WorldWideScience

Sample records for applied type thin

  1. Thin-film limit formalism applied to surface defect absorption.

    Science.gov (United States)

    Holovský, Jakub; Ballif, Christophe

    2014-12-15

    The thin-film limit is derived by a nonconventional approach and equations for transmittance, reflectance and absorptance are presented in highly versatile and accurate form. In the thin-film limit the optical properties do not depend on the absorption coefficient, thickness and refractive index individually, but only on their product. We show that this formalism is applicable to the problem of ultrathin defective layer e.g. on a top of a layer of amorphous silicon. We develop a new method of direct evaluation of the surface defective layer and the bulk defects. Applying this method to amorphous silicon on glass, we show that the surface defective layer differs from bulk amorphous silicon in terms of light soaking.

  2. Thermal pulse measurements of space charge distributions under an applied electric field in thin films

    International Nuclear Information System (INIS)

    Zheng, Feihu; An, Zhenlian; Zhang, Yewen; Liu, Chuandong; Lin, Chen; Lei, Qingquan

    2013-01-01

    The thermal pulse method is a powerful method to measure space charge and polarization distributions in thin dielectric films, but a complicated calibration procedure is necessary to obtain the real distribution. In addition, charge dynamic behaviour under an applied electric field cannot be observed by the classical thermal pulse method. In this work, an improved thermal pulse measuring system with a supplemental circuit for applying high voltage is proposed to realize the mapping of charge distribution in thin dielectric films under an applied field. The influence of the modified measuring system on the amplitude and phase of the thermal pulse response current are evaluated. Based on the new measuring system, an easy calibration approach is presented with some practical examples. The newly developed system can observe space charge evolution under an applied field, which would be very helpful in understanding space charge behaviour in thin films. (paper)

  3. Amorphous and microcrystalline silicon applied in very thin tandem solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Schicho, Sandra

    2011-07-28

    wider band gap of the intrinsic absorber and window-p-type doped material was achieved. Higher opencircuit voltages were observed using such materials. Two different types of high band gap amorphous absorber layers with the associated p-doped layers were implemented into very thin tandem cells. An elongation of the light path in the absorber material, which is usually accomplished by using textured front contacts and back reflectors, is crucial for the performance of very thin tandem cells. Periodically patterned aluminum plates, which had shown very good light trapping properties for {mu}c-Si:H single junction solar cells, were suggested as substrates for very thin tandem cells. In comparison to tandem cells on standard substrates, higher short-circuit current densities and quantum efficiencies were observed on Al that indicated good light trapping. However, tandem cells on aluminum plates exhibited much lower open-circuit voltages. Raman measurements revealed a higher crystallinity and compressive stress in the microcrystalline bottom cells deposited on aluminum plates compared to cells deposited on standard substrates under the same deposition conditions. The silane concentration that is applied for the deposition of {mu}c-Si:H influences the crystalline volume fraction in a way that under otherwise constant deposition conditions lower values lead to higher crystalline volume fractions. By means of a sample series for which different silane concentrations were applied the orientation of the cubic silicon crystals and the appearance of stacking faults or twinning in the microcrystalline layers were investigated depending on silane concentration and crystalline volume fraction. For these studies, Raman spectroscopy with two different excitation lasers and X-ray diffraction in Bragg-Brentano and Grazing Incidence geometry were carried out. No preferential orientation of the silicon crystals in the investigated materials was detected by asymmetrical Grazing Incidence XRD

  4. Grain-size distributions and grain boundaries of chalcopyrite-type thin films

    International Nuclear Information System (INIS)

    Abou-Ras, D.; Schorr, S.; Schock, H.W.

    2007-01-01

    CuInSe 2 , CuGaSe 2 , Cu(In,Ga)Se 2 and CuInS 2 thin-film solar absorbers in completed solar cells were studied in cross section by means of electronbackscatter diffraction. From the data acquired, grain-size distributions were extracted, and also the most frequent grain boundaries were determined. The grain-size distributions of all chalcopyrite-type thin films studied can be described well by lognormal distribution functions. The most frequent grainboundary types in these thin films are 60 - left angle 221 right angle tet and 71 - left angle 110 right angle tet (near) Σ3 twin boundaries. These results can be related directly to the importance of {112} tet planes during the topotactical growth of chalcopyrite-type thin films. Based on energetic considerations, it is assumed that the most frequent twin boundaries exhibit a 180 - left angle 221 right angle tet constellation. (orig.)

  5. Effect of length of thinning area on the failure behavior of carbon steel pipe containing a defect of wall thinning

    International Nuclear Information System (INIS)

    Kim, Jin Weon; Park, Chi Yong

    2003-01-01

    The present study performed pipe failure tests using 102 mm-Sch. 80 carbon steel pipe with various simulated wall thinning defects, to investigate the effect of axial length of wall thinning and internal pressure on the failure behavior of pipe thinned by flow accelerated corrosion (FAC). The tests were conducted under loading conditions of four-point bending with and without internal pressure. The results showed that a failure mode of pipe with a defect depended on the magnitude of internal pressure and axial thinning length as well as stress type and thinning depth and circumferential angle. Both load carrying capability (LCC) and deformation capability (DC) were depended on stress type in the thinning area and dimensions of thinning defect. For applying tensile stress to the thinned area, the dependence of LCC on the axial length of wall thinning was determined by circumferential thinning angle, and the DC was proportionally increased with increase in axial length of wall thinning regardless of the circumferential angle. For applying compressive stress to thinned area, however, the LCC was decreased with increase in axial length of the thinned area. Also, the effect of internal pressure on failure behavior was characterized by failure mode of thinned pipe, and it promoted crack occurrence and mitigated a local buckling of the thinned area

  6. Color change mechanism of niobium oxide thin film with incidental light angle and applied voltage

    Energy Technology Data Exchange (ETDEWEB)

    Komatsu, Isao [Course of Information Science and Technology, Graduate School of Science and Technology, Tokai University (Japan); Aoki, Hayata [Course of Electro Photo Optics, Graduate School of Engineering, Tokai University (Japan); Ebisawa, Mizue [Tokyo Metropolitan Industrial Technology Research Institute (Japan); Kuroda, Akihiro [Department of Optical and Imaging Science & Technology, Faculty of Engineering, Tokai University (Japan); Kuroda Consulting Incorporated (Japan); Kuroda, Koichi [Kuroda Consulting Incorporated (Japan); Maeda, Shuichi [Course of Information Science and Technology, Graduate School of Science and Technology, Tokai University (Japan); Course of Electro Photo Optics, Graduate School of Engineering, Tokai University (Japan); Department of Optical and Imaging Science & Technology, Faculty of Engineering, Tokai University (Japan)

    2016-03-31

    Niobium oxide thin layers made by the anodization process showed coloration owing to thin film interference. The reflection spectra depended on both the applied voltage and incident light angle. Large color differences were observed at incident light angles between 5° and 70°, when the applied voltage was over 60 V. In this study, we explored the cause of these results using ellipsometry and goniophotometry to understand the transition of optical constants and the reflection spectra with applied voltage. Finally, we concluded that the coloration of the reflection spectra, which included only a first-order interference peak, exhibits a smaller change because the first order interference peak has a wider half value width than higher order interference peaks. - Highlights: • We investigated color change of Nb{sub 2}O{sub 5} oxide thin layers with incidental light angle. • The reflection spectra shift to lower wavelength region with increasing incident light angle. • The reflection spectra shift to higher wavelength region with increasing applied voltage. • First-order interference has wider half value width, and exhibits small color change.

  7. Optoelectronic properties of transparent p-type semiconductor Cu{sub x}S thin films

    Energy Technology Data Exchange (ETDEWEB)

    Parreira, P.; Valente, J. [ICEMS, IST-UTL, Lisboa (Portugal); Lavareda, G. [Departamento de Fisica, IST-UTL, Lisboa (Portugal); Nunes, F.T. [Departamento de Ciencia dos Materiais, FCT-UNL, Caparica (Portugal); Amaral, A. [Departamento de Fisica, IST-UTL, Lisboa (Portugal); ICEMS, IST-UTL, Lisboa (Portugal); Carvalho, C.N. de [Departamento de Ciencia dos Materiais, FCT-UNL, Caparica (Portugal); ICEMS, IST-UTL, Lisboa (Portugal)

    2010-07-15

    Nowadays, among the available transparent semiconductors for device use, the great majority (if not all) have n-type conductivity. The fabrication of a transparent p-type semiconductor with good optoelectronic properties (comparable to those of n-type: InO{sub x}, ITO, ZnO{sub x} or FTO) would significantly broaden the application field of thin films. However, until now no material has yet presented all the required properties. Cu{sub 2}S is a p-type narrow-band-gap material with an average optical transmittance of about 60% in the visible range for 50 nm thick films. However, due to its high conductivity at room temperature, 10 nm in thickness seems to be appropriate for device use. Cu{sub 2}S thin films with 10 nm in thickness have an optical visible transmittance of about 85% rendering them as very good candidates for transparent p-type semiconductors. In this work Cu{sub x}S thin films were deposited on alkali-free (AF) glass by thermal evaporation. The objective was not only the determination of its optoelectronic properties but also the feasibility of an active layer in a p-type thin film transistor. In our Cu{sub x}S thin films, p-type high conductivity with a total visible transmittance of about 50% have been achieved. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  8. Influence of thinning intensity and canopy type on Scots pine stand and growth dynamics in a mixed managed forest

    Energy Technology Data Exchange (ETDEWEB)

    Primicia, I.; Artázcoz, R.; Imbert, J.B.; Puertas, F.; Traver, M.C.; Castillo, F.J.

    2016-07-01

    Aim of the study: We analysed the effects of thinning intensity and canopy type on Scots pine growth and stand dynamics in a mixed Scots pine-beech forest. Area of the study: Western Pyrenees. Material and methods: Three thinning intensities were applied in 1999 (0, 20 and 30% basal area removed) and 2009 (0, 20 and 40%) on 9 plots. Within each plot, pure pine and mixed pine-beech patches are distinguished. All pine trees were inventoried in 1999, 2009 and 2014. The effects of treatments on the tree and stand structure variables (density, basal area, stand and tree volume), on the periodic annual increment in basal area and stand and tree volume, and on mortality rates, were analysed using linear mixed effects models. Main Results: The enhancement of tree growth was mainly noticeable after the second thinning. Growth rates following thinning were similar or higher in the moderate than in the severe thinning. Periodic stand volume annual increments were higher in the thinned than in the unthinned plots, but no differences were observed between the thinned treatments. We observed an increase in the differences of the Tree volume annual increment between canopy types (mixed < pure) over time in the unthinned plots, as beech crowns developed. Research highlights: Moderate thinning is suggested as an appropriate forest practice at early pine age in these mixed forests, since it produced higher tree growth rates than the severe thinning and it counteracted the negative effect of beech on pine growth observed in the unthinned plots. (Author)

  9. Method for applying a thin film barrier stack to a device with microstructures, and device provided with such a thin film barrier stack

    NARCIS (Netherlands)

    2005-01-01

    A method for applying a thin film barrier stack to a device with microstructures, such as, for instance, an OLED, wherein the thin film barrier stack forms a barrier to at least moisture and oxygen, wherein the stack is built up from a combination of org. and inorg. layers, characterized in that a

  10. P-type CuxS thin films: Integration in a thin film transistor structure

    International Nuclear Information System (INIS)

    Nunes de Carvalho, C.; Parreira, P.; Lavareda, G.; Brogueira, P.; Amaral, A.

    2013-01-01

    Cu x S thin films, 80 nm thick, are deposited by vacuum thermal evaporation of sulfur-rich powder mixture, Cu 2 S:S (50:50 wt.%) with no intentional heating of the substrate. The process of deposition occurs at very low deposition rates (0.1–0.3 nm/s) to avoid the formation of Cu or S-rich films. The evolution of Cu x S films surface properties (morphology/roughness) under post deposition mild annealing in air at 270 °C and their integration in a thin film transistor (TFT) are the main objectives of this study. Accordingly, Scanning Electron Microscopy studies show Cu x S films with different surface morphologies, depending on the post deposition annealing conditions. For the shortest annealing time, the Cu x S films look to be constructed of grains with large dimension at the surface (approximately 100 nm) and consequently, irregular shape. For the longest annealing time, films with a fine-grained surface are found, with some randomly distributed large particles bound to this fine-grained surface. Atomic Force Microscopy results indicate an increase of the root-mean-square roughness of Cu x S surface with annealing time, from 13.6 up to 37.4 nm, for 255 and 345 s, respectively. The preliminary integration of Cu x S films in a TFT bottom-gate type structure allowed the study of the feasibility and compatibility of this material with the remaining stages of a TFT fabrication as well as the determination of the p-type characteristic of the Cu x S material. - Highlights: • Surface properties of annealed Cu x S films. • Variation of conductivity with annealing temperatures of Cu x S films. • Application of evaporated Cu x S films in a thin film transistor (TFT) structure. • Determination of Cu x S p-type characteristic from TFT behaviour

  11. Control of p-type and n-type thermoelectric properties of bismuth telluride thin films by combinatorial sputter coating technology

    International Nuclear Information System (INIS)

    Goto, Masahiro; Sasaki, Michiko; Xu, Yibin; Zhan, Tianzhuo; Isoda, Yukihiro; Shinohara, Yoshikazu

    2017-01-01

    Highlights: • p- and n-type bismuth telluride thin films have been synthesized using a combinatorial sputter coating system (COSCOS) while changing only one of the experimental conditions, the RF power. • The dimensionless figure of merit (ZT) was optimized by the technique. • The fabrication of a Π-structured TE device was demonstrated. - Abstract: p- and n-type bismuth telluride thin films have been synthesized by using a combinatorial sputter coating system (COSCOS). The crystal structure and crystal preferred orientation of the thin films were changed by controlling the coating condition of the radio frequency (RF) power during the sputter coating. As a result, the p- and n-type films and their dimensionless figure of merit (ZT) were optimized by the technique. The properties of the thin films such as the crystal structure, crystal preferred orientation, material composition and surface morphology were analyzed by X-ray diffraction, energy-dispersive X-ray spectroscopy and atomic force microscopy. Also, the thermoelectric properties of the Seebeck coefficient, electrical conductivity and thermal conductivity were measured. ZT for n- and p-type bismuth telluride thin films was found to be 0.27 and 0.40 at RF powers of 90 and 120 W, respectively. The proposed technology can be used to fabricate thermoelectric p–n modules of bismuth telluride without any doping process.

  12. Control of p-type and n-type thermoelectric properties of bismuth telluride thin films by combinatorial sputter coating technology

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Masahiro, E-mail: goto.masahiro@nims.go.jp [Thermoelectric Materials Group, Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Sasaki, Michiko [Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Xu, Yibin [Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Materials Database Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Zhan, Tianzhuo [Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Isoda, Yukihiro [Thermoelectric Materials Group, Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Shinohara, Yoshikazu [Thermoelectric Materials Group, Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Thermal Management and Thermoelectric Materials Group, Center for Materials Research by Information Integration (CMI2), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

    2017-06-15

    Highlights: • p- and n-type bismuth telluride thin films have been synthesized using a combinatorial sputter coating system (COSCOS) while changing only one of the experimental conditions, the RF power. • The dimensionless figure of merit (ZT) was optimized by the technique. • The fabrication of a Π-structured TE device was demonstrated. - Abstract: p- and n-type bismuth telluride thin films have been synthesized by using a combinatorial sputter coating system (COSCOS). The crystal structure and crystal preferred orientation of the thin films were changed by controlling the coating condition of the radio frequency (RF) power during the sputter coating. As a result, the p- and n-type films and their dimensionless figure of merit (ZT) were optimized by the technique. The properties of the thin films such as the crystal structure, crystal preferred orientation, material composition and surface morphology were analyzed by X-ray diffraction, energy-dispersive X-ray spectroscopy and atomic force microscopy. Also, the thermoelectric properties of the Seebeck coefficient, electrical conductivity and thermal conductivity were measured. ZT for n- and p-type bismuth telluride thin films was found to be 0.27 and 0.40 at RF powers of 90 and 120 W, respectively. The proposed technology can be used to fabricate thermoelectric p–n modules of bismuth telluride without any doping process.

  13. Thin-film antifuses for pellistor type gas sensors

    NARCIS (Netherlands)

    Kovalgin, Alexeij Y.; Holleman, J.; van den Berg, Albert; Wallinga, Hans

    2001-01-01

    This work extends our previously reported idea of using the nano-scale conductive link (antifuse) as a combined heating /detecting element in a Pellistor-type gas sensor. Our new thin-film antifuse is designed in such a way that the oxide, for minimising the bulk influence on surface temperature,

  14. n-Type Conductivity of Cu2O Thin Film Prepared in Basic Aqueous Solution Under Hydrothermal Conditions

    Science.gov (United States)

    Ursu, Daniel; Miclau, Nicolae; Miclau, Marinela

    2018-03-01

    We report for the first time in situ hydrothermal synthesis of n-type Cu2O thin film using strong alkaline solution. The use of copper foil as substrate and precursor material, low synthesis temperature and short reaction time represent the arguments of a new, simple, inexpensive and high field synthesis method for the preparation of n-type Cu2O thin film. The donor concentration of n-type Cu2O thin film obtained at 2 h of reaction time has increased two orders of magnitude than previous reported values. We have demonstrated n-type conduction in Cu2O thin film prepared in strong alkaline solution, in the contradiction with the previous works. Based on experimental results, the synthesis mechanism and the origin of n-type photo-responsive behavior of Cu2O thin film were discussed. We have proposed that the unexpected n-type character could be explained by H doping of Cu2O thin film in during of the hydrothermal synthesis that caused the p-to-n conductivity-type conversion. Also, this work raises new questions about the origin of n-type conduction in Cu2O thin film, the influence of the synthesis method on the nature of the intrinsic defects and the electrical conduction behavior.

  15. Removable Thin Films used for the Abatement and Mitigation of Beryllium

    International Nuclear Information System (INIS)

    Lumia, M.; Gentile, C.; Creek, K.; Sandoval, R.

    2003-01-01

    The use of removable thin films for the abatement of hazardous particulates has many advantages. Removable thin films are designed to trap and fix particulates in the film's matrix by adhesion. Thin films can be applied to an existing contaminated area to fix and capture the particulates for removal. The nature of the removable thin films, after sufficient cure time, is such that it can typically be removed as one continuous entity. The removable thin films can be applied to almost any surface type with a high success rate of removal

  16. Nanosphere lithography applied to magnetic thin films

    Science.gov (United States)

    Gleason, Russell

    Magnetic nanostructures have widespread applications in many areas of physics and engineering, and nanosphere lithography has recently emerged as promising tool for the fabrication of such nanostructures. The goal of this research is to explore the magnetic properties of a thin film of ferromagnetic material deposited onto a hexagonally close-packed monolayer array of polystyrene nanospheres, and how they differ from the magnetic properties of a typical flat thin film. The first portion of this research focuses on determining the optimum conditions for depositing a monolayer of nanospheres onto chemically pretreated silicon substrates (via drop-coating) and the subsequent characterization of the deposited nanosphere layer with scanning electron microscopy. Single layers of permalloy (Ni80Fe20) are then deposited on top of the nanosphere array via DC magnetron sputtering, resulting in a thin film array of magnetic nanocaps. The coercivities of the thin films are measured using a home-built magneto-optical Kerr effect (MOKE) system in longitudinal arrangement. MOKE measurements show that for a single layer of permalloy (Py), the coercivity of a thin film deposited onto an array of nanospheres increases compared to that of a flat thin film. In addition, the coercivity increases as the nanosphere size decreases for the same deposited layer. It is postulated that magnetic exchange decoupling between neighboring nanocaps suppresses the propagation of magnetic domain walls, and this pinning of the domain walls is thought to be the primary source of the increase in coercivity.

  17. A chip-type thin-layer electrochemical cell coupled with capillary electrophoresis for online separation of electrode reaction products

    Energy Technology Data Exchange (ETDEWEB)

    He, Jian-Bo, E-mail: jbhe@hfut.edu.cn; Cui, Ting; Zhang, Wen-Wen; Deng, Ning

    2013-07-05

    Graphical abstract: -- Highlights: •A new coupling of thin-layer electrolysis with capillary electrophoresis (CE). •Rapid electrolysis, direct sampling followed by online CE separation. •At least 13 products of quercetin oxidation were separated. •Thermodynamic and kinetic parameters were determined from CE peak areas. -- Abstract: A coupling technique of thin-layer electrolysis with high-performance capillary electrophoresis/UV–vis technique(EC/HPCE/UV–vis) is developed for online separation and determination of electrode reaction products. A chip-type thin-layer electrolytic (CTE) cell was designed and fabricated, which contains a capillary channel and a background electrolyte reservoir, allowing rapid electrolysis, direct sampling and online electrophoretic separation. This chip-type setup was characterized based on an electrophoresis expression of Nernst equation that was applied to the redox equilibrium of o-tolidine at different potentials. The utility of the method was demonstrated by separating and determining the electro-oxidation products of quercetin in different pH media. Two main products were always found in the studied time, potential and pH ranges. The variety of products increased not only with increasing potential but also with increasing pH value, and in total, at least 13 products were observed in the electropherograms. This work illustrates a novel example of capillary electrophoresis used online with thin-layer electrolysis to separate and detect electrode reaction products.

  18. A chip-type thin-layer electrochemical cell coupled with capillary electrophoresis for online separation of electrode reaction products

    International Nuclear Information System (INIS)

    He, Jian-Bo; Cui, Ting; Zhang, Wen-Wen; Deng, Ning

    2013-01-01

    Graphical abstract: -- Highlights: •A new coupling of thin-layer electrolysis with capillary electrophoresis (CE). •Rapid electrolysis, direct sampling followed by online CE separation. •At least 13 products of quercetin oxidation were separated. •Thermodynamic and kinetic parameters were determined from CE peak areas. -- Abstract: A coupling technique of thin-layer electrolysis with high-performance capillary electrophoresis/UV–vis technique(EC/HPCE/UV–vis) is developed for online separation and determination of electrode reaction products. A chip-type thin-layer electrolytic (CTE) cell was designed and fabricated, which contains a capillary channel and a background electrolyte reservoir, allowing rapid electrolysis, direct sampling and online electrophoretic separation. This chip-type setup was characterized based on an electrophoresis expression of Nernst equation that was applied to the redox equilibrium of o-tolidine at different potentials. The utility of the method was demonstrated by separating and determining the electro-oxidation products of quercetin in different pH media. Two main products were always found in the studied time, potential and pH ranges. The variety of products increased not only with increasing potential but also with increasing pH value, and in total, at least 13 products were observed in the electropherograms. This work illustrates a novel example of capillary electrophoresis used online with thin-layer electrolysis to separate and detect electrode reaction products

  19. Critical phenomena in Ising-type thin films by Monte Carlo study

    International Nuclear Information System (INIS)

    Masrour, R.; Jabar, A.; Benyoussef, A.; Hamedoun, M.

    2016-01-01

    The magnetic properties of ferrimagnetic spin-2 and 3/2 Ising-typed thin films are studied by Monte Carlo simulation. The critical temperature is obtained for different values of thickness of the thin film and for different exchange interactions. The total magnetization has been determined for different values of exchange interactions in surface and in bulk and different temperatures. The magnetic hysteresis cycle is obtained for different values of exchange interactions ferro and antiferromagnetic in the surface and in the bulk and for different values of temperatures for a fixed size of the film thickness. The coercive field increase with increasing the film thickness. - Highlights: • The magnetic properties of thin films are studied by Monte Carlo simulation. • The critical temperature is obtained for different values of thickness of thin film. • The magnetic hysteresis cycle is obtained in the surface and in the bulk. • The coercive field increase with increasing the thin film thickness.

  20. Critical phenomena in Ising-type thin films by Monte Carlo study

    Energy Technology Data Exchange (ETDEWEB)

    Masrour, R., E-mail: rachidmasrour@hotmail.com [Laboratory of Materials, Processes, Environment and Quality, Cady Ayyed University, National School of Applied Sciences, 63, 46000 Safi (Morocco); Laboratoire de Magnétisme et Physique des Hautes Energies L.M.P.H.E.URAC 12, Université Mohammed V, Faculté des Sciences, B.P. 1014, Rabat (Morocco); Jabar, A. [Laboratoire de Magnétisme et Physique des Hautes Energies L.M.P.H.E.URAC 12, Université Mohammed V, Faculté des Sciences, B.P. 1014, Rabat (Morocco); Benyoussef, A. [Laboratoire de Magnétisme et Physique des Hautes Energies L.M.P.H.E.URAC 12, Université Mohammed V, Faculté des Sciences, B.P. 1014, Rabat (Morocco); Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco); Hassan II Academy of Science and Technology, Rabat (Morocco); Hamedoun, M. [Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco)

    2016-04-01

    The magnetic properties of ferrimagnetic spin-2 and 3/2 Ising-typed thin films are studied by Monte Carlo simulation. The critical temperature is obtained for different values of thickness of the thin film and for different exchange interactions. The total magnetization has been determined for different values of exchange interactions in surface and in bulk and different temperatures. The magnetic hysteresis cycle is obtained for different values of exchange interactions ferro and antiferromagnetic in the surface and in the bulk and for different values of temperatures for a fixed size of the film thickness. The coercive field increase with increasing the film thickness. - Highlights: • The magnetic properties of thin films are studied by Monte Carlo simulation. • The critical temperature is obtained for different values of thickness of thin film. • The magnetic hysteresis cycle is obtained in the surface and in the bulk. • The coercive field increase with increasing the thin film thickness.

  1. Demonstration of high-performance p-type tin oxide thin-film transistors using argon-plasma surface treatments

    Science.gov (United States)

    Bae, Sang-Dae; Kwon, Soo-Hun; Jeong, Hwan-Seok; Kwon, Hyuck-In

    2017-07-01

    In this work, we investigated the effects of low-temperature argon (Ar)-plasma surface treatments on the physical and chemical structures of p-type tin oxide thin-films and the electrical performance of p-type tin oxide thin-film transistors (TFTs). From the x-ray photoelectron spectroscopy measurement, we found that SnO was the dominant phase in the deposited tin oxide thin-film, and the Ar-plasma treatment partially transformed the tin oxide phase from SnO to SnO2 by oxidation. The resistivity of the tin oxide thin-film increased with the plasma-treatment time because of the reduced hole concentration. In addition, the root-mean-square roughness of the tin oxide thin-film decreased as the plasma-treatment time increased. The p-type oxide TFT with an Ar-plasma-treated tin oxide thin-film exhibited excellent electrical performance with a high current on-off ratio (5.2 × 106) and a low off-current (1.2 × 10-12 A), which demonstrates that the low-temperature Ar-plasma treatment is a simple and effective method for improving the electrical performance of p-type tin oxide TFTs.

  2. Characterization of n and p-type ZnO thin films grown by pulsed filtered cathodic vacuum arc system

    International Nuclear Information System (INIS)

    Kavak, H.; Erdogan, E.N.; Ozsahin, I.; Esen, R.

    2010-01-01

    Full text : Semiconductor ZnO thin films with wide band gap attract much interest due to their properties such as chemical stability in hydrogen plasma, high optical transparency in the visible and nearinfrared region. Due to these properties ZnO oxide is a promising materials for electronic or optoelectronic applications such as solar cell (as an antireflecting coating and a transparent conducting material), gas sensors, surface acoustic wave devices. The purpose of this research is to improve the properties of n and p-type ZnO thin films for device applications. Polycrystalline ZnO is naturally n-type and very difficult to dope to make p-type. Therefore nowadays hardly produced p-type ZnO attracts a lot of attention. Nitrogen considered as the best dopant for p-type ZnO thin films.The transparent, conductive and very precise thickness controlled n and p-type semiconducting nanocrystalline ZnO thin films were prepared by pulsed filtered cathodic vacuum arc deposition (PFCVAD) method. Structural, optical and electrical properties of these films were investigated. And also photoluminescence properties of these films were investigated. Transparent p-type ZnO thin films were produced by oxidation of PFCVAD deposited zinc nitride. Zinc nitride thin films were deposited with various thicknesses and under different oxygen pressures on glass substrates. Zinc nitride thin films, which were deposited at room temperatures, were amorphous and the optical transmission was below 70%. For oxidation zinc nitride, the sample was annealed in air starting from 350 degrees Celsium up to 550 degrees Celsium for one hour duration. These XRD patterns imply that zinc nitride thin films converted to zinc oxide thin films with the same hexagonal crystalline structures of ZnO. The optical measurements were made for each annealing temperature and the optical transmissions of ZnO thin films were found better than 90 percent in visible range after annealing over 350 degrees Celsium. By

  3. Thin-film type Li-ion battery, using a polyethylene separator grafted with glycidyl methacrylate

    International Nuclear Information System (INIS)

    Ko, J.M.; Min, B.G.; Kim, D.-W.; Ryu, K.S.; Kim, K.M.; Lee, Y.G.; Chang, S.H.

    2004-01-01

    For the improvement of organic electrolyte holding ability, the hydrophobic surface of a porous polyethylene (PE)-membrane separator was modified by grafting a hydrophilic monomer, glycidyl methacrylate (GMA), PE-g-GMA, by using electron beam technology, and applied to a thin film type Li-ion battery to elucidate the effect of a surface modification of a PE membrane separator on the cyclic life of Li-ion batteries. The Li-ion battery using the PE-g-GMA membrane separator showed a better cycle life than that of the unmodified PE membrane separator, indicating that the surface hydrophilicity of the PE membrane separator improved the electrolyte holding capability between the electrodes in the Li-ion cell and prevented the electrolyte leakage

  4. Structural and morphological changes in P3HT thin film transistors applying an electric field

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, Deepak Kumar; Grigorian, Souren; Pietsch, Ullrich [University of Siegen (Germany); Flesch, Heinz; Resel, Roland [University of Siegen (Germany); Graz University of Technology (Austria)

    2010-07-01

    We report on electric field dependent crystalline structure and morphological changes of drop casting and spin coated poly(3-hexylthiophene) (P3HT) thin films. In order to probe the morphological changes induced by an applied electric field the samples were covered with thin source/drain electrodes separated by a small channel of 2 mm width. A series of x-ray reflectivity, X-ray grazing incidence out-of-plane and in-plane scans have been performed as function of the applied electric voltage. The (100) peak shows a decrease in intensity with increase of the applied electric field. This might be caused by Joule heating and the creation of current induced defects in the P3HT film. On other hand the (020) peak intensity shows much stronger changes with applied field. Considering the *-* stacking direction the measured effect can be directly related to a change in the electric transport. The observed changes in structure are reversible and the current-voltage cycle can be repeated several times. For X-ray reflectivity major changes have been found close to critical angle of total external reflection indicating the film becomes less dense and increases in surface roughness with increase of the voltage. This change in surface behaviour could be confirmed by in-situ AFM measurements.

  5. Reversible p-type conductivity in H passivated nitrogen and phosphorous codoped ZnO thin films using rapid thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Mannam, Ramanjaneyulu, E-mail: ramu.nov9@gmail.com [Department of Physics, Nano Functional Materials Technology Centre and Materials Science Research Centre, Indian Institute of Technology Madras, Chennai 600036 (India); Kumar, E. Senthil [SRM Research Institute, Department of Physics and Nanotechnology, SRM University, Kattankulathur 603203, Tamil Nadu (India); DasGupta, Nandita [Microelectronics and MEMS Laboratory, Electrical Engineering Department, Indian Institute of Technology Madras, Chennai 600036 (India); Ramachandra Rao, M.S., E-mail: msrrao@iitm.ac.in [Department of Physics, Nano Functional Materials Technology Centre and Materials Science Research Centre, Indian Institute of Technology Madras, Chennai 600036 (India)

    2017-04-01

    Highlights: • Electrical transport measurements revel that the (P, N) codoped ZnO thin films exhibited change in conductivity from p-type to n-type over a span of 120 days. • Hydrogen and carbon are found to be the main unintentional impurities in n-type (P, N) codoped ZnO thin films. • Rapid thermal annealing has been used to remove both H and C from the films. • Carbon can be removed at an annealing temperature of 600 °C, whereas, the dissociation of N−H complex takes place only at 800 °C. • The n-type (P, N) codoped ZnO thin film exhibited change in conductivity to p-type at an annealing temperature of 800 °C. - Abstract: We demonstrate reversible p-type nature of pulsed laser deposited (P, N) codoped ZnO thin films using rapid thermal annealing process. As grown thin films exhibited change in conductivity from p to n-type over a span of 120 days. Non-annealed n-type thin films contain unintentional donor impurities such as hydrogen and carbon. X-ray photoelectron spectroscopy and Raman measurements conclusively show that hydrogen passivates nitrogen acceptors by forming N−H complex. Carbon can be annealed out at 600 °C, whereas, the dissociation of N−H complex takes place at 800 °C. The films revert its p-type nature at an annealing temperature of 800 °C.

  6. Formation of p-type ZnO thin film through co-implantation

    Science.gov (United States)

    Chuang, Yao-Teng; Liou, Jhe-Wei; Woon, Wei-Yen

    2017-01-01

    We present a study on the formation of p-type ZnO thin film through ion implantation. Group V dopants (N, P) with different ionic radii are implanted into chemical vapor deposition grown ZnO thin film on GaN/sapphire substrates prior to thermal activation. It is found that mono-doped ZnO by N+ implantation results in n-type conductivity under thermal activation. Dual-doped ZnO film with a N:P ion implantation dose ratio of 4:1 is found to be p-type under certain thermal activation conditions. Higher p-type activation levels (1019 cm-3) under a wider thermal activation range are found for the N/P dual-doped ZnO film co-implanted by additional oxygen ions. From high resolution x-ray diffraction and x-ray photoelectron spectroscopy it is concluded that the observed p-type conductivities are a result of the promoted formation of PZn-4NO complex defects via the concurrent substitution of nitrogen at oxygen sites and phosphorus at zinc sites. The enhanced solubility and stability of acceptor defects in oxygen co-implanted dual-doped ZnO film are related to the reduction of oxygen vacancy defects at the surface. Our study demonstrates the prospect of the formation of stable p-type ZnO film through co-implantation.

  7. Quench and recovery characteristics of Au/YBCO thin film type SFCL

    International Nuclear Information System (INIS)

    Yim, S.-W.; Kim, H.-R.; Hyun, O.-B.; Sim, J.

    2007-01-01

    Although, a superconducting fault current limiter (SFCL) guarantees the fast limiting operation, it usually needs a considerably long time to recover to superconducting state after the quench. Considering the reclosing time in the protection coordination of power systems, the time required for the recovery should be investigated clearly. In this study, the quench and recovery characteristics of Au/YBCO thin films designed as an SFCL element with a bi-spiral pattern were investigated. The quench development of the SFCL was measured by two kinds of methods. Firstly, after applying the fault current of 5.5 cycles, we measured the resistance of the YBCO by a small current flowing through the pattern of Au/YBCO thin film. The temperature variation above the critical temperature, 85 K, was investigated indirectly from the resistance variation. Secondly, in order to measure the temperature from 85 K to 77 K, a meander line shape of Au thin film was evaporated on the back side and used as a temperature detecting sensor. The temperature variations detected by both methods were compared and analyzed. For the investigation of the recovery characteristics, the required time for the recovery of the superconductivity was measured for various magnitude and duration of the applied voltages. In addition, for the purpose of examining the dependence of the line impedance on the recovery time, resistors of various resistances were inserted in the fault current testing circuit and the recovery time was measured and analyzed

  8. Facile fabrication of wire-type indium gallium zinc oxide thin-film transistors applicable to ultrasensitive flexible sensors.

    Science.gov (United States)

    Kim, Yeong-Gyu; Tak, Young Jun; Kim, Hee Jun; Kim, Won-Gi; Yoo, Hyukjoon; Kim, Hyun Jae

    2018-04-03

    We fabricated wire-type indium gallium zinc oxide (IGZO) thin-film transistors (TFTs) using a self-formed cracked template based on a lift-off process. The electrical characteristics of wire-type IGZO TFTs could be controlled by changing the width and density of IGZO wires through varying the coating conditions of template solution or multi-stacking additional layers. The fabricated wire-type devices were applied to sensors after functionalizing the surface. The wire-type pH sensor showed a sensitivity of 45.4 mV/pH, and this value was an improved sensitivity compared with that of the film-type device (27.6 mV/pH). Similarly, when the wire-type device was used as a glucose sensor, it showed more variation in electrical characteristics than the film-type device. The improved sensing properties resulted from the large surface area of the wire-type device compared with that of the film-type device. In addition, we fabricated wire-type IGZO TFTs on flexible substrates and confirmed that such structures were very resistant to mechanical stresses at a bending radius of 10 mm.

  9. Heterojunction solar cell with 6% efficiency based on an n-type aluminum-gallium-oxide thin film and p-type sodium-doped Cu2O sheet

    Science.gov (United States)

    Minami, Tadatsugu; Nishi, Yuki; Miyata, Toshihiro

    2015-02-01

    In this paper, we describe efforts to enhance the efficiency of Cu2O-based heterojunction solar cells fabricated with an aluminum-gallium-oxide (Al-Ga-O) thin film as the n-type layer and a p-type sodium (Na)-doped Cu2O (Cu2O:Na) sheet prepared by thermally oxidizing copper sheets. The optimal Al content [X; Al/(Ga + Al) atomic ratio] of an AlX-Ga1-X-O thin-film n-type layer was found to be approximately 2.5 at. %. The optimized resistivity was approximately 15 Ω cm for n-type AlX-Ga1-X-O/p-type Cu2O:Na heterojunction solar cells. A MgF2/AZO/Al0.025-Ga0.975-O/Cu2O:Na heterojunction solar cell with 6.1% efficiency was fabricated using a 60-nm-thick n-type oxide thin-film layer and a 0.2-mm-thick Cu2O:Na sheet with the optimized resistivity.

  10. Thermal oxidation of Ni films for p-type thin-film transistors

    KAUST Repository

    Jiang, Jie; Wang, Xinghui; Zhang, Qing; Li, Jingqi; Zhang, Xixiang

    2013-01-01

    p-Type nanocrystal NiO-based thin-film transistors (TFTs) are fabricated by simply oxidizing thin Ni films at temperatures as low as 400 °C. The highest field-effect mobility in a linear region and the current on-off ratio are found to be 5.2 cm2 V-1 s-1 and 2.2 × 103, respectively. X-ray diffraction, transmission electron microscopy and electrical performances of the TFTs with "top contact" and "bottom contact" channels suggest that the upper parts of the Ni films are clearly oxidized. In contrast, the lower parts in contact with the gate dielectric are partially oxidized to form a quasi-discontinuous Ni layer, which does not fully shield the gate electric field, but still conduct the source and drain current. This simple method for producing p-type TFTs may be promising for the next-generation oxide-based electronic applications. © 2013 the Owner Societies.

  11. Fabrication of p-type conductivity in SnO{sub 2} thin films through Ga doping

    Energy Technology Data Exchange (ETDEWEB)

    Tsay, Chien-Yie, E-mail: cytsay@fcu.edu.tw; Liang, Shan-Chien

    2015-02-15

    Highlights: • P-type Ga-doped SnO{sub 2} semiconductor films were prepared by sol-gel spin coating. • Optical bandgaps of the SnO{sub 2}:Ga films are narrower than that of the SnO{sub 2} film. • SnO{sub 2}:Ga films exhibited p-type conductivity as Ga doping content higher than 10%. • A p-n heterojunction composed of p-type SnO{sub 2}:Ga and n-type ZnO:Al was fabricated. - Abstract: P-type transparent tin oxide (SnO{sub 2}) based semiconductor thin films were deposited onto alkali-free glass substrates by a sol-gel spin-coating method using gallium (Ga) as acceptor dopant. In this study, we investigated the influence of Ga doping concentration ([Ga]/[Sn] + [Ga] = 0%, 5%, 10%, 15%, and 20%) on the structural, optical and electrical properties of SnO{sub 2} thin films. XRD analysis results showed that dried Ga-doped SnO{sub 2} (SnO{sub 2}:Ga) sol-gel films annealed in oxygen ambient at 520 °C for 1 h exhibited only the tetragonal rutile phase. The average optical transmittance of as-prepared thin film samples was higher than 87.0% in the visible light region; the optical band gap energy slightly decreased from 3.92 eV to 3.83 eV with increases in Ga doping content. Hall effect measurement showed that the nature of conductivity of SnO{sub 2}:Ga thin films changed from n-type to p-type when the Ga doping level was 10%, and when it was at 15%, Ga-doped SnO{sub 2} thin films exhibited the highest mean hole concentration of 1.70 × 10{sup 18} cm{sup -3}. Furthermore, a transparent p-SnO{sub 2}:Ga (Ga doping level of 15%)/n-ZnO:Al (Al doping level of 2%) heterojunction was fabricated on alkali-free glass. The I-V curve measurement for the p-n heterojunction diode showed a typical rectifying characteristic with a forward turn-on voltage of 0.65 V.

  12. Magnetization reversal of a type-II superconductor thin disk under the action of a constant magnetic field

    International Nuclear Information System (INIS)

    Koval'chuk, D.G.; Chornomorets', M.P.

    2010-01-01

    The applicability of relations obtained by Clem and Sanchez for the ac magnetic susceptibility of type-II superconductor thin films to the case where an additional constant magnetic field is applied perpendicularly to the film has been analyzed in the framework of the critical state model. The issues concerning the sample 'memory' and the influence of the magnetic field change prehistory on the current sample state have been discussed. It has been shown that the ac component of the magnetic moment and, hence, the amplitudes of ac magnetic susceptibility harmonics are established within one period of the ac magnetic field irrespective of the field prehistory.

  13. Low-temperature preparation of rutile-type TiO2 thin films for optical coatings by aluminum doping

    Science.gov (United States)

    Ishii, Akihiro; Kobayashi, Kosei; Oikawa, Itaru; Kamegawa, Atsunori; Imura, Masaaki; Kanai, Toshimasa; Takamura, Hitoshi

    2017-08-01

    A rutile-type TiO2 thin film with a high refractive index (n), a low extinction coefficient (k) and small surface roughness (Ra) is required for use in a variety of optical coatings to improve the controllability of the reflection spectrum. In this study, Al-doped TiO2 thin films were prepared by pulsed laser deposition, and the effects of Al doping on their phases, optical properties, surface roughness and nanoscale microstructure, including Al distribution, were investigated. By doping 5 and 10 mol%Al, rutile-type TiO2 was successfully prepared under a PO2 of 0.5 Pa at 350-600 °C. The nanoscale phase separation in the Al-doped TiO2 thin films plays an important role in the formation of the rutile phase. The 10 mol%Al-doped rutile-type TiO2 thin film deposited at 350 °C showed excellent optical properties of n ≈ 3.05, k ≈ 0.01 (at λ = 400 nm) and negligible surface roughness, at Ra ≈ 0.8 nm. The advantages of the superior optical properties and small surface roughness of the 10 mol%Al-doped TiO2 thin film were confirmed by fabricating a ten-layered dielectric mirror.

  14. Solving “Antenna Array Thinning Problem” Using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Rajashree Jain

    2012-01-01

    Full Text Available Thinning involves reducing total number of active elements in an antenna array without causing major degradation in system performance. Dynamic thinning is the process of achieving this under real-time conditions. It is required to find a strategic subset of antenna elements for thinning so as to have its optimum performance. From a mathematical perspective this is a nonlinear, multidimensional problem with multiple objectives and many constraints. Solution for such problem cannot be obtained by classical analytical techniques. It will be required to employ some type of search algorithm which can lead to a practical solution in an optimal. The present paper discusses an approach of using genetic algorithm for array thinning. After discussing the basic concept involving antenna array, array thinning, dynamic thinning, and application methodology, simulation results of applying the technique to linear and planar arrays are presented.

  15. Process for forming thin film, heat treatment process of thin film sheet, and heat treatment apparatus therefor

    International Nuclear Information System (INIS)

    Watanabe, S.

    1984-01-01

    The invention provides a process for forming a magnetic thin film on a base film, a heat treatment process of a thin film sheet consisting of the base film and the magnetic thin film, and an apparatus for performing heat treatment of the thin film sheet. Tension applied to the thin film sheet is substantially equal to that applied to the base film when the magnetic thin film is formed thereon. Then, the thin film sheet is treated with heat. The thin film sheet is heated with a given temperature gradient to a reactive temperature at which heat shrinkage occurs, while the tension is being applied thereto. Thereafter, the thin film sheet to which the tension is still applied is cooled with substantially the same temperature gradient as applied in heating. The heat treatment apparatus has a film driving unit including a supply reel, a take-up reel, a drive source and guide rollers; a heating unit including heating plates, heater blocks and a temperature controller for heating the sheet to the reactive temperature; and a heat insulating unit including a thermostat and another temperature controller for maintaining the sheet at the nonreactive temperature which is slightly lower than the reactive temperature

  16. P-type SnO thin films and SnO/ZnO heterostructures for all-oxide electronic and optoelectronic device applications

    Energy Technology Data Exchange (ETDEWEB)

    Saji, Kachirayil J. [Nanostructured Materials Research Laboratory, Department of Materials Science & Engineering, University of Utah, Salt Lake City, UT 84112 (United States); Department of Physics, Govt. Victoria College, University of Calicut, Palakkad 678 001 (India); Venkata Subbaiah, Y.P. [Nanostructured Materials Research Laboratory, Department of Materials Science & Engineering, University of Utah, Salt Lake City, UT 84112 (United States); Department of Physics, Yogi Vemana University, Kadapa, Andhra Pradesh 516003 (India); Tian, Kun [Nanostructured Materials Research Laboratory, Department of Materials Science & Engineering, University of Utah, Salt Lake City, UT 84112 (United States); Tiwari, Ashutosh, E-mail: tiwari@eng.utah.edu [Nanostructured Materials Research Laboratory, Department of Materials Science & Engineering, University of Utah, Salt Lake City, UT 84112 (United States)

    2016-04-30

    Tin monoxide (SnO) is considered as one of the most important p-type oxides available to date. Thin films of SnO have been reported to possess both an indirect bandgap (~ 0.7 eV) and a direct bandgap (~ 2.8 eV) with quite high hole mobility (~ 7 cm{sup 2}/Vs) values. Moreover, the hole density in these films can be tuned from 10{sup 15}–10{sup 19} cm{sup −3} just by controlling the thin film deposition parameters. Because of the above attributes, SnO thin films offer great potential for fabricating modern electronic and optoelectronic devices. In this article, we are reviewing the most recent developments in this field and also presenting some of our own results on SnO thin films grown by pulsed laser deposition technique. We have also proposed a p–n heterostructure comprising of p-type SnO and n-type ZnO which can pave way for realizing next-generation, all-oxide transparent electronic devices. - Highlights: • We reviewed recent developments on p-type SnO thin film research. • Discussed the optical and electrical properties of SnO thin films • Bipolar conduction in SnO is discussed. • Optoelectronic properties of SnO–ZnO composite system are discussed. • Proposed SnO–ZnO heterojunction band structure.

  17. Analysis of MUSIC-type imaging functional for single, thin electromagnetic inhomogeneity in limited-view inverse scattering problem

    Science.gov (United States)

    Ahn, Chi Young; Jeon, Kiwan; Park, Won-Kwang

    2015-06-01

    This study analyzes the well-known MUltiple SIgnal Classification (MUSIC) algorithm to identify unknown support of thin penetrable electromagnetic inhomogeneity from scattered field data collected within the so-called multi-static response matrix in limited-view inverse scattering problems. The mathematical theories of MUSIC are partially discovered, e.g., in the full-view problem, for an unknown target of dielectric contrast or a perfectly conducting crack with the Dirichlet boundary condition (Transverse Magnetic-TM polarization) and so on. Hence, we perform further research to analyze the MUSIC-type imaging functional and to certify some well-known but theoretically unexplained phenomena. For this purpose, we establish a relationship between the MUSIC imaging functional and an infinite series of Bessel functions of integer order of the first kind. This relationship is based on the rigorous asymptotic expansion formula in the existence of a thin inhomogeneity with a smooth supporting curve. Various results of numerical simulation are presented in order to support the identified structure of MUSIC. Although a priori information of the target is needed, we suggest a least condition of range of incident and observation directions to apply MUSIC in the limited-view problem.

  18. Thin type inverter for machine-room-less elevator; Machine roomless elevator yo usugata inverter

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-01-10

    In the elevator industry, a machine-room-less elevator, which does not necessitate a machine room usually installed on the roof, has come into the spotlight in the domain of low and intermediate speed elevators. The lack of a machine room, however, will necessarily limit the space for the installation of the traction motor and control panel. Fuji Electric Co., Ltd., in order to properly cope with the situation, has developed in cooperation with Fujitec Co., Ltd., a very thin type inverter installable on an elevator hall floor. The inverter, based on Fuji Electric's high-performance vector control inverter FRENIC5000VG5, is as thin as 100mm, and is available in three series up to 11kW. For the embodiment of such a thin structure, a cooling structure of Fuji Electric's own is employed, and prudence is exercised as required at many locations so that maintainability will not be impaired throughout the very thin control panel design. (translated by NEDO)

  19. Exact harmonic solutions to Guyer-Krumhansl-type equation and application to heat transport in thin films

    Science.gov (United States)

    Zhukovsky, K.; Oskolkov, D.

    2018-03-01

    A system of hyperbolic-type inhomogeneous differential equations (DE) is considered for non-Fourier heat transfer in thin films. Exact harmonic solutions to Guyer-Krumhansl-type heat equation and to the system of inhomogeneous DE are obtained in Cauchy- and Dirichlet-type conditions. The contribution of the ballistic-type heat transport, of the Cattaneo heat waves and of the Fourier heat diffusion is discussed and compared with each other in various conditions. The application of the study to the ballistic heat transport in thin films is performed. Rapid evolution of the ballistic quasi-temperature component in low-dimensional systems is elucidated and compared with slow evolution of its diffusive counterpart. The effect of the ballistic quasi-temperature component on the evolution of the complete quasi-temperature is explored. In this context, the influence of the Knudsen number and of Cauchy- and Dirichlet-type conditions on the evolution of the temperature distribution is explored. The comparative analysis of the obtained solutions is performed.

  20. Superconducting oxypnictide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Reisner, Andreas; Kidszun, Martin; Reich, Elke; Holzapfel, Bernhard; Schultz, Ludwig; Haindl, Silvia [IFW Dresden, Institute of Metallic Materials (Germany); Thersleff, Thomas [Uppsala University, Angstrom Laboratory (Sweden)

    2012-07-01

    We present an overview on the oxypnictide thin film preparation. So far, only LaAlO{sub 3} (001) single crystalline substrates provided a successful growth using pulsed laser deposition in combination with a post annealing process. Further experiments on the in-situ deposition will be reported. The structure of the films was investigated by X-ray diffractometry and transmission electron microscopy. Transport properties were measured with different applied fields to obtain a magnetic phase diagram for this new type of superconductor.

  1. Preparation of p-type GaN-doped SnO2 thin films by e-beam evaporation and their applications in p-n junction

    Science.gov (United States)

    Lv, Shuliang; Zhou, Yawei; Xu, Wenwu; Mao, Wenfeng; Wang, Lingtao; Liu, Yong; He, Chunqing

    2018-01-01

    Various transparent GaN-doped SnO2 thin films were deposited on glass substrates by e-beam evaporation using GaN:SnO2 targets of different GaN weight ratios. It is interesting to find that carrier polarity of the thin films was converted from n-type to p-type with increasing GaN ratio higher than 15 wt.%. The n-p transition in GaN-doped SnO2 thin films was explained for the formation of GaSn and NO with increasing GaN doping level in the films, which was identified by Hall measurement and XPS analysis. A transparent thin film p-n junction was successfully fabricated by depositing p-type GaN:SnO2 thin film on SnO2 thin film, and a low leakage current (6.2 × 10-5 A at -4 V) and a low turn-on voltage of 1.69 V were obtained for the p-n junction.

  2. Synthesis of layered birnessite-type manganese oxide thin films on plastic substrates by chemical bath deposition for flexible transparent supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Hu Yu; Zhu Hongwei; Wang Jun [School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Chen Zhenxing, E-mail: chenzx65@mail.sysu.edu.cn [School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

    2011-10-20

    Highlights: > Layered birnessite-type MnO{sub 2} thin films are fabricated on ITO/PET substrates through a facile chemical bath deposition at room temperature. > The transmittance of the MnO{sub 2} thin films at 550 nm is up to 77.4%. > MnO{sub 2} thin films exhibit a special capacitance of 229.2 F g{sup -1} and 9.2 mF cm{sup -2}. > MnO{sub 2} thin films show a capacitance retention ratio of 83% after 1000 CV cycles. > MnO{sub 2} thin film electrodes show great mechanical flexibility and electrochemical stability even after 200 tensile and compressive bending cycles. - Abstract: Layered birnessite-type manganese oxide thin films are successfully fabricated on indium tin oxide coated polyethylene terephthalate substrates for flexible transparent supercapacitors by a facile, effective and inexpensive chemical bath deposition technology from an alkaline KMnO{sub 4} aqueous solution at room temperature. The effects of deposition conditions, including KMnO{sub 4} concentration, initial molar ratio of NH{sub 3}.H{sub 2}O and KMnO{sub 4}, bath temperature, and reaction time, on the electrochemical properties of MnO{sub 2} thin films are investigated. Layered birnessite-type MnO{sub 2} thin films deposited under optimum conditions display three-dimensional porous morphology, high hydrophilicity, and a transmittance of 77.4% at 550 nm. A special capacitance of 229.2 F g{sup -1} and a capacitance retention ratio of 83% are obtained from the films after 1000 cycles at 10 mV s{sup -1} in 1 M Na{sub 2}SO{sub 4}. Compressive and tensile bending tests show that as-prepared MnO{sub 2} thin film electrodes possess excellent mechanical flexibility and electrochemical stability.

  3. P-type thin films transistors with solution-deposited lead sulfide films as semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Carrillo-Castillo, A.; Salas-Villasenor, A.; Mejia, I. [Department of Materials Science and Engineering, The University of Texas at Dallas. 800 West Campbell Rd, Richardson, TX 75083 (United States); Aguirre-Tostado, S. [Centro de Investigacion en Materiales Avanzados, S. C. Alianza Norte 202, Parque de Investigacion e Innovacion Tecnologica, Apodaca, Nuevo Leon, C.P. 666000 (Mexico); Gnade, B.E. [Department of Materials Science and Engineering, University of Texas at Dallas. 800 West Campbell Rd, Richardson, TX 75083 (United States); Quevedo-Lopez, M.A., E-mail: mxq071000@utdallas.edu [Department of Materials Science and Engineering, University of Texas at Dallas. 800 West Campbell Rd, Richardson, TX 75083 (United States)

    2012-01-31

    In this paper we demonstrate p-type thin film transistors fabricated with lead sulfide (PbS) as semiconductor deposited by chemical bath deposition methods. Crystallinity and morphology of the resulting PbS films were characterized using X-ray diffraction, atomic force microscopy and scanning electron microscopy. Devices were fabricated using photolithographic processes in a bottom gate configuration with Au as source and drain top contacts. Field effect mobility for as-fabricated devices was {approx} 0.09 cm{sup 2} V{sup -1} s{sup -1} whereas the mobility for devices annealed at 150 Degree-Sign C/h in forming gas increased up to {approx} 0.14 cm{sup 2} V{sup -1} s{sup -1}. Besides the thermal annealing, the entire fabrications process was maintained below 100 Degree-Sign C. The electrical performance of the PbS-thin film transistors was studied before and after the 150 Degree-Sign C anneal as well as a function of the PbS active layer thicknesses. - Highlights: Black-Right-Pointing-Pointer Thin film transistors with PbS as semiconductor deposited by chemical bath deposition. Black-Right-Pointing-Pointer Photolithography-based thin film transistors with PbS films at low temperatures. Black-Right-Pointing-Pointer Electron mobility for anneal-PbS devices of {approx} 0.14 cm{sup 2} V{sup -1} s{sup -1}. Black-Right-Pointing-Pointer Highest mobility reported in thin film transistors with PbS as the semiconductor.

  4. Azaisoindigo conjugated polymers for high performance n-type and ambipolar thin film transistor applications

    KAUST Repository

    Yue, Wan

    2016-09-28

    Two new alternating copolymers, PAIIDBT and PAIIDSe have been prepared by incorporating a highly electron deficient azaisoindigo core. The molecular structure and packing of the monomer is determined from the single crystal X-ray diffraction. Both polymers exhibit high EAs and highly planar polymer backbones. When polymers are used as the semiconducting channel for solution-processed thin film transistor application, good properties are observed. A–A type PAIIDBT exhibits unipolar electron mobility as high as 1.0 cm2 V−1 s−1, D–A type PAIIDSe exhibits ambipolar charge transport behavior with predominately electron mobility up to 0.5 cm2 V−1 s−1 and hole mobility to 0.2 cm2 V−1 s−1. The robustness of the extracted mobility values are also commented on in detail. Molecular orientation, thin film morphology and energetic disorder of both polymers are systematically investigated.

  5. Skyrmion burst and multiple quantum walk in thin ferromagnetic films

    International Nuclear Information System (INIS)

    Ezawa, Motohiko

    2011-01-01

    We propose a new type of quantum walk in thin ferromagnetic films. A giant Skyrmion collapses to a singular point in a thin ferromagnetic film, emitting spin waves, when external magnetic field is increased beyond the critical one. After the collapse the remnant is a quantum walker carrying spin S. We determine its time evolution and show the diffusion process is a continuous-time quantum walk. We also analyze an interference of two quantum walkers after two Skyrmion bursts. The system presents a new type of quantum walk for S>1/2, where a quantum walker breaks into 2S quantum walkers. -- Highlights: → A giant Skyrmion collapses to a singular point by applying strong magnetic field. → Quantum walk is realized in thin ferromagnetic films by Skyrmion collapsing. → Quantum walks for S=1/2 and 1 are exact solvable, where S represents the spin. → Quantum walks for >1/2 presents a new type of quantum walks, i.e., 'multiple quantum walks'. → Skyrmion bursts which occur simultaneously exhibit an interference as a manifestation of quantum walk.

  6. Effect of doping concentration on the conductivity and optical properties of p-type ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Pathak, Trilok Kumar [Semiconductor Research Lab, Department of Physics, Gurukula Kangri University, Haridwar (India); Kumar, Vinod, E-mail: vinod.phy@gmail.com [Department of Physics, University of the Free State, Bloemfontein (South Africa); Swart, H.C., E-mail: swarthc@ufs.ac.za [Department of Physics, University of the Free State, Bloemfontein (South Africa); Purohit, L.P., E-mail: proflppurohitphys@gmail.com [Semiconductor Research Lab, Department of Physics, Gurukula Kangri University, Haridwar (India)

    2016-01-01

    Nitrogen doped ZnO (NZO) thin films were synthesized on glass substrates by the sol–gel and spin coating method. Zinc acetate dihydrates and ammonium acetate were used as precursors for zinc and nitrogen, respectively. X-ray diffraction study showed that the thin films have a hexagonal wurtzite structure corresponding (002) peak for undoped and doped ZnO thin films. The transmittance of the films was above 80% and the band gap of the film varies from 3.21±0.03 eV for undoped and doped ZnO. The minimum resistivity of NZO thin films was obtained as 0.473 Ω cm for the 4 at% of nitrogen (N) doping with a mobility of 1.995 cm{sup 2}/V s. The NZO thin films showed p-type conductivity at 2 and 3 at% of N doping. The AC conductivity measurements that were carried out in the frequency range 10 kHz to 0.1 MHz showed localized conduction in the NZO thin films. These highly transparent ZnO films can be used as a possible window layer in solar cells.

  7. Roughness analysis applied to niobium thin films grown on MgO(001) surfaces for superconducting radio frequency cavity applications

    Energy Technology Data Exchange (ETDEWEB)

    Beringer, D. B. [College of William and Mary, Williamsburg, VA (United States). Dept. of Physics; Roach, W. M. [College of William and Mary, Williamsburg, VA (United States). Dept. of Applied Science; Clavero, C. [College of William and Mary, Williamsburg, VA (United States). Dept. of Applied Science; Reece, C. E. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Lukaszew, R. A. [College of William and Mary, Williamsburg, VA (United States). Dept. of Physics; College of William and Mary, Williamsburg, VA (United States). Dept. of Applied Science

    2013-02-05

    This paper describes surface studies to address roughness issues inherent to thin film coatings deposited onto superconducting radio frequency (SRF) cavities. This is particularly relevant for multilayered thin film coatings that are being considered as a possible scheme to overcome technical issues and to surpass the fundamental limit of ~500 MV/m accelerating gradient achievable with bulk niobium. In 2006, a model by Gurevich [ Appl. Phys. Lett. 88 012511 (2006)] was proposed to overcome this limit that involves coating superconducting layers separated by insulating ones onto the inner walls of the cavities. Thus, we have undertaken a systematic effort to understand the dynamic evolution of the Nb surface under specific deposition thin film conditions onto an insulating surface in order to explore the feasibility of the proposed model. We examine and compare the morphology from two distinct Nb/MgO series, each with its own epitaxial registry, at very low growth rates and closely examine the dynamical scaling of the surface features during growth. Further, we apply analysis techniques such as power spectral density to the specific problem of thin film growth and roughness evolution to qualify the set of deposition conditions that lead to successful SRF coatings.

  8. The limitations on applying classical thin plate theory to thin annular plates clamped on the inner boundary

    Directory of Open Access Journals (Sweden)

    Daniel W. Zietlow

    2012-12-01

    Full Text Available The experimentally measured resonance frequencies of a thin annular plate with a small ratio of inner to outer radii and clamped on the inner boundary are compared to the predictions of classical thin-plate (CTP theory and a finite-element (FE model. The results indicate that, contrary to the conclusions presented in a number of publications, CTP theory does not accurately predict the frequencies of a relatively small number of resonant modes at lower frequencies. It is shown that these inaccuracies are attributable to shear deformations, which are thought to be negligible in thin plates and are neglected in CTP theory. Of particular interest is the failure of CTP theory to accurately predict the resonance frequency of the lowest vibrational mode, which was shifted approximately 30% by shear motion at the inner boundary.

  9. Contribution of apparently non-operating loadings to the buckling of thin shells and plates

    International Nuclear Information System (INIS)

    Delaigue, Didier.

    1980-02-01

    This work includes four parts: in the first part, the Kirchhoff-Love theory of thin shells is described, a theory taken up and developed by Koiter and whose modelling seems to meet the problems of engineers. The second part deals with the buckling of a thin plate subjected to a load along a part of its edge, of which a part or all is seemingly inoperative. In the third part the study is extended to shells of any shape subjected to a conservative loading of the ''dead-loading'' type along part of their edges. On the basis of the results of the previous study, a study is then made on the taking into account of any load applied to the edge of a thin shell. In the fourth part the previous results are applied to the study of the buckling of a thin shell with a circular base subjected along a part of its edge to a normal prestress and to twisting moments linear density [fr

  10. Dual-bath electrodeposition of n-type Bi–Te/Bi–Se multilayer thin films

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Ken; Okuhata, Mitsuaki; Takashiri, Masayuki, E-mail: takashiri@tokai-u.jp

    2015-11-15

    N-type Bi–Te/Bi–Se multilayer thin films were prepared by dual-bath electrodeposition. We varied the number of layers from 2 to 10 while the total film thickness was maintained at approximately 1 μm. All the multilayer films displayed the X-ray diffraction peaks normally observed from individual Bi{sub 2}Te{sub 3} and Bi{sub 2}Se{sub 3} crystal structures, indicating that both phases coexist in the multilayer. The cross-section of the 10-layer Bi–Te/Bi–Se film was composed of stacked layers with nano-sized grains but the boundaries between the layers were not planar. The Seebeck coefficient was almost constant throughout the entire range of our experiment, but the electrical conductivity of the multilayer thin films increased significantly as the number of layers was increased. This may be because the electron mobility increases as the thickness of each layer is decreased. As a result of the increased electrical conductivity, the power factor also increased with the number of layers. The maximum power factor was 1.44 μW/(cm K{sup 2}) for the 10-layer Bi–Te/Bi–Se film, this was approximately 3 times higher than that of the 2-layer sample. - Highlights: • N-type Bi–Te/Bi–Se multilayer thin films were deposited by electrodeposition. • We employed a dual-bath electrodeposition process for preparing the multilayers. • The Bi–Te/Bi–Se film was composed of stacked layers with nano-sized grains. • The electrical conductivity increased as the number of layers was increased. • The power factor improved by 3 times as the number of layers was increased.

  11. Roughness analysis applied to niobium thin films grown on MgO(001) surfaces for superconducting radio frequency cavity applications

    Science.gov (United States)

    Beringer, D. B.; Roach, W. M.; Clavero, C.; Reece, C. E.; Lukaszew, R. A.

    2013-02-01

    This paper describes surface studies to address roughness issues inherent to thin film coatings deposited onto superconducting radio frequency (SRF) cavities. This is particularly relevant for multilayered thin film coatings that are being considered as a possible scheme to overcome technical issues and to surpass the fundamental limit of ˜50MV/m accelerating gradient achievable with bulk niobium. In 2006, a model by Gurevich [Appl. Phys. Lett. 88, 012511 (2006)APPLAB0003-695110.1063/1.2162264] was proposed to overcome this limit that involves coating superconducting layers separated by insulating ones onto the inner walls of the cavities. Thus, we have undertaken a systematic effort to understand the dynamic evolution of the Nb surface under specific deposition thin film conditions onto an insulating surface in order to explore the feasibility of the proposed model. We examine and compare the morphology from two distinct Nb/MgO series, each with its own epitaxial registry, at very low growth rates and closely examine the dynamical scaling of the surface features during growth. Further, we apply analysis techniques such as power spectral density to the specific problem of thin film growth and roughness evolution to qualify the set of deposition conditions that lead to successful SRF coatings.

  12. Roughness analysis applied to niobium thin films grown on MgO(001 surfaces for superconducting radio frequency cavity applications

    Directory of Open Access Journals (Sweden)

    D. B. Beringer

    2013-02-01

    Full Text Available This paper describes surface studies to address roughness issues inherent to thin film coatings deposited onto superconducting radio frequency (SRF cavities. This is particularly relevant for multilayered thin film coatings that are being considered as a possible scheme to overcome technical issues and to surpass the fundamental limit of ∼50  MV/m accelerating gradient achievable with bulk niobium. In 2006, a model by Gurevich [Appl. Phys. Lett. 88, 012511 (2006APPLAB0003-695110.1063/1.2162264] was proposed to overcome this limit that involves coating superconducting layers separated by insulating ones onto the inner walls of the cavities. Thus, we have undertaken a systematic effort to understand the dynamic evolution of the Nb surface under specific deposition thin film conditions onto an insulating surface in order to explore the feasibility of the proposed model. We examine and compare the morphology from two distinct Nb/MgO series, each with its own epitaxial registry, at very low growth rates and closely examine the dynamical scaling of the surface features during growth. Further, we apply analysis techniques such as power spectral density to the specific problem of thin film growth and roughness evolution to qualify the set of deposition conditions that lead to successful SRF coatings.

  13. Measurement errors for thermocouples attached to thin plates

    International Nuclear Information System (INIS)

    Sobolik, K.B.; Keltner, N.R.; Beck, J.V.

    1989-01-01

    This paper discusses Unsteady Surface Element (USE) methods which are applied to a model of a thermocouple wire attached to a thin disk. Green's functions are used to develop the integral equations for the wire and the disk. The model can be used to evaluate transient and steady state responses for many types of heat flux measurement devices including thin skin calorimeters and circular foil (Gardon) head flux gauges. The model can accommodate either surface or volumetric heating of the disk. The boundary condition at the outer radius of the disk can be either insulated or constant temperature. Effect on the errors of geometrical and thermal factors can be assessed. Examples are given

  14. NMR characterization of thin films

    Science.gov (United States)

    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.

  15. NMR characterization of thin films

    Science.gov (United States)

    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.

  16. An Applied Method for Predicting the Load-Carrying Capacity in Compression of Thin-Wall Composite Structures with Impact Damage

    Science.gov (United States)

    Mitrofanov, O.; Pavelko, I.; Varickis, S.; Vagele, A.

    2018-03-01

    The necessity for considering both strength criteria and postbuckling effects in calculating the load-carrying capacity in compression of thin-wall composite structures with impact damage is substantiated. An original applied method ensuring solution of these problems with an accuracy sufficient for practical design tasks is developed. The main advantage of the method is its applicability in terms of computing resources and the set of initial data required. The results of application of the method to solution of the problem of compression of fragments of thin-wall honeycomb panel damaged by impacts of various energies are presented. After a comparison of calculation results with experimental data, a working algorithm for calculating the reduction in the load-carrying capacity of a composite object with impact damage is adopted.

  17. Applying Emax model and bivariate thin plate splines to assess drug interactions.

    Science.gov (United States)

    Kong, Maiying; Lee, J Jack

    2010-01-01

    We review the semiparametric approach previously proposed by Kong and Lee and extend it to a case in which the dose-effect curves follow the Emax model instead of the median effect equation. When the maximum effects for the investigated drugs are different, we provide a procedure to obtain the additive effect based on the Loewe additivity model. Then, we apply a bivariate thin plate spline approach to estimate the effect beyond additivity along with its 95 per cent point-wise confidence interval as well as its 95 per cent simultaneous confidence interval for any combination dose. Thus, synergy, additivity, and antagonism can be identified. The advantages of the method are that it provides an overall assessment of the combination effect on the entire two-dimensional dose space spanned by the experimental doses, and it enables us to identify complex patterns of drug interaction in combination studies. In addition, this approach is robust to outliers. To illustrate this procedure, we analyzed data from two case studies.

  18. Compositional ratio effect on the surface characteristics of CuZn thin films

    Science.gov (United States)

    Choi, Ahrom; Park, Juyun; Kang, Yujin; Lee, Seokhee; Kang, Yong-Cheol

    2018-05-01

    CuZn thin films were fabricated by RF co-sputtering method on p-type Si(100) wafer with various RF powers applied on metallic Cu and Zn targets. This paper aimed to determine the morphological, chemical, and electrical properties of the deposited CuZn thin films by utilizing a surface profiler, atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), UV photoelectron spectroscopy (UPS), and a 4-point probe. The thickness of the thin films was fixed at 200 ± 8 nm and the roughness of the thin films containing Cu was smaller than pure Zn thin films. XRD studies confirmed that the preferred phase changed, and this tendency is dependent on the ratio of Cu to Zn. AES spectra indicate that the obtained thin films consisted of Cu and Zn. The high resolution XPS spectra indicate that as the content of Cu increased, the intensities of Zn2+ decreased. The work function of CuZn thin films increased from 4.87 to 5.36 eV. The conductivity of CuZn alloy thin films was higher than pure metallic thin films.

  19. Controlled oxygen vacancy induced p-type conductivity in HfO{sub 2-x} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrandt, Erwin; Kurian, Jose; Mueller, Mathis M.; Kleebe, Hans-Joachim; Alff, Lambert [Institute of Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany); Schroeder, Thomas [IHP, 15236 Frankfurt/Oder (Germany)

    2011-09-12

    We have synthesized highly oxygen deficient HfO{sub 2-x} thin films by controlled oxygen engineering using reactive molecular beam epitaxy. Above a threshold value of oxygen vacancies, p-type conductivity sets in with up to 6 times 10{sup 21} charge carriers per cm{sup 3}. At the same time, the band-gap is reduced continuously by more than 1 eV. We suggest an oxygen vacancy induced p-type defect band as origin of the observed behavior.

  20. Controlled p-type to n-type conductivity transformation in NiO thin films by ultraviolet-laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Pranav; Dutta, Titas; Mal, Siddhartha; Narayan, Jagdish [Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27606 (United States)

    2012-01-01

    We report the systematic changes in structural, electrical, and optical properties of NiO thin films on c-sapphire introduced by nanosecond ultraviolet excimer laser pulses. Epitaxial nature of as deposited NiO was determined by x-ray diffraction phi scans and transmission electron microscopy (TEM) and it was established that NiO film growth takes place with twin domains on sapphire where two types of domains have 60 deg. in-plane rotation with respect to each other about the [111] growth direction. We determined that at pulsed laser energy density of 0.275 J/cm{sup 2}, NiO films exhibited conversion from p-type semiconducting to n-type conductive behavior with three orders of magnitude decrease in resistivity, while maintaining its cubic crystal structure and good epitaxial relationship. Our TEM and electron-energy-loss spectroscopy studies conclusively ruled out the presence of any Ni clustering or precipitation due to the laser treatment. The laser-induced n-type carrier transport and conductivity enhancement were shown to be reversible through subsequent thermal annealing in oxygen. This change in conductivity behavior was correlated with the nonequilibrium concentration of laser induced Ni{sup 0}-like defect states.

  1. MUSIC-type imaging of a thin penetrable inclusion from its multi-static response matrix

    International Nuclear Information System (INIS)

    Park, Won-Kwang; Lesselier, Dominique

    2009-01-01

    The imaging of a thin inclusion, with dielectric and/or magnetic contrasts with respect to the embedding homogeneous medium, is investigated. A MUSIC-type algorithm operating at a single time-harmonic frequency is developed in order to map the inclusion (that is, to retrieve its supporting curve) from scattered field data collected within the multi-static response matrix. Numerical experiments carried out for several types of inclusions (dielectric and/or magnetic ones, straight or curved ones), mostly single inclusions and also two of them close by as a straightforward extension, illustrate the pros and cons of the proposed imaging method

  2. MUSIC-type imaging of a thin penetrable inclusion from its multi-static response matrix

    Science.gov (United States)

    Park, Won-Kwang; Lesselier, Dominique

    2009-07-01

    The imaging of a thin inclusion, with dielectric and/or magnetic contrasts with respect to the embedding homogeneous medium, is investigated. A MUSIC-type algorithm operating at a single time-harmonic frequency is developed in order to map the inclusion (that is, to retrieve its supporting curve) from scattered field data collected within the multi-static response matrix. Numerical experiments carried out for several types of inclusions (dielectric and/or magnetic ones, straight or curved ones), mostly single inclusions and also two of them close by as a straightforward extension, illustrate the pros and cons of the proposed imaging method.

  3. In situ growth of p and n-type graphene thin films and diodes by pulsed laser deposition

    KAUST Repository

    Sarath Kumar, S. R.; Nayak, Pradipta K.; Hedhili, Mohamed N.; Khan, M. A.; Alshareef, Husam N.

    2013-01-01

    We report the in situ growth of p and n-type graphene thin films by ultraviolet pulsed laser deposition in the presence of argon and nitrogen, respectively. Electron microscopy and Raman studies confirmed the growth, while temperature dependent

  4. Pseudo-cubic thin-plate type Spline method for analyzing experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Crecy, F de

    1994-12-31

    A mathematical tool, using pseudo-cubic thin-plate type Spline, has been developed for analysis of experimental data points. The main purpose is to obtain, without any a priori given model, a mathematical predictor with related uncertainties, usable at any point in the multidimensional parameter space. The smoothing parameter is determined by a generalized cross validation method. The residual standard deviation obtained is significantly smaller than that of a least square regression. An example of use is given with critical heat flux data, showing a significant decrease of the conception criterion (minimum allowable value of the DNB ratio). (author) 4 figs., 1 tab., 7 refs.

  5. Pseudo-cubic thin-plate type Spline method for analyzing experimental data

    International Nuclear Information System (INIS)

    Crecy, F. de.

    1993-01-01

    A mathematical tool, using pseudo-cubic thin-plate type Spline, has been developed for analysis of experimental data points. The main purpose is to obtain, without any a priori given model, a mathematical predictor with related uncertainties, usable at any point in the multidimensional parameter space. The smoothing parameter is determined by a generalized cross validation method. The residual standard deviation obtained is significantly smaller than that of a least square regression. An example of use is given with critical heat flux data, showing a significant decrease of the conception criterion (minimum allowable value of the DNB ratio). (author) 4 figs., 1 tab., 7 refs

  6. Macular thinning in prediabetes or type 2 diabetes without diabetic retinopathy: the Maastricht Study.

    Science.gov (United States)

    De Clerck, Eline E B; Schouten, Jan S A G; Berendschot, Tos T J M; Goezinne, Fleur; Dagnelie, Pieter C; Schaper, Nicolaas C; Schram, Miranda T; Stehouwer, Coen D A; Webers, Carroll A B

    2018-03-01

    To assess macular thinning in individuals with prediabetes or type 2 diabetes without diabetic retinopathy (DM2 w/o DR) compared with individuals with normal glucose metabolism (NGM). Using spectral domain optical coherence tomography (SD-OCT), we measured macular thickness in six subfields as defined by the Early Treatment Diabetic Retinopathy Study (ETDRS) in 1838 participants from The Maastricht Study, a population-based cohort study (mean age 59 ± 8 years, 49% men, 1087 NGM, 279 prediabetes, 472 DM2 w/o DR). Multivariable linear regression was used to assess the association between macular thickness and glucose metabolism status. After adjustment for age, sex and spherical equivalent, individuals with prediabetes showed a significant decrease in pericentral superior macular thickness [β = -2.14 μm (95% confidence interval (CI): -4.24 to -0.03), p < 0.05] compared with individuals with NGM. In individuals with DM2 w/o DR, the fovea [β = -4.05 μm (95% CI: -6.30 to -1.79), p < 0.001] and the four pericentral quadrants (range: β = -4.64 to -5.29 μm, p < 0.001) were significantly thinner compared with individuals with NGM. There was a significant linear trend of macular thinning with severity of glucose metabolism status in five subfields (p < 0.001). Macular thickness is reduced in prediabetes and a greater reduction occurs in DM2, even before DR is clinically present. About half of the thinning observed in DM2 w/o DR was already found in prediabetes. Generalized thinning of the macula could be related to thinning of the temporal side of the optic nerve head through the connecting papillo-macular bundle. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  7. Inkjet-printed p-type nickel oxide thin-film transistor

    Science.gov (United States)

    Hu, Hailong; Zhu, Jingguang; Chen, Maosheng; Guo, Tailiang; Li, Fushan

    2018-05-01

    High-performance inkjet-printed nickel oxide thin-film transistors (TFTs) with Al2O3 high-k dielectric have been fabricated using a sol-gel precursor ink. The "coffee ring" effect during the printing process was facilely restrained by modifying the viscosity of the ink to control the outward capillary flow. The impacts on the device performance was studied in detail in consideration of annealing temperature of the nickel oxide film and the properties of dielectric layer. The optimized switching ability of the device were achieved at an annealing temperature of 280 °C on a 50-nm-thick Al2O3 dielectric layer, with a hole mobility of 0.78 cm2/V·s, threshold voltage of -0.6 V and on/off current ratio of 5.3 × 104. The as-printed p-type oxide TFTs show potential application in low-cost, large-area complementary electronic devices.

  8. Thin-film limit formalism applied to surface defect absorption

    Czech Academy of Sciences Publication Activity Database

    Holovský, Jakub; Ballif, C.

    2014-01-01

    Roč. 22, č. 25 (2014), s. 31466-31472 ISSN 1094-4087 R&D Projects: GA MŠk 7E12029; GA ČR(CZ) GA14-05053S EU Projects: European Commission(XE) 283501 - Fast Track Institutional support: RVO:68378271 Keywords : optical properties * absorption * thin films Subject RIV: BH - Optics , Masers, Lasers Impact factor: 3.488, year: 2014

  9. Study Of The Wet Multipass Drawing Process Applied On High Strength Thin Steel Wires

    Science.gov (United States)

    Thimont, J.; Felder, E.; Bobadilla, C.; Buessler, P.; Persem, N.; Vaubourg, JP.

    2011-05-01

    Many kinds of high strength thin steel wires are involved in so many applications. Most of the time, these wires are made of a pearlitic steel grade. The current developments mainly concern the wire last drawing operation: after a patenting treatment several reduction passes are performed on a slip-type multipass drawing machine. This paper focuses on modeling this multipass drawing process: a constitutive law based on the wire microstructure evolutions is created, a mechanical study is performed, a set of experiments which enables determining the process friction coefficients is suggested and finally the related analytical model is introduced. This model provides several general results about the process and can be used in order to set the drawing machines.

  10. Highly conducting p-type nanocrystalline silicon thin films preparation without additional hydrogen dilution

    Science.gov (United States)

    Patra, Chandralina; Das, Debajyoti

    2018-04-01

    Boron doped nanocrystalline silicon thin film has been successfully prepared at a low substrate temperature (250 °C) in planar inductively coupled RF (13.56 MHz) plasma CVD, without any additional hydrogen dilution. The effect of B2H6 flow rate on structural and electrical properties of the films has been studied. The p-type nc-Si:H films prepared at 5 ≤ B2H6 (sccm) ≤ 20 retains considerable amount of nanocrystallites (˜80 %) with high conductivity ˜101 S cm-1 and dominant crystallographic orientation which has been correlated with the associated increased ultra- nanocrystalline component in the network. Such properties together make the material significantly effective for utilization as p-type emitter layer in heterojunction nc-Si solar cells.

  11. Fabrication of air-stable n-type carbon nanotube thin-film transistors on flexible substrates using bilayer dielectrics.

    Science.gov (United States)

    Li, Guanhong; Li, Qunqing; Jin, Yuanhao; Zhao, Yudan; Xiao, Xiaoyang; Jiang, Kaili; Wang, Jiaping; Fan, Shoushan

    2015-11-14

    Single-walled carbon nanotube (SWNT) thin-film transistors hold great potential for flexible electronics. However, fabrication of air-stable n-type devices by methods compatible with standard photolithography on flexible substrates is challenging. Here, we demonstrated that by using a bilayer dielectric structure of MgO and atomic layer deposited (ALD) Al2O3 or HfO2, air-stable n-type devices can be obtained. The mechanism for conduction type conversion was elucidated and attributed to the hole depletion in SWNT, the decrease of the trap state density by MgO assimilating adsorbed water molecules in the vicinity of SWNT, and the energy band bending because of the positive fixed charges in the ALD layer. The key advantage of the method is the relatively low temperature (120 or 90 °C) required here for the ALD process because we need not employ this step to totally remove the absorbates on the SWNTs. This advantage facilitates the integration of both p-type and n-type transistors through a simple lift off process and compact CMOS inverters were demonstrated. We also demonstrated that the doping of SWNTs in the channel plays a more important role than the Schottky barriers at the metal contacts in carbon nanotube thin-film transistors, unlike the situation in individual SWNT-based transistors.

  12. Matérn thinned Cox processes

    DEFF Research Database (Denmark)

    Andersen, Ina Trolle; Hahn, Ute

    2016-01-01

    and hard core behaviour can be achieved by applying a dependent Matérn thinning to a Cox process. An exact formula for the intensity of a Matérn thinned shot noise Cox process is derived from the Palm distribution. For the more general class of Matérn thinned Cox processes, formulae for the intensity...

  13. Matérn thinned Cox processes

    DEFF Research Database (Denmark)

    Andersen, Ina Trolle; Hahn, Ute

    of clustering and hard core behaviour can be achieved by applying a dependent Matérn thinning to a Cox process. An exact formula for the intensity of a Matérn thinned shot noise Cox process is derived from the Palm distribution. For the more general class of Matérn thinned Cox processes, formulae...

  14. Consideration of BORAX-type reactivity accidents applied to research reactors

    International Nuclear Information System (INIS)

    Couturier, Jean; Meignen, Renaud; Bourgois, Thierry; Biaut, Guillaume; Mireau, Jean-Pierre; Natta, Marc

    2011-01-01

    Most of the research reactors discussed in this document are pool-type reactors in which the reactor vessel and some of the reactor coolant systems are located in a pool of water. These reactors generally use fuel in plate assemblies formed by a compact layer of uranium (or U 3 Si 2 ) and aluminium particles, sandwiched between two thin layers of aluminium serving as cladding. The fuel melting process begins at 660 deg. C when the aluminium melts, while the uranium (or U 3 Si 2 ) particles may remain solid. The accident that occurred in the American SL-1 reactor in 1961, together with tests carried out in the United States as of 1954 in the BORAX-1 reactor and then, in 1962, in the SPERT-1 reactor, showed that a sudden substantial addition of reactivity in this type of reactor could lead to explosive mechanisms caused by degradation, or even fast meltdown, of part of the reactor core. This is what is known as a 'BORAX-type' accident. The aim of this document is first to briefly recall the circumstances of the SL-1 reactor accident, the lessons learned, how this operational feedback has been factored into the design of various research reactors around the world and, second, to describe the approach taken by France with regard to this type of accident and how, led by IRSN, this approach has evolved in the last decade. (authors)

  15. [Ideal type and history--a critical review of applied criminology].

    Science.gov (United States)

    Köchel, Stefan

    2013-01-01

    Applied Criminology describes an established criminological school in the German-speaking area, which was founded by Hans Göppinger and Michael Bock, criminologists at Tübingen, in the 1980s and has meanwhile published a number of comprehensive basic methodological papers. The conceptual centrepiece with interdisciplinary approach is the formation and application of concepts referring to the so-called ideal type, which has been essentially inspired by the epistemology of Max Weber. However, the result of a critical reconstruction of these fundamentals is that the claimed interdisciplinary approach comes into conflict with a second much more phenomenological approach of Applied Criminology which is unable to comply with the political implications of criminological research and thus disavows the necessary historical relationality of the ideal type concepts.

  16. Evaluation of local allowable wall thickness of thinned pipe considering internal pressure and bending moment

    International Nuclear Information System (INIS)

    Kim, J. W.; Park, C. Y.; Kim, B. Y.

    2000-01-01

    This study proposed the local allowable wall thickness (LAWT) evaluation method for local wall thinned pipe subjected by internal pressure and bending moment. Also, LAWT was evaluated for simplified thinned pipe and the effect of axial extent of thinned area on LAWT was investigated. The results showed that LAWT predicted by present method was thinner, about 50%, than that evaluated by construction code and ASME Code Case N-597, while it was thicker, about 2 times, than that calculated by evaluation model based on pipe experiments. LAWT decreased with increasing axial extent of thinned area and was saturated above axial extent of pipe radius, which was a contrast to the results of ASME Code Case N-597 evaluation. The results of stress analysis with applied loading type indicated that the effect of axial extent of thinned area on LAWT was dependent on loading type considering in the evaluation. That is, the dependence of axial extent on LAWT is determined by magnitude of bending moment, and the contrary trend with axial extent in ASME Code Case is because ASME Code Case N-597 considers only internal pressure in the evaluation

  17. In situ growth of p and n-type graphene thin films and diodes by pulsed laser deposition

    KAUST Repository

    Sarath Kumar, S. R.

    2013-11-07

    We report the in situ growth of p and n-type graphene thin films by ultraviolet pulsed laser deposition in the presence of argon and nitrogen, respectively. Electron microscopy and Raman studies confirmed the growth, while temperature dependent electrical conductivity and Seebeck coefficient studies confirmed the polarity type of graphene films. Nitrogen doping at different sites of the honeycomb structure, responsible for n-type conduction, is identified using X-ray photoelectron spectroscopy, for films grown in nitrogen. A diode-like rectifying behavior is exhibited by p-n junction diodes fabricated using the graphene films.

  18. SNP typing on the NanoChip electronic microarray

    DEFF Research Database (Denmark)

    Børsting, Claus; Sanchez Sanchez, Juan Jose; Morling, Niels

    2005-01-01

    We describe a single nucleotide polymorphism (SNP) typing protocol developed for the NanoChip electronic microarray. The NanoChip array consists of 100 electrodes covered by a thin hydrogel layer containing streptavidin. An electric currency can be applied to one, several, or all electrodes...

  19. Monitoring of monooctanoyl phosphatidylcholine synthesis by enzymatic acidolysis between soybean phosphatidylcholine and caprylic acid by thin-layer chromatography with a flame ionization detector

    DEFF Research Database (Denmark)

    Vikbjerg, Anders Falk; Mu, Huiling; Xu, Xuebing

    2005-01-01

    Thin-layer chromatography with flame ionization detector (TLC-FID) method was used for monitoring the production of structured phospholipids (ML-type: L-long chain fatty acids; M-medium chain fatty acids) by enzyme-catalyzed acidolysis between soybean phosphatidylcholine (PC) and caprylic acid....... It was found that the structured PC fractionated into 2-3 distinct bands on both plate thin layer chromatography (TLC) and Chromarod TLC. These 3 bands represented PC of LL-type, ML-type and MM-type, respectively. The TLC-FID method was applied in the present study to examine the influence of enzyme dosage...

  20. Cortical thinning in type 2 diabetes mellitus and recovering effects of insulin therapy.

    Science.gov (United States)

    Chen, Zhiye; Sun, Jie; Yang, Yang; Lou, Xin; Wang, Yulin; Wang, Yan; Ma, Lin

    2015-02-01

    The purpose of this study was to explore the brain structural changes in type 2 diabetes and the effect of insulin on the brain using a surface-based cortical thickness analysis. High-resolution three-dimensional T1-weighted fast spoiled gradient recalled echo MRI were obtained from 11 patients with type 2 diabetes before and after insulin therapy. The cortical thickness over the entire brain was calculated, and cross-sectional and longitudinal surface-based cortical thickness analyses were also performed. Regional cortical thinning was demonstrated in the middle temporal gyrus, posterior cingulate gyrus, precuneus, right lateral occipital gyrus and entorhinal cortex bilaterally for patients with type 2 diabetes mellitus compared with normal controls. Cortical thickening was seen in the middle temporal gyrus, entorhinal cortex and left inferior temporal gyrus bilaterally after patients underwent 1 year of insulin therapy. These findings suggest that insulin therapy may have recovering effects on the brain cortex in type 2 diabetes mellitus. The precise mechanism should be investigated further. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Failure mode and fracture behavior evaluation of pipes with local wall thinning subjected to bending load

    International Nuclear Information System (INIS)

    Ahn, Seok Hwan; Nam, Ki Woo; Kim, Seon Jin; Kim, Jin Hwan; Kim, Hyun Soo; Do, Jae Yoon

    2003-01-01

    Fracture behaviors of pipes with local wall thinning are very important for the integrity of nuclear power plant. In pipes of energy plants, sometimes, the local wall thinning may result from severe Erosion-Corrosion (E/C) damage. However, the effects of local wall thinning on strength and fracture behaviors of piping system were not well studied. In this paper, the monotonic bending tests were performed of full-scale carbon steel pipes with local wall thinning. A monotonic bending load was applied to straight pipe specimens by four-point loading at ambient temperature without internal pressure. From the tests, fracture behaviors and fracture strength of locally thinned pipe were manifested systematically. The observed failure modes were divided into four types; ovalization, crack initiation/growth after ovalization, local buckling and crack initiating/growth after local buckling. Also, the strength and the allowable limit of piping system with local wall thinning were evaluated

  2. Preparation of thin films, with base to precursor materials of type Cu-In-Se elaborated by electrodeposition for the solar cells elaboration

    International Nuclear Information System (INIS)

    Fernandez, A.M.

    1999-01-01

    Thin films of chalcogenide compounds are promising because they have excellent optoelectronic characteristics to be applied in solar cells. In particular, CuInSe 2 and Cd Te thin films have shown high solar to electrical conversion efficiency. However, this efficiency is limited by the method of preparation, in this case, physical vapor deposition techniques are used. In order to increase the area of deposition t is necessary to use chemical methods, for example, electrodeposition technique. In this paper, the preparation of Cu-In-Se precursors thin films by electrochemical method is reported. These precursors were used to build solar cells with 7.9 % of efficiency. (Author)

  3. Low-field tunnel-type magnetoresistance properties of polycrystalline and epitaxial La sub 0 sub . sub 6 sub 7 Sr sub 0 sub . sub 3 sub 3 MnO sub 3 thin films

    CERN Document Server

    Shim, I B; Choi, S Y

    2000-01-01

    The low-field tunnel-type magnetoresistance (TMB) properties of sol-gel derived polycrystalline and epitaxial La sub 0 sub . sub 6 sub 7 Sr sub 0 sub . sub 3 sub 3 MnO sub 3 (LSMO) thin films were investigated. The polycrystalline thin films were fabricated on Si (100) with a thermally oxidized SiO sub 2 layer while the epitaxial thin films were grown on LaAlO sub 3 (001) single-crystal substrates. The epitaxial thin films displayed both typical intrinsic colossal magnetoresistance (CMR) and abnormal extrinsic tunnel-type magnetoresistance behaviors. Tunnel-type MR ratio as high as 0.4% were observed in the polycrystalline thin films at a field of 120 Oe at room temperature (300 K) whereas the ratios were less than 0.1% for the epitaxial films in the same field range. The low-field tunnel-type MR of polycrystalline LSMO/SiO sub 2 ?Si (100) thin films originated from the behaviors of the grain-boundary properties.

  4. Dielectric Scattering Patterns for Efficient Light Trapping in Thin-Film Solar Cells.

    Science.gov (United States)

    van Lare, Claire; Lenzmann, Frank; Verschuuren, Marc A; Polman, Albert

    2015-08-12

    We demonstrate an effective light trapping geometry for thin-film solar cells that is composed of dielectric light scattering nanocavities at the interface between the metal back contact and the semiconductor absorber layer. The geometry is based on resonant Mie scattering. It avoids the Ohmic losses found in metallic (plasmonic) nanopatterns, and the dielectric scatterers are well compatible with nearly all types of thin-film solar cells, including cells produced using high temperature processes. The external quantum efficiency of thin-film a-Si:H solar cells grown on top of a nanopatterned Al-doped ZnO, made using soft imprint lithography, is strongly enhanced in the 550-800 nm spectral band by the dielectric nanoscatterers. Numerical simulations are in good agreement with experimental data and show that resonant light scattering from both the AZO nanostructures and the embedded Si nanostructures are important. The results are generic and can be applied on nearly all thin-film solar cells.

  5. Reflectivity and diffraction of X rays applied to organic thin films

    International Nuclear Information System (INIS)

    Rieutord, Francois

    1987-01-01

    This research thesis reports the study of organic thin films by using X-ray-based technologies, and more particularly X-ray reflectivity. After some recalls on X ray diffraction, and on the fabrication of Langmuir-Blodgett films, the author shows how, by combining three X-ray-based techniques, it is possible to study a volume structure of a thin film. He describes the technique of measurement by X- ray reflexivity, its experimental implementation, and methods for result interpretation. In the next part, the author reports the study of peculiar interference effects which are noticed in reflexivity on Langmuir-Blodgett films, and then describes the nature of these films by correlating results of X ray reflexivity with direct observations performed by electronic microscopy on replica [fr

  6. Development of p-type amorphous Cu{sub 1−x}B{sub x}O{sub 2−δ} thin films and fabrication of pn hetero junction

    Energy Technology Data Exchange (ETDEWEB)

    Sanal, K.C., E-mail: sanalcusat@gmail.com [Nanophotonic and Optoelectronic Devices Laboratory, Department of Physics, Cochin University of Science and Technology, Kerala 682022 (India); Inter University Center for Nanomaterials and Devices (IUCND), Cochin University of Science and Technology, Kerala 682022 (India); Center for Advanced Materials, Cochin University of Science and Technology, Kerala 682022 (India); Jayaraj, M.K., E-mail: mkj@cusat.ac.in [Nanophotonic and Optoelectronic Devices Laboratory, Department of Physics, Cochin University of Science and Technology, Kerala 682022 (India); Center for Advanced Materials, Cochin University of Science and Technology, Kerala 682022 (India)

    2014-07-01

    Highlights: • Growth of p-type semiconducting amorphous Cu{sub 1−x}B{sub x}O{sub 2−δ} thin films by co-sputtering. • Atomic percentage of Cu{sub 1−x}B{sub x}O{sub 2−δ} thin films from the XPS analysis. • Variation of bandgap with boron concentration in Cu{sub 1−x}B{sub x}O{sub 2−δ} thin films. • Demonstration of p–n hetero junctions fabricated in the structure n-Si/p-Cu{sub 1−x}B{sub x}O{sub 2−δ}/Au. - Abstract: Transparent conducting amorphous p type Cu{sub 1−x}B{sub x}O{sub 2−δ} thin films were grown by RF magnetron co-sputtering at room temperature, using copper and boron targets in oxygen atmosphere. The structural, electrical as well as optical properties were studied. Composition of the films was analyzed by XPS. Amorphous structure of as deposited films was confirmed by GXRD. Surface morphology of the films was analyzed by AFM studies. p-Type nature and concentration of carriers were investigated by Hall effect measurement. Band gap of the films was found to increase with the atomic content of boron in the film. A p–n hetero junction using p-type Cu{sub 1−x}B{sub x}O{sub 2−δ} and n-type silicon was fabricated in the structure n-Si/p-Cu{sub 1−x}B{sub x}O{sub 2−δ}/Au which showed rectifying behavior. As deposited amorphous Cu{sub 1−x}B{sub x}O{sub 2−δ} thin films with lower carrier concentration can be used as a channel layer for thin film transistors.

  7. Thickness and temperature dependence of electrical resistivity of p-type Bi0.5Sb1.5Te3 thin films prepared by flash evaporation method

    International Nuclear Information System (INIS)

    Duan Xingkai; Yang Junyou; Zhu, W; Fan, X A; Bao, S Q

    2006-01-01

    P-type Bi 0.5 Sb 1.5 Te 3 thin films with thicknesses in the range 80-320 nm have been deposited by the flash evaporation method on glass substrates at 473 K. XRD and field emission scanning electron microscope were performed to characterize the thin films. The results show that the thin films are polycrystalline and the grain size of the thin films increases with increasing thickness of the thin films. Compositional analysis of the thin films was also carried out by energy-dispersive x-ray analysis. A near linear relationship was observed between the electrical resistivity and the inverse thickness of the annealed thin films, and it agrees with Tellier's model. Electrical resistivity of the annealed thin films was studied in the temperature range 300-350 K, and their thermal activation behaviour was characterized, the activation energy for conduction decreases with increasing thickness of the thin films

  8. Preparation and recording characteristics of granular-type perpendicular magnetic recording media with thin intermediate layer

    International Nuclear Information System (INIS)

    Shintaku, K.; Kiya, T.

    2008-01-01

    Granular-type media with thin Ru intermediate layer were prepared on a highly oriented high-B s FeCo soft underlayer (SUL). A CoPt-TiO 2 recording layer on a Ru intermediate layer of only 2 nm had high-crystal orientation, high H c of 6.5 kOe, and a high squareness ratio (SQ) of 0.99. The magnetic property of the SUL was also good. The recording performance was measured for the media with different Ru intermediate thicknesses by using a single-pole-type (SPT) head. The media had large reproduced output even for the Ru intermediate layer thickness of 2 nm

  9. Preparation and recording characteristics of granular-type perpendicular magnetic recording media with thin intermediate layer

    Energy Technology Data Exchange (ETDEWEB)

    Shintaku, K. [Akita Research Institute of Advanced Technology, Akita Prefectural R and D Center, 4-21 Sanuki, Araya, Akita 010-1623 (Japan)], E-mail: shintaku@ait.pref.akita.jp; Kiya, T. [Akita Research Institute of Advanced Technology, Akita Prefectural R and D Center, 4-21 Sanuki, Araya, Akita 010-1623 (Japan)

    2008-11-15

    Granular-type media with thin Ru intermediate layer were prepared on a highly oriented high-B{sub s} FeCo soft underlayer (SUL). A CoPt-TiO{sub 2} recording layer on a Ru intermediate layer of only 2 nm had high-crystal orientation, high H{sub c} of 6.5 kOe, and a high squareness ratio (SQ) of 0.99. The magnetic property of the SUL was also good. The recording performance was measured for the media with different Ru intermediate thicknesses by using a single-pole-type (SPT) head. The media had large reproduced output even for the Ru intermediate layer thickness of 2 nm.

  10. Type of precursor and synthesis of silicon oxycarbide (SiOxCyH) thin films with a surfatron microwave oxygen/argon plasma

    International Nuclear Information System (INIS)

    Walkiewicz-Pietrzykowska, Agnieszka; Espinos, J. P.; Gonzalez-Elipe, Agustin R.

    2006-01-01

    Siliconelike thin films (i.e., SiO x C y H z ) were prepared in a microwave plasma enhanced chemical vapor deposition reactor from structurally different organosilicon precursors [i.e., hexamethyldisiloxane (HMDSO), dimethylsilane (DMS), and tetramethylsilane (TMS)]. The films were deposited at room temperature by using different oxygen/argon ratios in the plasma gas. By changing the type of precursor and the relative concentration of oxygen in the plasma, thin films with different compositions (i.e., O/C ratio) and properties are obtained. In general, raising the oxygen concentration in the plasma produces the progressive removal of the organic moieties from the films whose composition and structure then approach those of silicon dioxide. The deposition rate was highly dependent on the type of precursor, following the order HMDSO>>DMS>TMS. The polarizabilities, optical band gaps, and surface free energy of the films also depended on the thin film composition and structure. It is proposed that the Si-O bonds existing in HMDSO is the main factor controlling the distinct reactivity of this precursor and is also responsible for the different compositions and properties of the SiO x C y H z thin films prepared with very low or no oxygen in the plasma gas

  11. Linking rigid multibody systems via controllable thin fluid films

    DEFF Research Database (Denmark)

    Estupinan, Edgar Alberto; Santos, Ilmar

    2009-01-01

    , this paper gives a theoretical contribution to the combined fields of fluid–structure interaction and vibration control. The methodology is applied to a reciprocating linear compressor, where the dynamics of the mechanical components are described with help of multibody dynamics. The crank is linked......This work deals with the mathematical modelling of multibody systems interconnected via thin fluid films. The dynamics of the fluid films can be actively controlled by means of different types of actuators, allowing significant vibration reduction of the system components. In this framework...... to the rotor via a thin fluid film, where the hydrodynamic pressure is described by the Reynolds equation, which is modified to accommodate the controllable lubrication conditions. The fluid film forces are coupled to the set of nonlinear equations that describes the dynamics of the reciprocating linear...

  12. Enhanced performance of CdS/CdTe thin-film devices through temperature profiling techniques applied to close-spaced sublimation deposition

    Energy Technology Data Exchange (ETDEWEB)

    Xiaonan Li; Sheldon, P.; Moutinho, H.; Matson, R. [National Renewable Energy Lab., Golden, CO (United States)

    1996-05-01

    The authors describe a methodology developed and applied to the close-spaced sublimation technique for thin-film CdTe deposition. The developed temperature profiles consisted of three discrete temperature segments, which the authors called the nucleation, plugging, and annealing temperatures. They have demonstrated that these temperature profiles can be used to grow large-grain material, plug pinholes, and improve CdS/CdTe photovoltaic device performance by about 15%. The improved material and device properties have been obtained while maintaining deposition temperatures compatible with commercially available substrates. This temperature profiling technique can be easily applied to a manufacturing environment by adjusting the temperature as a function of substrate position instead of time.

  13. A Variational approach to thin film hydrodynamics of binary mixtures

    KAUST Repository

    Xu, Xinpeng

    2015-02-04

    In order to model the dynamics of thin films of mixtures, solutions, and suspensions, a thermodynamically consistent formulation is needed such that various coexisting dissipative processes with cross couplings can be correctly described in the presence of capillarity, wettability, and mixing effects. In the present work, we apply Onsager\\'s variational principle to the formulation of thin film hydrodynamics for binary fluid mixtures. We first derive the dynamic equations in two spatial dimensions, one along the substrate and the other normal to the substrate. Then, using long-wave asymptotics, we derive the thin film equations in one spatial dimension along the substrate. This enables us to establish the connection between the present variational approach and the gradient dynamics formulation for thin films. It is shown that for the mobility matrix in the gradient dynamics description, Onsager\\'s reciprocal symmetry is automatically preserved by the variational derivation. Furthermore, using local hydrodynamic variables, our variational approach is capable of introducing diffusive dissipation beyond the limit of dilute solute. Supplemented with a Flory-Huggins-type mixing free energy, our variational approach leads to a thin film model that treats solvent and solute in a symmetric manner. Our approach can be further generalized to include more complicated free energy and additional dissipative processes.

  14. Thin-film photovoltaic technology

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, R.N. [National Renewable Energy Laboratory, Golden, CO (United States)

    2010-07-01

    The high material and processing costs associated with single-crystal and polycrystalline silicon wafers that are commonly used in photovoltaic cells render these modules expensive. This presentation described thin-film solar cell technology as a promising alternative to silicon solar cell technology. Cadmium telluride (CdTe) thin films along with copper, indium, gallium, and selenium (CIGS) thin films have become the leaders in this field. Their large optical absorption coefficient can be attributed to a direct energy gap that allows the use of thin layers (1-2 {mu}m) of active material. The efficiency of thin-film solar cell devices based on CIGS is 20 per cent, compared to 16.7 per cent for thin-film solar cell devices based on CdTe. IBM recently reported an efficiency of 9.7 per cent for a new type of inorganic thin-film solar cell based on a Cu{sub 2}ZnSn(S, Se){sub 4} compound. The efficiency of an organic thin-film solar cell is 7.9 per cent. This presentation included a graph of PV device efficiencies and discussed technological advances in non-vacuum deposited, CIGS-based thin-film solar cells. 1 fig.

  15. Sensitive Capacitive-type Hydrogen Sensor Based on Ni Thin Film in Different Hydrogen Concentrations.

    Science.gov (United States)

    Pour, Ghobad Behzadi; Aval, Leila Fekri; Eslami, Shahnaz

    2018-04-01

    Hydrogen sensors are micro/nano-structure that are used to locate hydrogen leaks. They are considered to have fast response/recovery time and long lifetime as compared to conventional gas sensors. In this paper, fabrication of sensitive capacitive-type hydrogen gas sensor based on Ni thin film has been investigated. The C-V curves of the sensor in different hydrogen concentrations have been reported. Dry oxidation was done in thermal chemical vapor deposition furnace (TCVD). For oxidation time of 5 min, the oxide thickness was 15 nm and for oxidation time 10 min, it was 20 nm. The Ni thin film as a catalytic metal was deposited on the oxide film using electron gun deposition. Two MOS sensors were compared with different oxide film thickness and different hydrogen concentrations. The highest response of the two MOS sensors with 15 nm and 20 nm oxide film thickness in 4% hydrogen concentration was 87.5% and 65.4% respectively. The fast response times for MOS sensors with 15 nm and 20 nm oxide film thickness in 4% hydrogen concentration was 8 s and 21 s, respectively. By increasing the hydrogen concentration from 1% to 4%, the response time for MOS sensor (20nm oxide thickness), was decreased from 28s to 21s. The recovery time was inversely increased from 237s to 360s. The experimental results showed that the MOS sensor based on Ni thin film had a quick response and a high sensitivity.

  16. Indirectly cooled large thin superconducting CDF solenoid

    International Nuclear Information System (INIS)

    Kondo, Kunitaka; Mori, Shigeki; Yoshizaki, Ryozo; Saito, Ryusei; Asano, Katsuhiko.

    1985-01-01

    The manufacturing technique of the indirectly cooled large thin superconducting solenoid for the collider detector facility (CDF solenoid) has been studied through cooperation of University of Tsukuba and the National Laboratory for High Energy Physics of the Ministry of Education of Japan, and the Fermi National Accelerator Laboratory in the U.S. Fabrication and testing of the solenoid has recently been completed by Hitachi. The CDF solenoid has a large-sized thin structure for meeting the requirement by experiments to be applied. Hitachi has thus developed a variety of new technologies including the design standard, coil cooling method, material selection, and manufacturing technique in accordance with experimental data, which were confirmed in a series of analyses and tests made on various prototypes. The CDF solenoid, built using Hitachi's new technologies, is of the world's top class among equipment of this type. This paper outlines the design criteria for the major components employed in the CDF solenoid and the test results of the solenoid. (author)

  17. 41 CFR 102-192.30 - What types of mail does this part apply to?

    Science.gov (United States)

    2010-07-01

    ... 192-MAIL MANAGEMENT Introduction to this Part § 102-192.30 What types of mail does this part apply to... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What types of mail does this part apply to? 102-192.30 Section 102-192.30 Public Contracts and Property Management Federal...

  18. Surface treatment of reinforced cement concrete mixtures of hpcm type

    OpenAIRE

    Vyrozhemsky, V.; Krayushkina, K.

    2006-01-01

    One of the most perspective ways of pavement roughness and durability improvement is the arrangement of thin cement concrete layer surface treatment reinforced with different types of fiber. The name of this material is known abroad as HPCM (High Performance Cementious Materials) durable thin layer concrete pavement in a thickness of 1 cm, dispersion-like reinforced with metal or polymer fibers. To enhance bind properties the stone material grade 3 7mm is applied on the top of concrete surfac...

  19. Evaluation of wall thinning of piping with reinforcing plates using ECT with controlled exciting field

    International Nuclear Information System (INIS)

    Ichihara, Toshiaki; Xie, Shejuan; Uchimoto, Tetsuya; Takagi, Toshiyuki

    2011-01-01

    No effective inspection method exists at present for detection and evaluation of wall thinning under the reinforcing plates to T-tubes in nuclear power plants, and the establishment of the inspection method is highly required. In this study, eddy current testing (ECT) with controlled exciting field is applied to evaluation of wall thinning under the reinforcing plates of T-tubes, and their feasibility is discussed. In order to induce eddy current field in deep region of doubled plates, pulse excitation and probe structures are investigated. Through experiments using specimens simulating tubes with reinforcing plates, it is shown that pulsed ECT and conventional TR type eddy current probe with optimized configuration have a capability of detecting and sizing the wall thinning under reinforcing plates. (author)

  20. Isotropic damage model and serial/parallel mix theory applied to nonlinear analysis of ferrocement thin walls. Experimental and numerical analysis

    Directory of Open Access Journals (Sweden)

    Jairo A. Paredes

    2016-01-01

    Full Text Available Ferrocement thin walls are the structural elements that comprise the earthquake resistant system of dwellings built with this material. This article presents the results drawn from an experimental campaign carried out over full-scale precast ferrocement thin walls that were assessed under lateral static loading conditions. The tests allowed the identification of structural parameters and the evaluation of the performance of the walls under static loading conditions. Additionally, an isotropic damage model for modelling the mortar was applied, as well as the classic elasto-plastic theory for modelling the meshes and reinforcing bars. The ferrocement is considered as a composite material, thus the serial/parallel mix theory is used for modelling its mechanical behavior. In this work a methodology for the numerical analysis that allows modeling the nonlinear behavior exhibited by ferrocement walls under static loading conditions, as well as their potential use in earthquake resistant design, is proposed.

  1. Electrical properties and surface morphology of electron beam evaporated p-type silicon thin films on polyethylene terephthalate for solar cells applications

    Energy Technology Data Exchange (ETDEWEB)

    Ang, P. C.; Ibrahim, K.; Pakhuruddin, M. Z. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, Minden 11800 Penang (Malaysia)

    2015-04-24

    One way to realize low-cost thin film silicon (Si) solar cells fabrication is by depositing the films with high-deposition rate and manufacturing-compatible electron beam (e-beam) evaporation onto inexpensive foreign substrates such as glass or plastic. Most of the ongoing research is reported on e-beam evaporation of Si films on glass substrates to make polycrystalline solar cells but works combining both e-beam evaporation and plastic substrates are still scarce in the literature. This paper studies electrical properties and surface morphology of 1 µm electron beam evaporated Al-doped p-type silicon thin films on textured polyethylene terephthalate (PET) substrate for application as an absorber layer in solar cells. In this work, Si thin films with different doping concentrations (including an undoped reference) are prepared by e-beam evaporation. Energy dispersion X-ray (EDX) showed that the Si films are uniformly doped by Al dopant atoms. With increased Al/Si ratio, doping concentration increased while both resistivity and carrier mobility of the films showed opposite relationships. Root mean square (RMS) surface roughness increased. Overall, the Al-doped Si film with Al/Si ratio of 2% (doping concentration = 1.57×10{sup 16} atoms/cm{sup 3}) has been found to provide the optimum properties of a p-type absorber layer for fabrication of thin film Si solar cells on PET substrate.

  2. Electrical properties and surface morphology of electron beam evaporated p-type silicon thin films on polyethylene terephthalate for solar cells applications

    Science.gov (United States)

    Ang, P. C.; Ibrahim, K.; Pakhuruddin, M. Z.

    2015-04-01

    One way to realize low-cost thin film silicon (Si) solar cells fabrication is by depositing the films with high-deposition rate and manufacturing-compatible electron beam (e-beam) evaporation onto inexpensive foreign substrates such as glass or plastic. Most of the ongoing research is reported on e-beam evaporation of Si films on glass substrates to make polycrystalline solar cells but works combining both e-beam evaporation and plastic substrates are still scarce in the literature. This paper studies electrical properties and surface morphology of 1 µm electron beam evaporated Al-doped p-type silicon thin films on textured polyethylene terephthalate (PET) substrate for application as an absorber layer in solar cells. In this work, Si thin films with different doping concentrations (including an undoped reference) are prepared by e-beam evaporation. Energy dispersion X-ray (EDX) showed that the Si films are uniformly doped by Al dopant atoms. With increased Al/Si ratio, doping concentration increased while both resistivity and carrier mobility of the films showed opposite relationships. Root mean square (RMS) surface roughness increased. Overall, the Al-doped Si film with Al/Si ratio of 2% (doping concentration = 1.57×1016 atoms/cm3) has been found to provide the optimum properties of a p-type absorber layer for fabrication of thin film Si solar cells on PET substrate.

  3. Memory and Electrical Properties of (100-Oriented AlN Thin Films Prepared by Radio Frequency Magnetron Sputtering

    Directory of Open Access Journals (Sweden)

    Maw-Shung Lee

    2014-01-01

    Full Text Available The (100-oriented aluminum nitride (AlN thin films were well deposited onto p-type Si substrate by radio frequency (RF magnetron sputtering method. The optimal deposition parameters were the RF power of 350 W, chamber pressure of 9 mTorr, and nitrogen concentration of 50%. Regarding the physical properties, the microstructure of as-deposited (002- and (100-oriented AlN thin films were obtained and compared by XRD patterns and TEM images. For electrical properties analysis, we found that the memory windows of (100-oriented AlN thin films are better than those of (002-oriented thin films. Besides, the interface and interaction between the silicon and (100-oriented AlN thin films was serious important problem. Finally, the current transport models of the as-deposited and annealed (100-oriented AlN thin films were also discussed. From the results, we suggested and investigated that large memory window of the annealed (100-oriented AlN thin films was induced by many dipoles and large electric field applied.

  4. Hadron-therapy beam monitoring: Towards a new generation of ultra-thin p-type silicon strip detectors

    International Nuclear Information System (INIS)

    Bouterfa, M.; Aouadi, K.; Bertrand, D.; Olbrechts, B.; Delamare, R.; Raskin, J. P.; Gil, E. C.; Flandre, D.

    2011-01-01

    Hadron-therapy has gained increasing interest for cancer treatment especially within the last decade. System commissioning and quality assurance procedures impose to monitor the particle beam using 2D dose measurements. Nowadays, several monitoring systems exist for hadron-therapy but all show a relatively high influence on the beam properties: indeed, most devices consist of several layers of materials that degrade the beam through scattering and energy losses. For precise treatment purposes, ultra-thin silicon strip detectors are investigated in order to reduce this beam scattering. We assess the beam size increase provoked by the Multiple Coulomb Scattering when passing through Si, to derive a target thickness. Monte-Carlo based simulations show a characteristic scattering opening angle lower than 1 mrad for thicknesses below 20 μm. We then evaluated the fabrication process feasibility. We successfully thinned down silicon wafers to thicknesses lower than 10 μm over areas of several cm 2 . Strip detectors are presently being processed and they will tentatively be thinned down to 20 μm. Moreover, two-dimensional TCAD simulations were carried out to investigate the beam detector performances on p-type Si substrates. Additionally, thick and thin substrates have been compared thanks to electrical simulations. Reducing the pitch between the strips increases breakdown voltage, whereas leakage current is quite insensitive to strips geometrical configuration. The samples are to be characterized as soon as possible in one of the IBA hadron-therapy facilities. For hadron-therapy, this would represent a considerable step forward in terms of treatment precision. (authors)

  5. Choroidal thinning in diabetes type 1 detected by 3-dimensional 1060 nm optical coherence tomography.

    Science.gov (United States)

    Esmaeelpour, Marieh; Brunner, Simon; Ansari-Shahrezaei, Siamak; Shahrezaei, Siamak Ansari; Nemetz, Susanne; Povazay, Boris; Kajic, Vedran; Drexler, Wolfgang; Binder, Susanne

    2012-10-03

    To map choroidal (ChT) and retinal thickness (RT) in patients with diabetes type 1 with and without maculopathy and retinopathy in order to compare them with healthy subjects using high speed 3-dimensional (3D) 1060 nm optical coherence tomography (OCT). Thirty-three eyes from 33 diabetes type 1 subjects (23-57 years, 15 male) divided into groups of without pathology (NDR) and with pathology (DR; including microaneurysms, exudates, clinically significant macular-oedema and proliferative retinopathy) were compared with 20 healthy axial eye length and age-matched subjects (24-57 years, 9 male), imaged by high speed (60.000 A-scans/s) 3D 1060 nm OCT performed over 36° × 36° field of view. Ocular health status, disease duration, body mass index, haemoglobin-A1c, and blood pressure (bp) measurements were recorded. Subfoveal ChT, and 2D topographic maps between retinal pigment epithelium and the choroidal/scleral-interface, were automatically generated and statistically analyzed. Subfoveal ChT (mean ± SD, μm) for healthy eyes was 388 ± 109; significantly thicker than all diabetic groups, 291 ± 64 for NDR, and 303 ± 82 for DR (ANOVA P 0.05). Compared with healthy eyes and the NDR, the averaged DR ChT-map demonstrated temporal thinning that extended superiorly and temporal-inferiorly (unpaired t-test, P 0.05). ChT is decreased in diabetes type 1, independent of the absence of pathology and of diabetic disease duration. In eyes with pathology, 3D 1060 nm OCT averaged maps showed an extension of the thinning area matching retinal lesions and suggesting its involvement on onset or progression of disease.

  6. Structural and optoelectronic properties of β-In{sub 2}S{sub 3} thin films to Be applied on cadmium reduced solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Galarza Gutierrez, Uziel; Albor Aguilera, Maria Lourdes de; Hernandez Vasquez, Cesar; Aguilar Hernandez, Jorge R.; Remolina Millan, Aduljay [Instituto Politecnico Nacional - ESFM, Dept. de Fisica, U.P.A.L.M., Zacatenco (Mexico); Flores Marquez, Jose M. [Instituto Politecnico Nacional - ESIQIE, Dept. Metalurgia y Mat., U.P.A.L.M., Zacatenco (Mexico); Gonzalez Trujillo, Miguel A. [Instituto Politecnico Nacional - ESCOM, Dept. de Ciencias Basicas, U.P.A.L.M., Zacatenco (Mexico); Jimenez Olarte, Daniel [Instituto Politecnico Nacional - ESIME, SEPI, U.P.A.L.M., Zacatenco (Mexico)

    2018-02-15

    In{sub 2}S{sub 3} thin films are prepared by chemical bath deposition (CBD) technique to be applied as buffer layer in CdTe solar cells. CdTe photovoltaic devices are developed using In{sub 2}S{sub 3} as ''standard buffer layer'' in order to reduce the CdS thickness used as window material. It is important to examine potential thin films in a prospective life cycle study, focusing on direct costs, resource availability, and environmental impacts. Open and closed CBD system influence on the In{sub 2}S{sub 3} physical properties is analyzed. Stable tetragonal β-In{sub 2}S{sub 3} phase was confirmed by X-ray diffraction. Electrical properties were determined by four-point probe technique obtaining a resistivity value of 10{sup 2} Ω cm. CdTe solar cells performance was studied by measuring J-V characteristics and spectral quantum efficiencies. These results reveal In{sub 2}S{sub 3} thin films as buffer layer reduce the cadmium quantity used in solar cells manufacture and improve their current collection in blue wavelength region (300-500 nm). (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Effects of vacuum annealing on the optical and electrical properties of p-type copper-oxide thin-film transistors

    International Nuclear Information System (INIS)

    Sohn, Joonsung; Song, Sang-Hun; Kwon, Hyuck-In; Nam, Dong-Woo; Cho, In-Tak; Lee, Jong-Ho; Cho, Eou-Sik

    2013-01-01

    We have investigated the effects of vacuum annealing on the optical and electrical properties of the p-type copper-oxide thin-film transistors (TFTs). The vacuum annealing of the copper-oxide thin-film was performed using the RF magnetron sputter at various temperatures. From the x-ray diffraction and UV-vis spectroscopy, it is demonstrated that the high-temperature vacuum annealing reduces the copper-oxide phase from CuO to Cu 2 O, and increases the optical transmittance in the visible part of the spectrum. The fabricated copper-oxide TFT does not exhibit the switching behavior under low-temperature vacuum annealing conditions. However, as the annealing temperature increases, the drain current begins to be modulated by a gate voltage, and the TFT exhibits a high current on–off ratio over 10 4 as the vacuum annealing temperature increases over 450 °C. These results show that the vacuum annealing process can be an effective method of simultaneously improving the optical and electrical performances in p-type copper-oxide TFTs. (paper)

  8. Formation of Ga2O3 by the oxidation of p-type GaN thin films

    Energy Technology Data Exchange (ETDEWEB)

    Pinnisch, Melanie; Reppin, Daniel; Stehr, Jan; Laufer, Andreas; Hofmann, Detlev M.; Meyer, Bruno K. [1. Physikalisches Institut, Justus-Liebig-University, Giessen (Germany)

    2010-07-01

    Both GaN and Ga{sub 2}O{sub 3} are wide band gap semiconductors with energies of 3.45 eV and 4.9 eV, respectively. While GaN can be achieved p- or n-type conducting by doping, Ga{sub 2}O{sub 3} is n-type or high resistive dependent on the presence of oxygen vacancies. We studied the conversion of p-type Mg doped GaN thin films to Ga{sub 2}O{sub 3} by thermal treatments in the temperature range from 600 C to 1200 C and in different atmospheres. Changes of the film properties were studied by means of X-ray diffraction, photo-electron spectroscopy and atomic force microscopy. Optical and magnetic resonance methods were used to investigate the evolution of the dopands and defects.

  9. Effect of local wall thinning on the collapse behavior of pipe elbows subjected to a combined internal pressure and in-plane bending load

    International Nuclear Information System (INIS)

    Kim, Jin-Weon; Na, Man-Gyun; Park, Chi-Yong

    2008-01-01

    The objective of this study was to investigate the effect of local wall thinning on the collapse behavior of pipe elbows subjected to a combined internal pressure and in-plane bending load. This study evaluated the global deformation behavior and collapse moment of the elbows, which contained various types of local wall-thinning defects at their intrados or extrados, using three-dimensional elastic-plastic finite element analysis. The analysis results showed that the global deformation behavior of locally wall-thinned elbows was largely governed by the mode of the bending and the elbow geometry rather than the wall-thinning parameters, except for elbows with considerably large and deep wall thinning that showed plastic instabilities induced by local buckling and plastic collapsing in the thinned area. The reduction in the collapse moment with wall-thinning depth was considerable when local buckling occurred in the thinned areas, whereas the effect of the thinning depth was small when ovalization occurred. The effects of the circumferential thinning angle and thinning length on the collapse moment of elbows were not major for shallow wall-thinning cases. For deeper wall-thinning cases, however, their effects were significant and the dependence of collapse moment on the axial thinning length was governed by the stress type applied to the wall-thinned area. Typically, the reduction in the collapse moment due to local wall thinning was clearer when the thinning defect was located at the intrados rather than the extrados, and it was apparent for elbows with larger bend radius

  10. Tuning Bandgap of p-Type Cu2Zn(Sn, Ge)(S, Se)4 Semiconductor Thin Films via Aqueous Polymer-Assisted Deposition.

    Science.gov (United States)

    Yi, Qinghua; Wu, Jiang; Zhao, Jie; Wang, Hao; Hu, Jiapeng; Dai, Xiao; Zou, Guifu

    2017-01-18

    Bandgap engineering of kesterite Cu 2 Zn(Sn, Ge)(S, Se) 4 with well-controlled stoichiometric composition plays a critical role in sustainable inorganic photovoltaics. Herein, a cost-effective and reproducible aqueous solution-based polymer-assisted deposition approach is developed to grow p-type Cu 2 Zn(Sn, Ge)(S, Se) 4 thin films with tunable bandgap. The bandgap of Cu 2 Zn(Sn, Ge)(S, Se) 4 thin films can be tuned within the range 1.05-1.95 eV using the aqueous polymer-assisted deposition by accurately controlling the elemental compositions. One of the as-grown Cu 2 Zn(Sn, Ge)(S, Se) 4 thin films exhibits a hall coefficient of +137 cm 3 /C. The resistivity, concentration and carrier mobility of the Cu 2 ZnSn(S, Se) 4 thin film are 3.17 ohm·cm, 4.5 × 10 16 cm -3 , and 43 cm 2 /(V·S) at room temperature, respectively. Moreover, the Cu 2 ZnSn(S, Se) 4 thin film when used as an active layer in a solar cell leads to a power conversion efficiency of 3.55%. The facile growth of Cu 2 Zn(Sn, Ge)(S, Se) 4 thin films in an aqueous system, instead of organic solvents, provides great promise as an environmental-friendly platform to fabricate a variety of single/multi metal chalcogenides for the thin film industry and solution-processed photovoltaic devices.

  11. Effect of the Process Parameters on the Formability, Microstructure, and Mechanical Properties of Thin Plates Fabricated by Rheology Forging Process with Electromagnetic Stirring Method

    Science.gov (United States)

    Jin, Chul Kyu; Jang, Chang Hyun; Kang, Chung Gil

    2014-01-01

    A thin plate (150 × 150 × 1.2 mm) with embedded corrugation is fabricated using the rheoforming method. Semisolid slurry is created using the electromagnetic stirring (EMS) system, and the thin plate is made with the forging die at the 200-ton hydraulic press. The cross sections and microstructures of the slurry with and without stirring are examined. To investigate the effect of the process parameters on the formability, microstructure, and mechanical properties of thin plate the slurry is subjected to 16 types of condition for the forging experiment. The 16 types included the following conditions: Whether the EMS is applied or not, three fractions of the solid phase at 35, 45 and 55 pct; two compression velocities at 30 and 300 mm s-1; and four different compression pressures—100, 150, 200 and 250 MPa. The thin plate's formability is enhanced at higher punch velocity for compressing the slurry, and fine solid particles are uniformly distributed, which in turn, enhances the plate's mechanical properties. The pressure between 150 and 200 MPa is an appropriate condition to form thin plates. A thin plate without defects can be created when the slurry at 35 pct of the solid fraction (f s) was applied at the compression velocity of 300 mm s-1 and 150 MPa of pressure. The surface state of thin plate is excellent with 220 MPa of tensile strength and 13.5 pct of elongation. The primary particles are fine over the entire plate, and there are no liquid segregation-related defects.

  12. Effect of boron implantation on the electrical and photoelectrical properties of e-beam deposited Ag-In-Se thin films

    International Nuclear Information System (INIS)

    Colakoglu, T; Parlak, M; Kulakci, M; Turan, R

    2008-01-01

    In this study, e-beam evaporated Ag-In-Se (AIS) thin films were doped by the implantation of boron (B) ions at 75 keV with a dose of 1 x 10 15 ions cm -2 and a subsequent annealing process was applied to the doped AIS films at different temperatures under nitrogen atmosphere. The effects of implantation and annealing on the electrical and photoelectrical properties of AIS thin films were investigated through temperature dependent conductivity, spectral photoresponse and photoconductivity measurements under different illumination intensities. The electrical conductivity measurements showed that the room temperature conductivity values were determined as 2.4 x 10 -7 (Ω cm) -1 , 1.7 x 10 -6 (Ω cm) -1 and 8.9 x 10 -5 (Ω cm) -1 for B-doped films (B0), B-doped and annealed films at 200 deg. C (B2) and at 300 deg. C (B3), respectively. It was observed that the electrical conductivity improved as the annealing temperature increased up to 400 deg. C at which the AIS thin films showed degenerate semiconductor behaviour. The spectral distribution of the photoresponse curves indicated three local maxima located at 1.63, 1.79 and 2.01 eV for B0 type films, 1.65, 1.87 and 2.07 eV for B2 type films and 1.73, 2.02 and 2.32 eV for B3 type films at room temperature. These three different energy values were ascribed to the splitting of the valence band due to spin-orbit interaction and crystalline lattice field effects. The first energy values of each set were determined to be energy band gaps of the AIS thin films. The photoconductivity measurements as a function of temperature and illumination intensity were performed on the B-doped AIS thin films in order to determine the nature of recombination processes in the films. The photoconductivity values were found to be thermally quenched for all types of thin films and the variation of photocurrent as a function of illumination intensity showed that the dependence of photocurrent on the intensity was supralinear. The two

  13. Applying RF Magnetron sputtering to prepare ZnO thin films and their characterization

    International Nuclear Information System (INIS)

    Saad, M.; Kassis, A.

    2009-05-01

    ZnO thin films were prepared using Rf magnetron sputtering under several preparation conditions (different values of deposition pressure, Rf power, substrate temperature). The optical properties of these films were investigated by measuring their transmission in the spectral range (300-1000 nm), and the electrical properties were investigated by measuring their electrical resistance. Results have been discussed in terms of the modified Thornton model for sputtered thin metal oxide films. Preparation conditions for depositing the highly resistive transparent i-ZnO buffer layer and the highly conducting transparent n-ZnO window layer for solar cells were proposed. (author)

  14. Evaluation on current-limiting performance of the YBCO thin-film wire considering electric coupling condition

    International Nuclear Information System (INIS)

    Du, H.-I.; Han, B.-S.; Kim, Y.-J.; Lee, D.-H.; Song, S.-S.; Han, T.-H.; Han, S.-C.

    2011-01-01

    The basic way to improve the performance of a superconducting current limiter is to apply and evaluate a superconducting device that is appropriate to the superconducting current limiter. Among the many types of superconducting devices, the YBCO thin film wire has excellent current-limiting performance that is appropriate for actual system application. For the application of the YBCO thin film wire to superconducting current limiters, its current-limiting performance as a unit device must be accurately evaluated, and measures to improve its current-limiting performance must be sought. Accordingly, to evaluate the current-limiting performance of the YBCO thin film wire, this study was conducted to evaluate its resistance-increasing trend, V max , T r , I max , I qt , and current-limiting rate as a unit device, after which the electric coupling condition that consists of a core and windings was used to evaluate the current-limiting performance of the YBCO thin film wire.

  15. Comparative evaluation of corrosion behaviour of type K thin film thermocouple and its bulk counterpart

    International Nuclear Information System (INIS)

    Mukherjee, S.K.; Barhai, P.K.; Srikanth, S.

    2011-01-01

    Highlights: → Anodic vacuum arc deposited chromel and alumel films are more 'noble' in 5% NaCl solution than their respective wires. → Chromel undergoes localised corrosion while alumel shows uniform corrosion. → Virgin samples of chromel-alumel TFTCs exhibit good thermoelectric response. → Their thermoelectric outputs remain largely unaffected when shelved under normal atmospheric conditions. → After 288 h of exposure in salt spray environment, their thermoelectric outputs show noticeable change due to size effects. - Abstract: This paper investigates the corrosion behaviour of type K thermoelements and their thin films, and compares the performance of chromel-alumel thin film thermocouple with its wire counterpart before and after exposure to 5% NaCl medium. Potentiodynamic polarisation tests reveal that chromel and alumel films are more 'noble' than their respective wires. Alumel corrodes faster when coupled with chromel in films than as wires. Secondary electron micrographs and electrochemical impedance spectroscopy measurements suggest that chromel shows localised corrosion while alumel undergoes uniform corrosion. Corrosion adversely affects the thermocouple output and introduces an uncertainty in the measurement.

  16. Role of oxygen in enhancing N-type conductivity of CuInS2 thin films

    International Nuclear Information System (INIS)

    Rabeh, M. Ben; Kanzari, M.; Rezig, B.

    2007-01-01

    Post-growth treatments in air atmosphere were performed on CuInS 2 films prepared by the single-source thermal evaporation method. Their effect on the structural, optical and electrical properties of the films was studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), optical reflection and transmission and resistance measurements. The films were annealed from 100 to 350 deg. C in air. The stability of the observed N-type conductivity after annealing depends strongly on the annealing temperature. Indeed it is shown that for annealing temperatures above 200 deg. C the N-type conductivity is stable. The resistance of the N-CuInS 2 thin films correlates well with the corresponding annealing temperature. The samples after annealing have direct bandgap energies of 1.45-1.50 eV

  17. Textured surface boron-doped ZnO transparent conductive oxides on polyethylene terephthalate substrates for Si-based thin film solar cells

    International Nuclear Information System (INIS)

    Chen Xinliang; Lin Quan; Ni Jian; Zhang Dekun; Sun Jian; Zhao Ying; Geng Xinhua

    2011-01-01

    Textured surface boron-doped zinc oxide (ZnO:B) thin films were directly grown via low pressure metal organic chemical vapor deposition (LP-MOCVD) on polyethylene terephthalate (PET) flexible substrates at low temperatures and high-efficiency flexible polymer silicon (Si) based thin film solar cells were obtained. High purity diethylzinc and water vapors were used as source materials, and diborane was used as an n-type dopant gas. P-i-n silicon layers were fabricated at ∼ 398 K by plasma enhanced chemical vapor deposition. These textured surface ZnO:B thin films on PET substrates (PET/ZnO:B) exhibit rough pyramid-like morphology with high transparencies (T ∼ 80%) and excellent electrical properties (Rs ∼ 10 Ω at d ∼ 1500 nm). Finally, the PET/ZnO:B thin films were applied in flexible p-i-n type silicon thin film solar cells (device structure: PET/ZnO:B/p-i-n a-Si:H/Al) with a high conversion efficiency of 6.32% (short-circuit current density J SC = 10.62 mA/cm 2 , open-circuit voltage V OC = 0.93 V and fill factor = 64%).

  18. Raman spectroscopy of optical properties in CdS thin films

    Directory of Open Access Journals (Sweden)

    Trajić J.

    2015-01-01

    Full Text Available Properties of CdS thin films were investigated applying atomic force microscopy (AFM and Raman spectroscopy. CdS thin films were prepared by using thermal evaporation technique under base pressure 2 x 10-5 torr. The quality of these films was investigated by AFM spectroscopy. We apply Raman scattering to investigate optical properties of CdS thin films, and reveal existence of surface optical phonon (SOP mode at 297 cm-1. Effective permittivity of mixture were modeled by Maxwell - Garnet approximation. [Projekat Ministarstva nauke Republike Srbije, br. 45003

  19. Plasma monitoring and PECVD process control in thin film silicon-based solar cell manufacturing

    Directory of Open Access Journals (Sweden)

    Gabriel Onno

    2014-02-01

    Full Text Available A key process in thin film silicon-based solar cell manufacturing is plasma enhanced chemical vapor deposition (PECVD of the active layers. The deposition process can be monitored in situ by plasma diagnostics. Three types of complementary diagnostics, namely optical emission spectroscopy, mass spectrometry and non-linear extended electron dynamics are applied to an industrial-type PECVD reactor. We investigated the influence of substrate and chamber wall temperature and chamber history on the PECVD process. The impact of chamber wall conditioning on the solar cell performance is demonstrated.

  20. Thin layer alanine dosimeter with optical spectrophotometric evaluation

    International Nuclear Information System (INIS)

    Zagorski, Z.P.

    2000-01-01

    Experience in the high dose dosimetry of gamma radiation, gathered in our group from the sixties till now, allows to express the opinion, that techniques applied are adequate to solve problems. It can be confirmed by the fact that 60% of laboratories participating in the international comparison during the duration of the contract obtained satisfactory results. Adaptation of these methods, in particular of the alanine-ESR dosimetry to highly inhomogeneous fields of EB gives poor results, as it has been shown on thin films of the alanine/polymer composite. However, the applications of these films give excellent results if the concentration of the radical CH 3 C·H CO 2 - is measured by diffuse reflection spectrophotometry, which tolerates poor transparency of the composite and is insensitive to the orientation of crystals of alanine in thin films, what is disqualifying the ESR measurements. The development of thin-film dosimeters for EB processing was possible due to new developments in solid state radiation chemistry. The research has revealed some unsolved questions, e.g. of the high temperature coefficient of alanine based dosimeters, of the role of the size of spurs and the necessity to adapt dosimetry to the energy spectrum of electrons, because every type of accelerators differs in that respect. (author)

  1. Spectroelectrochemical properties of ultra-thin indium tin oxide films under electric potential modulation

    Energy Technology Data Exchange (ETDEWEB)

    Han, Xue, E-mail: x0han004@louisville.edu; Mendes, Sergio B., E-mail: sbmend01@louisville.edu

    2016-03-31

    In this work, the spectroscopic properties of ultra-thin ITO films are characterized under an applied electric potential modulation. To detect minute spectroscopic features, the ultra-thin ITO film was coated over an extremely sensitive single-mode integrated optical waveguide, which provided a long pathlength with more than adequate sensitivity for optical interrogation of the ultra-thin film. Experimental configurations with broadband light and several laser lines at different modulation schemes of an applied electric potential were utilized to elucidate the nature of intrinsic changes. The imaginary component of the refractive index (absorption coefficient) of the ultra-thin ITO film is unequivocally shown to have a dependence on the applied potential and the profile of this dependence changes substantially even for wavelengths inside a small spectral window (500–600 nm). The characterization technique and the data reported here can be crucial to several applications of the ITO material as a transparent conductive electrode, as for example in spectroelectrochemical investigations of surface-confined redox species. - Highlights: • Optical waveguides are applied for spectroscopic investigations of ultra-thin films. • Ultra-thin ITO films in aqueous environment are studied under potential modulation. • Unique spectroscopic features of ultra-thin ITO films are unambiguously observed.

  2. Thin pentacene layer under pressure

    International Nuclear Information System (INIS)

    Srnanek, R.; Jakabovic, J.; Kovac, J.; Donoval, D.; Dobrocka, E.

    2011-01-01

    Organic semiconductors have got a lot of interest during the last years, due to their usability for organic thin film transistor. Pentacene, C 22 H 14 , is one of leading candidates for this purpose. While we obtain the published data about pressure-induced phase transition only on single crystal of pentacene we present pressure-induced phase transition in pentacene thin layers for the first time. Changes in the pentacene structure, caused by the pressure, were detected by micro-Raman spectroscopy. Applying the defined pressure to the pentacene layer it can be transformed from thin phase to bulk phase. Micro-Raman spectroscopy was found as useful method for detection of changes and phases identification in the pentacene layer induced by mechanical pressure. Such a pressure-induced transformation of pentacene thin layers was observed and identified for the first time. (authors)

  3. Thickness oscillations of the transport properties in n-type Bi{sub 2}Te{sub 3} topological insulator thin films

    Energy Technology Data Exchange (ETDEWEB)

    Rogacheva, E.I., E-mail: rogacheva@kpi.kharkov.ua [National Technical University “Kharkov Polytechnic Institute”, 21 Frunze Street, Kharkov 61002 (Ukraine); Budnik, A.V.; Sipatov, A.Yu.; Nashchekina, O.N. [National Technical University “Kharkov Polytechnic Institute”, 21 Frunze Street, Kharkov 61002 (Ukraine); Fedorov, A.G. [Institute for Single Crystals of NAS of Ukraine, 60 Lenin Prospect, Kharkov 61001 (Ukraine); Dresselhaus, M.S.; Tang, S. [Department of Electrical Engineering and Computer Science and Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 (United States)

    2015-11-02

    The dependences of the electrical conductivity, Seebeck coefficient and Hall coefficient on the thickness (d = 20–155 nm) of the n-type thin films grown on the glass substrates by the thermal evaporation in vacuum of the n-type Bi{sub 2}Te{sub 3} topological insulator crystals have been measured. It has been established that these dependences have an oscillatory character with a substantial amplitude. The obtained results are interpreted in terms of quantum size effects, taking into account the peculiar properties of the surface layers of the Bi{sub 2}Te{sub 3} films connected with the topological insulator nature of the bismuth telluride. - Highlights: • The thickness dependences of Bi{sub 2}Te{sub 3} thin films kinetic coefficients were obtained. • The dependences have oscillatory character with a substantial undamped amplitude. • The oscillation period increases with decreasing film thickness. • The oscillations are attributed to electron confinement in the film growth direction. • It is suggested that topological surface layer affects quantum processes in films.

  4. A novel application of the CuI thin film for preparing thin copper nanowires

    International Nuclear Information System (INIS)

    Shi Shuo; Sun Jialin; Zhang Jianhong; Cao Yang

    2005-01-01

    We present a novel application of the CuI thin film for preparing thin copper nanowires under a direct current electric field (DCEF). The CuI thin film was used as a medium for transmitting cuprous ions during the growing process of copper nanowires. As electrodes are the source of cuprous ions, high-purity copper films were deposited on both ends of the CuI thin film. At 353 K, under whole solid condition, without any templates, and having applied a DCEF of 1.5x10 4 V/m, cuprous ions were generated at the anode and migrated towards the cathode through the CuI film. At the edge of the cathode, cuprous ions obtained electrons and congregated to form a disordered thin copper nanowires bundle. The SEM images showed that these copper nanowires were from 10 to 20 nm in diameter and several hundred nanometers in length. The effect of the electric field intensity and the growth temperature on the diameter of the nanowires was also studied

  5. Microstructure, elastic deformation behavior and mechanical properties of biomedical β-type titanium alloy thin-tube used for stents.

    Science.gov (United States)

    Tian, Yuxing; Yu, Zhentao; Ong, Chun Yee Aaron; Kent, Damon; Wang, Gui

    2015-05-01

    Cold-deformability and mechanical compatibility of the biomedical β-type titanium alloy are the foremost considerations for their application in stents, because the lower ductility restricts the cold-forming of thin-tube and unsatisfactory mechanical performance causes a failed tissue repair. In this paper, β-type titanium alloy (Ti-25Nb-3Zr-3Mo-2Sn, wt%) thin-tube fabricated by routine cold rolling is reported for the first time, and its elastic behavior and mechanical properties are discussed for the various microstructures. The as cold-rolled tube exhibits nonlinear elastic behavior with large recoverable strain of 2.3%. After annealing and aging, a nonlinear elasticity, considered as the intermediate stage between "double yielding" and normal linear elasticity, is attributable to a moderate precipitation of α phase. Quantitive relationships are established between volume fraction of α phase (Vα) and elastic modulus, strength as well as maximal recoverable strain (εmax-R), where the εmax-R of above 2.0% corresponds to the Vα range of 3-10%. It is considered that the "mechanical" stabilization of the (α+β) microstructure is a possible elastic mechanism for explaining the nonlinear elastic behavior. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. stress distribution in continuo ribution in continuous thin ribution

    African Journals Online (AJOL)

    eobe

    studied stresses in thin-walled box girder bridges but stress distribution walled box girder bridges .... the classical thin plate theory and trigonometric series. Lertsima et al. ..... remedied by applying spline finite strip method. Compared to other ...

  7. Prediction and optimization of thinning in automotive sealing cover using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Ganesh M. Kakandikar

    2016-01-01

    Full Text Available Deep drawing is a forming process in which a blank of sheet metal is radially drawn into a forming die by the mechanical action of a punch and converted to required shape. Deep drawing involves complex material flow conditions and force distributions. Radial drawing stresses and tangential compressive stresses are induced in flange region due to the material retention property. These compressive stresses result in wrinkling phenomenon in flange region. Normally blank holder is applied for restricting wrinkles. Tensile stresses in radial direction initiate thinning in the wall region of cup. The thinning results into cracking or fracture. The finite element method is widely applied worldwide to simulate the deep drawing process. For real-life simulations of deep drawing process an accurate numerical model, as well as an accurate description of material behavior and contact conditions, is necessary. The finite element method is a powerful tool to predict material thinning deformations before prototypes are made. The proposed innovative methodology combines two techniques for prediction and optimization of thinning in automotive sealing cover. Taguchi design of experiments and analysis of variance has been applied to analyze the influencing process parameters on Thinning. Mathematical relations have been developed to correlate input process parameters and Thinning. Optimization problem has been formulated for thinning and Genetic Algorithm has been applied for optimization. Experimental validation of results proves the applicability of newly proposed approach. The optimized component when manufactured is observed to be safe, no thinning or fracture is observed.

  8. Electrical Switching of Perovskite Thin-Film Resistors

    Science.gov (United States)

    Liu, Shangqing; Wu, Juan; Ignatiev, Alex

    2010-01-01

    Electronic devices that exploit electrical switching of physical properties of thin films of perovskite materials (especially colossal magnetoresistive materials) have been invented. Unlike some related prior devices, these devices function at room temperature and do not depend on externally applied magnetic fields. Devices of this type can be designed to function as sensors (exhibiting varying electrical resistance in response to varying temperature, magnetic field, electric field, and/or mechanical pressure) and as elements of electronic memories. The underlying principle is that the application of one or more short electrical pulse(s) can induce a reversible, irreversible, or partly reversible change in the electrical, thermal, mechanical, and magnetic properties of a thin perovskite film. The energy in the pulse must be large enough to induce the desired change but not so large as to destroy the film. Depending on the requirements of a specific application, the pulse(s) can have any of a large variety of waveforms (e.g., square, triangular, or sine) and be of positive, negative, or alternating polarity. In some applications, it could be necessary to use multiple pulses to induce successive incremental physical changes. In one class of applications, electrical pulses of suitable shapes, sizes, and polarities are applied to vary the detection sensitivities of sensors. Another class of applications arises in electronic circuits in which certain resistance values are required to be variable: Incorporating the affected resistors into devices of the present type makes it possible to control their resistances electrically over wide ranges, and the lifetimes of electrically variable resistors exceed those of conventional mechanically variable resistors. Another and potentially the most important class of applications is that of resistance-based nonvolatile-memory devices, such as a resistance random access memory (RRAM) described in the immediately following article

  9. Tellipsometry in Twente : Dynamics of Thin Film Membranes Under Applied Temperature Profiles

    NARCIS (Netherlands)

    Kappert, Emiel J.; Ogieglo, Wojciech; Raaijmakers, Michiel; Koziara, Beata; Wormeester, Herbert; Benes, Nieck E.

    2014-01-01

    We use in-situ ellipsometry to study the structural and chemical evolution of thin films as function of the temperature (‘Tellipsometry’). Particular focus is on organic, inorganic, and hybrid materials that are relevant to artificial membrane fabrication and operation. Our poster shows some

  10. P-type Cu2O/SnO bilayer thin film transistors processed at low temperatures

    KAUST Repository

    Al-Jawhari, Hala A.

    2013-10-09

    P-type Cu2O/SnO bilayer thin film transistors (TFTs) with tunable performance were fabricated using room temperature sputtered copper and tin oxides. Using Cu2O film as capping layer on top of a SnO film to control its stoichiometry, we have optimized the performance of the resulting bilayer transistor. A transistor with 10 nm/15 nm Cu2O to SnO thickness ratio (25 nm total thickness) showed the best performance using a maximum process temperature of 170 C. The bilayer transistor exhibited p-type behavior with field-effect mobility, on-to-off current ratio, and threshold voltage of 0.66 cm2 V-1 s-1, 1.5×10 2, and -5.2 V, respectively. The advantages of the bilayer structure relative to single layer transistor are discussed. © 2013 American Chemical Society.

  11. Polycrystalline Mg2Si thin films: A theoretical investigation of their electronic transport properties

    International Nuclear Information System (INIS)

    Balout, H.; Boulet, P.; Record, M.-C.

    2015-01-01

    The electronic structures and thermoelectric properties of a polycrystalline Mg 2 Si thin film have been investigated by first-principle density-functional theory (DFT) and Boltzmann transport theory calculations within the constant-relaxation time approximation. The polycrystalline thin film has been simulated by assembling three types of slabs each having the orientation (001), (110) or (111) with a thickness of about 18 Å. The effect of applying the relaxation procedure to the thin film induces disorder in the structure that has been ascertained by calculating radial distribution functions. For the calculations of the thermoelectric properties, the energy gap has been fixed at the experimental value of 0.74 eV. The thermoelectric properties, namely the Seebeck coefficient, the electrical conductivity and the power factor, have been determined at three temperatures of 350 K, 600 K and 900 K with respect to both the energy levels and the p-type and n-type doping levels. The best Seebeck coefficient is obtained at 350 K: the S yy component of the tensor amounts to about ±1000 μV K −1 , depending on the type of charge carriers. However, the electrical conductivity is much too small which results in low values of the figure of merit ZT. Structure–property relationship correlations based on directional radial distribution functions allow us to tentatively draw some explanations regarding the anisotropy of the electrical conductivity. Finally, the low ZT values obtained for the polycrystalline Mg 2 Si thin film are paralleled with those recently reported in the literature for bulk chalcogenide glasses. - Graphical abstract: Structure of the polycrystalline thin film of Mg 2 Si. - Author-Highlights: • Polycrystalline Mg 2 Si film has been modelled by DFT approach. • Thermoelectric properties have been evaluated by semi-classical Boltzmann theory. • The structure was found to be slightly disordered after relaxation. • The highest value of Seebeck

  12. Thin film bismuth iron oxides useful for piezoelectric devices

    Science.gov (United States)

    Zeches, Robert J.; Martin, Lane W.; Ramesh, Ramamoorthy

    2016-05-31

    The present invention provides for a composition comprising a thin film of BiFeO.sub.3 having a thickness ranging from 20 nm to 300 nm, a first electrode in contact with the BiFeO.sub.3 thin film, and a second electrode in contact with the BiFeO.sub.3 thin film; wherein the first and second electrodes are in electrical communication. The composition is free or essentially free of lead (Pb). The BFO thin film is has the piezoelectric property of changing its volume and/or shape when an electric field is applied to the BFO thin film.

  13. Applying the behavioral economics principle of unit price to DRO schedule thinning.

    Science.gov (United States)

    Roane, Henry S; Falcomata, Terry S; Fisher, Wayne W

    2007-01-01

    Within the context of behavioral economics, the ratio of response requirements to reinforcer magnitude is called unit price. In this investigation, we yoked increases in reinforcer magnitude with increases in intervals of differential reinforcement of other behavior (DRO) to thin DRO intervals to a terminal value.

  14. Tellipsometry in Twente: Dynamics of Thin Film Membranes Under Applied Temperature Profiles

    OpenAIRE

    Kappert, Emiel J.; Ogieglo, Wojciech; Raaijmakers, Michiel; Koziara, Beata; Wormeester, Herbert; Benes, Nieck E.

    2014-01-01

    We use in-situ ellipsometry to study the structural and chemical evolution of thin films as function of the temperature (‘Tellipsometry’). Particular focus is on organic, inorganic, and hybrid materials that are relevant to artificial membrane fabrication and operation. Our poster shows some illustrative examples.

  15. Recovery of 15N-labelled fertilizers applied to bromegrass on a thin black chernozem soil

    International Nuclear Information System (INIS)

    Malhi, S.S.

    1995-01-01

    The availability of N fertilizers on established grass stands is a function of such processes as immobilization, gaseous loss, leaching and position of applied N. A field experiment was conducted on a Thin Black Chernozem soil at Crossfield, Alberta to determine the effect of source, time and method of application on the recovery of 15 N-labelled fertilizers applied to smooth bromegrass (Bromus inermis Leyss.). The treatments included two sources of N [urea and ammonium nitrate (AN)], four application times (early autumn, late autumn, early spring and late spring) and two methods of placement (surface-broadcast and subsurface banding). In most cases the 15 N recovery in soil did not differ much between urea and AN. However, when urea was surface-broadcast, there was, on average, 10.2% less 15 N recovery in plants than AN. The N recovery for late spring > early spring > late autumn = early autumn. When urea was banded 4 cm deep into the soil, N recovery in plants increased significantly compared with its surface-broadcast application. However, this was not observed when the source of N was AN. Banding generally increased the amount of immobilized N present in the soil and N recovery. We concluded that the N recovery in plants and in plants plus soil was less for urea than for AN and was less with autumn broadcast N application than with spring broadcast application. (author). 23 refs., 3 tabs

  16. Fluorinated copper-phthalocyanine-based n-type organic field-effect transistors with a polycarbonate gate insulator

    International Nuclear Information System (INIS)

    Sethuraman, Kunjithapatham; Kumar, Palanisamy; Santhakumar, Kannappan; Ochiai, Shizuyasu; Shin, Paikkyun

    2012-01-01

    Fluorinated copper-phthalocyanine (F 16 CuPc) thin films were prepared by using a vacuum evaporation technique and were applied to n-type organic field-effect transistors (OFETs) as active channel layers combined with a spin-coated polycarbonate thin-film gate insulator. The output characteristics of the resulting n-type OFET devices with bottom-gate/bottom-contact structures were investigated to evaluate the performances such as the field effect mobility (μ FE ), the on/off current ratio (I on/off ), and the threshold voltage (V th ). A relatively high field effect mobility of 6.0 x 10 -3 cm 2 /Vs was obtained for the n-type semiconductor under atmospheric conditions with an on/off current ratio of 1 x 10 4 and a threshold voltage of 5 V. The electron mobility of the n-type semiconductor was found to depend strongly on the growth temperature of the F 16 CuPc thin films. X-ray diffraction profiles showed that the crystallinity and the orientation of the F 16 CuPc on a polycarbonate thin film were enhanced with increasing growth temperature. Atomic force microscopy studies revealed various surface morphologies of the active layer. The field effect mobility of the F 16 CuPc-OFET was closely related to the crystallinity and the orientation of the F 16 CuPc thin film.

  17. Preparation of n-type semiconductor SnO2 thin films

    International Nuclear Information System (INIS)

    Rahal, Achour; Benramache, Said; Benhaoua, Boubaker

    2013-01-01

    We studied fluorine-doped tin oxide on a glass substrate at 350°C using an ultrasonic spray technique. Tin (II) chloride dehydrate, ammonium fluoride dehydrate, ethanol and NaOH were used as the starting material, dopant source, solvent and stabilizer, respectively. The SnO 2 : F thin films were deposited at 350°C and a pending time of 60 and 90 s. The as-grown films exhibit a hexagonal wurtzite structure and have (101) orientation. The G = 31.82 nm value of the grain size is attained from SnO 2 : F film grown at 90 s, and the transmittance is greater than 80% in the visible region. The optical gap energy is found to measure 4.05 eV for the film prepared at 90 s, and the increase in the electrical conductivity of the film with the temperature of the sample is up to a maximum value of 265.58 (Ω·cm) −1 , with the maximum activation energy value of the films being found to measure 22.85 meV, indicating that the films exhibit an n-type semiconducting nature. (semiconductor materials)

  18. Thin-plate-type embedded ultrasonic transducer based on magnetostriction for the thickness monitoring of the secondary piping system of a nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Tae Hoon; Cho, Seung Hyun [Center for Safety Measurement, Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2016-12-15

    Pipe wall thinning in the secondary piping system of a nuclear power plant is currently a major problem that typically affects the safety and reliability of the nuclear power plant directly. Regular in-service inspections are carried out to manage the piping system only during the overhaul. Online thickness monitoring is necessary to avoid abrupt breakage due to wall thinning. To this end, a transducer that can withstand a high-temperature environment and should be installed under the insulation layer. We propose a thin plate type of embedded ultrasonic transducer based on magnetostriction. The transducer was designed and fabricated to measure the thickness of a pipe under a high-temperature condition. A number of experimental results confirmed the validity of the present transducer.

  19. Thinning trials in lowland plantations in the Veneto Region (North-eastern Italy

    Directory of Open Access Journals (Sweden)

    Mario Pividori

    2014-06-01

    Full Text Available Thinning trials in lowland plantations in the Veneto Region (North-eastern Italy. More than 234 hectares of new plantations of lowland mixed forest have been realized in the last 20 years in the Veneto Region (North-eastern Italy. In many of these is now needed to start thinning operations, but there is a lack of experience about this topic. Aim of this work was to undertake an experimentation on different types of thinnings. The thinning trial has been performed at Bosco San Marco forest, municipality of Cessalto (Venice, in a very dense hornbeam-oak plantation aged 16. In 2010, three different thinning types were implemented on 9 hectares according to the following layout: geometrical (34% of woody mass removed, selective (15%, mixed geometrical-selective (30%, control plot. Three years later no significant differences between thinning trials in term of diametric growth, geometrical thinning excepted, were observed. These results provide a suite of solutions to the forest manager for choosing the early thinning type in high tree density condition.

  20. Deposition of magnetoelectric hexaferrite thin films on substrates of silicon

    Energy Technology Data Exchange (ETDEWEB)

    Zare, Saba; Izadkhah, Hessam; Vittoria, Carmine

    2016-12-15

    Magnetoelectric M-type hexaferrite thin films (SrCo{sub 2}Ti{sub 2}Fe{sub 8}O{sub 19}) were deposited using Pulsed Laser Deposition (PLD) technique on Silicon substrate. A conductive oxide layer of Indium-Tin Oxide (ITO) was deposited as a buffer layer with the dual purposes of 1) to reduce lattice mismatch between the film and silicon and 2) to lower applied voltages to observe magnetoelectric effects at room temperature on Silicon based devices. The film exhibited magnetoelectric effects as confirmed by vibrating sample magnetometer (VSM) techniques in voltages as low as 0.5 V. Without the oxide conductive layer the required voltages to observe magnetoelectric effects was typically about 1000 times larger. The magnetoelectric thin films were characterized by X-ray diffractometer, scanning electron microscope, energy-dispersive spectroscopy, vibrating sample magnetometer, and ferromagnetic resonance techniques. We measured saturation magnetization of 650 G, and coercive field of about 150 Oe for these thin films. The change in remanence magnetization was measured in the presence of DC voltages and the changes in remanence were in the order of 15% with the application of only 0.5 V (DC voltage). We deduced a magnetoelectric coupling, α, of 1.36×10{sup −9} s m{sup −1} in SrCo{sub 2}Ti{sub 2}Fe{sub 8}O{sub 19} thin films.

  1. Applying the Behavioral Economics Principle of Unit Price to DRO Schedule Thinning

    Science.gov (United States)

    Roane, Henry S.; Falcomata, Terry S.; Fisher, Wayne W.

    2007-01-01

    Within the context of behavioral economics, the ratio of response requirements to reinforcer magnitude is called "unit price." In this investigation, we yoked increases in reinforcer magnitude with increases in intervals of differential reinforcement of other behavior (DRO) to thin DRO intervals to a terminal value. (Contains 1 figure.)

  2. Switching process between bistable positons of multiquantum flux tubes in a thin-film type I superconductor

    International Nuclear Information System (INIS)

    Parisi, J.; Huebener, R.P.; Muhlemeier, B.

    1983-01-01

    A superconducting memory device based on a bistable vortex position represents an interesting storage medium for future Josephson computers. In order to study the operational mode of such a single-flux quantum memory cell, we use as a model system multiquantum flux tubes in a thin-film type I superconductor (Pb). By employing high-resolution stroboscopic magnetooptical flux detection, we are able to globally visualize both spatial and temporal behavior of rapidly switching individual flux tubes. All experimental results agree reasonably well with theoretical model considerations of the energy balance during the elementary switching process

  3. Application of Thinned-Skull Cranial Window to Mouse Cerebral Blood Flow Imaging Using Optical Microangiography

    Science.gov (United States)

    Wang, Ruikang K.

    2014-01-01

    In vivo imaging of mouse brain vasculature typically requires applying skull window opening techniques: open-skull cranial window or thinned-skull cranial window. We report non-invasive 3D in vivo cerebral blood flow imaging of C57/BL mouse by the use of ultra-high sensitive optical microangiography (UHS-OMAG) and Doppler optical microangiography (DOMAG) techniques to evaluate two cranial window types based on their procedures and ability to visualize surface pial vessel dynamics. Application of the thinned-skull technique is found to be effective in achieving high quality images for pial vessels for short-term imaging, and has advantages over the open-skull technique in available imaging area, surgical efficiency, and cerebral environment preservation. In summary, thinned-skull cranial window serves as a promising tool in studying hemodynamics in pial microvasculature using OMAG or other OCT blood flow imaging modalities. PMID:25426632

  4. Magnetic hysteresis measurements of thin films under isotropic stress.

    Science.gov (United States)

    Holland, Patrick; Dubey, Archana; Geerts, Wilhelmus

    2000-10-01

    Nowadays, ferromagnetic thin films are widely applied in devices for information technology (credit cards, video recorder tapes, floppies, hard disks) and sensors (air bags, anti-breaking systems, navigation systems). Thus, with the increase in the use of magnetic media continued investigation of magnetic properties of materials is necessary to help in determining the useful properties of materials for new or improved applications. We are currently interested in studying the effect of applied external stress on Kerr hysteresis curves of thin magnetic films. The Ni and NiFe films were grown using DC magnetron sputtering with Ar as the sputter gas (pAr=4 mTorr; Tsub=55-190 C). Seed and cap layers of Ti were used on all films for adhesion and oxidation protection, respectively. A brass membrane pressure cell was designed to apply in-plane isotropic stress to thin films. In this pressure cell, gas pressure is used to deform a flexible substrate onto which a thin magnetic film has been sputtered. The curvature of the samples could be controlled by changing the gas pressure to the cell. Magneto-Optical in-plane hysteresis curves at different values of strain were measured. The results obtained show that the stress sensitivity is dependent on the film thickness. For the 500nm NiFe films, the coercivity strongly decreased as a function of the applied stress.

  5. Tank wall thinning -- Process and programs

    International Nuclear Information System (INIS)

    Greer, S.D.; McBrine, W.J.

    1994-01-01

    In-service thinning of tank walls has occurred in the power industry and can pose a significant risk to plant safety and dependability. Appropriate respect for the energy stored in a high-pressure drain tank warrants a careful consideration of this possibility and appropriate action in order to assure the adequate safety margins against leakage or rupture. Although it has not proven to be a widespread problem, several cases of wall thinning and at least one recent tank rupture has highlighted this issue in recent years, particularly in nuclear power plants. However, the problem is not new or unique to the nuclear power industry. Severe wall thinning in deaerator tanks has been frequently identified at fossil-fueled power plants. There are many mechanisms which can contribute to tank wall thinning. Considerations for a specific tank are dictated by the system operating conditions, tank geometry, and construction material. Thinning mechanisms which have been identified include: Erosion/Corrosion Impingement Erosion Cavitation Erosion General Corrosion Galvanic Corrosion Microbial-induced Corrosion of course there are many other possible types of material degradation, many of which are characterized by pitting and cracking. This paper specifically addresses wall thinning induced by Erosion/Corrosion (also called Flow-Accelerated Corrosion) and Impingement Erosion of tanks in a power plant steam cycle. Many of the considerations presented are applicable to other types of vessels, such as moisture separators and heat exchangers

  6. Thinning in artificially regenerated young beech stands

    Directory of Open Access Journals (Sweden)

    Novák Jiří

    2015-12-01

    Full Text Available Although beech stands are usually regenerated naturally, an area of up to 5,000 ha year−1 is artificially regenerated by beech in the Czech Republic annually. Unfortunately, these stands often showed insufficient stand density and, consequently, lower quality of stems. Therefore, thinning methods developed for naturally regenerated beech stands are applicable with difficulties. The paper evaluates the data from two thinning experiments established in young artificially regenerated beech stands located in different growing conditions. In both experiments, thinning resulted in the lower amount of salvage cut in following years. Positive effect of thinning on periodic stand basal area increment and on periodic diameter increment of dominant trees was found in the beech stand located at middle elevations. On the other hand, thinning effects in mountain conditions were negligible. Thinning focusing on future stand quality cannot be commonly applied in artificially regenerated beech stands because of their worse initial quality and lower density. However, these stands show good growth and response to thinning, hence their management can be focused on maximising beech wood production.

  7. Differences observed in the surface morphology and microstructure of Ni-Fe-Cu ternary thin films electrochemically deposited at low and high applied current densities

    International Nuclear Information System (INIS)

    Sarac, U; Kaya, M; Baykul, M C

    2016-01-01

    In this research, nanocrystalline Ni-Fe-Cu ternary thin films using electrochemical deposition technique were produced at low and high applied current densities onto Indium Tin Oxide (ITO) coated conducting glass substrates. Change of surface morphology and microstructural properties of the films were investigated. Energy dispersive X-ray spectroscopy (EDX) measurements showed that the Ni-Fe-Cu ternary thin films exhibit anomalous codeposition behaviour during the electrochemical deposition process. From the X-ray diffraction (XRD) analyses, it was revealed that there are two segregated phases such as Cu- rich and Ni-rich within the films. The crystallographic structure of the films was face-centered cubic (FCC). It was also observed that the film has lower lattice micro-strain and higher texture degree at high applied current density. Scanning electron microscopy (SEM) studies revealed that the films have rounded shape particles on the base part and cauliflower-like structures on the upper part. The film electrodeposited at high current density had considerably smaller rounded shape particles and cauliflower-like structures. From the atomic force microscopy (AFM) analyses, it was shown that the film deposited at high current density has smaller particle size and surface roughness than the film grown at low current density. (paper)

  8. The effect of air thinning on dentin adhesive bond strength.

    Science.gov (United States)

    Hilton, T J; Schwartz, R S

    1995-01-01

    The purpose of this study was to determine if air thinning three dentin adhesives would affect bond strength to dentin. Ninety human molars were mounted in acrylic and the occlusal surfaces ground to expose a flat dentin surface. Thirty teeth were randomly assigned to one of the following dentin bonding agent/composite combinations: A) Universal Bond 3/TPH (Caulk), B) All-Bond 2/Bis-Fil-P (Bisco), and C) Scotchbond Multi-Purpose/Z-100 (3m). The primers were applied following the manufacturers' instructions. The adhesives were applied by two methods. A thin layer of adhesive was applied with a brush to 15 specimens in each group and light cured. Adhesive was brushed on to the remaining 15 teeth in the group, air thinned for 3 seconds, and then polymerized. The appropriate composite was applied in 2 mm increments and light cured utilizing a 5 mm-in-diameter split Teflon mold. Following 3 months of water storage, all groups were shear tested to failure on an Instron Universal Testing Machine. Bond strength was significantly higher in all groups when the dentin bonding agent was painted on without being air thinned. Scotchbond Multi-Purpose had significantly higher bond strength than All-Bond 2, which had significantly higher bond strength than Universal Bond 3.

  9. Tools to synthesize the learning of thin films

    International Nuclear Information System (INIS)

    Rojas, Roberto; Fuster, Gonzalo; Sluesarenko, Viktor

    2011-01-01

    After a review of textbooks written for undergraduate courses in physics, we have found that discussions on thin films are mostly incomplete. They consider the reflected and not the transmitted light for two instead of the four types of thin films. In this work, we complement the discussion in elementary textbooks, by analysing the phase differences required to match the conditions for constructive and destructive interference, in the reflected and transmitted light in four types of thin films. We consider thin films with varied sequences in the refractive index, which we identify as barriers, wells and stairs (up and down). Also, we use the conservation of energy in order to understand the complementary colour fringes observed in the reflected and transmitted light through thin films. We analyse systematically the phase changes by introducing a phase table and we synthesize the results in a circular diagram matching 16 physical situations of interference and their corresponding conditions on the film thickness. The phase table and the circular diagram are a pair of tools easily assimilated by students, and useful to organize, analyse and activate the knowledge about thin films.

  10. Electrical and optical properties of a n-type ZnO thin film deposited on a Si substrate by using a double RF Co-sputtering method

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jonghyun; Choi, Wonjoon; Kim, Chaeok; Hong, Jinpyo; Nahm, Tschanguh [Hanyang University, Seoul (Korea, Republic of); Cheong, Hyeonsik [Sogang University, Seoul (Korea, Republic of)

    2006-09-15

    Outstanding n-type ZnO thin films were prepared on Si substrates by utilizing a double RF cosputtering method. Our unique double RF technique has many attractive merits for synthesizing ZnO thin films with excellent optoelectronic properties at various temperatures. The ZnO thin films were also post-annealed at various temperatures. The X-ray diffraction patterns and X-ray photoelectron spectroscopy indicated well-grown ZnO films with a (002) orientation and with gorgeous chemically bond states, respectively. In addition, photoluminescence measurements indicated a band-gap of 3.4 eV in the ZnO films. The scanning electron microscopy images showed that the as-grown ZnO thin film had hexagonal column shapes, such as hexagonal rods. The ZnO film exhibited an UV light response with a cut-off wavelength of {approx}370 nm at room temperature.

  11. Amplitude various angles (AVA) phenomena in thin layer reservoir: Case study of various reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Nurhandoko, Bagus Endar B., E-mail: bagusnur@bdg.centrin.net.id, E-mail: bagusnur@rock-fluid.com [Wave Inversion and Subsurface Fluid Imaging Research Laboratory (WISFIR), Basic Science Center A 4" t" hfloor, Physics Dept., FMIPA, Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Bandung (Indonesia); Susilowati, E-mail: bagusnur@bdg.centrin.net.id, E-mail: bagusnur@rock-fluid.com [Rock Fluid Imaging Lab., Bandung (Indonesia)

    2015-04-16

    Amplitude various offset is widely used in petroleum exploration as well as in petroleum development field. Generally, phenomenon of amplitude in various angles assumes reservoir’s layer is quite thick. It also means that the wave is assumed as a very high frequency. But, in natural condition, the seismic wave is band limited and has quite low frequency. Therefore, topic about amplitude various angles in thin layer reservoir as well as low frequency assumption is important to be considered. Thin layer reservoir means the thickness of reservoir is about or less than quarter of wavelength. In this paper, I studied about the reflection phenomena in elastic wave which considering interference from thin layer reservoir and transmission wave. I applied Zoeppritz equation for modeling reflected wave of top reservoir, reflected wave of bottom reservoir, and also transmission elastic wave of reservoir. Results show that the phenomena of AVA in thin layer reservoir are frequency dependent. Thin layer reservoir causes interference between reflected wave of top reservoir and reflected wave of bottom reservoir. These phenomena are frequently neglected, however, in real practices. Even though, the impact of inattention in interference phenomena caused by thin layer in AVA may cause inaccurate reservoir characterization. The relation between classes of AVA reservoir and reservoir’s character are different when effect of ones in thin reservoir and ones in thick reservoir are compared. In this paper, I present some AVA phenomena including its cross plot in various thin reservoir types based on some rock physics data of Indonesia.

  12. Amplitude various angles (AVA) phenomena in thin layer reservoir: Case study of various reservoirs

    International Nuclear Information System (INIS)

    thfloor, Physics Dept., FMIPA, Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Bandung (Indonesia))" data-affiliation=" (Wave Inversion and Subsurface Fluid Imaging Research Laboratory (WISFIR), Basic Science Center A 4thfloor, Physics Dept., FMIPA, Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Bandung (Indonesia))" >Nurhandoko, Bagus Endar B.; Susilowati

    2015-01-01

    Amplitude various offset is widely used in petroleum exploration as well as in petroleum development field. Generally, phenomenon of amplitude in various angles assumes reservoir’s layer is quite thick. It also means that the wave is assumed as a very high frequency. But, in natural condition, the seismic wave is band limited and has quite low frequency. Therefore, topic about amplitude various angles in thin layer reservoir as well as low frequency assumption is important to be considered. Thin layer reservoir means the thickness of reservoir is about or less than quarter of wavelength. In this paper, I studied about the reflection phenomena in elastic wave which considering interference from thin layer reservoir and transmission wave. I applied Zoeppritz equation for modeling reflected wave of top reservoir, reflected wave of bottom reservoir, and also transmission elastic wave of reservoir. Results show that the phenomena of AVA in thin layer reservoir are frequency dependent. Thin layer reservoir causes interference between reflected wave of top reservoir and reflected wave of bottom reservoir. These phenomena are frequently neglected, however, in real practices. Even though, the impact of inattention in interference phenomena caused by thin layer in AVA may cause inaccurate reservoir characterization. The relation between classes of AVA reservoir and reservoir’s character are different when effect of ones in thin reservoir and ones in thick reservoir are compared. In this paper, I present some AVA phenomena including its cross plot in various thin reservoir types based on some rock physics data of Indonesia

  13. Uniaxially oriented polycrystalline thin films and air-stable n-type transistors based on donor-acceptor semiconductor (diC8BTBT)(FnTCNQ) [n = 0, 2, 4

    Science.gov (United States)

    Shibata, Yosei; Tsutsumi, Jun'ya; Matsuoka, Satoshi; Matsubara, Koji; Yoshida, Yuji; Chikamatsu, Masayuki; Hasegawa, Tatsuo

    2015-04-01

    We report the fabrication of high quality thin films for semiconducting organic donor-acceptor charge-transfer (CT) compounds, (diC8BTBT)(FnTCNQ) (diC8BTBT = 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene and FnTCNQ [n = 0,2,4] = fluorinated derivatives of 7,7,8,8,-tetracyanoquinodimethane), which have a high degree of layered crystallinity. Single-phase and uniaxially oriented polycrystalline thin films of the compounds were obtained by co-evaporation of the component donor and acceptor molecules. Organic thin-film transistors (OTFTs) fabricated with the compound films exhibited n-type field-effect characteristics, showing a mobility of 6.9 × 10-2 cm2/V s, an on/off ratio of 106, a sub-threshold swing of 0.8 V/dec, and an excellent stability in air. We discuss the suitability of strong intermolecular donor-acceptor interaction and the narrow CT gap nature in compounds for stable n-type OTFT operation.

  14. Superior light trapping in thin film silicon solar cells through nano imprint lithography

    Energy Technology Data Exchange (ETDEWEB)

    Soppe, W.J.; Dorenkamper, M.S.; Schropp, R.E.I.; Pex, P.P.A.C.

    2013-10-15

    ECN and partners have developed a fabrication process based on nanoimprint lithography (NIL) of textures for light trapping in thin film solar cells such as thin-film silicon, OPV, CIGS and CdTe. The process can be applied in roll-to-roll mode when using a foil substrate or in roll-to-plate mode when using a glass substrate. The lacquer also serves as an electrically insulating layer for cells if steel foil is used as substrate, to enable monolithic series interconnection. In this paper we will show the superior light trapping in thin film silicon solar cells made on steel foil with nanotextured back contacts. We have made single junction a-Si and {mu}c-Si and a-Si/{mu}c-Si tandem cells, where we applied several types of nano-imprints with random and periodic structures. We will show that the nano-imprinted back contact enables more than 30% increase of current in comparison with non-textured back contacts and that optimized periodic textures outperform state-of-the-art random textures. For a-Si cells we obtained Jsc of 18 mA/cm{sup 2} and for {mu}c-Si cells more than 24 mA/cm{sup 2}. Tandem cells with a total Si absorber layer thickness of only 1350 nm have an initial efficiency of 11%.

  15. Effects of strain on the magnetic and transport properties of the epitaxial La0.5Ca0.5MnO3 thin films

    Science.gov (United States)

    Zarifi, M.; Kameli, P.; Ehsani, M. H.; Ahmadvand, H.; Salamati, H.

    2016-12-01

    The epitaxial strain can considerably modify the physical properties of thin films compared to the bulk. This paper reports the effects of substrate-induced strain on La0.5Ca0.5MnO3 (LCMO) thin films, grown on (100) SrTiO3 (STO) and LaAlO3 (LAO) substrates by pulsed laser deposition technique. Transport and magnetic properties were found to be strongly dependent on strain type. It is also shown that compressive (tensile) strain leads to the increase (decrease) in the magnetization of the films. Moreover, it was observed that all LCMO films deposited on both LAO and STO substrates behave as an insulator, but LCMO/LAO thin films with compressive strain have lower resistivity than LCMO/STO thin films with tensile strain. Applying magnetic field to LCMO/STO thin films with thickness of 25 and 50 nm leads to very small change in the resistivity, while the effects of magnetic field on the sample with thickness of 125 nm leads to an insulator-metal transition. For LCMO/LAO thin films, the magnetic field has a strong impact on the resistivity of samples. The results show that the magnetoresistance (MR) is enhanced by increasing film thickness for LCMO/LAO samples, due to the relatively stronger phase separation. For LCMO/STO thin films MR is drastically decreased by reduction of film thickness, which is attributed to the enhancement of the charge-orbital order (CO-O) accompanying the complex spin order (the so-called CE type). The changes of the antiferromagnetic structure from the CE to C type and the enhancement of the CE type could be attributed to the in-plane compressive and tensile strain, respectively.

  16. Characterization of organic thin films

    CERN Document Server

    Ulman, Abraham; Evans, Charles A

    2009-01-01

    Thin films based upon organic materials are at the heart of much of the revolution in modern technology, from advanced electronics, to optics to sensors to biomedical engineering. This volume in the Materials Characterization series introduces the major common types of analysis used in characterizing of thin films and the various appropriate characterization technologies for each. Materials such as Langmuir-Blodgett films and self-assembled monolayers are first introduced, followed by analysis of surface properties and the various characterization technologies used for such. Readers will find detailed information on: -Various spectroscopic approaches to characterization of organic thin films, including infrared spectroscopy and Raman spectroscopy -X-Ray diffraction techniques, High Resolution EELS studies, and X-Ray Photoelectron Spectroscopy -Concise Summaries of major characterization technologies for organic thin films, including Auger Electron Spectroscopy, Dynamic Secondary Ion Mass Spectrometry, and Tra...

  17. Synaptic behaviors of thin-film transistor with a Pt/HfO x /n-type indium–gallium–zinc oxide gate stack

    Science.gov (United States)

    Yang, Paul; Park, Daehoon; Beom, Keonwon; Kim, Hyung Jun; Kang, Chi Jung; Yoon, Tae-Sik

    2018-07-01

    We report a variety of synaptic behaviors in a thin-film transistor (TFT) with a metal-oxide-semiconductor gate stack that has a Pt/HfO x /n-type indium–gallium–zinc oxide (n-IGZO) structure. The three-terminal synaptic TFT exhibits a tunable synaptic weight with a drain current modulation upon repeated application of gate and drain voltages. The synaptic weight modulation is analog, voltage-polarity dependent reversible, and strong with a dynamic range of multiple orders of magnitude (>104). This modulation process emulates biological synaptic potentiation, depression, excitatory-postsynaptic current, paired-pulse facilitation, and short-term to long-term memory transition behaviors as a result of repeated pulsing with respect to the pulse amplitude, width, repetition number, and the interval between pulses. These synaptic behaviors are interpreted based on the changes in the capacitance of the Pt/HfO x /n-IGZO gate stack, the channel mobility, and the threshold voltage that result from the redistribution of oxygen ions by the applied gate voltage. These results demonstrate the potential of this structure for three-terminal synaptic transistor using the gate stack composed of the HfO x gate insulator and the IGZO channel layer.

  18. Synaptic behaviors of thin-film transistor with a Pt/HfO x /n-type indium-gallium-zinc oxide gate stack.

    Science.gov (United States)

    Yang, Paul; Park, Daehoon; Beom, Keonwon; Kim, Hyung Jun; Kang, Chi Jung; Yoon, Tae-Sik

    2018-07-20

    We report a variety of synaptic behaviors in a thin-film transistor (TFT) with a metal-oxide-semiconductor gate stack that has a Pt/HfO x /n-type indium-gallium-zinc oxide (n-IGZO) structure. The three-terminal synaptic TFT exhibits a tunable synaptic weight with a drain current modulation upon repeated application of gate and drain voltages. The synaptic weight modulation is analog, voltage-polarity dependent reversible, and strong with a dynamic range of multiple orders of magnitude (>10 4 ). This modulation process emulates biological synaptic potentiation, depression, excitatory-postsynaptic current, paired-pulse facilitation, and short-term to long-term memory transition behaviors as a result of repeated pulsing with respect to the pulse amplitude, width, repetition number, and the interval between pulses. These synaptic behaviors are interpreted based on the changes in the capacitance of the Pt/HfO x /n-IGZO gate stack, the channel mobility, and the threshold voltage that result from the redistribution of oxygen ions by the applied gate voltage. These results demonstrate the potential of this structure for three-terminal synaptic transistor using the gate stack composed of the HfO x gate insulator and the IGZO channel layer.

  19. Photovoltaics: tests of thin-film technologies. 6 thin-film technologies in 3 different BIPV modes compared in a real outdoor performance test; PV-ThinFilmTest. 6 thin-film technologies in 3 different BIPV modes compared in a real outdoor performance test

    Energy Technology Data Exchange (ETDEWEB)

    Frei, R.; Meier, Ch.

    2005-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a comparison made between six types of thin-film, building-integrated photovoltaic (BIPV) technologies used in three different modes of building-integration. More than 450 thin-film modules including amorphous silicon and CIS technologies were monitored. Each type of module was installed in three different modes: inclined (20{sup o}), flat with free back air flow, and flat with thermal back insulation. The performance of these commercially available thin-film BIPV systems was monitored using an extensive monitoring program. Additionally, three mono-crystalline PV arrays allowed direct comparison of the technologies. The results of the monitoring work are presented and further work to be done is discussed, including the monitoring of possible long-term degradation.

  20. Delamination of Compressed Thin Layers at Corners

    DEFF Research Database (Denmark)

    Sørensen, Kim D.; Jensen, Henrik Myhre; Clausen, Johan

    2008-01-01

    An analysis of delamination for a thin elastic layer under compression, attached to a substrate at a corner is carried out. The analysis is performed by combining results from interface fracture mechanics and the theory of thin shells. In contrast with earlier results for delamination on a flat s...... layers, Fracture mechanics, Crack closure, Steady state crack propagation.......An analysis of delamination for a thin elastic layer under compression, attached to a substrate at a corner is carried out. The analysis is performed by combining results from interface fracture mechanics and the theory of thin shells. In contrast with earlier results for delamination on a flat...... results for the fracture mechanical properties have been obtained, and these are applied in a study of the effect of contacting crack faces. Special attention has been given to analyse conditions under which steady state propagation of buckling driven delamination takes place. Keywords: Delamination, Thin...

  1. Role of ferrite and phosphorus plus sulphur in the crack sensitivity of autogenously welded type 309 stainless steel

    International Nuclear Information System (INIS)

    Lambert, F.J. Jr.

    1976-07-01

    A study on autogenous welding of Type 309 thin stainless steel sheet was made after experiencing cracking difficulties on several commercial heats. A relationship exists between the sum of the phosphorus plus sulfur, the ferrite control of the weld metal, and the crack sensitivity of autogenously made welds. A new simple weld test for thin-gage sheet is utilized for studying the susceptibility to cracking. A chemistry modification is suggested to alleviate possible weld cracking when autogenously welding this grade. The principles of crack sensitivity prediction could apply to other austenitic stainless steel types where chemistry limits are such that ferrite is possible

  2. Low temperature (< 100 °C) deposited P-type cuprous oxide thin films: Importance of controlled oxygen and deposition energy

    International Nuclear Information System (INIS)

    Li, Flora M.; Waddingham, Rob; Milne, William I.; Flewitt, Andrew J.; Speakman, Stuart; Dutson, James; Wakeham, Steve; Thwaites, Mike

    2011-01-01

    With the emergence of transparent electronics, there has been considerable advancement in n-type transparent semiconducting oxide (TSO) materials, such as ZnO, InGaZnO, and InSnO. Comparatively, the availability of p-type TSO materials is more scarce and the available materials are less mature. The development of p-type semiconductors is one of the key technologies needed to push transparent electronics and systems to the next frontier, particularly for implementing p–n junctions for solar cells and p-type transistors for complementary logic/circuits applications. Cuprous oxide (Cu 2 O) is one of the most promising candidates for p-type TSO materials. This paper reports the deposition of Cu 2 O thin films without substrate heating using a high deposition rate reactive sputtering technique, called high target utilisation sputtering (HiTUS). This technique allows independent control of the remote plasma density and the ion energy, thus providing finer control of the film properties and microstructure as well as reducing film stress. The effect of deposition parameters, including oxygen flow rate, plasma power and target power, on the properties of Cu 2 O films are reported. It is known from previously published work that the formation of pure Cu 2 O film is often difficult, due to the more ready formation or co-formation of cupric oxide (CuO). From our investigation, we established two key concurrent criteria needed for attaining Cu 2 O thin films (as opposed to CuO or mixed phase CuO/Cu 2 O films). First, the oxygen flow rate must be kept low to avoid over-oxidation of Cu 2 O to CuO and to ensure a non-oxidised/non-poisoned metallic copper target in the reactive sputtering environment. Secondly, the energy of the sputtered copper species must be kept low as higher reaction energy tends to favour the formation of CuO. The unique design of the HiTUS system enables the provision of a high density of low energy sputtered copper radicals/ions, and when combined with a

  3. Simulation study of a single-grip harvester in thinning from below and thinning from above

    Energy Technology Data Exchange (ETDEWEB)

    Eliasson, Lars [Swedish Univ. of Agricultural Sciences, Umeaa (Sweden). Dept. of Silviculture; Lageson, Haakan [Forest Owner' s Ass. of Norrbotten, Boden (Sweden)

    1999-07-01

    The time consumption and productivity of a single-grip harvester were studied, using a simulation model, when thinning from below and above in eight randomly selected stands. The model estimated the time required for each work element, given machine and tree positions, and tree size. A 2 x 5 factorial design was used with factors thinning type [from below (T{sub b}) and above (T{sub a})] and tree size. Trees were subjectively selected for harvest according to thinning type. Total basal area removal was 30% plot{sup -1}. Approximately 50% more trees were harvested in T{sub b} than in T{sub a}. Time consumption tree{sup -1} was higher for T{sub a} than T{sub b}. Time consumption for machine and boom movements decreased with increasing number of harvested trees, and time for felling and processing of trees increased with harvested mean stem volume. Harvester productivity was 36% higher for T{sub a}, since the increase in harvested mean stem volume was higher than the increase in time consumption tree{sup -1}.

  4. Thermoelectric prospects of chemically deposited PbSe and SnSe thin films

    Science.gov (United States)

    Nair, P. K.; Martínez, Ana Karen; Rosa García Angelmo, Ana; Barrios Salgado, Enue; Nair, M. T. S.

    2018-03-01

    Thin films of PbSe of 400-600 nm in thickness, were obtained via chemical deposition from a solution containing lead nitrate, thiourea and selenosufate. SnSe thin films of 90-180 nm in thickness, were also obtained by chemical deposition from a solution containing selenosulfate. Optical and electrical properties of these thin films were significantly altered by heating them in selenium vapor at 300 °C. Thin film PbSe has a bandgap (Eg) of 1.17 eV (direct gap, forbidden transitions), which decreases to 0.77 eV when it has been heated. Its electrical conductivity (σ) is p-type: 0.18 Ω-1 cm-1 (as-prepared), and 6.4 Ω-1 cm-1 when heated. Thin film SnSe is of orthorhombic crystalline structure which remains stable when heated at 300 °C, but its Eg increases from 1.12 eV (indirect) in as-prepared film to 1.5 eV (direct, forbidden transitions) upon heating. Its electrical conductivity is p-type, which increases from 0.3 Ω-1 cm-1 (as-prepared) to 1 Ω-1 cm-1 when heated (without Se-vapor). When SnSe film is heated at 300 °C in the presence of Se-vapor, they transform to SnSe2, with Eg of 1.5 eV (direct, forbidden) with n-type electrical conductivity, 11 Ω-1 cm-1. The Seebeck coefficient for the PbSe films is: +0.55 mV K-1 (as prepared) and +0.275 mV K-1 (heated); for SnSe films it is: +0.3 mV K-1 (as prepared) and +0.20 mV K-1 (heated); and for SnSe2 film, - 0.35 mV K-1. A five-element PbSe-SnSe2-PbSe-SnSe2-PbSe thermoelectric device demonstrated 50 mV for a temperature difference ΔT = 20 °C (2.5 mV K-1). For SnSe-SnSe2-SnSe-SnSe2-SnSe device, the value is 15 mV for ΔT = 20 °C (0.75 mV K-1). Prospect of these thin films in thermoelectric devices of hybrid materials, in which the coatings may be applied on distinct substrate and geometries is attractive.

  5. Influence of reversible epitactical stress on the electronic properties of thin superconducting films

    International Nuclear Information System (INIS)

    Trommler, Sascha

    2014-01-01

    In this thesis new stress techniques are applied on thin superconducting (La,Sr) 2 CuO 4 and BaFe 1.8 Co 0.2 As 2 films. At one hand piezoelectric substrates are applied, which make a biaxial stress of the thin film deposed there possible, whereby the lattice parameters of the substrate are altered by an electric field. At the other hand on the base of flexible substrates by means of a bending experiment a uniaxial lattice deformation of thin film is realized.

  6. Transparent conductive p-type lithium-doped nickel oxide thin films deposited by pulsed plasma deposition

    Science.gov (United States)

    Huang, Yanwei; Zhang, Qun; Xi, Junhua; Ji, Zhenguo

    2012-07-01

    Transparent p-type Li0.25Ni0.75O conductive thin films were prepared on conventional glass substrates by pulsed plasma deposition. The effects of substrate temperature and oxygen pressure on structural, electrical and optical properties of the films were investigated. The electrical resistivity decreases initially and increases subsequently as the substrate temperature increases. As the oxygen pressure increases, the electrical resistivity decreases monotonically. The possible physical mechanism was discussed. And a hetero p-n junction of p-Li0.25Ni0.75O/n-SnO2:W was fabricated by depositing n-SnO2:W on top of the p-Li0.25Ni0.75O, which exhibits typical rectifying current-voltage characteristics.

  7. Transparent conductive p-type lithium-doped nickel oxide thin films deposited by pulsed plasma deposition

    International Nuclear Information System (INIS)

    Huang Yanwei; Zhang Qun; Xi Junhua; Ji Zhenguo

    2012-01-01

    Transparent p-type Li 0.25 Ni 0.75 O conductive thin films were prepared on conventional glass substrates by pulsed plasma deposition. The effects of substrate temperature and oxygen pressure on structural, electrical and optical properties of the films were investigated. The electrical resistivity decreases initially and increases subsequently as the substrate temperature increases. As the oxygen pressure increases, the electrical resistivity decreases monotonically. The possible physical mechanism was discussed. And a hetero p-n junction of p-Li 0.25 Ni 0.75 O/n-SnO 2 :W was fabricated by depositing n-SnO 2 :W on top of the p-Li 0.25 Ni 0.75 O, which exhibits typical rectifying current-voltage characteristics.

  8. Analytical methods applied to diverse types of Brazilian propolis

    Directory of Open Access Journals (Sweden)

    Marcucci Maria

    2011-06-01

    Full Text Available Abstract Propolis is a bee product, composed mainly of plant resins and beeswax, therefore its chemical composition varies due to the geographic and plant origins of these resins, as well as the species of bee. Brazil is an important supplier of propolis on the world market and, although green colored propolis from the southeast is the most known and studied, several other types of propolis from Apis mellifera and native stingless bees (also called cerumen can be found. Propolis is usually consumed as an extract, so the type of solvent and extractive procedures employed further affect its composition. Methods used for the extraction; analysis the percentage of resins, wax and insoluble material in crude propolis; determination of phenolic, flavonoid, amino acid and heavy metal contents are reviewed herein. Different chromatographic methods applied to the separation, identification and quantification of Brazilian propolis components and their relative strengths are discussed; as well as direct insertion mass spectrometry fingerprinting. Propolis has been used as a popular remedy for several centuries for a wide array of ailments. Its antimicrobial properties, present in propolis from different origins, have been extensively studied. But, more recently, anti-parasitic, anti-viral/immune stimulating, healing, anti-tumor, anti-inflammatory, antioxidant and analgesic activities of diverse types of Brazilian propolis have been evaluated. The most common methods employed and overviews of their relative results are presented.

  9. Tunable pinning effects produced by non-uniform antidot arrays in YBCO thin films

    Energy Technology Data Exchange (ETDEWEB)

    George, J.; Jones, A.; Al-Qurainy, M. [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW (Australia); Fedoseev, S.A. [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW (Australia); Centre for Medical Radiation Physics, University of Wollongong, NSW (Australia); Rosenfeld, A. [Centre for Medical Radiation Physics, University of Wollongong, NSW (Australia); Pan, A.V. [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW (Australia); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation)

    2017-04-15

    Uniform, graded and spaced arrays of 3 μm triangular antidots in pulsed laser deposited YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO) superconducting thin films are compared by examining the improvements in the critical current density J{sub c} they produced. The comparison is made to establish the role of their lithographically defined (non-)uniformity and the effectiveness to control and/or enhance the critical current density. It is found that almost all types of non-uniform arrays, including graded ones enhance J{sub c} over the broad applied magnetic field and temperature range due to the modified critical state. Whereas uniform arrays of antidots either reduce or produce no effect on J{sub c} compared to the original (as-deposited) thin films. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Hard X-ray photoemission spectroscopy of transition-metal oxide thin films and interfaces

    International Nuclear Information System (INIS)

    Wadati, H.; Fujimori, A.

    2013-01-01

    Highlights: •Photoemission spectroscopy is a powerful technique to study the electronic structures of transition-metal oxides. •Hard X-ray photoemission spectroscopy (HXPES) is a new type of photoemission spectroscopy which can probe bulk states. •HXPES is very suitable for studying oxide thin films such as the composition dependence and the film thickness dependence. -- Abstract: Photoemission spectroscopy is a powerful experimental technique to study the electronic structures of solids, especially of transition-metal oxides. Recently, hard X-ray photoemission spectroscopy (HXPES) has emerged as a more relevant experimental technique to obtain clear information about bulk states. Here, we describe how HXPES can be conveniently applied to study the interesting subjects on oxide thin films such as the composition dependence and the film thickness dependence of the electronic structures and the interfacial electronic structure of multilayers

  11. Effect of Sr doping on LaTiO3 thin films

    International Nuclear Information System (INIS)

    Vilquin, B.; Kanki, T.; Yanagida, T.; Tanaka, H.; Kawai, T.

    2005-01-01

    We report on the electric properties of La 1-x Sr x TiO 3 (0 ≤ x ≤ 0.5) thin films fabricated by pulsed laser deposition method. Crystallographic measurement of the thin films showed the epitaxial c-axis perovskite structure. The electric property of LaTiO 3 thin film, which is a typical Mott insulative material in bulk, showed insulative behaviour, while the Sr-doped films showed metallic conduction suffering electron-electron scattering. Below x = 0.1, the major carrier type was identified to be hole, and switched to electron with further increasing Sr-doping above x = 0.15. In fact, the switching from p-type to n-type for La 1-x Sr x TiO 3 thin films is first demonstrated in this study. The transition suggests that effective Coulomb gap vanishes due to over-additional Sr doping

  12. Plasmonic back contacts with non-ordered Ag nanostructures for light trapping in thin-film silicon solar cells

    International Nuclear Information System (INIS)

    Paetzold, Ulrich W.; Meier, Matthias; Moulin, Etienne; Smirnov, Vladimir; Pieters, Bart E.; Rau, Uwe; Carius, Reinhard

    2013-01-01

    In this work, we investigate the light trapping of thin-film silicon solar cells which apply plasmonic Ag back contacts with non-ordered Ag nanostructures. The preparation, characterization and three-dimensional electromagnetic simulations of these back contacts with various distributions of non-ordered Ag nanostructures are presented. The measured reflectance spectra of the Ag back contacts with non-ordered nanostructures in air are well reproduced in reflectance spectra derived from the three-dimensional electromagnetic simulations of isolated nanostructures on Ag back contacts. The light–matter interaction of these nanostructures is given by localized surface plasmons and, thus, the measured diffuse reflectance of the back contacts is attributed to plasmon-induced light scattering. A significant plasmonic light-trapping effect in n-i-p substrate-type μc-Si:H thin-film solar cell prototypes which apply a Ag back contact with non-ordered nanostructures is identified when compared with flat reference solar cells

  13. Plasmonic back contacts with non-ordered Ag nanostructures for light trapping in thin-film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Paetzold, Ulrich W., E-mail: u.paetzold@fz-juelich.de [IEK5-Photovoltaik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Meier, Matthias, E-mail: ma.meier@fz-juelich.de [IEK5-Photovoltaik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Moulin, Etienne, E-mail: e.moulin@fz-juelich.de [IEK5-Photovoltaik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Smirnov, Vladimir, E-mail: v.smirnov@fz-juelich.de [IEK5-Photovoltaik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Pieters, Bart E., E-mail: b.pieters@fz-juelich.de [IEK5-Photovoltaik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Rau, Uwe, E-mail: u.rau@fz-juelich.de [IEK5-Photovoltaik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Carius, Reinhard, E-mail: r.carius@fz-juelich.de [IEK5-Photovoltaik, Forschungszentrum Juelich, D-52425 Juelich (Germany)

    2013-05-15

    In this work, we investigate the light trapping of thin-film silicon solar cells which apply plasmonic Ag back contacts with non-ordered Ag nanostructures. The preparation, characterization and three-dimensional electromagnetic simulations of these back contacts with various distributions of non-ordered Ag nanostructures are presented. The measured reflectance spectra of the Ag back contacts with non-ordered nanostructures in air are well reproduced in reflectance spectra derived from the three-dimensional electromagnetic simulations of isolated nanostructures on Ag back contacts. The light–matter interaction of these nanostructures is given by localized surface plasmons and, thus, the measured diffuse reflectance of the back contacts is attributed to plasmon-induced light scattering. A significant plasmonic light-trapping effect in n-i-p substrate-type μc-Si:H thin-film solar cell prototypes which apply a Ag back contact with non-ordered nanostructures is identified when compared with flat reference solar cells.

  14. AC susceptibility of thin Pb films in intermediate and mixed state

    Energy Technology Data Exchange (ETDEWEB)

    Janu, Zdenek, E-mail: janu@fzu.cz [Institute of Physics of the AS CR, v.v.i., Na Slovance 2, CZ-182 21 Prague 8 (Czech Republic); Svindrych, Zdenek [Institute of Physics of the AS CR, v.v.i., Na Slovance 2, CZ-182 21 Prague 8 (Czech Republic); Trunecek, Otakar [Charles University in Prague, Faculty of Mathematics and Physics, Ke Karlovu 3, CZ-121 16 Prague 2 (Czech Republic); Kus, Peter; Plecenik, Andrej [Komenius University in Bratislava, Faculty of Mathematics, Physics, and Informatics, Mlynska dolina, 842 48 Bratislava 4 (Slovakia)

    2011-12-15

    Thickness dependent transition in AC susceptibility between intermediate and mixed state in type-I superconducting films. The temperature induced crossover between reversible and irreversible behavior was observed in the thicker film. The temperature dependence of the AC susceptibility in mixed state follows prediction of model based on Bean critical state. The temperature dependence of the harmonics of the complex AC susceptibility in the intermediate state is explained. Thin films of type I superconductors of a thickness comparable or less than a flux penetration length behave like type II superconductors in a mixed state. With decreasing film thickness normal domains carrying a magnetic flux get smaller with smaller number of flux quanta per domain and finally transform into single quantum flux lines, i.e. quantum vortices similar to those found in type II superconductors. We give an evidence of this behavior from the measurements of the nonlinear response of a total magnetic moment to an applied AC magnetic field, directly from the temperature dependence of an AC susceptibility.

  15. Test of the fast thin-film ferromagnetic shutters for ultracold neutrons

    International Nuclear Information System (INIS)

    Pokotilovskij, Yu.N.; Novopol'tsev, M.I.; Geltenbort, P.

    2008-01-01

    Test of thin-film ferromagnetic shutters of two types for ultracold neutrons has been performed. The first type is based on neutron reflection from the sequence of successively placed thin ferromagnetic layers with oppositely directed magnetization. The second one is based on neutron refraction in ferromagnetic foils inserted in the beam

  16. Synthesis and characterization of n-type NiO:Al thin films for fabrication of p-n NiO homojunctions

    Science.gov (United States)

    Sun, Hui; Liao, Ming-Han; Chen, Sheng-Chi; Li, Zhi-Yue; Lin, Po-Chun; Song, Shu-Mei

    2018-03-01

    n-type NiO:Al thin films were deposited by RF magnetron sputtering. Their optoelectronic properties versus Al target power was investigated. The results show that with increasing Al target power, the conduction type of NiO films changes from p-type to n-type. The variation of the film’s electrical and optical properties depends on Al amount in the film. When Al target power is relatively low, Al3+ cations tend to enter nickel vacancy sites, which makes the lattice structure of NiO more complete. This improves the carrier mobility and film’s transmittance. However, when Al target power exceeds 40 W, Al atoms begin to enter into interstitial sites and form an Al cluster in the NiO film. This behavior is beneficial for improving the film’s n-type conductivity but degrades the film’s transmittance. Finally, Al/(p-type NiO)/(n-type NiO:Al)/ITO homojunctions were fabricated. Their performance was compared with Al/(p-type NiO)/ITO heterojunctions without an n-type NiO layer. Thanks to the better interface quality between the two NiO layers, the homojunctions present better performance.

  17. The effects of anode material type on the optoelectronic properties of electroplated CdTe thin films and the implications for photovoltaic application

    Science.gov (United States)

    Echendu, O. K.; Dejene, B. F.; Dharmadasa, I. M.

    2018-03-01

    The effects of the type of anode material on the properties of electrodeposited CdTe thin films for photovoltaic application have been studied. Cathodic electrodeposition of two sets of CdTe thin films on glass/fluorine-doped tin oxide (FTO) was carried out in two-electrode configuration using graphite and platinum anodes. Optical absorption spectra of films grown with graphite anode displayed significant spread across the deposition potentials compared to those grown with platinum anode. Photoelectrochemical cell result shows that the CdTe grown with graphite anode became p-type after post-deposition annealing with prior CdCl2 treatment, as a result of carbon incorporation into the films, while those grown with platinum anode remained n-type after annealing. A review of recent photoluminescence characterization of some of these CdTe films reveals the persistence of a defect level at (0.97-0.99) eV below the conduction band in the bandgap of CdTe grown with graphite anode after annealing while films grown with platinum anode showed the absence of this defect level. This confirms the impact of carbon incorporation into CdTe. Solar cell made with CdTe grown with platinum anode produced better conversion efficiency compared to that made with CdTe grown using graphite anode, underlining the impact of anode type in electrodeposition.

  18. Novel chemical analysis for thin films

    International Nuclear Information System (INIS)

    Usui, Toshio; Kamei, Masayuki; Aoki, Yuji; Morishita, Tadataka; Tanaka, Shoji

    1991-01-01

    Scanning electron microscopy and total-reflection-angle X-ray spectroscopy (SEM-TRAXS) was applied for fluorescence X-ray analysis of 50A- and 125A-thick Au thin films on Si(100). The intensity of the AuM line (2.15 keV) emitted from the Au thin films varied as a function of the take-off angle (θ t ) with respect to the film surface; the intensity of AuM line from the 125A-thick Au thin film was 1.5 times as large as that of SiK α line (1.74 keV) emitted from the Si substrate when θ t = 0deg-3deg, in the vicinity of a critical angle for total external reflection of the AuM line at Si (0.81deg). In addition, the intensity of the AuM line emitted from the 50A-thick Au thin film was also sufficiently strong for chemical analysis. (author)

  19. Crystallization of sol-gel derived lead zirconate titanate thin films in argon and oxygen atmospheres

    International Nuclear Information System (INIS)

    Bursill, L.A.

    1994-01-01

    Electron diffraction and high-resolution electron microscopic techniques are applied to reveal the mechanisms of crystallization of 75 nm thin films of ferroelectric lead-zirconate-titanate (PZT). Sol-gel methods, followed by pyrolysis at 350 deg C, were used to provide a common starting point after which a variety of rapid-thermal annealing (RTA) experiments in the temperature range 400-700 deg C were made in argon, oxygen and nitrogen/hydrogen atmospheres. The results are interpreted in terms of the crystal chemical analysis, which points out that partial pressure of oxygen and heating rate are important experimental parameters which must be controlled if ferroelectric perovskite-type Pb 2 ZrTiO 6 , rather than pyrochlore-type Pb 2 ZrTiO 6+x , where O < X < 1 or -1 < X < O, is to be obtained after the RTA step. Thus significant improvements in the crystallization of perovskite-type PZT were clearly demonstrated by using argon atmospheres for the RTA step. The results have significance for the production of high-quality ferroelectric thin films, with improved switching and fatigue characteristics, since even small amounts of the pyrochlore phase prove detrimental for these properties. 18 refs., 1 tab., 10 figs

  20. Differentiation of bacterial and non-bacterial community-acquired pneumonia by thin-section computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Isao [Department of Respiratory Medicine, Kurashiki Central Hospital, 1-1-1 Miwa, Kurashiki 710-8602 (Japan); Department of Respiratory Medicine, Kyoto University, 54 Shogoin-kawaharacho, Sakyo-ku, Kyoto 606-8507 (Japan)], E-mail: isaoito@kuhp.kyoto-u.ac.jp; Ishida, Tadashi [Department of Respiratory Medicine, Kurashiki Central Hospital, 1-1-1 Miwa, Kurashiki 710-8602 (Japan)], E-mail: ishidat@kchnet.or.jp; Togashi, Kaori [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, 54 Shogoin-kawaharacho, Sakyo-ku, Kyoto 606-8507 (Japan)], E-mail: ktogashi@kuhp.kyoto-u.ac.jp; Niimi, Akio [Department of Respiratory Medicine, Kyoto University, 54 Shogoin-kawaharacho, Sakyo-ku, Kyoto 606-8507 (Japan)], E-mail: niimi@kuhp.kyoto-u.ac.jp; Koyama, Hiroshi [General Internal Medicine, National Hospital Organization Kyoto Medical Center, 1-1 Fukakusa-Mukohatacho, Fushimi-ku, Kyoto 612-8555 (Japan)], E-mail: hkoyama-kyt@umin.ac.jp; Ishimori, Takayoshi [Department of Radiology, Kurashiki Central Hospital, 1-1-1 Miwa, Kurashiki 710-8602 (Japan)], E-mail: ti10794@kchnet.or.jp; Kobayashi, Hisataka [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, 54 Shogoin-kawaharacho, Sakyo-ku, Kyoto 606-8507 (Japan); Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 10, Room 1B40, MSC1088, 10 Center Drive, Bethesda, MD 20892-1088 (United States)], E-mail: kobayash@mail.nih.gov; Mishima, Michiaki [Department of Respiratory Medicine, Kyoto University, 54 Shogoin-kawaharacho, Sakyo-ku, Kyoto 606-8507 (Japan)], E-mail: mishima@kuhp.kyoto-u.ac.jp

    2009-12-15

    Background and objective: The management of community-acquired pneumonia (CAP) depends, in part, on the identification of the causative agents. The objective of this study was to determine the potential of thin-section computed tomography (CT) in differentiating bacterial and non-bacterial pneumonia. Patients and methods: Thin-section CT studies were prospectively examined in hospitalized CAP patients within 2 days of admission, followed by retrospective assessment by two pulmonary radiologists. Thin-section CT findings on the pneumonias caused by each pathogen were examined, and two types of pneumonias were compared. Using multivariate logistic regression analyses, receiver operating characteristic (ROC) curves were produced. Results: Among 183 CAP episodes (181 patients, 125 men and 56 women, mean age {+-} S.D.: 61.1 {+-} 19.7) examined by thin-section CT, the etiologies of 125 were confirmed (94 bacterial pneumonia and 31 non-bacterial pneumonia). Centrilobular nodules were specific for non-bacterial pneumonia and airspace nodules were specific for bacterial pneumonia (specificities of 89% and 94%, respectively) when located in the outer lung areas. When centrilobular nodules were the principal finding, they were specific but lacked sensitivity for non-bacterial pneumonia (specificity 98% and sensitivity 23%). To distinguish the two types of pneumonias, centrilobular nodules, airspace nodules and lobular shadows were found to be important by multivariate analyses. ROC curve analysis discriminated bacterial pneumonia from non-bacterial pneumonia among patients without underlying lung diseases, yielding an optimal point with sensitivity and specificity of 86% and 79%, respectively, but was less effective when all patients were analyzed together (70% and 84%, respectively). Conclusion: Thin-section CT examination was applied for the differentiation of bacterial and non-bacterial pneumonias. Though showing some potential, this examination at the present time would

  1. Differentiation of bacterial and non-bacterial community-acquired pneumonia by thin-section computed tomography

    International Nuclear Information System (INIS)

    Ito, Isao; Ishida, Tadashi; Togashi, Kaori; Niimi, Akio; Koyama, Hiroshi; Ishimori, Takayoshi; Kobayashi, Hisataka; Mishima, Michiaki

    2009-01-01

    Background and objective: The management of community-acquired pneumonia (CAP) depends, in part, on the identification of the causative agents. The objective of this study was to determine the potential of thin-section computed tomography (CT) in differentiating bacterial and non-bacterial pneumonia. Patients and methods: Thin-section CT studies were prospectively examined in hospitalized CAP patients within 2 days of admission, followed by retrospective assessment by two pulmonary radiologists. Thin-section CT findings on the pneumonias caused by each pathogen were examined, and two types of pneumonias were compared. Using multivariate logistic regression analyses, receiver operating characteristic (ROC) curves were produced. Results: Among 183 CAP episodes (181 patients, 125 men and 56 women, mean age ± S.D.: 61.1 ± 19.7) examined by thin-section CT, the etiologies of 125 were confirmed (94 bacterial pneumonia and 31 non-bacterial pneumonia). Centrilobular nodules were specific for non-bacterial pneumonia and airspace nodules were specific for bacterial pneumonia (specificities of 89% and 94%, respectively) when located in the outer lung areas. When centrilobular nodules were the principal finding, they were specific but lacked sensitivity for non-bacterial pneumonia (specificity 98% and sensitivity 23%). To distinguish the two types of pneumonias, centrilobular nodules, airspace nodules and lobular shadows were found to be important by multivariate analyses. ROC curve analysis discriminated bacterial pneumonia from non-bacterial pneumonia among patients without underlying lung diseases, yielding an optimal point with sensitivity and specificity of 86% and 79%, respectively, but was less effective when all patients were analyzed together (70% and 84%, respectively). Conclusion: Thin-section CT examination was applied for the differentiation of bacterial and non-bacterial pneumonias. Though showing some potential, this examination at the present time would not

  2. Method of formation of thin film component

    Energy Technology Data Exchange (ETDEWEB)

    Wada, Chikara; Kato, Kinya

    1988-04-16

    In the production process of component which is carrying thin film device, such as thin film transistor, acid treatment is applied for etching or for preventing contamination. In case of barium borsilicate glass base, the base is affected by the acid treatment resulting the decrease of transparency. To avoid the effect, deposition of SiO/sub 2/ layer on the surface of the base is usually applied. This invention relates to the protective method of barium borosilicate surface by harnessing the effect of coexisting ion in the acid treatment bath. The method is to add 0.03-5 mol/l of phosphoric acid or its salt in the bath. By the effect of coexisting ion, barium borsilicate glass surface was protected from the damage. (2 figs)

  3. Thin shells joining local cosmic string geometries

    Energy Technology Data Exchange (ETDEWEB)

    Eiroa, Ernesto F. [Universidad de Buenos Aires, Ciudad Universitaria Pabellon I, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Instituto de Astronomia y Fisica del Espacio (IAFE, CONICET-UBA), Buenos Aires (Argentina); Rubin de Celis, Emilio; Simeone, Claudio [Universidad de Buenos Aires, Ciudad Universitaria Pabellon I, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Ciudad Universitaria Pabellon I, IFIBA-CONICET, Buenos Aires (Argentina)

    2016-10-15

    In this article we present a theoretical construction of spacetimes with a thin shell that joins two different local cosmic string geometries. We study two types of global manifolds, one representing spacetimes with a thin shell surrounding a cosmic string or an empty region with Minkowski metric, and the other corresponding to wormholes which are not symmetric across the throat located at the shell. We analyze the stability of the static configurations under perturbations preserving the cylindrical symmetry. For both types of geometries we find that the static configurations can be stable for suitable values of the parameters. (orig.)

  4. Thin shells joining local cosmic string geometries

    International Nuclear Information System (INIS)

    Eiroa, Ernesto F.; Rubin de Celis, Emilio; Simeone, Claudio

    2016-01-01

    In this article we present a theoretical construction of spacetimes with a thin shell that joins two different local cosmic string geometries. We study two types of global manifolds, one representing spacetimes with a thin shell surrounding a cosmic string or an empty region with Minkowski metric, and the other corresponding to wormholes which are not symmetric across the throat located at the shell. We analyze the stability of the static configurations under perturbations preserving the cylindrical symmetry. For both types of geometries we find that the static configurations can be stable for suitable values of the parameters. (orig.)

  5. Structural and biocompatible characterization of TiC/a:C nanocomposite thin films

    International Nuclear Information System (INIS)

    Balázsi, K.; Vandrovcová, M.; Bačáková, L.; Balázsi, Cs.

    2013-01-01

    In this work, sputtered TiC/amorphous C thin films have been developed in order to be applied as potential barrier coating for interfering of Ti ions from pure Ti or Ti alloy implants. Our experiments were based on magnetron sputtering method, because the vacuum deposition provides great flexibility for manipulating material chemistry and structure, leading to films and coatings with special properties. The films have been deposited on silicon (001) substrates with 300 nm thick oxidized silicon sublayer at 200 °C deposition temperature as model substrate. Transmission electron microscopy has been used for structural investigations. Thin films consisted of ∼ 20 nm TiC columnar crystals embedded by 5 nm thin amorphous carbon matrix. MG63 osteoblast cells have been applied for in vitro study of TiC nanocomposites. The cell culture tests give strong evidence of thin films biocompatibility. Highlights: ► The main goal of this work is the relatively easy preparation of nanocomposite TiC thin films by dc magnetron sputtering. ► TEM and HREM were applied for structural characterization of columnar TiC nanocrystals and amorphous carbon matrix. ► The biocompatibility of films was showed by MG63 human osteoblast like cells during 1, 3 and 7 days seeding

  6. High performance, transparent a-IGZO TFTs on a flexible thin glass substrate

    International Nuclear Information System (INIS)

    Lee, Gwang Jun; Jang, Jae Eun; Kim, Joonwoo; Kim, Jung-Hye; Jeong, Soon Moon; Jeong, Jaewook

    2014-01-01

    We investigated electrical properties of transparent amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) with amorphous indium zinc oxide (a-IZO) transparent electrodes on a flexble thin glass substrate. The TFTs show a high field-effect mobility, a good subthreshold slope and a high on/off ratio owing to the high temperature thermal annealing process which cannot be applied to typical transparent polymer-based flexible substrates. Bias stress instability tests applying tensile stress concurrently with the bending radius of up to 40 mm indicated that mechanically and electrically stable a-IGZO TFTs can be fabricated on the transparent thin glass substrate. (paper)

  7. The novel transparent sputtered p-type CuO thin films and Ag/p-CuO/n-Si Schottky diode applications

    Directory of Open Access Journals (Sweden)

    A. Tombak

    2015-01-01

    Full Text Available In the current paper, the physical properties and microelectronic parameters of direct current (DC sputtered p-type CuO film and diode have been investigated. The film of CuO as oxide and p-type semiconductor is grown onto glass and n-Si substrates by reactive DC sputtering at 250 °C. After deposition, a post-annealing procedure is applied at various temperatures in ambient. Through this research, several parameters are determined such structural, optical and electrical magnitudes. The thickness of CuO thin films goes from 122 to 254 nm. A (111-oriented cubic crystal structure is revealed by X-ray analysis. The grain size is roughly depending on the post-annealing temperature, it increases with temperature within the 144–285 nm range. The transmittance reaches 80% simultaneously in visible and infrared bands. The optical band gap is varied between 1.99 and 2.52 eV as a result of annealing temperature while the resistivity and the charge carrier mobility decrease with an increase in temperature from 135 to 14 Ω cm and 0.92 to 0.06 cm2/Vs, respectively. The surface of samples is homogenous, bright dots are visible when temperature reaches the highest value. As a diode, Ag/CuO/n-Si exhibits a non-ideal behavior and the ideality factor is about 3.5. By Norde method, the barrier height and the series resistance are extracted and found to be 0.96 V and 86.6 Ω respectively.

  8. High temperature annealing effects on chromel (Ni90Cr10) thin films and interdiffusion study for sensing applications

    International Nuclear Information System (INIS)

    Datta, Arindom; Cheng Xudong; Miller, Michael A.; Li Xiaochun

    2008-01-01

    Metal embedded thin film thermocouples are very attractive for various applications in harsh environments. One promising technique to embed thin films micro sensors is diffusion bonding, which requires high temperatures and pressures typically in a vacuum. In this study, high temperature annealing effects on chromel (Ni90Cr10) thin film, an important sensor material as one of the components in type K thermocouple, were investigated in a diffusion bonding environment. Annealing was carried out at 800 deg. C for one hour in a diffusion bonder under vacuum without applying pressure. Under such conditions; surface, interface and interdiffusion phenomena were investigated using different characterization techniques including X-ray Diffraction, X-ray Photoelectron Spectroscopy, Scanning Electron Microscopy, and Energy Dispersive Spectroscopy. Results indicate that the present combination of dielectrics is quite reliable and Ni90Cr10 films of 500 nm thickness can be used for applications at least up to 800 deg. C due to a protective thin chromium oxide layer formation on top of the sensor film during annealing

  9. Method and apparatus for coating thin foil with a boron coating

    Science.gov (United States)

    Lacy, Jeffrey L.

    2018-01-16

    An apparatus and a process is disclosed for applying a boron coating to a thin foil. Preferably, the process is a continuous, in-line process for applying a coating to a thin foil comprising wrapping the foil around a rotating and translating mandrel, cleaning the foil with glow discharge in an etching chamber as the mandrel with the foil moves through the chamber, sputtering the foil with boron carbide in a sputtering chamber as the mandrel moves through the sputtering chamber, and unwinding the foil off the mandrel after it has been coated. The apparatus for applying a coating to a thin foil comprises an elongated mandrel. Foil preferably passes from a reel to the mandrel by passing through a seal near the initial portion of an etching chamber. The mandrel has a translation drive system for moving the mandrel forward and a rotational drive system for rotating mandrel as it moves forward. The etching chamber utilizes glow discharge on a surface of the foil as the mandrel moves through said etching chamber. A sputtering chamber, downstream of the etching chamber, applies a thin layer comprising boron onto the surface of the foil as said mandrel moves through said sputtering chamber. Preferably, the coated foil passes from the mandrel to a second reel by passing through a seal near the terminal portion of the sputtering chamber.

  10. Zinc oxide integrated area efficient high output low power wavy channel thin film transistor

    International Nuclear Information System (INIS)

    Hanna, A. N.; Ghoneim, M. T.; Bahabry, R. R.; Hussain, A. M.; Hussain, M. M.

    2013-01-01

    We report an atomic layer deposition based zinc oxide channel material integrated thin film transistor using wavy channel architecture allowing expansion of the transistor width in the vertical direction using the fin type features. The experimental devices show area efficiency, higher normalized output current, and relatively lower power consumption compared to the planar architecture. This performance gain is attributed to the increased device width and an enhanced applied electric field due to the architecture when compared to a back gated planar device with the same process conditions

  11. Zinc oxide integrated area efficient high output low power wavy channel thin film transistor

    KAUST Repository

    Hanna, Amir; Ghoneim, Mohamed T.; Bahabry, Rabab R.; Hussain, Aftab M.; Hussain, Muhammad Mustafa

    2013-01-01

    We report an atomic layer deposition based zinc oxide channel material integrated thin film transistor using wavy channel architecture allowing expansion of the transistor width in the vertical direction using the fin type features. The experimental devices show area efficiency, higher normalized output current, and relatively lower power consumption compared to the planar architecture. This performance gain is attributed to the increased device width and an enhanced applied electric field due to the architecture when compared to a back gated planar device with the same process conditions.

  12. Zinc oxide integrated area efficient high output low power wavy channel thin film transistor

    KAUST Repository

    Hanna, Amir

    2013-11-26

    We report an atomic layer deposition based zinc oxide channel material integrated thin film transistor using wavy channel architecture allowing expansion of the transistor width in the vertical direction using the fin type features. The experimental devices show area efficiency, higher normalized output current, and relatively lower power consumption compared to the planar architecture. This performance gain is attributed to the increased device width and an enhanced applied electric field due to the architecture when compared to a back gated planar device with the same process conditions.

  13. Synthesis of organometallic hydroxides of titanium, vanadium, cobalt and chromium as precursors of thin films type MaOb

    International Nuclear Information System (INIS)

    Montero Villalobos, Mavis

    2001-01-01

    This study shows the results obtained from a general objective that was the synthesis and characterization of precursors of thin films of metallic oxides, two different routes of synthesis have been practiced: route molecular precursors and route Sol-Gel technic. In the first route one of the objectives of the investigation is to obtain a molecular precursor of material type M a O b a route of synthesis have been tried proved that involves anhydrous chlorides of the transition metals and linked R that are alcoxides of metal such as silicon, titanium and zirconium. In the second route the general objective to create thin films of metallic oxide has been maintained but the way to resolve the problem has changed, not giving so much emphasis to the molecular precursors as it was originally presented (this due mainly to its instability and difficulty of synthesis), but being supported in the sun-gel chemistry. It was started a new synthesis line through the sun-gel chemistry that is more versatile and simplifies the process in the film formation [es

  14. Metallic and Ceramic Thin Film Thermocouples for Gas Turbine Engines

    Directory of Open Access Journals (Sweden)

    Otto J. Gregory

    2013-11-01

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

  15. Failure probability assessment of wall-thinned nuclear pipes using probabilistic fracture mechanics

    International Nuclear Information System (INIS)

    Lee, Sang-Min; Chang, Yoon-Suk; Choi, Jae-Boong; Kim, Young-Jin

    2006-01-01

    The integrity of nuclear piping system has to be maintained during operation. In order to maintain the integrity, reliable assessment procedures including fracture mechanics analysis, etc., are required. Up to now, this has been performed using conventional deterministic approaches even though there are many uncertainties to hinder a rational evaluation. In this respect, probabilistic approaches are considered as an appropriate method for piping system evaluation. The objectives of this paper are to estimate the failure probabilities of wall-thinned pipes in nuclear secondary systems and to propose limited operating conditions under different types of loadings. To do this, a probabilistic assessment program using reliability index and simulation techniques was developed and applied to evaluate failure probabilities of wall-thinned pipes subjected to internal pressure, bending moment and combined loading of them. The sensitivity analysis results as well as prototypal integrity assessment results showed a promising applicability of the probabilistic assessment program, necessity of practical evaluation reflecting combined loading condition and operation considering limited condition

  16. Radiation transmission type pipe wall thinning detection device and measuring instruments utilizing ionizing radiation

    International Nuclear Information System (INIS)

    Higashi, Yasuhiko

    2009-01-01

    We developed the device to detect thinning of pipe thorough heat insulation in Power Plant, etc, even while the plant is under operation. It is necessary to test many parts of many pipes for pipe wall thinning management, but it is difficult within a limited time of the routine test. This device consists of detector and radiation source, which can detect the pipe (less than 500 mm in external diameter, less than 50 mm in thickness) with 1.6%-reproducibility (in a few-minutes measurement), based on the attenuation rate. Operation is easy and effective without removing the heat insulation. We will expand this thinning detection system, and contribute the safety of the Plant. (author)

  17. Radiodiagnosis of gastric diseases on the basis of thin contour findings

    International Nuclear Information System (INIS)

    Zubarev, A.V.; Zavodnov, V.Ya.; Sklyanskaya, O.A.

    1988-01-01

    The authors have analyzed the role of the thin contour in radiodiagnisis of various diseases of the gastric mucosa. Altogether 140 patients with various gastric diseases were investigated. Using X-ray examination of the stomach based on the common 2-phase method, thin contour images were obtained in 80 % of the cases. The results of the investigation have revealed direct correlation between the type of the thin contour and a morphological picture of the gastric mucosa in chronic gastritis. Early stomach cancer was characterized by the local absence or rearrangement of a usual pattern of the thin contour on stomach radiograms. It was difficult to defect single erosions or polyps with a diameter under 5 mm against a background of the gastric mucosa thin contour. Good visualization of stomach areolae, particularly those of a rough nodular type in the proximal part of the stomach was suggestive of an ulcerative lesion

  18. Epitaxial thin-film growth of Ruddlesden-Popper-type Ba3Zr2O7 from a BaZrO3 target by pulsed laser deposition

    International Nuclear Information System (INIS)

    Butt, Shariqa Hassan; Rafique, M.S.; Siraj, K.; Latif, A.; Afzal, Amina; Awan, M.S.; Bashir, Shazia; Iqbal, Nida

    2016-01-01

    Ruddlesden-Popper Ba 3 Zr 2 O 7 thin films have been synthesized via pulsed laser deposition (PLD) technique. The optimization of deposition parameters in PLD enables the formation of thin film of metastable Ba 3 Zr 2 O 7 phase from BaZrO 3 target. In order to see the post-annealing effects on the structural and optical properties, the deposited Ba 3 Zr 2 O 7 thin films were annealed at 500, 600 and 800 C. X-ray diffraction (XRD) reveals the formation of Ba 3 Zr 2 O 7 phase with tetragonal structure. The changes in the surface of the deposited films were analysed by FE-SEM and AFM. The thin film post-annealed at 500 C exhibited the best structural, optical and surface properties. Furthermore, the chemical states and chemical composition of the films were determined by X-ray photoelectron spectroscopy (XPS) near the surface. The XPS results show that Ba, Zr and O exist mainly in the form of Ba 3 Zr 2 O 7 Ruddlesden-Popper-type perovskite structure. (orig.)

  19. Artificial intelligence applied to fuel management in BWR type reactors

    International Nuclear Information System (INIS)

    Ortiz S, J.J.

    1998-01-01

    In this work two techniques of artificial intelligence, neural networks and genetic algorithms were applied to a practical problem of nuclear fuel management; the determination of the optimal fuel reload for a BWR type reactor. This is an important problem in the design of the operation cycle of the reactor. As a result of the application of these techniques, comparable or even better reloads proposals than those given by expert companies in the subject were obtained. Additionally, two other simpler problems in reactor physics were solved: the determination of the axial power profile and the prediction of the value of some variables of interest at the end of the operation cycle of the reactor. Neural networks and genetic algorithms have been applied to solve many problems of engineering because of their versatility but they have been rarely used in the area of fuel management. The results obtained in this thesis indicates the convenience of undertaking further work on this area and suggest the application of these techniques of artificial intelligence to the solution of other problems in nuclear reactor physics. (Author)

  20. Analysis of harvesting opportunities for thinning eastern hardwoods on steep terrain

    Science.gov (United States)

    Chris B. LeDoux; John E. Baumgras

    1988-01-01

    Harvesting cost and revenue models were used to evaluate yarding costs by yarder type and to compare stump-to-mill harvesting costs to revenues available from multiproduct thinnings in eastern hardwoods. This analysis includes six types of cable yarders and thinnings in stands where the average diameter at breast height of trees harvested ranged from 7 to 12 inches. To...

  1. Influence of applied stress on swelling behavior in Type 304 stainless steel

    International Nuclear Information System (INIS)

    Igata, N.; Fujihira, T.; Kohno, Y.; Tsunakawa, M.

    1984-01-01

    The swelling behavior of Type 304 stainless steel during stress application was investigated by means of electron irradiation using a high-voltage electron microscope (HVEM). The dose dependence of swelling under stress is similar to the linearafter-incubation swelling scheme of other electron irradiation studies. The effect of applied stress on the swelling characteristics appeared through the control of incubation regime of swelling rather than of the swelling rate. The incubation dose first increases, then decreases, and increases again with increasing applied stress. The prominent finding in this study, based on the advantage of HVEM in situ observation, is that the saturated void density is equal to the number density of interstitial dislocation loops observed in the early stage of irradiation. Essentially, applied stress affects the loop nucleation process. The dislocation loop density then affects the incubation dose of swelling through its control of dislocation behavior and the saturation dose of dislocation density

  2. Removable polytetrafluoroethylene template based epitaxy of ferroelectric copolymer thin films

    Science.gov (United States)

    Xia, Wei; Chen, Qiusong; Zhang, Jian; Wang, Hui; Cheng, Qian; Jiang, Yulong; Zhu, Guodong

    2018-04-01

    In recent years ferroelectric polymers have shown their great potentials in organic and flexible electronics. To meet the requirements of high-performance and low energy consumption of novel electronic devices and systems, structural and electrical properties of ferroelectric polymer thin films are expected to be further optimized. One possible way is to realize epitaxial growth of ferroelectric thin films via removable high-ordered polytetrafluoroethylene (PTFE) templates. Here two key parameters in epitaxy process, annealing temperature and applied pressure, are systematically studied and thus optimized through structural and electrical measurements of ferroelectric copolymer thin films. Experimental results indicate that controlled epitaxial growth is realized via suitable combination of both parameters. Annealing temperature above the melting point of ferroelectric copolymer films is required, and simultaneously moderate pressure (around 2.0 MPa here) should be applied. Over-low pressure (around 1.0 MPa here) usually results in the failure of epitaxy process, while over-high pressure (around 3.0 MPa here) often results in residual of PTFE templates on ferroelectric thin films.

  3. Manipulating Josephson junctions in thin-films by nearby vortices

    International Nuclear Information System (INIS)

    Kogan, V.G.; Mints, R.G.

    2014-01-01

    Highlights: • Vortex located in a bank of a planar Josephson junction changes its character. • Vortex located at some discreet positions in thin strip bank suppresses to zero the zero-field current. • The number of these positions is equal to the number of vortices trapped. • Critical current-field patterns are strongly affected by the vortex position. - Abstract: It is shown that a vortex trapped in one of the banks of a planar edge-type Josephson junction in a narrow thin-film superconducting strip can change drastically the dependence of the junction critical current on the applied field, I c (H). When the vortex is placed at certain discrete positions in the strip middle, the pattern I c (H) has zero at H=0 instead of the traditional maximum of ‘0-type’ junctions. The number of these positions is equal to the number of vortices trapped at the same location. When the junction–vortex separation exceeds ∼W, the strip width, I c (H) is no longer sensitive to the vortex presence. The same is true for any separation if the vortex approaches the strip edges

  4. Dependencies of surface plasmon coupling effects on the p-GaN thickness of a thin-p-type light-emitting diode.

    Science.gov (United States)

    Su, Chia-Ying; Lin, Chun-Han; Yao, Yu-Feng; Liu, Wei-Heng; Su, Ming-Yen; Chiang, Hsin-Chun; Tsai, Meng-Che; Tu, Charng-Gan; Chen, Hao-Tsung; Kiang, Yean-Woei; Yang, C C

    2017-09-04

    The high performance of a light-emitting diode (LED) with the total p-type thickness as small as 38 nm is demonstrated. By increasing the Mg doping concentration in the p-AlGaN electron blocking layer through an Mg pre-flow process, the hole injection efficiency can be significantly enhanced. Based on this technique, the high LED performance can be maintained when the p-type layer thickness is significantly reduced. Then, the surface plasmon coupling effects, including the enhancement of internal quantum efficiency, increase in output intensity, reduction of efficiency droop, and increase of modulation bandwidth, among the thin p-type LED samples of different p-type thicknesses that are compared. These advantageous effects are stronger as the p-type layer becomes thinner. However, the dependencies of these effects on p-type layer thickness are different. With a circular mesa size of 10 μm in radius, through surface plasmon coupling, we achieve the record-high modulation bandwidth of 625.6 MHz among c-plane GaN-based LEDs.

  5. Self-assembly of dodecaphenyl POSS thin films

    Science.gov (United States)

    Handke, Bartosz; Klita, Łukasz; Niemiec, Wiktor

    2017-12-01

    The self-assembly abilities of Dodecaphenyl Polyhedral Oligomeric Silsesquioxane thin films on Si(1 0 0) surfaces were studied. Due to their thermal properties - relatively low sublimation temperature and preservation of molecular structure - cage type silsesquioxanes are ideal material for the preparation of a thin films by Physical Vapor Deposition. The Ultra-High Vacuum environment and the deposition precision of the PVD method enable the study of early stages of thin film growth and its molecular organization. X-ray Reflectivity and Atomic Force Microscopy measurements allow to pursuit size-effects in the structure of thin films with thickness ranges from less than a single molecular layer up to several tens of layers. Thermal treatment of the thin films triggered phase change: from a poorly ordered polycrystalline film into a well-ordered multilayer structure. Self-assembly of the layers is the effect of the π-stacking of phenyl rings, which force molecules to arrange in a superlattice, forming stacks of alternating organic-inorganic layers.

  6. Effects of strain on the magnetic and transport properties of the epitaxial La0.5Ca0.5MnO3 thin films

    International Nuclear Information System (INIS)

    Zarifi, M.; Kameli, P.; Ehsani, M.H.; Ahmadvand, H.; Salamati, H.

    2016-01-01

    The epitaxial strain can considerably modify the physical properties of thin films compared to the bulk. This paper reports the effects of substrate-induced strain on La 0.5 Ca 0.5 MnO 3 (LCMO) thin films, grown on (100) SrTiO 3 (STO) and LaAlO 3 (LAO) substrates by pulsed laser deposition technique. Transport and magnetic properties were found to be strongly dependent on strain type. It is also shown that compressive (tensile) strain leads to the increase (decrease) in the magnetization of the films. Moreover, it was observed that all LCMO films deposited on both LAO and STO substrates behave as an insulator, but LCMO/LAO thin films with compressive strain have lower resistivity than LCMO/STO thin films with tensile strain. Applying magnetic field to LCMO/STO thin films with thickness of 25 and 50 nm leads to very small change in the resistivity, while the effects of magnetic field on the sample with thickness of 125 nm leads to an insulator–metal transition. For LCMO/LAO thin films, the magnetic field has a strong impact on the resistivity of samples. The results show that the magnetoresistance (MR) is enhanced by increasing film thickness for LCMO/LAO samples, due to the relatively stronger phase separation. For LCMO/STO thin films MR is drastically decreased by reduction of film thickness, which is attributed to the enhancement of the charge–orbital order (CO–O) accompanying the complex spin order (the so-called CE type). The changes of the antiferromagnetic structure from the CE to C type and the enhancement of the CE type could be attributed to the in-plane compressive and tensile strain, respectively. - Highlights: • Epitaxial La 0.5 Ca 0.5 MnO 3 thin films, grown on (100) SrTiO 3 and LaAlO 3 substrates. • The compressive strain leads to the increase in the magnetization of the films. • The tensile strain leads to the decrease in the magnetization of the films. • The magnetoresistance is enhanced by increasing film thickness.

  7. Nonglobal proof of the thin--sandwich conjecture

    International Nuclear Information System (INIS)

    Pereira, C.M.

    1981-01-01

    A gravitational thin--sandwich conjecture was first proposed by Wheeler and coworkers during the period 1962--4. The present paper contains a proof of the nonglobal form of this gravitational thin--sandwich conjecture. The proof (a) applies for arbitrary choices of the spatial metric and its time derivative; and (b) demonstrates the existence on a spacelike three-surface of solutions which satisfy conditions of continuity known to be sufficient to obtain existence and uniqueness of solutions to Einstein's equations off the three-surface and existence and uniqueness of geodesics. Riquier's existence theorem plays an important role in the proof. The relationship of the present results to previous work is discussed. Some global questions associated with the thin--sandwich conjecture are clarified. Some aspects of the relationship of the thin--sandwich conjecture to the problem of the quantization of the gravitational field are noted. Both the vacuum case and the case of a nonviscous fluid are included. The discussion allows for an arbitrary equation of state p = p

  8. Nitrogen incorporation in sputter deposited molybdenum nitride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Stöber, Laura, E-mail: laura.stoeber@tuwien.ac.at; Patocka, Florian, E-mail: florian.patocka@tuwien.ac.at; Schneider, Michael, E-mail: michael.schneider@tuwien.ac.at; Schmid, Ulrich, E-mail: ulrich.e366.schmid@tuwien.ac.at [Institute of Sensor and Actuator Systems, TU Wien, Gußhausstraße 27-29, A-1040 Vienna (Austria); Konrath, Jens Peter, E-mail: jenspeter.konrath@infineon.com; Haberl, Verena, E-mail: verena.haberl@infineon.com [Infineon Technologies Austria AG, Siemensstraße 2, 9500 Villach (Austria)

    2016-03-15

    In this paper, the authors report on the high temperature performance of sputter deposited molybdenum (Mo) and molybdenum nitride (Mo{sub 2}N) thin films. Various argon and nitrogen gas compositions are applied for thin film synthetization, and the amount of nitrogen incorporation is determined by Auger measurements. Furthermore, effusion measurements identifying the binding conditions of the nitrogen in the thin film are performed up to 1000 °C. These results are in excellent agreement with film stress and scanning electron microscope analyses, both indicating stable film properties up to annealing temperatures of 500 °C.

  9. Thinning increases climatic resilience of red pine

    Science.gov (United States)

    Magruder, Matthew; Chhin, Sophan; Palik, Brian; Bradford, John B.

    2013-01-01

    Forest management techniques such as intermediate stand-tending practices (e.g., thinning) can promote climatic resiliency in forest stands by moderating tree competition. Residual trees gain increased access to environmental resources (i.e., soil moisture, light), which in turn has the potential to buffer trees from stressful climatic conditions. The influences of climate (temperature and precipitation) and forest management (thinning method and intensity) on the productivity of red pine (Pinus resinosa Ait.) in Michigan were examined to assess whether repeated thinning treatments were able to increase climatic resiliency (i.e., maintaining productivity and reduced sensitivity to climatic stress). The cumulative productivity of each thinning treatment was determined, and it was found that thinning from below to a residual basal area of 14 m2·ha−1 produced the largest average tree size but also the second lowest overall biomass per acre. On the other hand, the uncut control and the thinning from above to a residual basal area of 28 m2·ha−1 produced the smallest average tree size but also the greatest overall biomass per acre. Dendrochronological methods were used to quantify sensitivity of annual radial growth to monthly and seasonal climatic factors for each thinning treatment type. Climatic sensitivity was influenced by thinning method (i.e., thinning from below decreased sensitivity to climatic stress more than thinning from above) and by thinning intensity (i.e., more intense thinning led to a lower climatic sensitivity). Overall, thinning from below to a residual basal area of 21 m2·ha−1 represented a potentially beneficial compromise to maximize tree size, biomass per acre, and reduced sensitivity to climatic stress, and, thus, the highest level of climatic resilience.

  10. Preparation and properties of KCl-doped Cu2O thin film by electrodeposition

    International Nuclear Information System (INIS)

    Yu, Xiaojiao; Li, Xinming; Zheng, Gang; Wei, Yuchen; Zhang, Ama; Yao, Binghua

    2013-01-01

    With the indium tin oxide-coated glass as working electrode, cuprous oxide thin film is fabricated by means of electrodeposition. The effects of KCl doped and annealing treatment upon Cu 2 O thin film morphology, surface resistivity, open-circuit voltage, electric conduction types and visible light response are studied. The research results indicate that KCl doped has a great effect upon Cu 2 O crystal morphology, thus, making Cu 2 O thin film surface resistivity drop, and the open-circuit voltage increase and that electric conduction types are transformed from p type into n type, and the visible light (400–500 nm) absorption rate is slightly reduced. Annealing treatment can obviously decrease Cu 2 O thin film surface resistivity and improve its open-circuit voltage. When KCl concentration in electrolytic solution reaches 7 mmol/L, Cu 2 O thin film morphology can be changed from the dendritic crystal into the cubic crystal and Cu 2 O thin film surface resistivity decreases from the initial 2.5 × 10 6 Ω cm to 8.5 × 10 4 Ω cm. After annealing treatment at 320 °C for 30 min, the surface resistivity decreases to 8.5 × 10 2 Ω cm, and the open-circuit voltage increases from the initial 3.1 mV to 79.2 mV.

  11. Thin films for precision optics

    International Nuclear Information System (INIS)

    Araujo, J.F.; Maurici, N.; Castro, J.C. de

    1983-01-01

    The technology of producing dielectric and/or metallic thin films for high precision optical components is discussed. Computer programs were developed in order to calculate and register, graphically, reflectance and transmittance spectra of multi-layer films. The technology of vacuum evaporation of several materials was implemented in our thin-films laboratory; various films for optics were then developed. The possibility of first calculate film characteristics and then produce the film is of great advantage since it reduces the time required to produce a new type of film and also reduces the cost of the project. (C.L.B.) [pt

  12. Crystallization of sol-gel derived lead zirconate titanate thin films in argon and oxygen atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Bursill, L A [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Brooks, K G [Ecole Polytechnique Federale, Lausanne (Switzerland)

    1994-12-31

    Electron diffraction and high-resolution electron microscopic techniques are applied to reveal the mechanisms of crystallization of 75 nm thin films of ferroelectric lead-zirconate-titanate (PZT). Sol-gel methods, followed by pyrolysis at 350 deg C, were used to provide a common starting point after which a variety of rapid-thermal annealing (RTA) experiments in the temperature range 400-700 deg C were made in argon, oxygen and nitrogen/hydrogen atmospheres. The results are interpreted in terms of the crystal chemical analysis, which points out that partial pressure of oxygen and heating rate are important experimental parameters which must be controlled if ferroelectric perovskite-type Pb{sub 2}ZrTiO{sub 6}, rather than pyrochlore-type Pb{sub 2}ZrTiO{sub 6+x}, where O < X < 1 or -1 < X < O, is to be obtained after the RTA step. Thus significant improvements in the crystallization of perovskite-type PZT were clearly demonstrated by using argon atmospheres for the RTA step. The results have significance for the production of high-quality ferroelectric thin films, with improved switching and fatigue characteristics, since even small amounts of the pyrochlore phase prove detrimental for these properties. 18 refs., 1 tab., 10 figs.

  13. synthesis and optical characterization of acid-doped polyaniline thin

    African Journals Online (AJOL)

    HOD

    SYNTHESIS AND OPTICAL CHARACTERIZATION OF ACID-DOPED. POLYANILINE THIN .... MATERIALS AND METHODS .... Characterization of Se Doped Polyaniline”,Current. Applied ... with Silver Nanoparticles”, Advances in Materials.

  14. Determination of the thickness of chemically removed thin layers on GaAs VPE structures

    Energy Technology Data Exchange (ETDEWEB)

    Somogyi, K.; Nemeth-Sallay, M.; Nemcsics, A. (Research Inst. for Technical Physics, Hungarian Academy of Sciences, Budapest (Hungary))

    1991-01-01

    Thinning of epitaxial GaAs layers was studied during the surface etching, with a special attention to submicron epitaxial structures, like MESFET or varactor-type structures. Each chemical treatment influences the crystal surface during the device preparation processes, though the possible thinning of the active layer is small. Therefore a method allowing determination of thicknesses as small as at about 20 nm of the layer removed by chemical etching from GaAs VPE structures was applied. Using special multilayered structures and a continuous electrochemical carrier concentration depth profiling, the influence of the layer thickness inhomogeneity and of some measurement errors can be minimized. Some frequently used etchants and the influence of different - so called - non-etching processes were compared in different combinations. It was shown that besides the direct etching a change of the surface conditions occurs, which influences the etch rate in the succeeding etching procedure. (orig.).

  15. Mechanical stability of cylindrical thin-shell wormholes

    Energy Technology Data Exchange (ETDEWEB)

    Sharif, M. [University of the Punjab, Department of Mathematics, Lahore (Pakistan); Azam, M. [University of Education, Division of Science and Technology, Lahore (Pakistan)

    2013-04-15

    In this paper, we apply the cut and paste procedure to the charged black string for the construction of a thin-shell wormhole. We consider the Darmois-Israel formalism to determine the surface stresses of the shell. We take the Chaplygin gas to deal with the matter distribution on shell. The radial perturbation approach (preserving the symmetry) is used to investigate the stability of static solutions. We conclude that stable static solutions exist both for uncharged and charged black string thin-shell wormholes for particular values of the parameters. (orig.)

  16. Charged thin-shell gravastars in noncommutative geometry

    Energy Technology Data Exchange (ETDEWEB)

    Oevguen, Ali [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Valparaiso (Chile); Eastern Mediterranean University, Physics Department, Famagusta, Northern Cyprus (Turkey); Banerjee, Ayan [Jadavpur University, Department of Mathematics, Kolkata, West Bengal (India); Jusufi, Kimet [State University of Tetovo, Physics Department, Tetovo (Macedonia, The Former Yugoslav Republic of); Institute of Physics, Ss. Cyril and Methodius University, Faculty of Natural Sciences and Mathematics, Skopje (Macedonia, The Former Yugoslav Republic of)

    2017-08-15

    In this paper we construct a charged thin-shell gravastar model within the context of noncommutative geometry. To do so, we choose the interior of the nonsingular de Sitter spacetime with an exterior charged noncommutative solution by cut-and-paste technique and apply the generalized junction conditions. We then investigate the stability of a charged thin-shell gravastar under linear perturbations around the static equilibrium solutions as well as the thermodynamical stability of the charged gravastar. We find the stability regions, by choosing appropriate parameter values, located sufficiently close to the event horizon. (orig.)

  17. Fluxons in thin-film superconductor-insulator superlattices

    DEFF Research Database (Denmark)

    Sakai, S.; Bodin, P.; Pedersen, Niels Falsig

    1993-01-01

    In a system of thin alternating layers of superconductors and insulators the equations describing static and dynamic fluxon solutions are derived. The approach, represented by a useful compact matrix form, is intended to describe systems fabricated for example of niobium or niobium-nitride thin...... films; in the limit of ultrathin superconductor films it may give a model for describing fluxon motion in layered high-Tc superconductors. Numerical examples of current versus voltage curves to be expected in such an experiment are presented. Journal of Applied Physics is copyrighted by The American...

  18. Newtech - Comparison of three 1 kW thin-film solar cell installations; Newtech. Vergleich 3 x 1 kWp Duennschichtzellenanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Renken, C.; Haeberlin, H.

    2003-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of tests made on 3 types of thin-film solar cells by the photovoltaics laboratory at the University of Applied Science in Burgdorf, Switzerland. The three 1-kW{sub p} installations are all mounted on the flat roof of an industrial building and deliver the power produced to the local electricity utility. The thin-film technologies tested are described. These include copper-indium-diselenide (CIS) cells, amorphous silicon tandem cells and amorphous silicon triple cells. The measurement equipment used is described and the results obtained are discussed. These showed that the CIS cells had the highest annual specific yield and that the triple cells had a relatively high performance ratio at low irradiance levels. The performance of the thin-film modules is also compared to that of conventional, crystalline modules installed at a nearby location.

  19. Synthesis of Ag-Cu-Pd alloy thin films by DC-magnetron sputtering: Case study on microstructures and optical properties

    Science.gov (United States)

    Rezaee, Sahar; Ghobadi, Nader

    2018-06-01

    The present study aims to investigate optical properties of Ag-Cu-Pd alloy thin films synthesized by DC-magnetron sputtering method. The thin films are deposited on the glass and silicon substrates using Argon gas and Ag-Cu-Pd target. XRD analysis confirms the successful growth of Ag, Cu, and Pd NPs with FCC crystalline structure. Moreover, UV-visible absorption spectroscopy is applied to determine optical properties of the prepared samples which are affected by changes in surface morphology. The existence of single surface plasmon resonance (SPR) peak near 350 nm proves the formation of silver nanoparticles with a slight red shift through increasing deposition time. Ineffective thickness method (ITM) and Derivation of ineffective thickness method (DITM) are applied to extract optical band gap and transition type via absorption spectrum. SEM and AFM analyses show the distribution of near-spherical nanoparticles covering the surface of thin films. Furthermore, thickness variation affects the grain size. In addition, TEM image reveals the uniform size distribution of nanoparticles with an average particle size of about 15 nm. The findings show that increasing grain size and crystallite order along with the decrease of structural defect and disorders decrease optical band gap from 3.86 eV to 2.58 eV.

  20. Fabrication of dye sensitized solar cell using Cr doped Cu-Zn-Se type chalcopyrite thin film

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, D. Paul; Venkateswaran, C. [Materials Science Centre, Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai-600 025 (India); Ganesan, S.; Suthanthiraraj, S. Austin; Maruthamuthu, P. [Department of Energy, University of Madras, Guindy Campus, Chennai 600 025 (India); Kovendhan, M. [Department of Physics, Presidency College, Chennai 600 005 (India)

    2011-09-15

    Chalcopyrites are a versatile class of semiconductors known for their potential in photovoltaic applications. Considering the well established CuInSe{sub 2} as a prototype system, a new compound of the chalcopyrite type, Cu{sub 1-x}Zn{sub 1-y}Se{sub 2-{delta}}, by replacing In with Zn, has been prepared (both undoped and 2% Cr doped) by the metallurgical method. Thin films have been deposited by the thermal evaporation technique using the stabilized polycrystalline compounds as charge. Structural, compositional, morphological, and optical properties of the films are analyzed and reported. Use of these films as electrodes in dye sensitized solar cell (DSSC) is demonstrated. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Implanted ZnO thin films: Microstructure, electrical and electronic properties

    International Nuclear Information System (INIS)

    Lee, J.; Metson, J.; Evans, P.J.; Kinsey, R.; Bhattacharyya, D.

    2007-01-01

    Magnetron sputtered polycrystalline ZnO thin films were implanted using Al, Ag, Sn, Sb and codoped with TiN in order to improve the conductivity and to attempt to achieve p-type behaviour. Structural and electrical properties of the implanted ZnO thin films were examined with X-ray diffractometry (XRD), scanning electron microscopy (SEM), secondary ion mass spectrometry (SIMS), atomic force microscopy (AFM) and conductivity measurements. Depth profiles of the implanted elements varied with the implant species. Implantation causes a partial amorphisation of the crystalline structure and decreases the effective grain size of the films. One of the findings is the improvement, as a consequence of implantation, in the conductivity of initially poorly conductive samples. Heavy doping may help for the conversion of conduction type of ZnO thin films. Annealing in vacuum mitigated structural damage and stress caused by implantation, and improved the conductivity of the implanted ZnO thin films

  2. Texture-Etched SnO2 Glasses Applied to Silicon Thin-Film Solar Cells

    Directory of Open Access Journals (Sweden)

    Bing-Rui Wu

    2014-01-01

    Full Text Available Transparent electrodes of tin dioxide (SnO2 on glasses were further wet-etched in the diluted HCl:Cr solution to obtain larger surface roughness and better light-scattering characteristic for thin-film solar cell applications. The process parameters in terms of HCl/Cr mixture ratio, etching temperature, and etching time have been investigated. After etching process, the surface roughness, transmission haze, and sheet resistance of SnO2 glasses were measured. It was found that the etching rate was increased with the additions in etchant concentration of Cr and etching temperature. The optimum texture-etching parameters were 0.15 wt.% Cr in 49% HCl, temperature of 90°C, and time of 30 sec. Moreover, silicon thin-film solar cells with the p-i-n structure were fabricated on the textured SnO2 glasses using hot-wire chemical vapor deposition. By optimizing the texture-etching process, the cell efficiency was increased from 4.04% to 4.39%, resulting from the increment of short-circuit current density from 14.14 to 15.58 mA/cm2. This improvement in cell performances can be ascribed to the light-scattering effect induced by surface texturization of SnO2.

  3. High-pressure oxygenation of thin-wall YBCO single-domain samples

    International Nuclear Information System (INIS)

    Chaud, X; Savchuk, Y; Sergienko, N; Prikhna, T; Diko, P

    2008-01-01

    The oxygen annealing of ReBCO bulk material, necessary to achieve superconducting properties, usually induces micro- and macro-cracks. This leads to a crack-assisted oxygenation process that allows oxygenating large bulk samples faster than single crystals. But excellent superconducting properties are cancelled by the poor mechanical ones. More progressive oxygenation strategy has been shown to reduce drastically the oxygenation cracks. The problem then arises to keep a reasonable annealing time. The concept of bulk Y123 single-domain samples with thin-wall geometry has been introduced to bypass the inherent limitation due to a slow oxygen diffusion rate. But it is not enough. The use of a high oxygen pressure (16 MPa) enables to speed up further the process. It introduces a displacement in the equilibrium phase diagram towards higher temperatures, i.e., higher diffusion rates, to achieve a given oxygen content in the material. Remarkable results were obtained by applying such a high pressure oxygen annealing process on thin-wall single-domain samples. The trapped field of 16 mm diameter Y123 thin-wall single-domain samples was doubled (0.6T vs 0.3T at 77K) using an annealing time twice shorter (about 3 days). The initial development was made on thin bars. The advantage of thin-wall geometry is that such an annealing can be applied directly to a much larger sample

  4. Nano structured TiO2 thin films by polymeric precursor method

    International Nuclear Information System (INIS)

    Stroppa, Daniel Grando; Giraldi, Tania Regina; Leite, Edson Roberto; Varela, Jose Arana; Longo, Elson

    2008-01-01

    This work focuses in optimizing setup for obtaining TiO 2 thin films by polymeric precursor route due to its advantages on stoichiometric and morphological control. Precursor stoichiometry, synthesis pH, solids concentration and rotation speed at deposition were optimized evaluating thin films morphology and thickness. Thermogravimetry and NMR were applied for precursor's characterization and AFM, XRD and ellipsometry for thin films evaluation. Results showed successful attainment of homogeneous nanocrystalline anatase TiO 2 thin films with outstanding control over morphological characteristics, mean grain size of 17 nm, packing densities between 57 and 75%, estimated surface areas of 90 m 2 /g and monolayers thickness within 20 and 128 nm. (author)

  5. An RBS study of thin PLD and MOCVD strontium copper oxide layers

    Energy Technology Data Exchange (ETDEWEB)

    Kantor, Z. [Institute of Physics, University of Pannonia, H-8200 Veszprem (Hungary); Papadopoulou, E.L.; Aperathitis, E. [Inst. Electronic Struture and Laser, Foundation for Research and Technology - Hellas, P.O. Box 1527, Heraklion 71110 (Greece); Deschanvres, J.-L. [LMPG INP Grenoble-Minatec, BP 257, 38016 Grenoble Cedex 1 (France); Somogyi, K. [MicroVacuum Ltd., Kerekgyarto u.: 10, H-1147 Budapest (Hungary)], E-mail: karoly.somogyi@microvacuum.com; Szendro, I. [MicroVacuum Ltd., Kerekgyarto u.: 10, H-1147 Budapest (Hungary)

    2008-09-30

    Strontium copper oxide (SCO) has been studied as p-type transparent (VIS) conductive oxide material. Also theoretical studies suggested p-type conductivity of the SrCu{sub 2}O{sub 2} composition. SCO thin layers, with thicknesses of 30-2000 nm, were deposited on glass and silicon substrates both by pulsed laser deposition (PLD) and by MOCVD method. The as-grown layers showed high electrical resistance. Due to an annealing process, the resistivity significantly decreased and the layers showed p-type conductivity. Optical transparency measured on samples grown on glass substrates was found about or above 80%, including also thickness dependence. RBS measurements were applied for the determination of the chemical composition profile of the layers. A comparison revealed some specific differences between as-grown and annealed PLD samples. Due to the annealing, the ratio of oxide phases was changed and a vertical inhomogeneity in chemical composition was observed. Our measurements revealed also the influence of the deposition technique and of the substrate.

  6. Efficiency enhancement using a Zn1- x Ge x -O thin film as an n-type window layer in Cu2O-based heterojunction solar cells

    Science.gov (United States)

    Minami, Tadatsugu; Nishi, Yuki; Miyata, Toshihiro

    2016-05-01

    Efficiency enhancement was achieved in Cu2O-based heterojunction solar cells fabricated with a zinc-germanium-oxide (Zn1- x Ge x -O) thin film as the n-type window layer and a p-type Na-doped Cu2O (Cu2O:Na) sheet prepared by thermally oxidizing Cu sheets. The Ge content (x) dependence of the obtained photovoltaic properties of the heterojunction solar cells is mainly explained by the conduction band discontinuity that results from the electron affinity difference between Zn1- x Ge x -O and Cu2O:Na. The optimal value of x in Zn1- x Ge x -O thin films prepared by pulsed laser deposition was observed to be 0.62. An efficiency of 8.1% was obtained in a MgF2/Al-doped ZnO/Zn0.38Ge0.62-O/Cu2O:Na heterojunction solar cell.

  7. Functionalized carbon nanotubes in ZnO thin films for photoinactivation of bacteria

    International Nuclear Information System (INIS)

    Akhavan, O.; Azimirad, R.; Safa, S.

    2011-01-01

    Highlights: → Unfunctionalized and functionalized MWCNT/ZnO thin films were synthesized by sol-gel method. → Zn-O-C carbonaceous bonds formed in the functionalized MWCNT/ZnO thin films. → The functionalized MWCNT/ZnO had stronger photoinactivation of the bacteria than the unfunctionalize type. → 10 wt% functionalized MWCNT content had the optimum antibacterial property. - Abstract: Two types of unfunctionalized and functionalized multi-wall carbon nanotubes (MWCNTs) were prepared to be applied in fabrication of MWCNT-ZnO nanocomposite thin films with various MWCNT contents. X-ray photoelectron spectroscopy indicated formation of functional groups on surface of the functionalized MWCNTs in the MWCNT-ZnO nanocomposite. Formation of the effective carbonaceous bonds between the ZnO and the MWCNTs was also investigated through photoinactivation of Escherichia coli bacteria on surface of the both unfunctionalized and functionalized MWCNT-ZnO nanocomposites. The functionalized MWCNT-ZnO nanocomposites showed significantly stronger photoinactivation of the bacteria than the unfunctionalized ones, for all of the various MWCNT contents (from 2 to 30 wt%). While the functionalized MWCNT-ZnO nanocomposites with the optimum MWCNT content of 10 wt% inactivated whole of the bacteria after 10 min UV-visible light irradiation, the unfunctionalized ones could inactivate only 63% of the bacteria under the same conditions. The significant enhancement of the photoinactivation of the bacteria onto the surface of the functionalized MWCNT-ZnO nanocomposites was assigned to charge transfer through Zn-O-C bands formed between the Zn atoms of the ZnO film and oxygen atoms of the carboxylic functional groups of the functionalized MWCNTs.

  8. Development in fiscal 1999 of technologies to put photovoltaic power generation systems into practical use. Development of thin film solar cell manufacturing technologies (Development of technologies to manufacture applied type thin film solar cells with new structure and development of high-efficiency hybrid thin film/sheet solar cells); 1999 nendo taiyoko hatsuden system jitsuyoka gijutsu kaihatsu seika hokokusho. Usumaku taiyo denchi no seizo gijutsu kaihatsu (oyogata shin kozo usumaku taiyo denchi no seizo gijutsu kaihatsu (kokoritsu hybrid gata usumaku / sheet taiyo denchi no seizo gijutsu kaihatsu))

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    With an objective to develop low-cost and high-efficiency hybrid thin film/sheet solar cells, research and development has been performed. This paper summarizes the achievements in fiscal 1999. The research is related to a hybrid construction, in which the upper cells of amorphous silicon thin film are formed on the lower cells bonded with micro-crystalline silicon thin film relative to a poly-crystalline silicon sheet. In the technology to form the upper cells, a pin-construction using amorphous silicon thin film made by using the plasma CVD process was adopted, whereas an open circuit voltage of 1.45V, a short circuit current of 13.6 mA/cm{sup 2}, and a conversion efficiency of 13.5% were obtained. In the technology to form the substrate for the lower cells, formation of flat silicon thin plate that can be peeled off was identified as a result of adopting the construction in which a graphite substrate is provided on a rotating cooling body of 12-prism type. With regard to the technology to bond and form the lower cells, electrical properties of hetero-bonded cells were discussed, and an open circuit voltage of 0.605V and a conversion efficiency of 14.3% were obtained as a result of enhancing the film quality and optimizing the film thickness. (NEDO)

  9. Preparation and properties of KCl-doped Cu{sub 2}O thin film by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xiaojiao, E-mail: yxjw@xaut.edu.cn [Xi’an University of Technology, Xi’an 710048 (China); Li, Xinming [Xi’an University of Technology, Xi’an 710048 (China); Zheng, Gang [Xi’an University of Technology, Xi’an 710048 (China); Northwestern Polytechnical University, Xi’an 710072 (China); Wei, Yuchen [The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China); Zhang, Ama; Yao, Binghua [Xi’an University of Technology, Xi’an 710048 (China)

    2013-04-01

    With the indium tin oxide-coated glass as working electrode, cuprous oxide thin film is fabricated by means of electrodeposition. The effects of KCl doped and annealing treatment upon Cu{sub 2}O thin film morphology, surface resistivity, open-circuit voltage, electric conduction types and visible light response are studied. The research results indicate that KCl doped has a great effect upon Cu{sub 2}O crystal morphology, thus, making Cu{sub 2}O thin film surface resistivity drop, and the open-circuit voltage increase and that electric conduction types are transformed from p type into n type, and the visible light (400–500 nm) absorption rate is slightly reduced. Annealing treatment can obviously decrease Cu{sub 2}O thin film surface resistivity and improve its open-circuit voltage. When KCl concentration in electrolytic solution reaches 7 mmol/L, Cu{sub 2}O thin film morphology can be changed from the dendritic crystal into the cubic crystal and Cu{sub 2}O thin film surface resistivity decreases from the initial 2.5 × 10{sup 6} Ω cm to 8.5 × 10{sup 4} Ω cm. After annealing treatment at 320 °C for 30 min, the surface resistivity decreases to 8.5 × 10{sup 2} Ω cm, and the open-circuit voltage increases from the initial 3.1 mV to 79.2 mV.

  10. High mobility n-type organic thin-film transistors deposited at room temperature by supersonic molecular beam deposition

    Energy Technology Data Exchange (ETDEWEB)

    Chiarella, F., E-mail: fabio.chiarella@spin.cnr.it; Barra, M.; Ciccullo, F.; Cassinese, A. [CNR-SPIN and Physics Department, University of Naples, Piazzale Tecchio 80, I-80125 Naples (Italy); Toccoli, T.; Aversa, L.; Tatti, R.; Verucchi, R. [IMEM-CNR-FBK Division of Trento, Via alla Cascata 56/C, I-38123 Povo (Italy); Iannotta, S. [IMEM-CNR, Parco Area delle Scienze 37/A, I-43124 Parma (Italy)

    2014-04-07

    In this paper, we report on the fabrication of N,N′-1H,1H-perfluorobutil dicyanoperylenediimide (PDIF-CN{sub 2}) organic thin-film transistors by Supersonic Molecular Beam Deposition. The devices exhibit mobility up to 0.2 cm{sup 2}/V s even if the substrate is kept at room temperature during the organic film growth, exceeding by three orders of magnitude the electrical performance of those grown at the same temperature by conventional Organic Molecular Beam Deposition. The possibility to get high-mobility n-type transistors avoiding thermal treatments during or after the deposition could significantly extend the number of substrates suitable to the fabrication of flexible high-performance complementary circuits by using this compound.

  11. Illumination estimation via thin-plate spline interpolation.

    Science.gov (United States)

    Shi, Lilong; Xiong, Weihua; Funt, Brian

    2011-05-01

    Thin-plate spline interpolation is used to interpolate the chromaticity of the color of the incident scene illumination across a training set of images. Given the image of a scene under unknown illumination, the chromaticity of the scene illumination can be found from the interpolated function. The resulting illumination-estimation method can be used to provide color constancy under changing illumination conditions and automatic white balancing for digital cameras. A thin-plate spline interpolates over a nonuniformly sampled input space, which in this case is a training set of image thumbnails and associated illumination chromaticities. To reduce the size of the training set, incremental k medians are applied. Tests on real images demonstrate that the thin-plate spline method can estimate the color of the incident illumination quite accurately, and the proposed training set pruning significantly decreases the computation.

  12. Antibacterial and barrier properties of oriented polymer films with ZnO thin films applied with atomic layer deposition at low temperatures

    International Nuclear Information System (INIS)

    Vähä-Nissi, Mika; Pitkänen, Marja; Salo, Erkki; Kenttä, Eija; Tanskanen, Anne; Sajavaara, Timo; Putkonen, Matti; Sievänen, Jenni; Sneck, Asko; Rättö, Marjaana; Karppinen, Maarit; Harlin, Ali

    2014-01-01

    Concerns on food safety, and need for high quality and extended shelf-life of packaged foods have promoted the development of antibacterial barrier packaging materials. Few articles have been available dealing with the barrier or antimicrobial properties of zinc oxide thin films deposited at low temperature with atomic layer deposition (ALD) onto commercial polymer films typically used for packaging purposes. The purpose of this paper was to study the properties of ZnO thin films compared to those of aluminum oxide. It was also possible to deposit ZnO thin films onto oriented polylactic acid and polypropylene films at relatively low temperatures using ozone instead of water as an oxidizing precursor for diethylzinc. Replacing water with ozone changed both the structure and the chemical composition of films deposited on silicon wafers. ZnO films deposited with ozone contained large grains covered and separated probably by a more amorphous and uniform layer. These thin films were also assumed to contain zinc salts of carboxylic acids. The barrier properties of a 25 nm ZnO thin film deposited with ozone at 100 °C were quite close to those obtained earlier with ALD Al 2 O 3 of similar apparent thickness on similar polymer films. ZnO thin films deposited at low temperature indicated migration of antibacterial agent, while direct contact between ZnO and Al 2 O 3 thin films and bacteria promoted antibacterial activity. - Highlights: • Thin films were grown from diethylzinc also with ozone instead of water at 70 and 100 °C. • ZnO films deposited with diethylzinc and ozone had different structures and chemistries. • Best barrier properties obtained with zinc oxide films close to those obtained with Al 2 O 3 • Ozone as oxygen source provided better barrier properties at 100 °C than water. • Both aluminum and zinc oxide thin films showed antimicrobial activity against E. coli

  13. Antibacterial and barrier properties of oriented polymer films with ZnO thin films applied with atomic layer deposition at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Vähä-Nissi, Mika, E-mail: mika.vaha-nissi@vtt.fi [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, VTT (Finland); Pitkänen, Marja; Salo, Erkki; Kenttä, Eija [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, VTT (Finland); Tanskanen, Anne, E-mail: Anne.Tanskanen@aalto.fi [Aalto University, School of Chemical Technology, Department of Chemistry, Laboratory of Inorganic Chemistry, P.O. Box 16100, FI-00076 Aalto (Finland); Sajavaara, Timo, E-mail: timo.sajavaara@jyu.fi [University of Jyväskylä, Department of Physics, P.O. Box 35, FI-40014 Jyväskylä (Finland); Putkonen, Matti; Sievänen, Jenni; Sneck, Asko; Rättö, Marjaana [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, VTT (Finland); Karppinen, Maarit, E-mail: Maarit.Karppinen@aalto.fi [Aalto University, School of Chemical Technology, Department of Chemistry, Laboratory of Inorganic Chemistry, P.O. Box 16100, FI-00076 Aalto (Finland); Harlin, Ali [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, VTT (Finland)

    2014-07-01

    Concerns on food safety, and need for high quality and extended shelf-life of packaged foods have promoted the development of antibacterial barrier packaging materials. Few articles have been available dealing with the barrier or antimicrobial properties of zinc oxide thin films deposited at low temperature with atomic layer deposition (ALD) onto commercial polymer films typically used for packaging purposes. The purpose of this paper was to study the properties of ZnO thin films compared to those of aluminum oxide. It was also possible to deposit ZnO thin films onto oriented polylactic acid and polypropylene films at relatively low temperatures using ozone instead of water as an oxidizing precursor for diethylzinc. Replacing water with ozone changed both the structure and the chemical composition of films deposited on silicon wafers. ZnO films deposited with ozone contained large grains covered and separated probably by a more amorphous and uniform layer. These thin films were also assumed to contain zinc salts of carboxylic acids. The barrier properties of a 25 nm ZnO thin film deposited with ozone at 100 °C were quite close to those obtained earlier with ALD Al{sub 2}O{sub 3} of similar apparent thickness on similar polymer films. ZnO thin films deposited at low temperature indicated migration of antibacterial agent, while direct contact between ZnO and Al{sub 2}O{sub 3} thin films and bacteria promoted antibacterial activity. - Highlights: • Thin films were grown from diethylzinc also with ozone instead of water at 70 and 100 °C. • ZnO films deposited with diethylzinc and ozone had different structures and chemistries. • Best barrier properties obtained with zinc oxide films close to those obtained with Al{sub 2}O{sub 3} • Ozone as oxygen source provided better barrier properties at 100 °C than water. • Both aluminum and zinc oxide thin films showed antimicrobial activity against E. coli.

  14. An optimal control model of crop thinning in viticulture

    OpenAIRE

    Schamel Guenter H.; Schubert Stefan F.

    2016-01-01

    We develop an economic model of cluster thinning in viticulture to control for grape quantity harvested and grape quality, applying a simple optimal control model with the aim to raise grape quality and related economic profits. The model maximizes vineyard owner profits and allows to discuss two relevant scenarios using a phase diagram analysis: (1) when the initial grape quantity is sufficiently small, thinning grapes will not be optimal and (2) when the initial grape quantity is high enoug...

  15. Reversible and nonvolatile ferroelectric control of two-dimensional electronic transport properties of ZrCuSiAs-type copper oxyselenide thin films with a layered structure

    Science.gov (United States)

    Zhao, Xu-Wen; Gao, Guan-Yin; Yan, Jian-Min; Chen, Lei; Xu, Meng; Zhao, Wei-Yao; Xu, Zhi-Xue; Guo, Lei; Liu, Yu-Kuai; Li, Xiao-Guang; Wang, Yu; Zheng, Ren-Kui

    2018-05-01

    Copper-based ZrCuSiAs-type compounds of LnCuChO (Ln =Bi and lanthanides, Ch =S , Se, Te) with a layered crystal structure continuously attract worldwide attention in recent years. Although their high-temperature (T ≥ 300 K) electrical properties have been intensively studied, their low-temperature electronic transport properties are little known. In this paper, we report the integration of ZrCuSiAs-type copper oxyselenide thin films of B i0.94P b0.06CuSeO (BPCSO) with perovskite-type ferroelectric Pb (M g1 /3N b2 /3 ) O3-PbTi O3 (PMN-PT) single crystals in the form of ferroelectric field effect devices that allow us to control the electronic properties (e.g., carrier density, magnetoconductance, dephasing length, etc.) of BPCSO films in a reversible and nonvolatile manner by polarization switching at room temperature. Combining ferroelectric gating and magnetotransport measurements with the Hikami-Larkin-Nagaoka theory, we demonstrate two-dimensional (2D) electronic transport characteristics and weak antilocalization effect as well as strong carrier-density-mediated competition between weak antilocalization and weak localization in BPCSO films. Our results show that ferroelectric gating using PMN-PT provides an effective and convenient approach to probe the carrier-density-related 2D electronic transport properties of ZrCuSiAs-type copper oxyselenide thin films.

  16. Improved photoelectrochemical performance of BiVO4/MoO3 heterostructure thin films

    Science.gov (United States)

    Kodan, Nisha; Mehta, B. R.

    2018-05-01

    Bismuth vanadate (BiVO4) and Molybdenum trioxide (MoO3) thin films have been prepared by RF sputtering technique. BiVO4 thin films were deposited on indium doped tin oxide (In: SnO2; ITO) substrates at room temperature and 80W applied rf power. The prepared BiVO4 thin films were further annealed at 450°C for 2 hours in air to obtain crystalline monoclinic phase and successively coated with MoO3 thin films deposited at 150W rf power and 400°C for 30 minutes. The effect of coupling BiVO4 and MoO3 on the structural, optical and photoelectrochemical (PEC) properties have been studied. Optical studies reveal that coupling of BiVO4 and MoO3 results in improvement of optical absorption in visible region of solar spectrum. PEC study shows approximate 3-fold and 38-fold increment in photocurrent values of BiVO4/MoO3 (0.38 mA/cm2) heterostructure thin film as compared to MoO3 (0.15 mA/cm2) and BiVO4 (10 µA/cm2) thin films at applied bias of 1 V vs Ag/AgCl in 0.5 M Na2SO4 (pH=7) electrolyte.

  17. Influences of overload on low cycle fatigue behaviors of elbow pipe with local wall thinning

    International Nuclear Information System (INIS)

    Sato, Kyohei; Ogino, Kanako; Takahashi, Koji; Ando, Kotoji; Urabe, Yoshio

    2011-01-01

    Low cycle fatigue tests were conducted using 100A elbow pipe specimens with or without local wall thinning. Local wall thinning was machined on the inside of the extrados of test elbows to simulate metal loss due to flow-accelerated corrosion or liquid droplet impingement erosion. Low cycle fatigue tests were carried out under displacement control with an inner pressure of 9 MPa. To simulate seismic events, low cycle fatigue tests were carried out on elbow pipe subjected to cyclic overloads. Regardless of local wall thinning, fatigue life of overload pipe was not so different from that of the non-overload pipe in appearance. Miner's rule can be applied to evaluate fatigue life of the elbow pipes with and without wall thinning, even if overload is applied. (author)

  18. Synthesis and characterization of Ba_0_._5Pb_0_._5TiO_3 perovskite - type thin films deposited by spin coating at low temperatures

    International Nuclear Information System (INIS)

    Wermuth, T.B.; Wiederkehr, N.A.; Alves, A.K.; Bergmann, C.P.

    2014-01-01

    In this paper we present a non-aqueous sol-gel route for the obtention of solid compounds and thin films of oxide type- perovskite ABO_3, such as Ba_0_._5 Pb_0_._5 TiO_3, synthesized by sol - gel route with subsequent heat treatment. The solid compounds were characterized by X-ray diffraction (XRD) techniques and thermal analysis (TGA / DTA). The thin film was obtained by using spin-coating techniques at low temperatures onto commercial substrates of polymethylmethacrylate (PMMA) and characterized by contact angle, atomic force microscopy (AFM) and scanning electron microscopy (SEM). The results show that the films present microstructures and roughness directly related to annealing temperatures, characterized by the formation of crystalline nanostructures with surface regularity and transparency. (author)

  19. Effects of strain on the magnetic and transport properties of the epitaxial La{sub 0.5}Ca{sub 0.5}MnO{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zarifi, M. [Department of Physics, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Kameli, P., E-mail: kameli@cc.iut.ac.ir [Department of Physics, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Ehsani, M.H. [Department of Physics, Semnan University, Semnan 35195-363 (Iran, Islamic Republic of); Ahmadvand, H.; Salamati, H. [Department of Physics, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2016-12-15

    The epitaxial strain can considerably modify the physical properties of thin films compared to the bulk. This paper reports the effects of substrate-induced strain on La{sub 0.5}Ca{sub 0.5}MnO{sub 3} (LCMO) thin films, grown on (100) SrTiO{sub 3} (STO) and LaAlO{sub 3} (LAO) substrates by pulsed laser deposition technique. Transport and magnetic properties were found to be strongly dependent on strain type. It is also shown that compressive (tensile) strain leads to the increase (decrease) in the magnetization of the films. Moreover, it was observed that all LCMO films deposited on both LAO and STO substrates behave as an insulator, but LCMO/LAO thin films with compressive strain have lower resistivity than LCMO/STO thin films with tensile strain. Applying magnetic field to LCMO/STO thin films with thickness of 25 and 50 nm leads to very small change in the resistivity, while the effects of magnetic field on the sample with thickness of 125 nm leads to an insulator–metal transition. For LCMO/LAO thin films, the magnetic field has a strong impact on the resistivity of samples. The results show that the magnetoresistance (MR) is enhanced by increasing film thickness for LCMO/LAO samples, due to the relatively stronger phase separation. For LCMO/STO thin films MR is drastically decreased by reduction of film thickness, which is attributed to the enhancement of the charge–orbital order (CO–O) accompanying the complex spin order (the so-called CE type). The changes of the antiferromagnetic structure from the CE to C type and the enhancement of the CE type could be attributed to the in-plane compressive and tensile strain, respectively. - Highlights: • Epitaxial La{sub 0.5}Ca{sub 0.5}MnO{sub 3} thin films, grown on (100) SrTiO{sub 3} and LaAlO{sub 3} substrates. • The compressive strain leads to the increase in the magnetization of the films. • The tensile strain leads to the decrease in the magnetization of the films. • The magnetoresistance is enhanced by

  20. Dense zig-zag microstructures in YSZ thin films by pulsed laser deposition

    Science.gov (United States)

    Stender, Dieter; Schäuble, Nina; Weidenkaff, Anke; Montagne, Alex; Ghisleni, Rudy; Michler, Johann; Schneider, Christof W.; Wokaun, Alexander; Lippert, Thomas

    2015-01-01

    The very brittle oxygen ion conductor yttria stabilized zirconia (YSZ) is a typical solid electrolyte for miniaturized thin film fuel cells. In order to decrease the fuel cell operating temperature, the thickness of yttria stabilized zirconia thin films is reduced. Often, these thin membranes suffer from mechanical failure and gas permeability. To improve these mechanical issues, a glancing angle deposition approach is used to grow yttria stabilized zirconia thin films with tilted columnar structures. Changes of the material flux direction during the deposition result in a dense, zigzag-like structure with columnar crystallites. This structure reduces the elastic modulus of these membranes as compared to columnar yttria stabilized zirconia thin films as monitored by nano-indentation which makes them more adaptable to applied stress.

  1. Dense zig-zag microstructures in YSZ thin films by pulsed laser deposition

    Directory of Open Access Journals (Sweden)

    Dieter Stender

    2015-01-01

    Full Text Available The very brittle oxygen ion conductor yttria stabilized zirconia (YSZ is a typical solid electrolyte for miniaturized thin film fuel cells. In order to decrease the fuel cell operating temperature, the thickness of yttria stabilized zirconia thin films is reduced. Often, these thin membranes suffer from mechanical failure and gas permeability. To improve these mechanical issues, a glancing angle deposition approach is used to grow yttria stabilized zirconia thin films with tilted columnar structures. Changes of the material flux direction during the deposition result in a dense, zigzag-like structure with columnar crystallites. This structure reduces the elastic modulus of these membranes as compared to columnar yttria stabilized zirconia thin films as monitored by nano-indentation which makes them more adaptable to applied stress.

  2. Rough Electrode Creates Excess Capacitance in Thin-Film Capacitors.

    Science.gov (United States)

    Torabi, Solmaz; Cherry, Megan; Duijnstee, Elisabeth A; Le Corre, Vincent M; Qiu, Li; Hummelen, Jan C; Palasantzas, George; Koster, L Jan Anton

    2017-08-16

    The parallel-plate capacitor equation is widely used in contemporary material research for nanoscale applications and nanoelectronics. To apply this equation, flat and smooth electrodes are assumed for a capacitor. This essential assumption is often violated for thin-film capacitors because the formation of nanoscale roughness at the electrode interface is very probable for thin films grown via common deposition methods. In this work, we experimentally and theoretically show that the electrical capacitance of thin-film capacitors with realistic interface roughness is significantly larger than the value predicted by the parallel-plate capacitor equation. The degree of the deviation depends on the strength of the roughness, which is described by three roughness parameters for a self-affine fractal surface. By applying an extended parallel-plate capacitor equation that includes the roughness parameters of the electrode, we are able to calculate the excess capacitance of the electrode with weak roughness. Moreover, we introduce the roughness parameter limits for which the simple parallel-plate capacitor equation is sufficiently accurate for capacitors with one rough electrode. Our results imply that the interface roughness beyond the proposed limits cannot be dismissed unless the independence of the capacitance from the interface roughness is experimentally demonstrated. The practical protocols suggested in our work for the reliable use of the parallel-plate capacitor equation can be applied as general guidelines in various fields of interest.

  3. The impact of twinning on the local texture of chalcopyrite-type thin films

    International Nuclear Information System (INIS)

    Abou-Ras, Daniel; Pantleon, Karen

    2007-01-01

    Twinning in a CuInS 2 layer in a completed thin-film solar cell was analyzed by means of electron backscatter diffraction. This technique revealed the microstructure of the CuInS 2 thin films and local orientation relationships between the grains. At various locations within the layer it was possible to retrace how twinning occurred comparing the local orientations with the theoretically possible changes in orientation by twinning. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) EBSD map of a CuInS 2 cross-section with Σ3 boundaries highlighted by red lines. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. Large-scale complementary macroelectronics using hybrid integration of carbon nanotubes and IGZO thin-film transistors.

    Science.gov (United States)

    Chen, Haitian; Cao, Yu; Zhang, Jialu; Zhou, Chongwu

    2014-06-13

    Carbon nanotubes and metal oxide semiconductors have emerged as important materials for p-type and n-type thin-film transistors, respectively; however, realizing sophisticated macroelectronics operating in complementary mode has been challenging due to the difficulty in making n-type carbon nanotube transistors and p-type metal oxide transistors. Here we report a hybrid integration of p-type carbon nanotube and n-type indium-gallium-zinc-oxide thin-film transistors to achieve large-scale (>1,000 transistors for 501-stage ring oscillators) complementary macroelectronic circuits on both rigid and flexible substrates. This approach of hybrid integration allows us to combine the strength of p-type carbon nanotube and n-type indium-gallium-zinc-oxide thin-film transistors, and offers high device yield and low device variation. Based on this approach, we report the successful demonstration of various logic gates (inverter, NAND and NOR gates), ring oscillators (from 51 stages to 501 stages) and dynamic logic circuits (dynamic inverter, NAND and NOR gates).

  5. Precise measurement of the transverse piezoelectric coefficient for thin films on anisotropic substrate

    International Nuclear Information System (INIS)

    Chun, Doo-Man; Sato, Masashi; Kanno, Isaku

    2013-01-01

    In this study, we propose a reliable measurement method for the effective transverse piezoelectric coefficient for thin films especially on anisotropic substrate. This coefficient for piezoelectric Pb(Zr, Ti)O 3 (PZT) thin films was calculated by measuring the electric field-induced tip displacement of unimorph cantilevers composed of PZT thin films and Si substrates. We evaluated the reliability of the proposed measurement method by comparing it with numerical analysis and confirmed that the relative error of the piezoelectric coefficient (e 31,f ) was less than 1%. We prepared 16 different unimorph cantilevers composed of identical PZT films on different Si beam geometries that had various substrate thicknesses and cantilever widths. Although the effective transverse piezoelectric coefficient e 31,f of PZT thin films ranged from −6.5 to −14 C/m 2 as a function of the applied voltage, the difference among the 16 samples with an applied voltage of 25 V was within 10%. These results demonstrate that the proposed measurement method has sufficient reliability and can be used to evaluate the effective transverse piezoelectric coefficient e 31,f of thin films.

  6. Spin Seebeck effect in Y-type hexagonal ferrite thin films

    Czech Academy of Sciences Publication Activity Database

    Hirschner, Jan; Maryško, Miroslav; Hejtmánek, Jiří; Uhrecký, Róbert; Soroka, Miroslav; Buršík, Josef; Anadón, P.; Aguirre, M.H.; Knížek, Karel

    2017-01-01

    Roč. 96, č. 6 (2017), s. 1-8, č. článku 064428. ISSN 2469-9950 R&D Projects: GA ČR(CZ) GA14-18392S Institutional support: RVO:68378271 ; RVO:61388980 Keywords : hexagonal ferrites * spin Seebeck effect * thin films * magnetization * ferrimagnetic ferrites Subject RIV: BM - Solid Matter Physics ; Magnetism; CA - Inorganic Chemistry (UACH-T) OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.); Inorganic and nuclear chemistry (UACH-T) Impact factor: 3.836, year: 2016

  7. Characterization of Sucrose Thin Films for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    S. L. Iconaru

    2011-01-01

    Full Text Available Sucrose is a natural osmolyte accumulated in the cells of organisms as they adapt to environmental stress. In vitro sucrose increases protein stability and forces partially unfolded structures to refold. Thin films of sucrose (C12H22O11 were deposited on thin cut glass substrates by the thermal evaporation technique (P∼10−5 torr. Characteristics of thin films were put into evidence by Fourier Transform Infrared Spectroscopy (FTIR, X-ray Photoelectron Spectroscopy (XPS, scanning electron microscopy (SEM, and differential thermal analysis and thermal gravimetric analysis (TG/DTA. The experimental results confirm a uniform deposition of an adherent layer. In this paper we present a part of the characteristics of sucrose thin films deposited on glass in medium vacuum conditions, as a part of a culture medium for osteoblast cells. Osteoblast cells were used to determine proliferation, viability, and cytotoxicity interactions with sucrose powder and sucrose thin films. The osteoblast cells have been provided from the American Type Culture Collection (ATCC Centre. The outcome of this study demonstrated the effectiveness of sucrose thin films as a possible nontoxic agent for biomedical applications.

  8. New exact solutions of sixth-order thin-film equation

    Directory of Open Access Journals (Sweden)

    Wafaa M. Taha

    2014-01-01

    Full Text Available TheG′G-expansion method is used for the first time to find traveling-wave solutions for the sixth-order thin-film equation, where related balance numbers are not the usual positive integers. New types of exact traveling-wave solutions, such as – solitary wave solutions, are obtained the sixth-order thin-film equation, when parameters are taken at special values.

  9. Composition-induced structural, electrical, and magnetic phase transitions in AX-type mixed-valence cobalt oxynitride epitaxial thin films

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Jumpei; Oka, Daichi [Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Kanagawa Academy of Science and Technology (KAST), 3-2-1 Sakado, Takatsu, Kawasaki 213-0012 (Japan); Hirose, Yasushi, E-mail: hirose@chem.s.u-tokyo.ac.jp; Yang, Chang; Fukumura, Tomoteru; Hasegawa, Tetsuya [Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Kanagawa Academy of Science and Technology (KAST), 3-2-1 Sakado, Takatsu, Kawasaki 213-0012 (Japan); CREST, Japan Science and Technology Agency, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Nakao, Shoichiro [Kanagawa Academy of Science and Technology (KAST), 3-2-1 Sakado, Takatsu, Kawasaki 213-0012 (Japan); CREST, Japan Science and Technology Agency, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Harayama, Isao; Sekiba, Daiichiro [University of Tsukuba Tandem Accelerator Complex (UTTAC), 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8577 (Japan)

    2015-12-07

    Synthesis of mid- to late-transition metal oxynitrides is generally difficult by conventional thermal ammonolysis because of thermal instability. In this letter, we synthesized epitaxial thin films of AX-type phase-pure cobalt oxynitrides (CoO{sub x}N{sub y}) by using nitrogen-plasma-assisted pulsed laser deposition and investigated their structural, electrical, and magnetic properties. The CoO{sub x}N{sub y} thin films with 0 ≤ y/(x + y) ≤ 0.63 grown on MgO (100) substrates showed a structural phase transition from rock salt (RS) to zinc blend at the nitrogen content y/(x + y) ∼ 0.5. As the nitrogen content increased, the room-temperature electrical resistivity of the CoO{sub x}N{sub y} thin films monotonically decreased from the order of 10{sup 5} Ω cm to 10{sup −4} Ω cm. Furthermore, we observed an insulator-to-metal transition at y/(x + y) ∼ 0.34 in the RS-CoO{sub x}N{sub y} phase, which has not yet been reported in Co{sup 2+}/Co{sup 3+} mixed-valence cobalt oxides with octahedral coordination. The low resistivity in the RS-CoO{sub x}N{sub y} phase, on the 10{sup −3} Ω cm order, may have originated from the intermediate spin state of Co{sup 3+} stabilized by the lowered crystal field symmetry of the CoO{sub 6−n}N{sub n} octahedra (n = 1, 2,…5). Magnetization measurements suggested that a magnetic phase transition occurred in the RS-CoO{sub x}N{sub y} films during the insulator-to-metal transition. These results demonstrate that low-temperature epitaxial growth is a promising approach for exploring novel electronic functionalities in oxynitrides.

  10. Composition-induced structural, electrical, and magnetic phase transitions in AX-type mixed-valence cobalt oxynitride epitaxial thin films

    International Nuclear Information System (INIS)

    Takahashi, Jumpei; Oka, Daichi; Hirose, Yasushi; Yang, Chang; Fukumura, Tomoteru; Hasegawa, Tetsuya; Nakao, Shoichiro; Harayama, Isao; Sekiba, Daiichiro

    2015-01-01

    Synthesis of mid- to late-transition metal oxynitrides is generally difficult by conventional thermal ammonolysis because of thermal instability. In this letter, we synthesized epitaxial thin films of AX-type phase-pure cobalt oxynitrides (CoO x N y ) by using nitrogen-plasma-assisted pulsed laser deposition and investigated their structural, electrical, and magnetic properties. The CoO x N y thin films with 0 ≤ y/(x + y) ≤ 0.63 grown on MgO (100) substrates showed a structural phase transition from rock salt (RS) to zinc blend at the nitrogen content y/(x + y) ∼ 0.5. As the nitrogen content increased, the room-temperature electrical resistivity of the CoO x N y thin films monotonically decreased from the order of 10 5  Ω cm to 10 −4  Ω cm. Furthermore, we observed an insulator-to-metal transition at y/(x + y) ∼ 0.34 in the RS-CoO x N y phase, which has not yet been reported in Co 2+ /Co 3+ mixed-valence cobalt oxides with octahedral coordination. The low resistivity in the RS-CoO x N y phase, on the 10 −3  Ω cm order, may have originated from the intermediate spin state of Co 3+ stabilized by the lowered crystal field symmetry of the CoO 6−n N n octahedra (n = 1, 2,…5). Magnetization measurements suggested that a magnetic phase transition occurred in the RS-CoO x N y films during the insulator-to-metal transition. These results demonstrate that low-temperature epitaxial growth is a promising approach for exploring novel electronic functionalities in oxynitrides

  11. Studies of oxide-based thin-layered heterostructures by X-ray scattering methods

    Energy Technology Data Exchange (ETDEWEB)

    Durand, O. [Thales Research and Technology France, Route Departementale 128, F-91767 Palaiseau Cedex (France)]. E-mail: olivier.durand@thalesgroup.com; Rogers, D. [Nanovation SARL, 103 bis rue de Versailles 91400 Orsay (France); Universite de Technologie de Troyes, 10-12 rue Marie Curie, 10010 (France); Teherani, F. Hosseini [Nanovation SARL, 103 bis rue de Versailles 91400 Orsay (France); Andrieux, M. [LEMHE, ICMMOCNRS-UMR 8182, Universite d' Orsay, Batiment 410, 91410 Orsay (France); Modreanu, M. [Tyndall National Institute, Lee Maltings, Prospect Row, Cork (Ireland)

    2007-06-04

    Some X-ray scattering methods (X-ray reflectometry and Diffractometry) dedicated to the study of thin-layered heterostructures are presented with a particular focus, for practical purposes, on the description of fast, accurate and robust techniques. The use of X-ray scattering metrology as a routinely working non-destructive testing method, particularly by using procedures simplifying the data-evaluation, is emphasized. The model-independent Fourier-inversion method applied to a reflectivity curve allows a fast determination of the individual layer thicknesses. We demonstrate the capability of this method by reporting X-ray reflectometry study on multilayered oxide structures, even when the number of the layers constitutive of the stack is not known a-priori. Fast Fourier transform-based procedure has also been employed successfully on high resolution X-ray diffraction profiles. A study of the reliability of the integral-breadth methods in diffraction line-broadening analysis applied to thin layers, in order to determine coherent domain sizes, is also reported. Examples from studies of oxides-based thin-layers heterostructures will illustrate these methods. In particular, X-ray scattering studies performed on high-k HfO{sub 2} and SrZrO{sub 3} thin-layers, a (GaAs/AlOx) waveguide, and a ZnO thin-layer are reported.

  12. Feasibility of Ultra-Thin Fiber-Optic Dosimeters for Radiotherapy Dosimetry.

    Science.gov (United States)

    Lee, Bongsoo; Kwon, Guwon; Shin, Sang Hun; Kim, Jaeseok; Yoo, Wook Jae; Ji, Young Hoon; Jang, Kyoung Won

    2015-11-17

    In this study, prototype ultra-thin fiber-optic dosimeters were fabricated using organic scintillators, wavelength shifting fibers, and plastic optical fibers. The sensor probes of the ultra-thin fiber-optic dosimeters consisted of very thin organic scintillators with thicknesses of 100, 150 and 200 μm. These types of sensors cannot only be used to measure skin or surface doses but also provide depth dose measurements with high spatial resolution. With the ultra-thin fiber-optic dosimeters, surface doses for gamma rays generated from a Co-60 therapy machine were measured. Additionally, percentage depth doses in the build-up regions were obtained by using the ultra-thin fiber-optic dosimeters, and the results were compared with those of external beam therapy films and a conventional fiber-optic dosimeter.

  13. Application of plasma silicon nitride to crystalline thin-film silicon solar cells. Paper

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, J.; Oberbeck, L.; Rinke, T.J.; Berge, C.; Bergmann, R.B.

    2002-07-01

    We use plasma-enhanced chemical vapour deposition to deposit silicon nitride (SiN{sub x}) films at low temperature(400 C) onto the front surface of two different types of crystalline thin-film Si solar cells. The silicon nitride acts as an excellent antireflection coating on Si and provides a very high degree of electronic surface passivation over a wide range of compositions, including near-stoichiometric and Si-rich SiN{sub x}. Application of stoichiometric SiN{sub x} to non-textured thin-film cells, epitaxially grown at low temperature by ion-assisted deposition onto a monocrystalline Si substrate, results in an open-circuit voltage of 622 mV, a short-circuit current density of 26.6 mA/cm{sup 2} and an efficiency of 12.7%. It is shown that the SiN{sub x}-passivated in-situ grown n{sup +}-emitter of this cell type allows to reach open-circuit voltages of up to 667 mV. Silicon-rich SiN{sub x} is applied to the phosphorus-diffused n{sup +}-emitter of a textured thin-film cell on a glass superstrate fabricated by layer-transfer. The emitter saturation current density of these cells is only 40-64 fA/cm{sup 2}, which allows for open-circuit voltages of up to 699 mV. An impressively high open-circuit voltage of 638 mV and a short-circuit current density of 32.0 mA/cm{sup 2} are obtained for a 25 {mu}m thick SiN{sub x}-passivated, random pyramid-textured transfer cell. A transfer cell efficiency of 15.3% is independently confirmed.

  14. Electrochemical studies of iron/carbonates system applied to the formation of thin layers of siderite on inert substrates

    International Nuclear Information System (INIS)

    Ithurbide, A.; Peulon, S.; Mandin, Ph.; Beaucaire, C.; Chausse, A.

    2007-01-01

    In order to understand the complex mechanisms of the reactions occurring, a methodology is developed. It is based on the use of compounds electrodeposited under the form of thin layers and which are used then as electrodes to study their interactions with the toxic species. It is in this framework that is studied the electrodeposition of siderite on inert substrates. At first, have been studied iron electrochemical systems in carbonated solutions. These studies have been carried out with classical electrochemical methods (cyclic voltametry, amperometry) coupled to in-situ measurements: quartz microbalance, pH. Different compounds have been obtained under the form of homogeneous and adherent thin layers. The analyses of these depositions, by different ex-situ characterizations (XRD, IR, SEM, EDS..) have revealed particularly the presence of siderite. Then, the influence of several experimental parameters (substrate, potential, medium composition, temperature) on the characteristics of siderite thin layers has been studied. From these experimental results, models have been proposed. (O.M.)

  15. Preparation of Cu{sub 2}ZnSnS{sub 4} thin films by sulfurizing stacked precursor thin films via successive ionic layer adsorption and reaction method

    Energy Technology Data Exchange (ETDEWEB)

    Su Zhenghua; Yan Chang; Sun Kaiwen; Han Zili [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Liu Fangyang, E-mail: liufangyang@csu.edu.cn [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Liu Jin [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Lai Yanqing, E-mail: laiyanqingcsu@163.com [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Li Jie; Liu Yexiang [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China)

    2012-07-15

    Earth-abundant Cu{sub 2}ZnSnS{sub 4} is a promising alternative photovoltaic material which has been examined as absorber layer of thin film solar cells. In this study, Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films have been successfully fabricated by sulfurizing stacked precursor thin films via successive ionic layer adsorption and reaction (SILAR) method. The prepared CZTS thin films have been characterized by X-ray diffraction, energy dispersive spectrometer, Raman spectroscopy, UV-vis spectroscopy, Hall effect measurements and photoelectrochemical tests. Results reveal that the thin films have kesterite structured Cu{sub 2}ZnSnS{sub 4} and the p-type conductivity with a carrier concentration in the order of 10{sup 18} cm{sup -3} and an optical band gap of 1.5 eV, which are suitable for applications in thin film solar cells.

  16. Zirconia thin film preparation by wet chemical methods at low temperature

    NARCIS (Netherlands)

    Popovici, M.; Graaf, de J.; Verschuuren, M.A.; Graat, P.C.J.; Verheijen, M.A.

    2010-01-01

    In this study the preparation of zirconia thin films with a high refractive index at low temperature is aimed for. Two non-hydrolytic type approaches of wet chemical synthesis are presented. Both by sol–gel and colloid chemistry, highly transmissive, smooth thin films of zirconia cubic and/or

  17. Defect detection of wall thinning defect in pipes using lock-in photo-infrared thermography technique

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Su Ok; Park, Jong Hyun; Choi, Tae Ho; Jung, Hyun Chul; Kim, Kyoung Suk [Chosun Univ., Gwangju (Korea, Republic of)

    2008-07-01

    Piping in the Nuclear Power plants (NPP) are mostly consisted of carbon steel pipe. The wall thinning defect is mainly occurred by the affect of the Flow Accelerated Corrosion (FAC) of fluid which flows in carbon steel pipes. This type of defect becomes the cause of damage or destruction of piping. Therefore, it is very important to measure defect which is existed not only on the welding partbut also on the whole field of pipe. Over the years, Infrared Thermography (IRT) has been used as a non destructive testing methods of the various kinds of materials. This technique has many merits and applied to the industrial field but has limitation to the materials. Therefore, this method was combined with lock-in technique. So IRT detection resolution has been progressively improved using lock-in technique. In this paper, the quantitative analysis results of the location and the size of wall thinning defect that is artificially processed inside the carbon steel pipe by using IRT are obtained.

  18. Conductance Thin Film Model of Flexible Organic Thin Film Device using COMSOL Multiphysics

    Science.gov (United States)

    Carradero-Santiago, Carolyn; Vedrine-Pauléus, Josee

    We developed a virtual model to analyze the electrical conductivity of multilayered thin films placed above a graphene conducting and flexible polyethylene terephthalate (PET) substrate. The organic layers of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as a hole conducting layer, poly(3-hexylthiophene-2,5-diyl) (P3HT), as a p-type, phenyl-C61-butyric acid methyl ester (PCBM) and as n-type, with aluminum as a top conductor. COMSOL Multiphysics was the software we used to develop the virtual model to analyze potential variations and conductivity through the thin-film layers. COMSOL Multiphysics software allows simulation and modeling of physical phenomena represented by differential equations such as heat transfer, fluid flow, electromagnetism, and structural mechanics. In this work, using the AC/DC, electric currents module we defined the geometry of the model and properties for each of the six layers: PET/graphene/PEDOT:PSS/P3HT/PCBM/aluminum. We analyzed the model with varying thicknesses of graphene and active layers (P3HT/PCBM). This simulation allowed us to analyze the electrical conductivity, and visualize the model with varying voltage potential, or bias across the plates, useful for applications in solar cell devices.

  19. Domain switching of fatigued ferroelectric thin films

    Science.gov (United States)

    Tak Lim, Yun; Yeog Son, Jong; Shin, Young-Han

    2014-05-01

    We investigate the domain wall speed of a ferroelectric PbZr0.48Ti0.52O3 (PZT) thin film using an atomic force microscope incorporated with a mercury-probe system to control the degree of electrical fatigue. The depolarization field in the PZT thin film decreases with increasing the degree of electrical fatigue. We find that the wide-range activation field previously reported in ferroelectric domains result from the change of the depolarization field caused by the electrical fatigue. Domain wall speed exhibits universal behavior to the effective electric field (defined by an applied electric field minus the depolarization field), regardless of the degree of the electrical fatigue.

  20. Domain switching of fatigued ferroelectric thin films

    International Nuclear Information System (INIS)

    Tak Lim, Yun; Yeog Son, Jong; Shin, Young-Han

    2014-01-01

    We investigate the domain wall speed of a ferroelectric PbZr 0.48 Ti 0.52 O 3 (PZT) thin film using an atomic force microscope incorporated with a mercury-probe system to control the degree of electrical fatigue. The depolarization field in the PZT thin film decreases with increasing the degree of electrical fatigue. We find that the wide-range activation field previously reported in ferroelectric domains result from the change of the depolarization field caused by the electrical fatigue. Domain wall speed exhibits universal behavior to the effective electric field (defined by an applied electric field minus the depolarization field), regardless of the degree of the electrical fatigue

  1. Mass productions of thin film silicon PV modules

    International Nuclear Information System (INIS)

    Tawada, Y.; Yamagishi, H.; Yamamoto, K.

    2003-01-01

    Mass production technologies of a-Si single junction and a-Si/poly-Si hybrid modules with stable 8% and 10% efficiency were developed in the Shiga factory of Kaneka Corporation. Kaneka instituted Kaneka Solartech Corporation (KST) as a subsidiary company of 100% shareholder and invested 20 MW production plant in Toyooka City in 1999. There are fully automatic thin film fabrication equipments. KST started the manufacturing amorphous silicon PV modules in 1999 and those of hybrid type PV modules in 2001. The largest size glass substrates used for these modules are 95x98 cm and variable size of modules are being produced by cutting these large area base modules. Recent production yields are higher than 98%. Production technologies of a-Si, thin c-Si and solar cells, performances of modules, applications to the rooftop PV systems will be presented. We estimate the production cost of a-Si solar modules and a-Si/thin c-Si hybrid solar modules. The future business plan of our new type solar modules and our production lines will be discussed. (author)

  2. Simulated Thin-Film Growth and Imaging

    Science.gov (United States)

    Schillaci, Michael

    2001-06-01

    Thin-films have become the cornerstone of the electronics, telecommunications, and broadband markets. A list of potential products includes: computer boards and chips, satellites, cell phones, fuel cells, superconductors, flat panel displays, optical waveguides, building and automotive windows, food and beverage plastic containers, metal foils, pipe plating, vision ware, manufacturing equipment and turbine engines. For all of these reasons a basic understanding of the physical processes involved in both growing and imaging thin-films can provide a wonderful research project for advanced undergraduate and first-year graduate students. After producing rudimentary two- and three-dimensional thin-film models incorporating ballsitic deposition and nearest neighbor Coulomb-type interactions, the QM tunneling equations are used to produce simulated scanning tunneling microscope (SSTM) images of the films. A discussion of computational platforms, languages, and software packages that may be used to accomplish similar results is also given.

  3. Flexible Mixed-Potential-Type (MPT) NO₂ Sensor Based on An Ultra-Thin Ceramic Film.

    Science.gov (United States)

    You, Rui; Jing, Gaoshan; Yu, Hongyan; Cui, Tianhong

    2017-07-29

    A novel flexible mixed-potential-type (MPT) sensor was designed and fabricated for NO₂ detection from 0 to 500 ppm at 200 °C. An ultra-thin Y₂O₃-doped ZrO₂ (YSZ) ceramic film 20 µm thick was sandwiched between a heating electrode and reference/sensing electrodes. The heating electrode was fabricated by a conventional lift-off process, while the porous reference and the sensing electrodes were fabricated by a two-step patterning method using shadow masks. The sensor's sensitivity is achieved as 58.4 mV/decade at the working temperature of 200 °C, as well as a detection limit of 26.7 ppm and small response time of less than 10 s at 200 ppm. Additionally, the flexible MPT sensor demonstrates superior mechanical stability after bending over 50 times due to the mechanical stability of the YSZ ceramic film. This simply structured, but highly reliable flexible MPT NO₂ sensor may lead to wide application in the automobile industry for vehicle emission systems to reduce NO₂ emissions and improve fuel efficiency.

  4. Thermochemical hydrogen generation of indium oxide thin films

    Directory of Open Access Journals (Sweden)

    Taekyung Lim

    2017-03-01

    Full Text Available Development of alternative energy resources is an urgent requirement to alleviate current energy constraints. As such, hydrogen gas is gaining attention as a future alternative energy source to address existing issues related to limited energy resources and air pollution. In this study, hydrogen generation by a thermochemical water-splitting process using two types of In2O3 thin films was investigated. The two In2O3 thin films prepared by chemical vapor deposition (CVD and sputtering deposition systems contained different numbers of oxygen vacancies, which were directly related to hydrogen generation. The as-grown In2O3 thin film prepared by CVD generated a large amount of hydrogen because of its abundant oxygen vacancies, while that prepared by sputtering had few oxygen vacancies, resulting in low hydrogen generation. Increasing the temperature of the In2O3 thin film in the reaction chamber caused an increase in hydrogen generation. The oxygen-vacancy-rich In2O3 thin film is expected to provide a highly effective production of hydrogen as a sustainable and efficient energy source.

  5. Thin films for the manipulation of light

    International Nuclear Information System (INIS)

    Piegari, Angela; Sytchkova, Anna

    2015-01-01

    The manipulation of light is typically accomplished by a series of optical surfaces on which the incident beam is reflected, or through which the beam is transmitted. Thin film coatings help to modify the behavior of such surfaces for obtaining the desired result: antireflection coatings to reduce reflection losses, high-reflectance mirrors, filters to divide or combine beams of different wavelengths, and many other types. The amount of light that is transmitted or reflected depends on the optical parameters of the materials and on interference phenomena in thin-film structures. Dedicated software is available to design the proper coating for each requirement. There are several applications of optical thin films, many of them are useful in the everyday life, many others are dedicated to scientific purposes, as will be described in this paper [it

  6. CuS p-type thin film characterization deposited on Ti, ITO and glass substrates using spray pyrolysis deposition (SPD) for light emitting diode (LED) application

    Energy Technology Data Exchange (ETDEWEB)

    Sabah, Fayroz A., E-mail: fayroz-arif@yahoo.com [Institue of Nano-Optoelectronics Research and Technology (INOR), School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Department of Electrical Engineering, College of Engineering, Al-Mustansiriya University, Baghdad (Iraq); Ahmed, Naser M., E-mail: naser@usm.my; Hassan, Z., E-mail: zai@usm.my; Azzez, Shrook A. [Institue of Nano-Optoelectronics Research and Technology (INOR), School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Rasheed, Hiba S., E-mail: hibasaad1980@yahoo.com [Institue of Nano-Optoelectronics Research and Technology (INOR), School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Department of Physics, College of Education, Al-Mustansiriya University, Baghdad (Iraq); Al-Hazim, Nabeel Z., E-mail: nabeelnano333@gmail.com [Institue of Nano-Optoelectronics Research and Technology (INOR), School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Ministry of Education, the General Directorate for Educational Anbar (Iraq)

    2016-07-06

    The copper sulphide (CuS) thin films were grown with good adhesion by spray pyrolysis deposition (SPD) on Ti, ITO and glass substrates at 200 °C. The distance between nozzle and substrate is 30 cm. The composition was prepared by mixing copper chloride CuCl{sub 2}.2H{sub 2}O as a source of Cu{sup 2+} and sodium thiosulfate Na{sub 2}S{sub 2}O{sub 3}.5H{sub 2}O as a source of and S{sup 2−}. Two concentrations (0.2 and 0.4 M) were used for each CuCl{sub 2} and Na{sub 2}S{sub 2}O{sub 3} to be prepared and then sprayed (20 ml). The process was started by spraying the solution for 3 seconds and after 10 seconds the cycle was repeated until the solution was sprayed completely on the hot substrates. The structural characteristics were studied using X-ray diffraction; they showed covellite CuS hexagonal crystal structure for 0.2 M concentration, and covellite CuS hexagonal crystal structure with two small peaks of chalcocite Cu{sub 2}S hexagonal crystal structure for 0.4 M concentration. Also the surface and electrical characteristics were investigated using Field Emission Scanning Electron Microscopy (FESEM) and current source device, respectively. The surface study for the CuS thin films showed nanorods to be established for 0.2 M concentration and mix of nanorods and nanoplates for 0.4 M concentration. The electrical study showed ohmic behavior and low resistivity for these films. Hall Effect was measured for these thin films, it showed that all samples of CuS are p- type thin films and ensured that the resistivity for thin films of 0.2 M concentration was lower than that of 0.4 M concentration; and for the two concentrations CuS thin film deposited on ITO had the lowest resistivity. This leads to the result that the conductivity was high for CuS thin film deposited on ITO substrate, and the conductivity of the three thin films of 0.2 M concentration was higher than that of 0.4 M concentration.

  7. Air-water ‘tornado’-type microwave plasmas applied for sugarcane biomass treatment

    Science.gov (United States)

    Bundaleska, N.; Tatarova, E.; Dias, F. M.; Lino da Silva, M.; Ferreira, C. M.; Amorim, J.

    2014-02-01

    The production of cellulosic ethanol from sugarcane biomass is an attractive alternative to the use of fossil fuels. Pretreatment is needed to separate the cellulosic material, which is packed with hemicellulose and lignin in cell wall of sugarcane biomass. A microwave ‘tornado’-type air-water plasma source operating at 2.45 GHz and atmospheric pressure has been applied for this purpose. Samples of dry and wet biomass (˜2 g) have been exposed to the late afterglow plasma stream. The experiments demonstrate that the air-water highly reactive plasma environment provides a number of long-lived active species able to destroy the cellulosic wrapping. Scanning electron microscopy has been applied to analyse the morphological changes occurring due to plasma treatment. The effluent gas streams have been analysed by Fourier-transform infrared spectroscopy (FT-IR). Optical emission spectroscopy and FT-IR have been applied to determine the gas temperature in the discharge and late afterglow plasma zones, respectively. The optimal range of the operational parameters is discussed along with the main active species involved in the treatment process. Synergistic effects can result from the action of singlet O2(a 1Δg) oxygen, NO2, nitrous acid HNO2 and OH hydroxyl radical.

  8. Air–water ‘tornado’-type microwave plasmas applied for sugarcane biomass treatment

    International Nuclear Information System (INIS)

    Bundaleska, N; Tatarova, E; Dias, F M; Lino da Silva, M; Ferreira, C M; Amorim, J

    2014-01-01

    The production of cellulosic ethanol from sugarcane biomass is an attractive alternative to the use of fossil fuels. Pretreatment is needed to separate the cellulosic material, which is packed with hemicellulose and lignin in cell wall of sugarcane biomass. A microwave ‘tornado’-type air–water plasma source operating at 2.45 GHz and atmospheric pressure has been applied for this purpose. Samples of dry and wet biomass (∼2 g) have been exposed to the late afterglow plasma stream. The experiments demonstrate that the air–water highly reactive plasma environment provides a number of long-lived active species able to destroy the cellulosic wrapping. Scanning electron microscopy has been applied to analyse the morphological changes occurring due to plasma treatment. The effluent gas streams have been analysed by Fourier-transform infrared spectroscopy (FT-IR). Optical emission spectroscopy and FT-IR have been applied to determine the gas temperature in the discharge and late afterglow plasma zones, respectively. The optimal range of the operational parameters is discussed along with the main active species involved in the treatment process. Synergistic effects can result from the action of singlet O 2 (a  1 Δ g ) oxygen, NO 2 , nitrous acid HNO 2 and OH hydroxyl radical. (paper)

  9. Self-compacting fibre reinforced concrete applied in thin plates

    NARCIS (Netherlands)

    Grunewald, S.; Shionaga, R.; Walraven, J.C.

    2013-01-01

    Floor panels produced with traditionally vibrated concrete are relatively thick due to the need to reinforce concrete and consequently, heavy. Without the need to place rebars in panels and by applying self-compacting fibre reinforced concrete (SCFRC) the production process becomes more efficient.

  10. Electrochromic Devices Based on Porous Tungsten Oxide Thin Films

    Directory of Open Access Journals (Sweden)

    Y. Djaoued

    2012-01-01

    Full Text Available Recent developments in the synthesis of transition metal oxides in the form of porous thin films have opened up opportunities in the construction of electrochromic devices with enhanced properties. In this paper, synthesis, characterization and electrochromic applications of porous WO3 thin films with different nanocrystalline phases, such as hexagonal, monoclinic, and orthorhombic, are presented. Asymmetric electrochromic devices have been constructed based on these porous WO3 thin films. XRD measurements of the intercalation/deintercalation of Li+ into/from the WO3 layer of the device as a function of applied coloration/bleaching voltages show systematic changes in the lattice parameters associated with structural phase transitions in LixWO3. Micro-Raman studies show systematic crystalline phase changes in the spectra of WO3 layers during Li+ ion intercalation and deintercalation, which agree with the XRD data. These devices exhibit interesting optical modulation (up to ~70% due to intercalation/deintercalation of Li ions into/from the WO3 layer of the devices as a function of applied coloration/bleaching voltages. The obtained optical modulation of the electrochromic devices indicates that, they are suitable for applications in electrochromic smart windows.

  11. Deposition and characterization of spray pyrolysed p-type Cu2SnS3 thin film for potential absorber layer of solar cell

    Science.gov (United States)

    Thiruvenkadam, S.; Sakthi, P.; Prabhakaran, S.; Chakravarty, Sujay; Ganesan, V.; Rajesh, A. Leo

    2018-06-01

    Thin film of ternary Cu2SnS3 (CTS), a potential absorber layer for solar cells was successfully deposited by chemical spray pyrolysis technique. The GIXRD pattern revealed that the film having tetragonal Cu2SnS3 phase with the preferential orientation along (112), (200), (220) and (312) plane and it is further confirmed using Raman spectroscopy by the existence of Raman peak at 320 cm-1. Atomic Force Microscopy (AFM) was used to estimate the surface roughness of 28.8 nm. The absorption coefficient was found to be greater than the order of 105 cm-1 and bandgap of 1.70 eV. Hall effect measurement indicates the p type nature of the film with a hole concentration of 1.03 × 1016cm-3 and a hall mobility of 404 cm2/V. The properties of CTS thin film confirmed suitable to be a potential absorber layer material for photovoltaic applications.

  12. Physical Vapor Deposition of Thin Films

    Science.gov (United States)

    Mahan, John E.

    2000-01-01

    A unified treatment of the theories, data, and technologies underlying physical vapor deposition methods With electronic, optical, and magnetic coating technologies increasingly dominating manufacturing in the high-tech industries, there is a growing need for expertise in physical vapor deposition of thin films. This important new work provides researchers and engineers in this field with the information they need to tackle thin film processes in the real world. Presenting a cohesive, thoroughly developed treatment of both fundamental and applied topics, Physical Vapor Deposition of Thin Films incorporates many critical results from across the literature as it imparts a working knowledge of a variety of present-day techniques. Numerous worked examples, extensive references, and more than 100 illustrations and photographs accompany coverage of: * Thermal evaporation, sputtering, and pulsed laser deposition techniques * Key theories and phenomena, including the kinetic theory of gases, adsorption and condensation, high-vacuum pumping dynamics, and sputtering discharges * Trends in sputter yield data and a new simplified collisional model of sputter yield for pure element targets * Quantitative models for film deposition rate, thickness profiles, and thermalization of the sputtered beam

  13. A statistical-thermodynamic model for ordering phenomena in thin film intermetallic structures

    International Nuclear Information System (INIS)

    Semenova, Olga; Krachler, Regina

    2008-01-01

    Ordering phenomena in bcc (110) binary thin film intermetallics are studied by a statistical-thermodynamic model. The system is modeled by an Ising approach that includes only nearest-neighbor chemical interactions and is solved in a mean-field approximation. Vacancies and anti-structure atoms are considered on both sublattices. The model describes long-range ordering and simultaneously short-range ordering in the thin film. It is applied to NiAl thin films with B2 structure. Vacancy concentrations, thermodynamic activity profiles and the virtual critical temperature of order-disorder as a function of film composition and thickness are presented. The results point to an important role of vacancies in near-stoichiometric and Ni-rich NiAl thin films

  14. Efficient thin-film stack characterization using parametric sensitivity analysis for spectroscopic ellipsometry in semiconductor device fabrication

    International Nuclear Information System (INIS)

    Likhachev, D.V.

    2015-01-01

    During semiconductor device fabrication, control of the layer thicknesses is an important task for in-line metrology since the correct thickness values are essential for proper device performance. At the present time, ellipsometry is widely used for routine process monitoring and process improvement as well as characterization of various materials in the modern nanoelectronic manufacturing. The wide recognition of this technique is based on its non-invasive, non-intrusive and non-destructive nature, high measurement precision, accuracy and speed, and versatility to characterize practically all types of materials used in modern semiconductor industry (dielectrics, semiconductors, metals, polymers, etc.). However, it requires the use of one of the multi-parameter non-linear optimization methods due to its indirect nature. This fact creates a big challenge for analysis of multilayered structures since the number of simultaneously determined model parameters, for instance, thin film thicknesses and model variables related to film optical properties, should be restricted due to parameter cross-correlations. In this paper, we use parametric sensitivity analysis to evaluate the importance of various model parameters and to suggest their optimal search ranges. In this work, the method is applied practically for analysis of a few structures with up to five-layered film stack. It demonstrates an evidence-based improvement in accuracy of multilayered thin-film thickness measurements which suggests that the proposed approach can be useful for industrial applications. - Highlights: • An improved method for multilayered thin-film stack characterization is proposed. • The screening-type technique based on so-called “elementary effects” was employed. • The model parameters were ranked according to relative importance for model output. • The method is tested using two examples of complex thin-film stack characterization. • The approach can be useful in many practical

  15. Efficient thin-film stack characterization using parametric sensitivity analysis for spectroscopic ellipsometry in semiconductor device fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Likhachev, D.V., E-mail: dmitriy.likhachev@globalfoundries.com

    2015-08-31

    During semiconductor device fabrication, control of the layer thicknesses is an important task for in-line metrology since the correct thickness values are essential for proper device performance. At the present time, ellipsometry is widely used for routine process monitoring and process improvement as well as characterization of various materials in the modern nanoelectronic manufacturing. The wide recognition of this technique is based on its non-invasive, non-intrusive and non-destructive nature, high measurement precision, accuracy and speed, and versatility to characterize practically all types of materials used in modern semiconductor industry (dielectrics, semiconductors, metals, polymers, etc.). However, it requires the use of one of the multi-parameter non-linear optimization methods due to its indirect nature. This fact creates a big challenge for analysis of multilayered structures since the number of simultaneously determined model parameters, for instance, thin film thicknesses and model variables related to film optical properties, should be restricted due to parameter cross-correlations. In this paper, we use parametric sensitivity analysis to evaluate the importance of various model parameters and to suggest their optimal search ranges. In this work, the method is applied practically for analysis of a few structures with up to five-layered film stack. It demonstrates an evidence-based improvement in accuracy of multilayered thin-film thickness measurements which suggests that the proposed approach can be useful for industrial applications. - Highlights: • An improved method for multilayered thin-film stack characterization is proposed. • The screening-type technique based on so-called “elementary effects” was employed. • The model parameters were ranked according to relative importance for model output. • The method is tested using two examples of complex thin-film stack characterization. • The approach can be useful in many practical

  16. Temperature-dependent thermal and thermoelectric properties of n -type and p -type S c1 -xM gxN

    Science.gov (United States)

    Saha, Bivas; Perez-Taborda, Jaime Andres; Bahk, Je-Hyeong; Koh, Yee Rui; Shakouri, Ali; Martin-Gonzalez, Marisol; Sands, Timothy D.

    2018-02-01

    Scandium Nitride (ScN) is an emerging rocksalt semiconductor with octahedral coordination and an indirect bandgap. ScN has attracted significant attention in recent years for its potential thermoelectric applications, as a component material in epitaxial metal/semiconductor superlattices, and as a substrate for defect-free GaN growth. Sputter-deposited ScN thin films are highly degenerate n -type semiconductors and exhibit a large thermoelectric power factor of ˜3.5 ×10-3W /m -K2 at 600-800 K. Since practical thermoelectric devices require both n- and p-type materials with high thermoelectric figures-of-merit, development and demonstration of highly efficient p-type ScN is extremely important. Recently, the authors have demonstrated p-type S c1 -xM gxN thin film alloys with low M gxNy mole-fractions within the ScN matrix. In this article, we demonstrate temperature dependent thermal and thermoelectric transport properties, including large thermoelectric power factors in both n- and p-type S c1 -xM gxN thin film alloys at high temperatures (up to 850 K). Employing a combination of temperature-dependent Seebeck coefficient, electrical conductivity, and thermal conductivity measurements, as well as detailed Boltzmann transport-based modeling analyses of the transport properties, we demonstrate that p-type S c1 -xM gxN thin film alloys exhibit a maximum thermoelectric power factor of ˜0.8 ×10-3W /m -K2 at 850 K. The thermoelectric properties are tunable by adjusting the M gxNy mole-fraction inside the ScN matrix, thereby shifting the Fermi energy in the alloy films from inside the conduction band in case of undoped n -type ScN to inside the valence band in highly hole-doped p -type S c1 -xM gxN thin film alloys. The thermal conductivities of both the n- and p-type films were found to be undesirably large for thermoelectric applications. Thus, future work should address strategies to reduce the thermal conductivity of S c1 -xM gxN thin-film alloys, without affecting

  17. Electrical transport characterization of Al and Sn doped Mg 2 Si thin films

    KAUST Repository

    Zhang, Bo; Zheng, Tao; Sun, Ce; Guo, Zaibing; Kim, Moon J.; Alshareef, Husam N.; Quevedo-Lopez, Manuel; Gnade, Bruce E.

    2017-01-01

    Thin-film Mg2Si was deposited using radio frequency (RF) magnetron sputtering. Al and Sn were incorporated as n-type dopants using co-sputtering to tune the thin-film electrical properties. X-ray diffraction (XRD) analysis confirmed

  18. Polarization Induced Changes in LSM Thin Film Electrode Composition Observed by In Operando Raman Spectroscopy and TOF-SIMS

    DEFF Research Database (Denmark)

    McIntyre, Melissa D.; Walker, Robert; Traulsen, Marie Lund

    2015-01-01

    an applied potential.1-3 The presented work explores the polarisation induced changes in LSM electrode composition by utilizing in operando Raman spectroscopy and post mortem ToF-SIMS depth profiling on LSM thin film model electrodes fabricated by pulsed laser deposition on YSZ substrates with a thin (200 nm...... recorded through the LSM thin film electrodes and revealed distinct compositional changes throughout the electrodes (Figure 2). The electrode elements and impurities separated into distinct layers that were more pronounced for the stronger applied polarisations. The mechanism behind this separation...

  19. An optimal control model of crop thinning in viticulture

    Directory of Open Access Journals (Sweden)

    Schamel Guenter H.

    2016-01-01

    Full Text Available We develop an economic model of cluster thinning in viticulture to control for grape quantity harvested and grape quality, applying a simple optimal control model with the aim to raise grape quality and related economic profits. The model maximizes vineyard owner profits and allows to discuss two relevant scenarios using a phase diagram analysis: (1 when the initial grape quantity is sufficiently small, thinning grapes will not be optimal and (2 when the initial grape quantity is high enough, it is optimal to thin grapes from the beginning of the relevant planning horizon and to reduce the quantity over time until the stock of grapes arrives at its optimum. Depending on the model's parameters, the “stopping time” for thinning grapes is reached sooner or later. After the stopping time, grape quantity evolves solely according to natural decay. The results relate to observed dynamics in viticulture and for other horticultural crops.

  20. Altered 5-HT2A Receptor Binding after Recovery from Bulimia-Type Anorexia Nervosa: Relationships to Harm Avoidance and Drive for Thinness

    Science.gov (United States)

    Bailer, Ursula F; Price, Julie C; Meltzer, Carolyn C; Mathis, Chester A; Frank, Guido K; Weissfeld, Lisa; McConaha, Claire W; Henry, Shannan E; Brooks-Achenbach, Sarah; Barbarich, Nicole C; Kaye, Walter H

    2015-01-01

    Several lines of evidence suggest that a disturbance of serotonin neuronal pathways may contribute to the pathogenesis of anorexia nervosa (AN) and bulimia nervosa (BN). This study applied positron emission tomography (PET) to investigate the brain serotonin 2A (5-HT2A) receptor, which could contribute to disturbances of appetite and behavior in AN and BN. To avoid the confounding effects of malnutrition, we studied 10 women recovered from bulimia-type AN (REC AN–BN, >1 year normal weight, regular menstrual cycles, no binging, or purging) compared with 16 healthy control women (CW) using PET imaging and a specific 5-HT2A receptor antagonist, [18F]altanserin. REC AN–BN women had significantly reduced [18F]altanserin binding potential relative to CW in the left subgenual cingulate, the left parietal cortex, and the right occipital cortex. [18F]altanserin binding potential was positively related to harm avoidance and negatively related to novelty seeking in cingulate and temporal regions only in REC AN–BN subjects. In addition, REC AN–BN had negative relationships between [18F]altanserin binding potential and drive for thinness in several cortical regions. In conclusion, this study extends research suggesting that altered 5-HT neuronal system activity persists after recovery from bulimia-type AN, particularly in subgenual cingulate regions. Altered 5-HT neurotransmission after recovery also supports the possibility that this may be a trait-related disturbance that contributes to the pathophysiology of eating disorders. It is possible that subgenual cingulate findings are not specific for AN–BN, but may be related to the high incidence of lifetime major depressive disorder diagnosis in these subjects. PMID:15054474

  1. Debt Financing and Thin-Capitalization: Case Study in Slovenia

    Directory of Open Access Journals (Sweden)

    Lidija Hauptman

    2014-03-01

    Full Text Available Since each form of financing provides a different level of security and risk, companies are often faced with a dilemma, which equity to debt ratio to choose in financial structure. In order to avoid overexploitation of certain types of debt financing, tax legislation defines a thin capitalization rule. In this paper we present, how the relationship between equity and debt financing has changed in the period 1997–2012 and how the thin capitalization rules affected this relationship in the selected parent companies in Slovenia. The analysis reveals that the proportion of debt financing increased before and after the introduction of thin capitalization rules throughout the period.

  2. Structural studies of n-type nc-Si-QD thin films for nc-Si solar cells

    Science.gov (United States)

    Das, Debajyoti; Kar, Debjit

    2017-12-01

    A wide optical gap nanocrystalline silicon (nc-Si) dielectric material is a basic requirement at the n-type window layer of nc-Si solar cells in thin film n-i-p structure on glass substrates. Taking advantage of the high atomic-H density inherent to the planar inductively coupled low-pressure (SiH4 + CH4)-plasma, development of an analogous material in P-doped nc-Si-QD/a-SiC:H network has been tried. Incorporation of C in the Si-network extracted from the CH4 widens the optical band gap; however, at enhanced PH3-dilution of the plasma spontaneous miniaturization of the nc-Si-QDs below the dimension of Bohr radius (∼4.5 nm) further enhances the band gap by virtue of the quantum size effect. At increased flow rate of PH3, dopant induced continuous amorphization of the intrinsic crystalline network is counterbalanced by the further crystallization promoted by the supplementary atomic-H extracted from PH3 (1% in H2) in the plasma, eventually holding a moderately high degree of crystallinity. The n-type wide band gap (∼1.93 eV) window layer with nc-Si-QDs in adequate volume fraction (∼52%) could furthermore be instrumental as an effective seed layer for advancing sequential crystallization in the i-layer of nc-Si solar cells with n-i-p structure in superstrate configuration.

  3. Nanostructured ZnO thin films prepared by sol–gel spin-coating

    Energy Technology Data Exchange (ETDEWEB)

    Heredia, E., E-mail: heredia.edu@gmail.com [UNIDEF (CONICET-MINDEF), J.B. de La Salle 4397, 1603 Villa Martelli, Pcia. de Buenos Aires (Argentina); Bojorge, C.; Casanova, J.; Cánepa, H. [UNIDEF (CONICET-MINDEF), J.B. de La Salle 4397, 1603 Villa Martelli, Pcia. de Buenos Aires (Argentina); Craievich, A. [Instituto de Física, Universidade de São Paulo, Cidade Universitária, 66318 São Paulo, SP (Brazil); Kellermann, G. [Universidade Federal do Paraná, 19044 Paraná (Brazil)

    2014-10-30

    Highlights: • ZnO films synthesized by sol–gel were deposited by spin-coating on flat substrates. • Structural features of ZnO films with several thicknesses were characterized by means of different techniques. • The thicknesses of different ZnO thin films were determined by means of FESEM and AFM. • The nanoporous structures of ZnO thin films were characterized by GISAXS using IsGISAXS software. • The average densities of ZnO thin films were derived from (i) the critical angle in 1D XR patterns, (ii) the angle of Yoneda peak in 2D GISAXS images, (iii) minimization of chi2 using IsGISAXS best fitting procedure. - Abstract: ZnO thin films deposited on silica flat plates were prepared by spin-coating and studied by applying several techniques for structural characterization. The films were prepared by depositing different numbers of layers, each deposition being followed by a thermal treatment at 200 °C to dry and consolidate the successive layers. After depositing all layers, a final thermal treatment at 450 °C during 3 h was also applied in order to eliminate organic components and to promote the crystallization of the thin films. The total thickness of the multilayered films – ranging from 40 nm up to 150 nm – was determined by AFM and FESEM. The analysis by GIXD showed that the thin films are composed of ZnO crystallites with an average diameter of 25 nm circa. XR results demonstrated that the thin films also exhibit a large volume fraction of nanoporosity, typically 30–40 vol.% in thin films having thicknesses larger than ∼70 nm. GISAXS measurements showed that the experimental scattering intensity is well described by a structural model composed of nanopores with shape of oblate spheroids, height/diameter aspect ratio within the 0.8–0.9 range and average diameter along the sample surface plane in the 5–7 nm range.

  4. Geometry of thin liquid sheet flows

    Science.gov (United States)

    Chubb, Donald L.; Calfo, Frederick D.; Mcconley, Marc W.; Mcmaster, Matthew S.; Afjeh, Abdollah A.

    1994-01-01

    Incompresible, thin sheet flows have been of research interest for many years. Those studies were mainly concerned with the stability of the flow in a surrounding gas. Squire was the first to carry out a linear, invicid stability analysis of sheet flow in air and compare the results with experiment. Dombrowski and Fraser did an experimental study of the disintegration of sheet flows using several viscous liquids. They also detected the formulation of holes in their sheet flows. Hagerty and Shea carried out an inviscid stability analysis and calculated growth rates with experimental values. They compared their calculated growth rates with experimental values. Taylor studied extensively the stability of thin liquid sheets both theoretically and experimentally. He showed that thin sheets in a vacuum are stable. Brown experimentally investigated thin liquid sheet flows as a method of application of thin films. Clark and Dumbrowski carried out second-order stability analysis for invicid sheet flows. Lin introduced viscosity into the linear stability analysis of thin sheet flows in a vacuum. Mansour and Chigier conducted an experimental study of the breakup of a sheet flow surrounded by high-speed air. Lin et al. did a linear stability analysis that included viscosity and a surrounding gas. Rangel and Sirignano carried out both a linear and nonlinear invisid stability analysis that applies for any density ratio between the sheet liquid and the surrounding gas. Now there is renewed interest in sheet flows because of their possible application as low mass radiating surfaces. The objective of this study is to investigate the fluid dynamics of sheet flows that are of interest for a space radiator system. Analytical expressions that govern the sheet geometry are compared with experimental results. Since a space radiator will operate in a vacuum, the analysis does not include any drag force on the sheet flow.

  5. Nonlinear Ballistic Transport in an Atomically Thin Material.

    Science.gov (United States)

    Boland, Mathias J; Sundararajan, Abhishek; Farrokhi, M Javad; Strachan, Douglas R

    2016-01-26

    Ultrashort devices that incorporate atomically thin components have the potential to be the smallest electronics. Such extremely scaled atomically thin devices are expected to show ballistic nonlinear behavior that could make them tremendously useful for ultrafast applications. While nonlinear diffusive electron transport has been widely reported, clear evidence for intrinsic nonlinear ballistic transport in the growing array of atomically thin conductors has so far been elusive. Here we report nonlinear electron transport of an ultrashort single-layer graphene channel that shows quantitative agreement with intrinsic ballistic transport. This behavior is shown to be distinctly different than that observed in similarly prepared ultrashort devices consisting, instead, of bilayer graphene channels. These results suggest that the addition of only one extra layer of an atomically thin material can make a significant impact on the nonlinear ballistic behavior of ultrashort devices, which is possibly due to the very different chiral tunneling of their charge carriers. The fact that we observe the nonlinear ballistic response at room temperature, with zero applied magnetic field, in non-ultrahigh vacuum conditions and directly on a readily accessible oxide substrate makes the nanogap technology we utilize of great potential for achieving extremely scaled high-speed atomically thin devices.

  6. Platonic scattering cancellation for bending waves in a thin plate

    KAUST Repository

    Farhat, Mohamed

    2014-04-10

    We propose an ultra-thin elastic cloak to control the scattering of bending waves in isotropic heterogeneous thin plates. The cloak design makes use of the scattering cancellation technique applied, for the first time, to the biharmonic operator describing the propagation of bending waves in thin plates. We first analyze scattering from hard and soft cylindrical objects in the quasistatic limit, then we prove that the scattering of bending waves from an object in the near and far-field regions can be suppressed significantly by covering it with a suitably designed coating. Beyond camouflaging, these findings may have potential applications in protection of buildings from earthquakes and isolating structures from vibrations in the motor vehicle industry.

  7. Platonic scattering cancellation for bending waves in a thin plate

    KAUST Repository

    Farhat, Mohamed; Chen, P.-Y.; Bagci, Hakan; Enoch, S.; Guenneau, S.; Alù , A.

    2014-01-01

    We propose an ultra-thin elastic cloak to control the scattering of bending waves in isotropic heterogeneous thin plates. The cloak design makes use of the scattering cancellation technique applied, for the first time, to the biharmonic operator describing the propagation of bending waves in thin plates. We first analyze scattering from hard and soft cylindrical objects in the quasistatic limit, then we prove that the scattering of bending waves from an object in the near and far-field regions can be suppressed significantly by covering it with a suitably designed coating. Beyond camouflaging, these findings may have potential applications in protection of buildings from earthquakes and isolating structures from vibrations in the motor vehicle industry.

  8. Impacts of Mastication: Soil Seed Bank Responses to a Forest Thinning Treatment in Three Colorado (USA Conifer Forest Types

    Directory of Open Access Journals (Sweden)

    Akasha M. Faist

    2015-08-01

    Full Text Available Mastication is a forest fuel thinning treatment that involves chipping or shredding small trees and shrubs and depositing the material across the forest floor. By decreasing forest density mastication has been shown to lessen crown fire hazard, yet other impacts have only recently started to be studied. Our study evaluates how mastication treatments alter the density and composition of soil seed banks in three Colorado conifer forest types. The three forest types were (1 lodgepole pine, (2 ponderosa pine and (3 pinyon pine-juniper. Results showed that masticated sites contained higher seed bank densities than untreated sites: a pattern primarily driven by treatment effects in ponderosa pine forests. The seed bank was dominated by forbs regardless of forest type or treatment. This pattern of forb dominance was not observed in the aboveground vegetation cover as it demonstrated more even proportions of the functional groups. Graminoids showed a higher seed density in treated sites than untreated and, similarly, the identified non-native species only occurred in the treated ponderosa pine sites suggesting a potential belowground invasion for this forest type. These results suggest that presence of masticated material might not be creating a physical barrier hindering the transfer of seeds as predicted.

  9. Infrared-transmittance tunable metal-insulator conversion device with thin-film-transistor-type structure on a glass substrate

    Directory of Open Access Journals (Sweden)

    Takayoshi Katase

    2017-05-01

    Full Text Available Infrared (IR transmittance tunable metal-insulator conversion was demonstrated on a glass substrate by using thermochromic vanadium dioxide (VO2 as the active layer in a three-terminal thin-film-transistor-type device with water-infiltrated glass as the gate insulator. Alternative positive/negative gate-voltage applications induce the reversible protonation/deprotonation of a VO2 channel, and two-orders of magnitude modulation of sheet-resistance and 49% modulation of IR-transmittance were simultaneously demonstrated at room temperature by the metal-insulator phase conversion of VO2 in a non-volatile manner. The present device is operable by the room-temperature protonation in an all-solid-state structure, and thus it will provide a new gateway to future energy-saving technology as an advanced smart window.

  10. The n-type conduction of indium-doped Cu{sub 2}O thin films fabricated by direct current magnetron co-sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Xing-Min; Su, Xiao-Qiang; Ye, Fan, E-mail: yefan@szu.edu.cn; Wang, Huan; Tian, Xiao-Qing; Zhang, Dong-Ping; Fan, Ping; Luo, Jing-Ting; Zheng, Zhuang-Hao; Liang, Guang-Xing [Institute of Thin Film Physics and Applications, School of Physical Science and Technology and Shenzhen Key Laboratory of Sensor Technology, Shenzhen University, Shenzhen 518060 (China); Roy, V. A. L. [Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong, Hong Kong (China)

    2015-08-24

    Indium-doped Cu{sub 2}O thin films were fabricated on K9 glass substrates by direct current magnetron co-sputtering in an atmosphere of Ar and O{sub 2}. Metallic copper and indium disks were used as the targets. X-ray diffraction showed that the diffraction peaks could only be indexed to simple cubic Cu{sub 2}O, with no other phases detected. Indium atoms exist as In{sup 3+} in Cu{sub 2}O. Ultraviolet-visible spectroscopy showed that the transmittance of the samples was relatively high and that indium doping increased the optical band gaps. The Hall effect measurement showed that the samples were n-type semiconductors at room temperature. The Seebeck effect test showed that the films were n-type semiconductors near or over room temperature (<400 K), changing to p-type at relatively high temperatures. The conduction by the samples in the temperature range of the n-type was due to thermal band conduction and the donor energy level was estimated to be 620.2–713.8 meV below the conduction band. The theoretical calculation showed that indium doping can raise the Fermi energy level of Cu{sub 2}O and, therefore, lead to n-type conduction.

  11. P-doped strontium titanate grown using two target pulsed laser deposition for thin film solar cells

    Science.gov (United States)

    Man, Hamdi

    Thin-film solar cells made of Mg-doped SrTiO3 p-type absorbers are promising candidates for clean energy generation. This material shows p-type conductivity and also demonstrates reasonable absorption of light. In addition, p-type SrTiO3 can be deposited as thin films so that the cost can be lower than the competing methods. In this work, Mg-doped SrTiO3 (STO) thin-films were synthesized and analyzed in order to observe their potential to be employed as the base semiconductor in photovoltaic applications. Mg-doped STO thin-films were grown by using pulsed laser deposition (PLD) using a frequency quadrupled Yttrium Aluminum Garnet (YAG) laser and with a substrate that was heated by back surface absorption of infrared (IR) laser light. The samples were characterized using X-ray photoelectron spectroscopy (XPS) and it was observed that Mg atoms were doped successfully in the stoichiometry. Reflection high energy electron diffraction (RHEED) spectroscopy proved that the thin films were polycrystalline. Kelvin Probe work function measurements indicated that the work function of the films were 4.167 eV after annealing. UV/Vis Reflection spectroscopy showed that Mg-doped STO thin-films do not reflect significantly except in the ultraviolet region of the spectrum where the reflection percentage increased up to 80%. Self-doped STO thin-films, Indium Tin Oxide (ITO) thin films and stainless steel foil (SSF) were studied in order to observe their characteristics before employing them in Mg-doped STO based solar cells. Self-doped STO thin films were grown using PLD and the results showed that they are capable of serving as the n-type semiconductor in solar cell applications with oxygen vacancies in their structure and low reflectivity. Indium Tin Oxide thin-films grown by PLD system showed low 25-50 ?/square sheet resistance and very low reflection features. Finally, commercially available stainless steel foil substrates were excellent substrates for the inexpensive growth of

  12. Cleaning of conveyor belt materials using ultrasound in a thin layer of water.

    Science.gov (United States)

    Axelsson, L; Holck, A; Rud, I; Samah, D; Tierce, P; Favre, M; Kure, C F

    2013-08-01

    Cleaning of conveyor belts in the food industry is imperative for preventing the buildup of microorganisms that can contaminate food. New technologies for decreasing water and energy consumption of cleaning systems are desired. Ultrasound can be used for cleaning a wide range of materials. Most commonly, baths containing fairly large amounts of water are used. One possibility to reduce water consumption is to use ultrasonic cavitation in a thin water film on a flat surface, like a conveyor belt. In order to test this possibility, a model system was set up, consisting of an ultrasound transducer/probe with a 70-mm-diameter flat bottom, operating at 19.8 kHz, and contaminated conveyor belt materials in the form of coupons covered with a thin layer of water or water with detergent. Ultrasound was then applied on the water surface at different power levels (from 46 to 260 W), exposure times (10 and 20 s), and distances (2 to 20 mm). The model was used to test two different belt materials with various contamination types, such as biofilms formed by bacteria in carbohydrate- or protein-fat-based soils, dried microorganisms (bacteria, yeasts, and mold spores), and allergens. Ultrasound treatment increased the reduction of bacteria and yeast by 1 to 2 log CFU under the most favorable conditions compared with water or water-detergent controls. The effect was dependent on the type of belt material, the power applied, the exposure time, and the distance between the probe and the belt coupon. Generally, dried microorganisms were more easily removed than biofilms. The effect on mold spores was variable and appeared to be species and material dependent. Spiked allergens were also efficiently removed by using ultrasound. The results in this study pave the way for new cleaning designs for flat conveyor belts, with possibilities for savings of water, detergent, and energy consumption.

  13. Cell culture arrays using micron-sized ferromagnetic ring-shaped thin films

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chen-Yu; Wei, Zung-Hang, E-mail: wei@pme.nthu.edu.tw [Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu City 300, Taiwan (China); Lai, Mei-Feng; Ger, Tzong-Rong [Institute of NanoEngineering and MicroSystems, National Tsing Hua University, Hsinchu City 300, Taiwan (China)

    2015-05-07

    Cell patterning has become an important technology for tissue engineering. In this research, domain walls are formed at the two ends of a ferromagnetic ring thin film after applying a strong external magnetic field, which can effectively attract magnetically labeled cells and control the position for biological cell. Magnetophoresis experiment was conducted to quantify the magnetic nanoparticle inside the cells. A ring-shaped magnetic thin films array was fabricated through photolithography. It is observed that magnetically labeled cells can be successfully attracted to the two ends of the ring-shaped magnetic thin film structure and more cells were attracted and further attached to the structures. The cells are co-cultured with the structure and kept proliferating; therefore, such ring thin film can be an important candidate for in-vitro biomedical chips or tissue engineering.

  14. Cell culture arrays using micron-sized ferromagnetic ring-shaped thin films

    International Nuclear Information System (INIS)

    Huang, Chen-Yu; Wei, Zung-Hang; Lai, Mei-Feng; Ger, Tzong-Rong

    2015-01-01

    Cell patterning has become an important technology for tissue engineering. In this research, domain walls are formed at the two ends of a ferromagnetic ring thin film after applying a strong external magnetic field, which can effectively attract magnetically labeled cells and control the position for biological cell. Magnetophoresis experiment was conducted to quantify the magnetic nanoparticle inside the cells. A ring-shaped magnetic thin films array was fabricated through photolithography. It is observed that magnetically labeled cells can be successfully attracted to the two ends of the ring-shaped magnetic thin film structure and more cells were attracted and further attached to the structures. The cells are co-cultured with the structure and kept proliferating; therefore, such ring thin film can be an important candidate for in-vitro biomedical chips or tissue engineering

  15. Roughness analysis applied to niobium thin films grown on MgO(001) surfaces for superconducting radio frequency cavity applications

    OpenAIRE

    D. B. Beringer; W. M. Roach; C. Clavero; C. E. Reece; R. A. Lukaszew

    2013-01-01

    This paper describes surface studies to address roughness issues inherent to thin film coatings deposited onto superconducting radio frequency (SRF) cavities. This is particularly relevant for multilayered thin film coatings that are being considered as a possible scheme to overcome technical issues and to surpass the fundamental limit of ∼50  MV/m accelerating gradient achievable with bulk niobium. In 2006, a model by Gurevich [Appl. Phys. Lett. 88, 012511 (2006)APPLAB0003-695110.1063/1.2162...

  16. Mesoscopic Fluctuations for the Thinned Circular Unitary Ensemble

    Science.gov (United States)

    Berggren, Tomas; Duits, Maurice

    2017-09-01

    In this paper we study the asymptotic behavior of mesoscopic fluctuations for the thinned Circular Unitary Ensemble. The effect of thinning is that the eigenvalues start to decorrelate. The decorrelation is stronger on the larger scales than on the smaller scales. We investigate this behavior by studying mesoscopic linear statistics. There are two regimes depending on the scale parameter and the thinning parameter. In one regime we obtain a CLT of a classical type and in the other regime we retrieve the CLT for CUE. The two regimes are separated by a critical line. On the critical line the limiting fluctuations are no longer Gaussian, but described by infinitely divisible laws. We argue that this transition phenomenon is universal by showing that the same transition and their laws appear for fluctuations of the thinned sine process in a growing box. The proofs are based on a Riemann-Hilbert problem for integrable operators.

  17. Liquid phase epitaxial growth of heterostructured hierarchical MOF thin films

    KAUST Repository

    Chernikova, Valeriya

    2017-05-10

    Precise control of epitaxial growth of MOF-on-MOF thin films, for ordered hierarchical tbo-type structures is demonstrated. The heterostructured MOF thin film was fabricated by successful sequential deposition of layers from two different MOFs. The 2-periodic layers, edge-transitive 4,4-square lattices regarded as supermolecular building layers, were commendably cross-linked using a combination of inorganic/organic and organic pillars.

  18. Liquid phase epitaxial growth of heterostructured hierarchical MOF thin films

    KAUST Repository

    Chernikova, Valeriya; Shekhah, Osama; Spanopoulos, Ioannis; Trikalitis, Pantelis N.; Eddaoudi, Mohamed

    2017-01-01

    Precise control of epitaxial growth of MOF-on-MOF thin films, for ordered hierarchical tbo-type structures is demonstrated. The heterostructured MOF thin film was fabricated by successful sequential deposition of layers from two different MOFs. The 2-periodic layers, edge-transitive 4,4-square lattices regarded as supermolecular building layers, were commendably cross-linked using a combination of inorganic/organic and organic pillars.

  19. In situ thin film measurement by X-rays induced by 10 KeV-100 KeV ion beams

    International Nuclear Information System (INIS)

    Torrisi, L.; Calcagno, L.; Trovato, A.; Foti, G.

    1982-01-01

    The in situ measurement of thin film thickness between 50 and 100 KeV is described. The method used seems to be flexible enough and can be applied to any type of material. The only parameter intervening in the thickness measurement is the specific energy loss of the proton beams. Film of Al, Cu and Ag have been considered. When the primary beam energy increases the perception in depth of the method grows, reaching 10 μm with 1 MeV beam. In this case the autoabsorption takes place

  20. Nanowire decorated, ultra-thin, single crystalline silicon for photovoltaic devices.

    Science.gov (United States)

    Aurang, Pantea; Turan, Rasit; Unalan, Husnu Emrah

    2017-10-06

    Reducing silicon (Si) wafer thickness in the photovoltaic industry has always been demanded for lowering the overall cost. Further benefits such as short collection lengths and improved open circuit voltages can also be achieved by Si thickness reduction. However, the problem with thin films is poor light absorption. One way to decrease optical losses in photovoltaic devices is to minimize the front side reflection. This approach can be applied to front contacted ultra-thin crystalline Si solar cells to increase the light absorption. In this work, homojunction solar cells were fabricated using ultra-thin and flexible single crystal Si wafers. A metal assisted chemical etching method was used for the nanowire (NW) texturization of ultra-thin Si wafers to compensate weak light absorption. A relative improvement of 56% in the reflectivity was observed for ultra-thin Si wafers with the thickness of 20 ± 0.2 μm upon NW texturization. NW length and top contact optimization resulted in a relative enhancement of 23% ± 5% in photovoltaic conversion efficiency.

  1. Hall effect of K-doped superconducting thin films

    Energy Technology Data Exchange (ETDEWEB)

    Son, Eunseon; Lee, Nam Hoon; Kang, Won Nam [Dept. of physics, Sungkyunkwan University, Suwon (Korea, Republic of); Hwang, Tae Jong; Kim, Dong Ho [Dept. of physics, Yeungnam University, Gyeongsan(Korea, Republic of)

    2013-09-15

    We have studied Hall effect for potassium (K)-doped BaFe{sub 2}As{sub 2}superconducting thin films by analyzing the relation between the longitudinal resistivity (ρ{sub xy}) and the Hall resistivity (ρ{sub xy}). The thin films used in this study were fabricated on Al{sub O3} (000l) substrates by using an ex-situ pulsed laser deposition (PLD) technique under a high-vacuum condition of ∼10{sup -6} Torr. The samples showed the high superconducting transition temperatures (T{sub C}) of ∼40 K. The ρ{sub xx} and ρ{sub xy}the for K-doped BaFeAs{sub 2} thin films were measured by using a physical property measurement system (PPMS) with a temperature sweep (T-sweep) mode at an applied current density of 100 A/cm{sup 2} and at magnetic fields from 0 up to 9 T. We report the T-sweep results of the ρ{sub xx} and the ρ{sub xy} to investigate Hall scaling behavior on the basis of the relation of ρ{sub xy} = A(ρ{sub xy}){sup β}. The ρ{sub xx} values are 3.0 ± 0.2 in the c-axis-oriented K-doped BaFeAs{sub 2} thin films, whereas the thin films with various oriented-directions like a polycrystal showed slightly lower β than that of c-axis-oriented thin films. Interestingly, the β value is decreased with increasing magnetic fields.

  2. Study of Local and Distortional Stability of Thin-Walled Structures

    Directory of Open Access Journals (Sweden)

    Imene Mahi

    2018-01-01

    Full Text Available Thin-walled structures have an increasingly large and growing field of application in the engineering sector, the goal behind using this type of structure is efficiency in terms of resistance and cost, however the stability of its components (the thin walls remains the first aspect of the behavior, and a primordial factor in the design process. The hot rolled sections are known by a consequent post-buckling reserve, cold-formed steel sections which are thin-walled elements also benefit, in this case, it seems essential to take into account the favorable effects of this reserve in to the verification procedure of the resistance with respect to the three modes of failures of this type of structure. The design method that takes into account this reserve of resistance is inevitably the effective width method. The direct strength method has been developed to improve the speed and efficiency of the design of thin-walled profiles. The latter mainly uses the buckling loads (for Local, Distortional and Global mode obtained from a numerical analysis and the resistance curves calibrated experimentally to predict the ultimate load of the profile. Among those, the behavior of a set of Cshaped profiles (highly industrialized is studied, this type of section is assumed to be very prone to modes of local and distortional instability. The outcome of this investigation revealed very relevant conclusions both scientifically and practically.

  3. Anisotropic behaviour of transmission through thin superconducting NbN film in parallel magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Šindler, M., E-mail: sindler@fzu.cz [Institute of Physics ASCR, v. v. i., Cukrovarnická 10, CZ-162 53 Praha 6 (Czech Republic); Tesař, R. [Institute of Physics ASCR, v. v. i., Cukrovarnická 10, CZ-162 53 Praha 6 (Czech Republic); Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, CZ-121 16 Praha (Czech Republic); Koláček, J. [Institute of Physics ASCR, v. v. i., Cukrovarnická 10, CZ-162 53 Praha 6 (Czech Republic); Skrbek, L. [Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, CZ-121 16 Praha (Czech Republic)

    2017-02-15

    Highlights: • Transmission through thin NbN film in parallel magnetic field exhibits strong anisotropic behaviour in the terahertz range. • Response for a polarisation parallel with the applied field is given as weighted sum of superconducting and normal state contributions. • Effective medium approach fails to describe response for linear polarisation perpendicular to the applied magnetic field. - Abstract: Transmission of terahertz waves through a thin layer of the superconductor NbN deposited on an anisotropic R-cut sapphire substrate is studied as a function of temperature in a magnetic field oriented parallel with the sample. A significant difference is found between transmitted intensities of beams linearly polarised parallel with and perpendicular to the direction of applied magnetic field.

  4. Mastering the biaxial stress state in nanometric thin films on flexible substrates

    Energy Technology Data Exchange (ETDEWEB)

    Faurie, D., E-mail: faurie@univ-paris13.fr [LSPM-CNRS, UPR3407, Université Paris 13, Villetaneuse (France); Renault, P.-O.; Le Bourhis, E. [Institut Pprime UPR3346, CNRS – Université de Poitiers, Futuroscope (France); Geandier, G. [Institut Jean Lamour, CNRS UMR7198, Université de Lorraine, Nancy Cedex (France); Goudeau, P. [Institut Pprime UPR3346, CNRS – Université de Poitiers, Futuroscope (France); Thiaudière, D. [SOLEIL Synchrotron, Saint-Aubin, Gif-Sur-Yvette (France)

    2014-07-01

    Biaxial stress state of thin films deposited on flexible substrate can be mastered thanks to a new biaxial device. This tensile machine allows applying in-plane loads F{sub x} and F{sub y} in the two principal directions x and y of a cruciform-shaped polymer substrate. The transmission of the deformation at film/substrate interface allows controlling the stress and strain field in the thin films. We show in this paper a few illustrations dealing with strain measurements in polycrystalline thin films deposited on flexible substrate. The potentialities of the biaxial device located at Soleil synchrotron are also discussed.

  5. Electrodeposited semiconductors at room temperature: an X-ray Absorption Spectroscopy study of Cu-, Zn-, S-bearing thin films

    International Nuclear Information System (INIS)

    Di Benedetto, Francesco; Cinotti, Serena; D’Acapito, Francesco; Vizza, Francesco; Foresti, Maria Luisa; Guerri, Annalisa; Lavacchi, Alessandro; Montegrossi, Giordano; Romanelli, Maurizio; Cioffi, Nicola; Innocenti, Massimo

    2015-01-01

    A SEM, DRS and XAS study was carried out on ultra-thin films with chemical composition belonging to the Cu-Zn-S ternary system, related to the kesterite-type materials, in the light of their potential application to thin film photovoltaic technology. The films, realized through the layer-by-layer E-ALD electrochemical technique, reveal variable phase composition as a function of the applied E-ALD sequence. In particular, by increasing the Zn cycles per Cu cycle from 1:1 to 9:1, the number of detected phases changes from 3 to 2. In all samples, Cu mainly crystallize in a Cu_2S type phase, whereas Zn occurs as ZnS. In the 1:1 sample, additional ZnO is detected. The variable phase composition parallels apparent changes in the sample morphology. In all samples, a sulphide thin film is covered by a net of elongated nanostructures, the length of which decreases with increasing the number of Zn cycles per Cu cycle. All these evidences are interpreted as due to the operating electrochemical route during the synthesis and confirm the lack of miscibility between Cu_2S and ZnS, thermodynamically relevant after the E-ALD has stopped. The band gap values exhibited by the three films, modulated by changing the copper:zinc ratio, progressively approach a value useful for solar energy conversion, thus strongly proposing these new sulfide nanomaterials for photovoltaics and photochemical applications.

  6. A novel design of submicron thin film point contacts

    International Nuclear Information System (INIS)

    Koch, H.

    1986-01-01

    A thin film point contact design applicable to SIS-, SNS-, and microbridge-type Josephson junctions is presented, which offers potentially advanced junction characteristics (low capacitance, low stray inductance, increased quasi-particle resistance). The design philosophy is based on the fact that a point contact results if two planes having a common symmetry axis but oriented perpendicular to each other are brought into contact with each other. For the case of thin films, instead of two-dimensional planes, the cross section of the resulting ''point''-contact is defined by the thicknesses of the two thin films. Film thicknesses can be controlled much more precisely than lateral dimensions created by lithography. Hence, submicron junction geometries can be achieved using only conventional fabrication techniques. Following this idea, Josephson weak links of the ultrashort microbridge-type have been fabricated by an all-Nb technique having a 0.3-μm X 0.2-μm cross section with a R /SUB q/ I /SUB c/ product (R /SUB q/ = quasiparticle resistance, I /SUB c/ = critical current) of more than 20 mV

  7. LASER CUTTING MACHINES FOR 3-D THIN SHEET PARTS

    Directory of Open Access Journals (Sweden)

    Miroslav RADOVANOVIC

    2012-11-01

    Full Text Available Laser cutting machines are used for precise contour cutting thin sheet. In industrial application nowadays various types and construction of laser cutting machines can be met. For contour cutting 3-D thin sheet parts laser cutting machines with rotation movements and laser robots are used. Laser generates the light beam, that presents a tool in working process. Application of laser cutting machines made possible good quality of products, flexibility of production and enlargement of economy

  8. Photocatalytic Activity of Nanostructured Titanium Dioxide Thin Films

    Directory of Open Access Journals (Sweden)

    Zdenek Michalcik

    2012-01-01

    Full Text Available The aim of this paper is to investigate the properties and photocatalytic activity of nanostructured TiO2 layers. The glancing angle deposition method with DC sputtering at low temperature was applied for deposition of the layers with various columnar structures. The thin-film structure and surface morphology were analyzed by XRD, SEM, and AFM analyses. The photocatalytic activity of the films was determined by the rate constant of the decomposition of the Acid Orange 7. In dependence on the glancing angle deposition parameters, three types of columnar structures were obtained. The films feature anatase/rutile and/or amorphous structures depending on the film architecture and deposition method. All the films give the evidence of the photocatalytic activity, even those without proved anatase or rutile structure presence. The impact of columnar boundary in perspective of the photocatalytic activity of nanostructured TiO2 layers was discussed as the possible factor supporting the photocatalytic activity.

  9. Influence of the Aluminium Alloy Type on Defects Formation in Friction Stir Lap Welding of Thin Sheets

    Directory of Open Access Journals (Sweden)

    M. I. Costa

    Full Text Available Abstract The weldability in Friction Stir Lap Welding (FSLW of heat and non-heat treatable aluminium alloys, the AA6082-T6 and the AA5754-H22 aluminium alloys, respectively, are compared. For both alloys, welds were produced in very thin sheets, using the same welding parameters and procedures, and strong differences in welds morphology were found. The strength of the welds was evaluated by performing tensile-shear tests under monotonic and cyclic loading conditions. As-welded and heat-treated samples of the AA6082- T6 were tested. It was found that the heat-treatable alloy is more sensitive to defects formation, in lap welding, than the non-heat-treatable alloy. The presence of defects has a strong influence on the monotonic and fatigue behaviour of the welds. In spite of this, for very high-applied stresses, the heat-treatable alloy welds perform better in fatigue than the non-heat-treatable alloy welds.

  10. Rare earth metals, rare earth hydrides, and rare earth oxides as thin films

    International Nuclear Information System (INIS)

    Gasgnier, M.

    1980-01-01

    The review deals with pure rare earth materials such as rare earth metals, rare earth hydrides, and rare earth oxides as thin films. Several preparation techniques, control methods, and nature of possible contaminations of thin films are described. These films can now be produced in an extremely well-known state concerning chemical composition, structure and texture. Structural, electric, magnetic, and optical properties of thin films are studied and discussed in comparison with the bulk state. The greatest contamination of metallic rare earth thin films is caused by reaction with hydrogen or with water vapour. The compound with an f.c.c. structure is the dihydride LnH 2 (Ln = lanthanides). The oxygen contamination takes place after annealing at higher temperatures. Then there appears a compound with a b.c.c. structure which is the C-type sesquioxide C-Ln 2 O 3 . At room atmosphere dihydride light rare earth thin films are converted to hydroxide Ln(OH) 3 . For heavy rare earth thin films the oxinitride LnNsub(x)Osub(y) is observed. The LnO-type compound was never seen. The present review tries to set the stage anew for the investigations to be undertaken in the future especially through the new generations of electron microscopes

  11. Self-enhancing effects of exposure to thin-body images.

    Science.gov (United States)

    Joshi, Ramona; Herman, C Peter; Polivy, Janet

    2004-04-01

    This study examines the effect of thin-body media images on mood, self-esteem, and self-image ratings of restrained and unrestrained eaters. A secondary purpose was to examine whether these effects were influenced by exposure duration. Under the guise of a perception study, participants were exposed to thin-body or control advertisements (e.g., perfume bottles) for either 7 or 150 ms and then completed a questionnaire packet. Restrained eaters reported more favorable self-image and social self-esteem (but not appearance self-esteem) scores after exposure to thin-body images than after exposure to control advertisements. The self-image and social self-esteem scores of unrestrained eaters were unaffected by advertisement type, but their appearance self-esteem scores were lower after exposure to thin-body advertisements. No differences were found for mood ratings and total self-esteem. We discuss restraint status as a moderator of the effects of thin-body images on women's body image. Copyright 2004 by Wiley Periodicals, Inc. Int J Eat Disord 35: 333-341, 2004.

  12. Pulsed Laser Annealing of Thin Films of Self-Assembled Nanocrystals

    KAUST Repository

    Baumgardner, William J.; Choi, Joshua J.; Bian, Kaifu; Fitting Kourkoutis, Lena; Smilgies, Detlef-M.; Thompson, Michael O.; Hanrath, Tobias

    2011-01-01

    We investigated how pulsed laser annealing can be applied to process thin films of colloidal nanocrystals (NCs) into interconnected nanostructures. We illustrate the relationship between incident laser fluence and changes in morphology of PbSe NC

  13. Biomass conversion and expansion factors are afected by thinning

    Directory of Open Access Journals (Sweden)

    Teresa Duque Enes

    2014-12-01

    Full Text Available Aim of the study: The objective of this paper is to investigate the use of Biomass Conversion and Expansion Factors (BCEFs in maritime pine (Pinus pinaster Ait. stands subjected to thinning.Area of the study: The study area refers to different ecosystems of maritime pine stands inNorthern Portugal.Material and methods: The study is supported by time data series and cross sectional data collected in permanent plots established in the North of Portugal. An assessment of BCEF values for the aboveground compartments and for total was completed for each studied stand. Identification of key variables affecting the value of the BCEFs in time and with thinning was conducted using correlation analysis. Predictive models for estimation of the BCEFs values in time and after thinning were developed using nonlinear regression analysis.Research highlights: For periods of undisturbed growth, the results show an allometric relationship between the BCEFs, the dominant height and the mean diameter. Management practices such as thinning also influence the factors. Estimates of the ratio change before and after thinning depend on thinning severity and thinning type. The developed models allow estimating the biomass of the stands, for the aboveground compartments and for total, based on information of stand characteristics and of thinning descriptors. These estimates can be used to assess the forest dry wood stocks to be used for pulp, bioenergy or other purposes, as well as the biomass quantification to support the evaluation of the net primary productivity.Keywords: carbon; softwood; thinning; volume; wood energy; maritime pine.

  14. Pyroelectric properties of finite size ferroelectric thin films with structural transition zones

    International Nuclear Information System (INIS)

    Zhou Jing; Lue Tianquan; Sun Punan; Xie Wenguang; Cao Wenwu

    2009-01-01

    A Fermi-type Green's function is used to study pyroelectric properties of the thin film with finite sizes in three dimensions based on a modified transverse Ising model. The results demonstrate that a decrease in the lateral size of the film has a disadvantageous influence on the pyroelectric coefficient of the thin film.

  15. Effect of Sb content on the thermoelectric properties of annealed CoSb_3 thin films deposited via RF co-sputtering

    International Nuclear Information System (INIS)

    Ahmed, Aziz; Han, Seungwoo

    2017-01-01

    Graphical abstract: The X-ray diffraction patterns and temperature dependence of the Seebeck coefficient of the annealed Co–Sb thin films. - Highlights: • CoSb_3 phase thin films were prepared using RF co sputtering method. • Thin film thermoelectric properties were hugely dependent on Sb content. • All thin films shows n-type conduction behavior at high temperatures. • The thin films with excess Sb possess the largest Seebeck coefficient. • The thin films with CoSb_2 phase possess the largest power factor. - Abstract: A series of CoSb_3 thin films with Sb contents in the range 70–79 at.% were deposited at room temperature via RF co-sputtering. The thin films were amorphous in the as-deposited state and annealed at 300 °C for 3 h to obtain crystalline samples. The annealed thin films were characterized using scanning electron microscopy and X-ray diffraction (XRD), and these data indicate that the films exhibited good crystallinity. The XRD patterns indicate single-phase CoSb_3 thin films in the Sb-rich samples. For the Sb-deficient samples, however, mixed-phase thin films consisting of CoSb_2 and CoSb_3 components were obtained. The electrical and thermoelectric properties were measured at temperatures up to 760 K and found to be highly sensitive to the phases that were present. We observed a change in the thermoelectric properties of the films from p-type at low temperatures to n-type at high temperatures, which indicates potential applications as n-type thermoelectric thin films. A large Seebeck coefficient and power factor was obtained for the single-phase CoSb_3 thin films. The CoSb_2 phase thin films were also found to possess a significant Seebeck coefficient, which coupled with the much smaller electrical resistivity, provided a larger power factor than the single-phase CoSb_3 thin films. We report maximum power factor of 7.92 mW/m K"2 for the CoSb_2-containing mixed phase thin film and 1.26 mW/m K"2 for the stoichiometric CoSb_3 thin film.

  16. High efficiency copper indium gallium diselenide (CIGS) thin film solar cells

    Science.gov (United States)

    Rajanikant, Ray Jayminkumar

    The generation of electrical current from the solar radiation is known as the photovoltaic effect. Solar cell, also known as photovoltaic (PV) cell, is a device that works on the principle of photovoltaic effect, and is widely used for the generation of electricity. Thin film polycrystalline solar cells based on copper indium gallium diselenide (CIGS) are admirable candidates for clean energy production with competitive prices in the near future. CIGS based polycrystalline thin film solar cells with efficiencies of 20.3 % and excellent temperature stability have already been reported at the laboratory level. The present study discusses about the fabrication of CIGS solar cell. Before the fabrication part of CIGS solar cell, a numerical simulation is carried out using One-Dimensional Analysis of Microelectronic and Photonic Structures (AMPS-ID) for understanding the physics of a solar cell device, so that an optimal structure is analyzed. In the fabrication part of CIGS solar cell, Molybdenum (Mo) thin film, which acts as a 'low' resistance metallic back contact, is deposited by RF magnetron sputtering on organically cleaned soda lime glass substrate. The major advantages for using Mo are high temperature, (greater than 600 °C), stability and inertness to CIGS layer (i.e., no diffusion of CIGS into Mo). Mo thin film is deposited at room temperature (RT) by varying the RF power and the working pressure. The Mo thin films deposited with 100 W RF power and 1 mTorr working pressure show a reflectivity of above average 50 % and the low sheet resistance of about 1 O/□. The p-type CIGS layer is deposited on Mo. Before making thin films of CIGS, a powder of CIGS material is synthesized using melt-quenching method. Thin films of CIGS are prepared by a single-stage flash evaporation process on glass substrates, initially, for optimization of deposition parameters and than on Mo coated glass substrates for device fabrication. CIGS thin film is deposited at 250 °C at a

  17. Thin Film Approaches to the SRF Cavity Problem Fabrication and Characterization of Superconducting Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Beringer, Douglas [College of William and Mary, Williamsburg, VA (United States)

    2017-08-01

    Superconducting Radio Frequency (SRF) cavities are responsible for the acceleration of charged particles to relativistic velocities in most modern linear accelerators, such as those employed at high-energy research facilities like Thomas Jefferson National Laboratory’s CEBAF and the LHC at CERN. Recognizing SRF as primarily a surface phenomenon enables the possibility of applying thin films to the interior surface of SRF cavities, opening a formidable tool chest of opportunities by combining and designing materials that offer greater performance benefit. Thus, while improvements in radio frequency cavity design and refinements in cavity processing techniques have improved accelerator performance and efficiency – 1.5 GHz bulk niobium SRF cavities have achieved accelerating gradients in excess of 35 MV/m – there exist fundamental material bounds in bulk superconductors limiting the maximally sustained accelerating field gradient (≈ 45 MV/m for Nb) where inevitable thermodynamic breakdown occurs. With state of the art Nb based cavity design fast approaching these theoretical limits, novel material innovations must be sought in order to realize next generation SRF cavities. One proposed method to improve SRF performance is to utilize thin film superconducting-insulating-superconducting (SIS) multilayer structures to effectively magnetically screen a bulk superconducting layer such that it can operate at higher field gradients before suffering critically detrimental SRF losses. This dissertation focuses on the production and characterization of thin film superconductors for such SIS layers for radio frequency applications. Correlated studies on structure, surface morphology and superconducting properties of epitaxial Nb and MgB2 thin films are presented.

  18. Alkylated selenophene-based ladder-type monomers via a facile route for high performance thin-film transistor applications

    KAUST Repository

    Fei, Zhuping; Han, Yang; Gann, Eliot; Hodsden, Thomas; Chesman, Anthony; McNeill, Christopher R.; Anthopoulos, Thomas D.; Heeney, Martin

    2017-01-01

    We report the synthesis of two new selenophene containing ladder-type monomers, cyclopentadiselenophene (CDS) and indacenodiselenophene (IDSe), via a twofold and fourfold Pd catalyzed coupling with a 1,1-diborylmethane derivative. Co-polymers with benzothiadiazole (BT) were prepared in high yield by Suzuki polymerization to afford co-polymers which exhibited excellent solubility in a range of non-chlorinated solvents. The CDS co-polymer exhibited a band gap of just 1.18 eV, which is amongst the lowest reported for donor-acceptor polymers. Thin-film transistors were fabricated using environmentally benign, non-chlorinated solvents with the CDS and IDSe co-polymers exhibiting hole mobility up to 0.15 and 6.4 cm2 /Vs, respectively. This high performance was achieved without the undesirable peak in mobility often observed at low gate voltages due to parasitic contact resistance.

  19. Alkylated selenophene-based ladder-type monomers via a facile route for high performance thin-film transistor applications

    KAUST Repository

    Fei, Zhuping

    2017-05-26

    We report the synthesis of two new selenophene containing ladder-type monomers, cyclopentadiselenophene (CDS) and indacenodiselenophene (IDSe), via a twofold and fourfold Pd catalyzed coupling with a 1,1-diborylmethane derivative. Co-polymers with benzothiadiazole (BT) were prepared in high yield by Suzuki polymerization to afford co-polymers which exhibited excellent solubility in a range of non-chlorinated solvents. The CDS co-polymer exhibited a band gap of just 1.18 eV, which is amongst the lowest reported for donor-acceptor polymers. Thin-film transistors were fabricated using environmentally benign, non-chlorinated solvents with the CDS and IDSe co-polymers exhibiting hole mobility up to 0.15 and 6.4 cm2 /Vs, respectively. This high performance was achieved without the undesirable peak in mobility often observed at low gate voltages due to parasitic contact resistance.

  20. Study on Brazil law type twinning in amethyst from Bahia (Brazil) by the X-ray topography and polarized light

    International Nuclear Information System (INIS)

    Baran, Z.

    1987-01-01

    Brazil law type twinning is very common in quartz. Generally is not observed in normal petrographic thin section but it is possible to study this kind of twinning under polarized light in thicker sections. X-ray topography will be another powerfull method to study and it was applied for the amethytst of the Mina Cabeluda of the state of Bahia. (author) [pt

  1. Correlation between the dielectric constant and X-ray diffraction pattern of Si-O-C thin films with hydrogen bonds

    International Nuclear Information System (INIS)

    Oh, Teresa; Oh, Kyoung Suk; Lee, Kwang-Man; Choi, Chi Kyu

    2004-01-01

    The amorphous structure of organic-inorganic hybrid type Si-O-C thin films was studied using the first principles molecular-dynamics method with density functional techniques. The correlation between the dielectric constant and the degree of amorphous structure in organic-inorganic hybrid type Si-O-C thin films was studied. Si-O-C thin films were deposited by high-density plasma chemical vapor deposition using bis-trimethylsilylmethane and oxygen precursors. As-deposited films and films annealed at 500 deg. C were analyzed by X-ray diffraction (XRD). For quantitative analysis, the X-ray diffraction patterns of the samples were transformed to the radial distribution function (RDF) using Fourier analysis. Hybrid type Si-O-C thin films can be divided into three types using their amorphous structure and the dielectric constant: those with organic, hybrid, and inorganic properties

  2. Effect of substrate mis-orientation on GaN thin films grown by MOCVD under different carrier gas condition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong-Woo; Suzuki, Toshimasa [Nippon Institute of Technology, 4-1 Gakuendai, Miyashiro, Saitama, 345-8501 (Japan); Aida, Hideo [NAMIKI Precision Jewel Co. Ltd., 3-8-22 Shinden, Adachi-ku, Tokyo, 123-8511 (Japan)

    2005-05-01

    We have studied the effect of a slight mis-orientation angle on surface and crystal quality of GaN thin films grown under different carrier gas conditions. Two types of carrier gas conditions were applied to the growth. One was pure H{sub 2} and the other was mixed N{sub 2}/H{sub 2}. As the result, we found dependence of surface and crystal quality of GaN thin films on the substrate mis-orientation angle, and they indicated almost the same tendency under both growth conditions. Therefore, it was confirmed that mis-orientation angle of sapphire substrate was one of the most critical factors for GaN thin films. Then, the effect of the additional N{sub 2} into the conventional H{sub 2} carrier gas was studied, and we found that the conversion of carrier gas from the conventional H{sub 2} to N{sub 2}/H{sub 2} mixture was effective against degradation of GaN crystallinity at any mis-orientation angle. Considering that the crystal quality of GaN thin films became insensitive to mis-orientation angle as the condition became more suitable for GaN growth, the optimal substrate mis-orientation angle was consequently decided to be approximately 0.15 from the morphological aspect. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Performance improvements of pouch-type flexible thin-film lithium-ion batteries by modifying sequential screen-printing process

    International Nuclear Information System (INIS)

    Kang, Kun-Young; Lee, Young-Gi; Shin, Dong Ok; Kim, Jin-Chul; Kim, Kwang Man

    2014-01-01

    A pouch-type flexible thin-film lithium-ion battery is fabricated by sequential screen-printing (wet) processes to produce consecutive layers of a current collector, positive and negative electrodes, and a gel polymer electrolyte. Optimum conditions of each process are determined by adjusting the paste or slurry compositions to achieve lower surface resistance of each layer (current collector and electrodes) and higher ionic conductivity of the gel polymer electrolyte. The fabricated flexible thin-film lithium-ion battery (5.5 × 5.5 cm 2 , 325 μm thick) shows superior electrochemical performance, including an energy density of 292.3 Wh L −1 based on electrode size (4.0 × 4.0 cm 2 ), an initial discharge capacity of 2.5 mAh cm −2 per electrode area, and capacity retention ratio of over 68% at the 50th cycle. To further improve the battery performance, the wet processes are modified by adopting hybrid (dry-wet) processes, which mainly consist of the formation of metallic current collector layers (Al and Cu) using a thermal evaporator and another optimized gel polymer electrolyte, to achieve an energy density of 332.8 Wh L −1 and capacity retention ratio of 84% at the 50th cycle. Cell flexibility is also confirmed by stable open circuit voltages after the system is subjected to several hundred iterations of bending, stretching, and even folding. There is the possibility that the suggested wet and dry-wet processes can be expanded to a high-speed mass-production roll-to-roll process

  4. Swimming efficiency in a shear-thinning fluid

    Science.gov (United States)

    Nganguia, Herve; Pietrzyk, Kyle; Pak, On Shun

    2017-12-01

    Micro-organisms expend energy moving through complex media. While propulsion speed is an important property of locomotion, efficiency is another factor that may determine the swimming gait adopted by a micro-organism in order to locomote in an energetically favorable manner. The efficiency of swimming in a Newtonian fluid is well characterized for different biological and artificial swimmers. However, these swimmers often encounter biological fluids displaying shear-thinning viscosities. Little is known about how this nonlinear rheology influences the efficiency of locomotion. Does the shear-thinning rheology render swimming more efficient or less? How does the swimming efficiency depend on the propulsion mechanism of a swimmer and rheological properties of the surrounding shear-thinning fluid? In this work, we address these fundamental questions on the efficiency of locomotion in a shear-thinning fluid by considering the squirmer model as a general locomotion model to represent different types of swimmers. Our analysis reveals how the choice of surface velocity distribution on a squirmer may reduce or enhance the swimming efficiency. We determine optimal shear rates at which the swimming efficiency can be substantially enhanced compared with the Newtonian case. The nontrivial variations of swimming efficiency prompt questions on how micro-organisms may tune their swimming gaits to exploit the shear-thinning rheology. The findings also provide insights into how artificial swimmers should be designed to move through complex media efficiently.

  5. Advances in copper-chalcopyrite thin films for solar energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Kaneshiro, Jess; Gaillard, Nicolas; Rocheleau, Richard; Miller, Eric [Hawaii Natural Energy Institute, University of Hawaii at Manoa, 1680 East-West Road, Post 109, Honolulu, HI 96822 (United States)

    2010-01-15

    Promising alternatives to crystalline silicon as the basic building block of solar cells include copper-chalcopyrite thin films such as copper indium gallium diselenide, a class of thin films exhibiting bandgap-tunable semiconductor behavior, direct bandgaps and high absorption coefficients. These properties allow for the development of novel solar-energy conversion configurations like ultra-high efficiency multi-junction solar cells utilizing combinations of photovoltaic and photoelectrochemical junctions for hydrogen production. This paper discusses the current worldwide status as well as the development and optimization of copper-chalcopyrite thin films deposited onto various substrate types for different photovoltaic and photoelectrochemical applications at the Hawaii Natural Energy Institute. (author)

  6. Thin films of metal-organic compounds and metal nanoparticle ...

    Indian Academy of Sciences (India)

    Optical limiting capability of the nanoparticle-embedded polymer film is demonstrated. Keywords. Polar crystal; uniaxial orientational order; thin film; second harmonic gen- eration; silver ... able content of metal nanoparticles would be of considerable value from an appli- ... polar chain and perpendicular to it [10].

  7. Size and dimensionality effects in superconducting Mo thin films

    International Nuclear Information System (INIS)

    Fabrega, L; Gil, O; Camon, A; Parra-BorderIas, M; Fernandez-MartInez, I; Costa-Kraemer, J L; Briones, F; Sese, J; Gonzalez-Arrabal, R

    2011-01-01

    Molybdenum is a low T c , type I superconductor whose fundamental properties are poorly known. Its importance as an essential constituent of new high performance radiation detectors, the so-called transition edge sensors (TESs) calls for better characterization of this superconductor, especially in thin film form. Here we report on a study of the basic superconducting features of Mo thin films as a function of their thickness. The resistivity is found to rise and the critical temperature decreases on decreasing film thickness, as expected. More relevant, the critical fields along and perpendicular to the film plane are markedly different, thickness dependent and much larger than the thermodynamic critical field of Mo bulk. These results are consistent with a picture of type II 2D superconducting films, and allow estimates of the fundamental superconducting lengths of Mo. The role of morphology in determining the 2D and type II character of the otherwise type I molybdenum is discussed. The possible consequences of this behaviour on the performance of radiation detectors are also addressed.

  8. Progress in Polycrystalline Thin-Film Cu(In,GaSe2 Solar Cells

    Directory of Open Access Journals (Sweden)

    Udai P. Singh

    2010-01-01

    Full Text Available For some time, the chalcopyrite semiconductor CuInSe2 and its alloy with Ga and/or S [Cu(InGaSe2 or Cu(InGa(Se,S2], commonly referred as CIGS, have been leading thin-film material candidates for incorporation in high-efficiency photovoltaic devices. CuInSe2-based solar cells have shown long-term stability and the highest conversion efficiencies among all thin-film solar cells, reaching 20%. A variety of methods have been reported to prepare CIGS thin film. Efficiency of solar cells depends upon the various deposition methods as they control optoelectronic properties of the layers and interfaces. CIGS thin film grown on glass or flexible (metal foil, polyimide substrates require p-type absorber layers of optimum optoelectronic properties and n-type wideband gap partner layers to form the p-n junction. Transparent conducting oxide and specific metal layers are used for front and back contacts. Progress made in the field of CIGS solar cell in recent years has been reviewed.

  9. Fabrication of read-only type triple-layered disc

    Science.gov (United States)

    Yang, Huei Wen; Jeng, Tzuan Ren; Yen, Wen Hsin; Chan, Rong Po; Shin, Kuo Ding; Huang, Der Ray

    2003-06-01

    The approach to increase optical recording density has become very popular research subject in these years. One direct and effective method is to increase the recording layer stack number. That is to say, to add one more recording layer can get one more recording capacity. In this paper, we will propose a new method for manufacturing read only type multi-layered disc. The process is described in the following. This first recorded data layer (called L0) still follows the traditional DVD disc manufacturing process. We obtain the polycarbonate substrate by replicating from Ni stamper. Then polycarbonate substrate is sputtered thin silicon film for semi-reflection layer. As for second layer (L1) and even more layer (Ln-1) producing, one special kind of duplication (called SKD) method is proposed. The duplication (or replication) source of second or nth recorded data is not only limited from Ni stamper. Even polycarbonate or PMMA substrate has recording data are also acceptable sources. At next step, the duplication source is deposited by thin gold film. Then we apply spin coating to bond the first layer (L0) substrate and second layer (L1) duplication source by choosing suitable UV curing glue. After being emitted by UV lamp for several seconds, we can easily separate the duplication source of second layer (L1) from (L0) substrate. Then we find the thin second data layer (L1) is replicated and stacks upon the first layer. On the same way, we sputter thin AgTi layer on the thin second data layer for another semi- reflective layer. By following the above manufacture step, we can produce more layers. In our experimental, we prepare triple layered read-only type disc. The total capacity is almost 12GB for one side of disc, and 24GB for two side of disc. The read-out intensity of laser from each data layer is expected to be similar. Thus we have designed particular reflectance and transmittance for each data layer by controlling the thickness of thin silicon film. We can

  10. Epitaxial thin-film growth of Ruddlesden-Popper-type Ba{sub 3}Zr{sub 2}O{sub 7} from a BaZrO{sub 3} target by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Butt, Shariqa Hassan; Rafique, M.S.; Siraj, K.; Latif, A.; Afzal, Amina [University of Engineering and Technology, Laser and Optronics Centre, Department of Physics, Lahore (Pakistan); Awan, M.S. [Ibn-e-Sina Institute of Science and Technology (ISIT), Islamabad (Pakistan); Bashir, Shazia [Government College University, Centre for Advanced Studies in Physics, Lahore (Pakistan); Iqbal, Nida [Universiti Teknologi Malaysia, Medical Devices and Technology Group (MEDITEG), Faculty of Biosciences and Medical Engineering, Johor Bahru, Johor (Malaysia)

    2016-07-15

    Ruddlesden-Popper Ba{sub 3}Zr{sub 2}O{sub 7} thin films have been synthesized via pulsed laser deposition (PLD) technique. The optimization of deposition parameters in PLD enables the formation of thin film of metastable Ba{sub 3}Zr{sub 2}O{sub 7} phase from BaZrO{sub 3} target. In order to see the post-annealing effects on the structural and optical properties, the deposited Ba{sub 3}Zr{sub 2}O{sub 7} thin films were annealed at 500, 600 and 800 C. X-ray diffraction (XRD) reveals the formation of Ba{sub 3}Zr{sub 2}O{sub 7} phase with tetragonal structure. The changes in the surface of the deposited films were analysed by FE-SEM and AFM. The thin film post-annealed at 500 C exhibited the best structural, optical and surface properties. Furthermore, the chemical states and chemical composition of the films were determined by X-ray photoelectron spectroscopy (XPS) near the surface. The XPS results show that Ba, Zr and O exist mainly in the form of Ba{sub 3}Zr{sub 2}O{sub 7} Ruddlesden-Popper-type perovskite structure. (orig.)

  11. Graphene-based copper oxide thin film nanostructures as high-efficiency photocathode for p-type dye-sensitized solar cells

    Science.gov (United States)

    Kilic, Bayram; Turkdogan, Sunay; Astam, Aykut; Baran, Sümeyra Seniha; Asgin, Mansur; Cebeci, Hulya; Urk, Deniz

    2017-10-01

    Graphene-based p-type dye-sensitized solar cells (p-DSSCs) have been proposed and fabricated using copper oxide urchin-like nanostructures (COUN) as photocathode with an FeS2 counter electrode (CE). COUN composed of Cu2O core sphere and CuO shell nanorods with overall diameters of 2 to 4 μm were grown by a simple hydrothermal method with self-assemble nucleation. It was figured out that the formation of copper oxide core/shell structures could be adjusted by an ammonia additive leading to pH change of the precursor solution. In addition to a photocathode, we also demonstrated FeS2 thin films as an efficient CE material alternative to the conventional Pt CEs in DSSCs. FeS2 nanostructures, with diameters of 50 to 80 nm, were synthesized by a similar hydrothermal approach. FeS2 nanostructures are demonstrated to be an outstanding CE material in p-DSSCs. We report graphene/COUN as photocathode and Pt/FeS2 as CE in p-DSSCs, and results show that the synergetic combination of electrodes in each side (increased interconnectivity between COUN and graphene layer, high surface area, and high catalytic activity of FeS2) increased the power conversion efficiency from 1.56% to 3.14%. The excellent performances of COUN and FeS2 thin film in working and CEs, respectively, make them unique choices among the various photocathode and CE materials studied.

  12. Characteristics of heat transfer fouling of thin stillage using model thin stillage and evaporator concentrates

    Science.gov (United States)

    Challa, Ravi Kumar

    , fiber and minerals, simulated thin stillage was prepared with carbohydrate mixtures and tested for fouling rates. Induction period, maximum fouling resistance and mean fouling rates were determined. Two experiments were performed with two varieties of starch, waxy and high amylose and short chain carbohydrates, corn syrup solids and glucose. Interaction effects of glucose with starch varieties were studied. In the first experiment, short chain carbohydrates individual and interaction effects with starch were studied. For mixtures prepared from glucose and corn syrup solids, no fouling was observed. Mixtures prepared from starch, a long glucose polymer, showed marked fouling. Corn syrup solids and glucose addition to pure starch decreased the mean fouling rates and maximum fouling resistances. Between corn syrup solids and glucose, starch fouling rates were reduced with addition of glucose. Induction periods of pure mixtures of either glucose or corn syrup solids were longer than the test period (5 h). Pure starch mixture had no induction period. Maximum fouling resistance was higher for mixtures with higher concentration of longer polymers. Waxy starch had a longer induction period than high amylose starch. Maximum fouling resistance was higher for waxy than high amylose starch. Addition of glucose to waxy or high amylose starch increased induction period of mixtures longer than 5 h test period. It appears that the bulk fluid temperature plays an important role on carbohydrate mixture fouling rates. Higher bulk fluid temperatures increased the initial fouling rates of the carbohydrate mixtures. Carbohydrate type, depending on the polymer length, influenced the deposit formation. Longer chain carbohydrate, starch, had higher fouling rates compared to shorter carbohydrates such as glucose and corn syrup solids. For insoluble carbohydrate mixtures, fouling was severe. As carbohydrate solubility increased with bulk fluid temperature, surface reaction increased at probe

  13. A FED Prototype Using Patterned DLC Thin Films as the Cathode

    Science.gov (United States)

    Li, W.; Feng, T.; Mao, D. S.; Wang, X.; Liu, X. H.; Zou, S. C.; Zhu, Y. K.; Li, Q.; Xu, J. F.; Jin, S.; Zheng, J. S.

    In our study, diamond-like-carbon (DLC) thin films were prepared by filtered arc deposition (FAD), which provided a way to deposit DLC thin films on large areas at room temperature. Glass slides coated 100nm chromium or titanium thin films were used as cathode substrates. Millions of rectangular holes with sizes of 5 × 5μm were made on the DLC films using a routine patterning process. Here a special reactive ion beam etching method was applied to etch the DLC films. The anodes of the devices were made by electrophoretic deposition. ZnO:Zn phosphor (P15) was employed, which has a broad band bluish green (centered at 490nm). Before electrophoretic deposition, the anode substrates (ITO glass slides) had been patterned into 50 anode electrodes. In order to improve the adherence of phosphor layers, the as-deposited screens were treated in Na2SiO3 solution for 24h to add additional binder. A kind of matrix-addressed diode FED prototype was designed and packaged. 50-100μm-thick glass slides were used as spacers and getters were applied to maintain the vacuum after the exhaustion. The applied DC voltage was ranged in 0-3000V and much higher current density was measured in the cathode-patterned prototypes than the unpatterned ones during the test. As a result, characters could be well displayed.

  14. Mutation-specific effects on thin filament length in thin filament myopathy.

    Science.gov (United States)

    Winter, Josine M de; Joureau, Barbara; Lee, Eun-Jeong; Kiss, Balázs; Yuen, Michaela; Gupta, Vandana A; Pappas, Christopher T; Gregorio, Carol C; Stienen, Ger J M; Edvardson, Simon; Wallgren-Pettersson, Carina; Lehtokari, Vilma-Lotta; Pelin, Katarina; Malfatti, Edoardo; Romero, Norma B; Engelen, Baziel G van; Voermans, Nicol C; Donkervoort, Sandra; Bönnemann, C G; Clarke, Nigel F; Beggs, Alan H; Granzier, Henk; Ottenheijm, Coen A C

    2016-06-01

    Thin filament myopathies are among the most common nondystrophic congenital muscular disorders, and are caused by mutations in genes encoding proteins that are associated with the skeletal muscle thin filament. Mechanisms underlying muscle weakness are poorly understood, but might involve the length of the thin filament, an important determinant of force generation. We investigated the sarcomere length-dependence of force, a functional assay that provides insights into the contractile strength of muscle fibers as well as the length of the thin filaments, in muscle fibers from 51 patients with thin filament myopathy caused by mutations in NEB, ACTA1, TPM2, TPM3, TNNT1, KBTBD13, KLHL40, and KLHL41. Lower force generation was observed in muscle fibers from patients of all genotypes. In a subset of patients who harbor mutations in NEB and ACTA1, the lower force was associated with downward shifted force-sarcomere length relations, indicative of shorter thin filaments. Confocal microscopy confirmed shorter thin filaments in muscle fibers of these patients. A conditional Neb knockout mouse model, which recapitulates thin filament myopathy, revealed a compensatory mechanism; the lower force generation that was associated with shorter thin filaments was compensated for by increasing the number of sarcomeres in series. This allowed muscle fibers to operate at a shorter sarcomere length and maintain optimal thin-thick filament overlap. These findings might provide a novel direction for the development of therapeutic strategies for thin filament myopathy patients with shortened thin filament lengths. Ann Neurol 2016;79:959-969. © 2016 American Neurological Association.

  15. Thin film Ag superlens towards lab-on-a-chip integration

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Nielsen, Rasmus Bundgaard; Boltasseva, Alexandra

    2009-01-01

    A thin metal film near-field superlens, as originally suggested by Pendry and realized by Fang et al. and Melville et al., is investigated with emphasis on materials suitable for integration on a lab-on-a-chip platform. A chemically resistant cyclo-olefin copolymer (COC), mr-I-T85 from microresist...... technology, is applied as dielectric matrix/spacer for an Ag thin film superlens. The superlens successfully resolves 80 nm half-pitch gratings when illuminated with UV radiation at a free space wavelength of 365 nm. The superlens design, fabrication and characterization is discussed....

  16. Repeated exposure to the thin ideal and implications for the self : Two weight loss program studies

    NARCIS (Netherlands)

    Klesse, A.K.; Goukens, C.; Geyskens, K.; de Ruyter, K.

    2012-01-01

    Exposure to thin models results in self-esteem shifts that influence people's motivation to diet. This research study applies a goal perspective to explain the effect of exposure to thin models on dieters' motivation to lose weight. Two (one-week) weight loss program studies that included treatment

  17. YIG: Bi2O3 Nanocomposite Thin Films for Magnetooptic and Microwave Applications

    Directory of Open Access Journals (Sweden)

    M. Nur-E-Alam

    2015-01-01

    Full Text Available Y3Fe5O12-Bi2O3 composite thin films are deposited onto Gd3Ga5O12 (GGG substrates and their annealing crystallization regimes are optimized (in terms of both process temperatures and durations to obtain high-quality thin film layers possessing magnetic properties attractive for a range of technological applications. The amount of bismuth oxide content introduced into these nanocomposite-type films is controlled by adjusting the RF power densities applied to both Y3Fe5O12 and Bi2O3 sputtering targets during the cosputtering deposition processes. The measured material properties of oven-annealed YIG-Bi2O3 films indicate that cosputtering of YIG-Bi2O3 composites can provide the flexibility of application-specific YIG layers fabrication of interest for several existing, emerging, and also frontier technologies. Experimental results demonstrate large specific Faraday rotation (of more than 1°/µm at 532 nm, achieved simultaneously with low optical losses in the visible range and very narrow peak-to-peak ferromagnetic resonance linewidth of around ΔHpp= 6.1 Oe at 9.77 GHz.

  18. Alkali-templated surface nanopatterning of chalcogenide thin films: a novel approach toward solar cells with enhanced efficiency.

    Science.gov (United States)

    Reinhard, Patrick; Bissig, Benjamin; Pianezzi, Fabian; Hagendorfer, Harald; Sozzi, Giovanna; Menozzi, Roberto; Gretener, Christina; Nishiwaki, Shiro; Buecheler, Stephan; Tiwari, Ayodhya N

    2015-05-13

    Concepts of localized contacts and junctions through surface passivation layers are already advantageously applied in Si wafer-based photovoltaic technologies. For Cu(In,Ga)Se2 thin film solar cells, such concepts are generally not applied, especially at the heterojunction, because of the lack of a simple method yielding features with the required size and distribution. Here, we show a novel, innovative surface nanopatterning approach to form homogeneously distributed nanostructures (<30 nm) on the faceted, rough surface of polycrystalline chalcogenide thin films. The method, based on selective dissolution of self-assembled and well-defined alkali condensates in water, opens up new research opportunities toward development of thin film solar cells with enhanced efficiency.

  19. Fiscal 1999 achievement report on the venture business assisting type regional consortium - Minor business creation base type. Development of hypersensitive photocatalyst using oxide semiconductor thin film having nanostructure; 1999 nendo chiiki consortium kenkyu kaihatsu jigyo seika hokokusho. Nano bisai kozo wo yusuru sankabutsu handotai usumaku ni yoru chokokando hikari shokubai no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    The thin film structure of photocatalytic titanium oxide, capable of efficiently decomposing hazardous pollutants or the like, is refined to have a nanometric scale structure for a larger specific surface for the development of a photocatalytic thin film or powder film and for the development of decomposition capable air cleaner using a thus developed photocatalytic film. Described in this report are the results of a study conducted to elucidate the fabrication conditions, nanostructures, and photocatalytic features of titanium oxide thin films formed by spray thermolysis, RF (radio frequency) sputtering, reactive sputtering, and sol-gel process, a study of hazardous pollutant decomposing capability and nanostructure, the establishment of fabrication technologies, and the construction of a prototype air cleaner with the results of the said studies applied thereto. Among the various fabrication methods, the technology involving a hypersensitive thin film photocatalyst was established by combining the reactive sputtering method and the sol-gel method. It was found that the formation of prismatic crystals in the sol-gel method was the most important in achieving high performance in the hypersensitive thin film photocatalyst. (NEDO)

  20. Thin layer activation technique applied to the measurement of wear

    Energy Technology Data Exchange (ETDEWEB)

    Humphries, P [UKAEA Research Group, Harwell. Atomic Energy Research Establishment

    1978-01-01

    A thin layer of radioactive atoms is produced in the material by bombardment with charged particles, and as the material is worn away the total activity level is monitored. If the activity to depth relationship is then known the amount of material worn away can be determined. By a selective choice of the charged particle species and energy the depth of the active layer, its natural decay rate, and the energy of the emitted radiation can be pre-determined. The Harwell Tandem Electrostatic Generator has been found very suitable for the work. The total activity level can be made as little or as large as required, but a level around 5 to 10 microcuries is usually found to be adequate, and the active layer usually has a depth of 50 to 300 ..mu..m. The activated area can be from < 1 mm/sup 2/ to 4 cm/sup 2/. Particular reference is made to the production of /sup 56/Co in Fe. Experimental arrangements for the irradiation of components are described. Some practical applications undertaken by Harwell for industry are briefly mentioned, including wear of diesel engine valve seatings and fuel injection equipment, engine testing of lubricants, surface loss of rails and railway wheels, wear of gears, wear of graphite bearing materials, and corrosion and erosion of materials. 4 references.

  1. Study of tensile test behavior of austenitic stainless steel type 347 seamless thin-walled tubes in cold worked condition

    Energy Technology Data Exchange (ETDEWEB)

    Terui, Clarice, E-mail: clarice.terui@marinha.mil.br [Centro Tecnológico da Marinha em São Paulo (CINA/CTMSP), Iperó, SP (Brazil). Centro Industrial Nuclear da Marinha; Lima, Nelson B. de, E-mail: nblima@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNE-SP), Sao Paulo, SP (Brazil)

    2017-07-01

    These austenitic stainless steel type 347 seamless thin-walled tubes are potential candidates to be used in fuel elements of nuclear power plants (as PWR - Pressurized Water Reactor). So, their metallurgical condition and mechanical properties, as the tensile strength and yield strength, normally are very restrict in demanding project and design requirements. Several full size tensile tests at room temperature and high temperature (315 deg C) were performed in these seamless tubes in cold-worked condition. The results of specified tensile and yield strengths were achieved but the elongation of the tube, in the geometry of the component, could not be measured at high temperature due to unconventional mode of rupture (helical mode without separation of parts). The average value of elongation was obtained from stress-strain curves of hot tensile tests and was around 5%. The results obtained in this research show that this behavior of the full size tensile test samples of thin-walled tube (wall thickness less than 0.5 mm) in high temperature (315°C) is due to the combination of the manufacturing process, the material (crystallographic structure and chemical composition) and the final geometry of the component. In other words, the strong crystallographic texture of material induced by tube drawing process in addition with the geometry of the component are responsible for the behavior in hot uniaxial tensile tests. (author)

  2. A flexible film type EMAT for inspection of small diameter pipe

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Cuixiang; Xiao, Pan; Zhao, Siqi; Chen, Zhenmao [Xi' an Jiaotong University, Xi' an (China); Takagi, Toshiyuki [Institute of Fluid Science, Tohoku University, Sendai (Japan)

    2017-08-15

    Pipe structures are widely applied in industries, and different kinds of defects may occur in the structures during their long-time service. For non-destructive testing of defects in pipes of small diameter, it has to be conducted from the inner side of the pipe when there is no space for detection from the outside or the geometry of the outside tube surface is too complicated. In this work, a flexible film type Electromagnetic acoustic transducer (EMAT) probe with a dual coil configuration is developed. The new probe is flexible and can be inserted into the pipe for inspection. First, the feasibility of the new probe was studied through numerical simulation. Then the feasibility of the proposed flexible EMAT for detection of wall thinning in small diameter pipe was verified experimentally. It was found that the new EMAT method is suitable for the detection of wall thinning defects for small pipes.

  3. Synthesis of Cu2O from CuO thin films: Optical and electrical properties

    Directory of Open Access Journals (Sweden)

    Dhanya S. Murali

    2015-04-01

    Full Text Available Hole conducting, optically transparent Cu2O thin films on glass substrates have been synthesized by vacuum annealing (5×10−6 mbar at 700 K for 1 hour of magnetron sputtered (at 300 K CuO thin films. The Cu2O thin films are p-type and show enhanced properties: grain size (54.7 nm, optical transmission 72% (at 600 nm and Hall mobility 51 cm2/Vs. The bulk and surface Valence band spectra of Cu2O and CuO thin films are studied by temperature dependent Hall effect and Ultra violet photo electron Spectroscopy (UPS. CuO thin films show a significant band bending downwards (due to higher hole concentration than Cu2O thin films.

  4. Fabrication and magnetization measurement of Ni thin films on silicon substrate by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Tang Yang [Key Laboratory of Excited State Process, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 16 East Nan-Hu Road, Open Economic Zone, Changchun 130033 (China); Graduate School of the Chinese Academy of Sciences (China); Zhao Dongxu [Key Laboratory of Excited State Process, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 16 East Nan-Hu Road, Open Economic Zone, Changchun 130033 (China)], E-mail: dxzhao2000@yahoo.com.cn; Shen Dezhen; Zhang Jiying; Li Binghui; Lu Youming; Fan Xiwu [Key Laboratory of Excited State Process, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 16 East Nan-Hu Road, Open Economic Zone, Changchun 130033 (China)

    2008-02-29

    Ni thin films were electrodeposited on n-Si (100) substrate from the electrolytes containing Ni(CH{sub 3}COO){sub 2} and CH{sub 3}COONH{sub 4} at room temperature. The scanning electron microscope images of the films reveals the uniform distribution of the nickel all over the substrate surface, which illustrates that the fine Ni films on large scales could be obtained through the method of electrodeposition. Vibrating sample magnetometer measurement with the applied field parallel to the surface shows obvious hysteresis loops of the magnetic thin films. The morphology and magnetism of the Ni thin films evolves with the deposition time increasing. The effect of deposition conditions on the properties of the Ni thin films is investigated.

  5. Effect of Sb content on the thermoelectric properties of annealed CoSb{sub 3} thin films deposited via RF co-sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Aziz, E-mail: aziz_ahmed@ust.ac.kr [Department of Nano-Mechatronics, Korea University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon, 305-350 (Korea, Republic of); Department of Nano-Mechanics, Korea Institute of Machinery and Materials (KIMM), 156 Gajeongbuk-ro, Yuseong-gu, Daejeon, 305-343 (Korea, Republic of); Han, Seungwoo, E-mail: swhan@kimm.re.kr [Department of Nano-Mechatronics, Korea University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon, 305-350 (Korea, Republic of); Department of Nano-Mechanics, Korea Institute of Machinery and Materials (KIMM), 156 Gajeongbuk-ro, Yuseong-gu, Daejeon, 305-343 (Korea, Republic of)

    2017-06-30

    Graphical abstract: The X-ray diffraction patterns and temperature dependence of the Seebeck coefficient of the annealed Co–Sb thin films. - Highlights: • CoSb{sub 3} phase thin films were prepared using RF co sputtering method. • Thin film thermoelectric properties were hugely dependent on Sb content. • All thin films shows n-type conduction behavior at high temperatures. • The thin films with excess Sb possess the largest Seebeck coefficient. • The thin films with CoSb{sub 2} phase possess the largest power factor. - Abstract: A series of CoSb{sub 3} thin films with Sb contents in the range 70–79 at.% were deposited at room temperature via RF co-sputtering. The thin films were amorphous in the as-deposited state and annealed at 300 °C for 3 h to obtain crystalline samples. The annealed thin films were characterized using scanning electron microscopy and X-ray diffraction (XRD), and these data indicate that the films exhibited good crystallinity. The XRD patterns indicate single-phase CoSb{sub 3} thin films in the Sb-rich samples. For the Sb-deficient samples, however, mixed-phase thin films consisting of CoSb{sub 2} and CoSb{sub 3} components were obtained. The electrical and thermoelectric properties were measured at temperatures up to 760 K and found to be highly sensitive to the phases that were present. We observed a change in the thermoelectric properties of the films from p-type at low temperatures to n-type at high temperatures, which indicates potential applications as n-type thermoelectric thin films. A large Seebeck coefficient and power factor was obtained for the single-phase CoSb{sub 3} thin films. The CoSb{sub 2} phase thin films were also found to possess a significant Seebeck coefficient, which coupled with the much smaller electrical resistivity, provided a larger power factor than the single-phase CoSb{sub 3} thin films. We report maximum power factor of 7.92 mW/m K{sup 2} for the CoSb{sub 2}-containing mixed phase thin film and 1

  6. Ellipsometric investigations of pyrolytically deposited thin indium oxide films

    International Nuclear Information System (INIS)

    Winkler, U.

    1980-01-01

    Ellipsometric measurements have been carried out of thin indium oxide films deposited pyrolytically on glass substrates. It was found that the roughness of the films affected the measuring results. Therefore, only after applying a two-layer model a reasonable interpretation of the measuring results became possible

  7. Electrophoretically applied dielectrics for amorphous metal foils used in pulsed power saturable reactors

    International Nuclear Information System (INIS)

    Sharp, D.J.; Harjes, H.C.; Mann, G.A.

    1989-01-01

    Amorphous metal foil-wound inductors have been tested as ferromagnetic saturable inductive elements for pulsed-power (multi-terawatt) switching modules in the inertial confinement fusion program at Sandia National Laboratories. In simulated capacitor testing premature dielectric breakdown of thin polyethylene terephthalate film insulation in the inductor windings occurs at considerably below 2500 V. This appears to be due to inadvertant dielectric damage from micro-spikes on the amorphous foil surface. Electron micrographs and dielectric breakdown data illustrate that electrophoretically-applied dielectric coatings, deposited from organic aqueous colloid dispersions, can be used to provide insulating coatings on the foil which provide a 240% improvement (6000 V) in the breakdown strength of wound amorphous foil inductors. The theory and operation of a dedicated electrophoretic continuous coating system is described. The machine was constructed and successfully applied for dielectric coating of amorphous metal foil. Additional possible applications exist for practical dielectric coating of metallic films or foils used in various commercial wound-type capacitor structures. 7 refs., 9 figs

  8. Light trapping with plasmonic back contacts in thin-film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Paetzold, Ulrich Wilhelm

    2013-02-08

    small potential for increasing the reflection at the back contact with dielectric interlayers of even lower refractive index, such as SiO{sub 2} and air, is demonstrated. The light-trapping effect of two types of plasmonic back contacts, which make use of large and efficiently scattering Ag nanostructures, is studied in thin-film silicon solar cell prototypes. The first type of plasmonic back contact applies non-ordered Ag nanostructures. The preparation, characterization and three-dimensional electromagnetic simulations of these back contacts with various distributions of non-ordered Ag nanostructures are presented. Measured reflectance spectra of the Ag back contacts with non-ordered nanostructures are correlated with reflectance spectra derived from three-dimensional electromagnetic simulations of isolated nanostructures on Ag back contacts. A microcrystalline silicon solar cell fabricated on one type of plasmonic Ag back contact with non-ordered Ag nanostructures shows a significantly enhanced plasmonic light trapping when compared with a flat solar cell. The second type of plasmonic back contact applies periodic arrangements of plasmonic Ag nanostructures in a square lattice at the surface of the Ag back contact. It is called a plasmonic reflection grating back contact. A particular advantage of this device is the control of the scattering angles via the diffraction orders of the grating while taking advantage of the efficient plasmon-induced light scattering at the Ag nanostructures. The plasmonic reflection grating back contacts are prepared with a nanoimprint process. The prototype microcrystalline silicon solar cells exhibit a very good light-trapping effect. Even in comparison with solar cells with a state-of-the-art random texture for light trapping, an enhanced light-trapping effect is demonstrated for a solar sell with a plasmonic reflection grating of optimized period. Based on electromagnetic simulations, the light-trapping effect is explained from the

  9. The Characterization of Thin Film Nickel Titanium Shape Memory Alloys

    Science.gov (United States)

    Harris Odum, Nicole Latrice

    Shape memory alloys (SMA) are able to recover their original shape through the appropriate heat or stress exposure after enduring mechanical deformation at a low temperature. Numerous alloy systems have been discovered which produce this unique feature like TiNb, AgCd, NiAl, NiTi, and CuZnAl. Since their discovery, bulk scale SMAs have undergone extensive material property investigations and are employed in real world applications. However, its thin film counterparts have been modestly investigated and applied. Researchers have introduced numerous theoretical microelectromechanical system (MEMS) devices; yet, the research community's overall unfamiliarity with the thin film properties has delayed growth in this area. In addition, it has been difficult to outline efficient thin film processing techniques. In this dissertation, NiTi thin film processing and characterization techniques will be outlined and discussed. NiTi thin films---1 mum thick---were produced using sputter deposition techniques. Substrate bound thin films were deposited to analysis the surface using Scanning Electron Microscopy; the film composition was obtained using Energy Dispersive Spectroscopy; the phases were identified using X-ray diffraction; and the transformation temperatures acquired using resistivity testing. Microfabrication processing and sputter deposition were employed to develop tensile membranes for membrane deflection experimentation to gain insight on the mechanical properties of the thin films. The incorporation of these findings will aid in the movement of SMA microactuation devices from theory to fruition and greatly benefit industries such as medicinal and aeronautical.

  10. Preparation of TiO2-based nanotubes/nanoparticles composite thin film electrodes for their electron transport properties

    International Nuclear Information System (INIS)

    Zhao, Wanyu; Fu, Wuyou; Chen, Jingkuo; Li, Huayang; Bala, Hari; Wang, Xiaodong; Sun, Guang; Cao, Jianliang; Zhang, Zhanying

    2015-01-01

    The composite thin film electrodes were prepared with one-dimensional (1D) TiO 2 -B nanotubes (NTs) and zero-dimensional TiO 2 nanoparticles (NPs) based on different weight ratios. The electron transport properties of the NTs/NPs composite thin film electrodes applied for dye-sensitized solar cells had been investigated systematically. The results indicated that although the amount of dye adsorption decreased slightly, the devices with the NTs/NPs composite thin film electrodes could obtain higher open-circuit voltage and overall conversion efficiency compared to devices with pure TiO 2 NPs electrodes by rational tuning the weight ratio of TiO 2 -B NTs and TiO 2 NPs. When the weight ratio of TiO 2 -B NTs in the NTs/NPs composite thin film electrodes increased, the density of states and recombination rate decreased. The 1D structure of TiO 2 -B NTs can provide direct paths for electron transport, resulting in higher electron lifetime, electron diffusion coefficient and electron diffusion length. The composite thin film electrodes possess the merits of the rapid electron transport of TiO 2 -B NTs and the high surface area of TiO 2 NPs, which has great applied potential in the field of photovoltaic devices. - Highlights: • The composite thin film electrodes (CTFEs) were prepared with nanotubes and nanoparticles. • The CTFEs possess the rapid electron transport and high surface area. • The CTFEs exhibit lower recombination rate and longer electron life time. • The CTFEs have great applied potential in the field of photovoltaic devices

  11. Application of irradiation process for the production of thin wall wires

    International Nuclear Information System (INIS)

    Saito, E.

    1977-01-01

    The demand for thin wall crosslinked PVC or polyethylene insulated wires in Japan was about 15,000,000 dollars in value in 1975. Their annual sales in 1980 are estimated at about 40 million dollars which will account for approximately 20% of the sales of all thin wall thermoplastic insulated wires expected for the same year. A comparative study was made of the irradiation process and the chemical process for manufacture of wires with crosslinked PVC or polyethylene insulation. Having found the excellence of the irradiation process an accelerator (500 KeV, 65mA) was installed in 1973 and production was begun of several types of thin wall irradiation crosslinked PVC and polyethylene insulated wires ranging from 0.06 mm 2 to 2.0 mm 2 in the cross-sectional area of conductor, successfully putting them in extensive commercial application. This report compares the irradiation process and the chemical process, properties of several types of irradiation crosslinked PVC, and polyethylene insulated wires and their applications. (author)

  12. Organic donor-acceptor thin film systems. Towards optimized growth conditions

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Kerstin Andrea

    2009-06-30

    In this work the preparation of organic donor-acceptor thin films was studied. A chamber for organic molecular beam deposition was designed and integrated into an existing deposition system for metallic thin films. Furthermore, the deposition system was extended by a load-lock with integrated bake-out function, a chamber for the deposition of metallic contacts via stencil mask technique and a sputtering chamber. For the sublimation of the organic compounds several effusion cells were designed. The evaporation characteristic and the temperature profile within the cells was studied. Additionally, a simulation program was developed, which calculates the evaporation characteristics of different cell types. The following processes were integrated: evaporation of particles, migration on the cell walls and collisions in the gas phase. It is also possible to consider a temperature gradient within the cell. All processes can be studied separately and their relative strength can be varied. To verify the simulation results several evaporation experiments with different cell types were employed. The thickness profile of the prepared thin films was measured position-dependently. The results are in good agreement with the simulation. Furthermore, the simulation program was extended to the field of electron beam induced deposition (EBID). The second part of this work deals with the preparation and characterization of organic thin films. The focus hereby lies on the charge transfer salt (BEDT-TTF)(TCNQ), which has three known structure variants. Thin films were prepared by different methods of co-evaporation and were studied with optical microscopy, X-ray diffraction and energy dispersive X-ray spectroscopy (EDX).The formation of the monoclinic phase of (BEDT-TTF)(TCNQ) could be shown. As a last part tunnel structures were prepared as first thin film devices and measured in a He{sub 4} cryostat. (orig.)

  13. Real-time Holographic Display Based on a Super Fast Response Thin Film

    International Nuclear Information System (INIS)

    Gao, Hongyue; Li, Xiao; He, Zhenghong; Su, Yikai; Poon, Ting-Chung

    2013-01-01

    Real-time dynamic holographic display is obtained with super fast response in a thin film without any applied electric field. Holograms can be refreshed in the order of a millisecond and there is no cross talk between the recorded holograms because the hologram formed in the film is transient and can be completely self erased, and the hologram formation time and self-erasure time are both ∼1 ms. Holographic video display is achieved, which shows the real-time holographic image display capability of the thin film, and its much higher resolution than those of commercially available spatial light modulators. Furthermore, multiplexed hologram display using two polarization directions of a recorded light and multiple color holographic display at different laser wavelengths are presented, which demonstrate the feasibility of a RGB color holographic three-dimensional display with the thin film. Because the sample is easy to be fabricated into a large size screen and needs no external applied electric field, we think that the film can be developed into a large-size, dynamic, and color holographic three-dimensional display in the future.

  14. Microwave Josephson generation in thin film superconducting bridges

    International Nuclear Information System (INIS)

    Gubankov, V.N.; Koshelets, V.P.; Ovsyannikov, G.A.

    1975-01-01

    Thin-film bridges have some advantage over other types of superconducting weak links: good definition of electromagnetic parameters and of weak region geometry. Up to now Josephson properties of bridges have been investigated by using indirect methods (the effect of magnetic field on the critical current I 0 , the bridge behavior in a microwave field, etc.). Direct experimental observation of Josephson radiation from autonomous thin film bridges is reported. Microwave radiation in tin bridges of 'variable' thickness has been investigated where the thickness of the film forming the bridge is far less than the thickness of the bank films. (Auth.)

  15. Controllable Electrochemical Synthesis of Reduced Graphene Oxide Thin-Film Constructed as Efficient Photoanode in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Soon Weng Chong

    2016-01-01

    Full Text Available A controllable electrochemical synthesis to convert reduced graphene oxide (rGO from graphite flakes was introduced and investigated in detail. Electrochemical reduction was used to prepare rGO because of its cost effectiveness, environmental friendliness, and ability to produce rGO thin films in industrial scale. This study aimed to determine the optimum applied potential for the electrochemical reduction. An applied voltage of 15 V successfully formed a uniformly coated rGO thin film, which significantly promoted effective electron transfer within dye-sensitized solar cells (DSSCs. Thus, DSSC performance improved. However, rGO thin films formed in voltages below or exceeding 15 V resulted in poor DSSC performance. This behavior was due to poor electron transfer within the rGO thin films caused by poor uniformity. These results revealed that DSSC constructed using 15 V rGO thin film exhibited high efficiency (η = 1.5211% attributed to its higher surface uniformity than other samples. The addition of natural lemon juice (pH ~ 2.3 to the electrolyte accelerated the deposition and strengthened the adhesion of rGO thin film onto fluorine-doped tin oxide (FTO glasses.

  16. Growth and characterization of tin oxide thin films and fabrication of transparent p-SnO/n-ZnO p–n hetero junction

    Energy Technology Data Exchange (ETDEWEB)

    Sanal, K.C., E-mail: sanalcusat@gmail.com [Nanophotonic and Optoelectronic Devices Laboratory, Department of Physics, Cochin University of Science and Technology, Kerala 682 022 (India); Inter University Center for Nanomaterials and Devices (IUCND), Cochin University of Science and Technology (India); Jayaraj, M.K. [Nanophotonic and Optoelectronic Devices Laboratory, Department of Physics, Cochin University of Science and Technology, Kerala 682 022 (India)

    2013-07-01

    Highlights: • Growth of p-type semiconducting SnO thin films by rf sputtering. • Varying the type of charge carriers with oxygen partial pressure. • Atomic percentage of SnO{sub x} thin films from the XPS analysis. • Demonstration of transparent p–n hetero junctions fabricated in the structure glass/ITO/n-ZnO/p-SnO. -- Abstract: p-Type and n-type tin oxide thin films were deposited by rf-magnetron sputtering of metal tin target by varying the oxygen pressure. Chemical composition of SnO thin film according to the intensity of the XPS peak is about 48.85% and 51.15% for tin and oxygen respectively. Nearest neighbor distance of the atoms calculated from SAED patterns is 2.9 Åand 2.7 Åfor SnO and SnO{sub 2} respectively. The Raman scattering spectrum obtained from SnO thin films showed two peaks, one at 113 cm{sup −1} and the other at 211 cm{sup −1}. Band gap of as-deposited SnO{sub x} thin films vary from 1.6 eV to 3.2 eV on varying the oxygen partial pressure from 3% to 30% which indicates the oxidization of metallic phase Sn to SnO and SnO{sub 2}. p-Type conductivity of SnO thin films and n-type conductivity of SnO{sub 2} thin films were confirmed through Hall coefficient measurement. Transparent p–n hetero junction fabricated in the structure glass/ITO/n-ZnO/p-SnO shows rectification with forward to reverse current ratio as 12 at 4.5 V.

  17. Investigation of phase transformation for ferrite–austenite structure in stainless steel thin films

    Energy Technology Data Exchange (ETDEWEB)

    Merakeb, Noureddine [Laboratory of Physical Metallurgy and Property of Materials (LM2PM), Metallurgy and Materials Engineering Department, Badji Mokhtar University, P.O. Box 12, Annaba 23000 (Algeria); Messai, Amel [Laboratoire d' Ingénierie et Sciences des Matériaux Avancés (ISMA), Institut des Sciences et Technologie, Abbès Laghrour University, Khenchela 40000 (Algeria); Ayesh, Ahmad I., E-mail: ayesh@qu.edu.qa [Department of Mathematics, Statistics and Physics, Qatar University, Doha (Qatar)

    2016-05-01

    In this work we report on phase transformation of 304 stainless steel thin films due to heat treatment. Ex-situ annealing was applied for evaporated 304 stainless steel thin films inside an ultra-high vacuum chamber with a pressure of 3 × 10{sup −7} Pa at temperatures of 500 °C and 600 °C. The structure of thin films was studied by X-ray diffraction (XRD) and conversion electron Mössbauer spectroscopy (CEMS) techniques. The results revealed a transformation from α-phase that exhibits a body-centered cubic structure (BCC) to γ-phase that exhibits a face-centered cubic (FCC) due to annealing. In addition, the percentage of γ-phase structure increased with the increase of annealing temperature. Annealing thin films increased the crystal size of both phases (α and γ), however, the increase was nonlinear. The results also showed that phase transformation was produced by recrystallization of α and γ crystals with a temporal evolution at each annealing temperature. The texture degree of thin films was investigated by XRD rocking curve method, while residual stress was evaluated using curvature method. - Highlights: • Stainless steel thin films were fabricated by thermal evaporation on quartz. • Alpha to gamma phase transformation of thin films was investigated. • Annealing of thin films reduces disruption in crystal lattice. • The stress of as-grown thin films was independent on the thin film thickness. • The stress of the thin films was reduced due to annealing.

  18. Nanoscale aluminum concaves for light-trapping in organic thin-films

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jaroslaw; Adam, Jost; Cielecki, Pawel Piotr

    2016-01-01

    Anodic aluminum oxide (AAO) templates, fabricated from oxalic acid and phosphoric acid, lead to non-periodic nanoscale concave structures in their underlying aluminum layer, which are investigated for their field-enhancement properties by applying a thin-film polymer coating based laser ablation...

  19. Thin Film Approaches to the SRF Cavity Problem: Fabrication and Characterization of Superconducting Thin Films

    Science.gov (United States)

    Beringer, Douglas B.

    Superconducting Radio Frequency (SRF) cavities are responsible for the acceleration of charged particles to relativistic velocities in most modern linear accelerators, such as those employed at high-energy research facilities like Thomas Jefferson National Laboratory's CEBAF and the LHC at CERN. Recognizing SRF as primarily a surface phenomenon enables the possibility of applying thin films to the interior surface of SRF cavities, opening a formidable tool chest of opportunities by combining and designing materials that offer greater benefit. Thus, while improvements in radio frequency cavity design and refinements in cavity processing techniques have improved accelerator performance and efficiency - 1.5 GHz bulk niobium SRF cavities have achieved accelerating gradients in excess of 35 MV/m - there exist fundamental material bounds in bulk superconductors limiting the maximally sustained accelerating field gradient (approximately 45 MV/m for Niobium) where inevitable thermodynamic breakdown occurs. With state of the art niobium based cavity design fast approaching these theoretical limits, novel material innovations must be sought in order to realize next generation SRF cavities. One proposed method to improve SRF performance is to utilize thin film superconducting-insulating-superconducting (SIS) multilayer structures to effectively magnetically screen a bulk superconducting layer such that it can operate at higher field gradients before suffering critically detrimental SRF losses. This dissertation focuses on the production and characterization of thin film superconductors for such SIS layers for radio-frequency applications.

  20. Repulsive effects of hydrophobic diamond thin films on biomolecule detection

    Energy Technology Data Exchange (ETDEWEB)

    Ruslinda, A. Rahim, E-mail: ruslindarahim@gmail.com [Institute of Nano Electronic Engineering, Universiti Malaysia Perlis, Jln Kgr-Alor Setar, Seriab, 01000 Kangar, Perlis (Malaysia); Department of Nano Science and Nano Engineering, School of Advance Science and Engineering, Ohkubo 3-4-1, Shinjuku, 169-8555 Tokyo (Japan); Ishiyama, Y. [Department of Nano Science and Nano Engineering, School of Advance Science and Engineering, Ohkubo 3-4-1, Shinjuku, 169-8555 Tokyo (Japan); Penmatsa, V. [Department of Mechanical and Materials Engineering, Florida International University, 10555 West Flagler Street, Miami, FL 33174 (United States); Ibori, S.; Kawarada, H. [Department of Nano Science and Nano Engineering, School of Advance Science and Engineering, Ohkubo 3-4-1, Shinjuku, 169-8555 Tokyo (Japan)

    2015-02-15

    Highlights: • We report the effect of fluorine plasma treatment on diamond thin film to resist the nonspecific adsorption of biomolecules. • The diamond thin film were highly hydrophobic with a surface energy value of ∼25 mN/m. • The repulsive effect shows excellent binding efficiency for both DNA and HIV-1 Tat protein. - Abstract: The repulsive effect of hydrophobic diamond thin film on biomolecule detection, such as single-nucleotide polymorphisms and human immunodeficiency virus type 1 trans-activator of transcription peptide protein detection, was investigated using a mixture of a fluorine-, amine-, and hydrogen-terminated diamond surfaces. These chemical modifications lead to the formation of a surface that effectively resists the nonspecific adsorption of proteins and other biomolecules. The effect of fluorine plasma treatment on elemental composition was also investigated via X-ray photoelectron spectroscopy (XPS). XPS results revealed a fluorocarbon layer on the diamond thin films. The contact angle measurement results indicated that the fluorine-treated diamond thin films were highly hydrophobic with a surface energy value of ∼25 mN/m.

  1. Repulsive effects of hydrophobic diamond thin films on biomolecule detection

    International Nuclear Information System (INIS)

    Ruslinda, A. Rahim; Ishiyama, Y.; Penmatsa, V.; Ibori, S.; Kawarada, H.

    2015-01-01

    Highlights: • We report the effect of fluorine plasma treatment on diamond thin film to resist the nonspecific adsorption of biomolecules. • The diamond thin film were highly hydrophobic with a surface energy value of ∼25 mN/m. • The repulsive effect shows excellent binding efficiency for both DNA and HIV-1 Tat protein. - Abstract: The repulsive effect of hydrophobic diamond thin film on biomolecule detection, such as single-nucleotide polymorphisms and human immunodeficiency virus type 1 trans-activator of transcription peptide protein detection, was investigated using a mixture of a fluorine-, amine-, and hydrogen-terminated diamond surfaces. These chemical modifications lead to the formation of a surface that effectively resists the nonspecific adsorption of proteins and other biomolecules. The effect of fluorine plasma treatment on elemental composition was also investigated via X-ray photoelectron spectroscopy (XPS). XPS results revealed a fluorocarbon layer on the diamond thin films. The contact angle measurement results indicated that the fluorine-treated diamond thin films were highly hydrophobic with a surface energy value of ∼25 mN/m

  2. Structural and Electrochemical Properties of Lithium Nickel Oxide Thin Films

    Directory of Open Access Journals (Sweden)

    Gyu-bong Cho

    2014-01-01

    Full Text Available LiNiO2 thin films were fabricated by RF magnetron sputtering. The microstructure of the films was determined by X-ray diffraction and field-emission scanning electron microscopy. The electrochemical properties were investigated with a battery cycler using coin-type half-cells. The LiNiO2 thin films annealed below 500°C had the surface carbonate. The results suggest that surface carbonate interrupted the Li intercalation and deintercalation during charge/discharge. Although the annealing process enhanced the crystallization of LiNiO2, the capacity did not increase. When the annealing temperature was increased to 600°C, the FeCrNiO4 oxide phase was generated and the discharge capacity decreased due to an oxygen deficiency in the LiNiO2 thin film. The ZrO2-coated LiNiO2 thin film provided an improved discharge capacity compared to bare LiNiO2 thin film suggesting that the improved electrochemical characteristic may be attributed to the inhibition of surface carbonate by ZrO2 coating layer.

  3. [Factors of the drive for thinness and dieting: from the viewpoint of impression management].

    Science.gov (United States)

    Suzuki, Tomohiro

    2012-12-01

    Thinness is considered as one type of adornment; as such, it has a psychological function for others. Thus the drive for thinness and dieting were investigated from the viewpoint of impression management. Study 1 investigated a model that the need for approval affects dieting through the outcome expectancies of others' evaluations and the drive for thinness. The results of structural equation modeling indicated high validity for this model. Study 2 investigated the moderating role of self-esteem in the relationship between positive/negative outcome expectancies of others' evaluations and the drive for thinness. The results showed that self-esteem did not act as a moderator between the two components and the drive for thinness.

  4. Transparent conducting oxide layers for thin film silicon solar cells

    NARCIS (Netherlands)

    Rath, J.K.; Liu, Y.; de Jong, M.M.; de Wild, J.; Schuttauf, J.A.; Brinza, M.; Schropp, R.E.I.

    2009-01-01

    Texture etching of ZnO:1%Al layers using diluted HCl solution provides excellent TCOs with crater type surface features for the front contact of superstrate type of thin film silicon solar cells. The texture etched ZnO:Al definitely gives superior performance than Asahi SnO2:F TCO in case of

  5. Magnetic-field induced semimetal in topological crystalline insulator thin films

    International Nuclear Information System (INIS)

    Ezawa, Motohiko

    2015-01-01

    We investigate electromagnetic properties of a topological crystalline insulator (TCI) thin film under external electromagnetic fields. The TCI thin film is a topological insulator indexed by the mirror-Chern number. It is demonstrated that the gap closes together with the emergence of a pair of gapless cones carrying opposite chirarities by applying in-plane magnetic field. A pair of gapless points have opposite vortex numbers. This is a reminiscence of a pair of Weyl cones in 3D Weyl semimetal. We thus present an a magnetic-field induced semimetal–semiconductor transition in 2D material. This is a giant-magnetoresistance, where resistivity is controlled by magnetic field. Perpendicular electric field is found to shift the gapless points and also renormalize the Fermi velocity in the direction of the in-plane magnetic field. - Highlights: • The band structure of topological crystalline insulator thin films can be controlled by applying in-plane magnetic field. • At the gap closing magnetic field, a pair of gapless cones carrying opposite chirarities emerge. • A pair of gapless points have opposite vortex numbers. • This is a reminiscence of a pair of Weyl cones in 3D Weyl semimetal. • A magnetic-field induced semimetal–semiconductor transition occurs in 2D material

  6. Magnetic-field induced semimetal in topological crystalline insulator thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ezawa, Motohiko, E-mail: ezawa@ap.t.u-tokyo.ac.jp

    2015-06-19

    We investigate electromagnetic properties of a topological crystalline insulator (TCI) thin film under external electromagnetic fields. The TCI thin film is a topological insulator indexed by the mirror-Chern number. It is demonstrated that the gap closes together with the emergence of a pair of gapless cones carrying opposite chirarities by applying in-plane magnetic field. A pair of gapless points have opposite vortex numbers. This is a reminiscence of a pair of Weyl cones in 3D Weyl semimetal. We thus present an a magnetic-field induced semimetal–semiconductor transition in 2D material. This is a giant-magnetoresistance, where resistivity is controlled by magnetic field. Perpendicular electric field is found to shift the gapless points and also renormalize the Fermi velocity in the direction of the in-plane magnetic field. - Highlights: • The band structure of topological crystalline insulator thin films can be controlled by applying in-plane magnetic field. • At the gap closing magnetic field, a pair of gapless cones carrying opposite chirarities emerge. • A pair of gapless points have opposite vortex numbers. • This is a reminiscence of a pair of Weyl cones in 3D Weyl semimetal. • A magnetic-field induced semimetal–semiconductor transition occurs in 2D material.

  7. EMHD micro-pumping of a non-conducting shear-thinning fluid under EDL phenomena

    International Nuclear Information System (INIS)

    Gaikwad, Harshad; Borole, Chetan; Basu, Dipankar N.; Mondal, Pranab K.

    2016-01-01

    The Electro-Magneto-Hydrodynamic (EMHD) pumping of a binary fluid system constituted by one non-conducting shear-thinning fluid (top layer) by exploiting the transverse momentum exchange through the interfacial viscous shearing effect from a conducting Newtonian fluid layer (bottom layer) in a microfluidic channel is investigated. An externally applied electric field drives the conducting fluid layer under the influence of an applied magnetic field as well. The study reveals that the volume transport of shear-thinning fluid gets augmented for low magnetic field strength, higher electrical double layer (EDL) effect, low viscosity ratio and moderate potential ratio. It is also established that the volumetric flow rate reduces significantly for the higher magnetic field strength. (author)

  8. Controlled Topological Transitions in Thin-Film Phase Separation

    KAUST Repository

    Hennessy, Matthew G.; Burlakov, Victor M.; Goriely, Alain; Wagner, Barbara; Mü nch, Andreas

    2015-01-01

    © 2015 Society for Industrial and Applied Mathematics. In this paper the evolution of a binary mixture in a thin-film geometry with a wall at the top and bottom is considered. By bringing the mixture into its miscibility gap so that no spinodal decomposition occurs in the bulk, a slight energetic bias of the walls toward each one of the constituents ensures the nucleation of thin boundary layers that grow until the constituents have moved into one of the two layers. These layers are separated by an interfacial region where the composition changes rapidly. Conditions that ensure the separation into two layers with a thin interfacial region are investigated based on a phase-field model. Using matched asymptotic expansions a corresponding sharp-interface problem for the location of the interface is established. It is then argued that this newly created two-layer system is not at its energetic minimum but destabilizes into a controlled self-replicating pattern of trapezoidal vertical stripes by minimizing the interfacial energy between the phases while conserving their area. A quantitative analysis of this mechanism is carried out via a thin-film model for the free interfaces, which is derived asymptotically from the sharp-interface model.

  9. Evaluating interfacial adhesion properties of Pt/Ti thin-film by using acousto-optic technique

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hae Sung [Graduate School of Automotive Engineering, Seoul National University of Science and Technology, Seoul (Korea, Republic of); Didie, David; Yoshida, Sanichiro [Dept. of Chemistry and Physics, Southeastern Louisiana University, Hammond (United States); Park, Ik Keun [Dept. of Mechanical and Automotive Engineering, Seoul National University of Science and Technology, Seoul (Korea, Republic of)

    2016-06-15

    We propose an acousto-optic technique for the nondestructive evaluation of adhesion properties of a Pt/Ti thin-film interface. Since there are some problems encountered when using prevailing techniques to nondestructively evaluate the interfacial properties of micro/nano-scale thin-films, we applied an interferometer that combined the acoustic and optical methods. This technique is based on the Michelson interferometer but the resultant surface of the thin film specimen makes interference instead of the mirror when the interface is excited from the acoustic transducer at the driving frequency. The thin film shows resonance-like behavior at a certain frequency range, resulting in a low-contrast fringe pattern. Therefore, we represented quantitatively the change in fringe pattern as a frequency spectrum and discovered the possibility that the interfacial adhesion properties of a thin film can be evaluated using the newly proposed technique.

  10. Poole-Frenkel-effect as dominating current mechanism in thin oxide films—An illusion?!

    International Nuclear Information System (INIS)

    Schroeder, Herbert

    2015-01-01

    oxide materials; the barriers for electrons and holes at the interfaces simulating different electrode materials; the temperature. The main results and conclusions are: (1) For a single type of trap present only (donor-like or acceptor-like), none of the simulated current density curves shows the expected behavior of the PFE and in most cases within the tested parameter field the effect of PFE is negligibly small. (2) For both types of traps present (compensation) only in the case of exact compensation, the expected slope in the PF-plot was nearly found for a wider range of the applied electric field, but for a very small range of the tested parameter field because of the very restricting additional conditions: first, the quasi-fermi level of the current controlling particle (electrons or holes) has to be 0.1 to 0.5 eV closer to the respective band limit than the zero-field energy level of the respective traps and, second, the compensating trap energy level has to be shallow. The conclusion from all these results is: the observation of the PFE as dominating current mechanism in MIM stacks with thin dielectric (oxide) films (typically 30 nm) is rather improbable!

  11. Poole-Frenkel-effect as dominating current mechanism in thin oxide films—An illusion?!

    Science.gov (United States)

    Schroeder, Herbert

    2015-06-01

    materials; the barriers for electrons and holes at the interfaces simulating different electrode materials; the temperature. The main results and conclusions are: (1) For a single type of trap present only (donor-like or acceptor-like), none of the simulated current density curves shows the expected behavior of the PFE and in most cases within the tested parameter field the effect of PFE is negligibly small. (2) For both types of traps present (compensation) only in the case of exact compensation, the expected slope in the PF-plot was nearly found for a wider range of the applied electric field, but for a very small range of the tested parameter field because of the very restricting additional conditions: first, the quasi-fermi level of the current controlling particle (electrons or holes) has to be 0.1 to 0.5 eV closer to the respective band limit than the zero-field energy level of the respective traps and, second, the compensating trap energy level has to be shallow. The conclusion from all these results is: the observation of the PFE as dominating current mechanism in MIM stacks with thin dielectric (oxide) films (typically 30 nm) is rather improbable!

  12. Using high thermal stability flexible thin film thermoelectric generator at moderate temperature

    Science.gov (United States)

    Zheng, Zhuang-Hao; Luo, Jing-Ting; Chen, Tian-Bao; Zhang, Xiang-Hua; Liang, Guang-Xing; Fan, Ping

    2018-04-01

    Flexible thin film thermoelectric devices are extensively used in the microscale industry for powering wearable electronics. In this study, comprehensive optimization was conducted in materials and connection design for fabricating a high thermal stability flexible thin film thermoelectric generator. First, the thin films in the generator, including the electrodes, were prepared by magnetron sputtering deposition. The "NiCu-Cu-NiCu" multilayer electrode structure was applied to ensure the thermal stability of the device used at moderate temperature in an air atmosphere. A design with metal layer bonding and series accordant connection was then employed. The maximum efficiency of a single PN thermocouple generator is >11%, and the output power loss of the generator is <10% after integration.

  13. Weak magnetism of Aurivillius-type multiferroic thin films probed by polarized neutron reflectivity

    Science.gov (United States)

    Zhai, Xiaofang; Grutter, Alexander J.; Yun, Yu; Cui, Zhangzhang; Lu, Yalin

    2018-04-01

    Unambiguous magnetic characterization of room-temperature multiferroic materials remains challenging due in part to the difficulty of distinguishing their very weak ferromagnetism from magnetic impurity phases and other contaminants. In this study, we used polarized neutron reflectivity to probe the magnetization of B i6FeCoT i3O18 and LaB i5FeCoT i3O18 in their epitaxial thin films while eliminating a variety of impurity contributions. Our results show that LaB i5FeCoT i3O18 exhibits a magnetization of about 0.016 ±0.027 μB/Fe -Co pair at room temperature, while the B i6FeCoT i3O18 thin film only exhibits a weak magnetic moment below room temperature, with a saturation magnetization of 0.049 ±0.015 μB/Fe -Co pair at 50 K. This polarized-neutron-reflectivity study places an upper magnetization limit on the matrix material of the magnetically doped Aurivillius oxides and helps to clarify the true mechanism behind the room-temperature magnetic performance.

  14. Thin films of soft matter

    CERN Document Server

    Kalliadasis, Serafim

    2007-01-01

    A detailed overview and comprehensive analysis of the main theoretical and experimental advances on free surface thin film and jet flows of soft matter is given. At the theoretical front the book outlines the basic equations and boundary conditions and the derivation of low-dimensional models for the evolution of the free surface. Such models include long-wave expansions and equations of the boundary layer type and are analyzed via linear stability analysis, weakly nonlinear theories and strongly nonlinear analysis including construction of stationary periodic and solitary wave and similarity solutions. At the experimental front a variety of very recent experimental developments is outlined and the link between theory and experiments is illustrated. Such experiments include spreading drops and bubbles, imbibitions, singularity formation at interfaces and experimental characterization of thin films using atomic force microscopy, ellipsometry and contact angle measurements and analysis of patterns using Minkows...

  15. Fabrication of Co thin films using pulsed laser deposition method with or without employing external magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Ehsani, M.H., E-mail: Ehsani@semnan.ac.ir [Thin Film Laboratory, Faculty of Physics, Semnan University (Iran, Islamic Republic of); Mehrabad, M. Jalali [Thin Film Laboratory, Faculty of Physics, Semnan University (Iran, Islamic Republic of); Kameli, P. [Department of Physics, Isfahan University of technology, Isfahan 8415683111 (Iran, Islamic Republic of)

    2016-11-01

    In this work, the external magnetic field effects on growth condition during deposition processes of the Co thin films were studied. Two specimens of Co films with different condition (with and without external magnetic field) were synthesized by pulsed laser deposition method. Structural and magnetic properties of the Co thin films were systematically studied, using atomic force microscope analysis and magnetization measurement, respectively. During the deposition processes, the external applied magnetic field had been provided by a permanent magnet. The experimental results show that the external magnetic field enables one to tune the magnetic properties of the deposited thin films. To clarify this effect, using Multi-Physics COMSOL simulation environment, a study of vapor flux by applied magnetic field during deposition were performed. Comparison between experimental data and output data of the simulation show promising accommodation and approve the existence of a strong correlation between the structural and magnetic properties of the specimens, and deposition rate of Co thin films. - Graphical abstract: Simulation results of the cobalt particles tracing sputtered from the source to substrate with an external magnetic field. Convergence of the particles flux (left) and also the spiral motion of the cobalt particles (right) increase dramatically as they approach the substrate and NdFe35 magnet. - Highlights: • The external magnetic field effects on growth condition during deposition processes of the Co thin films were studied. • Structural and magnetic properties of the Co thin films were systematically studied, using atomic force microscope analysis and magnetization measurement, respectively. • The experimental results show that the external magnetic field enables one to tune the magnetic properties of the deposited thin films. • To clarify this effect, using Multi-Physics COMSOL simulation environment, a study of vapor flux by applied magnetic field

  16. Photoelectrochemical study of nanostructured ZnO thin films for hydrogen generation from water splitting

    Energy Technology Data Exchange (ETDEWEB)

    Wolcott, Abraham; Zhang, Jin Z. [Department of Chemistry and Biochemistry, University of California, Santa Cruz 1156 High St. Santa Cruz, CA 95064 (United States); Smith, Wilson A.; Zhao, Yiping [Department of Physics and Astronomy, University of Georgia, Athens, GA 30602 (United States); Kuykendall, Tevye R. [Department of Chemistry, University of California, Berkeley Berkeley, CA 94720 (United States)

    2009-06-23

    Photoelectrochemical cells based on traditional and nanostructured ZnO thin films are investigated for hydrogen generation from water splitting. The ZnO thin films are fabricated using three different deposition geometries: normal pulsed laser deposition, pulsed laser oblique-angle deposition, and electron-beam glancing-angle deposition. The nanostructured films are characterized by scanning electron microscopy, X-ray diffraction, UV-vis spectroscopy and photoelectrochemical techniques. Normal pulsed laser deposition produces dense thin films with ca. 200 nm grain sizes, while oblique-angle deposition produces nanoplatelets with a fishscale morphology and individual features measuring ca. 900 by 450 nm on average. In contrast, glancing-angle deposition generates a highly porous, interconnected network of spherical nanoparticles of 15-40 nm diameter. Mott-Schottky plots show the flat band potential of pulsed laser deposition, oblique-angle deposition, and glancing-angle deposition samples to be -0.29, -0.28 and +0.20 V, respectively. Generation of photocurrent is observed at anodic potentials and no limiting photocurrents were observed with applied potentials up to 1.3 V for all photoelectrochemical cells. The effective photon-to-hydrogen efficiency is found to be 0.1%, 0.2% and 0.6% for pulsed laser deposition, oblique-angle deposition and glancing-angle deposition samples, respectively. The photoelectrochemical properties of the three types of films are understood to be a function of porosity, crystal defect concentration, charge transport properties and space charge layer characteristics. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  17. Evaluation of benign pulmonary lesions less than 20 mm in diameter by thin-section computed tomography

    International Nuclear Information System (INIS)

    Shiotani, Seiji; Yamada, Kouzo; Oshita, Fumihiro

    1997-01-01

    To establish diagnostic criteria for small solitary pulmonary nodules, the findings of thin-section computed tomography (CT) were compared with pathological findings. We evaluated thin-section CT images and compared them with pathological findings in 23 specimens of resected benign lesions less than 20 mm in diameter located in the peripheral region. The thin-section CT images were reconstructed using 2 mm thick sections taken by TCT-900S, HELIX (Toshiba, Tokyo) and were examined with two different windows and level settings. In every case, the surgical specimens were sliced transversely to correlate with the CT findings. The thin-section CT images were classified into two types; solid and air-containing types. The former consisted of benign pulmonary tumors, granulomas and some focal fibrosis, while the latter all consisted of focal fibrosis. Both types were difficult to distinguish from peripheral lung cancer based only on margin analysis of the lesion, but analysis of how pulmonary vessels relate to the lesion can allow benign pulmonary lesions to be distinguished from peripheral lung cancer. (author)

  18. Decoding Nucleation and Growth of Zeolitic Imidazolate Framework Thin Films with Atomic Force Microscopy and Vibrational Spectroscopy.

    Science.gov (United States)

    Öztürk, Zafer; Filez, Matthias; Weckhuysen, Bert M

    2017-08-10

    The synthesis of metal-organic framework (MOF) thin films has garnered significant attention during the past decade. By better understanding the parameters governing the nucleation and growth of such thin films, their properties can be rationally tuned, empowering their application as (reactive) membranes. Here, a combined AFM-vibrational spectroscopy research strategy is employed to detail the chemistries governing the nucleation and growth of zeolitic imidazolate framework (ZIF) thin films, in particular isostructural Co-ZIF-67 and Zn-ZIF-8. First, a single step direct synthesis approach is used to investigate the influence of different synthesis parameters -metal/linker ratio, temperature, and metal type- on the thin film nucleation and growth behaviour. While the metal/linker ratio has a pronounced effect on the thin film nucleation rate, the temperature mainly influences the growth kinetics of nuclei forming the thin film. In addition, the nucleation and growth of ZIF thin films is shown to be highly dependent on the electronegativity of the metal type. Thin-film thickness control can be achieved by using a multistep synthesis strategy, implying repetitive applications of single step deposition under identical synthesis conditions, for which a growth mechanism is proposed. This study provides insight into the influence of synthesis parameters on the ZIF thin film properties, using tools at hand to rationally tune MOF thin film properties. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  19. Highly spectrum-selective ultraviolet photodetector based on p-NiO/n-IGZO thin film heterojunction structure.

    Science.gov (United States)

    Li, H K; Chen, T P; Hu, S G; Li, X D; Liu, Y; Lee, P S; Wang, X P; Li, H Y; Lo, G Q

    2015-10-19

    Ultraviolet photodetector with p-n heterojunction is fabricated by magnetron sputtering deposition of n-type indium gallium zinc oxide (n-IGZO) and p-type nickel oxide (p-NiO) thin films on ITO glass. The performance of the photodetector is largely affected by the conductivity of the p-NiO thin film, which can be controlled by varying the oxygen partial pressure during the deposition of the p-NiO thin film. A highly spectrum-selective ultraviolet photodetector has been achieved with the p-NiO layer with a high conductivity. The results can be explained in terms of the "optically-filtering" function of the NiO layer.

  20. Deposition of thin ultrafiltration membranes on commercial SiC microfiltration tubes

    DEFF Research Database (Denmark)

    Facciotti, Marco; Boffa, Vittorio; Magnacca, Giuliana

    2014-01-01

    Porous SiC based materials present high mechanical, chemical and thermal robustness, and thus have been largely applied to water-filtration technologies. In this study, commercial SiC microfiltration tubes with nominal pore size of 0.04 m were used as carrier for depositing thin aluminium oxide....... After 5 times coating, a 5.6 µm thick γ-Al2O3 layer was obtained. This membrane shows retention of ~75% for polyethylene glycol molecules with Mn of 8 and 35 kDa, indicating that, despite their intrinsic surface roughness, commercial SiC microfiltration tubes can be applied as carrier for thin...... ultrafiltration membranes. This work also indicates that an improvement of the commercial SiC support surface smoothness may greatly enhance permeance and selectivity of Υ-Al2O3 ultrafiltration membranes by allowing the deposition of thinner defect-free layers....

  1. Direct observation of phase transition of GeSbTe thin films by Atomic Force Microscope

    Energy Technology Data Exchange (ETDEWEB)

    Yang Fei [National Laboratory of Solid State Microstructures and Jiangsu Provincial Key Laboratory of Photonic and Electronic Materials Sciences and Technology, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Xu Ling, E-mail: xuling@nju.edu.cn [National Laboratory of Solid State Microstructures and Jiangsu Provincial Key Laboratory of Photonic and Electronic Materials Sciences and Technology, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Zhang Rui; Geng Lei; Tong Liang; Xu Jun [National Laboratory of Solid State Microstructures and Jiangsu Provincial Key Laboratory of Photonic and Electronic Materials Sciences and Technology, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Su Weining; Yu Yao [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Ma Zhongyuan; Chen Kunji [National Laboratory of Solid State Microstructures and Jiangsu Provincial Key Laboratory of Photonic and Electronic Materials Sciences and Technology, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China)

    2012-10-01

    Graphical abstract: Nano-sized marks on GST thin film were fabricated using Conductive-AFM (Atomic Force Microscope). The AFM morphology images show that the marks are ablated at the center and a raised ring surrounding it. Highlights: Black-Right-Pointing-Pointer Microstructure of GeSbTe thin films was characterized by XRD and AFM. Black-Right-Pointing-Pointer Annealing and applying electrical field can induce crystallization on thin film. Black-Right-Pointing-Pointer Conductive-AFM was used to modify the surface of GeSbTe thin film. - Abstract: GeSbTe (GST) thin films were deposited on quartz substrates using electron beam evaporation system and then annealed in nitrogen atmosphere at different temperatures, ranging from 20 Degree-Sign C to 300 Degree-Sign C. X-ray diffraction (XRD) and Atomic Force microscope (AFM) measurements were used to characterize the as-deposited and post-annealed thin films. Annealing treatment was found to induce changes on microstructure, surface roughness and grain size, indicating that with the increase of annealing temperature, the amorphous GST films first changed to face-centered-cubic (fcc) phase and then the stable hexagonal (hex) phase. Meanwhile, conductive-AFM (C-AFM) was used to produce crystallized GST dots on thin films. I-V spectroscopy results show that GST films can switch from amorphous state to crystalline state at threshold voltage. After switching, I-V curve exhibits ohmic characteristic, which is usually observed in crystallized GST films. By applying repeated I-V spectroscopies on the thin films, crystallized nuclei were observed. As the times of I-V spectroscopies increases, the area of written dots increases, and the center of the mark begin to ablate. The AFM images show that the shape of marks is an ablated center with a raised ring surrounding it.

  2. Flexible Mixed-Potential-Type (MPT NO2 Sensor Based on An Ultra-Thin Ceramic Film

    Directory of Open Access Journals (Sweden)

    Rui You

    2017-07-01

    Full Text Available A novel flexible mixed-potential-type (MPT sensor was designed and fabricated for NO2 detection from 0 to 500 ppm at 200 °C. An ultra-thin Y2O3-doped ZrO2 (YSZ ceramic film 20 µm thick was sandwiched between a heating electrode and reference/sensing electrodes. The heating electrode was fabricated by a conventional lift-off process, while the porous reference and the sensing electrodes were fabricated by a two-step patterning method using shadow masks. The sensor’s sensitivity is achieved as 58.4 mV/decade at the working temperature of 200 °C, as well as a detection limit of 26.7 ppm and small response time of less than 10 s at 200 ppm. Additionally, the flexible MPT sensor demonstrates superior mechanical stability after bending over 50 times due to the mechanical stability of the YSZ ceramic film. This simply structured, but highly reliable flexible MPT NO2 sensor may lead to wide application in the automobile industry for vehicle emission systems to reduce NO2 emissions and improve fuel efficiency.

  3. Acceptor-modulated optical enhancements and band-gap narrowing in ZnO thin films

    Science.gov (United States)

    Hassan, Ali; Jin, Yuhua; Irfan, Muhammad; Jiang, Yijian

    2018-03-01

    Fermi-Dirac distribution for doped semiconductors and Burstein-Moss effect have been correlated first time to figure out the conductivity type of ZnO. Hall Effect in the Van der Pauw configuration has been applied to reconcile our theoretical estimations which evince our assumption. Band-gap narrowing has been found in all p-type samples, whereas blue Burstein-Moss shift has been recorded in the n-type films. Atomic Force Microscopic (AFM) analysis shows that both p-type and n-type films have almost same granular-like structure with minor change in average grain size (˜ 6 nm to 10 nm) and surface roughness rms value 3 nm for thickness ˜315 nm which points that grain size and surface roughness did not play any significant role in order to modulate the conductivity type of ZnO. X-ray diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDS) and X-ray Photoelectron Spectroscopy (XPS) have been employed to perform the structural, chemical and elemental analysis. Hexagonal wurtzite structure has been observed in all samples. The introduction of nitrogen reduces the crystallinity of host lattice. 97% transmittance in the visible range with 1.4 × 107 Ω-1cm-1 optical conductivity have been detected. High absorption value in the ultra-violet (UV) region reveals that NZOs thin films can be used to fabricate next-generation high-performance UV detectors.

  4. Acceptor-modulated optical enhancements and band-gap narrowing in ZnO thin films

    Directory of Open Access Journals (Sweden)

    Ali Hassan

    2018-03-01

    Full Text Available Fermi-Dirac distribution for doped semiconductors and Burstein-Moss effect have been correlated first time to figure out the conductivity type of ZnO. Hall Effect in the Van der Pauw configuration has been applied to reconcile our theoretical estimations which evince our assumption. Band-gap narrowing has been found in all p-type samples, whereas blue Burstein-Moss shift has been recorded in the n-type films. Atomic Force Microscopic (AFM analysis shows that both p-type and n-type films have almost same granular-like structure with minor change in average grain size (∼ 6 nm to 10 nm and surface roughness rms value 3 nm for thickness ∼315 nm which points that grain size and surface roughness did not play any significant role in order to modulate the conductivity type of ZnO. X-ray diffraction (XRD, Energy Dispersive X-ray Spectroscopy (EDS and X-ray Photoelectron Spectroscopy (XPS have been employed to perform the structural, chemical and elemental analysis. Hexagonal wurtzite structure has been observed in all samples. The introduction of nitrogen reduces the crystallinity of host lattice. 97% transmittance in the visible range with 1.4 × 107 Ω-1cm-1 optical conductivity have been detected. High absorption value in the ultra-violet (UV region reveals that NZOs thin films can be used to fabricate next-generation high-performance UV detectors.

  5. Electrodeposited Ni-W magnetic thin films with columnar nanocrystallites

    International Nuclear Information System (INIS)

    Sulitanu, N.; Brinza, F.

    2002-01-01

    Nanocrystalline Ni-W thin films (140 nm) containing from zero to 18 wt % W were electrolytically prepared and structural and magnetic characterized. XRD, SEM and TEM investigations have revealed that all segregated Ni columns are fcc-type whose [111] axis is oriented perpendicular to the film plane and have 140 nm in height and 6-27 nm in diameter. Depending on film composition, two types of nanostructures were observed: (a) single-phase nanostructure ( i nterphases , namely W enriched particles boundaries, and (b) two-phase nanostructure (7-18 wt %) in which a second Ni-W amorphous phase or even amorphous-disordered mixture separates the magnetic columnar Ni nanocrystallites (d = 6-14 nm). The columnar crystallites have an easy magnetization direction along their long axis mainly due to the in-plane internal biaxial stresses. Magnetic characteristics of prepared thin films are presented. (Authors)

  6. Comparison between bulk and thin foil ion irradiation of ultra high purity Fe

    Energy Technology Data Exchange (ETDEWEB)

    Prokhodtseva, A., E-mail: anna.prokhodtseva@psi.ch [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confédération Suisse, 5232 Villigen PSI (Switzerland); Décamps, B. [Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), CNRS-IN2P3-Univ. Paris-Sud 11, UMR 8609, Bât. 108, 91405 Orsay (France); Schäublin, R. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confédération Suisse, 5232 Villigen PSI (Switzerland)

    2013-11-15

    Accumulation of radiation damage in ultra high purity iron under self ion irradiation without and with simultaneous He implantation was investigated in bulk and thin foil form to assess, on the one hand, the effect of free surfaces and, on the other hand, the influence of He. Specimens were irradiated at room temperature to a dose of 0.8 dpa and ∼900 appm He content. We found in thin foils after irradiation with single beam a majority of a{sub 0} 〈1 0 0〉 type loops, while in the presence of He it is the ½ a{sub 0} 〈1 1 1〉 type loops that prevail. In single beam irradiated bulk samples most of the loops are of ½ a{sub 0} 〈1 1 1〉 type. In both bulk and thin foils density of defects visible in transmission electron microscope is considerably higher when He is implanted with prevailing ½ a{sub 0} 〈1 1 1〉 dislocation loops, indicating that He stabilizes them.

  7. Stable Dyonic Thin-Shell Wormholes in Low-Energy String Theory

    Directory of Open Access Journals (Sweden)

    Ali Övgün

    2017-01-01

    Full Text Available Considerable attention has been devoted to the wormhole physics in the past 30 years by exploring the possibilities of finding traversable wormholes without the need for exotic matter. In particular, the thin-shell wormhole formalism has been widely investigated by exploiting the cut-and-paste technique to merge two space-time regions and to research the stability of these wormholes developed by Visser. This method helps us to minimize the amount of the exotic matter. In this paper, we construct a four-dimensional, spherically symmetric, dyonic thin-shell wormhole with electric charge Q, magnetic charge P, and dilaton charge Σ, in the context of Einstein-Maxwell-dilaton theory. We have applied Darmois-Israel formalism and the cut-and-paste method by joining together two identical space-time solutions. We carry out the dyonic thin-shell wormhole stability analyses by using a linear barotropic gas, Chaplygin gas, and logarithmic gas for the exotic matter. It is shown that, by choosing suitable parameter values as well as equation of state parameter, under specific conditions, we obtain a stable dyonic thin-shell wormhole solution. Finally, we argue that the stability domain of the dyonic thin-shell wormhole can be increased in terms of electric charge, magnetic charge, and dilaton charge.

  8. Nanostructured tungsten trioxide thin films synthesized for photoelectrocatalytic water oxidation: a review.

    Science.gov (United States)

    Zhu, Tao; Chong, Meng Nan; Chan, Eng Seng

    2014-11-01

    The recent developments of nanostructured WO3 thin films synthesized through the electrochemical route of electrochemical anodization and cathodic electrodeposition for the application in photoelectrochemical (PEC) water splitting are reviewed. The key fundamental reaction mechanisms of electrochemical anodization and cathodic electrodeposition methods for synthesizing nanostructured WO3 thin films are explained. In addition, the effects of metal oxide precursors, electrode substrates, applied potentials and current densities, and annealing temperatures on size, composition, and thickness of the electrochemically synthesized nanostructured WO3 thin films are elucidated in detail. Finally, a summary is given for the general evaluation practices used to calculate the energy conversion efficiency of nanostructured WO3 thin films and a recommendation is provided to standardize the presentation of research results in the field to allow for easy comparison of reported PEC efficiencies in the near future. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Quantum effects on propagation of bulk and surface waves in a thin quantum plasma film

    International Nuclear Information System (INIS)

    Moradi, Afshin

    2015-01-01

    The propagation of bulk and surface plasma waves in a thin quantum plasma film is investigated, taking into account the quantum effects. The generalized bulk and surface plasma dispersion relation due to quantum effects is derived, using the quantum hydrodynamic dielectric function and applying appropriate additional boundary conditions. The quantum mechanical and film geometric effects on the bulk and surface modes are discussed. It is found that quantum effects become important for a thin film of small thickness. - Highlights: • New bulk and surface plasma dispersion relations due to quantum effects are derived, in a thin quantum plasma film. • It is found that quantum effects become important for a thin quantum film of small thickness

  10. Combustion synthesized indium-tin-oxide (ITO) thin film for source/drain electrodes in all solution-processed oxide thin-film transistors

    International Nuclear Information System (INIS)

    Tue, Phan Trong; Inoue, Satoshi; Takamura, Yuzuru; Shimoda, Tatsuya

    2016-01-01

    We report combustion solution synthesized (SCS) indium-tin-oxide (ITO) thin film, which is a well-known transparent conductive oxide, for source/drain (S/D) electrodes in solution-processed amorphous zirconium-indium-zinc-oxide TFT. A redox-based combustion synthetic approach is applied to ITO thin film using acetylacetone as a fuel and metal nitrate as oxidizer. The structural and electrical properties of SCS-ITO precursor solution and thin films were systematically investigated with changes in tin concentration, indium metal precursors, and annealing conditions such as temperature, time, and ambient. It was found that at optimal conditions the SCS-ITO thin film exhibited high crystalline quality, atomically smooth surface (RMS ∝ 4.1 Aa), and low electrical resistivity (4.2 x 10 -4 Ω cm). The TFT using SCS-ITO film as the S/D electrodes showed excellent electrical properties with negligible hysteresis. The obtained ''on/off'' current ratio, subthreshold swing factor, subthreshold voltage, and field-effect mobility were 5 x 10 7 , 0.43 V/decade, 0.7 V, and 2.1 cm 2 /V s, respectively. The performance and stability of the SCS-ITO TFT are comparable to those of the sputtered-ITO TFT, emphasizing that the SCS-ITO film is a promising candidate for totally solution-processed oxide TFTs. (orig.)

  11. Demand-type gas supply system for rocket borne thin-window proportional counters

    Science.gov (United States)

    Acton, L. W.; Caravalho, R.; Catura, R. C.; Joki, E. G.

    1977-01-01

    A simple closed loop control system has been developed to maintain the gas pressure in thin-window proportional counters during rocket flights. This system permits convenient external control of detector pressure and system flushing rate. The control system is activated at launch with the sealing of a reference volume at the existing system pressure. Inflight control to plus or minus 2 torr at a working pressure of 760 torr has been achieved on six rocket flights.

  12. Effects of thin heavily Mg-doped GaN capping layer on ohmic contact formation of p-type GaN

    International Nuclear Information System (INIS)

    Wu, L L; Zhao, D G; Jiang, D S; Chen, P; Le, L C; Li, L; Liu, Z S; Zhang, S M; Zhu, J J; Wang, H; Zhang, B S; Yang, H

    2013-01-01

    The growth condition of thin heavily Mg-doped GaN capping layer and its effect on ohmic contact formation of p-type GaN were investigated. It is confirmed that the excessive Mg doping can effectively enhance the Ni/Au contact to p-GaN after annealing at 550 °C. When the flow rate ratio between Mg and Ga gas sources is 6.4% and the layer width is 25 nm, the capping layer grown at 850 °C exhibits the best ohmic contact properties with respect to the specific contact resistivity (ρ c ). This temperature is much lower than the conventional growth temperature of Mg-doped GaN, suggesting that the deep-level-defect induced band may play an important role in the conduction of capping layer. (paper)

  13. Pipe Wall Thinning Evaluation through the Arrival Time Delay of A0 Lamb Wave Using Magnetostrictive Patch Transducers

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Seung Hyun; Kwon, Hyu Sang; Ahn, Bong Young; Lee, Seung Seok [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2008-12-15

    Guided wave technology is advantageous for fast inspection of pipe wall thinning since the guided wave propagates long distance. In this investigation, the method to evaluate gradual wall thinning in a pipe based on the arrival time delay with magnetostrictive patch transducers is presented. Low frequency A0 Lamb waves were generated and measured by the present transducer and it was applied to arrival time delay measurement experiments on a test pipe having gradual wall thinnings artificially manufactured. From experiments, consistent results that wall thinning increases the arrival time delay of A0 waves were obtained. Consequently, the feasibility of the magnetostrictive patch transducers to evaluate wall thinning was verified

  14. Pipe Wall Thinning Evaluation through the Arrival Time Delay of A0 Lamb Wave Using Magnetostrictive Patch Transducers

    International Nuclear Information System (INIS)

    Cho, Seung Hyun; Kwon, Hyu Sang; Ahn, Bong Young; Lee, Seung Seok

    2008-01-01

    Guided wave technology is advantageous for fast inspection of pipe wall thinning since the guided wave propagates long distance. In this investigation, the method to evaluate gradual wall thinning in a pipe based on the arrival time delay with magnetostrictive patch transducers is presented. Low frequency A0 Lamb waves were generated and measured by the present transducer and it was applied to arrival time delay measurement experiments on a test pipe having gradual wall thinnings artificially manufactured. From experiments, consistent results that wall thinning increases the arrival time delay of A0 waves were obtained. Consequently, the feasibility of the magnetostrictive patch transducers to evaluate wall thinning was verified

  15. Fire performance of basalt FRP mesh reinforced HPC thin plates

    DEFF Research Database (Denmark)

    Hulin, Thomas; Hodicky, Kamil; Schmidt, Jacob Wittrup

    2013-01-01

    An experimental program was carried out to investigate the influence of basalt FRP (BFRP) reinforcing mesh on the fire behaviour of thin high performance concrete (HPC) plates applied to sandwich elements. Samples with BFRP mesh were compared to samples with no mesh, samples with steel mesh...

  16. Laser nanostructuring of ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Nedyalkov, N., E-mail: nned@ie.bas.bg [Department of Electronics and Electrical Engineering, Keio University, 3-14-1 Hiyoshi Kohoku-ku, Yokohama-shi, Kanagawa-ken 223-8522 (Japan); Institute of Electronics, Bulgarian Academy of Sciences, Tzarigradsko shousse 72, Sofia 1784 (Bulgaria); Koleva, M.; Nikov, R.; Atanasov, P. [Institute of Electronics, Bulgarian Academy of Sciences, Tzarigradsko shousse 72, Sofia 1784 (Bulgaria); Nakajima, Y.; Takami, A.; Shibata, A.; Terakawa, M. [Department of Electronics and Electrical Engineering, Keio University, 3-14-1 Hiyoshi Kohoku-ku, Yokohama-shi, Kanagawa-ken 223-8522 (Japan)

    2016-06-30

    Highlights: • Nanosecond laser pulse nanostructuring of ZnO thin films on metal substrate is demonstrated. • Two regimes of the thin film modification are observed depending on the applied laser fluence. • At high fluence regime the ZnO film is homogeneously decomposed into nanosized particles. • The characteristic size of the formed nanostructures corresponds to the domain size of the thin film. - Abstract: In this work, results on laser processing of thin zinc oxide films deposited on metal substrate are presented. ZnO films are obtained by classical nanosecond pulsed laser deposition method in oxygen atmosphere on tantalum substrate. The produced films are then processed by nanosecond laser pulses at wavelength of 355 nm. The laser processing parameters and the film thickness are varied and their influence on the fabricated structures is estimated. The film morphology after the laser treatment is found to depend strongly on the laser fluence as two regimes are defined. It is shown that at certain conditions (high fluence regime) the laser treatment of the film leads to formation of a discrete nanostructure, composed of spherical like nanoparticles with narrow size distribution. The dynamics of the melt film on the substrate and fast cooling are found to be the main mechanisms for fabrication of the observed structures. The demonstrated method is an alternative way for direct fabrication of ZnO nanostructures on metal which can be easy implemented in applications as resistive sensor devices, electroluminescent elements, solar cell technology.

  17. Applied model of through-wall crack of coolant vessels of WWER-type reactors

    International Nuclear Information System (INIS)

    Petrosyan, V.; Hovakimyan, T.; Vardanyan, M.; Khachatryan, A.; Minasyan, K.

    2010-01-01

    We propose an applied-model of Through-Wall Crack (TWC) for WWER-type units primary vessels. The model allows to simulate the main morphological parameters of real TWC, i.e. length, area of inlet and outlet openings, channel depth and small and large size unevenness of the crack surface. The model can be used for developing and improving the coolant-leak detectors for the primary circuit vessels of WWER-units. Also, it can be used for research of the coolant two-phase leakage phenomenon through narrow cracks/channels and thermo-physical processes in heat-insulation layer of the Main Coolant Piping (MCP) during the leak

  18. Photoluminescence properties of perovskite multilayer thin films

    Energy Technology Data Exchange (ETDEWEB)

    Macario, Leilane Roberta; Longo, Elson, E-mail: leilanemacario@gmail.com [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil); Mazzo, Tatiana Martelli [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil); Bouquet, Valerie; Deputier, Stephanie; Ollivier, Sophie; Guilloux-Viry, Maryline [Universite de Rennes (France)

    2016-07-01

    Full text: The knowledge of the optical properties of thin films is important in many scientific, technological and industrial applications of thin films such as photoconductivity, solar energy, photography, and numerous other applications [1]. In this study, perovskite type oxides were grown by pulsed laser deposition [2] in order to obtain thin films with applicable optical properties. The LaNiO{sub 3} (LN), BaTiO{sub 3} (BT) and KNbO{sub 3} (KNb) targets were prepared by solid-state reaction. The X-ray Diffraction revealed the presence of the desired phases, containing the elements of interest in the targets and in the thin films that were produced. The LN, BT and KNb thin films were polycrystalline and the corresponding diffraction peaks were indexed in the with JCPDS cards n. 00-033-0711, n. 00-005-0626, and n. 00-009-0156, respectively. The multilayers films were polycrystalline. The majority of the micrographs obtained by scanning electron microscopy presented films with a thickness from 100 to 400 nm. The photoluminescent (PL) emission spectra of thin films show different broad bands that occupies large region of the visible spectrum, ranging from about 300-350 to 600-650 nm of the electromagnetic spectrum. The PL emission is associated with the order-disorder structural, even small structural changes can modify the interactions between electronic states. The structural disorder results in formation of new energy levels in the forbidden region. The proximity or distance of these new energy levels formed in relation to valence band and to the conduction band results in PL spectra located at higher or lower energies. These interactions change the electronic states which can be influenced by defects, particularly the interface defects between the layers of the thin films. The presence of defects results in changes in the broad band matrix intensity and in displacement of the PL emission maximum. (author)

  19. Atomic Structure Control of Silica Thin Films on Pt(111)

    KAUST Repository

    Crampton, Andrew S

    2015-05-27

    Metal oxide thin films grown on metal single crystals are commonly used to model heterogeneous catalyst supports. The structure and properties of thin silicon dioxide films grown on metal single crystals have only recently been thoroughly characterized and their spectral properties well established. We report the successful growth of a three- dimensional, vitreous silicon dioxide thin film on the Pt(111) surface and reproduce the closed bilayer structure previously reported. The confirmation of the three dimensional nature of the film is unequivocally shown by the infrared absorption band at 1252 cm−1. Temperature programmed desorption was used to show that this three-dimensional thin film covers the Pt(111) surface to such an extent that its application as a catalyst support for clusters/nanoparticles is possible. The growth of a three-dimensional film was seen to be directly correlated with the amount of oxygen present on the surface after the silicon evaporation process. This excess of oxygen is tentatively attributed to atomic oxygen being generated in the evaporator. The identification of atomic oxygen as a necessary building block for the formation of a three-dimensional thin film opens up new possibilities for thin film growth on metal supports, whereby simply changing the type of oxygen enables thin films with different atomic structures to be synthesized. This is a novel approach to tune the synthesis parameters of thin films to grow a specific structure and expands the options for modeling common amorphous silica supports under ultra high vacuum conditions.

  20. Properties of Ferrite Garnet (Bi, Lu, Y3(Fe, Ga5O12 Thin Film Materials Prepared by RF Magnetron Sputtering

    Directory of Open Access Journals (Sweden)

    Mohammad Nur-E-Alam

    2018-05-01

    Full Text Available This work is devoted to physical vapor deposition synthesis, and characterisation of bismuth and lutetium-substituted ferrite-garnet thin-film materials for magneto-optic (MO applications. The properties of garnet thin films sputtered using a target of nominal composition type Bi0.9Lu1.85Y0.25Fe4.0Ga1O12 are studied. By measuring the optical transmission spectra at room temperature, the optical constants and the accurate film thicknesses can be evaluated using Swanepoel’s envelope method. The refractive index data are found to be matching very closely to these derived from Cauchy’s dispersion formula for the entire spectral range between 300 and 2500 nm. The optical absorption coefficient and the extinction coefficient data are studied for both the as-deposited and annealed garnet thin-film samples. A new approach is applied to accurately derive the optical constants data simultaneously with the physical layer thickness, using a combination approach employing custom-built spectrum-fitting software in conjunction with Swanepoel’s envelope method. MO properties, such as specific Faraday rotation, MO figure of merit and MO swing factor are also investigated for several annealed garnet-phase films.

  1. Swift heavy ion induced modifications in optical and electrical properties of cadmium selenide thin films

    Science.gov (United States)

    Choudhary, Ritika; Chauhan, Rishi Pal

    2017-07-01

    The modification in various properties of thin films using high energetic ion beam is an exciting area of basic and applied research in semiconductors. In the present investigations, cadmium selenide (CdSe) thin films were deposited on ITO substrate using electrodeposition technique. To study the swift heavy ion (SHI) induced effects, the deposited thin films were irradiated with 120 MeV heavy Ag9+ ions using pelletron accelerator facility at IUAC, New Delhi, India. Structural phase transformation in CdSe thin film from metastable cubic phase to stable hexagonal phase was observed after irradiation leading to decrease in the band gap from 2.47 eV to 2.12 eV. The phase transformation was analyzed through X-ray diffraction patterns. During SHI irradiation, Generation of high temperature and pressure by thermal spike along the trajectory of incident ions in the thin films might be responsible for modification in the properties of thin films.[Figure not available: see fulltext.

  2. Thin film photovoltaic panel and method

    Science.gov (United States)

    Ackerman, Bruce; Albright, Scot P.; Jordan, John F.

    1991-06-11

    A thin film photovoltaic panel includes a backcap for protecting the active components of the photovoltaic cells from adverse environmental elements. A spacing between the backcap and a top electrode layer is preferably filled with a desiccant to further reduce water vapor contamination of the environment surrounding the photovoltaic cells. The contamination of the spacing between the backcap and the cells may be further reduced by passing a selected gas through the spacing subsequent to sealing the backcap to the base of the photovoltaic panels, and once purged this spacing may be filled with an inert gas. The techniques of the present invention are preferably applied to thin film photovoltaic panels each formed from a plurality of photovoltaic cells arranged on a vitreous substrate. The stability of photovoltaic conversion efficiency remains relatively high during the life of the photovoltaic panel, and the cost of manufacturing highly efficient panels with such improved stability is significantly reduced.

  3. Preparation of electrochromic thin films by transformation of manganese(II) carbonate

    Science.gov (United States)

    Stojkovikj, Sasho; Najdoski, Metodija; Koleva, Violeta; Demiri, Sani

    2013-10-01

    A new chemical bath method for deposition of manganese(II) carbonate thin film on electroconductive FTO glass substrates is designed. The homogeneous thin films with thickness in the range of 70 to 500 nm are deposited at about 98 °C from aqueous solution containing urea and MnCl2. The chemical process is based on a low temperature hydrolysis of the manganese complexes with urea. Three types of films are under consideration: as-deposited, annealed and electrochemically transformed thin films. The structure of the films is studied by XRD, IR and Raman spectroscopy. Electrochemical and optical properties are examined in eight different electrolytes (neutral and alkaline) and the best results are achieved in two component aqueous solution of 0.1 M KNO3 and 0.01 M KOH. It is established that the as-deposited MnCO3 film undergoes electrochemically transformation into birnessite-type manganese(IV) oxide films, which exhibit electrochromic color changes (from bright brown to pale yellow and vice versa) with 30% difference in the transmittance of the colored and bleached state at 400 nm.

  4. Investigation of AgInS2 thin films grown by coevaporation

    Science.gov (United States)

    Arredondo, C. A.; Clavijo, J.; Gordillo, G.

    2009-05-01

    AgInS2 thin films were grown on soda-lime glass substrates by co-evaporation of the precursors in a two-step process. X-ray diffraction (XRD) measurements indicated that these compounds grow in different phases and with different crystalline structure depending upon the deposition conditions. However, through a parameter study, conditions were found to grow thin films containing only the AgInS2 phase with chalcopyrite type structure. In samples containing a mixture of several phases, the contribution in percentage terms of each phase to the whole compound was estimated with the help of the PowderCell simulation package. It was also found that the AgInS2 films present p-type conductivity, a high absorption coefficient (greater than 104 cm-1) and an energy band gap Eg of about 1.95 eV, indicating that this compound has good properties to perform as absorbent layer in thin film tandem solar cells. The effect of the deposition conditions on the optical and morphological properties was also investigated through spectral transmitance and atomic force microscopy (AFM) measurements.

  5. Development of NDT simulator with method of mapping for detection of pipe wall thinning using EMAT

    International Nuclear Information System (INIS)

    Yamaguchi, Hiroshi; Kojima, Fumio; Kosaka, Daigo

    2009-01-01

    This paper is concerned with a simulator related to nondestructive test using Electromagnetic Acoustic Transducer (EMAT). The simulator developed here can be applied to pipe wall thinning of stainless steel used in nuclear power plants. First, mathematical models for the inspection are given by a transient eddy current equation and by a time dependent elastic wave equation in two dimensions. Secondly, shape of pipe wall thinning is modeled by B-spline function and is applied to the mathematical models using method of mapping. Finally, the validity of the proposed simulator is shown through numerical experiment. (author)

  6. Topotactic synthesis of strontium cobalt oxyhydride thin film with perovskite structure

    OpenAIRE

    Tsukasa Katayama; Akira Chikamatsu; Hideyuki Kamisaka; Yuichi Yokoyama; Yasuyuki Hirata; Hiroki Wadati; Tomoteru Fukumura; Tetsuya Hasegawa

    2015-01-01

    The substitution of hydride anions (H−) into transition metal oxides has recently become possible through topotactic reactions or high-pressure synthesis methods. However, the fabrication of oxyhydrides is still difficult because of their inherently less-stable frameworks. In this study, we successfully fabricated perovskite SrCoOxHy thin films via the topotactic hydride doping of brownmillerite SrCoO2.5 epitaxial thin films with CaH2. The perovskite-type cation framework was maintained durin...

  7. Compressing and focusing a short laser pulse by a thin plasma lens

    International Nuclear Information System (INIS)

    Ren, C.; Duda, B. J.; Hemker, R. G.; Mori, W. B.; Katsouleas, T.; Antonsen, T. M.; Mora, P.

    2001-01-01

    We consider the possibility of using a thin plasma slab as an optical element to both focus and compress an intense laser pulse. By thin we mean that the focal length is larger than the lens thickness. We derive analytic formulas for the spot size and pulse length evolution of a short laser pulse propagating through a thin uniform plasma lens. The formulas are compared to simulation results from two types of particle-in-cell code. The simulations give a greater final spot size and a shorter focal length than the analytic formulas. The difference arises from spherical aberrations in the lens which lead to the generation of higher-order vacuum Gaussian modes. The simulations also show that Raman side scattering can develop. A thin lens experiment could provide unequivocal evidence of relativistic self-focusing

  8. Thin-slice high-resolution CT study of pulmonary asbestosis and idiopathic interstitial pneumonia

    International Nuclear Information System (INIS)

    Hatakeyama, Masayuki; Maeda, Munehiro; Ohmura, Takuya

    1987-01-01

    Thin-slice high-resolution CT findings were compared between 36 patients with pulmonary asbestos exposure (AS) and 33 patients with idiopathic interstitial pneumonia (IIP). The CT scans of these patients were classified into 5 types (0-IV) by the subpleural curvilinear shadow (SCLS) and honey-comb shadow (HS). SCLS was detected in 22 (62 %) patients with AS and 7 (21 %) with IIP. HS was detected in 14 (39 %) patients with AS and 33 (100 %) with IIP. In both the diseases, SCLS was distributed mainly in the lower lobe in CT types I and II, and in mildly fibrotic segments in types III and IV. In CT types II, III and IV, SCLS was always communicated with HS. Thin-slice high-resolution CT is considered very helpful in diagnosis and staging of not only AS and IIP but also pulmonary fibrosis. (author)

  9. High-coercivity FePt nanoparticle assemblies embedded in silica thin films

    International Nuclear Information System (INIS)

    Yan, Q; Purkayastha, A; Singh, A P; Li, H; Ramanath, G; Li, A; Ramanujan, R V

    2009-01-01

    The ability to process assemblies using thin film techniques in a scalable fashion would be a key to transmuting the assemblies into manufacturable devices. Here, we embed FePt nanoparticle assemblies into a silica thin film by sol-gel processing. Annealing the thin film composite at 650 deg. C transforms the chemically disordered fcc FePt phase into the fct phase, yielding magnetic coercivity values H c >630 mT. The positional order of the particles is retained due to the protection offered by the silica host. Such films with assemblies of high-coercivity magnetic particles are attractive for realizing new types of ultra-high-density data storage devices and magneto-composites.

  10. Alkylated indacenodithieno[3,2-b]thiophene-based all donor ladder-type conjugated polymers for organic thin film transistors

    KAUST Repository

    Lu, Rimei

    2018-01-29

    We report the synthesis of a series of indacenodithieno[3,2-b]thiophene (IDTT) based conjugated polymers by copolymerization with three different electron rich co-monomers [thiophene (T), thieno[3,2-b]thiophene (TT) and dithieno[3,2-b:2\\',3\\'-d]thiophene (DTT)] under Stille coupling conditions. The resulting all-donor polymers show very good solubility in common solvents and exhibit similar optical, thermal and electronic properties. However, the performance of these semiconductors in thin film transistor devices varied and was highly dependent on the nature of the co-monomer. All polymers exhibited unipolar p-type charge transport behaviour, with the mobility values following the trend of IDTT-TT>IDTT-DTT>IDTT-T. The peak saturation mobility value of IDTT-TT was extracted to be 1.1 cm2V-1s-1, amongst the highest mobility for all-donor conjugated polymers reported to date.

  11. Fruit self-thinning: a trait to consider for genetic improvement of apple tree.

    Science.gov (United States)

    Celton, Jean-Marc; Kelner, Jean-Jacques; Martinez, Sébastien; Bechti, Abdel; Khelifi Touhami, Amina; James, Marie José; Durel, Charles-Eric; Laurens, François; Costes, Evelyne

    2014-01-01

    In apple (Malus×domestica Borkh), as in many fruiting crops, fruit maintenance vs abscission is a major criteria for production profitability. Growers routinely make use of chemical thinning agents to control total fruit load. However, serious threats for the environment lead to the demand for new apple cultivars with self-thinning properties. In this project, we studied the genetic determinism of this trait using a F1 progeny derived from the cross between the hybrid INRA X3263, assumed to possess the self-thinning trait, and the cultivar 'Belrène'. Both counting and percentage variables were considered to capture the fruiting behaviour on different shoot types and over three consecutive years. Besides low to moderate but significant genetic effects, mixed models showed considerable effects of the year and the shoot type, as well as an interaction effect. Year effect resulted mainly from biennial fruiting. Eight Quantitative Trait Locus (QTL) were detected on several linkage groups (LG), either independent or specific of the year of observation or the shoot type. The QTL with highest LOD value was located on the top third of LG10. The screening of three QTL zones for candidate genes revealed a list of transcription factors and genes involved in fruit nutrition, xylem differentiation, plant responses to starvation and organ abscission that open new avenues for further molecular investigations. The detailed phenotyping performed revealed the dependency between the self-thinning trait and the fruiting status of the trees. Despite a moderate genetic control of the self-thinning trait, QTL and candidate genes were identified which will need further analyses involving other progenies and molecular investigations.

  12. On the evaluation of micromatter thin standards by RBS

    International Nuclear Information System (INIS)

    Ionescu, M.; Stelcer, E.; Hawas, O.; Siegele, R.; Cohen, D.; Linch, D.; Sarbutt, A.; Garton, D.

    2005-01-01

    Thin film standards are routinely used in PIXE and PIGE techniques for elemental analysis of particulates present in air samples, collected on Teflon filters. A number of parameters such as thickness, homogeneity and the type and amount of impurities present in the standards are crucial in order to perform high accuracy measurements. In this paper we report the use of RBS on the new STAR 2MV accelerator for characterisation of thin film standards obtained commercially. All standards were produced by MicroMatter Co. on polymer substrates, using a room temperature evaporation method. (author). 4 refs., 5 figs., 1 tab

  13. Strategies towards controlling strain-induced mesoscopic phase separation in manganite thin films

    Science.gov (United States)

    Habermeier, H.-U.

    2008-10-01

    Complex oxides represent a class of materials with a plethora of fascinating intrinsic physical functionalities. The intriguing interplay of charge, spin and orbital ordering in these systems superimposed by lattice effects opens a scientifically rewarding playground for both fundamental as well as application oriented research. The existence of nanoscale electronic phase separation in correlated complex oxides is one of the areas in this field whose impact on the current understanding of their physics and potential applications is not yet clear. In this paper this issue is treated from the point of view of complex oxide thin film technology. Commenting on aspects of complex oxide thin film growth gives an insight into the complexity of a reliable thin film technology for these materials. Exploring fundamentals of interfacial strain generation and strain accommodation paves the way to intentionally manipulate thin film properties. Furthermore, examples are given for an extrinsic continuous tuning of intrinsic electronic inhomogeneities in perovskite-type complex oxide thin films.

  14. Strategies towards controlling strain-induced mesoscopic phase separation in manganite thin films

    International Nuclear Information System (INIS)

    Habermeier, H-U

    2008-01-01

    Complex oxides represent a class of materials with a plethora of fascinating intrinsic physical functionalities. The intriguing interplay of charge, spin and orbital ordering in these systems superimposed by lattice effects opens a scientifically rewarding playground for both fundamental as well as application oriented research. The existence of nanoscale electronic phase separation in correlated complex oxides is one of the areas in this field whose impact on the current understanding of their physics and potential applications is not yet clear. In this paper this issue is treated from the point of view of complex oxide thin film technology. Commenting on aspects of complex oxide thin film growth gives an insight into the complexity of a reliable thin film technology for these materials. Exploring fundamentals of interfacial strain generation and strain accommodation paves the way to intentionally manipulate thin film properties. Furthermore, examples are given for an extrinsic continuous tuning of intrinsic electronic inhomogeneities in perovskite-type complex oxide thin films.

  15. ZnO-Based Transparent Conductive Thin Films: Doping, Performance, and Processing

    International Nuclear Information System (INIS)

    Liu, Y.; Li, Y.; Zeng, H.

    2013-01-01

    ZnO-based transparent conductive thin films have attracted much attention as a promising substitute material to the currently used indium-tin-oxide thin films in transparent electrode applications. However, the detailed function of the dopants, acting on the electrical and optical properties of ZnO-based transparent conductive thin films, is not clear yet, which has limited the development and practical applications of ZnO transparent conductive thin films. Growth conditions such as substrate type, growth temperature, and ambient atmosphere all play important roles in structural, electrical, and optical properties of films. This paper takes a panoramic view on properties of ZnO thin films and reviews the very recent works on new, efficient, low-temperature, and high-speed deposition technologies. In addition, we highlighted the methods of producing ZnO-based transparent conductive film on flexible substrate, one of the most promising and rapidly emerging research areas. As optimum-processing-parameter conditions are being obtained and their influencing mechanism is becoming clear, we can see that there will be a promising future for ZnO-based transparent conductive films.

  16. Voltammetric Thin-Layer Ionophore-Based Films: Part 2. Semi-Empirical Treatment.

    Science.gov (United States)

    Yuan, Dajing; Cuartero, Maria; Crespo, Gaston A; Bakker, Eric

    2017-01-03

    This work reports on a semiempirical treatment that allows one to rationalize and predict experimental conditions for thin-layer ionophore-based films with cation-exchange capacity read out with cyclic voltammetry. The transition between diffusional mass transport and thin-layer regime is described with a parameter (α), which depends on membrane composition, diffusion coefficient, scan rate, and electrode rotating speed. Once the thin-layer regime is fulfilled (α = 1), the membrane behaves in some analogy to a potentiometric sensor with a second discrimination variable (the applied potential) that allows one to operate such electrodes in a multianalyte detection mode owing to the variable applied ion-transfer potentials. The limit of detection of this regime is defined with a second parameter (β = 2) and is chosen in analogy to the definition of the detection limit for potentiometric sensors provided by the IUPAC. The analytical equations were validated through the simulation of the respective cyclic voltammograms under the same experimental conditions. While simulations of high complexity and better accuracy satisfactorily reproduced the experimental voltammograms during the forward and backward potential sweeps (companion paper 1), the semiempirical treatment here, while less accurate, is of low complexity and allows one to quite easily predict relevant experimental conditions for this emergent methodology.

  17. Frequency-domain Harman technique for rapid characterization of bulk and thin film thermoelectric materials

    Science.gov (United States)

    Moran, Samuel

    Nanostructured thermoelectrics, often in the form of thin films, may potentially improve the generally poor efficiency of bulk thermoelectric power generators and coolers. In order to characterize the efficiency of these new materials it is necessary to measure their thermoelectric figure of merit, ZT. The only direct measurement of ZT is based on the Harman technique and relies on measuring the voltage drop across a sample subjected to a passing continuous current. Application of this technique to thin films is currently carried out as a time-domain measurement of the voltage as the thermal component decays after switching off an applied voltage. This work develops a technique for direct simultaneous measurement of figure of merit and Seebeck coefficient from the harmonic response of a thermoelectric material under alternating current excitation. A thermocouple mounted on the top surface measures voltage across the device as the frequency of the applied voltage is varied. A thermal model allows the sample thermal conductivity to also be determined and shows good agreement with measurements. This technique provides improved signal-to-noise ratio and accuracy compared to time-domain ZT measurements for comparable conditions while simultaneously measuring Seebeck coefficient. The technique is applied to both bulk and thin film thermoelectric samples.

  18. In situ 2D diffraction as a tool to characterize ferroelectric and piezoelectric thin films

    Science.gov (United States)

    Khamidy, N. I.; Kovacova, V.; Bernasconi, A.; Le Rhun, G.; Vaxelaire, N.

    2017-08-01

    In this paper the application of 2D x-ray diffraction (XRD2) as a technique to characterize in situ during electrical cycling the properties of a ferroelectric and piezoelectric thin film is discussed. XRD2 is one type of XRD on which a 2D detector is used instead of a point detector. This technique enables simultaneous recording of many sample information in a much shorter time compared to conventional XRD. The discussion is focused especially on the data processing technique of the huge data acquired. The methodology to calculate an effective piezoelectric coefficient, analyze the phase and texture, and estimate the domain size and shape is described in this paper. This methodology is then applied to a lead zirconate titanate (PZT) thin film at the morphotropic phase boundary (MPB) composition (i.e. Pb[Zr0.52Ti0.48]O3) with a preferred orientation of (1 0 0). The in situ XRD2 characterization was conducted in the European synchrotron radiation facility (ESRF) in Grenoble, France. Since a high-energy beam with vertical resolution as small as 100 nm was used, a cross-sectional scan of the sample was performed over the entire thickness of the film. From these experimental results, a better understanding on the piezoelectricity phenomena in PZT thin film at MPB composition were achieved, providing original feedback between the elaboration processes and functional properties of the film.

  19. Photoelectrocatalytic Degradation of Sodium Oxalate by TiO2/Ti Thin Film Electrode

    Directory of Open Access Journals (Sweden)

    Chen-Yu Chang

    2012-01-01

    Full Text Available The photocatalytically active TiO2 thin film was deposited on the titanium substrate plate by chemical vapor deposition (CVD method, and the photoelectrocatalytic degradation of sodium oxalate was investigated by TiO2 thin film reactor prepared in this study with additional electric potential at 365 nm irradiation. The batch system was chosen in this experiment, and the controlled parameters were pH, different supporting electrolytes, applied additional potential, and different electrolyte solutions that were examined and discussed. The experimental results revealed that the additional applied potential in photocatalytic reaction could prohibit recombination of electron/hole pairs, but the photoelectrocatalytic effect was decreased when the applied electric potential was over 0.25 V. Among the electrolyte solutions added, sodium sulfate improved the photoelectrocatalytic effect most significantly. At last, the better photoelectrocatalytic degradation of sodium oxalate occurred at pH 3 when comparing the pH influence.

  20. Thin films of NdFeB deposited by PLD technique

    International Nuclear Information System (INIS)

    Constantinescu, C.; Scarisoreanu, N.; Moldovan, A.; Dinescu, M.; Petrescu, L.; Epureanu, G.

    2007-01-01

    Neodymium-iron-boron (NdFeB) is a material with important magnetic properties, mostly used in permanent magnet fabrication. Thin layers of NdFeB are needed for miniaturization in electrical engineering, electronics and for high-tech devices. In this paper we applied pulsed lased deposition (PLD) in vacuum for obtaining thin films of NdFeB from stoichiometric targets. The influence of different buffer layers and of the laser parameters (wavelength and fluence) on the NdFeB structures, composition and magnetic properties have been investigated. The obtained structures were characterized by atomic force microscopy (AFM) and optical microscopy. Vibrating sample magnetometry (VSM) has been performed for specific magnetic characterization

  1. Thin films of NdFeB deposited by PLD technique

    Energy Technology Data Exchange (ETDEWEB)

    Constantinescu, C. [National Institute for Laser, Plasma and Radiation Physics, P.O. Box MG 16, RO-077125 Magurele, Bucharest (Romania); Scarisoreanu, N. [National Institute for Laser, Plasma and Radiation Physics, P.O. Box MG 16, RO-077125 Magurele, Bucharest (Romania); Moldovan, A. [National Institute for Laser, Plasma and Radiation Physics, P.O. Box MG 16, RO-077125 Magurele, Bucharest (Romania); Dinescu, M. [National Institute for Laser, Plasma and Radiation Physics, P.O. Box MG 16, RO-077125 Magurele, Bucharest (Romania)]. E-mail: dinescum@ifin.nipne.ro; Petrescu, L. [Department of Electrical Engineering, ' Politehnica' University of Bucharest, 313 Spl. Independentei, 060042 Bucharest (Romania); Epureanu, G. [Department of Electrical Engineering, ' Politehnica' University of Bucharest, 313 Spl. Independentei, 060042 Bucharest (Romania)

    2007-07-31

    Neodymium-iron-boron (NdFeB) is a material with important magnetic properties, mostly used in permanent magnet fabrication. Thin layers of NdFeB are needed for miniaturization in electrical engineering, electronics and for high-tech devices. In this paper we applied pulsed lased deposition (PLD) in vacuum for obtaining thin films of NdFeB from stoichiometric targets. The influence of different buffer layers and of the laser parameters (wavelength and fluence) on the NdFeB structures, composition and magnetic properties have been investigated. The obtained structures were characterized by atomic force microscopy (AFM) and optical microscopy. Vibrating sample magnetometry (VSM) has been performed for specific magnetic characterization.

  2. Single-Crystal Mesoporous ZnO Thin Films Composed of Nanowalls

    KAUST Repository

    Wang, Xudong

    2009-02-05

    This paper presents a controlled, large scale fabrication of mesoporous ZnO thin films. The entire ZnO mesoporous film is one piece of a single crystal, while high porosity made of nanowalls is present. The growth mechanism was proposed in comparison with the growth of ZnO nanowires. The ZnO mesoporous film was successfully applied as a gas sensor. The fabrication and growth analysis of the mesoporous ZnO thin film gi ve general guidance for the controlled growth of nanostructures. It also pro vides a unique structure with a superhigh surface-to-volume ratio for surface-related applications. © 2009 American Chemical Society.

  3. Enhanced magnetoelectric coupling in a composite multiferroic system via interposing a thin film polymer

    Science.gov (United States)

    Xiao, Zhuyun; Mohanchandra, Kotekar P.; Lo Conte, Roberto; Ty Karaba, C.; Schneider, J. D.; Chavez, Andres; Tiwari, Sidhant; Sohn, Hyunmin; Nowakowski, Mark E.; Scholl, Andreas; Tolbert, Sarah H.; Bokor, Jeffrey; Carman, Gregory P.; Candler, Rob N.

    2018-05-01

    Enhancing the magnetoelectric coupling in a strain-mediated multiferroic composite structure plays a vital role in controlling magnetism by electric fields. An enhancement of magnetoelastic coupling between ferroelectric single crystal (011)-cut [Pb(Mg1/3Nb2/3)O3](1-x)-[PbTiO3]x (PMN-PT, x≈ 0.30) and ferromagnetic polycrystalline Ni thin film through an interposed benzocyclobutene polymer thin film is reported. A nearly twofold increase in sensitivity of remanent magnetization in the Ni thin film to an applied electric field is observed. This observation suggests a viable method of improving the magnetoelectric response in these composite multiferroic systems.

  4. Solution-processed In2S3 buffer layer for chalcopyrite thin film solar cells

    OpenAIRE

    Wang Lan; Lin Xianzhong; Ennaoui Ahmed; Wolf Christian; Lux-Steiner Martha Ch.; Klenk Reiner

    2016-01-01

    We report a route to deposit In2S3 thin films from air-stable, low-cost molecular precursor inks for Cd-free buffer layers in chalcopyrite-based thin film solar cells. Different precursor compositions and processing conditions were studied to define a reproducible and robust process. By adjusting the ink properties, this method can be applied in different printing and coating techniques. Here we report on two techniques, namely spin-coating ...

  5. Some studies on successive ionic layer adsorption and reaction (SILAR) grown indium sulphide thin films

    International Nuclear Information System (INIS)

    Pathan, H.M.; Lokhande, C.D.; Kulkarni, S.S.; Amalnerkar, D.P.; Seth, T.; Han, Sung-Hwan

    2005-01-01

    Indium sulphide (In 2 S 3 ) thin films were grown on amorphous glass substrate by the successive ionic layer adsorption and reaction (SILAR) method. X-ray diffraction, optical absorption, scanning electron microscopy (SEM) and Rutherford back scattering (RBS) were applied to study the structural, optical, surface morphological and compositional properties of the indium sulphide thin films. Utilization of triethanolamine and hydrazine hydrate complexed indium sulphate and sodium sulphide as precursors resulted in nanocrystalline In 2 S 3 thin film. The optical band gap was found to be 2.7 eV. The film appeared to be smooth and homogeneous from SEM study

  6. Lithium battery electrodes with ultra-thin alumina coatings

    Science.gov (United States)

    Se-Hee, Lee; George, Steven M.; Cavanagh, Andrew S.; Yoon Seok, Jung; Dillon, Anne C.

    2015-11-24

    Electrodes for lithium batteries are coated via an atomic layer deposition process. The coatings can be applied to the assembled electrodes, or in some cases to particles of electrode material prior to assembling the particles into an electrode. The coatings can be as thin as 2 .ANG.ngstroms thick. The coating provides for a stable electrode. Batteries containing the electrodes tend to exhibit high cycling capacities.

  7. Carbon stocks across a chronosequence of thinned and unmanaged red pine (Pinus resinosa) stands

    Science.gov (United States)

    Matthew D. Powers; Randall K. Kolka; John B. Bradford; Brian J. Palik; Shawn Fraver; Martin F. Jurgensen

    2012-01-01

    Forests function as a major global C sink, and forest management strategies that maximize C stocks offer one possible means of mitigating the impacts of increasing anthropogenic CO2 emissions. We studied the effects of thinning, a common management technique in many forest types, on age-related trends in C stocks using a chronosequence of thinned...

  8. Uniaxial anisotropy in magnetite thin film-Magnetization studies

    International Nuclear Information System (INIS)

    Wiechec, A.; Korecki, J.; Handke, B.; Kakol, Z.; Owoc, D.; Antolak, D.A.; Kozlowski, A.

    2006-01-01

    Magnetization and electrical resistivity measurements have been performed on a stoichiometric single crystalline magnetite Fe 3 O 4 thin film (thickness of ca. 500 nm) MBE deposited on MgO (1 0 0) substrate. The aim of these studies was to check the influence of preparation method and sample form (bulk vs. thin film) on magnetic anisotropy properties in magnetite. The film magnetization along versus applied magnetic field has been determined both in the direction parallel and perpendicular to the film surface, and at temperatures above and below the Verwey transition. We have found, in agreement with published results, that the in-plane field of 10 kOe was not sufficient to saturate the sample. This can be understood if some additional factor, on top of the bulk magnetocrystalline anisotropy, is taken into account

  9. Solid thin film materials for use in thin film charge-coupled devices

    International Nuclear Information System (INIS)

    Lynch, S.J.

    1983-01-01

    Solid thin films deposited by vacuum deposition were evaluated to ascertain their effectiveness for use in the manufacturing of charge-coupled devices (CCDs). Optical and electrical characteristics of tellurium and Bi 2 Te 3 solid thin films were obtained in order to design and to simulate successfully the operation of thin film (TF) CCDs. In this article some of the material differences between single-crystal material and the island-structured thin film used in TFCCDs are discussed. The electrical parameters were obtained and tabulated, e.g. the mobility, conductivity, dielectric constants, permittivity, lifetime of holes and electrons in the thin films and drift diffusion constants. The optical parameters were also measured and analyzed. After the design was complete, experimental TFCCDs were manufactured and were successfully operated utilizing the aforementioned solid thin films. (Auth.)

  10. The Rayleigh law in silicon doped hafnium oxide ferroelectric thin films

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Yan; Liu, Xiaohua [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Materials Science and Engineering, Dalian University of Technology, Dalian (China); Zhou, Dayu [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Materials Science and Engineering, Dalian University of Technology, Dalian (China); State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu (China); Xu, Jin [Department of Electronic Engineering, Dalian Neusoft University of Information, Dalian (China); Cao, Fei; Dong, Xianlin [Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai (China); Mueller, Johannes [Fraunhofer IPMS-CNT, Dresden (Germany); Schenk, Tony; Schroeder, Uwe [NaMLab gGmbH/TU Dresden (Germany)

    2015-10-15

    A wealth of studies have confirmed that the low-field hysteresis behaviour of ferroelectric bulk ceramics and thin films can be described using Rayleigh relations, and irreversible domain wall motion across the array of pining defects has been commonly accepted as the underlying micro-mechanism. Recently, HfO{sub 2} thin films incorporated with various dopants were reported to show pronounced ferroelectricity, however, their microscopic domain structure remains unclear till now. In this work, the effects of the applied electric field amplitude, frequency and temperature on the sub-coercive polarization reversal properties were investigated for 10 nm thick Si-doped HfO{sub 2} thin films. The applicability of the Rayleigh law to ultra-thin ferroelectric films was first confirmed, indicating the existence of a multi-domain structure. Since the grain size is about 20-30 nm, a direct observation of domain walls within the grains is rather challenging and this indirect method is a feasible approach to resolve the domain structure. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. The Rayleigh law in silicon doped hafnium oxide ferroelectric thin films

    International Nuclear Information System (INIS)

    Guan, Yan; Liu, Xiaohua; Zhou, Dayu; Xu, Jin; Cao, Fei; Dong, Xianlin; Mueller, Johannes; Schenk, Tony; Schroeder, Uwe

    2015-01-01

    A wealth of studies have confirmed that the low-field hysteresis behaviour of ferroelectric bulk ceramics and thin films can be described using Rayleigh relations, and irreversible domain wall motion across the array of pining defects has been commonly accepted as the underlying micro-mechanism. Recently, HfO 2 thin films incorporated with various dopants were reported to show pronounced ferroelectricity, however, their microscopic domain structure remains unclear till now. In this work, the effects of the applied electric field amplitude, frequency and temperature on the sub-coercive polarization reversal properties were investigated for 10 nm thick Si-doped HfO 2 thin films. The applicability of the Rayleigh law to ultra-thin ferroelectric films was first confirmed, indicating the existence of a multi-domain structure. Since the grain size is about 20-30 nm, a direct observation of domain walls within the grains is rather challenging and this indirect method is a feasible approach to resolve the domain structure. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Sensing of volatile organic compounds by copper phthalocyanine thin films

    Science.gov (United States)

    Ridhi, R.; Saini, G. S. S.; Tripathi, S. K.

    2017-02-01

    Thin films of copper phthalocyanine have been deposited by thermal evaporation technique. We have subsequently exposed these films to the vapours of methanol, ethanol and propanol. Optical absorption, infrared spectra and electrical conductivities of these films before and after exposure to chemical vapours have been recorded in order to study their sensing mechanisms towards organic vapours. These films exhibit maximum sensing response to methanol while low sensitivities of the films towards ethanol and propanol have been observed. The changes in sensitivities have been correlated with presence of carbon groups in the chemical vapours. The effect of different types of electrodes on response-recovery times of the thin film with organic vapours has been studied and compared. The electrodes gap distance affects the sensitivity as well as response-recovery time values of the thin films.

  13. An assessment of thin cloud detection by applying bidirectional reflectance distribution function model-based background surface reflectance using Geostationary Ocean Color Imager (GOCI): A case study for South Korea

    Science.gov (United States)

    Kim, Hye-Won; Yeom, Jong-Min; Shin, Daegeun; Choi, Sungwon; Han, Kyung-Soo; Roujean, Jean-Louis

    2017-08-01

    In this study, a new assessment of thin cloud detection with the application of bidirectional reflectance distribution function (BRDF) model-based background surface reflectance was undertaken by interpreting surface spectra characterized using the Geostationary Ocean Color Imager (GOCI) over a land surface area. Unlike cloud detection over the ocean, the detection of cloud over land surfaces is difficult due to the complicated surface scattering characteristics, which vary among land surface types. Furthermore, in the case of thin clouds, in which the surface and cloud radiation are mixed, it is difficult to detect the clouds in both land and atmospheric fields. Therefore, to interpret background surface reflectance, especially underneath cloud, the semiempirical BRDF model was used to simulate surface reflectance by reflecting solar angle-dependent geostationary sensor geometry. For quantitative validation, Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) data were used to make a comparison with the proposed cloud masking result. As a result, the new cloud masking scheme resulted in a high probability of detection (POD = 0.82) compared with the Moderate Resolution Imaging Spectroradiometer (MODIS) (POD = 0.808) for all cloud cases. In particular, the agreement between the CALIPSO cloud product and new GOCI cloud mask was over 94% when detecting thin cloud (e.g., altostratus and cirrus) from January 2014 to June 2015. This result is relatively high in comparison with the result from the MODIS Collection 6 cloud mask product (MYD35).

  14. Spectral conversion for thin film solar cells and luminescent solar concentrators

    NARCIS (Netherlands)

    Sark, van W.G.J.H.M.; Wild, de J.; Krumer, Z.; Mello Donegá, de C.; Schropp, R.E.I.; Nozik, A.J.; Beard, M.C.; Conibeer, G.

    2014-01-01

    Full spectrum absorption combined with effective generation and collection of charge carriers is a prerequisite for attaining high efficiency solar cells. Two examples of spectral conversion are treated in this chapter, i.e., up-conversion and down-shifting. Up-conversion is applied to thin film

  15. Facile synthesis and photo electrochemical performance of SnSe thin films

    Science.gov (United States)

    Pusawale, S. N.; Jadhav, P. S.; Lokhande, C. D.

    2018-05-01

    Orthorhombic structured SnSe thin films are synthesized via SILAR (successive ionic layer adsorption and reaction) method on glass substrates. The structural properties of thin films are characterized by x-ray diffraction, scanning electron microscopy studies from which nanoparticles with an elongated shape and hydrophilic behavior are observed. UV -VIS absorption spectroscopy study showed the maximum absorption in the visible region with a direct band gap of 1.55 eV. The photo electrochemical study showed p-type electrical conductivity.

  16. Balancing Hole and Electron Conduction in Ambipolar Split-Gate Thin-Film Transistors.

    Science.gov (United States)

    Yoo, Hocheon; Ghittorelli, Matteo; Lee, Dong-Kyu; Smits, Edsger C P; Gelinck, Gerwin H; Ahn, Hyungju; Lee, Han-Koo; Torricelli, Fabrizio; Kim, Jae-Joon

    2017-07-10

    Complementary organic electronics is a key enabling technology for the development of new applications including smart ubiquitous sensors, wearable electronics, and healthcare devices. High-performance, high-functionality and reliable complementary circuits require n- and p-type thin-film transistors with balanced characteristics. Recent advancements in ambipolar organic transistors in terms of semiconductor and device engineering demonstrate the great potential of this route but, unfortunately, the actual development of ambipolar organic complementary electronics is currently hampered by the uneven electron (n-type) and hole (p-type) conduction in ambipolar organic transistors. Here we show ambipolar organic thin-film transistors with balanced n-type and p-type operation. By manipulating air exposure and vacuum annealing conditions, we show that well-balanced electron and hole transport properties can be easily obtained. The method is used to control hole and electron conductions in split-gate transistors based on a solution-processed donor-acceptor semiconducting polymer. Complementary logic inverters with balanced charging and discharging characteristics are demonstrated. These findings may open up new opportunities for the rational design of complementary electronics based on ambipolar organic transistors.

  17. Analysis of a Thin Optical Lens Model

    Science.gov (United States)

    Ivchenko, Vladimir V.

    2011-01-01

    In this article a thin optical lens model is considered. It is shown that the limits of its applicability are determined not only by the ratio between the thickness of the lens and the modules of the radii of curvature, but above all its geometric type. We have derived the analytical criteria for the applicability of the model for different types…

  18. Effects of morphological control on the characteristics of vertical-type OTFTs using Alq3.

    Science.gov (United States)

    Kim, Young Do; Park, Jong Wook; Kang, In Nam; Oh, Se Young

    2008-09-01

    We have fabricated vertical-type organic thin-film transistors (OTFTs) using tris-(8-hydroxyquinoline) aluminum (Alq(3)) as an n-type active material. Vertical-type OTFT using Alq(3) has a layered structure of Al(source electrode)/Alq(3)(active layer)/Al(gate electrode)/Alq(3)(active layer)/ITO glass(drain electrode). Alq(3) thin films containing various surface morphologies could be obtained by the control of evaporation rate and substrate temperature. The effects of the morphological control of Alq(3) thin layer on the grain size and the flatness of film surface were investigated. The characteristics of vertical-type OTFT significantly influenced the growth condition of Alq(3) layer.

  19. A Hierarchical Bayesian Model to Predict Self-Thinning Line for Chinese Fir in Southern China.

    Directory of Open Access Journals (Sweden)

    Xiongqing Zhang

    Full Text Available Self-thinning is a dynamic equilibrium between forest growth and mortality at full site occupancy. Parameters of the self-thinning lines are often confounded by differences across various stand and site conditions. For overcoming the problem of hierarchical and repeated measures, we used hierarchical Bayesian method to estimate the self-thinning line. The results showed that the self-thinning line for Chinese fir (Cunninghamia lanceolata (Lamb.Hook. plantations was not sensitive to the initial planting density. The uncertainty of model predictions was mostly due to within-subject variability. The simulation precision of hierarchical Bayesian method was better than that of stochastic frontier function (SFF. Hierarchical Bayesian method provided a reasonable explanation of the impact of other variables (site quality, soil type, aspect, etc. on self-thinning line, which gave us the posterior distribution of parameters of self-thinning line. The research of self-thinning relationship could be benefit from the use of hierarchical Bayesian method.

  20. Thermal conductivity of nanoscale thin nickel films

    Institute of Scientific and Technical Information of China (English)

    YUAN Shiping; JIANG Peixue

    2005-01-01

    The inhomogeneous non-equilibrium molecular dynamics (NEMD) scheme is applied to model phonon heat conduction in thin nickel films. The electronic contribution to the thermal conductivity of the film is deduced from the electrical conductivity through the use of the Wiedemann-Franz law. At the average temperature of T = 300 K, which is lower than the Debye temperature ()D = 450 K,the results show that in a film thickness range of about 1-11 nm, the calculated cross-plane thermal conductivity decreases almost linearly with the decreasing film thickness, exhibiting a remarkable reduction compared with the bulk value. The electrical and thermal conductivities are anisotropic in thin nickel films for the thickness under about 10 nm. The phonon mean free path is estimated and the size effect on the thermal conductivity is attributed to the reduction of the phonon mean free path according to the kinetic theory.

  1. Mathematical modeling of thin layer drying of pistachio by using solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Midilli, A [University of Nigde (Turkey). Dept. of Mechanical Engineering; Kucuk, H [Karadeniz Technical Univ., Trabzon (Turkey). Dept. of Mechanical Engineering

    2003-05-01

    This paper presents a mathematical modeling of thin layer forced and natural solar drying of shelled and unshelled pistachio samples. In order to estimate and select the suitable form of solar drying curves, eight different mathematical models, which are semi-theoretical and/or empirical, were applied to the experimental data and compared according to their coefficients of determination (r,{chi}{sup 2}), which were predicted by non-linear regression analysis using the Statistical Computer Program. It was deduced that the logarithmic model could sufficiently describe thin layer forced solar drying of shelled and unshelled pistachio, while the two term model could define thin layer natural solar drying of these products in evaluation by considering the coefficients of determination, r{sub sfsd}=0.9983, {chi}{sup 2}{sub sfsd}=2.697x10{sup -5}; r{sub ufsd}=0.9990, {chi}{sup 2}{sub ufsd}=1.639x10{sup -5} for thin layer forced solar drying and r{sub snsd}=0.9990, {chi}{sup 2}{sub snsd}=3.212x10{sup -6}; r{sub unsd}=0.9970, {chi}{sup 2}{sub unsd}=4.590x10{sup -5} for thin layer natural solar drying. (Author)

  2. Electrical Properties of Photodiode Ba0.25Sr0.75TiO3 (BST Thin Film Doped with Ferric Oxide on p-type Si (100 Substrate using Chemical Solution Deposition Method

    Directory of Open Access Journals (Sweden)

    Irzaman

    2011-12-01

    Full Text Available In this paper we have grown pure Ba0.25Sr0.75TiO3 (BST and BST doped by Ferric Oxide Fe2O3 (BFST with doping variations of 5%, 10%, and 15% above type-p Silicon (100 substrate using the chemical solution deposition (CSD method with spin coating technique at rotation speed of 3000 rpm, for 30 seconds. BST thin film are made with a concentration of 1 M 2-methoxyethanol and annealing temperature of 850OC for the Si (100 substrate. Characterization of the thin film is performed for the electrical properties such as the current-voltage (I-V curve using Keithley model 2400 as well as dielectric constant, time constant, pyroelectric characteristics, and depth measurement. The results show that the thin film depth increases if the concentration of the Ferric Oxide doping increases. The I-V characterization shows that the BST and BFST thin film has photodiode properties. The dielectric constant increases with the addition of doping. The maximum dielectric constant value is obtained for 15 % doping concentration namely 83.1 for pure BST and 6.89, 11.1, 41.63 and 83.1, respectively for the Ferric Oxide doping based BST with concentration of 5%, 10%, and 15%. XRD spectra of 15 % of ferric oxide doped BST thin film tetragonal phase, we carried out the lattice constant were a = b = 4.203 Å; c = 4.214 Å; c/a ratio = 1.003

  3. Characterization of CuS nanocrystalline thin films synthesized by chemical bath deposition and dip coating techniques

    International Nuclear Information System (INIS)

    Chaki, Sunil H.; Deshpande, M.P.; Tailor, Jiten P.

    2014-01-01

    CuS thin films were synthesized by chemical bath deposition and dip coating techniques at ambient temperature. The energy dispersive analysis of X-rays of the thin films confirmed that both the as synthesized thin films are stoichiometric. The X-ray diffraction of the chemical bath deposited and dip coating deposited thin films showed that the films possess hexagonal structure having lattice parameters, a = b = 3.79 A and c = 16.34 A. The crystallite sizes determined from the X-ray diffraction data using Scherrer's formula for the chemical bath deposition and dip coating deposition thin films came out to be nearly 11 nm and 13 nm, respectively. The optical microscopy of the as deposited thin films surfaces showed that the substrates are well covered in both the deposited films. The scanning electron microscopy of the thin films clearly showed that in chemical bath deposited thin films the grain size varies from few μm to nm, while in dip coating deposited films the grain size ranges in nm. The optical bandgap determined from the optical absorbance spectrum analysis showed, chemical bath deposited thin films possess direct bandgap of 2.2 eV and indirect bandgap of 1.8 eV. In the case of dip coating deposited thin films, the direct bandgap is 2.5 eV and indirect bandgap is 1.9 eV. The d.c. electrical resistivity variation with temperature for both the deposited films showed that the resistivity decreases with temperature thus confirming the semiconducting nature. The thermoelectric power variations with temperature and the room temperature Hall Effect study of both the synthesized CuS thin films showed them to be of p-type conductivity. The obtained results are discussed in details. - Highlights: • CuS thin films were synthesized by chemical bath deposition and dip coating techniques. • The films possessed hexagonal structure. • The optical absorption showed that the films had direct and indirect bandgap. • Study of electrical transport properties

  4. Thin film processes II

    CERN Document Server

    Kern, Werner

    1991-01-01

    This sequel to the 1978 classic, Thin Film Processes, gives a clear, practical exposition of important thin film deposition and etching processes that have not yet been adequately reviewed. It discusses selected processes in tutorial overviews with implementation guide lines and an introduction to the literature. Though edited to stand alone, when taken together, Thin Film Processes II and its predecessor present a thorough grounding in modern thin film techniques.Key Features* Provides an all-new sequel to the 1978 classic, Thin Film Processes* Introduces new topics, and sever

  5. Mechanics of fragmentation of crocodile skin and other thin films

    Science.gov (United States)

    Qin, Zhao; Pugno, Nicola M.; Buehler, Markus J.

    2014-01-01

    Fragmentation of thin layers of materials is mediated by a network of cracks on its surface. It is commonly seen in dehydrated paintings or asphalt pavements and even in graphene or other two-dimensional materials, but is also observed in the characteristic polygonal pattern on a crocodile's head. Here, we build a simple mechanical model of a thin film and investigate the generation and development of fragmentation patterns as the material is exposed to various modes of deformation. We find that the characteristic size of fragmentation, defined by the mean diameter of polygons, is strictly governed by mechanical properties of the film material. Our result demonstrates that skin fragmentation on the head of crocodiles is dominated by that it features a small ratio between the fracture energy and Young's modulus, and the patterns agree well with experimental observations. Understanding this mechanics-driven process could be applied to improve the lifetime and reliability of thin film coatings by mimicking crocodile skin. PMID:24862190

  6. Shape memory characteristics of sputter-deposited Ti-Ni thin films

    International Nuclear Information System (INIS)

    Miyazaki, Shuichi; Ishida, Akira.

    1994-01-01

    Ti-Ni shape memory alloy thin films were deposited using an RF magnetron sputtering apparatus. The as-sputtered films were heat-treated in order to crystallize and memorize. After the heat treatment, the shape memory characteristics have been investigated using DSC and thermomechanical tests. Upon cooling the thin films, the solution-treated films showed a single peak in the DSC curve indicating a single stage transformation occurring from B2 to the martensitic phase, while the age-treated films showed double peaks indicating a two-stage transformation, i.e., from B2 to the R-phase, then to the martensitic phase. A perfect shape memory effect was achieved in these sputter-deposited Ti-Ni thin films in association both with the R-phase and martensitic transformations. Transformation temperatures increased linearly with increasing applied stress. The transformation strain also increased with increasing stress. The shape memory characteristics were strongly affected by heat-treatment conditions. (author)

  7. Mechanics of fragmentation of crocodile skin and other thin films

    Science.gov (United States)

    Qin, Zhao; Pugno, Nicola M.; Buehler, Markus J.

    2014-05-01

    Fragmentation of thin layers of materials is mediated by a network of cracks on its surface. It is commonly seen in dehydrated paintings or asphalt pavements and even in graphene or other two-dimensional materials, but is also observed in the characteristic polygonal pattern on a crocodile's head. Here, we build a simple mechanical model of a thin film and investigate the generation and development of fragmentation patterns as the material is exposed to various modes of deformation. We find that the characteristic size of fragmentation, defined by the mean diameter of polygons, is strictly governed by mechanical properties of the film material. Our result demonstrates that skin fragmentation on the head of crocodiles is dominated by that it features a small ratio between the fracture energy and Young's modulus, and the patterns agree well with experimental observations. Understanding this mechanics-driven process could be applied to improve the lifetime and reliability of thin film coatings by mimicking crocodile skin.

  8. Nondestructive evaluation of wall thinning occurred under reinforced plate by MFL method

    International Nuclear Information System (INIS)

    Kikuchi, Hiroaki; Sato, Kaito; Shimizu, Isamu

    2013-01-01

    Basic study on applying magnetic flux leakage (MFL) method using ac excitation to a nondestructive evaluation of wall thinning occurred under reinforcing plates in nuclear power plants were performed. Frequently, MFL method by means of dc field for exciting specimens is adopted, and only intensity of magnetic flux density is evaluated. On the other hand, MFL with alternating current enable us to utilize not only amplitude of magnetic flux density but also phase difference, which contributes to evaluation with higher accuracy. Here, specimens with slit and pipe with imitated wall thinning are prepared and magnetized using magnetic yoke with ac field, and then the leakage magnetic flux density and the phase difference on the specimen surface are investigated. Additionally, specimens imitated wall thinning occurred under reinforcing plates were investigated by MFL with ac excitation. (author)

  9. Thin transparent film characterization by photothermal reflectance (abstract)

    Science.gov (United States)

    Li Voti, R.; Wright, O. B.; Matsuda, O.; Larciprete, M. C.; Sibilia, C.; Bertolotti, M.

    2003-01-01

    Photothermal reflectance methods have been intensively applied to the nondestructive testing of opaque thin films [D. P. Almond and P. M. Patel, Photothermal Science and Techniques (Chapman and Hall, London, 1996); C. Bento and D. P. Almond, Meas. Sci. Technol. 6, 1022 (1995); J. Opsal, A. Rosencwaig, and D. Willenborg, Appl. Opt. 22, 3169 (1983)]. The basic principle is based on thermal wave interferometry: the opaque specimen is illuminated by a laser beam, periodically chopped at the frequency f, so as to generate a plane thermal wave in the surface region. This wave propagates in the film, approaches the rear interface (film-bulk), is partially reflected back, reaches the front surface, is again partially reflected back and so on, giving rise to thermal wave interference. A consequence of this interference is that the surface temperature may be enhanced (constructive interference) or reduced (destructive interference) by simply scanning the frequency f (that is, the thermal diffusion length μ=√D/πf ), so as to observe damped oscillations as a function of f; in practice only the first oscillation may be clearly resolved and used to measure either the film thickness d or the film thermal diffusivity D, and this situation occurs when μ≈d. In general, photothermal reflectance does not measure directly the surface temperature variation, but rather a directly related signal determined by the thermo-optic coefficients and the sample geometry; for detection it is common to monitor the optical reflectivity variation of a probe beam normally incident on the sample. If the thin film is partially transparent to the probe, the theory becomes more difficult [O. Matsuda and O. B. Wright, J. Opt. Soc. Am. B (in press)] and one should consider the probe beam multiple reflections in the thin film. The probe modulation is optically inhomogeneous due to the temperature-induced changes in refractive index. Although in the past the complexity of the analysis has impeded

  10. Tunable thin-film optical filters for hyperspectral microscopy

    Science.gov (United States)

    Favreau, Peter F.; Rich, Thomas C.; Prabhat, Prashant; Leavesley, Silas J.

    2013-02-01

    Hyperspectral imaging was originally developed for use in remote sensing applications. More recently, it has been applied to biological imaging systems, such as fluorescence microscopes. The ability to distinguish molecules based on spectral differences has been especially advantageous for identifying fluorophores in highly autofluorescent tissues. A key component of hyperspectral imaging systems is wavelength filtering. Each filtering technology used for hyperspectral imaging has corresponding advantages and disadvantages. Recently, a new optical filtering technology has been developed that uses multi-layered thin-film optical filters that can be rotated, with respect to incident light, to control the center wavelength of the pass-band. Compared to the majority of tunable filter technologies, these filters have superior optical performance including greater than 90% transmission, steep spectral edges and high out-of-band blocking. Hence, tunable thin-film optical filters present optical characteristics that may make them well-suited for many biological spectral imaging applications. An array of tunable thin-film filters was implemented on an inverted fluorescence microscope (TE 2000, Nikon Instruments) to cover the full visible wavelength range. Images of a previously published model, GFP-expressing endothelial cells in the lung, were acquired using a charge-coupled device camera (Rolera EM-C2, Q-Imaging). This model sample presents fluorescently-labeled cells in a highly autofluorescent environment. Linear unmixing of hyperspectral images indicates that thin-film tunable filters provide equivalent spectral discrimination to our previous acousto-optic tunable filter-based approach, with increased signal-to-noise characteristics. Hence, tunable multi-layered thin film optical filters may provide greatly improved spectral filtering characteristics and therefore enable wider acceptance of hyperspectral widefield microscopy.

  11. Thin-film luminescent concentrators for integrated devices: a cookbook.

    Science.gov (United States)

    Evenson, S A; Rawicz, A H

    1995-11-01

    A luminescent concentrator (LC) is a nonimaging optical device used for collecting light energy. As a result of its unique properties, a LC also offers the possibility of separating different portions of the spectrum and concentrating them at the same time. Hence, LC's can be applied to a whole range of problems requiring the collection, manipulation, and distribution or measurement of light. Further-more, as described in our previous research, thin-film LC elements can be deposited directly over sensor and processing electronics in the form of integrated LC devices. As an aid to further research, the materials and technology required to fabricate these thin-film LC elements through the use of an ultraviolet-curable photopolymer are documented in detail.

  12. Thin-Sheet zinc-coated and carbon steels laser welding

    International Nuclear Information System (INIS)

    Pecas, P.; Gouveia, H.; Quintino, L.

    1998-01-01

    This paper describes the results of a research on CO 2 laser welding of thin-sheet carbon steels (Zinc-coated and uncoated), at several thicknesses combinations. Laser welding has an high potential to be applied on sub-assemblies welding before forming to the automotive industry-tailored blanks. The welding process is studied through the analysis of parameters optimization, metallurgical quality and induced distortions by the welding process. The clamping system and the gas protection system developed are fully described. These systems allow the minimization of common thin-sheet laser welding defects like misalignment, and zinc-coated laser welding defects like porous and zinc ventilation. The laser welding quality is accessed by DIN 8563 standard, and by tensile, microhardness and corrosion test. (Author) 8 refs

  13. Optical approach to thermopower and conductivity measurements in thin-film semiconductors

    International Nuclear Information System (INIS)

    Dersch, H.; Amer, N.M.

    1984-01-01

    An optical beam deflection technique is applied to measure the Joule and Peltier heat generated by electric currents through thin-film semiconductors. The method yields a spatially resolved conductivity profile and allows the determination of Peltier coefficients. Results obtained on doped hydrogenated amorphous silicon films are presented

  14. Development of thin pixel detectors on epitaxial silicon for HEP experiments

    International Nuclear Information System (INIS)

    Boscardin, Maurizio; Calvo, Daniela; Giacomini, Gabriele; Wheadon, Richard; Ronchin, Sabina; Zorzi, Nicola

    2013-01-01

    The foreseen luminosity of the new experiments in High Energy Physics will require that the innermost layer of vertex detectors will be able to sustain fluencies up to 10 16 n eq /cm 2 . Moreover, in many experiments there is a demand for the minimization of the material budget of the detectors. Therefore, thin pixel devices fabricated on n-type silicon are a natural choice to fulfill these requirements due to their rad-hard performances and low active volume. We present an R and D activity aimed at developing a new thin hybrid pixel device in the framework of PANDA experiments. The detector of this new device is a p-on-n pixel sensor realized starting from epitaxial silicon wafers and back thinned up to 50–100 μm after process completion. We present the main technological steps and some electrical characterization on the fabricated devices before and after back thinning and after bump bonding to the front-end electronics

  15. Development of thin pixel detectors on epitaxial silicon for HEP experiments

    Energy Technology Data Exchange (ETDEWEB)

    Boscardin, Maurizio, E-mail: boscardi@fbk.eu [FBK, CMM, Via Sommarive 18, I-38123 Povo, Trento (Italy); Calvo, Daniela [INFN and Dipartimento di Fisica, Università di Torino, Via Pietro Giuria, I-10125 Torino (Italy); Giacomini, Gabriele [FBK, CMM, Via Sommarive 18, I-38123 Povo, Trento (Italy); Wheadon, Richard [INFN and Dipartimento di Fisica, Università di Torino, Via Pietro Giuria, I-10125 Torino (Italy); Ronchin, Sabina; Zorzi, Nicola [FBK, CMM, Via Sommarive 18, I-38123 Povo, Trento (Italy)

    2013-08-01

    The foreseen luminosity of the new experiments in High Energy Physics will require that the innermost layer of vertex detectors will be able to sustain fluencies up to 10{sup 16} n{sub eq}/cm{sup 2}. Moreover, in many experiments there is a demand for the minimization of the material budget of the detectors. Therefore, thin pixel devices fabricated on n-type silicon are a natural choice to fulfill these requirements due to their rad-hard performances and low active volume. We present an R and D activity aimed at developing a new thin hybrid pixel device in the framework of PANDA experiments. The detector of this new device is a p-on-n pixel sensor realized starting from epitaxial silicon wafers and back thinned up to 50–100 μm after process completion. We present the main technological steps and some electrical characterization on the fabricated devices before and after back thinning and after bump bonding to the front-end electronics.

  16. Two-dimensional Dirac fermions in thin films of C d3A s2

    Science.gov (United States)

    Galletti, Luca; Schumann, Timo; Shoron, Omor F.; Goyal, Manik; Kealhofer, David A.; Kim, Honggyu; Stemmer, Susanne

    2018-03-01

    Two-dimensional states in confined thin films of the three-dimensional Dirac semimetal C d3A s2 are probed by transport and capacitance measurements under applied magnetic and electric fields. The results establish the two-dimensional Dirac electronic spectrum of these states. We observe signatures of p -type conduction in the two-dimensional states as the Fermi level is tuned across their charge neutrality point and the presence of a zero-energy Landau level, all of which indicate topologically nontrivial states. The resistance at the charge neutrality point is approximately h /e2 and increases rapidly under the application of a magnetic field. The results open many possibilities for gate-tunable topological devices and for the exploration of novel physics in the zero-energy Landau level.

  17. Applying microCT and 3D visualization to Jurassic silicified conifer seed cones: A virtual advantage over thin-sectioning.

    Science.gov (United States)

    Gee, Carole T

    2013-11-01

    As an alternative to conventional thin-sectioning, which destroys fossil material, high-resolution X-ray computed tomography (also called microtomography or microCT) integrated with scientific visualization, three-dimensional (3D) image segmentation, size analysis, and computer animation is explored as a nondestructive method of imaging the internal anatomy of 150-million-year-old conifer seed cones from the Late Jurassic Morrison Formation, USA, and of recent and other fossil cones. • MicroCT was carried out on cones using a General Electric phoenix v|tome|x s 240D, and resulting projections were processed with visualization software to produce image stacks of serial single sections for two-dimensional (2D) visualization, 3D segmented reconstructions with targeted structures in color, and computer animations. • If preserved in differing densities, microCT produced images of internal fossil tissues that showed important characters such as seed phyllotaxy or number of seeds per cone scale. Color segmentation of deeply embedded seeds highlighted the arrangement of seeds in spirals. MicroCT of recent cones was even more effective. • This is the first paper on microCT integrated with 3D segmentation and computer animation applied to silicified seed cones, which resulted in excellent 2D serial sections and segmented 3D reconstructions, revealing features requisite to cone identification and understanding of strobilus construction.

  18. Unsteady Aerodynamics of Deformable Thin Airfoils

    OpenAIRE

    Walker, William Paul

    2009-01-01

    Unsteady aerodynamic theories are essential in the analysis of bird and insect flight. The study of these types of locomotion is vital in the development of flapping wing aircraft. This paper uses potential flow aerodynamics to extend the unsteady aerodynamic theory of Theodorsen and Garrick (which is restricted to rigid airfoil motion) to deformable thin airfoils. Frequency-domain lift, pitching moment and thrust expressions are derived for an airfoil undergoing harmonic oscillations and def...

  19. 2D seismostratigraphic inversion applied to a thin reservoir characterization; Inversao sismoestratigrafica 2D aplicada a caracterizacao de um reservatorio delgado

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Antonio Carlos de Almeida

    1998-12-01

    The purpose of this work is to estimate thin reservoir properties even without counting on a good quality and a homogeneous database. Following a regional geological setting, well data such as logs, reports, cores had led to an interpretation of the depositional model in which the sandstone interval is inserted as an filling an incised valley system. This knowledge is essential to provide elements for a final work judgement. The main geological properties were then extracted from logs. The geophysical approach has counted on a 1D modeling of the main well acoustic parameters and a 2D Seismostratigraphic Inversion with a {alpha} priori acoustic impedance, which was able to enhance the frequency content of the original data. After the interpretation of the inverted data, seismic attributes were then extracted. A multivariate statistics was performed in order to establish which correlations between geological and seismic would be carried forward. An Ordinary Kriging was applied to the 2D seismic attributes. The External Drift Kriging was used to derive maps of the geological properties with the constraint of seismic variables. The final geological properties maps are similar in shape and coherent with the depositional model proposed. (author)

  20. Magneto-optical properties of BiFeO3 thin films using surface plasmon resonance technique

    International Nuclear Information System (INIS)

    Paliwal, Ayushi; Sharma, Anjali; Tomar, Monika; Gupta, Vinay

    2014-01-01

    Indigeneously assembled surface plasmon resonance (SPR) set up has been exploited to study the magnetic field dependent optical properties of BiFeO 3 thin films. BiFeO 3 thin films have been deposited onto gold (Au) coated glass prism by using pulsed laser deposition technique. The surface plasmon modes in prism/Au/BiFeO 3 /air structure have been excited in Kretschmann configuration at the interface of Au/BiFeO 3 thin films. The SPR reflectance curves obtained for prism/Au/BiFeO 3 /air structure were utilized to investigate the optical properties of BiFeO 3 thin films at optical frequency (λ=633 nm) as a function of applied magnetic field. SPR curves shows a continuous shift towards lower angles with increasing applied magnetic field, which indicate the promising application of ferromagnetic BiFeO 3 film as a magnetic field sensor. Complex dielectric constant of deposited BiFeO 3 film was determined by fitting the experimental SPR data with Fresnel's equations. The variation of complex dielectric constant and refractive index of BiFeO 3 film was studied with increase in magnetic field, and the sensitivity of magnetic field sensor was found to be about 0.52 RIU/T

  1. Ga-doped ZnO thin film surface characterization by wavelet and fractal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Chenlei; Tang, Wu, E-mail: tang@uestc.edu.cn

    2016-02-28

    Graphical abstract: - Highlights: • Multi-resolution signal decomposition of wavelet transform is applied to Ga-doped ZnO thin films with various thicknesses. • Fractal properties of GZO thin films are investigated by box counting method. • Fractal dimension is not in conformity with original RMS roughness. • Fractal dimension mainly depends on the underside diameter (grain size) and distance between adjacent grains. - Abstract: The change in roughness of various thicknesses Ga-doped ZnO (GZO) thin films deposited by magnetron reactive sputtering on glass substrates at room temperature was measured by atomic force microscopy (AFM). Multi-resolution signal decomposition based on wavelet transform and fractal geometry was applied to process surface profiles, to evaluate the roughness trend of relevant frequency resolution. The results give a six-level decomposition and the results change with deposited time and surface morphology. Also, it is found that fractal dimension is closely connected to the underside diameter (grain size) and the distance between adjacent grains that affect the change rate of surface and the increase of the defects such as abrupt changes lead to a larger value of fractal dimension.

  2. Tailoring the physical properties of manganite thin films by tuning the epitaxial strain

    International Nuclear Information System (INIS)

    Zhang, P.X.; Zhang, H.; Cha, L.M.; Habermeier, H.-U.

    2003-01-01

    Through a proper choice of the mismatch between substrate and films, the physical properties of manganite thin films can be tailored We show that two types of manganite thin films of the Ruddlesden-Popper family, n=∞ and n=2, demonstrate a dramatic variation of their physical properties. It is proved that the property variation can be tuned precisely by controlling the lattice mismatch and/or the film thickness

  3. Measurement of the thermal conductivity of thin insulating anisotropic material with a stationary hot strip method

    International Nuclear Information System (INIS)

    Jannot, Yves; Degiovanni, Alain; Félix, Vincent; Bal, Harouna

    2011-01-01

    This paper presents a method dedicated to the thermal conductivity measurement of thin insulating anisotropic materials. The method is based on three hot-strip-type experiments in which the stationary temperature is measured at the center of the hot strip. A 3D model of the heat transfer in the system is established and simulated to determine the validity of a 2D transfer hypothesis at the center of the hot strip. A simplified 2D model is then developed leading to the definition of a geometrical factor calculable from a polynomial expression. A very simple calculation method enabling the estimation of the directional thermal conductivities from the three stationary temperature measurements and from the geometrical factor is presented. The uncertainties on each conductivity are estimated. The method is then validated by measurements on polyethylene foam and Ayous (anistropic low-density tropical wood); the estimated values of the thermal conductivities are in good agreement with the values estimated using the hot plate and the flash method. The method is finally applied on a thin super-insulating fibrous material for which no other method is able to measure the in-plane conductivity

  4. Room temperature synthesis of porous SiO2 thin films by plasma enhanced chemical vapor deposition

    OpenAIRE

    Barranco Quero, Ángel; Cotrino Bautista, José; Yubero Valencia, Francisco; Espinós, J. P.; Rodríguez González-Elipe, Agustín

    2004-01-01

    Synthesis of porous SiO2 thin films in room temperature was carried out using plasma enhanced chemical vapor deposition (CVD) in an electron cyclotron resonance microwave reactor with a downstream configuration.The gas adsorption properties and the type of porosity of the SiO2 thin films were assessed by adsorption isotherms of toluene at room temperature.The method could also permit the tailoring synthesis of thin films when both composition and porosity can be simultaneously and independent...

  5. Stand quality management in a late-rotation, red oak-sweetgum stand in east Mississippi: preliminary results following thinning

    Science.gov (United States)

    James S. Meadows; Daniel A. Skojac

    2012-01-01

    Stand quality management is a new management strategy in which thinning prescriptions are based solely on tree quality rather than a quantitative level of residual stand density. As long as residual density falls within fairly broad limits, prescriptions are based on tree quality alone. We applied four thinning prescriptions based on stand quality management, along...

  6. Different Response of Sap Flow at Different Measurement Depths after Thinning in a Japanese Cypress Plantation

    Science.gov (United States)

    Chiu, C. W.; Gomi, T.; Onda, Y.; Kato, H.; Sakashita, W.; Sun, X.

    2017-12-01

    Thinning experiments in forests can alter light conditions and further affect growth rate and transpiration of the remained trees. Previous studies suggested transpiration was increased one year after thinning experiment due to improved canopy light condition. On the other hand, the anatomical and morphological responses to thinning are not react immediately because of the tree adaptation to the new surrounding conditions. It has been hypothesized that lower crown is connected to the inner part of sapwood and need more years to adapt new light conditions after thinning. However, our knowledge for the relationship between tree crown development and water movement inside the trunk after several years from thinning experiment was still limited due to lack of long-term field measurement after thinning. Therefore, in this study, we aim to examine the interannual variability of water movement inside the trunk accompanied the development of tree crown after thinning experiment. To do that, we applied sap flow measurement and terrestrial LiDAR survey from 2011 to 2017 in a Japanese cypress (Chamaecyparis obtusa) plantation in Japan, where 50% strip thinning experiment was conducted in the end of 2011. Consequently, we found sap flow densities at different measurement depths were not always increased year by year and those may relate to the crown development after thinning.

  7. Thin film preparation of semiconducting iron pyrite

    Science.gov (United States)

    Smestad, Greg P.; Ennaoui, Ahmed; Fiechter, Sebastian; Hofmann, Wolfgang; Tributsch, Helmut; Kautek, Wolfgang

    1990-08-01

    Pyrite (Fe52) has been investigated as a promising new absorber material for thin film solar cell applications because of its high optical absorption coefficient of 1OL cm1, and its bandgap of 0.9 to 1.0 eV. Thin layers have been prepared by Metal Organic Chemical Vapor Deposition, MOCVD, Chemical Spray Pyrolysis, CSP, Chemical Vapor Transport, CVT, and Sulfurization of Iron Oxide films, 510. It is postulated that for the material FeS2, if x is not zero, a high point defect concentration results from replacing 2 dipoles by single S atoms. This causes the observed photovoltages and solar conversion efficiencies to be lower than expected. Using the Fe-O-S ternary phase diagram and the related activity plots, a thermodynamic understanding is formulated for the resulting composition of each of these types of films. It is found that by operating in the oxide portion of the phase diagram, the resulting oxidation state favors pyrite formation over FeS. By proper orientation of the grains relative to the film surface, and by control of pinholes and stoichiometry, an efficient thin film photovolatic solar cell material could be achieved.

  8. Raman spectra of TiO2 thin films deposited electrochemically and by spray pyrolysis

    International Nuclear Information System (INIS)

    Shishiyanu, S.; Vartic, V.; Shishiyanu, T.; Stratan, Gh.; Rusu, E.; Zarrelli, M.; Giordano, M.

    2013-01-01

    In this paper we present our experimental results concerning the fabrication of TiO 2 thin films by spray pyrolysis and electrochemical deposition method onto different substrates - Corning glass, Si and optical fibers. The surface morphology of the TiO 2 thin films have been investigated by Atomic Force Microscopy. Raman shift spectra measurements have been done for the optical characterization of the fabricated titania thin films. The post-growth rapid photothermal processing (RPP) at temperatures of 100-800 degrees Celsius for 1-3 min have been applied. Our experimental results prove that by the application of post-growth RPP is possible to essentially improve the crystallinity of the deposited TiO 2 films. (authors)

  9. Spectral interferometry including the effect of transparent thin films to measure distances and displacements

    International Nuclear Information System (INIS)

    Hlubina, P.

    2004-01-01

    A spectral-domain interferometric technique is applied for measuring mirror distances and displacements in a dispersive Michelson interferometer when the effect of transparent thin films coated onto the interferometer beam splitter and compensator is known. We employ a low-resolution spectrometer in two experiments with different amounts of dispersion in a Michelson interferometer that includes fused-silica optical sample. Knowing the thickness of the optical sample and the nonlinear phase function of the thin films, the positions of the interferometer mirror are determined precisely by a least-squares fitting of the theoretical spectral interferograms to the recorded ones. We compare the results of the processing that include and do not include the effect of transparent thin films (Author)

  10. Properties of Exchange Coupled All-garnet Magneto-Optic Thin Film Multilayer Structures

    Science.gov (United States)

    Nur-E-Alam, Mohammad; Vasiliev, Mikhail; Kotov, Viacheslav A.; Balabanov, Dmitry; Akimov, Ilya; Alameh, Kamal

    2015-01-01

    The effects of exchange coupling on magnetic switching properties of all-garnet multilayer thin film structures are investigated. All-garnet structures are fabricated by sandwiching a magneto-soft material of composition type Bi1.8Lu1.2Fe3.6Al1.4O12 or Bi3Fe5O12:Dy2O3 in between two magneto-hard garnet material layers of composition type Bi2Dy1Fe4Ga1O12 or Bi2Dy1Fe4Ga1O12:Bi2O3. The fabricated RF magnetron sputtered exchange-coupled all-garnet multilayers demonstrate a very attractive combination of magnetic properties, and are of interest for emerging applications in optical sensors and isolators, ultrafast nanophotonics and magneto-plasmonics. An unconventional type of magnetic hysteresis behavior not observed previously in magnetic garnet thin films is reported and discussed. PMID:28788043

  11. Properties of Exchange Coupled All-garnet Magneto-Optic Thin Film Multilayer Structures

    Directory of Open Access Journals (Sweden)

    Mohammad Nur-E-Alam

    2015-04-01

    Full Text Available The effects of exchange coupling on magnetic switching properties of all-garnet multilayer thin film structures are investigated. All-garnet structures are fabricated by sandwiching a magneto-soft material of composition type Bi1.8Lu1.2Fe3.6Al1.4O12 or Bi3Fe5O12:Dy2O3 in between two magneto-hard garnet material layers of composition type Bi2Dy1Fe4Ga1O12 or Bi2Dy1Fe4Ga1O12:Bi2O3. The fabricated RF magnetron sputtered exchange-coupled all-garnet multilayers demonstrate a very attractive combination of magnetic properties, and are of interest for emerging applications in optical sensors and isolators, ultrafast nanophotonics and magneto-plasmonics. An unconventional type of magnetic hysteresis behavior not observed previously in magnetic garnet thin films is reported and discussed.

  12. Thermoelectric properties of cobalt–antimonide thin films prepared by radio frequency co-sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Aziz; Han, Seungwoo, E-mail: swhan@kimm.re.kr

    2015-07-31

    Co–Sb thin films with an Sb content in the range 65–76 at.%, were deposited on a thermally oxidized Si (100) substrate preheated at 200 °C using radio-frequency co-sputtering. Evaluation using scanning electron microscopy images and X-ray diffraction reveals that the films were polycrystalline, with a grain size in the range 100–250 nm. Energy-dispersive spectroscopy analysis indicates single-phase CoSb{sub 2} and CoSb{sub 3} films, as well as multiphase thin films with either CoSb{sub 2} or CoSb{sub 3} as the dominant phase. The electrical and thermoelectric properties were measured and found to be strongly dependent on the observed phases and the defect concentrations. The CoSb{sub 2} thin films were found to exhibit a significant n-type thermoelectric effect, which, coupled with the very low electrical resistivity, resulted in a larger power factor than that of the CoSb{sub 3} thin films. We find power factors of 0.73 mWm{sup −1} K{sup −2} and 0.67 mWm{sup −1} K{sup −2} for the CoSb{sub 2} and CoSb{sub 3} thin films, respectively. - Highlights: • Polycrystalline Co–Sb thin films were obtained by present deposition strategy. • CoSb{sub 2} and CoSb{sub 3} have semimetal and semiconductor characteristics respectively. • The Seebeck coefficient depends heavily on defect concentration and impurity phases. • Film properties in the second heating cycle were different from the first. • CoSb{sub 2} is found to possess significant n-type thermopower.

  13. Nanomechanics of biocompatible hollow thin-shell polymer microspheres.

    Science.gov (United States)

    Glynos, Emmanouil; Koutsos, Vasileios; McDicken, W Norman; Moran, Carmel M; Pye, Stephen D; Ross, James A; Sboros, Vassilis

    2009-07-07

    The nanomechanical properties of biocompatible thin-shell hollow polymer microspheres with approximately constant ratio of shell thickness to microsphere diameter were measured by nanocompression tests in aqueous conditions. These microspheres encapsulate an inert gas and are used as ultrasound contrast agents by releasing free microbubbles in the presence of an ultrasound field as a result of free gas leakage from the shell. The tests were performed using an atomic force microscope (AFM) employing the force-distance curve technique. An optical microscope, on which the AFM was mounted, was used to guide the positioning of tipless cantilevers on top of individual microspheres. We performed a systematic study using several cantilevers with spring constants varying from 0.08 to 2.3 N/m on a population of microspheres with diameters from about 2 to 6 microm. The use of several cantilevers with various spring constants allowed a systematic study of the mechanical properties of the microsphere thin shell at different regimes of force and deformation. Using thin-shell mechanics theory for small deformations, the Young's modulus of the thin wall material was estimated and was shown to exhibit a strong size effect: it increased as the shell became thinner. The Young's modulus of thicker microsphere shells converged to the expected value for the macroscopic bulk material. For high applied forces, the force-deformation profiles showed a reversible and/or irreversible nonlinear behavior including "steps" and "jumps" which were attributed to mechanical instabilities such as buckling events.

  14. Online monitoring of pipe wall thinning by electromagnetic acoustic resonance method

    International Nuclear Information System (INIS)

    Urayama, Ryoichi; Takagi, Toshiyuki; Uchimoto, Tetsuya; Kanemoto, Shigeru

    2013-01-01

    The electromagnetic acoustic resonance (EMAR) method provides accurate and stable evaluation in high temperature environment, and it is an effective tool for online monitoring. In this study, the EMAR method and the superposition of the n-th compression (SNC) for data processing are applied to online monitoring of pipe wall thinning, and the accuracy and reliability of the measurements are demonstrated through field tests using a large-scale corrosion test loop at high temperature. To measure the thickness of pipes with complicated wall thinning, the SNC extracts thickness information from the spectral responses of the EMAR. Results from monitoring test show that EMAR with SNC can evaluate pipe wall thinning with an accuracy of 10 μm at 165degC. In addition, time evaluation of evaluated thickness decreases monotonically all over the test duration, which indicates high stability of this measurement technique. (author)

  15. On dewetting of thin films due to crystallization (crystallization dewetting).

    Science.gov (United States)

    Habibi, Mehran; Rahimzadeh, Amin; Eslamian, Morteza

    2016-03-01

    Drying and crystallization of a thin liquid film of an ionic or a similar solution can cause dewetting in the resulting thin solid film. This paper aims at investigating this type of dewetting, herein termed "crystallization dewetting", using PbI2 dissolved in organic solvents as the model solution. PbI2 solid films are usually used in X-ray detection and lead halide perovskite solar cells. In this work, PbI2 films are fabricated using spin coating and the effect of major parameters influencing the crystallization dewetting, including the type of the solvent, solution concentration, drying temperature, spin speed, as well as imposed vibration on the substrate are studied on dewetting, surface profile and coverage, using confocal scanning laser microscopy. Simplified hydrodynamic governing equations of crystallization in thin films are presented and using a mathematical representation of the process, it is phenomenologically demonstrated that crystallization dewetting occurs due to the absorption and consumption of the solution surrounding a growing crystal. Among the results, it is found that a low spin speed (high thickness), a high solution concentration and a low drying temperature promote crystal growth, and therefore crystallization dewetting. It is also shown that imposed vibration on the substrate can affect the crystal size and crystallization dewetting.

  16. Thickness control in electrophoretic deposition of WO3 nanofiber thin films for solar water splitting

    International Nuclear Information System (INIS)

    Fang, Yuanxing; Lee, Wei Cheat; Canciani, Giacomo E.; Draper, Thomas C.; Al-Bawi, Zainab F.; Bedi, Jasbir S.; Perry, Christopher C.; Chen, Qiao

    2015-01-01

    Graphical abstract: - Highlights: • A novel method combining electrospinning and electrophoretic deposition was established for the creation of nanostructured semiconductor thin films. • The created thin films displayed a high chemical stability with a controllable thickness. • The PEC water splitting performance of the thin films was optimized by fine-tuning the thickness of the films. • A maximum photoconversion efficiency was achieved by 18 μm nanofibrous thin films. - Abstract: Electrophoretic deposition (EPD) of ground electrospun WO 3 nanofibers was applied to create photoanodes with controlled morphology for the application of photoelectrochemical (PEC) water splitting. The correlations between deposition parameters and film thicknesses were investigated with theoretical models to precisely control the morphology of the nanostructured porous thin film. The photoconversion efficiency was further optimized as a function of film thickness. A maximum photoconversion efficiency of 0.924% from electrospun WO 3 nanofibers that EPD deposited on a substrate was achieved at a film thickness of 18 μm.

  17. Impacts on soils and residual trees from cut-to-length thinning operations in California's redwood forests

    Science.gov (United States)

    Kyungrok Hwang; Han-sup Han; Susan E. Marshall; Deborah S. Page-Dumroese

    2017-01-01

    Cut-to-length (CTL) harvest systems have recently been introduced for thinning third-growth, young (<25 years old) redwood forests (Sequoia sempervirens (Lamb. ex D. Don) Endl.) in northern California. This type of harvesting can effective for thinning overstocked stands consisting of small-diameter trees. However, forestland managers and government agencies...

  18. Identification of the chemical inventory of different paint types applied in nuclear facilities

    International Nuclear Information System (INIS)

    Sabrina Tietze; Foreman, M.R.St.J.; Ekberg, CH.H.; Chalmers University of Technology, Chemical and Biological Engineering, Goeteborg; Dongen van, B.E.

    2013-01-01

    The floors, concrete walls and many of the metal surfaces in nuclear power plant containments are coated with zinc primers or paint films to preserve the metal surfaces and simplify decontamination in the containment after the occurrence of a severe nuclear incident or accident. A chemical examination of paint films from different nuclear installations out of operation, as well as current operating ones, reveals that different types of paints are used whose composition can vary significantly. Results obtained for one type of paint at a certain nuclear site are in most cases unlikely to be comparable with sites painted with another type of paint. During normal operation and particularly during nuclear accidents, the paints will degrade under the high temperature, steam and irradiation influence. As paint and its degradation products can act as sources and depots for volatile iodine compounds, the type and aging conditions of the paint films will have a significant impact on the source term of the volatile fission product iodine. Thus, great care should be taken when extrapolating any results obtained for the interaction of radioactive iodine with one paint product to a different paint product. The main focus of the study is a comparison of the chemical profile of paint films applied in Swedish nuclear power plants. Teknopox Aqua V A, an epoxy paint recently used at Ringhals 2, and an emulsion paint used in the scrubber buildings of Ringhals 1-4 are compared with a paint film from Barsebaeck nuclear power plant unit 1 that had been aged under real reactor conditions for 20 years. In addition, two paint films, an emulsion and a gloss paint, used in an international nuclear fuel reprocessing facility, are compared with the paints from the Swedish nuclear power plants. (author)

  19. Evaluation of thin discontinuities in planar conducting materials using the diffraction of electromagnetic field

    Science.gov (United States)

    Savin, A.; Novy, F.; Fintova, S.; Steigmann, R.

    2017-08-01

    The current stage of nondestructive evaluation techniques imposes the development of new electromagnetic (EM) methods that are based on high spatial resolution and increased sensitivity. In order to achieve high performance, the work frequencies must be either radifrequencies or microwaves. At these frequencies, at the dielectric/conductor interface, plasmon polaritons can appear, propagating between conductive regions as evanescent waves. In order to use the evanescent wave that can appear even if the slits width is much smaller that the wavwelength of incident EM wave, a sensor with metamaterial (MM) is used. The study of the EM field diffraction against the edge of long thin discontinuity placed under the inspected surface of a conductive plate has been performed using the geometrical optics principles. This type of sensor having the reception coils shielded by a conductive screen with a circular aperture placed in the front of reception coil of emission reception sensor has been developed and “transported” information for obtaining of magnified image of the conductive structures inspected. This work presents a sensor, using MM conical Swiss roll type that allows the propagation of evanescent waves and the electromagnetic images are magnified. The test method can be successfully applied in a variety of applications of maxim importance such as defect/damage detection in materials used in automotive and aviation technologies. Applying this testing method, spatial resolution can be improved.

  20. Post-annealing effects on pulsed laser deposition-grown GaN thin films

    International Nuclear Information System (INIS)

    Cheng, Yu-Wen; Wu, Hao-Yu; Lin, Yu-Zhong; Lee, Cheng-Che; Lin, Ching-Fuh

    2015-01-01

    In this work, the post-annealing effects on gallium nitride (GaN) thin films grown from pulsed laser deposition (PLD) are investigated. The as-deposited GaN thin films grown from PLD are annealed at different temperatures in nitrogen ambient. Significant changes of the GaN crystal properties are observed. Raman spectroscopy is used to observe the crystallinity, the change of residual stress, and the thermal decomposition of the annealed GaN thin films. X-ray diffraction is also applied to identify the crystal phase of GaN thin films, and the surface morphology of GaN thin films annealed at different temperatures is observed by scanning electron microscopy. Through the above analyses, the GaN thin films grown by PLD undergo three stages: phase transition, stress alteration, and thermal decomposition. At a low annealing temperature, the rock salt GaN in GaN films is transformed into wurtzite. The rock salt GaN diminishes with increasing annealing temperature. At a medium annealing temperature, the residual stress of the film changes significantly from compressive strain to tensile strain. As the annealing temperature further increases, the GaN undergoes thermal decomposition and the surface becomes granular. By investigating the annealing temperature effects and controlling the optimized annealing temperature of the GaN thin films, we are able to obtain highly crystalline and strain-free GaN thin films by PLD. - Highlights: • The GaN thin film is grown on sapphire by pulsed laser deposition. • The GaN film undergoes three stages with increasing annealing temperature. • In the first stage, the film transfers from rock salt to wurtzite phase. • In the second stage, the stress in film changes from compressive to tensile. • In the final stage, the film thermally decomposes and becomes granular

  1. Research Progress on Measurement Methods and Influence Factors of Thin-film Stress

    Directory of Open Access Journals (Sweden)

    MA Yibo

    2018-02-01

    Full Text Available With the size of thin-film electronic devices decreasing, the film stress became an important reason for the failure of thin film devices. Film stress not only affected the membrane structure, but also associated with film optics, electricity, mechanics and other properties, therefore film stress turned into one hot spot in the research field of thin-film materials. This paper reviewed the latest research progress of film stress, substrate curvature method, X-ray diffraction technique and Raman spectroscopy, several frequently used stress measuring techniques were compared and analyzed, and composition ratios of thin film, substrate types, magnetron sputtering process parameters (sputtering power, work pressure, substrate temperature and annealing etc. factors influencing thin film stress were summarized. It was found that substrate curvature method was suitable for measuring almost all kinds of thin film materials. X-ray diffraction and Raman spectroscopy were just fit for measuring materials with characteristic peaks. Nanoindentation method required extra stress-free samples as comparison experiments. During film fabrication and annealing process, film stress usually transited from compressive to tensile status, and several factors combined together could affect stress, so film stress could be reached the minimum value or even stress-free status through setting appropriate parameters. Finally, combined with film stress research status, accurate stress measurement methods for different materials as a thin-film stress research direction were introduced, and challenges in thin film detection range were pointed out.

  2. Interleukin-7 Plasma Levels in Human Differentiate Anorexia Nervosa, Constitutional Thinness and Healthy Obesity.

    Science.gov (United States)

    Germain, Natacha; Viltart, Odile; Loyens, Anne; Bruchet, Céline; Nadin, Katia; Wolowczuk, Isabelle; Estour, Bruno; Galusca, Bogdan

    2016-01-01

    Interleukin-7 (IL-7) is a cytokine involved in energy homeostasis as demonstrated in rodents. Anorexia nervosa is characterized by restrained eating behavior despite adaptive orexigenic regulation profile including high ghrelin plasma levels. Constitutional thinness is a physiological condition of resistance to weight gain with physiological anorexigenic profile including high Peptide YY plasma level. Healthy obesity can be considered as a physiological state of resistance to weight loss with opposite appetite regulating profile to constitutional thinness including low Peptide YY plasma level. No studies in IL-7 are yet available in those populations. Therefore we evaluated circadian plasma levels of IL-7 in anorexia nervosa compared to constitutional thinness, healthy obese and control females. 10 restrictive-type anorexia nervosa women, 5 bingeing/purging anorexia nervosa woman, 5 recovered restrictive anorexia nervosa women, 4 bulimic females, 10 constitutional thinness women, 7 healthy obese females, and 10 normal weight women controls were enrolled in this cross-sectional study, performed in endocrinology unit and academic laboratory. Twelve-point circadian profiles of plasma IL-7 levels were measured in each subject. 24h mean IL-7 plasma levels (pg/ml, mean±SEM) were decreased in restrictive-type anorexia nervosa (123.4±14.4, panorexia nervosa (24.2±5.6, panorexia nervosa (64.2±16.1, p = 0.01) and healthy obese patients (51±3.2, panorexia nervosa, confirming its difference with constitutional thinness. Healthy obesity, with low IL-7, is once again in mirror image of constitutional thinness with normal high IL-7.

  3. Nanocrystalline magnetite thin films grown by dual ion-beam sputtering

    International Nuclear Information System (INIS)

    Prieto, Pilar; Ruiz, Patricia; Ferrer, Isabel J.; Figuera, Juan de la; Marco, José F.

    2015-01-01

    Highlights: • We have grown tensile and compressive strained nanocrystalline magnetite thin films by dual ion beam sputtering. • The magnetic and thermoelectric properties can be controlled by the deposition conditions. • The magnetic anisotropy depends on the crystalline grain size. • The thermoelectric properties depend on the type of strain induced in the films. • In plane uniaxial magnetic anisotropy develops in magnetite thin films with grain sizes ⩽20 nm. - Abstract: We have explored the influence of an ion-assisted beam in the thermoelectric and magnetic properties of nanocrystalline magnetite thin films grown by ion-beam sputtering. The microstructure has been investigated by XRD. Tensile and compressive strained thin films have been obtained as a function of the parameters of the ion-assisted beam. The evolution of the in-plane magnetic anisotropy was attributed to crystalline grain size. In some films, magneto-optical Kerr effect measurements reveal the existence of uniaxial magnetic anisotropy induced by the deposition process related with a small grain size (⩽20 nm). Isotropic magnetic properties have observed in nanocrystalline magnetite thin film having larger grain sizes. The largest power factor of all the films prepared (0.47 μW/K 2 cm), obtained from a Seebeck coefficient of −80 μV/K and an electrical resistivity of 13 mΩ cm, is obtained in a nanocrystalline magnetite thin film with an expanded out-of-plane lattice and with a grain size ≈30 nm

  4. Seebeck coefficient of synthesized Titanium Dioxide thin film on FTO glass substrate

    Science.gov (United States)

    Usop, R.; Hamed, N. K. A.; Megat Hasnan, M. M. I.; Ikeda, H.; Sabri, M. F. M.; Ahmad, M. K.; Said, S. M.; Salleh, F.

    2018-04-01

    In order to fabricate a thermoelectric device on glass substrate for harvesting waste heat energy through house appliances, the Seebeck coefficient of translucent TiO2 thin film was investigated. The TiO2 thin film was synthesized by using hydrothermal method with F-SnO2 coated glass as substrate. From scanning electron microscopy analysis, the synthesized TiO2 thin film was found to be in nanometer-scale rod structure with a thickness of 4 µm. The Seebeck coefficient was measured in the temperature range of 300 – 400 K. The Seebeck coefficient is found to be in negative value which shows that synthesized film is an n-type semiconductor material, and is lower than the value of bulk-size material. This reduction in Seebeck coefficient of TiO2 thin film is likely due to the low dimensional effect and the difference of carrier concentration.

  5. Raviart–Thomas-type sources adapted to applied EEG and MEG: implementation and results

    International Nuclear Information System (INIS)

    Pursiainen, S

    2012-01-01

    This paper studies numerically electroencephalography and magnetoencephalography (EEG and MEG), two non-invasive imaging modalities in which external measurements of the electric potential and the magnetic field are, respectively, utilized to reconstruct the primary current density (neuronal activity) of the human brain. The focus is on adapting a Raviart–Thomas-type source model to meet the needs of EEG and MEG applications. The goal is to construct a model that provides an accurate approximation of dipole source currents and can be flexibly applied to different reconstruction strategies as well as to realistic computation geometries. The finite element method is applied in the simulation of the data. Least-squares fit interpolation is used to establish Cartesian source directions, which guarantee that the recovered current field is minimally dependent on the underlying finite element mesh. Implementation is explained in detail and made accessible, e.g., by using quadrature-free formulae and the Gaussian one-point rule in numerical integration. Numerical results are presented concerning, for example, the iterative alternating sequential inverse algorithm as well as resolution, smoothness and local refinement of the finite element mesh. Both spherical and pseudo-realistic head models, as well as real MEG data, are utilized in the numerical experiments. (paper)

  6. Photoelectric properties of thin films from the CdS-Ag2 S system

    International Nuclear Information System (INIS)

    Ristova-Lipanovikj, Mimoza

    1996-01-01

    Three different methods for preparation of thin films of CdS-Ag 2 S system are presented. Those methods are modified from the already existing methods of chemical deposition, and the method of spray pyrolysis, both widely utilized for preparation of wide range of binary, ternary and quaternary semiconductor thin films. The atomic absorption method was applied for quantitative analysis of the samples. The crystal structure of the thin films was studied by X-ray diffraction, while their morphology and the texture was analyzed from the microphotographs, taken on the samples by an optical microscope, in transmitted light. An extensive research was undertaken, to improve the crystallinity of the samples, by performing a post preparation thermal treatment. Photoelectric as well as some other physical properties were studied. VIS and NIR transmission spectra were recorded. The optical band gaps for various thin films containing different portions of Ag and Cd in the system, were evaluated. Spectral dependence of the photoconductivity was recorded. The optical band gaps were determined from the positions of the corresponding maxima of the photoconductivity. From the curves of the time relaxation of the photoconductivity, the carrier life times were calculates. Measurements of the thermal dependence of the resistivity on various samples were performed. Based on the extensive experimental research, the most convenient composition for PV application was selected. For the sake of comparison, two different types of PV cells were manufactured, Sn O 2 :F/CdS:Ag-Sn x S, and Sn O 2 :F/CdS-Sn x S, in order to study the influence of the silver content in the CdS. The plots of I-V and C-V characteristics are presented, and the parameters of the solar cells, were determined and taken in a relation with the content of the silver on the CdS. Finally, some directions of a possible future experimental and theoretical research in this field are given, based on the conclusions made. (author)

  7. Characterization of nanostructured photosensitive cadmium sulphide thin films grown by SILAR deposition technique

    International Nuclear Information System (INIS)

    Ubale, A.U.; Bargal, A.N.

    2010-01-01

    This paper reports the preparation of photosensitive nanostructured CdS thin films by successive ionic layer adsorption and reaction (SILAR) method at room temperature. To obtain good quality CdS thin films, preparative conditions such as concentration of cationic and anionic precursors, adsorption and rinsing time durations etc. are optimized. The structural, optical and electrical characterizations of the as-deposited and annealed CdS thin films were carried out using X-ray diffraction, scanning electron microscopy, optical absorption and electrical resistivity methods. The photoconductivity studies showed that the annealed films are more than that photosensitive. The TEP measurement shows that deposited films are of n-type. (author)

  8. Pyrolyzed thin film carbon

    Science.gov (United States)

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

    2010-01-01

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

  9. thin films

    Indian Academy of Sciences (India)

    microscopy (SEM) studies, respectively. The Fourier transform ... Thin films; chemical synthesis; hydrous tin oxide; FTIR; electrical properties. 1. Introduction ... dehydrogenation of organic compounds (Hattori et al 1987). .... SEM images of (a) bare stainless steel and (b) SnO2:H2O thin film on stainless steel substrate at a ...

  10. Microscopic local fatigue in PZT thin films

    International Nuclear Information System (INIS)

    Li, B S; Wu, A; Vilarinho, P M

    2007-01-01

    The reduction in switchable polarization during fatigue largely limits the application of PZT thin films in ferroelectric nonvolatile memories. So, it is very important to understand the fatigue mechanism in PZT films, especially at a nanoscale level. In this paper, nanoscale fatigue properties in PZT thin films have been studied by piezoresponse force microscopy and local piezoloops. It has been found that a piezoloop obtained on a fatigued point exhibits a much more pinched shape and a local imprint phenomenon is observed after severe fatigue. Furthermore, the domain structure evolves from a simple single-peak profile to a complex fluctuant one. However, there is only some shift of the piezoloop when a unipolar field with the same amplitude is applied on the film. The available experimental data show that there exist obvious domain wall pinning and injection of electrons into the film during fatigue. Finally, a schematic illustration is suggested to explain the possible fatigue mechanism

  11. Effects of bacteria on CdS thin films used in technological devices

    Science.gov (United States)

    Alpdoğan, S.; Adıgüzel, A. O.; Sahan, B.; Tunçer, M.; Metin Gubur, H.

    2017-04-01

    Cadmium sulfide (CdS) thin films were fabricated on glass substrates by the chemical bath deposition method at 70 {}^\\circ \\text{C} considering deposition times ranging from 2 h to 5 h. The optical band gaps of CdS thin films were found to be in the 2.42-2.37 eV range. CdS thin films had uniform spherical nano-size grains which had polycrystalline, hexagonal and cubic phases. The films had a characteristic electrical resistivity of the order of {{10}5} Ω \\text{cm} and n-type conductivity at room condition. CdS thin films were incubated in cultures of B.domonas aeruginosa and Staphylococcus aureus, which exist abundantly in the environment, and form biofilms. SEM images showed that S. aureus and K. pneumonia were detected significantly on the film surfaces with a few of P. aeruginosa and B. subtilis cells attached. CdS thin film surface exhibits relatively good resistance to the colonization of P. aeruginosa and B. subtilis. Optical results showed that the band gap of CdS thin films which interacted with the bacteria is 2.42 \\text{eV} . The crystal structure and electrical properties of CdS thin films were not affected by bacterial adhesion. The antimicrobial effect of CdS nanoparticles was different for different bacterial strains.

  12. Effect of annealing temperature on optical and electrical properties of metallophthalocyanine thin films deposited on silicon substrate

    Directory of Open Access Journals (Sweden)

    Skonieczny R.

    2016-09-01

    Full Text Available The cobalt phthalocyanine (CoPc thin films (300 nm thick deposited on n-type silicon substrate have been studied using micro-Raman spectroscopy, atomic force spectroscopy (AFM and I-V measurement. The CoPc thin layers have been deposited at room temperature by the quasi-molecular beam evaporation technique. The micro-Raman spectra of CoPc thin films have been recorded in the spectral range of 1000 cm-1 to 1900 cm-1 using 488 nm excitation wavelength. Moreover, using surface Raman mapping it was possible to obtain information about polymorphic forms distribution (before and after annealing of metallophthalocyanine (α and β form from polarized Raman spectra. The I-V characteristics of the Au/CoPc/n-Si/Al Schottky barrier were also investigated. The obtained results showed that influence of the annealing process plays a crucial role in the ordering and electrical conductivity of the molecular structure of CoPc thin films deposited on n-type silicon substrate.

  13. Pulsed Laser Deposition of BaTiO3 Thin Films on Different Substrates

    Directory of Open Access Journals (Sweden)

    Yaodong Yang

    2010-01-01

    Full Text Available We have studied the deposition of BaTiO3 (BTO thin films on various substrates. Three representative substrates were selected from different types of material systems: (i SrTiO3 single crystals as a typical oxide, (ii Si wafers as a semiconductor, and (iii Ni foils as a magnetostrictive metal. We have compared the ferroelectric properties of BTO thin films obtained by pulsed laser deposition on these diverse substrates.

  14. Infrared refractive index of thin YBa2Cu3O7 superconducting films

    International Nuclear Information System (INIS)

    Zhang, Z.M.; Choi, B.I.; Le, T.A.; Flik, M.I.; Siegal, M.P.; Phillips, J.M.

    1992-01-01

    This work investigates whether thin-film optics with a constant refractive index can be applied to high-T c superconducting thin films. The reflectance and transmittance of YBa 2 Cu 3 O 7 films on LaAlO 3 substrates are measured using a Fourier-transform infrared spectrometer at wavelengths from 1 to 100 μm at room temperature. The reflectance of these superconducting films at 10K in the wavelength region from 2.5 to 25 μm is measured using a cryogenic reflectance accessory. The film thickness varies from 10 to 200 nm. By modeling the frequency-dependent complex conductivity in the normal and superconducting states and applying electromagnetic-wave theory, the complex refractive index of YBa 2 Cu 3 O 7 films is obtained with a fitting technique. It is found that a thickness-independent refractive index can be applied even to a 25nm film, and average values of the spectral refractive index for film thicknesses between 25 and 200 nm are recommended for engineering applications

  15. Optimized pre-thinning procedures of ion-beam thinning for TEM sample preparation by magnetorheological polishing.

    Science.gov (United States)

    Luo, Hu; Yin, Shaohui; Zhang, Guanhua; Liu, Chunhui; Tang, Qingchun; Guo, Meijian

    2017-10-01

    Ion-beam-thinning is a well-established sample preparation technique for transmission electron microscopy (TEM), but tedious procedures and labor consuming pre-thinning could seriously reduce its efficiency. In this work, we present a simple pre-thinning technique by using magnetorheological (MR) polishing to replace manual lapping and dimpling, and demonstrate the successful preparation of electron-transparent single crystal silicon samples after MR polishing and single-sided ion milling. Dimples pre-thinned to less than 30 microns and with little mechanical surface damage were repeatedly produced under optimized MR polishing conditions. Samples pre-thinned by both MR polishing and traditional technique were ion-beam thinned from the rear side until perforation, and then observed by optical microscopy and TEM. The results show that the specimen pre-thinned by MR technique was free from dimpling related defects, which were still residual in sample pre-thinned by conventional technique. Nice high-resolution TEM images could be acquired after MR polishing and one side ion-thinning. MR polishing promises to be an adaptable and efficient method for pre-thinning in preparation of TEM specimens, especially for brittle ceramics. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Modulation of magnetic coercivity in Ni thin films by reversible control of strain

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Wen-Chin, E-mail: wclin@ntnu.edu.tw [Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan (China); Huang, Chia-Wei; Ting, Yi-Chieh; Lo, Fang-Yuh [Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan (China); Chern, Ming-Yau [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China)

    2015-05-01

    In this study, we demonstrated the magnetoelectric control of magnetic thin films. (111)-textured Pd/Ni/Pd thin films were prepared on mica/lead zirconium titanate (PZT) substrates for the investigation. The reversible modulation of magnetic coercivity in Ni films was observed through the electric-voltage-controlled strain variation from the PZT substrate. For 14 nm Ni film, the applied electric field of ±350 V/m led to ±0.5% strain variation of PZT, which was transferred to ±0.4% strain variation of Pd/Ni/Pd thin films on mica, and resulted in ∓17 Oe (∓5% of the preliminary magnetic coercivity). The reversible modulation of magnetic coercivity is supposed to be caused by the voltage-controlled strain through the magneto-elastic effect. - Highlights: • The magnetoelectric control of the magnetic coercivity of Pd/Ni/Pd thin films was demonstrated. • The ±0.4% strain variation of 14 nm Ni thin films resulted in ±17 Oe change of H{sub c}. • The reversible modulation of H{sub c} is supposed to be caused by the magneto-elastic effect.

  17. Thin layer model for nonlinear evolution of the Rayleigh-Taylor instability

    Science.gov (United States)

    Zhao, K. G.; Wang, L. F.; Xue, C.; Ye, W. H.; Wu, J. F.; Ding, Y. K.; Zhang, W. Y.

    2018-03-01

    On the basis of the thin layer approximation [Ott, Phys. Rev. Lett. 29, 1429 (1972)], a revised thin layer model for incompressible Rayleigh-Taylor instability has been developed to describe the deformation and nonlinear evolution of the perturbed interface. The differential equations for motion are obtained by analyzing the forces (the gravity and pressure difference) of fluid elements (i.e., Newton's second law). The positions of the perturbed interface are obtained from the numerical solution of the motion equations. For the case of vacuum on both sides of the layer, the positions of the upper and lower interfaces obtained from the revised thin layer approximation agree with that from the weakly nonlinear (WN) model of a finite-thickness fluid layer [Wang et al., Phys. Plasmas 21, 122710 (2014)]. For the case considering the fluids on both sides of the layer, the bubble-spike amplitude from the revised thin layer model agrees with that from the WN model [Wang et al., Phys. Plasmas 17, 052305 (2010)] and the expanded Layzer's theory [Goncharov, Phys. Rev. Lett. 88, 134502 (2002)] in the early nonlinear growth regime. Note that the revised thin layer model can be applied to investigate the perturbation growth at arbitrary Atwood numbers. In addition, the large deformation (the large perturbed amplitude and the arbitrary perturbed distributions) in the initial stage can also be described by the present model.

  18. Ultra-thin flexible GaAs photovoltaics in vertical forms printed on metal surfaces without interlayer adhesives

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Juho; Song, Kwangsun; Kim, Namyun; Lee, Jongho, E-mail: jong@gist.ac.kr [School of Mechanical Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005 (Korea, Republic of); Research Institute for Solar and Sustainable Energies (RISE), Gwangju Institute of Science and Technology (GIST), Gwangju 61005 (Korea, Republic of); Hwang, Jeongwoo [Photonic Bio Research Center, Korea Photonics Technology Institute (KOPTI), 9 Cheomdanventure-ro 108beon-gil, Gwangju 61007 (Korea, Republic of); Shin, Jae Cheol [Department of Physics, Yeungnam University, Gyeongsan, Gyeongbuk 38541 (Korea, Republic of)

    2016-06-20

    Wearable flexible electronics often require sustainable power sources that are also mechanically flexible to survive the extreme bending that accompanies their general use. In general, thinner microelectronic devices are under less strain when bent. This paper describes strategies to realize ultra-thin GaAs photovoltaics through the interlayer adhesiveless transfer-printing of vertical-type devices onto metal surfaces. The vertical-type GaAs photovoltaic devices recycle reflected photons by means of bottom electrodes. Systematic studies with four different types of solar microcells indicate that the vertical-type solar microcells, at only a quarter of the thickness of similarly designed lateral-type cells, generate a level of electric power similar to that of thicker cells. The experimental results along with the theoretical analysis conducted here show that the ultra-thin vertical-type solar microcells are durable under extreme bending and thus suitable for use in the manufacturing of wearable flexible electronics.

  19. Electron transport properties of some new 4-tert-butylcalix[4]arene derivatives in thin films

    Energy Technology Data Exchange (ETDEWEB)

    Leontie, Liviu, E-mail: lleontie@uaic.ro [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, B-dul Carol I, Nr. 11, 700506 Iasi (Romania); Danac, Ramona [Faculty of Chemistry, Alexandru Ioan Cuza University of Iasi, B-dul Carol I, Nr. 11, 700506 Iasi (Romania); Girtan, Mihaela [Laboratoire LPhiA, Angers University, 2, Bd. Lavoisier, 49045, Angers (France); Carlescu, Aurelian; Rambu, Alicia Petronela; Rusu, Gheorghe I. [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, B-dul Carol I, Nr. 11, 700506 Iasi (Romania)

    2012-07-16

    Temperature dependences of electric conductivity and thermoelectric power of some recently synthesized organic compounds, 4-tert-butylcalix[4]arene derivatives, are studied. Thin-film samples (d = 0.10-0.40 {mu}m) spin-coated from chloroform solutions onto glass substrates were used. Organic films with reproducible electron transport properties can be obtained if, after deposition, they are submitted to a heat treatment within temperature range of 295-575 K. The studied polycrystalline compounds show typical p-type semiconductor behavior. The activation energy of the electric conduction ranges between 0.82 and 1.12 eV, while the ratio of charge carrier mobilities was found in the range of 0.83-0.94. Some correlations between semiconducting parameters and molecular structure of the organic compounds have been discussed. In the higher temperature ranges (T > 420 K), the electron transport in examined compounds can be interpreted in terms of the band gap representation model, while in the lower temperature range, the Mott's variable-range hopping conduction model was found to be appropriate. The investigated compounds hold promise for thermistor applications. - Highlights: Black-Right-Pointing-Pointer 4-tert-butylcalix(4)arene derivatives in thin films are p-type semiconductors. Black-Right-Pointing-Pointer The electron transfer is favored by their extended conjugation and packing capacity. Black-Right-Pointing-Pointer The band gap representation is suitable in the higher temperature range. Black-Right-Pointing-Pointer The Mott's VRH conduction model may be applied in the lower temperature range. Black-Right-Pointing-Pointer As-prepared organic compounds are promising for thermistor applications.

  20. Electron transport properties of some new 4-tert-butylcalix[4]arene derivatives in thin films

    International Nuclear Information System (INIS)

    Leontie, Liviu; Danac, Ramona; Girtan, Mihaela; Carlescu, Aurelian; Rambu, Alicia Petronela; Rusu, Gheorghe I.

    2012-01-01

    Temperature dependences of electric conductivity and thermoelectric power of some recently synthesized organic compounds, 4-tert-butylcalix[4]arene derivatives, are studied. Thin-film samples (d = 0.10–0.40 μm) spin-coated from chloroform solutions onto glass substrates were used. Organic films with reproducible electron transport properties can be obtained if, after deposition, they are submitted to a heat treatment within temperature range of 295–575 K. The studied polycrystalline compounds show typical p-type semiconductor behavior. The activation energy of the electric conduction ranges between 0.82 and 1.12 eV, while the ratio of charge carrier mobilities was found in the range of 0.83–0.94. Some correlations between semiconducting parameters and molecular structure of the organic compounds have been discussed. In the higher temperature ranges (T > 420 K), the electron transport in examined compounds can be interpreted in terms of the band gap representation model, while in the lower temperature range, the Mott's variable-range hopping conduction model was found to be appropriate. The investigated compounds hold promise for thermistor applications. - Highlights: ► 4-tert-butylcalix(4)arene derivatives in thin films are p-type semiconductors. ► The electron transfer is favored by their extended conjugation and packing capacity. ► The band gap representation is suitable in the higher temperature range. ► The Mott's VRH conduction model may be applied in the lower temperature range. ► As-prepared organic compounds are promising for thermistor applications.