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Sample records for fluorine-doped yba2cu3oy films

  1. Influence of nano-particle diameter on superconducting properties in BaMO3(M = Sn, Hf)/YBa2Cu3Oy quasi-multilayered films

    NASA Astrophysics Data System (ADS)

    Kotaki, T.; Uraguchi, Y.; Makihara, T.; Suenaga, M.; Sueyoshi, T.; Fujiyoshi, T.; Mitugi, F.; Ikegami, T.

    2015-11-01

    In order to investigate the influence of diameter and spatial distribution of three-dimensional (3D) pinning centers on critical current density Jc, BMO (BaSnO3 (BSO) or BaHfO3 (BHO)) doped YBa2Cu3Oy (YBCO) thin films were fabricated by a quasi-multilayering process using a pulsed laser deposition method. The prepared films are referred as BMO(m,n)Ts, where m and n denotes the number of laser pulse on the BMO target and the total number of BMO/YBCO bilayers, respectively and Ts is the growth temperature. BSO(1,100)750 and BSO(1,100)770 show the improvement of Jc in comparison with the pure YBCO sample in wide range of magnetic field directions at 65 K. However, at 77.3 K, improvement of Jc was seen in only BSO(1,100)770. The BSO nano-particles within BSO(1,100)770 are considered to have larger diameter, so that BSO nano-particles can immobilize the flux lines in the high temperature region. In addition, BSO(1,100)770 shows the high peak of Jc centered at ? = 0 in the angular dependence of Jc. On the other hand, the Jc of BHO(1,100)770 falls below that of pure YBCO samples in all magnetic field orientation. In addition, at 65 K, there is no peak of Jc at any angles except for ? = 90. These results indicates that the diameter of BHO nano-particles in BHO(1,100)770 might be much smaller than that of BSO nano-particle and BHO nanoparticles cannot work as effective pinning center.

  2. Ferromagnetic transition of SrRuO3 in nanometer thick bilayers with YBa2Cu3Oy , La1.88Sr0.12CuO4-y , Au, and Cr: Signature of injected carriers in the pseudogap regime

    NASA Astrophysics Data System (ADS)

    Aharonovich, G.; Koren, G.; Polturak, E.

    2007-12-01

    The hypothesis regarding the existence of uncorrelated preformed pairs in the pseudogap regime of superconducting YBa2Cu3Oy is tested experimentally using bilayers of YBa2Cu3Oy and the itinerant ferromagnet SrRuO3 . In our study, we monitor the influence of YBa2Cu3Oy on Tp , the ferromagnetic ordering temperature of SrRuO3 . Here, Tp is the temperature of maximum dM/dT or dR/dT , where M and R are the magnetization and resistance of SrRuO3 , respectively. We compare the results with similar measurements carried out on bilayers of La1.88Sr0.12CuO4-y , Au, and Cr with SrRuO3 . We find that in bilayers made of underdoped 10nm YBa2Cu3Oy/5nm SrRuO3 , the Tp values are shifted to lower temperatures by up to 6 8K as compared to Tp?140K of the 5nm thick reference SrRuO3 film. In contrast, in the other type of bilayers, which are not in the pseudogap regime near Tp , only a smaller shift of up to 2K is observed. These differences are discussed in terms of a proximity effect, where carriers from the YBa2Cu3Oy layer are injected into the SrRuO3 layer and vice versa. We suggest that correlated electrons in the pseudogap regime of YBa2Cu3Oy are responsible for the observed large Tp shifts.

  3. Magnetoresistivity and microstructure of YBa2Cu3Oy prepared using planetary ball milling

    NASA Astrophysics Data System (ADS)

    Hamrita, A.; Ben Azzouz, F.; Madani, A.; Ben Salem, M.

    2012-01-01

    We have studied the microstructure and the magnetoresistivity of polycrystalline YBa2Cu3Oy (YBCO or Y-123 for brevity) embedded with nanoparticles of Y-deficient YBCO, generated by the planetary ball milling technique. Bulk samples were synthesized from a precursor YBCO powder, which was prepared from commercial high purity Y2O3, Ba2CO3 and CuO via a one-step annealing process in air at 950 C. After planetary ball milling of the precursor, the powder was uniaxially pressed and subsequently annealed at 950 C in air. Phase analysis by X-ray diffraction (XRD), granular structure examination by scanning electron microscopy (SEM), microstructure investigation by transmission electron microscopy (TEM) coupled with energy dispersive X-ray spectroscopy (EDXS) were carried out. TEM analyses show that nanoparticles of Y-deficient YBCO, generated by ball milling, are embedded in the superconducting matrix. Electrical resistance as a function of temperature, ?(T), revealed that the zero resistance temperature, Tco, is 84.5 and 90 K for the milled and unmilled samples respectively. The milled ceramics exhibit a large magnetoresistance in weak magnetic fields at liquid nitrogen temperature. This attractive effect is of high significance as it makes these materials promising candidates for practical application in magnetic field sensor devices.

  4. Magnetization of underdoped YBa2Cu3Oy above the irreversibility field

    NASA Astrophysics Data System (ADS)

    Yu, Jing Fei; Ramshaw, B. J.; Kokanovi?, I.; Modic, K. A.; Harrison, N.; Day, James; Liang, Ruixing; Hardy, W. N.; Bonn, D. A.; McCollam, A.; Julian, S. R.; Cooper, J. R.

    2015-11-01

    Torque magnetization measurements on YBa2Cu3Oy (YBCO) at doping y =6.67 (p =0.12 ), in dc fields (B ) up to 33 T and temperatures down to 4.5 K, show that weak diamagnetism persists above the extrapolated irreversibility field Hirr(T =0 ) ?24 T. The differential susceptibility d M /d B , however, is more rapidly suppressed for B ?16 T than expected from the properties of the low field superconducting state, and saturates at a low value for fields B ?24 T. In addition, torque measurements on a p =0.11 YBCO crystal in pulsed field up to 65 T and temperatures down to 8 K show similar behavior, with no additional features at higher fields. We offer two candidate scenarios to explain these observations: (a) superconductivity survives but is heavily suppressed at high field by competition with charge-density-wave (CDW) order; (b) static superconductivity disappears near 24 T and is followed by a region of fluctuating superconductivity, which causes d M /d B to saturate at high field. The diamagnetic signal observed above 50 T for the p =0.11 crystal at 40 K and below may be caused by changes in the normal state susceptibility rather than bulk or fluctuating superconductivity. There will be orbital (Landau) diamagnetism from electron pockets and possibly a reduction in spin susceptibility caused by the stronger three-dimensional ordered CDW.

  5. Incipient charge order observed by NMR in the normal state of YBa2Cu3Oy

    PubMed Central

    Wu, Tao; Mayaffre, Hadrien; Krmer, Steffen; Horvati?, Mladen; Berthier, Claude; Hardy, W.N.; Liang, Ruixing; Bonn, D.A.; Julien, Marc-Henri

    2015-01-01

    The pseudogap regime of high-temperature cuprates harbours diverse manifestations of electronic ordering whose exact nature and universality remain debated. Here, we show that the short-ranged charge order recently reported in the normal state of YBa2Cu3Oy corresponds to a truly static modulation of the charge density. We also show that this modulation impacts on most electronic properties, that it appears jointly with intra-unit-cell nematic, but not magnetic, order, and that it exhibits differences with the charge density wave observed at lower temperatures in high magnetic fields. These observations prove mostly universal, they place new constraints on the origin of the charge density wave and they reveal that the charge modulation is pinned by native defects. Similarities with results in layered metals such as NbSe2, in which defects nucleate halos of incipient charge density wave at temperatures above the ordering transition, raise the possibility that orderparameter fluctuations, but no static order, would be observed in the normal state of most cuprates if disorder were absent. PMID:25751448

  6. Effect of processing parameters on the characteristics of high-Tc superconductor YBa2Cu3Oy

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.

    1988-01-01

    SEM, thermogravimetric analysis, powder X-ray diffraction,and measurements of electrical resistivity and magnetic susceptibility, are presently used to characterize the influence of sintering temperature, sintering and annealing atmospheres, and quench-rate on the properties of the YBa2Cu3Oy superconducting oxide. It is established that annealing in oxygen, together with slow cooling rates, are required for preparation of high-Tc superconductors with sharp transitions; rapid quenching from high temperature does not yield good superconductors, due to low oxygen content.

  7. Evidence for a small hole pocket in the Fermi surface of underdoped YBa2Cu3Oy

    PubMed Central

    Doiron-Leyraud, N.; Badoux, S.; Ren de Cotret, S.; Lepault, S.; LeBoeuf, D.; Lalibert, F.; Hassinger, E.; Ramshaw, B. J.; Bonn, D. A.; Hardy, W. N.; Liang, R.; Park, J.-H..; Vignolles, D.; Vignolle, B.; Taillefer, L.; Proust, C.

    2015-01-01

    In underdoped cuprate superconductors, the Fermi surface undergoes a reconstruction that produces a small electron pocket, but whether there is another, as yet, undetected portion to the Fermi surface is unknown. Establishing the complete topology of the Fermi surface is key to identifying the mechanism responsible for its reconstruction. Here we report evidence for a second Fermi pocket in underdoped YBa2Cu3Oy, detected as a small quantum oscillation frequency in the thermoelectric response and in the c-axis resistance. The field-angle dependence of the frequency shows that it is a distinct Fermi surface, and the normal-state thermopower requires it to be a hole pocket. A Fermi surface consisting of one electron pocket and two hole pockets with the measured areas and masses is consistent with a Fermi-surface reconstruction by the chargedensitywave order observed in YBa2Cu3Oy, provided other parts of the reconstructed Fermi surface are removed by a separate mechanism, possibly the pseudogap. PMID:25616011

  8. Two types of nematicity in the phase diagram of the cuprate superconductor YBa2Cu3Oy

    NASA Astrophysics Data System (ADS)

    Cyr-Choinire, O.; Grissonnanche, G.; Badoux, S.; Day, J.; Bonn, D. A.; Hardy, W. N.; Liang, R.; Doiron-Leyraud, N.; Taillefer, Louis

    2015-12-01

    Nematicity has emerged as a key feature of cuprate superconductors, but its link to other fundamental properties such as superconductivity, charge order, and the pseudogap remains unclear. Here we use measurements of transport anisotropy in YBa2Cu3Oy to distinguish two types of nematicity. The first is associated with short-range charge-density-wave modulations in a doping region near p =0.12 . It is detected in the Nernst coefficient, but not in the resistivity. The second type prevails at lower doping, where there are spin modulations but no charge modulations. In this case, the onset of in-plane anisotropydetected in both the Nernst coefficient and the resistivityfollows a line in the temperature-doping phase diagram that tracks the pseudogap energy. We discuss two possible scenarios for the latter nematicity.

  9. Effect of growth temperature on superconducting properties of YBa2Cu3Oy bulk superconductors grown by seeded infiltration

    NASA Astrophysics Data System (ADS)

    Nakazato, K.; Muralidhar, M.; Koshizuka, N.; Inoue, K.; Murakami, M.

    2014-09-01

    We investigated the effect of growth temperature on the characteristics of YBa2Cu3Oy (Y-123) bulk superconductor prepared by seeded infiltration process. Homemade Y2BaCuO5 Y-211 particles and liquid phase of Ba3Cu5O8 were used to produce Y-123 bulks in air such that the liquid phase infiltrates into a Y-211 block. Y-123 samples of 20 mm diameter and 8 mm thickness were produced at different growth temperatures, i.e., 990, 985, 983, 980 and 978 C with the same holding time of 25 h. We found that single grain growth without multi-nucleation occurred at 980 C. Further, magnetization measurements indicated a sharp superconducting transition with Tc (onset) around 93.2 K. Trapped field measurements showed that the samples are single domain, and the sample 27 mm in diameter and 5 mm in thickness showed the maximum trapped field of around 0.45 T on the sample surface at 77 K. The critical current density (Jc) at 77 K and zero field was determined to be 175 kA/cm2, which is the highest value ever reported in the literature.

  10. The preparation of fluorine doped cadmium oxide thin film by sol-gel process.

    PubMed

    Kim, In Yea; Kim, Jong Sung

    2014-11-01

    During the several decades, CdO thin film has attracted many attentions as a candidate for the transparent conducting electrodes due to its high electrical conductivity and high optical transmittance. Various dopants such as F, In, Al, Sn, and Cr have been used to improve the optical and electrical properties of the film. Generally, the optical and electrical property of the thin film is dependent on its oxidation state, the amount of dopant materials, and the fabrication process. In this study, fluorine doped CdO thin films were prepared by using sol-gel process with various atomic ratios of Cd:F, and their electrical and optical properties were investigated. The precursor solution for sol-gel film was prepared with pH 5 and pH 8, and the film was annealed at 350 degrees C. X-ray diffraction pattern confirmed the cubic CdO:F phase formation, and the 10% fluorine doped film prepared with pH 8 precursor solution showed the lowest resistivity of 0.01574 Ω cm. PMID:25958514

  11. Fast Responsive Gas Sensor of Vertically Aligned Fluorine-Doped Tin Oxide Nanorod Thin Film

    NASA Astrophysics Data System (ADS)

    Cho, Chan-Woo; Lee, Jong-Heun; Riu, Doh-Hyung; Kim, Chang-Yeoul

    2012-04-01

    We prepared fluorine-doped tin oxide (FTO) nanorod films and a conventional FTO thin film for the application of a semiconducting gas sensor by spray pyrolysis method. The lengths of FTO nanorods (FTON, 100 and 500 nm) were controlled by changing deposition times, and FTO thin film (FTOT) was also prepared as a reference. The gas sensitivity test shows FTON with long nanorods had higher sensitivity for both hydrogen and ethanol gases but slow response and recovery times, despite an advantage of the higher gas sensitivity. FTO nanorod film with short length about 100 nm showed relatively lower sensitivity, but fast gas response and recovery characteristics. The fast response and recovery for the analyte gases are attributed to the conductance of FTO nanorods, which is closely related to the diameter and length of nanorods.

  12. Characteristic of Low Resistivity Fluorine-Doped SnO2 Thin Films Grown by Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Oshima, Minoru; Yoshino, Kenji

    2011-05-01

    Transparent conducting oxide films of fluorine-doped SnO2 (FTO) were deposited on glass substrates by spray pyrolysis in order to determine the effect of spray solution concentration. These films were prepared with different F-doping concentrations from 0 to 33 mol %. The films were all polycrystalline with tetragonal crystal structures. The best electro-optic properties were achieved with a fluorine doping concentration of 17 mol % at a substrate temperature of 500 °C. These conditions resulted in a film with an average transmittance of 82%, a resistivity of 4.0 ×10-4 Ω cm, a carrier concentration of 4.7 ×1020 cm-3 and a mobility of 34 cm2 V-1 s-1.

  13. Effect of solvent ratio on the optoelectronic properties of fluorine doped tin oxide thin films

    NASA Astrophysics Data System (ADS)

    Karthick, P.; Divya, V.; Sridharan, M.; Jeyadheepan, K.

    2015-06-01

    Fluorine doped tin oxide (FTO) thin films were deposited on to the well cleaned microscopic glass substrates using nebulized-spray pyrolysis (n-SP) technique by varying the water to ethanol solvent proportion. The deposited thin films were characterized by X-ray diffraction (XRD), UV-Vis-NIR spectroscopy, field emission scanning electron microscopy and Hall measurements to study the structural, optical, surface morphological and electrical properties of the films, respectively. Results of the analyzes show that the films are polycrystalline, having tetragonal structure with the preferred orientation along (110) plane. The grain size varies between 7 to 20 nm. The optimized films exhibit the optical transparency of 85 % at the wavelength of 580 nm. The optical bandgap lies in the range of 3.94 to 4 eV. The optimized films, deposited with 40 % of ethanol proportion are having the mean resistivity 4.72×10-3 Ω-cm, carrier concentration 1.79×1020 cm3 and the mobility 7 cm2/Vs.

  14. Influence of Preferred Orientation on the Electrical Conductivity of Fluorine-Doped Tin Oxide Films

    PubMed Central

    Wang, Jian Tao; Shi, Xiang Lei; Liu, Wei Wei; Zhong, Xin Hua; Wang, Jian Nong; Pyrah, Leo; Sanderson, Kevin D.; Ramsey, Philip M.; Hirata, Masahiro; Tsuri, Keiko

    2014-01-01

    Current development of high-performance transparent conductive oxide (TCO) films is limited with tradeoff between carrier mobility and concentration since none of them can be improved without sacrificing the other. In this study, we prepare fluorine doped tin oxide (FTO) films by chemical vapor deposition with inclusions of different additives and report that the mobility can be varied from 0.65 to 28.5 cm2 V−1 s−1 without reducing the achieved high carrier concentration of 4 × 1020 cm−3. Such an increase in mobility is shown to be clearly associated with the development of (200) preferred orientation (PO) but concurrent degradation of (110) PO in films. Thus, at a constant high carrier concentration, the electrical conductivity can be improved via carrier mobility simply by PO control. Such a one-step approach avoiding conventional post-deposition treatment is suggested for developing next-generation FTO as well as other TCO films with better than ever conductivities. PMID:24419455

  15. Fluorine-doped zinc oxide thin films: influence of precursor flow rate on violet luminescence

    NASA Astrophysics Data System (ADS)

    Muthukumar, Anusha; Dakshnamoorthy, Arivuoli

    2015-06-01

    Fluorine-doped zinc oxide (FZO) thin films were deposited by the aerosol-assisted chemical vapor deposition method with variable precursor flow rates (0.5-2.5 ml/min). X-ray diffraction patterns revealed the polycrystalline hexagonal wurtzite structure of the derived FZO nanocrystalline thin films. Extensive crystallinity analysis of the film deposited at 1 ml/min was done by grazing incidence X-ray diffraction. Field emission scanning electron microscope images apparent the gradual evolution from spherical grains and hexagonal platelet like surface morphology with increased flow rate. Optical transparency and photoluminescence (PL) are strongly influenced by flow rate. PL intensity and transparency increase with decreased flow rate. The optical bandgap was tuned significantly by increase in flow rate and especially tuned the PL emission from violet to UV. High intense violet PL observed at flow rate of 1 ml/min and radiative transition of electrons from zinc vacancies level to the conduction band were found. Crystallinity, growth rate and roughness increase with increased flow rate.

  16. Electron scattering mechanisms in fluorine-doped SnO2 thin films

    NASA Astrophysics Data System (ADS)

    Rey, G.; Ternon, C.; Modreanu, M.; Mescot, X.; Consonni, V.; Bellet, D.

    2013-11-01

    Polycrystalline fluorine-doped SnO2 (FTO) thin films have been grown by ultrasonic spray pyrolysis on glass substrate. By varying growth conditions, several FTO specimens have been deposited and the study of their structural, electrical, and optical properties has been carried out. By systematically investigating the mobility as a function of carrier density, grain size, and crystallite size, the contribution of each physical mechanism involved in the electron scattering has been derived. A thorough comparison of experimental data and calculations allows to disentangle these different mechanisms and to deduce their relative importance. In particular, the roles of extended structural defects such as grain or twin boundaries as revealed by electron microscopy or x-ray diffraction along with ionized impurities are discussed. As a consequence, based on the quantitative analysis presented here, an experimental methodology leading to the improvement of the electro-optical properties of FTO thin films is reported. FTO thin films assuming an electrical resistivity as low as 3.7 . 10-4 Ω cm (square sheet resistance of 8 Ω/◻) while retaining good transmittance up to 86% (including substrate effect) in the visible range have been obtained.

  17. Electron scattering mechanisms in fluorine-doped SnO{sub 2} thin films

    SciTech Connect

    Rey, G. Consonni, V.; Bellet, D.; Ternon, C.; Mescot, X.

    2013-11-14

    Polycrystalline fluorine-doped SnO{sub 2} (FTO) thin films have been grown by ultrasonic spray pyrolysis on glass substrate. By varying growth conditions, several FTO specimens have been deposited and the study of their structural, electrical, and optical properties has been carried out. By systematically investigating the mobility as a function of carrier density, grain size, and crystallite size, the contribution of each physical mechanism involved in the electron scattering has been derived. A thorough comparison of experimental data and calculations allows to disentangle these different mechanisms and to deduce their relative importance. In particular, the roles of extended structural defects such as grain or twin boundaries as revealed by electron microscopy or x-ray diffraction along with ionized impurities are discussed. As a consequence, based on the quantitative analysis presented here, an experimental methodology leading to the improvement of the electro-optical properties of FTO thin films is reported. FTO thin films assuming an electrical resistivity as low as 3.7??10{sup ?4}???cm (square sheet resistance of 8??/?) while retaining good transmittance up to 86% (including substrate effect) in the visible range have been obtained.

  18. Enhanced violet photoemission of nanocrystalline fluorine doped zinc oxide (FZO) thin films

    NASA Astrophysics Data System (ADS)

    Anusha, Muthukumar; Arivuoli, D.; Manikandan, E.; Jayachandran, M.

    2015-09-01

    Highly stable fluorine doped nanocrystalline zinc oxide thin films were prepared on corning glass substrates by aerosol assisted chemical vapor deposition (AACVD) at variable deposition temperature of 360 °C, 380 °C and 420 °C. Especially, the optimum deposition temperature was investigated for high intense violet emission. The film crystallinity improved with the increasing deposition temperature and highly textured film was obtained at 420 °C. The films exhibited surface morphology variation from spherical to platelets due to deposition temperature effect, analyzed by field emission scanning electron microscope (FE-SEM). Higher growth rate observed at 420 °C which leads larger grains and lowest resistivity of ∼5.77 Ω cm among the deposited films which may be due to reduction in zinc vacancies and grain boundary area. Zinc vacancies are acts as electron killer centres. UV-visible spectra indicated higher transmittance (83-90%) in the visible region. Red shift of optical absorption edges associated with the increase in particle size consistent well with the XRD results. Reduced E2(high) intensity was observed in Raman spectra, for the film deposited at 380 °C which indicates decreased oxygen incorporation confirmed by PL spectra. Especially, enhanced violet emission observed at 3.06 eV for the films deposited at 380 °C due to electronic transition from the defect level of zinc vacancies to the conduction band, probably attributed to enhanced incorporation of 'F' into 'O' sites associated with increased Zn vacancies and also decreased oxygen incorporation consistent with the electrical and Raman analyses.

  19. Fluorine doped tin oxide film with high haze and transmittance prepared for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Otsuka, Rena; Endo, Takeshi; Takano, Takafumi; Takemura, Shuichiro; Murakami, Ryo; Muramoto, Ryosuke; Madarsz, Jnos; Okuya, Masayuki

    2015-08-01

    Fluorine doped tin oxide (FTO) transparent conductive oxide (TCO) film for dye-sensitized solar cell (DSSC) was investigated. Haze of the incident light through TCO film was easily tuned by controlling the surface morphology of FTO deposited on tin doped indium oxide (ITO) nano-particle seed layer pre-coated on a glass substrate, and the light harvest within the cell was effectively enhanced with high haze TCO film. The conversion efficiency of DSSC fabricated with TCO film with the haze of 30.1% reached as high as 7.7%, attributing to the consequence of the effective light harvest with the scattering within the cell.

  20. Temperature behavior of sound velocity of fluorine-doped vitreous silica thin films studied by picosecond ultrasonics

    NASA Astrophysics Data System (ADS)

    Nagakubo, A.; Ogi, H.; Ishida, H.; Hirao, M.; Yokoyama, T.; Nishihara, T.

    2015-07-01

    Vitreous silica (v-SiO2) shows anomalous temperature dependence of velocity, including positive temperature coefficient of velocity (TCV) and velocity minimum around 70 K. The former characteristic allows its application in acoustic-resonator devices as a temperature compensating material. In this paper, we study the temperature dependence of velocity of fluorine-doped v-SiO2 (v-SiO2-xFx) thin films using picosecond ultrasonic spectroscopy. To correct the temperature increase caused by irradiation with light pulses, we calculated the steady temperature increase in the measuring volume with a finite volume method, considering the temperature dependence of thermal conductivity, and find that temperature in the measurement region remains high even when the back surface is cryogenically cooled. Using the corrected temperature, we determine TCV of v-SiO2-xFx thin films for 0 < x < 0.264 , which increases as x increases and is smaller than reported bulk values by a factor of 0.5 - 0.7 . The velocity minimum is absent for the film with x = 0, but it is clearly observed at 70 K for the film with the highest fluorine concentration of x = 0.264. These temperature behaviors are attributed to the change in the Si-O-Si bond angle caused by the fluorine doping.

  1. Evolution des quasiparticules nodales du cuprate supraconducteur YBa2Cu3Oy en conductivite thermique

    NASA Astrophysics Data System (ADS)

    Rene de Cotret, Samuel

    Ce memoire presente des mesures de conductivite thermique sur les supraconducteurs YBCO et Tl-2201 afin de statuer sur la presence possible d'un point critique quantique (QCP) dans le diagramme de phase de cuprates. Ce point critique quantique serait a l'origine de la reconstruction de la surface de Fermi, d'un large cylindre de trous en de petites poches de trous et d'electrons. La conductivite thermique dans le regime T ? 0 permet d'extraire une quantite purement electronique liee aux vitesses de Fermi et du gap, au noeud. Une discontinuite dans cette quantite pourrait signaler la traversee du dopage critique qui reconstruit la surface de Fermi. Plusieurs sondes experimentales distinguent une transition de phase ou un crossover a T* a temperature finie. D'autres sondes mettent en evidence une transition de phase sous l'effet d'un champ magnetique. La presence ou non de cet ordre, a temperature et champ magnetique nul questionne la communaute depuis plusieurs annees. Dans cette etude, nous detectons une variation brusque de kappa0/T a p = 0.18 dans YBCO et a p = 0.20 dans Tl-2201. Ces sauts sont interpretes comme un signe de la transition a temperature nulle et sont en faveur d'un QCP. Le manque de donnees d'un meme materiau a ces dopages ne permet pas de valider hors de tout doute l'existence d'un point critique quantique. Le modele theorique YRZ decrit aussi bien les donnees de conductivite thermique. Des pistes de travaux experimentaux a poursuivre sont proposees pour determiner la presence ou non du QCP de facon franche. Mots-cles : Supraconducteurs, cuprates, conductivite thermique, point critique quantique.

  2. Optical, Electrical, and UV Photoresponse Properties of Fluorine-Doped ZnO Thin Films Grown on Flexible Mica Substrates

    NASA Astrophysics Data System (ADS)

    Kim, Younggyu; Leem, Jae-Young

    2015-12-01

    Fluorine-doped ZnO (FZO) thin films have several potential applications, for instance, in low-cost optoelectronic devices; understanding how their optical, electrical, and photoresponse properties depend on and can be controlled via the synthesis conditions is essential for application of these systems. In this study, FZO thin films with different annealing temperatures were grown on muscovite mica substrates via sol-gel spin-coating. In photoluminescence measurements, a strong peak in the ultraviolet (UV) region and a broad peak in the visible region were observed for all films, being strongly dependent on the annealing temperature. The transmittance of the annealed films was slightly higher than that of as-grown film, and the absorption edges in the transmittance spectra red-shifted with increasing annealing temperature. The optical bandgap and Urbach energy of the films were calculated from the absorption coefficient values, using the Tauc and Urbach relations, respectively. Finally, the electrical (i.e., resistivity and carrier concentration) and photoresponse properties of the films were investigated to assess their applicability for use in FZO-based UV detectors.

  3. Growth mechanism and optical properties of Ti thin films deposited onto fluorine-doped tin oxide glass substrate

    SciTech Connect

    Einollahzadeh-Samadi, Motahareh; Dariani, Reza S.

    2015-03-15

    In this work, a detailed study of the influence of the thickness on the morphological and optical properties of titanium (Ti) thin films deposited onto rough fluorine-doped tin oxide glass by d.c. magnetron sputtering is carried out. The films were characterized by several methods for composition, crystallinity, morphology, and optical properties. Regardless of the deposition time, all the studied Ti films of 400, 1500, 2000, and 2500 nm in thickness were single crystalline in the α-Ti phase and also very similar to each other with respect to composition. Using the atomic force microscopy (AFM) technique, the authors analyzed the roughness evolution of the Ti films characteristics as a function of the film thickness. By applying the dynamic scaling theory to the AFM images, a steady growth roughness exponent α = 0.72 ± 0.02 and a dynamic growth roughness exponent β = 0.22 ± 0.02 were determined. The value of α and β are consistent with nonlinear growth model incorporating random deposition with surface diffusion. Finally, measuring the reflection spectra of the samples by a spectrophotometer in the spectral range of 300–1100 nm allowed us to investigate the optical properties. The authors observed the increments of the reflection of Ti films with thickness, which by employing the effective medium approximation theory showed an increase in thickness followed by an increase in the volume fraction of metal.

  4. The effect of laser patterning parameters on fluorine-doped tin oxide films deposited on glass substrates

    NASA Astrophysics Data System (ADS)

    Tseng, Shih-Feng; Hsiao, Wen-Tse; Huang, Kuo-Cheng; Chiang, Donyau

    2011-08-01

    The purpose of this study is to pattern the fluorine-doped tin oxide thin film deposited on the soda-lime glass substrates for touch screen applications by ultraviolet laser. The patterned film structures provide the electrical isolation and prevent the electrical contact from each region for various touch screens. The surface morphology, edge quality, three-dimensional topography, and profile of isolated lines and electrode structures after laser patterning were measured by a confocal laser scanning microscope. Moreover, a four-point probe instrument was used to measure the sheet resistance before and after laser patterning on film surfaces and also to discuss the electrical property at different laser spot overlaps. After laser patterning, a high overlapping area of laser spot was used to pattern the electrode layer on film surfaces that could obtain an excellent machined quality of edge profile. All sheet resistance values of film surfaces near the isolated line edge were larger than the original ones. Moreover, the sheet resistance values increased with increasing laser spot overlapping area.

  5. Optimization of the deposition and annealing conditions of fluorine-doped indium oxide films for silicon solar cells

    SciTech Connect

    Untila, G. G. Kost, T. N.; Chebotareva, A. B.; Timofeyev, M. A.

    2013-03-15

    Fluorine-doped indium oxide (IFO) films are deposited onto (pp{sup +})Si and (n{sup +}nn{sup +})Si structures made of single-crystal silicon by ultrasonic spray pyrolysis. The effect of the IFO deposition time and annealing time in an argon atmosphere with methanol vapor on the IFO chemical composition, the photovoltage and fill factor of the Illumination-U{sub oc} curves of IFO/(pp{sup +})Si structures, and the sheet resistance of IFO/(n{sup +}nn{sup +})Si structures, correlating with the IFO/(n{sup +})Si contact resistance, is studied. The obtained features are explained by modification of the properties of the SiO{sub x} transition layer at the IFO/Si interface during deposition and annealing. Analysis of the results made it possible to optimize the fabrication conditions of solar cells based on IFO/(pp{sup +})Si heterostructures and to increase their efficiency from 17% to a record 17.8%.

  6. Investigation of the ablation of fluorine-doped tin oxide thin films by square top-hat ultraviolet laser beams

    NASA Astrophysics Data System (ADS)

    Tseng, Shih-Feng; Hsiao, Wen-Tse; Chiang, Donyau; Chung, Chien-Kai; Andrew Yeh, Jer-Liang

    2014-01-01

    This paper presents a square top-hat beam shaper in an ultraviolet (UV) laser processing system for electrode patterning and investigates the interaction between square laser beams and fluorine-doped tin oxide (FTO) thin films deposited on glass substrates. The various patterning parameters to ablate the FTO films used in this experiment are included laser fluences, pulse repetition frequencies, and feeding rates of a motorized platform. The laser pulse repetition frequency and the feeding rate of the motorized platform were used to calculate the overlapping rate of laser spot and to determine the patterning quality. The line width and depth, edge quality, three-dimensional topography, and electrical conductivity properties of the patterned FTO films were measured and analyzed using a confocal laser scanning microscope and a four-point probe instrument. Experimental results indicated that the ablated line width and depth increased with increasing laser fluence. After electrode patterning with laser fluence of 2.07 J/cm2 and 80% overlapping rate, no damages were observed in the patterned lines on the glass substrate. Moreover, the patterned line paths were narrow, smooth, clear, and flat in response to uniform laser energy distribution interacted in FTO films. The measured values of sheet resistance ranged from 109.73.8 ?/? to 139.34.9 ?/? at 2.07 J/cm2 to 9.37 J/cm2 laser fluences, respectively. The proposed process can reduce the fabrication steps and improve the removal efficiency of transparent conductive oxide materials and no waste etching chemical solution is produced.

  7. Effect of solvent volume on the physical properties of undoped and fluorine doped tin oxide films deposited using a low-cost spray technique

    NASA Astrophysics Data System (ADS)

    Muruganantham, G.; Ravichandran, K.; Saravanakumar, K.; Ravichandran, A. T.; Sakthivel, B.

    2011-12-01

    Undoped and fluorine doped tin oxide films were deposited from starting solutions having different values of solvent volume (10-50 ml) by employing a low cost and simplified spray technique using perfume atomizer. X-ray diffraction studies showed that there was a change in the preferential orientation from (2 1 1) plane to (1 1 0) plane as the volume of the solvent was increased. The sheet resistance ( Rsh) of undoped SnO 2 film was found to be minimum (13.58 KΩ/□) when the solvent volume was lesser (10 ml) and there was a sharp increase in Rsh for higher values of solvent volume. Interestingly, it was observed that while the Rsh increases sharply with the increase in solvent volume for undoped SnO 2 films, it decreases gradually in the case of fluorine doped SnO 2 films. The quantitative analysis of EDAX confirmed that the electrical resistivity of the sprayed tin oxide film was mainly governed by the number of oxygen vacancies and the interstitial incorporation of Sn atoms which in turn was governed by the impinging flux on the hot substrate. The films were found to have good optical characteristics suitable for opto-electronic devices.

  8. High-T sub c fluorine-doped YBa2Cu3O(y) films on ceramic substrates by screen printing

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.

    1991-01-01

    Thick films of fluorine-doped YBa2Cu3O(y) were screen printed on highly polished alumina, magnesia spinel, strontium titanate, and yttria-stabilized zirconia (YSZ) substrates. They were annealed at 1000 C and soaked in oxygen at 450 C, followed by slow cooling to room temperature. The films were characterized by electrical resistivity measurements as a function of temperature and x-ray diffraction. The film on YSZ showed the best characteristics with a T sub c (onset) of 91 K, T sub c (R equals 0) of 88.2 K, and a transition width, delta T sub c (10-90 percent), of approximately 1.7 K. The film adhesion, probably controlled by interdiffusion of cations between the film and the substrate, was good in all cases except on strontium titanate where the film completely detached from the substrate.

  9. Thermal oxidation-grown vanadium dioxide thin films on FTO (Fluorine-doped tin oxide) substrates

    NASA Astrophysics Data System (ADS)

    Tong, Guoxiang; Li, Yi; Wang, Feng; Huang, Yize; Fang, Baoying; Wang, Xiaohua; Zhu, Huiqun; Li, Liu; Shen, Yujian; Zheng, Qiuxin; Liang, Qian; Yan, Meng; Qin, Yuan; Ding, Jie

    2013-11-01

    By deposition of metallic vanadium on FTO substrate in Argon atmosphere at room temperature, the sample was then annealed in furnace for 2 h at the temperature of 410 C in air ambient. (1 1 0) -orientated vanadium dioxide films were prepared on the FTO surface. A maximum transmittance of 40% happened at 900-1250 nm region at room temperature. The change of optical transmittance at this region was 25% between semiconducting and metallic states. In particular, vanadium dioxide thin films on FTO exhibit semiconductor-metal phase transition at 51 C, the width of the hysteresis loop is 8 C.

  10. Superconducting properties of REBa 2Cu 3O y (RE = Y and Gd) films prepared by BaF 2 process without water vapor

    NASA Astrophysics Data System (ADS)

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

    2006-10-01

    We have successfully fabricated YBa2Cu3Oy (Y123) and GdBa2Cu3Oy (Gd123) films on SrTiO3 substrates by the ex situ heat treatment of co-evaporated Y-BaF2-Cu and Gd-BaF2-Cu precursor films prepared by electron beam deposition technique without water vapor. Tc and Jc of the Y123 film were 91.6 K and 0.95 MA cm-2 at 77 K at self-field, respectively. The Gd123 film showed Tc of 93.4 K and Jc of 1.5 MA cm-2 at 77 K at self-field. It was found that the surface morphology of the Y123 and the Gd123 films depended on the partial oxygen pressure during the heat treatment.

  11. Physicochemical characterization of point defects in fluorine doped tin oxide films

    SciTech Connect

    El Akkad, Fikry; Joseph, Sudeep

    2012-07-15

    The physical and chemical properties of spray deposited FTO films are studied using FESEM, x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), electrical and optical measurements. The results of XRD measurements showed that the films are polycrystalline (grain size 20-50 nm) with Rutile structure and mixed preferred orientation along the (200) and (110) planes. An angular shift of the XRD peaks after F-doping is observed and interpreted as being due to the formation of substitutional fluorine defects (F{sub O}) in presence of high concentration of oxygen vacancies (V{sub O}) that are electrically neutral. The electrical neutrality of oxygen vacancies is supported by the observation that the electron concentration n is two orders of magnitude lower than the V{sub O} concentration calculated from chemical analyses using XPS measurements. It is shown that an agreement between XPS, XRD, and Hall effect results is possible provided that the degree of deviation from stoichiometry is calculated with the assumption that the major part of the bulk carbon content is involved in O-C bonds. High temperature thermal annealing is found to cause an increase in the F{sub O} concentration and a decrease in both n and V{sub O} concentrations with the increase of the annealing temperature. These results could be interpreted in terms of a high temperature chemical exchange reaction between the SnO{sub 2} matrix and a precipitated fluoride phase. In this reaction, fluorine is released to the matrix and Sn is trapped by the fluoride phase, thus creating substitutional fluorine F{sub O} and tin vacancy V{sub Sn} defects. The enthalpy of this reaction is determined to be approximately 2.4 eV while the energy of formation of a V{sub Sn} through the migration of Sn{sub Sn} host atom to the fluoride phase is approximately 0.45 eV.

  12. Solution-Processed Flexible Fluorine-doped Indium Zinc Oxide Thin-Film Transistors Fabricated on Plastic Film at Low Temperature

    PubMed Central

    Seo, Jin-Suk; Jeon, Jun-Hyuck; Hwang, Young Hwan; Park, Hyungjin; Ryu, Minki; Park, Sang-Hee Ko; Bae, Byeong-Soo

    2013-01-01

    Transparent flexible fluorine-doped indium zinc oxide (IZO:F) thin-film transistors (TFTs) were demonstrated using the spin-coating method of the metal fluoride precursor aqueous solution with annealing at 200°C for 2 hrs on polyethylene naphthalate films. The proposed thermal evolution mechanism of metal fluoride aqueous precursor solution examined by thermogravimetric analysis and Raman spectroscopy can easily explain oxide formation. The chemical composition analysed by XPS confirms that the fluorine was doped in the thin films annealed below 250°C. In the IZO:F thin films, a doped fluorine atom substitutes for an oxygen atom generating a free electron or occupies an oxygen vacancy site eliminating an electron trap site. These dual roles of the doped fluorine can enhance the mobility and improve the gate bias stability of the TFTs. Therefore, the transparent flexible IZO:F TFT shows a high mobility of up to 4.1 cm2/V·s and stable characteristics under the various gate bias and temperature stresses. PMID:23803977

  13. Effect of N2 Plasma Annealing on Properties of Fluorine Doped Silicon Dioxide Films with Low Dielectric Constant for Ultra-Large-Scale Integrated Circuits

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Wang, Peng-Fei; Ding, Shi-Jin; Wang, Ji-Tao; William, Wei Lee

    2002-06-01

    The influence of N2 plasma annealing on the properties of fluorine doped silicon oxide (SiOF) films is investigated. The stability of the dielectric constant of SiOF film is remarkably improved by the N2 plasma annealing. After enduring a moisture absorption test for six hours in a chamber with 60% humidity at 50C, the dielectric constant variation of the annealed SiOF films is only 1.5%, while the variation for those SiOF films without annealing is 15.5%. Fourier transform infrared spectroscopic results show that the absorption peaks of Si-OH and H-OH of SiOF films are reduced after the N2 plasma annealing because the annealing can wipe off some unstable Si-F2 bonds in SiOF films. These unstable Si-F2 bonds are suitable to react with water, resulting in the degradation of SiOF film properties. Therefore, the N2 plasma annealing meliorates the properties of SiOF films with low dielectric constant.

  14. Novel nanostructure zinc zirconate, zinc oxide or zirconium oxide pastes coated on fluorine doped tin oxide thin film as photoelectrochemical working electrodes for dye-sensitized solar cell.

    PubMed

    Hossein Habibi, Mohammad; Askari, Elham; Habibi, Mehdi; Zendehdel, Mahmoud

    2013-03-01

    Zinc zirconate (ZnZrO(3)) (ZZ), zinc oxide (ZnO) (ZO) and zirconium oxide (ZrO(2)) (ZRO) nano-particles were synthesized by simple sol-gel method. ZZ, ZO and ZRO nano-particles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and UV-Vis diffuse reflectance spectrum (DRS). Nanoporous ZZ, ZO and ZRO thin films were prepared doctor blade technique on the fluorine-doped tin oxide (FTO) and used as working electrodes in dye sensitized solar cells (DSSC). Their photovoltaic behavior were compared with standard using D35 dye and an electrolyte containing [Co(bpy)(3)](PF(6))(2), [Co(pby)(3)](PF(6))(3), LiClO(4), and 4-tert-butylpyridine (TBP). The properties of DSSC have been studied by measuring their short-circuit photocurrent density (Jsc), open-circuit voltage (VOC) and fill factor (ff). The application of ZnZrO(3) as working electrode produces a significant improvement in the fill factor (ff) of the dye-sensitized solar cells (ff=56%) compared to ZnO working electrode (ff=40%) under the same condition. PMID:23266694

  15. Characteristics of Fluorine-doped tin oxide thin films grown by Streaming process for Electrodeless Electrochemical Deposition

    NASA Astrophysics Data System (ADS)

    Yusuf, Gbadebo; Khalilzadeh-Rezaie, Farnood; Cleary, Justin W.; Oladeji, Isaiah O.; Suu, Koukou; Schoenfeld, Winston V.; Peale, Robert E.; Awodugba, Ayodeji O.

    2015-04-01

    This work investigated the characteristics of SnO2: F films grown by Streaming Process for Electrodeless Electrochemical Deposition (SPEED). Stannic chloride (SnCl4) and ammonium fluoride (NH4 F) was dissolved in a mixture of deionized water and organic solvents. The preheated substrate temperature was varied between 450 and 530 C. High quality SnO2: F films were grown at all the substrate temperatures studied. The typical film thickness was 250 nm. XRD shows that the grown films are polycrystalline SnO2 with a tetragonal crystal structure. The average optical transmission of the films was around 93% throughout the wavelength of 400 to 1000 nm. The lowest electrical resistivity achieved was 6 x 10-4 ? cm. The Hall measurements showed that the film is an n-type semiconductor, with the highest carrier mobility of 8.3 cm2/V.s, and concentration of 1 x 1021 cm-3. The direct band gap was determined to be 4 eV from the transmittance spectrum.

  16. Enhanced photoelectrochemical water oxidation via atomic layer deposition of TiO2 on fluorine-doped tin oxide nanoparticle films

    NASA Astrophysics Data System (ADS)

    Cordova, Isvar A.; Peng, Qing; Ferrall, Isa L.; Rieth, Adam J.; Hoertz, Paul G.; Glass, Jeffrey T.

    2015-04-01

    TiO2 is an exemplary semiconductor anode material for photoelectrochemical (PEC) water-splitting electrodes due to its functionality, long-term stability in corrosive environments, nontoxicity, and low cost. In this study, TiO2 photoanodes with enhanced photocurrent density were synthesized by atomic layer deposition (ALD) of TiO2 onto a porous, transparent, and conductive fluorine-doped tin oxide nanoparticle (nanoFTO) scaffold fabricated by solution processing. The simplicity and disordered nature of the nanoFTO nanostructure combined with the ultrathin conformal ALD TiO2 coatings offers advantages including decoupling charge carrier diffusion length from optical penetration depth, increased photon absorption probability through scattering, complimentary photon absorption, and favorable interfaces for charge separation and transfer across the various junctions. We examine the effects of porosity of the nanoFTO scaffold and thickness of the TiO2 coating on PEC performance and achieve an optimal photocurrent of 0.7 mA cm-2 at 0 V vs. Ag/AgCl under 100 mW cm-2 AM 1.5 G irradiation in a 1 M KOH aqueous electrolyte. Furthermore, the fundamental mechanisms behind the improvements are characterized via cyclic voltammetry, incident photon-to-current efficiency, transient photocurrent spectroscopy, and electrochemical impedance spectroscopy and are contrasted with those of single crystal rutile TiO2 nanowires. The strategies employed in this work highlight the opportunities inherent to these types of heteronanostructures, where the lessons may be applied to improve the PEC conversion efficiencies of other promising semiconductors, such as hematite (?-Fe2O3) and other materials more sensitive to visible light.TiO2 is an exemplary semiconductor anode material for photoelectrochemical (PEC) water-splitting electrodes due to its functionality, long-term stability in corrosive environments, nontoxicity, and low cost. In this study, TiO2 photoanodes with enhanced photocurrent density were synthesized by atomic layer deposition (ALD) of TiO2 onto a porous, transparent, and conductive fluorine-doped tin oxide nanoparticle (nanoFTO) scaffold fabricated by solution processing. The simplicity and disordered nature of the nanoFTO nanostructure combined with the ultrathin conformal ALD TiO2 coatings offers advantages including decoupling charge carrier diffusion length from optical penetration depth, increased photon absorption probability through scattering, complimentary photon absorption, and favorable interfaces for charge separation and transfer across the various junctions. We examine the effects of porosity of the nanoFTO scaffold and thickness of the TiO2 coating on PEC performance and achieve an optimal photocurrent of 0.7 mA cm-2 at 0 V vs. Ag/AgCl under 100 mW cm-2 AM 1.5 G irradiation in a 1 M KOH aqueous electrolyte. Furthermore, the fundamental mechanisms behind the improvements are characterized via cyclic voltammetry, incident photon-to-current efficiency, transient photocurrent spectroscopy, and electrochemical impedance spectroscopy and are contrasted with those of single crystal rutile TiO2 nanowires. The strategies employed in this work highlight the opportunities inherent to these types of heteronanostructures, where the lessons may be applied to improve the PEC conversion efficiencies of other promising semiconductors, such as hematite (?-Fe2O3) and other materials more sensitive to visible light. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr07377k

  17. Enhanced photoelectrochemical water oxidation via atomic layer deposition of TiO2 on fluorine-doped tin oxide nanoparticle films.

    PubMed

    Cordova, Isvar A; Peng, Qing; Ferrall, Isa L; Rieth, Adam J; Hoertz, Paul G; Glass, Jeffrey T

    2015-05-14

    TiO2 is an exemplary semiconductor anode material for photoelectrochemical (PEC) water-splitting electrodes due to its functionality, long-term stability in corrosive environments, nontoxicity, and low cost. In this study, TiO2 photoanodes with enhanced photocurrent density were synthesized by atomic layer deposition (ALD) of TiO2 onto a porous, transparent, and conductive fluorine-doped tin oxide nanoparticle (nanoFTO) scaffold fabricated by solution processing. The simplicity and disordered nature of the nanoFTO nanostructure combined with the ultrathin conformal ALD TiO2 coatings offers advantages including decoupling charge carrier diffusion length from optical penetration depth, increased photon absorption probability through scattering, complimentary photon absorption, and favorable interfaces for charge separation and transfer across the various junctions. We examine the effects of porosity of the nanoFTO scaffold and thickness of the TiO2 coating on PEC performance and achieve an optimal photocurrent of 0.7 mA cm(-2) at 0 V vs. Ag/AgCl under 100 mW cm(-2) AM 1.5 G irradiation in a 1 M KOH aqueous electrolyte. Furthermore, the fundamental mechanisms behind the improvements are characterized via cyclic voltammetry, incident photon-to-current efficiency, transient photocurrent spectroscopy, and electrochemical impedance spectroscopy and are contrasted with those of single crystal rutile TiO2 nanowires. The strategies employed in this work highlight the opportunities inherent to these types of heteronanostructures, where the lessons may be applied to improve the PEC conversion efficiencies of other promising semiconductors, such as hematite (?-Fe2O3) and other materials more sensitive to visible light. PMID:25899449

  18. Chemical vapor deposition of fluorine-doped zinc oxide

    DOEpatents

    Gordon, Roy G. (Cambridge, MA); Kramer, Keith (Avon Lake, OH); Liang, Haifan (Santa Clara, CA)

    2000-06-06

    Fims of fluorine-doped zinc oxide are deposited from vaporized precursor compounds comprising a chelate of a dialkylzinc, such as an amine chelate, an oxygen source, and a fluorine source. The coatings are highly electrically conductive, transparent to visible light, reflective to infrared radiation, absorbing to ultraviolet light, and free of carbon impurity.

  19. Fluorine doping into diamond-like carbon coatings inhibits protein adsorption and platelet activation.

    PubMed

    Hasebe, Terumitsu; Yohena, Satoshi; Kamijo, Aki; Okazaki, Yuko; Hotta, Atsushi; Takahashi, Koki; Suzuki, Tetsuya

    2007-12-15

    The first major event when a medical device comes in contact with blood is the adsorption of plasma proteins. Protein adsorption on the material surface leads to the activation of the blood coagulation cascade and the inflammatory process, which impair the lifetime of the material. Various efforts have been made to minimize protein adsorption and platelet adhesion. Recently, diamond-like carbon (DLC) has received much attention because of their antithrombogenicity. We recently reported that coating silicon substrates with fluorine-doped diamond-like carbon (F-DLC) drastically suppresses platelet adhesion and activation. Here, we evaluated the protein adsorption on the material surfaces and clarified the relationship between protein adsorption and platelet behaviors, using polycarbonate and DLC- or F-DLC-coated polycarbonate. The adsorption of albumin and fibrinogen were assessed using a colorimetric protein assay, and platelet adhesion and activation were examined using a differential interference contrast microscope. A higher ratio of albumin to fibrinogen adsorption was observed on F-DLC than on DLC and polycarbonate films, indicating that the F-DLC film should prevent thrombus formation. Platelet adhesion and activation on the F-DLC films were more strongly suppressed as the amount of fluorine doping was increased. These results show that the F-DLC coating may be useful for blood-contacting devices. PMID:17600326

  20. The surface modification of fluorine-doped tin oxide by the underpotential deposition of noble metals

    SciTech Connect

    Colton, R.H.; Hager, H.E.

    1986-12-01

    The surface modification of fluorine-doped tin oxide by the underpotential deposition of noble metals (Rh, Ru, Pd, Pt, and Au) strongly influences the rate of sulfide-polysulfide reduction at the SnO/sub 2/ electrode. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy are used to characterize as-prepared and surface modified tin oxide preceding and following electrode operation. The noble metal coverages follow the relative ordering: Au, Pt < Ru, Pd < Rh, showing an identical trend as the observed enhancement effects. Depth profile analysis shows that rhodium is found more than 100A into the tin oxide film. This spatial distribution is apparently an artifact of the columnar SnO/sub 2/ structure. The XPS atom bonding peaks for the noble metals are shifted from the peak values associated with metallic states by an amount which is dependent on the exposure history of the tin oxide and yet independent of the noble metal species.

  1. Comparison of characteristics of fluorine doped zinc and gallium tin oxide composite thin films deposited on stainless steel 316 bipolar plate by electron cyclotron resonance-metal organic chemical vapor deposition for proton exchange membrane fuel cells.

    PubMed

    Park, Jihun; Hudaya, Chairul; Lee, Joong Kee

    2011-09-01

    In order to replace the brittle graphite bipolar plates currently used for the PEMFC stack, coated SUS 316 was employed. As a metallic bipolar plate, coated SUS 316 can provide higher mechanical strength, better durability to shocks and vibration, less permeability, improved thermal and bulk electrical conductivity, as well as being thinner and lighter. To enhance the interfacial contact resistance and corrosion resistance of SUS 316, the deposition of GTO:F and ZTO:F composite films was carried out by ECR-MOCVD. The surface morphology of the films consisted of tiny elliptically shaped grains with a thickness of 1 microm. The corrosion current for GTO:F was 0.13 Acm(-2) which was much lower than that of bare SUS 316 (50.16 Acm(-2)). The GTO:F coated film had the smallest corrosion current due to the formation of a tight surface morphology with very few pin-holes. The GTO:F coated film exhibited the highest cell voltage and power density due to its lower ICR values. PMID:22097519

  2. Growth of fluorine doped SnO2 nanostructures by spin coating of ultrasonically prepared gel precursor

    NASA Astrophysics Data System (ADS)

    Goswami, Y. C.; Kumar, Vijay; Ganesan, V.; Rajaram, P.

    2013-02-01

    Fluorine doped SnO2 nanostructures have been grown by spin coating of ultrasonically prepared gel precursor. To prepare gel SnCl2.2H2O is dissolved in ethanol followed by ultrasonic treatment for few hours and keeping it for next 48 hours. Ammonium Fluoride (NH4F) was used as source of fluorine dopant. The gel is spin coated on Quartz and Glass slides followed by heat treatment at 275°C for 2hr. The films show both good conductivity and high transparency. These layers were characterized by structural, optical and morphological studies. XRD studies confirm the cassiterrite tetragonal structure. The size of the particles increases with the increase in F doping concentration. Blue shift is observed by optical transmission spectra. AFM images show the Ringlike structure at high doping concentration resulting in high roughness and porosity of the surface suitable for sensing application.

  3. Synthesis, characterization and photocatalytic activity of fluorine doped TiO2 nanoflakes synthesized using solid state reaction method.

    PubMed

    Umadevi, M; Parimaladevi, R; Sangari, M

    2014-01-01

    Fluorine doped TiO2 were synthesized by solid state reaction method. Optical and structural properties of fluorine doped TiO2 were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, UV-vis diffusion reflectance spectroscopy and scanning electron microscopic techniques. The prepared fluorine doped TiO2 was smaller in size with respect to pure TiO2 and it is tetragonal in crystalline structure. Nanoflakes like structure of pure and fluorine doped TiO2 was confirmed from SEM image. Fluorine doped TiO2 shows smaller band gap, high strain and dislocation density when compared to pure TiO2. It also has higher photocatalytic activity with respect to pure TiO2. PMID:24200650

  4. Preparation of fluorine-doped, carbon-encapsulated hollow Fe3O4 spheres as an efficient anode material for Li-ion batteries.

    PubMed

    Geng, Hongbo; Zhou, Qun; Pan, Yue; Gu, Hongwei; Zheng, Junwei

    2014-04-01

    Herein we report the design and synthesis of fluorine-doped, carbon-encapsulated hollow Fe3O4 spheres (h-Fe3O4@C/F) through mild heating of polyvinylidene fluoride (PVDF)-coated hollow Fe3O4 spheres. The spheres exhibit enhanced cyclic and rate performances. The as-prepared h-Fe3O4@C/F shows significantly improved electrochemical performance, with high reversible capacities of over 930 mA h g(-1) at a rate of 0.1 C after 70 cycles, 800 mA h g(-1) at a rate of 0.5 C after 120 cycles and 620 mA h g(-1) at a rate of 1 C after 200 cycles. This improved lithium storage performance is mainly ascribed to the encapsulation of the spheres with fluorine-doped carbon, which not only improves the reaction kinetics and stability of the solid electrolyte interface film but also prevents aggregation and drastic volume change of the Fe3O4 particles. These spheres thus represent a promising anode material in lithium-ion battery applications. PMID:24598908

  5. Porous fluorine-doped γ-Fe2O3 hollow spheres: synthesis, growth mechanism, and their application in photocatalysis.

    PubMed

    Zhu, Lu-Ping; Wang, Ling-Ling; Bing, Nai-Ci; Huang, Chao; Wang, Li-Jun; Liao, Gui-Hong

    2013-12-11

    Porous fluorine-doped maghemite(γ-Fe2O3) hollow spheres have been prepared by facile route based on solvothermal reaction and sequential calcinations. The composition and morphology of the as-prepared samples were characterized by various techniques. The SEM and TEM results showed that the as-synthesized products exhibited a spherical morphology with porous hollow structures. Ultraviolet-visible (UV-vis) diffuse reflectance spectra display that the optical performance of γ-Fe2O3 products are related to their structure and the fluorine concentrations. The porous hollow structured fluorine-doped γ-Fe2O3 spheres exhibit ferromagnetic properties with relatively high saturation magnetization at room temperature. According to the experimental results, a formation mechanism of the fluorine-doped γ-Fe2O3 hollow spheres has been presented. Under UV light irradiation, the photocatalytic degradation activities of the as-synthesized fluorine-doped γ-Fe2O3 samples for RhB dye were 2-5 times higher than that of the undoped sample. The prepared fluorine-doped γ-Fe2O3 hollow spheres will also aroused great interest for their application in catalysis, separation technology, sensors, nanotechnology, and biomedical fields. PMID:24245477

  6. Effects of Fluorine Doping on Structural and Optical Properties of Hydrothermally Grown ZnO Nanorods.

    PubMed

    Yoon, Hyunsik; Leem, Jae-Young

    2015-11-01

    Pure and fluorine-doped ZnO nanorods were hydrothermally grown on quartz substrates. The nanorod thickness and density were changed by varying the fluorine concentration. The full width at half-maximum and position of the diffraction peak corresponding to the ZnO (002) plane were used to calculate the decreased residual stress and increased c-axis lattice constant of the FZO nanorods. The near-band-edge PL emission peaks intensified and the deep-level emission peaks gradually weakened because more fluorine atoms occupied the ZnO lattice vacancies with increasing nanorod F concentration, thereby decreasing the nanorod surface-defect concentration. PMID:26726536

  7. Absence of superconductivity in fluorine-doped neptunium pnictide NpFeAsO

    NASA Astrophysics Data System (ADS)

    Walters, A. C.; Walker, H. C.; Springell, R.; Krisch, M.; Bosak, A.; Hill, A. H.; Zvorişte-Walters, C. E.; Colineau, E.; Griveau, J.-C.; Bouëxière, D.; Eloirdi, R.; Caciuffo, R.; Klimczuk, T.

    2015-08-01

    X-ray diffraction, specific heat, magnetic susceptibility and inelastic x-ray scattering measurements on the transurarium oxypnictides NpFeAsO and NpFeAsO0.85F0.15 are presented. No superconductivity down to 2 K was observed upon fluorine doping, contrary to the structurally analogous rare-earth pnictides. No modification of the phonon density of states was observed upon doping with fluorine. We discuss our results in light of the latest experimental and theoretical studies on the role of phonons in the superconducting pnictide compounds.

  8. Absence of superconductivity in fluorine-doped neptunium pnictide NpFeAsO.

    PubMed

    Walters, A C; Walker, H C; Springell, R; Krisch, M; Bosak, A; Hill, A H; Zvorişte-Walters, C E; Colineau, E; Griveau, J-C; Bouëxière, D; Eloirdi, R; Caciuffo, R; Klimczuk, T

    2015-08-19

    X-ray diffraction, specific heat, magnetic susceptibility and inelastic x-ray scattering measurements on the transurarium oxypnictides NpFeAsO and NpFeAsO0.85F0.15 are presented. No superconductivity down to 2 K was observed upon fluorine doping, contrary to the structurally analogous rare-earth pnictides. No modification of the phonon density of states was observed upon doping with fluorine. We discuss our results in light of the latest experimental and theoretical studies on the role of phonons in the superconducting pnictide compounds. PMID:26214712

  9. Investigation of fluorine-doped tin oxide based optically transparent E-shaped patch antenna for terahertz communications

    NASA Astrophysics Data System (ADS)

    Anand, S.; Darak, Mayur Sudesh; Kumar, D. Sriram

    2014-10-01

    In this paper, a fluorine-doped tin oxide based optically transparent E-shaped patch antenna is designed and its radiation performance is analyzed in the 705 - 804 GHz band. As optically transparent antennas can be mounted on optical display, they facilitate the reduction of overall system size. The proposed antenna design is simulated using electromagnetic solver - Ansys HFSS and its characteristics such as impedance bandwidth, directivity, radiation efficiency and gain are observed. Results show that the fluorine-doped tin oxide based optically transparent patch antenna overcomes the conventional patch antenna limitations and thus the same can be used for solar cell antenna used in satellite systems.

  10. Investigation of fluorine-doped tin oxide based optically transparent E-shaped patch antenna for terahertz communications

    SciTech Connect

    Anand, S. E-mail: darak.mayur@gmail.com Darak, Mayur Sudesh E-mail: darak.mayur@gmail.com Kumar, D. Sriram E-mail: darak.mayur@gmail.com

    2014-10-15

    In this paper, a fluorine-doped tin oxide based optically transparent E-shaped patch antenna is designed and its radiation performance is analyzed in the 705 – 804 GHz band. As optically transparent antennas can be mounted on optical display, they facilitate the reduction of overall system size. The proposed antenna design is simulated using electromagnetic solver - Ansys HFSS and its characteristics such as impedance bandwidth, directivity, radiation efficiency and gain are observed. Results show that the fluorine-doped tin oxide based optically transparent patch antenna overcomes the conventional patch antenna limitations and thus the same can be used for solar cell antenna used in satellite systems.

  11. Fluorine-Doped and Partially Oxidized Tantalum Carbides as Nonprecious Metal Electrocatalysts for Methanol Oxidation Reaction in Acidic Media.

    PubMed

    Yue, Xin; He, Chunyong; Zhong, Chengyong; Chen, Yuanping; Jiang, San Ping; Shen, Pei Kang

    2016-03-01

    A nonprecious metal electrocatalyst based on fluorine-doped tantalum carbide with an oxidative surface on graphitized carbon (TaCx Fy Oz /(g) C) is developed by using a simple one-pot in situ ion exchange and adsorption method, and the TaCx Fy Oz /(g) C shows superior performance and durability for methanol oxidation reaction and extreme tolerance to CO poisoning in acidic media. PMID:26779940

  12. Reductive electropolymerization of a vinyl-containing poly-pyridyl complex on glassy carbon and fluorine-doped tin oxide electrodes.

    PubMed

    Harrison, Daniel P; Carpenter, Logan S; Hyde, Jacob T

    2015-01-01

    Controllable electrode surface modification is important in a number of fields, especially those with solar fuels applications. Electropolymerization is one surface modification technique that electrodeposits a polymeric film at the surface of an electrode by utilizing an applied potential to initiate the polymerization of substrates in the Helmholtz layer. This useful technique was first established by a Murray-Meyer collaboration at the University of North Carolina at Chapel Hill in the early 1980s and utilized to study numerous physical phenomena of films containing inorganic complexes as the monomeric substrate. Here, we highlight a procedure for coating electrodes with an inorganic complex by performing reductive electropolymerization of the vinyl-containing poly-pyridyl complex onto glassy carbon and fluorine doped tin oxide coated electrodes. Recommendations on electrochemical cell configurations and troubleshooting procedures are included. Although not explicitly described here, oxidative electropolymerization of pyrrole-containing compounds follows similar procedures to vinyl-based reductive electropolymerization but are far less sensitive to oxygen and water. PMID:25741745

  13. Optoelectrochemical biorecognition by optically transparent highly conductive graphene-modified fluorine-doped tin oxide substrates.

    PubMed

    Lamberti, F; Brigo, L; Favaro, M; Luni, C; Zoso, A; Cattelan, M; Agnoli, S; Brusatin, G; Granozzi, G; Giomo, M; Elvassore, N

    2014-12-24

    Both optical and electrochemical graphene-based sensors have gone through rapid development, reaching high sensitivity at low cost and with fast response time. However, the complex validating biochemical operations, needed for their consistent use, currently limits their effective application. We propose an integration strategy for optoelectrochemical detection that overcomes previous limitations of these sensors used separately. We develop an optoelectrochemical sensor for aptamer-mediated protein detection based on few-layer graphene immobilization on selectively modified fluorine-doped tin oxide (FTO) substrates. Our results show that the electrochemical properties of graphene-modified FTO samples are suitable for complex biological detection due to the stability and inertness of the engineered electrodic interface. In addition, few-layer immobilization of graphene sheets through electrostatic linkage with an electrochemically grafted FTO surface allows obtaining an optically accessible and highly conductive platform. As a proof of concept, we used insulin as the target molecule to reveal in solution. Because of its transparency and low sampling volume (a few microliters), our sensing unit can be easily integrated in lab-on-a-chip cell culture systems for effectively monitoring subnanomolar concentrations of proteins relevant for biomedical applications. PMID:25438087

  14. Impact of carbon-fluorine doped titanium dioxide in the performance of an electrochemical sensing of dopamine and rosebengal sensitized solar cells

    NASA Astrophysics Data System (ADS)

    C, Abinaya; Dinesh, Bose; Sangari, M.; Ramar, A.; Umadevi, M.; Mayandi, J.

    2015-01-01

    The role of Fluorine and Carbon as dopants in the TiO2 based electrochemical sensor and DSSC were presented in this work. A series of Carbon nano-cones and disc doped TiO2 (TC), Fluorine doped TiO2 (FT) and C & F co-doped TiO2 (CFT) powdered samples were prepared via solid state synthesis. The CFT film showed excellent electrochemical sensitivity to the oxidation of dopamine in aqueous solution and could be employed as a dopamine sensor. The proposed sensor exhibited good linear response in the range of 10-820 μM with a detection limit of 3.6 μM under optimum conditions. The photovoltaic performances of Rose Bengal sensitized solar cells were assessed through I-V measurements. The CFT based DSSC shows a short-circuit current density and a power conversion efficiency (η) of 0.908 mA/cm2 and 0.163% respectively, which is 35% and 38% greater than the performance of other PT based cells. The characterization studies such as UV-Visible spectroscopy, Photoluminescence, TEM and EPR spectroscopy were utilized for further investigation, which helps us to understand how fluorine and carbon play a part in dopamine sensing and solar energy conversion.

  15. Fluorine-Doped Tin Oxide Nanocrystal/Reduced Graphene Oxide Composites as Lithium Ion Battery Anode Material with High Capacity and Cycling Stability.

    PubMed

    Xu, Haiping; Shi, Liyi; Wang, Zhuyi; Liu, Jia; Zhu, Jiefang; Zhao, Yin; Zhang, Meihong; Yuan, Shuai

    2015-12-16

    Tin oxide (SnO2) is a kind of anode material with high theoretical capacity. However, the volume expansion and fast capability fading during cycling have prevented its practical application in lithium ion batteries. Herein, we report that the nanocomposite of fluorine-doped tin oxide (FTO) and reduced graphene oxide (RGO) is an ideal anode material with high capacity, high rate capability, and high stability. The FTO conductive nanocrystals were successfully anchored on RGO nanosheets from an FTO nanocrystals colloid and RGO suspension by hydrothermal treatment. As the anode material, the FTO/RGO composite showed high structural stability during the lithiation and delithiation processes. The conductive FTO nanocrystals favor the formation of stable and thin solid electrolyte interface films. Significantly, the FTO/RGO composite retains a discharge capacity as high as 1439 mAhg(-1) after 200 cycles at a current density of 100 mAg(-1). Moreover, its rate capacity displays 1148 mAhg(-1) at a current density of 1000 mAg(-1). PMID:26606370

  16. Fluorine doping: a feasible solution to enhancing the conductivity of high-resistance wide bandgap Mg0.51Zn0.49O active components.

    PubMed

    Liu, Lishu; Mei, Zengxia; Hou, Yaonan; Liang, Huili; Azarov, Alexander; Venkatachalapathy, Vishnukanthan; Kuznetsov, Andrej; Du, Xiaolong

    2015-01-01

    N-type doping of high-resistance wide bandgap semiconductors, wurtzite high-Mg-content MgxZn1-xO for instance, has always been a fundamental application-motivated research issue. Herein, we report a solution to enhancing the conductivity of high-resistance Mg0.51Zn0.49O active components, which has been reliably achieved by fluorine doping via radio-frequency plasma assisted molecular beam epitaxial growth. Fluorine dopants were demonstrated to be effective donors in Mg0.51Zn0.49O single crystal film having a solar-blind 4.43?eV bandgap, with an average concentration of 1.0??10(19) F/cm(3).The dramatically increased carrier concentration (2.85??10(17)?cm(-3) vs ~10(14)?cm(-3)) and decreased resistivity (129????cm vs ~10(6)???cm) indicate that the electrical properties of semi-insulating Mg0.51Zn0.49O film can be delicately regulated by F doping. Interestingly, two donor levels (17?meV and 74?meV) associated with F were revealed by temperature-dependent Hall measurements. A Schottky type metal-semiconductor-metal ultraviolet photodetector manifests a remarkably enhanced photocurrent, two orders of magnitude higher than that of the undoped counterpart. The responsivity is greatly enhanced from 0.34?mA/W to 52?mA/W under 10?V bias. The detectivity increases from 1.89??10(9)?cm Hz(1/2)/W to 3.58??10(10)?cm Hz(1/2)/W under 10?V bias at room temperature.These results exhibit F doping serves as a promising pathway for improving the performance of high-Mg-content MgxZn1-xO-based devices. PMID:26489958

  17. Fluorine doping: a feasible solution to enhancing the conductivity of high-resistance wide bandgap Mg0.51Zn0.49O active components

    NASA Astrophysics Data System (ADS)

    Liu, Lishu; Mei, Zengxia; Hou, Yaonan; Liang, Huili; Azarov, Alexander; Venkatachalapathy, Vishnukanthan; Kuznetsov, Andrej; Du, Xiaolong

    2015-10-01

    N-type doping of high-resistance wide bandgap semiconductors, wurtzite high-Mg-content MgxZn1xO for instance, has always been a fundamental application-motivated research issue. Herein, we report a solution to enhancing the conductivity of high-resistance Mg0.51Zn0.49O active components, which has been reliably achieved by fluorine doping via radio-frequency plasma assisted molecular beam epitaxial growth. Fluorine dopants were demonstrated to be effective donors in Mg0.51Zn0.49O single crystal film having a solar-blind 4.43?eV bandgap, with an average concentration of 1.0??1019 F/cm3.The dramatically increased carrier concentration (2.85??1017?cm?3 vs ~1014?cm?3) and decreased resistivity (129????cm vs ~106???cm) indicate that the electrical properties of semi-insulating Mg0.51Zn0.49O film can be delicately regulated by F doping. Interestingly, two donor levels (17?meV and 74?meV) associated with F were revealed by temperature-dependent Hall measurements. A Schottky type metal-semiconductor-metal ultraviolet photodetector manifests a remarkably enhanced photocurrent, two orders of magnitude higher than that of the undoped counterpart. The responsivity is greatly enhanced from 0.34?mA/W to 52?mA/W under 10?V bias. The detectivity increases from 1.89??109?cm Hz1/2/W to 3.58??1010?cm Hz1/2/W under 10?V bias at room temperature.These results exhibit F doping serves as a promising pathway for improving the performance of high-Mg-content MgxZn1-xO-based devices.

  18. Effect of electrodeposition modes on surface characteristics and corrosion properties of fluorine-doped hydroxyapatite coatings on Mg-Zn-Ca alloy

    NASA Astrophysics Data System (ADS)

    Meng, E. C.; Guan, S. K.; Wang, H. X.; Wang, L. G.; Zhu, S. J.; Hu, J. H.; Ren, C. X.; Gao, J. H.; Feng, Y. S.

    2011-03-01

    The microstructure, morphology and composition highly determine the corrosion resistance and bioactivity of coating. In traditional cathodic electrodeposition process, because of the unfavorable effects of the polarization of concentration difference and H 2 evolution, fluorine-doped hydroxyapatite coating was loose and porous. This coating could not ensure the long-term stability of the Mg alloy implants. In order to improve the corrosion resistance and bioactivity of coating, pulse electrodeposition and H 2O 2 were introduced into the electrodeposition to deposit fluorine-doped hydroxyapatite coating. As a comparative study, microstructure, corrosion resistance properties and bioactivity of traditional cathodic electrodeposition coating and pulse electrodeposition coating were investigated, respectively. The results revealed that nano fluorine-doped hydroxyapatite coating could be prepared by pulse electrodeposition, and the coating was dense and uniform. The potentiodynamic polarization experiment indicated that the dense and uniform coating could effectively protect Mg alloy substrate from corrosion. Immersion testing was performed in simulated body fluid. It was found that pulse electrodeposition coating could more effectively induce the precipitation of Mg 2+, Ca 2+ and PO 43- in comparison with traditional cathodic electrodeposition coating, because the nano phase had comparatively high specific surface area. Thus magnesium alloy coated with fluorine-doped nano-hydroxyapatite coating may be a promising candidate as biodegradable bone implants, and was worthwhile to further investigate the in vivo degradation behavior.

  19. Deposition of nanostructured fluorine-doped hydroxyapatite-polycaprolactone duplex coating to enhance the mechanical properties and corrosion resistance of Mg alloy for biomedical applications.

    PubMed

    Bakhsheshi-Rad, H R; Hamzah, E; Kasiri-Asgarani, M; Jabbarzare, S; Iqbal, N; Abdul Kadir, M R

    2016-03-01

    The present study addressed the synthesis of a bi-layered nanostructured fluorine-doped hydroxyapatite (nFHA)/polycaprolactone (PCL) coating on Mg-2Zn-3Ce alloy via a combination of electrodeposition (ED) and dip-coating methods. The nFHA/PCL composite coating is composed of a thick (70-80μm) and porous layer of PCL that uniformly covered the thin nFHA film (8-10μm) with nanoneedle-like microstructure and crystallite size of around 70-90nm. Electrochemical measurements showed that the nFHA/PCL composite coating presented a high corrosion resistance (Rp=2.9×10(3)kΩcm(2)) and provided sufficient protection for a Mg substrate against galvanic corrosion. The mechanical integrity of the nFHA/PCL composite coatings immersed in SBF for 10days showed higher compressive strength (34% higher) compared with the uncoated samples, indicating that composite coatings can delay the loss of compressive strength of the Mg alloy. The nFHA/PCL coating indicted better bonding strength (6.9MPa) compared to PCL coating (2.2MPa). Immersion tests showed that nFHA/PCL composite-coated alloy experienced much milder corrosion attack and more nucleation sites for apatite compared with the PCL coated and uncoated samples. The bi-layered nFHA/PCL coating can be a good alternative method for the control of corrosion degradation of biodegradable Mg alloy for implant applications. PMID:26706560

  20. Ab-initio study of fluorine-doped tin dioxide: A prospective catalyst support for water electrolysis

    NASA Astrophysics Data System (ADS)

    Velikokhatnyi, Oleg I.; Kumta, Prashant N.

    2011-02-01

    In an attempt to identify new electrochemically stable catalyst supports for electrolysis of water, the electronic structure of SnO 2 doped with different fluorine concentrations has been calculated using the Vienna ab-initio simulation package (VASP) in the projector-augmented wave (PAW) method with the general gradient approximation (GGA) for conducting the exchange-correlation corrections. The role of fluorine in improving the electronic conductivity is discussed. An increase in the density of electronic states at the Fermi level with increase in the concentration of fluorine incorporated into the main SnO 2 matrix agrees well with published experimental observations. Despite a gradual decrease in the cohesive energies for the fluorine-doped tin oxide with increase in fluorine concentration, the doped material still remains an appropriate candidate for use as catalyst supports in water electrolysis warranting further experimental validation.

  1. Gamma-ray radiation response at 1550 nm of fluorine-doped radiation hard single-mode optical fiber.

    PubMed

    Kim, Youngwoong; Ju, Seongmin; Jeong, Seongmook; Lee, Seung Ho; Han, Won-Taek

    2016-02-22

    We have investigated gamma-ray radiation response at 1550 nm of fluorine-doped radiation hard single-mode optical fiber. Radiation-induced attenuation (RIA) of the optical fiber was measured under intermittent gamma-ray irradiations with dose rate of ~10 kGy/h. No radiation hardening effect on the RIA by the gamma-ray pre-dose was found when the exposed fiber was bleached for long periods of time (27~47 days) at room-temperature. Photo-bleaching scheme upon 980 nm LD pumping has proven to be an effective deterrent to the RIA, particularly by suppressing the incipient RIA due to room-temperature unstable self-trapped hole defects (STHs). Large temperature dependence of the RIA of the optical fiber together with the photo-bleaching effect are worthy of note for reinforcing its radiation hard characteristics. PMID:26907044

  2. The REPUSIL process and the capability of fluorine doping for the adjustment of optical and thermochemical properties in silica materials

    NASA Astrophysics Data System (ADS)

    Schuster, K.; Grimm, St.; Kalide, A.; Dellith, J.; Leich, M.; Schwuchow, A.; Unger, S.; Langner, A.; Schtz, G.; Bartelt, H.

    2015-03-01

    We report on the fluorine incorporation in powder based materials for the fabrication of Al and Al/Yb co-doped silica glasses. The achieved maximum Fluorine concentration of 1.55 mol% SiF4 corresponds to a refractive index decrease of -8 x 10-3. Simultaneously, the Tg of the doped material is reduced by about 200 K compared to pure silica. Moreover, the fluorine doping is also eminently suitable for the direct refractive index adjustment in active doped silica glass materials (e.g. Al/Yb or Al/Tm). The index matching with pure silica is possible to date up to 2.7 mol% Al2O3 and 0.1 mol% Yb2O3. The additional influence on the blue shift of the UV transmission will also be discussed.

  3. Fluorine doping: a feasible solution to enhancing the conductivity of high-resistance wide bandgap Mg0.51Zn0.49O active components

    PubMed Central

    Liu, Lishu; Mei, Zengxia; Hou, Yaonan; Liang, Huili; Azarov, Alexander; Venkatachalapathy, Vishnukanthan; Kuznetsov, Andrej; Du, Xiaolong

    2015-01-01

    N-type doping of high-resistance wide bandgap semiconductors, wurtzite high-Mg-content MgxZn1–xO for instance, has always been a fundamental application-motivated research issue. Herein, we report a solution to enhancing the conductivity of high-resistance Mg0.51Zn0.49O active components, which has been reliably achieved by fluorine doping via radio-frequency plasma assisted molecular beam epitaxial growth. Fluorine dopants were demonstrated to be effective donors in Mg0.51Zn0.49O single crystal film having a solar-blind 4.43 eV bandgap, with an average concentration of 1.0 × 1019 F/cm3.The dramatically increased carrier concentration (2.85 × 1017 cm−3 vs ~1014 cm−3) and decreased resistivity (129 Ω · cm vs ~106 Ω cm) indicate that the electrical properties of semi-insulating Mg0.51Zn0.49O film can be delicately regulated by F doping. Interestingly, two donor levels (17 meV and 74 meV) associated with F were revealed by temperature-dependent Hall measurements. A Schottky type metal-semiconductor-metal ultraviolet photodetector manifests a remarkably enhanced photocurrent, two orders of magnitude higher than that of the undoped counterpart. The responsivity is greatly enhanced from 0.34 mA/W to 52 mA/W under 10 V bias. The detectivity increases from 1.89 × 109 cm Hz1/2/W to 3.58 × 1010 cm Hz1/2/W under 10 V bias at room temperature.These results exhibit F doping serves as a promising pathway for improving the performance of high-Mg-content MgxZn1-xO-based devices. PMID:26489958

  4. PREFACE: Superconductivity in ultrathin films and nanoscale systems Superconductivity in ultrathin films and nanoscale systems

    NASA Astrophysics Data System (ADS)

    Bianconi, Antonio; Bose, Sangita; Garcia-Garcia, Antonio Miguel

    2012-12-01

    The recent technological developments in the synthesis and characterization of high-quality nanostructures and developments in the theoretical techniques needed to model these materials, have motivated this focus section of Superconductor Science and Technology. Another motivation is the compelling evidence that all new superconducting materials, such as iron pnictides and chalcogenides, diborides (doped MgB2) and fullerides (alkali-doped C60 compounds), are heterostrucures at the atomic limit, such as the cuprates made of stacks of nanoscale superconducting layers intercalated by different atomic layers with nanoscale periodicity. Recently a great amount of interest has been shown in the role of lattice nano-architecture in controlling the fine details of Fermi surface topology. The experimental and theoretical study of superconductivity in the nanoscale started in the early 1960s, shortly after the discovery of the BCS theory. Thereafter there has been rapid progress both in experiments and the theoretical understanding of nanoscale superconductors. Experimentally, thin films, granular films, nanowires, nanotubes and single nanoparticles have all been explored. New quantum effects appear in the nanoscale related to multi-component condensates. Advances in the understanding of shape resonances or Fano resonances close to 2.5 Lifshitz transitions near a band edge in nanowires, 2D films and superlattices [1, 2] of these nanosized modules, provide the possibility of manipulating new quantum electronic states. Parity effects and shell effects in single, isolated nanoparticles have been reported by several groups. Theoretically, newer techniques based on solving Richardson's equation (an exact theory incorporating finite size effects to the BCS theory) numerically by path integral methods or solving the entire Bogoliubov-de Gennes equation in these limits have been attempted, which has improved our understanding of the mechanism of superconductivity in these confined systems. In addition, the role of thermodynamic fluctuations on superconducting properties has been extensively studied in the context of nanoparticles and nanowires both experimentally and theoretically. In the past decade, a lot of work has been initiated in the area of interface superconductivity where different techniques have been demonstrated to tune Tc. Although the progress in this field has deepened our understanding of nanoscale superconductors, there are several open and key questions which need to be addressed. Some of these are: (1) can superconductivity be enhanced and Tc increased in nanostructures with respect to the bulk limit and if so, how can it be controlled? (2) What are the theoretical and experimental limits for the enhancement and control of superconductivity? (3) Can the phenomena identified in conventional nanostructures shed light on phenomena in high Tc superconductors and vice versa? (4) How will the new fundamental physics of superconductivity at the nanoscale promote advances in nanotechnology applications and vice versa? The papers in this focus section reflect the advances made in this field, in particular in nanowires and nanofilms, but also attempt to answer some of the key open questions outlined above. The theoretical papers explore unconventional quantum phenomena such as the role of confinement in the dynamics of single Cooper pairs in isolated grains [1] and Fano resonances in superconducting gaps in multi-condensate superconductors near a 2.5 Lifshitz transition [2]. Here a new emerging class of quantum phenomena of fundamental physics appear at the Bose-BCS crossover in multi-condensate superconductors [2]. Nanosize effects can now be manipulated by controlling defects in layered oxides [3]. A new approach is provided by controlling the self-organization of oxygen interstitials in layered copper oxides that show an intrinsic nanoscale phase separation [4]. In this case a non-trivial distribution of superconducting nanograins appears to enhance the critical temperature [4]. This is a hot topic as in the past year many works have clarified the nanoscale phase separation in electron-doped chalcogenides, showing the key role of a complex texture of nanograins and opening new avenues for the fundamental understanding of quantum phenomena in networks of superconducting nanograins. The advances in nanotechnology allow the exploration of the possible existence of superconductivity in single carbon nanotubes [5]. The technological applications presented by Gomez [6] and Lehtinen [7] show the fundamental physics of superconductivity at the nanoscale to promote new advances in quantum devices. We hope that this combination will make these focus papers in Superconductor Science and Technology interesting and promote cross-fertilization among the different sub-branches of the field which all share the same goal of addressing the key questions on nanoscale superconductors. References [1]Croitoru M D, Vagov A, Shanenko A A and Axt V M 2012 The Cooper problem in nanoscale: enhancement of the coupling due to confinement Supercond. Sci. Technol. 25 124001 [2]Perali A, Innocenti A, Valletta A and Bianconi A 2012 Anomalous isotope effect near a 2.5 Lifshitz transition in a multi-band multi-condensate superconductor made of a superlattice of stripes Supercond. Sci. Technol. 25 124002 [3]Zeng S W, Huang Z, Wang X, L W M, Liu Z Q, Zhang B M, Dhar S, Venkatesan T and Ariando 2012 The influence of La substitution and oxygen reduction in ambipolar La-doped YBa2Cu3Oy thin films Supercond. Sci. Technol. 25 124003 [4]Poccia N, Bianconi A, Campi G, Fratini M and Ricci A 2012 Size evolution of the oxygen interstitial nanowires in La2CuO4+y by thermal treatments and x-ray continuous illumination Supercond. Sci. Technol. 25 124004 [5]Yang Y, Fedorov G, Zhang J, Tselev A, Shafranjuk S and Barbara P 2012 The search for superconductivity at van Hove singularities in carbon nanotubes Supercond. Sci. Technol. 25 124005 [6]Gomez A, Gonzalez E M and Vicent J L 2012 Superconducting vortex dynamics on arrays with bicrystal-like structures: matching and rectifier effects Supercond. Sci. Technol. 25 124006 [7]Lehtinen J S and Arutyunov K Yu 2012 The quantum phase slip phenomenon in superconducting nanowires with a low-Ohmic environment Supercond. Sci. Technol. 25 124007

  5. Enhancement in the antibacterial efficiency of ZnO nanopowders by tuning the shape of the nanograins through fluorine doping

    NASA Astrophysics Data System (ADS)

    Ravichandran, K.; Snega, S.; Jabena Begum, N.; Swaminathan, K.; Sakthivel, B.; Rene Christena, L.; Chandramohan, G.; Ochiai, Shizuyasu

    2014-05-01

    Fluorine doped ZnO nanopowders were synthesized from starting solutions having different doping levels of F (0, 5, , 20 at.%) using a simple soft chemical route and the effects of the doping level on the structural, optical, surface morphological and antibacterial properties were investigated. The XRD studies reveal that all the products have preferential orientation along the (1 0 1) plane. The PL studies show that all the samples exhibit strong visible emission with a peak at 425 nm. The enhancement in the visible emission indicates an increasing number of surface defects caused by the doping of F. The obtained FTIR spectra confirm the incorporation of F into ZnO lattice. From the SEM studies, it is observed that the ZnO nanowires formed at 10 at.% of F doping level exhibit excellent antibacterial activities. Antibacterial activity of F doped ZnO nanopowders against Staphylococcus aureus was found to be significantly higher than that against the Escherichia coli and Pseudomonas aeruginosa micro-organisms. All the physical properties were corroborated well with the findings related to antibacterial activity. Finally, we conclude that, the analysis of all the results shows that F doping level of 10 at.% is optimal in all respects and is suitable for antibacterial applications.

  6. Micrometer-sized fluorine doped tin oxide as fast electron collector for enhanced dye-sensitized solar cells.

    PubMed

    Cui, Xiao Rui; Wang, Ye Feng; Li, Zhao; Zhou, Lu; Gao, Fei; Zeng, Jing Hui

    2014-10-01

    Titanium dioxide (TiO2)-layered fluorine doped tin oxide (FTO) powder was synthesized and applied as the photoanode in dye-sensitized solar cells (DSSCs). FTO powders are connected to form a direct electron pathway for the efficient extract of injected electrons, while the TiO2 layer serves as an energy barrier prohibiting the charge combination with oxidized dye or I3(-). The electrochemical impedance spectroscopy (EIS) analyses suggest that electrons have a longer combination lifetime (?e = 233 ms) than that of the electron in the DSSCs using traditional P25 photoanodes (?e = 28 ms). The DSSCs using 5 ?m thick TiO2@FTO as photoanodes eventually give a respectable and long-term stable photovoltaic performance with a current density of 23.8 mA/cm(2), an open circuit voltage of 0.69 V, and power conversion efficiency of 7.4%. The results are received on a low dye loading level (0.25 10(-7) mol/cm(2)), which is (1)/10 of that for traditional photoanode (2.79 10(-7) mol/cm(2)). PMID:25226086

  7. Fluorine-doped LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} for 5 V cathode materials of lithium-ion battery

    SciTech Connect

    Du Guodong; NuLi, Yanna; Yang Jun Wang Jiulin

    2008-12-01

    Fluorine-doped 5 V cathode materials LiNi{sub 0.5}Mn{sub 1.5}O{sub 4-x}F{sub x} (0.05 {<=} x {<=} 0.2) have been prepared by sol-gel and post-annealing treatment method. The results from X-ray diffraction and scanning electron microscopy (SEM) indicate that the spinel structure changes little after fluorine doping, but the particle size varies with fluorine doping and the preparation conditions. The electrochemical measurements show that stable cycling performance can be obtained when the fluorine amount x is higher than 0.1, but the specific capacity is decreased and 4 V plateau capacity resulting from a conversion of Mn{sup 4+}/Mn{sup 3+} remains. Moreover, influence of the particle size on the reversible capacity of the electrode, especially on the kinetic property, has been examined.

  8. Water Oxidation and Oxygen Monitoring by Cobalt-Modified Fluorine-Doped Tin Oxide Electrodes

    SciTech Connect

    Kent, CA; Concepcion, JJ; Dares, CJ; Torelli, DA; Rieth, AJ; Miller, AS; Hoertz, PG; Meyer, TJ

    2013-06-12

    Electrocatalytic water oxidation occurs at fluoride-doped tin oxide (FTO) electrodes that have been surface-modified by addition of Co(II). On the basis of X-ray photoelectron spectroscopy and transmission electron microscopy measurements, the active surface site appears to be a single site or small-molecule assembly bound as Co(II), with no evidence for cobalt oxide film or cluster formation. On the basis of cyclic voltammetry measurements, surface-bound Co(II) undergoes a pH-dependent 1e(-)/1H(+) oxidation to Co(III), which is followed by pH-dependent catalytic water oxidation. O-2 reduction at FTO occurs at -0.33 V vs NHE, allowing for in situ detection of oxygen as it is formed by water oxidation on the surface. Controlled-potential electrolysis at 1.61 V vs NHE at pH 7.2 resulted in sustained water oxidation catalysis at a current density of 0.16 mA/cm(2) with 29 000 turnovers per site over an electrolysis period of 2 h. The turnover frequency for oxygen production per Co site was 4 s(-1) at an overpotential of 800 mV at pH 7.2. Initial experiments with Co(II) on a mesoporous, high-surface-area nanoFTO electrode increased the current density by a factor of similar to 5

  9. Fluorine-doped nanocrystalline SnO{sub 2} powders prepared via a single molecular precursor method as anode materials for Li-ion batteries

    SciTech Connect

    Ha, Hyung-Wook; Kim, Keon . E-mail: kkim@korea.ac.kr; Borniol, Mervyn de; Toupance, Thierry . E-mail: t.toupance@lcoo.u-bordeaux1.fr

    2006-03-15

    Fluorine-doped nanocrystalline tin dioxide materials (F:SnO{sub 2}) have been successfully prepared by the sol-gel process from a single molecular precursor followed by a thermal treatment at 450-650 deg. C. The resulting materials were characterized by FTIR spectroscopy, powder X-ray diffraction, nitrogen adsorption porosimetry (BET) and transmission electron microscopy (TEM). The mean particle size increased from 5 to 20 nm and the specific surface area decreased from 123 to 37 m{sup 2}/g as the temperature of heat treatment was risen from 450 to 650 deg. C. Fluorine-doped nanocrystalline SnO{sub 2} exhibited capacity of 560, 502, and 702 mA h/g with 48%, 50%, and 40% capacity retention after 25 cycles between 1.2 V and 50 mV at the rate of 25 mA/g, respectively. In comparison, commercial SnO{sub 2} showed an initial capacity of 388 mA h/g, with only 23% capacity retention after 25 cycles.

  10. Effects of fluorine doping on thermoelectric properties of Sr0.61Ba0.39Nb2O6 ceramics

    NASA Astrophysics Data System (ADS)

    Li, Yi; Liu, Jian; Wang, Zhen; Zhou, YuCheng; Wang, Chunlei; Li, Jichao; Zhu, Yuanhu; Li, Maokui; Mei, Liangmo

    2015-02-01

    The thermoelectric properties of Sr0.61Ba0.39Nb2O6 ceramics, doped with different contents of fluorine at the oxygen sites, were investigated in the temperature range of 323 to 1073 K. The electrical resistivity is reduced significantly after fluorine doping. However, the magnitudes of electrical resistivity, Seebeck coefficient (S), and slope of S at high temperatures (dS/dT) vary non-monotonically with increasing doping contents, indicating that doped fluorine ions not only act as electron donors, but also influence band structure. The lattice thermal conductivity decreases when fluorine ions are slightly doped, and increases with increasing fluorine content because of the increasing average grain size. The thermoelectric performance is enhanced by slight fluorine doping due to the increase of the power factor and the reduction of thermal conductivity. The thermoelectric figure of merit reaches maximum value (0.21 at 1073 K) in the Sr0.61Ba0.39Nb2O5.95F0.05 sample.

  11. Microwave shielding of fluorine-doped tin oxide film obtained by spray pyrolysis studied by electrical characterization

    NASA Astrophysics Data System (ADS)

    Rubinger, C. P. L.; da Cunha, A. F.; Vinagre, F.; Ribeiro, G. M.; Costa, L. C.

    2009-04-01

    In this work, we report dc conductivity and Hall effect results for glasses coated with commercial In2O3:Sn and SnO2:F. Van der Pauw Hall effect and resistivity measurements were used to carry out the sheet resistance of the samples and to determine their carrier density, mobility, and conductivity from 10 to 325 K. We calculated the transmission from the dc measurements and compared it with the microwave response of a typical microwave oven door used as a barrier on a cavity resonator, at 2.8 GHz. By controlling the oxygen doping through the H2O amount in the solution, we were able to increase the mobility of SnO2:F sample and as a consequence obtained an improved microwave shielding power. We estimated that, for the best case, a coating 13.2 ?m thick should suffice for a shielding power similar to that of a microwave oven door.

  12. The effect of fluorine doping on electronic structure and ferromagnetic stability of Os-doped TiO2 rutile phase: First-principles calculations

    NASA Astrophysics Data System (ADS)

    Fakhim Lamrani, A.; Ouchri, M.; Belaiche, M.; El Kenz, A.; Loulidi, M.; Benyoussef, A.

    2016-03-01

    We have investigated the effect of fluorine doping on electronic structure and ferromagnetic stability of Os-doped TiO2 rutile using the first-principles calculations within generalized gradient approximation. We find that Ti14 Os2 O32 is half metallic ferromagnetic with homogenous of physical properties in different directions of osmium, but the obtained results show that the antiferromagnetic order is energetically much favored relative to the ferromagnetic order in all the considered directions. The addition of fluorine in this system plays an important role in the stability of the ferromagnetic state. Indeed, the Ti14 Os2 O30 F2 compound presents a high electronic concentration at the Fermi level. In fact, the F-dopant behaves as an n-donor and introduces an extra electron in the system with 100% spin polarization of the conduction electrons crossing the Fermi level.

  13. High performance dye-sensitized solar cells using graphene modified fluorine-doped tin oxide glass by Langmuir-Blodgett technique

    NASA Astrophysics Data System (ADS)

    Roh, Ki-Min; Jo, Eun-Hee; Chang, Hankwon; Han, Tae Hee; Jang, Hee Dong

    2015-04-01

    Since the introduction of dye-sensitized solar cells (DSSCs) with low fabrication cost and high power conversion efficiency, extensive studies have been carried out to improve the charge transfer rate and performance of DSSCs. In this paper, we present DSSCs that use surface modified fluorine-doped tin oxide (FTO) substrates with reduced graphene oxide (r-GO) sheets prepared using the Langmuir-Blodgett (LB) technique to decrease the charge recombination at the TiO2/FTO interface. R-GO sheets were excellently attached on FTO surface without physical deformations such as wrinkles; effects of the surface coverage of r-GO on the DSSC performance were also investigated. By using graphene modified FTO substrates, the resistance at the interface of TiO2/FTO was reduced and the power conversion efficiency was increased to 8.44%.

  14. Longitudinal and transverse spin dynamics of donor-bound electrons in fluorine-doped ZnSe: Spin inertia versus Hanle effect

    NASA Astrophysics Data System (ADS)

    Heisterkamp, F.; Zhukov, E. A.; Greilich, A.; Yakovlev, D. R.; Korenev, V. L.; Pawlis, A.; Bayer, M.

    2015-06-01

    The spin dynamics of strongly localized donor-bound electrons in fluorine-doped ZnSe epilayers is studied using pump-probe Kerr rotation techniques. A method exploiting the spin inertia is developed and used to measure the longitudinal spin relaxation time T1 in a wide range of magnetic fields, temperatures, and pump densities. The T1 time of the donor-bound electron spin of about 1.6 ? s remains nearly constant for external magnetic fields varied from zero up to 2.5 T (Faraday geometry) and in a temperature range 1.8-45 K. These findings impose severe restrictions on possible spin relaxation mechanisms. In our opinion they allow us to rule out scattering between free and donor-bound electrons, jumping of electrons between different donor centers, scattering between phonons and donor-bound electrons, and with less certainty charge fluctuations in the environment of the donors caused by the 1.5 ps pulsed laser excitation.

  15. Rectifying properties of ZnO thin films deposited on FTO by electrodeposition technique

    NASA Astrophysics Data System (ADS)

    Lv, Jianguo; Sun, Yue; Zhao, Min; Cao, Li; Xu, Jiayuan; He, Gang; Zhang, Miao; Sun, Zhaoqi

    2016-03-01

    ZnO thin films were successfully grown on fluorine-doped tin oxide glass by electrodeposition technique. The crystal structure, surface morphology and optical properties of the thin films were investigated. The average crystallite size and intensity of A1(LO) mode increase with improving the absolute value of deposition potential. The best preferential orientation along c-axis and the richest oxygen interstitial defects have been observed in the sample deposited at -0.8 V. A heterojunction device consisting of ZnO thin film and n-type fluorine-doped tin oxide was fabricated. The current-voltage (I-V) characteristic of the p-n heterojunction device deposited at -0.8 V shows the best rectifying diode behavior. The p-type conductivity of the ZnO thin film could be attributed to complex defect of unintentional impurity and interstitial oxygen.

  16. Comparison of Power Handling Capability of Double-strip Resonator Filters with Stripline Structure and Conventional Microstrip Line Filters

    NASA Astrophysics Data System (ADS)

    Sekiya, N.

    The power handling capability of a high temperature superconducting transmit filter with a double-strip resonator (DSR) was investigated by comparing the performances of such a filter with conventional microstrip-line (MSL) filter. The DSR structure consists of two coupled strips and the center pin of the SMA connector as feed line. The idea is to increase the effective film thickness to reduce the current concentration at the edges of the resonator compared with that of an MSL resonator. The two three-pole filters were designed using electromagnetic simulator. The center frequency and 3dB-bandwidth are a 5.0-GHz and a 100-MHz. The two filters were fabricated using YBa2Cu3Oy thin films on a CeO2-buffered r-Al2O3 substrate. The measured frequency responses of the filters were in reasonable agreement with the simulated ones. The measured power handling capability of the DSR filter was 3.5 dBm larger than that of the MSL filter.

  17. HTS Dual-band Bandpass Filter Using Stub-loaded Hair-pin Resonators with Independently Controllable Bandwidths

    NASA Astrophysics Data System (ADS)

    Sekiya, N.; Sugiyama, S.

    We have developed a high-temperature superconducting (HTS) dual-band bandpass filter (BPF) using stub-loaded hair-pin resonators with independently controllable bandwidths. The proposed dual-band BPF is composed of five stub-loaded hair-pin resonators with H-shaped waveguides placed at the center in the spaces between them. The resonator enables independent control of the first and second band resonant frequencies. The main advantage of the proposed filter was to enable independent control of the bandwidths of the first and second band. The coupling coefficient of the second one was controlled by the distance between the resonators, which did not affect the coupling coefficient of the first one. On the other hand, the coupling coefficient of the first one was controlled by the H-shaped waveguide, which did not affect the coupling coefficient of the secondone. An electromagnetic simulator was used to design and analyze the filter. The filter was designed at 3.5 GHz with a 70-MHz (2%) bandwidth for the first band and at 5.0 GHz with a 250-MHz (5%) bandwidth for the second band. The filter was fabricated using YBa2Cu3Oy thin film on a CeO2-bufferd Al2O3 substrate. The measured results agree well with the simulated ones.

  18. Effect of substrate temperature on electrochromic properties of spray-deposited Ir-oxide thin films

    NASA Astrophysics Data System (ADS)

    Patil, P. S.; Kawar, R. K.; Sadale, S. B.

    2005-08-01

    Electrochromic iridium oxide thin films were prepared by using a simple and inexpensive spray pyrolysis technique onto fluorine doped tin oxide (FTO)-coated glass substrates, from iridium chloride solution. The substrate temperature was varied between 250 and 400 C. The as-deposited samples were amorphous. The electrochromic properties of thin films were studied in aqueous electrolyte (0.5N H 2SO 4) using cyclic voltammetry (CV), chronoamperometry (CA) and spectroelectrochemical techniques. The films exhibit anodic electrochromism upon intercalation and deintercalation of H + ions. The colouration efficiency at 630 nm was calculated and found maximum for I 250 sample, owing its hydration.

  19. Control of threshold voltage in E-mode and D-mode GaN-on-Si metal-insulator-semiconductor heterostructure field effect transistors by in-situ fluorine doping of atomic layer deposition Al2O3 gate dielectrics

    NASA Astrophysics Data System (ADS)

    Roberts, J. W.; Chalker, P. R.; Lee, K. B.; Houston, P. A.; Cho, S. J.; Thayne, I. G.; Guiney, I.; Wallis, D.; Humphreys, C. J.

    2016-02-01

    We report the modification and control of threshold voltage in enhancement and depletion mode AlGaN/GaN metal-insulator-semiconductor heterostructure field effect transistors through the use of in-situ fluorine doping of atomic layer deposition Al2O3. Uniform distribution of F ions throughout the oxide thickness are achievable, with a doping level of up to 5.5 × 1019 cm-3 as quantified by secondary ion mass spectrometry. This fluorine doping level reduces capacitive hysteretic effects when exploited in GaN metal-oxide-semiconductor capacitors. The fluorine doping and forming gas anneal also induces an average positive threshold voltage shift of between 0.75 and 1.36 V in both enhancement mode and depletion mode GaN-based transistors compared with the undoped gate oxide via a reduction of positive fixed charge in the gate oxide from +4.67 × 1012 cm-2 to -6.60 × 1012 cm-2. The application of this process in GaN based power transistors advances the realisation of normally off, high power, high speed devices.

  20. RF Sputtered Iridium (Ir) Film as a Counter Electrode for Dye-Sensitized Solar Cells

    NASA Astrophysics Data System (ADS)

    Mokurala, Krishnaiah; Kamble, Anvita; Bhargava, Parag; Mallick, Sudhanshu

    2015-11-01

    Iridium (Ir) films were deposited on fluorine-doped tin oxide substrate by radio-frequency sputtering at room temperature and the as-deposited films were used as counter electrodes (CE) for dye-sensitized solar cells (DSSC). The photo conversion efficiency (PCE) of DSSC fabricated with Ir-based CE was 7.2%. Electrocatalytic activity and electrochemical data for Ir-based CE were compared with those for conventional Pt-based CE. The results were indicative of potential use of Ir as an alternative CE material for DSSC.

  1. Indium-free Cu/fluorine doped ZnO composite transparent conductive electrodes with stretchable and flexible performance on poly(ethylene terephthalate) substrate

    NASA Astrophysics Data System (ADS)

    Han, Jun; Gong, Haibo; Yang, Xiaopeng; Qiu, Zhiwen; Zi, Min; Qiu, Xiaofeng; Wang, Hongqiang; Cao, Bingqiang

    2015-03-01

    Material-abundant ZnO and metal thin film have been proposed as potential alternatives for the most widely commercial indium tin oxide (ITO) transparent and conductive electrode. Yet the deterioration of optical transparency and conductivity for these materials makes them difficult to compete with ITO. In this work, a double-layer structured film-composed of FZO and Cu film is presented at room temperature, which combines the high transparency of FZO and high conductivity of Cu film. We first studied the effect of oxygen pressure on the transparency and conductivity of free-standing FZO layer deposited on poly(ethylene terephthalate) (PET) by PLD method. Also the structural, electrical, and optical properties of bilayers electrode dependence on the Cu layer thickness were optimized in detail. As the Cu layer thickness increases, the resistivity decreases. The lowest resistivity of 6.6 10-5 ? cm with a carrier concentration of 1.11 1022 cm-3 and mobility of 8.52 cm2 V-1 s-1 was obtained at the optimum Cu (12 nm) layer thickness. We find that FZO layer have anti-reflection effect for Cu/FZO (250 nm) bilayer in the wavelength range of 650-1000 nm compared with single Cu layer. And we firstly study the stretchable performance for Cu film-based composite electrodes with stretching ratio changing from 0 to 5%. Furthermore, we study excellent mechanical flexibility and stability of composite electrodes by bending test.

  2. Resistive switching model change induced by electroforming in α-Fe2O3 films

    NASA Astrophysics Data System (ADS)

    Yan, Xiaobing; Li, Yucheng; Zhao, Jianhui; Xia, Yidong; Zhang, Minglong; Liu, Zhiguo

    2015-10-01

    Two types of bipolar resistive switching (RS) model were revealed respectively, before and after electroforming in the α-Fe2O3 films fabricated by ultrasonic spray pyrolysis on fluorine-doped SnO2 conducting glass. The current-voltage curves of cell before and after electroforming were fitted. The conduction mechanism at high resistance state of the model before electroforming was attributed to Schottky emission, whereas after electroforming it can be explained by space-charge-limited conduction. These two types of RS model originate from interface and bulk effect, respectively. The retention of the cells with different RS models was studied comparatively and the possible mechanism was discussed.

  3. Double junction photoelectrochemical solar cells based on Cu2ZnSnS4/Cu2ZnSnSe4 thin film as composite photocathode

    NASA Astrophysics Data System (ADS)

    Zhu, L.; Qiang, Y. H.; Zhao, Y. L.; Gu, X. Q.

    2014-02-01

    A solvothermal method was used to synthesize Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe) nanoparticles. CZTS/CZTSe bilayer films have been fabricated via a layer-by-layer blade coating process on the fluorine dope tin oxide (FTO) substrates. We converted conventional dye-sensitized solar cells (DSSCs) into double junction photoelectrochemical solar cells with the replacement of the Pt-coated counter electrode with the as-prepared films as composite photocathodes. Compared with conventional DSSCs, the cells show an increased short circuit current and power conversion efficiency.

  4. Design of a TiO2 nanosheet/nanoparticle gradient film photoanode and its improved performance for dye-sensitized solar cells.

    PubMed

    Wang, Wenguang; Zhang, Haiyan; Wang, Rong; Feng, Ming; Chen, Yiming

    2014-02-21

    A TiO2 film photoanode with gradient structure in nanosheet/nanoparticle concentration on the fluorine-doped tin oxide glass from substrate to surface was prepared by a screen printing method. The as-prepared dye-sensitized solar cell (DSSC) based on the gradient film electrode exhibited an enhanced photoelectric conversion efficiency of 6.48%, exceeding that of a pure nanoparticle-based DSSC with the same film thickness by a factor of 2.6. The enhanced photovoltaic performance of the gradient film-based DSSC was attributed to the superior light scattering ability of TiO2 nanosheets within the gradient structure, which was beneficial to light harvesting. Furthermore, the TiO2 nanosheets with exposed {001} facets facilitated the electron transport from dye molecules to the conduction band of TiO2 and further to the conductive glass. Meanwhile, the high specific surface area of TiO2 nanosheets helped the adsorption of dye molecules, and the TiO2 nanoparticle underlayer ensured good electronic contact between the TiO2 film and the fluorine-doped tin oxide glass substrate. The electrochemical impedance spectroscopy measurements further confirmed the electron transport differences between DSSCs based on nanosheet/nanoparticle gradient film electrodes and DSSCs based on nanosheet/nanoparticle homogeneous mixtures, pure TiO2 nanoparticles and pure TiO2 nanosheets with the same film thickness. PMID:24435106

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

    SciTech Connect

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

    2013-06-13

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

  6. Electrochromic properties of vanadium oxide thin films prepared by PSPT: Effect of substrate temperature

    NASA Astrophysics Data System (ADS)

    Patil, C. E.; Jadhav, P. R.; Tarwal, N. L.; Deshmukh, H. P.; Karanjakar, M. M.; Wali, A. A.; Patil, P. S.

    2013-06-01

    Electrochromic vanadium oxide (V2O5) thin films were deposited onto glass and fluorine doped tin oxide (FTO) coated glass substrates from methanolic vanadium chloride solution by pulsed spray pyrolysis technique (PSPT). The films were synthesized at different substrate temperatures ranging from 350C-450C with a temperature step of 50C. The structural, morphological, optical and electrochromic properties of the synthesized films were investigated. The films were polycrystalline with tetragonal crystal structure. Scanning electron microscopy reveals compact morphology at high temperature. All films exhibited cathodic electrochromism in lithium containing electrolyte (0.5 M LiClO4 + Propylene Carbonate). Maximum coloration efficiency (CE) 15.16 cm2C-1, was observed for the films deposited at 350C.

  7. Morphology-tailored synthesis of tungsten trioxide (hydrate) thin films and their photocatalytic properties.

    PubMed

    Jiao, Zhihui; Wang, Jinmin; Ke, Lin; Sun, Xiao Wei; Demir, Hilmi Volkan

    2011-02-01

    Tungsten trioxide hydrate (3WO(3)H(2)O) films with different morphologies were directly grown on fluorine doped tin oxide (FTO) substrate via a facile crystal-seed-assisted hydrothermal method. Scanning electron microscopy (SEM) analysis showed that 3WO(3)H(2)O thin films composed of platelike, wedgelike, and sheetlike nanostructures could be selectively synthesized by adding Na(2)SO(4), (NH(4))(2)SO(4), and CH(3)COONH(4) as capping agents, respectively. X-ray diffraction (XRD) studies indicated that these films were of orthorhombic structure. The as-prepared thin films after dehydration showed obvious photocatalytic activities. The best film grown using CH(3)COONH(4) as a capping agent generated anodic photocurrents of 1.16 mA/cm(2) for oxidization of methanol and 0.5 mA/cm(2) for water splitting with the highest photoconversion efficiency of about 0.3% under simulated solar illumination. PMID:21218846

  8. Photoelectrochemical characterization of nanocrystalline thin-film Cu?ZnSnS? photocathodes.

    PubMed

    Riha, Shannon C; Fredrick, Sarah J; Sambur, Justin B; Liu, Yuejiao; Prieto, Amy L; Parkinson, B A

    2011-01-01

    Cu?ZnSnS? (CZTS) nanocrystals, synthesized by a hot injection solution method, have been fabricated into thin films by dip-casting onto fluorine doped tin oxide (FTO) substrates. The photoresponse of the CZTS nanocrystal films was evaluated using absorbance measurements along with photoelectrochemical methods in aqueous electrolytes. Photoelectrochemical characterization revealed a p-type photoresponse when the films were illuminated in an aqueous Eu(3+) redox electrolyte. The effects of CZTS stoichiometry, film thickness, and low-temperature annealing on the photocurrents from front and back illumination suggest that the minority carrier diffusion and recombination at the back contact (via reaction of photogenerated holes with Eu(2+) produced from photoreduction by minority carriers) are the main loss mechanisms in the cell. Low-temperature annealing resulted in significant increases in the photocurrents for films made from both Zn-rich and stoichiometric CZTS nanocrystals. PMID:21194208

  9. Effect of molarity on properties of spray pyrolysed SnO2:F thin films

    NASA Astrophysics Data System (ADS)

    Deepu, D. R.; Kartha, C. Sudha; Vijayakumar, K. P.

    2014-01-01

    Fluorine doped tin oxide (FTO) thin films were prepared by using automated Chemical Spray Pyrolysis (CSP) machine and the effect of concentration of the precursors on the conductivity and transmittance of the films were studied. The resistivity (ρ) and mobility (μ) are in the range of 10-3-10-4 Ω-cm and 8.2-13.5 cm2V-1s-1 respectively. The electron density lies between 3.4 × 1020 and 6.6×1020 cm-3. The film transmittance varies between 70 to 80% and the films shows very good reflectivity in the IR-NIR region. Prepared films can be used as transparent electrodes in photo voltaic and optoelectronic devices.

  10. Effect of molarity on properties of spray pyrolysed SnO{sub 2}:F thin films

    SciTech Connect

    Deepu, D. R. Kartha, C. Sudha Vijayakumar, K. P.

    2014-01-28

    Fluorine doped tin oxide (FTO) thin films were prepared by using automated Chemical Spray Pyrolysis (CSP) machine and the effect of concentration of the precursors on the conductivity and transmittance of the films were studied. The resistivity (ρ) and mobility (μ) are in the range of 10{sup −3}–10{sup −4} Ω-cm and 8.2–13.5 cm{sup 2}V{sup −1}s{sup −1} respectively. The electron density lies between 3.4 × 10{sup 20} and 6.6×10{sup 20} cm{sup −3}. The film transmittance varies between 70 to 80% and the films shows very good reflectivity in the IR-NIR region. Prepared films can be used as transparent electrodes in photo voltaic and optoelectronic devices.

  11. Effect of growth potential on the electrodeposition of CIS thin films

    NASA Astrophysics Data System (ADS)

    Dhanwate, Vishakha N.; Chaure, N. B.

    2013-02-01

    Thin films of copper indium diselenide (CIS) were prepared in aqueous bath by low-cost potentiostatic electrodeposition technique onto Fluorine doped tin oxide substrates. The deposition potential was optimized using cyclic voltammetry study in a ternary Cu-In-Se system. The films were characterized systematically with the aid of UV-Vis spectroscopy, IV measurements, X-ray diffraction, Scanning electron microscopy and Energy dispersive X-ray analysis. CIS films deposited for different growth potential shows the tetragonal structure with (112) preferential orientation. Annealing of the films at temperature 400°C not only improves the crystallinity of layers, but it also increases the grain size, which is suitable for the development of high efficiency solar cells.

  12. Hydrothermal synthesis and photoelectrochemical properties of In2S3 thin films with a wedgelike structure

    NASA Astrophysics Data System (ADS)

    Zhang, Lina; Zhang, Wei; Yang, Haibin; Fu, Wuyou; Li, Minghui; Zhao, Hui; Ma, Jinwen

    2012-09-01

    Indium sulfide (In2S3) thin films with a wedgelike structure were prepared on fluorine-doped tin oxide (FTO) substrate by a facile hydrothermal method. By properly monitoring the experimental conditions, including the reaction time, concentrations of tartaric acid, precursor concentration ratio and the reaction temperature, the In2S3 films with different morphologies and thickness could be obtained, and the growth mechanism of ?-In2S3 films was also proposed in this work. Furthermore, UV-vis absorption study revealed that the absorption range broadened with the growth of the In2S3 crystals. In addition, a photocurrent of 0.48 mA cm-2 was obtained under 100 mW cm-2 UV-visible illuminations of the wedgelike In2S3 thin films.

  13. Film formation of CdSe quantum dot embedded phosphate glass on an FTO glass substrate

    NASA Astrophysics Data System (ADS)

    Han, Karam; Kim, Yoon Hwa; Im, Won Bin; Chung, Woon Jin

    2015-07-01

    A thick film with CdSe quantum dot (QD) embedded glass was formed on a fluorine-doped tin oxide (FTO) glass substrate. Phosphate glasses with different CdO and ZnSe concentrations were synthesized, and the heat treatment conditions were varied to determine the appropriate QD and film formation conditions. Phosphate glass with 1 mol. % CdO and 1.5 mol. % ZnSe showed controlled crystallization of CdSe QDs when they were heat treated at 550? for 1 hr. Absorption spectra and Raman spectroscopy identified the QD formation. Precursor glass was ground into powder and pasted onto FTO only and TiO2/FTO glass substrates via the screen printing method. Glass film embedded with QDs was successfully formed after sintering, thus demonstrating its potential for film applications. [Figure not available: see fulltext.

  14. Perovskite solar cell using a two-dimensional titania nanosheet thin film as the compact layer.

    PubMed

    Li, Can; Li, Yahui; Xing, Yujin; Zhang, Zelin; Zhang, Xianfeng; Li, Zhen; Shi, Yantao; Ma, Tingli; Ma, Renzhi; Wang, Kunlin; Wei, Jinquan

    2015-07-22

    The compact layer plays an important role in conducting electrons and blocking holes in perovskite solar cells (PSCs). Here, we use a two-dimensional titania nanosheet (TNS) thin film as the compact layer in CH3NH3PbI3 PSCs. TNS thin films with thicknesses ranging from 8 to 75 nm were prepared by an electrophoretic deposition method from a dilute TNS/tetrabutylammonium hydroxide solution. The TNS thin films contact the fluorine-doped tin oxide grains perfectly. Our results show that a 8-nm-thick TNS film is sufficient for acting as the compact layer. Currently, the PSC with a TNS compact layer has a high efficiency of 10.7% and relatively low hysteresis behavior. PMID:26158908

  15. Fabrication of organic-inorganic perovskite thin films for planar solar cells via pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Liang, Yangang; Yao, Yangyi; Zhang, Xiaohang; Hsu, Wei-Lun; Gong, Yunhui; Shin, Jongmoon; Wachsman, Eric D.; Dagenais, Mario; Takeuchi, Ichiro

    2016-01-01

    We report on fabrication of organic-inorganic perovskite thin films using a hybrid method consisting of pulsed laser deposition (PLD) of lead iodide and spin-coating of methylammonium iodide. Smooth and highly crystalline CH3NH3PbI3 thin films have been fabricated on silicon and glass coated substrates with fluorine doped tin oxide using this PLD-based hybrid method. Planar perovskite solar cells with an inverted structure have been successfully fabricated using the perovskite films. Because of its versatility, the PLD-based hybrid fabrication method not only provides an easy and precise control of the thickness of the perovskite thin films, but also offers a straightforward platform for studying the potential feasibility in using other metal halides and organic salts for formation of the organic-inorganic perovskite structure.

  16. Calorimetric determination of the magnetic phase diagram of underdoped ortho II YBa2Cu3O6.54 single crystals

    PubMed Central

    Marcenat, C.; Demuer, A.; Beauvois, K.; Michon, B.; Grockowiak, A.; Liang, R.; Hardy, W.; Bonn, D. A.; Klein, T.

    2015-01-01

    The recent discovery of a charge order in underdoped YBa2Cu3Oy raised the question of the interplay between superconductivity and this competing phase. Understanding the normal state of high-temperature superconductors is now an essential step towards the description of the pairing mechanism in those materials and determining the upper critical field is therefore of fundamental importance. We present here a calorimetric determination of the field–temperature phase diagram in underdoped YBa2Cu3Oy single crystals. We show that the specific heat saturates in high magnetic fields. This saturation is consistent with a normal state without any significant superconducting contribution and a total Sommerfeld coefficient γN∼6.5±1.5 mJ mol−1 K−2 putting strong constraints on the theoretical models for the Fermi surface reconstruction. PMID:26294047

  17. Photoelectrochemical properties of chemosynthesized CdS thin film

    NASA Astrophysics Data System (ADS)

    Pawar, S. B.; Pawar, S. A.; Bhosale, P. N.; Patil, P. S.

    2012-06-01

    Thin film of cadmium sulphide (CdS) consisting cabbage like morphology was chemically synthesized at room temperature from an aqueous alkaline bath onto soda lime glass and fluorine-doped tin oxide (FTO)-coated glass substrates. The synthesized cabbages of CdS were characterized using X-ray diffraction (XRD), UV-vis spectroscopy and scanning electron microscopy (SEM). The XRD pattern revealed the formation of CdS particles with a cubic crystal structure. SEM micrographs show that the cabbage like morphology is composed of nanopetals. Further, the photoelectochemical (PEC) performance was tested in Na2S-NaOH-S electrolyte which has maximum short circuit current of (Isc) 359μA/cm2.

  18. Facile solution deposition of Cu2ZnSnS4 (CZTS) nano-worm films on FTO substrates and its photoelectrochemical property

    NASA Astrophysics Data System (ADS)

    Huang, Yaohan; Li, Guangli; Fan, Qingfei; Zhang, Meili; Lan, Qi; Fan, Ximei; Zhou, Zuowan; Zhang, Chaoliang

    2016-02-01

    In this work, Cu2ZnSnS4 (CZTS) nanoworm films have been directly deposited on fluorine-doped tin oxide (FTO) conductive glass substrates by a solvothermal method using polyethylene glycol 400 (PEG-400) as the solvent and structure-directing agent. The as-obtained CZTS thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectrum (XPS), UV-vis spectra and photoelectrochemical measurement. The synthetic conditions, such as reaction temperature, reaction time, solvents, were investigated to know the formation of CZTS thin films. The results showed that PEG-400 plays a key role in the formation of the nanoworms by affecting the crystal growth process. The p-type CZTS nanoworm film with the band gap of 1.62 eV was synthesized at 180 °C for 22 h and the photovoltaic performance was studied by forming a photoelectrochemical cell.

  19. Perovskite solar cells based on nanocolumnar plasma-deposited ZnO thin films.

    PubMed

    Ramos, F Javier; López-Santos, Maria C; Guillén, Elena; Nazeeruddin, Mohammad Khaja; Grätzel, Michael; Gonzalez-Elipe, Agustin R; Ahmad, Shahzada

    2014-04-14

    ZnO thin films having a nanocolumnar microstructure are grown by plasma-enhanced chemical vapor deposition at 423 K on pre-treated fluorine-doped tin oxide (FTO) substrates. The films consist of c-axis-oriented wurtzite ZnO nanocolumns with well-defined microstructure and crystallinity. By sensitizing CH3NH3PbI3 on these photoanodes a power conversion of 4.8% is obtained for solid-state solar cells. Poly(triarylamine) is found to be less effective when used as the hole-transport material, compared to 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD), while the higher annealing temperature of the perovskite leads to a better infiltration in the nanocolumnar structure and an enhancement of the cell efficiency. PMID:24643984

  20. Structural, compositional and morphological studies of thermally evaporated MoO{sub 3} thin films

    SciTech Connect

    Senthilkumar, R. E-mail: gravicrc@gmail.com; Ravi, G. E-mail: gravicrc@gmail.com

    2014-04-24

    Molybdenum oxide (MoO{sub 3}) nanostructures were grown on different substrates such as glass, indium tin oxide coated glass and fluorine doped glass by thermal evaporation of MoO{sub 3} powder at elevated temperature (750C) using tube furnace without any catalyst and then by subsequent O{sub 2}/Ar flow rate. The morphology, composition and crystal structure were examined by using SEM, EDAX, Laser Raman and XRD. The films are polycrystalline with well-defined diffraction peaks and it consist of MoO{sub 3} with ?-orthorhombic structure. The synthesized MoO{sub 3} belongs to different morphologies, generally nanobelt and nanohunk structures. The EDAX spectra confirm the films are composed only of Mo and O atoms. The O/Mo ratio is nearly equal to 3 that shows the stoichiometry of MoO{sub 3}.

  1. Aqueous phase deposition of dense tin oxide films with nano-structured surfaces

    SciTech Connect

    Masuda, Yoshitake Ohji, Tatsuki; Kato, Kazumi

    2014-06-01

    Dense tin oxide films were successfully fabricated in an aqueous solution. The pH of the solutions was controlled to pH 1.3 by addition of HCl. Precise control of solution condition and crystal growth allowed us to obtain dense tin oxide films. Concaveconvex surface of fluorine-doped tin oxide (FTO) substrates was entirely-covered with the continuous films. The films were about 65 nm in thickness and had nano-structured surfaces. Morphology of the films was strikingly different from our previous reported nano-sheet assembled structures. The films were not removed from the substrates by strong water flow or air blow to show strong adhesion strength. The aqueous solution process can be applied to surface coating of various materials such as nano/micro-structured surfaces, particles, fibers, polymers, metals or biomaterials. - Graphical abstract: Dense tin oxide films of 65 nm were successfully fabricated in an aqueous solution. They had nano-structured surfaces. Concave-convex substrates were entirely-covered with the continuous films. - Highlights: Dense tin oxide films of 65 nm were successfully fabricated in an aqueous solution. They had nano-structured surfaces. Concaveconvex substrates were entirely-covered with the continuous films.

  2. Influences of Pr and Ta doping concentration on the characteristic features of FTO thin film deposited by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Gven, Turgut; Adem, Koyi?it; Erdal, Snmez

    2015-10-01

    The Pr and Ta separately doped FTO (10 at.% F incorporated SnO2) films are fabricated via spray pyrolysis. The microstructural, topographic, optical, and electrical features of fluorine-doped TO (FTO) films are investigated as functions of Pr and Ta dopant concentrations. The x-ray diffraction (XRD) measurements reveal that all deposited films show polycrystalline tin oxide crystal property. FTO film has (200) preferential orientation, but this orientation changes to (211) direction with Pr and Ta doping ratio increasing. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) analyses show that all films have uniform and homogenous nanoparticle distributions. Furthermore, morphologies of the films depend on the ratio between Pr and Ta dopants. From ultraviolet-visible (UV-Vis) spectrophotometer measurements, it is shown that the transmittance value of FTO film decreases with Pr and Ta doping elements increasing. The band gap value of FTO film increases only at 1 at.% Ta doping level, it drops off with Pr and Ta doping ratio increasing at other doped FTO films. The electrical measurements indicate that the sheet resistance value of FTO film initially decreases with Pr and Ta doping ratio decreasing and then it increases with Pr and Ta doping ratio increasing. The highest value of figure of merit is obtained for 1 at.% Ta- and Pr-doped FTO film. These results suggest that Pr- and Ta-doped FTO films may be appealing candidates for TCO applications.

  3. Hierarchical growth of SnO2 nanostructured films on FTO substrates: structural defects induced by Sn(II) self-doping and their effects on optical and photoelectrochemical properties.

    PubMed

    Wang, Hongkang; Kalytchuk, Sergii; Yang, Haihua; He, Lifang; Hu, Chenyan; Teoh, Wey Yang; Rogach, Andrey L

    2014-06-01

    Direct hydrothermal growth of Sn(II)-doped SnO2 films on fluorine-doped tin oxide (FTO) substrates results in the formation of upstanding SnO2 nanosheet arrays covered by hierarchical SnO2 nanoflowers. The n-type semiconductor films show extended photoresponse in the visible spectrum arising from the coexistence of Sn(II) dopant ions and oxygen vacancies in these hierarchical SnO2 nanostructures, which leads to a narrowed bandgap. Photoluminescence spectroscopy revealed that the emission in the UV, blue and red spectral ranges is related to the evolution of Sn(II) dopants and oxygen vacancies with annealing temperature, whereas oxygen vacancies are mostly responsible for visible emission. The Sn(II)-doped SnO2 films show higher photocurrent when sensitized with narrow bandgap CdS nanoparticles, serving as efficient electron acceptors. PMID:24781385

  4. Growth of TiO2 nanosheet-array thin films by quick chemical bath deposition for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Zhu, Hu; Yang, Junyou; Feng, Shuanglong; Liu, Ming; Zhang, Jiansheng; Li, Gen

    2011-11-01

    Rutile TiO2 nanofilms, which were composed of many nanosheet-array domains with different orientations, were synthesized directly on fluorine-doped SnO2 conductive glass (FTO) substrates by a chemical deposition method in a short time in this paper. The average thickness of the nanosheets is about 10 nm; the nanosheets in each domain were parallel to each other and perpendicular to the substrate. The size and profile of the domains have a good correspondence to those of the FTO grains of the substrate, indicating a coherent nucleating and epitaxial growing nature of the films. The nanosheets split gradually and finally developed into nanofibers on prolonging the growing time to 20 h. Dye-sensitized solar cells, which were fabricated with the films, present an open-circuit voltage of 0.63 V and a short-circuit current of 7.02 mA/cm2, respectively.

  5. Fluorine compounds for doping conductive oxide thin films

    SciTech Connect

    Gessert, Tim; Li, Xiaonan; Barnes, Teresa M; Torres, Jr., Robert; Wyse, Carrie L

    2013-04-23

    Methods of forming a conductive fluorine-doped metal oxide layer on a substrate by chemical vapor deposition are described. The methods may include heating the substrate in a processing chamber, and introducing a metal-containing precursor and a fluorine-containing precursor to the processing chamber. The methods may also include adding an oxygen-containing precursor to the processing chamber. The precursors are reacted to deposit the fluorine-doped metal oxide layer on the substrate. Methods may also include forming the conductive fluorine-doped metal oxide layer by plasma-assisted chemical vapor deposition. These methods may include providing the substrate in a processing chamber, and introducing a metal-containing precursor, and a fluorine-containing precursor to the processing chamber. A plasma may be formed that includes species from the metal-containing precursor and the fluorine-containing precursor. The species may react to deposit the fluorine-doped metal oxide layer on the substrate.

  6. Photoelectrochemical properties of spray deposited n-CdSe thin films

    SciTech Connect

    Yadav, A.A.; Barote, M.A.; Masumdar, E.U.

    2010-05-15

    Polycrystalline cadmium selenide (CdSe) thin films have been prepared by spraying a mixture of an equimolar aqueous solutions of cadmium chloride and selenourea on preheated fluorine doped tin oxide (FTO) coated glass substrates at different substrate temperatures. The cell configuration n-CdSe/1 M (NaOH + Na{sub 2}S + S)/C is used for studying the capacitance-voltage (C-V) characteristics in dark, current-voltage (I-V) characteristics in dark and under illumination, photovoltaic power output and spectral response characteristics of the as deposited films. Photoelectrochemical study shows that as deposited CdSe thin films exhibits n-type of conductivity. The spectral response characteristics of the films at room temperature show a prominent sharp peak at 725 nm. The measured values of efficiency ({eta}) and fill factor (FF) are found to be 0.50% and 0.44 respectively for film deposited at 300 C. Electrochemical impedance spectroscopy studies show that the CdSe film deposited at 300 C shows better performance in PEC cell. (author)

  7. Growth of highly textured PbTiO3 films on conductive substrate under hydrothermal conditions

    NASA Astrophysics Data System (ADS)

    Tang, Haixiong; Zhou, Zhi; Bowland, Christopher C.; Sodano, Henry A.

    2015-08-01

    Perovskite structure (ABO3) thin films have wide applications in electronic devices due to their unique properties, including high dielectric permittivity, ferroelectricity and piezoelectric coupling. Here, we report an approach to grow highly textured thick lead titanate (PbTiO3) films on conductive substrates by a two-step hydrothermal reaction. Initially, vertically aligned TiO2 nanowire arrays are grown on fluorine-doped tin oxide (FTO) coated glass, which act as template crystals for conversion to the perovskite structure. The PbTiO3 films are then converted from TiO2 NW arrays by diffusing Pb2+ ions into the template through a second hydrothermal reaction. The dielectric permittivity and piezoelectric coupling coefficient (d33) of the PbTiO3 films are as high as 795 at 1 kHz and 52 pm V-1, respectively. The reported process can also potentially be expanded for the assembly of other complex perovskite ATiO3 (A = Ba, Ca, Cd, etc) films by using the highly aligned TiO2 NW arrays as templates. Therefore, the approach introduced here opens up a new door to synthesize ferroelectric thin films on conductive substrates for application in sensors, actuators, and ultrasonic transducers that are important in various industrial and scientific areas.

  8. Reference of Temperature and Time during tempering process for non-stoichiometric FTO films

    NASA Astrophysics Data System (ADS)

    Yang, J. K.; Liang, B.; Zhao, M. J.; Gao, Y.; Zhang, F. C.; Zhao, H. L.

    2015-10-01

    In order to enhance the mechanical strength of Low-E glass, Fluorine-doped tin oxide (FTO) films have to be tempered at high temperatures together with glass substrates. The effects of tempering temperature (600?C?~?720?C) and time (150?s?~?300?s) on the structural and electrical properties of FTO films were investigated. The results show all the films consist of non-stoichiometric, polycrystalline SnO2 without detectable amounts of fluoride. 700?C and 260?s may be the critical tempering temperature and time, respectively. FTO films tempered at 700?C for 260?s possesses the resistivity of 7.54??10-4??cm, the average transmittance in 400?~?800?nm of ~80%, and the calculated emissivity of 0.38. Hall mobility of FTO films tempered in this proper condition is mainly limited by the ionized impurity scattering. The value of [O]/[Sn] at the film surface is much higher than the stoichiometric value of 2.0 of pure crystalline SnO2.

  9. Reference of Temperature and Time during tempering process for non-stoichiometric FTO films

    PubMed Central

    Yang, J. K.; Liang, B.; Zhao, M. J.; Gao, Y.; Zhang, F. C.; Zhao, H. L.

    2015-01-01

    In order to enhance the mechanical strength of Low-E glass, Fluorine-doped tin oxide (FTO) films have to be tempered at high temperatures together with glass substrates. The effects of tempering temperature (600 °C ~ 720 °C) and time (150 s ~ 300 s) on the structural and electrical properties of FTO films were investigated. The results show all the films consist of non-stoichiometric, polycrystalline SnO2 without detectable amounts of fluoride. 700 °C and 260 s may be the critical tempering temperature and time, respectively. FTO films tempered at 700 °C for 260 s possesses the resistivity of 7.54 × 10−4 Ω•cm, the average transmittance in 400 ~ 800 nm of ~80%, and the calculated emissivity of 0.38. Hall mobility of FTO films tempered in this proper condition is mainly limited by the ionized impurity scattering. The value of [O]/[Sn] at the film surface is much higher than the stoichiometric value of 2.0 of pure crystalline SnO2. PMID:26462875

  10. Reference of Temperature and Time during tempering process for non-stoichiometric FTO films.

    PubMed

    Yang, J K; Liang, B; Zhao, M J; Gao, Y; Zhang, F C; Zhao, H L

    2015-01-01

    In order to enhance the mechanical strength of Low-E glass, Fluorine-doped tin oxide (FTO) films have to be tempered at high temperatures together with glass substrates. The effects of tempering temperature (600 °C ~ 720 °C) and time (150 s ~  300 s) on the structural and electrical properties of FTO films were investigated. The results show all the films consist of non-stoichiometric, polycrystalline SnO2 without detectable amounts of fluoride. 700 °C and 260 s may be the critical tempering temperature and time, respectively. FTO films tempered at 700 °C for 260 s possesses the resistivity of 7.54 × 10(-4) Ω • cm, the average transmittance in 400 ~ 800 nm of ~80%, and the calculated emissivity of 0.38. Hall mobility of FTO films tempered in this proper condition is mainly limited by the ionized impurity scattering. The value of [O]/[Sn] at the film surface is much higher than the stoichiometric value of 2.0 of pure crystalline SnO2. PMID:26462875

  11. Films

    NASA Astrophysics Data System (ADS)

    Li, Ming; Zhang, Yang; Shao, Yayun; Zeng, Min; Zhang, Zhang; Gao, Xingsen; Lu, Xubing; Liu, J.-M.; Ishiwara, Hiroshi

    2014-09-01

    In this paper, we investigated the microstructure and electrical properties of Bi2SiO5 (BSO) doped SrBi2Ta2O9 (SBT) films deposited by chemical solution deposition. X-ray diffraction observation indicated that the crystalline structures of all the BSO-doped SBT films are nearly the same as those of a pure SBT film. Through BSO doping, the 2Pr and 2Ec values of SBT films were changed from 15.3 ?C/cm2 and 138 kV/cm of pure SBT to 1.45 ?C/cm2 and 74 kV/cm of 10 wt.% BSO-doped SBT. The dielectric constant at 1 MHz for SBT varied from 199 of pure SBT to 96 of 10 wt.% BSO-doped SBT. The doped SBT films exhibited higher leakage current than that of non-doped SBT films. Nevertheless, all the doped SBT films still had small dielectric loss and low leakage current. Our present work will provide useful insights into the BSO doping effects to the SBT films, and it will be helpful for the material design in the future nonvolatile ferroelectric memories.

  12. Intrinsic Doping in Electrodeposited ZnS Thin Films for Application in Large-Area Optoelectronic Devices

    NASA Astrophysics Data System (ADS)

    Madugu, Mohammad Lamido; Olusola, Olajide Ibukun-Olu; Echendu, Obi Kingsley; Kadem, Burak; Dharmadasa, Imyhamy Mudiy

    2016-01-01

    Zinc sulphide (ZnS) thin films with both n- and p-type electrical conductivity were grown on glass/fluorine-doped tin oxide-conducting substrates from acidic and aqueous solution containing ZnSO4 and (NH4)2S2O3 by simply changing the deposition potential in a two-electrode cell configuration. After deposition, the films were characterised using various analytical techniques. X-ray diffraction analysis reveals that the materials are amorphous even after heat treatment. Optical properties (transmittance, absorbance and optical bandgap) of the films were studied. The bandgaps of the films were found to be in the range (3.68-3.86) eV depending on the growth voltage. Photoelectrochemical cell measurements show both n- and p-type electrical conductivity for the films depending on the growth voltage. Scanning electron microscopy shows material clusters on the surface with no significant change after heat treatment at different temperatures. Atomic force microscopy shows that the surface roughness of these materials remain fairly constant reducing only from 18 nm to 17 nm after heat treatment. Thickness estimation of the films was also carried out using theoretical and experimental methods. Direct current conductivity measurements on both as-deposited and annealed films show that resistivity increased after heat treatment.

  13. Synthesis of cauliflower-like ZnO-TiO 2 composite porous film and photoelectrical properties

    NASA Astrophysics Data System (ADS)

    Jiang, Yinhua; Yan, Yun; Zhang, Wenli; Ni, Liang; Sun, Yueming; Yin, Hengbo

    2011-05-01

    A series of cauliflower-like TiO 2-ZnO composite porous films with various molar ratios of Zn/Ti were prepared by the screen printing technique on the fluorine-doped SnO 2 (FTO) conducting glasses. The composite films were characterized by field-emission scanning electron microscopy (FE-SEM), X-ray energy-dispersive spectrometry (EDS) and UV-vis transmittance spectrum. The results showed composite film electrode had a novel cauliflower-like morphology, which could effectively increase the dye absorption. The corresponding dye-sensitized solar cells (DSCs) were made by the composite film, and effects of ZnO incorporation on the photovoltaic performances of the DSCs were studied. With the Zn/Ti molar ratio not more than 3% in ZnO-TiO 2 composite film of about 5 ?m-thickness, the photocurrent density ( Jsc) and the solar-to-electricity conversion efficiency ( ?) were greatly improved compared with those of the DSC based on bare TiO 2 film of same thickness. This increases in efficiency and Jsc were attributed to high electron conductivity of ZnO, the improved dye adsorption and large light transmittance of composite film.

  14. Hydrogenated TiO{sub 2} film for enhancing photovoltaic properties of solar cells and self-sensitized effect

    SciTech Connect

    He, Hongcai; Yang, Kui; Wang, Ning Luo, Feifei; Chen, Haijun

    2013-12-07

    Hydrogenated TiO{sub 2} film was obtained by annealing TiO{sub 2} film at 350?C for 2?h with hydrogen, and TiO{sub 2} films were prepared by screen printing on fluorine-doped tin oxide glass. Structural characterization by X-ray diffraction and electron microscopy did not show obvious difference between hydrogenated TiO{sub 2} film and pristine TiO{sub 2} film. Through optical and electrochemical characterization, the hydrogenated TiO{sub 2} film showed enhanced absorption and narrowed band gap, as well as reduced TiO{sub 2} surface impedance and dark current. As a result, an obviously enhanced photovoltaic effect was observed in the solar cell with hydrogenated TiO{sub 2} as photoanode without adding any dye due to the self-sensitized effect of hydrogenated TiO{sub 2} film, which excited electrons injecting internal conduction band of TiO{sub 2} to generate more photocurrent.

  15. Electrochromic performance of sol-gel-deposited CeO2 films

    NASA Astrophysics Data System (ADS)

    Ozer, Nilgun; Cronin, John P.; Akyuz, Sevim

    1999-10-01

    Ceria (CeO2) films were prepared by a sol-gel technique onto fluorine doped tin oxide coated glass substrates. The coating solution was derived from cerium ammonium nitrate dissolved in ethanol with diethanolamine used as a complexing agent. Lithium intercalating properties of the films were investigated using cyclic voltammetry (CV) and UV-visible spectroscopy. The electrochemical examinations were performed in a 0.5 M LiClO4 propylene carbonate electrolyte. The additional film characterizations were performed in X-ray diffractometry (XRD), x-ray photoelectron spectroscopy, scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy. XRD of the films showed that they had an cerianite structure for heat treatment temperatures at or above 450 degree(s)C. The SEM examinations showed that the surface texture was uniform and homogeneous. CV examinations showed a reversible electrochemical insertion or extraction of Li+/e- ions maintaining a high optical transmissivity. Spectroelectrochemistry showed that these films can be used as optically passive counter-electrode in transmissive electrochromic devices.

  16. Direct growth of superconducting NdFeAs(O,F) thin films by MBE

    NASA Astrophysics Data System (ADS)

    Chihara, Masashi; Sumiya, Naoki; Arai, Kenta; Ichinose, Ataru; Tsukada, Ichiro; Hatano, Takafumi; Iida, Kazumasa; Ikuta, Hiroshi

    2015-11-01

    We report on the growth of NdFeAs(O,F) superconducting thin films by molecular beam epitaxy without having a NdOF secondary layer that was necessary for fluorine doping in our previous studies. The key to realizing the direct growth of a superconducting film was the enhancement of migration of the raw materials on the substrate, which was accomplished by two steps. Firstly, we increased the growth temperature that improved the crystalline quality of parent NdFeAsO thin films. Secondly, the atmosphere in the chamber during the growth was improved by changing the crucible material of the Fe source cell. Highly textured NdFeAs(O,F) thin films with critical temperatures up to 50 K were obtained, and terraces were observed by atomic force microscope, indicating a two-dimensional growth. However, precipitates were also found on the surface, which suggests that enhancing further the migration is necessary for obtaining a NdFeAs(O,F) thin film with a better quality.

  17. Effect of F doping on physical properties of (211) oriented SnO2 thin films prepared by jet nebulizer spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Thirumoorthi, M.; Prakash, J. Thomas Joseph

    2016-01-01

    Transparent conducting fluorine doped tin oxide (FTO) thin films have been prepared jet nebulizer spray pyrolysis technique at 500 °C for different doping concentrations. The X-ray diffraction spectra confirm the polycrystalline nature of SnO2: F with tetragonal structure. All the films show a preferred growth orientation along (211) diffraction plane. Scanning electron microscope images show that the films have a uniform surface morphology with well defined pyramid like grains. The AFM results of the films indicate that the surface roughness is increased with F doping. The optical transmittance of FTO films is improved from 75 to 92% in the visible region of the solar spectrum and the optical absorption of the films is very low. The blue shift of optical band of the films is explained by Burstain-Mass effect. The observed blue shift of the UV emission band in the photoluminescence spectra confirms the incorporation of F into tin oxide crystal lattice. The presence of functional groups and chemical bonding were confirmed by FTIR. Hall Effect measurements show that the prepared films having n-type conductivity with low resistivity (2.3 × 10-4 Ω-cm) and high carrier concentrations (6.9 × 1020 cm-3).

  18. Triton-X mediated interconnected nanowalls network of cadmium sulfide thin films via chemical bath deposition and their photoelectrochemical performance

    NASA Astrophysics Data System (ADS)

    Vanalakar, S. A.; Mali, S. S.; Jo, E. A.; Kim, J. Y.; Kim, J. H.; Patil, P. S.

    2014-10-01

    Thin films of cadmium sulfide (CdS) have been wet chemically deposited onto fluorine-doped tin oxide (FTO) coated conducting glass substrates by using non-ionic surfactant; Triton-X 100. An aqueous solution contains cadmium sulphate as a cadmium and thiourea as sulphur precursor. Ammonia used as a complexing agent. The results of measurements of the x-ray diffraction, Raman spectroscopy, optical spectroscopy, energy dispersive spectroscopy, scanning electron microscopy, Brunauer Emmett Teller (BET) surface areas and atomic force microscopy were used for the characterization of the films. These results revealed that the films are polycrystalline, consisting of CdS cubic phase. The films show a direct band gap with energy 2.39 eV. The films show interconnected nanowalls like morphology with well-defined surface area. Finally, the photoelectrochemical (PEC) performance of Triton-X mediated CdS thin film samples were studied. The sample shows photoelectrochemical (PEC) performance with maximum short circuit current density (Jsc) 1.71 mA/cm2 for larger area (1 cm2) solar cells.

  19. Optical and electrochemical properties of Cu-doped NiO films prepared by electrochemical deposition

    NASA Astrophysics Data System (ADS)

    Zhao, Lili; Su, Ge; Liu, Wei; Cao, Lixin; Wang, Jing; Dong, Zheng; Song, Meiqin

    2011-02-01

    Cu-doped nickel oxide (NiO) thin films were prepared by electrochemial deposition (cathodic deposition) technique onto the fluorine doped tin oxide (F: SnO2; FTO) coated glass substrates from organic solutions. Effects of Cu content on the morphology, structure, optical and electrochromic properties of NiO films were investigated by means of scanning electron microscope (SEM), X-ray diffraction (XRD), ultraviolet-visible spectrophotometer (UV-vis) and cyclic voltammetry (CV), respectively. SEM images indicated the formation of nanorods after Cu was added. The films were formed with amorphous or short-range ordered NiO grains and a trace of face-centered cubic NixCu1-xO confirmed by XRD. The transmittances of both bleached state and colored state were significantly lowered when Cu was added. The NiO films doped with Cu (the molar ratio was 1/8) exhibited the optimum electrochromic behavior with a variation of transmittance (ΔT) up to ∼80% at the wavelength range of 350-600 nm. Cu doping reduces the response time for both the coloring and bleaching states, and the reversibility of the redox reaction was increased as well.

  20. Enhanced Bactericidal Activity of Silver Thin Films Deposited via Aerosol-Assisted Chemical Vapor Deposition.

    PubMed

    Ponja, Sapna D; Sehmi, Sandeep K; Allan, Elaine; MacRobert, Alexander J; Parkin, Ivan P; Carmalt, Claire J

    2015-12-30

    Silver thin films were deposited on SiO2-barrier-coated float glass, fluorine-doped tin oxide (FTO) glass, Activ glass, and TiO2-coated float glass via AACVD using silver nitrate at 350 C. The films were annealed at 600 C and analyzed by X-ray powder diffraction, X-ray photoelectron spectroscopy, UV/vis/near-IR spectroscopy, and scanning electron microscopy. All the films were crystalline, and the silver was present in its elemental form and of nanometer dimension. The antibacterial activity of these samples was tested against Escherichia coli and Staphylococcus aureus in the dark and under UV light (365 nm). All Ag-deposited films reduced the numbers of E. coli by 99.9% within 6 h and the numbers of S. aureus by 99.9% within only 2 h. FTO/Ag reduced bacterial numbers of E. coli to below the detection limit after 60 min and caused a 99.9% reduction of S. aureus within only 15 min of UV irradiation. Activ/Ag reduced the numbers of S. aureus by 66.6% after 60 min and TiO2/Ag killed 99.9% of S. aureus within 60 min of UV exposure. More remarkably, we observed a 99.9% reduction in the numbers of E. coli within 6 h and the numbers of S. aureus within 4 h in the dark using our novel TiO2/Ag system. PMID:26632854

  1. Spray pyrolytic deposition and characterization of lanthanum selenide (La 2Se 3) thin films

    NASA Astrophysics Data System (ADS)

    Bagde, G. D.; Sartale, S. D.; Lokhande, C. D.

    2003-05-01

    The versatile spray pyrolysis technique was employed to prepare thin films of lanthanum selenide (La 2Se 3) on glass and fluorine doped tin oxide (FTO) coated glass substrates under optimized conditions. The deposition temperature was 250 C. The X-ray studies reveal that the films are polycrystalline with single La 2Se 3 phase. The estimated optical band gap was found to be 2.6 eV. The dielectric properties such as dielectric constant and dielectric loss of the films deposited on FTO coated glass substrates were measured with FTO-La 2Se 3-Ag structure as a function of frequency and the results are reported. At room temperature dielectric constant and dielectric loss for 1 kHz frequency were found to be 6.2 and 0.048, respectively. The room temperature electrical resistivity was of the order of 10 5 ? cm. The La 2Se 3 films are found to be n-type semiconductor.

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

    PubMed

    Romero, Luz; Binions, Russell

    2013-11-01

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

  3. Enhancement of the photoelectrochemical performance of CuWO4 films for water splitting by hydrogen treatment

    NASA Astrophysics Data System (ADS)

    Tang, Yulin; Rong, Nannan; Liu, Feila; Chu, Mengsha; Dong, Hongmei; Zhang, Yunhuai; Xiao, Peng

    2016-01-01

    CuWO4 films with feature particle sizes of 100-200 nm and thickness up to 700-900 nm on fluorine-doped tin oxide (FTO) substrates were prepared by hydrothermal synthesis. The prepared CuWO4 films were treated in hydrogen atmosphere at constant temperature 300 °C for different annealing time and used for photoelectrochemical (PEC) water oxidation. Compared with pristine CuWO4 film, the optimized hydrogen-treated CuWO4 film presented three times enhanced photocurrent density of 0.75 mA/cm2 at 1.2 V vs. Ag/AgCl in 0.1 M Na2SO4 solution under the illumination. The donor density of hydrogenated CuWO4 film determined by Mott-Schottky analysis was improved one order of magnitude as well. The enhanced photoelectrochemical activity could be attributed to the formation of oxygen vacancies after hydrogen treatment, which facilitated the charge transport and collection.

  4. Photovoltaic characteristics and dye regeneration kinetics in D149-sensitized ZnO with varied dye loading and film thickness.

    PubMed

    Tefashe, Ushula Mengesha; Rudolph, Melanie; Miura, Hidetoshi; Schlettwein, Derck; Wittstock, Gunther

    2012-05-28

    Porous ZnO electrodes on fluorine-doped tin oxide (FTO) were prepared by electrochemical deposition from an O(2)-saturated ZnCl(2) solution in the presence of eosin Y as a structure directing agent (SDA). Sensitization was reached by desorption of the SDA and subsequent adsorption of the indoline dye D149. The influence of film thickness and dye concentration in the films on their photovoltaic characteristics, recombination, and dye regeneration kinetics was investigated. The recombination kinetics was analyzed by time-resolved photovoltage measurements. The dye regeneration by iodide ions in the electrolyte was investigated using scanning electrochemical microscopy (SECM) feedback mode approach curves. Analysis of a SECM kinetic model shows strongly different effective D149 regeneration rate constants k'(ox) for D149-ZnO electrodes of systematically varied film thickness and dye loading. It was found that the short-circuit current density J(sc) and k'(ox) correlated directly with the adsorbed dye concentration. k'(ox) was found to be independent of the dye loading but correlated strongly with the dye concentration in the film or inversely with the film thickness. Furthermore, we discussed the perspective of correlating macroscopic cell characteristics with SECM kinetics data. PMID:22510720

  5. Deposition of F-doped ZnO transparent thin films using ZnF2-doped ZnO target under different sputtering substrate temperatures

    PubMed Central

    2014-01-01

    Highly transparent and conducting fluorine-doped ZnO (FZO) thin films were deposited onto glass substrates by radio-frequency (RF) magnetron sputtering, using 1.5 wt% zinc fluoride (ZnF2)-doped ZnO as sputtering target. Structural, electrical, and optical properties of the FZO thin films were investigated as a function of substrate temperature ranging from room temperature (RT) to 300C. The cross-sectional scanning electron microscopy (SEM) observation and X-ray diffraction analyses showed that the FZO thin films were of polycrystalline nature with a preferential growth along (002) plane perpendicular to the surface of the glass substrate. Secondary ion mass spectrometry (SIMS) analyses of the FZO thin films showed that there was incorporation of F atoms in the FZO thin films, even if the substrate temperature was 300C. Finally, the effect of substrate temperature on the transmittance ratio, optical energy gap, Hall mobility, carrier concentration, and resistivity of the FZO thin films was also investigated. PMID:24572004

  6. Synthesis and characterization of Cd{sub 0.7}Pb{sub 0.3}Se thin films for photoelectrochemical solar cell

    SciTech Connect

    Delekar, S.D.; Patil, M.K.; Jadhav, B.V.; Sanadi, K.R.; Hankare, P.P.

    2010-03-15

    Optimum composition Cd{sub 0.7}Pb{sub 0.3}Se thin films have been deposited using the chemical bath containing cadmium sulfate octahydrate, lead nitrate, tartaric acid, potassium hydroxide, ammonia, and sodium selenosulfate onto fluorine-doped tin oxide glass substrate. The various deposition parameters such as composition of reactive bath, pH of the solution, deposition temperature, deposition time, speed of rotation, etc. have been optimized for obtaining good quality film. X-ray diffraction studies revealed the polycrystalline nature of sample with the solid solution of lead (II) ions in CdSe host lattice, having a hexagonal phase structure. Scanning electron micrograph suggested that the grains were non-uniformly distributed over the substrate surface. Film composition was determined by atomic absorption spectroscopy as well as energy dispersive X-ray atomic spectroscopy. Optical absorption data showed the presence of direct transition with energy band gap 1.80 eV for the deposited thin films. The dark specific conductance of Cd{sub 0.7}Pb{sub 0.3}Se thin films was found to the order of 10{sup -6} ({omega} cm){sup -1} having n-type semiconducting nature. Photoelectrochemical characterization was carried out using sulfide/polysulfide electrolyte with 1.401% efficiency. (author)

  7. Effects of Zn amount on the properties of Zn-Zu2O composite films grown for PEC photoelectrodes by using electrochemical deposition

    NASA Astrophysics Data System (ADS)

    Kim, Tae Gyoum; Lee, Hu Joong; Ryu, Hyukhyun; Lee, Won-Jae

    2015-10-01

    In this study, Zn-Cu2O composite films were grown on fluorine-doped tin-oxide (FTO) substrates by using the electrochemical deposition method. Various amounts of Zinc (Zn) were added to grow the Zn-Cu2O composite films. We analyzed the morphological, structural, optical energy band gap and photocurrent density properties of the Zn-Cu2O composite films by using various measurements such as field-emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), UV-visible spectrophotometry and potentiostat/galvanostat measurements, respectively. As a result, the highest photocurrent density value of -4.04 mA/cm2 was obtained for the 30-wt% sample, which had the lowest Cu2O (111)/ ZnO (101) XRD peak intensity ratio. The highest photocurrent density value from the 30-wt% sample was approximately 2.35 times higher than that from the non-composite Cu2O film (0-wt% sample). From this study, we found that adding Zn could improve the photocurrent values of Zn-Cu2O composite films.

  8. Preparation and characterization of indium doped CdS{sub 0.2}Se{sub 0.8} thin films by spray pyrolysis

    SciTech Connect

    Yadav, A.A.; Masumdar, E.U.

    2010-10-15

    The CdS{sub 0.2}Se{sub 0.8} and indium doped CdS{sub 0.2}Se{sub 0.8} thin films have been deposited onto the amorphous glass and fluorine doped tin oxide coated glass substrates by spray pyrolysis. The doping concentration of indium has been optimized by photoelectrochemical characterization technique. The structural, surface morphological, optical and electrical properties of CdS{sub 0.2}Se{sub 0.8} and indium doped CdS{sub 0.2}Se{sub 0.8} thin films have been studied. X-ray diffraction studies reveal that the films are polycrystalline in nature with hexagonal crystal structure. Scanning electron microscopy studies reveal that the grains are uniform with uneven spherically shaped, distributed over the entire substrate surface. The complete surface morphology has been changed after doping. In optical studies, the transition of the deposited films is found to be direct allowed with optical energy gaps decreasing from 1.91 to 1.67 eV with indium doping. Semiconducting behavior has been observed from resistivity measurements. The thermoelectric power measurements reveal that the films exhibit n-type conductivity.

  9. Layer-by-layer TiO(2)/WO(3) thin films as efficient photocatalytic self-cleaning surfaces.

    PubMed

    Patrocinio, Antonio Otavio T; Paula, Leonardo F; Paniago, Roberto M; Freitag, Janna; Bahnemann, Detlef W

    2014-10-01

    New TiO2/WO3 films were produced by the layer-by-layer (LbL) technique and successfully applied as self-cleaning photocatalytic surfaces. The films were deposited on fluorine doped tin oxide (FTO) glass substrates from the respective metal oxide nanoparticles obtained by the sol-gel method. Thirty alternative immersions in pH = 2 TiO2 and pH = 10 WO3 sols resulted in ca. 400 nm thick films that exhibited a W(VI)/Ti(IV) molar ratio of 0.5, as determined by X-ray photoelectron spectroscopy. Scanning electron microscopy, along with atomic force images, showed that the resulting layers are constituted by aggregates of very small nanoparticles (<20 nm) and exhibited nanoporous and homogeneous morphology. The electronic and optical properties of the films were investigated by UV-vis spectrophotometry and ultraviolet photoelectron spectroscopy. The films behave as nanoscale heterojunctions, and the presence of WO3 nanoparticles caused a decrease in the optical band gap of the bilayers compared to that of pure LbL TiO2 films. The TiO2/WO3 thin films exhibited high hydrophilicity, which is enhanced after exposition to UV light, and they can efficiently oxidize gaseous acetaldehyde under UV(A) irradiation. Photonic efficiencies of ξ = 1.5% were determined for films constituted by 30 TiO2/WO3 bilayers in the presence of 1 ppm of acetaldehyde, which are ∼2 times higher than those observed for pure LbL TiO2 films. Therefore, these films can act as efficient and cost-effective layers for self-cleaning, antifogging applications. PMID:25216058

  10. Comparative study of ITO and FTO thin films grown by spray pyrolysis

    SciTech Connect

    Ait Aouaj, M.; Diaz, R.; Belayachi, A.; Rueda, F.; Abd-Lefdil, M.

    2009-07-01

    Tin doped indium oxide (ITO) and fluorine doped tin oxide (FTO) thin films have been prepared by one step spray pyrolysis. Both film types grown at 400 deg. C present a single phase, ITO has cubic structure and preferred orientation (4 0 0) while FTO exhibits a tetragonal structure. Scanning electron micrographs showed homogeneous surfaces with average grain size around 257 and 190 nm for ITO and FTO respectively. The optical properties have been studied in several ITO and FTO samples by transmittance and reflectance measurements. The transmittance in the visible zone is higher in ITO than in FTO layers with a comparable thickness, while the reflectance in the infrared zone is higher in FTO in comparison with ITO. The best electrical resistivity values, deduced from optical measurements, were 8 x 10{sup -4} and 6 x 10{sup -4} {Omega} cm for ITO (6% of Sn) and FTO (2.5% of F) respectively. The figure of merit reached a maximum value of 2.15 x 10{sup -3} {Omega}{sup -1} for ITO higher than 0.55 x 10{sup -3} {Omega}{sup -1} for FTO.

  11. Fabrication and photoelectrochemical characteristics of In2S3 nano-flower films on TiO2 nanorods arrays

    NASA Astrophysics Data System (ADS)

    Han, Minmin; Yu, Limin; Chen, Wenyuan; Wang, Wenzhen; Jia, Junhong

    2016-04-01

    The In2S3 nano-flower films on TiO2/FTO (Fluorine-doped tin oxide) substrates were synthesized via hydrothermal method and the photoelectrochemical performances of In2S3/TiO2 photoelectrodes were characterized. The roles of PSS (poly(sodium-p-styrenesul-fonate)) and PEG (polyethylene glycol) on the structure controlling of In2S3 films were also discussed. The results show that the In2S3 nano-flower films consisted of ultrathin nanoflakes with a thickness of 5 nm are successfully grew on the surface of TiO2 nanorod arrays. PEG could play a role as the morphology-directing agent by confining crystal growth in certain directions, while PSS could provide coordination sites with long chains and lead to the formation of spherical structure. The energy conversion efficiency of In2S3 nano-flower/TiO2 photoelectrodes enhances thrice compared with that of bare TiO2 photoelectrode. This research presents further insight for improving the efficiency of semiconductors by using the suitable electron transfer channels, which may be promising for rational construction of solar conversion and storage devices.

  12. Photovoltaic effect of TiO2 thick films with an ultrathin BiFeO3 as buffer layer

    NASA Astrophysics Data System (ADS)

    Wu, Fen; Song, Linyu; Guo, Yiping; Jin, Song; Bi, Enbing; Chen, Han; Duan, Huanan; Li, Hua; Liu, Hezhou; Kang, Hongmei

    2014-06-01

    The photovoltaic (PV) effect of a bilayer anatase TiO2/BiFeO3 (BFO) film has been studied. The 20-nm ultrathin BFO layers were deposited on the fluorine-doped tin oxide (FTO) glass substrates by the chemical solution deposition method. An anatase TiO2 layer is deposited subsequently on the BFO surface via a screen-printing technique. It is found that the FTO/TiO2/Au cell exhibits negligible PV effect under solar exposure, while the one after introducing an ultrathin BFO film between TiO2 and FTO leads to a considerable PV effect with an open-circuit voltage of -0.58 V and a photocurrent density of 18.27 A/cm2. The FTO/BiVO4 (BVO)/TiO2/Au cell was constructed to investigate the underlying mechanism for the observed effect. A negligible PV effect of the FTO/BVO/TiO2/Au cell indicates that the PV effect of the FTO/BFO/TiO2/Au cell arises mainly from a built-in electric field in the BFO film induced by the self-polarization. Our work opens up a new path to utilize TiO2 and may influence the future design of solar cells.

  13. Fabrication of ZnFe2O4 films and its application in photoelectrocatalytic degradation of salicylic acid.

    PubMed

    Kumbhar, S S; Mahadik, M A; Shinde, S S; Rajpure, K Y; Bhosale, C H

    2015-01-01

    ZnFe2O4 thin films are successfully deposited onto bare and fluorine doped tin oxide (FTO) coated quartz substrate using the spray pyrolysis method. The structure and morphology of ZnFe2O4 photoelectrodes were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). The X-ray diffraction pattern confirms the polycrystalline nature of films with a spinel cubic crystal structure. The AFM micrographs shows the granular nature of the films. The dielectric constant and dielectric loss shows dispersion behavior as a function of frequency measured in the range from 20Hz to 1MHz. Photoelectrocatalysis degradation of salicylic acid using ZnFe2O4 photoelectrode under sunlight illumination has been investigated. The result shows that the degradation percentage of salicylic acid on ZnFe2O4 photoelectrodes is reached 49% under neutral conditions after 320min illumination. The decrease in values of COD from 19.4mg/L to 6.4mg/L indicates there is mineralization of salicylic acid with time. PMID:25528302

  14. Performance and stability studies of inverted polymer solar cells with TiO2 film as a buffer layer

    NASA Astrophysics Data System (ADS)

    Peng, Ruixiang; Yang, Feng; Ouyang, Xinhua; Liu, Ying; Kim, Yong-Sang; Ge, Ziyi

    2014-02-01

    TiO2 based inverted polymer solar cells (PSCs) with a structure of fluorine-doped tin oxide (FTO)/TiO2/P3HT:PCBM/PEDOT:PSS/Ag presented excellent air stabilities,; the power conversion efficiency (PCE) of devices exhibited only 15 % decay as compared to the highest value while being exposed in air-condition for more than 20 days. Interestingly, an overall enhancement of PCE from 3.5 % to 3.9 % was observed while the PSCs were exposed in air-condition up to 3 days; the improvement of performance was attributed to the TiO2 films' oxygen and water protection effect and the oxidation of Ag, which will benefit to form an effective work function match with the HOMO of P3HT leading to improved ohmic contact. However, the performance slowly decreased when the exposure time remains longer due to the physical adsorbed oxygen. UV-ozone treatment on the TiO2 films' leads to the formation of a metal-deficient oxide that results in a decreased PCE for the devices. Finally, X-ray photo-emission spectroscopy (XPS) was used to analyze the compositional changes of the TiO2 films while they were exposed in air-condition or treated by UV-ozone.

  15. Formation of an electron hole doped film in the ?-Fe2O3 photoanode upon electrochemical oxidation.

    PubMed

    Gajda-Schrantz, Krisztina; Tymen, Simon; Boudoire, Florent; Toth, Rita; Bora, Debajeet K; Calvet, Wolfram; Grtzel, Michael; Constable, Edwin C; Braun, Artur

    2013-02-01

    Solar hydrogen generation by water splitting in photoelectrochemical cells (PEC) is an appealing technology for a future hydrogen economy. Hematite is a prospective photoanode material in this respect because of its visible light conjugated band gap, its corrosion stability, its environmentally benign nature and its low cost. Its bulk and surface electronic structure has been under scrutiny for many decades and is considered critical for improvement of efficiency. In the present study, hematite films of nominally 500 nm thickness were obtained by dip-coating on fluorine doped tin oxide (FTO) glass slides and then anodised in 1 molar KOH at 500, 600, and 700 mV for 1, 10, 120 and 1440 minutes under dark conditions. X-ray photoelectron spectra recorded at the Fe 3p resonant absorption threshold show that the e(g) transition before the Fermi energy, which is well developed in the pristine hematite film, becomes depleted upon anodisation. The spectral weight of the e(g) peak decreases with the square-root of the anodisation time, pointing to a diffusion controlled process. The speed of this process increases with the anodisation potential, pointing to Arrhenius behaviour. Concomitantly, the weakly developed t(2g) peak intensity becomes enhanced in the same manner. This suggests that the surface of the photoanode contains Fe(2+) species which become oxidized toward Fe(3+) during anodisation. The kinetic behaviour derived from the experimental data suggests that the anodisation forms an electron hole doped film on and below the hematite surface. PMID:23165453

  16. Preparation and characterization of spray deposited n-type WO{sub 3} thin films for electrochromic devices

    SciTech Connect

    Sivakumar, R.; Moses Ezhil Raj, A.; Subramanian, B.; Jayachandran, M.; Trivedi, D.C.; Sanjeeviraja, C

    2004-08-03

    The n-type tungsten oxide (WO{sub 3}) polycrystalline thin films have been prepared at an optimized substrate temperature of 250 deg. C by spray pyrolysis technique. Precursor solution of ammonium tungstate ((NH{sub 4}){sub 2}WO{sub 4}) was sprayed onto the well cleaned, pre-heated fluorine doped tin oxide coated (FTO) and glass substrates with a spray rate of 15 ml/min. The structural, surface morphological and optical properties of the as-deposited WO{sub 3} thin films were studied. Mott-Schottky (M-S) studies of WO{sub 3}/FTO electrodes were conducted in Na{sub 2}SO{sub 4} solution to identify their nature and extract semiconductor parameters. The electrochromic properties of the as-deposited and lithiated WO{sub 3}/FTO thin films were analyzed by employing them as working electrodes in three electrode electrochemical cell using an electrolyte containing LiClO{sub 4} in propylene carbonate (PC) solution.

  17. Dissipation mechanisms in polycrystalline YBCO prepared by sintering of ball-milled precursor powder

    NASA Astrophysics Data System (ADS)

    Hannachi, E.; Ben Salem, M. K.; Slimani, Y.; Hamrita, A.; Zouaoui, M.; Ben Azzouz, F.; Ben Salem, M.

    2013-12-01

    Magnetoresistivity (?(T,H)) measurements of polycrystalline YBa2Cu3Oy (Y-123) and YBa2Cu3Oy embedded with nanoparticles of Y-deficient Y-123, generated by the planetary ball milling, have been compared and analyzed by the Ambegaokar and Halperin phase slip model (AH) and thermally activated flux creep (TAFC). Phase analysis by X-ray diffraction (XRD), granular structure examination by scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDXS), were carried out. SEM analyses show that nanoparticles of Y-deficient Y-123, generated by ball milling, are embedded in the superconducting matrix. The broadening of the resistive transition under magnetic field is found to possess two distinct regions, which suggests that dissipation phenomenon in milled and unmilled samples is caused by two mechanisms: the order parameter fluctuations and the vortex-dynamics separated by a crossover temperature T. The critical current Jc(0) at zero temperature in the grain boundaries decreases as a power law, H, which is an indication of the sensitivity of a single junction between the superconducting grains to the applied magnetic field. Jc(0) of the milled material is higher than the one of the unmilled and the activation energies of vortex flux motion U(H) behavior in the applied magnetic field is enhanced by the presence of the nanoparticles embedded in the matrix.

  18. Competition between charge and superconducting orders in underdoped YBCO

    NASA Astrophysics Data System (ADS)

    Julien, Marc-Henri

    2012-02-01

    We report nuclear magnetic resonance measurements (NMR) showing that high magnetic fields induce a static, unidirectional, modulation of the charge density in the CuO2 planes of underdoped YBa2Cu3Oy [T. Wu et al., Nature 477, 191 (2011)]. The appearance of the charge order coincides with the Fermi surface reconstruction inferred from quantum oscillation and other transport measurements. This charge order appears to be most probably the same 4a-periodic stripe modulation as in La-214 cuprates. That it develops only when superconductivity fades away (no charge order is observed under strong fields parallel to the planes) and near the same 1/8 hole doping as in La-214 suggests that charge order, although visibly pinned by CuO chains in YBa2Cu3Oy, is an intrinsic propensity of the superconducting planes of high-Tc copper oxides. Since field induced stripe order is also compatible with neutron scattering data in La-214 and with STM data in Bi-2212, charge order could be a generic competitor of high Tc superconductivity. [4pt] Work performed with T. Wu, H. Mayaffre, S. Kr"amer, M. Horvatic, C. Berthier (LNCMI Grenoble), W.N. Hardy, R. Liang, D.A. Bonn (University of British Columbia, Vancouver)

  19. Shaping and reinforcement of melt textured YBa2Cu3O7-? superconductors

    NASA Astrophysics Data System (ADS)

    Meslin, S.; Harnois, C.; Chubilleau, C.; Horvath, D.; Grossin, D.; Suddhakar, E. R.; Noudem, J. G.

    2006-07-01

    From porous Y2BaCuO5 (Y211) with various grain sizes, single domain ceramic composites YBa2Cu3Oy/Y2BaCuO5 have been prepared by combination of the infiltration and top seed growth (ITSG) process. In addition, perforated Y123 has been prepared from Y211 by the ITSG method in order to magnify the specific surface and then increase oxygen diffusion into the core of the material. Magnetic and electrical properties were determined and correlate well with the microstructure of the composites and were compared to the conventional doped or undoped YBa2Cu3Oy (Y123). From magnetic measurements, high critical current densities, Jc, of 86 000 A cm-2 have been measured. Transport Jc values higher than 10 600 A cm-2 are reached at 77 K and 0 T, corresponding to the nominal critical currents of 325 A injected reproducibly through sections less than 3.082 mm2. This confirms the high quality of single domains obtained with a well controlled ITSG process. On the other hand, the perforated samples were reinforced using resin impregnation and the flux mapping has been investigated.

  20. Fabrication of textured YBCO bulks with artificial holes

    NASA Astrophysics Data System (ADS)

    Noudem, J. G.; Meslin, S.; Horvath, D.; Harnois, C.; Chateigner, D.; Eve, S.; Gomina, M.; Chaud, X.; Murakami, M.

    2007-10-01

    The recently reported hole-patterned YBa2Cu3Oy (Y123) bulks with improved superconducting properties are highly interesting from the aspects of the material qualities and application various points of view. It is well known that the core of plain bulk superconductors needs to be fully oxygenated and some defects like cracks, pores and voids must be suppressed in order that the material can trap high magnetic field or carry high current densities. To minimize the above defects, we have used the infiltration and top seed growth (ITSG) process to prepare regularly perforated YBa2Cu3Oy (Y123) bulk superconductors. This process involves less shrinkage during annealing and a uniform distribution of Y211 inclusions. The texture was evidenced by neutron pole figure measurements. Flux mapping was used to verify the superconducting homogeneity of the samples and to investigate the field trapping ability. Large increase of the trapped field in pulsed magnetization up to 60% in comparison to the hole-free parent sample with the same thermal history has been obtained. In addition, the textured drilled samples were reinforced using resin or metal impregnation and the influence of the different processing steps on the hardness of the materials is investigated.

  1. Direct measurement of the upper critical field in cuprate superconductors

    PubMed Central

    Grissonnanche, G.; Cyr-Choinire, O.; Lalibert, F.; Ren de Cotret, S.; Juneau-Fecteau, A.; Dufour-Beausjour, S.; Delage, M. -.; LeBoeuf, D.; Chang, J.; Ramshaw, B. J.; Bonn, D. A.; Hardy, W. N.; Liang, R.; Adachi, S.; Hussey, N. E.; Vignolle, B.; Proust, C.; Sutherland, M.; Krmer, S.; Park, J. -H.; Graf, D.; Doiron-Leyraud, N.; Taillefer, Louis

    2014-01-01

    In the quest to increase the critical temperature Tc of cuprate superconductors, it is essential to identify the factors that limit the strength of superconductivity. The upper critical field Hc2 is a fundamental measure of that strength, yet there is no agreement on its magnitude and doping dependence in cuprate superconductors. Here we show that the thermal conductivity can be used to directly detect Hc2 in the cuprates YBa2Cu3Oy, YBa2Cu4O8 and Tl2Ba2CuO6+?, allowing us to map out Hc2 across the doping phase diagram. It exhibits two peaks, each located at a critical point where the Fermi surface of YBa2Cu3Oy is known to undergo a transformation. Below the higher critical point, the condensation energy, obtained directly from Hc2, suffers a sudden 20-fold collapse. This reveals that phase competitionassociated with Fermi-surface reconstruction and charge-density-wave orderis a key limiting factor in the superconductivity of cuprates. PMID:24518054

  2. Effects of TiO{sub 2} film thickness on photovoltaic properties of dye-sensitized solar cell and its enhanced performance by graphene combination

    SciTech Connect

    Zhang, Haiyan; Wang, Wenguang; Liu, Hui; Wang, Rong; Chen, Yiming; Wang, Zhiwei

    2014-01-01

    Graphical abstract: - Highlights: • DSSC based on TiO{sub 2} film with 8 printing layers showed the highest efficiency. • The photoelectric conversion efficiency of the DSSC increased from 5.52% to 6.49% by graphene combination. • A mechanism for the enhanced performance of the DSSC was proposed. - Abstract: Dye-sensitized solar cells based on TiO{sub 2} films with different printing layers (6-10) were fabricated by screen printing method. The prepared samples were characterized by scanning electron microscopy, X-ray diffraction and UV–vis absorption spectroscopy. The effects of thickness on the photoelectric conversion performance of the as-fabricated DSSCs were investigated. An optimum photoelectric conversion efficiency of 5.52% was obtained in a DSSC with 8 printing layers. Furthermore, after a moderate amount of graphene was combined with TiO{sub 2}, the photoelectric conversion efficiency of the DSSC based on graphene/TiO{sub 2} composite film rose from 5.52% to 6.49%, with an increase of η by 17.6%. The results indicated that graphene not only enhances the transport of electrons from the film to the fluorine doped tin oxide substrates and reduces the charge recombination rate, but also reduces the electrolyte–electrode interfacial resistance, clearly increasing the photoelectric conversion efficiency.

  3. Investigation of x-ray photoelectron spectroscopic (XPS), cyclic voltammetric analyses of WO3 films and their electrochromic response in FTO/WO3/electrolyte/FTO cells

    NASA Astrophysics Data System (ADS)

    Sivakumar, R.; Gopalakrishnan, R.; Jayachandran, M.; Sanjeeviraja, C.

    2006-06-01

    Electrochromic thin films of tungsten oxide (WO3) were prepared on transparent conducting oxide substrates, i.e., fluorine doped tin oxide coated (FTO or SnO2:F) glass and microscopic glass substrates by the electron beam evaporation technique using pure WO3 (99.99%) pellets at various substrate temperatures (i.e., Tsub = room temperature (RT, 30 C), 100 C and 200 C). The films were prepared under vacuum of the order of 1 10-5 mbar. The room temperature prepared films were further post-heat-treated (Tanne) at 200 and 300 C for about 1 h in the vacuum environment. The prepared films are in monoclinic phase. The chemical composition has been characterized by using the XPS technique. The W 4f and O 1s core levels of WO3 films have been studied on the samples. The obtained core level binding energies revealed the WO3 films contained six-valent tungsten (W6+). The electrochemical nature of the films was studied by a three-electrode electrochemical cell in the configuration of FTO/WO3/H2SO4/Pt, SCE, using the cyclic voltammetry (CV) technique. Electrochromic devices (ECDs) of the general type FTO/WO3/electrolyte/FTO were studied. The films produced at higher substrate temperature show smaller modulation of the visible spectrum, compared with the films produced at lower temperatures. The significant chemical bonding nature associated with the coloring/bleaching process which follows the H+ ion incorporation in the film is studied by FTIR analysis. The W-O-W framework peak was observed at 563 cm-1 and confirms the stability of the films in the electrochemical analysis. The results obtained from cyclic voltammetry technique and ECD cell characterization are used to emphasize the suitability for some applications of the solar control systems.

  4. CdS nanoparticles sensitization of Al-doped ZnO nanorod array thin film with hydrogen treatment as an ITO/FTO-free photoanode for solar water splitting

    PubMed Central

    2012-01-01

    Aluminum-doped zinc oxide (AZO) nanorod array thin film with hydrogen treatment possesses the functions of transparent conducting oxide thin film and 1-D nanostructured semiconductor simultaneously. To enhance the absorption in the visible light region, it is sensitized by cadmium sulfide (CdS) nanoparticles which efficiently increase the absorption around 460 nm. The CdS nanoparticles-sensitized AZO nanorod array thin film with hydrogen treatment exhibits significantly improved photoelectrochemical property. After further heat treatment, a maximum short current density of 5.03 mA cm?2 is obtained under illumination. They not only are much higher than those without CdS nanoparticles sensitization and those without Al-doping and/or hydrogen treatment, but also comparable and even slightly superior to some earlier works for the CdS-sensitized zinc oxide nanorod array thin films with indium tin oxide (ITO) or fluorine-doped tin oxide (FTO) as substrates. This demonstrated successfully that the AZO nanorod array thin film with hydrogen treatment is quite suitable as an ITO/FTO-free photoanode and has great potentials in solar water splitting after sensitization by quantum dots capable of visible light absorption. PMID:23098050

  5. High-Performance Platinum-Free Dye-Sensitized Solar Cells with Molybdenum Disulfide Films as Counter Electrodes.

    PubMed

    Hussain, Sajjad; Shaikh, Shoyebmohamad F; Vikraman, Dhanasekaran; Mane, Rajaram S; Joo, Oh-Shim; Naushad, Mu; Jung, Jongwan

    2015-12-01

    By using a radio-frequency sputtering method, we synthesized large-area, uniform, and transparent molybdenum disulfide film electrodes (1, 3, 5, and 7 min) on transparent and conducting fluorine-doped tin oxide (FTO), as ecofriendly, cost-effective counter electrodes (CE) for dye-sensitized solar cells (DSSCs). These CEs were used in place of the routinely used expensive platinum CEs for the catalytic reduction of a triiodide electrolyte. The structure and morphology of the MoS2 was analyzed by using Raman spectroscopy, X-ray diffraction, and X-ray photoemission spectroscopy measurements and the DSSC characteristics were investigated. An unbroken film of MoS2 was identified on the FTO crystallites from field-emission scanning electron microscopy. Cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel curve measurements reveal the promise of MoS2 as a CE with a low charge-transfer resistance, high electrocatalytic activity, and fast reaction kinetics for the reduction of triiodide to iodide. Finally, an optimized transparent MoS2 CE, obtained after 5 min synthesis time, showed a high power-conversion efficiency of 6.0 %, which comparable to the performance obtained with a Pt CE (6.6 %) when used in TiO2 -based DSCCs, thus signifying the importance of sputtering time on DSSC performance. PMID:26472540

  6. Morphology, structural and optical properties of iron oxide thin film photoanodes in photoelectrochemical cell: Effect of electrochemical oxidation

    NASA Astrophysics Data System (ADS)

    Maabong, Kelebogile; Machatine, Augusto G.; Hu, Yelin; Braun, Artur; Nambala, Fred J.; Diale, Mmantsae

    2016-01-01

    Hematite (α-Fe2O3) is a promising semiconductor as photoanode in solar hydrogen production from photoelectrolysis of water due to its appropriate band gap, low cost and high electrochemical stability in aqueous caustic electrolytes. Operation of such photoanode in a biased photoelectrochemical cell constitutes an anodization with consequent redox reactions at the electrode surface. α-Fe2O3 thin film photoanodes were prepared by simple and inexpensive dip coating method on fluorine doped tin oxide (FTO) glass substrate, annealed in air at 500 °C for 2 h, then electrochemically oxidized (anodized) in 1 M KOH at 500 mV for 1 min in dark and light conditions. Changes in structural properties and morphology of α-Fe2O3 nanoparticles films were investigated by XRD, Raman spectroscopy and a high resolution FE-SEM. The average grain size was observed to increase from ~57 nm for pristine samples to 73 and 77 nm for anodized samples in dark and light respectively. Broadening and red shift in Raman spectra in anodized samples may be attributed to lattice expansion upon oxidation. The UV-visible measurements revealed enhanced absorption in the photoanodes after the treatment. The findings suggest that the anodization of the photoelectrode in a biased cell causes not only changes of the molecular structure at the surface, but also changes in the crystallographic structure which can be detected with x-ray diffractometry.

  7. Dye sensitized solar cell applications of CdTiO3-TiO2 composite thin films deposited from single molecular complex

    NASA Astrophysics Data System (ADS)

    Ehsan, Muhammad Ali; Khaledi, Hamid; Pandikumar, Alagarsamy; Huang, Nay Ming; Arifin, Zainudin; Mazhar, Muhammad

    2015-10-01

    A heterobimetallic complex [Cd2Ti4(μ-O)6(TFA)8(THF)6]·1.5THF (1) (TFA=trifluoroacetato, THF=tetrahydrofuran) comprising of Cd:Ti (1:2) ratio was synthesized by a chemical reaction of cadmium (II) acetate with titanium (IV) isopropoxide and triflouroacetic acid in THF. The stoichiometry of (1) was recognized by single crystal X-ray diffraction, spectroscopic and elemental analyses. Thermal studies revealed that (1) neatly decomposes at 450 °C to furnish 1:1 ratio of cadmium titanate:titania composite oxides material. The thin films of CdTiO3-TiO2 composite oxides were deposited at 550 °C on fluorine doped tin oxide coated conducting glass substrate in air ambient. The micro-structure, crystallinity, phase identification and chemical composition of microspherical architectured CdTiO3-TiO2 composite thin film have been determined by scanning electron microscopy, X-ray diffraction, Raman spectroscopy and energy dispersive X-ray analysis. The scope of composite thin film having band gap of 3.1 eV was explored as photoanode for dye-sensitized solar cell application.

  8. 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.

  9. 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

  10. Critical Current Limitation in High Temperature Superconductors

    NASA Astrophysics Data System (ADS)

    Gorzkowski, W.; Baran, M.; Szymczak, H.

    1992-03-01

    The Table of Contents for the full book PDF is as follows: * Organizing Committee * Foreword * Invited Lectures * Critical currents in neutron irradiated high temperature superconductors * Radiation induced disorder as a unique method for studying electronic states of HTSC's and modifying their properties * Influence of fast neutron irradiation on various types of HTSC materials: comprehensive study * Critical currents and angular dependence in magnetic a.c. response: test for intrinsic pinning * Why the critical current densities of high Tc's vary anomalously with temperature, field and time * The effect of the intragranular irreversible magnetization on the intergranular and intragranular critical currents * Bean-Livingstone surface barrier in high temperature superconductors * NMR and NQR studies of high-Tc superconductors * Pinning centers in c-axis oriented Bi-Sr-Ca-Cu-O thin films * The preparation methods leading to practical Y-Ba-Cu-O and Bi-Pb-Sr-Ca-Cu-O wires and tapes * Contributed Papers * Defects of structure and critical parameters of HTSC * Influence of neutron irradiation on the distribution of activation energies in a Bi2Sr2CaCu2Ox single crystal * Neutron irradiation effect on magnetic flux distribution in Bi-Sr-Ca-Cu-O crystals * Thermoelectric study of neutron irradiated YBa2Cu3Oy superconductors * Increase of pinning in Pb-Sr-(Y,Ca)-Cu-O single crystal by neutron irradiation * Thermoelectric power and thermal conductivity of superconducting single crystals Bi2Sr2CaCu2Oy * Hysteretic time relaxation behavior of the critical intergrain transport current in granular YBa2Cu3O7 * Flux pinning anisotropy in YBa2Cu3O7 films * Flux dynamics and pinning in high-Tc films * The influence of additional pinning centers on the critical current in weakly coupled percolative structures * The inductance of a granulated superconductor of YBa2Cu3O7-y type * The contact resistance in the YBaCuO/Ag System * Magnetic irreversibility and critical current in yttrium based high temperature superconducting compounds * Normal and inverse peak effect in high Tc oxide superconductors * Critical fields of high-temperature superconductors REBa2Cu3O7 where RE = Y and Dy * The effect of 211 phase on Jc value of YBCO superconductor by powder melting process * Critical current density and preparation of YBa2Cu3O7-x textured samples * Critical currents in Ag-sheated Y-Ba-Cu-O wires and Bi-Pb-Sr-Ca-Cu-O tapes * DC and microwave properties of epitaxial, in-situ YBaCuO thin films * Thermally activated flux creep in view of some recent experiments on YBaCuO and BiSrCaCuO single crystals * Series Josephson junctions and transport properties of high-Tc superconductors * Thermally activated flux flow and anisotropy of the pinning force density in epitaxially grown YBa2(Cu1-xZnx)3O7-δ thin films * Transport critical current limitation in the oriented and nonoriented YBa2Cu3O7-x thin films * The effect of an electric current on microwave absorption in a YBaCuO ceramic superconductor * Irreversibility of the microwave absorption in high Tc superconductors * Superconductivity of potassium doped carbon C60 * Author Index * Subject Index

  11. Effects of graphene oxide (GO) on GO-Cu2O composite films grown by using electrochemical deposition for a PEC photoelectrode

    NASA Astrophysics Data System (ADS)

    Kim, Tae Gyoum; Ryu, Hyukhyun; Lee, Won-Jae; Yoon, Jang-Hee

    2015-05-01

    In this study, GO-Cu2O composite films were grown on fluorine-doped tin-oxide (FTO) substrates with various amounts of GO by using an electrochemical deposition. We investigated the effects of the GO content on the morphological, structural, optical, and photoelectrochemical (PEC) properties of the GO-Cu2O composite film and on its XPS spectrum. The highest XRD (111) peak intensity was obtained for the 10-wt% sample, which had an optical energy band gap of 2.15 eV. However, the highest photocurrent density was -4.74 mA/cm2 for the 1-wt% sample, which had an optical energy band gap of 1.94 eV. The photocurrent density for the 1-wt% sample was approximately 1.75 times greater than that for the 0-wt% sample. From the XPS measurements, we observed that the oxygen concentration for the sample with 1-wt% GO was higher than it was for the 0-wt% GO, which may have improved the photocurrent density of the sample with 1-wt% GO.

  12. Energy and charge transfers between (Bu{sub 4}N){sub 2}(Ru)(dcbpyH){sub 2}(NCS){sub 2} (N719) and ZnO thin films

    SciTech Connect

    Ni Manman; Cheng Qiang; Zhang, W. F.

    2010-03-15

    ZnO thin films and (Bu{sub 4}N){sub 2}(Ru)(dcbpyH){sub 2}(NCS){sub 2} (called N719) sensitized ZnO thin films are grown on fluorine-doped tin oxide (FTO) conducting glass substrates using laser molecular beam epitaxy. Ultraviolet-visible absorption, photoluminescence (PL), surface photovoltage spectroscopy, and Raman scattering are employed to probe into the transition process of photogenerated charges and the interaction between ZnO and N719. The experimental results indicate that there is a significant electronic interaction between N719 and ZnO through chemiadsorption. The interaction greatly enhances the photogenerated charge separation and thus the photovoltaic response of the ZnO film but remarkedly weakens its radiative recombination, i.e., PL, implying strong energy and charge transfer occurring between N719 and ZnO. In addition, a new PL peak observed at about 720 nm in N719 sensitized ZnO/FTO is attributed to the electron-hole recombination of N719.

  13. Pulsing frequency induced change in optical constants and dispersion energy parameters of WO3 films grown by pulsed direct current magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Punitha, K.; Sivakumar, R.; Sanjeeviraja, C.

    2014-03-01

    In this work, we present the pulsing frequency induced change in the structural, optical, vibrational, and luminescence properties of tungsten oxide (WO3) thin films deposited on microscopic glass and fluorine doped tin oxide (SnO2:F) coated glass substrates by pulsed dc magnetron sputtering technique. The WO3 films deposited on SnO2:F substrate belongs to monoclinic phase. The pulsing frequency has a significant influence on the preferred orientation and crystallinity of WO3 film. The maximum optical transmittance of 85% was observed for the film and the slight shift in transmission threshold towards higher wavelength region with increasing pulsing frequency revealed the systematic reduction in optical energy band gap (3.78 to 3.13 eV) of the films. The refractive index (n) of films are found to decrease (1.832 to 1.333 at 550 nm) with increasing pulsing frequency and the average value of extinction coefficient (k) is in the order of 10-3. It was observed that the dispersion data obeyed the single oscillator of the Wemple-Didomenico model, from which the dispersion energy (Ed) parameters, dielectric constants, plasma frequency, oscillator strength, and oscillator energy (Eo) of WO3 films were calculated and reported for the first time due to variation in pulsing frequency during deposition by pulsed dc magnetron sputtering. The Eo is change between 6.30 and 3.88 eV, while the Ed varies from 25.81 to 7.88 eV, with pulsing frequency. The Raman peak observed at 1095 cm-1 attributes the presence of W-O symmetric stretching vibration. The slight shift in photoluminescence band is attributed to the difference in excitons transition. We have made an attempt to discuss and correlate these results with the light of possible mechanisms underlying the phenomena.

  14. A comparative investigation on structure and multiferroic properties of bismuth ferrite thin films by multielement co-doping

    SciTech Connect

    Dong, Guohua; Tan, Guoqiang Luo, Yangyang; Liu, Wenlong; Xia, Ao; Ren, Huijun

    2014-12-15

    Highlights: • Multielement (Tb, Cr and Mn) co-doped BiFeO{sub 3} films were fabricated by CSD method. • Multielement co-doping induces a structural transition. • It is found effective to stabilize the valence of Fe ions at +3 by the strategy. • The co-doping at A/B-sites gives rise to the superior multiferroic properties. - Abstract: (Tb, Cr and Mn) multielement co-doped BiFeO{sub 3} (BTFCMO) thin films were prepared by the chemical solution deposition method on fluorine doped tin oxide (FTO) substrates. X-ray diffraction, Rietveld refinement and Raman analyses revealed that a phase transition from rhombohedral to triclinic structure occurs in the multielement co-doped BiFeO{sub 3} films. It is found that the doping is conducive to stabilizing the valence of Fe ions and reducing leakage current. In addition, the highly enhanced ferroelectric properties with a huge remanent polarization (2P{sub r}) of 239.6 μC/cm{sup 2} and a low coercive field (2E{sub c}) of 615.6 kV/cm are ascribed to the well film texture, the structure transition and the reduced leakage current by the co-doping. Moreover, the structure transition is the dominant factor resulting in the significant enhancement observed in magnetization (M{sub s} ∼ 10.5 emu/cm{sup 3}), owing to the collapse of the space-modulated spin structure. In this contribution, these results demonstrate that the multielement co-doping is in favor of the enhanced multiferroic properties of the BFO films for possible multifunctional applications.

  15. Fast Classification of Meat Spoilage Markers Using Nanostructured ZnO Thin Films and Unsupervised Feature Learning

    PubMed Central

    Längkvist, Martin; Coradeschi, Silvia; Loutfi, Amy; Rayappan, John Bosco Balaguru

    2013-01-01

    This paper investigates a rapid and accurate detection system for spoilage in meat. We use unsupervised feature learning techniques (stacked restricted Boltzmann machines and auto-encoders) that consider only the transient response from undoped zinc oxide, manganese-doped zinc oxide, and fluorine-doped zinc oxide in order to classify three categories: the type of thin film that is used, the type of gas, and the approximate ppm-level of the gas. These models mainly offer the advantage that features are learned from data instead of being hand-designed. We compare our results to a feature-based approach using samples with various ppm level of ethanol and trimethylamine (TMA) that are good markers for meat spoilage. The result is that deep networks give a better and faster classification than the feature-based approach, and we thus conclude that the fine-tuning of our deep models are more efficient for this kind of multi-label classification task. PMID:23353140

  16. Pulsed voltage deposited lead selenide thin film as efficient counter electrode for quantum-dot-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Jin, Bin Bin; Wang, Ye Feng; Wang, Xue Qing; Zeng, Jing Hui

    2016-04-01

    Lead selenide (PbSe) thin films were deposited on fluorine doped tin oxide (FTO) glass by a facile one-step pulse voltage electrodeposition method, and used as counter electrode (CE) in CdS/CdSe quantum dot-sensitized solar cells (QDSSCs). A power conversion efficiency of 4.67% is received for the CdS/CdSe co-sensitized solar cells, which is much better than that of 2.39% received using Pt CEs. The enhanced performance is attributed to the extended absorption in the near infrared region, superior electrocatalytic activity and p-type conductivity with a reflection of the incident light at the back electrode in addition. The physical and chemical properties were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), reflectance spectra, electrochemical impedance spectroscopy (EIS) and Tafel polarization measurements. The present work provides a facile pathway to an efficient CE in the QDSSCs.

  17. Enhanced photovoltaic performance of inverted hybrid bulk-heterojunction solar cells using TiO2/reduced graphene oxide films as electron transport layers

    NASA Astrophysics Data System (ADS)

    Morais, Andreia; Alves, Joo Paulo C.; Lima, Francisco Anderson S.; Lira-Cantu, Monica; Nogueira, Ana Flavia

    2015-01-01

    In this study, we investigated inverted hybrid bulk-heterojunction solar cells with the following configuration: fluorine-doped tin oxide (FTO) |TiO2/RGO|P3HT:PC61BM|V2O5 or PEDOT:PSS|Ag. The TiO2/GO dispersions were prepared by sol-gel method, employing titanium isopropoxide and graphene oxide (GO) as starting materials. The GO concentration was varied from 0.1 to 4.0 wt%. The corresponding dispersions were spin-coated onto FTO substrates and a thermal treatment was performed to remove organic materials and to reduce GO to reduced graphene oxide (RGO). The TiO2/RGO films were characterized by x-ray diffraction, Raman spectroscopy, and microscopy techniques. Atomic force microscopy (AFM) images showed that the addition of RGO significantly changes the morphology of the TiO2 films, with loss of uniformity and increase in surface roughness. Independent of the use of V2O5 or PEDOT: PSS films as the hole transport layer, the incorporation of 2.0 wt% of RGO into TiO2 films was the optimal concentration for the best organic photovoltaic performance. The solar cells based on TiO2/RGO (2.0 wt%) electrode exhibited a 22.3% and 28.9% short circuit current density (Jsc) and a power conversion efficiency enhancement, respectively, if compared with the devices based on pure TiO2 films. Kelvin probe force microscopy images suggest that the incorporation of RGO into TiO2 films can promote the appearance of regions with different charge dissipation capacities.

  18. Influence of growth conditions on the electrochemical synthesis of SnS thin films and their optical properties

    NASA Astrophysics Data System (ADS)

    Kafashan, Hosein; Jamali-Sheini, Farid; Ebrahimi-Kahrizsangi, Reza; Yousefi, Ramin

    2016-03-01

    Tin sulfide (SnS) thin films were prepared by electrodeposition onto fluorine-doped tin oxide (FTO) glass substrates using an aqueous solution containing SnCl2 and Na2S2O3 at various deposition potentials ( E) and bath concentrations. The pH value and temperature of the solution were kept constant. The deposited films were characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), photoluminescence (PL), and ultraviolet-visible (UV-Vis) spectroscopy. The FESEM images demonstrated that changes in the deposition potential ( E) and solution concentration led to marked changes in the morphology of the deposited SnS films. Energy-dispersive X-ray analysis (EDXA) results showed that the Sn/S atomic ratio strongly depended on both the solution concentration and the deposition potential. To obtain an Sn/S atomic ratio approximately equal to 1, the optimal Sn2+/S2O 3 2- molar ratio and E parameter were 1/8 and -1.0 V, respectively. The XRD patterns showed that the synthesized SnS was obviously polycrystalline, with an orthorhombic structure. The effects of the variations of bath concentration and deposition potential on the band-gap energy ( E g) were studied using PL and UV-Vis experiments. The PL spectra of all the SnS films contained two peaks in the visible region and one peak in the infrared (IR) region. The UV-Vis spectra showed that the optical band-gap energy varies from 1.21 to 1.44 eV.

  19. Low-cost solution processed nano millet like structure CoS2 film superior to pt as counter electrode for quantum dot sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Rao, S. Srinivasa; Punnosse, Dinah; Kim, Soo-Kyoung; Kim, Hee-Je

    2015-05-01

    Cobalt Sulfide (CoS2) counter electrodes (CE) with uniform size distribution were obtained on fluorine-doped tin oxide (FTO) substrate as counter electrodes for polysulfide redox electrolyte in CdS/CdSe/ ZnS quantum dot-sensitized solar cells (QDSSCs) by chemical bath deposition (CBD) technique. In this study, we optimized the cobalt source, deposition temperature and time in the preparation of CoS2 thin film to achieve greater conversion efficiency with strong adhesion on FTO. Relative to the platinum (Pt) electrodes, the CoS2 electrode shows a higher catalytic activity, faster electron transport and lower chargetransfer resistance, which can play a role in rendering higher power conversion efficiency. As a result, QDSSCs with the optimized CoS2 CE achieved a higher short-circuit current density of 13.08 mA cm-2, open-circuit voltage of 0.47 V, fill factor of 0.34 and overall photovoltaic conversion efficiency of 2.17% obtained under one sun illumination (100 mW cm-2). Therefore, CoS2 CE can be used as a promising CE in QDSSCs with efficiency exceeding that of high-cost Pt-based cells (1.64%). [Figure not available: see fulltext.

  20. Synchronous Electrochromism of Lithium Ion Battery with Chemically Fabricated Transparent Thin Films

    NASA Astrophysics Data System (ADS)

    Nagai, Hiroki; Hara, Hiroki; Enomoto, Mitsuhiro; Mochizuki, Chihiro; Honda, Tohru; Takano, Ichiro; Sato, Mitsunobu

    2013-04-01

    Electrochromism synchronous to the charge/discharge of a novel Li ion battery having Li3Fe2(PO4)3 and Li4Ti5O12 thin-film electrodes fabricated by a chemical process, the molecular precursor method, was discovered. A cathode of transparent Li3Fe2(PO4)3 thin film with a thickness of 80 nm was fabricated by heat treating a precursor ethanol solution including a Li(I) complex of nitrilotriacetic acid, an Fe(III) complex of ethylenediaminetetraacetic acid, and (dibutylammonium)2H2P2O7 ? 0.5H2O at 550C for 10 min in air. An anode of transparent Li4Ti5O12 thin film with a thickness of 90 nm was fabricated by heat treating a precursor ethanol solution including a Li(I) complex of nitrilotriacetic acid, a Ti(IV) complex of the identical organic ligand, and hydrogen peroxide at 550C for 30 min in air. The precursor films for both electrodes were fabricated with a spin-coating method. The thermal reactions of the novel precursors were examined in detail by means of thermogravimetry and differential thermal analysis in order to examine the components and heat-treatment temperature. The crystal structure and surface morphology of the thin-film electrodes fabricated on glass substrates pre-coated with a fluorine-doped tin oxide film were examined with X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The rechargeable function of the assembled sandwich-type battery using an electrolytic solution containing LiPF6 was measured by the repeated charge and discharge test at a constant current of 10 ?A; a maximum voltage of 3.6 V was recorded. The color changes of the transparent thin-film battery between colorless before charging and a blue-gray color after charging occurred synchronously and repeatedly with the charge/discharge cycles. The intercalation of Li+ ions into the Li4Ti5O12 thin-film anode may be related to the drastic color change and the unprecedented visualization of the electrochemical reaction of a novel Li ion battery.

  1. Development of 10 kA high temperature superconducting power cable for railway systems

    NASA Astrophysics Data System (ADS)

    Tomita, M.; Muralidhar, M.; Suzuki, K.; Fukumoto, Y.; Ishihara, A.

    2012-03-01

    The superconducting Bi2Sr2Ca2Cu3Oy "Bi-2223" tapes made with a powder-in-tube process laminated with a copper alloy have been used to design and develop a 5 m long multilayer concentric cable to be applied in railway systems. The electrical performance of the conductor has been evaluated with DC transport current at an economical 77 K (liquid nitrogen temperature) in the self-field. The inner and outer sheet wires were able to sustain electric currents of 10 130 A and 10 910 A, respectively. These values are sufficient for several types of commercial applications. The current values are significantly higher than the earlier reported ones in Bi-2223 or YBa2Cu3Oy "Y-123" superconducting cables, indicating that the tape quality has considerably improved.

  2. Catalytic and photoelectrochemical performances of Cu-Zn-Sn-Se thin films prepared using selenization of electrodeposited Cu-Zn-Sn metal precursors

    NASA Astrophysics Data System (ADS)

    Shao, Pin-Wen; Li, Chun-Ting; Ho, Kuo-Chuan; Cheng, Kong-Wei

    2015-07-01

    In this study, Cu2ZnSnSe4 (CZTSe) films are deposited onto the fluorine-doped-tin-oxide-coated glass substrate via the selenization of electrodeposited Cu-Zn-Sn metal precursors in an acidic solution with the applied potential of -0.9 V vs. an Ag/AgCl electrode. X-ray diffraction patterns reveal that the samples are the quaternary tetragonal CZTSe phase. The thicknesses and direct band gaps of the samples are in the ranges of 2.3 to 2.7 ?m and 0.95 to 1.02 eV, respectively. All samples are p-type semiconductors with carrier density, mobility and flat-band potential in the ranges of 3.88 1017 to 1.37 1018 cm-3, 10.31 to 12.6 cm2 V-1 s-1 and -0.01 V to -0.08 V vs. Ag/AgCl reference electrode, respectively. The sample with [Cu]/[Zn + Sn] and [Zn]/[Sn] molar ratios of 0.87 and 0.66, respectively, has a maximum photo-enhanced current density of 0.41 mA cm-2 at an applied bias of -0.5 V vs. an Ag/AgCl electrode in 0.5 M H2SO4 solution under illumination. The best photo-conversion efficiency of dye-sensitized solar cells using CZTSe with [Cu]/[Zn + Sn] and [Zn]/[Sn] molar ratios of 0.87 and 0.66, respectively, as the counter electrode was 7.98%. The results show the high quality CZTSe films have potentials in applications of photoelectrochemical water splitting and dye-sensitized solar cells.

  3. Near-infrared luminescence of bismuth in fluorine-doped-core silica fibres.

    PubMed

    Bazakutsa, A P; Golant, K M

    2015-02-01

    Photoluminescence spectra and decay kinetics of bismuth inclusions in silica optical fibres containing fluorine additive in the core glass are studied in the vicinity of a wavelength of 1420 nm at temperatures of 80-900 K under a continuous wave (CW) and a pulsed diode laser pump at a wavelength of 808 nm. At high fluorine concentration and low temperatures, luminescence decay kinetics becomes essentially bi-exponential, typical lifetimes being 720 and 1200 s. Hydrogen and deuterium loading at pressures of up to 125 bar leads to a decrease of the steady-state luminescence intensity and lifetime. We attribute this to the appearance of an energy transfer bridge from bismuth clusters to vibrational degrees of freedom of diatomic molecules. It is found that in the presence of H(2) or D(2) molecules experiencing random walking in silica, luminescence decay kinetics stop following a single exponential function even in fluorine-free silica-core fibre, deviation from the single exponent being greater at higher temperatures. The induced quenching rate increases with the increase of temperature as well and is greater for H(2) molecules. All conditions being equal, the equilibrium concentration of hydrogen molecules is greater in heavily fluorinated silica. At temperatures below ~250 K, the presence of dissolved molecules has no effect, which speaks for the primary importance of having rotational degrees of freedom of migrating interstitial diatomic molecules in an excited state for effective quenching of bismuth electronic excitations. It is found that the influence of dissolved deuterium is weaker than that of hydrogen. We attribute this feature to a greater angular momentum of the D(2) molecule and correspondingly smaller energy of the molecule's rotational quantum. The results of the experiments show that bismuth clusters mainly located in voids of the silica network, rather than bismuth point defects, are responsible for near-infrared luminescence. PMID:25836233

  4. Pulsing frequency induced change in optical constants and dispersion energy parameters of WO{sub 3} films grown by pulsed direct current magnetron sputtering

    SciTech Connect

    Punitha, K.; Sivakumar, R.; Sanjeeviraja, C.

    2014-03-21

    In this work, we present the pulsing frequency induced change in the structural, optical, vibrational, and luminescence properties of tungsten oxide (WO{sub 3}) thin films deposited on microscopic glass and fluorine doped tin oxide (SnO{sub 2}:F) coated glass substrates by pulsed dc magnetron sputtering technique. The WO{sub 3} films deposited on SnO{sub 2}:F substrate belongs to monoclinic phase. The pulsing frequency has a significant influence on the preferred orientation and crystallinity of WO{sub 3} film. The maximum optical transmittance of 85% was observed for the film and the slight shift in transmission threshold towards higher wavelength region with increasing pulsing frequency revealed the systematic reduction in optical energy band gap (3.78 to 3.13?eV) of the films. The refractive index (n) of films are found to decrease (1.832 to 1.333 at 550?nm) with increasing pulsing frequency and the average value of extinction coefficient (k) is in the order of 10{sup ?3}. It was observed that the dispersion data obeyed the single oscillator of the Wemple-Didomenico model, from which the dispersion energy (E{sub d}) parameters, dielectric constants, plasma frequency, oscillator strength, and oscillator energy (E{sub o}) of WO{sub 3} films were calculated and reported for the first time due to variation in pulsing frequency during deposition by pulsed dc magnetron sputtering. The E{sub o} is change between 6.30 and 3.88?eV, while the E{sub d} varies from 25.81 to 7.88?eV, with pulsing frequency. The Raman peak observed at 1095?cm{sup ?1} attributes the presence of W-O symmetric stretching vibration. The slight shift in photoluminescence band is attributed to the difference in excitons transition. We have made an attempt to discuss and correlate these results with the light of possible mechanisms underlying the phenomena.

  5. Film Reviews.

    ERIC Educational Resources Information Center

    Lance, Larry M.; Atwater, Lynn

    1987-01-01

    Reviews four Human Sexuality films and videos. These are: "Personal Decisions" (Planned Parenthood Federation of America, 1985); "The Touch Film" (Sterling Production, 1986); "Rethinking Rape" (Film Distribution Center, 1985); "Not A Love Story" (National Film Board of Canada, 1981). (AEM)

  6. Chemical Vapor Deposition of FeOCl Nanosheet Arrays and Their Conversion to Porous ?-Fe2 O3 Photoanodes for Photoelectrochemical Water Splitting.

    PubMed

    Wang, Chong Wu; Yang, Shuang; Jiang, Hai Bo; Yang, Huagui

    2015-12-01

    FeOCl nanosheet arrays were deposited on fluorine-doped tin oxide glass substrates through a chemical vapor deposition method and further converted to hematite porous nanosheet arrays. A much enhanced photocurrent was obtained for such hematite films, which was three times higher than that of a planar hematite film at 1.23?V versus a reversible hydrogen reference electrode. PMID:26507080

  7. Film Boxes.

    ERIC Educational Resources Information Center

    Osterer, Irv

    2002-01-01

    Presents an art lesson in which students created three-dimensional designs for 35mm film packages to improve graphic arts learning. Describes how the students examined and created film boxes using QuarkXPress software. (CMK)

  8. Film Reviews

    ERIC Educational Resources Information Center

    Dowling, John, Ed.

    1976-01-01

    Reviews five instructional films on: P-N junctions; crystal diodes; nuclear fusion research; Schlieren photography; and the energy crisis; including discussions of solar, nuclear, and fossil fuel energy. Also lists numerous other available films. (MLH)

  9. Reconstruction de la surface de Fermi dans l'etat normal d'un supraconducteur a haute Tc: Une etude du transport electrique en champ magnetique intense

    NASA Astrophysics Data System (ADS)

    Le Boeuf, David

    Des mesures de resistance longitudinale et de resistance de Hall en champ magnetique intense transverse (perpendiculaire aux plans CuO2) ont ete effectuees au sein de monocristaux de YBa2Cu3Oy (YBCO) demacles, ordonnes et de grande purete, afin d'etudier l'etat fondamental des supraconducteurs a haute Tc dans le regime sous-dope. Cette etude a ete realisee en fonction du dopage et de l'orientation du courant d'excitation J par rapport a l'axe orthorhombique b de la structure cristalline. Les mesures en champ magnetique intense revelent par suppression de la supraconductivite des oscillations magnetiques des resistances longitudinale et de Hall dans YBa2Cu 3O6.51 et YBa2Cu4O8. La conformite du comportement de ces oscillations quantiques au formalisme de Lifshitz-Kosevich, apporte la preuve de l'existence d'une surface de Fermi fermee a caractere quasi-2D, abritant des quasiparticules coherentes respectant la statistique de Fermi-Dirac, dans la phase pseudogap d'YBCO. La faible frequence des oscillations quantiques, combinee avec l'etude de la partie monotone de la resistance de Hall en fonction de la temperature indique que la surface de Fermi d'YBCO sous-dope comprend une petite poche de Fermi occupee par des porteurs de charge negative. Cette particularite de la surface de Fermi dans le regime sous-dope incompatible avec les calculs de structure de bande est en fort contraste avec la structure electronique presente dans le regime surdope. Cette observation implique ainsi l'existence d'un point critique quantique dans le diagramme de phase d'YBCO, au voisinage duquel la surface de Fermi doit subir une reconstruction induite par l'etablissement d'une brisure de la symetrie de translation du reseau cristallin sous-jacent. Enfin, l'etude en fonction du dopage de la resistance de Hall et de la resistance longitudinale en champ magnetique intense suggere qu'un ordre du type onde de densite (DW) est responsable de la reconstruction de la surface de Fermi. L'analogie de la phenomenologie entourant le comportement des resistances longitudinale et de Hall dans YBa2Cu3Oy, avec des systemes dans lesquels l'existence d'un ordre du type DW est etablie, notamment des cuprates a structure tetragonale a basse temperature ("Low Temperature Tetragonal", LTT), indique que l'ordre causant la reconstruction de la surface de Fermi est stabilise au voisinage du dopage p = 1/8, et est en competition directe avec la supraconductivite.

  10. Nanocomposite films

    DOEpatents

    Mitlin, David; , Ophus, Colin; Evoy, Stephane; Radmilovic, Velimir; Mohammadi, Reza; Westra, Ken; Nelson-Fitzpatrick, Nathaniel; Lee, Zonghoon

    2010-07-20

    A thin-film composition of nanocrystal molybdenum in an amorphous metallic matrix may be formed by co-sputtering Mo with aluminum or nickel. NEMS cantilevers may be formed from the film. The films exhibit high nanoindentation hardness and a reduction in roughness and intrinsic stress, while maintaining resistivity in the metallic range.

  11. On Film

    ERIC Educational Resources Information Center

    Watts, Marty

    2006-01-01

    In this article, the author discusses the role of window films in enhancing indoor air quality in schools. Historically, window film has been used to reduce temperatures in buildings prone to overheating. Too much solar energy entering through windows makes occupants uncomfortable and air conditioning more costly. Film has been a simple solution

  12. On Film

    ERIC Educational Resources Information Center

    Watts, Marty

    2006-01-01

    In this article, the author discusses the role of window films in enhancing indoor air quality in schools. Historically, window film has been used to reduce temperatures in buildings prone to overheating. Too much solar energy entering through windows makes occupants uncomfortable and air conditioning more costly. Film has been a simple solution…

  13. Formation of core@multi-shell CdSe@CdZnS-ZnS quantum dot heterostructure films by pulse electrophoresis deposition

    NASA Astrophysics Data System (ADS)

    Raj, Sudarsan; Yun, Jin Hyeon; Adilbish, Ganpurev; Ch, Rama Krishna; Lee, In Hwan; Lee, Min Sang; Yu, Yeon-Tae

    2015-07-01

    CdSe@CdZnS-ZnS core@multi-shell quantum dot (QD) heterostructures were deposited on fluorine doped tinoxide (FTO) glass substrate by pulse electrophoresis deposition (EPD). Field emissions scanning electron microscopy (FESEM) images reveal that the number of QDs deposited on the substrate increased with prolonged deposition time. Ethanol is the better solution medium as compared to 2-propanol for pulse electrophoresis deposition. For longer deposition time the intensity of photo luminescence (PL) peak increased.

  14. Thin Films

    NASA Astrophysics Data System (ADS)

    Bagade, A. A.; Ganbavle, V. V.; Rajpure, K. Y.

    2014-08-01

    Cobalt ferrite thin films are deposited onto quartz glass substrates by chemical spray pyrolysis technique at different substrate temperatures using ferric nitrate and cobalt nitrate as precursors. Thermogravimetric analysis (TGA) study indicates the formation of CoFe2O4 by decomposition of cobalt and ferric nitrates after 800 C. X-ray diffraction studies reveal that annealed films are polycrystalline in nature and exhibit spinel cubic crystal structure. Crystallite size varies from 39 to 44 nm with the substrate temperatures. Direct optical band gap energy of CoFe2O4 thin films is found to be 2.57 eV. The AFM images show that roughness and grain size of the CoFe2O4 thin film are about 9 and 138 nm, respectively. The measured DC resistivity of the deposited thin films indicates that as temperature increases the resistivity decreases indicating the semiconductor nature of the films. Decrease in dielectric constant (?') and loss tangent (tan?) has been observed with frequency and attains the constant value at higher frequencies. The AC conductivity of cobalt ferrite thin films increases with increase in frequency. Thus, the prepared films show normal dielectric performance of the spinel ferrite thin film. Room-temperature complex impedance spectra show the incomplete semicircles as films exhibit high resistance values at lower frequencies.

  15. Film ispalators

    SciTech Connect

    Startsev, Aleksandr V; Stoilov, Yurii Yu

    2002-05-31

    New physical objects, ispalators based on free soap films, exhibit persistent flows of the soap solution in open and closed volumes in air with additions of gases of the C{sub 8}F{sub 18} type (p = 20 Torr) at temperature drops on the films of the order of tenths and hundredths of kelvin. The flows move continuously at a velocity of 5 - 20 cm s{sup -1}. It is found that the parts of an inclined ispalator film show anomalous behaviour upon heating: their weight increases and they move downward over the film, whereas the unheated parts of the film move upward. Continuous radial vortex flows accompanied by the formation and washing of the regions of a thin black film are observed on circular films in closed volumes upon their uniform external cooling by evaporating water for 5 - 10 hours. The rapid flows make film ispalators the efficient heat carriers, which operate at small temperature drops (tenths and hundredths of kelvin) and surpass copper in the amount of thermal energy being transferred. The outlook for the further study and applications of film ispalators for detecting thermal fields and laser radiation is discussed. (laser applications and other topics in quantum electronics)

  16. Anodic films

    SciTech Connect

    Muller, R.H.

    1983-08-01

    Surface layers are formed on many metals by anodic reaction. Such layers include the products of charge and discharge in many storage batteries, dielectric films used in electronic and optical circuits and display devices, layers responsible for passivity and corrosion protection, and films generated in metal shaping and finishing operations such as anodization, coloring, electropolishing, electrochemical machining and deburring. Anodic films are formed by solid-solid transformations or by dissolution-precipitation processes. Film properties and mechanisms of formation can be determined in situ by a number of optical techniques which have recently become available.

  17. A bi-overlayer type plasmonic photocatalyst consisting of mesoporous Au/TiO2 and CuO/SnO2 films separately coated on FTO.

    PubMed

    Naya, Shin-ichi; Kume, Takahiro; Okumura, Nozomi; Tada, Hiroaki

    2015-07-21

    The principal purpose of this study is to present a new design for preparing highly active immobilized gold nanoparticle-based plasmonic photocatalysts. Gold nanoparticles were loaded on rutile TiO2 particles with a mean size of 80 nm (Au/TiO2) by the deposition precipitation method. The surface of SnO2 particles with a mean size of 100 nm was modified by copper(ii) oxide clusters (CuO/SnO2) with the loading amount (Γ/Cu ions nm(-2)) precisely controlled by the chemisorption-calcination cycle technique. Two mesoporous overlayers of Au/TiO2 and CuO/SnO2 were coated side by side on glass substrates with a fluorine-doped tin oxide film (FTO) using the doctor blade method (Au/mp-TiO2|FTO|CuO/mp-SnO2). As test reactions for assessing the visible-light activity, we carried out gas-phase decomposition of acetaldehyde and liquid-phase oxidation of alcohol. In each reaction, this bi-overlayer type catalyst shows a high level of visible-light activity much exceeding those of Au/TiO2 particles and a Au/mp-TiO2|FTO mono-overlayer type catalyst [J. Phys. Chem. C, 2014, 118, 26887]. To confirm the origin of the striking visible-light activity, we studied the electrocatalytic activity of CuO/mp-SnO2|FTO electrodes for the oxygen reduction reaction (ORR). Both the visible-light activity of Au/mp-TiO2|FTO|CuO/mp-SnO2 and the electrocatalytic activity of CuO/mp-SnO2|FTO for ORR strongly depend on the Γ value. A good positive correlation has been found between the visible-light activities and the electrocatalytic activity for ORR. The striking activity of the present bi-overlayer type catalyst can be attributed to the efficient and long-range charge separation by the vectorial electron transport (Au(oxidation sites) → TiO2→ FTO, SnO2→ CuO(reduction sites)) and the excellent electrocatalytic activity of the CuO clusters. PMID:26094620

  18. About Films.

    ERIC Educational Resources Information Center

    Christman, Robert

    1984-01-01

    Describes 12 video films constituting the "What About" series of the Skills Essential to Learning project. Films begin with an introductory sequence showing a teenager using a particular science skill and concludes with a longer sequence showing a scientist using the same skill. Programs last 15 minutes and follow an identical format. (BC)

  19. About Films.

    ERIC Educational Resources Information Center

    Christman, Robert; Krockover, Gerald H.

    1984-01-01

    Lists and briefly describes 46 college-level films. Films are arranged in the following categories: volcanism and earthquakes; plate tectonics; energy, water, and environmental concerns; petroleum and coal; astronomy; space exploration, space shuttle; paleontology; geomorphology; and mineralogy, petrology, and economic geology. (BC)

  20. Film Makers On Film Making.

    ERIC Educational Resources Information Center

    Geduld, Harry M., Ed.

    This collection includes essays by and interviews with more than 30 film-makers, both classic and contemporary, on the subjects of their major interests and procedures in making films. The directors are: Louis Lumiere, Cecil Hepworth, Edwin S. Porter, Mack Sennett, David W. Griffith, Robert Flaherty, Charles Chaplin, Eric von Stroheim, Dziga

  1. Optimization of transparent and reflecting electrodes for amorphous silicon solar cells. Final technical report

    SciTech Connect

    Gordon, R.G.; Kramer, K.; Liang, H.; Liu, X.; Pang, D.; Teff, D.

    1998-09-01

    Transparent conducting fluorine doped zinc oxide was deposited as thin films on soda lime glass substrates by atmospheric pressure chemical vapor deposition (CVD) at substrate temperatures of 460 to 500 degrees C. The precursors diethylzinc, tetramethylethylenediamine and benzoyl fluoride were dissolved in xylene. This solution was nebulized ultrasonically and then flash vaporized by a carrier gas of nitrogen preheated to 150 degrees C. Ethanol was vaporized separately, and these vapors were then mixed to form a homogeneous vapor mixture. Good reproducibility was achieved using this new CVD method. Uniform thicknesses were obtained by moving the heated glass substrates through the deposition zone. The best electrically and optical properties were obtained when the precursor solution was aged for more than a week before use. The films were polycrystalline and highly oriented with the c-axis perpendicular to the substrate. More than 90% of the incorporated fluorine atoms were electrically active as n-type dopants. The electrical resistivity of the films was as low as 5 x 10/sup -4/ Omega cm. The mobility was about 45 cm ²/Vs. The electron concentration was up to 3 x 10 %sup20;/cm³. The optical absorption of the films was about 3-4% at a sheet resistance of 7 ohms/square. The diffuse transmittance was about 10% at a wavelength of 650 nm. Amorphous ilicon solar cells were deposited using the textured fluorine doped zinc oxide films as a front electrode. The short circuit current was increased over similar cells made with fluorine doped tin oxide, but the open circuit voltages and fill factors were reduced. The voltage was restored by overcoating the fluorine-doped zinc oxide with a thin layer of fluorine-doped tin oxide.

  2. Flux pinning by Al-based nanoparticles embedded in YBCO: A transmission electron microscopic study

    NASA Astrophysics Data System (ADS)

    Ben Azzouz, F.; Zouaoui, M.; Mellekh, A.; Annabi, M.; Van Tendeloo, G.; Ben Salem, M.

    2007-05-01

    A series of YBa2Cu3Oy (YBCO) samples with small amounts (0-0.6 wt.%) of nanosized alumina particles (50 nm) are synthesized in air by solid state reaction. The microstructure has been characterized by transmission electron microscopy (TEM) and the critical current density Jc has been measured by the standard four-probe method in the applied magnetic field at 77 K. TEM and energy dispersive X-ray spectroscopy (EDS) analysis have shown that alumina reacts with the YBCO matrix to form nanometric aluminium-rich inhomogeneities intergrown within the YBCO superconducting matrix. These inhomogeneities reduce the onset transition temperature Tconset and the zero resistance temperature Tc. In spite of the monotonic decrease of the superconducting temperature Tc with increasing alumina addition, the Jc(H) behaviour is remarkably improved. The characteristic behaviour of Jc can be explained in terms of the counterbalance of two effects simultaneously caused by the nanometric alumina addition in the system. One effect is the formation of the Al-rich nanometric inhomogeneities relevant for the flux pinning, and the other effect is the reduction of matrix superconducting volume, which is reflected by a decrease of the critical current density Jc at zero applied magnetic field.

  3. Change of carrier density at the pseudogap critical point of a cuprate superconductor.

    PubMed

    Badoux, S; Tabis, W; Laliberté, F; Grissonnanche, G; Vignolle, B; Vignolles, D; Béard, J; Bonn, D A; Hardy, W N; Liang, R; Doiron-Leyraud, N; Taillefer, Louis; Proust, Cyril

    2016-03-10

    The pseudogap is a partial gap in the electronic density of states that opens in the normal (non-superconducting) state of cuprate superconductors and whose origin is a long-standing puzzle. Its connection to the Mott insulator phase at low doping (hole concentration, p) remains ambiguous and its relation to the charge order that reconstructs the Fermi surface at intermediate doping is still unclear. Here we use measurements of the Hall coefficient in magnetic fields up to 88 tesla to show that Fermi-surface reconstruction by charge order in the cuprate YBa2Cu3Oy ends sharply at a critical doping p = 0.16 that is distinctly lower than the pseudogap critical point p* = 0.19 (ref. 11). This shows that the pseudogap and charge order are separate phenomena. We find that the change in carrier density n from n = 1 + p in the conventional metal at high doping (ref. 12) to n = p at low doping (ref. 13) starts at the pseudogap critical point. This shows that the pseudogap and the antiferromagnetic Mott insulator are linked. PMID:26901870

  4. Change of carrier density at the pseudogap critical point of a cuprate superconductor

    NASA Astrophysics Data System (ADS)

    Badoux, S.; Tabis, W.; Laliberté, F.; Grissonnanche, G.; Vignolle, B.; Vignolles, D.; Béard, J.; Bonn, D. A.; Hardy, W. N.; Liang, R.; Doiron-Leyraud, N.; Taillefer, Louis; Proust, Cyril

    2016-03-01

    The pseudogap is a partial gap in the electronic density of states that opens in the normal (non-superconducting) state of cuprate superconductors and whose origin is a long-standing puzzle. Its connection to the Mott insulator phase at low doping (hole concentration, p) remains ambiguous and its relation to the charge order that reconstructs the Fermi surface at intermediate doping is still unclear. Here we use measurements of the Hall coefficient in magnetic fields up to 88 tesla to show that Fermi-surface reconstruction by charge order in the cuprate YBa2Cu3Oy ends sharply at a critical doping p = 0.16 that is distinctly lower than the pseudogap critical point p* = 0.19 (ref. 11). This shows that the pseudogap and charge order are separate phenomena. We find that the change in carrier density n from n = 1 + p in the conventional metal at high doping (ref. 12) to n = p at low doping (ref. 13) starts at the pseudogap critical point. This shows that the pseudogap and the antiferromagnetic Mott insulator are linked.

  5. Berry phase in cuprate superconductors

    NASA Astrophysics Data System (ADS)

    Doiron-Leyraud, N.; Szkopek, T.; Pereg-Barnea, T.; Proust, C.; Gervais, G.

    2015-06-01

    The geometrical Berry phase is widely recognized as having profound implications for the properties of electronic systems. Over the last decade or so, the Berry phase has been essential to our understanding of new materials such as graphene and topological insulators. In general, a nontrivial Berry phase is a result of band crossing as in the case of a massless Dirac point. The Berry phase can be accessed in quantum oscillation measurements as it contributes to the phase mismatch of electrons in their cyclotron orbits. With their enigmatic pseudogap and superconducting phases, the cuprates are materials where the Berry phase is thus far unknown. Based on quantum oscillation data in the high-field normal state of underdoped cuprates, we determined the Berry phase contribution to the phase mismatch unambiguously in this family of materials. In the hole-doped materials YBa2Cu3Oy , YBa2Cu4O8 , and HgBa2CuO4 +δ , a trivial Berry phase of 0 mod (2 π ) is systematically observed, while the electron-doped Nd2 -xCexCuO4 exhibits a significant nonzero Berry phase of 1.4 π . Our results set significant constraints on the microscopic description of the high-field normal state and, in particular, do not support a nodal structure or broken time-reversal symmetry in the hole-doped compounds.

  6. Infrared pseudogap in cuprate and pnictide high-temperature superconductors

    SciTech Connect

    Moon, S. J.; Lee, Y. S.; Schafgans, A. A.; Chubukov, A. V.; Kasahara, S.; Shibauchi, T.; Terashima, T.; Matsuda, Y.; Tanatar, M. A.; Prozorov, R.; Thaler, A.; Canfield, Paul C.; Bud'ko, Sergey L.; Sefat, A. S.; Mandrus, D.; Segawa, K.; Ando, Y.; Basov, D. N.

    2014-07-01

    We investigate infrared manifestations of the pseudogap in the prototypical cuprate and pnictide superconductors, YBa2Cu3Oy and BaFe2As2 (Ba122) systems. We find remarkable similarities between the spectroscopic features attributable to the pseudogap in these two classes of superconductors. The hallmarks of the pseudogap state in both systems include a weak absorption feature at about 500cm−1 followed by a featureless continuum between 500 and 1500cm−1 in the conductivity data and a significant suppression in the scattering rate below 700–900 cm−1. The latter result allows us to identify the energy scale associated with the pseudogap ΔPG. We find that in the Ba122-based materials the superconductivity-induced changes of the infrared spectra occur in the frequency region below 100–200 cm−1, which is much lower than the energy scale of the pseudogap. We performed theoretical analysis of the scattering rate data of the two compounds using the same model, which accounts for the effects of the pseudogap and electron-boson coupling. We find that the scattering rate suppression in Ba122-based compounds below ΔPG is solely due to the pseudogap formation, whereas the impact of the electron-boson coupling effects is limited to lower frequencies. The magnetic resonance modes used as inputs in our modeling are found to evolve with the development of the pseudogap, suggesting an intimate correlation between the pseudogap and magnetism

  7. Polymer films

    DOEpatents

    Granick, Steve; Sukhishvili, Svetlana A.

    2008-12-30

    A film contains a first polymer having a plurality of hydrogen bond donating moieties, and a second polymer having a plurality of hydrogen bond accepting moieties. The second polymer is hydrogen bonded to the first polymer.

  8. Polymer films

    DOEpatents

    Granick, Steve; Sukhishvili, Svetlana A.

    2004-05-25

    A film contains a first polymer having a plurality of hydrogen bond donating moieties, and a second polymer having a plurality of hydrogen bond accepting moieties. The second polymer is hydrogen bonded to the first polymer.

  9. Film Reviews

    ERIC Educational Resources Information Center

    Ladd, George T.

    1974-01-01

    Briefly describes films about the following topics: water cycles, the energy crisis, the eruption of Mt. Aetna, the hot springs of Yellowstone National Park, and methods of using pine cones to determine the ages of ancient civilizations. (MLH)

  10. Piezoelectric Film.

    ERIC Educational Resources Information Center

    Garrison, Steve

    1992-01-01

    Presents activities that utilize piezoelectric film to familiarize students with fundamental principles of electricity. Describes classroom projects involving chemical sensors, microbalances, microphones, switches, infrared sensors, and power generation. (MDH)

  11. Thin films

    SciTech Connect

    Doermer, M.F. ); Oliver, W.C. ); Pharr, G.M.; Brotzen, F.R. )

    1990-01-01

    This volume is a compilation of papers presented at the 1990 Spring Meeting of the Materials Research Society in a symposium entitled Thin Films: Stresses and Mechanical Properties II. As indicated by the title, the symposium was the second in a series, the first of which was held at the Fall Meeting in 1988. The importance of thin film mechanical properties is now recognized to the extent that basic characterization techniques such as microindentation and thin film stress measurement are performed routinely, and new characterization techniques are being developed on a daily basis. Many of the papers in the symposium dealt with the developments in these characterization methods and their application to a broad spectrum of materials such as compositionally modulated structures, ion implanted materials, optical coatings, and the numerous metals, ceramics and organics used in semiconductor device manufacture.

  12. Film Credits

    ERIC Educational Resources Information Center

    Borja, Rhea R.

    2006-01-01

    With the advent of easy-to-use digital technology, schools are responding to the interests of their media-savvy students by offering more courses in filmmaking. In this article, the author features different films produced by students. Among other things, she discusses the students' growing interest in filmmaking.

  13. Thin Films

    NASA Astrophysics Data System (ADS)

    Naffouti, Wafa; Nasr, Tarek Ben; Mehdi, Ahmed; Kamoun-Turki, Najoua

    2014-11-01

    Titanium dioxide (TiO2) thin films were synthesized on glass substrates by spray pyrolysis. The effect of solution flow rate on the physical properties of the films was investigated by use of x-ray diffraction (XRD), scanning electron microscopy, atomic force microscopy (AFM), and spectrophotometry techniques. XRD analysis revealed the tetragonal anatase phase of TiO2 with highly preferred (101) orientation. AFM images showed that grain size on top of TiO2 thin films depended on solution flow rate. An indirect band gap energy of 3.46 eV was determined by means of transmission and reflection measurements. The envelope method, based on the optical transmission spectrum, was used to determine film thickness and optical constants, for example real and imaginary parts of the dielectric constant, refractive index, and extinction coefficient. Ultraviolet and visible photoluminescence emission peaks were observed at room temperature. These peaks were attributed to the intrinsic emission and to the surface defect states, respectively.

  14. Black Films and Film-Makers.

    ERIC Educational Resources Information Center

    Patterson, Lindsay, Ed.

    The development of black films and the attitudes of the film industry toward black films and black actors are some of the topics examined in this anthology of essays. Section 1, "Nigger to Supernigger," contains such articles as "The Death of Rastus: Negroes in American Films" by Thomas R. Cripps and "Folk Values in a New Medium" by Alain Locke…

  15. Black Films and Film-Makers.

    ERIC Educational Resources Information Center

    Patterson, Lindsay, Ed.

    The development of black films and the attitudes of the film industry toward black films and black actors are some of the topics examined in this anthology of essays. Section 1, "Nigger to Supernigger," contains such articles as "The Death of Rastus: Negroes in American Films" by Thomas R. Cripps and "Folk Values in a New Medium" by Alain Locke

  16. International Film Guide 1972.

    ERIC Educational Resources Information Center

    Cowie, Peter, Ed.

    Brief descriptions of film production activity in 44 countries and reviews of important films from these countries are presented, along with lists of films recently in production. A paragraph-long description of film festivals slated for 1972 is given. Sound track music available on records, 16mm films available in the United Kingdom and the…

  17. Film: An Introduction.

    ERIC Educational Resources Information Center

    Fell, John L.

    "Understanding Film," the opening section of this book, discusses perceptions of and responses to film and the way in which experiences with and knowledge of other media affect film viewing. The second section, "Film Elements," analyzes the basic elements of film: the use of space and time, the impact of editing, sound and color, and the effects

  18. International Film Guide 1972.

    ERIC Educational Resources Information Center

    Cowie, Peter, Ed.

    Brief descriptions of film production activity in 44 countries and reviews of important films from these countries are presented, along with lists of films recently in production. A paragraph-long description of film festivals slated for 1972 is given. Sound track music available on records, 16mm films available in the United Kingdom and the

  19. Film and History.

    ERIC Educational Resources Information Center

    Schaber, Robin L.

    2002-01-01

    Provides an annotated bibliography of Web sites that focus on using film to teach history. Includes Web sites in five areas: (1) film and education; (2) history of cinema; (3) film and history resources; (4) film and women; and (5) film organizations. (CMK)

  20. Filming The Man Hunters

    ERIC Educational Resources Information Center

    Hockings, Paul

    1976-01-01

    "The Man Hunters" is a film about paleoanthropology. This article is a personal account of how the film was put together using anthropological knowledge and numerous anthropologists and how the film was received by the American public. (Author)

  1. Ferroelectric ultrathin perovskite films

    DOEpatents

    Rappe, Andrew M; Kolpak, Alexie Michelle

    2013-12-10

    Disclosed herein are perovskite ferroelectric thin-film. Also disclosed are methods of controlling the properties of ferroelectric thin films. These films can be used in a variety materials and devices, such as catalysts and storage media, respectively.

  2. [Films: China and Japan].

    ERIC Educational Resources Information Center

    Gumport, Roberta H.

    The history of filmmaking in China and Japan and film usage in teaching are considered in this document. Pointing out how films describe historical context and culture, the document also describes various techniques of film making. Films in China were heavily influenced by western models and have tended to be tools of the power structure, as

  3. Film advance indicator

    NASA Technical Reports Server (NTRS)

    Freeman, E. T.; Stump, C. W.; Dreisbach, F. W. (inventors)

    1982-01-01

    A film advancement indicator which includes an optical sensor that detects the rotational movement of a disc that rotates only when the film advance is described. When the film does not advance, an indicator light is activated. A counter is included in the electronic circuit to determine the number of film frames advanced.

  4. Hydrogen film cooling investigation

    NASA Technical Reports Server (NTRS)

    Rousar, D. C.; Ewen, R. L.

    1973-01-01

    Effects of flow turning, flow acceleration, and supersonic flow on film cooling were determined experimentally and correlated in terms of an entrainment film cooling model. Experiments were conducted using thin walled metal test sections, hot nitrogen mainstream gas, and ambient hydrogen or nitrogen as film coolants. The entrainment film cooling model relates film cooling effectiveness to the amount of mainstream gases entrained with the film coolant in a mixing layer. The experimental apparatus and the analytical model used are described in detail and correlations for the entrainment fraction and film coolant-to-wall heat transfer coefficient are presented.

  5. Carbon thin film thermometry

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

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

  6. Laminating Polyimide Films

    NASA Technical Reports Server (NTRS)

    St. Clair, A. K.; St. Clair, T. L.; Robinson, P. D.

    1983-01-01

    Thermoplastic polyimide adhesive is used to bond polyimide sheets into flexible laminates. Films are first primed with polyimide adhesive, then bonded together under heat and pressure. Adhesive is cast on separate surface, then sandwiched between polyimide and/or metal films for final assembly. Objectives of process are to improve bonding of high-temperature polyimide film, prepare flexible, large-area, void-free laminates from polyimide film, and laminate polyimide film not only to itself but to metal surfaces.

  7. Preparation and properties of transparent conductors

    SciTech Connect

    Gordon, R.G.

    1996-12-31

    Transparent, electrically conductive films have been prepared from several different metal oxides, including those of tin, indium and zinc. Deposition methods for these materials are reviewed, and their properties summarized and compared. A figure of merit for a transparent conductor may be defined as the ratio of the electrical conductivity to the optical absorption coefficient of the film. The figure of merit for fluorine-doped zinc oxide is shown to be larger than that of other transparent conductors, such as boron-doped zinc oxide, fluorine-doped tin oxide, and tin-doped indium oxide. Physical, chemical and thermal durability, deposition temperature, and cost are other factors which may also influence the choice of material for a particular application.

  8. Optimization of transparent and reflecting electrodes for amorphous-silicon solar cells. Final subcontract report, 1 May 1991--30 April 1994

    SciTech Connect

    Gordon, R.G.; Hu, J.; Lacks, D.; Musher, J.; Thornton, J.; Liang, H.

    1994-07-01

    Fluorine-doped zinc oxide was shown to have the lowest absorption loss of any of the known transparent conductors. An apparatus was constructed to deposit textured, transparent, conductive, fluorine-doped zinc oxide layers with uniform thickness over a 10 cm by 10 cm area, using inexpensive, high-productivity atmospheric pressure chemical vapor deposition. Amorphous silicon solar cells grown on these textured films show very high peak quantum efficiencies (over 90%). However, a significant contact resistance develops at the interface between the amorphous silicon and the zinc oxide. Transparent, conductive gallium-doped zinc oxide films were grown by APCVD at a low enough temperature (260{degree}C) to be deposited on amorphous silicon as a final conductive back contact to solar cells. A quantum-mechanical theory of bonding was developed and applied to some metal oxides; it forms a basis for understanding TCO structures and the stability of their interfaces with silicon.

  9. Understanding Electrical Conduction States in WO3 Thin Films Applied for Resistive Random-Access Memory

    NASA Astrophysics Data System (ADS)

    Ta, Thi Kieu Hanh; Pham, Kim Ngoc; Dao, Thi Bang Tam; Tran, Dai Lam; Phan, Bach Thang

    2016-02-01

    The electrical conduction and associated resistance switching mechanism of top electrode/WO3/bottom electrode devices [top electrode (TE): Ag, Ti; bottom electrode (BE): Pt, fluorine-doped tin oxide] have been investigated. The direction of switching and switching ability depended on both the top and bottom electrode material. Multiple electrical conduction mechanisms control the leakage current of such switching devices, including trap-controlled space-charge, ballistic, Ohmic, and Fowler-Nordheim tunneling effects. The transition between electrical conduction states is also linked to the switching (SET-RESET) process. This is the first report of ballistic conduction in research into resistive random-access memory. The associated resistive switching mechanisms are also discussed.

  10. Carbon films from polyacrylonitrile

    SciTech Connect

    Renschler, C.L.; Sylwester, A.P.; Salgado, L.V.

    1989-03-01

    Polyacrylonitrile (PAN) films have been fabricated by both spin and solvent casting techniques, and pyrolyzed to produce carbon films in the thickness range of 200--50 000 A. These films have higher electrical conductivities than carbon films produced from most other precursors at similar temperatures. The chemical structure of the films at different stages of processing was investigated by UV, IR, Raman, and XPS spectroscopies. An extra degree of control over the final electrical conductivity was obtained by varying the PAN content of copolymer precursors. Oxidation rates and an activation energy were determined. Finally, processing techniques are described which allow both dry and wet film transfer and lithographic patterning.

  11. Thin film nano solar cells--from device optimization to upscaling.

    PubMed

    Toivola, Minna; Peltola, Time; Miettunen, Kati; Halme, Janne; Lund, Peter

    2010-02-01

    Stainless steel based dye solar cells have been upscaled from small, laboratory size test cells of 0.32 cm2 active area to 6 cm x 6 cm "mini-modules" with active areas ca. 15 cm2. Stainless steel works as the photoelectrode substrate whilst the counter electrode is prepared on indium-doped tin oxide coated polyethyleneterephtalate or polyethylenenaphtalate plastic foil (fluorine-doped tin oxide coated glass as a reference). Additional current collector structures were deposited on the counter electrode substrate with inkjet-printing of silver nanoparticle ink in order to reduce the lateral resistance of the plastic foil. Flexible substrates enable roll-to-roll type industrial manufacturing of the cells and the steel's superior conductivity compared to the typical substrate materials such as glass and plastic makes it possible to prepare even substantially larger modules. The best efficiencies obtained this far with the "mini-module" using a stainless steel photoelectrode are 2.5% with a platinum-sputtered indium-doped tin oxide coated polyethyleneterephtalate counter electrode and 3.4% with a thermally platinized fluorine-doped tin oxide coated glass counter electrode. These efficiencies are on the same level than those measured with small cells prepared with similar methods and materials (3.4%-4.7%, depending on configuration, which are amongst the highest reported for this kind of a dye solar cell). Replacing expensive conducting glass with steel and plastic foils as the substrate materials leads also to economical savings in the cell production. PMID:20352759

  12. Fluorine-doped SiO2 glasses for F2 excimer laser optics: fluorine content and color-center formation.

    PubMed

    Hosono, H; Mizuguchi, M; Skuja, L; Ogawa, T

    1999-11-15

    Color-center formation in F-doped, OH-free synthetic SiO(2) glasses by irradiation with F(2) excimer lasers (157 nm) was examined as a function of the F content. The concentration of photoinduced E(') centers was reduced to approximately 1/20 by 1 mol.% F(2) doping and remained almost constant on further doping to 7.3 mol. %. The absorption edge was considerably shifted to a lower wavelength (157.4 nm -->153 nm for a 5-mm-thick sample) by 1-mol. % doping and decreased only slightly on further doping. The intensities of the Raman bands that are due to three- and four-membered ring structures were significantly reduced by 1-mol. % F doping. These results strongly suggest that elimination of strained Si-O-Si bonds by F doping plays a central role in the improvement of radiation resistance of SiO(2) glasses to F(2) laser light. PMID:18079859

  13. High performance fluorine doped (Sn,Ru)O2 oxygen evolution reaction electro-catalysts for proton exchange membrane based water electrolysis

    NASA Astrophysics Data System (ADS)

    Kadakia, Karan; Datta, Moni Kanchan; Velikokhatnyi, Oleg I.; Jampani, Prashanth; Park, Sung Kyoo; Chung, Sung Jae; Kumta, Prashant N.

    2014-01-01

    Identification of electro-catalysts containing non-noble metal or significantly reduced amounts of expensive noble metals (e.g. RuO2) is highly desirable. Development of such a catalyst with comparable electrochemical performance to the standard noble metal oxide for proton exchange membrane (PEM) based water electrolysis would constitute a pioneering breakthrough in hydrogen generation by water electrolysis. In line with these goals, by exploiting a two-pronged theoretical first principles and experimental approach herein we demonstrate that a nano-structured solid solution of SnO2:10 wt% F containing only 20 at.% RuO2 [e.g. (Sn0.80Ru0.20)O2:10F] displays a remarkably similar electrochemical activity and moreover, comparable or even much improved electrochemical stability and durability compared to pure the noble metal counterpart, RuO2. Density functional theory calculations have demonstrated direct dependence of the catalytic activity on the electronic structure peculiarities of the F-doped (Ru,Sn)O2 which corresponds well with the experimental results.

  14. Film as Film; Understanding and Judging Movies.

    ERIC Educational Resources Information Center

    Perkins, V. F.

    The criteria for judging movies which are presented here are based on the belief that film criticism becomes rational, if not "objective", when it displays and inspects the nature of its evidence and the bases of its arguments. The author dissents from the view of early film theorists that montage is the essence of cinema, and that cinema is to be

  15. Film as Film; Understanding and Judging Movies.

    ERIC Educational Resources Information Center

    Perkins, V. F.

    The criteria for judging movies which are presented here are based on the belief that film criticism becomes rational, if not "objective", when it displays and inspects the nature of its evidence and the bases of its arguments. The author dissents from the view of early film theorists that montage is the essence of cinema, and that cinema is to be…

  16. Exploring the Film.

    ERIC Educational Resources Information Center

    Kuhns, William; Stanley, Robert

    The purpose of film study is defined here in the words of D. W. Griffiths: "My goal is above all to make you see." This book is intended to be used as a text in a film study course. It traces the development of films from a scientific curiosity through silent films to modern wide screen productions. A comic strip is used to demonstrate the effect

  17. Getting into Film.

    ERIC Educational Resources Information Center

    London, Mel

    This book describes the various aspects of the film industry and the many jobs related to filmmaking, stressing that no "formula" exists for finding a successful career in the film industry. Chapters provide information on production, writing for film, cinematography, editing, music, sound, animation and graphics, acting and modeling, the "unsung

  18. Particle film technology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Particle Film Technology involves establishing a mineral particle film on the surface of a plant or plant product that: (1) is chemically inert, (2) has a mean particle diameter < 2 um, (3) is formulated to spread and create a uniform film, (4) does not physically disrupt gas exchange from the le...

  19. Health Careers Film Guide.

    ERIC Educational Resources Information Center

    National Institutes of Health (DHEW), Bethesda, MD. Bureau of Health Manpower Education.

    This document, which represents a survey of the entire health career film field, was designed to provide information for people interested in a health career. The guide indicates that a major criteria for film selection was recency; however, some older films that give a fairly accurate image of a profession were included, with some emphasis given

  20. The Craft of Film.

    ERIC Educational Resources Information Center

    Fisher, J. David, Ed.

    Standardized fundamental principles of design, universalized practices and procedures, and standardized equipment specifications are presented in this film maker's manual. These essentials of film making are analyzed so that the work can stand as a reference for all film makers, from the amateur to the experienced professional. Topics covered

  1. Getting into Film.

    ERIC Educational Resources Information Center

    London, Mel

    This book describes the various aspects of the film industry and the many jobs related to filmmaking, stressing that no "formula" exists for finding a successful career in the film industry. Chapters provide information on production, writing for film, cinematography, editing, music, sound, animation and graphics, acting and modeling, the "unsung…

  2. Mental Retardation Film List.

    ERIC Educational Resources Information Center

    National Library of Medicine (DHEW), Bethesda, MD.

    A list of films on mental retardation includes titles, publication information, physical descriptions, language revisions when other than English, series reference, technical description of film content, sale source, and distributor. Films intended for the general public are grouped under the heading Nonprofessional; others are listed as

  3. Film Resources on Japan.

    ERIC Educational Resources Information Center

    Michigan Univ., Ann Arbor. Audio-Visual Education Center.

    Sixteen millimeter motion pictures dealing with Japan are listed alphabetically by title and annotated. Length of film, whether color or black and white, and name of producer or distributor is given for each, and a subject index is provided. Films produced before 1960, "sponsored" films, and 35 mm filmstrips are listed without annotations. A list

  4. Amorphous-Carbon Films

    NASA Technical Reports Server (NTRS)

    Pouch, John J.; Alterovitz, Samuel A.

    1993-01-01

    Report describes structure, preparation, characterization, and applications of films of amorphous-carbon. Amorphous-carbon films potentially useful as masks in x-ray lithography, layers for passivation of high-speed microelectronic circuits, hard films to protect magnetic recording media and optical components from degradation by chemical etching or wear, and radiation detectors.

  5. Literature and Film.

    ERIC Educational Resources Information Center

    Richardson, Robert

    The differences, similarities, and common goals of film and literature, as well as the ways in which each form and its associated criticism is able to illuminate the other, are discussed in this book. Individual chapters are "Literature and Film,""Literary Origins and Backgrounds of the Film,""Griffith and Eisenstein: The Uses of Literature in

  6. Australian Film Studies.

    ERIC Educational Resources Information Center

    Breen, Myles P.

    Although Australia had a vigorous film industry in the silent film era, it was stifled in the 1930s when United States and British interests bought up the Australian distribution channels and closed down the indigenous industry. However, the industry and film study have undergone a renaissance since the advent of the Labor government in 1972,

  7. Focus on Shakespearean Films.

    ERIC Educational Resources Information Center

    Eckert, Charles W., Ed.

    This is an anthology of reviews and critical pieces of the significant and available Shakespearean films made between 1935 and 1966. Included are three general essays on Shakespearean film by Ian Johnson, Henri Lemaitre, and Geoffrey Reeves. The specific films and their reviewers are: A Midsummer's Night Dream (1935) Allardyce Nicoll and Richard…

  8. Focus on Shakespearean Films.

    ERIC Educational Resources Information Center

    Eckert, Charles W., Ed.

    This is an anthology of reviews and critical pieces of the significant and available Shakespearean films made between 1935 and 1966. Included are three general essays on Shakespearean film by Ian Johnson, Henri Lemaitre, and Geoffrey Reeves. The specific films and their reviewers are: A Midsummer's Night Dream (1935) Allardyce Nicoll and Richard

  9. Thick Film Interference.

    ERIC Educational Resources Information Center

    Trefil, James

    1983-01-01

    Discusses why interference effects cannot be seen with a thick film, starting with a review of the origin of interference patterns in thin films. Considers properties of materials in films, properties of the light source, and the nature of light. (JN)

  10. Film Program Notes from the Current Holdings of the Anthology Film Archives; Outlines of 41 Films.

    ERIC Educational Resources Information Center

    Anthology Film Archives, New York, NY.

    This collection of film program notes includes mixed commentary on some of the films held in the Anthology Film Archives (a film and book library in New York City). Some of the films are described by synopsis of the episodes and others by translation into English of the foreign language subtitles. However, each film noted is identified by full

  11. Pyrolyzed thin film carbon

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

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

  12. Ceramic Composite Thin Films

    NASA Technical Reports Server (NTRS)

    Ruoff, Rodney S. (Inventor); Stankovich, Sasha (Inventor); Dikin, Dmitriy A. (Inventor); Nguyen, SonBinh T. (Inventor)

    2013-01-01

    A ceramic composite thin film or layer includes individual graphene oxide and/or electrically conductive graphene sheets dispersed in a ceramic (e.g. silica) matrix. The thin film or layer can be electrically conductive film or layer depending the amount of graphene sheets present. The composite films or layers are transparent, chemically inert and compatible with both glass and hydrophilic SiOx/silicon substrates. The composite film or layer can be produced by making a suspension of graphene oxide sheet fragments, introducing a silica-precursor or silica to the suspension to form a sol, depositing the sol on a substrate as thin film or layer, at least partially reducing the graphene oxide sheets to conductive graphene sheets, and thermally consolidating the thin film or layer to form a silica matrix in which the graphene oxide and/or graphene sheets are dispersed.

  13. Interplay between unidirectional and bidirectional charge-density-wave orders in underdoped cuprates

    NASA Astrophysics Data System (ADS)

    Wang, Yuxuan; Chubukov, Andrey V.

    2015-12-01

    We analyze the interplay between charge-density-wave (CDW) orders with axial momenta (Q ,0 ) and (0 ,Q ) (?x and ?y, respectively), detected in the underdoped cuprates. The CDW order in real space can be unidirectional (either ?x or ?y is nonzero) or bidirectional (both ?x and ?y are nonzero). To understand which of the two orders develop, we adopt the magnetic scenario, in which the CDW order appears due to spin-fluctuation exchange, and derive the Ginzburg-Landau action to the sixth order in ?x and ?y. We argue that at the mean-field level, the CDW order is bidirectional at the onset, with equal amplitudes of ?x and ?y, but changes to unidirectional inside the CDW phase. This implies that at a given temperature, CDW order is unidirectional at smaller dopings but becomes bidirectional at larger dopings. This is consistent with recent x-ray data on YBa2Cu3Oy , which detected tendency towards bidirectional order at larger dopings. We discuss the role of discrete symmetry breaking at a higher temperature for the interplay between bidirectional and unidirectional CDW orders and also discuss the role of pair-density-wave (PDW) order, which may appear along with CDW. We argue that PDW with the same momentum as CDW changes the structure of the bidirectional charge order by completely replacing either ?x or ?y CDW components by PDW. However, if a so-called Amperean PDW order, which pairs fermions with approximately the same momenta, is also present, both ?x and ?y remain nonzero in the bidirectional phase, albeit with nonequal amplitudes. This is again consistent with x-ray experiments, which at larger doping found nonequal ?x and ?y in every domain.

  14. Coating of plasma polymerized film

    NASA Technical Reports Server (NTRS)

    Morita, S.; Ishibashi, S.

    1980-01-01

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

  15. Clinical careers film.

    PubMed

    2015-09-01

    Those interested in developing clinical academic careers might be interested in a short animated film by Health Education England (HEE) and the National Institute for Health Research. The three-minute film, a frame from which is shown below, describes the sort of opportunities that are on offer to all professionals as part of the HEE's clinical academic careers framework. You can view the film on YouTube at tinyurl.com/pelb95c. PMID:26309005

  16. Renaissance of the Film.

    ERIC Educational Resources Information Center

    Bellone, Julius, Ed.

    The post-World War II period was one of the liveliest in the history of the cinema. This is a collection of 33 critical articles on some of the best films of the perd. Most of the essays explicate the themes and symbols of the films. The essays deal with these films: "The Apu Trilogy,""L'Avventura,""Balthazar,""Blow-Up,""Bonnie and Clyde," Citizen

  17. Renaissance of the Film.

    ERIC Educational Resources Information Center

    Bellone, Julius, Ed.

    The post-World War II period was one of the liveliest in the history of the cinema. This is a collection of 33 critical articles on some of the best films of the perd. Most of the essays explicate the themes and symbols of the films. The essays deal with these films: "The Apu Trilogy,""L'Avventura,""Balthazar,""Blow-Up,""Bonnie and Clyde," Citizen…

  18. Protective overcoating of films

    NASA Technical Reports Server (NTRS)

    Maas, K. A.

    1972-01-01

    Kodak Film Type SO-212 was emulsion overcoated with gelatin and lacquer to evaluate the feasibility of application of the coatings, any image degradation, and the relative protection offered against abrasion. Evaluated were: Eastman motion picture film lacquer Type 485, water solutions of Eastman purified Calfskin gelatin, and experimental Eastman gelatin stripping film of 4 and 6 microns. Conclusions reached were: (1) All coatings can be applied with relative ease with the only limitation being that of equipment. (2) None of the coatings degrade the processed image. (3) All of the coatings provide protection to the emulsion. These conclusions apply to any film which may be considered for overcoating.

  19. Microfilm--Which Film Type, Which Application?

    ERIC Educational Resources Information Center

    Dodson, Suzanne Cates

    1985-01-01

    Report on characteristics of different kinds of microfilm available indicates proper film for specific needs. Silver halide and nonsilver films, diazo film, vesicular film, reaction of films to light, effect of heat and humidity on films, film susceptibility to scratching, and potential longevity of film types are covered. (35 references) (EJS)

  20. Water depth penetration film test

    NASA Technical Reports Server (NTRS)

    Lockwood, H. E.; Perry, L.; Sauer, G. E.; Lamar, N. T.

    1974-01-01

    As part of the National Aeronautics and Space Administration Earth Resources Program, a comparative and controlled evaluation of nine film-filter combinations was completed to establish the relative effectiveness in recording water subsurface detail if exposed from an aerial platform over a typical water body. The films tested, with one exception, were those which prior was suggested had potential. These included an experimental 2-layer positive color film, a 2-layer (minus blue layer) film, a normal 3-layer color film, a panchromatic black-and-white film, and a black-and-white infrared film. Selective filtration was used with all films.

  1. Thin-film forces in pseudoemulsion films

    SciTech Connect

    Bergeron, V.; Radke, C.J. |

    1991-06-01

    Use of foam for enhanced oil recovery (EOR) has shown recent success in steam-flooding field applications. Foam can also provide an effective barrier against gas coning in thin oil zones. Both of these applications stem from the unique mobility-control properties a stable foam possesses when it exists in porous media. Unfortunately, oil has a major destabilizing effect on foam. Therefore, it is important for EOR applications to understand how oil destroys foam. Studies all indicate that stabilization of the pseudoemulsion film is critical to maintain foam stability in the presence of oil. Hence, to aid in design of surfactant formulations for foam insensitivity to oil the authors pursue direct measurement of the thin-film or disjoining forces that stabilize pseudoemulsion films. Experimental procedures and preliminary results are described.

  2. Construction of Meaning: Film.

    ERIC Educational Resources Information Center

    Pryluck, Calvin

    1995-01-01

    Notes that film has no clear set of rules, unlike all languages, which are deductive systems interpreted according to clear sets of rules. Suggests that film is an inductive system whose interpretation is based on a general understanding of events depicted as modified by production variables such as lighting, camera angles, and the context of

  3. On Teaching Ethnographic Film

    ERIC Educational Resources Information Center

    Clarfield, Geoffrey

    2013-01-01

    The author of this article, a developmental anthropologist, illustrates how the instructor can use ethnographic films to enhance the study of anthropology and override notions about the scope and efficacy of Western intervention in the Third World, provided the instructor places such films in their proper historical and cultural context. He

  4. Discovery in Film.

    ERIC Educational Resources Information Center

    Heyer, Robert; Meyer, Anthony

    Seventy-eight "classic" short, non-feature films, cataloged according to six themes--communication, freedom, love, peace, happiness, and the underground--are discussed in this guide. The standard critique for each film has a fourfold purpose: (1) to indicate content and style; (2) to pose questions which provoke discussion; (3) to suggest resource

  5. Children As Film Makers.

    ERIC Educational Resources Information Center

    Lidstone, John; McIntosh, Don

    Based on the premise that film making can be of much greater value in education than is generally realized, this book tells the classroom teacher how to help children make their own films from beginning to end. A detailed text illustrated by drawings and photographs explains the basics of camera operation, editing, splicing, animation, titling,

  6. Film Study Hang Ups.

    ERIC Educational Resources Information Center

    Grenier, Charles F.

    1969-01-01

    The interest and delight which students find in film should be preserved from a teacher's excessive zeal to analyze and explain. As the beauty of poetry is frequently diminished through exhaustive analyses of similes, rhyme schemes, and other technical devices, the value of film to high school students can be weakened through too great an emphasis…

  7. Creative Film-Making.

    ERIC Educational Resources Information Center

    Smallman, Kirk

    The fundamentals of motion picture photography are introduced with a physiological explanation for the illusion of motion in a film. Film stock formats and emulsions, camera features, and lights are listed and described. Various techniques of exposure control are illustrated in terms of their effects. Photographing action with a stationary or a

  8. Creative Film-Making.

    ERIC Educational Resources Information Center

    Smallman, Kirk

    The fundamentals of motion picture photography are introduced with a physiological explanation for the illusion of motion in a film. Film stock formats and emulsions, camera features, and lights are listed and described. Various techniques of exposure control are illustrated in terms of their effects. Photographing action with a stationary or a…

  9. Abstract Film and Beyond.

    ERIC Educational Resources Information Center

    Le Grice, Malcolm

    A theoretical and historical account of the main preoccupations of makers of abstract films is presented in this book. The book's scope includes discussion of nonrepresentational forms as well as examination of experiments in the manipulation of time in films. The ten chapters discuss the following topics: art and cinematography, the first

  10. Children As Film Makers.

    ERIC Educational Resources Information Center

    Lidstone, John; McIntosh, Don

    Based on the premise that film making can be of much greater value in education than is generally realized, this book tells the classroom teacher how to help children make their own films from beginning to end. A detailed text illustrated by drawings and photographs explains the basics of camera operation, editing, splicing, animation, titling,…

  11. Stabilized chromium oxide film

    DOEpatents

    Nyaiesh, A.R.; Garwin, E.L.

    1986-08-04

    Stabilized air-oxidized chromium films deposited on high-power klystron ceramic windows and sleeves having a thickness between 20 and 150A are useful in lowering secondary electron emission yield and in avoiding multipactoring and window failure due to overheating. The ceramic substrate for the film is chosen from alumina, sapphire or beryllium oxide.

  12. Stabilized chromium oxide film

    DOEpatents

    Garwin, Edward L. (Los Altos, CA); Nyaiesh, Ali R. (Palo Alto, CA)

    1988-01-01

    Stabilized air-oxidized chromium films deposited on high-power klystron ceramic windows and sleeves having a thickness between 20 and 150.ANG. are useful in lowering secondary electron emission yield and in avoiding multipactoring and window failure due to overheating. The ceramic substrate for the film is chosen from alumina, sapphire or beryllium oxide.

  13. Dental Training Films.

    ERIC Educational Resources Information Center

    Veterans Administration Medical Center, Washington, DC.

    This dental training films catalog is organized into two sections. Section I is a category listing of the films by number and title, indexed according to generalized headings; categories are as follow: anatomy, articulator systems, complete dentures, dental assisting, dental laboratory technology, dental materials, dental office emergencies,…

  14. Film Canister Science

    ERIC Educational Resources Information Center

    Ferstl, Andrew; Schneider, Jamie L.

    2007-01-01

    Opaque film canisters are readily available, cheap, and useful for scientific inquiry in the classroom. They can also be surprisingly versatile and useful as a tool for stimulating scientific inquiry. In this article, the authors describe inquiry activities using film canisters for preservice teachers, including a "black box" activity and several…

  15. Abstract Film and Beyond.

    ERIC Educational Resources Information Center

    Le Grice, Malcolm

    A theoretical and historical account of the main preoccupations of makers of abstract films is presented in this book. The book's scope includes discussion of nonrepresentational forms as well as examination of experiments in the manipulation of time in films. The ten chapters discuss the following topics: art and cinematography, the first…

  16. Thallium thin films

    SciTech Connect

    Kang, J.; Kampwirth, R.; Gray, K.

    1988-06-01

    Researchers at Sandia National Laboratories, Argonne National Laboratory, and IBM Alamden Research Center have created thin films from thallium barium calcium copper oxide (TlBaCaCuO). Their work which is discussed here, has given us higher T/sub c/'s in thin films, appreciation for the properties of the thallium system, and provocative ideas about structure-property relationships.

  17. Thick film hydrogen sensor

    SciTech Connect

    Hoffheins, B.S.; Lauf, R.J.

    1995-09-19

    A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors. 8 figs.

  18. Superconducting electronic film structures

    NASA Astrophysics Data System (ADS)

    Gavaler, J. R.; Talvacchio, J.

    1991-02-01

    The objective was to obtain both an understanding and control of superconducting and normal-state properties of layered, mostly epitaxial film structures incorporating high-critical-temperature oxide superconductors. Fulfillment is a step in the development of a technology base for superconducting electronics capable of operating above the temperature of 50 K, particularly for passive devices. The technology is based primarily on single-crystal YBCO films deposited by single-target sputtering. Based on a wide variety of characterization techniques, including tunneling and RF surface resistance, they are equal or superior to films made by any other method. Microwave devices fabricated with such films (in other programs at Westinghouse) showed markedly improved performance compared to conventional devices. The capability of sputtering YBCO films on large areas and on both sides of substrates was developed. State-of-the-art TBCCO and LSCO films were also prepared and evaluated. Procedures were developed for control of film orientation. Particular attention was given to film surfaces and interfaces with substrates, epitaxial buffer layers, and tunnel barriers. Specific results of the program are detailed in published papers appended to this report.

  19. Thick film hydrogen sensor

    DOEpatents

    Hoffheins, Barbara S. (Knoxville, TN); Lauf, Robert J. (Oak Ridge, TN)

    1995-01-01

    A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors.

  20. Film Canister Science

    ERIC Educational Resources Information Center

    Ferstl, Andrew; Schneider, Jamie L.

    2007-01-01

    Opaque film canisters are readily available, cheap, and useful for scientific inquiry in the classroom. They can also be surprisingly versatile and useful as a tool for stimulating scientific inquiry. In this article, the authors describe inquiry activities using film canisters for preservice teachers, including a "black box" activity and several

  1. FAA Film Catalog.

    ERIC Educational Resources Information Center

    Federal Aviation Administration (DOT), Washington, DC.

    Some 75 films from the U.S. Department of Transportation's Federal Aviation Administration are listed in this catalog. Topics dealt with include aerodynamics, airports, aviation history and careers, flying clubs, navigation and weather. Most of the films are 16mm sound and color productions. Filmstrips requiring a 35mm projector and phonograph or…

  2. Protolytic carbon film technology

    SciTech Connect

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

    1996-04-01

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

  3. Authors on Film.

    ERIC Educational Resources Information Center

    Geduld, Harry M., Ed.

    Different authors' attitudes toward film are revealed through five different sections of this book: (1) articles, essays, and reviews pertaining to the silent cinema and the transition to sound; (2) general statements on the film medium or filmmakers and their messages; (3) essays dealing with the problems, involvements, and reflections of the…

  4. The Film Idea.

    ERIC Educational Resources Information Center

    Solomon, Stanley J.

    The purpose of this book is to examine the nature of the narrative film in regard to those characteristics that distinguish this art form from the other narrative arts. Elements of the film medium are examined for their possibilities for cinematic expressiveness. The major procedures for shaping and organizing a cinematic narrative are discussed,

  5. Elements of Film.

    ERIC Educational Resources Information Center

    Bobker, Lee R.

    A film is the successful combination of two distinct groups of elements: (1) the technical elements by which the film is made (camera, lighting, sound and editing) and (2) the esthetic elements that transform the craft into an art. This book attempts to combine the study of these elements by providing technical information about the process of

  6. On Teaching Ethnographic Film

    ERIC Educational Resources Information Center

    Clarfield, Geoffrey

    2013-01-01

    The author of this article, a developmental anthropologist, illustrates how the instructor can use ethnographic films to enhance the study of anthropology and override notions about the scope and efficacy of Western intervention in the Third World, provided the instructor places such films in their proper historical and cultural context. He…

  7. Authors on Film.

    ERIC Educational Resources Information Center

    Geduld, Harry M., Ed.

    Different authors' attitudes toward film are revealed through five different sections of this book: (1) articles, essays, and reviews pertaining to the silent cinema and the transition to sound; (2) general statements on the film medium or filmmakers and their messages; (3) essays dealing with the problems, involvements, and reflections of the

  8. Filming for Television.

    ERIC Educational Resources Information Center

    Englander, A. Arthur; Petzold, Paul

    Film makers, professional or amateur, will find in this volume an extensive discussion of the adaptation of film technique to television work, of the art of the camera operator, and of the productive relationships between people, organization, and hardware. Chapters include "The Beginnings," an overview of the interrelationship between roles in…

  9. Bursting of soap films

    NASA Astrophysics Data System (ADS)

    Chowdhury, Debashish; Stauffer, Dietrich

    1992-07-01

    Soap films consist of thin films of water in between two monolayers of amphiphilic molecules. Newton black films (NBFs) are the thinnest possible soap films. We have developed a microscopic model of NBFs; this model is a variant of the Widom model for microemulsions. By carrying out Monte Carlo simulations of this model, we have investigated the dependence of the lifetime of the NBFs on (a) the initial concentration of the amphiphilic molecules, (b) the temperature and (c) the bending rigidity of the constituent amphiphilic monolayers. We compare our results with the corresponding experimental observations and suggest further specific experiments. We establish that the edge energy of the model bilayer tends to stabilize the NBF; a similar mechanism leads to the well known phenomenon of self-healing of small enough holes in pierced vesicles. We also review the laws of growth of holes in soap films during rupture. Finally, we speculate on some other possible applications of our ideas.

  10. Osmolality and tear film dynamics.

    PubMed

    Stahl, Ulrike; Willcox, Mark; Stapleton, Fiona

    2012-01-01

    The tear film is a nourishing, lubricating and protecting layer that bathes the ocular surface. It is continuously replenished through cycles of production and elimination via evaporation, absorption and drainage. These processes are often referred to as tear film dynamics. Osmolality is an objective clinical measurement that provides insight into the balance of these complex tear film dynamics. Balanced tear production and elimination is vital for tear film integrity, stability and normal osmolality. Imbalances cause alterations of the tear film structure and composition, ultimately leading to tear film instability and measurable tear film hyperosmolality. Elevated tear film osmolality is considered a core mechanism in dry eye, forming the basis of dry eye symptoms and leading to ocular surface damage. Despite its immense potential in the diagnosis of dry eye, tear film osmolality is not commonly assessed. This review will focus on the current knowledge of tear film dynamics and tear film osmolality. PMID:22022802

  11. The National Film Registry: Acquiring Our Film Heritage.

    ERIC Educational Resources Information Center

    Ziegler, Roy A.

    The National Film Registry, which is primarily a designated list of films to be preserved by the Library of Congress, is also a valuable tool for selecting "films that are culturally, historically, and aesthetically significant." Following a brief discussion of the history and selection process of the National Film Registry, Southeast Missouri

  12. Preparation and Surface Analysis of a Fluorinated Amorphous Silicon for Photo-voltaic Device Application

    NASA Technical Reports Server (NTRS)

    McWhinney, Hylton G.; Burton, Dawn; Fogarty, Thomas N.

    1998-01-01

    Amorphous silicon films (a-Si:H) have been routinely deposited on a variety of substrates. Surface and interfacial studies were carried out with a PHI 5600 X-ray photo electron spectrometer. Co-deposition with fluorine yielded films having oxygen present as bulk oxide. The higher the fluorine content, the greater the amount of bulk oxygen observed. The presence of oxygen may be a contributing factor to inconsistent film properties of fluorine doped silicon materials, reported else where. A definite chemical interface between a layer containing fluorine and a layer made from pure silane has been delineated.

  13. Fluid film lubrication

    SciTech Connect

    Gross, W.A.; Matsch, L.A.; Castelli, V.; Eshel, A.; Vohr, J.H.; Wildmann, M.

    1980-01-01

    The purpose of this book is to review the fundamentals of fluid lubricating films and to serve as a reference by applying these fundamentals to a variety of examples. Theory and anaysis are emphasized, and important equations, design fundamentals, and some design data are presented. Experimental results are introduced chiefly to corroborate the theory. Normalized notation is used whenever practical to stress the common characteristics of lubricating films and to simplify comparison. This presentation has the additional advantage of saving the reader the labor of confronting the wide range of terminology now in use. Tribology, the theory and practice of lubrication, is a broad subject, the exhaustive treatment of which would include thorough consideration both of the variety of mechanisms of lubrication and of bearing types. The treatment here is limited to those continuum fluid films, called simply ''films,'' which are associated with slider, journal, and sector thrust bearings. Considerable attention is given to incompressible films because films are often effectively incompressible. Thin film and boundary lubrication, the other important mechanisms of lubrication, are not examined here. There is a special focus upon gas lubrication.

  14. Film Images of Private Schools.

    ERIC Educational Resources Information Center

    Resnick, David

    2000-01-01

    Examines public debate over private education in the context of the Hollywood dramatic feature film. Analyses four recent films that all portray private schools negatively. Film representation of public schools is more optimistic. Asserts that the films ignore or misrepresent three strengths of private education: effective leadership, small school

  15. Film and the Liberal Arts.

    ERIC Educational Resources Information Center

    Ross, T. J.

    The essays in this book explore the relationship between films and some of the liberal arts. The first set of essays revolves around the topic of films and rhetoric. They describe the special language of films and its unique mode of communication. A second group of essays deals with films and literature and includes discussions on writing for

  16. Children's Film Programming: A Handbook.

    ERIC Educational Resources Information Center

    Gallery Association of New York State, Inc.

    Directed at the staffs of art institutions, community centers, libraries, historical societies, and schools, this practical guide is intended to help in the selection and use of films for children. "Film," in this handbook refers to 16mm films presented in public screenings--not videotape versions of films, and not material originally produced in

  17. Children's Film Programming: A Handbook.

    ERIC Educational Resources Information Center

    Gallery Association of New York State, Inc.

    Directed at the staffs of art institutions, community centers, libraries, historical societies, and schools, this practical guide is intended to help in the selection and use of films for children. "Film," in this handbook refers to 16mm films presented in public screenings--not videotape versions of films, and not material originally produced in…

  18. The Art of the Film.

    ERIC Educational Resources Information Center

    Lindgren, Ernest

    The author prefaces his consideration of films as an art form with a discussion of the mechanics of filmmaking. He describes the division of talent on a movie set, details the history of the tools of filmmakers, and explains the production and reproduction of a film. The influence of film techniques on plot development in a fiction film is…

  19. Film Scriptwriting: A Practical Manual.

    ERIC Educational Resources Information Center

    Swain, Dwight V.

    Dealing with both documentary and feature films, this book is a guide to using particular tools and procedures in developing ideas and concepts for writing film scripts. Part one deals with the factual, or documentary, film and discusses the proposal outline, film treatment, sequence outline, shooting script, and narration writing. Part two

  20. A Film Guide on China.

    ERIC Educational Resources Information Center

    Wiley, Christopher J., Ed.

    Over 80 films are listed in this annotated film guide on China. Designed to help educators select films about China, each entry contains a short annotation which gives a capsule and sometimes evaluative summary of film content. The booklet is divided into four sections on China before and after 1949, Taiwan, and Chinese culture. Each listing

  1. Thin film hydrogen sensor

    DOEpatents

    Cheng, Yang-Tse (Rochester Hills, MI); Poli, Andrea A. (Livonia, MI); Meltser, Mark Alexander (Pittsford, NY)

    1999-01-01

    A thin film hydrogen sensor, includes: a substantially flat ceramic substrate with first and second planar sides and a first substrate end opposite a second substrate end; a thin film temperature responsive resistor on the first planar side of the substrate proximate to the first substrate end; a thin film hydrogen responsive metal resistor on the first planar side of the substrate proximate to the fist substrate end and proximate to the temperature responsive resistor; and a heater on the second planar side of the substrate proximate to the first end.

  2. Ultrahard carbon nanocomposite films

    SciTech Connect

    SIEGAL,MICHAEL P.; TALLANT,DAVID R.; PROVENCIO,PAULA P.; OVERMYER,DONALD L.; SIMPSON,REGINA L.; MARTINEZ-MIRANDA,L.J.

    2000-01-27

    Modest thermal annealing to 600 C of diamondlike amorphous-carbon (a-C) films grown at room temperature results in the formation of carbon nanocomposites with hardness similar to diamond. These nanocomposite films consist of nanometer-sized regions of high density a-C embedded in an a-C matrix with a reduced density of 5--10%. The authors report on the evolution of density and bonding topologies as a function of annealing temperature. Despite a decrease in density, film hardness actually increases {approximately} 15% due to the development of the nanocomposite structure.

  3. Negative birefringent polyimide films

    NASA Technical Reports Server (NTRS)

    Harris, Frank W. (Inventor); Cheng, Stephen Z. D. (Inventor)

    1994-01-01

    A negative birefringent film, useful in liquid crystal displays, and a method for controlling the negative birefringence of a polyimide film is disclosed which allows the matching of an application to a targeted amount of birefringence by controlling the degree of in-plane orientation of the polyimide by the selection of functional groups within both the diamine and dianhydride segments of the polyimide which affect the polyimide backbone chain rigidity, linearity, and symmetry. The higher the rigidity, linearity and symmetry of the polyimide backbone, the larger the value of the negative birefringence of the polyimide film.

  4. Thin film hydrogen sensor

    DOEpatents

    Cheng, Y.T.; Poli, A.A.; Meltser, M.A.

    1999-03-23

    A thin film hydrogen sensor includes a substantially flat ceramic substrate with first and second planar sides and a first substrate end opposite a second substrate end; a thin film temperature responsive resistor on the first planar side of the substrate proximate to the first substrate end; a thin film hydrogen responsive metal resistor on the first planar side of the substrate proximate to the fist substrate end and proximate to the temperature responsive resistor; and a heater on the second planar side of the substrate proximate to the first end. 5 figs.

  5. Superhard nanocrystalline silicon carbide films

    SciTech Connect

    Liao Feng; Girshick, S.L.; Mook, W.M.; Gerberich, W.W.; Zachariah, M.R.

    2005-04-25

    Nanocrystalline silicon carbide films were deposited by thermal plasma chemical vapor deposition, with film growth rates on the order of 10 {mu}m/min. Films were deposited on molybdenum substrates, with substrate temperature ranging from 750-1250 deg. C. The films are composed primarily of {beta}-SiC nanocrystallites. Film mechanical properties were investigated by nanoindentation. As substrate temperature increased the average grain size, the crystalline fraction in the film, and the hardness all increased. For substrate temperatures above 1200 deg. C the average grain size equaled 10-20 nm, the crystalline fraction equaled 80-85 %, and the film hardness equaled approximately 50 GPa.

  6. Magnetron sputtered boron films

    DOEpatents

    Makowiecki, D.M.; Jankowski, A.F.

    1998-06-16

    A method is described for the production of thin boron and titanium/boron films by magnetron sputter deposition. The amorphous boron films contain no morphological growth features, unlike those found when thin films are prepared by various physical vapor deposition processes. Magnetron sputter deposition method requires the use of a high density crystalline boron sputter target which is prepared by hot isostatic pressing. Thin boron films prepared by this method are useful for producing hardened surfaces, surfacing machine tools, etc. and for ultra-thin band pass filters as well as the low Z element in low Z/high Z optical components, such as mirrors which enhance reflectivity from grazing to normal incidence. 8 figs.

  7. Magnetron sputtered boron films

    DOEpatents

    Makowiecki, Daniel M.; Jankowski, Alan F.

    1998-01-01

    A method is described for the production of thin boron and titanium/boron films by magnetron sputter deposition. The amorphous boron films contain no morphological growth features, unlike those found when thin films are prepared by various physical vapor deposition processes. Magnetron sputter deposition method requires the use of a high density crystalline boron sputter target which is prepared by hot isostatic pressing. Thin boron films prepared by this method are useful for producing hardened surfaces, surfacing machine tools, etc. and for ultra-thin band pass filters as well as the low Z element in low Z/high Z optical components, such as mirrors which enhance reflectivity from grazing to normal incidence.

  8. Amorphous diamond films

    DOEpatents

    Falabella, S.

    1998-06-09

    Amorphous diamond films having a significant reduction in intrinsic stress are prepared by biasing a substrate to be coated and depositing carbon ions thereon under controlled temperature conditions. 1 fig.

  9. Nanostructured thermoplastic polyimide films

    SciTech Connect

    Aglan, Heshmat

    2015-05-19

    Structured films containing multi-walled carbon nanotubes ("MWCNTs") have enhanced mechanical performance in terms of strength, fracture resistance, and creep recovery of polyimide ("PI") films. Preferably, the loadings of MWCNTs can be in the range of 0.1 wt % to 0.5 wt %. The strength of the new PI films dried at 60.degree. C. increased by 55% and 72% for 0.1 wt % MWCNT and 0.5 wt % MWCNT loadings, respectively, while the fracture resistance increased by 23% for the 0.1 wt % MWCNTs and then decreases at a loading of 0.5 wt % MWCNTs. The films can be advantageously be created by managing a corresponding shift in the annealing temperature at which the maximum strength occurs as the MWCNT loadings increase.

  10. Quantitative film radiography

    SciTech Connect

    Devine, G.; Dobie, D.; Fugina, J.; Hernandez, J.; Logan, C.; Mohr, P.; Moss, R.; Schumacher, B.; Updike, E.; Weirup, D.

    1991-02-26

    We have developed a system of quantitative radiography in order to produce quantitative images displaying homogeneity of parts. The materials that we characterize are synthetic composites and may contain important subtle density variations not discernible by examining a raw film x-radiograph. In order to quantitatively interpret film radiographs, it is necessary to digitize, interpret, and display the images. Our integrated system of quantitative radiography displays accurate, high-resolution pseudo-color images in units of density. We characterize approximately 10,000 parts per year in hundreds of different configurations and compositions with this system. This report discusses: the method; film processor monitoring and control; verifying film and processor performance; and correction of scatter effects.

  11. Buckling in nanomechanical films

    SciTech Connect

    Hendricks, Troy R; Lee, Professor Ilsoon

    2010-01-01

    Wrinkling is a common everyday occurrence. Over the last decade wrinkling in thin films has become an interesting topic. Nearly all studies to date have focused on the underlying physics or how the wrinkles can be used for a final purpose. With more and more devices being created from stacked materials, a need for ways to prevent buckling has arisen. In this article we highlight the prevention of wrinkling of nanoscale thin films.

  12. Magnetoresistance of Au films

    DOE PAGESBeta

    Zhang, D. L.; Song, X. H.; Zhang, X; Zhang, Xiaoguang

    2014-01-01

    Measurement of the magnetoresistance (MR) of Au films as a function of temperature and film thickness reveals a strong dependence on grain size distribution and clear violation of the Kohler s rule. Using a model of random resistor network, we show that this result can be explained if the MR arises entirely from inhomogeneity due to grain boundary scattering and thermal activation of grain boundary atoms.

  13. Polymer film composite transducer

    DOEpatents

    Owen, Thomas E.

    2005-09-20

    A composite piezoelectric transducer, whose piezoeletric element is a "ribbon wound" film of piezolectric material. As the film is excited, it expands and contracts, which results in expansion and contraction of the diameter of the entire ribbon winding. This is accompanied by expansion and contraction of the thickness of the ribbon winding, such that the sound radiating plate may be placed on the side of the winding.

  14. Multifunctional thin film surface

    DOEpatents

    Brozik, Susan M.; Harper, Jason C.; Polsky, Ronen; Wheeler, David R.; Arango, Dulce C.; Dirk, Shawn M.

    2015-10-13

    A thin film with multiple binding functionality can be prepared on an electrode surface via consecutive electroreduction of two or more aryl-onium salts with different functional groups. This versatile and simple method for forming multifunctional surfaces provides an effective means for immobilization of diverse molecules at close proximities. The multifunctional thin film has applications in bioelectronics, molecular electronics, clinical diagnostics, and chemical and biological sensing.

  15. Physics of thin films

    SciTech Connect

    Francombe, M.H. ); Vossen, J.L. )

    1992-01-01

    This book of Physics of Thin Films emphasizes two main technical themes. The first is essentially an extension of the topical thrust on Thin Films for Advance Electronic Devices, developed in Volume 15 of this series. The second deals primarily with the physical and mechanical behavior of films and the influence of these in relation to various applications. The first of the four articles in this volume, by Neelkanth G. Dhere, discusses high-transition-temperature (T{sub c}) superconducting films. Since their discovery in 1986, both world-wide research activity and published literature on high-T{sub c} oxide films have exploded at a phenomenal rate. In his treatment, the author presents an effective survey of the already vast literature on this subject, discusses the numerous techniques under development for the growth of these perovskite-related complex oxides, and describes their key properties and applications. In particular, factors affecting the epitaxial structure, critical current capability, and microwave conductivity in Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O based film compositions are evaluated in relation to their use at 77K. An overview of potential applications in a variety of microwave devices, wide-band optical detectors, SQUID-type high-sensitivity magnetometers, etc., is included.

  16. Liquid films, foams and emulsions

    NASA Astrophysics Data System (ADS)

    Langevin, D.

    1999-06-01

    Studies of thin liquid films, made from surfactant solutions, are presented. The film drainage and the interaction between film surfaces are characterized with an experimental device called "Thin Film Balance". Cases where film stratification is observed will be discussed. These experiments allow to model thin films which form between bubbles and drops in foams and emulsions respectively. Nous prsentons des tudes de films liquides forms partir de solutions de tensioactifs. Nous avons tudi le drainage et les forces entre surfaces l'aide d'un dispositif exprimental appel "Balance Films". Dans certains cas, on observe des phnomnes de stratification que l'on dcrira. Ces expriences permettent de modliser les films entre bulles et gouttes que l'on rencontre dans les mousses et les mulsions respectivement.

  17. Heterogeneity in Polymer Thin Films

    NASA Astrophysics Data System (ADS)

    Kanaya, Toshiji; Inoue, Rintaro; Nishida, Koji

    2011-07-01

    In the last two decades very extensive studies have been performed on polymer thin films to reveal very interesting but unusual properties. One of the most interesting findings is the decrease in glass transition temperature Tg with film thickness in polystyrene (PS) thin film supported on Si substrate. Another interesting finding is apparent negative thermal expansivity in glassy state for thin films below 25 nm. In order to understand the unusual properties of polymer thin films we have studied temperature dependence of thickness of polystyrene thin films by means of X-ray and neutron reflectivity. In addition, we also studied dynamics of PS thin films using inelastic neutron scattering. In the presentation we will discuss the results from viewpoints of heterogeneity of polymer thin films. Finally we did neutron reflectivity measurements on a 5-layer thin film, consisting of alternatively stacked d-PS and h-PS layers to see the distribution of glass transition temperature and thermal expansivity directly.

  18. Thin film scintillators

    NASA Astrophysics Data System (ADS)

    McDonald, Warren; McKinney, George; Tzolov, Marian

    2015-03-01

    Scintillating materials convert energy flux (particles or electromagnetic waves) into light with spectral characteristic matching a subsequent light detector. Commercial scintillators such as yttrium aluminum garnet (YAG) and yttrium aluminum perovskite (YAP) are commonly used. These are inefficient at lower energies due to the conductive coating present on their top surface, which is needed to avoid charging. We hypothesize that nano-structured thin film scintillators will outperform the commercial scintillators at low electron energies. We have developed alternative thin film scintillators, zinc tungstate and zinc oxide, which show promise for higher sensitivity to lower energy electrons since they are inherently conductive. Zinc tungstate films exhibit photoluminescence quantum efficiency of 74%. Cathodoluminescence spectroscopy was applied in transmission and reflection geometries. The comparison between the thin films and the YAG and YAP commercial scintillators shows much higher light output from the zinc tungstate and zinc oxide at electron energies less than 5 keV. Our films were integrated in a backscattered electron detector. This detector delivers better images than an identical detector with commercial YAG scintillator at low electron energies. Dr. Nicholas Barbi from PulseTor LLC, Dr. Anura Goonewardene, NSF Grants: #0806660, #1058829, #0923047.

  19. Epitaxial thin films

    DOEpatents

    Hunt, Andrew Tye; Deshpande, Girish; Lin, Wen-Yi; Jan, Tzyy-Jiuan

    2006-04-25

    Epitatial thin films for use as buffer layers for high temperature superconductors, electrolytes in solid oxide fuel cells (SOFC), gas separation membranes or dielectric material in electronic devices, are disclosed. By using CCVD, CACVD or any other suitable deposition process, epitaxial films having pore-free, ideal grain boundaries, and dense structure can be formed. Several different types of materials are disclosed for use as buffer layers in high temperature superconductors. In addition, the use of epitaxial thin films for electrolytes and electrode formation in SOFCs results in densification for pore-free and ideal gain boundary/interface microstructure. Gas separation membranes for the production of oxygen and hydrogen are also disclosed. These semipermeable membranes are formed by high-quality, dense, gas-tight, pinhole free sub-micro scale layers of mixed-conducting oxides on porous ceramic substrates. Epitaxial thin films as dielectric material in capacitors are also taught herein. Capacitors are utilized according to their capacitance values which are dependent on their physical structure and dielectric permittivity. The epitaxial thin films of the current invention form low-loss dielectric layers with extremely high permittivity. This high permittivity allows for the formation of capacitors that can have their capacitance adjusted by applying a DC bias between their electrodes.

  20. Film Report: Independent Multicultural Films at the Sundance Festival.

    ERIC Educational Resources Information Center

    McDonald, Christine L.

    1997-01-01

    Reviews independent multicultural films and videos shown at the Sundance Film Festival, January 1997. The festival included a special symposium and reception honoring Native American writers and filmmakers. This article reviews 4 Native American videos and 10 other multicultural films the author was able to see, and it lists other noteworthy…

  1. The New Film Technologies: Computerized Video-Assisted Film Production.

    ERIC Educational Resources Information Center

    Mott, Donald R.

    Over the past few years, video technology has been used to assist film directors after they have shot a scene, to control costs, and to create special effects, especially computer assisted graphics. At present, a computer based editing system called "Film 5" combines computer technology and video tape with film to save as much as 50% of the cost

  2. Film Report: Independent Multicultural Films at the Sundance Festival.

    ERIC Educational Resources Information Center

    McDonald, Christine L.

    1997-01-01

    Reviews independent multicultural films and videos shown at the Sundance Film Festival, January 1997. The festival included a special symposium and reception honoring Native American writers and filmmakers. This article reviews 4 Native American videos and 10 other multicultural films the author was able to see, and it lists other noteworthy

  3. Thin film temperature sensor

    NASA Technical Reports Server (NTRS)

    Grant, H. P.; Przybyszewski, J. S.

    1980-01-01

    Thin film surface temperature sensors were developed. The sensors were made of platinum-platinum/10 percent rhodium thermocouples with associated thin film-to-lead wire connections and sputtered on aluminum oxide coated simulated turbine blades for testing. Tests included exposure to vibration, low velocity hydrocarbon hot gas flow to 1250 K, and furnace calibrations. Thermal electromotive force was typically two percent below standard type S thermocouples. Mean time to failure was 42 hours at a hot gas flow temperature of 1250 K and an average of 15 cycles to room temperature. Failures were mainly due to separation of the platinum thin film from the aluminum oxide surface. Several techniques to improve the adhesion of the platinum are discussed.

  4. Autostereoscopic Film Display

    NASA Astrophysics Data System (ADS)

    Butterfield, James F.

    1981-07-01

    Three dimensional projected film displays without glasses are now possible as a result of recent developments in autostereoscopy of the parallax panoramagram type. These dis-plays have the features of: full color; excellent resolution; horizontal parallax; con-ventional illumination sources; recording with conventional filming techniques; and in some cases, full motion. The applications include: three dimensional aerial and satellite reconnaisance pictures; 3D computerized axial tomography displays for medicine, seismology and industrial purposes; scientific stereoscopic displays; and educational, advertizing and entertainment slides and motion pictures in depth. A Stereorama film projector has been developed, which back projects a sequence of slides on to a lenticular-type screen. A motion picture projector is being designed.

  5. Thin films and uses

    DOEpatents

    Baskaran, Suresh; Graff, Gordon L.; Song, Lin

    1998-01-01

    The invention provides a method for synthesizing a titanium oxide-containing film comprising the following steps: (a) preparing an aqueous solution of a titanium chelate with a titanium molarity in the range of 0.01M to 0.6M. (b) immersing a substrate in the prepared solution, (c) decomposing the titanium chelate to deposit a film on the substrate. The titanium chelate maybe decomposed acid, base, temperature or other means. A preferred method provides for the deposit of adherent titanium oxide films from C2 to C5 hydroxy carboxylic acids. In another aspect the invention is a novel article of manufacture having a titanium coating which protects the substrate against ultraviolet damage. In another aspect the invention provides novel semipermeable gas separation membranes, and a method for producing them.

  6. A multilayer sonic film

    NASA Astrophysics Data System (ADS)

    Munteanu, L.; Chiroiu, V.; Sireteanu, T.; Dumitriu, D.

    2015-10-01

    A non-periodic multilayer film was analyzed to show that, despite its non-periodicity, the film exhibits full band-gaps and localized modes at its interfaces, as well as in the sonic composites. The film consists of alternating layers of two different materials that follow a triadic Cantor sequence. The Cantor structure shows extremely low thresholds for subharmonic generation of ultrasonic waves, compared with homogeneous and periodic structures. The coupling between the extended-mode (phonon) and the localized-mode (fracton) vibration regimes explains the generation of full band-gaps, for which there are no propagating Lamb waves. The large enhancement of the nonlinear interaction results from a more favorable frequency and spatial matching of coupled modes. A full band-gap that excludes Love waves is also analyzed.

  7. Thin film temperature sensor

    NASA Astrophysics Data System (ADS)

    Grant, H. P.; Przybyszewski, J. S.

    1980-02-01

    Thin film surface temperature sensors were developed. The sensors were made of platinum-platinum/10 percent rhodium thermocouples with associated thin film-to-lead wire connections and sputtered on aluminum oxide coated simulated turbine blades for testing. Tests included exposure to vibration, low velocity hydrocarbon hot gas flow to 1250 K, and furnace calibrations. Thermal electromotive force was typically two percent below standard type S thermocouples. Mean time to failure was 42 hours at a hot gas flow temperature of 1250 K and an average of 15 cycles to room temperature. Failures were mainly due to separation of the platinum thin film from the aluminum oxide surface. Several techniques to improve the adhesion of the platinum are discussed.

  8. Photographic film image enhancement

    NASA Technical Reports Server (NTRS)

    Horner, J. L.

    1975-01-01

    A series of experiments were undertaken to assess the feasibility of defogging color film by the techniques of optical spatial filtering. A coherent optical processor was built using red, blue, and green laser light input and specially designed Fourier transformation lenses. An array of spatial filters was fabricated on black and white emulsion slides using the coherent optical processor. The technique was first applied to laboratory white light fogged film, and the results were successful. However, when the same technique was applied to some original Apollo X radiation fogged color negatives, the results showed no similar restoration. Examples of each experiment are presented and possible reasons for the lack of restoration in the Apollo films are discussed.

  9. The Nuclear Debate in Film

    ERIC Educational Resources Information Center

    Dowling, John

    1977-01-01

    Provides a nuclear film bibliography grouped into the areas of: building and using the bomb; living with the bomb; and living with nuclear power. These films are for mature high school students and older. (MLH)

  10. Thin film photovoltaic device

    DOEpatents

    Catalano, Anthony W. (Wilmington, DE); Bhushan, Manjul (Wilmington, DE)

    1982-01-01

    A thin film photovoltaic solar cell which utilizes a zinc phosphide semiconductor is of the homojunction type comprising an n-type conductivity region forming an electrical junction with a p-type region, both regions consisting essentially of the same semiconductor material. The n-type region is formed by treating zinc phosphide with an extrinsic dopant such as magnesium. The semiconductor is formed on a multilayer substrate which acts as an opaque contact. Various transparent contacts may be used, including a thin metal film of the same chemical composition as the n-type dopant or conductive oxides or metal grids.

  11. Thin film photovoltaic device

    DOEpatents

    Catalano, A.W.; Bhushan, M.

    1982-08-03

    A thin film photovoltaic solar cell which utilizes a zinc phosphide semiconductor is of the homojunction type comprising an n-type conductivity region forming an electrical junction with a p-type region, both regions consisting essentially of the same semiconductor material. The n-type region is formed by treating zinc phosphide with an extrinsic dopant such as magnesium. The semiconductor is formed on a multilayer substrate which acts as an opaque contact. Various transparent contacts may be used, including a thin metal film of the same chemical composition as the n-type dopant or conductive oxides or metal grids. 5 figs.

  12. Thin film ceramic thermocouples

    NASA Technical Reports Server (NTRS)

    Gregory, Otto (Inventor); Fralick, Gustave (Inventor); Wrbanek, John (Inventor); You, Tao (Inventor)

    2011-01-01

    A thin film ceramic thermocouple (10) having two ceramic thermocouple (12, 14) that are in contact with each other in at least on point to form a junction, and wherein each element was prepared in a different oxygen/nitrogen/argon plasma. Since each element is prepared under different plasma conditions, they have different electrical conductivity and different charge carrier concentration. The thin film thermocouple (10) can be transparent. A versatile ceramic sensor system having an RTD heat flux sensor can be combined with a thermocouple and a strain sensor to yield a multifunctional ceramic sensor array. The transparent ceramic temperature sensor that could ultimately be used for calibration of optical sensors.

  13. Biomimetic thin film deposition

    NASA Astrophysics Data System (ADS)

    Rieke, P. C.; Campbell, A. A.; Tarasevich, B. J.; Fryxell, G. E.; Bentjen, S. B.

    1991-04-01

    Surfaces derivatized with organic functional groups were used to promote the deposition of thin films of inorganic minerals. These derivatized surfaces were designed to mimic the nucleation proteins that control mineral deposition during formation of bone, shell, and other hard tissues in living organisms. By the use of derivatized substrates control was obtained over the phase of mineral deposited, the orientation of the crystal lattice and the location of deposition. These features are of considerable importance in many technically important thin films, coatings, and composite materials. Methods of derivatizing surfaces are considered and examples of controlled mineral deposition are presented.

  14. Dual clearance squeeze film damper

    NASA Technical Reports Server (NTRS)

    Fleming, D. P. (Inventor)

    1985-01-01

    A dual clearance hydrodynamic liquid squeeze film damper for a gas turbine engine is described. Under normal operating conditions, the device functions as a conventional squeeze film damper, using only one of its oil films. When an unbalance reaches abusive levels, as may occur with a blade loss or foreign object damage, a second, larger clearance film becomes active, controlling vibration amplitudes in a near optimum manner until the engine can be safely shut down and repaired.

  15. NMR characterization of thin films

    SciTech Connect

    Gerald II, Rex E.; Klingler, Robert J.; Rathke, Jerome W.; Diaz, Rocio; Vukovic, Lela

    2010-06-15

    A method, apparatus, and system for characterizing thin film materials. The method, apparatus, and system includes a container for receiving a starting material, applying a gravitational force, a magnetic force, and an electric force or combinations thereof to at least the starting material, forming a thin film material, sensing an NMR signal from the thin film material and analyzing the NMR signal to characterize the thin film of material.

  16. NMR characterization of thin films

    SciTech Connect

    Gerald, II, Rex E.; Klingler, Robert J.; Rathke, Jerome W.; Diaz, Rocio; Vukovic, Lela

    2008-11-25

    A method, apparatus, and system for characterizing thin film materials. The method, apparatus, and system includes a container for receiving a starting material, applying a gravitational force, a magnetic force, and an electric force or combinations thereof to at least the starting material, forming a thin film material, sensing an NMR signal from the thin film material and analyzing the NMR signal to characterize the thin film of material.

  17. Making Diamondlike Films More Transparent

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

    Diamondlike carbon films highly transparent to visible light made by dual-ion-beam deposition process. Hard, resistant to scratching, and hermetic. Used as protective coatings on eyeglasses, magnetic recording heads, computer hard disks, and windows in bar-code scanners. Amorphous diamondlike carbon films preferable to polycrystalline diamond films in these and other applications. Smooth and adherent and deposited at room temperature.

  18. Archaeology on Film. Second Edition.

    ERIC Educational Resources Information Center

    Downs, Mary, Ed.; And Others

    This document provides a comprehensive guide to archaeological films and video tapes of archaeological interest. Individual films and film series are listed alphabetically by title. Each entry includes the following information: title, series, date, length, color/black & white, format, purchase and rental prices, distributor/rental source,

  19. Infrared presensitization photography - Film comparison

    NASA Astrophysics Data System (ADS)

    Geary, Joseph M.; Sessions, Ron; Duneman, Dennis C.

    1992-06-01

    An investigation was made of five common 35-mm black and white Kodak films showing their relative sensitivity to the IR presensitization photographic effect. The basis of comparison was the density versus IR energy (DIRE) curve. It was found that fine-grain films are more sensitive than coarse-grain films to the presensitization.

  20. Radical Pedagogy, Prison, and Film

    ERIC Educational Resources Information Center

    O'Neill, Dierdre

    2015-01-01

    This article explores the work of The Inside Film project. Inside Film works with a specific group of people (prisoners and ex-prisoners) in a particular set of circumstances (in prison or on parole) exploring how film making can be used within prison education or with people who have been to prison as a means of fostering a critical engagement

  1. Coated Aluminized Film Resists Corrosion

    NASA Technical Reports Server (NTRS)

    Rockoff, H. J.

    1982-01-01

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

  2. Film Study in Higher Education.

    ERIC Educational Resources Information Center

    Stewart, David C., Ed.

    This resource book on the place of film study today is designed to assist in the planning of college courses in the history, criticism, and appreciation of motion pictures. Representative course descriptions and appraisals are given by (1) Jack C. Ellis, who describes a two-part course in film aesthetics and types of films, (2) Edward Fischer, who

  3. Radical Pedagogy, Prison, and Film

    ERIC Educational Resources Information Center

    O'Neill, Dierdre

    2015-01-01

    This article explores the work of The Inside Film project. Inside Film works with a specific group of people (prisoners and ex-prisoners) in a particular set of circumstances (in prison or on parole) exploring how film making can be used within prison education or with people who have been to prison as a means of fostering a critical engagement…

  4. Longevity Of Dry Film Lubricants

    NASA Technical Reports Server (NTRS)

    Kannel, J. W.; Stockwell, R. D.

    1993-01-01

    Report describes evaluation of dry film lubricants candidate for use in rotary joints of proposed Space Station. Study included experiments and theoretical analyses focused on longevity of sputtered molybdenum disulfide films and ion-plated lead films under conditions partially simulating rolling contact.

  5. Methods for producing complex films, and films produced thereby

    DOEpatents

    Duty, Chad E.; Bennett, Charlee J. C.; Moon, Ji -Won; Phelps, Tommy J.; Blue, Craig A.; Dai, Quanqin; Hu, Michael Z.; Ivanov, Ilia N.; Jellison, Jr., Gerald E.; Love, Lonnie J.; Ott, Ronald D.; Parish, Chad M.; Walker, Steven

    2015-11-24

    A method for producing a film, the method comprising melting a layer of precursor particles on a substrate until at least a portion of the melted particles are planarized and merged to produce the film. The invention is also directed to a method for producing a photovoltaic film, the method comprising depositing particles having a photovoltaic or other property onto a substrate, and affixing the particles to the substrate, wherein the particles may or may not be subsequently melted. Also described herein are films produced by these methods, methods for producing a patterned film on a substrate, and methods for producing a multilayer structure.

  6. Diamond films: Historical perspective

    SciTech Connect

    Messier, R.

    1993-01-01

    This section is a compilation of notes and published international articles about the development of methods of depositing diamond films. Vapor deposition articles are included from American, Russian, and Japanese publications. The international competition to develop new deposition methodologies is stressed. The current status of chemical vapor deposition of diamond is assessed.

  7. Film, Radio, and Television.

    ERIC Educational Resources Information Center

    Hardesty, Carolyn, Ed.

    1990-01-01

    This journal issue covers the history of film, radio, and television in Iowa. The first article, "When Pictures and Sound Came to Iowa," summarizes the origin of movies and radio and their early beginnings in Iowa. Using old photographs and measurement charts, the viewing, reading, and listening habits of young people in 1950 and 1958 are

  8. Rating Films on TV.

    ERIC Educational Resources Information Center

    Herman, Ginette; Leyens, Jacques-Philippe

    1977-01-01

    An analysis of the film viewing habits of Belgian television viewers reveals that movies with advisories regarding sex and violence are watched more than the movies without them. However, movies with qualifications tend to be judged less interesting than movies without qualifications. (JMF)

  9. Mobile Library Filming Device.

    ERIC Educational Resources Information Center

    Martin, Claud E.

    This report contains details of the study and performance test of the Mobile Filming Library Device which consists of a camera and self contained power source. Because of the cost savings and service improvement characteristics, this technique involving the use of a microfilm intermediate in the preparation of copies of material filed in full size

  10. Soap Films and Bubbles.

    ERIC Educational Resources Information Center

    Rice, Karen

    1986-01-01

    Develops and explains a format for a workshop which focuses on soap films and bubbles. The plan consists of: a discussion to uncover what children know about bubbles; explanations of the demonstration equipment; the presentation itself; the assembly of the workshop kit; and time to play with the bubbles. (ML)

  11. Paradoxes in Film Ratings

    ERIC Educational Resources Information Center

    Moore, Thomas L.

    2006-01-01

    The author selected a simple random sample of 100 movies from the "Movie and Video Guide" (1996), by Leonard Maltin. The author's intent was to obtain some basic information on the population of roughly 19,000 movies through a small sample. The "Movie and Video Guide" by Leonard Maltin is an annual ratings guide to movies. While not all films ever

  12. Thin film photovoltaic cell

    DOEpatents

    Meakin, John D. (Newark, DE); Bragagnolo, Julio (Newark, DE)

    1982-01-01

    A thin film photovoltaic cell having a transparent electrical contact and an opaque electrical contact with a pair of semiconductors therebetween includes utilizing one of the electrical contacts as a substrate and wherein the inner surface thereof is modified by microroughening while being macro-planar.

  13. Film: The Creative Eye.

    ERIC Educational Resources Information Center

    Sohn, David A.

    Short films are often experimental in nature. They can place aspects of the environment which are usually unnoticed in such a way as to sharpen our observations of the world, and "create a new awareness, a fuller sense of life and being." Based on the premise that visual literacy is becoming increasingly important, this book describes several

  14. Intercultural Training with Films

    ERIC Educational Resources Information Center

    Roell, Christine

    2010-01-01

    Films are a great medium to use not only to practice English, but also to facilitate intercultural learning. Today English is a global language spoken by people from many countries and cultural backgrounds. Since culture greatly impacts communication, it is helpful for teachers to introduce lessons and activities that reveal how different…

  15. Films in Depth.

    ERIC Educational Resources Information Center

    Schrievogel, Paul A.; Prete, Anthony T.

    Bound in a slipcover rather than in signatures, this "book" is made up of thirteen separately bound booklets. The first booklet is an introduction to the use of film in the classroom both in teaching the filmic art and in increasing the visual literacy of students on the high school and early college levels. The twelve other booklets each treat a

  16. Surrealism and Film.

    ERIC Educational Resources Information Center

    Matthews, J. H.

    This book is a critical, genre study of surrealist films including a general discussion of the backgrounds, influences, and overall traits of surrealism as a mode of artistic response to an absurdist world. Citing the impetus of Jacques Vache and Andre Breton as the originators of surrealism, the work expands upon the themes of fractured realism

  17. A Film Canister Colorimeter.

    ERIC Educational Resources Information Center

    Gordon, James; James, Alan; Harman, Stephanie; Weiss, Kristen

    2002-01-01

    A low-cost, low-tech colorimeter was constructed from a film canister. The student-constructed colorimeter was used to show the Beer-Lambert relationship between absorbance and concentration and to calculate the value of the molar absorptivity for permanganate at the wavelength emission maximum for an LED. Makes comparisons between this instrument

  18. Film, Radio, and Television.

    ERIC Educational Resources Information Center

    Hardesty, Carolyn, Ed.

    1990-01-01

    This journal issue covers the history of film, radio, and television in Iowa. The first article, "When Pictures and Sound Came to Iowa," summarizes the origin of movies and radio and their early beginnings in Iowa. Using old photographs and measurement charts, the viewing, reading, and listening habits of young people in 1950 and 1958 are…

  19. Films on Deafness.

    ERIC Educational Resources Information Center

    Parlato, Salvatore J., Jr., Comp.

    This filmography on deafness, which contains summaries of 192 16mm films arranged in alphabetical order by title, covers a wide variety of topics as evidenced by the categorical title index: communication, the nature of deafness, detection and measurement of deafness, education and training, multi-handicaps, and noise pollution. Running time, date

  20. Films in Depth.

    ERIC Educational Resources Information Center

    Schrievogel, Paul A.; Prete, Anthony T.

    Bound in a slipcover rather than in signatures, this "book" is made up of thirteen separately bound booklets. The first booklet is an introduction to the use of film in the classroom both in teaching the filmic art and in increasing the visual literacy of students on the high school and early college levels. The twelve other booklets each treat a…

  1. Introduction to Film.

    ERIC Educational Resources Information Center

    Burns, Gary

    There are numerous ways to structure the introduction to film course so as to meet the needs of the different types of students who typically enroll. Assuming there is no production component in the course, the teacher is left with two major approaches to choose from--historical and aesthetic. The units in the course will typically be built around

  2. Paradoxes in Film Ratings

    ERIC Educational Resources Information Center

    Moore, Thomas L.

    2006-01-01

    The author selected a simple random sample of 100 movies from the "Movie and Video Guide" (1996), by Leonard Maltin. The author's intent was to obtain some basic information on the population of roughly 19,000 movies through a small sample. The "Movie and Video Guide" by Leonard Maltin is an annual ratings guide to movies. While not all films ever…

  3. Thin film mechanics

    NASA Astrophysics Data System (ADS)

    Cooper, Ryan C.

    This doctoral thesis details the methods of determining mechanical properties of two classes of novel thin films suspended two-dimensional crystals and electron beam irradiated microfilms of polydimethylsiloxane (PDMS). Thin films are used in a variety of surface coatings to alter the opto-electronic properties or increase the wear or corrosion resistance and are ideal for micro- and nanoelectromechanical system fabrication. One of the challenges in fabricating thin films is the introduction of strains which can arise due to application techniques, geometrical conformation, or other spurious conditions. Chapters 2-4 focus on two dimensional materials. This is the intrinsic limit of thin films-being constrained to one atomic or molecular unit of thickness. These materials have mechanical, electrical, and optical properties ideal for micro- and nanoelectromechanical systems with truly novel device functionality. As such, the breadth of applications that can benefit from a treatise on two dimensional film mechanics is reason enough for exploration. This study explores the anomylously high strength of two dimensional materials. Furthermore, this work also aims to bridge four main gaps in the understanding of material science: bridging the gap between ab initio calculations and finite element analysis, bridging the gap between ab initio calculations and experimental results, nanoscale to microscale, and microscale to mesoscale. A nonlinear elasticity model is used to determine the necessary elastic constants to define the strain-energy density function for finite strain. Then, ab initio calculations-density functional theory-is used to calculate the nonlinear elastic response. Chapter 2 focuses on validating this methodology with atomic force microscope nanoindentation on molybdenum disulfide. Chapter 3 explores the convergence criteria of three density functional theory solvers to further verify the numerical calculations. Chapter 4 then uses this model to investigate the role of grain boundaries on the strength of chemical vapor deposited graphene. The results from these studies suggest that two dimensional films have remarkably high strength-reaching the intrinsic limit of molecular bonds. Chapter 5 explores the viscoelastic properties of heterogeneous polydimethylsiloxane (PDMS) microfilms through dynamic nanoindentation. PDMS microfilms are irradiated with an electron beam creating a 3 m-thick film with an increased cross-link density. The change in mechanical properties of PDMS due to thermal history and accelerator have been explored by a variety of tests, but the effect of electron beam irradiation is still unknown. The resulting structure is a stiff microfilm embedded in a soft rubber with some transformational strain induced by the cross-linking volume changes. Chapter 5 employs a combination of dynamic nanoindentation and finite element analysis to determine the change in stiffness as a function of electron beam irradiation. The experimental results are compared to the literature. The results of these experimental and numerical techniques provide exciting opportu- nities in future research. Two dimensional materials and flexible thin films are exciting materials for novel applications with new form factors, such as flexible electronics and microfluidic devices. The results herein indicate that you can accurately model the strength of two dimsensional materials and that these materials are robust against nanoscale defects. The results also reveal local variation of mechanical properties in PDMS microfilms. This allows one to design substrates that flex with varying amounts of strain on the surface. Combining the mechanics of two dimensional materials with that of a locally irradiated PDMS film could achieve a new class of flexible microelectromechanical systems. Large-scale growth of two dimensional materials will be structurally robust-even in the presence of nanostructural defects-and PDMS microfilms can be irradiated to vary strain of the electromechanical systems. These systems could be designed to investigate electromechanical coupling in two dimensional films or for a substitute to traditional silicon microdevices. (Abstract shortened by UMI.)

  4. Process to form mesostructured films

    DOEpatents

    Brinker, C. Jeffrey (Albuquerque, NM); Anderson, Mark T. (Woodbury, MN); Ganguli, Rahul (Camarillo, CA); Lu, Yunfeng (Albuquerque, NM)

    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. Colorless, Transparent, Aromatic Polyimide Films

    NASA Technical Reports Server (NTRS)

    St. Clair, A. K.; St. Clair, T. L.; Ezzell, K. S.; Ely, R. M.

    1986-01-01

    New process yields aromatic condensation polyimide films essentially colorless. Films between 90- and 100-percent transparent at visible wavelength of 500 nm. Optically transparent polyimide films made from variety of aromatic condensation polyimides. Range from very pale in color to colorless, compared to bright yellow color of conventional/ commercial aromatic polyimide film. Increased transparency achieved at no sacrifice in thermal stability, flexibility, toughness, or mechanical properties. These features extremely attractive as films or coating materials for aerospace applications or for any other applications where high optical transparency or thermal stability is required.

  6. Orientation filtering for crystalline films

    DOEpatents

    Smith, H.I.; Atwater, H.A.; Thompson, C.V.; Geis, M.W.

    1986-12-30

    A substrate is coated with a film to be recrystallized. A pattern of crystallization barriers is created in the film, for example, by etching voids in the film. An encapsulation layer is generally applied to protect the film, fill the voids and otherwise enhance a recrystallization process. Recrystallization is carried out such that certain orientations pass preferentially through the barrier, generally as a result of growth-velocity anisotropy. The result is a film of a specific predetermined crystallographic orientation, a range of orientations or a set of discrete orientations. 7 figs.

  7. Orientation filtering for crystalline films

    DOEpatents

    Smith, Henry I. (Sudbury, MA); Atwater, Harry A. (Somerville, MA); Thompson, Carl V. (Watertown, MA); Geis, Michael W. (Acton, MA)

    1986-12-30

    A substrate is coated with a film to be recrystallized. A pattern of crystallization barriers is created in the film, for example, by etching voids in the film. An encapsulation layer is generally applied to protect the film, fill the voids and otherwise enhance a recrystallization process. Recrystallization is carried out such that certain orientations pass preferentially through the barrier, generally as a result of growth-velocity anisotropy. The result is a film of a specific predetermined crystallographic orientation, a range of orientations or a set of discrete orientations.

  8. Structured films of magnetizable surfactants

    NASA Astrophysics Data System (ADS)

    Taktarov, N. G.

    1982-12-01

    Qualitative results are presented of an experimental study of surfactants obtained by the deposition of small amount of ferrofluid to the surface of a nonmagnetic fluid. It is shown that the film of magnetic surfactant can be mainly in one of three states of aggregation: gaseous, liquid, or solid. Spontaneous crimping of solid surfactant films is observed in the absence of an external magnetic field, a phenomenon explained by the interaction of linear clusters perpendicular to the edge of the film. The properties of magnetic surfactant films are analogous to those of thin ferromagnetic films on a solid substrate.

  9. Thin-film optical initiator

    DOEpatents

    Erickson, Kenneth L. (Albuquerque, NM)

    2001-01-01

    A thin-film optical initiator having an inert, transparent substrate, a reactive thin film, which can be either an explosive or a pyrotechnic, and a reflective thin film. The resultant thin-film optical initiator system also comprises a fiber-optic cable connected to a low-energy laser source, an output charge, and an initiator housing. The reactive thin film, which may contain very thin embedded layers or be a co-deposit of a light-absorbing material such as carbon, absorbs the incident laser light, is volumetrically heated, and explodes against the output charge, imparting about 5 to 20 times more energy than in the incident laser pulse.

  10. Method for making carbon films

    DOEpatents

    Tan, M.X.

    1999-07-29

    A method for treating an organic polymer material, preferably a vinylidene chloride/vinyl chloride copolymer (Saran) to produce a flat sheet of carbon film material having a high surface area ([approx equal]1000 m[sup 2] /g) suitable as an electrode material for super capacitor applications. The method comprises heating a vinylidene chloride/vinyl chloride copolymer film disposed between two spaced apart graphite or ceramic plates to a first temperature of about 160 C for about 14 hours to form a stabilized vinylidene chloride/vinyl chloride polymer film, thereafter heating the stabilized film to a second temperature of about 750 C in an inert atmosphere for about one hour to form a carbon film; and finally activating the carbon film to increase the surface area by heating the carbon film in an oxidizing atmosphere to a temperature of at least 750--850 C for between 1--6 hours. 2 figs.

  11. Thin film superconductor magnetic bearings

    SciTech Connect

    Weinberger, Bernard R.

    1995-12-26

    A superconductor magnetic bearing includes a shaft (10) that is subject to a load (L) and rotatable around an axis of rotation, a magnet (12) mounted to the shaft, and a stator (14) in proximity to the shaft. The stator (14) has a superconductor thin film assembly (16) positioned to interact with the magnet (12) to produce a levitation force on the shaft (10) that supports the load (L). The thin film assembly (16) includes at least two superconductor thin films (18) and at least one substrate (20). Each thin film (18) is positioned on a substrate (20) and all the thin films are positioned such that an applied magnetic field from the magnet (12) passes through all the thin films. A similar bearing in which the thin film assembly (16) is mounted on the shaft (10) and the magnet (12) is part of the stator (14) also can be constructed.

  12. Professor Camillo Negro's Neuropathological Films.

    PubMed

    Chiò, Adriano; Gianetto, Claudia; Dagna, Stella

    2016-01-01

    Camillo Negro, Professor in Neurology at the University of Torino, was a pioneer of scientific film. From 1906 to 1908, with the help of his assistant Giuseppe Roasenda and in collaboration with Roberto Omegna, one of the most experienced cinematographers in Italy, he filmed some of his patients for scientific and educational purposes. During the war years, he continued his scientific film project at the Military Hospital in Torino, filming shell-shocked soldiers. In autumn 2011, the Museo Nazionale del Cinema, in partnership with the Faculty of Neurosciences of the University of Torino, presented a new critical edition of the neuropathological films directed by Negro. The Museum's collection also includes 16 mm footage probably filmed in 1930 by Doctor Fedele Negro, Camillo's son. One of these films is devoted to celebrating the effects of the so-called "Bulgarian cure" on Parkinson's disease. PMID:26684422

  13. Epitaxial gadolinium nitride thin films

    SciTech Connect

    Gerlach, J. W.; Mennig, J.; Rauschenbach, B.

    2007-02-05

    GdN thin films are deposited on MgO(100) by low-energy ion-beam-assisted molecular-beam epitaxy at elevated temperatures. Elemental analysis by secondary-ion mass spectrometry proves that a protective layer is imperative to avoid oxidation of the GdN films in air. In situ surface structural investigation of the growing GdN films by reflection high-energy electron diffraction reveals epitaxial film growth. This result is confirmed by x-ray diffraction structure and texture analysis. Accordingly, the GdN films on MgO(100) exhibit cube-on-cube epitaxy. Due to the epitaxial growth the crystalline quality of the films is by far higher than that of films previously reported of in literature.

  14. Method for making carbon films

    DOEpatents

    Tan, Ming X.

    1999-01-01

    A method for treating an organic polymer material, preferably a vinylidene chloride/vinyl chloride copolymer (Saran) to produce a flat sheet of carbon film material having a high surface area (.apprxeq.1000 m.sup.2 /g) suitable as an electrode material for super capacitor applications. The method comprises heating a vinylidene chloride/vinyl chloride copolymer film disposed between two spaced apart graphite or ceramic plates to a first temperature of about 160.degree. C. for about 14 hours to form a stabilized vinylidene chloride/vinyl chloride polymer film, thereafter heating the stabilized film to a second temperature of about 750.degree. C. in an inert atmosphere for about one hour to form a carbon film; and finally activating the carbon film to increase the surface area by heating the carbon film in an oxidizing atmosphere to a temperature of at least 750-850.degree. C. for between 1-6 hours.

  15. Combustion effects on film cooling

    NASA Technical Reports Server (NTRS)

    Rousar, D. C.; Ewen, R. L.

    1977-01-01

    The effects of: (1) a reactive environment on film cooling effectiveness, and (2) film cooling on rocket engine performance were determined experimentally in a rocket thrust chamber assembly operating with hydrogen and oxygen propellants at 300 psi chamber pressure. Tests were conducted using hydrogen, helium, and nitrogen film coolants in an instrumented, thin walled, steel thrust chamber. The film cooling, performance loss, and heat transfer coefficient data were correlated with the ALRC entrainment film cooling model which relates film coolant effectiveness and mixture ratio at the wall to the amount of mainstream gases entrained with the film coolant in a mixing layer. In addition, a comprehensive thermal analysis computer program, HOCOOL, was prepared from previously existing ALRC computer programs and analytical techniques.

  16. Efficient hole-blocking layer-free planar halide perovskite thin-film solar cells.

    PubMed

    Ke, Weijun; Fang, Guojia; Wan, Jiawei; Tao, Hong; Liu, Qin; Xiong, Liangbin; Qin, Pingli; Wang, Jing; Lei, Hongwei; Yang, Guang; Qin, Minchao; Zhao, Xingzhong; Yan, Yanfa

    2015-01-01

    Efficient lead halide perovskite solar cells use hole-blocking layers to help collection of photogenerated electrons and to achieve high open-circuit voltages. Here, we report the realization of efficient perovskite solar cells grown directly on fluorine-doped tin oxide-coated substrates without using any hole-blocking layers. With ultraviolet-ozone treatment of the substrates, a planar Au/hole-transporting material/CH₃NH₃PbI₃-xClx/substrate cell processed by a solution method has achieved a power conversion efficiency of over 14% and an open-circuit voltage of 1.06 V measured under reverse voltage scan. The open-circuit voltage is as high as that of our best reference cell with a TiO₂ hole-blocking layer. Besides ultraviolet-ozone treatment, we find that involving Cl in the synthesis is another key for realizing high open-circuit voltage perovskite solar cells without hole-blocking layers. Our results suggest that TiO₂ may not be the ultimate interfacial material for achieving high-performance perovskite solar cells. PMID:25798925

  17. Switched photocurrent direction in Au/TiO2 bilayer thin films

    PubMed Central

    Chen, Hongjun; Liu, Gang; Wang, Lianzhou

    2015-01-01

    Switched photocurrent direction in photoelectrodes is a very interesting phenomenon and has demonstrated their potentials in important applications including photodiodes, phototransistors, light-driven sensors and biosensors. However, the design and mechanism understanding of such photoelectrodes remain challenging to date. Here we report a new phenomenon of sequence-driven the photocurrent direction on a simple bilayer structure of 5 nm thick Au and 10 nm TiO2 under visible-light irradiation. It is found that when Au layer are deposited as the outer layer on TiO2 coated fluorine doped tin oxide (FTO) substrate (designated as FTO/TiO2/Au), anodic photocurrent is obtained due to the band bending formed at the electrode-electrolyte interface. Interestingly, simply swapping the deposition sequence of Au and TiO2 leads to cathodic photocurrent on FTO/Au/TiO2 electrode. Characterization and calculations on the photoelectrode reveals that the photogenerated electrons can be easily trapped in the energy well formed between the band bending and the Schottky contact, which allows electronic tunnelling through the 1.6 nm thick space charge layer, resulting in a unique anodic to cathodic photocurrent conversion. The understanding of this new phenomenon can be important for designing new generation optoelectronic converting devices in a low-cost and facile manner. PMID:26028118

  18. Efficient hole-blocking layer-free planar halide perovskite thin-film solar cells

    NASA Astrophysics Data System (ADS)

    Ke, Weijun; Fang, Guojia; Wan, Jiawei; Tao, Hong; Liu, Qin; Xiong, Liangbin; Qin, Pingli; Wang, Jing; Lei, Hongwei; Yang, Guang; Qin, Minchao; Zhao, Xingzhong; Yan, Yanfa

    2015-03-01

    Efficient lead halide perovskite solar cells use hole-blocking layers to help collection of photogenerated electrons and to achieve high open-circuit voltages. Here, we report the realization of efficient perovskite solar cells grown directly on fluorine-doped tin oxide-coated substrates without using any hole-blocking layers. With ultraviolet-ozone treatment of the substrates, a planar Au/hole-transporting material/CH3NH3PbI3-xClx/substrate cell processed by a solution method has achieved a power conversion efficiency of over 14% and an open-circuit voltage of 1.06?V measured under reverse voltage scan. The open-circuit voltage is as high as that of our best reference cell with a TiO2 hole-blocking layer. Besides ultraviolet-ozone treatment, we find that involving Cl in the synthesis is another key for realizing high open-circuit voltage perovskite solar cells without hole-blocking layers. Our results suggest that TiO2 may not be the ultimate interfacial material for achieving high-performance perovskite solar cells.

  19. Shock Waves in Soap Films

    NASA Astrophysics Data System (ADS)

    Wen, C. Y.; Chang-Jian, S. K.; Chen, Y. M.; Kuo, W. S.

    1997-11-01

    The nature of shock waves in soap films is investigated theoretically and experimentally. For one-dimensional flows in soap films, the basic normal shock relations and Rankine-Hugoniot equations are derived. At low concentrations, the results are similar to those of compressible gases. On short time scales, soap films are analogous to compressible gases of ? = 1.0. The role of pressure in gases is played by surface tension in the film and that of compressibility by Gibbs or Marangoni elasticity, depending on the time scales of the film stretching. The thickness of the film is an active scalar which responds to the dynamics of the film motion in a manner similar to shallow water flows. A series of experiments is performed. The bursting of plane vertical soap films is studied by means of the high-speed flash photography and the line scan CCD imaging technique. An aureole and a shock wave preceding the expanding hole are clearly observed. The analogy between thickness jumps in soap films and shock waves in gases are then investigated experimentally. Photographs of supersonic flows over blunt bodies are presented. The results suggest the feasibility of the soap film shock tube.

  20. Magnetoresistance of Au films

    SciTech Connect

    Zhang, D. L. Song, X. H.; Zhang, X.; Zhang, X.-G.

    2014-12-14

    Classical magnetoresistance (MR) in nonmagnetic metals are conventionally understood in terms of the Kohler rule, with violation usually viewed as anomalous electron transport, in particular, as evidence of non-Fermi liquid behavior. Measurement of the MR of Au films as a function of temperature and film thickness reveals a strong dependence on grain size distribution and clear violation of the Kohler rule. Using a model of random resistor network, we show that this result can be explained if the MR arises entirely from inhomogeneity due to grain boundary scattering and thermal activation of grain boundary atoms. Consequently, the Kohler rule should not be used to distinguish normal and anomalous electron transport in solids.

  1. Biomimetic thin film deposition

    SciTech Connect

    Rieke, P.R.; Graff, G.E.; Campbell, A.A.; Bunker, B.C.; Baskaran, S.; Song, L.; Tarasevich, B.J.; Fryxell, G.E.

    1995-09-01

    Biological mineral deposition for the formation of bone, mollusk shell and other hard tissues provides materials scientists with illustrative materials processing strategies. This presentation will review the key features of biomineralization and how these features can be of technical importance. We have adapted existing knowledge of biomineralization to develop a unique method of depositing inorganic thin films and coating. Our approach to thin film deposition is to modify substrate surfaces to imitate the proteins found in nature that are responsible for controlling mineral deposition. These biomimetic surfaces control the nucleation and growth of the mineral from a supersaturated aqueous solution. This has many processing advantages including simple processing equipment, environmentally benign reagents, uniform coating of highly complex shapes, and enhanced adherence of coating. Many different types of metal oxide, hydroxide, sulfide and phosphate materials with useful mechanical, optical, electronic and biomedical properties can be deposited.

  2. Freely floating smectic films.

    PubMed

    May, Kathrin; Harth, Kirsten; Trittel, Torsten; Stannarius, Ralf

    2014-05-19

    We have investigated the dynamics of freely floating smectic bubbles using high-speed optical imaging. Bubbles in the size range from a few hundred micrometers to several centimeters were prepared from collapsing catenoids. They represent ideal model systems for the study of thin-film fluid dynamics under well-controlled conditions. Owing to the internal smectic layer structure, the bubbles combine features of both soap films and vesicles in their unique shape dynamics. From a strongly elongated initial shape after pinch-off, they relax towards the spherical equilibrium, first by a slow redistribution of the smectic layers, and finally by weak, damped shape oscillations. In addition, we describe the rupture of freely floating smectic bubbles, and the formation and stability of smectic filaments. PMID:24692347

  3. Advanced thin film thermocouples

    NASA Technical Reports Server (NTRS)

    Kreider, K. G.; Semancik, S.; Olson, C.

    1984-01-01

    The fabrication, materials characterization, and performance of thin film platinum rhodium thermocouples on gas turbine alloys was investigated. The materials chosen for the study were the turbine blade alloy systems MAR M200+Hf with NiCoCrAlY and FeCrAlY coatings, and vane alloy systems MAR M509 with FeCrAlY. Research was focussed on making improvements in the problem areas of coating substrate stability, adhesion, and insulation reliability and durability. Diffusion profiles between the substrate and coating with and without barrier coatings of Al2O3 are reported. The relationships between fabrication parameters of thermal oxidation and sputtering of the insulator and its characterization and performance are described. The best thin film thermocouples were fabricated with the NiCoCrAlY coatings which were thermally oxidized and sputter coated with Al2O3.

  4. Thin film composite electrolyte

    DOEpatents

    Schucker, Robert C. (The Woodlands, TX)

    2007-08-14

    The invention is a thin film composite solid (and a means for making such) suitable for use as an electrolyte, having a first layer of a dense, non-porous conductive material; a second layer of a porous ionic conductive material; and a third layer of a dense non-porous conductive material, wherein the second layer has a Coefficient of thermal expansion within 5% of the coefficient of thermal expansion of the first and third layers.

  5. Protein thin film machines.

    PubMed

    Federici, Stefania; Oliviero, Giulio; Hamad-Schifferli, Kimberly; Bergese, Paolo

    2010-12-01

    We report the first example of microcantilever beams that are reversibly driven by protein thin film machines fueled by cycling the salt concentration of the surrounding solution. We also show that upon the same salinity stimulus the drive can be completely reversed in its direction by introducing a surface coating ligand. Experimental results are throughout discussed within a general yet simple thermodynamic model. PMID:20936224

  6. Nonlinear optical thin films

    NASA Technical Reports Server (NTRS)

    Leslie, Thomas M.

    1993-01-01

    A focused approach to development and evaluation of organic polymer films for use in optoelectronics is presented. The issues and challenges that are addressed include: (1) material synthesis, purification, and the tailoring of the material properties; (2) deposition of uniform thin films by a variety of methods; (3) characterization of material physical properties (thermal, electrical, optical, and electro-optical); and (4) device fabrication and testing. Photonic materials, devices, and systems were identified as critical technology areas by the Department of Commerce and the Department of Defense. This approach offers strong integration of basic material issues through engineering applications by the development of materials that can be exploited as the active unit in a variety of polymeric thin film devices. Improved materials were developed with unprecedented purity and stability. The absorptive properties can be tailored and controlled to provide significant improvement in propagation losses and nonlinear performance. Furthermore, the materials were incorporated into polymers that are highly compatible with fabrication and patterning processes for integrated optical devices and circuits. By simultaneously addressing the issues of materials development and characterization, keeping device design and fabrication in mind, many obstacles were overcome for implementation of these polymeric materials and devices into systems. We intend to considerably improve the upper use temperature, poling stability, and compatibility with silicon based devices. The principal device application that was targeted is a linear electro-optic modulation etalon. Organic polymers need to be properly designed and coupled with existing integrated circuit technology to create new photonic devices for optical communication, image processing, other laser applications such as harmonic generation, and eventually optical computing. The progression from microscopic sample to a suitable film-forming material in a working device is a complex, multifaceted endeavor. It requires close attention to maintaining the optical properties of the electro-optic active portion of the polymer while manipulating the polymer structure to obtain the desired secondary polymer properties.

  7. Thin Hot-Film Sensors On Polyimide Film

    NASA Technical Reports Server (NTRS)

    Hopson, Purnell

    1993-01-01

    Array of closely spaced hot-film sensors with thickness well below critical reference height with regard to air-flow pattern nonintrusively detect laminar boundary-layer transitions with very high resolution. Method developed at NASA Langley Research Center to fabricate such sensors on polyimide films to detect boundary-layer transitions with resolution as high as 0.050 in. These films formed by combination of vacuum deposition and photolithography.

  8. Stability of soap films: hysteresis and nucleation of black films.

    PubMed

    Casteletto, Valeria; Cantat, Isabelle; Sarker, Dipak; Bausch, Richard; Bonn, Daniel; Meunier, Jacques

    2003-01-31

    We study the stability of soap films of a nonionic surfactant under different applied capillary pressures on the film. Depending on the pressure, either a thick common black film (CBF), or a micro-scopically thin Newton black film (NBF) is formed as a (metastable) equilibrium state, with a first-order (discontinuous) transition between the two. Studying the dynamics of the CBF-NBF transition, it is found that under certain conditions a hysteresis for the transition is observed: for a given range of pressures, either of the two states may be observed. We quantify the nucleation process that is at the basis of these observations both experimentally and theoretically. PMID:12570466

  9. Stability of Soap Films: Hysteresis and Nucleation of Black Films

    NASA Astrophysics Data System (ADS)

    Casteletto, Valeria; Cantat, Isabelle; Sarker, Dipak; Bausch, Richard; Bonn, Daniel; Meunier, Jacques

    2003-01-01

    We study the stability of soap films of a nonionic surfactant under different applied capillary pressures on the film. Depending on the pressure, either a thick common black film (CBF), or a microscopically thin Newton black film (NBF) is formed as a (metastable) equilibrium state, with a first-order (discontinuous) transition between the two. Studying the dynamics of the CBF-NBF transition, it is found that under certain conditions a hysteresis for the transition is observed: for a given range of pressures, either of the two states may be observed. We quantify the nucleation process that is at the basis of these observations both experimentally and theoretically.

  10. Sound for Film: Audio Education for Filmmakers.

    ERIC Educational Resources Information Center

    Lazar, Wanda

    1998-01-01

    Identifies the specific, unique, and important elements of audio education required by film professionals. Presents a model unit to be included in a film studies program, either as a separate course or as part of a film production or introduction to film course. Offers a model syllabus for such a course or unit on sound in film. (SR)

  11. Silent Film in the German Classroom.

    ERIC Educational Resources Information Center

    Caldwell, David

    In addition to using films in the German classroom to introduce students to German culture and history, it is important to show and study the film as film. This procedure emphasizes the importance of the film as a part of creative arts in Germany and demands student participation in observation and discussion. Many German silent films are…

  12. Short Films for Physics Teaching, A Catalog.

    ERIC Educational Resources Information Center

    Bluestone, Barbara Z.; Roth, Richard F.

    This annotated film catalog is a product of the Conference on Single Concept Films in College Physics Teaching sponsored by the Commission on College Physics. Both 8mm and 16mm single concept films are listed for physics and related disciplines. The catalog includes commercial, noncommercial, and foreign films. However, the film coverage was

  13. Women and Film: A Resource Handbook.

    ERIC Educational Resources Information Center

    Association of American Colleges, Washington, DC. Project on the Status and Education of Women.

    This resource handbook provides a summary of the media resources available concerning women. Emphasis is placed on some questions to consider in planning a film festival, suggestions for reducing costs, feature length films pertinent to women's roles, films shown at the first International Festival of Women's Films, short films, slide programs,…

  14. Fracture characteristics of balloon films

    NASA Technical Reports Server (NTRS)

    Portanova, Marc A.

    1989-01-01

    An attempt was made to determine the failure modes of high altitude scientific balloons through an investigation of the fracture characteristics of the thin polyethylene films. Two films were the subject of the evaluation, Winzen Int.'s Stratafilm SF-85 and Raven Industries' Astro-E. Research began with an investigation of the film's cold brittleness point and it's effect on the ultimate strength and elasticity of the polyethylene film. A series of preliminary investigations were conducted to develop an understanding of the material characteristics. The primary focus of this investigation was on the notch sensitivity of the films. Simple stress strain tests were also conducted to enable analysis employing fracture toughness parameters. Studies were conducted on both film types at 23 C (room temperature), -60 C, -90 C, and -120 C.

  15. Films on the arms race

    SciTech Connect

    Dowling, J.

    1983-01-01

    Films convey the historical perspectives, the biographical stories, the insights of the participants, and the horror of nuclear war - far better than can any physicist. While films are not very efficient for covering details, derivation, or numbers, they can not be beaten in showing what really happens in a nuclear explosion, in getting across general concepts, in illustrating the parameters of a problem, and the problem itself. Most importantly, films and TV can reach the people who must be informed about these issues if we are to resolve the problems. The author points out how films can contribute to an understanding of the issues of the arms race and nuclear war, with references to specific films. An annotated bibliography of 37 films is then presented.

  16. Diamond films for laser hardening

    NASA Technical Reports Server (NTRS)

    Albin, S.; Watkins, L.; Ravi, K.; Yokota, S.

    1989-01-01

    Laser-damage experiments were performed on free-standing polycrystalline diamond films prepared by plasma-enhanced CVD. The high laser-induced stress resistance found for this material makes it useful for thin-film coatings for laser optics. Results for diamond-coated silicon substrates demonstrate the enhanced damage threshold imparted by diamond thin-film coatings to materials susceptible to laser damage.

  17. Nanoporous glass films on liquids.

    PubMed

    Zuber, Kamil; Evans, Drew; Murphy, Peter

    2014-01-01

    Glass-like thin films are used in many applications as dielectric layers, barrier coatings, abrasion-resistant films, and/or transparent films. We report the first direct application of such materials to liquid substrates using a plasma-deposition process at atmospheric pressure. The study demonstrates the broader utilization of these materials, for example, as robust membranes for water harvesting or drug delivery. PMID:24295063

  18. Testing Conductive Films For Continuity

    NASA Technical Reports Server (NTRS)

    Leung, Philip L.

    1991-01-01

    Apparatus tests thin conductive films for continuity without touching them. Specimen irradiated with 10-keV electrons; then noncontacting electrostatic probe scans specimen and measures charge on spot directly under it. Avoids damage to film and error from contact resistance resulting from touching film with conventional probe. Developed to determine integrity of conductive coats applied to surfaces of dielectric materials to inhibit accumulation of electrostatic charges.

  19. Drying of thin colloidal films

    NASA Astrophysics Data System (ADS)

    Routh, Alexander F.

    2013-04-01

    When thin films of colloidal fluids are dried, a range of transitions are observed and the final film profile is found to depend on the processes that occur during the drying step. This article describes the drying process, initially concentrating on the various transitions. Particles are seen to initially consolidate at the edge of a drying droplet, the so-called coffee-ring effect. Flow is seen to be from the centre of the drop towards the edge and a front of close-packed particles passes horizontally across the film. Just behind the particle front the now solid film often displays cracks and finally the film is observed to de-wet. These various transitions are explained, with particular reference to the capillary pressure which forms in the solidified region of the film. The reasons for cracking in thin films is explored as well as various methods to minimize its effect. Methods to obtain stratified coatings through a single application are considered for a one-dimensional drying problem and this is then extended to two-dimensional films. Different evaporative models are described, including the physical reason for enhanced evaporation at the edge of droplets. The various scenarios when evaporation is found to be uniform across a drying film are then explained. Finally different experimental techniques for examining the drying step are mentioned and the article ends with suggested areas that warrant further study.

  20. 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.

  1. The Environment Film Review. A Critical Guide to Ecology Films.

    ERIC Educational Resources Information Center

    Environment Information Center, New York, NY.

    Critical reviews of more than 600 environmental films selected from a field of several thousand are contained in this reference guide. Designed to provide a comprehensive selection of films covering all aspects of environmental affairs, from air pollution to wildlife, the guide is primarily user-oriented. It consists of two parts: a Review

  2. Some Suggestions for Conducting Film Competitions and Film Festivals.

    ERIC Educational Resources Information Center

    Eastman Kodak Co., Rochester, NY.

    Four essentials in staging film festivals and competitions are: facilities, films, equipment, and an audience. Basic steps in getting these essentials together are outlined. Surveying available facilities first helps you gauge the scale of the festival, estimate the likely costs and receipts, and plan for the projection equipment necessary.…

  3. "Kuleshov on Film": A Spectator-Centered Film Theory.

    ERIC Educational Resources Information Center

    Curran, Trisha

    This paper describes some of the theories of cinematography of Soviet film theorist and filmmaker Lev Kuleshov. It points out that for him, film was communication portraying people's activities emanating from the environment. It explains that he was especially interested in audience response, particularly that of the proletariat, and that he felt

  4. "Kuleshov on Film": A Spectator-Centered Film Theory.

    ERIC Educational Resources Information Center

    Curran, Trisha

    This paper describes some of the theories of cinematography of Soviet film theorist and filmmaker Lev Kuleshov. It points out that for him, film was communication portraying people's activities emanating from the environment. It explains that he was especially interested in audience response, particularly that of the proletariat, and that he felt…

  5. Film Music: Implications for Instructional Films and Television.

    ERIC Educational Resources Information Center

    Hlynka, D.

    This paper provides a critical review of the behavioral research on film music, indicates that there is a visual bias in media attribute research which needs to be balanced, and provides media producers and instructional developers with a theoretical basis and practical guidelines for using music in audiovisual presentations. The question of film

  6. Drop dynamics on a thin film: Thin film rupture

    NASA Astrophysics Data System (ADS)

    Carlson, Andreas; Kim, Pilnam; Stone, Howard A.

    2011-11-01

    The spreading of a water drop on an oil film that covers a solid substrate is a common event in many industrial processes. We study in experiments the dynamics of a water drop on a thin silicone oil film and quantify its interaction with the solid substrate that supports the film. The oil film becomes unstable and ruptures for solids that are hydrophilic. We determine the ``waiting time,'' the time it takes the water drop to drain the silicone film. This timescale is found to highly depend on how well water wets the solid, illustrating the interplay between intermolecular and hydrodynamic forces in the phenomenon. A phase diagram for the thin film stability is extracted based on waters equilibrium contact angle on the solid, which shows that we can either promote or inhibit de-wetting. As water comes in direct contact with the solid, it spreads and peels off the silicone film. We show the influence of viscosity, equilibrium contact angle and film height on the opening radius of the hole formed as the solid de-wets.

  7. Protective Film Moves Aside

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Relatively warmer daytime temperatures on Mars have allowed the biobarrier -- a shiny, protective film -- to peel away a little more from the robotic arm of NASA's Phoenix Mars Lander.

    This image shows the spacecraft's robotic arm in its stowed configuration, with the biobarrier unpeeled on landing day, or Sol (Martian day) 0, and the lander's first full day on Mars, Sol 1.

    The 'elbow' of the arm can be seen at the top center of the picture, and the biobarrier is the shiny film seen to the left of the arm.

    The biobarrier is an extra precaution to protect Mars from contamination with any bacteria from Earth. While the whole spacecraft was decontaminated through cleaning, filters and heat, the robotic arm was given additional protection because it is the only spacecraft part that will directly touch the ice below the surface of Mars.

    Before the arm was heated, it was sealed in the biobarrier, which is made of a trademarked film called Tedlar that holds up to baking like a turkey-basting bag. This ensures that any new bacterial spores that might have appeared during the final steps before launch and during the journey to Mars will not contact the robotic arm.

    After Phoenix landed, springs were used to pop back the barrier, giving it room to deploy.

    These images were taken on May 25, 2008 and May 26, 2008 by the spacecraft's Surface Stereo Imager.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  8. Antibacterial Biomimetic Hybrid Films.

    PubMed

    Ferrer, M Carme Coll; Hickok, Noreen J; Eckmann, David M; Composto, Russell J

    2013-02-28

    In this work, we present a novel method to prepare a hybrid coating based on dextran grafted to a substrate and embedded with silver nanoparticles (Ag NPs). First, the Ag NPs are synthesized in situ in the presence of oxidized dextran in solution. Second, the oxidized dextran is exposed to an amine functionalized surface resulting in the simultaneous grafting of dextran and the trapping of Ag NPs within the layer. The NP loading is controlled by the concentration of silver nitrate, which is 2 mM (DEX-Ag2) and 5 mM (DEX-Ag5). The dried film thickness increases with silver nitrate concentration from 2 nm for dextran to 7 nm and 12 nm for DEX-Ag2 and DEX-Ag5, respectively. The grafted dextran film displays features with a diameter and height of ~ 50 nm and 2 nm, respectively. For the DEX-Ag2 and DEX-Ag5, the dextran features as well as individual Ag NPs (~ 5 nm) and aggregates of Ag NPs are observed. Larger and more irregular aggregates are observed for DEX-Ag5. Overall, the Ag NPs are embedded in the dextran film as suggested by AFM and UVO studies. In terms of its antimicrobial activity, DEX-Ag2 resists bacterial adhesion to a greater extent than DEX-Ag5, which in turn is better than dextran and silicon. Because these antibacterial hybrid coatings can be grafted to a variety of surfaces, many biomedical applications can be envisioned, ranging from coating implants to catheters. PMID:23807896

  9. Antibacterial Biomimetic Hybrid Films

    PubMed Central

    Ferrer, M. Carme Coll; Hickok, Noreen J.; Eckmann, David M.; Composto, Russell J.

    2012-01-01

    In this work, we present a novel method to prepare a hybrid coating based on dextran grafted to a substrate and embedded with silver nanoparticles (Ag NPs). First, the Ag NPs are synthesized in situ in the presence of oxidized dextran in solution. Second, the oxidized dextran is exposed to an amine functionalized surface resulting in the simultaneous grafting of dextran and the trapping of Ag NPs within the layer. The NP loading is controlled by the concentration of silver nitrate, which is 2 mM (DEX-Ag2) and 5 mM (DEX-Ag5). The dried film thickness increases with silver nitrate concentration from 2 nm for dextran to 7 nm and 12 nm for DEX-Ag2 and DEX-Ag5, respectively. The grafted dextran film displays features with a diameter and height of ~ 50 nm and 2 nm, respectively. For the DEX-Ag2 and DEX-Ag5, the dextran features as well as individual Ag NPs (~ 5 nm) and aggregates of Ag NPs are observed. Larger and more irregular aggregates are observed for DEX-Ag5. Overall, the Ag NPs are embedded in the dextran film as suggested by AFM and UVO studies. In terms of its antimicrobial activity, DEX-Ag2 resists bacterial adhesion to a greater extent than DEX-Ag5, which in turn is better than dextran and silicon. Because these antibacterial hybrid coatings can be grafted to a variety of surfaces, many biomedical applications can be envisioned, ranging from coating implants to catheters. PMID:23807896

  10. Radiation grafting on natural films

    NASA Astrophysics Data System (ADS)

    Lacroix, M.; Khan, R.; Senna, M.; Sharmin, N.; Salmieri, S.; Safrany, A.

    2014-01-01

    Different methods of polymer grafting using gamma irradiation are reported in the present study for the preparation of newly functionalized biodegradable films, and some important properties related to their mechanical and barrier properties are described. Biodegradable films composed of zein and poly(vinyl alcohol) (PVA) were gamma-irradiated in presence of different ratios of acrylic acid (AAc) monomer for compatibilization purpose. Resulting grafted films (zein/PVA-g-AAc) had their puncture strength (PS=37-40 N mm-1) and puncture deformation (PD=6.5-9.8 mm) improved for 30% and 50% PVA in blend, with 5% AAc under 20 kGy. Methylcellulose (MC)-based films were irradiated in the presence of 2-hydroxyethyl methacrylate (HEMA) or silane, in order to determine the effect of monomer grafting on the mechanical properties of films. It was found that grafted films (MC-g-HEMA and MC-g-silane) using 35% monomer performed higher mechanical properties with PS values of 282-296 N mm-1 and PD of 5.0-5.5 mm under 10 kGy. Compatibilized polycaprolactone (PCL)/chitosan composites were developed via grafting silane in chitosan films. Resulting trilayer grafted composite film (PCL/chitosan-g-silane/PCL) presented superior tensile strength (TS=22 MPa) via possible improvement of interfacial adhesion (PCL/chitosan) when using 25% silane under 10 kGy. Finally, MC-based films containing crystalline nanocellulose (CNC) as a filling agent were prepared and irradiated in presence of trimethylolpropane trimethacrylate (TMPTMA) as a grafted plasticizer. Grafted films (MC-g-TMPTMA) presented superior mechanical properties with a TS of 47.9 MPa and a tensile modulus (TM) of 1792 MPa, possibly due to high yield formation of radicals to promote TMPTMA grafting during irradiation. The addition of CNC led to an additional improvement of the barrier properties, with a significant 25% reduction of water vapor permeability (WVP) of grafted films.

  11. Electrically conductive palladium-containing polyimide films

    NASA Technical Reports Server (NTRS)

    St.clair, A. K.; Furtsch, T. A.; Taylor, L. T.

    1981-01-01

    Palladium addition makes light, flexible film with low resistivity to relieve space charging. Polyimide film is prepared in four steps: preparation of polyamic acid in polar solvent; addition of soluable palladium complex salt; fabrication of film of "palladium polyamic acid" solution; and thermal imidization of film to palladium-containing polyimide by 300 C heating. Lowered resistivities were achieved without loss in film flexibility or increase in film weight.

  12. Carbonaceous film coating

    DOEpatents

    Maya, Leon (Oak Ridge, TN)

    1989-01-01

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

  13. Turbine airfoil film cooling

    NASA Astrophysics Data System (ADS)

    Hylton, Larry D.

    1986-10-01

    Emphasis is placed on developing more accurate analytical models for predicting turbine airfoil external heat transfer rates. Performance goals of new engines require highly refined, accurate design tools to meet durability requirements. In order to obtain improvements in analytical capabilities, programs are required which focus on enhancing analytical techniques through verification of new models by comparison with relevant experimental data. The objectives of the current program are to develop an analytical approach, based on boundary layer theory, for predicting the effects of airfoil film cooling on downstream heat transfer rates and to verify the resulting analytical method by comparison of predictions with hot cascade data obtained under this program.

  14. Carbonaceous film coating

    DOEpatents

    Maya, L.

    1988-04-27

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

  15. Thin film hydrogen sensor

    DOEpatents

    Lauf, Robert J.; Hoffheins, Barbara S.; Fleming, Pamela H.

    1994-01-01

    A hydrogen sensor element comprises an essentially inert, electrically-insulating substrate having a thin-film metallization deposited thereon which forms at least two resistors on the substrate. The metallization comprises a layer of Pd or a Pd alloy for sensing hydrogen and an underlying intermediate metal layer for providing enhanced adhesion of the metallization to the substrate. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors, and at least one of the resistors is left uncovered. The difference in electrical resistances of the covered resistor and the uncovered resistor is related to hydrogen concentration in a gas to which the sensor element is exposed.

  16. A Film Canister Colorimeter

    NASA Astrophysics Data System (ADS)

    Gordon, James; James, Alan; Harman, Stephanie; Weiss, Kristen

    2002-08-01

    A low-cost, low-tech colorimeter was constructed from a film canister. The light source and filter monochromator was an interchangeable LED. The detector for this system was a voltage-divider circuit composed of a photoresistor in series with a fixed resistor. The student-constructed colorimeter was used to show the Beer–Lambert relationship between absorbance and concentration and to calculate the value of the molar absorptivity for permanganate at the wavelength emission maximum for the LED. Comparisons were made between this instrument and three commercial spectrometers and colorimeters.

  17. Liquid film demonstration experiment Skylab SL-4

    NASA Technical Reports Server (NTRS)

    Darbro, W.

    1975-01-01

    The liquid film demonstration experiment performed on Skylab 4 by Astronaut Gerald Carr, which involved the construction of water and soap films by boundary expansion and inertia, is discussed. Results include a 1-ml globule of water expanded into a 7-cm-diameter film as well as complex film structures produced by inertia whose lifetimes are longer in the low-g environment. Also discussed are 1-g acceleration experiments in which the unprovoked rupture of films was photographed and film lifetimes of stationary and rotated soap films were compared. Finally, there is a mathematical discussion regarding minimal surfaces, an isoperimetric problem, and liquid films.

  18. Beryllium thin films for resistor applications

    NASA Technical Reports Server (NTRS)

    Fiet, O.

    1972-01-01

    Beryllium thin films have a protective oxidation resistant property at high temperature and high recrystallization temperature. However, the experimental film has very low temperature coefficient of resistance.

  19. Predicting film genres with implicit ideals.

    PubMed

    Olney, Andrew McGregor

    2012-01-01

    We present a new approach to defining film genre based on implicit ideals. When viewers rate the likability of a film, they indirectly express their ideal of what a film should be. Across six studies we investigate the category structure that emerges from likability ratings and the category structure that emerges from the features of film. We further compare these data-driven category structures with human annotated film genres. We conclude that film genres are structured more around ideals than around features of film. This finding lends experimental support to the notion that film genres are set of shifting, fuzzy, and highly contextualized psychological categories. PMID:23423823

  20. Fire resistant films for aircraft applications

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.

    1983-01-01

    Alternative sandwich panel decorative films were investigated as replacements for the polyvinyl fluoride currently used in aircraft interiors. Candidate films were studied for flammability, smoke emission, toxic gas emission, flame spread, and suitability as a printing surface for the decorative acrylic ink system. Several of the candidate films tested were flame modified polyvinyl fluoride, polyvinylidene fluoride, polyimide, polyamide, polysulfone, polyphenylsulfone, polyethersulfone, polybenzimidazole, polycarbonate, polyparabanic acid, polyphosphazene, polyetheretherketon, and polyester. The films were evaluated as pure films only, films silk-screened with an acrylic ink, and films adhered to a phenolic fiberglass substrate. Films which exhibited the highest fire resistant properties included PEEK polyetheretherketon, Aramid polyamide, and ISO-BPE polyester.

  1. Electrical initiation of an energetic nanolaminate film

    DOEpatents

    Tringe, Joseph W. (Walnut Creek, CA); Gash, Alexander E. (Brentwood, CA); Barbee, Jr., Troy W. (Palo Alto, CA)

    2010-03-30

    A heating apparatus comprising an energetic nanolaminate film that produces heat when initiated, a power source that provides an electric current, and a control that initiates the energetic nanolaminate film by directing the electric current to the energetic nanolaminate film and joule heating the energetic nanolaminate film to an initiation temperature. Also a method of heating comprising providing an energetic nanolaminate film that produces heat when initiated, and initiating the energetic nanolaminate film by directing an electric current to the energetic nanolaminate film and joule heating the energetic nanolaminate film to an initiation temperature.

  2. Predicting Film Genres with Implicit Ideals

    PubMed Central

    Olney, Andrew McGregor

    2013-01-01

    We present a new approach to defining film genre based on implicit ideals. When viewers rate the likability of a film, they indirectly express their ideal of what a film should be. Across six studies we investigate the category structure that emerges from likability ratings and the category structure that emerges from the features of film. We further compare these data-driven category structures with human annotated film genres. We conclude that film genres are structured more around ideals than around features of film. This finding lends experimental support to the notion that film genres are set of shifting, fuzzy, and highly contextualized psychological categories. PMID:23423823

  3. Bibliography of Cinderella Stories & Films.

    ERIC Educational Resources Information Center

    Rodriguez-Price, Marisol

    This annotated bibliography considers diverse versions of Cinderella, including books for all ages and reading abilities and film versions. The bibliography is organized into four categories: picture books, books for youths, books for adults with a Cinderella theme, and Cinderella films. Noting that Cinderella is one of the few stories with many

  4. Uses for Free Film Cans

    ERIC Educational Resources Information Center

    Batoff, Mitchell E.; Harmen, Jerry

    1973-01-01

    Describes multiple uses of empty film cans for equipping an elementary school science classroom. Instructional units in which film cans may be useful include buoyancy, mobiles, growing seeds, peas and particles, rocks and minerals, structures, field studies, sound, balancing, electricity, pedulums, chemical change, and optics, light, color. (PS)

  5. Automatic marker for photographic film

    NASA Technical Reports Server (NTRS)

    Gabbard, N. M.; Surrency, W. M.

    1974-01-01

    Commercially-produced wire-marking machine is modified to title or mark film rolls automatically. Machine is used with film drive mechanism which is powered with variable-speed, 28-volt dc motor. Up to 40 frames per minute can be marked, reducing time and cost of process.

  6. The Public Library Film Redefined.

    ERIC Educational Resources Information Center

    Peltier, Euclid

    1978-01-01

    An historical discussion of three types of film--teaching, information, and entertainment--is presented. The numbers of films in each category, especially the last, which includes the animated, unnarrated, iconographic, underground, and avant-garde, has grown substantially. Libraries have quickly accepted all except the revolutionary philosophies

  7. System for measuring film thickness

    DOEpatents

    Batishko, Charles R. (West Richland, WA); Kirihara, Leslie J. (Richland, WA); Peters, Timothy J. (Richland, WA); Rasmussen, Donald E. (Richland, WA)

    1990-01-01

    A system for determining the thicknesses of thin films of materials exhibiting fluorescence in response to exposure to excitation energy from a suitable source of such energy. A section of film is illuminated with a fixed level of excitation energy from a source such as an argon ion laser emitting blue-green light. The amount of fluorescent light produced by the film over a limited area within the section so illuminated is then measured using a detector such as a photomultiplier tube. Since the amount of fluorescent light produced is a function of the thicknesses of thin films, the thickness of a specific film can be determined by comparing the intensity of fluorescent light produced by this film with the intensity of light produced by similar films of known thicknesses in response to the same amount of excitation energy. The preferred embodiment of the invention uses fiber optic probes in measuring the thicknesses of oil films on the operational components of machinery which are ordinarily obscured from view.

  8. Thin film atomic hydrogen detectors

    NASA Technical Reports Server (NTRS)

    Gruber, C. L.

    1977-01-01

    Thin film and bead thermistor atomic surface recombination hydrogen detectors were investigated both experimentally and theoretically. Devices were constructed on a thin Mylar film substrate. Using suitable Wheatstone bridge techniques sensitivities of 80 microvolts/2x10 to the 13th power atoms/sec are attainable with response time constants on the order of 5 seconds.

  9. Thin film ion conducting coating

    DOEpatents

    Goldner, Ronald B. (Lexington, MA); Haas, Terry (Sudbury, MA); Wong, Kwok-Keung (Watertown, MA); Seward, George (Arlington, MA)

    1989-01-01

    Durable thin film ion conducting coatings are formed on a transparent glass substrate by the controlled deposition of the mixed oxides of lithium:tantalum or lithium:niobium. The coatings provide durable ion transport sources for thin film solid state storage batteries and electrochromic energy conservation devices.

  10. Latino Film and Video Images.

    ERIC Educational Resources Information Center

    Vazquez, Blanca, Ed.

    1990-01-01

    This theme issue of the "Centro Bulletin" examines media stereotypes of Latinos and presents examples of alternatives. "From Assimilation to Annihilation: Puerto Rican Images in U.S. Films" (R. Perez) traces the representation of Puerto Ricans from the early days of television to the films of the 1970s. "The Latino 'Boom' in Hollywood" (C. Fusco)…

  11. Liquid-film electron stripper

    DOEpatents

    Gavin, Basil F. (Albion, CA)

    1986-01-01

    An improved liquid-film electron stripper particularly for high intensity heavy ion beams which produces constant regenerated, stable, free-standing liquid films having an adjustable thickness between 0.3 to 0.05 microns. The improved electron stripper is basically composed of at least one high speed, rotating disc with a very sharp, precision-like, ground edge on one said of the disc's periphery and with a highly polished, flat, radial surface adjacent the sharp edge. A fine stream of liquid, such as oil, impinges at a 90.degree. angle adjacent the disc's sharp outer edge. Film terminators, located at a selected distance from the disc perimeter are positioned approximately perpendicular to the film. The terminators support, shape, and stretch the film and are arranged to assist in the prevention of liquid droplet formation by directing the collected film to a reservoir below without breaking or interfering with the film. One embodiment utilizes two rotating discs and associated terminators, with the discs rotating so as to form films in opposite directions, and with the second disc being located down beam-line relative to the first disc.

  12. Film Portraits of Aging Men.

    ERIC Educational Resources Information Center

    Trojan, Judith

    1980-01-01

    Discusses the cinema verite works "Best Boy,""Grandpa," and "Murita Cycles" as well as selected dramatic films that deal with the problems and concerns of aging men and how they relate to a younger male generation. Briefly reviews 15 film portraits of aging women. (FL)

  13. Thin films: Past, present, future

    SciTech Connect

    Zweibel, K.

    1995-04-01

    This report describes the characteristics of the thin film photovoltaic modules necessary for an acceptable rate of return for rural areas and underdeveloped countries. The topics of the paper include a development of goals of cost and performance for an acceptable PV system, a review of current technologies for meeting these goals, issues and opportunities in thin film technologies.

  14. Symbolism in the Feature Film.

    ERIC Educational Resources Information Center

    Bakony, Edward

    A study of symbolism in feature films reveals how the symbolism employed by film makers can serve as a bridge between feeling and thought, and between aesthetics and cognition. What individuals read from and learn through a symbol varies with what they bring to it. The filmmaker's symbolims must be universal and not private. However, symbolism in

  15. Evaluation of Agfacontour professional film

    NASA Technical Reports Server (NTRS)

    Goodding, R. A.

    1972-01-01

    The results obtained by the Photo Science Office in the evaluation of Agfacontour Professional Film are presented. The feasibility of utilizing this film in the evaluation of aerial or extraterrestrial imagery has been investigated. Sensitometric properties have been determined, and optimum handling techniques have been identified in an attempt to facilitate better use of the material.

  16. Method to prepare oxide films

    NASA Technical Reports Server (NTRS)

    Hirota, T.

    1986-01-01

    This invention pertains to a method for producing metal oxide films characterized by the fact that the metal elements constituting the main metal alloys contain at least one kind of transition element, and that the metal elements which constitute said metal alloy are thin films of barium and titanium in almost the same mol ratio.

  17. Latino Film and Video Images.

    ERIC Educational Resources Information Center

    Vazquez, Blanca, Ed.

    1990-01-01

    This theme issue of the "Centro Bulletin" examines media stereotypes of Latinos and presents examples of alternatives. "From Assimilation to Annihilation: Puerto Rican Images in U.S. Films" (R. Perez) traces the representation of Puerto Ricans from the early days of television to the films of the 1970s. "The Latino 'Boom' in Hollywood" (C. Fusco)

  18. Feminist Film Theory and Criticism.

    ERIC Educational Resources Information Center

    Mayne, Judith

    1985-01-01

    Discusses Laura Mulvey's 1975 essay, "Visual Pleasure and Narrative Cinema," and the ideas about feminist film theory and psychoanalysis as a critical tool which it raises. Suggests contradiction is the central issue in feminist film theory. Explores definitions of women's cinema. (SA)

  19. Cinemabilia; Catalogue of Film Literature.

    ERIC Educational Resources Information Center

    Cinemabilia, New York, NY.

    The catalog lists and briefly annotates more than 3,500 current, second-hand, and out-of-print books about film that are available from Cinemabilia, New York City. The catalog is divided into 37 categories. The section on special genre lists works on horror, science fiction, Westerns, and Tarzan films, ranging from "Drums of Fu-Manchu" to "Movie

  20. Films and the English Class.

    ERIC Educational Resources Information Center

    Donelson, Kenneth, Ed.

    1971-01-01

    The importance of film in the English classroom and its vitality in the English curriculum are discussed. Articles that comprise this issue of the bulletin are: The Trouble with Film Teaching by James E. Cutts; "You Ain't Heard Nothin' Yet" or Send Your Students to the Flicks Tonight by Bob Haskett; It's the Reel Thing: The Verite of Cinema Is

  1. Laser refractometry of edible films

    NASA Astrophysics Data System (ADS)

    Panchev, I.; Nikolova, K.; Sainov, Simeon C.

    2004-06-01

    Refraction index of edible films from polysaccharides (pectin, xanthan, carboxy-methyl-cellulose, polymixan) has been investigated using laser microrefractomeeter, constructed by the authors. Experimental data about the optical density and the thickness of the edible films have been obtained. The results from the investigation can be used in the development of new packing technologies for food products.

  2. Teaching Film Animation to Children.

    ERIC Educational Resources Information Center

    Andersen, Yvonne

    Under the author's direction, students from 5 to 18 years old have been making prize-winning animated films. In this guide intended for any adult who wishes to teach film animation, she describes and illustrates the techniques she has developed in her seven years of experience teaching animation to children in a workshop setting. All essential

  3. The Thin Oil Film Equation

    NASA Technical Reports Server (NTRS)

    Brown, James L.; Naughton, Jonathan W.

    1999-01-01

    A thin film of oil on a surface responds primarily to the wall shear stress generated on that surface by a three-dimensional flow. The oil film is also subject to wall pressure gradients, surface tension effects and gravity. The partial differential equation governing the oil film flow is shown to be related to Burgers' equation. Analytical and numerical methods for solving the thin oil film equation are presented. A direct numerical solver is developed where the wall shear stress variation on the surface is known and which solves for the oil film thickness spatial and time variation on the surface. An inverse numerical solver is also developed where the oil film thickness spatial variation over the surface at two discrete times is known and which solves for the wall shear stress variation over the test surface. A One-Time-Level inverse solver is also demonstrated. The inverse numerical solver provides a mathematically rigorous basis for an improved form of a wall shear stress instrument suitable for application to complex three-dimensional flows. To demonstrate the complexity of flows for which these oil film methods are now suitable, extensive examination is accomplished for these analytical and numerical methods as applied to a thin oil film in the vicinity of a three-dimensional saddle of separation.

  4. Deformation of an asymmetric film

    NASA Astrophysics Data System (ADS)

    Geng, Jun; Selinger, Jonathan

    2010-03-01

    Recent experiments have investigated shape changes of polymer films induced by asymmetric swelling by a chemical vapor. Inspired by recent work on the shaping of elastic sheets by non-Euclidean metrics [1,2], we represent the effect of chemical vapors by a change in the target metric tensor. In this problem, unlike Refs. [1,2], the target metric is asymmetric between the two sides of the film. Changing this metric induces a curvature of the film, which may be Gaussian curvature into a sphere or mean curvature into a cylinder. We calculate the elastic energy for each of these shapes, and show that the sphere is favored for films smaller than a critical size, which depends on the film thickness, while the cylinder is favored for larger films. We compare the formalism for asymmetric films with previous theoretical work on symmetric films, and compare the predictions with experimental results. [4pt] [1] Y. Klein, E. Efrati, and E. Sharon, Science 315, 1116 (2007).[0pt] [2] E. Efrati, E. Sharon, and R. Kupferman, J. Mech. Phys. Solids 57, 762 (2009).

  5. Teaching the Holocaust through Film.

    ERIC Educational Resources Information Center

    Michalczyk, John J.

    The use of Holocaust-related films and Holocaust survivors as classroom resources is analyzed. The perspective and function of four film genres are outlined as follows. Newsreels, made by the Nazis to chronicle their "progress," provide powerful raw footage of the concentration camp experience. Documentaries, generally made by Allied sources after

  6. Metal oxide films on metal

    DOEpatents

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

    1995-01-01

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

  7. Pectin films for various applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article presents 4 examples of new uses of pectin films: (I) edible pectin and protein films as packaging or coating materials; (II) pectin and poly(lactic acid) composites for antimicrobial packaging, (III) moisture-sensitive pectin-sponges for the controlled release of chlorine dioxide; and (...

  8. Nonfiction Film; A Critical History.

    ERIC Educational Resources Information Center

    Barsam, Richard Meran

    In this survey history of the documentary or nonfiction cinema, major emphasis is placed upon John Grierson and the British documentary movement as exemplary of the factual films with goals of social improvement and on Robert Flaherty, whose movement stressed poetic or humanistic nonfiction film treatment. Newsreels and current trends in

  9. Soap film gas flowmeter

    SciTech Connect

    Lalin, H.S.; Bermudez, J.E.; Fleming, W.T.

    1987-09-08

    A soap film gas flowmeter is described comprising: a flow tube having a hollow body with opposite open ends through which a soap film is propelled and a first closed chamber housing a soap solution. It also includes means for supporting the flow tube in a substantially vertical position with the open bottom end of the flow tube disposed in the first chamber above the soap solution; a second closed chamber into which the open top end of the flow tube extends and gas inlet means for introducing gas into the first chamber at a flow rate to be measured using the flowmeters. A gas exit means is included for discharging the gas introduced into the first chamber through the second chamber. Plus there are means for generating a single soap bubble from the soap solution substantially at the bottom end of the flow tube and a relatively large opening in the flowtube for providing an open passageway for inlet gas to pass through the flowtube when the bottom open end of the flowtube is covered by the soap solution.

  10. Growth, characterization and reactivity studies: Oxide films, metal-oxide films and layered oxide films

    NASA Astrophysics Data System (ADS)

    Oh, Weon Sik

    This work presents studies of the growth, characterization and reactivity of oxide thin films, metal-oxide films and layered oxide films under vacuum conditions. The growth mode of the films, the geometric, electronic and chemical properties of overlayers and supports as well as the thermal stability of the overlayers were studied using the techniques and methodology of surface science. These model studies provide a convenient approach to understanding oxide surfaces and interfaces on the atomic scale. Epitaxial titanium oxide and calcium oxide films were synthesized on a refractory substrate, Mo(100), by vapor deposition of metals in the presence of an oxygen background and characterized by various surface analytical techniques. The 90 A thick titanium oxide film is stoichiometric. LEED and STM results show a (2sqrt{2}sqrt{2})R45sp reconstruction of the TiOsb2(001) film upon annealing. CaO films grow stoichiometrically on the Mo(100) with (100) orientation. The interfacial reactions between oxide thin films and refractory metal substrates were investigated. The thermal stability of an oxide overlayer is found to be mainly dependent upon the heat of formation and film thicknesses of the oxide. The growth mode, electronic and chemical properties of Au clusters supported on the TiOsb2(001)/Mo(100) surface were studied to understand the catalytic properties of Au supported catalysts. The bonding of Au on TiOsb2/Mo(100) is weak and Au clusters easily agglomerate upon annealing. Finally, layered binary thin-film oxides of NiO, MgO and CaO were studied as models to understand how the lattice constant mismatch influences the growth, thermal stability and chemical properties of the layered oxides. The influence of MgO and CaO on the NO adsorption on NiO was also studied and correlated to the growth mode of the mixed oxides.

  11. Anode film formation and control

    DOEpatents

    Koski, Oscar (Richland, WA); Marschman, Steven C. (Richland, WA)

    1990-01-01

    A protective film is created about the anode within a cryolite-based electrolyte during electrolytic production of aluminum from alumina. The film function to minimize corrosion of the anode by the cryolitic electrolyte and thereby extend the life of the anode. Various operating parameters of the electrolytic process are controlled to maintain the protective film about the anode in a protective state throughout the electrolytic reduction of alumina. Such parameters include electrolyte temperature, electrolyte ratio, current density, and Al.sub.2 O.sub.3 concentration. An apparatus is also disclosed to enable identification of the onset of anode corrosion due to disruption of the film to provide real time information regarding the state of the film.

  12. Film Fabrication Technologies at NREL

    NASA Technical Reports Server (NTRS)

    Mcconnell, Robert D.

    1993-01-01

    The National Renewable Energy Laboratory (NREL) has extensive capabilities for fabricating a variety of high-technology films. Much of the in-house work in NREL's large photovoltaics (PV) program involves the fabrication of multiple thin-film semiconducting layers constituting a thin-film PV device. NREL's smaller program in superconductivity focuses on the fabrication of superconducting films on long, flexible tape substrates. This paper focuses on four of NREL's in-house research groups and their film fabrication techniques, developed for a variety of elements, alloys, and compounds to be deposited on a variety of substrates. As is the case for many national laboratories, NREL's technology transfer efforts are focusing on Cooperative Research and Development Agreements (CRADA's) between NREL researchers and private industry researchers.

  13. Thermopower of thin iron films

    NASA Astrophysics Data System (ADS)

    Schepis, Randy; Schrder, Klaus

    1992-02-01

    Thin iron films were prepared by evaporation in a high vacuum system (pressure in the 10 -5 MPa range). The thermopower was measured in situ near room temperature as a function of film thickness. Iron films with rather high resistivity values showed a strong thickness effect of the Seeback coefficient, S, with the difference between S (bulk) and S (film) reaching values of up to (193) ?V/K for a sample 5 nm thick. The difference between S (bulk) and S (film) decreased with increasing d values. However, a sample with a resistance value of 50 ?? cm at d = 5 n had an S value which differed by less than 3 ?V/K from S (bulk).

  14. Anode film formation and control

    DOEpatents

    Koski, O.; Marschman, S.C.

    1990-05-01

    A protective film is created about the anode within a cryolite-based electrolyte during electrolytic production of aluminum from alumina. The film functions to minimize corrosion of the anode by the cryolitic electrolyte and thereby extend the life of the anode. Various operating parameters of the electrolytic process are controlled to maintain the protective film about the anode in a protective state throughout the electrolytic reduction of alumina. Such parameters include electrolyte temperature, electrolyte ratio, current density, and Al[sub 2]O[sub 3] concentration. An apparatus is also disclosed to enable identification of the onset of anode corrosion due to disruption of the film to provide real time information regarding the state of the film. 3 figs.

  15. Laser damage threshold of diamond films

    NASA Technical Reports Server (NTRS)

    Albin, Sacharia; Cropper, Andre D.; Watkins, Linwood C.; Byvik, Charles E.; Buoncristiani, A. Martin

    1989-01-01

    The possibility that diamond films may inhibit laser-induced damage to optical components in laser systems films was investigated by measuring laser damage thresholds of free-standing diamond film windows, diamond films deposited on silicon substrates, and bare silicon substrate. Polycrystalline diamond films were deposited using a dc plasma-enhanced CVD process. It was found that free-standing diamond films had the highest laser damage threshold at 1064 nm. For a diamond film of 630 nm, the damage threshold was found to be 7 J/sq cm, as compared to a damage threshold of 4.5 J/sq cm for bare silicon, and a low value of 1.5 J/sq cm for the film/substrate combination. The damage mechanism is considered to involve melting or dielectric breakdown induced by laser radiation. The low value of the film/substrate combination is attributed to film stress and conditions of film deposition.

  16. Oriented lead zirconate titanate thin films: Characterization of film crystallization

    SciTech Connect

    Voigt, J.A.; Tuttle, B.A.; Headley, T.J.; Eatough, M.O.; Lamppa, D.L.; Goodnow, D.

    1993-11-01

    Film processing temperature and time was varied to characterize the pyrochlore-to-perovskite crystallization of solution-derived PZT 20/80 thin films. 3000 {Angstrom} thick films were prepared by spin deposition using <100> single crystal MgO as substrate. By controlled rapid thermal processing, films at different stages in the perovskite crystallization process were prepared with the tetragonal PZT 20/80 phase being <100>/<001> oriented relative to the MgO surface. An activation energy for the conversion process of 326 kJ/mole was determined by use of an Arrhenius expression using rate constants found by application of the method of Avrami. Activation energy for formation of the PZT 20/80 perovskite phase of the solution-derived films compared favorably with that calculated from data by Kwok and Desu for sputter-deposited 3500 {Angstrom} thick PZT 55/45 films. Similarity in activation energies indicates that the energetics of the conversion process are not strongly dependent on the method used for film deposition.

  17. Flow fields in soap films: Relating viscosity and film thickness

    NASA Astrophysics Data System (ADS)

    Prasad, V.; Weeks, Eric R.

    2009-08-01

    We follow the diffusive motion of colloidal particles in soap films with varying h/d , where h is the thickness of the film and d is the diameter of the particles. The hydrodynamics of these films are determined by looking at the correlated motion of pairs of particles as a function of separation R . The Trapeznikov approximation [A. A. Trapeznikov, Proceedings of the 2nd International Congress on Surface Activity (Butterworths, London, 1957), p. 242] is used to model soap films as an effective two-dimensional (2D) fluid in contact with bulk air phases. The flow fields determined from correlated particle motions show excellent agreement with what is expected for the theory of 2D fluids for all our films where 0.6?h/d?14.3 , with the 2D shear viscosity matching that predicted by Trapeznikov. However, the parameters of these flow fields change markedly for thick films (h/d>73) . Our results indicate that three-dimensional effects become important for these thicker films, despite the flow fields still having a 2D character.

  18. Calorimetry of epitaxial thin films

    SciTech Connect

    Cooke, David W.; Hellman, F.; Groves, J. R.; Clemens, B. M.; Moyerman, S.; Fullerton, E. E.

    2011-02-15

    Thin film growth allows for the manipulation of material on the nanoscale, making possible the creation of metastable phases not seen in the bulk. Heat capacity provides a direct way of measuring thermodynamic properties of these new materials, but traditional bulk calorimetric techniques are inappropriate for such a small amount of material. Microcalorimetry and nanocalorimetry techniques exist for the measurements of thin films but rely on an amorphous membrane platform, limiting the types of films which can be measured. In the current work, ion-beam-assisted deposition is used to provide a biaxially oriented MgO template on a suspended membrane microcalorimeter in order to measure the specific heat of epitaxial thin films. Synchrotron x-ray diffraction showed the biaxial order of the MgO template. X-ray diffraction was also used to prove the high quality of epitaxy of a film grown onto this MgO template. The contribution of the MgO layer to the total heat capacity was measured to be just 6.5% of the total addenda contribution. The heat capacity of a Fe{sub .49}Rh{sub .51} film grown epitaxially onto the device was measured, comparing favorably to literature data on bulk crystals. This shows the viability of the MgO/SiN{sub x}-membrane-based microcalorimeter as a way of measuring the thermodynamic properties of epitaxial thin films.

  19. Fast dissolving films: a review.

    PubMed

    Chaturvedi, Ankita; Srivastava, Pranati; Yadav, Sunita; Bansal, Mayank; Garg, Garima; Sharma, Pramod Kumar

    2011-07-01

    Fast-dissolving drug delivery systems have been developed as an alternative to conventional dosage form as an oral means of drug delivery in case of chronic conditions. Now a day's fast dissolving films are preferred over conventional tablets and capsules for masking the taste of bitter drugs to increase the patient compliance. Fast dissolving films consist of a very thin oral strip which dissolves in less than one minute when placed on the tongue. Dissolvable oral thin films are in the market since past few years in the form of breath strips and are widely accepted by consumers for delivering vitamins, vaccines and other drug products. The various manufacturing techniques for the preparation of films have also been detailed in the review. The present review details most of the patents on such fast dissolving films in recent years. A brief study has been made on various parameters which are used to evaluate such films. In case of chronic disorders these fast dissolving films are better for delivering drugs and obtaining faster therapeutic blood levels and superior in comparison to other oral conventional dosage forms. PMID:21453260

  20. Polyimide Aerogel Thin Films

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann; Guo, Haiquan

    2012-01-01

    Polyimide aerogels have been crosslinked through multifunctional amines. This invention builds on "Polyimide Aerogels With Three-Dimensional Cross-Linked Structure," and may be considered as a continuation of that invention, which results in a polyimide aerogel with a flexible, formable form. Gels formed from polyamic acid solutions, end-capped with anhydrides, and cross-linked with the multifunctional amines, are chemically imidized and dried using supercritical CO2 extraction to give aerogels having density around 0.1 to 0.3 g/cubic cm. The aerogels are 80 to 95% porous, and have high surface areas (200 to 600 sq m/g) and low thermal conductivity (as low as 14 mW/m-K at room temperature). Notably, the cross-linked polyimide aerogels have higher modulus than polymer-reinforced silica aerogels of similar density, and can be fabricated as both monoliths and thin films.

  1. Pyrolyzed carbon film diodes.

    PubMed

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

    2013-11-13

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

  2. Thin film hydrogen sensor

    SciTech Connect

    Lauf, R.J.; Hoffheins, B.S.; Fleming, P.H.

    1994-11-22

    A hydrogen sensor element comprises an essentially inert, electrically-insulating substrate having a thin-film metallization deposited thereon which forms at least two resistors on the substrate. The metallization comprises a layer of Pd or a Pd alloy for sensing hydrogen and an underlying intermediate metal layer for providing enhanced adhesion of the metallization to the substrate. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors, and at least one of the resistors is left uncovered. The difference in electrical resistances of the covered resistor and the uncovered resistor is related to hydrogen concentration in a gas to which the sensor element is exposed. 6 figs.

  3. Ferromagnetic thin films

    DOEpatents

    Krishnan, Kannan M. (Berkeley, CA)

    1994-01-01

    A ferromagnetic .delta.-Mn.sub.1-x Ga.sub.x thin film having perpendicular anisotropy is described which comprises: (a) a GaAs substrate, (b) a layer of undoped GaAs overlying said substrate and bonded thereto having a thickness ranging from about 50 to about 100 nanometers, (c) a layer of .delta.-Mn.sub.1-x Ga.sub.x overlying said layer of undoped GaAs and bonded thereto having a thickness ranging from about 20 to about 30 nanometers, and (d) a layer of GaAs overlying said layer of .delta.-Mn.sub.1-x Ga.sub.x and bonded thereto having a thickness ranging from about 2 to about 5 nanometers, wherein x is 0.4 .+-.0.05.

  4. Ferromagnetic thin films

    DOEpatents

    Krishnan, K.M.

    1994-12-20

    A ferromagnetic [delta]-Mn[sub 1[minus]x]Ga[sub x] thin film having perpendicular anisotropy is described which comprises: (a) a GaAs substrate, (b) a layer of undoped GaAs overlying said substrate and bonded thereto having a thickness ranging from about 50 to about 100 nanometers, (c) a layer of [delta]-Mn[sub 1[minus]x]Ga[sub x] overlying said layer of undoped GaAs and bonded thereto having a thickness ranging from about 20 to about 30 nanometers, and (d) a layer of GaAs overlying said layer of [delta]-Mn[sub 1[minus]x]Ga[sub x] and bonded thereto having a thickness ranging from about 2 to about 5 nanometers, wherein x is 0.4[+-]0.05. 7 figures.

  5. Effects on film structure on mechanical and adhesion properties of latex films

    SciTech Connect

    Charmeau, J.Y.; Holl, Y.; Kientz, E.

    1995-12-31

    In order to investigate the effect of the particular structure of latex films on mechanical (stress-strain behavior) and adhesion (measured by peeling) properties, this work compares these characteristics for latex films and corresponding {open_quotes}solution films{close_quotes}. Solution films were obtained by dissolving the latex film in an appropriate solvent and forming a new film by evaporating the solvent. Four different systems were studied. It was shown that latex films have Young`s moduli systematically much higher than the corresponding solution films. This is due to the fact that the hydrophilic shells of the latex particles form a continuous phase in the latex film which increases the modulus thanks to polar interactions. However, adhesion energy for latex films is always smaller than for solution films. This is interpreted in terms of structure of the film-support interface and dissipative processes within the bulk of the films.

  6. Antimicrobial edible films and coatings.

    PubMed

    Cagri, Arzu; Ustunol, Zeynep; Ryser, Elliot T

    2004-04-01

    Increasing consumer demand for microbiologically safer foods, greater convenience, smaller packages, and longer product shelf life is forcing the industry to develop new food-processing, cooking, handling, and packaging strategies. Nonfluid ready-to-eat foods are frequently exposed to postprocess surface contamination, leading to a reduction in shelf life. The food industry has at its disposal a wide range of nonedible polypropylene- and polyethylene-based packaging materials and various biodegradable protein- and polysaccharide-based edible films that can potentially serve as packaging materials. Research on the use of edible films as packaging materials continues because of the potential for these films to enhance food quality, food safety, and product shelf life. Besides acting as a barrier against mass diffusion (moisture, gases, and volatiles), edible films can serve as carriers for a wide range of food additives, including flavoring agents, antioxidants, vitamins, and colorants. When antimicrobial agents such as benzoic acid, sorbic acid, propionic acid, lactic acid, nisin, and lysozyme have been incorporated into edible films, such films retarded surface growth of bacteria, yeasts, and molds on a wide range of products, including meats and cheeses. Various antimicrobial edible films have been developed to minimize growth of spoilage and pathogenic microorganisms, including Listeria monocytogenes, which may contaminate the surface of cooked ready-to-eat foods after processing. Here, we review the various types of protein-based (wheat gluten, collagen, corn zein, soy, casein, and whey protein), polysaccharide-based (cellulose, chitosan, alginate, starch, pectin, and dextrin), and lipid-based (waxes, acylglycerols, and fatty acids) edible films and a wide range of antimicrobial agents that have been or could potentially be incorporated into such films during manufacture to enhance the safety and shelf life of ready-to-eat foods. PMID:15083740

  7. Adhesive for solar control film

    SciTech Connect

    Penn, H.J.

    1984-01-31

    A water-activatable adhesive useful for adhering a solar film, polyester (polyethylene terephthalate) film, to glass or to metal substrates. The adhesive comprises the reacted product of (A) gamma-isocyanatopropyltriethoxy silane, containing a free isocyanate (NCO) group, and (B) a thermoplastic polyester formed by reacting (i) a dibasic acid selected from the group consisting of terephthalic acid, isophthalic acid and hexahydrophthalic acid, and mixtures thereof, with (ii) a polymethylene glycol of the formula HO(CH/sub 2/) /SUB x/ OH where x is an integer from 2 to 10, neopentyl glycol and glycerin, and mixtures thereof, and (iii) an aliphatic dibasic acid selected from the group consisting of those having the formula HOOC(CH/sub 2/) /SUB n/ COOH where n is an integer from 1 to 8, and mixtures of such acids, whereby substantially no free NCO remains in the adhesive. Solar film is used for absorbing and/or reflecting solar radiation. Solar film can be a single sheet of polyester dyed sufficiently to absorb the glare of bright sunlight, or it can be a single sheet of polyester, on one side of which a reflective metal (most often aluminum) is deposited in an amount which can be totally reflective or in an amount which still allows visible light transmission and over which a protective coating is deposited, or it can be a laminated structure of the reflective film adhered to a clear or dyed polyester film by which means the reflective metal is sandwiched between two layers of polyester film, or it can be a laminated structure of a reflective film to a polyolefin film.

  8. Morphology of Microscopic Thin Rubber Films

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Briber, Robert; Wang, Howard

    2014-03-01

    Microscopic thin rubber films have been prepared using photolithographic methods. Thin films of low molecular weight polybutadiene have been spun cast on positive photoresists, and transferred to various substrates upon UV exposure for crosslinking and defining the lateral dimension. The morphological scaling of thin rubber films as a function of film dimension and temperature is discussed.

  9. 19 CFR 12.41 - Prohibited films.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Prohibited films. 12.41 Section 12.41 Customs... SPECIAL CLASSES OF MERCHANDISE Immoral Articles 12.41 Prohibited films. (a) Importers of films, shall certify on Customs Form 3291 that the imported films contain no obscene or immoral matter, nor any...

  10. 19 CFR 12.41 - Prohibited films.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Prohibited films. 12.41 Section 12.41 Customs... SPECIAL CLASSES OF MERCHANDISE Immoral Articles 12.41 Prohibited films. (a) Importers of films, shall certify on Customs Form 3291 that the imported films contain no obscene or immoral matter, nor any...

  11. 19 CFR 12.41 - Prohibited films.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Prohibited films. 12.41 Section 12.41 Customs... SPECIAL CLASSES OF MERCHANDISE Immoral Articles 12.41 Prohibited films. (a) Importers of films, shall certify on Customs Form 3291 that the imported films contain no obscene or immoral matter, nor any...

  12. Using Popular Children's Films in Science

    ERIC Educational Resources Information Center

    Wadsworth, Elle; Croker, Stev; Harrison, Tim

    2012-01-01

    Watching films is a common activity for children outside of school, and incorporating popular films that contain scientific references has the potential to spark interest in the classroom. Clips rather than entire films can be used, as the children will maintain focus on the lesson objectives while being excited by the appeal of the film. The use

  13. 16 CFR 501.1 - Camera film.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Camera film. 501.1 Section 501.1 Commercial... 500 § 501.1 Camera film. Camera film packaged and labeled for retail sale is exempt from the net... should be expressed, provided: (a) The net quantity of contents on packages of movie film and bulk...

  14. 19 CFR 12.41 - Prohibited films.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Prohibited films. 12.41 Section 12.41 Customs... SPECIAL CLASSES OF MERCHANDISE Immoral Articles § 12.41 Prohibited films. (a) Importers of films, shall certify on Customs Form 3291 that the imported films contain no obscene or immoral matter, nor any...

  15. 16 CFR 501.1 - Camera film.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Camera film. 501.1 Section 501.1 Commercial... 500 § 501.1 Camera film. Camera film packaged and labeled for retail sale is exempt from the net... should be expressed, provided: (a) The net quantity of contents on packages of movie film and bulk...

  16. Using Popular Children's Films in Science

    ERIC Educational Resources Information Center

    Wadsworth, Elle; Croker, Stev; Harrison, Tim

    2012-01-01

    Watching films is a common activity for children outside of school, and incorporating popular films that contain scientific references has the potential to spark interest in the classroom. Clips rather than entire films can be used, as the children will maintain focus on the lesson objectives while being excited by the appeal of the film. The use…

  17. 19 CFR 12.41 - Prohibited films.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Prohibited films. 12.41 Section 12.41 Customs... SPECIAL CLASSES OF MERCHANDISE Immoral Articles § 12.41 Prohibited films. (a) Importers of films, shall certify on Customs Form 3291 that the imported films contain no obscene or immoral matter, nor any...

  18. 35-Flicks: Review of 35 Short Films.

    ERIC Educational Resources Information Center

    Arizona State Univ., Tempe. EPDA Inst. in Media and the Teaching of English.

    Comments about these short films, written by participants of the EPDA Institute in Media and the Teaching of English, include an abstract of the film's main points, a plot synopsis, appropriate age level of the audience, strengths and weakenesses of the film, possible unit themes or topics to be developed around the film, a list of books and

  19. Film-Making and the Curriculum.

    ERIC Educational Resources Information Center

    Schwartz, Elizabeth

    A guide to filmmaking techniques and the use of class-made films in the curriculum covers techniques of both animated and live-action films. The purposes of single concept, documentary, interpretive, and time-lapse films are discussed briefly. Production techniques covered include organization of personnel, scripting, filming, directing, editing,

  20. Estimating Plastic Film Permeability Under Field Conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fumigant emission is an important air quality and human health concern. Plastic films are used to reduce emissions. Laboratory tests have shown large differences in permeability between various films, including the typical polyethylene films (PEs), virtually impermeable films (VIFs), and semi-impe...

  1. Cultural Dependency in Canada's Feature Film Industry.

    ERIC Educational Resources Information Center

    Pendakur, Manjunath

    1981-01-01

    Examines the ownership and policies of the dominant firms in the Canadian film market to explain Canada's dependence on imported films. Demonstrates how the economic relations existing between Canadian and U.S. film industries limit the profitability of films made in Canada. (JMF)

  2. Geoflicks Reviewed--Films about Hawaiian Volcanoes.

    ERIC Educational Resources Information Center

    Bykerk-Kauffman, Ann

    1994-01-01

    Reviews 11 films on volcanic eruptions in the United States. Films are given a one- to five-star rating and the film's year, length, source and price are listed. Top films include "Inside Hawaiian Volcanoes" and "Kilauea: Close up of an Active Volcano." (AIM)

  3. Historical Films in the Latin Classroom.

    ERIC Educational Resources Information Center

    Buller, Jeffrey L.

    Guidelines and lesson plans are presented for teachers of Latin using historical films as instructional and support materials. A discussion of the use of historical films addresses these issues in classroom practice: the legality of using films in the classroom (copyrights); techniques for using historical films as sources of cultural information;

  4. Squeeze-Film Damper Controls High Vibrations

    NASA Technical Reports Server (NTRS)

    Fleming, D. P.

    1986-01-01

    Dual-clearance (two oil films) squeeze-film damper developed for controlling vibrations in aircraft turbine engines and other rotating machinery. New damper under normal conditions uses only one low-clearance film. Under high imbalance, both films active, controlling shaft vibration in nearoptimum manner and allowing continued operation until safe shutdown made.

  5. A 3M high temperature dielectric film

    NASA Technical Reports Server (NTRS)

    Hampl, Edward, Jr.

    1994-01-01

    The performance characteristics of a dielectric film are summarized. Additionally, the film's environmental and chemical properties are listed: low shrinkage to 300 C; moisture insensitive; low outgassing under vacuum; excellent surface qualities--easy metallization of film; flame retardant; and low smoke generation. A series of graphs that display the performance characteristics of the film are also presented.

  6. Tensile Strength Measurements on Biopolymer Films

    NASA Astrophysics Data System (ADS)

    Stevens, Eugene S.; Poliks, Mark D.

    2003-07-01

    An experiment is described in which students prepare biopolymer (agar, gelatin, and starch) films from aqueous solution and measure the tensile strengths of the films using easily constructed equipment. Agar and gelatin form moderately strong films. Starch forms weak films but the strength is increased by combining with agar and gelatin.

  7. FILM WORKSHOP SUCCESSFUL WITH TSU STUDENTS.

    ERIC Educational Resources Information Center

    BAHRENBERG, JIM

    AN UPWARD BOUND FILM WORKSHOP AT TEXAS SOUTHERN UNIVERSITY EXPOSED STUDENTS TO FILMS AS A CREATIVE ART FORM, A MEANS OF COMMUNICATION, AND A BASIS FOR DISCUSSING VALUES. IN ADDITION TO VIEWING SEVERAL SHORT, PROFESSIONALLY-DEVELOPED FILMS, STUDENTS WROTE AND PRODUCED TWO OF THEIR OWN. ONE STUDENT-PRODUCED FILM--A LIGHT SHOW--ILLUMINATED THE UNITY…

  8. "Space slitter" for film or tape

    NASA Technical Reports Server (NTRS)

    Johnson, W. H.

    1978-01-01

    Device cuts film or tape into strips by guiding film in channel under cutting blades. Device is operated by lifting pressure bar to insert blades into film. Film is then pulled through blades. Cutter has potential uses in advertising, commercial art, and publishing fields.

  9. Subjective Sexual Arousal to Films of Masturbation

    ERIC Educational Resources Information Center

    Mosher, Donald L.; Abramson, Paul R.

    1977-01-01

    A film of a male or female masturbating was viewed by 96 males and 102 females. Males reported the highest level of sexual arousal to the female film and the lowest level of arousal to the male film. Females were sexually aroused by both films. (Author)

  10. Lifelong Learning Films; 1972-1973.

    ERIC Educational Resources Information Center

    California Univ., Berkeley. Media Extension Center.

    Over 450 newly acquired films are described in this brochure. They are, for the most part, short black-and-white 16 mm films produced by the University of California Extension Media Center and selected films from other producers. The main entry section arranges the films alphabetically by title; it gives an annotation, the running time,

  11. Historical Films in the Latin Classroom.

    ERIC Educational Resources Information Center

    Buller, Jeffrey L.

    Guidelines and lesson plans are presented for teachers of Latin using historical films as instructional and support materials. A discussion of the use of historical films addresses these issues in classroom practice: the legality of using films in the classroom (copyrights); techniques for using historical films as sources of cultural information;…

  12. Historians and Film: Some Problems and Prospects

    ERIC Educational Resources Information Center

    O'Connor, John E.

    1973-01-01

    The growing interest towards using film in history classes and by historians developing a methodology for research into film is discussed in this article. Problems of using films for teachers focus on cost and poor quality. Difficulties for historical researchers concern the treatment of historical documents in film medium -- recording,

  13. Flight test comparison of film type SO-289 and film type 2424 in the AMPS camera

    NASA Technical Reports Server (NTRS)

    Perry, L.

    1975-01-01

    A flight test was conducted to determine the suitability of SO-289 multispectral infrared aerial film for Earth Resources' use. It was directly compared to film type 2424, infrared aerographic film, the IR film in current use. The exposure parameters for both films are given.

  14. American Film Genres: Approaches to a Critical Theory of Popular Film.

    ERIC Educational Resources Information Center

    Kaminsky, Stuart M.

    This book is divided into twelve sections and contains photographs from many of the films discussed. The introduction defines film genre and describes the general theories behind this book; "The Individual Film" analyzes the film "Little Caesar" as it relates to the genre of gangster films; "Comparative Forms" describes the similarities and

  15. Surface Nanostructures in Manganite Films

    PubMed Central

    Gambardella, A.; Graziosi, P.; Bergenti, I.; Prezioso, M.; Pullini, D.; Milita, S.; Biscarini, F.; Dediu, V. A.

    2014-01-01

    Ultrathin manganite films are widely used as active electrodes in organic spintronic devices. In this study, a scanning tunnelling microscopy (STM) investigation with atomic resolution revealed previously unknown surface features consisting of small non-stoichiometric islands. Based upon this evidence, a new mechanism for the growth of these complex materials is proposed. It is suggested that the non-stoichiometric islands result from nucleation centres that are below the critical threshold size required for stoichiometric crystalline growth. These islands represent a kinetic intermediate of single-layer growth regardless of the film thickness, and should be considered and possibly controlled in manganite thin-film applications. PMID:24941969

  16. Liquid-film electron stripper

    DOEpatents

    Leemann, B.T.; Yourd, R.B.

    1982-03-09

    A thin freestanding oil film is produced in vacuum by directing an oil stream radially inward to the hollow-ground sharp outer edge of a rotating disc. The sides of the edge are roughened somewhat to aid in dispersing oil from the disc. Oil is removed from the surface of disc to prevent formation of oil droplets which might spin off the disc and disrupt the oil film. An ion beam is directed through the thin oil film so that electrons are stripped from the ions to increase their charge.

  17. Liquid-film electron stripper

    DOEpatents

    Leemann, Beat T. (Walnut Creek, CA); Yourd, Roland B. (Kensington, CA)

    1984-01-01

    A thin freestanding oil film is produced in vacuum by directing an oil stream radially inward to the hollow-ground sharp outer edge of a rotating disc. The sides of the edge are roughened somewhat to aid in dispersing oil from the disc. Oil is removed from the surface of disc to prevent formation of oil droplets which might spin off the disc and disrupt the oil film. An ion beam is directed through the thin oil film so that electrons are stripped from the ions to increase their charge.

  18. Tailoring nanocrystalline diamond film properties

    DOEpatents

    Gruen, Dieter M. (Downers Grove, IL); McCauley, Thomas G. (Somerville, MA); Zhou, Dan (Orlando, FL); Krauss, Alan R. (Naperville, IL)

    2003-07-15

    A method for controlling the crystallite size and growth rate of plasma-deposited diamond films. A plasma is established at a pressure in excess of about 55 Torr with controlled concentrations of hydrogen up to about 98% by volume, of unsubstituted hydrocarbons up to about 3% by volume and an inert gas of one or more of the noble gases and nitrogen up to about 98% by volume. The volume ratio of inert gas to hydrogen is preferably maintained at greater than about 4, to deposit a diamond film on a suitable substrate. The diamond film is deposited with a predetermined crystallite size and at a predetermined growth rate.

  19. Vapor deposition of thin films

    DOEpatents

    Smith, David C.; Pattillo, Stevan G.; Laia, Jr., Joseph R.; Sattelberger, Alfred P.

    1992-01-01

    A highly pure thin metal film having a nanocrystalline structure and a process of preparing such highly pure thin metal films of, e.g., rhodium, iridium, molybdenum, tungsten, rhenium, platinum, or palladium by plasma assisted chemical vapor deposition of, e.g., rhodium(allyl).sub.3, iridium(allyl).sub.3, molybdenum(allyl).sub.4, tungsten(allyl).sub.4, rhenium(allyl).sub.4, platinum(allyl).sub.2, or palladium(allyl).sub.2 are disclosed. Additionally, a general process of reducing the carbon content of a metallic film prepared from one or more organometallic precursor compounds by plasma assisted chemical vapor deposition is disclosed.

  20. Slippage of nonsuperfluid helium films

    NASA Astrophysics Data System (ADS)

    Suzuki, Masaru; Hieda, Mitsunori

    2003-05-01

    We measured the slippage of nonsuperfluid 4He films adsorbed on two kinds of substrates, grafoil and hectorite, and found that a large part of these films undergo slipping at low temperatures. Furthermore, it was found that the 4He areal density dependence of the slippage is rather different between these substrates. In hectorite, the slippage is inhibited as the fluid state appears at absolute zero. On the other hand, in grafoil, this state does not suppress the slippage, at least, as the 4He areal density is low. This may be attributed to the difference in the structure of these films.

  1. Film boiling of mercury droplets

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J.; Schoessow, G. J.; Chmielewski, C. E.

    1975-01-01

    Vaporization times of mercury droplets in Leidenfrost film boiling on a flat horizontal plate are measured in an air atmosphere. Extreme care was used to prevent large amplitude droplet vibrations and surface wetting; therefore, these data can be compared to film boiling theory. Diffusion from the upper surface of the drop appears as a dominant mode of mass transfer from the drop. A closed-form analytical film boiling theory is developed to account for the diffusive evaporation. Reasonable agreement between data and theory is seen.

  2. Photovoltaic properties of polymer films

    NASA Astrophysics Data System (ADS)

    Reucroft, P. J.; Ullal, H.

    1980-03-01

    The effect of metal electrode and film thickness on the photovoltaic energy conversion efficiency in (1:1) mole ratio films of poly (N-vinylcarbazole) (PVK) and 2,4,7-trinitrofluorenone (TNF) has been investigated. Low work function metals increase the Schottky barrier height which leads to increases in the photovoltaic energy conversion efficiency. A ten-fold decrease in film thickness produces a thousand-fold increase in photovoltaic energy conversion efficiency. A theoretical model which assumes that the photovoltaic current is limited by Child's law predicts photovoltaic efficiencies which are in good agreement with the measured efficiencies.

  3. Electrostatic fluctuations in soap films

    NASA Astrophysics Data System (ADS)

    Dean, D. S.; Horgan, R. R.

    2002-06-01

    A field theory to describe electrostatic interactions in soap films, described by electric multilayers with a generalized thermodynamic surface-charging mechanism, is studied. In the limit where the electrostatic interactions are weak, this theory is exactly soluble. The theory incorporates in a consistent way, the surface-charging mechanism and the fluctuations in the electrostatic field that correspond to the zero-frequency component of the van der Waals force. It is shown that these terms lead to a Casimir-like attraction that can be sufficiently large to explain the transition between the common black film to a Newton black film.

  4. Electrostatic fluctuations in soap films.

    PubMed

    Dean, D S; Horgan, R R

    2002-06-01

    A field theory to describe electrostatic interactions in soap films, described by electric multilayers with a generalized thermodynamic surface-charging mechanism, is studied. In the limit where the electrostatic interactions are weak, this theory is exactly soluble. The theory incorporates in a consistent way, the surface-charging mechanism and the fluctuations in the electrostatic field that correspond to the zero-frequency component of the van der Waals force. It is shown that these terms lead to a Casimir-like attraction that can be sufficiently large to explain the transition between the common black film to a Newton black film. PMID:12188739

  5. Importance of combining convection with film cooling

    NASA Technical Reports Server (NTRS)

    Colladay, R. S.

    1971-01-01

    The interaction of film and convection cooling and its effect on wall cooling efficiency is investigated analytically for two cooling schemes for advanced gas turbine applications. The two schemes are full coverage- and counterflow-film cooling. In full coverage film cooling, the cooling air issues from a large number of small discrete holes in the surface. Counterflow film cooling is a film-convection scheme with film injection from a slot geometry. The results indicate that it is beneficial to utilize as much of the cooling air heat sink as possible for convection cooling prior to ejecting it as a film.

  6. Importance of combining convection with film cooling.

    NASA Technical Reports Server (NTRS)

    Colladay, R. S.

    1972-01-01

    The interaction of film and convection cooling and its effect on wall cooling efficiency is investigated analytically for two cooling schemes for advanced gas turbine applications. The two schemes are full coverage- and counterflow-film cooling. In full coverage film cooling, the cooling air issues from a large number of small discrete holes in the surface. Counterflow film cooling is a film-convection scheme with film injection from a slot geometry. The results indicate that it is beneficial to utilize as much of the cooling air heat sink as possible for convection cooling prior to ejecting it as a film.

  7. Étude par résonance quadrupolaire nucléaire de la rétention de carbone dans l'{YBa_2Cu_3O_{{y}≈ 7}}

    NASA Astrophysics Data System (ADS)

    Grévin, B.; Berthiercw, Y.; Monot, I.; Wang, J.; Weiss, F.

    1998-03-01

    We present a Nuclear Quadrupole Resonance (NQR) study of Cu(2) (planes) and Cu(1) (chains) sites in two YBa_2Cu_3O_{{y}≈ 7} powder samples with carbon concentration equal to 500 ppm and 3000 ppm, and in a free-carbon sample. By comparison with standard spectra in YBa_2Cu_3Oy, we show that a new NQR line appears at 30.90 MHz, the intensity of which is strongly correlated with the amount of carbon in the sample. Moreover, according to the spin-lattice relaxation rate 1/T_1 measurements at different frequencies of the spectrum, we attribute this anomalous line to the formation of clusters in which the superconductivity is destroyed by the presence of carbonate groups, which substitute preferentially for copper chain site. Those results are in good agreement with those of Wang et al. [CITE], obtained by high resolution electron microscopy. Nous présentons une étude par Résonance Quadrupolaire Nucléaire (RQN) des sites Cu(2) (plans) et Cu(1) (chaînes) dans deux échantillons de poudre d'YBa_2Cu_3O_{{y}≈ 7} contenant 500 ppm et 3000 ppm de carbone, ainsi que dans un échantillon de poudre supposé ne pas contenir de carbone. Par comparaison avec les spectres traditionnellement obtenus dans l'YBa_2Cu_3O_{{y}≈ 7}, nous avons mis en évidence l'apparition d'une raie supplémentaire à 30,90 MHz dont l'intensité augmente sensiblement avec le taux de carbone. De plus, l'analyse du taux de relaxation spin-réseau 1/T_1 mesuré à différentes fréquences nous a permis d'attribuer l'origine de cette raie anormale à la formation de domaines ou la supraconductivité est détruite par la présence de carbonates localisés de manière préférentielle sur les sites des chaînes. Cette étude confirme les résultats de Wang et al. [CITE] obtenus en microscopie électronique à haute résolution.

  8. STABILITY OF AQUEOUS FILMS BETWEEN BUBBLES

    PubMed Central

    Yaminsky, Vassili V.; Ohnishi, Satomi; Vogler, Erwin A.; Horn, Roger G.

    2013-01-01

    The stability of water films has been investigated with a Mysels-Scheludko type film balance. Minor trace impurities in water do not affect the lifetime of water films under vapor saturation, but significantly influence the stability in free evaporation. Trace amounts of positively adsorbed contaminants induce Marangoni-driven flow that destabilizes films under evaporation conditions whereas negatively-adsorbed electrolytes actually prolong stability by reversing interfacial tension gradients and driving a steady circulation within the film. At high thinning rates, pure-water films develop exotic-appearing flow patterns and break due to a strong coupling between hydrodynamic and interfacial tension-gradient adsorption stresses. The most dominant factor of transient film stabilization in dynamic conditions under evaporation is a surface tension gradient created in the film. We discuss surface tension gradients in transient films created by temperature differences, impurity concentration, and expansion of the films. PMID:20146432

  9. Polyvinylpyrrolidone oral films of enrofloxacin: film characterization and drug release.

    PubMed

    Kumar, G Prem; Phani, A R; Prasad, R G S V; Sanganal, Jagadeesh S; Manali, N; Gupta, R; Rashmi, N; Prabhakara, G S; Salins, C Paul; Sandeep, K; Raju, D B

    2014-08-25

    Enrofloxacin is a fluoroquinolone derivative used for treating urinary tract, respiratory and skin infections in animals. However, low solubility and low bioavailability prevented it from using on humans. Polyvinylpyrrolidone (PVP) is an inert, non toxic polymer with excellent hydrophilic properties, besides it can enhance bioavailability by forming drug polymer conjugates. With the aim of increasing solubility and bioavailability, enrofloxacin thin films were prepared using PVP as a polymer matrix. The obtained oral thin films exhibited excellent uniformity and mechanical properties. Swelling properties of the oral thin films revealed that the water uptake was enhanced by 21%. The surface pH has been found to be 6.80.1 indicating that these films will not cause any irritation to oral mucosa. FTIR data of the oral thin films indicated physical interaction between drug and polymer. SEM analysis revealed uniform distribution of drug in polymer matrix. In vitro drug release profiles showed enhanced release profiles (which are also pH dependant) for thin films compared to pure drug. Antibacterial activity was found to be dose dependent and maximum susceptibility was found on Klebsiella pneumonia making this preparation more suitable for respiratory infections. PMID:24858388

  10. Photographic film and the Skylab environment

    NASA Technical Reports Server (NTRS)

    Oldham, L. P.; Atkins, H. L.

    1977-01-01

    An overview is presented of an investigation which was conducted to determine the actual effects of the Skylab environment on flight films. Examples of the flight film performance data are provided. Attention is given to the Skylab film, the environmental parameters, a major events profile of the Skylab mission, and a film environmental effects analysis. Representative Skylab film environmental response data are shown in a graph.

  11. Testing Bonds Between Brittle And Ductile Films

    NASA Technical Reports Server (NTRS)

    Wheeler, Donald R.; Ohsaki, Hiroyuki

    1989-01-01

    Simple uniaxial strain test devised to measure intrinsic shear strength. Brittle film deposited on ductile stubstrate film, and combination stretched until brittle film cracks, then separates from substrate. Dimensions of cracked segments related in known way to tensile strength of brittle film and shear strength of bond between two films. Despite approximations and limitations of technique, tests show it yields semiquantitative measures of bond strengths, independent of mechanical properties of substrates, with results reproducible with plus or minus 6 percent.

  12. Thin film characterization using spectroscopic ellipsometry

    NASA Technical Reports Server (NTRS)

    Alterovitz, Samuel A.

    1990-01-01

    The application of the multiple angle and wavelength (MAW) technique to measure the dielectric function of semiconducting films is discussed. This technique evaluates unambiguously the complex dielectric function, epsilon (E), of the film without any pre-assumptions. In some cases the effective medium approximation (EMA) was used to determine the volume fraction of the film components. Application of the MAW technique to several semiconducting films was published previously. Different applications and examples are given, including metal and insulator films.

  13. Refractory films from spin-cast polyacrylonitrile

    SciTech Connect

    Renschler, C.L.; Sylwester, A.P.

    1987-01-01

    Polyacrylonitrile (PAN) films have been spin-cast and pyrolyzed to produce thin (500 to 1500 A) carbon films. These films have higher electrical conductivities than carbon films produced by other methods at similar temperatures. The conductivity can be varied by at least four orders of magnitude by changing the pyrolysis temperature. UV, IR, and Raman spectroscopies were used to investigate the chemical structure of the films during different stages of processing.

  14. Thin film cell development workshop report

    NASA Technical Reports Server (NTRS)

    Woodyard, James R.

    1991-01-01

    The Thin Film Development Workshop provided an opportunity for those interested in space applications of thin film cells to debate several topics. The unique characteristics of thin film cells as well as a number of other issues were covered during the discussions. The potential of thin film cells, key research and development issues, manufacturing issues, radiation damage, substrates, and space qualification of thin film cells were discussed.

  15. Cellulose triacetate, thin film dielectric capacitor

    NASA Technical Reports Server (NTRS)

    Yen, Shiao-Ping S. (Inventor); Jow, T. Richard (Inventor)

    1993-01-01

    Very thin films of cellulose triacetate are cast from a solution containing a small amount of high boiling temperature, non-solvent which evaporates last and lifts the film from the casting surface. Stretched, oriented, crystallized films have high electrical breakdown properties. Metallized films less than about 2 microns in thickness form self-healing electrodes for high energy density, pulsed power capacitors. Thicker films can be utilized as a dielectric for a capacitor.

  16. Cellulose triacetate, thin film dielectric capacitor

    NASA Technical Reports Server (NTRS)

    Yen, Shiao-Ping S. (Inventor); Jow, T. Richard (Inventor)

    1995-01-01

    Very thin films of cellulose triacetate are cast from a solution containing a small amount of high boiling temperature, non-solvent which evaporates last and lifts the film from the casting surface. Stretched, oriented, crystallized films have high electrical breakdown properties. Metallized films less than about 2 microns in thickness form self-healing electrodes for high energy density, pulsed power capacitors. Thicker films can be utilized as a dielectric for a capacitor.

  17. The Art of Teaching Social Studies with Film

    ERIC Educational Resources Information Center

    Russell, William B., III

    2012-01-01

    Teaching with film is a powerful and meaningful instructional strategy. This article discusses five classroom-tested methods for teaching with film: (1) film as a visual textbook, (2) film as a depicter of atmosphere, (3) film as an analogy, (4) film as a historiography, and (5) film as a springboard. Each of the methods discussed includes

  18. The Art of Teaching Social Studies with Film

    ERIC Educational Resources Information Center

    Russell, William B., III

    2012-01-01

    Teaching with film is a powerful and meaningful instructional strategy. This article discusses five classroom-tested methods for teaching with film: (1) film as a visual textbook, (2) film as a depicter of atmosphere, (3) film as an analogy, (4) film as a historiography, and (5) film as a springboard. Each of the methods discussed includes…

  19. Hygroscopic Expansion of Polyester Films

    NASA Astrophysics Data System (ADS)

    Ouchi, Isuke; Hosoi, Masahiro; Tomie, Takashi

    1992-08-01

    The hygroscopic expansion of polyethylene terephthalate (PET) and polyethylene 2,6-naphthalate (PEN) films was measured by use of a thermomechanical analyzer at 30, 40 or 50C. Their initial weight increase was proportional to the square root of time after exposure to moisture, obeying Ficks law; the hygroscopic expansion with time showed the same relationship. The equilibrium moisture content was 1.0 10-5/% RH for both films; the hygroscopic expansion at equilibrium was also about the same for these films. However, the diffusion constant for moisture in PEN films was 1\\cdot6 10-9 cm2/s at 30C in comparison with 4\\cdot8 10-8 for PET, although the activation energies were 45 kJ/mol for PET and 41 for PEN.

  20. Thin-film temperature sensor.

    NASA Technical Reports Server (NTRS)

    Maserjian, J.

    1972-01-01

    A new device has been developed for sensing small and rapid temperature changes accompanying biochemical reactions. The active element consists of an evaporated thin-film capacitor having a relatively strong temperature dependence. This dependence is derived from electron trapping effects in the thin amorphous dielectric film. A voltage output of at least 50 mV/deg can be obtained prior to amplification by using a resonant ac bridge circuit operating at 100 kHz. The corresponding noise output for a 10 kHz bandwidth can with an optimum circuit be as low as 4 microvolts. Therefore, the minimum detectable temperature change would be 80 microdegrees at 10 kHz. Rapid thermal response is assured by supporting the thin-film capacitor on a thin anodic tantalum oxide film suspended across an electrolytically etched window in a tantalum foil.