing through various techniques, including electrolysis of molten silicates, carbothermic/silicothermic reduction, carbo-chlorination process, NaOH basic-leach process, and HF acid-leach process. Several options for chemical processing of lunar materials are well within the state of the art of applied chemistry and chemical engineering to begin development based on the extensive knowledge of lunar materials.

  6. Processing and characterization of extruded zein-based biodegradable films

    NASA Astrophysics Data System (ADS)

    Wang, Ying

    The objectives of this study were to prepare biodegradable zein films by extrusion processing and to evaluate relevant physical properties of resulting films with respect to their potential as packaging materials. The manufacture of protein-based packaging films by extrusion has remained a challenge. In this study, a zein resin was prepared by combining zein and oleic acid. This resin was formed into films by blown extrusion at the bench-top scale. Resin moisture content and extruder barrel temperature profile were identified as major parameters controlling the process. The optimum temperature of the blowing head was determined to be 40--45°C, while optimum moisture at film collection was 14--15%. Physico-chemical properties of the extruded products were characterized. Extruded products exhibited plastic behavior and ductility. Morphology characterization by SEM showed micro voids in extruded zein sheets, caused by entrapped air bubbles or water droplets. DSC characterization showed that zein was effectively plasticized by oleic acid as evidenced by the lowered glass transition temperature of zein films. X-ray scattering was used to investigate changes in zein molecular aggregation during processing. It was observed that higher mechanical energy treatment progressively disrupted zein molecular aggregates, resulting in a more uniform distribution of individual zein molecules. With the incorporation of oleic acid as plasticizer and monoglycerides as emulsifier, zein formed structures with long-range periodicity which varied depending on the formulation and processing methods. Processing methods for film formation affected the binding of oleic acid to zein with higher mechanical energy treatment resulting in better interaction between the two components. The moisture sorption capacity of extruded zein films was reduced due to the compact morphology caused by extrusion. Plasticization with oleic acid further reduced moisture sorption of zein films. The overall

  7. Physical Properties of Thin Film Semiconducting Materials

    NASA Astrophysics Data System (ADS)

    Bouras, N.; Djebbouri, M.; Outemzabet, R.; Sali, S.; Zerrouki, H.; Zouaoui, A.; Kesri, N.

    2005-10-01

    The physics and chemistry of semiconducting materials is a continuous question of debate. We can find a large stock of well-known properties but at the same time, many things are not understood. In recent years, porous silicon (PS-Si), diselenide of copper and indium (CuInSe2 or CIS) and metal oxide semiconductors like tin oxide (SnO2) and zinc oxide (ZnO) have been subjected to extensive studies because of the rising interest their potential applications in fields such as electronic components, solar panels, catalysis, gas sensors, in biocompatible materials, in Li-based batteries, in new generation of MOSFETS. Bulk structure and surface and interface properties play important roles in all of these applications. A deeper understanding of these fundamental properties would impact largely on technological application performances. In our laboratory, thin films of undoped and antimony-doped films of tin oxide have been deposited by chemical vapor deposition. Spray pyrolysis was used for ZnO. CIS was prepared by flash evaporation or close-space vapor transport. Some of the deposition parameters have been varied, such as substrate temperature, time of deposition (or anodization), and molar concentration of bath preparation. For some samples, thermal annealing was carried out under oxygen (or air), under nitrogen gas and under vacuum. Deposition and post-deposition parameters are known to strongly influence film structure and electrical resistivity. We investigated the influence of film thickness and thermal annealing on structural optical and electrical properties of the films. Examination of SnO2 by x-ray diffraction showed that the main films are polycrystalline with rutile structure. The x-ray spectra of ZnO indicated a hexagonal wurtzite structure. Characterizations of CIS films with compositional analysis, x-ray diffraction, scanning microscopy, spectrophotometry, and photoluminescence were carried out.

  8. Fundamental Materials Research and Advanced Process Development for Thin-Film CIS-Based Photovoltaics: Final Technical Report, 2 October 2001 - 30 September 2005

    SciTech Connect

    Anderson, T. J.; Li, S. S.; Crisalle, O. D.; Craciun, V.

    2006-09-01

    The objectives for this thin-film copper-indium-diselenide (CIS) solar cell project cover the following areas: Develop and characterize buffer layers for CIS-based solar cell; grow and characterize chemical-bath deposition of Znx Cd1-xS buffer layers grown on CIGS absorbers; study effects of buffer-layer processing on CIGS thin films characterized by the dual-beam optical modulation technique; grow epitaxial CuInSe2 at high temperature; study the defect structure of CGS by photoluminescence spectroscopy; investigate deep-level defects in Cu(In,Ga)Se2 solar cells by deep-level transient spectroscopy; conduct thermodynamic modeling of the isothermal 500 C section of the Cu-In-Se system using a defect model; form alpha-CuInSe2 by rapid thermal processing of a stacked binary compound bilayer; investigate pulsed non-melt laser annealing on the film properties and performance of Cu(In,Ga)Se2 solar cells; and conduct device modeling and simulation of CIGS solar cells.

  9. Process to form mesostructured films

    DOEpatents

    Brinker, C.J.; Anderson, M.T.; Ganguli, R.; Lu, Y.F.

    1999-01-12

    This invention comprises a method to form a family of supported films with pore size in the approximate range 0.8-20 nm exhibiting highly ordered microstructures and porosity derived from an ordered micellar or liquid-crystalline organic-inorganic precursor structure that forms during film deposition. Optically transparent, 100-500-nm thick films exhibiting a unique range of microstructures and uni-modal pore sizes are formed in seconds in a continuous coating operation. Applications of these films include sensors, membranes, low dielectric constant interlayers, anti-reflective coatings, and optical hosts. 12 figs.

  10. Polycrystalline thin film materials and devices

    NASA Astrophysics Data System (ADS)

    Baron, B. N.; Birkmire, R. W.; Phillips, J. E.; Shafarman, W. N.; Hegedus, S. S.; McCandless, B. E.

    1991-11-01

    Results and conclusions of Phase 1 of a multi-year research program on polycrystalline thin film solar cells are presented. The research comprised investigation of the relationships among processing, materials properties and device performance of both CuInSe2 and CdTe solar cells. The kinetics of the formation of CuInSe2 by selenization with hydrogen selenide was investigated and a CuInSe2/Cds solar cell was fabricated. An alternative process involving the reaction of deposited copper-indium-selenium layers was used to obtain single phase CuInSe2 films and a cell efficiency of 7 percent. Detailed investigations of the open circuit voltage of CuInSe2 solar cells showed that a simple Shockley-Read-Hall recombination mechanism can not account for the limitations in open circuit voltage. Examination of the influence of CuInSe2 thickness on cell performance indicated that the back contact behavior has a significant effect when the CuInSe2 is less than 1 micron thick. CdTe/CdS solar cells with efficiencies approaching 10 percent can be repeatedly fabricated using physical vapor deposition and serial post deposition processing. The absence of moisture during post deposition was found to be critical. Improvements in short circuit current of CdTe solar cells to levels approaching 25 mA/cm(exp 2) are achievable by making the CdS window layer thinner. Further reductions in the CdS window layer thickness are presently limited by interdiffusion between the CdS and the CdTe. CdTe/CdS cells stored without protection from the atmosphere were found to degrade. The degradation was attributed to the metal contact. CdTe cells with ZnTe:Cu contacts to the CdTe were found to be more stable than cells with metal contacts. Analysis of current-voltage and spectral response of CdTe/CdS cells indicates the cell operates as a p-n heterojunction with the diode current dominated by SRH recombination in the junction region of the CdTe.

  11. Research on resistance properties of conductive layer materials of microchannel plate film dynode

    NASA Astrophysics Data System (ADS)

    Peng, Ling-ling; Duanmu, Qingduo; Yang, Ji-kai; Wang, Guo-zheng

    2015-03-01

    Silicon Microchannel Plate - MCP - is a new image multiplier devices based semiconductor process technology. Compared with the traditional glass MCP, Silicon MCP has an advantage in technology that the dynode materials and the substrate materials are separate. At the same time, the dynode preparation process and the microchannel arrays are also separate. Two different dynode conductive layer films are prepared: polysilicon conductive films prepared by low pressure chemical vapor deposition (LPCVD) and AZO thin films coated by atomic layer deposition (ALD). The conductive films coated by ALD are superior to dynode conductive films prepared by LPCVD. By comparing the resistivity of conductive polysilicon thin film and AZO thin film of different Al concentrations doped, AZO thin film of different Al concentrations doped is a more suitable conductive layer dynode material to satisfy the MCP conductive layer resistivity requirements.

  12. Dynamic Characterization of Thin Film Magnetic Materials

    NASA Astrophysics Data System (ADS)

    Gu, Wei

    A broadband dynamic method for characterizing thin film magnetic material is presented. The method is designed to extract the permeability and linewidth of thin magnetic films from measuring the reflection coefficient (S11) of a house-made and short-circuited strip line testing fixture with or without samples loaded. An adaptive de-embedding method is applied to remove the parasitic noise of the housing. The measurements were carried out with frequency up to 10GHz and biasing magnetic fields up to 600 Gauss. Particular measurement setup and 3-step experimental procedures are described in detail. The complex permeability of a 330nm thick continuous FeGaB, 435nm thick laminated FeGaB film and a 100nm thick NiFe film will be induced dynamically in frequency-biasing magnetic field spectra and compared with a theoretical model based on Landau-Lifshitz-Gilbert (LLG) equations and eddy current theories. The ferromagnetic resonance (FMR) phenomenon can be observed among these three magnetic materials investigated in this thesis.

  13. Thick-film materials for silicon photovoltaic cell manufacture

    NASA Technical Reports Server (NTRS)

    Field, M. B.

    1977-01-01

    Thick film technology is applicable to three areas of silicon solar cell fabrication; metallization, junction formation, and coating for protection of screened ohmic contacts, particularly wrap around contacts, interconnection and environmental protection. Both material and process parameters were investigated. Printed ohmic contacts on n- and p-type silicon are very sensitive to the processing parameters of firing time, temperature, and atmosphere. Wrap around contacts are easily achieved by first printing and firing a dielectric over the edge and subsequently applying a low firing temperature conductor. Interconnection of cells into arrays can be achieved by printing and cofiring thick film metal pastes, soldering, or with heat curing conductive epoxies on low cost substrates. Printed (thick) film vitreous protection coatings do not yet offer sufficient optical uniformity and transparency for use on silicon. A sprayed, heat curable SiO2 based resin shows promise of providing both optical matching and environmental protection.

  14. Gas permeability measurements for film envelope materials

    DOEpatents

    Ludtka, G.M.; Kollie, T.G.; Watkin, D.C.; Walton, D.G.

    1998-05-12

    Method and apparatus for measuring the permeability of polymer film materials such as used in super-insulation powder-filled evacuated panels (PEPs) reduce the time required for testing from several years to weeks or months. The method involves substitution of a solid non-outgassing body having a free volume of between 0% and 25% of its total volume for the usual powder in the PEP to control the free volume of the ``body-filled panel.`` Pressure versus time data for the test piece permit extrapolation to obtain long term performance of the candidate materials. 4 figs.

  15. Gas permeability measurements for film envelope materials

    DOEpatents

    Ludtka, Gerard M.; Kollie, Thomas G.; Watkin, David C.; Walton, David G.

    1998-01-01

    Method and apparatus for measuring the permeability of polymer film materials such as used in super-insulation powder-filled evacuated panels (PEPs) reduce the time required for testing from several years to weeks or months. The method involves substitution of a solid non-outgassing body having a free volume of between 0% and 25% of its total volume for the usual powder in the PEP to control the free volume of the "body-filled panel". Pressure versus time data for the test piece permit extrapolation to obtain long term performance of the candidate materials.

  16. Process for preparing superconducting film having substantially uniform phase development

    DOEpatents

    Bharacharya, Raghuthan; Parilla, Philip A.; Blaugher, Richard D.

    1995-01-01

    A process for preparing a superconducting film, such as a thallium-barium-calcium-copper oxide superconducting film, having substantially uniform phase development. The process comprises providing an electrodeposition bath having one or more soluble salts of one or more respective potentially superconducting metals in respective amounts adequate to yield a superconducting film upon subsequent appropriate treatment. Should all of the metals required for producing a superconducting film not be made available in the bath, such metals can be a part of the ambient during a subsequent annealing process. A soluble silver salt in an amount between about 0.1% and about 4.0% by weight of the provided other salts is also provided to the bath, and the bath is electrically energized to thereby form a plated film. The film is annealed in ambient conditions suitable to cause formation of a superconductor film. Doping with silver reduces the temperature at which the liquid phase appears during the annealing step, initiates a liquid phase throughout the entire volume of deposited material, and influences the nucleation and growth of the deposited material.

  17. Process for preparing superconducting film having substantially uniform phase development

    DOEpatents

    Bharacharya, R.; Parilla, P.A.; Blaugher, R.D.

    1995-12-19

    A process is disclosed for preparing a superconducting film, such as a thallium-barium-calcium-copper oxide superconducting film, having substantially uniform phase development. The process comprises providing an electrodeposition bath having one or more soluble salts of one or more respective potentially superconducting metals in respective amounts adequate to yield a superconducting film upon subsequent appropriate treatment. Should all of the metals required for producing a superconducting film not be made available in the bath, such metals can be a part of the ambient during a subsequent annealing process. A soluble silver salt in an amount between about 0.1% and about 4.0% by weight of the provided other salts is also provided to the bath, and the bath is electrically energized to thereby form a plated film. The film is annealed in ambient conditions suitable to cause formation of a superconductor film. Doping with silver reduces the temperature at which the liquid phase appears during the annealing step, initiates a liquid phase throughout the entire volume of deposited material, and influences the nucleation and growth of the deposited material. 3 figs.

  18. Characterization of diamond thin films and related materials

    NASA Astrophysics Data System (ADS)

    McKindra, Travis Kyle

    Thin carbon films including sputtered deposited graphite and CO 2 laser-assisted combustion-flame deposited graphite and diamond thin films were characterized using optical and electron microscopy, X-ray diffraction and micro-Raman spectroscopy. Amorphous carbon thin films were deposited by DC magnetron sputtering using Ar/O2 gases. The film morphology changed with the oxygen content. The deposition rate decreased as the amount of oxygen increased due to oxygen reacting with the growing film. The use of oxygen in the working gas enhanced the crystalline nature of the films. Graphite was deposited on WC substrates by a CO2 laser-assisted O2/C2H2 combustion-flame method. Two distinct microstructural areas were observed; an inner core of dense material surrounded by an outer shell of lamellar-like material. The deposits were crystalline regardless of the laser power and deposition times of a few minutes. Diamond films were deposited by a CO2 laser-assisted O 2/C2H2/C2H4 combustion-flame method with the laser focused parallel to the substrate surface. The laser enhanced diamond growth was most pronounced when deposited with a 10.532 microm CO2 laser wavelength tuned to the CH2-wagging vibrational mode of the C2H4 molecule. Nucleation of diamond thin films deposited with and without using a CO 2 laser-assisted combustion-flame process was investigated. With no laser there was nucleation of a sub-layer of grains followed by irregular grain growth. An untuned laser wavelength yielded nucleation of a sub-layer then columnar grain growth. The 10.532 microm tuned laser wavelength caused growth of columnar grains.

  19. Transparent materials processing system

    NASA Technical Reports Server (NTRS)

    Hetherington, J. S.

    1977-01-01

    A zero gravity processing furnace system was designed that will allow acquisition of photographic or other visual information while the sample is being processed. A low temperature (30 to 400 C) test model with a flat specimen heated by quartz-halide lamps was constructed. A high temperature (400 to 1000 C) test model heated by resistance heaters, utilizing a cylindrical specimen and optics, was also built. Each of the test models is discussed in detail. Recommendations are given.

  20. Advanced Materials and Processing 2010

    NASA Astrophysics Data System (ADS)

    Zhang, Yunfeng; Su, Chun Wei; Xia, Hui; Xiao, Pengfei

    2011-06-01

    Strain sensors made from MWNT/polymer nanocomposites / Gang Yin, Ning Hu and Yuan Li -- Shear band evolution and nanostructure formation in titanium by cold rolling / Dengke Yang, Peter D. Hodgson and Cuie Wen -- Biodegradable Mg-Zr-Ca alloys for bone implant materials / Yuncang Li ... [et al.] -- Hydroxyapatite synthesized from nanosized calcium carbonate via hydrothermal method / Yu-Shiang Wu, Wen-Ku Chang and Min Jou -- Modeling of the magnetization process and orthogonal fluxgate sensitivity of ferromagnetic micro-wire arrays / Fan Jie ... [et al.] -- Fabrication of silicon oxide nanowires on Ni coated silicon substrate by simple heating process / Bo Peng and Kwon-Koo Cho -- Deposition of TiOxNy thin films with various nitrogen flow rate: growth behavior and structural properties / S.-J. Cho ... [et al.] -- Observation on photoluminescence evolution in 300 KeV self-ion implanted and annealed silicon / Yu Yang ... [et al.] -- Facile synthesis of lithium niobate from a novel precursor H[symbol] / Meinan Liu ... [et al.] -- Effects of the buffer layers on the adhesion and antimicrobial properties of the amorphous ZrAlNiCuSi films / Pai-Tsung Chiang ... [et al.] -- Fabrication of ZnO nanorods by electrochemical deposition process and its photovoltaic properties / Jin-Hwa Kim ... [et al.] -- Cryogenic resistivities of NbTiAlVTaLax, CoCrFeNiCu and CoCrFeNiAl high entropy alloys / Xiao Yang and Yong Zhang -- Modeling of centrifugal force field and the effect on filling and solidification in centrifugal casting / Wenbin Sheng, Chunxue Ma and Wanli Gu -- Electrochemical properties of TiO[symbol] nanotube arrays film prepared by anodic oxidation / Young-Jin Choi ... [et al.] -- Effect of Ce additions on high temperature properties of Mg-5Sn-3Al-1Zn alloy / Byoung Soo Kang ... [et al.] -- Sono-electroless plating of Ni-Mo-P film / Atsushi Chiba, Masato Kanou and Wen-Chang Wu -- Diameter dependence of giant magneto-impedance effect in co-based melt extracted amorphous

  1. Advanced composite materials and processes

    NASA Technical Reports Server (NTRS)

    Baucom, Robert M.

    1991-01-01

    Composites are generally defined as two or more individual materials, which, when combined into a single material system, results in improved physical and/or mechanical properties. The freedom of choice of the starting components for composites allows the generation of materials that can be specifically tailored to meet a variety of applications. Advanced composites are described as a combination of high strength fibers and high performance polymer matrix materials. These advanced materials are required to permit future aircraft and spacecraft to perform in extended environments. Advanced composite precursor materials, processes for conversion of these materials to structures, and selected applications for composites are reviewed.

  2. Cibachrome testing. [photographic processing and printing materials

    NASA Technical Reports Server (NTRS)

    Weinstein, M. S.

    1974-01-01

    The use of Cibachrome products as a solution to problems encountered when contact printing Kodak film type SO-397 onto Kodak Ektrachrome color reversal paper type 1993 is investigated. A roll of aerial imagery consisting of Kodak film types SO-397 and 2443 was contact printed onto Cibachrome and Kodak materials and compared in terms of color quality, resolution, cost, and compatibility with existing equipment and techniques. Objective measurements are given in terms of resolution and sensitometric response. Comparison prints and transparencies were viewed and ranked according to overall quality and aesthetic appeal. It is recommended that Cibachrome Print material be used in place of Kodak Ektachrome paper because it is more easily processed, the cost is equivalent, and it provides improved resolution, color quality, and image fade resistance.

  3. Extrusion process optimization for toughness in balloon films

    NASA Technical Reports Server (NTRS)

    Cantor, K. M.; Harrison, I. R.

    1993-01-01

    An experimental optimization process for blown film extrusion is described and examined in terms of the effects of the technique on the toughness of balloon films. The optimization technique by Cantor (1990) is employed which involves the identification of key process variables including screw speed, nip speed, bubble diameter, and frost-line height for analysis to optimize the merit function. The procedure is employed in the extrusion of a low-density polyethylene polymer, and the resulting optimized materials are toughness- and puncture-tested. Balloon toughness is optimized in the analytical relationship, and the process parameters are modified to attain optimal toughness. The film produced is shown to have an average toughness of 24.5 MPa which is a good value for this key property of balloon materials for high-altitude flights.

  4. Advanced Materials and Processing 2010

    NASA Astrophysics Data System (ADS)

    Zhang, Yunfeng; Su, Chun Wei; Xia, Hui; Xiao, Pengfei

    2011-06-01

    Strain sensors made from MWNT/polymer nanocomposites / Gang Yin, Ning Hu and Yuan Li -- Shear band evolution and nanostructure formation in titanium by cold rolling / Dengke Yang, Peter D. Hodgson and Cuie Wen -- Biodegradable Mg-Zr-Ca alloys for bone implant materials / Yuncang Li ... [et al.] -- Hydroxyapatite synthesized from nanosized calcium carbonate via hydrothermal method / Yu-Shiang Wu, Wen-Ku Chang and Min Jou -- Modeling of the magnetization process and orthogonal fluxgate sensitivity of ferromagnetic micro-wire arrays / Fan Jie ... [et al.] -- Fabrication of silicon oxide nanowires on Ni coated silicon substrate by simple heating process / Bo Peng and Kwon-Koo Cho -- Deposition of TiOxNy thin films with various nitrogen flow rate: growth behavior and structural properties / S.-J. Cho ... [et al.] -- Observation on photoluminescence evolution in 300 KeV self-ion implanted and annealed silicon / Yu Yang ... [et al.] -- Facile synthesis of lithium niobate from a novel precursor H[symbol] / Meinan Liu ... [et al.] -- Effects of the buffer layers on the adhesion and antimicrobial properties of the amorphous ZrAlNiCuSi films / Pai-Tsung Chiang ... [et al.] -- Fabrication of ZnO nanorods by electrochemical deposition process and its photovoltaic properties / Jin-Hwa Kim ... [et al.] -- Cryogenic resistivities of NbTiAlVTaLax, CoCrFeNiCu and CoCrFeNiAl high entropy alloys / Xiao Yang and Yong Zhang -- Modeling of centrifugal force field and the effect on filling and solidification in centrifugal casting / Wenbin Sheng, Chunxue Ma and Wanli Gu -- Electrochemical properties of TiO[symbol] nanotube arrays film prepared by anodic oxidation / Young-Jin Choi ... [et al.] -- Effect of Ce additions on high temperature properties of Mg-5Sn-3Al-1Zn alloy / Byoung Soo Kang ... [et al.] -- Sono-electroless plating of Ni-Mo-P film / Atsushi Chiba, Masato Kanou and Wen-Chang Wu -- Diameter dependence of giant magneto-impedance effect in co-based melt extracted amorphous

  5. Materials availability for thin film solar cells

    NASA Astrophysics Data System (ADS)

    Makita, Yunosuke

    1997-04-01

    Materials availability is one of the most important factors when we consider the mass-production of next generation photovoltaic devices. "In (indium)" is a vital element to produce high efficient thin film solar cells such as InP and CuIn(Ga)Se2 but its lifetime as a natural resource is suggested to be of order of 10˜15 years. The lifetime of a specific natural resource as an element to produce useful device substances is directly related with its abundance in the earth's crust, consumption rate and recycling rate (if recycling is economically meaningful). The chemical elements having long lifetime as a natural resource are those existing in the atmosphere such as N (nitrogen) and O (oxygen); the rich elements in the earth's crust such as Si, Ca, Sr and Ba; the mass-used metals such as Fe (iron), Al (aluminum) and Cu (copper) that reached the stage of large-scale recycling. We here propose a new paradigm of semiconductor material-science for the future generation thin film solar cells in which only abundant chemical elements are used. It is important to remark that these abundant chemical elements are normally not toxic and are fairly friendly to the environment. β-FeSi2 is composed of two most abundant and nontoxic chemical elements. This material is one of the most promising device materials for future generation energy devices (solar cells and thermoelectric device that is most efficient at temperature range of 700-900 °C). One should remind of the versatility of β-FeSi2 that this material can be used not only as energy devices but also as photodetector, light emitting diode and/or laser diode at the wavelength of 1.5 μm that can be monolithically integrated on Si substrates due to the relatively small lattice mismatch.

  6. Electrochromic materials, devices and process of making

    DOEpatents

    Richardson, Thomas J.

    2003-11-11

    Thin films of transition metal compositions formed with magnesium that are metals, alloys, hydrides or mixtures of alloys, metals and/or hydrides exhibit reversible color changes on application of electric current or hydrogen. Thin films of these materials are suitable for optical switching elements, thin film displays, sun roofs, rear-view mirrors and architectural glass.

  7. PROCESS OF FORMING POWDERED MATERIAL

    DOEpatents

    Glatter, J.; Schaner, B.E.

    1961-07-14

    A process of forming high-density compacts of a powdered ceramic material is described by agglomerating the powdered ceramic material with a heat- decompossble binder, adding a heat-decompossble lubricant to the agglomerated material, placing a quantity of the material into a die cavity, pressing the material to form a compact, pretreating the compacts in a nonoxidizing atmosphere to remove the binder and lubricant, and sintering the compacts. When this process is used for making nuclear reactor fuel elements, the ceramic material is an oxide powder of a fissionsble material and after forming, the compacts are placed in a cladding tube which is closed at its ends by vapor tight end caps, so that the sintered compacts are held in close contact with each other and with the interior wall of the cladding tube.

  8. Thermoplastic processing of proteins for film formation--a review.

    PubMed

    Hernandez-Izquierdo, V M; Krochta, J M

    2008-03-01

    Increasing interest in high-quality food products with increased shelf life and reduced environmental impact has encouraged the study and development of edible and/or biodegradable polymer films and coatings. Edible films provide the opportunity to effectively control mass transfer among different components in a food or between the food and its surrounding environment. The diversity of proteins that results from an almost limitless number of side-chain amino-acid sequential arrangements allows for a wide range of interactions and chemical reactions to take place as proteins denature and cross-link during heat processing. Proteins such as wheat gluten, corn zein, soy protein, myofibrillar proteins, and whey proteins have been successfully formed into films using thermoplastic processes such as compression molding and extrusion. Thermoplastic processing can result in a highly efficient manufacturing method with commercial potential for large-scale production of edible films due to the low moisture levels, high temperatures, and short times used. Addition of water, glycerol, sorbitol, sucrose, and other plasticizers allows the proteins to undergo the glass transition and facilitates deformation and processability without thermal degradation. Target film variables, important in predicting biopackage performance under various conditions, include mechanical, thermal, barrier, and microstructural properties. Comparisons of film properties should be made with care since results depend on parameters such as film-forming materials, film formulation, fabrication method, operating conditions, testing equipment, and testing conditions. Film applications include their use as wraps, pouches, bags, casings, and sachets to protect foods, reduce waste, and improve package recyclability. PMID:18298745

  9. Thermochromic Materials Research For Optical Switching Films

    NASA Astrophysics Data System (ADS)

    Jorgenson, G. V.; Lee, J. C.

    1985-12-01

    A dual-ion-beam-sputtering (DIBS) deposition system is used to deposit doped vanadium dioxide (V1-xMx02), where M is a dopant that decreases the transition temperature (Tt) from that of stoichiometric V02. The objective is to synthesize a material that will passively switch between a heat- transmitting-and a heat-reflecting-state at specific design temperatures. The technique is reactive ion beam sputtering of vanadium and a dopant (separate beams) in a well controlled atmosphere of Ar with a partial pressure of O2. The films are deposited at elevated temperature (>700K) onto glass and sapphire substrates for spectrophotometric evaluation above and below Tt. The longer range goals of this research are to develop the material for: (1) thin film application to building glazings and (2) pigments for opaque wall coatings. The glazings will transmit and the walls will absorb solar energy when the V1-xMxO2 temperature (T) is low (TTt, both glazings and walls will reflect the solar infrared.

  10. Extraterrestrial materials processing and construction

    NASA Technical Reports Server (NTRS)

    Criswell, D. R.

    1978-01-01

    Applications of available terrestrial skills to the gathering of lunar materials and the processing of raw lunar materials into industrial feed stock were investigated. The literature on lunar soils and rocks was reviewed and the chemical processes by which major oxides and chemical elements can be extracted were identified. The gathering of lunar soil by means of excavation equipment was studied in terms of terrestrial experience with strip mining operations on earth. The application of electrostatic benefication techniques was examined for use on the moon to minimize the quantity of materials requiring surface transport and to optimize the stream of raw materials to be transported off the moon for subsequent industrial use.

  11. Discrete component bonding and thick film materials study

    NASA Technical Reports Server (NTRS)

    Kinser, D. L.

    1975-01-01

    The results are summarized of an investigation of discrete component bonding reliability and a fundamental study of new thick film resistor materials. The component bonding study examined several types of solder bonded components with some processing variable studies to determine their influence upon bonding reliability. The bonding reliability was assessed using the thermal cycle: 15 minutes at room temperature, 15 minutes at +125 C 15 minutes at room temperature, and 15 minutes at -55 C. The thick film resistor materials examined were of the transition metal oxide-phosphate glass family with several elemental metal additions of the same transition metal. These studies were conducted by preparing a paste of the subject composition, printing, drying, and firing using both air and reducing atmospheres. The resulting resistors were examined for adherence, resistance, thermal coefficient of resistance, and voltage coefficient of resistance.

  12. Process for manufacture of thick film hydrogen sensors

    DOEpatents

    Perdieu, Louisa H.

    2000-09-09

    A thick film process for producing hydrogen sensors capable of sensing down to a one percent concentration of hydrogen in carrier gasses such as argon, nitrogen, and air. The sensor is also suitable to detect hydrogen gas while immersed in transformer oil. The sensor includes a palladium resistance network thick film printed on a substrate, a portion of which network is coated with a protective hydrogen barrier. The process utilizes a sequence of printing of the requisite materials on a non-conductive substrate with firing temperatures at each step which are less than or equal to the temperature at the previous step.

  13. Processing dependent thermal conductivity of nanoporous silica xerogel films

    NASA Astrophysics Data System (ADS)

    Jain, Anurag; Rogojevic, Svetlana; Ponoth, Shom; Gill, William N.; Plawsky, Joel L.; Simonyi, Eva; Chen, Shyng-Tsong; Ho, P. S.

    2002-03-01

    Sintered xerogel films (porous SiO2) show a much higher thermal conductivity than other low dielectric constant (low-K) materials available for the same value of K. The thermal conductivity of xerogels which we have processed using different methods is compared with that of other low-K materials such as silica hybrid (silsesquioxanes) and polymeric low-K materials. The methods used were: (1) single solvent (ethanol) method, (2) binary solvent (mixture of ethanol and ethylene glycol) method, (3) sintering. For the xerogel films, we show that process history is as important as the chemistry of the solid matrix or the porosity in determining the thermal conductivity. The thermal conductivity, measured by the 3-ω method or the photothermal deflection method, is affected by phonon scattering, which in turn is effected by the size and distribution of pores and particles and the presence of imperfections such as interfaces, substituted chemical species, impurities, microcracks, and microporosity. The thermal conductivity extrapolated to zero porosity for porous sintered xerogel films approaches that of thermally grown SiO2 indicating the least phonon scattering of all processing methods. For these films, the elastic modulus is proportional to thermal conductivity squared, in agreement with theories developed for materials with few defects and a connected matrix.

  14. Support Assembly for Composite Laminate Materials During Roll Press Processing

    NASA Technical Reports Server (NTRS)

    Catella, Luke A.

    2011-01-01

    A composite laminate material is supported during the roll press processing thereof by an assembly having: first and second perforated films disposed adjacent to first and second opposing surfaces of a mixture of uncured resin and fibers defining the composite laminate material, a gas permeable encasement surrounding the mixture and the first and second films, a gas impervious envelope sealed about the gas permeable encasement, and first and second rigid plates clamped about the gas impervious envelope.

  15. Processes for treating cellulosic material

    NASA Technical Reports Server (NTRS)

    Ladisch, Michael R. (Inventor); Kohlman, Karen L. (Inventor); Westgate, Paul L. (Inventor); Weil, Joseph R. (Inventor); Yang, Yiqi (Inventor)

    1998-01-01

    Disclosed are processes for pretreating cellulosic materials in liquid water by heating the materials in liquid water at a temperature at or above their glass transition temperature but not substantially exceeding 220.degree. C., while maintaining the pH of the reaction medium in a range that avoids substantial autohydrolysis of the cellulosic materials. Such pretreatments minimize chemical changes to the cellulose while leading to physical changes which substantially increase susceptibility to hydrolysis in the presence of cellulase.

  16. Laser Material Processing in Manufacturing

    NASA Astrophysics Data System (ADS)

    Jones, Marshall

    2014-03-01

    This presentation will address some of the past, present, and potential uses of lasers for material processing in manufacturing. Laser processing includes welding, drilling, cutting, cladding, etc. The U.S. was the hot bed for initial uses of lasers for material processing in the past with Europe, especially Germany, presently leading the way. The future laser processing leader may still be Germany. Selected uses, past and present, of lasers within GE will also be highlighted as seen in such business units as Aviation, Lighting, Power and Water, Healthcare, and Transportation.

  17. Energy Implications of Materials Processing

    ERIC Educational Resources Information Center

    Hayes, Earl T.

    1976-01-01

    Processing of materials could become energy-limited rather than resource-limited. Methods to extract metals, industrial minerals, and energy materials and convert them to useful states requires more than one-fifth of the United States energy budget. Energy accounting by industries must include a total systems analysis of costs to insure net energy…

  18. Microstructural processes in irradiated materials

    NASA Astrophysics Data System (ADS)

    Byun, Thak Sang; Morgan, Dane; Jiao, Zhijie; Almer, Jonathan; Brown, Donald

    2016-04-01

    These proceedings contain the papers presented at two symposia, the Microstructural Processes in Irradiated Materials (MPIM) and Characterization of Nuclear Reactor Materials and Components with Neutron and Synchrotron Radiation, held in the TMS 2015, 144th Annual Meeting & Exhibition at Walt Disney World, Orlando, Florida, USA on March 15-19, 2015.

  19. Nonlinear Optical Image Processing with Bacteriorhodopsin Films

    NASA Technical Reports Server (NTRS)

    Downie, John D.; Deiss, Ron (Technical Monitor)

    1994-01-01

    The transmission properties of some bacteriorhodopsin film spatial light modulators are uniquely suited to allow nonlinear optical image processing operations to be applied to images with multiplicative noise characteristics. A logarithmic amplitude transmission feature of the film permits the conversion of multiplicative noise to additive noise, which may then be linearly filtered out in the Fourier plane of the transformed image. The bacteriorhodopsin film displays the logarithmic amplitude response for write beam intensities spanning a dynamic range greater than 2.0 orders of magnitude. We present experimental results demonstrating the principle and capability for several different image and noise situations, including deterministic noise and speckle. Using the bacteriorhodopsin film, we successfully filter out image noise from the transformed image that cannot be removed from the original image.

  20. Novel solutions for thin film layer deposition for organic materials

    NASA Astrophysics Data System (ADS)

    Keiper, Dietmar; Long, Michael; Schwambera, Markus; Gersdorff, Markus; Kreis, Juergen; Heuken, Michael

    2011-03-01

    Innovative systems for carrier-gas enhanced vapor phase deposition of organic layers offer advanced methods for the precise deposition of complex thin-film layer stacks. The approach inherently avoids potential short-comings from solvent-based polymer deposition and offers new opportunities. The process operates at low pressure (thus avoiding complex vacuum setups), and, by employing AIXTRON's extensive experience in freely scalable solutions, can be adapted to virtually any production process and allows for R&D and production systems alike. Deposition of organic layers and stacks recommends the approach for a wide range of organic small molecule and polymer materials (including layers with gradual change of the composition), for conductive layers, for dielectric layers, for barrier systems, for OLED materials, and surface treatments such as oleophobic / hydrophobic coatings. With the combination of other vapor phase deposition solutions, hybrid systems combining organic and inorganic materials and other advanced stacks can be realized.

  1. Thin film resistive materials: past, present and future

    NASA Astrophysics Data System (ADS)

    Cherian Lukose, C.; Zoppi, G.; Birkett, M.

    2016-01-01

    This paper explores the key developments in thin film resistive materials for use in the fabrication of discrete precision resistors. Firstly an introduction to the preparation of thin films and their fundamental properties is given with respect to well established systems such as NiCr, TaN and CrSiO. The effect of doping these systems in both solid and gaseous forms to further refine their structural and electrical properties is then discussed before the performance of more recent materials systems such as CuAlMo and MmAgCuN are reviewed. In addition to performance of the materials themselves, the effect of varying processing parameters such as deposition pressure and temperature and subsequent annealing environment, as well as laser trimming energy and geometry are also studied. It is shown how these parameters can be systematically controlled to produce films of the required properties for varying applications such as high precision, long term stability and high power pulse performance.

  2. A superior process for forming titanium hydrogen isotopic films

    NASA Technical Reports Server (NTRS)

    Steinberg, R.; Alger, D. L.; Cooper, D. W.

    1975-01-01

    Process forms stoichiometric, continuous, strongly bonded titanium hydrogen isotopic films. Films have thermal and electrical conductivities approximately the same as bulk pure titanium, ten times greater than those of usual thin films.

  3. Hyperthermal neutral beam sources for material processing (invited)

    SciTech Connect

    Yoo, S. J.; Kim, D. C.; Joung, M.; Kim, J. S.; Lee, B. J.; Oh, K. S.; Kim, K. U.; Kim, Y. H.; Kim, Y. W.; Choi, S. W.; Son, H. J.; Park, Y. C.; Jang, J.-N.; Hong, M. P.

    2008-02-15

    Hyperthermal neutral beams have a great potential for material processes, especially for etching and thin film deposition for semiconductor and display fabrication as well as deposition for various thin film applications. Plasma-induced damage during plasma etching is a serious problem for manufacturing deep submicron semiconductor devices and is expected to be a problem for future nanoscale devices. Thermal and plasma-induced damage is also problematic for thin film depositions such as transparent conductive oxide films on organic light emitting diodes or flexible displays due to high temperature processes in plasma environments. These problems can be overcome by damage-free and low-temperature processes with hyperthermal neutral beams. We will present the status of the hyperthermal neutral beam development and the applications, especially, in semiconductor and display fabrication and introduce potential applications of thin film growing for optoelectronic devices such as light emitting diodes.

  4. Plasma characterization studies for materials processing

    SciTech Connect

    Pfender, E.; Heberlein, J.

    1995-12-31

    New applications for plasma processing of materials require a more detailed understanding of the fundamental processes occurring in the processing reactors. We have developed reactors offering specific advantages for materials processing, and we are using modeling and diagnostic techniques for the characterization of these reactors. The emphasis is in part set by the interest shown by industry pursuing specific plasma processing applications. In this paper we report on the modeling of radio frequency plasma reactors for use in materials synthesis, and on the characterization of the high rate diamond deposition process using liquid precursors. In the radio frequency plasma torch model, the influence of specific design changes such as the location of the excitation coil on the enthalpy flow distribution is investigated for oxygen and air as plasma gases. The diamond deposition with liquid precursors has identified the efficient mass transport in form of liquid droplets into the boundary layer as responsible for high growth, and the chemical properties of the liquid for the film morphology.

  5. New materials and new processes. Volume 3. 1985

    SciTech Connect

    Not Available

    1985-01-01

    New materials and processes in electronic surface and electrochemical technologies are discussed. Among the specific technologies considered are: organic electronic materials; polyoxymethane whiskers; and thin film SAW devices. Consideration is also given to: multipurpose corrosion inhibitors for naval aerospace applications; methods of improving lead-acid battery performance; graphite intercalation compounds; and molybdenum metal coatings. Addditional topics discussed include: electrolytic processes; sensors; and biomedical materials.

  6. Color infrared film as a negative material

    USGS Publications Warehouse

    Pease, Robert W.

    1970-01-01

    Original problems encountered in endeavors to use color infraredfilm as a negative material have been overcome by a simple modification in processing. This makes more feasible the production of infrared color prints for field use and yields an infrared counterpart to Aero-Neg.

  7. Boundary film for structural ceramic materials

    SciTech Connect

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

    1992-05-01

    Structural ceramic materials, like metals, will require lubrication if they are to be used extensively for tribological applications. The use of thin soft metallic coatings (specifically Ag) as a boundary film during mineral oil lubrication of silicon nitride (Si{sub 3}N{sub 4}) and zirconia (ZrO{sub 2}) ceramic materials was investigated in this study. With a pin-on-flat contact configuration in reciprocating sliding, the steady friction coefficient was reduced by a factor of 2 (0.14 {minus}0.16 vs. 0.06--0.07) when the flats were coated with Ag. Also, with Ag coatings the wear of pins was reduced to an unmeasurable level, whereas, in the absence of Ag coatings specific wear rates of {approx}2 {times} 10{sup {minus}9} -- 4 {times} 10{sup {minus}8} mm{sup 3}/Nm and {approx}7 {times} 10{sup {minus}8} -- 2 {times} 10{sup {minus}7} mm{sup 3}/Nm were measured for Si{sub 3}N{sub 4} and ZrO{sub 2} pins respectively. In addition to preventing direct contact between pins and flats, thereby reducing wear, the Ag coatings also act as a solid lubricant, help dissipate flash heating, and accelerate modification of the {lambda} ratio.

  8. Boundary film for structural ceramic materials

    SciTech Connect

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

    1992-05-01

    Structural ceramic materials, like metals, will require lubrication if they are to be used extensively for tribological applications. The use of thin soft metallic coatings (specifically Ag) as a boundary film during mineral oil lubrication of silicon nitride (Si[sub 3]N[sub 4]) and zirconia (ZrO[sub 2]) ceramic materials was investigated in this study. With a pin-on-flat contact configuration in reciprocating sliding, the steady friction coefficient was reduced by a factor of 2 (0.14 [minus]0.16 vs. 0.06--0.07) when the flats were coated with Ag. Also, with Ag coatings the wear of pins was reduced to an unmeasurable level, whereas, in the absence of Ag coatings specific wear rates of [approx]2 [times] 10[sup [minus]9] -- 4 [times] 10[sup [minus]8] mm[sup 3]/Nm and [approx]7 [times] 10[sup [minus]8] -- 2 [times] 10[sup [minus]7] mm[sup 3]/Nm were measured for Si[sub 3]N[sub 4] and ZrO[sub 2] pins respectively. In addition to preventing direct contact between pins and flats, thereby reducing wear, the Ag coatings also act as a solid lubricant, help dissipate flash heating, and accelerate modification of the [lambda] ratio.

  9. Processing of materials for uniform field emission

    DOEpatents

    Pam, Lawrence S.; Felter, Thomas E.; Talin, Alec; Ohlberg, Douglas; Fox, Ciaran; Han, Sung

    1999-01-01

    This method produces a field emitter material having a uniform electron emitting surface and a low turn-on voltage. Field emitter materials having uniform electron emitting surfaces as large as 1 square meter and turn-on voltages as low as 16V/.mu.m can be produced from films of electron emitting materials such as polycrystalline diamond, diamond-like carbon, graphite and amorphous carbon by the method of the present invention. The process involves conditioning the surface of a field emitter material by applying an electric field to the surface, preferably by scanning the surface of the field emitter material with an electrode maintained at a fixed distance of at least 3 .mu.m above the surface of the field emitter material and at a voltage of at least 500V. In order to enhance the uniformity of electron emission the step of conditioning can be preceeded by ion implanting carbon, nitrogen, argon, oxygen or hydrogen into the surface layers of the field emitter material.

  10. Processing of materials for uniform field emission

    DOEpatents

    Pam, L.S.; Felter, T.E.; Talin, A.; Ohlberg, D.; Fox, C.; Han, S.

    1999-01-12

    This method produces a field emitter material having a uniform electron emitting surface and a low turn-on voltage. Field emitter materials having uniform electron emitting surfaces as large as 1 square meter and turn-on voltages as low as 16V/{micro}m can be produced from films of electron emitting materials such as polycrystalline diamond, diamond-like carbon, graphite and amorphous carbon by the method of the present invention. The process involves conditioning the surface of a field emitter material by applying an electric field to the surface, preferably by scanning the surface of the field emitter material with an electrode maintained at a fixed distance of at least 3 {micro}m above the surface of the field emitter material and at a voltage of at least 500V. In order to enhance the uniformity of electron emission the step of conditioning can be preceded by ion implanting carbon, nitrogen, argon, oxygen or hydrogen into the surface layers of the field emitter material. 2 figs.

  11. Heat for film processing from solar energy

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Report describes solar water heating system for laboratory in Mill Valley, California. System furnishes 59 percent of hot water requirements for photographic film processing. Text of report discusses system problems and modifications, analyzes performance and economics, and supplies drawings and operation/maintenance manual.

  12. The materials processing sciences glovebox

    NASA Technical Reports Server (NTRS)

    Traweek, Larry

    1990-01-01

    The Materials Processing Sciences Glovebox is a rack mounted workstation which allows on orbit sample preparation and characterization of specimens from various experiment facilities. It provides an isolated safe, clean, and sterile environment for the crew member to work with potentially hazardous materials. It has to handle a range of chemicals broader than even PMMS. The theme is that the Space Station Laboratory experiment preparation and characterization operations provide the fundamental glovebox design characteristics. Glovebox subsystem concepts and how internal material handling operations affect the design are discussed.

  13. Acoustic Techniques for Thin Film Thickness Measurement in Semiconductor Processing

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Sanjay

    In modern semiconductor manufacturing, process monitoring and control are important issues limited at the present time by a lack of sensors and instrumentation capable of measuring process parameters like film thickness. In order to address this problem, two novel systems for thin film thickness measurement in semiconductor processing based upon contacting acoustic techniques have been developed. Both of these systems couple acoustic energy into the wafer via a nondestructive Hertzian contact and achieve high resolution by exciting and receiving ultrasonic signals from a ZnO transducer with microwave frequency electronics. The basic physical mechanism for film thickness determination is to analyze reflected waves due to acoustic impedance mismatches between various material layers on a silicon substrate. The first system requires frontside contacting of a sapphire buffer rod to an opaque film deposited on a silicon wafer and involves the use of broadband, high frequency pulse-echo electronics in the 0.5-5 GHz range. With this system, ex-situ measurements of aluminum and gold thin films on a silicon substrate have been done in the 0.25-2.5 mum. range with 3-6% accuracy as compared to surface profilometer measurements. Possible applications for this system include using it as a post -deposition process monitor, generating film thickness contour maps, or examining multilayer structures. The second system requires backside contacting of a sapphire buffer rod to a silicon wafer, which is in a vacuum station, and involves monitoring the changes in phase of CW 1-2 GHz acoustic waves as a function of frontside film growth. Using this technique, in-situ indium and aluminum film thickness monitoring has been done in both evaporator and sputtering environments with a resolution of 40 A. Temperature experiments in an oven have shown a resolution of 0.05 K for the sapphire buffer rod. Finally, multistep processing has been done and a multilayer film structure has been measured

  14. Residual stresses in material processing

    SciTech Connect

    Kozaczek, K.J.; Watkins, T.R.; Hubbard, C.R.; Wang, Xun-Li; Spooner, S.

    1994-09-01

    Material manufacturing processes often introduce residual stresses into the product. The residual stresses affect the properties of the material and often are detrimental. Therefore, the distribution and magnitude of residual stresses in the final product are usually an important factor in manufacturing process optimization or component life prediction. The present paper briefly discusses the causes of residual stresses. It then adresses the direct, nondestructive methods of residual stress measurement by X-ray and neutron diffraction. Examples are presented to demonstrate the importance of residual stress measurement in machining and joining operations.

  15. Microwave processing of polymide thin films for electronics

    SciTech Connect

    Lewis, D.A.; LaMaire, S.J.; Viehbeck, A.

    1995-12-31

    Microwave energy was utilized to quickly and efficiently cure polyimide thin films as interlayer dielectrics in high performance multi-chip modules. The process results in a 33% reduction in raw process time for a 4 level electrical structure (8 levels of dielectric) and an even greater reduction in the manufacturing cycle time, since single part processing reduces the effect of batching for curing cycles. As a part of the feasibility study, a test vehicle was successfully completed using microwave processing for all curing steps. Materials retained the necessary mechanical properties after microwave processing and there were no problems due to the effects of the metal wiring, either in the glass ceramic substrate or in the thin film structure.

  16. Failure processes unidirectional composite materials

    SciTech Connect

    Sundaresan, M.J.

    1988-01-01

    Failure processes in unidirectional composite materials subjected to quasi-static tensile load along the fiber direction are investigated. The emphasis in this investigation is to identify the physical processes taking place during the evolution of failure in these materials. An extensive literature review is conducted and the information relevant to the present topic is summarized. The nature of damage growth in five different commercially available composite systems are studied. In-situ scanning electron microscopy is employed for identifying the failure events taking place at the microscopic level. Acoustic emission monitoring is used for estimating the rate of damage growth on a global scale and determining the size of individual failure events. Results show the important roles of the matrix material and the interphase in determining the tensile strength of unidirectional composite materials. Several failure modes occurring at the microscopic scale are revealed for the first time. Further, the results indicate that dynamic fracture participates to a significant extent in determining the failure process in these materials. Based on the results the influence of various parameters in determining the composite strength is described.

  17. FNAS materials processing and characterization

    NASA Technical Reports Server (NTRS)

    Golben, John P.

    1991-01-01

    Research on melt-sintered high temperature superconducting materials is presented. The vibrating sample magnetometer has become a useful characterization tool for the study of high temperature superconductors. Important information regarding the superconducting properties of a sample can be obtained without actually making contact with the sample itself. A step toward microgravity processing of high temperature superconductors was taken. In the future, the samples need to be optimized prior to this processing of the sample before the specific effects of the microgravity environment can be isolated. A series of melt-sintered samples show that bulk processing of high temperature superconductors is getting better.

  18. Space processing of composite materials

    NASA Technical Reports Server (NTRS)

    Steurer, W. H.; Kaye, S.

    1975-01-01

    Materials and processes for the testing of aluminum-base fiber and particle composites, and of metal foams under extended-time low-g conditions were investigated. A wetting and dispersion technique was developed, based on the theory that under the absence of a gas phase all solids are wetted by liquids. The process is characterized by a high vacuum environment and a high temperature cycle. Successful wetting and dispersion experiments were carried out with sapphire fibers, whiskers and particles, and with fibers of silicon carbide, pyrolytic graphite and tungsten. The developed process and facilities permit the preparation of a precomposite which serves as sample material for flight experiments. Low-g processing consists then merely in the uniform redistribution of the reinforcements during a melting cycle. For the preparation of metal foams, gas generation by means of a thermally decomposing compound was found most adaptable to flight experiments. For flight experiments, the use of compacted mixture of the component materials limits low-g processing to a simple melt cycle.

  19. The materials processing research base of the Materials Processing Center

    NASA Technical Reports Server (NTRS)

    Latanision, R. M.

    1986-01-01

    An annual report of the research activities of the Materials Processing Center of the Massachusetts Institute of Technology is given. Research on dielectrophoresis in the microgravity environment, phase separation kinetics in immiscible liquids, transport properties of droplet clusters in gravity-free fields, probes and monitors for the study of solidification of molten semiconductors, fluid mechanics and mass transfer in melt crystal growth, and heat flow control and segregation in directional solidification are discussed.

  20. Materials processing in low gravity

    NASA Technical Reports Server (NTRS)

    Workman, Gary L.

    1990-01-01

    The final report of the Materials Processing in Low Gravity Program in which The University of Alabama in Huntsville designed, fabricated and performed various low gravity experiments in materials processing from November 7, 1989 through November 6, 1990 is presented. The facilities used in these short duration low gravity experiments include the Drop Tube and Drop Tower at Marshall Space Flight Center (MSFC), and the KC-135 aircraft at Ellington Field. During the performance of this contract, the utilization of these ground-based low gravity facilities for materials processing experiments have been instrumental in providing the opportunity to determine the feasibility of performing a number of experiments in the microgravity of Space, without the expense of a space-based experiment. Since the KC-135 was out for repairs during the latter part of the reporting period, a number of the KC-135 activities concentrated on repair and maintenance of the equipment that normally is flown on the aircraft. A number of periodic reports were given to the TCOR during the course of this contract, hence this final report is meant only to summarize the many activities performed and not redundantly cover materials already submitted.

  1. Oxidation processes in magneto-optic and related materials

    NASA Technical Reports Server (NTRS)

    Lee, Paul A.; Armstrong, Neal R.; Danzinger, James L.; England, Craig D.

    1992-01-01

    The surface oxidation processes of thin films of magneto-optic materials, such as the rare-earth transition metal alloys have been studied, starting in ultrahigh vacuum environments, using surface analysis techniques, as a way of modeling the oxidation processes which occur at the base of a defect in an overcoated material, at the instant of exposure to ambient environments. Materials examined have included FeTbCo alloys, as well as those same materials with low percentages of added elements, such a Ta, and their reactivities to both O2 and H2O compared with materials such as thin Fe films coated with ultrathin adlayers of Ti. The surface oxidation pathways for these materials is reviewed, and XPS data presented which indicates the type of oxides formed, and a critical region of Ta concentration which provides optimum protection.

  2. Environmentally compatible solder materials for thick film hybrid assemblies

    SciTech Connect

    Hosking, F.M.; Vianco, P.T.; Rejent, J.A.; Hernandez, C.L.

    1997-02-01

    New soldering materials and processes have been developed over the last several years to address a variety of environmental issues. One of the primary efforts by the electronics industry has involved the development of alternative solders to replace the traditional lead-containing alloys. Sandia National Laboratories is developing such alternative solder materials for printed circuit board and hybrid microcircuit (HMC) applications. This paper describes the work associated with low residue, lead-free soldering of thick film HMC`s. The response of the different materials to wetting, aging, and mechanical test conditions was investigated. Hybrid test vehicles were designed and fabricated with a variety of chip capacitors and leadless ceramic chip carriers to conduct thermal, electrical continuity, and mechanical evaluations of prototype joints. Microstructural development along the solder and thick film interface, after isothermal solid state aging over a range of elevated temperatures and times, was quantified using microanalytical techniques. Flux residues on soldered samples were stressed (temperature-humidity aged) to identify potential corrosion problems. Mechanical tests also supported the development of a solder joint lifetime prediction model. Progress of this effort is summarized.

  3. Process for buried metallization in diamond film

    NASA Astrophysics Data System (ADS)

    Lake, Max L.; Ting, Jyh-Ming; Lagounov, Alex; Tang, Chi

    1996-03-01

    The objective of this research was to investigate methods of combining chemical vapor deposition diamond growth techniques with state-of-the-art physical vapor deposition or ion beam enhanced deposition to produce buried metallization of polycrystalline diamond films. The mechanical and electrical integrity of both the insulating and conducting elements following metallization and diamond overgrowth was shown. Both methods were shown to have bonding strength sufficient to withstand tape lift-off, which is regarded to be a good indication of strength needed for die attachment and wire bonding. Diamond overgrowth was also shown, thus enabling buried metallized layers to be created. Electrical resistivity property measurements on metallized layers and between metallization separated by diamond films were shown to be sufficient to allow the use of diamond as an insulating inter-layer material for multi-layer circuit boards.

  4. Process for preparing energetic materials

    DOEpatents

    Simpson, Randall L.; Lee, Ronald S.; Tillotson, Thomas M.; Swansiger, Rosalind W.; Fox, Glenn A.

    2011-12-13

    Sol-gel chemistry is used for the preparation of energetic materials (explosives, propellants and pyrotechnics) with improved homogeneity, and/or which can be cast to near-net shape, and/or made into precision molding powders. The sol-gel method is a synthetic chemical process where reactive monomers are mixed into a solution, polymerization occurs leading to a highly cross-linked three dimensional solid network resulting in a gel. The energetic materials can be incorporated during the formation of the solution or during the gel stage of the process. The composition, pore, and primary particle sizes, gel time, surface areas, and density may be tailored and controlled by the solution chemistry. The gel is then dried using supercritical extraction to produce a highly porous low density aerogel or by controlled slow evaporation to produce a xerogel. Applying stress during the extraction phase can result in high density materials. Thus, the sol-gel method can be used for precision detonator explosive manufacturing as well as producing precision explosives, propellants, and pyrotechnics, along with high power composite energetic materials.

  5. Metal containing material processing on coater/developer system

    NASA Astrophysics Data System (ADS)

    Kawakami, Shinichiro; Mizunoura, Hiroshi; Matsunaga, Koichi; Hontake, Koichi; Nakamura, Hiroshi; Shimura, Satoru; Enomoto, Masashi

    2016-03-01

    Challenges of processing metal containing materials need to be addressed in order apply this technology to Behavior of metal containing materials on coater/developer processing including coating process, developer process and tool metal contamination is studied using CLEAN TRACKTM LITHIUS ProTM Z (Tokyo Electron Limited). Through this work, coating uniformity and coating film defectivity were studied. Metal containing material performance was comparable to conventional materials. Especially, new dispense system (NDS) demonstrated up to 80% reduction in coating defect for metal containing materials. As for processed wafer metal contamination, coated wafer metal contamination achieved less than 1.0E10 atoms/cm2 with 3 materials. After develop metal contamination also achieved less than 1.0E10 atoms/cm2 with 2 materials. Furthermore, through the metal defect study, metal residues and metal contamination were reduced by developer rinse optimization.

  6. 27 CFR 18.51 - Processing material.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Processing material. 18.51... material. (a) General. A proprietor may produce processing material or receive processing material produced elsewhere. Fermented processing material may not be used in the manufacture of concentrate....

  7. 27 CFR 18.51 - Processing material.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Processing material. 18.51... material. (a) General. A proprietor may produce processing material or receive processing material produced elsewhere. Fermented processing material may not be used in the manufacture of concentrate....

  8. Thermoelastic response of thin metal films and their adjacent materials

    SciTech Connect

    Kang, S.; Yoon, Y.; Kim, J.; Kim, W.

    2013-01-14

    A pulsed laser beam applied to a thin metal film is capable of launching an acoustic wave due to thermal expansion. Heat transfer from the thin metal film to adjacent materials can also induce thermal expansion; thus, the properties of these adjacent materials (as well as the thin metal film) should be considered for a complete description of the thermoelastic response. Here, we show that adjacent materials with a small specific heat and large thermal expansion coefficient can generate an enhanced acoustic wave and we demonstrate a three-fold increase in the peak pressure of the generated acoustic wave on substitution of parylene for polydimethylsiloxane.

  9. Electrodeposited polymer encapsulated nickel sulphide thin films: frequency switching material

    NASA Astrophysics Data System (ADS)

    Jana, Sumanta; Mukherjee, Nillohit; Chakraborty, Biswajit; Mitra, Bibhas Chandra; Mondal, Anup

    2014-05-01

    Polyvinylpyrrolidone (PVP) encapsulated nickel sulfide (NiS) thin films have been synthesized electrochemically from aqueous solution of hydrated nickel chloride (NiCl2, 6H2O), thioacetamide (CH3C(S) NH2) (TAA) and polyvinylpyrrolidone (PVP). Surface modification of nickel sulfide (NiS) thin films was achieved by this polymer encapsulation. X-ray diffraction (XRD), high resolution transmission electron microscope (HRTEM), field emission scanning electron microscopy (FESEM) and Energy dispersive X-radiation (EDAX) techniques were used for the characterization of thin films. Infrared spectroscopy (IR) confirmed the formation of polymer encapsulated semiconductor. Frequency switching generation study shows that the encapsulated material could be used as a frequency switching device that generates a frequency ∼ 50 Hz under 1 Sun illumination. Encapsulation with PVP causes surface modification that reduces the surface states and barrier height. As a result, the width of the depletion region decreases. So the number of electron-hole pairs increases. Consequently, the number of excitons and exciton related emission increases and this leads to reduction of recombination process and shows photo induced frequency switching phenomenon.

  10. High throughput growth and characterization of thin film materials

    NASA Astrophysics Data System (ADS)

    Mao, Samuel S.

    2013-09-01

    It usually takes more than 10 years for a new material from initial research to its first commercial application. Therefore, accelerating the pace of discovery of new materials is critical to tackling challenges in areas ranging from clean energy to national security. As discovery of new materials has not kept pace with the product design cycles in many sectors of industry, there is a pressing need to develop and utilize high throughput screening and discovery technologies for the growth and characterization of new materials. This article presents two distinctive types of high throughput thin film material growth approaches, along with a number of high throughput characterization techniques, established in the author's group. These approaches include a second-generation "discrete" combinatorial semiconductor discovery technology that enables the creation of arrays of individually separated thin film semiconductor materials of different compositions, and a "continuous" high throughput thin film material screening technology that enables the realization of ternary alloy libraries with continuously varying elemental ratios.

  11. Thermal plasma processing of materials

    SciTech Connect

    Pfender, E.; Heberlein, J.

    1992-02-01

    Emphasis has been on plasma synthesis of fine powders, plasma Chemical Vapor Deposition (CVD), on related diagnostics, and on modeling work. Since plasma synthesis as well as plasma CVD make frequent use of plasma jets, the beginning has been devoted of plasma jets and behavior of particulates injected into such plasma jets. Although most of the construction of the Triple-Torch Plasma Reactor (TTPR) has already been done, modifications have been made in particular modifications required for plasma CVD of diamond. A new reactor designed for Counter-Flow Liquid Injection Plasma Synthesis (CFLIPS) proved to be an excellent tool for synthesis of fine powders as well as for plasma CVD. An attempt was made to model flow and temperature fields in this reactor. Substantial efforts were made to single out those parameters which govern particle size, size distribution, and powder quality in our plasma synthesis experiments. This knowledge is crucial for controlling the process and for meaningful diagnostics and modeling work. Plasma CVD of diamond films using both reactors has been very successful and we have been approached by a number of companies interested in using this technology for coating of tools.

  12. Process for making dense thin films

    DOEpatents

    Jacobson, Craig P.; Visco, Steven J.; DeJonghe, Lutgard C.

    2005-07-26

    Provided are low-cost, mechanically strong, highly electronically conductive porous substrates and associated structures for solid-state electrochemical devices, techniques for forming these structures, and devices incorporating the structures. The invention provides solid state electrochemical device substrates of novel composition and techniques for forming thin electrode/membrane/electrolyte coatings on the novel or more conventional substrates. In particular, in one embodiment the invention provides techniques for firing of device substrate to form densified electrolyte/membrane films 5 to 20 microns thick. In another embodiment, densified electrolyte/membrane films 5 to 20 microns thick may be formed on a pre-sintered substrate by a constrained sintering process. In some cases, the substrate may be a porous metal, alloy, or non-nickel cermet incorporating one or more of the transition metals Cr, Fe, Cu and Ag, or alloys thereof.

  13. Solution processed silver sulfide thin films for filament memory applications

    NASA Astrophysics Data System (ADS)

    Yin, Shong

    Filament Memories based on resistive switching have been attracting attention in recent years as a potential replacement for flash memory in CMOS technology and as a potential candidate memory for low-cost, large-area electronics. These memories operate at low voltages with fast switching speeds. These devices are based on ionic conduction through an electrolyte layer and differ fundamentally in operation from conventional flash memory, which is based on the field effect transistor. To facilitate development of this technology, effects of film structure on ionic and electronic conducting properties and the filament formation processes must be studied. In this work, silver sulfide, a mixed ionic-electronic conductor, is used as a model material for studying the solution processing of filament memories, and to study the impact of film structure on conducting and switching properties. Three different solution processing methods are investigated for depositing silver sulfide: sulfidation of elemental silver films, and sintering of two types of silver sulfide nanoparticles. Effects of nanoparticle sintering conditions on electrolyte structured and mixed conducting properties are investigated by a combination of X-ray diffraction, electrical impedance spectroscopy and thermo-gravimetric analysis. Impact of forming voltage and time on filament morphology is examined to provide an overall view of the impact of electrical and material parameters on device operation.

  14. Thin films of energetic materials by physical vapor deposition: TATB and LLM-105

    NASA Astrophysics Data System (ADS)

    Williamson, David; Gymer, Sue; O'Conner, Colum; Hazelwood, Adam; Jardine, Andrew

    2015-06-01

    Thin films of energetic materials enable a diverse range of characterization measurements: structure, surface energy and adhesion, and even reactivity. Here we present a method to grow thin films by a physical vapor deposition method (sublimation) using a dedicated instrument which can operate at ultra-high vacuum. The approach enables fabrication of thin films of energetic materials that are otherwise difficult to process by traditional methods, for example because of their low solubility. The intention is to use this instrument as a platform for studying pure materials and co-deposited materials grown either as multi-layers or as co-crystals. Examples of TATB and LLM-105 film morphologies grown using this technique are presented.

  15. Computational Material Processing in Microgravity

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Working with Professor David Matthiesen at Case Western Reserve University (CWRU) a computer model of the DPIMS (Diffusion Processes in Molten Semiconductors) space experiment was developed that is able to predict the thermal field, flow field and concentration profile within a molten germanium capillary under both ground-based and microgravity conditions as illustrated. These models are coupled with a novel nonlinear statistical methodology for estimating the diffusion coefficient from measured concentration values after a given time that yields a more accurate estimate than traditional methods. This code was integrated into a web-based application that has become a standard tool used by engineers in the Materials Science Department at CWRU.

  16. Thick film laser induced forward transfer for deposition of thermally and mechanically sensitive materials

    SciTech Connect

    Kattamis, Nicholas T.; Purnick, Priscilla E.; Weiss, Ron; Arnold, Craig B.

    2007-10-22

    Laser forward transfer processes incorporating thin absorbing films can be used to deposit robust organic and inorganic materials but the deposition of more delicate materials has remained elusive due to contamination and stress induced during the transfer process. Here, we present the approach to high resolution patterning of sensitive materials by incorporating a thick film polymer absorbing layer that is able to dissipate shock energy through mechanical deformation. Multiple mechanisms for transfer as a function of incident laser energy are observed and we show viable and contamination-free deposition of living mammalian embryonic stem cells.

  17. Thick film laser induced forward transfer for deposition of thermally and mechanically sensitive materials

    NASA Astrophysics Data System (ADS)

    Kattamis, Nicholas T.; Purnick, Priscilla E.; Weiss, Ron; Arnold, Craig B.

    2007-10-01

    Laser forward transfer processes incorporating thin absorbing films can be used to deposit robust organic and inorganic materials but the deposition of more delicate materials has remained elusive due to contamination and stress induced during the transfer process. Here, we present the approach to high resolution patterning of sensitive materials by incorporating a thick film polymer absorbing layer that is able to dissipate shock energy through mechanical deformation. Multiple mechanisms for transfer as a function of incident laser energy are observed and we show viable and contamination-free deposition of living mammalian embryonic stem cells.

  18. Reaction-Diffusion Processes in Ultrathin Films of Photoresist

    NASA Astrophysics Data System (ADS)

    Perera, Ginusha; Stein, Gila

    2011-03-01

    Projection lithography is the primary technology used for patterning semiconductor devices. High-throughput manufacturing requires imaging materials (resists) that are highly sensitive to radiation, and this demand is satisfied through a process termed chemical amplification (CA). CA resists are comprised of a polymer resin (reactant) and photoacid generator (catalyst); a coupled reaction-diffusion mechanism drives image formation, where image resolution is limited by slow diffusion of the acid catalyst. There is evidence that thin film reaction rates deviate from the bulk behavior, and current models for image formation do not capture such effects. We demonstrate that X-Ray Diffraction can measure spatial extent-of-reaction in ultrathin films of a nanopatterned poly(4-hydroxystyrene-co-tertbutylacrylate) CA resist. The feedback acquired is used to construct predictive models for the coupled reaction-diffusion processes that incorporate the physics of confined polymers. Funded by NSF ECCS 0927147.

  19. Liquid-Phase Processing of Barium Titanate Thin Films

    NASA Astrophysics Data System (ADS)

    Harris, David Thomas

    Processing of thin films introduces strict limits on the thermal budget due to substrate stability and thermal expansion mismatch stresses. Barium titanate serves as a model system for the difficulty in producing high quality thin films because of sensitivity to stress, scale, and crystal quality. Thermal budget restriction leads to reduced crystal quality, density, and grain growth, depressing ferroelectric and nonlinear dielectric properties. Processing of barium titanate is typically performed at temperatures hundreds of degrees above compatibility with metalized substrates. In particular integration with silicon and other low thermal expansion substrates is desirable for reductions in costs and wider availability of technologies. In bulk metal and ceramic systems, sintering behavior has been encouraged by the addition of a liquid forming second phase, improving kinetics and promoting densification and grain growth at lower temperatures. This approach is also widespread in the multilayer ceramic capacitor industry. However only limited exploration of flux processing with refractory thin films has been performed despite offering improved dielectric properties for barium titanate films at lower temperatures. This dissertation explores physical vapor deposition of barium titanate thin films with addition of liquid forming fluxes. Flux systems studied include BaO-B2O3, Bi2O3-BaB2O 4, BaO-V2O5, CuO-BaO-B2O3, and BaO-B2O3 modified by Al, Si, V, and Li. Additions of BaO-B2O3 leads to densification and an increase in average grain size from 50 nm to over 300 nm after annealing at 900 °C. The ability to tune permittivity of the material improved from 20% to 70%. Development of high quality films enables engineering of ferroelectric phase stability using residual thermal expansion mismatch in polycrystalline films. The observed shifts to TC match thermodynamic calculations, expected strain from the thermal expansion coefficients, as well as x-ray diffract measurements

  20. Processes and Materials for Organic Photovoltaics

    NASA Astrophysics Data System (ADS)

    Cox, Marshall

    The field of organic photovoltaics is driven by the desire for better and cheaper solar cells. While showing much promise, current generations of organic photovoltaic (OPV) devices do not exhibit properties that are suited for wide scale commercialization. While much research has been dedicated towards this goal, more yet needs to be done before it can be clear whether this is an achievable goal. This thesis describes new materials investigations for higher efficiency better stability organic photovoltaics, as well as new processes that broaden the application and fabrication space for these devices. The application of electro-polymerization, a deposition process, towards organic thin-film fabrication is discussed. This novel process for OPVs is followed by an analysis of new and interesting materials for OPV devices, including a higher efficiency hole-transporting material, and two hole-transporting molecules that exhibit self-assembly during OPV fabrication. The results of these investigations indicate the possibility for increased fabrication freedom and control, molecular species design that could allow higher efficiency devices, as well as indications of the role that molecular interactions in OPV heterojunctions play. In addition, the possibilities of integrating graphene, the two-dimensional form of carbon, into OPV architectures is discussed. A new process for graphene transfer that allows the integration of graphene into chemically and physically more fragile systems including those composed of small molecule semiconductors is described and experimentally verified. Graphene is then integrated as a cathode in OPVs, and a modeling and experimental investigation is performed to evaluate the potential for integrating graphene as a recombination layer in tandem OPVs. Based on this investigation, the integration of graphene into tandem OPVs could enable higher efficiency devices and significantly broadened architectural freedom for tandem fabrication.

  1. Solution processed chalcogenide films and micro-patterns via self-assembly

    NASA Astrophysics Data System (ADS)

    Singh, Radhakant; Sachan, Priyanka; Dwivedi, Prabhat K.; Sharma, Ashutosh

    2016-05-01

    Chalcogenide (ChG) are the choice materials for IR applications due to their high refractive index, mid IR transparency and high nonlinear optical properties. In this work, we study the characteristics of solution processed Chalcogenide films, As2S3 prepared by various amine solvents, for possible pattern fabrications. Since solution processed ChG films tend to contain solvent related defects, it is important to optimize the process parameters to create defect free films, structurally similar to bulk ChG. We have studied the physical integrity and morphology of solution processed ChG films as a function of annealing conditions and film thickness. Optical and morphological characterizations of these films are carried out in order to fabricate defect free, optically useful micro-structures.

  2. X-ray photoelectron spectroscopy study of the nucleation processes and chemistry of CdS thin films deposited by sublimation on different solar cell substrate materials

    SciTech Connect

    Espinos, J.P.; Martin-Concepcion, A.I.; Mansilla, C.; Yubero, F.; Gonzalez-Elipe, A.R.

    2006-07-15

    Cadmium sulfide has been deposited by evaporation on five different substrates: CdTe, ZnO, Ag, TiO{sub 2}, and partially reduced titanium oxide (i.e., TiO{sub 1.73}). The deposition rate and the evolution of the Cd/S ratio on the different substrates have been determined by x-ray photoelectron spectroscopy. The growth mode of the films has been also studied by analyzing the shape of the backgrounds behind the photoemission peaks (peak shape analysis). It has been found that, under completely equivalent conditions, the deposition efficiency (i.e., sticking coefficient) is large on CdTe and TiO{sub 1.73}, but very small on ZnO and TiO{sub 2}. Silver constitutes an intermediate situation characterized by a long induction period where the deposition rate is small and a later increase in deposition efficiency comparable to that on CdTe. For the initial stages of deposition, below an equivalent monolayer, it has been also found that the Cd/S ratio is smaller than unity on TiO{sub 1.73} and ZnO but larger than unity on CdTe and Ag substrates. For sufficiently long deposition times the Cd/S ratio on the surface reaches unity. Except for silver substrate, cadmium appears as Cd{sup 2+} and sulfur as S{sup -2} species at the initial stages of deposition. On the silver surface, cadmium adsorbs as Cd{sup 0} at low coverage. Peak shape analysis has shown that cadmium sulfide grows according to layer-by-layer mechanism (Frank-van de Merwe model) when the substrates are CdTe and TiO{sub 1.73}, but large particles are formed that do not cover the surface for ZnO and Ag substrates (Volmer-Weber growth model). These results are consistent with the different chemical affinities of the substrate towards the atoms of cadmium and sulfur produced during the evaporation of the cadmium sulfide.

  3. Laser processing of thin films for industrial packaging

    NASA Astrophysics Data System (ADS)

    Sozzi, Michele; Lutey, Adrian H. A.; Cucinotta, Annamaria; Selleri, Stefano; Molari, Pier Gabriele

    2014-05-01

    Single layer thin-film materials such as aluminum, polyethylene, polypropylene, and their multi-layer combinations such as aluminum-paper have been exposed to different laser radiation. A wide number of samples have been processed with 10 - 12.5 ns IR and Green, and 500 - 800 ps IR laser radiation at different translating speeds ranging from 50 mm/s to 1 m/s. High quality incisions have been obtained for all tested materials within the experimental conditions. The presented results provide the necessary parameters for an efficient cut and processing of the tested materials, for the employment of pulsed laser sources in the packaging industry, allowing the laser to prevail in lieu of more costly and energy intensive methods.

  4. Scrounge data processing film products for the thematic mapper

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Information on the format of the film product and type of film used for the LANDSAT-4 scrounge processed thematic mapper data is presented. Image gray scale, annotation field, and general layout are described.

  5. Process for fabricating composite material having high thermal conductivity

    DOEpatents

    Colella, Nicholas J.; Davidson, Howard L.; Kerns, John A.; Makowiecki, Daniel M.

    2001-01-01

    A process for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost.

  6. Integrated lunar materials manufacturing process

    NASA Technical Reports Server (NTRS)

    Gibson, Michael A. (Inventor); Knudsen, Christian W. (Inventor)

    1990-01-01

    A manufacturing plant and process for production of oxygen on the moon uses lunar minerals as feed and a minimum of earth-imported, process materials. Lunar feed stocks are hydrogen-reducible minerals, ilmenite and lunar agglutinates occurring in numerous, explored locations mixed with other minerals in the pulverized surface layer of lunar soil known as regolith. Ilmenite (FeTiO.sub.3) and agglutinates contain ferrous (Fe.sup.+2) iron reducible by hydrogen to yield H.sub.2 O and metallic Fe at about 700.degree.-1,200.degree. C. The H.sub.2 O is electrolyzed in gas phase to yield H.sub.2 for recycle and O.sub.2 for storage and use. Hydrogen losses to lunar vacuum are minimized, with no net hydrogen (or any other earth-derived reagent) consumption except for small leaks. Feed minerals are surface-mined by front shovels and transported in trucks to the processing area. The machines are manned or robotic. Ilmenite and agglutinates occur mixed with silicate minerals which are not hydrogen-reducible at 700.degree.-1,200.degree. C. and consequently are separated and concentrated before feeding to the oxygen generation process. Solids rejected from the separation step and reduced solids from the oxygen process are returned to the mine area. The plant is powered by nuclear or solar power generators. Vapor-phase water electrolysis, a staged, countercurrent, fluidized bed reduction reactor and a radio-frequency-driven ceramic gas heater are used to improve thermal efficiency.

  7. Development of a Process Analytical Technology (PAT) for in-line monitoring of film thickness and mass of coating materials during a pan coating operation.

    PubMed

    Gendre, Claire; Genty, Muriel; Boiret, Mathieu; Julien, Marc; Meunier, Loïc; Lecoq, Olivier; Baron, Michel; Chaminade, Pierre; Péan, Jean Manuel

    2011-07-17

    The aim of this study was to perform in-line Near Infrared (NIR) measurements inside a pan coater to monitor a coating operation in real-time, by predicting the increases in mass of coating materials and coating thickness. A polymer combination of ethylcellulose/poly(vinyl-alcohol)-poly(ethylene-glycol) graft copolymer was used as functional aqueous coating. Coated tablets were sampled at regular intervals during the coating operation, then subjected to either simple and fast weighing (n=50) or accurate and non-destructive Terahertz Pulsed Imaging (TPI) measurements (n=3). Off-line NIR spectra analysis revealed that the coating operation could efficiently be controlled by focusing on two distinct NIR regions, related to absorption bands of ethylcellulose. Principal component analysis of in-line NIR spectra gave a clear classification of the collected coated tablets. Real-time quantitative monitoring of the coating operation was successfully performed from partial least square calibration models built using either TPI or weighing as reference method. Coating thicknesses as well as mass of coating materials used as primary values provided accurate NIR predictions. A comparison study demonstrated that both reference methods led to reliable and accurate real-time monitoring of the coating operation. This work demonstrated that in-line NIR measurements associated with multivariate analyses can be implemented to monitor in real-time a pan coating operation in order to fulfil the expectations of ICH Q8 guideline on pharmaceutical development, especially in terms of PAT control strategy and reduced end-product testing. PMID:21569842

  8. Lunar materials processing system integration

    NASA Technical Reports Server (NTRS)

    Sherwood, Brent

    1992-01-01

    The theme of this paper is that governmental resources will not permit the simultaneous development of all viable lunar materials processing (LMP) candidates. Choices will inevitably be made, based on the results of system integration trade studies comparing candidates to each other for high-leverage applications. It is in the best long-term interest of the LMP community to lead the selection process itself, quickly and practically. The paper is in five parts. The first part explains what systems integration means and why the specialized field of LMP needs this activity now. The second part defines the integration context for LMP -- by outlining potential lunar base functions, their interrelationships and constraints. The third part establishes perspective for prioritizing the development of LMP methods, by estimating realistic scope, scale, and timing of lunar operations. The fourth part describes the use of one type of analytical tool for gaining understanding of system interactions: the input/output model. A simple example solved with linear algebra is used to illustrate. The fifth and closing part identifies specific steps needed to refine the current ability to study lunar base system integration. Research specialists have a crucial role to play now in providing the data upon which this refinement process must be based.

  9. Lunar materials processing system integration

    NASA Astrophysics Data System (ADS)

    Sherwood, Brent

    1992-02-01

    The theme of this paper is that governmental resources will not permit the simultaneous development of all viable lunar materials processing (LMP) candidates. Choices will inevitably be made, based on the results of system integration trade studies comparing candidates to each other for high-leverage applications. It is in the best long-term interest of the LMP community to lead the selection process itself, quickly and practically. The paper is in five parts. The first part explains what systems integration means and why the specialized field of LMP needs this activity now. The second part defines the integration context for LMP -- by outlining potential lunar base functions, their interrelationships and constraints. The third part establishes perspective for prioritizing the development of LMP methods, by estimating realistic scope, scale, and timing of lunar operations. The fourth part describes the use of one type of analytical tool for gaining understanding of system interactions: the input/output model. A simple example solved with linear algebra is used to illustrate. The fifth and closing part identifies specific steps needed to refine the current ability to study lunar base system integration. Research specialists have a crucial role to play now in providing the data upon which this refinement process must be based.

  10. Investigation of Zerodur material processing

    NASA Astrophysics Data System (ADS)

    Johnson, R. Barry

    1993-07-01

    The Final Report of the Center for Applied Optics (CAO), of The University of Alabama (UAH) study entitled 'Investigation of Zerodur Material Processing' is presented. The objectives of the effort were to prepare glass samples by cutting, grinding, etching, and polishing block Zerodur to desired specifications using equipment located in the optical shop located in the Optical System Branch at NASA/MSFC; characterize samples for subsurface damage and surface roughness; utilize Zerodur samples for coating investigations; and perform investigations into enhanced optical fabrication and metrology techniques. The results of this investigation will be used to support the Advanced X Ray Astrophysics Facility (AXAF) program as well as other NASA/MSFC research programs. The results of the technical effort are presented and discussed.

  11. Investigation of Zerodur material processing

    NASA Technical Reports Server (NTRS)

    Johnson, R. Barry

    1993-01-01

    The Final Report of the Center for Applied Optics (CAO), of The University of Alabama (UAH) study entitled 'Investigation of Zerodur Material Processing' is presented. The objectives of the effort were to prepare glass samples by cutting, grinding, etching, and polishing block Zerodur to desired specifications using equipment located in the optical shop located in the Optical System Branch at NASA/MSFC; characterize samples for subsurface damage and surface roughness; utilize Zerodur samples for coating investigations; and perform investigations into enhanced optical fabrication and metrology techniques. The results of this investigation will be used to support the Advanced X Ray Astrophysics Facility (AXAF) program as well as other NASA/MSFC research programs. The results of the technical effort are presented and discussed.

  12. Cosolvent approach for solution-processable electronic thin films.

    PubMed

    Lin, Zhaoyang; He, Qiyuan; Yin, Anxiang; Xu, Yuxi; Wang, Chen; Ding, Mengning; Cheng, Hung-Chieh; Papandrea, Benjamin; Huang, Yu; Duan, Xiangfeng

    2015-04-28

    Low-temperature solution-processable electronic materials are of considerable interest for large-area, low-cost electronics, thermoelectrics, and photovoltaics. Using a soluble precursor and suitable solvent to formulate a semiconductor ink is essential for large-area fabrication of semiconductor thin films. To date, it has been shown that hydrazine can be used as a versatile solvent to process a wide range of inorganic semiconductors. However, hydrazine is highly toxic and not suitable for large-scale manufacturing. Here we report a binary mixed solvent of amine and thiol for effective dispersion and dissolution of a large number of inorganic semiconductors including Cu2S, Cu2Se, In2S3, In2Se3, CdS, SnSe, and others. The mixed solvent is significantly less toxic and safer than hydrazine, while at the same time offering the comparable capability of formulating diverse semiconductor ink with a concentration as high as >200 mg/mL. We further show that such ink material can be readily processed into high-performance semiconducting thin films (Cu2S and Cu2Se) with the highest room-temperature conductivity among solution-based materials. Furthermore, we show that complex semiconductor alloys with tunable band gaps, such as CuIn(S(x)Se(1-x))2 (0 ≤ x ≤ 1), can also be readily prepared by simply mixing Cu2S, Cu2Se, In2S3, and In2Se3 ink solutions in a proper ratio. Our study outlines a general strategy for the formulation of inorganic semiconductor ink for low-temperature processing of large-area electronic thin films on diverse substrates and can greatly impact diverse areas including flexible electronics, thermoelectrics, and photovoltaics. PMID:25867535

  13. Molecular solution processing of metal chalcogenide thin film solar cells

    NASA Astrophysics Data System (ADS)

    Yang, Wenbing

    The barrier to utilize solar generated electricity mainly comes from their higher cost relative to fossil fuels. However, innovations with new materials and processing techniques can potentially make cost effective photovoltaics. One such strategy is to develop solution processed photovoltaics which avoid the expensive vacuum processing required by traditional solar cells. The dissertation is mainly focused on two absorber material system for thin film solar cells: chalcopyrite CuIn(S,Se)2 (CISS) and kesterite Cu2ZnSn(S,Se) 4 organized in chronological order. Chalcopyrite CISS is a very promising material. It has been demonstrated to achieve the highest efficiency among thin film solar cells. Scaled-up industry production at present has reached the giga-watt per year level. The process however mainly relies on vacuum systems which account for a significant percentage of the manufacturing cost. In the first section of this dissertation, hydrazine based solution processed CISS has been explored. The focus of the research involves the procedures to fabricate devices from solution. The topics covered in Chapter 2 include: precursor solution synthesis with a focus on understanding the solution chemistry, CISS absorber formation from precursor, properties modification toward favorable device performance, and device structure innovation toward tandem device. For photovoltaics to have a significant impact toward meeting energy demands, the annual production capability needs to be on TW-level. On such a level, raw materials supply of rare elements (indium for CIS or tellurium for CdTe) will be the bottleneck limiting the scalability. Replacing indium with zinc and tin, earth abundant kesterite CZTS exhibits great potential to reach the goal of TW-level with no limitations on raw material availability. Chapter 3 shows pioneering work towards solution processing of CZTS film at low temperature. The solution processed devices show performances which rival vacuum

  14. Structure development of polyesters and their blends in film formation processes

    NASA Astrophysics Data System (ADS)

    Song, Kwangjin

    A fundamental study of structure development in cast, single and double bubble, and biaxial film stretching processes of polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN) and PBT/PET blends was carried out. The deformation mechanisms and physical properties of films were described in terms of various structural parameters. We established a new process technique to fabricate double bubble biaxially orientated films from rapidly crystallizing polymers. Polyesters were largely stable in various film forming processes. In film casting, the rate of crystallization tended to dominate the processability of materials. The stability of first bubble was substantially improved with an increase in molecular rigidity. In cold-drawing processes, the stability was dominated by the strain hardening behavior of materials. PBT cast and first bubble films were semicrystalline with only the alpha phase. Cold-drawn films revealed Xsb{c}'s of 20-30% and polymorphism. The polymer chains increasingly oriented into the film plane with biaxial stretching. PBT biaxial films had a maximum tensile strength of 210 MPa. Cast and first bubble films of PET were largely amorphous. PET films stretched in a rubbery state possessed Xsb{c}'s of 20-35%. PET films exhibited (100) planar orientation with crystallites oriented either to the drawing direction or in the plane of the film. A maximum tensile strength of 400 MPa was obtained. Twin screw melt extruded PBT/PET blends exhibited equilibrium melting point depression. The interaction parameters (chisb{12}) were determined to be negative and composition dependent, ranging from -0.75 to -0.55 at 285sp°C. Cast and first bubble films of PBT/PET blends exhibited decreased Xsb{c} with rising PET content. Cold-drawn blend films possessed a Xsb{c}'s of 20-45%. The orientation in the PBT phase decreased with increasing PET content while that in the PET phase increased. The mechanical properties of the films

  15. Fundamentals of polycrystalline thin film materials and devices

    NASA Astrophysics Data System (ADS)

    Baron, Bill N.; Birkmire, Robert W.; Phillips, James E.; Shafarman, William N.; Hegedus, Steven S.; McCandless, Brian E.

    1991-01-01

    This report presents the results of a one-year research program on polycrystalline thin-film solar cells. The research was conducted to better understand the limitations and potential of solar cells using CuInSe2 and CdTe by systematically investigating the fundamental relationships linking material processing, material properties, and device behavior. By selenizing Cu and In layers, we fabricated device-quality CuInSe2 thin films and demonstrated a CuInSe2 solar cell with 7 percent efficiency. We added Ga, to increase the band gap of CuInSe2 devices to increase the open-circuit voltage to 0.55 V. We fabricated and analyzed CuInGaSe2/CuInSe2 devices to demonstrate the potential for combining the benefits of higher V(sub oc) while retaining the current-generating capacity of CuInSe2. We fabricated an innovative superstrate device design with more than 5 percent efficiency, as well as a bifacial spectral-response technique for determining the electron diffusion length and optical absorption coefficient of CuInSe2 in an operational cell. The diffusion length was found to be greater than 1 micron. We qualitatively modeled the effect of reducing heat treatments in hydrogen and oxidizing treatments in air on the I-V behavior of CuInSe2 devices. We also investigated post-deposition heat treatments and chemical processing and used them to fabricate a 9.6 percent-efficient CdTe/CdS solar cell using physical vapor deposition.

  16. Fundamentals of polycrystalline thin film materials and devices

    SciTech Connect

    Baron, B.N.; Birkmire, R.W.; Phillips, J.E.; Shafarman, W.N.; Hegedus, S.S.; McCandless, B.E. . Inst. of Energy Conversion)

    1991-01-01

    This report presents the results of a one-year research program on polycrystalline thin-film solar cells. The research was conducted to better understand the limitations and potential of solar cells using CuInSe{sub 2} and CdTe by systematically investigating the fundamental relationships linking material processing, material properties, and device behavior. By selenizing Cu and In layers, we fabricated device-quality CuInSe{sub 2} thin films and demonstrated a CuInSe{sub 2} solar cell with 7% efficiency. We added Ga, to increase the band gap of CuInSe{sub 2} devices to increase the open-circuit voltage to 0.55 V. We fabricated and analyzed Cu(InGa)Se{sub 2}/CuInSe{sub 2} devices to demonstrate the potential for combining the benefits of higher V{sub oc} while retaining the current-generating capacity of CuInSe{sub 2}. We fabricated an innovative superstrate device design with more than 5% efficiency, as well as a bifacial spectral-response technique for determining the electron diffusion length and optical absorption coefficient of CuInSe{sub 2} in an operational cell. The diffusion length was found to be greater than 1 {mu}m. We qualitatively modeled the effect of reducing heat treatments in hydrogen and oxidizing treatments in air on the I-V behavior of CuInSe{sub 2} devices. We also investigated post-deposition heat treatments and chemical processing and used them to fabricate a 9.6%-efficient CdTe/CdS solar cell using physical vapor deposition.

  17. Packaging material for thin film lithium batteries

    DOEpatents

    Bates, John B.; Dudney, Nancy J.; Weatherspoon, Kim A.

    1996-01-01

    A thin film battery including components which are capable of reacting upon exposure to air and water vapor incorporates a packaging system which provides a barrier against the penetration of air and water vapor. The packaging system includes a protective sheath overlying and coating the battery components and can be comprised of an overlayer including metal, ceramic, a ceramic-metal combination, a parylene-metal combination, a parylene-ceramic combination or a parylene-metal-ceramic combination.

  18. Progress toward developing high performance immersion compatible materials and processes

    NASA Astrophysics Data System (ADS)

    Petrillo, Karen; Patel, Kaushal; Chen, Rex; Li, Wenjie; Kwong, Ranee; Lawson, Peggy; Varanasi, Rao; Robinson, Chris; Holmes, Steven J.; Gil, Dario; Kimmel, Kurt; Slezak, Mark; Dabbagh, Gary; Chiba, Takashi; Shimokawa, Tsutomu

    2005-05-01

    To make immersion lithography a reality in manufacturing, several challenges related to materials and defects must be addressed. Two such challenges include the development of water immersion compatible materials, and the vigorous pursuit of defect reduction with respect to both the films and the processes. Suitable resists and topcoats must be developed to be compatible with the water-soaked environment during exposure. Going beyond the requisite studies of component leaching from films into the water, and absorption of water into the films, application-specific optimization of photoresists and top coats will be required. This would involve an understanding of how a wide array of resist chemistry and formulations behave under immersion conditions. The intent of this paper is to compare lithographic performance under immersion and dry conditions of resists containing different polymer platforms, protecting groups, and formulations. The compatibility of several developer-soluble top-coat materials with a variety of resists is also studied with emphasis on profile control issues. With respect to defects, the sources are numerous. Bubbles and particles created during the imaging process, material remnants from incomplete removal of topcoats, and image collapse as related to resist swelling from water infusion are all sources of yield-limiting defects. Parallel efforts are required in the material development cycle focusing both on meeting the lithographic requirements, and on understanding and eliminating sources of defects. In this paper, efforts in the characterization and reduction of defects as related to materials chemistry and processing effects will be presented.

  19. Biocomposite cellulose-alginate films: promising packaging materials.

    PubMed

    Sirviö, Juho Antti; Kolehmainen, Aleksi; Liimatainen, Henrikki; Niinimäki, Jouko; Hormi, Osmo E O

    2014-05-15

    Biocomposite films based on cellulose and alginate were produced using unmodified birch pulp, microfibrillated cellulose (MFC), nanofibrillated cellulose (NFC) and birch pulp derivate, nanofibrillated anionic dicarboxylic acid cellulose (DCC), having widths of fibres ranging from 19.0 μm to 25 nm as cellulose fibre materials. Ionically cross-linked biocomposites were produced using Ca(2+) cross-linking. Addition of micro- and nanocelluloses as a reinforcement increased the mechanical properties of the alginate films remarkably, e.g. addition of 15% of NFC increased a tensile strength of the film from 70.02 to 97.97 MPa. After ionic cross-linking, the tensile strength of the film containing 10% of DCC was increased from 69.63 to 125.31 MPa. The biocomposite films showed excellent grease barrier properties and reduced water vapour permeability (WVP) after the addition of cellulose fibres, except when unmodified birch pulp was used. PMID:24423542

  20. High Pressure Hydrogen Materials Compatibility of Piezoelectric Films

    SciTech Connect

    Alvine, Kyle J.; Shutthanandan, V.; Bennett, Wendy D.; Bonham, Charles C.; Skorski, Daniel C.; Pitman, Stan G.; Dahl, Michael E.; Henager, Charles H.

    2010-12-02

    Abstract: Hydrogen is being considered as a next-generation clean burning fuel. However, hydrogen has well known materials issues, including blistering and embrittlement in metals. Piezoelectric materials are used as actuators in hydrogen fuel technology. We present studies of materials compatibility of piezoelectric films in a high pressure hydrogen environment. Absorption of high pressure hydrogen was studied with Elastic Recoil Detection Analysis (ERDA) and Rutherford Back Scattering (RBS) in lead zirconate titanate (PZT) and barium titanate (BTO) thin films. Hydrogen surface degradation in the form of blistering and Pb mixing was also observed.

  1. Scanning Tunneling Microscopy Studies of Diamond Films and Optoelectronic Materials

    NASA Technical Reports Server (NTRS)

    Perez, Jose M.

    1996-01-01

    We present a summary of the research, citations of publications resulting from the research and abstracts of such publications. We have made no inventions in the performance of the work in this project. The main goals of the project were to set up a Chemical Vapor Deposition (CVD) diamond growth system attached to an UltraHigh Vacuum (UHV) atomic resolution Scanning Tunneling Microscopy (STM) system and carry out experiments aimed at studying the properties and growth of diamond films using atomic resolution UHV STM. We successfully achieved these goals. We observed, for the first time, the atomic structure of the surface of CVD grown epitaxial diamond (100) films using UHV STM. We studied the effects of atomic hydrogen on the CVD diamond growth process. We studied the electronic properties of the diamond (100) (2x1) surface, and the effect of alkali metal adsorbates such as Cs on the work function of this surface using UHV STM spectroscopy techniques. We also studied, using STM, new electronic materials such as carbon nanotubes and gold nanostructures. This work resulted in four publications in refereed scientific journals and five publications in refereed conference proceedings.

  2. Thin film photovoltaic device and process of manufacture

    DOEpatents

    Albright, Scot P.; Chamberlin, Rhodes

    1997-10-07

    Provided is a thin film photovoltaic device and a method of manufacturing the device. The thin film photovoltaic device comprises a film layer having particles which are smaller than about 30 microns in size held in an electrically insulating matrix material to reduce the potential for electrical shorting through the film layer. The film layer may be provided by depositing preformed particles onto a surrogate substrate and binding the particles in a film-forming matrix material to form a flexible sheet with the film layer. The flexible sheet may be separated from the surrogate substrate and cut into flexible strips. A plurality of the flexible strips may be located adjacent to and supported by a common supporting substrate to form a photovoltaic module having a plurality of electrically interconnected photovoltaic cells.

  3. Thin film photovoltaic device and process of manufacture

    DOEpatents

    Albright, Scot P.; Chamberlin, Rhodes

    1999-02-09

    Provided is a thin film photovoltaic device and a method of manufacturing the device. The thin film photovoltaic device comprises a film layer having particles which are smaller than about 30 microns in size held in an electrically insulating matrix material to reduce the potential for electrical shorting through the film layer. The film layer may be provided by depositing preformed particles onto a surrogate substrate and binding the particles in a film-forming matrix material to form a flexible sheet with the film layer. The flexible sheet may be separated from the surrogate substrate and cut into flexible strips. A plurality of the flexible strips may be located adjacent to and supported by a common supporting substrate to form a photovoltaic module having a plurality of electrically interconnected photovoltaic cells.

  4. Thin film photovoltaic device and process of manufacture

    DOEpatents

    Albright, S.P.; Chamberlin, R.

    1997-10-07

    Provided is a thin film photovoltaic device and a method of manufacturing the device. The thin film photovoltaic device comprises a film layer having particles which are smaller than about 30 microns in size held in an electrically insulating matrix material to reduce the potential for electrical shorting through the film layer. The film layer may be provided by depositing preformed particles onto a surrogate substrate and binding the particles in a film-forming matrix material to form a flexible sheet with the film layer. The flexible sheet may be separated from the surrogate substrate and cut into flexible strips. A plurality of the flexible strips may be located adjacent to and supported by a common supporting substrate to form a photovoltaic module having a plurality of electrically interconnected photovoltaic cells. 13 figs.

  5. Thin film photovoltaic device and process of manufacture

    DOEpatents

    Albright, S.P.; Chamberlin, R.

    1999-02-09

    Provided is a thin film photovoltaic device and a method of manufacturing the device. The thin film photovoltaic device comprises a film layer having particles which are smaller than about 30 microns in size held in an electrically insulating matrix material to reduce the potential for electrical shorting through the film layer. The film layer may be provided by depositing preformed particles onto a surrogate substrate and binding the particles in a film-forming matrix material to form a flexible sheet with the film layer. The flexible sheet may be separated from the surrogate substrate and cut into flexible strips. A plurality of the flexible strips may be located adjacent to and supported by a common supporting substrate to form a photovoltaic module having a plurality of electrically interconnected photovoltaic cells. 13 figs.

  6. Semiconducting boron carbide thin films: Structure, processing, and diode applications

    NASA Astrophysics Data System (ADS)

    Bao, Ruqiang

    The high energy density and long lifetime of betavoltaic devices make them very useful to provide the power for applications ranging from implantable cardiac pacemakers to deep space satellites and remote sensors. However, when made with conventional semiconductors, betavoltaic devices tend to suffer rapid degradation as a result of radiation damage. It has been suggested that the degradation problem could potentially be alleviated by replacing conventional semiconductors with a radiation hard semiconducting material like icosahedral boron carbide. The goal of my dissertation was to better understand the fundamental properties and structure of boron carbide thin films and to explore the processes to fabricate boron carbide based devices for voltaic applications. A pulsed laser deposition system and a radio frequency (RF) magnetron sputtering deposition system were designed and built to achieve the goals. After comparing the experimental results obtained using these two techniques, it was concluded that RF magnetron sputtering deposition technique is a good method to make B4C boron carbide thin films to fabricate repeatable and reproducible voltaic devices. The B4C thin films deposited by RF magnetron sputtering require in situ dry pre-cleaning to make ohmic contacts for B4C thin films to fabricate the devices. By adding another RF sputtering to pre-clean the substrate and thin films, a process to fabricate B4C / n-Si heterojunctions has been established. In addition, a low energy electron accelerator (LEEA) was built to mimic beta particles emitted from Pm147 and used to characterize the betavoltaic performance of betavoltaic devices as a function of beta energy and beta flux as well as do accelerated lifetime testing for betavoltaic devices. The energy range of LEEA is 20 - 250 keV with the current from several nA to 50 muA. High efficiency Si solar cells were used to demonstrate the powerful capabilities of LEEA, i.e., the characterization of betavoltaic

  7. Microgravity Processing and Photonic Applications of Organic and Polymeric Materials

    NASA Technical Reports Server (NTRS)

    Frazier, Donald O.; Paley, Mark S.; Penn, Benjamin G.; Abdeldayem, Hossin A.; Smith, David D.; Witherow, William K.

    1997-01-01

    Some of the primary purposes of this work are to study important technologies, particularly involving thin films, relevant to organic and polymeric materials for improving applicability to optical circuitry and devices and to assess the contribution of convection on film quality in unit and microgravity environments. Among the most important materials processing techniques of interest in this work are solution-based and by physical vapor transport, both having proven gravitational and acceleration dependence. In particular, PolyDiAcetylenes (PDA's) and PhthaloCyanines (Pc's) are excellent NonLinear Optical (NLO) materials with the promise of significantly improved NLO properties through order and film quality enhancements possible through microgravity processing. Our approach is to focus research on integrated optical circuits and optoelectronic devices relevant to solution-based and vapor processes of interest in the Space Sciences Laboratory at the Marshall Space Flight Center (MSFC). Modification of organic materials is an important aspect of achieving more highly ordered structures in conjunction with microgravity processing. Parallel activities include characterization of materials for particular NLO properties and determination of appropriation device designs consistent with selected applications. One result of this work is the determination, theoretically, that buoyancy-driven convection occurs at low pressures in an ideal gas in a thermalgradient from source to sink. Subsequent experiment supports the theory. We have also determined theoretically that buoyancy-driven convection occurs during photodeposition of PDA, an MSFC-patented process for fabricating complex circuits, which is also supported by experiment. Finally, the discovery of intrinsic optical bistability in metal-free Pc films enables the possibility of the development of logic gate technology on the basis of these materials.

  8. The Effect of Plasma Surface Treatment on a Porous Green Ceramic Film with Polymeric Binder Materials

    NASA Astrophysics Data System (ADS)

    Jeong, Woo Yun

    2013-06-01

    To reduce time and energy during thermal binder removal in the ceramic process, plasma surface treatment was applied before the lamination process. The adhesion strength in the lamination films was enhanced by oxidative plasma treatment of the porous green ceramic film with polymeric binding materials. The oxygen plasma characteristics were investigated through experimental parameters and weight loss analysis. The experimental results revealed the need for parameter analysis, including gas material, process time, flow rate, and discharge power, and supported a mechanism consisting of competing ablation and deposition processes. The weight loss analysis was conducted for cyclic plasma treatment rather than continuous plasma treatment for the purpose of improving the film's permeability by suppressing deposition of the ablated species. The cyclic plasma treatment improved the permeability compared to the continuous plasma treatment.

  9. Process for making thin film solar cell

    SciTech Connect

    Eberspacher, C.; Ermer, J.H.; Mitchell, K.W.

    1991-09-03

    This paper describes a semiconducting thin film forced on a substrate by the method. It comprises: depositing a composite film of copper and indium on a substrate, the film having an atomic copper to indium ratio of about one, depositing a film of selenium on the composite copper indium film, the selenium film thickness selected to provide an atomic ratio of selenium to copper and indium of less than one, and heating the substrate with the composite copper indium film and the selenium film in the presence of H{sub 2}S gas for a time and at a temperature sufficient to cause interdiffusion of copper, indium, selenium and sulfur to form a semiconductor of the class CuInSe{sub 2{minus}x}S{sub x} where x is less than two.

  10. Thick film silicon growth techniques. [die materials

    NASA Technical Reports Server (NTRS)

    Bates, H. E.; Mlavsky, A. I.; Jewett, D. N.; White, V. E.

    1973-01-01

    The research which was directed toward finding an improved die material is reported. Wetting experiments were conducted with various materials to determine their compatibility with silicon. Work has also continued toward the development of quartz as a die material as new techniques have provided more optimistic results than observed in the past. As a result of the thermal modification previously described, improvements in growth stability have contributed to an increase in ribbon quality.

  11. Materials genomics of thin film strain relaxation by misfit dislocations

    NASA Astrophysics Data System (ADS)

    Hull, R.; Parvaneh, H.; Andersen, D.; Bean, John C.

    2015-12-01

    We summarize the development and implementation of a "process simulator" for modeling thin film strain relaxation by injection of misfit dislocations. The process simulator, initially developed for GexSi1-x/Si(100) lattice-mismatched epitaxy, integrates elasticity and dislocation theory with experimental measurements of kinetic parameters describing dislocation nucleation, propagation, and interactions. This enables predictive simulation of the development of misfit dislocation arrays during growth and thermal annealing sequences. Further, in the spirit of the materials genome initiative, we show how once a relatively complete description is built for one materials system, extension to a related system may be implemented using a greatly reduced data set. We illustrate this concept by translation of the simulator for GexSi1-x/Si(100) epitaxy into predictive simulation for the GexSi1-x/Si(110) system (which has quite different dislocation microstructure and kinetics) using greatly reduced data sets for the latter system and incorporating data refinement methods to extract unknown kinetic parameters. This sets the platform for extension of these methods to a broader set of strained layer systems.

  12. Materials and processes control for space applications

    NASA Technical Reports Server (NTRS)

    Blackburn, G. A.

    1985-01-01

    Materials and processes control relative to space applications is discussed. The components of a total material and process control system are identified, contamination control issues are listed, and recommendations are made.

  13. Photoexcited carriers in organic light emitting materials and blended films observed by surface photovoltage spectroscopy

    NASA Astrophysics Data System (ADS)

    Yang, Jihua; Gordon, Keith C.; McQuillan, A. James; Zidon, Yigal; Shapira, Yoram

    2005-04-01

    The electronic structure of the widely-used light emitting materials, 2,5-bis(5-tert-butyl-2-benzoxazolyl) thiophene (BBOT), poly( N -vinylcarbazole) (PVK) thin films have been characterized using surface photovoltage spectroscopy. The photo-induced charge separation and transfer processes in both blend films of PVK:BBOT and PVK:TPD:BBOT, where TPD is N,N' -diphenyl- N,N' -bis(3-methylphenyl)-[ 1,1' -biphenyl]- 4,4' -diamine have also been investigated. The results of the photo-induced contact potential difference (CPD) change show that BBOT film is an electron-transporting material while PVK film is a hole-transporting one. The photoluminescence and electroluminescence results of the blend films suggest an exciplex interaction between BBOT and PVK or TPD. A positive CPD change due to photo-excitation of the BBOT in PVK:BBOT blend film is attributed to electron trapping at the localized state induced by dispersed BBOT species. In the PVK:TPD:BBOT blend films, a positive CPD change, which starts at the same transition energy as in the former blend film but is significantly enhanced, is observed and explained in terms of charge transfer between the involved energy structures of the blend components. The dependence of the observed effects on the blend composition and ensuing electronic structure is discussed.

  14. Microgravity Processing and Photonic Applications of Organic and Polymeric Materials

    NASA Technical Reports Server (NTRS)

    Frazier, Donald O.; Penn, Benjamin G.; Smith, David D.; Witherow, William K.; Paley, Mark S.; Abdeldayem, Hossin A.

    1997-01-01

    In recent years, a great deal of interest has been directed toward the use of organic materials in the development of high-efficiency optoelectronic and photonic devices. There is a myriad of possibilities among organics which allow flexibility in the design of unique structures with a variety of functional groups. The use of nonlinear optical (NLO) organic materials such as thin-film waveguides allows full exploitation of their desirable qualities by permitting long interaction lengths and large susceptibilities allowing modest power input. There are several methods in use to prepare thin films, such as Langmuir-Blodgett (LB) and self-assembly techniques, vapor deposition, growth from sheared solution or melt, and melt growth between glass plates. Organics have many features that make them desirable for use in optical devices such as high second- and third-order nonlinearities, flexibility of molecular design, and damage resistance to optical radiation. However, their use in devices has been hindered by processing difficulties for crystals and thin films. In this chapter, we discuss photonic and optoelectronic applications of a few organic materials and the potential role of microgravity on processing these materials. It is of interest to note how materials with second- and third-order nonlinear optical behavior may be improved in a diffusion-limited environment and ways in which convection may be detrimental to these materials.

  15. Advanced aerial film processing system for long range reconnaissance

    NASA Astrophysics Data System (ADS)

    Ryman, I. G.

    1980-01-01

    An introduction is given to the system features and development histories of continuous aerial film processing equipment. The advantages and disadvantages of (1) deep tank, full immersion processing, (2) spray processing, and (3) viscous processing are enumerated, with respect to load end, supply accumulator, spray cabinet, squeegee section, dryer, film take-up section and film transport system functions. Future research efforts are recommended toward the incorporation of water regeneration, pollution control, and pH monitoring and control systems, and the greater use of computer technology to prevent operator errors and permit the handling of thinner, advanced films.

  16. Control method and system for use when growing thin-films on semiconductor-based materials

    DOEpatents

    McKee, Rodney A.; Walker, Frederick J.

    2001-01-01

    A process and system for use during the growth of a thin film upon the surface of a substrate by exposing the substrate surface to vaporized material in a high vacuum (HV) facility involves the directing of an electron beam generally toward the surface of the substrate as the substrate is exposed to vaporized material so that electrons are diffracted from the substrate surface by the beam and the monitoring of the pattern of electrons diffracted from the substrate surface as vaporized material settles upon the substrate surface. When the monitored pattern achieves a condition indicative of the desired condition of the thin film being grown upon the substrate, the exposure of the substrate to the vaporized materials is shut off or otherwise adjusted. To facilitate the adjustment of the crystallographic orientation of the film relative to the electron beam, the system includes a mechanism for altering the orientation of the surface of the substrate relative to the electron beam.

  17. Antireflection effects at nanostructured material interfaces and the suppression of thin-film interference

    NASA Astrophysics Data System (ADS)

    Yang, Qiaoyin; Zhang, Xu A.; Bagal, Abhijeet; Guo, Wei; Chang, Chih-Hao

    2013-06-01

    Thin-film interference is a well-known effect, and it is commonly observed in the colored appearance of many natural phenomena. Caused by the interference of light reflected from the interfaces of thin material layers, such interference effects can lead to wavelength and angle-selective behavior in thin-film devices. In this work, we describe the use of interfacial nanostructures to eliminate interference effects in thin films. Using the same principle inspired by moth-eye structures, this approach creates an effective medium where the index is gradually varying between the neighboring materials. We present the fabrication process for such nanostructures at a polymer-silicon interface, and experimentally demonstrate its effectiveness in suppressing thin-film interference. The principle demonstrated in this work can lead to enhanced efficiency and reduce wavelength/angle sensitivity in multilayer optoelectronic devices.

  18. Research on polycrystalline thin-film materials, cells, and modules

    NASA Astrophysics Data System (ADS)

    Mitchell, R. L.; Zweibel, K.; Ullal, H. S.

    1990-11-01

    DOE supports research activities in polycrystalline thin films through the Polycrystalline Thin Film Program. This program includes includes R and D in both copper indium diselenide and cadmium telluride thin films for photovoltaic applications. The objective is to support R and D of photovoltaic cells and modules that meet the DOE long term goals of high efficiency (15 to 20 percent), low cost ($50/sq cm), and reliability (30-year life time). Research carried out in this area is receiving increased recognition due to important advances in polycrystalline thin film CuInSe2 and CdTe solar cells and modules. These have become the leading thin film materials for photovoltaics in terms of efficiency and stability. DOE has recognized this potential through a competitive initiative for the development of CuInSe(sub 2) and CdTe modules. The recent progress and future directions are studied of the Polycrystalline Thin Film Program and the status of the subcontracted research on these promising photovoltaic materials.

  19. Research on polycrystalline thin-film materials, cells, and modules

    SciTech Connect

    Mitchell, R.L.; Zweibel, K.; Ullal, H.S.

    1990-11-01

    The US Department of Energy (DOE) supports research activities in polycrystalline thin films through the Polycrystalline Thin-Film Program at the Solar Energy Research Institute (SERI). This program includes research and development (R D) in both copper indium diselenide and cadmium telluride thin films for photovoltaic applications. The objective of this program is to support R D of photovoltaic cells and modules that meet the DOE long-term goals of high efficiency (15%--20%), low cost ($50/m{sup 2}), and reliability (30-year life time). Research carried out in this area is receiving increased recognition due to important advances in polycrystalline thin-film CuInSe{sub 2} and CdTe solar cells and modules. These have become the leading thin-film materials for photovoltaics in terms of efficiency and stability. DOE has recognized this potential through a competitive initiative for the development of CuInSe{sub 2} and CdTe modules. This paper focuses on the recent progress and future directions of the Polycrystalline Thin-Film Program and the status of the subcontracted research on these promising photovoltaic materials. 26 refs., 12 figs, 1 tab.

  20. Apparatus and method for treating a cathode material provided on a thin-film substrate

    DOEpatents

    Hanson, Eric J.; Kooyer, Richard L.

    2001-01-01

    An apparatus and method for treating a cathode material provided on a surface of a continuous thin-film substrate and a treated thin-film cathode having increased smoothness are disclosed. A web of untreated cathode material is moved between a feed mechanism and a take-up mechanism, and passed through a treatment station. The web of cathode material typically includes areas having surface defects, such as prominences extending from the surface of the cathode material. The surface of the cathode material is treated with an abrasive material to reduce the height of the prominences so as to increase an 85 degree gloss value of the cathode material surface by at least approximately 10. The web of cathode material may be subjected to a subsequent abrasive treatment at the same or other treatment station. Burnishing or lapping film is employed at a treatment station to process the cathode material. An abrasive roller may alternatively be used to process the web of cathode material. The apparatus and method of the present invention may also be employed to treat the surface of a lithium anode foil so as to cleanse and reduce the roughness of the anode foil surface.

  1. Apparatus and method for treating a cathode material provided on a thin-film substrate

    DOEpatents

    Hanson, Eric J.; Kooyer, Richard L.

    2003-01-01

    An apparatus and method for treating a cathode material provided on a surface of a continuous thin-film substrate and a treated thin-film cathode having increased smoothness are disclosed. A web of untreated cathode material is moved between a feed mechanism and a take-up mechanism, and passed through a treatment station. The web of cathode material typically includes areas having surface defects, such as prominences extending from the surface of the cathode material. The surface of the cathode material is treated with an abrasive material to reduce the height of the prominences so as to increase an 85 degree gloss value of the cathode material surface by at least approximately 10. The web of cathode material may be subjected to a subsequent abrasive treatment at the same or other treatment station. Burnishing or lapping film is employed at a treatment station to process the cathode material. An abrasive roller may alternatively be used to process the web of cathode material. The apparatus and method of the present invention may also be employed to treat the surface of a lithium anode foil so as to cleanse and reduce the roughness of the anode foil surface.

  2. Scanning tunneling microscopy studies of diamond films and optoelectronic materials

    NASA Technical Reports Server (NTRS)

    Perez, Jose M.

    1993-01-01

    In this report, we report on progress achieved from 12/1/92 to 10/1/93 under the grant entitled 'Scanning Tunneling Microscopy Studies of Diamond Films and Optoelectronic Materials'. We have set-up a chemical vapor deposition (CVD) diamond film growth system and a Raman spectroscopy system to study the nucleation and growth of diamond films with atomic resolution using scanning tunneling microscopy (STM). A unique feature of the diamond film growth system is that diamond films can be transferred directly to the ultrahigh vacuum (UHV) chamber of a scanning tunneling microscope without contaminating the films by exposure to air. The University of North Texas (UNT) provided $20,000 this year as matching funds for the NASA grant to purchase the diamond growth system. In addition, UNT provided a Coherent Innova 90S Argon ion laser, a Spex 1404 double spectrometer, and a Newport optical table costing $90,000 to set-up the Raman spectroscopy system. The CVD diamond growth system and Raman spectroscopy system will be used to grow and characterize diamond films with atomic resolution using STM as described in our proposal. One full-time graduate student and one full-time undergraduate student are supported under this grant. In addition, several graduate and undergraduate students were supported during the summer to assist in setting-up the diamond growth and Raman spectroscopy systems. We have obtained research results concerning STM of the structural and electronic properties of CVD grown diamond films, and STM and scanning tunneling spectroscopy of carbon nanotubes. In collaboration with the transmission electron microscopy (TEM) group at UNT, we have also obtained results concerning the optoelectronic material siloxene. These results were published in refereed scientific journals, submitted for publication, and presented as invited and contributed talks at scientific conferences.

  3. Materials processing in space: Early experiments

    NASA Technical Reports Server (NTRS)

    Naumann, R. J.; Herring, H. W.

    1980-01-01

    The characteristics of the space environment were reviewed. Potential applications of space processing are discussed and include metallurgical processing, and processing of semiconductor materials. The behavior of fluid in low gravity is described. The evolution of apparatus for materials processing in space was reviewed.

  4. Process for fabrication of metal oxide films

    SciTech Connect

    Tracy, C.E.; Benson, D.; Svensson, S.

    1990-07-17

    This invention is comprised of a method of fabricating metal oxide films from a plurality of reactants by inducing a reaction by plasma deposition among the reactants. The plasma reaction is effective for consolidating the reactants and producing thin films of metal oxides, e.g. electro-optically active transition metal oxides, at a high deposition rate. The presence of hydrogen during the plasma reaction enhances the deposition rate of the metal oxide. Various types of metal oxide films can be produced.

  5. Repair materials and processes for the MD-11 Composite Tailcone

    NASA Astrophysics Data System (ADS)

    Yamamoto, Tetsuya; Bonnar, Gerard R.

    This paper describes field and depot level repair methods for the MD-11 Composite Tailcone. The repair materials, processing methods, and mechanical properties of the test specimens and subcomponents are discussed. According to recent tests, the dry carbon cloth and the liquid resin matrix that can be cured under 93 C have better processing and mechanical properties than the 121 C curing prepregs and film adhesives. The moisture in the parent CFRP is the main cause of creating voids in the adhesive layer during the 121 C/vacuum pressure cure cycle. The lower processing temperature (wet layup) showed better results than higher processing temperature (prepreg/adhesive layup) for composite repair.

  6. Thick-film MEMS thermoelectric sensor fabricated using a thermally assisted lift-off process

    NASA Astrophysics Data System (ADS)

    Jia, Yuan; Cai, Haogang; Lin, Qiao

    2016-04-01

    This paper presents a thick-film microelectromechanical systems thermoelectric sensor fabricated by a low-temperature thermally assisted lift-off process. During the process, thick metal or semiconductor films experience controlled breakup due to thermal reflow of the underlying lithographically defined photoresist patterns, thereby facilitating the sacrificial removal of the photoresist. This enables rapid and reliable patterning of thick films that can otherwise be difficult to achieve by conventional processes. Experimental results with a sensor consisting of a 60-junction thick-film antimony-bismuth thermopile demonstrate an electric conductivity of 5.44×106 S/m and a Seebeck coefficient of 114 μV/K per junction, which are comparable to those obtained from bulk materials. Thus, the thick-film sensor can potentially allow low-noise, high-efficiency thermoelectric measurements.

  7. Pulsed RF Plasma Source for Materials Processing

    NASA Astrophysics Data System (ADS)

    Nasiruddin, Abutaher Mohammad

    A pulsed rf plasma source was evaluated for materials processing. A pulsed rf discharge of carbon tetrafluoride (CF_4), sulfur hexafluoride (SF _6), oxygen (O_2), or acetylene (C_2H_2 ) created the plasmas. The frequency and duration of the rf discharge were about 290 kHz and 30 musec, respectively. The repetition rate was 1 discharge per minute. Plasma diagnostics included Langmuir probes, a photodiode dectector, an optical multichannel analyzer (OMA), and a microwave interferometer. Langmuir probe measurements showed that at a position 67 cm away from the rf coil, CF_4 plasma arrived in separate packets. Plasma densities and electron temperatures at this position were in the range 4 times 10^{11} cm ^{-3} to 1.8 times 10^{13} cm ^{-3} and 2 eV to 8.3 eV, respectively. The OMA measurements identified neutral atomic fluorine in the CF_4 plasma and neutral atomic oxygen in the O_2 plasma. A plasma slab model of the microwave interferometer was applied to predict the interferometer response. The measured response was found to be almost identical to the predicted response. The influence of different reactor parameters on plasma parameters was studied. Metal barriers of different geometry were used to control the ratio of charged particles to atomic neutrals in the plasma chamber. Four plasma structures were identified: precursor plasma, shock induced plasma, driver plasma, and delayed glow plasma. Pulsed CF _4 and SF_6 plasmas were used to etch silicon dioxide (SiO_2 ) grown on silicon wafers. The SF_6 plasma etched SiO_2 at a rate of about 0.71 A per discharge and the CF_4 plasma deposited a non-uniform film (possibly polymer) instead of etching. The C_2H _2 plasma deposited plasma polymerized acetylene on a KBr pellet with a deposition rate of 127 A per discharge. An FT-IR spectrum of the deposited film showed that carbon -to-carbon double bonds as well as carbon-to-hydrogen bonds were present. This device can be used in plasma assisted deposition and/or synthesis

  8. Organic thin film transistors: from active materials to novel applications

    NASA Astrophysics Data System (ADS)

    Torsi, L.; Cioffi, N.; Di Franco, C.; Sabbatini, L.; Zambonin, P. G.; Bleve-Zacheo, T.

    2001-08-01

    In this paper, a bird's eye view of most of the organic materials employed as n-channel and p-channel transistor active layers is given along with the relevant device performances; organic thin film transistors (OTFT) operation regimes are discussed and an interesting perspective application of OTFT as multi-parameter gas sensor is proposed.

  9. Dielectric Spectroscopy Analysis of Aged EVOH films with Application to Deterioration of Food Packaging Materials

    NASA Astrophysics Data System (ADS)

    Hoeller, Timothy

    2007-06-01

    Samples of EVOH films from compositions of 29 - 44 mol% ethylene content were exposed to thermal aging with and without light exposure. The results of Dielectric Spectroscopy on select samples showed Cole-Cole plots of skewed dielectric constant indicating multiple distributions of dipole relaxation times. The onset for decreases in dielectric response occurs earlier in samples exposed to elevated temperature under light exposure. Lower permittivity is exhibited in samples of higher ethylene content. Results from heat exposed samples are presented. Colorimetric analysis indicates only a slight film yellowing in one case. Raman spectroscopy on untreated films discerns changes in the C-C-O stretch associated with the alcohol. The effects of aging on microstructure may cause hindrance of molecular motion from moisture desorption. Slight material degradation occurs from film hardening presumably due to crosslinking. An electrical circuit model of the conduction processes associated with the EVOH films is presented. Dielectric analysis shows promise for monitoring material changes related to deterioration. We are also using these methods to understand Fluorescence Imaging which has been recently released for paper and plastic materials analysis. Future work may include refinement of these techniques for identification of changes in material properties correlated to packaging material barrier resistance.

  10. Dual ion beam processed diamondlike films for industrial applications

    NASA Technical Reports Server (NTRS)

    Mirtich, M. J.; Kussmaul, M. T.; Banks, B. A.; Sovey, J. S.

    1991-01-01

    Single and dual beam ion source systems are used to generate amorphous diamondlike carbon (DLC) films, which were evaluated for a variety of applications including protective coatings on transmitting materials, power electronics as insulated gates and corrosion resistant barriers. A list of the desirable properties of DLC films along with potential applications are presented.

  11. Synthesis of thin films and materials utilizing a gaseous catalyst

    SciTech Connect

    Morse, Daniel E; Schwenzer, Birgit; Gomm, John R; Roth, Kristian M; Heiken, Brandon; Brutchey, Richard

    2013-10-29

    A method for the fabrication of nanostructured semiconducting, photoconductive, photovoltaic, optoelectronic and electrical battery thin films and materials at low temperature, with no molecular template and no organic contaminants. High-quality metal oxide semiconductor, photovoltaic and optoelectronic materials can be fabricated with nanometer-scale dimensions and high dopant densities through the use of low-temperature biologically inspired synthesis routes, without the use of any biological or biochemical templates.

  12. Efficient production of nanoparticle-loaded orodispersible films by process integration in a stirred media mill.

    PubMed

    Steiner, Denise; Finke, Jan Henrik; Kwade, Arno

    2016-09-25

    Orodispersible films possess a great potential as a versatile platform for nanoparticle-loaded oral dosage forms. In this case, poorly water-soluble organic materials were ground in a stirred media mill and embedded into a polymer matrix. The aim of this study was the shortening of this manufacturing process by the integration of several process steps into a stirred media mill without facing disadvantages regarding the film quality. Furthermore, this process integration is time conserving due to the high stress intensities provided in the mill and applicable for high solids contents and high suspension viscosities. Two organic materials, the model compound Anthraquinone and the active pharmaceutical ingredient Naproxen were investigated in this study. Besides the impact of the film processing on the crystallinity of the particles in the orodispersible film, a particle load of up to 50% was investigated with the new developed processing route. Additionally, a disintegration test was developed, combining an appropriate amount of saliva substitute and a clear endpoint determination. In summary, high nanoparticle loads in orodispersible films with good particle size preservation after film redispersion in water as well as a manufacturing of the film casting mass within a few minutes in a stirred media mill was achieved. PMID:27477101

  13. Materials Analysis of CED Nb Films Being Coated on Bulk Nb Single Cell SRF Cavities

    SciTech Connect

    Zhao, Xin; Reece, Charles; Palczewski, Ari; Ciovati, Gianluigi; Krishnan, Mahadevan; James, Colt; Irfan, Irfan

    2013-09-01

    This study is an on-going research on depositing a Nb film on the internal wall of bulk Nb single cell SRF cavities, via a cathodic arc Nb plasma ions source, an coaxial energetic condensation (CED) facility at AASC company. The motivation is to firstly create a homoepitaxy-like Nb/Nb film in a scale of a ~1.5GHz RF single cell cavity. Next, through SRF measurement and materials analysis, it might reveal the baseline properties of the CED-type homoepitaxy Nb films. Literally, a top-surface layer of Nb films which sustains SRF function, always grows up in homo-epitaxy mode, on top of a Nb nucleation layer. Homo-epitaxy growth of Nb must be the final stage (a crystal thickening process) of any coatings of Nb film on alternative cavity structure materials. Such knowledge of Nb-Nb homo-epitaxy is useful to create future realistic SRF cavity film coatings, such as hetero-epitaxy Nb/Cu Films, or template-layer-mitigated Nb films. One large-grain, and three fine grain bulk Nb cavities were coated. They went through cryogenic RF measurement. Preliminary results show that the Q0 of a Nb film could be as same as the pre-coated bulk Nb surface (which received a chemically-buffered polishing plus a light electro-polishing); but quality factor of two tested cavities dropped quickly. We are investigating if the severe Q-slope is caused by hydrogen incorporation before deposition, or is determined by some structural defects during Nb film growth.

  14. Influence Of Film And Processing On Film-Screen Image Noise

    NASA Astrophysics Data System (ADS)

    Holland, R. S.

    1982-12-01

    This paper describes experiments which explore the ways in which variations in film and processing influence noise through their effects on the sensitometric curve shape and silver granularity. These include comparisons of several film types and processing conditions for which total radiographic noise from screen exposures and granularity from light exposures are analyzed relative to the instantaneous gradient at the measured density. It is seen that film granularity may indeed contribute substantially to total noise under conditions of low quantum mottle visualization.

  15. Polymers for nuclear materials processing

    SciTech Connect

    Jarvinen, G.; Benicewicz, B.; Duke, J.

    1996-10-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The use of open-celled microcellular foams as solid sorbents for metal ions and other solutes could provide a revolutionary development in separation science. Macroreticular and gel-bead materials are the current state-of-the-art for solid sorbents to separate metal ions and other solutes from solution. The new polymer materials examined in this effort offer a number of advantages over the older materials that can have a large impact on industrial separations. The advantages include larger usable surface area in contact with the solution, faster sorption kinetics, ability to tailor the uniform cell size to a specific application, and elimination of channeling and packing instability.

  16. Microgravity Processing and Photonic Applications of Organic and Polymeric Materials

    NASA Technical Reports Server (NTRS)

    Frazier, Donald 0; Penn, Benjamin G.; Smith, David; Witherow, William K.; Paley, M. S.; Abdeldayem, Hossin A.

    1998-01-01

    In recent years, a great deal of interest has been directed toward the use of organic materials in the development of high-efficiency optoelectronic and photonic devices. There is a myriad of possibilities among organic which allow flexibility in the design of unique structures with a variety of functional groups. The use of nonlinear optical (NLO) organic materials such as thin-film waveguides allows full exploitation of their desirable qualities by permitting long interaction lengths and large susceptibilities allowing modest power input. There are several methods in use to prepare thin films, such as Langmuir-Blodgett (LB) and self-assembly techniques, vapor deposition, growth from sheared solution or melt, and melt growth between glass plates. Organics have many features that make Abstract: them desirable for use in optical devices such as high second- and third-order nonlinearities, flexibility of molecular design, and damage resistance to optical radiation. However, their use in devices has been hindered by processing difficulties for crystals and thin films. In this chapter, we discuss photonic and optoelectronic applications of a few organic materials and the potential role of microgravity on processing these materials. It is of interest to note how materials with second- and third-order nonlinear optical behavior may be improved in a diffusion-limited environment and ways in which convection may be detrimental to these materials. We focus our discussion on third-order materials for all-optical switching, and second-order materials for all-optical switching, and second-order materials for frequency conversion and electrooptics.

  17. Thin film thermocouples for thermoelectric characterization of nanostructured materials

    NASA Astrophysics Data System (ADS)

    Grayson, Matthew; Zhou, Chuanle; Varrenti, Andrew; Chyung, Seung Hye; Long, Jieyi; Memik, Seda

    2011-03-01

    The increased use of nanostructured materials as thermoelectrics requires reliable and accurate characterization of the anisotropic thermal coefficients of small structures, such as superlattices and quantum wire networks. Thin evaporated metal films can be used to create thermocouples with a very small thermal mass and low thermal conductivity, in order to measure thermal gradients on nanostructures and thereby measure the thermal conductivity and the Seebeck coefficient of the nanostructure. In this work we confirm the known result that thin metal films have lower Seebeck coefficients than bulk metals, and we also calibrate the Seebeck coefficient of a thin-film Ni/Cr thermocouple with 50 nm thickness, showing it to have about 1/4 the bulk value. We demonstrate reproducibility of this thin-filmSeebeck coefficient on multiple substrates, and we show that this coefficient does, in fact, change as a function of film thickness. We will discuss prototype measurement designs and preliminary work as to how these thin films can be used to study both Seebeck coefficients and thermal conductivities of superlattices in various geometries. The same technology can in principle be used on integrated circuits for thermal mapping, under the name ``Integrated On-Chip Thermocouple Array'' (IOTA).

  18. Cellulose Nanofibril Film as a Piezoelectric Sensor Material.

    PubMed

    Rajala, Satu; Siponkoski, Tuomo; Sarlin, Essi; Mettänen, Marja; Vuoriluoto, Maija; Pammo, Arno; Juuti, Jari; Rojas, Orlando J; Franssila, Sami; Tuukkanen, Sampo

    2016-06-22

    Self-standing films (45 μm thick) of native cellulose nanofibrils (CNFs) were synthesized and characterized for their piezoelectric response. The surface and the microstructure of the films were evaluated with image-based analysis and scanning electron microscopy (SEM). The measured dielectric properties of the films at 1 kHz and 9.97 GHz indicated a relative permittivity of 3.47 and 3.38 and loss tangent tan δ of 0.011 and 0.071, respectively. The films were used as functional sensing layers in piezoelectric sensors with corresponding sensitivities of 4.7-6.4 pC/N in ambient conditions. This piezoelectric response is expected to increase remarkably upon film polarization resulting from the alignment of the cellulose crystalline regions in the film. The CNF sensor characteristics were compared with those of polyvinylidene fluoride (PVDF) as reference piezoelectric polymer. Overall, the results suggest that CNF is a suitable precursor material for disposable piezoelectric sensors, actuators, or energy generators with potential applications in the fields of electronics, sensors, and biomedical diagnostics. PMID:27232271

  19. Self-Assembling Process for Fabricating Tailored Thin Films

    ScienceCinema

    Sandia

    2009-09-01

    A simple, economical nanotechnology coating process that enables the development of nanoparticle thin films with architectures and properties unattainable by any other processing method. 2007 R&D 100 winner (SAND2007-1878P)

  20. Self-Assembling Process for Fabricating Tailored Thin Films

    ScienceCinema

    None

    2010-01-08

    A simple, economical nanotechnology coating process that enables the development of nanoparticle thin films with architectures and properties unattainable by any other processing method. 2007 R&D 100 winner (SAND2007-1878P)

  1. Self-Assembling Process for Fabricating Tailored Thin Films

    SciTech Connect

    2008-07-31

    A simple, economical nanotechnology coating process that enables the development of nanoparticle thin films with architectures and properties unattainable by any other processing method. 2007 R&D 100 winner (SAND2007-1878P)

  2. Materials processing with superposed Bessel beams

    NASA Astrophysics Data System (ADS)

    Yu, Xiaoming; Trallero-Herrero, Carlos A.; Lei, Shuting

    2016-01-01

    We report experimental results of femtosecond laser processing on the surface of glass and metal thin film using superposed Bessel beams. These beams are generated by a combination of a spatial light modulator (SLM) and an axicon with >50% efficiency, and they possess the long depth-of-focus (propagation-invariant) property as found in ordinary Bessel beams. Through micromachining experiments using femtosecond laser pulses, we show that multiple craters can be fabricated on glass with single-shot exposure, and the 1+(-1) superposed beam can reduce collateral damage caused by the rings in zero-order Bessel beams in the scribing of metal thin film.

  3. Ambient pressure process for preparing aerogel thin films reliquified sols useful in preparing aerogel thin films

    DOEpatents

    Brinker, Charles Jeffrey; Prakash, Sai Sivasankaran

    1999-01-01

    A method for preparing aerogel thin films by an ambient-pressure, continuous process. The method of this invention obviates the use of an autoclave and is amenable to the formation of thin films by operations such as dip coating. The method is less energy intensive and less dangerous than conventional supercritical aerogel processing techniques.

  4. Ion beam processing of advanced electronic materials

    SciTech Connect

    Cheung, N.W.; Marwick, A.D.; Roberto, J.B.; International Business Machines Corp., Yorktown Heights, NY . Thomas J. Watson Research Center; Oak Ridge National Lab., TN )

    1989-01-01

    This report contains research programs discussed at the materials research society symposia on ion beam processing of advanced electronic materials. Major topics include: shallow implantation and solid-phase epitaxy; damage effects; focused ion beams; MeV implantation; high-dose implantation; implantation in III-V materials and multilayers; and implantation in electronic materials. Individual projects are processed separately for the data bases. (CBS)

  5. FMR study of thin film FeGe skyrmionic material

    NASA Astrophysics Data System (ADS)

    Bhallamudi, Vidya P.; Page, Michael R.; Gallagher, James; Purser, Carola; Schulze, Joseph; Yang, Fengyuan; Hammel, P. Chris

    Magnetic Skyrmions have attracted intense interest due to their novel topological properties and the potential for energy efficient computing. Magnetic dynamics play an important part in enabling some of these functionalities. Understanding these dynamics can shed light on the interplay of the various magnetic interactions that exist in these materials and lead to a rich magnetic phase diagram, including the Skyrmion phase. We have grown phase-pure FeGe epitaxial films on Si (111) and studied them using ferromagnetic resonance (FMR). FeGe has one of the highest recorded skyrmion transition temperatures, close to room temperature, and thin films are known to further stabilize the Skyrmion phase in the magnetic field-temperature space. We have performed cavity-based single frequency FMR from liquid nitrogen to room temperature on 120 nm thick films in both in-plane and out-of-plane geometries. The resulting complex spectra are consistent with those reported in literature for the bulk material and can be understood in terms of a conical model for the magnetism. Variable temperature broadband spectroscopy and measurements on thinner films, to better identify the various magnetic phases and their dynamic behavior, are ongoing and their progress will be discussed. Funding for this research was provided by the Center for Emergent Materials: an NSF MRSEC under Award Number DMR-1420451.

  6. Effect of varying processing solution temperature on radiographic contrast and relative film speed of dental film.

    PubMed

    Matthee, M J; Becker, P J; Seeliger, J E

    1990-12-01

    The aim of this study was to determine the effect of a stepwise rise in temperature on three film types processed in six different processing solutions and to identify the combinations of film, solution and temperature which produced the best results in terms of radiographic contrast and relative film speed. The film types were Agfa Dentus M2, Flow X-ray and Kodak Ultra Speed while the processing solutions were Agfa, Dürr, EBX, Kolchem, MEMS and Pro-tech. An aluminium step-wedge was exposed under standardised conditions. Processing was carried out in a Dürr 245L automatic processor with variable temperature settings from 25 degrees to 35 degrees C. Unexposed films were processed at each temperature setting to determine the base plus fog values. Densitometric readings were taken using a digital densitometer, and the base plug fog values subtracted from each reading. Radiographic contrast and relative film speed were calculated and the data obtained subjected to statistical analysis using Duncan's Multiple Range Test. It could be concluded that, as the processing solution temperature rose from 25 degrees C to 35 degrees C, both radiographic contrast and relative film speed increased. The highest radiographic contrast was obtained by Agfa film in Kolchem solution at 35 degrees C, while Kodak Ultra Speed film in MEMS solution at 35 degrees C gave the highest relative film speed. An acceptable base plus fog level of 0.25 was obtained in the case of Agfa film in combination with Agfa, Dürr and Pro-tech solutions and Flow X-ray film with Dürr solutions. All the other combinations produced a base plug fog level higher than 0.25. PMID:2098942

  7. Screening of Novel Li-Air Battery Catalyst Materials by a Thin Film Combinatorial Materials Approach.

    PubMed

    Hauck, John G; McGinn, Paul J

    2015-06-01

    A combinatorial synthesis and high-throughput screening process was developed for the investigation of potential oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalysts for use as Li-air battery cathode materials. Libraries of discrete ternary metal alloy compositions were deposited via thin-film sputtering. The samples were electrochemically tested in parallel using cyclic voltammetry in O2-saturated KOH electrolyte. Compositions were ranked by ORR and OER onset potentials with respect to an internal Pt reference. Results from the Pt-Mn-Co, Cr-Mn-Co, Pd-Mn-Co, and Pd-Mn-Ru systems are reported. Many alloy compositions showed marked improvement in catalytic activity compared to pure Pt. Among the systems considered, Pt12Mn44Co44, Pd43Co57 and Pd36Mn28Ru36 in particular exhibited lower overpotentials for oxygen reactions, which occur at the cathode in Li-air batteries. PMID:25965839

  8. Waveguides in Thin Film Polymeric Materials

    NASA Technical Reports Server (NTRS)

    Sakisov, Sergey; Abdeldayem, Hossin; Venkateswarlu, Putcha; Teague, Zedric

    1996-01-01

    Results on the fabrication of integrated optical components in polymeric materials using photo printing methods will be presented. Optical waveguides were fabricated by spin coating preoxidized silicon wafers with organic dye/polymer solution followed by soft baking. The waveguide modes were studied using prism coupling technique. Propagation losses were measured by collecting light scattered from the trace of a propagation mode by either scanning photodetector or CCD camera. We observed the formation of graded index waveguides in photosensitive polyimides after exposure of UV light from a mercury arc lamp. By using a theoretical model, an index profile was reconstructed which is in agreement with the profile reconstructed by the Wentzel-Kramers-Brillouin calculation technique using a modal spectrum of the waveguides. Proposed mechanism for the formation of the graded index includes photocrosslinking followed by UV curing accompanied with optical absorption increase. We also developed the prototype of a novel single-arm double-mode interferometric sensor based on our waveguides. It demonstrates high sensitivity to the chance of ambient temperature. The device can find possible applications in aeropropulsion control systems.

  9. Materials processing in space bibliography

    NASA Technical Reports Server (NTRS)

    Pentecost, E. (Compiler)

    1982-01-01

    Literature dealing with flight experiments utilizing a low gravity environment to elucidate and control various processes or with ground based activities that provide supporting research is listed. Included are Government reports, contractor reports, conference proceedings, and journal articles. Subdivisions of the bibliography include the five categories: crystal growth; metals, alloys, and composites, fluids and transport; glasses and ceramics; and Ultrahigh Vacuum and Containerless Processing Technologies, in addition to a list of patents and a compilation of anonymously authored collections and reports and a cross reference index.

  10. Solution-Processed Indium Oxide Based Thin-Film Transistors

    NASA Astrophysics Data System (ADS)

    Xu, Wangying

    Oxide thin-film transistors (TFTs) have attracted considerable attention over the past decade due to their high carrier mobility and excellent uniformity. However, most of these oxide TFTs are usually fabricated using costly vacuum-based techniques. Recently, the solution processes have been developed due to the possibility of low-cost and large-area fabrication. In this thesis, we have carried out a detailed and systematic study of solution-processed oxide thin films and TFTs. At first, we demonstrated a passivation method to overcome the water susceptibility of solution-processed InZnO TFTs by utilizing octadecylphosphonic acid (ODPA) self-assembled monolayers (SAMs). The unpassivated InZnO TFTs exhibited large hysteresis in their electrical characteristics due to the adsorbed water at the semiconductor surface. Formation of a SAM of ODPA on the top of InZnO removed water molecules weakly absorbed at the back channel and prevented water diffusion from the surroundings. Therefore the passivated devices exhibited significantly reduced hysteretic characteristics. Secondly, we developed a simple spin-coating approach for high- k dielectrics (Al2O3, ZrO2, Y 2O3 and TiO2). These materials were used as gate dielectrics for solution-processed In2O3 or InZnO TFTs. Among the high-k dielectrics, the Al2O3-based devices showed the best performance, which is attributed to the smooth dielectric/semiconductor interface and the low interface trap density besides its good insulating property. Thirdly, the formation and properties of Al2O3 thin films under various annealing temperatures were intensively studied, revealing that the sol-gel-derived Al2O3 thin film undergoes the decomposition of organic residuals and nitrate groups, as well as conversion of aluminum hydroxides to form aluminum oxide. Besides, the Al2O 3 film was used as gate dielectric for solution-processed oxide TFTs, resulting in high mobility and low operating voltage. Finally, we proposed a green route for

  11. Nanocrystalline diamond films: new material for IR optics

    NASA Astrophysics Data System (ADS)

    Konov, Vitali I.; Obraztsova, E. D.; Pimenov, Sergej M.; Ralchenko, Victor G.; Smolin, Andrey A.; Khomich, A. V.; Polyakov, Vladimir I.; Rukovishnikov, A. I.; Perov, Polievet I.; Loubnin, E. N.

    1995-07-01

    Thin nanocrystalline diamond films promising for IR optical applications were grown on Si substrates from methane-hydrogen gas mixture in a DC arc plasma CVD reactor. Three stages for the synthesis of the highly smooth noncrystalline diamond films are important: (i) substrate pretreatment with ultrafine diamond powder, (ii) excimer laser irradiation of seeded substrates, and (iii) two-step deposition process. A correlation between optical properties of the films and growth conditions has been established by means of Raman spectroscopy, spectroscopic ellipsometry and optical transmission spectroscopy techniques. Surface roughness, which was Ra equals 8 - 40 nm for the 1 micrometers thick films, significantly decreased the transmission in the visible because of light scattering, but it had a negligible effect in the IR range. The films are transparent in the IR and have optical constants n equals 2.34-2.36 and k equals 0.005- 0.03. The hydrogen incorporation in the films in amounts up to 1.5% have been deduced from intensity of C-H absorption band around 2900 cm(superscript -1.

  12. Bulk and Thin Film Contact Resistance with Dissimilar Materials

    NASA Astrophysics Data System (ADS)

    Lau, Y. Y.; Zhang, P.; Tang, W.; Gomez, M. R.; French, D. M.; Zier, J. C.; Gilgenbach, R. M.

    2011-10-01

    Contact resistance is important to integrated circuits, thin film devices, carbon nanotube based cathodes, MEMS relays and interconnectors, wire-array z-pinches, metal-insulator-vacuum junctions, and high power microwave sources, etc. This paper summarizes the recent modeling efforts at U of M, addressing the effect of dissimilar materials and of finite dimensions on the contact resistance of both bulk contacts and thin film contacts. Accurate analytical scaling laws are constructed for the contact resistance of both bulk and thin film contacts over a large range of resistivity ratios and aspect ratios in Cartesian and cylindrical geometries. They were validated against known limiting cases; and spot-checks with numerical simulations and experiments. Supported by AFOSR, AFRL, L-3, and Northrop-Grumman.

  13. Densitometric evaluation of four rapid dental film processing solutions.

    PubMed

    Matthee, M J; Seeliger, J E

    1991-09-01

    The aim of this study was to evaluate densitometrically four rapid processing solutions for dental films; also to identify those combinations of film, solution and temperature which produced the best results in terms of radiographic contrast and relative film speed at a given temperature. The film types used were Agfa Dentus M2, Flow X-ray and Kodak Ultra-speed while the rapid processing solutions tested were Kolchem Rapid Dev 1, Kolchem Rapid Dev 2, MEMS Ultra-Neg and Siemens Insta-Neg. An aluminium step-wedge was radiographed under standardized conditions. Processing was done manually at 18, 20, 22, 25, 27, 29 and 32 degrees C, the temperatures being controlled with the aid of two Julabo thermostatically controlled immersion circulators, to ensure constant temperatures. Unexposed films were processed at each temperature setting to determine base plus fog values. Densitometric readings were taken using a digital densitometer, and base plus fog values were subtracted from each reading. Radiographic contrast and relative film speed were calculated and the data obtained subjected to statistical analysis using Duncan's Multiple Range Test. It was concluded that Agfa Dentus M2 film processed with Kolchem Rapid Dev 2 at 18 degrees C gave the highest radiographic contrast of 0.44 and relative film speed of 4.36. All base plus fog values were within the acceptable limit of 0.25. PMID:1820681

  14. Possibilities of Laser Processing of Paper Materials

    NASA Astrophysics Data System (ADS)

    Stepanov, Alexander; Saukkonen, Esa; Piili, Heidi

    Nowadays, lasers are applied in many industrial processes: the most developed technologies include such processes as laser welding, hybrid welding, laser cutting of steel, etc. In addition to laser processing of metallic materials, there are also many industrial applications of laser processing of non-metallic materials, like laser welding of polymers, laser marking of glass and laser cutting of wood-based materials. It is commonly known that laser beam is suitable for cutting of paper materials as well as all natural wood-fiber based materials. This study reveals the potential and gives overview of laser application in processing of paper materials. In 1990's laser technology increased its volume in papermaking industry; lasers at paper industry gained acceptance for different perforating and scoring applications. Nowadays, with reduction in the cost of equipment and development of laser technology (especially development of CO2 technology), laser processing of paper material has started to become more widely used and more efficient. However, there exists quite little published research results and reviews about laser processing of paper materials. In addition, forest industry products with pulp and paper products in particular are among major contributors for the Finnish economy with 20% share of total exports in the year 2013. This has been the standpoint of view and motivation for writing this literature review article: when there exists more published research work, knowledge of laser technology can be increased to apply it for processing of paper materials.

  15. Space processing of electronic materials

    NASA Technical Reports Server (NTRS)

    Holland, L. R.

    1982-01-01

    The bulk growth of solid solution alloys of mercury telluride and cadmium telluride is discussed. These alloys are usually described by the formula Hg1-xCdxTe, and are useful for the construction of infrared detectors. The electronic energy band gap can be controlled between zero and 1.6 electron volts by adjusting the composition x. The most useful materials are at x approximately 20%, suitable for detection wavelengths of about 10 micrometers. The problems of growing large crystals are rooted in the wide phase diagram of the HgTe-CdTe pseudobinary system which leads to exaggerate segregation in freezing, constitutional supercooling, and other difficulties, and in the high vapor pressure of mercury at the growth temperatures, which leads to loss of stoichiometry and to the necessity of working in strong, pressure resistant sealed containers.

  16. Thin film materials and devices for resistive temperature sensing applications

    NASA Astrophysics Data System (ADS)

    Basantani, Hitesh A.

    Thin films of vanadium oxide (VOx) and hydrogenated amorphous silicon (a-Si:H) are the two dominant material systems used in resistive infrared radiation detectors (microbolometers) for sensing long wave infrared (LWIR) wavelengths in the 8--14 microm range. Typical thin films of VO x (x < 2) currently used in the bolometer industry have a magnitude of temperature coefficient of resistance (TCR) between 2%/K -- 3%/K. In contrast, thin films of hydrogenated germanium (SiGe:H) have |TCR| between 3%/K to 4%/K. Devices made from either of these materials have resulted in similar device performance with NETD ≈ 25 mK. The performance of the microbolometers is limited by the electronic noise, especially 1/f noise. Therefore, regardless of the choice of bolometer sensing material and read out circuitry, manufacturers are constantly striving to reduce 1/f noise while simultaneously increasing TCR to give better signal to noise ratios in their bolometers and ultimately, better image quality with more thermal information to the end user. In this work, thin films of VOx and hydrogenated germanium (Ge:H), having TCR values > 4 %/K are investigated as potential candidates for higher sensitivity next generation of microbolometers. Thin films of VO x were deposited by Biased Target Ion Beam Deposition (BTIBD) (˜85 nm thick). Electrical characterization of lateral resistor structures showed resistivity ranging from 104 O--cm to 2.1 x 104 O--cm, TCR varying from --4%/K to --5%/K, normalized Hooge parameter (alphaH/n) of 5 x 10 -21 to 5 x 10-18 cm3. Thin films of Ge:H were deposited by plasma enhanced chemical vapor deposition (PECVD) by incorporating an increasing amount of crystal fraction in the growing thin films. Thin films of Ge:H having a mixed phase, amorphous + nanocrystalline, having a |TCR| > 6 %/K were deposited with resistivity < 2,300 O--cm and a normalized Hooge's parameter 'alphaH/n' < 2 x 10-20 cm3. Higher TCR materials are desired, however, such materials have

  17. Laser Material Processing for Microengineering Applications

    NASA Technical Reports Server (NTRS)

    Helvajian, H.

    1995-01-01

    The processing of materials via laser irradiation is presented in a brief survey. Various techniques currently used in laser processing are outlined and the significance to the development of space qualified microinstrumentation are identified. In general the laser processing technique permits the transferring of patterns (i.e. lithography), machining (i.e. with nanometer precision), material deposition (e.g., metals, dielectrics), the removal of contaminants/debris/passivation layers and the ability to provide process control through spectroscopy.

  18. Mixed metal oxide films as pH sensing materials

    NASA Astrophysics Data System (ADS)

    Arshak, Khalil; Gill, Edric; Korostynska, Olga; Arshak, Arousian

    2007-05-01

    Due to the demand for accurate, reliable and highly sensitive pH sensors, research is being pursued to find novel materials to achieve this goal. Semiconducting metal oxides, such as TiO, SnO and SnO II and insulating oxides such as Nb IIO 5 and Bi IIO 3, and their mixtures in different proportions are being investigated for this purpose. The films of these materials mixtures are used in conjunction with an interdigitated electrode pattern to produce a conductimetric/capacitive pH sensor. The advantages of this approach include straightforward manufacturing, versatility and cost-effectiveness. It was noted that upon contact with a solution, the electrical parameters of the films, such as resistance etc., change. The correlation of these changes with pH values is the basis for the proposed system development. The ultimate goal is to find materials composition, which would have the highest sensitivity towards the pH level of the solutions. It was found that the materials that produced the highest sensitivity either had a long response time or were unstable over a wide pH range. Those exhibiting lower sensitivities were found to be more stable over a wide pH range. All oxide films tested demonstrated a change in electrical parameters upon contact with buffers of known pH value.

  19. Infrared Database for Process Support Materials

    NASA Technical Reports Server (NTRS)

    Bennett, K. E.; Boothe, R. E.; Burns, H. D.

    2003-01-01

    Process support materials' compatibility with cleaning processes is critical to ensure final hardware cleanliness and that performance requirements are met. Previous discovery of potential contaminants in process materials shows the need for incoming materials testing and establishment of a process materials database. The Contamination Control Team of the Materials, Processes, and Manufacturing (MP&M) Department at Marshall Space Flight Center (MSFC) has initiated the development of such an infrared (IR) database, called the MSFC Process Materials IR database, of the common process support materials used at MSFC. These process support materials include solvents, wiper cloths, gloves, bagging materials, etc. Testing includes evaluation of the potential of gloves, wiper cloths, and other items to transfer contamination to handled articles in the absence of solvent exposure, and the potential for solvent exposure to induce material degradation. This Technical Memorandum (TM) summarizes the initial testing completed through December 2002. It is anticipated that additional testing will be conducted with updates provided in future TMs.Materials were analyzed using two different IR techniques: (1) Dry transference and (2) liquid extraction testing. The first of these techniques utilized the Nicolet Magna 750 IR spectrometer outfitted with a horizontal attenuated total reflectance (HATR) crystal accessory. The region from 650 to 4,000 wave numbers was analyzed, and 50 scans were performed per IR spectrum. A dry transference test was conducted by applying each sample with hand pressure to the HATR crystal to first obtain a spectrum of the parent material. The material was then removed from the HATR crystal and analyzed to determine the presence of any residues. If volatile, liquid samples were examined both prior to and following evaporation.The second technique was to perform an extraction test with each sample in five different solvents.Once the scans were complete for

  20. Thin film processing of photorefractive BaTiO3

    NASA Technical Reports Server (NTRS)

    Schuster, Paul R.; Potember, Richard S.

    1991-01-01

    The principle objectives of this ongoing research involve the preparation and characterization of polycrystalline single-domain thin films of BaTiO3 for photorefractive applications. These films must be continuous, free of cracks, and of high optical quality. The two methods proposed are sputtering and sol-gel related processing.

  1. Roadmap for Process Equipment Materials Technology

    SciTech Connect

    none,

    2003-10-01

    This Technology Roadmap addresses the ever-changing material needs of the chemical and allied process industries, and the energy, economic and environmental burdens associated with corrosion and other materials performance and lifetime issues. This Technology Roadmap outlines the most critical of these R&D needs, and how they can impact the challenges facing today’s materials of construction.

  2. Utilizing stretch-tunable thermochromic elastomeric opal films as novel reversible switchable photonic materials.

    PubMed

    Schäfer, Christian G; Lederle, Christina; Zentel, Kristina; Stühn, Bernd; Gallei, Markus

    2014-11-01

    In this work, the preparation of highly thermoresponsive and fully reversible stretch-tunable elastomeric opal films featuring switchable structural colors is reported. Novel particle architectures based on poly(diethylene glycol methylether methacrylate-co-ethyl acrylate) (PDEGMEMA-co-PEA) as shell polymer are synthesized via seeded and stepwise emulsion polymerization protocols. The use of DEGMEMA as comonomer and herein established synthetic strategies leads to monodisperse soft shell particles, which can be directly processed to opal films by using the feasible melt-shear organization technique. Subsequent UV crosslinking strategies open access to mechanically stable and homogeneous elastomeric opal films. The structural colors of the opal films feature mechano- and thermoresponsiveness, which is found to be fully reversible. Optical characterization shows that the combination of both stimuli provokes a photonic bandgap shift of more than 50 nm from 560 nm in the stretched state to 611 nm in the fully swollen state. In addition, versatile colorful patterns onto the colloidal crystal structure are produced by spatial UV-induced crosslinking by using a photomask. This facile approach enables the generation of spatially cross-linked switchable opal films with fascinating optical properties. Herein described strategies for the preparation of PDEGMEMA-containing colloidal architectures, application of the melt-shear ordering technique, and patterned crosslinking of the final opal films open access to novel stimuli-responsive colloidal crystal films, which are expected to be promising materials in the field of security and sensing applications. PMID:25243892

  3. Materials, Processes, and Environmental Engineering Network

    NASA Technical Reports Server (NTRS)

    White, Margo M.

    1993-01-01

    Attention is given to the Materials, Processes, and Environmental Engineering Network (MPEEN), which was developed as a central holding facility for materials testing information generated by the Materials and Processes Laboratory of NASA-Marshall. It contains information from other NASA centers and outside agencies, and also includes the NASA Environmental Information System (NEIS) and Failure Analysis Information System (FAIS) data. The data base is NEIS, which is accessible through MPEEN. Environmental concerns are addressed regarding materials identified by the NASA Operational Environment Team (NOET) to be hazardous to the environment. The data base also contains the usage and performance characteristics of these materials.

  4. Development of Bismuth-based Lead-free Piezoelectric Materials: Thin Film Piezoelectric Materials via PVD and CSD Routes

    NASA Astrophysics Data System (ADS)

    Jeon, Yu Hong

    Piezoelectric materials have been widely used in electromechanical actuators, sensors, and ultrasonic transducers. Among these materials, lead zirconate titanate Pb(Zr1-xTix)O3 (PZT) has been primarily investigated due to its excellent piezoelectric properties. However, environmental concerns due to the toxicity of PbO have led to investigations into alternative materials systems. Bismuth-based perovskite piezoelectric materials such as (Bi0.5,Na0.5)TiO3 - (Bi0.5K 0.5)TiO3 (BNT - BKT), (Bi0.5,Na0.5 )TiO3 - (Bi0.5K0.5)TiO3 - BaTiO3(BNT - BKT - BT), (Bi0.5K 0.5)TiO3 - Bi(Zn0.5,Ti0.5)O 3 (BKT - BZT), and (Bi0.5,Na0.5)TiO 3 - (Bi0.5K0.5)TiO3 - Bi(Mg 0.5,Ti0.5)O3 (BNT - BKT - BMgT) have been explored as potential alternatives to PZT. These materials systems have been extensively studied in bulk ceramic form, however many of the ultimate applications will be in thin film embodiments (i.e., microelectromechanical systems). For this reason, in this thesis these lead-free piezoelectrics are synthesized in thin film form to understand the structure-property-processing relationships and their impact on the ultimate device response. Fabrication of high quality of 0.95BKT - 0.05BZT thin films on platinized silicon substrates was attempted by pulsed laser deposition. Due to cation volatility, deposition parameters such as substrate temperature, deposition pressure, and target-substrate distance, as well as target overdoping were explored to achieve phase pure materials. This route led to high dielectric loss, indicative of poor ferroelectric behavior. This was likely a result of the poor thin film morphology observed in films deposited via this method. Subsequently, 0.8BNT - 0.2BKT, 85BNT - 10BKT - 5BT, and 72.5BNT - 22.5BKT - 5BMgT (near morphotropic phase boundary composition) were synthesized via chemical solution deposition. To compensate the loss of A-site cations, overdoped precursor solutions were prepared. Crystallization after each spin cast layer were required to

  5. Mathematical and physical modelling of materials processing

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Mathematical and physical modeling of turbulence phenomena in metals processing, electromagnetically driven flows in materials processing, gas-solid reactions, rapid solidification processes, the electroslag casting process, the role of cathodic depolarizers in the corrosion of aluminum in sea water, and predicting viscoelastic flows are described.

  6. Precision grinding process development for brittle materials

    SciTech Connect

    Blaedel, K L; Davis, P J; Piscotty, M A

    1999-04-01

    High performance, brittle materials are the materials of choice for many of today's engineering applications. This paper describes three separate precision grinding processes developed at Lawrence Liver-more National Laboratory to machine precision ceramic components. Included in the discussion of the precision processes is a variety of grinding wheel dressing, truing and profiling techniques.

  7. Investigation of solution-processed bismuth-niobium-oxide films

    SciTech Connect

    Inoue, Satoshi; Ariga, Tomoki; Matsumoto, Shin; Onoue, Masatoshi; Miyasako, Takaaki; Tokumitsu, Eisuke; Shimoda, Tatsuya; Chinone, Norimichi; Cho, Yasuo

    2014-10-21

    The characteristics of bismuth-niobium-oxide (BNO) films prepared using a solution process were investigated. The BNO film annealed at 550°C involving three phases: an amorphous phase, Bi₃NbO₇ fluorite microcrystals, and Nb-rich cubic pyrochlore microcrystals. The cubic pyrochlore structure, which was the main phase in this film, has not previously been reported in BNO films. The relative dielectric constant of the BNO film was approximately 140, which is much higher than that of a corresponding film prepared using a conventional vacuum sputtering process. Notably, the cubic pyrochlore microcrystals disappeared with increasing annealing temperature and were replaced with triclinic β-BiNbO₄ crystals at 590°C. The relative dielectric constant also decreased with increasing annealing temperature. Therefore, the high relative dielectric constant of the BNO film annealed at 550°C is thought to result from the BNO cubic pyrochlore structure. In addition, the BNO films annealed at 500°C contained approximately 6.5 atm.% carbon, which was lost at approximately 550°C. This result suggests that the carbon in the BNO film played an important role in the formation of the cubic pyrochlore structure.

  8. Failure and fracture of thin film materials for MEMS

    NASA Astrophysics Data System (ADS)

    Jonnalagadda, Krishna Nagasai

    Design and reliable operation of Microelectromechanical systems (MEMS) depend on the material parameters that influence the failure and fracture properties of brittle and metallic thin films. Failure in brittle materials is quantified by the onset of catastrophic fracture, while in metals, the onset of inelastic deformation is considered as failure as it increases the material compliance. This dissertation research developed new experimental methods to address three aspects on the failure response of these two categories of materials: (a) the role of microstructure and intrinsic stress gradients in the opening mode fracture of mathematically sharp pre-cracks in amorphous and polycrystalline brittle thin films, (b) the critical conditions for mixed mode I/II pre-cracks and their comparison with linear elastic fracture mechanics (LEFM) criteria for crack initiation in homogeneous materials, and (c) the strain rate sensitivity of textured nanocrystalline Au and Pt films with grain sizes of 38 nm and 25 nm respectively. One of the technical objectives of this research was to develop experimental methods and tools that could become standards in MEMS and thin film experimental mechanics. In this regard, a new method was introduced to conduct mode I and mixed mode I/II fracture studies with microscale thin film specimens containing sharp edge pre-cracks. The mode I experiments permitted the direct application of LEFM handbook solutions. On the other hand, the newly introduced mixed mode I/II experiments in thin films were conducted by establishing a new protocol that employs non-standard oblique edge pre-cracks and a numerical analysis based on the J-integral to calculate the stress intensity factors. Similarly, a new experimental protocol has been implemented to carry out experiments with metallic thin films at strain rates that vary by more than six orders of magnitude. The results of mode I fracture experiments concluded that grain inhomogeneity in polycrystalline

  9. High mobility amorphous zinc oxynitride semiconductor material for thin film transistors

    SciTech Connect

    Ye Yan; Lim, Rodney; White, John M.

    2009-10-01

    Zinc oxynitride semiconductor material is produced through a reactive sputtering process in which competition between reactions responsible for the growth of hexagonal zinc oxide (ZnO) and for the growth of cubic zinc nitride (Zn{sub 3}N{sub 2}) is promoted. In contrast to processes in which the reaction for either the oxide or the nitride is dominant, the multireaction process yields a substantially amorphous or a highly disordered nanocrystalline film with higher Hall mobility, 47 cm{sup 2} V{sup -1} s{sup -1} for the as-deposited film produced at 50 deg. C and 110 cm{sup 2} V{sup -1} s{sup -1} after annealing at 400 deg. C. In addition, it has been observed that the Hall mobility of the material increases as the carrier concentration decreases in a carrier concentration range where a multicomponent metal oxide semiconductor, indium-gallium-zinc oxide, follows the opposite trend. This indicates that the carrier transports in the single-metal compound and the multimetal compound are probably dominated by different mechanisms. Film stability and thin film transistor performance of the material have also been tested, and results are presented herein.

  10. Thin film microelectronics materials production in the vacuum of space

    NASA Astrophysics Data System (ADS)

    Ignatiev, A.; Sterling, M.; Horton, C.; Freundlich, A.; Pei, S.; Hill, R.

    1997-01-01

    The international Space Station era will open up a new dimension in the use of one of the unique attributes of space, vacuum, for the production of advanced semiconductor materials and devices for microelectronics applications. Ultra-vacuum is required for the fabrication in thin film form of high quality semiconductors. This can be accomplished behind a free flying platform similar to the current Wake Shield Facility which is specifically designed to support in-space production. The platform will require apparatus for thin film growth, a robotics interface to allow for the change out of raw materials and the harvesting of finished product, and a servicing plant incorporating Space Station that will support long-term utilization of the platform.

  11. Hydrogen gettering packing material, and process for making same

    DOEpatents

    LeMay, James D.; Thompson, Lisa M.; Smith, Henry Michael; Schicker, James R.

    2001-01-01

    A hydrogen gettering system for a sealed container is disclosed comprising packing material for use within the sealed container, and a coating film containing hydrogen gettering material on at least a portion of the surface of such packing material. The coating film containing the hydrogen gettering material comprises a mixture of one or more organic materials capable of reacting with hydrogen and one or more catalysts capable of catalyzing the reaction of hydrogen with such one or more organic materials. The mixture of one or more organic materials capable of reacting with hydrogen and the one or more catalysts is dispersed in a suitable carrier which preferably is a curable film-forming material. In a preferred embodiment, the packing material comprises a foam material which is compatible with the coating film containing hydrogen gettering material thereon.

  12. Photo-thermal processing of semiconductor fibers and thin films

    NASA Astrophysics Data System (ADS)

    Gupta, Nishant

    Furnace processing and rapid thermal processing (RTP) have been an integral part of several processing steps in semiconductor manufacturing. The performance of RTP techniques can be improved many times by exploiting quantum photo-effects of UV and vacuum ultraviolet (VUV) photons in thermal processing and this technique is known as rapid photo-thermal processing (RPP). As compared to furnace processing and RTP, RPP provides higher diffusion coefficient, lower stress and lower microscopic defects. In this work, a custom designed automated photo assisted processing system was built from individual parts and an incoherent light source. This photo-assisted processing system is used to anneal silica clad silicon fibers and deposit thin-films. To the best of our knowledge, incoherent light source based rapid photo-thermal processing (RPP) was used for the first time to anneal glass-clad silicon core optical fibers. X-ray diffraction examination, Raman spectroscopy and electrical measurements showed a considerable enhancement of structural and crystalline properties of RPP treated silicon fibers. Photons in UV and vacuum ultraviolet (VUV) regions play a very important role in improving the bulk and carrier transport properties of RPP-treated silicon optical fibers, and the resultant annealing permits a path forward to in situ enhancement of the structure and properties of these new crystalline core optical fibers. To explore further applications of RPP, thin-films of Calcium Copper Titanate (CaCu3Ti4O12) or CCTO and Copper (I) Oxide (Cu2O) were also deposited using photo-assisted metal-organic chemical vapor deposition (MOCVD) on Si/SiO2 and n-Si substrate respectively. CCTO is one of the most researched giant dielectric constant materials in recent years. The given photo-assisted MOCVD approach provided polycrystalline CCTO growth on a SiO2 surface with grain sizes as large as 410 nm. Copper (I) oxide (Cu2O) is a direct band gap semiconductor with p-type conductivity and

  13. Dual-mode ion switching conducting polymer films as high energy supercapacitor materials

    SciTech Connect

    Naoi, Katsuhiko; Oura, Yasushi

    1995-12-31

    The electropolymerized polypyrrole films formed from micellar solution of anionic surfactants, viz., Dodecylbenzene sulfonate (DBS), showed potential-dependent anion and cation ion switching behavior and the peculiar columnar structure. The formation process and the redox of the polypyrrole was studied with the in situ atomic force microscopy (AFM) and electrochemical quartz crystal microbalance (EQCM) methods. In-situ AFM observation clearly indicated that such a columnar structure started to form around critical charge densities of 60--100 mC cm{sup {minus}2}. The cyclic voltammogram for the PPy doped with DBS{sup {minus}} film showed two redox couples, each of which corresponds to a cation and an anion exchange process. Thus, the film behaves as a dual-mode ion doping/undoping exchanger. As the PPy film was prepared in higher concentration of the surfactant dopant, where the micelles are formed in solution, the resulting film showed a considerably higher (ca. three orders of magnitude) diffusion coefficient compared to ordinary PPy films so far reported. Such an enhanced diffusivity of ions could be attributed to a peculiar structure of the polymer formed. The feasibility of such polypyrrole in use of supercapacitor material was discussed.

  14. Do Films Make You Learn? Inference Processes in Expository Film Comprehension

    ERIC Educational Resources Information Center

    Tibus, Maike; Heier, Anke; Schwan, Stephan

    2013-01-01

    The present article examines how suitable expository films are for learning. This question was motivated by the assumption that films are processed in a superficial manner. However, previous research has been dominated by the analyses of outcome measures and has never taken a look at online measures so that no clear conclusions have been drawn.…

  15. Optical storage in azobenzene-containing epoxy polymers processed as Langmuir Blodgett films.

    PubMed

    Fernández, Raquel; Mondragon, Iñaki; Sanfelice, Rafaela C; Pavinatto, Felippe J; Oliveira, Osvaldo N; Oyanguren, Patricia; Galante, María J

    2013-04-01

    In this study, azocopolymers containing different main-chain segments have been synthesized with diglycidyl ether of bisphenol A (DGEBA, DER 332, n=0.03) and the azochromophore Disperse Orange 3 (DO3) cured with two monoamines, viz. benzylamine (BA) and m-toluidine (MT). The photoinduced birefringence was investigated in films produced with these azopolymers using the spin coating (SC) and Langmuir Blodgett (LB) techniques. In the LB films, birefringence increased with the content of azochromophore and the film thickness, as expected. The nanostructured nature of the LB films led to an enhanced birefringence and faster dynamics in the writing process, compared to the SC films. In summary, the combination of azocopolymers and the LB method may allow materials with tuned properties for various optical applications, including in biological systems were photoisomerization may be used to trigger actions such as drug delivery. PMID:23827588

  16. ALD/MLD processes for Mn and Co based hybrid thin films.

    PubMed

    Ahvenniemi, E; Karppinen, M

    2016-06-28

    Here we report the growth of novel transition metal-organic thin-film materials consisting of manganese or cobalt as the metal component and terephthalate as the rigid organic backbone. The hybrid thin films are deposited by the currently strongly emerging atomic/molecular layer deposition (ALD/MLD) technique using the combination of a metal β-diketonate, i.e. Mn(thd)3, Co(acac)3 or Co(thd)2, and terephthalic acid (1,4-benzenedicarboxylic acid) as precursors. All the processes yield homogeneous and notably smooth amorphous metal-terephthalate hybrid thin films with growth rates of 1-2 Å per cycle. The films are stable towards humidity and withstand high temperatures up to 300 or 400 °C under an oxidative or a reductive atmosphere. The films are characterized with XRR, AFM, GIXRD, XPS and FTIR techniques. PMID:27277668

  17. Positron annihilation studies of vacancy related defects in ceramic and thin film Pb(Zr,Ti)O{sub 3} materials

    SciTech Connect

    Keeble, D.J.; Krishnan, A.; Umlor, M.T.; Lynn, K.G.; Warren, W.L.; Dimos, D.; Tuttle, B.A.; Ramesh, R.; Poindexter, E.H.

    1994-07-01

    Preliminary positron annihilation studies of ceramic and thin film Pb(Zr,Ti)O{sub 3} (PZT) materials have been completed. This paper examines effects of processing conditions on vacancy related defects. Positron lifetime measurements on bulk PLZT plates showed an increase in positron trapping to a defect state with increasing grain size consistent with trapping to lead vacancy related defects formed through lead oxide loss during processing. Variable energy positron beam measurements were completed on bulk PLZT plates, sol-gel PZT thin films and laser ablated PLZT thin films. Films processed in a reduced oxygen atmosphere were found to give a higher S-parameter, due to an increase in concentration of neutral or negatively charged vacancy type defects, compared with material processed in an oxidizing ambient.

  18. Selectiveness of laser processing due to energy coupling localization: case of thin film solar cell scribing

    NASA Astrophysics Data System (ADS)

    Račiukaitis, G.; Grubinskas, S.; Gečys, P.; Gedvilas, M.

    2013-07-01

    Selectiveness of the laser processing is the top-most important for applications of the processing technology in thin-film electronics, including photovoltaics. Coupling of laser energy in multilayered thin-film structures, depending on photo-physical properties of the layers and laser wavelength was investigated experimentally and theoretically. Energy coupling within thin films highly depends on the film structure. The finite element and two-temperature models were applied to simulate the energy and temperature distributions inside the stack of different layers of a thin-film solar cell during a picosecond laser irradiation. Reaction of the films to the laser irradiation was conditioned by optical properties of the layers at the wavelength of laser radiation. Simulation results are consistent with the experimental data achieved in laser scribing of copper-indium-gallium diselenide (CIGS) solar cells on a flexible polymer substrate using picosecond-pulsed lasers. Selection of the right laser wavelength (1064 nm or 1572 nm) enabled keeping the energy coupling in a well-defined volume at the interlayer interface. High absorption at inner interface of the layers triggered localized temperature increase. Transient stress caused by the rapid temperature rise facilitating peeling of the films rather than evaporation. Ultra-short pulses ensured high energy input rate into absorbing material permitting peeling of the layers with no influence on the remaining material.

  19. Physical and Material Properties of Yttrium Barium Copper Oxide High Critical Temperature Superconducting Thin Films.

    NASA Astrophysics Data System (ADS)

    Ma, Qiyuan

    1990-01-01

    A simple method of using layered structures and rapid thermal annealing to produce Y_1 Ba_2 Cu_3 O_{7-x} (YBCO) superconducting thin films is presented. Material properties of the films depend strongly on the processing conditions, the film stoichiometry, and the substrates. The films with critical temperature (T_{ rm c}) higher than liquid nitrogen temperature (77 K) have been made on various substrates including magnesium oxide, sapphire, and silicon. The best film was obtained on a MgO substrate with T_{rm c} of 84 K. Silicon diffusion and reaction with oxygen during a high temperature anneal degrade the superconductivity of the film on a Si substrate. Using a buffer layer of gold, the Si-YBCO interaction is greatly reduced. Typical resistivity of the film shows a linear temperature dependence which may be attributed to an electron -phonon interaction. Anisotropic resistance behavior has been observed due to the layered structures. Different metal contacts to the YBCO films have been used to study the chemical and electrical properties of metal-YBCO film interfaces. Gold has been found nonreactive to YBCO film, thus, it has the lowest contact resistivity. Near the T_{rm c}, the contact resistivity of a Au-YBCO contact approaches zero. This may be due to the proximity effect. Other metals such as Pt, Pd, Sn and Ti, react with the YBCO film and form thin oxide layers at the interfaces. The oxide layer acts as an insulating barrier which forbids the proximity effect and causes a large contact resistivity. The structural and electrical properties of the Si-YBCO intermixed film have been studied for different thicknesses of the silicon layers. A novel patterning technique of using Si-YBCO intermixing has been developed for fabricating the YBCO superconducting device structures. A superconductor sample has a critical current value I _{rm c}. Below the I _{rm c} the material is superconducting, and above I_{rm c} the sample has a finite resistance. Based on this effect

  20. Ablation of film stacks in solar cell fabrication processes

    SciTech Connect

    Harley, Gabriel; Kim, Taeseok; Cousins, Peter John

    2013-04-02

    A dielectric film stack of a solar cell is ablated using a laser. The dielectric film stack includes a layer that is absorptive in a wavelength of operation of the laser source. The laser source, which fires laser pulses at a pulse repetition rate, is configured to ablate the film stack to expose an underlying layer of material. The laser source may be configured to fire a burst of two laser pulses or a single temporally asymmetric laser pulse within a single pulse repetition to achieve complete ablation in a single step.

  1. Metabonomics for detection of nuclear materials processing.

    SciTech Connect

    Alam, Todd Michael; Luxon, Bruce A.; Neerathilingam, Muniasamy; Ansari, S.; Volk, David; Sarkar, S.; Alam, Mary Kathleen

    2010-08-01

    Tracking nuclear materials production and processing, particularly covert operations, is a key national security concern, given that nuclear materials processing can be a signature of nuclear weapons activities by US adversaries. Covert trafficking can also result in homeland security threats, most notably allowing terrorists to assemble devices such as dirty bombs. Existing methods depend on isotope analysis and do not necessarily detect chronic low-level exposure. In this project, indigenous organisms such as plants, small mammals, and bacteria are utilized as living sensors for the presence of chemicals used in nuclear materials processing. Such 'metabolic fingerprinting' (or 'metabonomics') employs nuclear magnetic resonance (NMR) spectroscopy to assess alterations in organismal metabolism provoked by the environmental presence of nuclear materials processing, for example the tributyl phosphate employed in the processing of spent reactor fuel rods to extract and purify uranium and plutonium for weaponization.

  2. Solution-processed Optoelectronic Devices from Colloidal Inorganic Semiconductor Materials

    NASA Astrophysics Data System (ADS)

    Tchieu, Andrew A.

    This dissertation contains design, synthesis, fabrication and testing of optoelectronic devices which are composed of colloidal inorganic semiconductor materials and fabricated by potentially low-cost solution-processing methods. The first part of this dissertation demonstrates a novel fabrication method where colloidal quantum dots (QDs) are self-assembled layer-by-layer into a thin film structure through electrostatic interaction. This process allows precise control of QD thin film thickness by self-assembly and can in principle be applied to a wide range of substrates. Using such QD thin films, photoconductor photodetectors and metal-intrinsic-metal photodiodes have been demonstrated. In the second part of this dissertation, heavy-metal-free colloidal Si materials are synthesized by electrochemical etching Si wafers, followed by surface modification and ultra-sonication for dispersion of Si nano- and/or micro-particles in various solvents. Demonstrated applications include RGB photoluminescent Si phosphors, scattering-enhanced Si nano-/micro-particle composite photodetectors and hybrid Si QD-organic light-emitting-diodes (LEDs).

  3. Fluid bed technology in materials processing

    SciTech Connect

    Gupta, C.K.; Sathiyamoorthy, D.

    1999-01-01

    The author explores the various aspects of fluidization engineering and examines its applications in a multitude of materials processing techniques. Topics include process metallurgy, fluidization in nuclear engineering, and the pros and cons of various fluidization equipment. Gupta emphasizes fluidization engineering in high temperature processing, and high temperature fluidized bed furnaces.

  4. Planning for Materials Processing in Space

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A systems design study to describe the conceptual evolution, the institutional interrelationshiphs, and the basic physical requirements to implement materials processing in space was conducted. Planning for a processing era, rather than hardware design, was emphasized. Product development in space was examined in terms of fluid phenomena, phase separation, and heat and mass transfer. The effect of materials processing on the environment was studied. A concept for modular, unmanned orbiting facilities using the modified external tank of the space shuttle is presented. Organizational and finding structures which would provide for the efficient movement of materials from user to space are discussed.

  5. Spray Chemical Vapor Deposition of Single-Source Precursors for Chalcopyrite I-III-VI2 Thin-Film Materials

    NASA Technical Reports Server (NTRS)

    Hepp, Aloysius F.; Banger, Kulbinder K.; Jin, Michael H.-C.; Harris, Jerry D.; McNatt, Jeremiah S.; Dickman, John E.

    2008-01-01

    Thin-film solar cells on flexible, lightweight, space-qualified substrates provide an attractive approach to fabricating solar arrays with high mass-specific power. A polycrystalline chalcopyrite absorber layer is among the new generation of photovoltaic device technologies for thin film solar cells. At NASA Glenn Research Center we have focused on the development of new single-source precursors (SSPs) for deposition of semiconducting chalcopyrite materials onto lightweight, flexible substrates. We describe the syntheses and thermal modulation of SSPs via molecular engineering. Copper indium disulfide and related thin-film materials were deposited via aerosol-assisted chemical vapor deposition using SSPs. Processing and post-processing parameters were varied in order to modify morphology, stoichiometry, crystallography, electrical properties, and optical properties to optimize device quality. Growth at atmospheric pressure in a horizontal hotwall reactor at 395 C yielded the best device films. Placing the susceptor closer to the evaporation zone and flowing a more precursor-rich carrier gas through the reactor yielded shinier-, smoother-, and denser-looking films. Growth of (112)-oriented films yielded more Cu-rich films with fewer secondary phases than growth of (204)/(220)-oriented films. Post-deposition sulfur-vapor annealing enhanced stoichiometry and crystallinity of the films. Photoluminescence studies revealed four major emission bands and a broad band associated with deep defects. The highest device efficiency for an aerosol-assisted chemical vapor deposited cell was one percent.

  6. Electrohydrodynamic processing and characterisation of titanium dioxide films

    NASA Astrophysics Data System (ADS)

    Mahalingam, Suntharavathanan

    The research in this thesis demonstrates a novel electrohydrodynamic preparation of titanium dioxide (TiC>2) films. In this process, a liquid breaks up into spray droplets under influence of an electric field. This process is influenced by many factors properties of the liquid - surface tension, electrical conductivity, relative permittivity, viscosity, density and liquid flow rate and applied voltage. This technique has unique advantage like simple set-up and economical way to formulate the films. Many modes of processing were identified by drawing the mode-selection map for various applied voltage and flow rate using a titania sol. For a fixed flow rate, changing the applied voltage changed the processing mode. For a fixed applied voltage, changing the flow rate changed the shape of the liquid filament at the end of the needle. The stable cone-jet mode processing produced a near mono-disperse of droplets. The stable cone-jet processing of TiC>2 films showed anatase phase and converted to rutile phase at higher annealing temperature. The morphological characterisation revealed the dense and crack free surfaces of the TiC>2 films. The dielectric constant of the electrohydrodynamically processed TiC>2 films was 7. The increase in annealing temperature reduced the dielectric constant of the films. The leakage current density of the films was improved by post deposition annealing. The optical characterisation of the films showed a good transparency in the visible light region. The transmission in the visible range varied between 70-90%. The annealing temperature influenced the transmittance of the films. The energy bandgap is -3.50 eV for indirect transition. The larger coverage area nitrogen doped titanium dioxide films were obtained by using a metal clamped needle - ground electrode set-up for the first time. Metal clamping the needle lowered the stable cone-jet operating voltage window. The nitrogen doping in TiC>2 films retarded the phase formation however, showed

  7. Materials, processes, and environmental engineering network

    NASA Technical Reports Server (NTRS)

    White, Margo M.

    1993-01-01

    The Materials, Processes, and Environmental Engineering Network (MPEEN) was developed as a central holding facility for materials testing information generated by the Materials and Processes Laboratory. It contains information from other NASA centers and outside agencies, and also includes the NASA Environmental Information System (NEIS) and Failure Analysis Information System (FAIS) data. Environmental replacement materials information is a newly developed focus of MPEEN. This database is the NASA Environmental Information System, NEIS, which is accessible through MPEEN. Environmental concerns are addressed regarding materials identified by the NASA Operational Environment Team, NOET, to be hazardous to the environment. An environmental replacement technology database is contained within NEIS. Environmental concerns about materials are identified by NOET, and control or replacement strategies are formed. This database also contains the usage and performance characteristics of these hazardous materials. In addition to addressing environmental concerns, MPEEN contains one of the largest materials databases in the world. Over 600 users access this network on a daily basis. There is information available on failure analysis, metals and nonmetals testing, materials properties, standard and commercial parts, foreign alloy cross-reference, Long Duration Exposure Facility (LDEF) data, and Materials and Processes Selection List data.

  8. Photoacoustic characterization of the mechanical properties of thin film materials

    NASA Astrophysics Data System (ADS)

    Zhang, Feifei; Krishnaswamy, Sridhar; Fei, Dong; Rebinsky, Douglas A.

    2005-05-01

    Two high frequency photoacoustic techniques were applied to investigate the mechanical properties of two sets of thin film materials in this work. Broadband photoacoustic guided-wave method was used to measure the guided-wave phase velocity dispersion curves of nano-structured diamond-like carbon hard coatings. The experimental velocity spectra were analyzed by a nonlinear optimization approach in conjunction with a multi-layer wave-propagation model. The derived Young"s moduli using the broadband photoacoustic technique were compared with line-focus acoustic microscopy and nano-indentation tests and good quantitative agreement is found. In a second set of experiments, ultra-thin two-layer aluminum and silicon nitride thin film materials were tested using the femtosecond transient pump-probe method using high frequency bulk waves generated by the ultra-fast laser pulses. The measured moduli of silicon nitride thin layers are in the range of 270 - 340 GPa. Photoacoustic methods are shown to be suitable for in-situ and non-destructive evaluation of the mechanical properties of thin films.

  9. Effects of acetylacetone additions on PZT thin film processing

    SciTech Connect

    Schwartz, R.W.; Assink, R.A.; Dimos, D.; Sinclair, M.B.; Boyle, T.J.; Buchheit, C.D.

    1995-02-01

    Sol-gel processing methods are frequently used for the fabrication of lead zirconate titanate (PZT) thin films for many electronic applications. Our standard approach for film fabrication utilizes lead acetate and acetic acid modified metal alkoxides of zirconium and titanium in the preparation of our precursor solutions. This report highlights some of our recent results on the effects of the addition of a second chelating ligand, acetylacetone, to this process. The authors discuss the changes in film drying behavior, densification and ceramic microstructure which accompany acetylacetone additions to the precursor solution and relate the observed variations in processing behavior to differences in chemical precursor structure induced by the acetylacetone ligand. Improvements in thin film microstructure, ferroelectric and optical properties are observed when acetylacetone is added to the precursor solution.

  10. Thin-film perovskites-ferroelectric materials for integrated optics

    SciTech Connect

    Walker, F.J. |; McKee, R.A.

    1995-12-31

    Optical guided wave (OGW) devices, based on LiNbO{sub 3} or GaAs. are commercially available products with established markets and applications. While LiNbO{sub 3} presently dominates the commercial applications, there are several drivers for the development of improved electro-optic (EO) materials. If the appropriate crystal quality could be obtained for thin-film BaTiO{sub 3} supported on MgO for example, or for an integrated BaTiO{sub 3}/Mg0 structure on silicon or GaAs, then the optimum OGW device structure might be realized. We report on our results for the growth of optical quality, epitaxial BaTiO{sub 3} and SrTiO{sub 3} on single-crystal MgO substrates using source shuttering molecular beam epitaxy (MBE) techniques. We also discuss how these materials can be integrated onto silicon. Our MBE studies show that, for this important class of perovskite oxides, heteroepitaxy between the perovskites and alkaline earth oxides is dominated by interfacial electrostatics at the first atomic layers. We have been able to demonstrate that a layer-by-layer energy minimization associated with interfacial electrostatics leads to the growth of high quality thin films of these materials. We have fabricated waveguides from these materials, and the optical clarity and loss coefficients have been characterized and found to be comparable to in-diffused waveguide structures typically represented by Ti drifted LiNbO{sub 3}.

  11. The Constitutive Modeling of Thin Films with Randon Material Wrinkles

    NASA Technical Reports Server (NTRS)

    Murphey, Thomas W.; Mikulas, Martin M.

    2001-01-01

    Material wrinkles drastically alter the structural constitutive properties of thin films. Normally linear elastic materials, when wrinkled, become highly nonlinear and initially inelastic. Stiffness' reduced by 99% and negative Poisson's ratios are typically observed. This paper presents an effective continuum constitutive model for the elastic effects of material wrinkles in thin films. The model considers general two-dimensional stress and strain states (simultaneous bi-axial and shear stress/strain) and neglects out of plane bending. The constitutive model is derived from a traditional mechanics analysis of an idealized physical model of random material wrinkles. Model parameters are the directly measurable wrinkle characteristics of amplitude and wavelength. For these reasons, the equations are mechanistic and deterministic. The model is compared with bi-axial tensile test data for wrinkled Kaptong(Registered Trademark) HN and is shown to deterministically predict strain as a function of stress with an average RMS error of 22%. On average, fitting the model to test data yields an RMS error of 1.2%

  12. Magnetization Processes During FM Transitions of Supercooled Er Films

    NASA Astrophysics Data System (ADS)

    Durfee, C. S.; Flynn, C. P.

    2000-03-01

    FM transitions are generally accompanied by dimensional changes of the crystal lattice. In magnetic films, the in-plane dimensional changes are inhibited by clamping to the substrate, creating a rich variety of phenomena (e.g. supercooling, dislocation formation and motion, bowing of dislocations, and altered magnetization processes), which can be directly observed with x-rays. Here we characterize the magnetization processes exhibited by unstrained Er films. Below the Curie temperature, the film exhibits supercooling, remaining in a metastable non-FM state and only relaxing to the FM state when a magnetic field is applied. This occurs by two distinct processes. The first process, which broadens the x-ray line shape, is nucleation and growth of FM domains. The second, which produces no line broadening, is isotropic magnetization of the entire film. Once magnetized, the film remains in the FM state until the temperature is raised several degrees above the Curie temperature, at which point the film relaxes to the non-FM state via one of these two paths. This process depends on the temperature when the field is removed.

  13. Chalcogenide phase-change thin films used as grayscale photolithography materials.

    PubMed

    Wang, Rui; Wei, Jingsong; Fan, Yongtao

    2014-03-10

    Chalcogenide phase-change thin films are used in many fields, such as optical information storage and solid-state memory. In this work, we present another application of chalcogenide phase-change thin films, i.e., as grayscale photolithgraphy materials. The grayscale patterns can be directly inscribed on the chalcogenide phase-change thin films by a single process through direct laser writing method. In grayscale photolithography, the laser pulse can induce the formation of bump structure, and the bump height and size can be precisely controlled by changing laser energy. Bumps with different height and size present different optical reflection and transmission spectra, leading to the different gray levels. For example, the continuous-tone grayscale images of lifelike bird and cat are successfully inscribed onto Sb(2)Te(3) chalcogenide phase-change thin films using a home-built laser direct writer, where the expression and appearance of the lifelike bird and cat are fully presented. This work provides a way to fabricate complicated grayscale patterns using laser-induced bump structures onto chalcogenide phase-change thin films, different from current techniques such as photolithography, electron beam lithography, and focused ion beam lithography. The ability to form grayscale patterns of chalcogenide phase-change thin films reveals many potential applications in high-resolution optical images for micro/nano image storage, microartworks, and grayscale photomasks. PMID:24663836

  14. Front and backside processed thin film electronic devices

    DOEpatents

    Yuan, Hao-Chih; Wang, Guogong; Eriksson, Mark A.; Evans, Paul G.; Lagally, Max G.; Ma, Zhenqiang

    2010-10-12

    This invention provides methods for fabricating thin film electronic devices with both front- and backside processing capabilities. Using these methods, high temperature processing steps may be carried out during both frontside and backside processing. The methods are well-suited for fabricating back-gate and double-gate field effect transistors, double-sided bipolar transistors and 3D integrated circuits.

  15. Method for double-sided processing of thin film transistors

    DOEpatents

    Yuan, Hao-Chih; Wang, Guogong; Eriksson, Mark A.; Evans, Paul G.; Lagally, Max G.; Ma, Zhenqiang

    2008-04-08

    This invention provides methods for fabricating thin film electronic devices with both front- and backside processing capabilities. Using these methods, high temperature processing steps may be carried out during both frontside and backside processing. The methods are well-suited for fabricating back-gate and double-gate field effect transistors, double-sided bipolar transistors and 3D integrated circuits.

  16. Laser Materials Processing for NASA's Aerospace Structural Materials

    NASA Technical Reports Server (NTRS)

    Nagarathnam, Karthik; Hunyady, Thomas A.

    2001-01-01

    Lasers are useful for performing operations such as joining, machining, built-up freeform fabrication, and surface treatment. Due to the multifunctional nature of a single tool and the variety of materials that can be processed, these attributes are attractive in order to support long-term missions in space. However, current laser technology also has drawbacks for space-based applications. Specifically, size, power efficiency, lack of robustness, and problems processing highly reflective materials are all concerns. With the advent of recent breakthroughs in solidstate laser (e.g., diode-pumped lasers) and fiber optic technologies, the potential to perform multiple processing techniques in space has increased significantly. A review of the historical development of lasers from their infancy to the present will be used to show how these issues may be addressed. The review will also indicate where further development is necessary to realize a laser-based materials processing capability in space. The broad utility of laser beams in synthesizing various classes of engineering materials will be illustrated using state-of-the art processing maps for select lightweight alloys typically found on spacecraft. Both short- and long-term space missions will benefit from the development of a universal laser-based tool with low power consumption, improved process flexibility, compactness (e.g., miniaturization), robustness, and automation for maximum utility with a minimum of human interaction. The potential advantages of using lasers with suitable wavelength and beam properties for future space missions to the moon, Mars and beyond will be discussed. The laser processing experiments in the present report were performed using a diode pumped, pulsed/continuous wave Nd:YAG laser (50 W max average laser power), with a 1064 nm wavelength. The processed materials included Ti-6AI-4V, Al-2219 and Al-2090. For Phase I of this project, the laser process conditions were varied and optimized

  17. Aqueous processing in materials science and engineering

    NASA Astrophysics Data System (ADS)

    Mooiman, Michael B.; Sole, Kathryn C.

    1994-06-01

    Reviews of aqueous processing in JOM have traditionally focused on hydrometallurgical process routes. This article, however, addresses the application of aqueous processing in materials engineering and presents some promising developments that employ aqueous-based routes for the manufacture of high-tech components and specialty products. Such applications include producing metallic and ceramic powders; etching; surface modification by electroplating and electroless plating; manufacturing jewelry and intricate components by electroforming; and producing advanced ceramics, composites, and nanophase materials by sol-gel and biomimetic processing.

  18. The processing of materials in outer space

    NASA Technical Reports Server (NTRS)

    Gelles, S. H.; Colling, E. W.

    1977-01-01

    Zero-gravity environment may lead to fabrication of new and improved materials. According to comprehensive study of application of this promising technology to superconducting and electrical contact materials, outer space processing could improve microstructure and homogeneity of many single and multicomponent systems formed from solidification of fluid phases. New structures that are impossible to form terrestrially may also be accessible in space environment.

  19. ATMOSPHERIC PROCESSES AND EFFECTS ON MATERIALS

    EPA Science Inventory

    These two chapters summarize the effects expected from the depletion of stratospheric ozone by the presence of CFCs. he two areas considered by these two reports are materials damage and atmospheric processes. ncreased UV can affect materials in the following ways: (1) corrosion ...

  20. Material removal processes: Engineering mechanics consideration

    SciTech Connect

    Anderson, C.A.

    1993-01-01

    In the material removal process called machining, a layer of material of constant thickness is removed from the workpiece by a wedge-shaped tool that travels parallel to the workpiece at a preselected depth. Even though the speed of relative movement between workpiece and tool is low (typical 1--10 M/S), the strain-rates in the workpiece near the tool can be high, on the order of 10[sup 4]-10[sup 5] s[sup [minus]1]. When machining brittle materials or unlubricated ductile materials at low speed, the removed metal (or chip) will be discontinuous and made up of small fractured segments. On the other hand, when machining ductile material under lubricated conditions, the removed material forms a continuous coil. In this case, we can represent the material removal process as a steady-state process. In this presentation, we will restrict ourselves to orthogonal machining where the cutting edge is perpendicular to the relative motion-a situation also approximated by other material removal processes such as planing and broaching, and turning on a lathe.

  1. Material removal processes: Engineering mechanics consideration

    SciTech Connect

    Anderson, C.A.

    1993-04-01

    In the material removal process called machining, a layer of material of constant thickness is removed from the workpiece by a wedge-shaped tool that travels parallel to the workpiece at a preselected depth. Even though the speed of relative movement between workpiece and tool is low (typical 1--10 M/S), the strain-rates in the workpiece near the tool can be high, on the order of 10{sup 4}-10{sup 5} s{sup {minus}1}. When machining brittle materials or unlubricated ductile materials at low speed, the removed metal (or chip) will be discontinuous and made up of small fractured segments. On the other hand, when machining ductile material under lubricated conditions, the removed material forms a continuous coil. In this case, we can represent the material removal process as a steady-state process. In this presentation, we will restrict ourselves to orthogonal machining where the cutting edge is perpendicular to the relative motion-a situation also approximated by other material removal processes such as planing and broaching, and turning on a lathe.

  2. Heat and mass transfer in materials processing

    NASA Astrophysics Data System (ADS)

    Tanasawa, Ichiro; Lior, Noam

    Various papers on heat and mass transfer in materials processing are presented. The topics addressed include: heat transfer in plasma spraying, structure of ultrashort pulse plasma for CVD processing, heat flow and thermal contraction during plasma spray deposition, metal melting process by laser heating, improved electron beam weld design and control with beam current profile measurements, transport phenomena in laser materials processing, perspectives on integrated modeling of transport processes in semiconductor crystal growth, numerical simulation of natural convection in crystal growth in space and on the earth, conjugate heat transfer in crystal growth, effects of convection on the solidification of binary mixtures. Also discussed are: heat transfer in in-rotating-liquid-spinning process, thermal oscillations in materials processing, modeling and simulation of manufacturing processes of advanced composite materials, reaction engineering principles of combustion synthesis of advanced materials, numerical evaluation of the physical properties of magnetic fluids suitable for heat transfer control, and measurement techniques of thermophysical properties of high temperature melts. (For individual items see A93-10827 to A93-10843)

  3. Extraterrestrial materials processing and construction. [space industrialization

    NASA Technical Reports Server (NTRS)

    Criswell, D. R.; Waldron, R. D.; Mckenzie, J. D.

    1980-01-01

    Three different chemical processing schemes were identified for separating lunar soils into the major oxides and elements. Feedstock production for space industry; an HF acid leach process; electrorefining processes for lunar free metal and metal derived from chemical processing of lunar soils; production and use of silanes and spectrally selective materials; glass, ceramics, and electrochemistry workshops; and an econometric model of bootstrapping space industry are discussed.

  4. Electronic materials processing and the microgravity environment

    NASA Technical Reports Server (NTRS)

    Witt, A. F.

    1988-01-01

    The nature and origin of deficiencies in bulk electronic materials for device fabrication are analyzed. It is found that gravity generated perturbations during their formation account largely for the introduction of critical chemical and crystalline defects and, moreover, are responsible for the still existing gap between theory and experiment and thus for excessive reliance on proprietary empiricism in processing technology. Exploration of the potential of reduced gravity environment for electronic materials processing is found to be not only desirable but mandatory.

  5. Growth processes and surface properties of diamondlike carbon films

    NASA Astrophysics Data System (ADS)

    Liu, Dongping; Zhang, Jialiang; Liu, Yanhong; Xu, Jun; Benstetter, Günther

    2005-05-01

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

  6. Magnetic anisotropy and permeability in sputtered iron aluminum nitride thin-film materials

    NASA Astrophysics Data System (ADS)

    Liu, Yi-Kuang

    Significant improvement in magnetic properties of FeXN (X = Al, Zr, Ta...) thin films deposited on the sloping surfaces, especially at 60°, was achieved by using various interlayer materials or proper sputtering conditions. The oblique incidence problems in permalloy and CoZrRe thin films were also greatly improved. Test heads fabricated using these materials showed improved permeability. Significant improvement of the thermal stability in FeXN thin films was also achieved. Sputtered at the reduced target-substrate spacing of 38 mm, 200 nm thick thermally stable FeXN thin films were obtained. They had hard axis coercivity ≈0.1--2.0 Oe, easy axis coercivity ≈1.5--3.0 Oe, Hk = 8--16 Oe and Bs = 19--20 kG. Results from transverse field annealing experiments in a uniform field of 700 Oe show no significant change of magnetic properties at 150°C for 3 hours. At 150°C for 24 hours, Hk decreased by 2--4 Oe. Their easy/hard axes did not rotate and the coercivity remained almost unchanged. This superior thermal stability of FeXN films is promising for high moment write heads. The effects of N doping on the magnetic and structural properties of a series of 100 nm FeAlN films sputtered in the presence of N partial pressures were investigated. Increasing N doping increased film resistivity but decreased MS. Extended x-ray absorption fine structure spectra of the short-range atomic order in the Fe(Al) lattices directly indicated that the N went into octahedral sites of bcc Fe and fcc Fe in alpha-Fe and gamma'-Fe 4N phases, respectively, and triggered the order-disorder phase transition observed in x-ray 0--20 diffraction spectra. Mild N doping decreased the grain size and reduced Hc. It also increased the local atomic disorder, which coincided with the maximal value of Ku and the in-plane anisotropic behaviors in the as-deposited films. The roles of N doping in FeXN film optimization processes and its effects on magnetic and structural properties, especially the uniaxial

  7. Novel wide band gap materials for highly efficient thin film tandem solar cells. Final report

    SciTech Connect

    Brian E. Hardin; Connor, Stephen T.; Peters, Craig H.

    2012-06-11

    Tandem solar cells (TSCs), which use two or more materials to absorb sunlight, have achieved power conversion efficiencies of >25% versus 11-20% for commercialized single junction solar cell modules. The key to widespread commercialization of TSCs is to develop the wide-band, top solar cell that is both cheap to fabricate and has a high open-circuit voltage (i.e. >1V). Previous work in TSCs has generally focused on using expensive processing techniques with slow growth rates resulting in costs that are two orders of magnitude too expensive to be used in conventional solar cell modules. The objective of the PLANT PV proposal was to investigate the feasibility of using Ag(In,Ga)Se2 (AIGS) as the wide-bandgap absorber in the top cell of a thin film tandem solar cell (TSC). Despite being studied by very few in the solar community, AIGS solar cells have achieved one of the highest open-circuit voltages within the chalcogenide material family with a Voc of 949 mV when grown with an expensive processing technique (i.e. Molecular Beam Epitaxy). PLANT PV's goal in Phase I of the DOE SBIR was to (1) develop the chemistry to grow AIGS thin films via solution processing techniques to reduce costs and (2) fabricate new device architectures with high open-circuit voltage to produce full tandem solar cells in Phase II. PLANT PV attempted to translate solution processing chemistries that were successful in producing >12% efficient Cu(In,Ga)Se2 solar cells by replacing copper compounds with silver. The main thrust of the research was to determine if it was possible to make high quality AIGS thin films using solution processing and to fully characterize the materials properties. PLANT PV developed several different types of silver compounds in an attempt to fabricate high quality thin films from solution. We found that silver compounds that were similar to the copper based system did not result in high quality thin films. PLANT PV was able to deposit AIGS thin

  8. Plasma-assisted microwave processing of materials

    NASA Technical Reports Server (NTRS)

    Barmatz, Martin (Inventor); Ylin, Tzu-yuan (Inventor); Jackson, Henry (Inventor)

    1998-01-01

    A microwave plasma assisted method and system for heating and joining materials. The invention uses a microwave induced plasma to controllably preheat workpiece materials that are poorly microwave absorbing. The plasma preheats the workpiece to a temperature that improves the materials' ability to absorb microwave energy. The plasma is extinguished and microwave energy is able to volumetrically heat the workpiece. Localized heating of good microwave absorbing materials is done by shielding certain parts of the workpiece and igniting the plasma in the areas not shielded. Microwave induced plasma is also used to induce self-propagating high temperature synthesis (SHS) process for the joining of materials. Preferably, a microwave induced plasma preheats the material and then microwave energy ignites the center of the material, thereby causing a high temperature spherical wave front from the center outward.

  9. Aircraft gas turbine materials and processes.

    PubMed

    Kear, B H; Thompson, E R

    1980-05-23

    Materials and processing innovations that have been incorporated into the manufacture of critical components for high-performance aircraft gas turbine engines are described. The materials of interest are the nickel- and cobalt-base superalloys for turbine and burner sections of the engine, and titanium alloys and composites for compressor and fan sections of the engine. Advanced processing methods considered include directional solidification, hot isostatic pressing, superplastic foring, directional recrystallization, and diffusion brazing. Future trends in gas turbine technology are discussed in terms of materials availability, substitution, and further advances in air-cooled hardware. PMID:17772808

  10. Materials Processing in Space (MPS) program description

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Insight is provided into the scientific rotationale for materials processing in space (MPS), and a comprehensive and cohesive approach for implementation and integration of the many, diverse aspects of MPS is described. The programmatic and management functions apply to all projects and activities implemented under MPS. It is intended that specific project plans, providing project unique details, will be appended to this document for endeavors such as the Space Processing Applications Rocket (SPAR) Project, the Materials Experiment Assembly (MEA) Project, the MPS/Spacelab (MPS/SL) Project, and the Materials Experiment Carrier (MEC) Payloads.

  11. Surface energy characteristics of zeolite embedded PVDF nanofiber films with electrospinning process

    NASA Astrophysics Data System (ADS)

    Kang, Dong Hee; Kang, Hyun Wook

    2016-11-01

    Electrospinning is a nano-scale fiber production method with various polymer materials. This technique allows simple fiber diameters control by changing the physical conditions such as applied voltage and polymer solution viscosity during the fabrication process. The electrospun polymer fibers form a thin porous film with high surface area to volume ratio. Due to these unique characteristics, it is widely used for many application fields such as photocatalyst, electric sensor, and antibacterial scaffold for tissue engineering. Filtration is one of the main applications of electrospun polymer fibers for specific application of filtering out dust particles and dehumidification. Most polymers which are commonly used in electrospinning are hard to perform the filtering and dehumidification simultaneously because of their low hygroscopic property. To overcome this obstacle, the desiccant polymers are developed such as polyacrylic acid and polysulfobetaine methacrylate. However, the desiccant polymers are generally expensive and need special solvent for electrospinning. An alternating way to solve these problems is mixing desiccant material like zeolite in polymer solution during an electrospinning process. In this study, the free surface energy characteristics of electrospun polyvinylidene fluoride (PVDF) film with various zeolite concentrations are investigated to control the hygroscopic property of general polymers. Fundamental physical property of wettability with PVDF shows hydrophobicity. The electrospun PVDF film with small weight ratio with higher than 0.1% of zeolite powder shows diminished contact angles that certifying the wettability of PVDF can be controlled using desiccant material in electrospinning process. To quantify the surface energy of electrospun PVDF films, sessile water droplets are introduced on the electrospun PVDF film surface and the contact angles are measured. The contact angles of PVDF film are 140° for without zeolite and 80° for with 5

  12. Molybdenum as a contact material in zinc tin oxide thin film transistors

    SciTech Connect

    Hu, W.; Peterson, R. L.

    2014-05-12

    Amorphous oxide semiconductors are of increasing interest for a variety of thin film electronics applications. Here, the contact properties of different source/drain electrode materials to solution-processed amorphous zinc tin oxide (ZTO) thin-film transistors are studied using the transmission line method. The width-normalized contact resistance between ZTO and sputtered molybdenum is measured to be 8.7 Ω-cm, which is 10, 20, and 600 times smaller than that of gold/titanium, indium tin oxide, and evaporated molybdenum electrodes, respectively. The superior contact formed using sputtered molybdenum is due to a favorable work function lineup, an insulator-free interface, bombardment of ZTO during molybdenum sputtering, and trap-assisted tunneling. The transfer length of the sputtered molybdenum/ZTO contact is 0.34 μm, opening the door to future radio-frequency sub-micron molybdenum/ZTO thin film transistors.

  13. Commercial use of materials processing in space

    NASA Technical Reports Server (NTRS)

    Zoller, L. K.; Brown, R. L.

    1979-01-01

    The paper examines the scientific and commercial aspects of Materials Processing in the Space program. The elimination of gravity driven convection in molten materials can preclude undesirable stirring and mixing during crystal growth, and improve the casting of alloys and composites, chemical reactions, and the separation of biological materials. The elimination of hydrostatic pressure will allow alloy heat-treatment without distortion and growth of heavy crystals, such as thorium oxide, and containerless processing of liquids and molten materials. On the other hand, more sophisticated process control and diagnostic methods in sample preparation and temperature control must be developed, concluding that space made products of commercial interest are likely to be low volume, high value items.

  14. Laser Processing of Carbon Nanotube Transparent Conducting Films

    NASA Astrophysics Data System (ADS)

    Mann, Andrew

    Transparent conducting films, or TCFs, are 2D electrical conductors with the ability to transmit light. Because of this, they are used in many popular electronics including smart phones, tablets, solar panels, and televisions. The most common material used as a TCF is indium tin oxide, or ITO. Although ITO has great electrical and optical characteristics, it is expensive, brittle, and difficult to pattern. These limitations have led researchers toward other materials for the next generation of displays and touch panels. The most promising material for next generation TCFs is carbon nanotubes, or CNTs. CNTs are cylindrical tubes of carbon no more than a few atoms thick. They have different electrical and optical properties depending on their atomic structure, and are extremely strong. As an electrode, they conduct electricity through an array of randomly dispersed tubes. The array is highly transparent because of gaps between the tubes, and size and optical properties of the CNTs. Many research groups have tried making CNT TCFs with opto-electric properties similar to ITO but have difficultly achieving high conductivity. This is partly attributed to impurities from fabrication and a mix of different tube types, but is mainly caused by low junction conductivity. In functionalized nanotubes, junction conductivity is impaired by covalently bonded molecules added to the sidewalls of the tubes. The addition of this molecule, known as functionalization, is designed to facilitate CNT dispersion in a solvent by adding properties of the molecule to the CNTs. While necessary for a good solution, functionalization decreases the conductivity in the CNT array by creating defects in the tube's structures and preventing direct inter-carbon bonding. This research investigates removing the functional coating (after tube deposition) by laser processing. Laser light is able to preferentially heat the CNTs because of their optical and electrical properties. Through local conduction

  15. Magnetic Properties of FeNi-Based Thin Film Materials with Different Additives.

    PubMed

    Liang, Cai; Gooneratne, Chinthaka P; Wang, Qing Xiao; Liu, Yang; Gianchandani, Yogesh; Kosel, Jurgen

    2014-09-01

    This paper presents a study of FeNi-based thin film materials deposited with Mo, Al and B using a co-sputtering process. The existence of soft magnetic properties in combination with strong magneto-mechanical coupling makes these materials attractive for sensor applications. Our findings show that FeNi deposited with Mo or Al yields magnetically soft materials and that depositing with B further increases the softness. The out-of-plane magnetic anisotropy of FeNi thin films is reduced by depositing with Al and completely removed by depositing with B. The effect of depositing with Mo is dependent on the Mo concentration. The coercivity of FeNiMo and FeNiAl is reduced to less than a half of that of FeNi, and a value as low as 40 A/m is obtained for FeNiB. The surfaces of the obtained FeNiMo, FeNiAl and FeNiB thin films reveal very different morphologies. The surface of FeNiMo shows nano-cracks, while the FeNiAl films show large clusters and fewer nano-cracks. When FeNi is deposited with B, a very smooth morphology is obtained. The crystal structure of FeNiMo strongly depends on the depositant concentration and changes into an amorphous structure at a higher Mo level. FeNiAl thin films remain polycrystalline, even at a very high concentration of Al, and FeNiB films are amorphous, even at a very low concentration of B. PMID:25587418

  16. Bacteriorhodopsin Material and Film Fabrication Issues for Holographic Applications

    NASA Technical Reports Server (NTRS)

    Downie, John D.; Timucin, Dogan A.; Smithey, Daniel T.; Crew, Marshall; Rayfield, George W.; Lan, Sonie (Technical Monitor)

    1998-01-01

    We discuss issues associated with bacteriorhodopsin (BR) materials and films that affect optical performance in holographic applications. For the D85N variant, some critical parameters include degree of hydration and recording wavelength. The quantum efficiency of the molecular state transition is observed to be apparently dependent on the illumination wavelength. We explain this effect by modeling the photo-activity of the D85N variant as two competing photocycles between the 9-cis and 13-cis retinal configurations. We are able to determine the pure excited P-state absorbance spectrum from the ground state spectrum and mixed population spectra obtained by bleaching to steady-state conditions.

  17. Designing thin film materials — Ternary borides from first principles

    PubMed Central

    Euchner, H.; Mayrhofer, P.H.

    2015-01-01

    Exploiting the mechanisms responsible for the exceptional properties of aluminum based nitride coatings, we apply ab initio calculations to develop a recipe for designing functional thin film materials based on ternary diborides. The combination of binary diborides, preferring different structure types, results in supersaturated metastable ternary systems with potential for phase transformation induced effects. For the exemplary cases of MxW1 − xB2 (with M = Al, Ti, V) we show by detailed ab initio calculations that the respective ternary solid solutions are likely to be experimentally accessible by modern depositions techniques. PMID:26082562

  18. Materials processing using a variable frequency microwave furnace

    SciTech Connect

    Lauf, R.J.; Bible, D.W.; Maddox, S.R.; Everleigh, C.A.; Espinosa, R.J.; Johnson, A.C.

    1993-12-31

    We describe a materials processing system that uses a high power traveling wave tube (TWT) as the microwave source. The TWT provides approximately one octave bandwidth and variable power levels up to 2 kW into a multimode cavity. By controlling the frequency, efficient coupling to the load can be maintained even as the load`s dielectric properties change. Alternatively, can be used as a means of mode stirring at rates far beyond those attainable through mechanical stirring. The system has been tested for sintering alumina ceramics, annealing a tungsten penetrator alloy, curing epoxy resin, and depositing diamond films from a microwave plasma.

  19. Microwave processing of radioactive materials-I

    SciTech Connect

    White, T.L.; Berry, J.B.

    1989-01-01

    This paper is the first of two papers that reviews the major past and present applications of microwave energy for processing radioactive materials, with particular emphasis on processing radioactive wastes. Microwave heating occurs through the internal friction produced inside a dielectric material when its molecules vibrate in response to an oscillating microwave field. For this presentation, we shall focus on the two FCC-approved microwave frequencies for industrial, scientific, and medical use, 915 and 2450 MHz. Also, because of space limitations, we shall postpone addressing plasma processing of hazardous wastes using microwave energy until a later date. 13 refs., 4 figs.

  20. Chemically Deposited Thin-Film Solar Cell Materials

    NASA Technical Reports Server (NTRS)

    Raffaelle, R.; Junek, W.; Gorse, J.; Thompson, T.; Harris, J.; Hehemann, D.; Hepp, A.; Rybicki, G.

    2005-01-01

    We have been working on the development of thin film photovoltaic solar cell materials that can be produced entirely by wet chemical methods on low-cost flexible substrates. P-type copper indium diselenide (CIS) absorber layers have been deposited via electrochemical deposition. Similar techniques have also allowed us to incorporate both Ga and S into the CIS structure, in order to increase its optical bandgap. The ability to deposit similar absorber layers with a variety of bandgaps is essential to our efforts to develop a multi-junction thin-film solar cell. Chemical bath deposition methods were used to deposit a cadmium sulfide (CdS) buffer layers on our CIS-based absorber layers. Window contacts were made to these CdS/CIS junctions by the electrodeposition of zinc oxide (ZnO). Structural and elemental determinations of the individual ZnO, CdS and CIS-based films via transmission spectroscopy, x-ray diffraction, x-ray photoelectron spectroscopy and energy dispersive spectroscopy will be presented. The electrical characterization of the resulting devices will be discussed.

  1. Space Environmental Effects on Materials and Processes

    NASA Technical Reports Server (NTRS)

    Sabbann, Leslie M.

    2009-01-01

    The Materials and Processes (M&P) Branch of the Structural Engineering Division at Johnson Space Center (JSC) seeks to uphold the production of dependable space hardware through materials research, which fits into NASA's purpose of advancing human exploration, use, and development of space. The Space Environmental Effects projects fully support these Agency goals. Two tasks were assigned to support M&P. Both assignments were to further the research of material behavior outside of Earth's atmosphere in order to determine which materials are most durable and safe to use in space for mitigating risks. One project, the Materials on International Space Station Experiments (MISSE) task, was to compile data from International Space Station (ISS) experiments to pinpoint beneficial space hardware. The other project was researching the effects on composite materials of exposure to high doses of radiation for a Lunar habitat project.

  2. Artificial intelligence in the materials processing laboratory

    NASA Technical Reports Server (NTRS)

    Workman, Gary L.; Kaukler, William F.

    1990-01-01

    Materials science and engineering provides a vast arena for applications of artificial intelligence. Advanced materials research is an area in which challenging requirements confront the researcher, from the drawing board through production and into service. Advanced techniques results in the development of new materials for specialized applications. Hand-in-hand with these new materials are also requirements for state-of-the-art inspection methods to determine the integrity or fitness for service of structures fabricated from these materials. Two problems of current interest to the Materials Processing Laboratory at UAH are an expert system to assist in eddy current inspection of graphite epoxy components for aerospace and an expert system to assist in the design of superalloys for high temperature applications. Each project requires a different approach to reach the defined goals. Results to date are described for the eddy current analysis, but only the original concepts and approaches considered are given for the expert system to design superalloys.

  3. Thin films of copper antimony sulfide: A photovoltaic absorber material

    SciTech Connect

    Ornelas-Acosta, R.E.; Shaji, S.; Avellaneda, D.; Castillo, G.A.; Das Roy, T.K.; Krishnan, B.

    2015-01-15

    Highlights: • CuSbS{sub 2} thin films were prepared by heating Sb{sub 2}S{sub 3}/Cu layers. • Analyzed the structure, composition, optical, and electrical properties. • PV structures: glass/SnO{sub 2}:F/n-CdS/p-CuSbS{sub 2}/C/Ag were formed at different conditions. • The PV parameters (J{sub sc}, V{sub oc}, and FF) were evaluated from the J–V characteristics. • J{sub sc}: 0.52–3.20 mA/cm{sup 2}, V{sub oc}:187–323 mV, FF: 0.27–0.48 were obtained. - Abstract: In this work, we report preparation and characterization of CuSbS{sub 2} thin films by heating glass/Sb{sub 2}S{sub 3}/Cu layers and their use as absorber material in photovoltaic structures: glass/SnO{sub 2}:F/n-CdS/p-CuSbS{sub 2}/C/Ag. The Sb{sub 2}S{sub 3} thin films of 600 nm were prepared by chemical bath deposition on which copper thin films of 50 nm were thermally evaporated, and the glass/Sb{sub 2}S{sub 3}/Cu multilayers were heated in vacuum at different temperatures. X-ray diffraction analysis showed the formation of orthorhombic CuSbS{sub 2} after heating the precursor layers. Studies on identification and chemical state of the elements were done using X-ray photoelectron spectroscopy. The optical band gap of the CuSbS{sub 2} thin films was 1.55 eV and the thin films were photoconductive. The photovoltaic parameters of the devices using CuSbS{sub 2} as absorber and CdS as window layer were evaluated from the J–V curves, yielding J{sub sc}, V{sub oc}, and FF values in the range of 0.52–3.20 mA/cm{sup 2}, 187–323 mV, and 0.27–0.48, respectively, under illumination of AM1.5 radiation.

  4. Vapor-gel processing and applications in oxide film depositions

    SciTech Connect

    Chour, K.W.; Xu, R.; Takada, T.

    1995-12-31

    The Vapor-gel processing of oxide films is discussed for the prototypic system of LiTa(OBut{sup n}){sub 6}-LiTaO{sub 3}. It is found that the hydrolysis-polycondensation reaction scheme, commonly used in Sol-gel processing, can be used in a vapor deposition environment. High quality films can be deposited at low temperatures. We present some initial results regarding this deposition method and discuss its advantages and disadvantages as compared with Sol-gel processing and typical MOCVD.

  5. Structure and properties of polypropylene cast films: Polymer type and processing effects

    NASA Astrophysics Data System (ADS)

    Mileva, Daniela; Gahleitner, Markus; Gloger, Dietrich

    2016-05-01

    The influence of processing parameters in a cast film extrusion process of thin films of isotactic polypropylene homopolymer and random propylene-ethylene copolymer was analyzed. Variation of the chill roll temperature allowed changing the supercooling of the melt and thus the generation of different crystal polymorphs of iPP. Additional focus was placed on the effect of flow induced crystallization via changing the output rate of the line. The crystal structure and morphology of the materials were evaluated and correlated to selected optical and mechanical properties.

  6. Materials And Processes Technical Information System (MAPTIS) LDEF materials database

    NASA Technical Reports Server (NTRS)

    Davis, John M.; Strickland, John W.

    1992-01-01

    The Materials and Processes Technical Information System (MAPTIS) is a collection of materials data which was computerized and is available to engineers in the aerospace community involved in the design and development of spacecraft and related hardware. Consisting of various database segments, MAPTIS provides the user with information such as material properties, test data derived from tests specifically conducted for qualification of materials for use in space, verification and control, project management, material information, and various administrative requirements. A recent addition to the project management segment consists of materials data derived from the LDEF flight. This tremendous quantity of data consists of both pre-flight and post-flight data in such diverse areas as optical/thermal, mechanical and electrical properties, atomic concentration surface analysis data, as well as general data such as sample placement on the satellite, A-O flux, equivalent sun hours, etc. Each data point is referenced to the primary investigator(s) and the published paper from which the data was taken. The MAPTIS system is envisioned to become the central location for all LDEF materials data. This paper consists of multiple parts, comprising a general overview of the MAPTIS System and the types of data contained within, and the specific LDEF data element and the data contained in that segment.

  7. The cognitive processing of film and musical soundtracks.

    PubMed

    Boltz, Marilyn G

    2004-10-01

    Previous research has demonstrated that musical soundtracks can influence the interpretation, emotional impact, and remembering of film information. The intent here was to examine how music is encoded into the cognitive system and subsequently represented relative to its accompanying visual action. In Experiment 1, participants viewed a set of music/film clips that were either congruent or incongruent in their emotional affects. Selective attending was also systematically manipulated by instructing viewers to attend to and remember the music, film, or both in tandem. The results from tune recognition, film recall, and paired discrimination tasks collectively revealed that mood-congruent pairs lead to a joint encoding of music/film information as well as an integrated memory code. Incongruent pairs, on the other hand, result in an independent encoding in which a given dimension, music or film, is only remembered well if it was selectively attended to at the time of encoding. Experiment 2 extended these findings by showing that tunes from mood-congruent pairs are better recognized when cued by their original scenes, while those from incongruent pairs are better remembered in the absence of scene information. These findings both support and extend the "Congruence Associationist Model" (A. J. Cohen, 2001), which addresses those cognitive mechanisms involved in the processing of music/film information. PMID:15813500

  8. Radiopacity of resin-based materials measured in film radiographs and storage phosphor plate (Digora).

    PubMed

    Sabbagh, Joseph; Vreven, José; Leloup, Gaetane

    2004-01-01

    This study compared the radiopacity of 41 resin-based materials using conventional dental x-ray film (Ultraspeed-D) and a digital system (Digora) based on storage phosphor plate technology. For the film-based technique, optical density measurements were carried out using an X-Rite densitometer. Al equivalents (mm) were calculated as described in the literature using a calibration curve of Optical Density versus the thickness of aluminum. Regarding the digital system after exposures of 0.16 and 0.32 seconds, the images were exported to an image processing software (NIH Image Engineering). An approach similar to that used for optical density was used to generate a calibration curve for gray pixel values. Linear correlations were found between the percentage of fillers by weight and x-ray film radiopacity and the Digora system, and the same coefficient of estimation was recorded (r=0.60; p< or = 0.05). A linear correlation was also observed between the conventional x-ray film technique and the Digora system (r=0.93;p< or = 0.05). Using two different exposure times did not affect the radiopacity. Considerable differences were found among materials of the same category. Flowable resin composites were more radiopaque than dentin, while microfine composites were "radiolucent." Most of the available resin-based materials were more radiopaque than enamel. The radiopacity of resin composites depended on their fillers (percentage and type). Using elements with low atomic numbers (Si) resulted in radiolucent materials, while adding elements with high molecular numbers (Ba, Y, Yb), resulted in radiopaque resin composites. Despite the numerous benefits offered by the digital imaging system (low irradiation dose, instant image, image manipulation), the conventional x-ray film technique seems to be more accurate for radiopacity measurements. PMID:15646224

  9. Theoretical and material studies on thin-film electroluminescent devices

    NASA Technical Reports Server (NTRS)

    Summers, C. J.; Brennan, K. F.

    1986-01-01

    Electroluminescent materials and device technology were assessed. The evaluation strongly suggests the need for a comprehensive theoretical and experimental study of both materials and device structures, particularly in the following areas: carrier generation and multiplication; radiative and nonradiative processes of luminescent centers; device modeling; new device concepts; and single crystal materials growth and characterization. Modeling of transport properties of hot electrons in ZnSe and the generation of device concepts were initiated.

  10. Determination of mechanical properties of polymer film materials

    NASA Technical Reports Server (NTRS)

    Hughes, E. J.; Rutherford, J. L.

    1975-01-01

    Five polymeric film materials, Tedlar, Teflon, Kapton H, Kapton F, and a fiberglass reinforced polyimide, PG-402, in thickness ranging from 0.002 to 0.005 inch, were tested over a temperature range of -195 to 200 C in the "machine" and transverse direction to determine: elastic modulus, Poisson's ratio, three percent offset yield stress, fracture stress, and strain to fracture. The elastic modulus, yield stress and fracture stress decreased with increasing temperature for all the materials while the fracture strain increased. Teflon and Tedlar had the greatest temperature dependence and PG-402 the least. At 200 C the Poisson ratio values ranged from 0.39 to 0.5; they diminished as the temperature decreased covering a range of 0.26 to 0.42 at -195 C. Shortening the gauge length from eight inches to one inch increased the strain to fracture and lowered the elastic modulus values.

  11. Process optimization of ultrasonic spray coating of polymer films.

    PubMed

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

    2013-06-11

    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 μm) 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

  12. Reactive Evaporation And Plasma Processes For Thin Film Optical Coatings

    NASA Astrophysics Data System (ADS)

    Ebert, Johannes

    1989-02-01

    Bombardment of growing films with reactive particles has developed into a powerful technology over the last 3o years. Compared to normal evaporation methods, important improvements are: better adhesion between film and substrate, high film density, fast coating rate and stoichiometric layers with low optical losses. Although the techniques used to achieve the desired properties vary quite dramatically from high pressure plasma processing to bombardment with monoenergetic ion beams in ultra high vacuum environment, from particles with nearly thermal to some keV energy and from discharge currents of some μA to more than 1oo A in industrial applications, the ion-surface interaction, which causes the modification of the films, is the basic of all reactive deposition processes. The purpose of this paper is to review plasma processes for the production of optical coatings including ion assisted deposition, ion plating and ion cluster beam deposition, comparing the structural and optical properties of the films. Some applications of reactive evaporation presented in the following papers demonstrate the potential use of reactive evaporation and plasma processes for solving optical problems.

  13. Process for Polycrystalline film silicon growth

    DOEpatents

    Wang, Tihu; Ciszek, Theodore F.

    2001-01-01

    A process for depositing polycrystalline silicon on substrates, including foreign substrates, occurs in a chamber at about atmospheric pressure, wherein a temperature gradient is formed, and both the atmospheric pressure and the temperature gradient are maintained throughout the process. Formation of a vapor barrier within the chamber that precludes exit of the constituent chemicals, which include silicon, iodine, silicon diiodide, and silicon tetraiodide. The deposition occurs beneath the vapor barrier. One embodiment of the process also includes the use of a blanketing gas that precludes the entrance of oxygen or other impurities. The process is capable of repetition without the need to reset the deposition zone conditions.

  14. Solution-processing of chalcogenide materials for device applications

    NASA Astrophysics Data System (ADS)

    Zha, Yunlai

    Chalcogenide glasses are well-known for their desirable optical properties, which have enabled many infrared applications in the fields of photonics, medicine, environmental sensing and security. Conventional deposition methods such as thermal evaporation, chemical vapor deposition, sputtering or pulse laser deposition are efficient for fabricating structures on flat surfaces. However, they have limitations in deposition on curved surfaces, deposition of thick layers and component integration. In these cases, solution-based methods, which involve the dissolution of chalcogenide glasses and processing as a liquid, become a better choice for their flexibility. After proper treatment, the associated structures can have similar optical, chemical and physical properties to the bulk. This thesis presents an in-depth study of solution-processing chalcogenide glasses, starting from the "solution state" to the "film state" and the "structure state". Firstly, chalcogenide dissolution is studied to reveal the mechanisms at molecular level and build a foundation for material processing. Dissolution processes for various chalcogenide solvent pairs are reviewed and compared. Secondly, thermal processing, in the context of high temperature annealing, is explained along with the chemical and physical properties of the annealed films. Another focus is on nanopore formation in propylamine-processed arsenic sulfide films. Pore density changes with respect to annealing temperatures and durations are characterized. Base on a proposed vacancy coalescence theory, we have identified new dissolution strategies and achieved the breakthrough of pore-free film deposition. Thirdly, several solution methods developed along with the associated photonic structures are demonstrated. The first example is "spin-coating and lamination", which produces thick (over 10 mum) chalcogenide structures. Both homogeneous thick chalcogenide structures and heterogeneous layers of different chalcogenide glasses

  15. Advanced Technology Composite Fuselage - Materials and Processes

    NASA Technical Reports Server (NTRS)

    Scholz, D. B.; Dost, E. F.; Flynn, B. W.; Ilcewicz, L. B.; Nelson, K. M.; Sawicki, A. J.; Walker, T. H.; Lakes, R. S.

    1997-01-01

    The goal of Boeing's Advanced Technology Composite Aircraft Structures (ATCAS) program was to develop the technology required for cost and weight efficient use of composite materials in transport fuselage structure. This contractor report describes results of material and process selection, development, and characterization activities. Carbon fiber reinforced epoxy was chosen for fuselage skins and stiffening elements and for passenger and cargo floor structures. The automated fiber placement (AFP) process was selected for fabrication of monolithic and sandwich skin panels. Circumferential frames and window frames were braided and resin transfer molded (RTM'd). Pultrusion was selected for fabrication of floor beams and constant section stiffening elements. Drape forming was chosen for stringers and other stiffening elements. Significant development efforts were expended on the AFP, braiding, and RTM processes. Sandwich core materials and core edge close-out design concepts were evaluated. Autoclave cure processes were developed for stiffened skin and sandwich structures. The stiffness, strength, notch sensitivity, and bearing/bypass properties of fiber-placed skin materials and braided/RTM'd circumferential frame materials were characterized. The strength and durability of cocured and cobonded joints were evaluated. Impact damage resistance of stiffened skin and sandwich structures typical of fuselage panels was investigated. Fluid penetration and migration mechanisms for sandwich panels were studied.

  16. Advances in Processing of Bulk Ferroelectric Materials

    NASA Astrophysics Data System (ADS)

    Galassi, Carmen

    The development of ferroelectric bulk materials is still under extensive investigation, as new and challenging issues are growing in relation to their widespread applications. Progress in understanding the fundamental aspects requires adequate technological tools. This would enable controlling and tuning the material properties as well as fully exploiting them into the scale production. Apart from the growing number of new compositions, interest in the first ferroelectrics like BaTiO3 or PZT materials is far from dropping. The need to find new lead-free materials, with as high performance as PZT ceramics, is pushing towards a full exploitation of bariumbased compositions. However, lead-based materials remain the best performing at reasonably low production costs. Therefore, the main trends are towards nano-size effects and miniaturisation, multifunctional materials, integration, and enhancement of the processing ability in powder synthesis. Also, in control of dispersion and packing, to let densification occur in milder conditions. In this chapter, after a general review of the composition and main properties of the principal ferroelectric materials, methods of synthesis are analysed with emphasis on recent results from chemical routes and cold consolidation methods based on the colloidal processing.

  17. Robot development for nuclear material processing

    SciTech Connect

    Pedrotti, L.R.; Armantrout, G.A.; Allen, D.C.; Sievers, R.H. Sr.

    1991-07-01

    The Department of Energy is seeking to modernize its special nuclear material (SNM) production facilities and concurrently reduce radiation exposures and process and incidental radioactive waste generated. As part of this program, Lawrence Livermore National Laboratory (LLNL) lead team is developing and adapting generic and specific applications of commercial robotic technologies to SNM pyrochemical processing and other operations. A working gantry robot within a sealed processing glove box and a telerobot control test bed are manifestations of this effort. This paper describes the development challenges and progress in adapting processing, robotic, and nuclear safety technologies to the application. 3 figs.

  18. Simulation of materials processing: Fantasy or reality?

    NASA Technical Reports Server (NTRS)

    Jenkins, Thomas J.; Bright, Victor M.

    1994-01-01

    This experiment introduces students to the application of computer-aided design (CAD) and analysis of materials processing in the context of integrated circuit (IC) fabrication. The fabrication of modern IC's is a complex process which consists of several sequential steps. These steps involve the precise control of processing variables such as temperature, humidity, and ambient gas composition. In essence, the particular process employed during the fabrication becomes a 'recipe'. Due to economic and other considerations, CAD is becoming an indispensable part of the development of new recipes for IC fabrication. In particular, this experiment permits the students to explore the CAD of the thermal oxidation of silicon.

  19. Coprecal: materials accounting in the modified process

    SciTech Connect

    Dayem, H.A.; Kern, E.A.; Shipley, J.P.

    1980-05-01

    This report presents the design and evaluation of an advanced materials accounting system for a uranium-plutonium nitrate-to-oxide coconversion facility based on the General Electric Coprecal process as modified by Savannah River Laboratory and Plant and DuPont Engineering. The modifications include adding small aliquot tanks to feed the process and reconfiguring the calciner filter systems. Diversion detection sensitivities for the modified Coprecal process are somewhat better than the original Coprecal design, but they are still significantly worse than a same-sized conversion facility based on the oxalate (III) precipitation process.

  20. Solution processable semiconductor thin films: Correlation between morphological, structural, optical and charge transport properties

    NASA Astrophysics Data System (ADS)

    Isik, Dilek

    This Ph.D. thesis is a result of multidisciplinary research bringing together fundamental concepts in thin film engineering, materials science, materials processing and characterization, electrochemistry, microfabrication, and device physics. Experiments were conducted by tackling scientific problems in the field of thin films and interfaces, with the aim to correlate the morphology, crystalline structure, electronic structure of thin films with the functional properties of the films and the performances of electronic devices based thereon. Furthermore, novel strategies based on interfacial phenomena at electrolyte/thin film interfaces were explored and exploited to control the electrical conductivity of the thin films. Three main chemical systems were the object of the studies performed during this Ph.D., two types of organic semiconductors (azomethine-based oligomers and polymers and soluble pentacene derivatives) and one metal oxide semiconductor (tungsten trioxide, WO3). To explore the morphological properties of the thin films, atomic force microscopy was employed. The morphological properties were further investigated by hyperspectral fluorescence microscopy and tentatively correlated to the charge transport properties of the films. X-ray diffraction (Grazing incidence XRD, GIXRD) was used to investigate the crystallinity of the film and the effect of the heat treatment on such crystallinity, as well as to understand the molecular arrangement of the organic molecules in the thin film. The charge transport properties of the films were evaluated in thin film transistor configuration. For electrolyte gated thin film transistors, time dependent transient measurements were conducted, in parallel to more conventional transistor characterizations, to explore the specific effects played on the gating by the anion and cation constituting the electrolyte. The capacitances of the electrical double layers at the electrolyte/WO3 interface were obtained from

  1. Laser materials processing at Sandia National Laboratories

    SciTech Connect

    Jellison, J.L.; Cieslak, M.J.

    1994-11-01

    The interest in laser processing has been driven by Sandia`s responsibility to design, prototype, manufacture, and steward high reliability defense hardware for the Department of Energy. The system requirements for the hardware generally necessitate hermetic sealing for ensured long life operation. With the advent of miniaturized electronic devices, traditional welding processes were no longer practical choices because of their limited ability to make very small weld closures without heat damage to the hardware. Gas and solid state lasers offered the opportunity to make hermetic closure welds in small, heat sensitive hardware. In order to consistently produce quality product, the Sandia laser materials processing team performed research aimed at identifying those critical parameters which controlled the laser welding process. This has been directed towards both the development of quantitative engineering data needed in product design and process control, and research to achieve fundamental process understanding. In addition, they have developed novel diagnostic systems to measure these important parameters, pioneered the use of calorimetric techniques to measure energy transfer efficiencies, and correlated the occurrence of welding defects with alloy compositions and type of laser welding process. Today, Sandia`s laser materials processing team continues to advance the state of laser processing technology in many areas, including aluminum laser welding, the design of novel optics for specific laser processing needs, laser micromachining of silicon and diamond for microelectronics applications, and fluxless laser soldering. This paper will serve to highlight some examples of where Sandia has made contributions to the field of laser materials processing and will indicate the directions where they expect to focus their future efforts.

  2. Laser-induced metallic nanograined thin films processing

    SciTech Connect

    Tosa, Nicoleta E-mail: florin.toadere@itim-cj.ro; Toadere, Florin E-mail: florin.toadere@itim-cj.ro; Hojbota, Calin E-mail: florin.toadere@itim-cj.ro; Tosa, Valer E-mail: florin.toadere@itim-cj.ro

    2013-11-13

    A direct laser writing method for designing metallic nanograined thin films is presented. This method takes advantage of photon conversion within a chemical process localized at the focal point. A computer controlled positioning system allows the control of experimental parameters and spatial resolution of the pattern. Spectroscopic investigations reveal variable attenuation of the optical properties in UV-visible range and a spectral imaging processing algorithm simulated the functionality of these films in visible light. This could be an important step for obtaining neutral density attenuators.

  3. Applications of membrane processes for in-process materials recycling

    SciTech Connect

    Kim, B.M.; Thornton, R.F.; Shapiro, A.P.; Freshour, A.R.; El-Shoubary, Y.

    1996-12-31

    Zero discharge of wastes should be the ultimate goal of manufacturers. Waste reduction lowers costs and lessens liability associated with plant effluents. One approach toward this goal is elimination or minimization of wastes by in-process recycling of waste materials. We have examined opportunities for waste minimization for many equipment manufacturing plants and have evaluated membrane processes for in-process recycling. Membrane processes evaluated include vibrating membranes for suspended solid removal, ion exchange membranes for acid recovery, reverse osmosis and electrodialysis for dissolved salt removal, microporous membranes for recycling of machining coolants, oil emulsions, alkaline cleaners and others. This paper presents several examples of evaluations of membrane processes for materials recycling in manufacturing plants. 5 figs., 1 tab.

  4. Densitometric evaluation of seven dental film processing solutions.

    PubMed

    Matthee, M J; Seeliger, J E

    1990-02-01

    In order to determine the effect of 7 dental film processing solutions on the quality of the radiographic image, an aluminium step-wedge phantom was exposed, using Agfa Dentus M2, speed group D, intra-oral x-ray films. The exposures were done under standardized conditions. Processing was carried out, using each of the 7 processing solutions, namely Agfa, Dürr, EBX, Kolchem, MEMS, Premier and Pro-tech strictly in accordance with the manufacturers' recommendations. After the processed films were subjected to densitometric evaluation, a step-wedge curve was drawn for each processing solution. The data pertaining to the radiographic contrast and relative speed values were calculated from the step-wedge curve and, together with the base plus fog values, were tabulated. Kolchem produced the highest radiographic contrast, followed closely by MEMS and Dürr. The relative film speed was almost identical for Kolchem, MEMS and Dürr. Regarding the base plus fog values, all 7 processing solutions were within the acceptable limit of 0.25. PMID:2385845

  5. Materials evaluation for a transuranic processing facility

    SciTech Connect

    Barker, S.A., Schwenk, E.B. ); Divine, J.R. )

    1990-11-01

    The Westinghouse Hanford Company, with the assistance of the Pacific Northwest Laboratory, is developing a transuranium extraction process for preheating double-shell tank wastes at the Hanford Site to reduce the volume of transuranic waste being sent to a repository. The bench- scale transuranium extraction process development is reaching a stage where a pilot plant design has begun for the construction of a facility in the existing B Plant. Because of the potential corrosivity of neutralized cladding removal waste process streams, existing embedded piping alloys in B Plant are being evaluated and new'' alloys are being selected for the full-scale plant screening corrosion tests. Once the waste is acidified with HNO{sub 3}, some of the process streams that are high in F{sup {minus}} and low in Al and zr can produce corrosion rates exceeding 30,000 mil/yr in austenitic alloys. Initial results results are reported concerning the applicability of existing plant materials to withstand expected process solutions and conditions to help determine the feasibility of locating the plant at the selected facility. In addition, process changes are presented that should make the process solutions less corrosive to the existing materials. Experimental work confirms that Hastelloy B is unsatisfactory for the expected process solutions; type 304L, 347 and 309S stainless steels are satisfactory for service at room temperature and 60{degrees}C, if process stream complexing is performed. Inconel 625 was satisfactory for all solutions. 17 refs., 5 figs., 8 tabs.

  6. Heat accumulation during pulsed laser materials processing.

    PubMed

    Weber, Rudolf; Graf, Thomas; Berger, Peter; Onuseit, Volkher; Wiedenmann, Margit; Freitag, Christian; Feuer, Anne

    2014-05-01

    Laser materials processing with ultra-short pulses allows very precise and high quality results with a minimum extent of the thermally affected zone. However, with increasing average laser power and repetition rates the so-called heat accumulation effect becomes a considerable issue. The following discussion presents a comprehensive analytical treatment of multi-pulse processing and reveals the basic mechanisms of heat accumulation and its consequence for the resulting processing quality. The theoretical findings can explain the experimental results achieved when drilling microholes in CrNi-steel and for cutting of CFRP. As a consequence of the presented considerations, an estimate for the maximum applicable average power for ultra-shorts pulsed laser materials processing for a given pulse repetition rate is derived. PMID:24921828

  7. CaTiO.sub.3 Interfacial template structure on semiconductor-based material and the growth of electroceramic thin-films in the perovskite class

    DOEpatents

    McKee, Rodney Allen; Walker, Frederick Joseph

    1998-01-01

    A structure including a film of a desired perovskite oxide which overlies and is fully commensurate with the material surface of a semiconductor-based substrate and an associated process for constructing the structure involves the build up of an interfacial template film of perovskite between the material surface and the desired perovskite film. The lattice parameters of the material surface and the perovskite of the template film are taken into account so that during the growth of the perovskite template film upon the material surface, the orientation of the perovskite of the template is rotated 45.degree. with respect to the orientation of the underlying material surface and thereby effects a transition in the lattice structure from fcc (of the semiconductor-based material) to the simple cubic lattice structure of perovskite while the fully commensurate periodicity between the perovskite template film and the underlying material surface is maintained. The film-growth techniques of the invention can be used to fabricate solid state electrical components wherein a perovskite film is built up upon a semiconductor-based material and the perovskite film is adapted to exhibit ferroelectric, piezoelectric, pyroelectric, electro-optic or large dielectric properties during use of the component.

  8. Space processing applications of ion beam technology. [surface finishing, welding, milling and film deposition

    NASA Technical Reports Server (NTRS)

    Grodzka, P. G.

    1977-01-01

    Ion thruster engines for spacecraft propulsion can serve as ion beam sources for potential space processing applications. The advantages of space vacuum environments and the possible gravity effects on thruster ion beam materials operations such as thin film growth, ion milling, and surface texturing were investigated. The direct gravity effect on sputter deposition and vapor deposition processes are discussed as well as techniques for cold and warm welding.

  9. Structural Formation Process of Microphase Separated Films with Liquid Crystalline Phase Transition

    NASA Astrophysics Data System (ADS)

    Komura, Motonori; Iyoda, Tomokazu

    2008-03-01

    Ordered nanostructures arising from the microphase separation of block copolymers have driven one to fabricate nanofunctional materials as fundamental technology of the coming electronic and photonic materials. Thin films of a series of newly designed amphiphilic block copolymer consisting of hydrophilic polyethylene oxide (PEO) and hydrophobic polymethacrylate with azobenzene-mesogen in side-chain (PMA(Az)) show highly ordered microphase separation with PEO cylinders perpendicularly oriented to the film surface. In the present report, we investigated a structural formation process of the microphase separated films by temperature controlled atomic force microscopy (AFM) and grazing incidence small angle X-ray scattering (GISAXS). These measurements revealed that homeotropic alignments of Az liquid crystalline layers predominated the cylinder orientation, which corresponded to a <110> direction of body centered cubic structure under annealing condition, in disagreement with cylinder orientation of order-order transition of traditional block copolymers.

  10. Permanent laser conditioning of thin film optical materials

    DOEpatents

    Wolfe, C. Robert; Kozlowski, Mark R.; Campbell, John H.; Staggs, Michael; Rainer, Frank

    1995-01-01

    The invention comprises a method for producing optical thin films with a high laser damage threshold and the resulting thin films. The laser damage threshold of the thin films is permanently increased by irradiating the thin films with a fluence below an unconditioned laser damage threshold.

  11. Permanent laser conditioning of thin film optical materials

    DOEpatents

    Wolfe, C.R.; Kozlowski, M.R.; Campbell, J.H.; Staggs, M.; Rainer, F.

    1995-12-05

    The invention comprises a method for producing optical thin films with a high laser damage threshold and the resulting thin films. The laser damage threshold of the thin films is permanently increased by irradiating the thin films with a fluence below an unconditioned laser damage threshold. 9 figs.

  12. Photovoltaic Effects of Retinal-Related Materials in Langmuir-Blodgett Films

    NASA Astrophysics Data System (ADS)

    Okazaki, Choichiro

    1998-03-01

    Multilayer films consisting of retinal, retinoic acid, and retinol were fabricated using the Langmuir-Blodgett method. It was found for the first time that these three materials in Langmuir-Blodgett films exhibit different photovoltaic characteristics. To study this difference of photovoltaic characteristics, the surface pressure vs area isotherms of these materials were measured and the dipole moment of the materials were calculated.

  13. Alternative starting materials for industrial processes.

    PubMed Central

    Mitchell, J W

    1992-01-01

    In the manufacture of chemical feedstocks and subsequent processing into derivatives and materials, the U.S. chemical industry sets the current standard of excellence for technological competitiveness. This world-class leadership is attributed to the innovation and advancement of chemical engineering process technology. Whether this status is sustained over the next decade depends strongly on meeting increasingly demanding challenges stimulated by growing concerns about the safe production and use of chemicals without harmful impacts on the environment. To comply with stringent environmental regulations while remaining economically competitive, industry must exploit alternative benign starting materials and develop environmentally neutral industrial processes. Opportunities are described for development of environmentally compatible alternatives and substitutes for some of the most abundantly produced, potentially hazardous industrial chemicals now labeled as "high-priority toxic chemicals." For several other uniquely important commodity chemicals where no economically competitive, environmentally satisfactory, nontoxic alternative starting material exists, we advocate the development of new dynamic processes for the on-demand generation of toxic chemicals. In this general concept, which obviates mass storage and transportation of chemicals, toxic raw materials are produced in real time, where possible, from less-hazardous starting materials and then chemically transformed immediately into the final product. As a selected example for semiconductor technology, recent progress is reviewed for the on-demand production of arsine in turnkey electrochemical generators. Innovation of on-demand chemical generators and alternative processes provide rich areas for environmentally responsive chemical engineering processing research and development for next-generation technology. Images PMID:11607260

  14. Citrate complexing sol-gel process of lead-free (K,Na)NbO3 ferroelectric films

    NASA Astrophysics Data System (ADS)

    Yao, Linlin; Zhu, Kongjun

    2016-05-01

    The citrate complexing sol-gel process to fabricate lead-free (K,Na)NbO3 ferroelectric thin films was studied. Soluble niobium source of niobium-citric acid (Nb-CA) solution was utilized as a raw material to synthesize (K,Na)NbO3 thin films, by pyrolyzing at 450-550∘C and annealing at 650∘C. The film pyrolyzed at 450∘C shows poor crystallization with porous morphology, whereas the film pyrolyzed at 550∘C appear to be well-crystallized and denser, and the ferroelectricity was also proved by the P-E hysteresis loop measurement.

  15. Microwave processing of lunar materials: potential applications

    SciTech Connect

    Meek, T.T.; Cocks, F.H.; Vaniman, D.T.; Wright, R.A.

    1984-01-01

    The microwave processing of lunar materials holds promise for the production of either water, oxygen, primary metals, or ceramic materials. Extra high frequency microwave (EHF) at between 100 and 500 gigahertz have the potential for selective coupling to specific atomic species and a concomitant low energy requirement for the extraction of specific materials, such as oxygen, from lunar ores. The coupling of ultra high frequency (UHF) (e.g., 2.45 gigahertz) microwave frequencies to hydrogen-oxygen bonds might enable the preferential and low energy cost removal (as H/sub 2/O) of implanted protons from the sun or of adosrbed water which might be found in lunar dust in permanently shadowed polar areas. Microwave melting and selective phase melting of lunar materials could also be used either in the preparation of simplified ceramic geometries (e.g., bricks) with custom-tailored microstructures, or for the direct preparation of hermetic walls in underground structures. Speculatively, the preparation of photovoltaic devices based on lunar materials, especially ilmenite, may be a potential use of microwave processing on the moon. Preliminary experiments on UHF melting of terrestrial basalt, basalt/ilmenite and mixtures show that microwave processing is feasible.

  16. Polycrystalline thin film materials and devices. Final subcontract report, 16 January 1990--15 January 1993

    SciTech Connect

    Birkmire, R.W.; Phillips, J.E.; Shafarman, W.N.; Hegedus, S.S.; McCandless, B.E.; Yokimcus, T.A.

    1993-08-01

    This report describes results and conclusions of the final phase (III) of a three-year research program on polycrystalline thin-film heterojunction solar cells. The research consisted of the investigation of the relationships between processing, materials properties, and device performance. This relationship was quantified by device modeling and analysis. The analysis of thin-film polycrystalline heterojunction solar cells explains how minority-carrier recombination at the metallurgical interface and at grain boundaries can be greatly reduced by the proper doping of the window and absorber layers. Additional analysis and measurements show that the present solar cells are limited by the magnitude of the diode current, which appears to be caused by recombination in the space charge region. Developing an efficient commercial-scale process for fabricating large-area polycrystalline, thin-film solar cells from a research process requires a detailed understanding of the individual steps in making the solar cell, and their relationship to device performance and reliability. The complexities involved in characterizing a process are demonstrated with results from our research program on CuInSe{sub 2}, and CdTe processes.

  17. Gadolinium nitride films deposited using a PEALD based process

    NASA Astrophysics Data System (ADS)

    Fang, Ziwen; Williams, Paul A.; Odedra, Rajesh; Jeon, Hyeongtag; Potter, Richard J.

    2012-01-01

    Gadolinium nitride films have been deposited on Si(100) using a plasma-enhanced ALD (PEALD) based process. The deposition was carried out using tris(methylcyclopentadienyl)gadolinium {Gd(MeCp) 3} and remote nitrogen plasma, separated by argon pulses. Films were deposited at temperatures between 150 and 300 °C and capped with tantalum nitride to prevent post-deposition oxidation. Film composition was initially assessed using EDX and selected samples were subsequently depth profiled using medium energy ion scattering (MEIS) or AES. X-ray diffraction appears to show that the films are effectively amorphous. Films deposited at 200 °C were found to have a Gd:N ratio close to 1:1 and a low oxygen incorporation (˜5%). Although the growth was affected by partial thermal decomposition of the Gd(MeCp) 3, it was still possible to obtain smooth (Ra.=˜0.7 nm) films with good thickness uniformity (97%). Less successful attempts to deposit gadolinium nitride using thermal ALD with ammonia or mono-methyl-hydrazine are also reported.

  18. Materials processing in space program tasks

    NASA Technical Reports Server (NTRS)

    Naumann, R. J. (Editor)

    1980-01-01

    The history, strategy, and overall goal of NASA's Office of Space and Terrestrial Applications program for materials processing in space are described as well as the organizational structures and personnel involved. An overview of each research task is presented and recent publications are listed.

  19. Food Processing Curriculum Material and Resource Guide.

    ERIC Educational Resources Information Center

    Louisiana State Dept. of Education, Baton Rouge.

    Intended for secondary vocational agriculture teachers, this curriculum guide contains a course outline and a resource manual for a seven-unit food processing course on meats. Within the course outline, units are divided into separate lessons. Materials provided for each lesson include preparation for instruction (student objectives, review of…

  20. ENVIRONMENTAL TOOLS FOR MATERIAL AND PROCESS SELECTION

    EPA Science Inventory

    A number of tools are being used within the Sustainable Technology Division of the U.S. Environmental Protection Agency to provide decision-makers with information on environmentally favorable materials and processes. These tools include LCA (Life Cycle Assessment), GREENSCOPE (...

  1. Materials processing in space program support

    NASA Technical Reports Server (NTRS)

    Glicksman, Martin; Vanalstine, James M.

    1987-01-01

    Activities in support of NASA's Materials Processing in Space (MPS) program are reported. The overall task of the MPS project support contract was to provide the organization and administration of colloquiums, science reviews, workshops, technical meetings, bibliographic services, and visiting scientist programs. The research objectives and accomplishments of the University Space Research Association visiting scientist team are also summarized.

  2. PREFACE: Processing, Microstructure and Performance of Materials

    NASA Astrophysics Data System (ADS)

    Chiu, Yu Lung; Chen, John J. J.; Hodgson, Michael A.; Thambyah, Ashvin

    2009-07-01

    A workshop on Processing, Microstructure and Performance of Materials was held at the University of Auckland, School of Engineering, on 8-9 April 2009. Organised by the Department of Chemical and Materials Engineering, University of Auckland, this meeting consisted of international participants and aimed at addressing the state-of-the-art research activities in processing, microstructure characterization and performance integrity investigation of materials. This two-day conference brought together scientists and engineers from New Zealand, Australia, Hong Kong, France, and the United Kingdom. Undoubtedly, this diverse group of participants brought a very international flair to the proceedings which also featured original research papers on areas such as Materials processing; Microstructure characterisation and microanalysis; Mechanical response at different length scales, Biomaterials and Material Structural integrity. There were a total of 10 invited speakers, 16 paper presentations, and 14 poster presentations. Consequently, the presentations were carefully considered by the scientific committee and participants were invited to submit full papers for this volume. All the invited paper submissions for this volume have been peer reviewed by experts in the various fields represented in this conference, this in accordance to the expected standards of the journal's Peer review policy for IOP Conference Series: Materials Science and Engineering. The works in this publication consists of new and original research as well as several expert reviews of current state-of-the art technologies and scientific developments. Knowing some of the real constraints on hard-copy publishing of high quality, high resolution images, the editors are grateful to IOP Publishing for this opportunity to have the papers from this conference published on the online open-access platform. Listed in this volume are papers on a range of topics on materials research, including Ferguson's high strain

  3. Polytellurophenes as Solution Processable Materials for Applications in Organic Electronics

    NASA Astrophysics Data System (ADS)

    Jahnke, Ashlee Anne

    With very few previous publications on polytellurophenes prior to 2009, this is a largely unexplored class of conjugated polymers. This thesis details investigations into two types of tellurophene polymers. The synthesis of four novel tellurophene containing polymers is described and the characterization of their optical, solid-state, and electronic properties is discussed. The first chapter provides an introduction to the history of the field of polytellurophenes and provides context for the work presented in this thesis. The second chapter describes the synthesis of a novel bitellurophene monomer and its use in palladium-catalyzed polymerization. Once synthesized, the polymer is used to explore the unique chemistry of tellurium and its ability to form coordination species with bromine. Upon treatment with elemental bromine, changes in the optical properties of the system are observed. In chapter three, the synthesis of the first examples of soluble tellurophene homopolymers is presented. These poly(3-alkyltellurophene)s are solution processable materials and are fully characterized in solution and the solid-state. Chapter four describes further studies into the thin-film morphology of the materials presented in chapter three. Furthermore, semiconductor:insulator blends are prepared using poly(3-alkyltellurophene)s and high-density polyethylene. Taking advantage of the elemental contrast provided by the tellurium heavy atom, the micro- and nanostructure of the blend thin-films are investigated with various microscopy techniques providing insight into these types of blends that was previously unavailable. In the final chapter, the performance of these materials in thin-film field-effect transistors was investigated.

  4. High-performance and flexible thermoelectric films by screen printing solution-processed nanoplate crystals.

    PubMed

    Varghese, Tony; Hollar, Courtney; Richardson, Joseph; Kempf, Nicholas; Han, Chao; Gamarachchi, Pasindu; Estrada, David; Mehta, Rutvik J; Zhang, Yanliang

    2016-01-01

    Screen printing allows for direct conversion of thermoelectric nanocrystals into flexible energy harvesters and coolers. However, obtaining flexible thermoelectric materials with high figure of merit ZT through printing is an exacting challenge due to the difficulties to synthesize high-performance thermoelectric inks and the poor density and electrical conductivity of the printed films. Here, we demonstrate high-performance flexible films and devices by screen printing bismuth telluride based nanocrystal inks synthesized using a microwave-stimulated wet-chemical method. Thermoelectric films of several tens of microns thickness were screen printed onto a flexible polyimide substrate followed by cold compaction and sintering. The n-type films demonstrate a peak ZT of 0.43 along with superior flexibility, which is among the highest reported ZT values in flexible thermoelectric materials. A flexible thermoelectric device fabricated using the printed films produces a high power density of 4.1 mW/cm(2) with 60 °C temperature difference between the hot side and cold side. The highly scalable and low cost process to fabricate flexible thermoelectric materials and devices demonstrated here opens up many opportunities to transform thermoelectric energy harvesting and cooling applications. PMID:27615036

  5. Effect of annealing process on the phase formation in poly(vinylidene fluoride) thin films

    SciTech Connect

    Abdullah, Ibtisam Yahya; Yahaya, Muhammad; Jumali, Mohd Hafizuddin Haji; Shanshool, Haider Mohammed

    2014-09-03

    This work reports the initial study on the effect of annealing process on the crystalline phase of poly(vinylidene fluoride) (PVDF) thin film. PVDF powder was dissolved in N,N-dimethylformamide before spin-coated onto a glass substrate to form a film. The films were annealed at 30°C, 90°C and 110°C for 5 hrs. The crystalline phase of the powder PVDF as received was investigated by using XRD and FTIR techniques. Moreover, the crystalline phases of thin films after annealing were investigated by using the same techniques. XRD analysis showed that in powder form PVDF exists in α-phase. Each annealed PVDF thin films exhibited identical formation of three-phases material namely γ (as major phase) while α and β phases as the minor phases. The FTIR analysis showed that the powder form of PVDF exists in α and β phases. FTIR measurement further confirmed the XRD results implying that the annealing process has no significant effect on the phase formation in PVDF films.

  6. Polycrystalline thin film materials and devices. Annual subcontract report, 16 January 1991--15 January 1992

    SciTech Connect

    Baron, B.N.; Birkmire, R.W.; Phillips, J.E.; Shafarman, W.N.; Hegedus, S.S.; McCandless, B.E.

    1992-10-01

    Results of Phase II of a research program on polycrystalline thin film heterojunction solar cells are presented. Relations between processing, materials properties and device performance were studied. The analysis of these solar cells explains how minority carrier recombination at the interface and at grain boundaries can be reduced by doping of windows and absorber layers, such as in high efficiency CdTe and CuInSe{sub 2} based solar cells. The additional geometric dimension introduced by the polycrystallinity must be taken into consideration. The solar cells are limited by the diode current, caused by recombination in the space charge region. J-V characteristics of CuInSe{sub 2}/(CdZn)S cells were analyzed. Current-voltage and spectral response measurements were also made on high efficiency CdTe/CdS thin film solar cells prepared by vacuum evaporation. Cu-In bilayers were reacted with Se and H{sub 2}Se gas to form CuInSe{sub 2} films; the reaction pathways and the precursor were studied. Several approaches to fabrication of these thin film solar cells in a superstrate configuration were explored. A self-consistent picture of the effects of processing on the evolution of CdTe cells was developed.

  7. Laser induced deflection (LID) method for absolute absorption measurements of optical materials and thin films

    NASA Astrophysics Data System (ADS)

    Mühlig, Christian; Bublitz, Simon; Paa, Wolfgang

    2011-05-01

    We use optimized concepts to measure directly low absorption in optical materials and thin films at various laser wavelengths by the laser induced deflection (LID) technique. An independent absolute calibration, using electrical heaters, is applied to obtain absolute absorption data without the actual knowledge of the photo-thermal material properties. Verification of the absolute calibration is obtained by measuring different silicon samples at 633 nm where all laser light, apart from the measured reflection/scattering, is absorbed. Various experimental results for bulk materials and thin films are presented including measurements of fused silica and CaF2 at 193 nm, nonlinear crystals (LBO) for frequency conversion and AR coated fused silica for high power material processing at 1030 nm and Yb-doped silica raw materials for high power fiber lasers at 1550 nm. In particular for LBO the need of an independent calibration is demonstrated since thermal lens generation is dominated by stress-induced refractive index change which is in contrast to most of the common optical materials. The measured results are proven by numerical simulations and their influence on the measurement strategy and the obtained accuracy are shown.

  8. Novel Low Temperature Processing for Enhanced Properties of Ion Implanted Thin Films and Amorphous Mixed Oxide Thin Film Transistors

    NASA Astrophysics Data System (ADS)

    Vemuri, Rajitha

    This research emphasizes the use of low energy and low temperature post processing to improve the performance and lifetime of thin films and thin film transistors, by applying the fundamentals of interaction of materials with conductive heating and electromagnetic radiation. Single frequency microwave anneal is used to rapidly recrystallize the damage induced during ion implantation in Si substrates. Volumetric heating of the sample in the presence of the microwave field facilitates quick absorption of radiation to promote recrystallization at the amorphous-crystalline interface, apart from electrical activation of the dopants due to relocation to the substitutional sites. Structural and electrical characterization confirm recrystallization of heavily implanted Si within 40 seconds anneal time with minimum dopant diffusion compared to rapid thermal annealed samples. The use of microwave anneal to improve performance of multilayer thin film devices, e.g. thin film transistors (TFTs) requires extensive study of interaction of individual layers with electromagnetic radiation. This issue has been addressed by developing detail understanding of thin films and interfaces in TFTs by studying reliability and failure mechanisms upon extensive stress test. Electrical and ambient stresses such as illumination, thermal, and mechanical stresses are inflicted on the mixed oxide based thin film transistors, which are explored due to high mobilities of the mixed oxide (indium zinc oxide, indium gallium zinc oxide) channel layer material. Semiconductor parameter analyzer is employed to extract transfer characteristics, useful to derive mobility, subthreshold, and threshold voltage parameters of the transistors. Low temperature post processing anneals compatible with polymer substrates are performed in several ambients (oxygen, forming gas and vacuum) at 150 °C as a preliminary step. The analysis of the results pre and post low temperature anneals using device physics fundamentals

  9. Microwave plasma assisted supersonic gas jet deposition of thin film materials

    DOEpatents

    Schmitt, III, Jerome J.; Halpern, Bret L.

    1993-01-01

    An apparatus for fabricating thin film materials utilizing high speed gas dynamics relies on supersonic free jets of carrier gas to transport depositing vapor species generated in a microwave discharge to the surface of a prepared substrate where the vapor deposits to form a thin film. The present invention generates high rates of deposition and thin films of unforeseen high quality at low temperatures.

  10. Catalogo de peliculas educativas y otros materiales audiovisuales (Catalogue of Educational Films and other Audiovisual Materials).

    ERIC Educational Resources Information Center

    Encyclopaedia Britannica, Inc., Chicago, IL.

    This catalogue of educational films and other audiovisual materials consists predominantly of films in Spanish and English which are intended for use in elementary and secondary schools. A wide variety of topics including films for social studies, language arts, humanities, physical and natural sciences, safety and health, agriculture, physical…

  11. Investigation of the influence of cadmium processing on zinc gallium oxide:manganese thin films for photoluminescent and thin film electroluminescent applications

    NASA Astrophysics Data System (ADS)

    Flynn, Michael John

    Cadmium processing of ZnGa2O4 films provides a new fabrication route for phosphor powders and thin films. It relies on the enhanced diffusion due to the large vacancy concentration left by the sublimation of cadmium. Photoluminescent powders can be made with a single high temperature firing. Thin film devices can be processed at a significantly lower temperature, expanding the range of available substrates. Powders and thin films of ZnGa2O4:Mn were fabricated using starting materials in which between 0% and 50% of the ZnO was substituted by CdO. It was found that the emission spectra of the various compositions was unaffected by the change in composition, peaking at 504 nm, with the colour coordinates x = 0.08 and y = 0.69. The invariance of the emission spectrum is due to the spinel crystal structure exhibited by the compound. However, the maximum PL brightness was obtained from powders in which 10% of the ZnO had been substituted by CdO in the starting materials. The improved brightness is the result of better manganese incorporation which resulted from CdO sublimation during processing. This left a large vacancy concentration which enhanced the diffusion, and hence the manganese incorporation. In the case of thin films sputtered from cadmium processed targets, the composition of the films as deposited closely mirrored that of the target starting materials. The as deposited films were not luminescent and had to be annealed in vacuum in order to activate the manganese. EDX of these films showed that all of the cadmium had sublimed during the anneal. Very long anneal times also resulted in the loss of zinc. The decomposition products were amorphous or nanocrystalline. These films had an identical PL emission to the powders. The loss of cadmium correlated with the onset of bright 254 nm photoluminescence in the films, indicating that cadmium loss aided in the activation of the manganese. This was the result of the enhanced diffusion due to the large vacancy

  12. Optical and electrochemical properties of Ni doped WO 3-MoO 3 films prepared by sol-gel process

    NASA Astrophysics Data System (ADS)

    Li, Zhuying; Zhang, Minliang; Zhang, Yan

    2007-12-01

    The electrochromic effect, change of optical transmittance with respect to the applied DC voltage,is a well-known phenomenon. The electrochromic film can be fabricated with various methods such as rf and dc sputtering, chemical vapour deposition, electron, thermal and ion cluster beams and several other methods. Sol-gel process offeres several advantages over conventional deposition method for the control of stoichiometry and film structure. It was known that WO 3 thin film doped with niobium and with Lithium exhibits a well bleaching process as compared with pure tungsten oxide film [1-4]. The presence of Li, Ta, Ti and Nb in WO 3 film improves the spectroelectrochemical response of these materials. So in this paper, we presented a mixed-metal oxide sol-gel synthesis, deposition, optical and electrochromic performances of Nickel (II) acetate doped tungsten molybdenum oxide film WO 3-MoO 3--Ni(CH 3COO) II. The range of dopant concentration was 0.75ml-7.5ml V%. Film made from WO 3-MoO 3 precursor solutions was also used for comparison. The film has been studied and characterized by ultraviolet-visible spectroscopy, X-ray diffractometry (XRD), scanning electron microscopy (SEM) and electrochemistric station. The good coloring and bleaching behaviors of doped Ni film mean that they are suitable for electrochromic material.

  13. Front and backside processed thin film electronic devices

    DOEpatents

    Evans, Paul G.; Lagally, Max G.; Ma, Zhenqiang; Yuan, Hao-Chih; Wang, Guogong; Eriksson, Mark A.

    2012-01-03

    This invention provides thin film devices that have been processed on their front- and backside. The devices include an active layer that is sufficiently thin to be mechanically flexible. Examples of the devices include back-gate and double-gate field effect transistors, double-sided bipolar transistors and 3D integrated circuits.

  14. Dual-beam laser thermal processing of silicon photovoltaic materials

    NASA Astrophysics Data System (ADS)

    Simonds, Brian J.; Teal, Anthony; Zhang, Tian; Hadler, Josh; Zhou, Zibo; Varlamov, Sergey; Perez-Würfl, Ivan

    2016-03-01

    We have developed an all-laser processing technique by means of two industrially-relevant continuous-wave fiber lasers operating at 1070 nm. This approach is capable of both substrate heating with a large defocused beam and material processing with a second scanned beam, and is suitable for a variety of photovoltaic applications. We have demonstrated this technique for rapid crystallization of thin film (~10 μm) silicon on glass, which is a low cost alternative to wafer-based solar cells. We have also applied this technique to wafer silicon to control dopant diffusion at the surface region where the focused line beam rapidly melts the substrate that then regrows epitaxially. Finite element simulations have been used to model the melt depth as a function of preheat temperature and line beam power. This process is carried out in tens of seconds for an area approximately 10 cm2 using only about 1 kW of total optical power and is readily scalable. In this paper, we will discuss our results with both c-Si wafers and thin-film silicon.

  15. Materials for Conoco zinc chloride hydrocracking process

    SciTech Connect

    Baylor, V.B.; Keiser, J.R.; DeVan, J.H.

    1980-01-01

    Use of zinc chloride to augment hydrogenation of coal and yield a high-octane gasoline product is the most significant feature of a coal liquefaction process being developed by Conoco Coal Development Company. The zinc chloride catalyst is regenerated in a fluidized sand bed, where the spent melt is mixed with air and hydrogen chloride at about 1000/sup 0/C. Recovery is completed at 370/sup 0/C in a condenser, where the zinc chloride is collected and the oxygen and sulfur are separated as H/sub 2/O and SO/sub 2/. The economic viability of the entire process is highly dependent on almost complete recovery of the zinc chloride. The severe environmental conditions of this recovery process cause unique materials problems. Although high-temperature oxidation and sulfidation are being studied in related programs, suitable materials to resist their combined effects along with those of chlorides have not yet been specifically addressed. Common engineering materials, such as the austenitic stainless steels and many nickel-base alloys, are unsuitable because of their inability to tolerate the elevated temperatures and sulfidation, respectively. The objectives of this task are to screen various metallic and ceramic materials for resistance to the zinc chloride recovery system environment and to determine the nature of the attack by exposing coupons to the simulated environment in the laboratory.

  16. Early space experiments in materials processing

    NASA Technical Reports Server (NTRS)

    Naumann, R. J.

    1979-01-01

    A comprehensive survey of the flight experiments conducted in conjunction with the United States Materials Processing in Space Program is presented. Also included are a brief description of the conditions prevailing in an orbiting spacecraft and the research implications provided by this unique environment. What was done and what was learned are summarized in order to serve as a background for future experiments. It is assumed that the reader has some knowledge of the physical sciences but no background in spaceflight experimentation or in the materials science per se.

  17. Characterization of the deposition and materials parameters of thin-film TiNi for microactuators and smart materials

    SciTech Connect

    Jardine, A.P.; Madsen, J.S.; Mercado, P.G. . Dept. of Materials Science)

    1994-04-01

    Development of smart materials and materials for microelectromechanical systems (MEMS) are complicated by the need to grow dissimilar active or adaptive materials in close proximity. This entails discouraging unwanted chemical and physical interactions that prevent production of the appropriate phases. An important component of these systems will be thin-film shape memory effect TiNi. This article discusses the characterization of the deposition of thin film TiNi for these applications as well as the cycling speed for MEMS.

  18. Transparent megahertz circuits from solution-processed composite thin films

    NASA Astrophysics Data System (ADS)

    Liu, Xingqiang; Wan, Da; Wu, Yun; Xiao, Xiangheng; Guo, Shishang; Jiang, Changzhong; Li, Jinchai; Chen, Tangsheng; Duan, Xiangfeng; Fan, Zhiyong; Liao, Lei

    2016-04-01

    Solution-processed amorphous oxide semiconductors have attracted considerable interest in large-area transparent electronics. However, due to its relative low carrier mobility (~10 cm2 V-1 s-1), the demonstrated circuit performance has been limited to 800 kHz or less. Herein, we report solution-processed high-speed thin-film transistors (TFTs) and integrated circuits with an operation frequency beyond the megahertz region on 4 inch glass. The TFTs can be fabricated from an amorphous indium gallium zinc oxide/single-walled carbon nanotube (a-IGZO/SWNT) composite thin film with high yield and high carrier mobility of >70 cm2 V-1 s-1. On-chip microwave measurements demonstrate that these TFTs can deliver an unprecedented operation frequency in solution-processed semiconductors, including an extrinsic cut-off frequency (fT = 102 MHz) and a maximum oscillation frequency (fmax = 122 MHz). Ring oscillators further demonstrated an oscillation frequency of 4.13 MHz, for the first time, realizing megahertz circuit operation from solution-processed semiconductors. Our studies represent an important step toward high-speed solution-processed thin film electronics.Solution-processed amorphous oxide semiconductors have attracted considerable interest in large-area transparent electronics. However, due to its relative low carrier mobility (~10 cm2 V-1 s-1), the demonstrated circuit performance has been limited to 800 kHz or less. Herein, we report solution-processed high-speed thin-film transistors (TFTs) and integrated circuits with an operation frequency beyond the megahertz region on 4 inch glass. The TFTs can be fabricated from an amorphous indium gallium zinc oxide/single-walled carbon nanotube (a-IGZO/SWNT) composite thin film with high yield and high carrier mobility of >70 cm2 V-1 s-1. On-chip microwave measurements demonstrate that these TFTs can deliver an unprecedented operation frequency in solution-processed semiconductors, including an extrinsic cut-off frequency (f

  19. Alternative nano-structured thin-film materials used as durable thermal nanoimprint lithography templates

    NASA Astrophysics Data System (ADS)

    Bossard, M.; Boussey, J.; Le Drogoff, B.; Chaker, M.

    2016-02-01

    Nanoimprint templates made of diamond-like carbon (DLC) and amorphous silicon carbide (SiC) thin films and fluorine-doped associated materials, i.e. F-DLC and F-SiC were investigated in the context of thermal nanoimprint lithography (NIL) with respect to their release properties. Their performances in terms of durability and stability were evaluated and compared to those of conventional silicon or silica molds coated with antisticking molecules applied as a self-assembled monolayer. Plasma-enhanced chemical vapor deposition parameters were firstly tuned to optimize mechanical and structural properties of the DLC and SiC thin films. The impact of the amount of fluorine dopant on the deposited thin films properties was then analyzed. A comparative analysis of DLC, F-DLC as well as SiC and F-SiC molds was then carried out over multiple imprints, performed into poly (methyl methacrylate) (PMMA) thermo-plastic resist. The release properties of un-patterned films were evaluated by the measurement of demolding energies and surface energies, associated with a systematic analysis of the mold surface contamination. These analyses showed that the developed materials behave as intrinsically easy-demolding and contamination-free molds over series of up to 40 imprints. To our knowledge, it is the first time that such a large number of imprints has been considered within an exhaustive comparative study of materials for NIL. Finally, the developed materials went through standard e-beam lithography and plasma etching processes to obtain nanoscale-patterned templates. The replicas of those patterned molds, imprinted into PMMA, were shown to be of high fidelity and good stability after several imprints.

  20. Alternative nano-structured thin-film materials used as durable thermal nanoimprint lithography templates.

    PubMed

    Bossard, M; Boussey, J; Le Drogoff, B; Chaker, M

    2016-02-19

    Nanoimprint templates made of diamond-like carbon (DLC) and amorphous silicon carbide (SiC) thin films and fluorine-doped associated materials, i.e. F-DLC and F-SiC were investigated in the context of thermal nanoimprint lithography (NIL) with respect to their release properties. Their performances in terms of durability and stability were evaluated and compared to those of conventional silicon or silica molds coated with antisticking molecules applied as a self-assembled monolayer. Plasma-enhanced chemical vapor deposition parameters were firstly tuned to optimize mechanical and structural properties of the DLC and SiC thin films. The impact of the amount of fluorine dopant on the deposited thin films properties was then analyzed. A comparative analysis of DLC, F-DLC as well as SiC and F-SiC molds was then carried out over multiple imprints, performed into poly (methyl methacrylate) (PMMA) thermo-plastic resist. The release properties of un-patterned films were evaluated by the measurement of demolding energies and surface energies, associated with a systematic analysis of the mold surface contamination. These analyses showed that the developed materials behave as intrinsically easy-demolding and contamination-free molds over series of up to 40 imprints. To our knowledge, it is the first time that such a large number of imprints has been considered within an exhaustive comparative study of materials for NIL. Finally, the developed materials went through standard e-beam lithography and plasma etching processes to obtain nanoscale-patterned templates. The replicas of those patterned molds, imprinted into PMMA, were shown to be of high fidelity and good stability after several imprints. PMID:26783068

  1. Materials, design and processing of air encapsulated MEMS packaging

    NASA Astrophysics Data System (ADS)

    Fritz, Nathan T.

    integrity. The development of mechanical models complimented the experimental studies. A model of the overcoat materials used the film properties and elastic deformations to study the stress-strain behavior of the suspended dielectric films under external forces. The experimental molding tests and mechanical models were used to establish processing conditions and physical designs for the cavities as a function of cavity size. A novel, metal-free chip package was investigated combining the in-situ thermal decomposition of the sacrificial material during post-mold curing of the lead frame molding compound. Sacrificial materials were characterized for their degree of decomposition during the molding cure to provide a chip package with improved mechanical support and no size restrictions. Improvements to the air cavities for MEMS packaging led to investigations and refinements of other microfabrication processes. The sacrificial polycarbonate materials were shown to be useful as temporary bonding materials for wafer-level bonding. The release temperature and conditions of the processed wafer can be changed based on the polycarbonates formulation. The electroless deposition of metal was investigated as an alternative process for metalizing the air cavities. The deposition of silver and copper using a Sn/Ag catalyst as a replacement for costly palladium activation was demonstrated. The electroless deposition was tested on polymer and silicon dioxide surfaces for organic boards and through-silicon vias.

  2. Fabrication of polycrystalline thin films by pulsed laser processing

    DOEpatents

    Mitlitsky, Fred; Truher, Joel B.; Kaschmitter, James L.; Colella, Nicholas J.

    1998-02-03

    A method for fabricating polycrystalline thin films on low-temperature (or high-temperature) substrates which uses processing temperatures that are low enough to avoid damage to the substrate, and then transiently heating select layers of the thin films with at least one pulse of a laser or other homogenized beam source. The pulse length is selected so that the layers of interest are transiently heated to a temperature which allows recrystallization and/or dopant activation while maintaining the substrate at a temperature which is sufficiently low to avoid damage to the substrate. This method is particularly applicable in the fabrication of solar cells.

  3. Fabrication of polycrystalline thin films by pulsed laser processing

    DOEpatents

    Mitlitsky, F.; Truher, J.B.; Kaschmitter, J.L.; Colella, N.J.

    1998-02-03

    A method is disclosed for fabricating polycrystalline thin films on low-temperature (or high-temperature) substrates which uses processing temperatures that are low enough to avoid damage to the substrate, and then transiently heating select layers of the thin films with at least one pulse of a laser or other homogenized beam source. The pulse length is selected so that the layers of interest are transiently heated to a temperature which allows recrystallization and/or dopant activation while maintaining the substrate at a temperature which is sufficiently low to avoid damage to the substrate. This method is particularly applicable in the fabrication of solar cells. 1 fig.

  4. Solution-processed thin films for electronics from single-walled carbon nanotubes and graphene

    NASA Astrophysics Data System (ADS)

    Eda, Goki

    Single-walled carbon nanotubes (SWNTs) and graphene are sp 2 hybridized carbon nanostructures which exhibit extraordinary electronic properties arising from their unique energy dispersions and dimensionalities. A major issue preventing implementation of these materials into integrated electronic devices is the absence of large-scale controllable synthesis and subsequent manipulation. To circumvent this issue, solution processing of SWNTs and graphene has been proposed. Deposition of thin film networks allows the realization of a new class of materials that are useful for large-area or "macro-electronics" on flexible and inexpensive platforms. In this thesis, controllable and efficient solution-based deposition of SWNT and graphene thin film networks and their opto-electronic properties are investigated. Topics such as material dynamics in liquid, chemical structures, defects, morphology, and doping are studied utilizing various spectroscopy and microscopy analysis along with complementary electrical measurements. Further insight is provided through demonstrations of proof-of-principle thin film transistors, organic photovoltaics, and field emitters based on solution-processed SWNT and graphene thin films.

  5. Process for thin film deposition of cadmium sulfide

    DOEpatents

    Muruska, H. Paul; Sansregret, Joseph L.; Young, Archie R.

    1982-01-01

    The present invention teaches a process for depositing layers of cadmium sulfide. The process includes depositing a layer of cadmium oxide by spray pyrolysis of a cadmium salt in an aqueous or organic solvent. The oxide film is then converted into cadmium sulfide by thermal ion exchange of the O.sup.-2 for S.sup.-2 by annealing the oxide layer in gaseous sulfur at elevated temperatures.

  6. Relationships between processing temperature and microstructure in isothermal melt processed Bi-2212 thick films

    SciTech Connect

    Holesinger, T.G.; Phillips, D.S.; Willis, J.O.; Peterson, D.E.

    1995-05-01

    The microstructure and phase assemblage of isothermal melt processed (IMP) Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub y} (Bi-2212) thick films have been evaluated. Results from compositional analysis and phase identification indicate that the characteristics of the partial melt greatly influence the microstructural and chemical development of the thick films. The highest critical current densities were obtained in films processed below 800{degrees}C where the partial melt uniformly coats the substrate without excessive phase segregation.

  7. Computer simulation of surface and film processes

    NASA Technical Reports Server (NTRS)

    Tiller, W. A.; Halicioglu, M. T.

    1983-01-01

    Adequate computer methods, based on interactions between discrete particles, provide information leading to an atomic level understanding of various physical processes. The success of these simulation methods, however, is related to the accuracy of the potential energy function representing the interactions among the particles. The development of a potential energy function for crystalline SiO2 forms that can be employed in lengthy computer modelling procedures was investigated. In many of the simulation methods which deal with discrete particles, semiempirical two body potentials were employed to analyze energy and structure related properties of the system. Many body interactions are required for a proper representation of the total energy for many systems. Many body interactions for simulations based on discrete particles are discussed.

  8. 76 FR 72902 - Materials Processing Equipment Technical Advisory Committee;

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-28

    ... Bureau of Industry and Security Materials Processing Equipment Technical Advisory Committee; Notice of Partially Closed Meeting The Materials Processing Equipment Technical Advisory Committee (MPETAC) will meet... controls applicable to materials processing equipment and related technology. Agenda Open Session...

  9. Limited reaction processing for semiconductor materials preparation

    NASA Astrophysics Data System (ADS)

    Hoyt, J. L.

    1991-07-01

    Limited Reaction Processing (LRP) is a layer deposition technique based upon a combination of rapid thermal processing (RTP) and chemical vapor deposition. The versatility of LRP was shwon in research on epitaxial growth in three different materials systems. Research was spurred at several other laboratories in the area of epitaxial growth and applications involving RTP techniques, particularly in the Si(1-x)Ge(x) materials system. The first CVD grown Si/Si(1-x)Ge(x) heterojunction bipolar transistors were fabricated using this technique, with maximum oscillation frequencies on the order of 40 GHz. In the III-V area, arsine alternative sources were explored for GaAs expitaxy which greatly improve the safety of MOCVD. A new atomic layer growth technique was developed by combining LRP with an alternating gas pulse method.

  10. Materials processing in space program tasks

    NASA Technical Reports Server (NTRS)

    Mckannan, E. C. (Editor)

    1978-01-01

    A list of active research tasks as of the end of 1978 of the Materials Processing in Space Program of the Office of Space and Terrestrial Applications, involving several NASA Centers and other organizations is reported. An overview of the program scope for managers and scientists in industry, university and government communities is provided. The program, its history, strategy and overall goal; the organizational structures and people involved; and each research task are described. Tasks are categorized by ground based research according to four process areas. Cross references to the performing organizations and principal investigators are provided.

  11. Tubular filamentation for laser material processing.

    PubMed

    Xie, Chen; Jukna, Vytautas; Milián, Carles; Giust, Remo; Ouadghiri-Idrissi, Ismail; Itina, Tatiana; Dudley, John M; Couairon, Arnaud; Courvoisier, Francois

    2015-01-01

    An open challenge in the important field of femtosecond laser material processing is the controlled internal structuring of dielectric materials. Although the availability of high energy high repetition rate femtosecond lasers has led to many advances in this field, writing structures within transparent dielectrics at intensities exceeding 10(13) W/cm(2) has remained difficult as it is associated with significant nonlinear spatial distortion. This letter reports the existence of a new propagation regime for femtosecond pulses at high power that overcomes this challenge, associated with the generation of a hollow uniform and intense light tube that remains propagation invariant even at intensities associated with dense plasma formation. This regime is seeded from higher order nondiffracting Bessel beams, which carry an optical vortex charge. Numerical simulations are quantitatively confirmed by experiments where a novel experimental approach allows direct imaging of the 3D fluence distribution within transparent solids. We also analyze the transitions to other propagation regimes in near and far fields. We demonstrate how the generation of plasma in this tubular geometry can lead to applications in ultrafast laser material processing in terms of single shot index writing, and discuss how it opens important perspectives for material compression and filamentation guiding in atmosphere. PMID:25753215

  12. Tubular filamentation for laser material processing

    PubMed Central

    Xie, Chen; Jukna, Vytautas; Milián, Carles; Giust, Remo; Ouadghiri-Idrissi, Ismail; Itina, Tatiana; Dudley, John M.; Couairon, Arnaud; Courvoisier, Francois

    2015-01-01

    An open challenge in the important field of femtosecond laser material processing is the controlled internal structuring of dielectric materials. Although the availability of high energy high repetition rate femtosecond lasers has led to many advances in this field, writing structures within transparent dielectrics at intensities exceeding 1013 W/cm2 has remained difficult as it is associated with significant nonlinear spatial distortion. This letter reports the existence of a new propagation regime for femtosecond pulses at high power that overcomes this challenge, associated with the generation of a hollow uniform and intense light tube that remains propagation invariant even at intensities associated with dense plasma formation. This regime is seeded from higher order nondiffracting Bessel beams, which carry an optical vortex charge. Numerical simulations are quantitatively confirmed by experiments where a novel experimental approach allows direct imaging of the 3D fluence distribution within transparent solids. We also analyze the transitions to other propagation regimes in near and far fields. We demonstrate how the generation of plasma in this tubular geometry can lead to applications in ultrafast laser material processing in terms of single shot index writing, and discuss how it opens important perspectives for material compression and filamentation guiding in atmosphere. PMID:25753215

  13. Computational Modeling in Structural Materials Processing

    NASA Technical Reports Server (NTRS)

    Meyyappan, Meyya; Arnold, James O. (Technical Monitor)

    1997-01-01

    High temperature materials such as silicon carbide, a variety of nitrides, and ceramic matrix composites find use in aerospace, automotive, machine tool industries and in high speed civil transport applications. Chemical vapor deposition (CVD) is widely used in processing such structural materials. Variations of CVD include deposition on substrates, coating of fibers, inside cavities and on complex objects, and infiltration within preforms called chemical vapor infiltration (CVI). Our current knowledge of the process mechanisms, ability to optimize processes, and scale-up for large scale manufacturing is limited. In this regard, computational modeling of the processes is valuable since a validated model can be used as a design tool. The effort is similar to traditional chemically reacting flow modeling with emphasis on multicomponent diffusion, thermal diffusion, large sets of homogeneous reactions, and surface chemistry. In the case of CVI, models for pore infiltration are needed. In the present talk, examples of SiC nitride, and Boron deposition from the author's past work will be used to illustrate the utility of computational process modeling.

  14. Hydrothermal processing of lead titanate powders and thin films

    NASA Astrophysics Data System (ADS)

    Peterson, Chad Robert

    The influence of processing parameters on the formation and morphology of hydrothermally derived lead titanate (PbTiO3) powders was investigated. These experimental findings were then used to establish hydrothermal synthesis conditions under which continuous sub-micron PbTiO3 thin films could be processed. PbTiO3 powder was synthesized by suspending nanocrystalline powders of TiO2 in aqueous solutions of KOH and Pb(CH3COO) 2.3H2O at temperatures ranging from 120 to 200°C. PbTiO3 growth initiated in the <100> exposing (001) surfaces, and resulted in a faceted platelet morphology. Particle growth proceeded by further nucleation and growth on existing (001) surfaces. Through repeated dissolution and precipitation, the platelet clusters coarsened into larger cuboidal particles. PbTiO3 particle size was controlled by either inhibiting or promoting dissolution-precipitation. Dissolution-precipitation was inhibited by lowering the KOH concentration, reaction temperature, or maintaining an excess of Pb relative to Ti ions in solution, while it was promoted by increasing the KOH concentration and temperature. Coarsening of PbTiO3 particles coincided with decreases in: the x-ray diffraction (XRD) peak breadth, the asymmetry of l component XRD reflections, and the c-axis length. PbTiO3 and PbTiO3/polymer thin films were synthesized from a metallo-organic precursor on metallized quartz substrates. Titanium dimethoxy dineodecanoate (TDD) was spin-cast onto the substrates and converted to polycrystalline TiO2 via hydrolysis in deionized water for 5 h at 80°C. Polycrystalline PbTiO3 films were then formed by reacting the TiO2 films for 4 h at 200°C in aqueous solutions of KOH and Pb(CH3COO)2.3H 2O. Low KOH concentrations suppressed film coarsening, thereby facilitating the formation of fine-grain continuous PbTiO3 films. PbTiO 3/polymer thin films were processed in the same manner after first dissolving TDD and a polystyrene/polybutadiene triblock copolymer in p-xylene. Pb

  15. Review of solution-processed oxide thin-film transistors

    NASA Astrophysics Data System (ADS)

    Kim, Si Joon; Yoon, Seokhyun; Kim, Hyun Jae

    2014-02-01

    In this review, we summarize solution-processed oxide thin-film transistors (TFTs) researches based on our fulfillments. We describe the fundamental studies of precursor composition effects at the beginning in order to figure out the role of each component in oxide semiconductors, and then present low temperature process for the adoption of flexible devices. Moreover, channel engineering for high performance and reliability of solution-processed oxide TFTs and various coating methods: spin-coating, inkjet printing, and gravure printing are also presented. The last topic of this review is an overview of multi-functional solution-processed oxide TFTs for various applications such as photodetector, biosensor, and memory.

  16. Formation of CuInSSe thin films by conventional two-stage process

    NASA Astrophysics Data System (ADS)

    Shrotriya, Vipin; Rajaram, P.

    2016-05-01

    We have fabricated Crystalline CuInSSe thin films on glass substrate by conventional two-stage process. In first stage CuInS2 thin films have been grown on glass substrate by spray pyrolysis method at constant temperature 320°C. The CuCl2, InCl3, and thiourea were used as source materials for the Cu, In, and S precursors respectively and the Cu/In ratio is kept at 1.0. In second stage the precursor films of CuInS2 are selenized to get CuInSSe. The grown thin films of CuInS2 and CuInSSe were characterized by XRD, SEM and optical studies. The average crystallite size of the CISS thin films is found to be in the range 10-20 nm, using the Scherrer formula. The band gap value of the CuInSSe films is found to be 1.26 eV.

  17. Fabrication of solution processed 3D nanostructured CuInGaS₂ thin film solar cells.

    PubMed

    Chu, Van Ben; Cho, Jin Woo; Park, Se Jin; Hwang, Yun Jeong; Park, Hoo Keun; Do, Young Rag; Min, Byoung Koun

    2014-03-28

    In this study we demonstrate the fabrication of CuInGaS₂ (CIGS) thin film solar cells with a three-dimensional (3D) nanostructure based on indium tin oxide (ITO) nanorod films and precursor solutions (Cu, In and Ga nitrates in alcohol). To obtain solution processed 3D nanostructured CIGS thin film solar cells, two different precursor solutions were applied to complete gap filling in ITO nanorods and achieve the desirable absorber film thickness. Specifically, a coating of precursor solution without polymer binder material was first applied to fill the gap between ITO nanorods followed by deposition of the second precursor solution in the presence of a binder to generate an absorber film thickness of ∼1.3 μm. A solar cell device with a (Al, Ni)/AZO/i-ZnO/CdS/CIGS/ITO nanorod/glass structure was constructed using the CIGS film, and the highest power conversion efficiency was measured to be ∼6.3% at standard irradiation conditions, which was 22.5% higher than the planar type of CIGS solar cell on ITO substrate fabricated using the same precursor solutions. PMID:24569126

  18. Effects of Under Bump Metallurgy (UBM) Materials on the Corrosion of Electroless Nickel Films

    NASA Astrophysics Data System (ADS)

    Yu, Jin; Kim, Kyoungdoc

    2015-07-01

    The "black pad" phenomenon, which refers to the blackening of electroless-plated nickel-phosphorus [Ni(P)] films during the immersion Au process, is reproduced using pure chemicals and its fundamental mechanisms are investigated. In the present analysis, under bump metallurgy (UBM) materials have profound effects on the black pad susceptibility, and the presence of abnormally large nodules (ALNs) is essential to the black pad occurrence. The Ni(P) films over Cu, Ag, and Au substrates all exhibit ALNs and are susceptible to black pads, while those over Ni and Co substrates do not have ALNs and therefore are not susceptible to black pad. In the former cases, submicron scale nodular variations of the surface curvature lead to variations in the P concentration in the Ni(P) films, which induces sufficiently large potential differences to drive galvanic corrosion when exposed to the electrolyte, which is a gold cyanide solution in this study. The UBM effect is ascribed to differences in the Ni(P) film growth mode, where the transition from a layer-by-layer growth mode to an island growth mode is easier over Cu, Ag, and Au UBMs.

  19. [Study on preparation of lanthanum-doped TiO2 nanometer thin film materials and its photocatalytic activity].

    PubMed

    Zheng, Huai-li; Tang, Ming-fang; Gong, Ying-kun; Deng, Xiao-jun; Wu, Bang-hua

    2003-04-01

    In this paper, lanthanum-doped TiO2 nanometer film materials coated on glass were prepared in Ti(OBu)4 precursor solutions by sol-gel processing. Transmittance and photocatalytic activity were respectively investigated and tested for these nanometer thin films prepared with different amount of lanthanum (La), different amount of polyethylene glycol (PEG), and different coating layer times. Some reactive mechanisms were also discussed. For one layer La-addition had little effect on the film transmissivity; but the photocatalytic activity was significantly improved due to La-addition. With increasing PEG, the transmittance of the film decreased for one layer film; but its photocatalytic activity did not rise. Increasing layer number did not affect the transmissivity of multilayer film. After coating two times, increasing layer number did not significantly improve the photocatalytic activity. The highest photocatalytic activity and best transmissivity were obtained for two layer TiO2 film when the dosage of lanthanum was 0.5 g and the dosage of polyethylene was 0.2 g in the precursor solutions. These materials will probably be used in the protection of environment, waste water treatment, and air purification. PMID:12961861

  20. Pyroelectric Materials for Uncooled Infrared Detectors: Processing, Properties, and Applications

    NASA Technical Reports Server (NTRS)

    Aggarwal, M. D.; Batra, A. K.; Guggilla, P.; Edwards, M. E.; Penn, B. G.; Currie, J. R., Jr.

    2010-01-01

    Uncooled pyroelectric detectors find applications in diverse and wide areas such as industrial production; automotive; aerospace applications for satellite-borne ozone sensors assembled with an infrared spectrometer; health care; space exploration; imaging systems for ships, cars, and aircraft; and military and security surveillance systems. These detectors are the prime candidates for NASA s thermal infrared detector requirements. In this Technical Memorandum, the physical phenomena underlying the operation and advantages of pyroelectric infrared detectors is introduced. A list and applications of important ferroelectrics is given, which is a subclass of pyroelectrics. The basic concepts of processing of important pyroelectrics in various forms are described: single crystal growth, ceramic processing, polymer-composites preparation, and thin- and thick-film fabrications. The present status of materials and their characteristics and detectors figures-of-merit are presented in detail. In the end, the unique techniques demonstrated for improving/enhancing the performance of pyroelectric detectors are illustrated. Emphasis is placed on recent advances and emerging technologies such as thin-film array devices and novel single crystal sensors.

  1. Growth of mesoporous materials within colloidal crystal films by spin-coating.

    PubMed

    Villaescusa, Luis A; Mihi, Agustín; Rodríguez, Isabel; García-Bennett, Alfonso E; Míguez, Hernan

    2005-10-27

    A combination of colloidal crystal planarization, stabilization, and novel infiltration techniques is used to build a bimodal porous silica film showing order at both the micron and the nanometer length scale. An infiltration method based on the spin-coating of the mesophase precursor onto a three-dimensional polystyrene colloidal crystal film allows a nanometer control tuning of the filling fraction of the mesoporous phase while preserving the optical quality of the template. These materials combine a high specific surface arising from the nanopores with increased mass transport and photonic crystal properties provided by the order of the macropores. Optical Bragg diffraction from these type of hierarchically ordered oxides is observed, allowing performing of optical monitoring of the different processes involved in the formation of the bimodal silica structure. PMID:16853540

  2. Transparent megahertz circuits from solution-processed composite thin films.

    PubMed

    Liu, Xingqiang; Wan, Da; Wu, Yun; Xiao, Xiangheng; Guo, Shishang; Jiang, Changzhong; Li, Jinchai; Chen, Tangsheng; Duan, Xiangfeng; Fan, Zhiyong; Liao, Lei

    2016-04-21

    Solution-processed amorphous oxide semiconductors have attracted considerable interest in large-area transparent electronics. However, due to its relative low carrier mobility (∼10 cm(2) V(-1) s(-1)), the demonstrated circuit performance has been limited to 800 kHz or less. Herein, we report solution-processed high-speed thin-film transistors (TFTs) and integrated circuits with an operation frequency beyond the megahertz region on 4 inch glass. The TFTs can be fabricated from an amorphous indium gallium zinc oxide/single-walled carbon nanotube (a-IGZO/SWNT) composite thin film with high yield and high carrier mobility of >70 cm(2) V(-1) s(-1). On-chip microwave measurements demonstrate that these TFTs can deliver an unprecedented operation frequency in solution-processed semiconductors, including an extrinsic cut-off frequency (f(T) = 102 MHz) and a maximum oscillation frequency (f(max) = 122 MHz). Ring oscillators further demonstrated an oscillation frequency of 4.13 MHz, for the first time, realizing megahertz circuit operation from solution-processed semiconductors. Our studies represent an important step toward high-speed solution-processed thin film electronics. PMID:27009830

  3. Laser processing for manufacturing nanocarbon materials

    NASA Astrophysics Data System (ADS)

    Van, Hai Hoang

    CNTs have been considered as the excellent candidate to revolutionize a broad range of applications. There have been many method developed to manipulate the chemistry and the structure of CNTs. Laser with non-contact treatment capability exhibits many processing advantages, including solid-state treatment, extremely fast processing rate, and high processing resolution. In addition, the outstanding monochromatic, coherent, and directional beam generates the powerful energy absorption and the resultant extreme processing conditions. In my research, a unique laser scanning method was developed to process CNTs, controlling the oxidation and the graphitization. The achieved controllability of this method was applied to address the important issues of the current CNT processing methods for three applications. The controllable oxidation of CNTs by laser scanning method was applied to cut CNT films to produce high-performance cathodes for FE devices. The production method includes two important self-developed techniques to produce the cold cathodes: the production of highly oriented and uniformly distributed CNT sheets and the precise laser trimming process. Laser cutting is the unique method to produce the cathodes with remarkable features, including ultrathin freestanding structure (~200 nm), greatly high aspect ratio, hybrid CNT-GNR emitter arrays, even emitter separation, and directional emitter alignment. This unique cathode structure was unachievable by other methods. The developed FE devices successfully solved the screening effect issue encounter by current FE devices. The laser-control oxidation method was further developed to sequentially remove graphitic walls of CNTs. The laser oxidation process was directed to occur along the CNT axes by the laser scanning direction. Additionally, the oxidation was further assisted by the curvature stress and the thermal expansion of the graphitic nanotubes, ultimately opening (namely unzipping) the tubular structure to

  4. Enhanced field emission from cerium hexaboride coated multiwalled carbon nanotube composite films: A potential material for next generation electron sources

    SciTech Connect

    Patra, Rajkumar; Ghosh, S.; Sheremet, E.; Rodriguez, R. D.; Lehmann, D.; Gordan, O. D.; Zahn, D. R. T.; Jha, M.; Ganguli, A. K.; Schmidt, H.; Schulze, S.; Schmidt, O. G.

    2014-03-07

    Intensified field emission (FE) current from temporally stable cerium hexaboride (CeB{sub 6}) coated carbon nanotubes (CNTs) on Si substrate is reported aiming to propose the new composite material as a potential candidate for future generation electron sources. The film was synthesized by a combination of chemical and physical deposition processes. A remarkable increase in maximum current density, field enhancement factor, and a reduction in turn-on field and threshold field with comparable temporal current stability are observed in CeB{sub 6}-coated CNT film when compared to pristine CeB{sub 6} film. The elemental composition and surface morphology of the films, as examined by scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray measurements, show decoration of CeB{sub 6} nanoparticles on top and walls of CNTs. Chemical functionalization of CNTs by the incorporation of CeB{sub 6} nanoparticles is evident by a remarkable increase in intensity of the 2D band in Raman spectrum of coated films as compared to pristine CeB{sub 6} films. The enhanced FE properties of the CeB{sub 6} coated CNT films are correlated to the microstructure of the films.

  5. Femtosecond laser processing of fuel injectors - a materials processing evaluation

    SciTech Connect

    Stuart, B C; Wynne, A

    2000-12-16

    Lawrence Livermore National Laboratory (LLNL) has developed a new laser-based machining technology that utilizes ultrashort-pulse (0.1-1.0 picosecond) lasers to cut materials with negligible generation of heat or shock. The ultrashort pulse laser, developed for the Department of Energy (Defense Programs) has numerous applications in operations requiring high precision machining. Due to the extremely short duration of the laser pulse, material removal occurs by a different physical mechanism than in conventional machining. As a result, any material (e.g., hardened steel, ceramics, diamond, silicon, etc.) can be machined with minimal heat-affected zone or damage to the remaining material. As a result of the threshold nature of the process, shaped holes, cuts, and textures can be achieved with simple beam shaping. Conventional laser tools used for cutting or high-precision machining (e.g., sculpting, drilling) use long laser pulses (10{sup -8} to over 1 sec) to remove material by heating it to the melting or boiling point (Figure 1.1a). This often results in significant damage to the remaining material and produces considerable slag (Figure 1.2a). With ultrashort laser pulses, material is removed by ionizing the material (Figure 1.1b). The ionized plasma expands away from the surface too quickly for significant energy transfer to the remaining material. This distinct mechanism produces extremely precise and clean-edged holes without melting or degrading the remaining material (Figures 1.2 and 1.3). Since only a very small amount of material ({approx} <0.5 microns) is removed per laser pulse, extremely precise machining can be achieved. High machining speed is achieved by operating the lasers at repetition rates up to 10,000 pulses per second. As a diagnostic, the character of the short-pulse laser produced plasma enables determination of the material being machined between pulses. This feature allows the machining of multilayer materials, metal on metal or metal on

  6. Materials and processes for space shuttle's engines

    NASA Technical Reports Server (NTRS)

    Lewis, J. R.

    1975-01-01

    It is pointed out that over 50 different alloys are used in construction of the space shuttle main engines (SSME). Primary construction of the SSME is by welding or brazing of wrought and cast components. Welding processes involve both gas tungsten-arc welds and electron-beam welds. Electroforming has been developed as a process to fabricate and bond structural members for the SSME. Important aspects in the selection of materials and processes are related to weight saving considerations and the high-pressure hydrogen environment. Special problems and their solution in the case of various engine components are discussed, giving attention to the oxidizer preburner, the high pressure oxidizer turbopump, and the heat exchanger.

  7. Process Research of Polycrystalline Silicon Material (PROPSM)

    NASA Technical Reports Server (NTRS)

    Culik, J. S.

    1984-01-01

    A passivation process (hydrogenation) that will improve the power generation of solar cells fabricated from presently produced, large grain, cast polycrystalline silicon (Semix), a potentially low cost material are developed. The first objective is to verify the operation of a DC plasma hydrogenation system and to investigate the effect of hydrogen on the electrical performance of a variety of polycrystalline silicon solar cells. The second objective is to parameterize and optimize a hydrogenation process for cast polycrystalline silicon, and will include a process sensitivity analysis. The sample preparation for the first phase is outlined. The hydrogenation system is described, and some early results that were obtained using the hydrogenation system without a plasma are summarized. Light beam induced current (LBIC) measurements of minicell samples, and their correlation to dark current voltage characteristics, are discussed.

  8. Materials processing in space program tasks

    NASA Technical Reports Server (NTRS)

    Pentecost, E. (Compiler)

    1982-01-01

    Active research areas as of the end of the fiscal year 1982 of the Materials Processing in Space Program, NASA-Office of Space and Terrestrial Applications, involving several NASA centers and other organizations are highlighted to provide an overview of the program scope for managers and scientists in industry, university, and government communities. The program is described as well as its history, strategy and overall goal; the organizational structures and people involved are identified and each research task is described together with a list of recent publications. The tasks are grouped into four categories: crystal growth; solidification of metals, alloys, and composites; fluids, transports, and chemical processes; and ultrahigh vacuum and containerless processing technologies.

  9. Optical signal processing on photorefractive crystal substrate and bacteriorhodopsin thin film

    NASA Astrophysics Data System (ADS)

    Azimipour, Mehdi; Pashaie, Ramin

    2013-03-01

    In this article we present a new approach for implementation of computation algorithms to perform nonlinear signal processing with light on the surface of a photorefractive crystal and Bacteriorhodopsin thin film. Using the developed mathematical models for the photodynamics of these materials, we demonstrate a specific operation mode and a design procedure to obtain nonlinear response which can be used for implementation of high-performance photonic computers.

  10. Oxide films at the nanoscale: new structures, new functions, and new materials.

    PubMed

    Giordano, Livia; Pacchioni, Gianfranco

    2011-11-15

    We all make use of oxide ultrathin films, even if we are unaware of doing so. They are essential components of many common devices, such as mobile phones and laptops. The films in these ubiquitous electronics are composed of silicon dioxide, an unsurpassed material in the design of transistors. But oxide films at the nanoscale (typically just 10 nm or less in thickness) are integral to many other applications. In some cases, they form under normal reactive conditions and confer new properties to a material: one example is the corrosion protection of stainless steel, which is the result of a passive film. A new generation of devices for energy production and communications technology, such as ferroelectric ultrathin film capacitors, tunneling magnetoresistance sensors, solar energy materials, solid oxide fuel cells, and many others, are being specifically designed to exploit the unusual properties afforded by reduced oxide thickness. Oxide ultrathin films also have tremendous potential in chemistry, representing a rich new source of catalytic materials. About 20 years ago, researchers began to prepare model systems of truly heterogeneous catalysts based on thin oxide layers grown on single crystals of metal. Only recently, however, was it realized that these systems may behave quite differently from their corresponding bulk oxides. One of the phenomena uncovered is the occurrence of a spontaneous charge transfer from the metal support to an adsorbed species through the thin insulating layer (or vice versa). The importance of this property is clear: conceptually, the activation and bond breaking of adsorbed molecules begin with precisely the same process, electron transfer into an antibonding orbital. But electron transfer can also be harnessed to make a supported metal particle more chemically active, increase its adhesion energy, or change its shape. Most importantly, the basic principles underlying electron transfer and other phenomena (such as structural

  11. Bamboo (Neosinocalamus affinis)-based thin film, a novel biomass material with high performances.

    PubMed

    Song, Fei; Xu, Chen; Bao, Wen-Yi; Wang, Xiu-Li; Wang, Yu-Zhong

    2015-03-30

    Exploration of biomass based materials to replace conventional petroleum based ones has been a trend in recent decades. In this work, bamboo (Neosinocalamus affinis) with abundant resources was used for the first time to prepare films in the presence of cellulose. The effects of weight ratio of bamboo/cellulose on the appearances and properties of the films were investigated. It was confirmed there existed strong interactions between bamboo and cellulose, which were favorable to formation of homogeneous structure of blend films. Particularly, the presence of bamboo could improve the surface hydrophobicity, water resistance and thermal stability of blend films, and the films possessed an excellent oxygen barrier property, compared with generally used commercial packaging films. The bamboo biomass, therefore, is successfully used to create a new film material with a good application prospect in the fields of packaging, coating, and food industry. PMID:25563957

  12. Evaluation of nonaqueous processes for nuclear materials

    SciTech Connect

    Musgrave, B.C.; Grens, J.Z.; Knighton, J.B.; Coops, M.S.

    1983-12-01

    A working group was assigned the task of evaluating the status of nonaqueous processes for nuclear materials and the prospects for successful deployment of these technologies in the future. In the initial evaluation, the study was narrowed to the pyrochemical/pyrometallurgical processes closely related to the processes used for purification of plutonium and its conversion to metal. The status of the chemistry and process hardware were reviewed and the development needs in both chemistry and process equipment technology were evaluated. Finally, the requirements were established for successful deployment of this technology. The status of the technology was evaluated along three lines: (1) first the current applications were examined for completeness, (2) an attempt was made to construct closed-cycle flow sheets for several proposed applications, (3) and finally the status of technical development and future development needs for general applications were reviewed. By using these three evaluations, three different perspectives were constructed that together present a clear picture of how complete the technical development of these processes are.

  13. Hard X-rays for processing hybrid organic-inorganic thick films.

    PubMed

    Jiang, Yu; Carboni, Davide; Pinna, Alessandra; Marmiroli, Benedetta; Malfatti, Luca; Innocenzi, Plinio

    2016-01-01

    Hard X-rays, deriving from a synchrotron light source, have been used as an effective tool for processing hybrid organic-inorganic films and thick coatings up to several micrometres. These coatings could be directly modified, in terms of composition and properties, by controlled exposure to X-rays. The physico-chemical properties of the coatings, such as hardness, refractive index and fluorescence, can be properly tuned using the interaction of hard X-rays with the sol-gel hybrid films. The changes in the microstructure have been correlated especially with the modification of the optical and the mechanical properties. A relationship between the degradation rate of the organic groups and the rise of fluorescence from the hybrid material has been observed; nanoindentation analysis of the coatings as a function of the X-ray doses has shown a not linear dependence between thickness and film hardness. PMID:26698073

  14. Active barrier films of PET for solar cell application: Processing and characterization

    SciTech Connect

    Rossi, Gabriella; Scarfato, Paola; Incarnato, Loredana

    2014-05-15

    A preliminary investigation was carried out on the possibility to improve the protective action offered by the standard multilayer structures used to encapsulate photovoltaic devices. With this aim, a commercial active barrier PET-based material, able to absorb oxygen when activated by liquid water, was used to produce flexible and transparent active barrier films, by means of a lab-scale film production plant. The obtained film, tested in terms of thermal, optical and oxygen absorption properties, shows a slow oxygen absorption kinetics, an acceptable transparency and an easy roll-to-roll processability, so proving itself as a good candidate for the development of protective coating for solar cells against the atmospheric degradation agents like the rain.

  15. Manned Spacecraft Requirements for Materials and Processes

    NASA Technical Reports Server (NTRS)

    Vaughn, Timothy P.

    2006-01-01

    A major cause of project failure can be attributed to an emphasized focus on end products and inadequate attention to resolving development risks during the initial phases of a project. The initial phases of a project, which we will call the "study period", are critical to determining project scope and costs, and can make or break most projects. If the requirements are not defined adequately, how can the scope be adequately determined, also how can the costs of the entire project be effectively estimated, and how can the risk of project success be accurately assessed? Using the proper material specifications and standards and incorporating these specifications and standards in the design process should be considered inherently crucial to the technical success of a project as just as importantly, crucial to the cost and schedule success. This paper will intertwine several important aspects or considerations for project success: 1) Characteristics of a "Good Material Requirement"; 2) Linking material requirements to the implementation of "Design for Manufacturing"; techniques and 3) The importance of decomposing materials requirements during the study phase/development phase to mitigate project risk for the maturation of technologies before the building of hardware.

  16. Effects of anode materials on resistive characteristics of NiO thin films

    SciTech Connect

    Jia, Ze; Wang, Linkai; Zhang, Naiwen; Ren, Tianling; Liou, Juin J.

    2013-01-28

    This letter shows that the NiO-based structure with different anodes has different resistive switching properties. A conical conductive filament (CF) model is proposed for oxygen vacancies distributed in NiO films. Modeling analysis reveals much larger dissolution velocity of CF near anodes than near cathodes during the reset process. Different interfaces shown in Auger electron spectroscopy can be bound with the model to reveal that CF is dissolved in the structure with Pt or Au as anodes, while CF remains constant if the anode material is Ti or Al, which can explain whether switching properties occur in the specific NiO-based structures.

  17. Exposures and their determinants in radiographic film processing.

    PubMed

    Teschke, Kay; Chow, Yat; Brauer, Michael; Chessor, Ed; Hirtle, Bob; Kennedy, Susan M; Yeung, Moira Chan; Ward, Helen Dimich

    2002-01-01

    Radiographers process X-ray films using developer and fixer solutions that contain chemicals known to cause or exacerbate asthma. In a study in British Columbia, Canada, radiographers' personal exposures to glutaraldehyde (a constituent of the developer chemistry), acetic acid (a constituent of the fixer chemistry), and sulfur dioxide (a byproduct of sulfites, present in both developer and fixer solutions) were measured. Average full-shift exposures to glutaraldehyde, acetic acid, and sulfur dioxide were 0.0009 mg/m3, 0.09 mg/m3, and 0.08 mg/m3, respectively, all more than one order of magnitude lower than current occupational exposure limits. Local exhaust ventilation of the processing machines and use of silver recovery units lowered exposures, whereas the number of films processed per machine and the time spent near the machines increased exposures. Personnel in clinic facilities had higher exposures than those in hospitals. Private clinics were less likely to have local exhaust ventilation and silver recovery units. Their radiographers spent more time in the processor areas and processed more films per machine. Although exposures were low compared with exposure standards, there are good reasons to continue practices to minimize or eliminate exposures: glutaraldehyde and hydroquinone (present in the developer) are sensitizers; the levels at which health effects occur are not yet clearly established, but appear to be lower than current standards; and health effects resulting from the mixture of chemicals are not understood. Developments in digital imaging technology are making available options that do not involve wet-processing of photographic film and therefore could eliminate the use of developer and fixer chemicals altogether. PMID:11843420

  18. Redox processes in silicon dioxide thin films using copper microelectrodes

    NASA Astrophysics Data System (ADS)

    Tappertzhofen, S.; Menzel, S.; Valov, I.; Waser, R.

    2011-11-01

    Although SiO2 is a typical insulator, we demonstrate an electrochemical characteristic of the Cu/Cu+ oxidation at the interface with 30 nm thick silicon dioxide thin films studied by cyclic voltammetry. This study reveals the process of anodic oxidation and subsequent reduction of oxidized Cu ions injected in the SiO2 layer with special attention to the kinetics of the redox process. We estimated the diffusion coefficient and the mobility of Cu ions in SiO2. The results gain deeper insight in the processes involved during resistive switching of Cu/SiO2 based nonvolatile memory devices.

  19. Skylab materials processing facility experiment developer's report

    NASA Technical Reports Server (NTRS)

    Parks, P. G.

    1975-01-01

    The development of the Skylab M512 Materials Processing Facility is traced from the design of a portable, self-contained electron beam welding system for terrestrial applications to the highly complex experiment system ultimately developed for three Skylab missions. The M512 experiment facility was designed to support six in-space experiments intended to explore the advantages of manufacturing materials in the near-zero-gravity environment of Earth orbit. Detailed descriptions of the M512 facility and related experiment hardware are provided, with discussions of hardware verification and man-machine interfaces included. An analysis of the operation of the facility and experiments during the three Skylab missions is presented, including discussions of the hardware performance, anomalies, and data returned to earth.

  20. Microwave processing of materials. Final report

    SciTech Connect

    McMillan, A.D.; Lauf, R.J.; Garard, R.S.

    1997-11-01

    A Cooperative Research and Development Agreement (CRADA) between Lockheed Martin Energy Systems, Inc. (LMES) and Lambda Technologies, Inc. (Lambda) of Raleigh, N.C., was initiated in May 1995. [Lockheed Martin Energy Research, Corp. (LMER) has replaced LMES]. The completion data for the Agreement was December 31, 1996. The purpose of this work is to explore the feasibility of several advanced microwave processing concepts to develop new energy-efficient materials and processes. The project includes two tasks: (1) commercialization of the variable-frequency microwave furnace (VFMF); and (2) microwave curing of polymer composites. The VFMF, whose initial conception and design was funded by the Advanced Industrial Concepts (AIC) Materials Program, will allow us, for the first time, to conduct microwave processing studies over a wide frequency range. This novel design uses a high-power traveling wave tube (TWT) originally developed for electronic warfare. By using this microwave source, one can not only select individual microwave frequencies for particular experiments, but also achieve uniform power densities over a large area by the superposition of many different frequencies.

  1. 2010 Membranes: Materials & Processes Gordon Research Conference

    SciTech Connect

    Jerry Lin

    2010-07-30

    The GRC series on Membranes: Materials and Processes have gained significant international recognition, attracting leading experts on membranes and other related areas from around the world. It is now known for being an interdisciplinary and synergistic meeting. The next summer's edition will keep with the past tradition and include new, exciting aspects of material science, chemistry, chemical engineering, computer simulation with participants from academia, industry and national laboratories. This edition will focus on cutting edge topics of membranes for addressing several grand challenges facing our society, in particular, energy, water, health and more generally sustainability. During the technical program, we want to discuss new membrane structure and characterization techniques, the role of advanced membranes and membrane-based processes in sustainability/environment (including carbon dioxide capture), membranes in water processes, and membranes for biological and life support applications. As usual, the informal nature of the meeting, excellent quality of the oral presentations and posters, and ample opportunity to meet many outstanding colleagues make this an excellent conference for established scientists as well as for students. A Gordon Research Seminar (GRS) on the weekend prior to the GRC meeting will provide young researchers an opportunity to present their work and network with outstanding experts. It will also be a right warm-up for the conference participants to join and enjoy the main conference.

  2. Numerical simulation of film coating process in a novel rotating fluidized bed.

    PubMed

    Nakamura, Hideya; Iwasaki, Tomohiro; Watano, Satoru

    2006-06-01

    In this study, numerical simulation of film coating process in a novel rotating fluidized bed (RFB) was conducted by using a Discrete Element Method (DEM)-Computational Fluid Dynamics (CFD) coupling model. Particle movements and fluid motions in a centrifugal force field were simulated at three-dimensional cylindrical coordinate, and this model was applied to film coating process. Film coating process in a RFB was numerically analyzed by using a simplified assumption that a particle was coated only when a particle existed within a spray zone. The experiments were also conducted and uniformity of sprayed material was evaluated by investigating color difference of the coated particles. As a result of the numerical simulation, three-dimensional bubble movements and particle circulation could be well simulated. In addition, mass of the sprayed material on a single particle in a RFB could be visualized by using our proposed model. The relationship between distribution of the sprayed material and the coating time was also analyzed. Calculated mass distributions of the sprayed material could be expressed by a normal distribution function, showing qualitative good agreement with the previous studies. Effect of the operating parameters, such as gas velocity and centrifugal acceleration, on the uniformity of the sprayed material was also investigated by both numerical and experimental approaches. Comparison of the coating process in a RFB with that in a conventional fluidized bed was also conducted by the numerical simulation. The result showed that uniformity of the sprayed material was greatly improved in a RFB due to the much smaller circulation time. PMID:16755055

  3. Chemistry and Processing of Nanostructured Materials

    SciTech Connect

    Fox, G A; Baumann, T F; Hope-Weeks, L J; Vance, A L

    2002-01-18

    Nanostructured materials can be formed through the sol-gel polymerization of inorganic or organic monomer systems. For example, a two step polymerization of tetramethoxysilane (TMOS) was developed such that silica aerogels with densities as low as 3 kg/m{sup 3} ({approx} two times the density of air) could be achieved. Organic aerogels based upon resorcinol-formaldehyde and melamine-formaldehyde can also be prepared using the sol-gel process. Materials of this type have received significant attention at LLNL due to their ultrafine cell sizes, continuous porosity, high surface area and low mass density. For both types of aerogels, sol-gel polymerization depends upon the transformation of these monomers into nanometer-sized clusters followed by cross-linking into a 3-dimensional gel network. While sol-gel chemistry provides the opportunity to synthesize new material compositions, it suffers from the inability to separate the process of cluster formation from gelation. This limitation results in structural deficiencies in the gel that impact the physical properties of the aerogel, xerogel or nanocomposite. In order to control the properties of the resultant gel, one should be able to regulate the formation of the clusters and their subsequent cross-linking. Towards this goal, we are utilizing dendrimer chemistry to separate the cluster formation from the gelation so that new nanostructured materials can be produced. Dendrimers are three-dimensional, highly branched macromolecules that are prepared in such a way that their size, shape and surface functionality are readily controlled. The dendrimers will be used as pre-formed clusters of known size that can be cross-linked to form an ordered gel network.

  4. Hydrothermal Synthesis and Processing of Barium Titanate Nanoparticles Embedded in Polymer Films.

    PubMed

    Toomey, Michael D; Gao, Kai; Mendis, Gamini P; Slamovich, Elliott B; Howarter, John A

    2015-12-30

    Barium titanate nanoparticles embedded in flexible polymer films were synthesized using hydrothermal processing methods. The resulting films were characterized with respect to material composition, size distribution of nanoparticles, and spatial location of particles within the polymer film. Synthesis conditions were varied based on the mechanical properties of the polymer films, ratio of polymer to barium titanate precursors, and length of aging time between initial formulations of the solution to final processing of nanoparticles. Block copolymers of poly(styrene-co-maleic anhydride) (SMAh) were used to spatially separate titanium precursors based on specific chemical interactions with the maleic anhydride moiety. However, the glassy nature of this copolymer restricted mobility of the titanium precursors during hydrothermal processing. The addition of rubbery butadiene moieties, through mixing of the SMAh with poly(styrene-butadiene-styrene) (SBS) copolymer, increased the nanoparticle dispersion as a result of greater diffusivity of the titanium precursor via higher mobility of the polymer matrix. Additionally, an aminosilane was used as a means to retard cross-linking in polymer-metalorganic solutions, as the titanium precursor molecules were shown to react and form networks prior to hydrothermal processing. By adding small amounts of competing aminosilane, excessive cross-linking was prevented without significantly impacting the quality and composition of the final barium titanate nanoparticles. X-ray diffraction and X-ray photoelectron spectroscopy were used to verify nanoparticle compositions. Particle sizes within the polymer films were measured to be 108 ± 5 nm, 100 ± 6 nm, and 60 ± 5 nm under different synthetic conditions using electron microscopy. Flexibility of the films was assessed through measurement of the glass transition temperature using dynamic mechanical analysis. Dielectric permittivity was measured using an impedance analyzer. PMID

  5. Self-Assembly, Molecular Ordering, and Charge Mobility in Solution-Processed Ultrathin Oligothiophene Films

    SciTech Connect

    Murphy,A.; Chang, P.; VanDyke, P.; Liu, J.; Frechet, J.; Subramanian, V.; Delongchamp, D.; Sambasivan, S.; Fischer, D.; Lin, E.

    2005-01-01

    Symmetrical {alpha}, {omega}-substituted quarter-(T4), penta-(T5), sexi-(T6), and heptathiophene (T7) oligomers containing thermally removable aliphatic ester solubilizing groups were synthesized, and their UV-vis and thermal characteristics were compared. Spun-cast thin films of each oligomer were examined with atomic force microscopy and near-edge X-ray absorption fine structure spectroscopy to evaluate the ability of the material to self-assemble from a solution-based process while maintaining complete surface coverage. Films of the T5-T7 oligomers self-assemble into crystalline terraces after thermal annealing with higher temperatures required to affect this transformation as the size of the oligomers increases. A symmetrical {alpha}, {omega}-substituted sexithiophene (T6-acid) that reveals carboxylic acids after thermolysis was also prepared to evaluate the effect of the presence of hydrogen-bonding moieties. The charge transport properties for these materials evaluated in top-contact thin film transistor devices were found to correlate with the observed morphology of the films. Therefore, the T4 and the T6-acid performed poorly because of incomplete surface coverage after thermolysis, while T5-T7 exhibited much higher performance as a result of molecular ordering. Increases in charge mobility correlated to increasing conjugation length with measured mobilities ranging from 0.02 to 0.06 cm2/(V{center_dot}s). The highest mobilities were measured when films of each oligomer had an average thickness between one and two monolayers, indicating that the molecules become exceptionally well-ordered during the thermolysis process. This unprecedented ordering of the solution-cast molecules results in efficient charge mobility rarely seen in such ultrathin films.

  6. Enhanced peak power CO2 laser processing of PCB materials

    NASA Astrophysics Data System (ADS)

    Moorhouse, C. J.; Villarreal, F.; Wendland, J. J.; Baker, H. J.; Hall, D. R.; Hand, D. P.

    2005-06-01

    Laser drilling has become a common processing step in the fabrication of printed circuit boards (PCB's). For this work, a recently developed enhanced peak power CO2 laser (~2.5 kW peak power, 200W average) or ultra-super pulse (USP) laser is used to drill alumina and copper coated dielectric laminate materials. The higher peak power and faster response times (than conventional CO2 lasers) produced by the USP laser are used to produce high speed alumina laser scribing and copper coated laminate microvia drilling processes. Alumina is a common PCB material used for applications, where its resistance to mechanical and thermal stresses is required. Here we present a comprehensive study of the melt eject mechanisms and recast formation to optimise the speed and quality of alumina laser scribing. Scribe speeds of up to 320 mms-1 (1.8 times current scribe rate) have been achieved using novel temporal pulse shapes unique to the USP laser. Also presented is the microvia drilling process of copper dielectric laminates, where the multi-level configuration presents different optical and thermal properties complicating their simultaneous laser ablation. In our experiments the USP laser has been used to drill standard thickness copper films (up to 50 μm thick) in a single shot. This investigation concentrates on understanding the mechanisms that determine the dielectric undercut dimensions.

  7. Bacteriorhodopsin films for optical signal processing and data storage

    NASA Technical Reports Server (NTRS)

    Walkup, John F. (Principal Investigator); Mehrl, David J. (Principal Investigator)

    1996-01-01

    This report summarizes the research results obtained on NASA Ames Grant NAG 2-878 entitled 'Investigations of Bacteriorhodopsin Films for Optical Signal Processing and Data Storage.' Specifically we performed research, at Texas Tech University, on applications of Bacteriorhodopisin film to both (1) dynamic spatial filtering and (2) holographic data storage. In addition, measurements of the noise properties of an acousto-optical matrix-vestor multiplier built for NASA Ames by Photonic Systems Inc. were performed at NASA Ames' Photonics Laboratory. This research resulted in two papers presented at major optical data processing conferences and a journal paper which is to appear in APPLIED OPTICS. A new proposal for additional BR research has recently been submitted to NASA Ames Research Center.

  8. Thin film processing of photorefractive BaTiO3

    NASA Technical Reports Server (NTRS)

    Schuster, Paul R.

    1993-01-01

    During the period covered by this report, October 11, 1991 through October 10, 1992, the research has progressed in a number of different areas. The sol-gel technique was initially studied and experimentally evaluated for depositing films of BaTiO3. The difficulties with the precursors and the poor quality of the films deposited lead to the investigation of pulsed laser deposition as an alternative approach. The development of the pulsed laser deposition technique has resulted in continuous improvements to the quality of deposited films of BaTiO3. The initial depositions of BaTiO3 resulted in amorphous films, however, as the pulsed laser deposition technique continued to evolve, films were deposited in the polycrystalline state, then the textured polycrystalline state, and most recently heteroepitaxial films have also been successfully deposited on cubic (100) oriented SrTiO3 substrates. A technique for poling samples at room temperature and in air is also undergoing development with some very preliminary but positive results. The analytical techniques, which include x-ray diffraction, ferroelectric analysis, UV-Vis spectrophotometry, scanning electron microscopy with x-ray compositional analysis, optical and polarized light microscopy, and surface profilometry have been enhanced to allow for more detailed evaluation of the samples. In the area of optical characterization, a pulsed Nd:YAG laser has been incorporated into the experimental configuration. Now data can also be acquired within various temporal domains resulting in more detailed information on the optical response of the samples and on their photorefractive sensitivity. The recent establishment of collaborative efforts with two departments at Johns Hopkins University and the Army Research Lab at Fort Belvoir has also produced preliminary results using the metallo-organic decomposition technique as an alternative method for thin film processing of BaTiO3. RF and DC sputtering is another film deposition

  9. Phosphorous and aluminum gettering in Silicon-Film{trademark} Product II material

    SciTech Connect

    Cotter, J.E.; Barnett, A.M.; Hall, R.B.

    1995-08-01

    Gettering processes are being developed for the Silicon-Film{trademark} Product II solar cell structure. These processes have been developed specifically for films of silicon grown on dissimilar substrates with barrier layers. Gettering with both phosphorous- and aluminum-based processing sequences has resulted in enhancement of minority carrier diffusion length. Long diffusion lengths have allowed the characterization of light trapping in thin films of silicon grown on barrier-coated substrates.

  10. Optimization and testing of solid thin film lubrication deposition processes

    NASA Astrophysics Data System (ADS)

    Danyluk, Michael J.

    A novel method for testing solid thin films in rolling contact fatigue (RCF) under ultra-high vacuum (UHV) and high rotational speeds (130 Hz) is presented in this thesis. The UHV-RCF platform is used to quantify the adhesion and lubrication aspects of two thin film coatings deposited on ball-bearings using a physical vapor deposition ion plating process. Plasma properties during ion plating were measured using a Langmuir probe and there is a connection between ion flux, film stress, film adhesion, process voltage, pressure, and RCF life. The UHV-RCF platform and vacuum chamber were constructed using off-the-shelf components and 88 RCF tests in high vacuum have been completed. Maximum RCF life was achieved by maintaining an ion flux between 10 13 to 1015 (cm-2 s-1) with a process voltage and pressure near 1.5 kV and 15 mTorr. Two controller schemes were investigated to maintain optimal plasma conditions for maximum RCF life: PID and LQR. Pressure disturbances to the plasma have a detrimental effect on RCF life. Control algorithms that mitigate pressure and voltage disturbances already exist. However, feedback from the plasma to detect disturbances has not been explored related to deposition processes in the thin-film science literature. Manometer based pressure monitoring systems have a 1 to 2 second delay time and are too slow to detect common pressure bursts during the deposition process. Plasma diagnostic feedback is much faster, of the order of 0.1 second. Plasma total-current feedback was used successfully to detect a typical pressure disturbance associated with the ion plating process. Plasma current is related to ion density and process pressure. A real-time control application was used to detect the pressure disturbance by monitoring plasma-total current and converting it to feedback-input to a pressure control system. Pressure overshoot was eliminated using a nominal PID controller with feedback from a plasma-current diagnostic measurement tool.

  11. All solution processed organic thin film transistor-backplane with printing technology for electrophoretic display

    USGS Publications Warehouse

    Lee, Myung W.; Song, C.K.

    2012-01-01

    In this study, solution processes were developed for backplane using an organic thin film transistor (OTFT) as a driving device for an electrophoretic display (EPD) panel. The processes covered not only the key device of OTFTs but also interlayer and pixel electrodes. The various materials and printing processes were adopted to achieve the requirements of devices and functioning layers. The performance of OTFT of the backplane was sufficient to drive EPD sheet by producing a mobility of 0.12 cm2/v x sec and on/off current ratio of 10(5).

  12. C60 as an Active Smart Spacer Material on Silver Thin Film Substrates for Enhanced Surface Plasmon Coupled Emission

    PubMed Central

    Mulpur, Pradyumna; Podila, Ramakrishna; Ramamurthy, Sai Sathish; Kamisetti, Venkataramaniah; Rao, Apparao M.

    2015-01-01

    In this study, we present the use of C60 as an active spacer material on a silver (Ag) based surface plasmon coupled emission (SPCE) platform. In addition to its primary role of protecting the Ag thin film from oxidation, the incorporation of C60 facilitated the achievement of 30-fold enhancement in the emission intensity of rhodamine b (RhB) fluorophore. The high signal yield was attributed to the unique π-π interactions between C60 thin films and RhB, which enabled efficient transfer of energy of RhB emission to Ag plasmon modes. Furthermore, minor variations in the C60 film thickness yielded large changes in the enhancement and angularity properties of the SPCE signal, which can be exploited for sensing applications. Finally, the low-cost fabrication process of the Ag-C60 thin film stacks render C60 based SPCE substrates ideal, for the economic and simplistic detection of analytes. PMID:25785916

  13. Processing of functional polymers and organic thin films by the matrix-assisted pulsed laser evaporation (MAPLE) technique

    NASA Astrophysics Data System (ADS)

    Piqué, A.; Wu, P.; Ringeisen, B. R.; Bubb, D. M.; Melinger, J. S.; McGill, R. A.; Chrisey, D. B.

    2002-01-01

    The matrix-assisted pulsed laser evaporation (MAPLE) technique has been successfully used to deposit highly uniform thin films of various functional materials such as non-linear optical (NLO) organic materials, conductive polymers, luminescent organic molecules and several types of proteinaceous compounds. MAPLE is a laser evaporation technique for growing thin films of organic and polymeric materials which involves directing a pulsed laser beam (λ=193 nm; fluence=0.01-0.5 J cm -2) onto a frozen target (-40 to -160 °C) consisting of a solute polymeric or organic compound dissolved in a solvent matrix. Using MAPLE, thin films of N-(4-nitrophenyl)-( L)-prolinol or NPP, an NLO material; polypyrrole, a conductive polymer; and tris-(8-hydroxyquinoline) aluminum or Alq3, a luminescent organic compound, have been separately deposited with minor (in the case of Alq3) or no degradation (for the NPP and polypyrrole) to their optical and electrical properties. The MAPLE process has also been used to deposit discrete thin film micro-arrays of biotinylated bovine serum albumin (BSA). The deposited BSA films, after washing with a blocking protein and fluorescently tagged streptavidin, fluoresce when exposed to UV. This fluorescence indicates that the biochemical specificity of the transferred biotinylated protein is unaffected by the MAPLE process. These results demonstrate that the MAPLE technique can be used for growing thin films of functional polymer and active biomaterials.

  14. Evaporation system and method for gas jet deposition of thin film materials

    DOEpatents

    Schmitt, Jerome J.; Halpern, Bret L.

    1994-01-01

    A method and apparatus for depositing thin films of materials such as metals, oxides and nitrides at low temperature relies on a supersonic free jet of inert carrier gas to transport vapor species generated from an evaporation source to the surface of a substrate. Film deposition vapors are generated from solid film precursor materials, including those in the form of wires or powders. The vapor from these sources is carried downstream in a low pressure supersonic jet of inert gas to the surface of a substrate where the vapors deposit to form a thin film. A reactant gas can be introduced into the gas jet to form a reaction product with the evaporated material. The substrate can be moved from the gas jet past a gas jet containing a reactant gas in which a discharge has been generated, the speed of movement being sufficient to form a thin film which is chemically composed of the evaporated material and reactant gases.

  15. Materials that can replace liquid electrolytes in Li batteries: Superionic conductivities in Li1.7Al0.3Ti1.7Si0.4P2.6O12. Processing combustion synthesized nanopowders to free standing thin films

    NASA Astrophysics Data System (ADS)

    Yi, Eongyu; Wang, Weimin; Mohanty, Som; Kieffer, John; Tamaki, Ryo; Laine, Richard M.

    2014-12-01

    We demonstrate that liquid-feed flame spray pyrolysis (LF-FSP) processing provides non-aggregated nanopowders that can be used immediately to tape cast, producing thin films (<100 μm) of Li+ ion conducting membranes when sintered. Glass-ceramic or sol-gel processing methods are commonly used for such but require additional high-energy milling and/or calcining to obtain powder feedstock. Li1+x+yAlxTi2-xSiyP3-yO12 (x = 0.1, 0.3/y = 0.2, 0.4) nanopowders were prepared by LF-FSP with a primary focus on the effects of Al0.3/Si0.4 doping on conductivities. Furthermore, the effects of excess Li2O on Al0.3/Si0.4 doped materials were studied. Li1.7Al0.3Ti1.7Si0.4P2.6O12 pellets sintered to 93-94% of theoretical density and samples with varying excess Li2O contents all show superionic conductivities of 2-3 × 10-3 S cm-1 at room temperature. Li2O lowers both the crystallization temperatures and temperatures required to sinter. Total conductivities range from 2 × 10-3 to 5 × 10-2 S cm-1 in the temperature span of 25°-125 °C. Small grain sizes of 600 ± 200 nm were produced. Initial attempts to make thin films gave films with thicknesses of 52 ± 1 μm on sintering just to 1000 °C. Measured conductivities were 3-5 × 10-4 S cm-1; attributed to final densities of only ≈88%.

  16. Fabrication and characterization of thermomechanically processed sulfur and boron doped amorphous carbon films

    NASA Astrophysics Data System (ADS)

    Carlson, Lonnie

    Small scale, high power density, reliable, and long-life power supplies would be useful or even critical for space missions or the growing number of microdetectors, microsensors, and miniature vehicles. Alpha or beta particle voltaic devices could satisfy these requirements but have been shown to degrade quickly due to radiation damage. Amorphous carbon (a-C) PN junctions or PIN devices could provide radiation hardness and sufficiently high efficiency. As the range of alpha and beta particles in a-C is ˜20-120microm, much thicker films than are typical are needed to maximize collection of the particle energy. In this work, the fabrication of thermomechanically processed p- and n-type doped a-C films were investigated as a first step in the future development of radiation hard voltaic devices. Boron carbide (B4C) powder was mixed with a-C nanopowders as a possible p-type dopant with sulfur powder utilized as a possible n-type dopant. Doping levels of 2.5at%, 5.0at%, and 10.0at% were investigated for both dopants with films pressed at 109°C over a pressure range of 0.3-5.0GPa. Initial attempts to fabricate rectifying PN junctions and PIN devices was unsuccessful. Bonding properties were characterized using Raman spectroscopy with electronic properties primarily assessed using the van der Pauw method. Undoped a-C and boron-doped films were found to be slightly p-type with sulfur-doped films converting to n-type. All films were found to consist almost entirely of nano-graphitic sp2 rings with only slight changes in disorder at different pressures. Sulfur doped films were less brittle which is indicative of crosslinking. Boron doping did not significantly change the film electronic properties and is not an effective dopant at these temperatures and pressures. Sulfur doping had a greater effect and could likely be utilized as basis for an n-type material in a device. Initial irradiation studies using alpha particles showed that boron and undoped films became more p

  17. Solar Energy: Materials, Materials Handling, and Fabrication Processes: Student Material. First Edition.

    ERIC Educational Resources Information Center

    Bolin, William Everet; Orsak, Charles G., Jr.

    Designed for student use in "Materials, Materials Handling, and Fabrication Processes," one of 11 courses in a 2-year associate degree program in solar technology, this manual provides readings, exercises, worksheets, bibliographies, and illustrations for 13 course modules. The manual, which corresponds to an instructor guide for the same course,…

  18. Commercial-scale process design for thin-film solar cells

    NASA Astrophysics Data System (ADS)

    Russell, T. W. F.; Baron, B. N.; Rocheleau, R. E.

    Process and manufacturing costs for commercial-scale production of thin-film solar cells are examined from the viewpoint of the chemical process industry, with emphasis on CdS/Cu2S cells. The cells comprise opaque contact, collector/converter, absorber/generator, transparent contact, and encapsulation/antireflective coating layers. Each layer is deposited as a separate unit operation, through either continuous or batch processing methods. The scale-up of laboratory-verified cell manufacturing steps to commercial processing is detailed from the choice of a Zn-plated copper foil substrate to the bonding of a 1/16 in. tempered glass protective layer with polyvinyl butyral. The total product cost is calculated as a sum of raw materials, utilities, labor, and capital investment costs, using a cost/W for a 1 GW plant. Continuous processing results in a $0.50/W cell with raw materials accounting for 38% of the total product cost.

  19. Dynamics of ultrathin metal films on amorphous substrates under fast thermal processing

    SciTech Connect

    Favazza, Christopher; Kalyanaraman, Ramki; Sureshkumar, Radhakrishna

    2007-11-15

    to surface deformation. Hence, surface deformation caused by liquid phase instabilities is rapidly quenched-in during the cooling phase. This deformed state is further evolved by subsequent laser pulses. These results have implications to developing accurate computer simulations of thin-film dewetting by energetic beams aimed at the manufacturing of optically active nanoscale materials for applications including information processing, optical devices, and solar energy harvesting.

  20. Process Controlled Multiscale Morphologies in Metal-containing Block Copolymer Thin Films

    SciTech Connect

    Ramanathan, Nathan Muruganathan; Kilbey, II, S Michael; Darling, Seth B.

    2014-01-01

    Poly(styrene-block-ferrocenyldimethylsilane) (PS-b-PFS) is a metal-containing block copolymer that exhibits certain advantages as a mask for lithographic applications. These advantages include compatibility with a wide range of substrates, ease of control over domain morphologies and robust stability to etch plasma, which aid in the development of high-aspect-ratio patterns. An asymmetric cylinder-forming PS-b-PFS copolymer is subjected to different processing to manipulate the morphology of the phase-separated domains. Control of film structure and domain morphology is achieved by adjusting the film thickness, mode of annealing, and/or annealing time. Changing the process from thermal or solvent annealing to hybrid annealing (thermal and then solvent annealing in sequence) leads to the formation of mesoscale spherulitic and dendritic morphologies. In this communication, we show that reversing the order of the hybrid annealing (solvent annealing first and then thermal annealing) of relatively thick films (>100 nm) on homogeneously thick substrates develops disordered lamellar structure. Furthermore, the same processing applied on a substrate with a thin, mechanically flexible window in the center leads to the formation of sub-micron scale concentric ring patterns. Enhanced material mobility in the thick film during hybrid annealing along with dynamic rippling effects that may arise from the vibration of the thin window during spin casting are likely causes for these morphologies.

  1. Real time intelligent process control system for thin film solar cell manufacturing

    SciTech Connect

    George Atanasoff

    2010-10-29

    This project addresses the problem of lower solar conversion efficiency and waste in the typical solar cell manufacturing process. The work from the proposed development will lead toward developing a system which should be able to increase solar panel conversion efficiency by an additional 12-15% resulting in lower cost panels, increased solar technology adoption, reduced carbon emissions and reduced dependency on foreign oil. All solar cell manufacturing processes today suffer from manufacturing inefficiencies that currently lead to lower product quality and lower conversion efficiency, increased product cost and greater material and energy consumption. This results in slower solar energy adoption and extends the time solar cells will reach grid parity with traditional energy sources. The thin film solar panel manufacturers struggle on a daily basis with the problem of thin film thickness non-uniformity and other parameters variances over the deposited substrates, which significantly degrade their manufacturing yield and quality. Optical monitoring of the thin films during the process of the film deposition is widely perceived as a necessary step towards resolving the non-uniformity and non-homogeneity problem. In order to enable the development of an optical control system for solar cell manufacturing, a new type of low cost optical sensor is needed, able to acquire local information about the panel under deposition and measure its local characteristics, including the light scattering in very close proximity to the surface of the film. This information cannot be obtained by monitoring from outside the deposition chamber (as traditional monitoring systems do) due to the significant signal attenuation and loss of its scattering component before the reflected beam reaches the detector. In addition, it would be too costly to install traditional external in-situ monitoring systems to perform any real-time monitoring over large solar panels, since it would require

  2. Mechanical property changes in porous low-k dielectric thin films during processing

    SciTech Connect

    Stan, G. Gates, R. S.; Kavuri, P.; Torres, J.; Michalak, D.; Ege, C.; Bielefeld, J.; King, S. W.

    2014-10-13

    The design of future generations of Cu-low-k dielectric interconnects with reduced electronic crosstalk often requires engineering materials with an optimal trade off between their dielectric constant and elastic modulus. This is because the benefits associated with the reduction of the dielectric constant by increasing the porosity of materials, for example, can adversely affect their mechanical integrity during processing. By using load-dependent contact-resonance atomic force microscopy, the changes in the elastic modulus of low-k dielectric materials due to processing were accurately measured. These changes were linked to alterations sustained by the structure of low-k dielectric films during processing. A two-phase model was used for quantitative assessments of the elastic modulus changes undergone by the organosilicate skeleton of the structure of porous and pore-filled dielectrics.

  3. Mechanical property changes in porous low-k dielectric thin films during processing

    NASA Astrophysics Data System (ADS)

    Stan, G.; Gates, R. S.; Kavuri, P.; Torres, J.; Michalak, D.; Ege, C.; Bielefeld, J.; King, S. W.

    2014-10-01

    The design of future generations of Cu-low-k dielectric interconnects with reduced electronic crosstalk often requires engineering materials with an optimal trade off between their dielectric constant and elastic modulus. This is because the benefits associated with the reduction of the dielectric constant by increasing the porosity of materials, for example, can adversely affect their mechanical integrity during processing. By using load-dependent contact-resonance atomic force microscopy, the changes in the elastic modulus of low-k dielectric materials due to processing were accurately measured. These changes were linked to alterations sustained by the structure of low-k dielectric films during processing. A two-phase model was used for quantitative assessments of the elastic modulus changes undergone by the organosilicate skeleton of the structure of porous and pore-filled dielectrics.

  4. Chemical-vapor deposition of complex oxides: materials and process development

    SciTech Connect

    Muenchausen, R.

    1996-11-01

    This is the final report of a six-month, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL) part of the Advanced Materials Laboratory (AML). The demand for higher performance and lower cost in electronics is driving the need for advanced materials and consequent process integration. Ceramic thin-film technology is becoming more important in the manufacture of microelectronic devices, photovoltaics, optoelectronics, magneto-optics, sensors, microwave, and radio frequency communication devices, and high-Tc superconducting tapes. A flexible processing approach for potential large-scale manufacturing of novel electronic ceramic thin films is desirable. Current thin- film deposition technologies based on physical vapor-deposition techniques are limited in scale potential and have limited control of processing parameters. The lack of control over multiple process parameters inhibits the versatility and reproducibility of the physical vapor deposition processes applied to complex oxides. Chemical vapor deposition is emerging as a viable approach for large- scale manufacturing of electronic materials. Specifically, the ability to control more processing parameters with chemical vapor deposition than with other processing techniques provides the reliability and material property reproducibility required by manufacturing. This project sought to investigate the chemical vapor deposition of complex oxides.

  5. Composite material having high thermal conductivity and process for fabricating same

    DOEpatents

    Colella, N.J.; Davidson, H.L.; Kerns, J.A.; Makowiecki, D.M.

    1998-07-21

    A process is disclosed for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost. 7 figs.

  6. Composite material having high thermal conductivity and process for fabricating same

    DOEpatents

    Colella, Nicholas J.; Davidson, Howard L.; Kerns, John A.; Makowiecki, Daniel M.

    1998-01-01

    A process for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost.

  7. Exposure of Polymer Film Thermal Control Materials on the Materials International Space Station Experiment (MISSE)

    NASA Technical Reports Server (NTRS)

    Dever, Joyce; Miller, Sharon; Messer, Russell; Sechkar, Edward; Tollis, Greg

    2002-01-01

    Seventy-nine samples of polymer film thermal control (PFTC) materials have been provided by the National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) for exposure to the low Earth orbit environment on the exterior of the International Space Station (ISS) as part of the Materials International Space Station Experiment (MISSE). MISSE is a materials flight experiment sponsored by the Air Force Research Lab/Materials Lab and NASA. This paper will describe background, objectives, and configurations for the GRC PFTC samples for MISSE. These samples include polyimides, fluorinated polyimides, and Teflon fluorinated ethylene propylene (FEP) with and without second-surface metallizing layers and/or surface coatings. Also included are polyphenylene benzobisoxazole (PBO) and a polyarylene ether benzimidazole (TOR-LM). On August 16, 2001, astronauts installed passive experiment carriers (PECs) on the exterior of the ISS in which were located twenty-eight of the GRC PFTC samples for 1-year space exposure. MISSE PECs for 3-year exposure, which will contain fifty-one GRC PFTC samples, will be installed on the ISS at a later date. Once returned from the ISS, MISSE GRC PFTC samples will be examined for changes in optical and mechanical properties and atomic oxygen (AO) erosion. Additional sapphire witness samples located on the AO exposed trays will be examined for deposition of contaminants.

  8. Processing and modeling issues for thin-film solar cell devices. Annual subcontract report, January 16, 1993--January 15, 1994

    SciTech Connect

    Birkmire, R.W.; Phillips, J.E.; Buchanan, W.A.; Hegedus, S.S.; McCandless, B.E.; Shafarman, W.N.; Yokimcus, T.A.

    1994-09-01

    The overall objective of the research presented in this report is to advance the development and acceptance of thin-film photovoltaic modules by increasing the understanding of film growth and processing and its relationship to materials properties and solar cell performance. The specific means toward meeting this larger goal include: (1) investigating scalable, cost-effective deposition processes; (2) preparing thin-film materials and device layers and completed cell structures; (3) performing detailed material and device analysis; and (4) participating in collaborative research efforts that address the needs of PV-manufacturers. These objectives are being pursued with CuInSe{sub 2}, CdTe and a-Si based solar cells.

  9. Apparatus and process for deposition of hard carbon films

    DOEpatents

    Nyaiesh, Ali R.; Garwin, Edward L.

    1989-01-01

    A process and an apparatus for depositing thin, amorphous carbon films having extreme hardness on a substrate is described. An enclosed chamber maintained at less than atmospheric pressure houses the substrate and plasma producing elements. A first electrode is comprised of a cavity enclosed within an RF coil which excites the plasma. A substrate located on a second electrode is excited by radio frequency power applied to the substrate. A magnetic field confines the plasma produced by the first electrode to the area away from the walls of the chamber and focuses the plasma onto the substrate thereby yielding film deposits having higher purity and having more rapid buildup than other methods of the prior art.

  10. Apparatus and process for deposition of hard carbon films

    DOEpatents

    Nyaiesh, Ali R.; Garwin, Edward L.

    1989-01-03

    A process and an apparatus for depositing thin, amorphous carbon films having extreme hardness on a substrate is described. An enclosed chamber maintained at less than atmospheric pressure houses the substrate and plasma producing elements. A first electrode is comprised of a cavity enclosed within an RF coil which excites the plasma. A substrate located on a second electrode is excited by radio frequency power applied to the substrate. A magnetic field confines the plasma produced by the first electrode to the area away from the walls of the chamber and focuses the plasma onto the substrate thereby yielding film deposits having higher purity and having more rapid buildup than other methods of the prior art.

  11. Reaction Time and Film Thickness Effects on Phase Formation and Optical Properties of Solution Processed Cu2ZnSnS4 Thin Films

    NASA Astrophysics Data System (ADS)

    Safdar, Amna; Islam, Mohammad; Akram, Muhammad Aftab; Mujahid, Mohammad; Khalid, Yasir; Shah, S. Ismat

    2016-02-01

    Copper-zinc-tin-sulfide (Cu2ZnSnS4 or CZTS) is a promising p-type semiconductor material as absorber layer in thin film solar cells. The sulfides of copper and tin as well as zinc and sulfur powders were dissolved in hydrazine. The effect of chemical reaction between precursor species, at room temperature, was assessed for 6 to 22 h. For 22 h reaction time, the effect of spin coated film thickness on the resulting composition, after annealing under N2 flow at 500 °C for 1 h, was investigated. The morphology, composition, and optical properties of the annealed films were determined by means of x-ray diffraction, scanning electron microscope, and spectrophotometer studies. It was found that, for less than optimal reaction time of 22 h or film thickness below 1.2 µm, other ternary phases namely Cu4SnS4, Cu5Sn2S7, and ZnS co-exist in different proportions besides CZTS. Formation of phase-pure CZTS films also exhibited a tendency to minimize film cracking during annealing. Depending on the processing conditions, the band gap ( E g) values were determined to be in the range of 1.55 to 1.97 eV. For phase-pure annealed CZTS film, an increase in the E g value may be attributed to quantum confinement effect due to small crystallite size.

  12. Large area ceramic thin films on plastics: A versatile route via solution processing

    SciTech Connect

    Kozuka, H.; Yamano, A.; Uchiyama, H.; Takahashi, M.; Fukui, T.; Yoki, M.; Akase, T.

    2012-01-01

    A new general route for large area, submicron thick ceramic thin films (crystalline metal oxide thin films) on plastic substrates is presented, where the crystallization of films is guaranteed by a firing process. Gel films are deposited on silicon substrates with a release layer and fired to be ceramic films, followed by transferring onto plastic substrates using adhesives. The ceramic films thus fabricated on plastics exhibit a certain degree of flexibility, implying the possibility of the technique to be applied to high-throughput roll-to-roll processes. Using this technique, we successfully realized transparent anatase thin films that provide high optical reflectance and transparent indium tin oxide thin films that exhibit electrical conductivity on polycarbonate and acrylic resin substrates, respectively. Crystallographically oriented zinc oxide films and patterned zinc oxide films are also demonstrated to be realized on acrylic resin substrates.

  13. Apollo-Soyuz test project photographic film processing and sensitometric summary

    NASA Technical Reports Server (NTRS)

    Lockwood, H. E.

    1975-01-01

    The Photographic Technology Division at the NASA Lyndon B. Johnson Space Center processed original photographic films exposed in flight during the Apollo Soyuz Test Project (ASTP). Integrated with processing of the original films were strict sensitometric controls and certification procedures established prior to the flight. Information relative to the processing of the 54 rolls of original ASTP flight film and sensitometric data pertinent to each of these rolls of film is presented.

  14. Polycrystalline VO2 thin films via femtosecond laser processing of amorphous VO x

    NASA Astrophysics Data System (ADS)

    Charipar, N. A.; Kim, H.; Breckenfeld, E.; Charipar, K. M.; Mathews, S. A.; Piqué, A.

    2016-05-01

    Femtosecond laser processing of pulsed laser-deposited amorphous vanadium oxide thin films was investigated. Polycrystalline VO2 thin films were achieved by femtosecond laser processing in air at room temperature. The electrical transport properties, crystal structure, surface morphology, and optical properties were characterized. The laser-processed films exhibited a metal-insulator phase transition characteristic of VO2, thus presenting a pathway for the growth of crystalline vanadium dioxide films on low-temperature substrates.

  15. Microwave plasma assisted supersonic gas jet deposition of thin film materials

    DOEpatents

    Schmitt, J.J. III; Halpern, B.L.

    1993-10-26

    An apparatus for fabricating thin film materials utilizing high speed gas dynamics relies on supersonic free jets of carrier gas to transport depositing vapor species generated in a microwave discharge to the surface of a prepared substrate where the vapor deposits to form a thin film. The present invention generates high rates of deposition and thin films of unforeseen high quality at low temperatures. 5 figures.

  16. High-gravity-assisted pulsed laser ablation system for the fabrication of functionally graded material thin film.

    PubMed

    Nishiyama, T; Morinaga, S; Nagayama, K

    2009-03-01

    This paper describes a novel method for the fabrication of a thin film deposited on an appropriate substrate having a continuous composition gradient. The composition gradient was achieved by a combination of pulsed laser ablation (PLA) of the target material with a very strong acceleration field generated on a moving disk rotating at a very high speed. The PLA process was used to produce a cloud of high-energy particles of the target material that will be deposited on a substrate placed on the rotating disk. After deposition, the particles will diffuse on the surface of the thin film under a strong acceleration field. The high energy of the particles and their diffusion on the substrate surface in a high-vacuum environment produces a macroscopic composition distribution in the thin film. We have constructed an experimental apparatus consisting of a vacuum chamber in which a circular disk made of titanium is driven by a high-frequency inductive motor. An acceleration field of up to 10,000 G can be generated by this apparatus. Functionally graded material thin films of FeSi(2) with a continuous concentration gradient were successfully fabricated by this method under a gravity field of 5400 G. A significant advantage of this method is that it allows us to fabricate graded thin films with a very smooth surface covered by few droplets. PMID:19334931

  17. Containerless processing of materials by acoustic levitation

    NASA Astrophysics Data System (ADS)

    Gao, J. R.; Cao, C. D.; Wei, B.

    1999-01-01

    A single-axis ultrasonic levitator which can be applied to containerless processing of materials was described. Analytical expressions of acoustic pressure, acoustic radiation potential and force were derived from the velocity potential function of the applied acoustic field. The levitation region and the levitation stability were then discussed. A sphere of liquid crystal, 4-pentylphenyl-4‧-methylbenzoate, was also selected for containerless melting and solidification using the levitator. The results showed that rapid heating of the sample is necessary so as to avoid its escape from the levitation region. However, the measured bulk undercooling of the melt is smaller than that obtained using a container. It was supposed that ultrasonic cavitation produce a local undercooling large enough to initiate solidification of the melt, thus leading to a limited bulk undercooling.

  18. Solution processable semiconductor thin films: Correlation between morphological, structural, optical and charge transport properties

    NASA Astrophysics Data System (ADS)

    Isik, Dilek

    This Ph.D. thesis is a result of multidisciplinary research bringing together fundamental concepts in thin film engineering, materials science, materials processing and characterization, electrochemistry, microfabrication, and device physics. Experiments were conducted by tackling scientific problems in the field of thin films and interfaces, with the aim to correlate the morphology, crystalline structure, electronic structure of thin films with the functional properties of the films and the performances of electronic devices based thereon. Furthermore, novel strategies based on interfacial phenomena at electrolyte/thin film interfaces were explored and exploited to control the electrical conductivity of the thin films. Three main chemical systems were the object of the studies performed during this Ph.D., two types of organic semiconductors (azomethine-based oligomers and polymers and soluble pentacene derivatives) and one metal oxide semiconductor (tungsten trioxide, WO3). To explore the morphological properties of the thin films, atomic force microscopy was employed. The morphological properties were further investigated by hyperspectral fluorescence microscopy and tentatively correlated to the charge transport properties of the films. X-ray diffraction (Grazing incidence XRD, GIXRD) was used to investigate the crystallinity of the film and the effect of the heat treatment on such crystallinity, as well as to understand the molecular arrangement of the organic molecules in the thin film. The charge transport properties of the films were evaluated in thin film transistor configuration. For electrolyte gated thin film transistors, time dependent transient measurements were conducted, in parallel to more conventional transistor characterizations, to explore the specific effects played on the gating by the anion and cation constituting the electrolyte. The capacitances of the electrical double layers at the electrolyte/WO3 interface were obtained from

  19. Investigation of test methods, material properties and processes for solar cell encapsulants

    NASA Technical Reports Server (NTRS)

    Willis, P. B.; Baum, B.

    1983-01-01

    Low cost encapsulation materials for the Flat Plate Solar Array Program (FSA) are investigated. The goal of the program is to identify, test, evaluate and recommend encapsulation materials and processes for the fabrication of cost effective and long life solar modules. Accelerated aging techniques for module component lifetime studies, investigation of candidate outer cover films and continued evaluation of soil repellant coatings are also included.

  20. 5th Conference on Aerospace Materials, Processes, and Environmental Technology

    NASA Technical Reports Server (NTRS)

    Cook, M. B. (Editor); Stanley, D. Cross (Editor)

    2003-01-01

    Records are presented from the 5th Conference on Aerospace Materials, Processes, and Environmental Technology. Topics included pollution prevention, inspection methods, advanced materials, aerospace materials and technical standards,materials testing and evaluation, advanced manufacturing,development in metallic processes, synthesis of nanomaterials, composite cryotank processing, environmentally friendly cleaning, and poster sessions.

  1. Integration mockup and process material management system

    NASA Astrophysics Data System (ADS)

    Verble, Adas James, Jr.

    1992-02-01

    Work to define and develop a full scale Space Station Freedom (SSF) mockup with the flexibility to evolve into future designs, to validate techniques for maintenance and logistics and verify human task allocations and support trade studies is described. This work began in early 1985 and ended in August, 1991. The mockups are presently being used at MSFC in Building 4755 as a technology and design testbed, as well as for public display. Micro Craft also began work on the Process Material Management System (PMMS) under this contract. The PMMS simulator was a sealed enclosure for testing to identify liquids, gaseous, particulate samples, and specimen including, urine, waste water, condensate, hazardous gases, surrogate gasses, liquids, and solids. The SSF would require many trade studies to validate techniques for maintenance and logistics and verify system task allocations; it was necessary to develop a full scale mockup which would be representative of current SSF design with the ease of changing those designs as the SSF design evolved and changed. The tasks defined for Micro Craft were to provide the personnel, services, tools, and materials for the SSF mockup which would consist of four modules, nodes, interior components, and part task mockups of MSFC responsible engineering systems. This included the Engineering Control and Life Support Systems (ECLSS) testbed. For the initial study, the mockups were low fidelity, soft mockups of graphics art bottle, and other low cost materials, which evolved into higher fidelity mockups as the R&D design evolved, by modifying or rebuilding, an important cost saving factor in the design process. We designed, fabricated, and maintained the full size mockup shells and support stands. The shells consisted of cylinders, end cones, rings, longerons, docking ports, crew airlocks, and windows. The ECLSS required a heavier cylinder to support the ECLSS systems test program. Details of this activity will be covered. Support stands were

  2. Integration mockup and process material management system

    NASA Technical Reports Server (NTRS)

    Verble, Adas James, Jr.

    1992-01-01

    Work to define and develop a full scale Space Station Freedom (SSF) mockup with the flexibility to evolve into future designs, to validate techniques for maintenance and logistics and verify human task allocations and support trade studies is described. This work began in early 1985 and ended in August, 1991. The mockups are presently being used at MSFC in Building 4755 as a technology and design testbed, as well as for public display. Micro Craft also began work on the Process Material Management System (PMMS) under this contract. The PMMS simulator was a sealed enclosure for testing to identify liquids, gaseous, particulate samples, and specimen including, urine, waste water, condensate, hazardous gases, surrogate gasses, liquids, and solids. The SSF would require many trade studies to validate techniques for maintenance and logistics and verify system task allocations; it was necessary to develop a full scale mockup which would be representative of current SSF design with the ease of changing those designs as the SSF design evolved and changed. The tasks defined for Micro Craft were to provide the personnel, services, tools, and materials for the SSF mockup which would consist of four modules, nodes, interior components, and part task mockups of MSFC responsible engineering systems. This included the Engineering Control and Life Support Systems (ECLSS) testbed. For the initial study, the mockups were low fidelity, soft mockups of graphics art bottle, and other low cost materials, which evolved into higher fidelity mockups as the R&D design evolved, by modifying or rebuilding, an important cost saving factor in the design process. We designed, fabricated, and maintained the full size mockup shells and support stands. The shells consisted of cylinders, end cones, rings, longerons, docking ports, crew airlocks, and windows. The ECLSS required a heavier cylinder to support the ECLSS systems test program. Details of this activity will be covered. Support stands were

  3. Low temperature plasma processing for cell growth inspired carbon thin films fabrication.

    PubMed

    Kumar, Manish; Piao, Jin Xiang; Jin, Su Bong; Lee, Jung Heon; Tajima, Satomi; Hori, Masaru; Han, Jeon Geon

    2016-09-01

    The recent bio-applications (i.e. bio-sensing, tissue engineering and cell proliferation etc.) are driving the fundamental research in carbon based materials with functional perspectives. High stability in carbon based coatings usually demands the high density deposition. However, the standard techniques, used for the large area and high throughput deposition of crystalline carbon films, often require very high temperature processing (typically >800 °C in inert atmosphere). Here, we present a low temperature (<150 °C) pulsed-DC plasma sputtering process, which enables sufficient ion flux to deposit dense unhydrogenated carbon thin films without any need of substrate-bias or post-deposition thermal treatments. It is found that the control over plasma power density and pulsed frequency governs the density and kinetic energy of carbon ions participating during the film growth. Subsequently, it controls the contents of sp(3) and sp(2) hybridizations via conversion of sp(2) to sp(3) hybridization by ion's energy relaxation. The role of plasma parameters on the chemical and surface properties are presented and correlated to the bio-activity. Bioactivity tests, carried out in mouse fibroblast L-929 and Sarcoma osteogenic (Saos-2) bone cell lines, demonstrate promising cell-proliferation in these films. PMID:27036854

  4. Using Organic Light-Emitting Electrochemical Thin-Film Devices to Teach Materials Science

    ERIC Educational Resources Information Center

    Sevian, Hannah; Muller, Sean; Rudmann, Hartmut; Rubner, Michael F.

    2004-01-01

    Materials science can be taught by applying organic light-emitting electrochemical thin-film devices and in this method students were allowed to make a light-emitting device by spin coating a thin film containing ruthenium (II) complex ions onto a glass slide. Through this laboratory method students are provided with the opportunity to learn about…

  5. Thermal Imaging System For Material Processing

    NASA Astrophysics Data System (ADS)

    Auric, Daniel; Hanonge, Eric; Kerrand, Emmanuel; de Miscault, Jean-Claude; Cornillault, Jean

    1987-09-01

    In the field of lasers for welding and surface processing, we need to measure the map of temperatures in order to control the processing in real time by adjusting the laser power, the beam pointing and focussing and the workpiece moving speed. For that purpose, we studied, realized and evaluated a model of thermal imaging system at 2 wavelengths in the mid-infrared. The device is connected to a 3 axis table and to a 3 kW CO2 laser. The range of measured temperatures is 800 C to 1 500 C. The device includes two AGEMA infrared cameras fixed to the welding torch each operating with a choice of filters in the 3, 4 and 5 micrometre band. The field of view of each is about 14 mm by 38 mm. The cameras are connected to an M68000 microprocessor family based microcomputer in which the images enter at the rate of 6. 25 Hz with 64 x 128 pixels by image at both wavelengths. The microcomputer stores the pictures into memory and floppy disk, displays them in false colours and calculates for each pixel the surface temperature of the material with the grey body assumption. The results have been compared with metallurgic analysis of the samples. The precision is about 20 C in most cases and depends on the sample surface state. Simplifications of the laboratory device should lead to a cheap, convenient and reliable product.

  6. Development of High Band Gap Absorber and Buffer Materials for Thin Film Solar Cell Applications

    NASA Astrophysics Data System (ADS)

    Dwyer, Dan

    2011-12-01

    CuInGaSe2 (CIGS) device efficiencies are the highest of the thin film absorber materials (vs. CdTe, alpha-Si, CuInSe2). However, the band gap of the highest efficiency CIGS cells deviates from the expected ideal value predicted by models [1]. Widening the band gap to the theoretically ideal value is one way to increase cell efficiencies. Widening the band gap can be accomplished in two ways; by finding a solution to the Ga-related defects which limit the open circuit voltage at high Ga ratios, or by utilizing different elemental combinations to form an alternative high band gap photoactive Cu-chalcopyrite (which includes any combination of the cations Cu, Al, Ga, and In along with the anions S, Se, and Te). This thesis focuses on the second option, substituting aluminum for gallium in the chalcopyrite lattice to form a CuInAlSe2 (CIAS) film using a sputtering and selenization approach. Both sequential and co-sputtering of metal precursors is performed. Indium was found to be very mobile during both sputtering processes, with a tendency to diffuse to the film surface even when deposited as the base layer in a sequential sputtering process. Elemental diffusion was controlled to a degree using thicker Cu top layer in co-sputtering. The greater thermal conductivity of stainless steel foil (16 W/mK) vs. glass (0.9-1.3 W/mK) can also be used to limit indium diffusion, by keeping the substrate cooler during sputtering. In both sputtering methods aluminum is deposited oxygen-free by capping the film with a Cu capping layer in combination with controlling the indium diffusion. Selenization of metal precursor films is completed using two different techniques. The first is a thermal evaporation approach from a heated box source (method 1 -- reactive thermal evaporation (RTE-Se)). The second is batch selenization using a heated tube furnace (method 2 -- batch selenization). Some batch selenized precursors were capped with ˜ 1mum of selenium. In both selenization methods

  7. Influence of film structure on the dewetting kinetics of thin polymer films in the solvent annealing process.

    PubMed

    Zhang, Huanhuan; Xu, Lin; Lai, Yuqing; Shi, Tongfei

    2016-06-28

    On a non-wetting solid substrate, the solvent annealing process of a thin polymer film includes the swelling process and the dewetting process. Owing to difficulties in the in situ analysis of the two processes simultaneously, a quantitative study on the solvent annealing process of thin polymer films on the non-wetting solid substrate is extremely rare. In this paper, we design an experimental method by combining spectroscopic ellipsometry with optical microscopy to achieve the simultaneous in situ study. Using this method, we investigate the influence of the structure of swollen film on its dewetting kinetics during the solvent annealing process. The results show that for a thin PS film with low Mw (Mw = 4.1 kg mol(-1)), acetone molecules can form an ultrathin enriched layer between the PS film and the solid substrate during the swelling process. The presence of the acetone enriched layer accounts for the exponential kinetic behavior in the case of a thin PS film with low Mw. However, the acetone enriched layer is not observed in the case of a thin PS film with high Mw (Mw = 400 kg mol(-1)) and the slippage effect of polymer chains is valid during the dewetting process. PMID:27254136

  8. The Effects of Ground and Space Processing on the Properties of Organic, Polymeric, and Colloidal Materials

    NASA Technical Reports Server (NTRS)

    Frazier, Donald O.; Penn, Benjamin G.; Paley, M. S.; Abdeldayem, Hossain A.; Witherow, W. K.; Smith, D.

    1998-01-01

    In recent years, a great deal of interest has been directed toward the use of organic materials in the development of high-efficiency optoelectronic and phototonic devices. There is a myriad of possibilities among organic materials which allow flexibility in the design of unique structures with a variety of functional groups. The use of nonlinear optical (NLO) organic materials as thin film wave-guides allows full exploitation of their desirable qualifies by permitting long interaction lengths and large susceptibilities allowing modest power input. There are several methods in use to prepare thin films such as Langmuir-Blodgett (LB) and self-assembly techniques, vapor deposition, growth from sheared solution or melt, and melt growth between glass plates. Organic-based materials have many features that make them desirable for use in optical devices, such as high second-and third-order nonlinearity, flexibility of molecular design, and damage resistance to optical radiation. However, their use in devices has been hindered by processing difficulties for crystals and thin films. We discuss the potential role of microgravity processing of a few organic and polymeric materials. It is of interest to note how materials with second-and third-order NLO behavior may be improved in a diffusion-limited environment and ways in which convection may be detrimental to these materials. We focus our discussion on third-order materials for all-optical switching, and second-order materials for frequency conversion and electrooptics. The goal of minimizing optical loss obviously depends on processing methods. For solution-based processes, such as solution crystal growth and solution photopolymerization, it is well known that thermal and solutal density gradients can initiate buoyancy-driven convection. Resultant fluid flows can affect transport of material to and from growth interfaces and become manifest in the morphology and homogeneity of the growing film or crystal. Likewise

  9. A pilot study on the quality control of film processing in medical radiology laboratories in Greece.

    PubMed

    Hourdakis CJ-; Delakis, J; Kamenopoulou, V; Balougias, H; Papageorgiou, E

    2000-01-01

    The results of a pilot study on the quality of film processing in 80 medical diagnostic radiology laboratories all over Greece are presented. The sensitometric technique for the evaluation of processing has been used to calculate film's base + fog, maximum optical density, speed and contrast, parameters which describe the performance characteristics of automatic film processors and films. The mean values of the base + fog and the maximum optical density were well within the acceptance limits. The film speed was almost constant while the film contrast showed significant variation. PMID:10674786

  10. Thin film superconductors and process for making same

    DOEpatents

    Nigrey, P.J.

    1988-01-21

    A process for the preparation of oxide superconductors from high-viscosity non-aqueous solution is described. Solutions of lanthanide nitrates, alkaline earth nitrates and copper nitrates in a 1:2:3 stoichiometric ratio, when added to ethylene glycol containing citric acid solutions, have been used to prepare highly viscous non-aqueous solutions of metal mixed nitrates-citrates. Thin films of these compositions are produced when a layer of the viscous solution is formed on a substrate and subjected to thermal decomposition.

  11. Electron cyclotron resonance microwave ion sources for thin film processing

    SciTech Connect

    Berry, L.A.; Gorbatkin, S.M.

    1990-01-01

    Plasmas created by microwave absorption at the electron cyclotron resonance (ECR) are increasingly used for a variety of plasma processes, including both etching and deposition. ECR sources efficiently couple energy to electrons and use magnetic confinement to maximize the probability of an electron creating an ion or free radical in pressure regimes where the mean free path for ionization is comparable to the ECR source dimensions. The general operating principles of ECR sources are discussed with special emphasis on their use for thin film etching. Data on source performance during Cl base etching of Si using an ECR system are presented. 32 refs., 5 figs.

  12. Resistive substrate heater for film processing by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Rousseau, B.; De Barros, D.; La Manna, J.; Weiss, F.; Duneau, G.; Odier, P.; De Sousa Meneses, D.; Auger, Y.; Melin, P.; Echegut, P.

    2004-09-01

    We describe a simple and inexpensive resistive heater usable in the spray pyrolysis process. It is based on a resistively heated ceramic plate. By using such a heater substrate temperatures exceeding 900 °C are easily achieved on the substrate. The heater consists of a ceramic plate enclosed in a stainless steel box. A refractory wire woven in a regular frame inside the ceramic provides an excellent heating uniformity over the entire surface. Performances and parameters of the system are given. We apply this device to the preparation of thick films of HTc oxides such as (Hg,Re)Ba2Ca2Cu3O8+δ.

  13. High speed television camera system processes photographic film data for digital computer analysis

    NASA Technical Reports Server (NTRS)

    Habbal, N. A.

    1970-01-01

    Data acquisition system translates and processes graphical information recorded on high speed photographic film. It automatically scans the film and stores the information with a minimal use of the computer memory.

  14. Thin film lithium-based batteries and electrochromic devices fabricated with nanocomposite electrode materials

    DOEpatents

    Gillaspie, Dane T; Lee, Se-Hee; Tracy, C. Edwin; Pitts, John Roland

    2014-02-04

    Thin-film lithium-based batteries and electrochromic devices (10) are fabricated with positive electrodes (12) comprising a nanocomposite material composed of lithiated metal oxide nanoparticles (40) dispersed in a matrix composed of lithium tungsten oxide.

  15. ZnO Thin Films Deposited on Textile Material Substrates for Biomedical Applications

    NASA Astrophysics Data System (ADS)

    Duta, L.; Popescu, A. C.; Dorcioman, G.; Mihailescu, I. N.; Stan, G. E.; Zgura, I.; Enculescu, I.; Dumitrescu, I.

    We report on the coating with ZnO adherent thin films of cotton woven fabrics by Pulsed laser deposition technique in order to obtain innovative textile materials, presenting protective effects against UV radiations and antifungal action.

  16. Development of a continuous roll-to-roll processing system for mass production of plastic optical film

    NASA Astrophysics Data System (ADS)

    Chang, Chih-Yuan; Tsai, Meng-Hsun

    2015-12-01

    This paper reports a highly effective method for the mass production of large-area plastic optical films with a microlens array pattern based on a continuous roll-to-roll film extrusion and roller embossing process. In this study, a thin steel mold with a micro-circular hole array pattern is fabricated by photolithography and a wet chemical etching process. The thin steel mold was then wrapped onto a metal cylinder to form an embossing roller mold. During the roll-to-roll process operation, a thermoplastic raw material (polycarbonate grains) was put into the barrel of the plastic extruder with a flat T-die. Then, the molten polymer film was extruded and immediately pressed against the surface of the embossing roller mold. Under the proper processing conditions, the molten polymer will just partially fill the micro-circular holes of the mold and due to surface tension form a convex lens surface. A continuous plastic optical film with a microlens array pattern was obtained. Experiments are carried out to investigate the effect of plastic microlens formation on the roll-to-roll process. Finally, the geometrical and optical properties of the fabricated plastic optical film were measured and proved satisfactory. This technique shows great potential for the mass production of large-area plastic optical films with a microlens array pattern.

  17. Precision Photothermal Annealing of Nanoporous Gold Thin Films for the Microfabrication of a Single-chip Material Libraries

    SciTech Connect

    Harris, C. D.; Shen, N.; Rubenchik, A.; Demos, S. G.; Matthews, M. J.

    2015-06-30

    Single-chip material libraries of thin films of nanostructured materials are a promising approach for high throughput studies of structure-property relationship in the fields of physics and biology. Nanoporous gold (np-Au), produced by an alloy corrosion process, is a nanostructured material of specific interest in both these fields. One attractive property of np-Au is its self-similar coarsening behavior by thermally induced surface diffusion. However, traditional heat application techniques for the modification of np-Au are bulk processes that cannot be used to generate a library of different pore sizes on a single chip. Laser micromachining offers an attractive solution to this problem by providing a means to apply energy with high spatial and temporal resolution. In the present study we use finite element multiphysics simulations to predict the effects of laser mode (continuous-wave vs. pulsed) and supporting substrate thermal conductivity on the local np-Au film temperatures during photothermal annealing and subsequently investigate the mechanisms by which the np-Au network is coarsening. Our simulations predict that continuous-wave mode laser irradiation on a silicon supporting substrate supports the widest range of morphologies that can be created through the photothermal annealing of thin film np-Au. Using this result we successfully fabricate a single-chip material library consisting of 81 np-Au samples of 9 different morphologies for use in increased throughput material interaction studies.

  18. Fully Solution-Processed Flexible Organic Thin Film Transistor Arrays with High Mobility and Exceptional Uniformity

    PubMed Central

    Fukuda, Kenjiro; Takeda, Yasunori; Mizukami, Makoto; Kumaki, Daisuke; Tokito, Shizuo

    2014-01-01

    Printing fully solution-processed organic electronic devices may potentially revolutionize production of flexible electronics for various applications. However, difficulties in forming thin, flat, uniform films through printing techniques have been responsible for poor device performance and low yields. Here, we report on fully solution-processed organic thin-film transistor (TFT) arrays with greatly improved performance and yields, achieved by layering solution-processable materials such as silver nanoparticle inks, organic semiconductors, and insulating polymers on thin plastic films. A treatment layer improves carrier injection between the source/drain electrodes and the semiconducting layer and dramatically reduces contact resistance. Furthermore, an organic semiconductor with large-crystal grains results in TFT devices with shorter channel lengths and higher field-effect mobilities. We obtained mobilities of over 1.2 cm2 V−1 s−1 in TFT devices with channel lengths shorter than 20 μm. By combining these fabrication techniques, we built highly uniform organic TFT arrays with average mobility levels as high as 0.80 cm2 V−1 s−1 and ideal threshold voltages of 0 V. These results represent major progress in the fabrication of fully solution-processed organic TFT device arrays. PMID:24492785

  19. Fully Solution-Processed Flexible Organic Thin Film Transistor Arrays with High Mobility and Exceptional Uniformity

    NASA Astrophysics Data System (ADS)

    Fukuda, Kenjiro; Takeda, Yasunori; Mizukami, Makoto; Kumaki, Daisuke; Tokito, Shizuo

    2014-02-01

    Printing fully solution-processed organic electronic devices may potentially revolutionize production of flexible electronics for various applications. However, difficulties in forming thin, flat, uniform films through printing techniques have been responsible for poor device performance and low yields. Here, we report on fully solution-processed organic thin-film transistor (TFT) arrays with greatly improved performance and yields, achieved by layering solution-processable materials such as silver nanoparticle inks, organic semiconductors, and insulating polymers on thin plastic films. A treatment layer improves carrier injection between the source/drain electrodes and the semiconducting layer and dramatically reduces contact resistance. Furthermore, an organic semiconductor with large-crystal grains results in TFT devices with shorter channel lengths and higher field-effect mobilities. We obtained mobilities of over 1.2 cm2 V-1 s-1 in TFT devices with channel lengths shorter than 20 μm. By combining these fabrication techniques, we built highly uniform organic TFT arrays with average mobility levels as high as 0.80 cm2 V-1 s-1 and ideal threshold voltages of 0 V. These results represent major progress in the fabrication of fully solution-processed organic TFT device arrays.

  20. Method of forming particulate materials for thin-film solar cells

    DOEpatents

    Eberspacher, Chris; Pauls, Karen Lea

    2004-11-23

    A method for preparing particulate materials useful in fabricating thin-film solar cells is disclosed. Particulate materials is prepared by the method include for example materials comprising copper and indium and/or gallium in the form of single-phase, mixed-metal oxide particulates; multi-phase, mixed-metal particulates comprising a metal oxide; and multinary metal particulates.

  1. Unraveling the Material Processing Conditions for Optimizing FSW Process

    NASA Technical Reports Server (NTRS)

    Schneider, Judy; Nunes, Arthur C., Jr.

    2005-01-01

    In friction stir welding (FSW), a rotating threaded pin tool is inserted into a weld seam and literally stirs the edges of the seam together. This environmentally friendly, solid-state technique has been successfully used in the joining of materials that are difficult to fusion weld. To determine optimal processing parameters for producing a defect free weld a better understanding of the resulting metal deformation flow path and velocity is required. In this study the metal flow fields are marked by the use of thin (0.001? tungsten) wires embedded in the weld seam at various locations. X-ray radiographs record the position and segmentation of the wire and are used to elucidate the flow field. Microstructures observed in a FSW cross-section in an aluminum alloy are related to their respective strain-strain rate-temperature histories along their respective flow trajectories. Two kinds of trajectories, each subjecting the weld metal to a distinct thermomechanical process and imparting a distinct microstructure, can be differentiated within the weld structure.

  2. Quantifying the Material Processing Conditions for an Optimized FSW Process

    NASA Technical Reports Server (NTRS)

    Schneider, Judy; Nunes, Arthur C., Jr.

    2005-01-01

    In friction stir welding (FSW), a rotating threaded pin tool is inserted into a weld seam and literally stirs the edgs of the seam together. This environmentally friendly, solid-state technique has been successfully used in the joining of materials that are difficult to fusion weld. To determine optimal processing parameters for producing a defect free weld, a better understanding of the resulting metal deformation flow path and velocity is required. In this study the metal flow fields are marked by the use of thin (0.001 in. tungsten) wires embedded in the weld seam at various locations. X-ray radiographs record the position and segmentation of the wire and are used to elucidate the flow field. Microstructures observed in a FSW cross-section in an aluminum alloy are related to their respective strain-strain rate-temperature histones along their respective flow trajectories. Two kinds of trajectories, each subjecting the weld metal to a distinct thermomechanical process and imparting a distinct microstructure, can be differentiated within the weld structure.

  3. Supercritical fluid processing: opportunities for new resist materials and processes

    NASA Astrophysics Data System (ADS)

    Gallagher-Wetmore, Paula M.; Ober, Christopher K.; Gabor, Allen H.; Allen, Robert D.

    1996-05-01

    Over the past two decades supercritical fluids have been utilized as solvents for carrying out separations of materials as diverse as foods, polymers, pharmaceuticals, petrochemicals, natural products, and explosives. More recently they have been used for non-extractive applications such as recrystallization, deposition, impregnation, surface modification, and as a solvent alternative for precision parts cleaning. Today, supercritical fluid extraction is being practiced in the foods and beverage industries; there are commercial plants for decaffeinating coffee and tea, extracting beer flavoring agents from hops, and separating oils and oleoresins from spices. Interest in supercritical fluid processing of polymers has grown over the last ten years, and many new purification, fractionation, and even polymerization techniques have emerged. One of the most significant motivations for applying this technology to polymers has been increased performance demands. More recently, with increasing scrutiny of traditional solvents, supercritical fluids, and in particular carbon dioxide, are receiving widespread attention as 'environmentally conscious' solvents. This paper describes several examples of polymers applications, including a few involving photoresists, which demonstrate that as next- generation advanced polymer systems emerge, supercritical fluids are certain to offer advantages as cutting edge processing tools.

  4. 49 CFR 175.706 - Separation distances for undeveloped film from packages containing Class 7 (radioactive) materials.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Separation distances for undeveloped film from... Classification of Material § 175.706 Separation distances for undeveloped film from packages containing Class 7... film. Transport index Minimum separation distance to nearest undeveloped film for various times...

  5. 49 CFR 175.706 - Separation distances for undeveloped film from packages containing Class 7 (radioactive) materials.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Separation distances for undeveloped film from... Classification of Material § 175.706 Separation distances for undeveloped film from packages containing Class 7... film. Transport index Minimum separation distance to nearest undeveloped film for various times...

  6. 49 CFR 175.706 - Separation distances for undeveloped film from packages containing Class 7 (radioactive) materials.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Separation distances for undeveloped film from... Classification of Material § 175.706 Separation distances for undeveloped film from packages containing Class 7... film. Transport index Minimum separation distance to nearest undeveloped film for various times...

  7. 49 CFR 175.706 - Separation distances for undeveloped film from packages containing Class 7 (radioactive) materials.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Separation distances for undeveloped film from... Classification of Material § 175.706 Separation distances for undeveloped film from packages containing Class 7... film. Transport index Minimum separation distance to nearest undeveloped film for various times...

  8. 49 CFR 175.706 - Separation distances for undeveloped film from packages containing Class 7 (radioactive) materials.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Separation distances for undeveloped film from... Classification of Material § 175.706 Separation distances for undeveloped film from packages containing Class 7... film. Transport index Minimum separation distance to nearest undeveloped film for various times...

  9. Processing and applications of carbon based nano-materials

    NASA Astrophysics Data System (ADS)

    Yu, Aiping

    Carbon-based nanomaterials, including single walled carbon nanotubes (SWNTs) and graphite nanoplatelets (GNPs, multi-layer graphene), possess exceptional electrical, thermal and mechanical properties coupled with high aspect ratio and high temperature stability. These unique properties have attracted increased attention during the past decade. These materials form the basis of the work presented here, which includes research targeting fabrication, processing and applications in new composites and devices. As-prepared SWNTs are typically contaminated with amorphous carbon as well as metal catalyst and graphitic nanoparticles. We have demonstrated an efficient approach for removing most of these impurities by the combination of nitric acid treatment and both low speed (2000 g) and high speed centrifugation (20,000 g). This approach gives rise to the highest-purified arc-discharge SWNTs which are almost free from impurities, and in addition are left in a low state of aggregation. The new purification process offers a convenient way to obtain different grade of SWNTs and allows the study of the effect purity on the thermal conductivity of SWNT epoxy composite. Purified functionalized SWNTs provide a significantly greater enhancement of the thermal conductivity, whereas AP-SWNTs allow the best electrical properties because of their ability to form efficient percolating network. We found that purified SWNTs provide ˜5 times greater enhancement of the thermal conductivity than the impure SWNT fraction demonstrating the significance of SWNTs quality for thermal management. The introduced GNPs have directed the thermal management project to a new avenue due to the significant improvement of the thermal conductivity of the composites in comparison with that of SWNTs. A novel process was demonstrated to achieve a 4-graphene layer structure referred to GNPs with a thickness of ˜2 nm. This material was embedded in an epoxy resin matrix and the measured thermal conductivity of

  10. Processes for fabricating composite reinforced material

    DOEpatents

    Seals, Roland D.; Ripley, Edward B.; Ludtka, Gerard M.

    2015-11-24

    A family of materials wherein nanostructures and/or nanotubes are incorporated into a multi-component material arrangement, such as a metallic or ceramic alloy or composite/aggregate, producing a new material or metallic/ceramic alloy. The new material has significantly increased strength, up to several thousands of times normal and perhaps substantially more, as well as significantly decreased weight. The new materials may be manufactured into a component where the nanostructure or nanostructure reinforcement is incorporated into the bulk and/or matrix material, or as a coating where the nanostructure or nanostructure reinforcement is incorporated into the coating or surface of a "normal" substrate material. The nanostructures are incorporated into the material structure either randomly or aligned, within grains, or along or across grain boundaries.

  11. High Performance, Low Temperature Solution-Processed Barium and Strontium Doped Oxide Thin Film Transistors

    PubMed Central

    2013-01-01

    Amorphous mixed metal oxides are emerging as high performance semiconductors for thin film transistor (TFT) applications, with indium gallium zinc oxide, InGaZnO (IGZO), being one of the most widely studied and best performing systems. Here, we investigate alkaline earth (barium or strontium) doped InBa(Sr)ZnO as alternative, semiconducting channel layers and compare their performance of the electrical stress stability with IGZO. In films fabricated by solution-processing from metal alkoxide precursors and annealed to 450 °C we achieve high field-effect electron mobility up to 26 cm2 V–1 s–1. We show that it is possible to solution-process these materials at low process temperature (225–200 °C yielding mobilities up to 4.4 cm2 V–1 s–1) and demonstrate a facile “ink-on-demand” process for these materials which utilizes the alcoholysis reaction of alkyl metal precursors to negate the need for complex synthesis and purification protocols. Electrical bias stress measurements which can serve as a figure of merit for performance stability for a TFT device reveal Sr- and Ba-doped semiconductors to exhibit enhanced electrical stability and reduced threshold voltage shift compared to IGZO irrespective of the process temperature and preparation method. This enhancement in stability can be attributed to the higher Gibbs energy of oxidation of barium and strontium compared to gallium. PMID:24511184

  12. High Performance, Low Temperature Solution-Processed Barium and Strontium Doped Oxide Thin Film Transistors.

    PubMed

    Banger, Kulbinder K; Peterson, Rebecca L; Mori, Kiyotaka; Yamashita, Yoshihisa; Leedham, Timothy; Sirringhaus, Henning

    2014-01-28

    Amorphous mixed metal oxides are emerging as high performance semiconductors for thin film transistor (TFT) applications, with indium gallium zinc oxide, InGaZnO (IGZO), being one of the most widely studied and best performing systems. Here, we investigate alkaline earth (barium or strontium) doped InBa(Sr)ZnO as alternative, semiconducting channel layers and compare their performance of the electrical stress stability with IGZO. In films fabricated by solution-processing from metal alkoxide precursors and annealed to 450 °C we achieve high field-effect electron mobility up to 26 cm(2) V(-1) s(-1). We show that it is possible to solution-process these materials at low process temperature (225-200 °C yielding mobilities up to 4.4 cm(2) V(-1) s(-1)) and demonstrate a facile "ink-on-demand" process for these materials which utilizes the alcoholysis reaction of alkyl metal precursors to negate the need for complex synthesis and purification protocols. Electrical bias stress measurements which can serve as a figure of merit for performance stability for a TFT device reveal Sr- and Ba-doped semiconductors to exhibit enhanced electrical stability and reduced threshold voltage shift compared to IGZO irrespective of the process temperature and preparation method. This enhancement in stability can be attributed to the higher Gibbs energy of oxidation of barium and strontium compared to gallium. PMID:24511184

  13. Ultrathin Co/Pt and Co/Pd multilayered films as magneto-optical recording materials

    NASA Astrophysics Data System (ADS)

    Hashimoto, S.; Ochiai, Y.; Aso, K.

    1990-02-01

    Co/Pt and Co/Pd multilayered films were prepared by two-source dc magnetron sputtering. The multilayers with thin Co layers, one to three atoms thick, exhibited a perfect squareness of Kerr loop and an enhancement of Kerr rotation when the total film thickness became below several hundred angstroms. These ultrathin films have a high Kerr rotation of 0.2°-0.45° and strong perpendicular magnetic anisotropy even in the very thin-film thickness. The figure of merit of the ultrathin Co/Pt films is superior to that of TbFeCo system at 780 nm and becomes larger at shorter wavelength. The ultrathin multilayers possess very high corrosion resistance, and the layered structure is thermally stable up to 400 °C. Consequently, the ultrathin Co/Pt and Co/Pd multilayered films can be new magneto-optical recording materials, especially for higher density recording using a shorter wavelength laser.

  14. Low temperature process for obtaining thin glass films

    DOEpatents

    Brinker, C. Jeffrey; Reed, Scott T.

    1984-01-01

    A method for coating a substrate with a glass-like film comprises, applying to the substrate an aqueous alcoholic solution containing a polymeric network of partially hydrolyzed metal alkoxide into which network there is incorporated finely powdered glass, whereby there is achieved on the substrate a coherent and adherent initial film; and heating said film to a temperature sufficient to melt said powdered glass component, thereby converting said initial film to a final densified film.

  15. Low temperature process for obtaining thin glass films

    DOEpatents

    Brinker, C.J.; Reed, S.T.

    A method for coating a substrate with a glass-like film comprises, applying to the substrate an aqueous alcoholic solution containing a polymeric network of partially hydrolyzed metal alkoxide into which network there is incorporated finely powdered glass, whereby there is achieved on the substrate a coherent and adherent initial film; and heating said film to a temperature sufficient to melt said powdered glass component, thereby converting said initial film to a final densified film.

  16. Fabrication of nanostructured metal oxide films with supercritical carbon dioxide: Processing and applications

    NASA Astrophysics Data System (ADS)

    You, Eunyoung

    Nanostructured metal oxide films have many applications in catalysis, microelectronics, microfluidics, photovoltaics and other fields. Since the performance of a device depends greatly on the structure of the material, the development of methodologies that enable prescriptive control of morphology are of great interest. The focus of this work is to control the structure and properties of the nanostructured metal oxide films using novel synthetic schemes in supercritical fluids and to use those films as key building components in alternative energy applications. A supercritical fluid is a substance at a temperature and pressure above its critical point. It typically exhibits gas-like transport properties and liquid-like densities. Supercritical fluid deposition (SFD) utilizes these properties of supercritical CO2 (scCO2) to deposit chemically pure metal, oxides and alloys of metal films. SFD is a chemical vapor deposition (CVD)-like process in the sense that it uses similar metal organic precursors and deposits films at elevated temperatures. Instead of vaporizing or subliming the precursors, they are dissolved in supercritical fluids. SFD has typically shown to exhibit higher precursor concentrations, lower deposition temperatures, conformal deposition of films on high aspect ratio features as compared to CVD. In2 O3, ZnO and SnO2 are attractive materials because they are used in transparent conductors. SFD of these materials were studied and In2 O3 deposition kinetics using tris(2,2,6,6-tetramethyl-3,5-heptanedionato) In (III) as precursor were determined. Growth rate dependence on the deposition temperature and the precursor concentrations were studied and the physicochemical and optical properties of In2 O3 films were characterized. Metal oxide nanochannels that can potentially be used for microfluidics have been fabricated by sequentially performing nanoimprint lithography (NIL) and SFD. NIL was used to pattern photoresist grating on substrates and SFD of TiO2

  17. The effect of Ta interface on the crystallization of amorphous phase change material thin films

    SciTech Connect

    Ghezzi, G. E.; Noé, P. Marra, M.; Sabbione, C.; Fillot, F.; Bernier, N.; Ferrand, J.; Maîtrejean, S.; Hippert, F.

    2014-06-02

    The crystallization of amorphous GeTe and Ge{sub 2}Sb{sub 2}Te{sub 5} phase change material films, with thickness between 10 and 100 nm, sandwiched between either Ta or SiO{sub 2} layers, was investigated by optical reflectivity. Ta cladding layers were found to increase the crystallization temperature, even for films as thick as 100 nm. X-Ray diffraction investigations of crystallized GeTe films showed a very weak texture in Ta cladded films, in contrast with the strong texture observed for SiO{sub 2} cladding layers. This study shows that crystallization mechanism of phase change materials can be highly impacted by interface effects, even for relatively thick films.

  18. Pulsed laser processing of electronic materials in micro/nanoscale

    NASA Astrophysics Data System (ADS)

    Hwang, David Jen

    2005-08-01

    Time-resolved pump-and-probe side-view imaging has been performed to investigate the energy coupling to the target specimen over a wide range of fluences. Plasmas generated during the laser ablation process are visualized and the decrease of the ablation efficiency in the high fluence regime (>10 J/cm2) is attributed to the strong interaction of the laser pulse with the laser-induced plasmas. The high intensity ultra-short laser pulses also trigger volumetric multi-photon absorption (MPA) processes that can be beneficial in applications such as three-dimensional bulk modification of transparent materials. Femtosecond laser pulses were used to fabricate straight and bent through-channels in the optical glass. Drilling was initiated from the rear surface to preserve consistent absorbing conditions of the laser pulse. Machining in the presence of a liquid solution assisted the debris ejection. Drilling process was further enhanced by introducing ultrasonic waves, thereby increasing the aspect ratio of drilled holes and improving the quality of the holes. In conventional lens focusing schemes, the minimum feature size is determined by the diffraction limit. Finer resolution is accomplished by combining pulsed laser radiation with Near-field Scanning Optical Microscopy (NSOM) probes. Short laser pulses are coupled to a fiber-based NSOM probes in order to ablate thin metal films. A detailed parametric study on the effects of probe aperture size, laser pulse energy, temporal width and environment gas is performed. The significance of lateral thermal diffusion is highlighted and the dependence of the ablation process on the imparted near-field distribution is revealed. As a promising application of laser ablation in nanoscale, laser induced breakdown spectroscopy (LIBS) system has been built up based on NSOM ablation configuration. NSOM-LIBS is demonstrated with nanosecond pulsed laser excitation on Cr sample. Far-field collecting scheme by top objective lens was chosen as

  19. Process Research on Polycrystalline Silicon Material (PROPSM)

    NASA Technical Reports Server (NTRS)

    Culik, J. S.; Wrigley, C. Y.

    1984-01-01

    Results of hydrogen-passivated polycrystalline silicon solar cells are summarized. Very small grain or short minority-carrier diffusion length silicon was used. Hydrogenated solar cells fabricated from this material appear to have effective minority-carrier diffusion lengths that are still not very long, as shown by the open-circuit voltages of passivated cells that are still significantly less than those of single-crystal solar cells. The short-circuit current of solar cells fabricated from large-grain cast polycrystalline silicon is nearly equivalent to that of single-crystal cells, which indicates long bulk minority-carrier diffusion length. However, the open-circuit voltage, which is sensitive to grain boundary recombination, is sometimes 20 to 40 mV less. The goal was to minimize variations in open-circuit voltage and fill-factor caused by defects by passivating these defects using a hydrogenation process. Treatments with molecular hydrogen showed no effect on large-grain cast polycrystaline silicon solar cells.

  20. Integration of advanced nuclear materials separation processes

    SciTech Connect

    Jarvinen, G.D.; Worl, L.A.; Padilla, D.D.; Berg, J.M.; Neu, M.P.; Reilly, S.D.; Buelow, S.

    1998-12-31

    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project has examined the fundamental chemistry of plutonium that affects the integration of hydrothermal technology into nuclear materials processing operations. Chemical reactions in high temperature water allow new avenues for waste treatment and radionuclide separation.Successful implementation of hydrothermal technology offers the potential to effective treat many types of radioactive waste, reduce the storage hazards and disposal costs, and minimize the generation of secondary waste streams. The focus has been on the chemistry of plutonium(VI) in solution with carbonate since these are expected to be important species in the effluent from hydrothermal oxidation of Pu-containing organic wastes. The authors investigated the structure, solubility, and stability of the key plutonium complexes. Installation and testing of flow and batch hydrothermal reactors in the Plutonium Facility was accomplished. Preliminary testing with Pu-contaminated organic solutions gave effluent solutions that readily met discard requirements. A new effort in FY 1998 will build on these promising initial results.

  1. Materials processing with intense pulsed ion beams

    SciTech Connect

    Rej, D.J.; Davis, H.A.; Olson, J.C.

    1996-12-31

    We review research investigating the application of intense pulsed ion beams (IPIBs) for the surface treatment and coating of materials. The short range (0.1-10 {mu}m) and high-energy density (1-50 J/cm{sup 2}) of these short-pulsed ({le} 1 {mu}s) beams (with ion currents I = 5 - 50 kA, and energies E = 100 - 1000 keV) make them ideal to flash-heat a target surface, similar to the more familiar pulsed laser processes. IPIB surface treatment induces rapid melt and solidification at up to 10{sup 10} K/s to cause amorphous layer formation and the production of non-equilibrium microstructures. At higher energy density the target surface is vaporized, and the ablated vapor is condensed as coatings onto adjacent substrates or as nanophase powders. Progress towards the development of robust, high-repetition rate IPIB accelerators is presented along with economic estimates for the cost of ownership of this technology.

  2. Facile synthesis of multilayer-like Si thin film as high-performance anode materials for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Wang, Mingxu; Geng, Zhongrong

    2016-05-01

    For the silicon anodes in lithium-ion batteries, it is well known that the enormous volumetric expansion/contraction is also the mainly reason for the capacity fading. In this manuscript, a new kind of Si thin films was prepared with a radio frequency magnetron sputtering method. By using a periodic modulation negative bias on the substrate, a density-modulated multilayer-like silicon thin films with different layer densities were used as anode materials of lithium-ion batteries, and which displayed a high capacity and stable cycling performances. The reason for the charming electrochemical performances may be owned to the particular density modulated microstructure of the Si thin films. It is conjectured that the lower density can as compliant layers and which provided the volume for the higher-density layer expansion in the process of the lithiation/delithiation. In contrast to the conventional silicon anodes, the density modulated microstructure in this work could exploit a new approach to silicon thin-film anode materials with outstanding electrochemical properties and mechanical stability. And these reports may be provide a new way to prepare the Si thin films for the high-energy, safe, and low-cost batteries.

  3. The space technology demand on materials and processes

    NASA Technical Reports Server (NTRS)

    Dauphin, J.

    1983-01-01

    Space technology requires a rational and accurate policy of materials and processes selection. This paper examines some areas of space technology where materials and process problems have occurred in the past and how they can be solved in the future.

  4. Controlled Growth of Ultrathin Film of Organic Semiconductors by Balancing the Competitive Processes in Dip-Coating for Organic Transistors.

    PubMed

    Wu, Kunjie; Li, Hongwei; Li, Liqiang; Zhang, Suna; Chen, Xiaosong; Xu, Zeyang; Zhang, Xi; Hu, Wenping; Chi, Lifeng; Gao, Xike; Meng, Yancheng

    2016-06-28

    Ultrathin film with thickness below 15 nm of organic semiconductors provides excellent platform for some fundamental research and practical applications in the field of organic electronics. However, it is quite challenging to develop a general principle for the growth of uniform and continuous ultrathin film over large area. Dip-coating is a useful technique to prepare diverse structures of organic semiconductors, but the assembly of organic semiconductors in dip-coating is quite complicated, and there are no reports about the core rules for the growth of ultrathin film via dip-coating until now. In this work, we develop a general strategy for the growth of ultrathin film of organic semiconductor via dip-coating, which provides a relatively facile model to analyze the growth behavior. The balance between the three direct factors (nucleation rate, assembly rate, and recession rate) is the key to determine the growth of ultrathin film. Under the direction of this rule, ultrathin films of four organic semiconductors are obtained. The field-effect transistors constructed on the ultrathin film show good field-effect property. This work provides a general principle and systematic guideline to prepare ultrathin film of organic semiconductors via dip-coating, which would be highly meaningful for organic electronics as well as for the assembly of other materials via solution processes. PMID:27267545

  5. High performance organic thin film transistors with solution processed TTF-TCNQ charge transfer salt as electrodes.

    PubMed

    Mukherjee, Biswanath; Mukherjee, Moumita

    2011-09-01

    Fabrication of high-performance organic thin film transistors (OTFTs) with solution processed organic charge transfer complex (TTF-TCNQ) film as bottom contact source-drain electrodes is reported. A novel capillary based method was used to deposit the source-drain electrodes from solution and to create the channel between the electrodes. Both p- and n-type OTFTs have been fabricated with solution deposited organic charge transfer film as contact electrodes. Comparison of the device performances between OTFTs with TTF-TCNQ as source-drain electrodes and those with Au electrodes (both top and bottom contact) indicate that better results have been obtained in organic complex film contacted OTFT. The high mobility, low threshold voltage, and efficient carrier injection in both types of OTFTs implies the potential use of the TTF-TCNQ based complex material as low-cost contact electrodes. The lower work function of the TTF-TCNQ electrode and better contact of the complex film with the organic thin film owing to the organic-organic interface results in efficient charge transfer into the semiconductor yielding high device performance. The present method having organic metal as contact materials promises great potential for the fabrication of all-organics and plastic electronics devices with high throughput and low-cost processing. PMID:21812432

  6. Solution processing of YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} thin films

    SciTech Connect

    Singhal, A.; Paranthaman, M.; Specht, E.D.; Hunt, R.D.; Beach, D.B.; Martin, P.M.; Lee, D.F.

    1997-12-01

    The aim of this work was to develop a non-vacuum chemical deposition technique for YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} (YBCO) coated conductors on rolling-assisted biaxially textured substrates (RABiTS). The authors have chosen the metal-organic decomposition (MOD) and sol-gel precursor routes to grow textured YBCO films. In the MOD process, yttrium 2-ethylhexonate, barium neodecanoate, copper 2-ethylhexonate and toluene were used as the starting reagents. YBCO films processed by the MOD method on SrTiO{sub 3} (100) single crystal substrates were consisted of c and a-axis oriented materials. These films also contained some amount of the random phase. The c and a-axis oriented materials were epitaxial on SrTiO{sub 3} substrates. Films have a T{sub c,onset} of 89K and the best superconducting transition temperature of 63K. Films pyrolyzed at 525 C and subsequently annealed at 780 C in a p(O{sub 2}) of 3.5 {times} 10{sup {minus}4} atm contained YBCO phase predominantly in a-axis orientation. In the sol-gel route, yttrium-isopropoxide, barium metal, copper methoxide and 2-methoxyethanol were used as the starting reagents. Sol-gel YBCO films on SrTiO{sub 3} substrates were epitaxial and c-axis oriented.

  7. Process for growing a film epitaxially upon an oxide surface and structures formed with the process

    DOEpatents

    McKee, Rodney Allen; Walker, Frederick Joseph

    1998-01-01

    A process and structure wherein a film comprised of a perovskite or a spinel is built epitaxially upon a surface, such as an alkaline earth oxide surface, involves the epitaxial build up of alternating constituent metal oxide planes of the perovskite or spinel. The first layer of metal oxide built upon the surface includes a metal element which provides a small cation in the crystalline structure of the perovskite or spinel, and the second layer of metal oxide built upon the surface includes a metal element which provides a large cation in the crystalline structure of the perovskite or spinel. The layering sequence involved in the film build up reduces problems which would otherwise result from the interfacial electrostatics at the first atomic layers, and these oxides can be stabilized as commensurate thin films at a unit cell thickness or grown with high crystal quality to thicknesses of 0.5-0.7 .mu.m for optical device applications.

  8. Process for growing a film epitaxially upon an oxide surface and structures formed with the process

    DOEpatents

    McKee, Rodney A.; Walker, Frederick J.

    1995-01-01

    A process and structure wherein a film comprised of a perovskite or a spinel is built epitaxially upon a surface, such as an alkaline earth oxide surface, involves the epitaxial build up of alternating constituent metal oxide planes of the perovskite or spinel. The first layer of metal oxide built upon the surface includes a metal element which provides a small cation in the crystalline structure of the perovskite or spinel, and the second layer of metal oxide built upon the surface includes a metal element which provides a large cation in the crystalline structure of the perovskite or spinel. The layering sequence involved in the film build up reduces problems which would otherwise result from the interfacial electrostatics at the first atomic layers, and these oxides can be stabilized as commensurate thin films at a unit cell thickness or grown with high crystal quality to thicknesses of 0.5-0.7 .mu.m for optical device applications.

  9. Concurrent materials and process selection in conceptual design

    SciTech Connect

    Kleban, S.D.

    1998-07-01

    The sequential manner in which materials and processes for a manufactured product are selected is inherently less than optimal. Designers` tendency to choose processes and materials with which they are familiar exacerbate this problem. A method for concurrent selection of materials and a joining process based on product requirements using a knowledge-based, constraint satisfaction approach is presented.

  10. A fast method to produce strong NFC films as a platform for barrier and functional materials.

    PubMed

    Osterberg, Monika; Vartiainen, Jari; Lucenius, Jessica; Hippi, Ulla; Seppälä, Jukka; Serimaa, Ritva; Laine, Janne

    2013-06-12

    In this study, we present a rapid method to prepare robust, solvent-resistant, nanofibrillated cellulose (NFC) films that can be further surface-modified for functionality. The oxygen, water vapor, and grease barrier properties of the films were measured, and in addition, mechanical properties in the dry and wet state and solvent resistance were evaluated. The pure unmodified NFC films were good barriers for oxygen gas and grease. At a relative humidity below 65%, oxygen permeability of the pure and unmodified NFC films was below 0.6 cm(3) μm m(-2) d(-1) kPa(-1), and no grease penetrated the film. However, the largest advantage of these films was their resistance to various solvents, such as water, methanol, toluene, and dimethylacetamide. Although they absorbed a substantial amount of solvent, the films could still be handled after 24 h of solvent soaking. Hot-pressing was introduced as a convenient method to not only increase the drying speed of the films but also enhance the robustness of the films. The wet strength of the films increased due to the pressing. Thus, they can be chemically or physically modified through adsorption or direct chemical reaction in both aqueous and organic solvents. Through these modifications, the properties of the film can be enhanced, introducing, for example, functionality, hydrophobicity, or bioactivity. Herein, a simple method using surface coating with wax to improve hydrophobicity and oxygen barrier properties at very high humidity is described. Through this modification, the oxygen permeability decreased further and was below 17 cm(3) μm m(-2) d(-1) kPa(-1) even at 97.4% RH, and the water vapor transmission rate decreased from 600 to 40 g/m(2) day. The wax treatment did not deteriorate the dry strength of the film. Possible reasons for the unique properties are discussed. The developed robust NFC films can be used as a generic, environmentally sustainable platform for functional materials. PMID:23635431

  11. Solution-Based Processing of the Phase-Change Material KSb5S8

    SciTech Connect

    Mitzi,D.; Raoux, S.; Schrott, A.; Copel, M.; Kellock, A.; Jordan-Sweet, J.

    2006-01-01

    A hydrazine-based process for solution-depositing phase-change materials (PCMs) is demonstrated, using KSb{sub 5}S{sub 8} (KSS) as an example. The process involves dissolving the elemental metals and chalcogen in hydrazine at room temperature and spin-coating the solution onto a substrate, followed by a short low-temperature (T {<=} 250 C) anneal. The spin-coated KSS films, which range in thickness from 10 to 90 nm, are examined using variable temperature X-ray diffraction, medium energy ion scattering (MEIS), Rutherford backscattering spectroscopy (RBS), and scanning electron microscopy (SEM). The spin-coated KSS films exhibit a reversible amorphous-crystalline transition with a relatively high crystallization temperature ({approx}280 C). Selected other chalcogenide-based PCMs are also expected to be suitable for thin-film deposition using this approach.

  12. High-optical-quality ferroelectric film wet-processed from a ferroelectric columnar liquid crystal as observed by non-linear-optical microscopy.

    PubMed

    Araoka, Fumito; Masuko, Shiori; Kogure, Akinori; Miyajima, Daigo; Aida, Takuzo; Takezoe, Hideo

    2013-08-01

    The self-organization of ferroelectric columnar liquid crystals (FCLCs) is demonstrated. Columnar order is spontaneously formed in thin films made by the wet-process due to its liquid crystallinity. Electric-field application results in high optical quality and uniform spontaneous polarization. Such good processability and controllability of the wet-processed FCLC films provide us with potential organic ferroelectric materials for device applications. PMID:23740767

  13. 'Beautiful' unconventional synthesis and processing technologies of superconductors and some other materials

    NASA Astrophysics Data System (ADS)

    Badica, Petre; Crisan, Adrian; Aldica, Gheorghe; Endo, Kazuhiro; Borodianska, Hanna; Togano, Kazumasa; Awaji, Satoshi; Watanabe, Kazuo; Sakka, Yoshio; Vasylkiv, Oleg

    2011-02-01

    Superconducting materials have contributed significantly to the development of modern materials science and engineering. Specific technological solutions for their synthesis and processing helped in understanding the principles and approaches to the design, fabrication and application of many other materials. In this review, we explore the bidirectional relationship between the general and particular synthesis concepts. The analysis is mostly based on our studies where some unconventional technologies were applied to different superconductors and some other materials. These technologies include spray-frozen freeze-drying, fast pyrolysis, field-assisted sintering (or spark plasma sintering), nanoblasting, processing in high magnetic fields, methods of control of supersaturation and migration during film growth, and mechanical treatments of composite wires. The analysis provides future research directions and some key elements to define the concept of 'beautiful' technology in materials science. It also reconfirms the key position and importance of superconductors in the development of new materials and unconventional synthesis approaches.

  14. Fabrication of advanced electrochemical energy materials using sol-gel processing techniques

    NASA Technical Reports Server (NTRS)

    Chu, C. T.; Chu, Jay; Zheng, Haixing

    1995-01-01

    Advanced materials play an important role in electrochemical energy devices such as batteries, fuel cells, and electrochemical capacitors. They are being used as both electrodes and electrolytes. Sol-gel processing is a versatile solution technique used in fabrication of ceramic materials with tailored stoichiometry, microstructure, and properties. The application of sol-gel processing in the fabrication of advanced electrochemical energy materials will be presented. The potentials of sol-gel derived materials for electrochemical energy applications will be discussed along with some examples of successful applications. Sol-gel derived metal oxide electrode materials such as V2O5 cathodes have been demonstrated in solid-slate thin film batteries; solid electrolytes materials such as beta-alumina for advanced secondary batteries had been prepared by the sol-gel technique long time ago; and high surface area transition metal compounds for capacitive energy storage applications can also be synthesized with this method.

  15. Advanced materials for geothermal energy processes

    SciTech Connect

    Kukacka, L.E.

    1985-08-01

    The primary goal of the geothermal materials program is to ensure that the private sector development of geothermal energy resources is not constrained by the availability of technologically and economically viable materials of construction. This requires the performance of long-term high risk GHTD-sponsored materials R and D. Ongoing programs described include high temperature elastomers for dynamic sealing applications, advanced materials for lost circulation control, waste utilization and disposal, corrosion resistant elastomeric liners for well casing, and non-metallic heat exchangers. 9 refs.

  16. A simple solution to the problem of effective utilisation of the target material for pulsed laser deposition of thin films

    SciTech Connect

    Kuzanyan, A S; Kuzanyan, A A; Petrosyan, V A; Pilosyan, S Kh; Grasiuk, A Z

    2013-12-31

    The factors determining the efficiency of the target material utilisation for pulsed laser deposition of films are considered. The target volume is calculated, which is evaporated in the ablation process by the focused laser radiation having a rectangular form. The new device is suggested and developed for obtaining thin films by the method of laser deposition, which is specific in the employment of a simple optical system mounted outside a deposition chamber that comprises two lenses and the diaphragm and focuses the laser beam onto a target in the form of a sector-like spot. Thin films of CuO and YBaCuO were deposited with this device. Several deposition cycles revealed that the target material is consumed uniformly from the entire surface of the target. A maximal spread of the target thickness was not greater than ±2% both prior to deposition and after it. The device designed provides a high coefficient of the target material utilisation efficiency. (laser deposition of thin films)

  17. Studies of ferroelectric heterostructure thin films, interfaces, and device-related processes via in situ analytical techniques.

    SciTech Connect

    Aggarwal, S.; Auciello, O.; Dhote, A. M.; Gao, Y.; Gruen, D. M.; Im, J.; Irene, E. A.; Krauss, A. R.; Muller, A. H.; Ramesh, R.

    1999-06-29

    The science and technology of ferroelectric thin films has experienced an explosive development during the last ten years. Low-density non-volatile ferroelectric random access memories (NVFRAMS) are now incorporated in commercial products such as ''smart cards'', while high permittivity capacitors are incorporated in cellular phones. However, substantial work is still needed to develop materials integration strategies for high-density memories. We have demonstrated that the implementation of complementary in situ characterization techniques is critical to understand film growth and device processes relevant to device development. We are using uniquely integrated time of flight ion scattering and recoil spectroscopy (TOF-ISARS) and spectroscopic ellipsometry (SE) techniques to perform in situ, real-time studies of film growth processes in the high background gas pressure required to growth ferroelectric thin films. TOF-ISARS provides information on surface processes, while SE permits the investigation of buried interfaces as they are being formed. Recent studies on SrBi{sub 2}Ta{sub 2}O{sub 9} (SBT) and Ba{sub x}Sr{sub 1{minus}x}TiO{sub 3} (BST) film growth and interface processes are discussed. Direct imaging of ferroelectric domains under applied electric fields can provide valuable information to understand domain dynamics in ferroelectric films. We discuss results of piezoresponse scanning force microscopy (SFM) imaging for nanoscale studies of polarization reversal and retention loss in Pb(Zr{sub x}Ti{sub 1{minus}x})O{sub 3} (PZT)-based capacitors. Another powerful technique suitable for in situ, real-time characterization of film growth processes and ferroelectric film-based device operation is based on synchrotrons X-ray scattering, which is currently being implemented at Argonne National Laboratory.

  18. Determination of optical properties of PLZT thin films using transmittance spectra processing

    NASA Astrophysics Data System (ADS)

    Pencheva, Tamara G.; Nenkov, Milen; Jelinek, Miroslav; Lancok, Jan; Bulir, Jiri; Deineka, Alexandr; Xu, Chao-Nan

    2002-08-01

    This investigation deals with determination of optical parameters of thin PLZT films prepared by pulsed laser deposition on fused silica substrates at different oxygen pressure. Film composition and structure are investigated by WDX and XRD. Defects concentration in the films is studied using triboluminescence. Changes of film refractive index n((lambda) ), extinction k((lambda) ) with wavelength in the spectral region 0.3 - 1.1 micrometers and film thickness d are determined as a result of transmittance spectra processing. Waveguiding properties of the films are investigated.

  19. Plasma-based ion implantation: a valuable technology for the elaboration of innovative materials and nanostructured thin films

    NASA Astrophysics Data System (ADS)

    Vempaire, D.; Pelletier, J.; Lacoste, A.; Béchu, S.; Sirou, J.; Miraglia, S.; Fruchart, D.

    2005-05-01

    Plasma-based ion implantation (PBII), invented in 1987, can now be considered as a mature technology for thin film modification. After a brief recapitulation of the principle and physics of PBII, its advantages and disadvantages, as compared to conventional ion beam implantation, are listed and discussed. The elaboration of thin films and the modification of their functional properties by PBII have already been achieved in many fields, such as microelectronics (plasma doping/PLAD), biomaterials (surgical implants, bio- and blood-compatible materials), plastics (grafting, surface adhesion) and metallurgy (hard coatings, tribology), to name a few. The major advantages of PBII processing lie, on the one hand, in its flexibility in terms of ion implantation energy (from 0 to 100 keV) and operating conditions (plasma density, collisional or non-collisional ion sheath), and, on the other hand, in the easy transferrability of processes from the laboratory to industry. The possibility of modifying the composition and physical nature of the films, or of drastically changing their physical properties over several orders of magnitude makes this technology very attractive for the elaboration of innovative materials, including metastable materials, and the realization of micro- or nanostructures. A review of the state of the art in these domains is presented and illustrated through a few selected examples. The perspectives opened up by PBII processing, as well as its limitations, are discussed.

  20. Evaluation of Cadmium-Free Thick Film Materials on Alumina Substrates

    SciTech Connect

    L. H. Perdieu

    2009-09-01

    A new cadmium-free material system was successfully evaluated for the fabrication of thick film hybrid microcircuits at Honeywell Federal Manufacturing & Technologies (FM&T). The characterization involved screen printing, drying and firing two groups of resistor networks which were made using the current material system and the cadmium-free material system. Electrical, environmental and adhesion tests were performed on both groups to determine the more suitable material system. Additionally, untrimmed test coupons were evaluated to further characterize the new materials. The cadmiumfree material system did as well or better than the current material system. Therefore, the new cadmium-free material system was approved for use on production thick film product.

  1. Chemical Fabrication Used to Produce Thin-Film Materials for High Power-to- Weight-Ratio Space Photovoltaic Arrays

    NASA Technical Reports Server (NTRS)

    Hepp, Aloysius F.; Rybicki, George C.; Raffaelle, Ryne P.; Harris, Jerry D.; Hehemann, David G.; Junek, William; Gorse, Joseph; Thompson, Tracy L.; Hollingsworth, Jennifer A.; Buhro, William E.

    2000-01-01

    The key to achieving high specific power (watts per kilogram) space solar arrays is the development of a high-efficiency, thin-film solar cell that can be fabricated directly on a flexible, lightweight, space-qualified durable substrate such as Kapton (DuPont) or other polyimide or suitable polymer film. Cell efficiencies approaching 20 percent at AM0 (air mass zero) are required. Current thin-film cell fabrication approaches are limited by either (1) the ultimate efficiency that can be achieved with the device material and structure or (2) the requirement for high-temperature deposition processes that are incompatible with all presently known flexible polyimide or other polymer substrate materials. Cell fabrication processes must be developed that will produce high-efficiency cells at temperatures below 400 degrees Celsius, and preferably below 300 degress Celsius to minimize the problems associated with the difference between the coefficients of thermal expansion of the substrate and thin-film solar cell and/or the decomposition of the substrate.

  2. Hydrogenation process for solid carbonaceous materials

    DOEpatents

    Cox, John L.; Wilcox, Wayne A.

    1979-01-01

    Coal or other solid carbonaceous material is contacted with an organic solvent containing both hydrogen and a transition metal catalyst in solution to hydrogenate unsaturated bonds within the carbonaceous material. This benefaction step permits subsequent pyrolysis or hydrogenolysis of the carbonaceous fuel to form gaseous and liquid hydrocarbon products of increased yield and quality.

  3. Biodegradation of PVP-CMC hydrogel film: a useful food packaging material.

    PubMed

    Roy, Niladri; Saha, Nabanita; Kitano, Takeshi; Saha, Petr

    2012-06-20

    Hydrogels can offer new opportunities for the design of efficient packaging materials with desirable properties (i.e. durability, biodegradability and mechanical strength). It is a promising and emerging concept, as most of the biopolymer based hydrogels are supposed to be biodegradable, they can be considered as alternative eco-friendly packaging materials. This article reports about synthetic (polyvinylpyrrolidone (PVP)) and biopolymer (carboxymethyl cellulose (CMC)) based a novel hydrogel film and its nature of biodegradability under controlled environmental condition. The dry hydrogel films were prepared by solution casting method and designated as 'PVP-CMC hydrogel films'. The hydrogel film containing PVP and CMC in a ratio of 20:80 shows best mechanical properties among all the test samples (i.e. 10:90, 20:80, 50:50, 80:20 and 90:10). Thus, PVP-CMC hydrogel film of 20:80 was considered as a useful food packaging material and further experiments were carried out with this particular hydrogel film. Biodegradation of the PVP-CMC hydrogel films were studied in liquid state (Czapec-Dox liquid medium+soil extracts) until 8 weeks. Variation in mechanical, viscoelastic properties and weight loss of the hydrogel films with time provide the direct evidence of biodegradation of the hydrogels. About 38% weight loss was observed within 8 weeks. FTIR spectra of the hydrogel films (before and after biodegradation) show shifts of the peaks and also change in the peak intensities, which refer to the physico-chemical change in the hydrogel structure and SEM views of the hydrogels show how internal structure of the PVP-CMC film changes in the course of biodegradation. PMID:24750729

  4. Process for producing Ti-Cr-Al-O thin film resistors

    DOEpatents

    Jankowski, Alan F.; Schmid, Anthony P.

    2001-01-01

    Thin films of Ti-Cr-Al-O are used as a resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O.sub.2. Resistivity values from 10.sup.4 to 10.sup.10 Ohm-cm have been measured for Ti-Cr-Al-O film <1 .mu.m thick. The film resistivity can be discretely selected through control of the target composition and the deposition parameters. The application of Ti-Cr-Al-O as a thin film resistor has been found to be thermodynamically stable, unlike other metal-oxide films. The Ti-Cr-Al-O film can be used as a vertical or lateral resistor, for example, as a layer beneath a field emission cathode in a flat panel display; or used to control surface emissivity, for example, as a coating on an insulating material such as vertical wall supports in flat panel displays.

  5. DETERMINATION OF LIQUID FILM THICKNESS FOLLOWING DRAINING OF CONTACTORS, VESSELS, AND PIPES IN THE MCU PROCESS

    SciTech Connect

    Poirier, M; Fernando Fondeur, F; Samuel Fink, S

    2006-06-06

    The Department of Energy (DOE) identified the caustic side solvent extraction (CSSX) process as the preferred technology to remove cesium from radioactive waste solutions at the Savannah River Site (SRS). As a result, Washington Savannah River Company (WSRC) began designing and building a Modular CSSX Unit (MCU) in the SRS tank farm to process liquid waste for an interim period until the Salt Waste Processing Facility (SWPF) begins operations. Both the solvent and the strip effluent streams could contain high concentrations of cesium which must be removed from the contactors, process tanks, and piping prior to performing contactor maintenance. When these vessels are drained, thin films or drops will remain on the equipment walls. Following draining, the vessels will be flushed with water and drained to remove the flush water. The draining reduces the cesium concentration in the vessels by reducing the volume of cesium-containing material. The flushing, and subsequent draining, reduces the cesium in the vessels by diluting the cesium that remains in the film or drops on the vessel walls. MCU personnel requested that Savannah River National Laboratory (SRNL) researchers conduct a literature search to identify models to calculate the thickness of the liquid films remaining in the contactors, process tanks, and piping following draining of salt solution, solvent, and strip solution. The conclusions from this work are: (1) The predicted film thickness of the strip effluent is 0.010 mm on vertical walls, 0.57 mm on horizontal walls and 0.081 mm in horizontal pipes. (2) The predicted film thickness of the salt solution is 0.015 mm on vertical walls, 0.74 mm on horizontal walls, and 0.106 mm in horizontal pipes. (3) The predicted film thickness of the solvent is 0.022 mm on vertical walls, 0.91 mm on horizontal walls, and 0.13 mm in horizontal pipes. (4) The calculated film volume following draining is: (a) Salt solution receipt tank--1.6 gallons; (b) Salt solution feed

  6. Optimization study of the femtosecond laser-induced forward-transfer process with thin aluminum films

    NASA Astrophysics Data System (ADS)

    Bera, Sudipta; Sabbah, A. J.; Yarbrough, J. M.; Allen, C. G.; Winters, Beau; Durfee, Charles G.; Squier, Jeff A.

    2007-07-01

    The parameters for an effective laser-induced forward-transfer (LIFT) process of aluminum thin films using a femtosecond laser are studied. Deposited feature size as a function of laser fluence, donor film thickness, quality of focus, and the pulse duration are varied, providing a metric of the most desirable conditions for femtosecond LIFT with thin aluminum films.

  7. Study on the effect of process conditions on the thermo-optic coefficient of amorphous silicon films

    NASA Astrophysics Data System (ADS)

    Zhou, Xiang; Liu, Shuang; Tang, Haihua; Zhong, Zhiyong; Liu, Yong

    2016-05-01

    A thermo-optical coefficient (TOC) test platform based on FILMeasure-20 was designed and the thermal coefficient of hydrogenated amorphous silicon (a-Si:H) thin films material at 1330 nm was tested. a-Si:H were deposited on the quartz glass using a plasma-enhanced chemical vapor deposition (PECVD) system. Fourier transform infrared spectrometer (FTIR) was used to characterize the infrared spectral feature of films. The hydrogen content of films was influenced by different radio frequency (RF) power and deposition pressure conditions according to the FTIR spectra and theoretical analysis, and the thermo-optic effect of a-Si:H varied with temperature characteristics. Experimental results indicated that selecting the appropriate process conditions to prepare a-Si:H films can effectively increase or avoid the impact of thermo-optical effect on the optical devices.

  8. Process for levelling film surfaces and products thereof

    DOEpatents

    Birkmire, Robert W.; McCandless, Brian E.

    1990-03-20

    Semiconductor films and photovoltaic devices prepared therefrom are provided wherein the semiconductor films have a specular surface with a texture less than about 0.25 micron greater than the average planar film surface and wherein the semiconductor films are surface modified by exposing the surface to an aqueous solution of bromine containing an acid or salt and continuing such exposure for a time sufficient to etch the surface.

  9. Process for leveling film surfaces and products thereof

    DOEpatents

    Birkmire, R.W.; McCandless, B.E.

    1990-03-20

    Semiconductor films and photovoltaic devices prepared therefrom are provided wherein the semiconductor films have a specular surface with a texture less than about 0.25 micron greater than the average planar film surface and wherein the semiconductor films are surface modified by exposing the surface to an aqueous solution of bromine containing an acid or salt and continuing such exposure for a time sufficient to etch the surface. 8 figs.

  10. Chemically deposited thin films of sulfides and selenides of antimony and bismuth as solar energy materials

    NASA Astrophysics Data System (ADS)

    Nair, M. T.; Nair, Padmanabhan K.; Garcia, V. M.; Pena, Y.; Arenas, O. L.; Garcia, J. C.; Gomez-Daza, O.

    1997-10-01

    Chemical bath deposition techniques for bismuth sulfide, bismuth selenide, antimony sulfide, and antimony selenide thin films of about 0.20 - 0.25 micrometer thickness are reported. All these materials may be considered as solar absorber films: strong optical absorption edges, with absorption coefficient, (alpha) , greater than 104 cm-1, are located at 1.31 eV for Bi2Se3, 1.33 eV for Bi2S3, 1.8 eV for Sb2S3, and 1.35 eV for Sb2Se3. As deposited, all the films are nearly amorphous. However, well defined crystalline peaks matching bismuthinite (JCPDS 17- 0320), paraguanajuatite (JCPDS 33-0214), and stibnite (JCPDS 6-0474) and antimony selenide (JCPDS 15-0861) for Bi2S3, Bi2Se3, Sb2S3 and Sb2Se3 respectively, are observed when the films are annealed in nitrogen at 300 degrees Celsius. This is accompanied by a substantial modification of the electrical conductivity in the films: from 10-7 (Omega) -1 cm-1 (in as prepared films) to 10 (Omega) -1 cm-1 in the case of bismuth sulfide and selenide films, and enhancement of photosensitivity in the case of antimony sulfide films. The chemical deposition of a CuS/CuxSe film on these Vx- VIy films and subsequent annealing at 300 degrees Celsius for 1 h at 1 torr of nitrogen leads to the formation of p-type films (conductivity of 1 - 100 (Omega) -1 cm-1) of multinary composition. Among these, the formation of Cu3BiS3 (JCPDS 9-0488) and Cu3SbS4 (JCPDS 35- 0581), CuSbS2 (JCPDS 35-0413) have been clearly detected. Solar energy applications of these films are suggested.

  11. Characterization of carbon nitride films deposited by hollow cathode discharge process

    NASA Astrophysics Data System (ADS)

    Balaceanu, M.; Grigore, E.; Truica-Marasescu, F.; Pantelica, D.; Negoita, F.; Pavelescu, G.; Ionescu, F.

    2000-03-01

    Elastic recoil detection analysis (ERDA) has been applied to determine the composition of carbon nitride and hydrogenated carbon nitride films prepared by hollow cathode discharge process. The films were deposited on Si (1 1 1) substrates. The films were also characterized by Fourier transform infrared spectroscopy (FTIR). The influence of the main deposition parameters (substrate bias voltage, nitrogen injection mode) on the film properties was investigated.

  12. Enhancing performing characteristics of organic semiconducting films by improved solution processing

    SciTech Connect

    Bazan, Guillermo C; Moses, Daniel; Peet, Jeffrey; Heeger, Alan J

    2014-05-13

    Improved processing methods for enhanced properties of conjugated polymer films are disclosed, as well as the enhanced conjugated polymer films produced thereby. Addition of low molecular weight alkyl-containing molecules to solutions used to form conjugated polymer films leads to improved photoconductivity and improvements in other electronic properties. The enhanced conjugated polymer films can be used in a variety of electronic devices, such as solar cells and photodiodes.

  13. Enhancing performance characteristics of organic semiconducting films by improved solution processing

    DOEpatents

    Bazan, Guillermo C.; Heeger, Alan J.; Moses, Daniel; Peet, Jeffrey

    2013-09-25

    Improved processing methods for enhanced properties of conjugated polymer films are disclosed, as well as the enhanced conjugated polymer films produced thereby. Addition of low molecular weight alkyl-containing molecules to solutions used to form conjugated polymer films leads to improved photoconductivity and improvements in other electronic properties. The enhanced conjugated polymer films can be used in a variety of electronic devices, such as solar cells and photodiodes.

  14. Enhancing performance characteristics of organic semiconducting films by improved solution processing

    DOEpatents

    Bazan, Guillermo C; Mikhailovsky, Alexander; Moses, Daniel; Nguyen, Thuc-Quyen; Peet, Jeffrey; Soci, Cesare

    2012-11-27

    Improved processing methods for enhanced properties of conjugated polymer films are disclosed, as well as the enhanced conjugated polymer films produced thereby. Addition of low molecular weight alkyl-containing molecules to solutions used to form conjugated polymer films leads to improved photoconductivity and improvements in other electronic properties. The enhanced conjugated polymer films can be used in a variety of electronic devices, such as solar cells and photodiodes.

  15. Femtosecond laser processing of photovoltaic and transparent materials

    NASA Astrophysics Data System (ADS)

    Ahn, Sanghoon

    The photovoltaic semiconducting and transparent dielectric materials are of high interest in current industry. Femtosecond laser processing can be an effective technique to fabricate such materials since non-linear photochemical mechanisms predominantly occur. In this series of studies, femtosecond (fs) laser processing techniques that include laser drilling on Si wafer, laser scribing on CIGS thin film, laser ablation on Lithium Niobate (LN) crystal, and fabrication of 3D structures in fused silica were studied. The fs laser drilling on Si wafer was performed to fabricate via holes for wrap-through PV devices. For reduction of the number of shots in fs laser drilling process, self-action of laser light in the air was initiated. To understand physical phenomena during laser drilling, scanning electron microscopy (SEM), emission, and shadowgraph images were studied. The result indicated the presence of two mechanisms that include fabrication by self-guided beam and wall-guided beam. Based on our study, we could fabricate ~16 micrometer circular-shaped via holes with ~200 laser pulses on 160-170 micrometer thick c- and mc-Si wafer. For the fs laser scribing on ink jet printed CIGS thin film solar cell, the effect of various parameters that include pulse accumulation, wavelength, pulse energy, and overlapping were elucidated. In our processing regime, the effect of wavelength could be diminished due to compensation between beam size, pulse accumulation, energy fluence, and the absorption coefficient. On the other hand, for high PRF fs laser processing, pulse accumulation effect cannot be ignored, while it can be negligible in low PRF fs laser processing. The result indicated the presence of a critical energy fluence for initiating delamination of CIGS layer. To avoid delamination and fabricate fine isolation lines, the overlapping method can be applied. With this method, ~1 micrometer width isolation lines were fabricated. The fs laser ablation on LN wafer was studied

  16. Study of materials for space processing

    NASA Technical Reports Server (NTRS)

    Lal, R. B.

    1975-01-01

    Materials were selected for device applications and their commercial use. Experimental arrangements were also made for electrical characterization of single crystals using electrical resistivity and Hall effect measurements. The experimental set-up was tested with some standard samples.

  17. Consideration of the condensation processes of thin films in the crystal substrate's potential field

    NASA Astrophysics Data System (ADS)

    Tupik, V. A.; Margolin, V. I.; Trong Su, Chu

    2016-07-01

    The condensation process of a single particle in an ideal crystal substrate's potential field is considered. The optimal deposition path and the potential barrier of deposited particle's motion are shown. Some computer modeling examples of thin film's growth process were carried out on the basis of the implemented programs. A fractal analysis of obtained thin films was made, on the basis of which the possibility of estimating the performance of thin film's growth process will be discussed.

  18. Effect of different film packaging on microbial growth in minimally processed cactus pear (Opuntia ficus-indica).

    PubMed

    Palma, A; Mangia, N P; Fadda, A; Barberis, A; Schirra, M; D'Aquino, S

    2013-01-01

    Microorganisms are natural contaminants of fresh produce and minimally processed products, and contamination arises from a number of sources, including the environment, postharvest handling and processing. Fresh-cut products are particularly susceptible to microbial contaminations because of the changes occurring in the tissues during processing. In package gas composition of modified atmosphere packaging (MAP) in combination with low storage temperatures besides reducing physiological activity of packaged produce, can also delay pathogen growth. Present study investigated on the effect of MAPs, achieved with different plastic films, on microbial growth of minimally processed cactus pear (Opuntio ficus-indica) fruit. Five different plastic materials were used for packaging the manually peeled fruit. That is: a) polypropylene film (Termoplast MY 40 micron thickness, O2 transmission rate 300 cc/m2/24h); b) polyethylene film (Bolphane BHE, 11 micron thickness, O2 transmission rate 19000 cc/m2/24h); c) polypropylene laser-perforated films (Mach Packaging) with 8, 16 or 32 100-micron holes. Total aerobic psychrophilic, mesophilic microorganisms, Enterobacteriaceae, yeast, mould populations and in-package CO2, O2 and C2H4 were determined at each storage time. Different final gas compositions, ranging from 7.8 KPa to 17.1 KPa O2, and 12.7 KPa to 2.6 KPa CO2, were achieved with MY and micro perforated films, respectively. Differences were detected in the mesophilic, Enterobacteriaceae and yeast loads, while no difference was detected in psychrophilic microorganisms. At the end of storage, microbial load in fruits sealed with MY film was significantly lower than in those sealed with BHE and micro perforated films. Furthermore, fruits packed with micro-perforated films showed the highest microbial load. This occurrence may in part be related to in-package gas composition and in part to a continuous contamination of microorganisms through micro-holes. PMID:25145227

  19. Surface chemistry relevant to material processing for semiconductor devices

    NASA Astrophysics Data System (ADS)

    Okada, Lynne Aiko

    Metal-oxide-semiconductor (MOS) structures are the core of many modern integrated circuit (IC) devices. Each material utilized in the different regions of the device has its own unique chemistry. Silicon is the base semiconductor material used in the majority of these devices. With IC device complexity increasing and device dimensions decreasing, understanding material interactions and processing becomes increasingly critical. Hsb2 desorption is the rate-limiting step in silicon growth using silane under low temperature conditions. Activation energies for Hsb2 desorption measured during Si chemical vapor deposition (CVD) versus single-crystal studies are found to be significantly lower. It has been proposed that defect sites on the silicon surface could explain the observed differences. Isothermal Hsb2 desorption studies using laser induced thermal desorption (LITD) techniques have addressed this issue. The growth of low temperature oxides is another relevant issue for fabrication of IC devices. Recent studies using 1,4-disilabutane (DSB) (SiHsb3CHsb2CHsb2SiHsb3) at 100sp°C in ambient Osb2 displayed the successful low temperature growth of silicon dioxide (SiOsb2). However, these studies provided no information about the deposition mechanism. We performed LITD and Fourier transform infrared (FTIR) studies on single-crystal and porous silicon surfaces to examine the adsorption, decomposition, and desorption processes to determine the deposition mechanism. Titanium nitride (TiN) diffusion barriers are necessary in modern metallization structures. Controlled deposition using titanium tetrachloride (TiClsb4) and ammonia (NHsb3) has been demonstrated using atomic layered processing (ALP) techniques. We intended to study the sequential deposition method by monitoring the surface intermediates using LITD techniques. However, formation of a Cl impurity source, ammonium chloride (NHsb4sp+Clsp-), was observed, thereby, limiting our ability for effective studies. Tetrakis

  20. Graphene films with large domain size by a two-step chemical vapor deposition process.

    PubMed

    Li, Xuesong; Magnuson, Carl W; Venugopal, Archana; An, Jinho; Suk, Ji Won; Han, Boyang; Borysiak, Mark; Cai, Weiwei; Velamakanni, Aruna; Zhu, Yanwu; Fu, Lianfeng; Vogel, Eric M; Voelkl, Edgar; Colombo, Luigi; Ruoff, Rodney S

    2010-11-10

    The fundamental properties of graphene are making it an attractive material for a wide variety of applications. Various techniques have been developed to produce graphene and recently we discovered the synthesis of large area graphene by chemical vapor deposition (CVD) of methane on Cu foils. We also showed that graphene growth on Cu is a surface-mediated process and the films were polycrystalline with domains having an area of tens of square micrometers. In this paper, we report on the effect of growth parameters such as temperature, and methane flow rate and partial pressure on the growth rate, domain size, and surface coverage of graphene as determined by Raman spectroscopy, and transmission and scanning electron microscopy. On the basis of the results, we developed a two-step CVD process to synthesize graphene films with domains having an area of hundreds of square micrometers. Scanning electron microscopy and Raman spectroscopy clearly show an increase in domain size by changing the growth parameters. Transmission electron microscopy further shows that the domains are crystallographically rotated with respect to each other with a range of angles from about 13 to nearly 30°. Electrical transport measurements performed on back-gated FETs show that overall films with larger domains tend to have higher carrier mobility up to about 16,000 cm(2) V(-1) s(-1) at room temperature. PMID:20957985