Stronger multilayer acrylic dielectric elastomer actuators with silicone gel coatings

Science.gov (United States)

Lau, Gih-Keong; La, Thanh-Giang; Sheng-Wei Foong, Ervin; Shrestha, Milan

2016-12-01

Multilayer dielectric elastomer actuators (DEA) perform worst off than single-layer DEAs due to higher susceptibility to electro-thermal breakdown. This paper presents a hot-spot model to predict the electro-thermal breakdown field of DEAs and its dependence on thermal insulation. To inhibit the electrothermal breakdown, silicone gel coating was applied as barrier coating to multilayer acrylic DEA. The gel coating helps suppress the electro-thermally induced puncturing of DEA membrane at the hot spot. As a result, the gel-coated DEAs, in either a single layer or a multilayer stack, can produce 30% more isometric stress change as compared to those none-coated. These gel-coated acrylic DEAs show great potential to make stronger artificial muscles.

Rocket flight of a multilayer coated high-density EUV toroidal grating

Science.gov (United States)

Keski-Kuha, Ritva A. M.; Thomas, Roger J.; Davila, Joseph M.

1992-01-01

A multilayer coated high density toroidal grating was flown on a sounding rocket experiment in the Solar EUV Rocket Telescope and Spectrograph (SERTS) instrument. To our knowledge this is the first space flight of a multilayer coated grating. Pre-flight performance evaluation showed that the application of a 10-layer Ir/Si multilayer coating to the 3600 l/mm blazed toroidal replica grating produced a factor of 9 enhancement in peak efficiency near the design wavelength around 30 nm in first order over the standard gold coating, with a measured EUV efficiency that peaked at 3.3 percent. In addition, the grating's spectral resolution of better than 5000 was maintained. The region of enhanced grating efficiency due to the multilayer coating is clearly evident in the flight data. Within the bandpass of the multilayer coating, the recorded film densities were roughly equivalent to those obtained with a factor of six longer exposure on the previous flight of the SERTS instrument.

Searching for optimal mitigation geometries for laser resistant multilayer high reflector coatings

Energy Technology Data Exchange (ETDEWEB)

Qiu, S R; Wolfe, J E; Monterrosa, A M; Feit, M D; Pistor, T V; STolz, C J

2011-02-11

Growing laser damage sites on multilayer high reflector coatings can limit mirror performance. One of the strategies to improve laser damage resistance is to replace the growing damage sites with pre-designed benign mitigation structures. By mitigating the weakest site on the optic, the large aperture mirror will have a laser resistance comparable to the intrinsic value of the multilayer coating. To determine the optimal mitigation geometry, the finite difference time domain method (FDTD) was used to quantify the electric-field intensification within the multilayer, at the presence of different conical pits. We find that the field intensification induced by the mitigation pit is strongly dependent on the polarization and the angle of incidence (AOI) of the incoming wave. Therefore the optimal mitigation conical pit geometry is application specific. Furthermore, our simulation also illustrates an alternative means to achieve an optimal mitigation structure by matching the cone angle of the structure with the AOI of the incoming wave, except for the p-polarization wave at a range of incident angles between 30{sup o} and 45{sup o}.

Characterization of multilayer nitride coatings by electron microscopy and modulus mapping

International Nuclear Information System (INIS)

Pemmasani, Sai Pramod; Rajulapati, Koteswararao V.; Ramakrishna, M.; Valleti, Krishna; Gundakaram, Ravi C.; Joshi, Shrikant V.

2013-01-01

This paper discusses multi-scale characterization of physical vapour deposited multilayer nitride coatings using a combination of electron microscopy and modulus mapping. Multilayer coatings with a triple layer structure based on TiAlN and nanocomposite nitrides with a nano-multilayered architecture were deposited by Cathodic arc deposition and detailed microstructural studies were carried out employing Energy Dispersive Spectroscopy, Electron Backscattered Diffraction, Focused Ion Beam and Cross sectional Transmission Electron Microscopy in order to identify the different phases and to study microstructural features of the various layers formed as a result of the deposition process. Modulus mapping was also performed to study the effect of varying composition on the moduli of the nano-multilayers within the triple layer coating by using a Scanning Probe Microscopy based technique. To the best of our knowledge, this is the first attempt on modulus mapping of cathodic arc deposited nitride multilayer coatings. This work demonstrates the application of Scanning Probe Microscopy based modulus mapping and electron microscopy for the study of coating properties and their relation to composition and microstructure. - Highlights: • Microstructure of a triple layer nitride coating studied at multiple length scales. • Phases identified by EDS, EBSD and SAED (TEM). • Nanolayered, nanocomposite structure of the coating studied using FIB and TEM. • Modulus mapping identified moduli variation even in a nani-multilayer architecture

Multilayer DLC coatings via alternating bias during magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Li Fengji [School of Mechanical and Aerospace Engineering, Nanyang Technological University (Singapore); Zhang, Sam, E-mail: msyzhang@ntu.edu.sg [School of Mechanical and Aerospace Engineering, Nanyang Technological University (Singapore); Kong Junhua [School of Materials Science and Engineering, Nanyang Technological University (Singapore); Zhang Yujuan [Key Laboratory of Special Functional Material, Henan University (China); Zhang Wali [School of Mechanical and Aerospace Engineering, Nanyang Technological University (Singapore)

2011-05-31

To combat the high residual stress problem in monolayer diamond-like carbon coatings, this paper fabricated multilayer diamond-like carbon coatings with alternate soft and hard layers via alternating bias during magnetron sputtering. The surface, cross sectional morphology, bonding structures and mechanical properties are investigated. The atomic force microscopy images indicate low bias results in rougher surface with large graphite clusters and voids suggesting low coating density. The multilayered coatings demonstrate relatively smooth surface stemming from higher bias. The cross sectional images from field emission scanning electron microscopy indicate coating thickness decreases as substrate bias increases and confirm that higher bias results in denser coating. Delamination is observed in monolayer coatings due to high residual stress. The trend of sp{sup 3}/sp{sup 2} fraction estimated by X-ray photoelectron spectroscopy is consistent with that of I{sub D}/I{sub G} ratios from Raman spectra, indicating the change of bonding structure with change of substrate bias. Hardness of multilayer diamond-like carbon coating is comparable to the coatings deposited at low constant bias but the adhesion strength and toughness are significantly improved. Alternately biased sputtering deposition provides an alternative when combination of hardness, toughness and adhesion strength is needed in an all diamond-like carbon coating.

High-power optical coatings for a mega-joule class ICF laser

International Nuclear Information System (INIS)

Kozlowski, M.R.; Thomas, I.M.; Campbell, J.H.; Rainer, F.

1992-11-01

As a consequence of advancements in Inertial Confinement Fusion research, LLNL is developing plans for a new 1.5 to 2 mega-joule solid-state Nd:glass laser designed to achieve fusion ignition. The new design is possible in part due to advances in optical coatings suitable for high power laser systems. High damage threshold mirrors and polarizers are comprised of electron beam deposited dielectric multilayers. Subthreshold illumination, or laser conditioning, of the multilayer coatings results in an increase in the damage thresholds by factors of 2 to 3 at 1.06μm, thus meeting the fluence requirements of the advanced architecture. For anti-reflective coatings, protective organic coatings for non-linear crystals and phase plates for beam smoothing, sol-gel films provide high damage thresholds coatings at low cost

NuSTAR calibration facility and multilayer reference database: Optic response model comparison to NuSTAR on-ground calibration data

DEFF Research Database (Denmark)

Brejnholt, Nicolai

. To couple the as-coated multilayer to the actual optics, ray tracing is carried out in a detailed geometric model of the optic, including in-situ measured figure error for the mounted substrates. The effective area as a function of energy estimated from ray tracing is compared to NuSTAR on......The Nuclear Spectroscopic Telescope ARray (NuSTAR) is a NASA Small Explorer mission carrying the first focusing hard X-ray telescope (5 − 80 keV ) to orbit. NuSTAR is slated for launch in 2012. Through a leap in sensitivity, the realization of focusing optics holds promise of heralding in a golden...... the optic response for both on- and off-axis NuSTAR observations, detailed knowledge of the as-coated multilayer is required. The purpose of this thesis is to establish a multilayer reference database. As an integral part of this effort, a hard X-ray calibration facility was designed and constructed. Each...

Enhanced corrosion protective PANI-PAA/PEI multilayer composite coatings for 316SS by spin coating technique

Energy Technology Data Exchange (ETDEWEB)

Syed, Junaid Ali; Lu, Hongbin; Tang, Shaochun; Meng, Xiangkang, E-mail: mengxk@nju.edu.cn

2015-01-15

Highlights: • PANI-PAA/PEI multilayers with controllable thickness were fabricated by spin assembly. • PAA matrix results in the homogeneous dispersion of PANI in the composite coatings. • Spin coating combined with heating assures the linear increase in thickness with n. • The corrosion protection property of PANI-PAA/PEI coatings were optimized at n = 20. • Enhanced protection owing to multilayer structure that lengthens the diffusion pathway of ions. - Abstract: In the present study, polyaniline-polyacrylic acid/polyethyleneimine (PANI-PAA/PEI) composite coatings with a multilayer structure for corrosion protection of 316 stainless steels (316SS) were prepared by an alternate deposition. Spin coating combined with heating assists removal of residual water that result in a linear increase in thickness with layer number (n). The combination of PANI-PAA composite with PEI and their multilayer structure provides a synergistic enhancement of corrosion resistance properties as determined by electrochemical measurements in 3.5% NaCl solution. Importantly, the PANI-PAA/PEI coating with an optimized layer number of n = 20 shows improved corrosion protection. The superior performance was attributed to the formation of an interfacial oxide layer as well as the multilayer structure that extend the diffusion pathway of corrosive ions.

Investigation on surface, electrical and optical properties of ITO-Ag-ITO coated glass

International Nuclear Information System (INIS)

Aslan Necdet; Sen, Tuba; Coruhlu Turgay; Senturk Kenan; Keskin Sinan; Seker Sedat; Dobrovolskiy Andrey

2015-01-01

The aim of this work was to study the optical and electrical properties of thick ITO-Ag-ITO multilayer coating onto glass. ITO-Ag-ITO coatings with thickness of ITO layers 110 nm, 185 nm and intermediate Ag layer thickness 40 nm were prepared by magnetron sputtering. The optical, electrical and atomic properties of the coating were examined by scanning electron microscope, atomic force microscope, X-ray diffraction analysis and ultraviolet-visible spectroscopy

Multilayer Antireflection Coating for Triple Junction Solar Cells

International Nuclear Information System (INIS)

Zhan Feng; Wang Hai-Li; He Ji-Fang; Wang Juan; Huang She-Song; Ni Hi-Qiao; Niu Zhi-Chuan

2011-01-01

According to the theory of optical films, we simulate the reflectivity of antireflection coatings (ARCs) for solar cells of Ga 0.5 In 0.5 P/GaAs/Ge based on an optical transfer matrix. In order to provide sufficient consideration of the refractive index dispersion effect of multilayer ARCs, we use multi-dimensional matrix data for reliable simulation. After the reflection curves are obtained, the effective average reflectance R e is introduced to optimize the film system by minimizing R e . Optimization of single layer (Al 2 O 3 ), double layer (MgF 2 /ZnS) and triple layer (MgF 2 /Al 2 O 3 /ZnS) ARCs is realized by using this method for space and terrestrial applications. Effects of these ARCs are compared after optimization. These theoretical parameters can be used to guide experiments. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Nanolaminated TiN/Mo2N hard multilayer coatings

International Nuclear Information System (INIS)

Martev, I N; Dechev, D A; Ivanov, N P; Uzunov, T S D; Kashchieva, E P

2010-01-01

The paper presents results on the synthesis of hard multilayer coatings consisting of titanium nitride and molybdenum nitride thin films with thickness of several nm. The TiN and Mo 2 N films were successively deposited by reactive DC magnetron sputtering. These multilayer structures were investigated by Auger electron spectroscopy (AES), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), cross-section scanning electron microscopy (CSSEM) and cross-section electron probe microanalysis (CSEPMA). The mechanical properties of the multilayer coatings, namely, hardness, Young's modulus and the coefficient of plastic deformation were measured. The adhesion was evaluated by the Rockwell-C-impact test. Coatings with different total thickness were examined with respect to adhesion to substrates of tool materials.

Characterizations of multilayer ZnO thin films deposited by sol-gel spin coating technique

Directory of Open Access Journals (Sweden)

M.I. Khan

Full Text Available In this work, zinc oxide (ZnO multilayer thin films are deposited on glass substrate using sol-gel spin coating technique and the effect of these multilayer films on optical, electrical and structural properties are investigated. It is observed that these multilayer films have great impact on the properties of ZnO. X-ray Diffraction (XRD confirms that ZnO has hexagonal wurtzite structure. Scanning Electron Microscopy (SEM showed the crack-free films which have uniformly distributed grains structures. Both micro and nano particles of ZnO are present on thin films. Four point probe measured the electrical properties showed the decreasing trend between the average resistivity and the number of layers. The optical absorption spectra measured using UV–Vis. showed the average transmittance in the visible region of all films is 80% which is good for solar spectra. The performance of the multilayer as transparent conducting material is better than the single layer of ZnO. This work provides a low cost, environment friendly and well abandoned material for solar cells applications. Keywords: Multilayer films, Semiconductor, ZnO, XRD, SEM, Optoelectronic properties

Multilayer stacks obtained by ion assisted EB PVD aimed at thermal barrier coating

Energy Technology Data Exchange (ETDEWEB)

Roos, E.; Maile, K.; Lyutovich, A. [Stuttgart Univ. (DE). Materialpruefungsanstalt (MPA)

2010-07-01

Thermal Barrier Coating (TBC) using Electron Beam Physical Vapour Deposition (EB PVD) is widely implemented, especially for aero-engine turbine blades. Generally, multilayer stacks are used for these aims. For the additional improvement of intermediate layers with graded transitions to the initial Ni-based alloy, the use of accelerated ions in the EBPVD-process is advantageous. The effect of the substrate bias potential, ion current density and deposition temperature on the structure and properties of Ti and Zr intermediate layers are investigated. The morphology of the films is studied using optical microscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM). It is found that the surface morphology becomes smoother with rising bias potential and decreasing ion current density. Measurements of Vicker's micro-hardness performed on these coatings have shown its increase with higher values of the bias and its reduction with the growing temperature. This effect is caused by the observed decrease in grain size and higher porosity of the films. A multilayer coating system Ni (based substrate)-Si-Si{sub x}Al{sub y}-Al with graded transitions between the layers is obtained using ion assisted EBPVD. Architecture of a multilayer stack for TBC with graded transitions is proposed. (orig.)

Near-infrared radiation curable multilayer coating systems and methods for applying same

Science.gov (United States)

Bowman, Mark P; Verdun, Shelley D; Post, Gordon L

2015-04-28

Multilayer coating systems, methods of applying and related substrates are disclosed. The coating system may comprise a first coating comprising a near-IR absorber, and a second coating deposited on a least a portion of the first coating. Methods of applying a multilayer coating composition to a substrate may comprise applying a first coating comprising a near-IR absorber, applying a second coating over at least a portion of the first coating and curing the coating with near infrared radiation.

Substrate and coating defect planarization strategies for high-laser-fluence multilayer mirrors

International Nuclear Information System (INIS)

Stolz, Christopher J.; Wolfe, Justin E.; Mirkarimi, Paul B.; Folta, James A.; Adams, John J.; Menor, Marlon G.; Teslich, Nick E.; Soufli, Regina; Menoni, Carmen S.; Patel, Dinesh

2015-01-01

Planarizing or smoothing over nodular defects in multilayer mirrors can be accomplished by a discrete deposit-and-etch process that exploits the angle-dependent etching rate of optical materials. Typically, nodular defects limit the fluence on mirrors irradiated at 1064 nm with 10 ns pulse lengths due to geometrically- and interference-induced light intensification. Planarized hafina/silica multilayer mirrors have demonstrated > 125 J/cm 2 laser resistance for single-shot testing and 50 J/cm 2 for multi-shot testing for nodular defects originating on the substrate surface. Two planarization methods were explored: thick planarization layers on the substrate surface and planarized silica layers throughout the multilayer in which only the silica layers that are below one half of the incoming electric field value are etched. This paper also describes the impact of planarized defects that are buried within the multilayer structure compared to planarized substrate particulate defects. - Highlights: • Defect planarization significantly improves multilayer mirror laser resistance • Substrate and coating defects have both been effectively planarized • Single and multishot laser resistance improvement was demonstrated

Highly efficient blazed grating with multilayer coating for tender X-ray energies

NARCIS (Netherlands)

Senf, F.; Bijkerk, Frederik; Eggenstein, F.; Gwalt, G.; Huang, Qiushi; van de Kruijs, Robbert Wilhelmus Elisabeth; Kutz, O.; Lemke, S.; Louis, Eric; Mertin, M.; Packe, I.; Rudolph, I.; Schafers, F.; Siewert, F.; Sokolov, A.; Sturm, Jacobus Marinus; Waberski, C.; Wang, Z.; Wolf, J.; Zeschke, T.; Erko, A.

2016-01-01

For photon energies of 1 – 5 keV, blazed gratings with multilayer coating are ideally suited for the suppression of stray and higher orders light in grating monochromators. We developed and characterized a blazed 2000 lines/mm grating coated with a 20 period Cr/C- multilayer. The multilayer

Multilayer polymer light-emitting diodes by blade coating method

Science.gov (United States)

Tseng, Shin-Rong; Meng, Hsin-Fei; Lee, Kuan-Chen; Horng, Sheng-Fu

2008-10-01

Multilayer polymer light-emitting diodes fabricated by blade coating are presented. Multilayer of polymers can be easily deposited by blade coating on a hot plate. The multilayer structure is confirmed by the total thickness and the cross section view in the scanning electron microscope. The film thickness variation is only 3.3% in 10cm scale and the film roughness is about 0.3nm in the micron scale. The efficiency of single layer poly(para-phenylene vinylene) copolymer Super Yellow and poly(9,9-dioctylfluorene) (PFO, deep blue) devices are 9 and 1.7cd/A, respectively, by blade coating. The efficiency of the PFO device is raised to 2.9cd/A with a 2-(4-tert-butylphenyl)-5-(4-biphenylyl)-1,3,4-oxadiazole (PBD) hole-blocking layer and to 2.3cd/A with a poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl))diphenylamine)] elec-tron-blocking layer added by blade coating.

Multilayer oxidation resistant coating for SiC coated carbon/carbon composites at high temperature

International Nuclear Information System (INIS)

Li Hejun; Jiao Gengsheng; Li Kezhi; Wang Chuang

2008-01-01

To prevent carbon/carbon (C/C) composites from oxidation, a multilayer coating based on molybdenum disilicide and titanium disilicide was formed using a two-step pack cementation technique in argon atmosphere. XRD and SEM analysis showed that the internal coating was a bond SiC layer that acts as a buffer layer, and that the external multilayer coating formed in the two-step pack cementation was composed of two MoSi 2 -TiSi 2 -SiC layers. This coating, which is characterized by excellent thermal shock resistance, could effectively protect the composites from exposure to an oxidizing atmosphere at 1773 K for 79 h. The oxidation of the coated C/C composites was primarily due to the reaction of C/C matrix and oxygen diffusing through the penetrable cracks in the coating

Study on the wear of TiN/Ti duplex and multilayer coatings in microabrasion tests

International Nuclear Information System (INIS)

Flores, M; De Las Heras, E; Ruelas, R; Rodriguez, E; Bautista, A; Pazos, L; Corengia, P

2008-01-01

Ionic nitriding, on steels, is used to harden the surface of components improving resistance to corrosion and wear and increasing the stress life. Duplex treatments are an alternative for resolving the limitations of very hard coatings on less hard substrates. In this case the duplex treatment consists of an ionic nitriding treatment followed by a single or multilayer coatings deposited by means of the PVD technique. This work presents the influence of the variation in the severity of contact on the kind of wear present in the microabrasion test used to measure the wear coefficient of duplex coatings, consisting of a layer nitrided by DC-pulsed plasma plus TiN coatings and multilayers of TiN/Ti deposited on non-nitrided and nitrided AISI 316L stainless steel and H13 steel. The severity of contact was modified by varying the charge (0.25 to 1 N). The abrasives used were a suspension of 0.1μm diameter diamond particles and a suspension of an average 5 μm diameter aluminum particles. The influence of the presence of relatively soft metallic layers on the determination of the wear coefficient was analyzed in the metal-ceramic multilayers. Two sphere revolving speeds of de 0.05 and 0.154 m/s were used on two microabrasion machines: one commercial and the other built in the UdeG laboratory. The wear marks were photographed and measured with an optic microscope. The value of the critical charge at which the transition occurs between the methods of wear of the substrates and the nitrited samples was determined. Resistance to the AISI 316L steel's microabrasive wear increases with the ionic nitriding treatment. The duplex coatings increase resistance to the wear from the nitrited samples. The wear resistance of the samples with multilayer coatings surpassed that of the duplex samples with multilayer coatings. The greater resistance of the multilayers may be explained by an increase in the resistance to the fracture and not by a increase in surface hardness. The transition

Thick CrN/NbN multilayer coating deposited by cathodic arc technique

Energy Technology Data Exchange (ETDEWEB)

Araujo, Juliano Avelar; Tschiptschin, Andre Paulo; Souza, Roberto Martins, E-mail: antschip@usp.br [Universidade de Sao Paulo (USP), SP (Brazil); Lima, Nelson Batista de [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2017-01-15

The production of tribological nanoscale multilayer CrN/NbN coatings up to 6 μm thick by Sputtering/HIPIMS has been reported in literature. However, high demanding applications, such as internal combustion engine parts, need thicker coatings (>30 μm). The production of such parts by sputtering would be economically restrictive due to low deposition rates. In this work, nanoscale multilayer CrN/NbN coatings were produced in a high-deposition rate, industrial-size, Cathodic Arc Physical Vapor Deposition (ARC-PVD) chamber, containing three cathodes in alternate positions (Cr/ Nb/Cr). Four 30 μm thick NbN/CrN multilayer coatings with different periodicities (20, 10, 7.5 and 4 nm) were produced. The coatings were characterized by X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). The multilayer coating system was composed of alternate cubic rock salt CrN and NbN layers, coherently strained due to lattice mismatch. The film grew with columnar morphology through the entire stratified structure. The periodicities adopted were maintained throughout the entire coating. The 20 nm periodicity coating showed separate NbN and CrN peaks in the XRD patterns, while for the lower periodicity (≤10nm) coatings, just one intermediate lattice (d-spacing) was detected. An almost linear increase of hardness with decreasing bilayer period indicates that interfacial effects can dominate the hardening mechanisms. (author)

Barrier mechanism of multilayers graphene coated copper against atomic oxygen irradiation

Science.gov (United States)

Zhang, Haijing; Ren, Siming; Pu, Jibin; Xue, Qunji

2018-06-01

Graphene has been demonstrated as a protective coating for Cu under ambient condition because of its high impermeability and light-weight oxidation barrier. However, it lacks the research of graphene as a protective coating in space environment. Here, we experimentally and theoretically study the oxidation behavior of graphene-coated Cu in vacuum atomic oxygen (AO) condition. After AO irradiation, the experimental results show multilayer graphene has better anti-oxidation than monolayer graphene. Meanwhile, the calculation results show the oxidation appeared on the graphene's grain boundaries or the film's vacancy defects for the monolayer graphene coated Cu foil. Moreover, the calculation results show the oxidation process proceeds slowly in multilayers because of the matched defects overlaps each other to form a steric hindrance to suppress the O atom diffusion in the vertical direction, and the mismatched defects generates potential energy barriers for interlayer to suppress the O atom diffusion in the horizontal direction. Hence, multilayer graphene films could serve as protection coatings to prevent diffusion of O atom.

Laser Processing of Multilayered Thermal Spray Coatings: Optimal Processing Parameters

Science.gov (United States)

Tewolde, Mahder; Zhang, Tao; Lee, Hwasoo; Sampath, Sanjay; Hwang, David; Longtin, Jon

2017-12-01

Laser processing offers an innovative approach for the fabrication and transformation of a wide range of materials. As a rapid, non-contact, and precision material removal technology, lasers are natural tools to process thermal spray coatings. Recently, a thermoelectric generator (TEG) was fabricated using thermal spray and laser processing. The TEG device represents a multilayer, multimaterial functional thermal spray structure, with laser processing serving an essential role in its fabrication. Several unique challenges are presented when processing such multilayer coatings, and the focus of this work is on the selection of laser processing parameters for optimal feature quality and device performance. A parametric study is carried out using three short-pulse lasers, where laser power, repetition rate and processing speed are varied to determine the laser parameters that result in high-quality features. The resulting laser patterns are characterized using optical and scanning electron microscopy, energy-dispersive x-ray spectroscopy, and electrical isolation tests between patterned regions. The underlying laser interaction and material removal mechanisms that affect the feature quality are discussed. Feature quality was found to improve both by using a multiscanning approach and an optional assist gas of air or nitrogen. Electrically isolated regions were also patterned in a cylindrical test specimen.

Stress in tungsten carbide-diamond like carbon multilayer coatings

NARCIS (Netherlands)

Pujada, B.R.; Tichelaar, F.D.; Janssen, G.C.A.M.

2007-01-01

Tungsten carbide-diamond like carbon (WC-DLC) multilayer coatings have been prepared by sputter deposition from a tungsten-carbide target and periodic switching on and off of the reactive acetylene gas flow. The stress in the resulting WC-DLC multilayers has been studied by substrate curvature.

Optical coating preparation

International Nuclear Information System (INIS)

Belleville, P.; Sabary, F.; Marcel, C.

2003-01-01

In order to optimize the properties of optical components, thin film deposition with controlled thickness and refractive index is often needed. Two different deposition techniques are proposed in this article and illustrated with examples: physical vapor deposition (PVD) and liquid sol-gel process (LSG). PVD and LSG techniques are equivalent as far as the following topics are concerned: elaboration of oxide or composite coated material, optical performance, mechanical performance, and laser performance. PVD is better for the elaboration of metallic films, the design of multi-layers or complex pile-up of layers. LSG is better for the treatment of large surfaces, for substrates with complicated shapes and for its low cost. PVD technique has been widely used so it benefited from an industrial maturity and a clean technology concerning wastes and effluents. On the contrary LSG is a new technique not yet widely used in industrial processes but that looks promising. (A.C.)

Optical measurement of thermal deformation of multilayer optics under synchrotron radiation

International Nuclear Information System (INIS)

Revesz, P.; Kazimirov, A.; Bazarov, I.

2007-01-01

An in situ optical technique to visualize surface distortions of the first monochromator crystal under synchrotron beam heat loading has been developed and applied to measure surface profiles of multilayer optics under white wiggler beam at the CHESS A2 beamline. Two identical multilayer structures deposited on Si and SiC substrates have been tested. Comparison of the reconstructed 3D heatbump profiles showed the surface distortions of the multilayer on SiC a factor of two smaller than the same multilayer on a Si substrate

Optical measurement of thermal deformation of multilayer optics under synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Revesz, P. [Cornell University, CHESS, Ithaca, NY 14850 (United States)], E-mail: pr20@cornell.edu; Kazimirov, A.; Bazarov, I. [Cornell University, CHESS, Ithaca, NY 14850 (United States)

2007-11-11

An in situ optical technique to visualize surface distortions of the first monochromator crystal under synchrotron beam heat loading has been developed and applied to measure surface profiles of multilayer optics under white wiggler beam at the CHESS A2 beamline. Two identical multilayer structures deposited on Si and SiC substrates have been tested. Comparison of the reconstructed 3D heatbump profiles showed the surface distortions of the multilayer on SiC a factor of two smaller than the same multilayer on a Si substrate.

Surface self-organization in multilayer film coatings

Science.gov (United States)

Shuvalov, Gleb M.; Kostyrko, Sergey A.

2017-12-01

It is a recognized fact that during film deposition and subsequent thermal processing the film surface evolves into an undulating profile. Surface roughness affects many important aspects in the engineering application of thin film materials such as wetting, heat transfer, mechanical, electromagnetic and optical properties. To accurately control the morphological surface modifications at the micro- and nanoscale and improve manufacturing techniques, we design a mathematical model of the surface self-organization process in multilayer film materials. In this paper, we consider a solid film coating with an arbitrary number of layers under plane strain conditions. The film surface has a small initial perturbation described by a periodic function. It is assumed that the evolution of the surface relief is governed by surface and volume diffusion. Based on Gibbs thermodynamics and linear theory of elasticity, we present a procedure for constructing a governing equation that gives the amplitude change of the surface perturbation with time. A parametric study of the evolution equation leads to the definition of a critical undulation wavelength that stabilizes the surface. As a numerical result, the influence of geometrical and physical parameters on the morphological stability of an isotropic two-layered film coating is analyzed.

Oxidation behavior of Ru–Al multilayer coatings

Energy Technology Data Exchange (ETDEWEB)

Chen, Yung-I, E-mail: yichen@mail.ntou.edu.tw; Zheng, Zhi-Ting; Kai, Wu; Huang, Yu-Ren

2017-06-01

Highlights: • Ru{sub 0.63}Al{sub 0.37} multilayer coatings were fabricated using cosputtering. • Oxidation behavior of Ru{sub 0.63}Al{sub 0.37} coatings in 1% O{sub 2}–99% Ar was studied. • Internal oxidation of Ru{sub 0.63}Al{sub 0.37} coatings at 400–600 °C was multi stage parabolic. • External oxidation of Ru{sub 0.63}Al{sub 0.37} was conducted after annealing at 700–800 °C. - Abstract: Ru{sub 0.63}Al{sub 0.37} coatings were deposited through a cyclical gradient concentration deposition at 400 °C with a substrate-holder rotation speed of 1 rpm by direct current magnetron cosputtering. Scanning electron microscopy revealed that the as-deposited coatings exhibited a multilayer structure along with the columnar structure. The oxidation behavior of the Ru{sub 0.63}Al{sub 0.37} coatings was examined through X-ray diffraction, Auger electron spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. Oxidation kinetics was measured using a thermogravimetric analyzer. Internal oxidation was observed for Ru{sub 0.63}Al{sub 0.37} coatings annealed in a 1% O{sub 2}–99% Ar atmosphere at 400–600 °C accompanied with activation energies of 72–84 kJ/mol. By contrast, external oxidation was observed after annealing at 700–800 °C, resulting in the formation of a continuous alumina scale consisting of crystalline δ-Al{sub 2}O{sub 3} domains, which can be attributable to the outward diffusion of Al.

Development of Nanostructured Antireflection Coatings for Infrared and Electro-Optical Systems

Directory of Open Access Journals (Sweden)

Gopal G. Pethuraja

2017-07-01

Full Text Available Electro-optic infrared technologies and systems operating from ultraviolet (UV to long-wave infrared (LWIR spectra are being developed for a variety of defense and commercial systems applications. Loss of a significant portion of the incident signal due to reflection limits the performance of electro-optic infrared (IR sensing systems. A critical technology being developed to overcome this limitation and enhance the performance of sensing systems is advanced antireflection (AR coatings. Magnolia is actively involved in the development and advancement of nanostructured AR coatings for a wide variety of defense and commercial applications. Ultrahigh AR performance has been demonstrated for UV to LWIR spectral bands on various substrates. The AR coatings enhance the optical transmission through optical components and devices by significantly minimizing reflection losses, a substantial improvement over conventional thin-film AR coating technologies. Nanostructured AR coatings have been fabricated using a nanomanufacturable self-assembly process on substrates that are transparent for a given spectrum of interest ranging from UV to LWIR. The nanostructured multilayer structures have been designed, developed and optimized for various optoelectronic applications. The optical properties of optical components and sensor substrates coated with AR structures have been measured and the process parameters fine-tuned to achieve a predicted high level of performance. In this paper, we review our latest work on high quality nanostructure-based AR coatings, including recent efforts on the development of nanostructured AR coatings on IR substrates.

Structural and optical properties of ZnO nanostructures electrochemically synthesized on AZO/Ag/AZO-multilayer-film-coated polyethersulfone substrates

International Nuclear Information System (INIS)

Oh, Dohyun; Yoo, Chanho; No, Youngsoo; Kim, Suyoun; Kim, Taewhan; Cho, Woonjo; Kim, Jinyoung

2012-01-01

ZnO nanostructures were formed on Al-doped ZnO (AZO)/Ag/AZO-multilayer-film-coated flexible polyethersulfone (PES) substrates at low temperature by using an electrochemical deposition method. The resistivity of the AZO/Ag/AZO multilayer films decreased with increasing thickness of the Ag film. X-ray diffraction patterns for the ZnO nanostructures showed that the crystal structure of the ZnO was hexagonal wurtzite and that the orientation was along the c-axis perpendicular to the substrate. Scanning electron microscopy images showed that the ZnO nanostructures grown at current densities of - 1.0 and - 1.5 mA/cm 2 were ZnO nanorods with diameters of 150 nm and ZnO nanoflowers with a planar dimension, respectively. Photoluminescence spectra showed that the band-edge emission peak of the ZnO nanostructures dominantly appeared in the ultraviolet region. These results showed that ZnO nanorods and nanoflowers with high quality were synthesized on AZO/Ag/AZO-multilayer-film-coated PES substrates.

Sprayed and Spin-Coated Multilayer Antireflection Coating Films for Nonvacuum Processed Crystalline Silicon Solar Cells

Directory of Open Access Journals (Sweden)

Abdullah Uzum

2017-01-01

Full Text Available Using the simple and cost-effective methods, spin-coated ZrO2-polymer composite/spray-deposited TiO2-compact multilayer antireflection coating film was introduced. With a single TiO2-compact film on the surface of a crystalline silicon wafer, 5.3% average reflectance (the reflectance average between the wavelengths of 300 nm and 1100 nm was observed. Reflectance decreased further down to 3.3% after forming spin-coated ZrO2 on the spray-deposited TiO2-compact film. Silicon solar cells were fabricated using CZ-Si p-type wafers in three sets: (1 without antireflection coating (ARC layer, (2 with TiO2-compact ARC film, and (3 with ZrO2-polymer composite/TiO2-compact multilayer ARC film. Conversion efficiency of the cells improved by a factor of 0.8% (from 15.19% to 15.88% owing to the multilayer ARC. Jsc was improved further by 2 mA cm−2 (from 35.3 mA cm−2 to 37.2 mA cm−2 when compared with a single TiO2-compact ARC.

Plasma Spray and Pack Cementation Process Optimization and Oxidation Behaviour of Novel Multilayered Coatings

Science.gov (United States)

Gao, Feng

The hot section components in gas turbines are subjected to a harsh environment with the temperature being increased continuously. The higher temperature has directly resulted in severe oxidation of these components. Monolithic coatings such as MCrAIY and aluminide have been traditionally used to protect the components from oxidation; however, increased operating temperature quickly deteriorates the coatings due to accelerated diffusion of aluminum in the coatings. To improve the oxidation resistance a group of multilayered coatings are developed in this study. The multilayered coatings consist of a Cr-Si co-deposited layer as the diffusion barrier, a plasma sprayed NiCrA1Y coating as the middle layer and an aluminized top layer. The Cr-Si and aluminized layers are fabricated using pack cementation processes and the NiCrA1Y coatings are produced using the Mettech Axial III(TM) System. All of the coating processes are optimized using the methodology of Design of Experiments (DOE) and the results are analyzed using statistical method. The optimal processes are adopted to fabricate the multilayered coatings for oxidation tests. The coatings are exposed in air at 1050°C and 1150°C for 1000 hr. The results indicate that a Cr layer and a silicon-rich barrier layer have formed on the interface between the Cr-Si coating and the NiCrA1Y coating. This barrier layer not only prevents aluminum and chromium from diffusing into the substrate, but also impedes the diffusion of other elements from the substrate into the coating. The results also reveal that, for optimal oxidation resistance at 1050°C, the top layer in a multilayered coating should have at least Al/Ni ratio of one; whereas the multilayered coating with the All Ni ratio of two in the top layer exhibits the best oxidation resistance at 1150°C. The DOE methodology provides an excellent means for process optimization and the selection of oxidation test matrix, and also offers a more thorough understanding of the

Electrochemical Formation of Multilayer SnO2-Sb x O y Coating in Complex Electrolyte.

Science.gov (United States)

Maizelis, Antonina; Bairachniy, Boris

2017-12-01

The multilayer antimony-doped tin dioxide coating was obtained by cathodic deposition of multilayer metal-hydroxide coating with near 100-nm thickness layers on the alloy underlayer accompanied by the anodic oxidation of this coating. The potential regions of deposition of tin, antimony, tin-antimony alloy, and mixture of this metals and their hydroxides in the pyrophosphate-tartrate electrolyte were revealed by the cyclic voltammetric method. The possibility of oxidation of cathodic deposit consisting of tin and Sn(II) hydroxide compounds to the hydrated tin dioxide in the same electrolyte was demonstrated.The operations of alloy underlayer deposition and oxidation of multilayer metal-hydroxide coating were proposed to carry out in the diluted pyrophosphate-tartrate electrolyte, similar to the main electrolyte.The accelerated tests showed higher service life of the titanium electrode with multilayer antimony-doped tin dioxide coating compared to both electrode with single-layer electrodeposited coating and the electrode with the coating obtained using prolonged heat treatment step.

Ultra-short-period WC/SiC multilayer coatings for x-ray applications

International Nuclear Information System (INIS)

Fernández-Perea, Mónica; Pivovaroff, Mike J.; Soufli, Regina; Alameda, Jennifer; Mirkarimi, Paul; Descalle, Marie-Anne; Baker, Sherry L.; McCarville, Tom; Ziock, Klaus; Hornback, Donald; Romaine, Suzanne; Bruni, Ric; Zhong, Zhong; Honkimäki, Veijo; Ziegler, Eric; Christensen, Finn E.; Jakobsen, Anders C.

2013-01-01

Multilayer coatings enhance x-ray mirror performance at incidence angles steeper than the critical angle, allowing for improved flux, design flexibility and facilitating alignment. In an attempt to extend the use of multilayer coatings to photon energies higher than previously achieved, we have developed multilayers with ultra-short periods between 1 and 2 nm based on the material system WC/SiC. This material system was selected because it possesses very sharp and stable interfaces. In this article, we show highlights from a series of experiments performed in order to characterize the stress, microstructure and morphology of the multilayer films, as well as their reflective performance at photon energies from 8 to 384 keV

Microstructure, mechanical and tribological characterization of CrN/DLC/Cr-DLC multilayer coating with improved adhesive wear resistance

Science.gov (United States)

Sui, Xudong; Liu, Jinyu; Zhang, Shuaituo; Yang, Jun; Hao, Junying

2018-05-01

Adhesive wear is one of the major reasons for the failure of components during various tribological application, especially for rubbing with viscous materials. This study presents CrN/DLC/Cr-DLC multilayer composite coatings prepared on a plasma enhanced chemical vapor deposition (PECVD) device with the close field unbalanced magnetron sputtering ion plating (CFUBMSIP) technique. SEM, XRD and Raman spectroscopy were used to determine the structure of multilayer coatings. It was found that the multilayer coatings are composed by the alternating CrN and DLC layers. Compared with the single CrN coatings, the friction coefficient of the CrN/DLC/Cr-DLC multilayer coating decreases about more than seven times after sliding a distance of 500 m. This helps to reduce the adhesive wear of multilayer coatings. Compared with the single CrN and DLC coating, the wear rate of the CrN/DLC/Cr-DLC multilayer coating is reduced by an order of magnitude to 7.10 × 10-17 (sliding with AISI 440C) and 2.64 × 10-17 (sliding with TC4) m3/(N m). The improved tribological performance of multilayer coatings mainly attributes to the introduction of lubricant DLC and hard support CrN layers, the enhancement of crack propagation inhibition, and the increment of elastic recovery value We (71.49%) by multilayer design method.

High-Reflectivity Multi-Layer Coatings for the CLASP Sounding Rocket Project

Science.gov (United States)

Narukage, Noriyuki; Kano, Ryohei; Bando, Takamasa; Ishikawa, Ryoko; Kubo, Masahito; Katsukawa, Yukio; Ishikawa, Shin-nosuke; Kobiki, Toshihiko; Giono, Gabriel; Auchere, Frederic;

Multilayered Zn-Ni alloy coatings for better corrosion protection of mild steel

Directory of Open Access Journals (Sweden)

Sadananda Rashmi

2017-06-01

Full Text Available A simple aqueous electrolyte for the deposition of anti-corrosive Zn-Ni alloy coatings was optimized using conventional Hull cell method. The corrosion protection value of the electrodeposited coatings at a current density (c.d. range of 2.0–5.0 A dm−2 has been testified in 5 wt% NaCl solution, as representative corrosion medium. The electrochemical behavior of the coatings towards corrosion was related to its surface topography, elemental composition and phase structure using scanning electron microscopy (SEM, energy dispersive spectroscopy (EDS and X-ray diffraction (XRD analyses, respectively. Among the monolithic coatings developed at different c.d.’s, the coating obtained at 3.0 A dm−2 was found to be the best with least corrosion current (icorr value. Further, the corrosion protection efficacy of the monolayer coatings were improved to many folds through multilayer coating approach, by modulating the cyclic cathode current densities (CCCD’s. The composition modulated multilayer (CMM Zn-Ni alloy coating with 60 layers, developed from the combination of CCCD’s 3.0 and 5.0 A dm−2 was found to be the best with 3 fold enhancement in corrosion protection efficiency. The formation of multilayer coatings was confirmed using cross-sectional SEM, and the experimental results are discussed with tables and figures.

Corrosion behaviour in saline environments of single-layer titanium and aluminium coatings, and of Ti/Al alternated multi-layers elaborated by a multi-beam PVD technique

International Nuclear Information System (INIS)

Merati, Abdenacer

1994-01-01

This research thesis reports the characterization of anti-corrosion titanium and aluminium coatings deposited on a 35CD4 steel under the form of mono-metallic layers or alternated Ti/Al multi-layers, and obtained by a multibeam PVD technique. The influence of different parameters is studied: single-layer thickness (5, 15 or 30 micro-metres), multi-layer distribution (5 to 6) and substrate (smooth or threaded). Layer nature and microstructure are studied by optical microscopy and scanning electron microscopy (SEM), as well as corrosion toughness in aqueous saline environments. Coated threaded samples have been studied after tightening tests. It appears that titanium layers are denser and more uniform than aluminium layers, and that multi-layer coatings provide a better protection than single-layer coatings. The best behaviour is obtained when titanium is in contact with steel, and aluminium is the outer layer in contact with the corroding environment [fr

Multilayer optics for x-ray analysis: design - fabrication - application

International Nuclear Information System (INIS)

Dietsch, R.; Holz, Th.; Bruegemann, L.

2002-01-01

Full text: The use of multilayer optics induced a decisive extension of opportunities in laboratory based X-ray analysis. With the growing number of different applications, more and more dedicated X-ray optics are required, optimized for the spectral range they are intended to be used for. Both the characteristic of the used X-ray source and the design of the multilayer optics finally define the performance of the conditioned incident beam for the application. In any case, qualified spacer and absorber materials have to be selected for the deposition of the multilayer in respect to the designated X-ray wavelength. X-ray optical devices based on uniform multilayers have the advantage of a wide acceptance angle but show chromatic aberrations. This effect can be avoided by synthesizing a multilayer with a lateral thickness gradient. The gradient ensures that any beam of a certain wavelength emitted from an infinite narrow X-ray source impinging the multilayer optics fulfills the Bragg condition. Three different types of curvature of laterally graded multilayer mirrors are used for X-ray analysis experiments: parabolic, elliptic and planar, which result in parallel, focusing and divergent beam conditions, respectively. Furthermore, the X-ray beam characteristics: intensity, monochromasy, divergence, beam width and brilliance can be additionally conditioned by combining one multilayer optics with either a different optic and/or with a crystal monochromator. The deposition of nanometer-multilayers, used as X-ray optical components, result in extraordinary requirements of the deposition process concerning precision, reproducibility and long term stability. Across a stack of more than 150 individual layers with thicknesses in the range between 1 to 10 nm, a variation of single layer thickness considerably lower than σ D = 0.1 nm and an interface roughness below σ R = 0.25 nm have to be achieved. Thickness homogeneity Δd/d -8 have to be guaranteed across macroscopic

Design and development of the multilayer optics for the new hard x-ray mission

Science.gov (United States)

Pareschi, G.; Basso, S.; Citterio, O.; Spiga, D.; Tagliaferri, G.; Civitani, M.; Raimondi, L.; Sironi, G.; Cotroneo, V.; Negri, B.; Parodi, Giancarlo; Martelli, F.; Borghi, G.; Orlandi, A.; Vernani, D.; Valsecchi, G.; Binda, R.; Romaine, S.; Gorenstein, P.; Attinà, P.

2017-11-01

The New Hard X-ray Mission (NHXM) project will be operated by 2017 and is currently undergoing a Phase B study, under the coordination of the Italian Space Agency (ASI). The project is being proposed by an international team in the context of the ESA Call CV M3 as a Small Mission program, with a large Italian participation. It is based on 4 hard X-ray optics modules, each formed by 60 evenly spaced multilayer coated Wolter I mirror shells. An extensible bench is used to reach the 10 m focal length. The Wolter I monolithic substrates with multilayer coating are produced in NiCo by electroforming replication. Three of the mirror modules will host in the focal plane a hybrid a detector system (a soft X-ray Si DEPFET array plus a high energy CdTe detector). The detector of the fourth telescope will be a photoelectric polarimeter with imaging capabilities, operating from 2 up to 35 keV. The total on axis effective area of the three telescopes at 1 keV and 30 kev is of 1500 cm2 and 350 cm2 respectively, with an angular resolution of 20 arcsec HEW at 30 keV. In this paper we report on the design and development of the multilayer coated X-ray mirrors based on NiCo shells.

Phosphorus-based compounds for EUV multilayer optics materials

NARCIS (Netherlands)

Medvedev, Viacheslav; Yakshin, Andrey; van de Kruijs, Robbert Wilhelmus Elisabeth; Bijkerk, Frederik

2015-01-01

We have evaluated the prospects of phosphorus-based compounds in extreme ultraviolet multilayer optics. Boron phosphide (BP) is suggested to be used as a spacer material in reflective multilayer optics operating just above the L-photoabsorption edge of P (λ ≈9.2 nm). Mo, Ag, Ru, Rh, and Pd were

Plastic Deformation Induced by Nanoindentation Test Applied on ZrN/Si3N4 Multilayer Coatings

Directory of Open Access Journals (Sweden)

Zhengtao Wu

2017-12-01

Full Text Available ZrN/Si3N4 multilayer coating that alternates with either nanocrystalline ZrN or amorphous Si3N4 interlayers was fabricated by reactively magnetron sputtering in an Ar-N2 mixture atmosphere. The thicknesses of the nanocrystalline ZrN and the amorphous Si3N4 interlayers are ~12.5 and 2.5 nm, respectively. The ZrN/Si3N4 coating exhibits a promoted hardness of 28.6 ± 1.2 GPa when compared to the binary ZrN. Microstructure evolution just underneath the nanoindentation impression of the ZrN/Si3N4 multilayer coating has been investigated. The result indicates that both ZrN nanograin rotations and plastic flow of the Si3N4 interlayers contribute to the permanent deformation of the multilayer coating induced by the nanoindentation. In addition, the introduction of the a-Si3N4 interlayers hinders both the initiation and propagation of microcracks when the multilayer coating was applied to the scratch test. The propagation deflection of the microcracks was observed attributed to the heterogenous interface, which produces the hardness promotion of the multilayer coating eventually.

Deconsolidation and combustion performance of thermally consolidated propellants deterred by multi-layers coating

Directory of Open Access Journals (Sweden)

Zheng-gang Xiao

2014-06-01

Full Text Available Both heating and solvent-spray methods are used to consolidate the standard grains of double-base oblate sphere propellants plasticized with triethyleneglycol dinitrate (TEGDN (TEGDN propellants to high density propellants. The obtained consolidated propellants are deterred and coated with the slow burning multi-layer coating. The maximum compaction density of deterred and coated consolidated propellants can reach up to 1.39 g/cm3. Their mechanic, deconsolidation and combustion performances are tested by the materials test machine, interrupted burning set-up and closed vessel, respectively. The static compression strength of consolidated propellants deterred by multi-layer coating increases significantly to 18 MPa, indicating that they can be applied in most circumstances of charge service. And the samples are easy to deconsolidate in the interrupted burning test. Furthermore, the closed bomb burning curves of the samples indicate a two-stage combustion phenomenon under the condition of certain thickness of coated multi-layers. After the outer deterred multi-layer coating of consolidated samples is finished burning, the inner consolidated propellants continue to burn and breakup into aggregates and grains. The high burning progressivity can be carefully obtained by the smart control of deconsolidation process and duration of consolidated propellants. The preliminary results of consolidated propellants show that a rapid deconsolidation process at higher deconsolidation pressure is presented in the dynamic vivacity curves of closed bomb test. Higher density and higher macro progressivity of consolidated propellants can be obtained by the techniques in this paper.

Cast iron cutting with nano TiN and multilayer TiN-CrN coated inserts

Science.gov (United States)

Perucca, M.; Durante, S.; Semmler, U.; Rüger, C.; Fuentes, G. G.; Almandoz, E.

2012-09-01

During the past decade great success has been achieved in the development of duplex and multilayer multi-functional surface systems. Among these surface systems outstanding properties have nanoscale multilayer coatings. Within the framework of the M3-2S project funded in the 7th European Framework Programme, several nanoscale multilayer coatings have been developed and investigated for experimental and industrial validation. This paper shows the performance of TiN and TiN/CrN nanoscale multilayer coatings on WC cutting inserts when machining GJL250 cast iron. The thin films have been deposited by cathodic arc evaporation in an industrial PVD system. The multilayer deposition characteristic and its properties are shown. The inserts have been investigated in systematic cutting experiments of cast iron bars on a turning machine specifically equipped for force measurements, accompanied by wear determination. Furthermore, equivalent experiments have been carried out on an industrial turning unit. Industrial validation criteria have been applied to assess the comparative performance of the coatings. The choice of the material and the machined parts is driven by an interest in automotive applications. The industrial tests show the need to further optimise the multi-scale modelling approach in order to reduce the lead time of the coating development as well as to improve simulation reliability.

Cast iron cutting with nano TiN and multilayer TiN-CrN coated inserts

International Nuclear Information System (INIS)

Perucca, M; Durante, S; Semmler, U; Rüger, C; Fuentes, G G; Almandoz, E

2012-01-01

During the past decade great success has been achieved in the development of duplex and multilayer multi-functional surface systems. Among these surface systems outstanding properties have nanoscale multilayer coatings. Within the framework of the M3-2S project funded in the 7th European Framework Programme, several nanoscale multilayer coatings have been developed and investigated for experimental and industrial validation. This paper shows the performance of TiN and TiN/CrN nanoscale multilayer coatings on WC cutting inserts when machining GJL250 cast iron. The thin films have been deposited by cathodic arc evaporation in an industrial PVD system. The multilayer deposition characteristic and its properties are shown. The inserts have been investigated in systematic cutting experiments of cast iron bars on a turning machine specifically equipped for force measurements, accompanied by wear determination. Furthermore, equivalent experiments have been carried out on an industrial turning unit. Industrial validation criteria have been applied to assess the comparative performance of the coatings. The choice of the material and the machined parts is driven by an interest in automotive applications. The industrial tests show the need to further optimise the multi-scale modelling approach in order to reduce the lead time of the coating development as well as to improve simulation reliability.

Selective emission multilayer coatings for a molybdenum thermophotovoltaic radiator

Science.gov (United States)

Cockeram, Brian Vern

2004-01-27

Multilayer coating designs have been developed to provide selective emission for a molybdenum thermophotovoltaic (TPV) radiator surface. These coatings increase the surface emissivity of a molybdenum TPV radiator substrate in the wavelength range that matches the bandgap of the TPV cells to increase the power density of the TPV system. Radiator emission at wavelengths greater than the bandgap energy of the TPV cells is greatly reduced through the use of these coatings, which significantly increases the efficiency of the TPV system. The use of this coating greatly improves the performance of a TPV system, and the coating can be tailored to match the bandgap of any practical TPV system.

Improving the tribological and corrosive properties of MoS2-based coatings by dual-doping and multilayer construction

Science.gov (United States)

Shang, Kedong; Zheng, Shaoxian; Ren, Siming; Pu, Jibin; He, Dongqing; Liu, Shuan

2018-04-01

The pure MoS2 coating always performs high friction coefficient and short service life when used in high humidity or after long-time storage in humid atmospheric environment. In this study, the MoS2/Pb-Ti composite and MoS2/Pb-Ti multilayer coatings are deposited to improve the corrosion resistance in 3.5 wt% NaCl solution and tribological performance in high humidity condition. The electrochemical impedance spectra and salt spray test shown that the MoS2/Pb-Ti composite and multilayer coatings can inhibit the permeation of oxygen and other corrosive elements, thus resulting a high corrosion resistance. Furthermore, compared with pure MoS2 coating, the tribological performance of the MoS2/Pb-Ti composite and multilayer coatings is also improved significantly owing to the high mechanical properties and compact structure. Moreover, the heterogenous interfaces in MoS2/Pb-Ti multilayer coating play an important role to improve the corrosion resistance and tribological performance of coatings. Overall, the dual-doping and multilayer construction are promising approaches to design the MoS2 coatings as the environmentally adaptive lubricants.

Multilayer thin films: sequential assembly of nanocomposite materials

National Research Council Canada - National Science Library

Decher, Gero; Schlenoff, Joseph B

2003-01-01

... polymeric or nanoparticulate building blocks, understanding the polymer physical chemistry of multilayers, or characterizing their optical, electrical or biological activities. The reasons for the intense interest in the field are also clearly evident: multilayers bridge the gap between monolayers and spun-on or dip-coated films, ...

C/SiC/MoSi2-Si multilayer coatings for carbon/carbon composites for protection against oxidation

International Nuclear Information System (INIS)

Zhang Yulei; Li Hejun; Qiang Xinfa; Li Kezhi; Zhang Shouyang

2011-01-01

Highlights: → A C/SiC/MoSi 2 -Si multilayer coating was prepared on C/C by slurry and pack cementation. → Multilayer coating can protect C/C for 300 h at 1873 K or 103 h at 1873 K in air. → The penetration cracks in the coating result in the weight loss of the coated C/C. → The fracture of the coated C/C in wind tunnel result from the excessive local stress. - Abstract: To improve the oxidation resistance of carbon/carbon (C/C) composites, a C/SiC/MoSi 2 -Si multilayer oxidation protective coating was prepared by slurry and pack cementation. The microstructure of the as-prepared coating was characterized by scanning electron microscopy, X-ray diffraction and energy dispersive spectroscopy. The isothermal oxidation and erosion resistance of the coating was investigated in electrical furnace and high temperature wind tunnel. The results showed that the multilayer coating could effectively protect C/C composites from oxidation in air for 300 h at 1773 K and 103 h at 1873 K, and the coated samples was fractured after erosion for 27 h at 1873 K h in wind tunnel. The weight loss of the coated specimens was considered to be caused by the formation of penetration cracks in the coating. The fracture of the coated C/C composites might result from the excessive local stress in the coating.

Structural, mechanical and tribocorrosion behaviour in artificial seawater of CrN/AlN nano-multilayer coatings on F690 steel substrates

Science.gov (United States)

Ma, Fuliang; Li, Jinlong; Zeng, Zhixiang; Gao, Yimin

2018-01-01

The CrN monolayer and CrN/AlN nano-multilayer coating were successfully fabricated by reactive magnetron sputtering on F690 steel. The results show that CrN monolayer exhibits a face centered cubic crystalline structure with (111) preferred orientation and CrN/AlN nano-multilayer coating has a (200) preferred orientation. This design of the nano-multilayer can interrupt the continuous growth of columnar crystals making the coating denser. The CrN/AlN nano-multilayer coating has a better wear resistance and corrosion resistance compared with the CrN monolayer coating. The tribocorrosion tests reveal that the evolution of potential and current density of F690 steel and CrN monolayer or CrN/AlN nano-multilayer coating see an opposite trend under the simultaneous action of wear and corrosion, which is attributed to that F690 steel is a non-passive material and PVD coatings is a passive material. The nano-multilayer structure has a good ;Pore Sealing Effect;, and the corrosive solution is difficult to pass through the coating to corrode the substrate.

Design and manufacture of super-multilayer optical filters based on PARMS technology

Science.gov (United States)

Lü, Shaobo; Wang, Ruisheng; Ma, Jing; Jiang, Chao; Mu, Jiali; Zhao, Shuaifeng; Yin, Xiaojun

2018-04-01

Three multilayer interference optical filters, including a UV band-pass, a VIS dual-band-pass and a notch filter, were designed by using Ta2O5, Nb2O5, Al2O3 and SiO2 as high- and low-index materials. During the design of the coating process, a hybrid optical monitoring and RATE-controlled layer thickness control scheme was adopted. The coating process was simulated by using the optical monitoring system (OMS) Simulator, and the simulation result indicated that the layer thickness can be controlled within an error of less than ±0.1%. The three filters were manufactured on a plasma-assisted reactive magnetic sputtering (PARMS) coating machine. The measurements indicate that for the UV band-pass filter, the peak transmittance is higher than 95% and the blocking density is better than OD6 in the 300-1100 nm region, whereas for the dual-band-pass filter, the center wavelength positioning accuracy of the two passbands are less than ±2 nm, the peak transmittance is higher than 95% and blocking density is better than OD6 in the 300-950 nm region. Finally, for the notch filter, the minimum transmittance rates are >90% and >94% in the visible and near infrared, respectively, and the blocking density is better than OD5.5 at 808 nm.

Structure, properties and wear behaviour of multilayer coatings consisting of metallic and covalent hard materials, prepared by magnetron sputtering

International Nuclear Information System (INIS)

Schier, V.

1995-12-01

Novel multilayer coatings with metallic and covalent layer materials were prepared by magnetron sputtering and characterised concerning structure, properties and application behaviour. At first single layer coatings were deposited for the determination of the material properties. To evaluate relations between structure and properties of the multilayer coatings, different multilayer concepts were realised: - coatings consisting of at most 7 layers of metallic hard materials, - 100-layer coatings consisting of metallic and covalent hard materials, - TiN-TiC multilayer coatings with different numbers of layers (between 10 and 1000), - 150-layer coatings, based on TiN-TiC multilayers, with thin ( 4 C, AlN, SiC, a:C, Si 3 N 4 , SiAlON). X-rays and electron microscopic analysis indicate in spite of nonstoichiometric compositions single phase crystalline structures for nonreactively and reactively sputtered metastable single layer Ti(B,C)-, Ti(B,N)- and Ti(B,C,N)-coatings. These single layer coatings show excellent mechanical properties (e.g. hardness values up to 6000 HV0,05), caused by lattice stresses as well as by atomic bonding conditions similar to those in c:BN and B 4 C. The good tribological properties shown in pin-on-disk-tests can be attributed to the very high hardness of the coatings. The coatings consisting of at most 7 layers of metallic hard materials show good results mainly for the cutting of steel Ck45, due to the improved mechanical properties (e.g. hardness, toughness) of the multilayers compared to the single layer coatings. This improvement is caused by inserting the hard layer materials and the coherent reinforcement of the coatings. (orig.)

Single layer and multilayer wear resistant coatings of (Ti,Al)N: a review

International Nuclear Information System (INIS)

PalDey, S.; Deevi, S.C.

2003-01-01

We review the status of (Ti,Al)N based coatings obtained by various physical vapor deposition (PVD) techniques and compare their properties. PVD techniques based on sputtering and cathodic arc methods are widely used to deposit wear resistant (Ti,Al)N coatings. These techniques were further modified to improve the metal ionization rate and to eliminate macrodroplets from plasma streams. We summarize manufacture of target/cathode, substrate materials for deposition of coatings, deposition parameters, and the effect of deposition parameters on the physical and mechanical properties of (Ti,Al)N coatings. It is shown that (Ti,Al)N coatings by PVD enhance the wear, thermal, and oxidation resistance of a wide variety of tool materials. We discuss the wear resistant properties of (Ti,Al)N for various machining applications as compared with coatings such as TiN, Ti(C,N) and (Ti,Zr)N. High hardness (∼28-32 GPa), relatively low residual stress (∼5 GPa), superior oxidation resistance, high hot hardness, and low thermal conductivity make (Ti,Al)N coatings most desirable in dry machining and machining of abrasive alloys at high speeds. Multicomponent coatings based on different metallic and nonmetallic elements combine the benefit of individual components leading to a further refinement of coating properties. Alloying additions such as Cr and Y drastically improve the oxidation resistance, Zr and V improve the wear resistance, whereas, Si increases the hardness and resistance to chemical reactivity of the film. Addition of boron improves the abrasive wear behavior of Ti-Al based coatings due to the formation of TiB 2 and BN phases depending on the deposition conditions. Hafnium based nitrides and carbides have potential for resistance to flank and crater wear. The presence of a large number of interfaces between individual layers of a multilayered structure results in a drastic increase in hardness and strength. (Ti,Al)N multilayer super lattice coatings with lattice

Synthesis of dense TiO2 nanoparticle multilayers using spin coating technique

Science.gov (United States)

DeSilva, L. Ajith; Thakurdesai, Madhavi; Bandara, T. M. W. J.; Preston, Joshua; Johnson, Wyatt; Gaquere-Parker, Anne; Survase, Smita

2018-04-01

A stack of nine layers is prepared by sequential spun casting of commercially available colloidal TiO2 nanoparticles of average size of 10-15 nm. Scanning electron microscopy (SEM) is employed to investigate the surface morphology of the multilayers. SEM micrographs exhibit formation of highly uniform and dense TiO2 nanoparticle layers. The uniformity and density is found to be increasing with layer thickness. Structural characterization is carried out using X-ray diffraction (XRD) technique. XRD spectra indicate improvement in crystalline quality of all the layers with increasing layer thickness. All the layers are having mainly the anatase phase of TiO2. Optical characterization is carried out by UV-visible spectroscopy. The value of bandgap estimated on the basis of absorption coefficient is found to be 3.26 eV and approximately remains the same for the layers. The electrical characterization suggests that multilayer resistivity increases with increasing layer thickness. The good quality spin coated thin dense TiO2 layers have many applications in optoelectronics.

In situ 3D characterization of historical coatings and wood using multimodal nonlinear optical microscopy

OpenAIRE

Latour , Gaël; Echard , Jean-Philippe; Didier , Marie; Schanne-Klein , Marie-Claire

2012-01-01

International audience; We demonstrate multimodal nonlinear optical imaging of historical artifacts by combining Second Harmonic Generation (SHG) and Two-Photon Excited Fluorescence (2PEF) microscopies. We first identify the nonlinear optical response of materials commonly encountered in coatings of cultural heritage artifacts by analyzing one- and multi-layered model samples. We observe 2PEF signals from cochineal lake and sandarac and show that pigments and varnish films can be discriminate...

Ion assisted deposition of refractory oxide thin film coatings for improved optical and structural properties

International Nuclear Information System (INIS)

Sahoo, N.K.; Thakur, S.; Bhattacharyya, D.; Das, N.C.

1999-03-01

Ion assisted deposition technique (IAD) has emerged as a powerful tool to control the optical and structural properties of thin film coatings. Keeping in view the complexity of the interaction of ions with the films being deposited, sophisticated ion sources have been developed that cater to the need of modern optical coatings with stringent spectral and environmental specifications. In the present work, the results of ion assisted deposition (IAD) of two commonly used refractory oxides, namely TiO 2 and ZrO 2 , using cold cathode ion source (CC-102R) are presented. Through successive feedback and calibration techniques, various ion beams as well as deposition parameters have been optimized to achieve the best optical and structural film properties in the prevalent deposition geometry of the coating system. It has been possible to eliminate the unwanted optical and structural inhomogeneities from these films using and optimized set of process parameters. Interference modulated spectrophotometric and phase modulated ellipsometric techniques have been very successfully utilized to analyze the optical and structural parameters of the films. Several precision multilayer coatings have been developed and are being used for laser and spectroscopic applications. (author)

Glow discharge optical emission spectroscopy for accurate and well resolved analysis of coatings and thin films

KAUST Repository

Wilke, Marcus

2011-12-01

In the last years, glow discharge optical emission spectrometry (GDOES) gained more and more acceptance in the analysis of functional coatings. GDOES thereby represents an interesting alternative to common depth profiling techniques like AES and SIMS, based on its unique combination of high erosion rates and erosion depths, sensitivity, analysis of nonconductive layers and easy quantification even for light elements such as C, N, O and H. Starting with the fundamentals of GDOES, a short overview on new developments in instrument design for accurate and well resolved thin film analyses is presented. The article focuses on the analytical capabilities of glow discharge optical emission spectrometry in the analysis of metallic coatings and thin films. Results illustrating the high depth resolution, confirmation of stoichiometry, the detection of light elements in coatings as well as contamination on the surface or interfaces will be demonstrated by measurements of: a multilayer system Cr/Ti on silicon, interface contamination on silicon during deposition of aluminum, Al2O3-nanoparticle containing conversion coatings on zinc for corrosion resistance, Ti3SiC2 MAX-phase coatings by pulsed laser deposition and hydrogen detection in a V/Fe multilayer system. The selected examples illustrate that GDOES can be successfully adopted as an analytical tool in the development of new materials and coatings. A discussion of the results as well as of the limitations of GDOES is presented. © 2011 Elsevier B.V.

Enhancement of mechanical and tribological properties in AISI D3 steel substrates by using a non-isostructural CrN/AlN multilayer coating

Energy Technology Data Exchange (ETDEWEB)

Cabrera, G. [Thin Film Group, Universidad del Valle in Cali (Colombia); Caicedo, J.C., E-mail: jcaicedoangulo@gmail.com [Thin Film Group, Universidad del Valle in Cali (Colombia); Amaya, C. [Thin Film Group, Universidad del Valle in Cali (Colombia); Laboratory of Hard Coatings, CDT-ASTIN SENA in Cali (Colombia); Yate, L. [Department de Fisica Aplicada i Optica, Universitat de Barcelona, Catalunya (Spain); Munoz Saldana, J. [Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Queretaro (Mexico); Prieto, P. [Thin Film Group, Universidad del Valle in Cali (Colombia); Center of Excellence for Novel Materials - CENM, Calle 13 100-00 320-026, Cali (Colombia)

2011-02-15

Enhancement of mechanical and tribological properties on AISI D3 steel surfaces coated with CrN/AlN multilayer systems deposited in various bilayer periods ({Lambda}) via magnetron sputtering has been studied in this work exhaustively. The coatings were characterized in terms of structural, chemical, morphological, mechanical and tribological properties by X-ray diffraction (XRD), electron dispersive spectrograph, atomic force microscopy, scanning and transmission electron microscopy, nanoindentation, pin-on-disc and scratch tests. The failure mode mechanisms were observed via optical microscopy. Results from X-ray diffraction analysis revealed that the crystal structure of CrN/AlN multilayer coatings has a NaCl-type lattice structure and hexagonal structure (wurtzite-type) for CrN and AlN, respectively, i.e., made was non-isostructural multilayers. An enhancement of both hardness and elastic modulus up to 28 GPa and 280 GPa, respectively, was observed as the bilayer periods ({Lambda}) in the coatings were decreased. The sample with a bilayer period ({Lambda}) of 60 nm and bilayer number n = 50 showed the lowest friction coefficient ({approx}0.18) and the highest critical load (43 N), corresponding to 2.2 and 1.6 times better than those values for the coating deposited with n = 1, respectively. The best behavior was obtained when the bilayer period ({Lambda}) is 60 nm (n = 50), giving the highest hardness 28 GPa and elastic modulus of 280 GPa, the lowest friction coefficient ({approx}0.18) and the highest critical load of 43 N. These results indicate an enhancement of mechanical, tribological and adhesion properties, comparing to the CrN/AlN multilayer systems with 1 bilayer at 28%, 21%, 40%, and 30%, respectively. This enhancement in hardness and toughness for multilayer coatings could be attributed to the different mechanisms for layer formation with nanometric thickness such as the Hall-Petch effect and the number of interfaces that act as obstacles for the

Multilayered and composite PVD-CVD coatings in cemented carbides manufacture

International Nuclear Information System (INIS)

Glushkov, V.N.; Anikeev, A.I.; Anikin, V.N.; Vereshchaka, A.S.

2001-01-01

Carbide cutting tools with wear-resistant coatings deposited by CVD process are widely employed in mechanical engineering to ensure a substantially longer service life of tool systems. However, the relatively high temperature and long time of the process make the substrate decarburise and, as a result, the bend strength and performance characteristics of a tool decrease. The present study suggests the problem of deteriorated strength of CVD-coated carbide tools be solved by the development of a technology that combines arc-PVD and CVD processes to deposit multilayered coatings of titanium and aluminium compounds. (author)

Zinc/manganese multilayer coatings for corrosion protection

International Nuclear Information System (INIS)

Muenz, R.; Wolf, G.K.; Guzman, L.; Adami, M.

2004-01-01

Zn alloys are able to surpass the performance of electrogalvanised or hot-dip Zn (at same thickness) for corrosion protection of car bodies. In particular, vacuum deposited Zn alloy layers have higher protection power on non-painted steel surfaces as compared with pure Zn layers. In the present work the Zn-Mn system was investigated: Zn/Mn alloys of different compositions as well as Zn/Mn multilayers of 5-6 μm total thickness were prepared on low alloy steel by ion beam assisted deposition (IBAD). The equipment contained two electron beam evaporators and a slit extraction ion source, delivering ions of 100-1500 eV energy. The corrosion behaviour of the samples was evaluated by standard salt spray tests (SST). The composition and microstructure of the coatings was studied by scanning electron microscopy (SEM) and EDX-depth profiling. The behaviour of the coating/substrate system is discussed in comparison with 'state of the art' Zn-coatings (EZ) produced by electrogalvanizing. Generally speaking, the performance of the optimised coatings is as good or better than the reference standard

Efficient use of energy in buildings - New optical coatings for transparent building elements; Rationelle Energienutzung in Gebaeuden. Neue optische Beschichtungen fuer transparente Gebaeudeteile im Hinblick auf einen verbesserten sommerlichen Waermeschutz - Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Oelhafen, P.; Mack, I.; Reber, G.; Romanyuk, A.; Steiner, R.

2008-07-01

This final report for the Swiss Federal Office of Energy (SFOE) reports on optical coatings for transparent building elements with respect to improving protection against overheating in summer. Newly developed multi-layer coating systems using standard materials and methods are reported on. With these multi-layer coatings, the solar radiation is said to be reduced by between 17% and 29% compared to commercially available sun-protection windows. The report reviews the new materials being looked at and describes the measurement methods used and the results obtained. The optical characteristics of the coatings are discussed in detail and the results of measurements made are presented in detail. Also, the effect of varying angles of incidence is discussed.

The confinement of phonon propagation in TiAlN/Ag multilayer coatings with anomalously low heat conductivity

Energy Technology Data Exchange (ETDEWEB)

Kovalev, A. I.; Wainstein, D. L., E-mail: d-wainstein@sprg.ru [Surface Phenomena Researches Group, Radio Str., 23/9, Bld. 2, Off. 475, CNIICHERMET, 105005 Moscow (Russian Federation); Rashkovskiy, A. Yu. [Surface Phenomena Researches Group, Radio Str., 23/9, Bld. 2, Off. 475, CNIICHERMET, 105005 Moscow (Russian Federation); National University of Science and Technology MISiS, Leninskiy pr-t, 4, 119049 Moscow (Russian Federation); Gago, R. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas, E-28049 Madrid (Spain); Soldera, F. [Department of Materials Science and Engineering, Saarland University, 66123 Saarbruecken (Germany); Endrino, J. L. [School of Aerospace, Transport and Manufacturing (SATM), Surface Engineering and Nanotechnology Institute, Cranfield University, College Road, Cranfield, MK43 0AL Bedfordshire (United Kingdom)

2016-05-30

TiAlN/Ag multilayer coatings with a different number of bilayers and thicknesses of individual layers were fabricated by DC magnetron co-sputtering. Thermal conductivity was measured in dependence of Ag layer thickness. It was found anomalous low thermal conductivity of silver comparing to TiAlN and Ag bulk standards and TiAlN/TiN multilayers. The physical nature of such thermal barrier properties of the multilayer coatings was explained on the basis of reflection electron energy loss spectroscopy. The analysis shows that nanostructuring of the coating decreases the density of states and velocity of acoustic phonons propagation. At the same time, multiphonon channels of heat propagation degenerate. These results demonstrate that metal-dielectric interfaces in TiAlN/Ag coatings are insurmountable obstacles for acoustic phonons propagation.

Roughness characterization of EUV multilayer coatings and ultra-smooth surfaces by light scattering

Science.gov (United States)

Trost, M.; Schröder, S.; Lin, C. C.; Duparré, A.; Tünnermann, A.

2012-09-01

Optical components for the extreme ultraviolet (EUV) face stringent requirements for surface finish, because even small amounts of surface and interface roughness can cause significant scattering losses and impair image quality. In this paper, we investigate the roughness evolution of Mo/Si multilayers by analyzing the scattering behavior at a wavelength of 13.5 nm as well as taking atomic force microscopy (AFM) measurements before and after coating. Furthermore, a new approach to measure substrate roughness is presented, which is based on light scattering measurements at 405 nm. The high robustness and sensitivity to roughness of this method are illustrated using an EUV mask blank with a highspatial frequency roughness of as low as 0.04 nm.

Ta2O5/ Al2O3/ SiO2 - antireflective coating for non-planar optical surfaces by atomic layer deposition

Science.gov (United States)

Pfeiffer, K.; Schulz, U.; Tünnermann, A.; Szeghalmi, A.

2017-02-01

Antireflective coatings are essential to improve transmittance of optical elements. Most research and development of AR coatings has been reported on a wide variety of plane optical surfaces; however, antireflection is also necessary on nonplanar optical surfaces. Physical vapor deposition (PVD), a common method for optical coatings, often results in thickness gradients on strongly curved surfaces, leading to a failure of the desired optical function. In this work, optical thin films of tantalum pentoxide, aluminum oxide and silicon dioxide were prepared by atomic layer deposition (ALD), which is based on self-limiting surface reactions. The results demonstrate that ALD optical layers can be deposited on both vertical and horizontal substrate surfaces with uniform thicknesses and the same optical properties. A Ta2O5/Al2O3/ SiO2 multilayer AR coating (400-700 nm) was successfully applied to a curved aspheric glass lens with a diameter of 50 mm and a center thickness of 25 mm.

Formation and investigation of multilayer nanostructured coatings TiN/MoN for different layers thicknesses with c-pvd

International Nuclear Information System (INIS)

Pogrebnyak, A.D.; Bondar, O.V.; Postol'nyj, B.A.; Andreev, A.A.; Abadias, G.; Beresnev, V.M.; Sobol', O.B.

2013-01-01

Multilayer coatings based on TiN/MoN were obtained using the vacuum arc evaporation cathode method (C-PVD). Multilayers thickness was in the range 6,7 ÷ 8,7 μm and monolayers thickness was 2, 10, 20 and 40 nm. Vacuum-arc unit Bulat 6 was used for depositions. For the analysis of multilayer structures and properties of nanostructured coatings XRD analysis method was used (D8 ADVANCE, Bruker). For elemental composition and morphology investigation of the surface layers and multilayered coatings SEM (JEOL-7001F) with EDX attachment was used. Also HRTEM method was used to analyze the phase composition. In addition, this article provides investigation of hardness by Micro-Hardness Tester CSM (Switzerland). AFM was used for additional analysis of the topography and surface roughness of these coatings. This investigation have revealed the relationship between the layers thicknesses, substrate potential, the annealing process, physical and mechanical properties of samples. (authors)

Fiber/matrix interfaces for SiC/SiC composites: Multilayer SiC coatings

Energy Technology Data Exchange (ETDEWEB)

Halverson, H.; Curtin, W.A. [Virginia Polytechnic Institute and State Univ., Blacksburg, VA (United States)

1996-08-01

Tensile tests have been performed on composites of CVI SiC matrix reinforced with 2-d Nicalon fiber cloth, with either pyrolitic carbon or multilayer CVD SiC coatings [Hypertherm High-Temperature Composites Inc., Huntington Beach, CA.] on the fibers. To investigate the role played by the different interfaces, several types of measurements are made on each sample: (i) unload-reload hysteresis loops, and (ii) acoustic emission. The pyrolitic carbon and multilayer SiC coated materials are remarkably similar in overall mechanical responses. These results demonstrate that low-modulus, or compliant, interface coatings are not necessary for good composite performance, and that complex, hierarchical coating structures may possibly yield enhanced high-temperature performance. Analysis of the unload/reload hysteresis loops also indicates that the usual {open_quotes}proportional limit{close_quotes} stress is actually slightly below the stress at which the 0{degrees} load-bearing fibers/matrix interfaces slide and are exposed to atmosphere.

High Temperature Multilayer Environmental Barrier Coatings Deposited Via Plasma Spray-Physical Vapor Deposition

Science.gov (United States)

Harder, Bryan James; Zhu, Dongming; Schmitt, Michael P.; Wolfe, Douglas E.

2014-01-01

Si-based ceramic matrix composites (CMCs) require environmental barrier coatings (EBCs) in combustion environments to avoid rapid material loss. Candidate EBC materials have use temperatures only marginally above current technology, but the addition of a columnar oxide topcoat can substantially increase the durability. Plasma Spray-Physical Vapor Deposition (PS-PVD) allows application of these multilayer EBCs in a single process. The PS-PVD technique is a unique method that combines conventional thermal spray and vapor phase methods, allowing for tailoring of thin, dense layers or columnar microstructures by varying deposition conditions. Multilayer coatings were deposited on CMC specimens and assessed for durability under high heat flux and load. Coated samples with surface temperatures ranging from 2400-2700F and 10 ksi loads using the high heat flux laser rigs at NASA Glenn. Coating morphology was characterized in the as-sprayed condition and after thermomechanical loading using electron microscopy and the phase structure was tracked using X-ray diffraction.

Surface plasmon resonance-based fiber-optic hydrogen gas sensor utilizing palladium supported zinc oxide multilayers and their nanocomposite.

Science.gov (United States)

Tabassum, Rana; Gupta, Banshi D

2015-02-10

We analyze surface plasmon resonance-based fiber-optic sensor for sensing of small concentrations of hydrogen gas in the visible region of the electromagnetic spectrum. One of the two probes considered has multilayers of zinc oxide (ZnO) and palladium (Pd) while the other has layer of their composite over a silver coated unclad core of the fiber. The analysis is carried out for different volume fractions of palladium nanoparticles dispersed in zinc oxide host material in the nanocomposite layer. For the analysis, a Maxwell-Garnett model is adopted for calculating the dielectric function of a ZnO:Pd nanocomposite having nanoparticles of dimensions smaller than the wavelength of radiation used. The effects of the volume fraction of the nanoparticles in the nanocomposite and the thickness of the nanocomposite layer on the figure of merit of the sensor have been studied. The film thickness of the layer and the volume fraction of nanoparticles in the ZnO:Pd nanocomposite layer have been optimized to achieve the maximum value of the figure of merit of the sensor. It has been found that the figure of merit of the sensing probe coated with ZnO:Pd nanocomposite is more than twofold of the sensing probe coated with multilayers of Pd and ZnO over a silver coated unclad core of the fiber; hence, the sensor with a nanocomposite layer works better than that with multilayers of zinc oxide and palladium. The sensor can be used for online monitoring and remote sensing of hydrogen gas.

Sol-gel coatings: An alternative route for producing planar optical waveguides

Energy Technology Data Exchange (ETDEWEB)

Rey-Garcia, F.; Gomez-Reino, C. [Unidad Asociada de Optica and Microoptica GRIN (CSIC-ICMA), Departamento de Fisica Aplicada, Escola Universitaria de Optica e Optometria, Universidade de Santiago de Compostela, Campus Sur s/n, E-15782 Santiago de Compostela (Spain); Flores-Arias, M.T., E-mail: maite.flores@usc.es [Unidad Asociada de Optica and Microoptica GRIN (CSIC-ICMA), Departamento de Fisica Aplicada, Escola Universitaria de Optica e Optometria, Universidade de Santiago de Compostela, Campus Sur s/n, E-15782 Santiago de Compostela (Spain); De La Fuente, G.F., E-mail: xerman@unizar.es [Instituto de Ciencia de Materiales de Aragon (CSIC-Universidad de Zaragoza), Maria de Luna 3, E-50018 Zaragoza (Spain); Duran, A. [Instituto de Ceramica y Vidrio (CSIC), Kelsen 5, E-28049, Madrid (Spain); Castro, Y., E-mail: castro@icv.csic.es [Instituto de Ceramica y Vidrio (CSIC), Kelsen 5, E-28049, Madrid (Spain)

2011-09-01

Inorganic and hybrid planar waveguides with different compositions (silica-titania, methacrylate-silica-cerium oxide, zirconia-cerium oxide and silica-zirconia) have been obtained by sol-gel synthesis followed by dip-coating. Soda-lime glass slides and conventional commercial window glass were used as substrates. The thickness and refractive index of the coatings were determined by profilometry and Spectroscopic Ellipsometry. Waveguide efficiency was measured at ca. 70.8% with a He-Ne laser beam, coupled with an optical microscope objective into and out of the waveguiding layer via a double prism configuration. Thicknesses between 150 and 2000 nm, along with refractive index values ranging between 1.45 and {approx} 1.99 ({lambda} = 633 nm) were obtained depending on the sol composition and the dip-coating conditions. This wide range of values allows designing multilayered guides that can be used in a variety of applications.

Sol-gel coatings: An alternative route for producing planar optical waveguides

International Nuclear Information System (INIS)

Rey-Garcia, F.; Gomez-Reino, C.; Flores-Arias, M.T.; De La Fuente, G.F.; Duran, A.; Castro, Y.

2011-01-01

Inorganic and hybrid planar waveguides with different compositions (silica-titania, methacrylate-silica-cerium oxide, zirconia-cerium oxide and silica-zirconia) have been obtained by sol-gel synthesis followed by dip-coating. Soda-lime glass slides and conventional commercial window glass were used as substrates. The thickness and refractive index of the coatings were determined by profilometry and Spectroscopic Ellipsometry. Waveguide efficiency was measured at ca. 70.8% with a He-Ne laser beam, coupled with an optical microscope objective into and out of the waveguiding layer via a double prism configuration. Thicknesses between 150 and 2000 nm, along with refractive index values ranging between 1.45 and ∼ 1.99 (λ = 633 nm) were obtained depending on the sol composition and the dip-coating conditions. This wide range of values allows designing multilayered guides that can be used in a variety of applications.

A Magnetron Sputter Deposition System for the Development of X-Ray Multilayer Optics

Science.gov (United States)

Broadway, David

2015-01-01

The project objective is to establish the capability to deposit multilayer structures for x-ray, neutron, and extreme ultraviolet (EUV) optic applications through the development of a magnetron sputtering deposition system. A specific goal of this endeavor is to combine multilayer deposition technology with the replication process in order to enhance NASA Marshall Space Flight Center's (MSFC's) position as a world leader in the design of innovative x-ray instrumentation through the development of full shell replicated multilayer optics. The development of multilayer structures are absolutely necessary in order to advance the field of x-ray astronomy by pushing the limit for observing the universe to ever-increasing photon energies (i.e., up to 200 keV or higher), well beyond Chandra's (approx.10 keV) and NuStar's (approx.75 keV) capability. The addition of multilayer technology would significantly enhance the x-ray optics capability at MSFC and allow NASA to maintain its world leadership position in the development, fabrication, and design of innovative x-ray instrumentation, which would be the first of its kind by combining multilayer technology with the mirror replication process. This marriage of these technologies would allow astronomers to see the universe in a new light by pushing to higher energies that are out of reach with today's instruments. To this aim, a magnetron vacuum sputter deposition system for the deposition of novel multilayer thin film x-ray optics is proposed. A significant secondary use of the vacuum deposition system includes the capability to fabricate multilayers for applications in the field of EUV optics for solar physics, neutron optics, and x-ray optics for a broad range of applications including medical imaging.

A Magnetron Sputter Deposition System for the Development of Multilayer X-Ray Optics

Science.gov (United States)

Broadway, David; Ramsey, Brian; Gubarev, Mikhail

2014-01-01

The proposal objective is to establish the capability to deposit multilayer structures for x-ray, neutron, and EUV optic applications through the development of a magnetron sputtering deposition system. A specific goal of this endeavor is to combine multilayer deposition technology with the replication process in order to enhance the MSFC's position as a world leader in the design of innovative X-ray instrumentation through the development of full shell replicated multilayer optics. The development of multilayer structures is absolutely necessary in order to advance the field of X-ray astronomy by pushing the limit for observing the universe to ever increasing photon energies (i. e. up to 200 keV or higher); well beyond Chandra (approx. 10 keV) and NuStar's (approx. 75 keV) capability. The addition of multilayer technology would significantly enhance the X-ray optics capability at MSFC and allow NASA to maintain its world leadership position in the development, fabrication and design of innovative X-ray instrumentation which would be the first of its kind by combining multilayer technology with the mirror replication process. This marriage of these technologies would allow astronomers to see the universe in a new light by pushing to higher energies that are out of reach with today's instruments.To this aim, a magnetron vacum sputter deposition system for the deposition of novel multilayer thin film X-ray optics is proposed. A significant secondary use of the vacuum deposition system includes the capability to fabricate multilayers for applications in the field of EUV optics for solar physics, neutron optics, and X-ray optics for a broad range of applications including medical imaging.

Niobium–niobium oxide multilayered coatings for corrosion protection of proton-irradiated liquid water targets for ["1"8F] production

International Nuclear Information System (INIS)

Skliarova, Hanna; Renzelli, Marco; Azzolini, Oscar; Felicis, Daniele de; Bemporad, Edoardo; Johnson, Richard R.; Palmieri, Vincenzo

2015-01-01

Chemically inert coatings on Havar"® entrance foils of the targets for ["1"8F] production via proton irradiation of enriched water at pressurized conditions are needed to decrease the amount of ionic contaminants released from Havar"®. During current investigation, magnetron sputtered niobium and niobium oxide were chosen as the candidates for protective coatings because of their superior chemical resistance. Aluminated quartz substrates allowed us to verify the protection efficiency of the desirable coatings as diffusion barriers. Two modeling corrosion tests based on the extreme susceptibility of aluminum to liquid gallium and acid corrosion were applied. As far as niobium coatings obtained by magnetron sputtering are columnar, the grain boundaries provide a fast diffusion path for active species of corrosive media to penetrate and to corrode the substrate. Amorphous niobium oxide films obtained by reactive magnetron sputtering showed superior barrier properties according to the corrosion tests performed. In order to prevent degrading of brittle niobium oxide at high pressures, multilayers combining high ductility of niobium with superior diffusion barrier efficiency of niobium oxide were proposed. The intercalation of niobium oxide interlayers was proved to interrupt the columnar grain growth of niobium during sputtering, resulting in improved diffusion barrier efficiency of obtained multilayers. The thin layer multilayer coating architecture with 70 nm bi-layer thickness was found preferential because of higher thermal stability. - Highlights: • Diffusion barrier efficiency of niobium, niobium oxide and their multilayers was studied. • The intercalation of niobium oxide layers interrupted the columnar grain growth of niobium. • The bilayer architectures influenced the stability of the multilayer coatings. • The thin layer multilayer coating with 70 nm double-layer was found superior.

Niobium–niobium oxide multilayered coatings for corrosion protection of proton-irradiated liquid water targets for [{sup 18}F] production

Energy Technology Data Exchange (ETDEWEB)

Skliarova, Hanna, E-mail: Hanna.Skliarova@lnl.infn.it [National Institute of Nuclear Physics, Legnaro National Laboratories, Viale dell' Università, 2, 35020 Legnaro, Padua (Italy); University of Ferrara, Ferrara (Italy); Renzelli, Marco, E-mail: marco.renzelli@uniroma3.it [University of Rome “Roma TRE”, Via della Vasca Navale, 79, 00146 Rome (Italy); Azzolini, Oscar, E-mail: Oscar.Azzolini@lnl.infn.it [National Institute of Nuclear Physics, Legnaro National Laboratories, Viale dell' Università, 2, 35020 Legnaro, Padua (Italy); Felicis, Daniele de, E-mail: daniele.defelicis@uniroma3.it [University of Rome “Roma TRE”, Via della Vasca Navale, 79, 00146 Rome (Italy); Bemporad, Edoardo, E-mail: edoardo.bemporad@uniroma3.it [University of Rome “Roma TRE”, Via della Vasca Navale, 79, 00146 Rome (Italy); Johnson, Richard R., E-mail: richard.johnson@teambest.com [BEST Cyclotron Systems Inc., 8765 Ash Street Unit 7, Vancouver BC V6P 6T3 (Canada); Palmieri, Vincenzo, E-mail: Vincenzo.Palmieri@lnl.infn.it [National Institute of Nuclear Physics, Legnaro National Laboratories, Viale dell' Università, 2, 35020 Legnaro, Padua (Italy); University of Padua, Padua (Italy)

2015-09-30

Chemically inert coatings on Havar{sup ®} entrance foils of the targets for [{sup 18}F] production via proton irradiation of enriched water at pressurized conditions are needed to decrease the amount of ionic contaminants released from Havar{sup ®}. During current investigation, magnetron sputtered niobium and niobium oxide were chosen as the candidates for protective coatings because of their superior chemical resistance. Aluminated quartz substrates allowed us to verify the protection efficiency of the desirable coatings as diffusion barriers. Two modeling corrosion tests based on the extreme susceptibility of aluminum to liquid gallium and acid corrosion were applied. As far as niobium coatings obtained by magnetron sputtering are columnar, the grain boundaries provide a fast diffusion path for active species of corrosive media to penetrate and to corrode the substrate. Amorphous niobium oxide films obtained by reactive magnetron sputtering showed superior barrier properties according to the corrosion tests performed. In order to prevent degrading of brittle niobium oxide at high pressures, multilayers combining high ductility of niobium with superior diffusion barrier efficiency of niobium oxide were proposed. The intercalation of niobium oxide interlayers was proved to interrupt the columnar grain growth of niobium during sputtering, resulting in improved diffusion barrier efficiency of obtained multilayers. The thin layer multilayer coating architecture with 70 nm bi-layer thickness was found preferential because of higher thermal stability. - Highlights: • Diffusion barrier efficiency of niobium, niobium oxide and their multilayers was studied. • The intercalation of niobium oxide layers interrupted the columnar grain growth of niobium. • The bilayer architectures influenced the stability of the multilayer coatings. • The thin layer multilayer coating with 70 nm double-layer was found superior.

Multilayer coating facility for the HEFT hard x-ray telescope

DEFF Research Database (Denmark)

Cooper-Jensen, Carsten P.; Christensen, Finn Erland; Chen, Hubert

2001-01-01

A planar magnetron sputtering facility has been established at the Danish Space Research Institute (DSRI) for the production coating of depth graded multilayers on the thermally slumped glass segments which form the basis for the hard X-ray telescope on the HEFT balloon project. The facility...

High-temperature oxidation of CrN/AlN multilayer coatings

International Nuclear Information System (INIS)

Bardi, U.; Chenakin, S.P.; Ghezzi, F.; Giolli, C.; Goruppa, A.; Lavacchi, A.; Miorin, E.; Pagura, C.; Tolstogouzov, A.

2005-01-01

Experiments are reported on sputter depth profiling of CrN/AlN multilayer abrasive coatings by secondary ion mass spectrometry (SIMS) coupled with sample current measurements (SCM). The coatings were deposited by a closed-field unbalanced magnetron sputtering. It is shown that after oxidation tests, performed in air at 900 deg. C for 2 h and at 1100 deg. C for 4 h, the layered structure begins to degrade but is not destroyed completely. Oxidation at 1100 deg. C for 20 h causes total destruction of the coatings that can be attributed to a fast diffusion of oxygen, nickel, manganese and other elements along defect paths (grain boundaries, dislocations, etc.) in the coating. There are practically no nitrides in the near-surface layer after such a treatment and all the metallic components are in the oxidized form as follows from the data obtained by X-ray photoelectron spectroscopy (XPS). According to XPS and mass-resolved ion scattering spectrometry (MARISS), the surface content of Al in the heat-treated coatings has decreased in comparison with the as-received sample and that of Cr increased. Both XPS and MARISS data exhibit real increase in superficial concentration of the substrate materials (Mn and Ni) that is controversial if using SIMS alone. SCM turned out to be an informative depth profiling method complementary to more expensive and complicated SIMS, being particularly useful for structures with different secondary electron emission properties of the layers. SCM with predetermined SIMS calibration allows a routine characterization of coatings and other multilayer structures, particularly, in situations where the expenses of analysis can be justified

A mechanical and tribological study of Cr/CrN multilayer coatings

Energy Technology Data Exchange (ETDEWEB)

Arias, D.F., E-mail: diegomas@gmail.com [Grupo GEMA, Universidad Católica de Pereira, Pereira (Colombia); Gómez, A. [Laboratório de Fenômenos de Superficie, Escola Politécnica, Universidade de Sao Paulo, Sao Paulo (Brazil); Pontificia Universidad Javeriana Cali (Colombia); Vélez, J.M. [Escuela de Ingeniería de Materiales, Universidad Nacional de Colombia Sede Medellín (Colombia); Souza, R.M. [Laboratório de Fenômenos de Superficie, Escola Politécnica, Universidade de Sao Paulo, Sao Paulo (Brazil); Olaya, J.J. [Departamento de Ingeniería Mecánica y Mecatrónica, Universidad Nacional de Colombia, Bogotá (Colombia)

2015-06-15

Multilayer Cr/CrN coatings with different periodicities were grown on silicon substrates by means of a magnetron sputtering technique. Thin films with only Cr or CrN were also grown, in order to use them as reference samples. Structural, morphological, mechanical and tribological characterization were carried out by using X-ray diffraction (XRD), atomic force microscopy (AFM), nanohardness and nanoscratch techniques, respectively. The characterization results were analyzed as a function of the bilayer thickness (period). In general, the multilayer hardness value increased with the decrease in period. In addition, the validity of the Hall-Petch relationship was confirmed for grain sizes and period values greater than 146 nm and 333 nm, respectively. The coefficient of friction (COF) increased with increasing load, which indicates the contribution of the adhesion to the COF. - Highlights: • Multilayer Cr/CrN coatings with layer thickness between 200 and 1000 nm were grown. • Neither bias voltage not temperature were applied during deposition. • The hardness improves with the increase of the number of bilayers. • The wear rate decreases with the increase of the number of bilayers.

Fretting wear behaviour of TiC/Ti(C,N)/TiN multi-layer coatings at elevated temperature in gross slip regime

International Nuclear Information System (INIS)

Liu Hanwei; Huang Kunpeng; Zhu Minhao; Zhou Zhongrong

2005-01-01

Tic/Ti(C,N)/TiN multi-layer coatings are prepared on the 1Cr13 stainless steel substrate by the technique of Chemical Vapour Deposition, and the fretting wear behaviour of 1Cr13 stainless steel and TiC/Ti(C,N)/TiN coatings are investigated and studied controversially from 25 degree C to 400 degree C in the gross slip regime. It shows that the temperature has great influence on the fretting wear in the gross slip regime for the 1Cr13 stainless steel but little for Ti/C/Ti(C,N)/TiN multi-layer coatings. With the temperature increasing, the friction coefficient and the wear volume of the 1Cr13 alloy decreases and the wear volume of TiC/Ti(C, N)/TiN multi-layer coatings is invariant. TiC/Ti(C,N)/TiN multi-layer coatings have better wear-resistant capability than the 1Cr13 stainless steel, but the wear volume of the substrate increases greatly because of the grain-abrasion resulted from hard debris when TiC/Ti(C,N)/TiN multi-layer coatings are ground off. (authors)

Tribological Behavior of Multilayered WC-Ti1-xAlxN Coatings Deposited by Cathodic Arc Deposition Process on High Speed Steel

International Nuclear Information System (INIS)

Kim, Jung Gu; Hwang, Woon Suk

2006-01-01

Recently, much of the current development in surface modification engineering are focused on multilayered coatings. Multilayered coatings have the potential to improve the tribological properties. Four different multilayered coatings were deposited on AISI D2 steel. The prepared samples are designed as WC-Ti 0.6 Al 0.4 N, WC-Ti 0.53 Al 0.47 N, WC-Ti 0.5 Al 0.5 N and WC-Ti 0.43 Al 0.57 N. The multilayered coatings were investigated with respect to coating surface and cross-sectional morphology, roughness, adhesion, hardness, porosity and tribological behavior. Especially, wear tests of four multilayered coatings were preformed by using a ball-on-disc configuration with a linear sliding speed of 0.017 m/sec, 5.38 N load. The tests were carried out at room temperature in air by employing AISI 52100 steel ball (H R = 66) having a diameter of 10 mm. The surface morphology, and topography of the wear scars of samples and balls have been determined by using scanning electron spectroscopy (SEM). Results have showed an improved wear resistance of the WC-Ti 1-x 6Al x N coatings with increasing of Al concentration. WC-Ti 0.43 Al 0.57 N coating with the lower surface roughness and porosity with good adhesion enhanced wear resistance

Performance of Ti-multilayer coated tool during machining of MDN431 alloyed steel

Science.gov (United States)

Badiger, Pradeep V.; Desai, Vijay; Ramesh, M. R.

2018-04-01

Turbine forgings and other components are required to be high resistance to corrosion and oxidation because which they are highly alloyed with Ni and Cr. Midhani manufactures one of such material MDN431. It's a hard-to-machine steel with high hardness and strength. PVD coated insert provide an answer to problem with its state of art technique on the WC tool. Machinability studies is carried out on MDN431 steel using uncoated and Ti-multilayer coated WC tool insert using Taguchi optimisation technique. During the present investigation, speed (398-625rpm), feed (0.093-0.175mm/rev), and depth of cut (0.2-0.4mm) varied according to Taguchi L9 orthogonal array, subsequently cutting forces and surface roughness (Ra) were measured. Optimizations of the obtained results are done using Taguchi technique for cutting forces and surface roughness. Using Taguchi technique linear fit model regression analysis carried out for the combination of each input variable. Experimented results are compared and found the developed model is adequate which supported by proof trials. Speed, feed and depth of cut are linearly dependent on the cutting force and surface roughness for uncoated insert whereas Speed and depth of cut feed is inversely dependent in coated insert for both cutting force and surface roughness. Machined surface for coated and uncoated inserts during machining of MDN431 is studied using optical profilometer.

Tunable thick porous silica coating fabricated by multilayer-by-multilayer bonding of silica nanoparticles for open-tubular capillary chromatographic separation.

Science.gov (United States)

Qu, Qishu; Liu, Yuanyuan; Shi, Wenjun; Yan, Chao; Tang, Xiaoqing

2015-06-19

A simple coating procedure employing a multilayer-by-multilayer process to modify the inner surface of bare fused-silica capillaries with silica nanoparticles was established. The silica nanoparticles were adsorbed onto the capillary wall via a strong electrostatic interaction between amino functional groups and silica particles. The thickness of the coating could be tuned from 130 to 600 nm by increasing the coating cycles from one to three. Both the retention factor and the resolution were greatly increased with increasing coating cycles. The loading capacity determined by naphthalene in the column with three coating cycles is 152.1 pmol. The effects of buffer concentration and pH value on the stability of the coating were evaluated. The retention reproducibility of the separation of toluene was 0.8, 1.2, 2.3, and 4.5%, respectively, for run-to-run, day-to-day, column-to-column, and batch-to-batch, respectively. The chromatographic performance of these columns was evaluated by both capillary liquid chromatography and open-tubular capillary electrochromatography (OT-CEC). Separation of aromatic hydrocarbons in the column with three coating cycles provided high theoretical plate numbers (up to 269,280 plates m(-1) for toluene) and short separation time (<15 min) by using OT-CEC mode. The method was also used to separate egg white proteins. Both acidic and basic proteins as well as four glycoisoforms were separated in a single run. Copyright © 2015 Elsevier B.V. All rights reserved.

Coatings for the NuSTAR mission

DEFF Research Database (Denmark)

Christensen, Finn Erland; Jakobsen, Anders Clemen; Brejnholt, Nicolai

2011-01-01

The NuSTAR mission will be the first mission to carry a hard X-ray(5-80 keV) focusing telescope to orbit. The optics are based on the use of multilayer coated thin slumped glass. Two different material combinations were used for the flight optics, namely W/Si and Pt/C. In this paper we describe...... the entire coating effort including the final coating design that was used for the two flight optics. We also present data on the performance verification of the coatings both on Si witness samples as well as on individual flight mirrors....

Alkali resistant optical coatings for alkali lasers and methods of production thereof

Science.gov (United States)

Soules, Thomas F; Beach, Raymond J; Mitchell, Scott C

2014-11-18

In one embodiment, a multilayer dielectric coating for use in an alkali laser includes two or more alternating layers of high and low refractive index materials, wherein an innermost layer includes a thicker, >500 nm, and dense, >97% of theoretical, layer of at least one of: alumina, zirconia, and hafnia for protecting subsequent layers of the two or more alternating layers of high and low index dielectric materials from alkali attack. In another embodiment, a method for forming an alkali resistant coating includes forming a first oxide material above a substrate and forming a second oxide material above the first oxide material to form a multilayer dielectric coating, wherein the second oxide material is on a side of the multilayer dielectric coating for contacting an alkali.

Error Analysis of Indirect Broadband Monitoring of Multilayer Optical Coatings using Computer Simulations

Science.gov (United States)

Semenov, Z. V.; Labusov, V. A.

2017-11-01

Results of studying the errors of indirect monitoring by means of computer simulations are reported. The monitoring method is based on measuring spectra of reflection from additional monitoring substrates in a wide spectral range. Special software (Deposition Control Simulator) is developed, which allows one to estimate the influence of the monitoring system parameters (noise of the photodetector array, operating spectral range of the spectrometer and errors of its calibration in terms of wavelengths, drift of the radiation source intensity, and errors in the refractive index of deposited materials) on the random and systematic errors of deposited layer thickness measurements. The direct and inverse problems of multilayer coatings are solved using the OptiReOpt library. Curves of the random and systematic errors of measurements of the deposited layer thickness as functions of the layer thickness are presented for various values of the system parameters. Recommendations are given on using the indirect monitoring method for the purpose of reducing the layer thickness measurement error.

Corrosion Resistance Of Electroless Ni-P/Cu/Ni-P Multilayer Coatings

Directory of Open Access Journals (Sweden)

Zhao G.L.

2015-06-01

Full Text Available Ni-P/Cu/Ni-P multilayer coatings were prepared by deposition of Cu layer between two Ni–P layers. The Cu layer was deposited by metal displacement reaction between Cu2+ and Fe atoms. Corrosion behavior of single-layer Ni-P coatings, double-layer Ni-P/Cu coatings, and three-layer Ni-P/Cu/Ni-P coatings were investigated by electrochemical tests in 3.5% NaCl solution. The three-layer coatings exhibited more positive Ecorr and decreased Icorr compared with conventional single-layer Ni-P coatings, which indicated an improved corrosion resistance. The polarization curves of the three-layer coatings were characterized by two passive regions. The improved corrosion resistance was not only attributed to the function of the blocked pores of Cu. The Cu interlayer also acted as a sacrificial layer instead of a barrier in the coatings, which altered the corrosion mechanism and further improved the corrosion resistance of the coatings.

Coating multilayer material with improved tribological properties obtained by magnetron sputtering

Science.gov (United States)

Mateescu, A. O.; Mateescu, G.; Balasoiu, M.; Pompilian, G. O.; Lungu, M.

2017-02-01

This work is based on the Patent no. RO 128094 B1, granted by the Romanian State Office for Inventions and Trademarks. The goal of the work is to obtain for investigations tribological coatings with multilayer structure with improved tribological properties, deposited by magnetron sputtering process from three materials (sputtering targets). Starting from compound chemical materials (TiC, TiB2 and WC), as sputtering targets, by deposition in argon atmosphere on polished stainless steel, we have obtained, based on the claims of the above patent, thin films of multilayer design with promising results regarding their hardness, elastic modulus, adherence, coefficient of friction and wear resistance. The sputtering process took place in a special sequence in order to ensure better tribological properties to the coating, comparing to those of the individual component materials. The tribological properties, such as the coefficient of friction, are evaluated using the tribometer test.

Damping Oriented Design of Thin-Walled Mechanical Components by Means of Multi-Layer Coating Technology

Directory of Open Access Journals (Sweden)

Giuseppe Catania

2018-02-01

Full Text Available The damping behaviour of multi-layer composite mechanical components, shown by recent research and application papers, is analyzed. A local dissipation mechanism, acting at the interface between any two different layers of the composite component, is taken into account, and a beam model, to be used for validating the known experimental results, is proposed. Multi-layer prismatic beams, consisting of a metal substrate and of some thin coated layers exhibiting variable stiffness and adherence properties, are considered in order to make it possible to study and validate this assumption. A dynamical model, based on a simple beam geometry but taking into account the previously introduced local dissipation mechanism and distributed visco-elastic constraints, is proposed. Some different application examples of specific multi-layer beams are considered, and some numerical examples concerning the beam free and forced response are described. The influence of the multilayer system parameters on the damping behaviour of the free and forced response of the composite beam is investigated by means of the definition of some damping estimators. Some effective multi-coating configurations, giving a relevant increase of the damping estimators of the coated structure with respect to the same uncoated structure, are obtained from the model simulation, and the results are critically discussed.

STUDY OF REFLECTION COEFFICIENT DISTRIBUTION FOR ANTI-REFLECTION COATINGS ON SMALL-RADIUS OPTICAL PARTS

Directory of Open Access Journals (Sweden)

L. A. Gubanova

2015-03-01

Full Text Available The paper deals with findings for the energy reflection coefficient distribution of anti- reflection coating along the surface of optical elements with a very small radius (2-12 mm. The factors influencing the magnitude of the surface area of the optical element, in which the energy reflection coefficient is constant, were detected. The main principles for theoretical models that describe the spectral characteristics of the multilayer interference coatings were used to achieve these objectives. The relative size of the enlightenment area is defined as the ratio of the radius for the optical element surface, where the reflection is less than a certain value, to its radius (ρ/r. The result of research is the following: this size is constant for a different value of the curvature radius for the optical element made of the same material. Its value is determined by the refractive index of material (nm, from which the optical element was made, and the design of antireflection coatings. For single-layer coatings this value is ρ/r = 0.5 when nm = 1.51; and ρ/r = 0.73 when nm = 1.75; for two-layer coatings ρ/r = 0.35 when nm = 1.51 and ρ/r = 0.41 when nm = 1.75. It is shown that with increasing of the material refractive index for the substrate size, the area of minimum reflection coefficient is increased. The paper considers a single-layer, two-layer, three-layer and five-layer structures of antireflection coatings. The findings give the possibility to conclude that equal thickness coverings formed on the optical element surface with a small radius make no equal reflection from the entire surface, and distribution of the layer thickness needs to be looked for, providing a uniform radiation reflection at all points of the spherical surface.

Calculated efficiencies of three-material low stress coatings for diffractive x-ray transmission optics

International Nuclear Information System (INIS)

Kubec, Adam; Braun, Stefan; Gawlitza, Peter; Menzel, Maik; Leson, Andreas

2016-01-01

Diffractive X-ray optical elements made by thin film coating techniques such as multilayer Laue lenses (MLL) and multilayer zone plates (MZP) are promising approaches to achieve resolutions in hard X-ray microscopy applications of less than 10 nm. The challenge is to make a lens with a large numerical aperture on the one hand and a decent working distance on the other hand. One of the limiting factors with the coated structures is the internal stress in the films, which can lead to significant bending of the substrate and various types of unwanted diffraction effects. Several approaches have been discussed to overcome this challenge. One of these is a three-material combination such as Mo/MoSi_2/Si, where four single layers per period are deposited. Mo and Si represent the absorber and spacer in this case while MoSi_2 forms a diffusion barrier; in addition the thicknesses of absorber and spacer are chosen to minimize residual stress of the overall coating. Here the diffraction efficiency as well as the profile of the beam in the focal plane are discussed in order to find a tradeoff between lowest residual stress and best diffraction properties.

Preparation of multi-layer film consisting of hydrogen-free DLC and nitrogen-containing DLC for conductive hard coating

Science.gov (United States)

Iijima, Yushi; Harigai, Toru; Isono, Ryo; Degai, Satoshi; Tanimoto, Tsuyoshi; Suda, Yoshiyuki; Takikawa, Hirofumi; Yasui, Haruyuki; Kaneko, Satoru; Kunitsugu, Shinsuke; Kamiya, Masao; Taki, Makoto

2018-01-01

Conductive hard-coating films have potential application as protective films for contact pins used in the electrical inspection process for integrated circuit chips. In this study, multi-layer diamond-like carbon (DLC) films were prepared as conductive hard-coating films. The multi-layer DLC films consisting of DLC and nitrogen-containing DLC (N-DLC) film were prepared using a T-shape filtered arc deposition method. Periodic DLC/N-DLC four-layer and eight-layer films had the same film thickness by changing the thickness of each layer. In the ball-on-disk test, the N-DLC mono-layer film showed the highest wear resistance; however, in the spherical polishing method, the eight-layer film showed the highest polishing resistance. The wear and polishing resistance and the aggressiveness against an opponent material of the multi-layer DLC films improved by reducing the thickness of a layer. In multi-layer films, the soft N-DLC layer between hard DLC layers is believed to function as a cushion. Thus, the tribological properties of the DLC films were improved by a multi-layered structure. The electrical resistivity of multi-layer DLC films was approximately half that of the DLC mono-layer film. Therefore, the periodic DLC/N-DLC eight-layer film is a good conductive hard-coating film.

Ion Diffusion-Directed Assembly Approach to Ultrafast Coating of Graphene Oxide Thick Multilayers.

Science.gov (United States)

Zhao, Xiaoli; Gao, Weiwei; Yao, Weiquan; Jiang, Yanqiu; Xu, Zhen; Gao, Chao

2017-10-24

The layer-by-layer (LbL) assembly approach has been widely used to fabricate multilayer coatings on substrates with multiple cycles, whereas it is hard to access thick films efficiently. Here, we developed an ion diffusion-directed assembly (IDDA) strategy to rapidly make multilayer thick coatings in one step on arbitrary substrates. To achieve multifunctional coatings, graphene oxide (GO) and metallic ions were selected as the typical building blocks and diffusion director in IDDA, respectively. With diffusion of metallic ions from substrate to negatively charged GO dispersion spontaneously (i.e., from high-concentration region to low-concentration region), GO was assembled onto the substrate sheet-by-sheet via sol-gel transformation. Because metallic ions with size of subnanometers can diffuse directionally and freely in the aqueous dispersion, GO was coated on the substrate efficiently, giving rise to films with desired thickness up to 10 μm per cycle. The IDDA approach shows three main merits: (1) high efficiency with a μm-scale coating rate; (2) controllability over thickness and evenness; and (3) generality for substrates of plastics, metals and ceramics with any shapes and morphologies. With these merits, IDDA strategy was utilized in the efficient fabrication of functional graphene coatings that exhibit outstanding performance as supercapacitors, electromagnetic interference shielding textiles, and anticorrosion coatings. This IDDA approach can be extended to other building blocks including polymers and colloidal nanoparticles, promising for the scalable production and application of multifunctional coatings.

The anti-corrosion behavior under multi-factor impingement of Hastelloy C22 coating prepared by multilayer laser cladding

Science.gov (United States)

Chen, Lin; Bai, Shu-Lin

2018-04-01

Hastelloy C22 coating was prepared on substrate of Q235 steel by high power multilayer laser cladding. The microstructure, hardness and anti-corrosion properties of coating were investigated. The corrosion tests in 3.5% NaCl solution were carried out with variation of impingement angle and velocity, and vibration frequency of sample. The microstructure of coating changes from equiaxed grain at the top surface to dendrites oriented at an angle of 60° to the substrate inside the coating. The corrosion rate of coating increases with the increase of impingement angle and velocity, and vibrant frequency of sample. Corrosion mechanisms relate to repassivation and depassivation of coating according to electrochemical measurements. Above results show that multilayer laser cladding can endow Hastelloy C22 coating with fine microstructures, high hardness and good anti-corrosion performances.

Laser-induced damage threshold tests of ultrafast multilayer dielectric coatings in various environmental conditions relevant for operation of ELI beamlines laser systems

Science.gov (United States)

Ďurák, Michal; Velpula, Praveen Kumar; Kramer, Daniel; Cupal, Josef; Medřík, Tomáš; Hřebíček, Jan; Golasowski, Jiří; Peceli, Davorin; Kozlová, Michaela; Rus, Bedřich

2017-01-01

Increasing the laser-induced damage resistance of optical components is one of the major challenges in the development of Peta-watt (PW) class laser systems. The extreme light infrastructure (ELI) beamlines project will provide ultrafast laser systems with peak powers up to 10 PW available every minute and PW class beams at 10 Hz complemented by a 5-TW, 1-kHz beamline. Sustainable performance of PW class laser systems relies on the durability of the employed optical components. As part of an effort to evaluate the damage resistance of components utilized in ELI beamlines systems, damage thresholds of several optical multilayer dielectric coatings were measured with different laser parameters and in different environments. Three coatings were tested with 10 Hz and 1 kHz pulse repetition rates, and the effect of a cleaning treatment on their damage resistance was examined. To explore the damage threshold behavior at different vacuum levels, one coating was subject to tests at various residual gas pressures. No change of damage threshold in a high vacuum with respect to ambient pressure was recorded. The effect of the cleaning treatment was found to be inconsistent, suggesting that development of the optimal cleaning treatment for a given coating requires consideration of its specific properties.

In situ 3D characterization of historical coatings and wood using multimodal nonlinear optical microscopy.

Science.gov (United States)

Latour, Gaël; Echard, Jean-Philippe; Didier, Marie; Schanne-Klein, Marie-Claire

2012-10-22

We demonstrate multimodal nonlinear optical imaging of historical artifacts by combining Second Harmonic Generation (SHG) and Two-Photon Excited Fluorescence (2PEF) microscopies. We first identify the nonlinear optical response of materials commonly encountered in coatings of cultural heritage artifacts by analyzing one- and multi-layered model samples. We observe 2PEF signals from cochineal lake and sandarac and show that pigments and varnish films can be discriminated by exploiting their different emission spectral ranges as in luminescence linear spectroscopy. We then demonstrate SHG imaging of a filler, plaster, composed of bassanite particles which exhibit a non centrosymmetric crystal structure. We also show that SHG/2PEF imaging enables the visualization of wood microstructure through typically 60 µm-thick coatings by revealing crystalline cellulose (SHG signal) and lignin (2PEF signal) in the wood cell walls. Finally, in situ multimodal nonlinear imaging is demonstrated in a historical violin. SHG/2PEF imaging thus appears as a promising non-destructive and contactless tool for in situ 3D investigation of historical coatings and more generally for wood characterization and coating analysis at micrometer scale.

Soft X-ray imaging of thick carbon-based materials using the normal incidence multilayer optics.

Science.gov (United States)

Artyukov, I A; Feschenko, R M; Vinogradov, A V; Bugayev, Ye A; Devizenko, O Y; Kondratenko, V V; Kasyanov, Yu S; Hatano, T; Yamamoto, M; Saveliev, S V

2010-10-01

The high transparency of carbon-containing materials in the spectral region of "carbon window" (lambda approximately 4.5-5nm) introduces new opportunities for various soft X-ray microscopy applications. The development of efficient multilayer coated X-ray optics operating at the wavelengths of about 4.5nm has stimulated a series of our imaging experiments to study thick biological and synthetic objects. Our experimental set-up consisted of a laser plasma X-ray source generated with the 2nd harmonics of Nd-glass laser, scandium-based thin-film filters, Co/C multilayer mirror and X-ray film UF-4. All soft X-ray images were produced with a single nanosecond exposure and demonstrated appropriate absorption contrast and detector-limited spatial resolution. A special attention was paid to the 3D imaging of thick low-density foam materials to be used in design of laser fusion targets.

Single layer and multilayer vacuum-arc coatings based on the nitride TiAlSiYN: composition, structure, properties

International Nuclear Information System (INIS)

Beresnev, V.M.; Litovchenko, S.V.; Nemchenko, U.S.; Srebnyuk, P.A.; Mazilin, B.A.; Sobol, O.V.; Mejlekhov, A.A.; Barmin, A.E.; Serenko, TA.; Pogrebnyak, A.D.; Ivanov, O.N.; Kritsyna, E.V.; Stolbovoj, V.A.; Novikov, V.Yu.; Malikov, L.V.

2017-01-01

Using high-technological vacuum-arc evaporation in the atmosphere of nitrogen with ion bombardment, single- and multilayer coatings based on TiAlSiYN with high mechanical characteristics were obtained: hardness of the coatings reached 49.5 GPa, resistance to wear, with the value of the critical point L_C_5 reaching 184.92 N. The peculiarities of radiation-induced effect at applying bias potential U_b were found: formation of nitride coatings based on fcc metallic lattice with the preferred orientation of crystallites with the texture axis [111], as well as simultaneous growth of hardness. Hardness of both single- and multilayer coatings increases by 40...50% at the increase of U_b from 50 to 200 V. Formation of silicon-containing layers of TiAlSiYN during the deposition contributes to reaching increased hardness, which, in the case of single-layer coating obtained at U_b = -200 V is 49.5 GPa, which corresponds to superhard state. The mechanisms of structure formation, defining the resulting mechanical characteristics of single- and multi-layer coatings based on TiAlSiYN nitride have been discussed.

Lubricated sliding wear behaviour of Ni-P-W multilayered alloy coatings produced by pulse plating

DEFF Research Database (Denmark)

Panagopoulos, C. N.; Papachristos, V. D.; Christoffersen, Lasse

2000-01-01

The lubricated sliding wear behaviour of Ni-P-W multilayered alloy coatings sliding against hardened steel discs was studied, in a pin-on-disc set-up. The multilayered coatings had been deposited on mild steel pins by pulse plating and they consisted of ternary Ni-P-W layers of high and low W con...... lubrication regimes. The wear mechanisms in each lubrication regime were studied and in mixed lubrication regime, the effect of normal load and sliding speed on wear volume and friction coefficient was also studied. (C) 2000 Elsevier Science S.A. All rights reserved....

Atomic hydrogen cleaning of EUV multilayer optics

Science.gov (United States)

Graham, Samuel, Jr.; Steinhaus, Charles A.; Clift, W. Miles; Klebanoff, Leonard E.; Bajt, Sasa

2003-06-01

Recent studies have been conducted to investigate the use of atomic hydrogen as an in-situ contamination removal method for EUV optics. In these experiments, a commercial source was used to produce atomic hydrogen by thermal dissociation of molecular hydrogen using a hot filament. Samples for these experiments consisted of silicon wafers coated with sputtered carbon, Mo/Si optics with EUV-induced carbon, and bare Si-capped and Ru-B4C-capped Mo/Si optics. Samples were exposed to an atomic hydrogen source at a distance of 200 - 500 mm downstream and angles between 0-90° with respect to the source. Carbon removal rates and optic oxidation rates were measured using Auger electron spectroscopy depth profiling. In addition, at-wavelength peak reflectance (13.4 nm) was measured using the EUV reflectometer at the Advanced Light Source. Data from these experiments show carbon removal rates up to 20 Å/hr for sputtered carbon and 40 Å/hr for EUV deposited carbon at a distance of 200 mm downstream. The cleaning rate was also observed to be a strong function of distance and angular position. Experiments have also shown that the carbon etch rate can be increased by a factor of 4 by channeling atomic hydrogen through quartz tubes in order to direct the atomic hydrogen to the optic surface. Atomic hydrogen exposures of bare optic samples show a small risk in reflectivity degradation after extended periods. Extended exposures (up to 20 hours) of bare Si-capped Mo/Si optics show a 1.2% loss (absolute) in reflectivity while the Ru-B4C-capped Mo/Si optics show a loss on the order of 0.5%. In order to investigate the source of this reflectivity degradation, optic samples were exposed to atomic deuterium and analyzed using low energy ion scattering direct recoil spectroscopy to determine any reactions of the hydrogen with the multilayer stack. Overall, the results show that the risk of over-etching with atomic hydrogen is much less than previous studies using RF discharge cleaning

Optical interference coatings for optics and photonics [Invited].

Science.gov (United States)

Lee, Cheng-Chung

2013-01-01

Optical interference coatings play as an important role in the progress in optics and photonics. In this article we give a minireview of the evolution of optical interference coatings from the theory, the design, to the manufacture. Some interesting but challenging topics for the future are also discussed.

Optical Properties of Multilayer CdSe/POLYMER Structures

Science.gov (United States)

Red'Ko, V. P.; Voitenkov, A. I.; Kovalenko, O. E.

The effects of preparation condition, concentration and size of particles upon optical and photoelectrical characteristics of multilayer structures CdSe/polyethylene terephthalate obtained by electron-beam evaporation were investigated.

Structural and Morphological Difference Between Ti/TiN/TiCN Coatings Grown in Multilayer and Graded Form

International Nuclear Information System (INIS)

Restrepo, E.; Baena, A.; Agudelo, C.; Castillo, H.; Devia, A.; Marino, A.

2006-01-01

Thin films can be grown in super-lattice, multilayers and graded form, having each one advantages and disadvantages. The difference between multilayer and graded coatings is the interface. In multilayers the interface is abrupt and in graded coatings it is diffuse. The interface influences many chemical and physical properties of the materials, and its choice depends on the application. Graded coatings have the advantage of having gradual properties such as thermal expansion coefficient and lattice parameter, avoiding adherence problems due to good match between their component materials. In this work the comparison between some properties of coatings grown as multilayer and graded is performed. The materials are produced using the sputtering DC technique because of its facility to control the deposition parameters and generate a slow growth. The target is a disc of titanium and the samples are made of stainless steel 304. The working gases are argon, nitrogen and methane, which are mixed according to the material to be produced, i.e. Ti layer is grown with argon, the TiN film is produced with a mixture of argon and nitrogen, and the TiCN material is obtained mixing argon, nitrogen and methane. These materials are characterized with AFM in order to determine grain size and with XPS studying the chemical composition and performing depth profiles

Multilayer (TiN, TiAlN) ceramic coatings for nuclear fuel cladding

Energy Technology Data Exchange (ETDEWEB)

Alat, Ece, E-mail: exa179@psu.edu [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Motta, Arthur T. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Comstock, Robert J.; Partezana, Jonna M. [Westinghouse Electric Co., Beulah Rd, Pittsburgh, PA 1332 (United States); Wolfe, Douglas E. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Applied Research Laboratory, The Pennsylvania State University, 119 Materials Research Building, University Park, PA 16802 (United States)

2016-09-15

In an attempt to develop an accident-tolerant fuel (ATF) that can delay the deleterious consequences of loss-of-coolant-accidents (LOCA), multilayer coatings were deposited onto ZIRLO{sup ®} coupon substrates by cathodic arc physical vapor deposition (CA-PVD). Coatings were composed of alternating TiN (top) and Ti{sub 1-x}Al{sub x}N (2-layer, 4-layer, 8-layer and 16-layer) layers. The minimum TiN top coating thickness and coating architecture were optimized for good corrosion and oxidation resistance. Corrosion tests were performed in static pure water at 360 °C and 18.7 MPa for up to 90 days. The optimized coatings showed no spallation/delamination and had a maximum of 6 mg/dm{sup 2} weight gain, which is 6 times smaller than that of a control sample of uncoated ZIRLO{sup ®} which showed a weight gain of 40.2 mg/dm{sup 2}. The optimized architecture features a ∼1 μm TiN top layer to prevent boehmite phase formation during corrosion and a TiN/TiAlN 8-layer architecture which provides the best corrosion performance. - Highlights: • The first study on multilayer TiAlN and TiN ceramic coatings on ZIRLO{sup ®} coupons. • Corrosion tests were performed at 360°C and 18.7 MPa for up to 90 days. • Coatings adhered well to the substrate, and showed no spallation/delamination. • Weight gains were six times lower than those of uncoated ZIRLO{sup ®} samples. • Longer and higher temperature corrosion tests will be discussed in a further paper.

Deformation sensor based on polymer-supported discontinuous graphene multi-layer coatings

International Nuclear Information System (INIS)

Carotenuto, G.; Schiavo, L.; Romeo, V.; Nicolais, L.

2014-01-01

Graphene can be conveniently used in the modification of polymer surfaces. Graphene macromolecules are perfectly transparent to the visible light and electrically conductive, consequently these two properties can be simultaneously provided to polymeric substrates by surface coating with thin graphene layers. In addition, such coating process provides the substrates of: water-repellence, higher surface hardness, low-friction, self-lubrication, gas-barrier properties, and many other functionalities. Polyolefins have a non-polar nature and therefore graphene strongly sticks on their surface. Nano-crystalline graphite can be used as graphene precursor in some chemical processes (e.g., graphite oxide synthesis by the Hummer method), in addition it can be directly applied to the surface of a polyolefin substrate (e.g., polyethylene) to cover it by a thin graphene multilayer. In particular, the nano-crystalline graphite perfectly exfoliate under the application of a combination of shear and friction forces and the produced graphene single-layers perfectly spread and adhere on the polyethylene substrate surface. Such polymeric materials can be used as ITO (indium-tin oxide) substitute and in the fabrication of different electronic devices. Here the fabrication of transparent resistive deformation sensors based on low-density polyethylene films coated by graphene multilayers is described. Such devices are very sensible and show a high reversible and reproducible behavior

The structure and mechanical properties of multilayer nanocrystalline TiN/ZrN coatings obtained by vacuum-arc deposition

Directory of Open Access Journals (Sweden)

A.V. Demchyshyn

2007-12-01

Full Text Available TiN/ZrN multilayered condensates on BK-8 carbide tips substrates (62 HRC were produced by the vacuumarc deposition technique, using Ti and Zr plasma flows in reactive nitrogen gas medium with working pressure of 6.6·10–1 Pa. The TiN/ZrN multilayered condensates consist of TiN and ZrN sublayers, which have a thickness of ~100 nm, controlled by the processing parameters of the used deposition technique. The obtained coatings have hardness of 45 GPa and Young’s modulus of 320 GPa. The obtained results show that mechanical properties of such multilayered composites are considerably improved in comparison to those for the single-component coatings, TiN and ZrN. The dependence of hardness and Young’s modulus of the composites on sublayer thickness within a range of 100 nm was determined. The investigated structure and improved mechanical properties of the TiN/ZrN multilayered condensates would be very good platform for finding their industrial application, such as hard coatings with different purposes.

Flame Retardant Multilayered Coatings on Acrylic Fabrics Prepared by One-Step Deposition of Chitosan/Montmorillonite Complexes

Directory of Open Access Journals (Sweden)

Federico Carosio

2018-06-01

Full Text Available Multilayered coatings deposited using the layer-by-layer (LbL assembly technique have attracted great interest in recent years as a sustainable and efficient solution for conferring flame retardant properties to fabrics. The unique structure and interaction established upon the coating assembly are the key factors for successful flame retardant properties. In this study we aimed at the deposition of multilayered coatings comprising chitosan and montmorillonite with a LbL-like structure and interactions by the simple processing of compacted chitosan/montmorillonite complexes obtained by the direct mixing of an oppositely charged solution/suspension. Upon drying, the prepared complex yielded a continuous coating characterized by a brick-and-mortar multi-layered structure, in which oriented clay nanoplatelets were held together by a continuous chitosan matrix. When deposited on acrylic fabrics these coatings were able to suppress the melt-dripping phenomenon, and at 10 and 20% add-ons achieved self-extinguishing behavior within a few seconds after ignition. Cone calorimetry testing revealed an increase in time to ignition (up to +46% and considerable reductions of the rates at which heat is released (up to −62 and −49% for peak of heat release rate and total heat release, respectively. A reduction in the total smoke release (up to −49% was also observed.

High temperature tribological performance of CrAlYN/CrN nanoscale multilayer coatings deposited on ?-TiAl

OpenAIRE

Walker, J.C.; Ross, I.M.; Reinhard, C.; Rainforth, W.M.; Hovsepian, P.Eh.

2009-01-01

This paper details the effect of temperature on the frictional behaviour of highly novel CrAlYN/CrN multilayer coatings, deposited by High Power Impulse Magnetron Sputtering (HIPIMS) on a Titanium Aluminide alloy used as fan blade material in the aerospace and a turbo-charger wheel in the automotive industries. The work was the first to discover the high temperature oxide 'glaze' layer formation which occurred on CrN multilayer-type coatings at higher temperatures and has received significant...

Intelligent saline enabled self-healing of multilayer coatings and its optimization to achieve redox catalytically provoked anti-corrosion ability

Energy Technology Data Exchange (ETDEWEB)

Syed, Junaid Ali; Tang, Shaochun; Meng, Xiangkang, E-mail: mengxk@nju.edu.cn

2016-10-15

Highlights: • Multilayer coatings were prepared with good self-healing and anti-corrosion ability. • The lifespan of SS is much improved and it is stable even after 120 h in 3.5% NaCl. • Multilayer structure with redox catalytic and self-healing ability leads to high P{sub e}. • Saline-triggered self-healing and anti-corrosion mechanisms were envisaged. - Abstract: To obtain a coating with both self-healing and redox catalytic ability to protect a metal substrate from corrosion under aggressive environment is strongly desired. Herein, we report the design and fabrication of intelligent polyaniline-polyacrylic acid/polyethyleneimine (PANI-PAA/PEI) multilayer composite coatings by spin assembly. The main influencing factors, including solution concentration (c) and disk rotating speed (ω) were studied in order to gain excellent performance. The resulting multilayer coatings with thickness in a range from 0.47 to 2.94 μm can heal severe structural damages and sustain a superior anti-corrosive performance for 120 h in 3.5% NaCl. The PANI-PAA layer enhances the anti-corrosion property and PEI layer contributes to the self-healing ability as well as their multilayer combination strengthens them. The improved self-healing ability is attributed to the rearrangement and reversible non-covalent interactions of the PANI-PAA and PEI layers that facilitates electrostatic repairing.

Multilayer coatings containing diamond and other hard materials on hardmetal substrates

International Nuclear Information System (INIS)

Koepf, A.; Haubner, R.; Lux, B.

2001-01-01

In order to improve the wear resistance of hardmetal cutting tools, coatings of hard materials were established. Especially the production of multilayer coatings, which combine useful properties of different materials was a topic of industrial and academic research. The present work examined the possibilities of combining diamond as basic layer with protective CVD layers of TiC, TiN, Ti(C,N) and Al 2 O 3 . All these combinations could be realized and some showed quite good adherence under strain, which offers possibilities for technical applications. (author)

Thin film and multilayer optics for XUV spectral domain (1 nm to 60 nm)

International Nuclear Information System (INIS)

Delmotte, Franck

2010-02-01

The XUV spectral domain (1-60 nm wavelength range) has experienced rapid growth in recent years. On one side, the sources (synchrotron radiation, harmonic generation, x-ray laser, free-electron laser...) require ever more efficient optics, on the other hand, applications (diagnostics of hot plasma, solar physics, x-ray microscopy, EUV lithography, x-ray analysis...) provide new constraints on the design of multilayer stacks. The multilayer mirrors are the only way to achieve efficient optics operating at non-grazing incidence angles in this spectral range. Our work within the team XUV Optics at Laboratoire Charles Fabry de l'Institut d'Optique focuses on the study of materials in thin layers correlated to the study of optical properties of multilayers. The objective is to achieve new multilayer components previously unavailable in the XUV domain, through a better understanding of physical phenomena in these nano-layer stacks. We show through several examples of how we have managed both to improve the performance of multilayer mirrors in a broad spectral range, and secondly, to develop new optical functions: beam splitters, broadband mirrors, dual-band mirrors or phase compensation mirrors. (author)

Study of ion implantation in grown layers of multilayer coatings under ion-plasma vacuum deposition

International Nuclear Information System (INIS)

Voevodin, A.A.; Erokhin, A.L.

1993-01-01

The model of ion implantation into growing layers of a multilayer coating produced with vacuum ion-plasma deposition was developed. The model takes into account a possibility for ions to pass through the growing layer and alloys to find the distribution of implanted atoms over the coating thickness. The experimental vitrification of the model was carried out on deposition of Ti and TiN coatings

Improvement of Wear Performance of Nano-Multilayer PVD Coatings under Dry Hard End Milling Conditions Based on Their Architectural Development

Directory of Open Access Journals (Sweden)

Shahereen Chowdhury

2018-02-01

Full Text Available The TiAlCrSiYN-based family of PVD (physical vapor deposition hard coatings was specially designed for extreme conditions involving the dry ultra-performance machining of hardened tool steels. However, there is a strong potential for further advances in the wear performance of the coatings through improvements in their architecture. A few different coating architectures (monolayer, multilayer, bi-multilayer, bi-multilayer with increased number of alternating nano-layers were studied in relation to cutting-tool life. Comprehensive characterization of the structure and properties of the coatings has been performed using XRD, SEM, TEM, micro-mechanical studies and tool-life evaluation. The wear performance was then related to the ability of the coating layer to exhibit minimal surface damage under operation, which is directly associated with the various micro-mechanical characteristics (such as hardness, elastic modulus and related characteristics; nano-impact; scratch test-based characteristics. The results presented exhibited that a substantial increase in tool life as well as improvement of the mechanical properties could be achieved through the architectural development of the coatings.

Radiation cured coatings for fiber optics

International Nuclear Information System (INIS)

Ketley, A.D.; Morgan, C.R.

1978-01-01

A continuous protective coating is formed on a fiber optic by coating the fiber optic in a bath of a liquid radiation curable composition at a temperature up to 90 0 C and exposing the coated conductor to ultraviolet or high energy ionizing radiation to cure the coating

Low-threshold optical bistability with multilayer graphene-covering Otto configuration

International Nuclear Information System (INIS)

Wang, Hengliang; Wu, Jipeng; Xiang, Yuanjiang; Wen, Shuangchun; Guo, Jun; Jiang, Leyong

2016-01-01

In this paper, we propose a modified Otto configuration to realize tunable and low-threshold optical bistability at terahertz frequencies by attaching multilayer graphene sheets to a nonlinear substrate interface. Our work demonstrates that the threshold of optical bistability can be markedly reduced (three orders of magnitude) by covering the nonlinear substrate with multilayer graphene sheets, due to strong local field enhancement with the excitation of surface plasmons. We present the influences of the Fermi energy of graphene, the incident angle, the thickness of air gap and the relaxation time of graphene on the hysteresis phenomenon and give a way to optimize the surface plasmon resonance, which will enable us to further lower the minimal power requirements for realizing optical bistability due to the strong interaction of light with graphene sheets. These results are promising for realization of terahertz optical switches, optical modulators and logical devices. (paper)

Preparation and properties of DLC/MoS2 multilayer coatings for high humidity tribology

Science.gov (United States)

Zhao, Xiaoyu; Lu, Zhibin; Wu, Guizhi; Zhang, Guangan; Wang, Liping; Xue, Qunji

2016-06-01

The DLC/MoS2 multilayer coatings with different modulus ratios were deposited by magnetron sputtering in this study. The morphology, structure, composition, mechanical properties and tribological properties were investigated using several analytical techniques (FESEM, AFM, TEM, AES, XPS, nanoindentation and high humidity tribological test). The results showed that the well-defined multilayer coatings were composed of densely packed particles in which many nanocrystallines with some kinds of defects were distributed in matrix. The incorporation of oxygen into the lattice led to the degraded chemical stability. The coating’s hardness and elastic modulus were almost in the same range. Moderate improvement on the high humidity tribological properties were obtained, which was important for the extension of the service life of MoS2 in humid air.

Determination of the fatigue properties of multilayer PVD coatings on various substrates, based on the impact test and its FEM simulation

Energy Technology Data Exchange (ETDEWEB)

Bouzakis, K.D.; Vidakis, N. [Aristotle Univ., Thessaloniki (Greece). Dept. of Mech. Eng.; Leyendecker, T.; Erkens, G.; Wenke, R.

1997-10-31

The coating impact test, in combination with its finite elements method (FEM) simulation, is used to quantitatively characterize the fatigue behaviour of thin hard physical vapour deposited (PVD) coatings as well as of multilayer ones. Successive impacts of a cemented carbide ball onto a plane coated specimen induce severe contact loads and strain superficially the layered compound. The fatigue failure mode of each specimen is classified by means of scanning electron microscope (SEM) observations, microspectral analyses and profilometry. FEM simulating models of the impact test are used to determine the critical stress components, which introduce coating fatigue failure. The FEM computational results are correlated to the experimental ones and used to interpret them quantitatively. Herewith, critical values for stress components, responsible for distinctive fatigue failure modes of the coating substrate compounds are obtained and the fatigue limits of the examined multilayer coatings are inserted in general applicable Smith diagrams. Furthermore, the derived critical stresses are verified by investigating the same multilayer coatings on different substrates. (orig.) 14 refs.

Structure, mechanical and tribological properties of self-toughening TiSiN/Ag multilayer coatings on Ti6Al4V prepared by arc ion plating

Energy Technology Data Exchange (ETDEWEB)

Dang, Chaoqun [School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Li, Jinlong, E-mail: lijinlong11@126.com [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Wang, Yue; Chen, Jianmin [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

2016-11-15

Graphical abstract: Hardness and elastic modulus of TiSiN coating (C1) and TiSiN/Ag multilayer coatings with different thickness of individual Ag layers of 33.87 nm (C2), 30.01 nm (C3), 26.67 nm (C4), 22.22 nm (C5) and 10.67 nm (C6), together with SEM micrographs of indention morphologies after Vickers indentation tests. Display Omitted - Highlights: • TiSiN/Ag multilayer coatings design for microstructure was shown by cross-sectional SEM micrographs. • The TiSiN/Ag multilayer coatings showed a significantly improved toughness compared with the TiSiN coating. • The individual Ag layers as a self-lubricating. • TiSiN/Ag multilayer coating (individual Ag layers of 22.22 nm) exhibits high hardness, H/E and H{sup 3}/E{sup *2} values and excellent wear resistance. - Abstract: The TiSiN/Ag multilayer coatings deposited on Ti6Al4V alloy substrate using the multi-arc ion plating system. All multilayer coatings had a same total thickness of about 2.5 μm, and the TiSiN layer had a fixed thickness and the Ag layer had different thicknesses. Evidence concluded from X-ray diffraction, scanning electron microcopies, X-ray photoelectron spectroscopy revealed that nanocrystallites and amorphous microstructure of nc-TiN and amorphous Si{sub 3}N{sub 4} for individual TiSiN layers, where amorphous Si{sub 3}N{sub 4} around nanocrystallites TiN boundaries, and ductile nanocrystallites silver clusters and metallic silver for individual Ag layers which can limit continuous growth of single (200) preferential orientation coarse columnar TiN crystal. In addition, the TiN grain size presented a decreasing trend with the decrease of the thickness of Ag layers. The TiSiN/Ag multilayer coatings showed a significantly improved toughness compared with the TiSiN coating. The individual Ag layers of nano-multilayer coatings, not only as a self-lubricating but also as a barrier which inhibited micro cracks propagation, the formation of threading defects throughout all coatings, cause

Heparin-mimicking multilayer coating on polymeric membrane via LbL assembly of cyclodextrin-based supramolecules.

Science.gov (United States)

Deng, Jie; Liu, Xinyue; Ma, Lang; Cheng, Chong; Shi, Wenbin; Nie, Chuanxiong; Zhao, Changsheng

2014-12-10

In this study, multifunctional and heparin-mimicking star-shaped supramolecules-deposited 3D porous multilayer films with improved biocompatibility were fabricated via a layer-by-layer (LbL) self-assembly method on polymeric membrane substrates. Star-shaped heparin-mimicking polyanions (including poly(styrenesulfonate-co-sodium acrylate; Star-PSS-AANa) and poly(styrenesulfonate-co-poly(ethylene glycol)methyl ether methacrylate; Star-PSS-EGMA)) and polycations (poly(methyl chloride-quaternized 2-(dimethylamino)ethyl methacrylate; Star-PMeDMA) were first synthesized by atom transfer radical polymerization (ATRP) from β-cyclodextrin (β-CD) based cores. Then assembly of 3D porous multilayers onto polymeric membrane surfaces was carried out by alternating deposition of the polyanions and polycations via electrostatic interaction. The surface morphology and composition, water contact angle, blood activation, and thrombotic potential as well as cell viability for the coated heparin-mimicking films were systematically investigated. The results of surface ATR-FTIR spectra and XPS spectra verified successful deposition of the star-shaped supramolecules onto the biomedical membrane surfaces; scanning electron microscopy (SEM) and atomic force microscopy (AFM) observations revealed that the modified substrate had 3D porous surface morphology, which might have a great biological influence on the biointerface. Furthermore, systematic in vitro investigation of protein adsorption, platelet adhesion, human platelet factor 4 (PF4, indicates platelet activation), activate partial thromboplastin time (APTT), thrombin time (TT), coagulation activation (thrombin-antithrombin III complex (TAT, indicates blood coagulant)), and blood-related complement activation (C3a and C5a, indicates inflammation potential) confirmed that the heparin-mimicking multilayer coated membranes exhibited ultralow blood component activations and excellent hemocompatibility. Meanwhile, after surface coating

Improved irradiation tolerance of reactive gas pulse sputtered TiN coatings with a hybrid architecture of multilayered and compositionally graded structures

Science.gov (United States)

Liang, Wei; Yang, Jijun; Zhang, Feifei; Lu, Chenyang; Wang, Lumin; Liao, Jiali; Yang, Yuanyou; Liu, Ning

2018-04-01

This study investigates the improved irradiation tolerance of reactive gas pulse (RGP) sputtered TiN coatings which has hybrid architecture of multilayered and compositionally graded structures. The multilayered RGP-TiN coating is composed of hexagonal close-packed Ti phase and face-centred cubic TiN phase sublayers, where the former sublayer has a compositionally graded structure and the latter one maintains constant stoichiometric atomic ratio of Ti:N. After 100 keV He ion irradiation, the RGP-TiN coating exhibits improved irradiation resistance compared with its single layered (SL) counterpart. The size and density of He bubbles are smaller in the RGP-TiN coating than in the SL-TiN coating. The irradiation-induced surface blistering of the coatings shows a similar tendency. Meanwhile, the irradiation hardening and adhesion strength of the RGP-TiN coatings were not greatly affected by He irradiation. Moreover, the irradiation damage tolerance of the coatings can be well tuned by changing the undulation period number of N2 gas flow rate. Detailed analysis suggested that this improved irradiation tolerance could be related to the combined contribution of the multilayered and compositionally graded structures.

Threshold response using modulated continuous wave illumination for multilayer 3D optical data storage

Science.gov (United States)

Saini, A.; Christenson, C. W.; Khattab, T. A.; Wang, R.; Twieg, R. J.; Singer, K. D.

2017-01-01

In order to achieve a high capacity 3D optical data storage medium, a nonlinear or threshold writing process is necessary to localize data in the axial dimension. To this end, commercial multilayer discs use thermal ablation of metal films or phase change materials to realize such a threshold process. This paper addresses a threshold writing mechanism relevant to recently reported fluorescence-based data storage in dye-doped co-extruded multilayer films. To gain understanding of the essential physics, single layer spun coat films were used so that the data is easily accessible by analytical techniques. Data were written by attenuating the fluorescence using nanosecond-range exposure times from a 488 nm continuous wave laser overlapping with the single photon absorption spectrum. The threshold writing process was studied over a range of exposure times and intensities, and with different fluorescent dyes. It was found that all of the dyes have a common temperature threshold where fluorescence begins to attenuate, and the physical nature of the thermal process was investigated.

Microstructure and mechanical properties of nanostructure multilayer CrN/Cr coatings on titanium alloy

International Nuclear Information System (INIS)

Wiecinski, Piotr; Smolik, Jerzy; Garbacz, Halina; Kurzydlowski, Krzysztof J.

2011-01-01

Five different nanostructured, multilayer coatings (CrN/Cr)x8 with different thickness ratio of Cr and CrN layers were deposited by PAPVD (Plasma Assisted Physical Vapour Deposition) vacuum arc method on Ti6Al4V titanium alloy. The microstructure, chemical and phase composition of the CrN and Cr sub-layers were characterized by SEM with EDX and Cs-corrected dedicated STEM on cross-sections prepared by focus ion beam. Besides, hardness and Young's modulus of the (Cr/CrN)x8 coatings has been measured. The adhesion has been tested by scratch test method. The obtained (CrN/Cr) multilayer coatings, 5-6 μm in thickness, have homogeneous and nanocrystalline structure, free of pores and cracks. The microstructures of Cr and CrN layers consist of columnar grains below 100 nm in diameter. The hardness and Young's modulus of these coatings depend linearly on thickness ratio of Cr and CrN layers. The decrease of the thickness ratio Cr/CrN 0.81 to 0.15 results in the increase of hardness from 1275 HV to 1710 HV and Young's modulus from 260 GPa to 271 GPa.

Optical thin films and coatings from materials to applications

CERN Document Server

Flory, Francois

2013-01-01

Optical coatings, including mirrors, anti-reflection coatings, beam splitters, and filters, are an integral part of most modern optical systems. This book provides an overview of thin film materials, the properties, design and manufacture of optical coatings and their use across a variety of application areas.$bOptical coatings, including mirrors, anti-reflection coatings, beam splitters, and filters, are an integral part of most modern optical systems. Optical thin films and coatings provides an overview of thin film materials, the properties, design and manufacture of optical coatings and their use across a variety of application areas. Part one explores the design and manufacture of optical coatings. Part two highlights unconventional features of optical thin films including scattering properties of random structures in thin films, optical properties of thin film materials at short wavelengths, thermal properties and colour effects. Part three focusses on novel materials for optical thin films and coatings...

Optical and structural study of BST multilayers

Czech Academy of Sciences Publication Activity Database

Železný, Vladimír; Chvostová, Dagmar; Pajasová, Libuše; Jelínek, Miroslav; Kocourek, Tomáš; Daniš, S.; Valvoda, V.

2010-01-01

Roč. 12, č. 3 (2010), 538-541 ISSN 1454-4164 R&D Projects: GA ČR GA202/07/0591 Institutional research plan: CEZ:AV0Z10100522; CEZ:AV0Z10100520 Keywords : ellipsometry * structure * ferroelectric multilayers Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.412, year: 2010

Precision Cleaning and Protection of Coated Optical Components for NIF Small Optics

Energy Technology Data Exchange (ETDEWEB)

Phelps, Jim [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-10-19

The purpose of this procedure shall be to define the precision cleaning of finished, coated, small optical components for NIF at Lawrence Livermore National Laboratories. The term “small optical components” includes coated optics that are set into simple mounts, as well as coated, un-mounted optics.

Optical coatings:trends and challenges

Institute of Scientific and Technical Information of China (English)

Norbert Kaiser; Torsten Feigl; Olaf Stenzel; Ulrike Schulz; Ming-hong Yang

2005-01-01

New applications in optoelectronics, photonics, telecommunication, displays, optical data processing, biomedicine, sensors, energy control, automobile, aerospace, and architecture stimulation are important developments in physics and technology of optical coatings. This paper will focus on the latest advances in the areas of new optical film systems and devices, new optical coating materials and film fabrication techniques, process control and monitoring, and different advanced applications. Particularly, focus is on optical films that combine optical design with microstructural features tailored on the nanometer and micrometer scales. Evaluation of film stability and integrity in harsh industrial environments and their compatibility with organic polymers are important as well.

Tribological behavior at elevated temperature of multilayer TiCN/TiC/TiN hard coatings produced by chemical vapor deposition

International Nuclear Information System (INIS)

Bao Mingdong; Xu Xuebo; Zhang Haijun; Liu Xiaoping; Tian Linhai; Zeng Zhaoxin; Song Yubin

2011-01-01

Multilayer hard coatings of TiCN/TiC/TiN on high speed steel substrates were deposited using a chemical vapor deposition system. Evaluations of microstructure, wear morphology of coatings were characterized by scanning electron microscopy, and optical microscopy. Friction coefficient and wear rates of coatings were investigated using ball-on-disk tester sliding against a WC ball at a constant load of 20 N. Tribological behavior of the coatings at room and elevated temperature were discussed. Different changing tendency of friction coefficient were observed from ball-on-disc experiments. Results showed that the friction coefficient of coatings increased gradually to a highest value, then to a relatively constant value at room temperature dry sliding wear. The friction coefficient exhibited a reverse variation tendency at temperature of 550 °C. It got a higher value at the first sliding friction cycles. Then the value of friction coefficient decreased, suffered irregular oscillations and kept a relatively lower value with increasing sliding time. Reasons of the variation of friction coefficient with sliding time and wear mechanism were analyzed and discussed at room and elevated temperatures, respectively.

Electrochemical behavior of single layer CrN, TiN, TiAlN coatings and nanolayered TiAlN/CrN multilayer coatings prepared by reactive direct current magnetron sputtering

International Nuclear Information System (INIS)

William Grips, V.K.; Barshilia, Harish C.; Selvi, V. Ezhil; Kalavati; Rajam, K.S.

2006-01-01

The corrosion behaviors of single layer TiN, CrN, TiAlN and multilayer TiAlN/CrN coatings, deposited on steel substrate using a multi-target reactive direct current magnetron sputtering process, were studied in 3.5% NaCl solution by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The total thickness of the coatings was about 1.5 μm. About 0.5 μm thick chromium interlayer was used for improved adhesion of the coatings. The potentiodynamic polarization measurements showed that for all the coatings the corrosion potential shifted to higher values as compared to the uncoated substrate. Similarly, the corrosion current density decreased for coated samples, indicating better corrosion resistance of the coated samples. The multilayer coatings of TiAlN/CrN exhibited superior corrosion behavior as compared to the single layer coatings. The Nyquist and the Bode plots obtained from the EIS measurements were fitted by appropriate equivalent circuits to calculate the pore resistance, the charge transfer resistance and the capacitance. These studies revealed that the pore resistance was lowest for TiN coatings, which increased for TiAlN coatings. TiAlN/CrN multilayer coatings exhibited highest pore resistance. No significant change in the capacitive behavior of the coatings was observed, suggesting minimal morphological changes as a result of immersion in the electrolyte. This could be attributed to shorter immersion durations. These studies were confirmed by examining the corroded samples under scanning electron microscope. Preliminary experiments conducted with additional interlayer of electroless nickel (5.0 μm thick) have shown significant improvement in the corrosion resistance of the coatings

Characterization of multilayer anti-fog coatings.

Science.gov (United States)

Chevallier, Pascale; Turgeon, Stéphane; Sarra-Bournet, Christian; Turcotte, Raphaël; Laroche, Gaétan

2011-03-01

Fog formation on transparent substrates constitutes a major challenge in several optical applications requiring excellent light transmission characteristics. Anti-fog coatings are hydrophilic, enabling water to spread uniformly on the surface rather than form dispersed droplets. Despite the development of several anti-fog coating strategies, the long-term stability, adherence to the underlying substrate, and resistance to cleaning procedures are not yet optimal. We report on a polymer-based anti-fog coating covalently grafted onto glass surfaces by means of a multistep process. Glass substrates were first activated by plasma functionalization to provide amino groups on the surface, resulting in the subsequent covalent bonding of the polymeric layers. The anti-fog coating was then created by the successive spin coating of (poly(ethylene-maleic anhydride) (PEMA) and poly(vinyl alcohol) (PVA) layers. PEMA acted as an interface by covalently reacting with both the glass surface amino functionalities and the PVA hydroxyl groups, while PVA added the necessary surface hydrophilicity to provide anti-fog properties. Each step of the procedure was monitored by XPS, which confirmed the successful grafting of the coating. Coating thickness was evaluated by profilometry, nanoindentation, and UV visible light transmission. The hydrophilic nature of the anti-fog coating was assessed by water contact angle (CA), and its anti-fog efficiency was determined visually and tested quantitatively for the first time using an ASTM standard protocol. Results show that the PEMA/PVA coating not only delayed the initial period required for fog formation but also decreased the rate of light transmission decay. Finally, following a 24 hour immersion in water, these PEMA/PVA coatings remained stable and preserved their anti-fog properties.

Performance of multilayer coated silicon pore optics

DEFF Research Database (Denmark)

Ackermann, M. D.; Collon, M. J.; Cooper-Jensen, Carsten P.

2010-01-01

simultaneously requirements for effective area of 2.5 m2 at 1.25 keV, 0.65 m2 at 6 keV and 150 cm2 at 30 keV. The reflectivity of the bare mirror substrate materials does not allow these requirements to be met. As such the IXO baseline design contains a coating layout that varies as a function of mirror radius...

Effect of electroless nickel interlayer on the electrochemical behavior of single layer CrN, TiN, TiAlN coatings and nanolayered TiAlN/CrN multilayer coatings prepared by reactive dc magnetron sputtering

International Nuclear Information System (INIS)

Grips, V.K. William; Ezhil Selvi, V.; Barshilia, Harish C.; Rajam, K.S.

2006-01-01

The electrochemical behavior of single layer TiN, CrN, TiAlN and multilayer TiAlN/CrN coatings, deposited on steel substrates using a multi-target reactive direct current (dc) magnetron sputtering process, was studied in 3.5% NaCl solution. The total thickness of the coatings was about 1.5 μm. About 0.5 μm thick chromium interlayer was used to improve adhesion of the coatings. With an aim to improve the corrosion resistance, an additional interlayer of approximately 5 μm thick electroless nickel (EN) was deposited on the substrate. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were used to study the corrosion behavior of the coatings. Scanning electron microscopy and energy dispersive X-ray analysis were used to characterize the corroded samples. The potentiodynamic polarization tests showed lower corrosion current density and higher polarization resistance (R p ) for the coatings with EN interlayer. For example, the corrosion current density of TiN coated steel was decreased by a factor of 10 by incorporating 5 μm thick EN interlayer. Similarly, multilayer coatings of TiAlN/CrN with EN interlayer showed about 30 times improved corrosion resistance as compared to the multilayers without EN interlayer. The porosity values were calculated from the potentiodynamic polarization data. The Nyquist and the Bode plots obtained from the EIS data were fitted by appropriate equivalent circuits. The pore resistance (R pore ), the charge transfer resistance (R ct ), the coating capacitance (Q coat ) and the double layer capacitance (Q dl ) of the coatings were obtained from the equivalent circuit. Multilayer coatings showed higher R pore and R ct values as compared to the single layer coatings. Similarly, the Q coat and Q dl values decreased from uncoated substrate to the multilayer coatings, indicating a decrease in the defect density by the addition of EN interlayer. These studies were confirmed by examining the corroded samples under

Development and production of hard X-ray multilayer optics for HEFT

DEFF Research Database (Denmark)

Koglin, J.E; Christensen, Finn Erland; Chonko, J.

2002-01-01

approximation Wolter-I design. The segmented mirrors that form these layers are made of thermally formed glass substrates coated with depth-graded multilayer films for enhanced reflectivity. The mirrors are assembled using an over-constraint method that forces the overall shape of the nominally cylindrical...

Analysis of Capillary Coating Die Flow in an Optical Fiber Coating Applicator

OpenAIRE

Kyoungjin Kim

2011-01-01

Viscous heating becomes significant in the high speed resin coating process of glass fibers for optical fiber manufacturing. This study focuses on the coating resin flows inside the capillary coating die of optical fiber coating applicator and they are numerically simulated to examine the effects of viscous heating and subsequent temperature increase in coating resin. Resin flows are driven by fast moving glass fiber and the pressurization at the coating die inlet, while ...

MECHANICAL PROPERTIES AND ANTIWEARABILITY STUDIES OF MULTILAYER THIN COATINGS ON CUTTING TOOLS

Institute of Scientific and Technical Information of China (English)

无

2000-01-01

The nanoindentation fracture of multilayer hard coatings, such as TiN, TiN/Ti(C,N)/TiC, TiN/Ti(C,N)/TiC/Ti(C,N)/TiC and TiN/Ti(C,N)/TiC/Ti(C,N)/TiC/Ti(C,N)/TiC coatings, deposited on cemented carbide using a CVD technique are studied. It is found that these coatings have high hardness. Based on the analysis of the energy release in cracking, the fracture toughness of these coatings are calculated. The observations clearly establish a step occurs in the forcedisplacement curves at the onset of coating fracture and a straigh t line segment in the loadpenetration depth squared curves to identify the interfacial failure of coatings. The hardness, fracture toughness and antiwearability of these coatings are clearly compared. The results show that with the layes increasing, the fracture toughness and antiwearability are getting larger.

Morphologies of laser-induced damage in hafnia-silica multilayer mirror and polarizer coatings

International Nuclear Information System (INIS)

Genin, F.Y.; Stolz, C.J.

1996-08-01

Hafnium-silica multilayer mirrors and polarizers were deposited by e-beam evaporation onto BK7 glass substrates. The mirrors and polarizers were coated for operation at 1053 nm at 45 degree and at Brewster's angle (56 degree), respectively. They were tested with a single 3-ns laser pulse. Morphology of the laser-induced damage was characterized by optical and scanning electron microscopy. Four distinct damage morphologies were found: pits, flatbottom pits, scalds, and delaminates. The pits and flat bottom pits ( 2 ). The pits seemed to result from ejection of nodular defects by causing local enhancement of the electric field. Scalds and delaminates could be observed at higher fluences (above 13 J/cm 2 ) and seemed to result from the formation of plasmas on the surface. These damage types often originated at pits and were less than 300 μm diameter; their size increased almost linearly with fluence. Finally, effects of the damage on the beam (reflectivity degradation and phase modulations) were measured

Extraction of optical scattering parameters and attenuation compensation in optical coherence tomography images of multi-layered tissue structures

DEFF Research Database (Denmark)

Thrane, Lars; Frosz, Michael Henoch; Tycho, Andreas

2004-01-01

A recently developed analytical optical coherence tomography (OCT) model [Thrane et al., J. Opt. Soc. Am. A 17, 484 (2000)] allows the extraction of optical scattering parameters from OCT images, thereby permitting attenuation compensation in those images. By expanding this theoretical model, we...... have developed a new method for extracting optical scattering parameters from multilayered tissue structures in vivo. To verify this, we used a Monte Carlo (MC) OCT model as a numerical phantom to simulate the OCT signal for het-erogeneous multilayered tissue. Excellent agreement between the extracted......, and the results hold promise for expanding the functional imaging capabilities of OCT....

Friction Modifier Using Adherent Metallic Multilayered or Mixed Element Layer Conversion Coatings

Science.gov (United States)

Schramm, Harry F. (Inventor); Defalco, Francis G. (Inventor); Starks, Lloyd L., Sr. (Inventor)

2013-01-01

A process for creating conversion coatings and spin, drawing, and extrusion finishes for surfaces, wherein the conversion coatings and spin, drawing, and extrusion finishes contain potassium, phosphorus, nitrogen, and one or more non-alkaline metals and/or one or more metalloids. The process comprises forming an aqueous solution of water, phosphoric acid or sulfuric acid, ammonium hydroxide, an alkali metal hydroxide, and one or more non-alkaline metals and/or one or more metalloids. The aqueous solution forms an anti-friction multilayer conversion and/or mixed element coating or a spin, drawing, and extrusion finish on a surface when applied to the surface, either directly without the use of applied external electromotive force, or as an additive in lubricating fluids.

High-temperature polyimide coating for optical fibres

Energy Technology Data Exchange (ETDEWEB)

Semjonov, S L; Dianov, E M [Fiber Optics Research Center, Russian Academy of Sciences, Moscow (Russian Federation); Sapozhnikov, D A; Erin, D Yu; Zabegaeva, O N; Kushtavkina, I A; Vygodskii, Ya S [A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow (Russian Federation); Nishchev, K N [N.P. Ogarev Mordovia State University, Saransk (Russian Federation)

2015-04-30

We present our first results on the fabrication of new, high-performance polyimide coatings. The key components of the coatings are polyimides containing various cardo and/or fluoroalkylene groups, which allows the coatings to retain their high-temperature stability and facilitates the storage of the starting polymer and the optical fibre coating process owing to the good solubility of such copolymers in many organic solvents. Annealing for 30 s, 1 h and 24 h at temperatures of 430, 350 and 300 °C, respectively, reduces the strength of optical fibres having such coating by no more than 10%. (optical fibres)

Sculpted-multilayer optical effects in two species of Papilio butterfly

International Nuclear Information System (INIS)

Vukusic, Peter; Sambles, Roy; Lawrence, Christopher; Wakely, Gavin

2001-01-01

The wing-scale microstructures associated with two species of Papilio butterfly are described and characterized. Despite close similarities in their structures, they do not exhibit analogous optical effects. With Papilio palinurus, deep modulations in its multilayering create bicolor reflectivity with strong polarization effects, and this leads to additive color mixing in certain visual systems. In contrast to this, Papilio ulysses features shallow multilayer modulation that produces monocolor reflectivity without significant polarization effects

Analysis of buried interfaces in multilayer mirrors using grazing incidence extreme ultraviolet reflectometry near resonance edges.

Science.gov (United States)

Sertsu, M G; Nardello, M; Giglia, A; Corso, A J; Maurizio, C; Juschkin, L; Nicolosi, P

2015-12-10

Accurate measurements of optical properties of multilayer (ML) mirrors and chemical compositions of interdiffusion layers are particularly challenging to date. In this work, an innovative and nondestructive experimental characterization method for multilayers is discussed. The method is based on extreme ultraviolet (EUV) reflectivity measurements performed on a wide grazing incidence angular range at an energy near the absorption resonance edge of low-Z elements in the ML components. This experimental method combined with the underlying physical phenomenon of abrupt changes of optical constants near EUV resonance edges enables us to characterize optical and structural properties of multilayers with high sensitivity. A major advantage of the method is to perform detailed quantitative analysis of buried interfaces of multilayer structures in a nondestructive and nonimaging setup. Coatings of Si/Mo multilayers on a Si substrate with period d=16.4  nm, number of bilayers N=25, and different capping structures are investigated. Stoichiometric compositions of Si-on-Mo and Mo-on-Si interface diffusion layers are derived. Effects of surface oxidation reactions and carbon contaminations on the optical constants of capping layers and the impact of neighboring atoms' interactions on optical responses of Si and Mo layers are discussed.

Antimicrobial coatings on polyethylene terephthalate based on curcumin/cyclodextrin complex embedded in a multilayer polyelectrolyte architecture.

Science.gov (United States)

Shlar, Ilya; Droby, Samir; Rodov, Victor

2018-04-01

Bacterial contamination is a growing concern worldwide. The aim of this work was to develop an antimicrobial coating based on curcumin-cyclodextrin inclusion complex and using polyethylene terephthalate (PET) film as a support matrix. After a pre-treatment aimed to provide sufficient electric charge to the PET surface, it was electrostatically coated with repeated multilayers comprising alternately deposited positively-charged poly-l-lysine (PLL) and negatively-charged poly-l-glutamic acid (PLGA) and carboxymethyl-β-cyclodextrin (CMBCD). The coatings had an architecture (PLL-PLGA) 6 -(PLL-PLGA-PLL-CMBCD) n , with the number of repeated multilayers n varying from 5 to 20. The CMBCD molecules were either covalently cross-linked using carbodiimide crosslinker chemistry or left unbound. The surface morphology, structure and elemental composition of the coatings were analysed by scanning electron microscopy and energy dispersive x-ray spectroscopy. To impart antimicrobial properties to the coatings they were loaded with a natural phenolic compound curcumin forming inclusion complexes with β-cyclodextrin. The non-cross-linked coatings showed bactericidal activity towards Escherichia coli in the dark, and this activity was further enhanced upon illumination with white light. Curcumin was released from the non-cross-linked coatings into an aqueous medium in the form of cyclodextrin inclusion complex. After the cross-linking, the coating lost its dark antimicrobial activity but retained the photodynamic properties. Stabilized cross-linked curcumin-loaded coatings can serve a basis for developing photoactivated antimicrobial surfaces controlling bacterial contamination and spread. Copyright © 2018 Elsevier B.V. All rights reserved.

Corrosion surface protection by using titanium carbon nitride/titanium-niobium carbon nitride multilayered system

Energy Technology Data Exchange (ETDEWEB)

Caicedo, J.C., E-mail: jcesarca@calima.univalle.edu.co [Grupo de Peliculas Delgadas, Universidad del Valle, Cali (Colombia); Amaya, C. [Grupo de Peliculas Delgadas, Universidad del Valle, Cali (Colombia); Laboratorio de Recubrimientos Duros, CDT-ASTIN SENA, Cali (Colombia); Cabrera, G. [Grupo de Peliculas Delgadas, Universidad del Valle, Cali (Colombia); Esteve, J. [Department de Fisica Aplicada i Optica, Universitat de Barcelona, Catalunya (Spain); Aperador, W. [Universidad Militar Nueva Granada Bogota D.C (Colombia); Gomez, M.E. [Grupo de Peliculas Delgadas, Universidad del Valle, Cali (Colombia); Prieto, P. [Grupo de Peliculas Delgadas, Universidad del Valle, Cali (Colombia); Centro de Excelencia en Nuevos Materiales, CENM, Calle 13 100-00 Edificio 320, espacio 1026, Cali (Colombia)

2011-07-29

The aim of this work is the improvement of the electrochemical behavior of 4140 steel substrate using TiCN/TiNbCN multilayered system as a protective coating. We have grown [TiCN/TiNbCN]{sub n} multilayered via reactive r.f. magnetron sputtering technique in which was varied systematically the bilayer period ({Lambda}), and the bilayer number (n), maintaining constant the total thickness of the coatings ({approx} 3 {mu}m). The coatings were characterized by X-ray diffraction (XRD), optical microscopy, electron microscopy and transmission electron microscopy assisted with selected area electron diffraction. The electrochemical properties were studied by Electrochemical Impedance Spectroscopy and Tafel curves. XRD results showed a preferential growth in the face-centered cubic (111) crystal structure for [TiCN/TiNbCN]{sub n} multilayered coatings [1]. In this work was obtained the maximum corrosion resistance for the coating with ({Lambda}) equal to 15 nm, corresponding to n = 200 bilayered. The polarization resistance and corrosion rate were around 8.6 kOhm cm{sup 2} and 7.59 . 10{sup -4} mm/year, these values were 8.6 and 0.001 times better than those showed by the uncoated 4140 steel substrate (1.0 kOhm and 0.57 mm/year), respectively. The improvement of the electrochemical behavior of the 4140 coated with this TiCN/TiNbCN multilayered system can be attributed to the presence of several interfaces that act as obstacles for the inward and outward diffusions of Cl{sup -} ion species, generating an increment in the energy or potential required for translating the corrosive ions across the coating/substrate interface. Moreover, the interface systems affect the means free path on the ions toward the metallic substrate, due to the decreasing of the defects presented in the multilayered coatings.

Corrosion surface protection by using titanium carbon nitride/titanium-niobium carbon nitride multilayered system

International Nuclear Information System (INIS)

Caicedo, J.C.; Amaya, C.; Cabrera, G.; Esteve, J.; Aperador, W.; Gomez, M.E.; Prieto, P.

2011-01-01

The aim of this work is the improvement of the electrochemical behavior of 4140 steel substrate using TiCN/TiNbCN multilayered system as a protective coating. We have grown [TiCN/TiNbCN] n multilayered via reactive r.f. magnetron sputtering technique in which was varied systematically the bilayer period (Λ), and the bilayer number (n), maintaining constant the total thickness of the coatings (∼ 3 μm). The coatings were characterized by X-ray diffraction (XRD), optical microscopy, electron microscopy and transmission electron microscopy assisted with selected area electron diffraction. The electrochemical properties were studied by Electrochemical Impedance Spectroscopy and Tafel curves. XRD results showed a preferential growth in the face-centered cubic (111) crystal structure for [TiCN/TiNbCN] n multilayered coatings [1]. In this work was obtained the maximum corrosion resistance for the coating with (Λ) equal to 15 nm, corresponding to n = 200 bilayered. The polarization resistance and corrosion rate were around 8.6 kOhm cm 2 and 7.59 . 10 -4 mm/year, these values were 8.6 and 0.001 times better than those showed by the uncoated 4140 steel substrate (1.0 kOhm and 0.57 mm/year), respectively. The improvement of the electrochemical behavior of the 4140 coated with this TiCN/TiNbCN multilayered system can be attributed to the presence of several interfaces that act as obstacles for the inward and outward diffusions of Cl - ion species, generating an increment in the energy or potential required for translating the corrosive ions across the coating/substrate interface. Moreover, the interface systems affect the means free path on the ions toward the metallic substrate, due to the decreasing of the defects presented in the multilayered coatings.

Nanointaglio fabrication of optical lipid multilayer diffraction gratings with applications in biosensing

Science.gov (United States)

Lowry, Troy Warren

The dynamic self-organization of lipids in biological systems is a highly regulated process that enables the compartmentalization of living systems at microscopic and nanoscopic levels. Exploiting the self-organization and innate biofunctionality of lyotropic liquid crystalline phospholipids, a novel nanofabrication process called "nanointaglio" was invented in order to rapidly and scalably integrate lipid nanopatterns onto the surface. The work presented here focuses on using nanointaglio fabricated lipid diffraction micro- and nanopatterns for the development of new sensing and bioactivity studies. The lipids are patterned as diffraction gratings for sensor functionality. The lipid multilayer gratings operate as nanomechanical sensor elements that are capable of transducing molecular binding to fluid lipid multilayers into optical signals in a label free manner due to shape changes in the lipid nanostructures. To demonstrate the label free detection capabilities, lipid nanopatterns are shown to be suitable for the integration of chemically different lipid multilayer gratings into a sensor array capable of distinguishing vapors by means of an optical nose. Sensor arrays composed of six different lipid formulations are integrated onto a surface and their optical response to three different vapors (water, ethanol and acetone) in air as well as pH under water is monitored as a function of time. Principal component analysis of the array response results in distinct clustering, indicating the suitability of the arrays for distinguishing these analytes. Importantly, the nanointaglio process used is capable of producing lipid gratings out of different materials with sufficiently uniform heights for the fabrication of an optical nose. A second main application is demonstrated for the study of membrane binding proteins. Although in vitro methods for assaying the catalytic activity of individual enzymes are well established, quantitative methods for assaying the kinetics of

Multilayer Protective Coatings for High-Level Nuclear Waste Storage Containers

Science.gov (United States)

Fusco, Michael

, as opposed to bare, mild steel. Passivation and passive breakdown was largely unaffected by the coating materials. Activation parameters were determined for corrosion rates and passive breakdown potential based on measurements performed between 20°C and 80°C to simulate elevated waste canister temperatures due to decay heat. Electrochemical impedance spectroscopy (EIS) was used to study the metal-electrolyte interface and the passive film formed on types 304 and 316 stainless steel. Capacitance values were calculated by utilizing the constant phase element and a conversion technique proposed in the literature. This method was shown to remove the frequency dependence of the capacitance that is often seen in electrochemical analysis. The dielectric constant was estimated from impedance and potentiostatic current measurements, and film defect densities were calculated to be on the order of 1020 cm-3, which is consistent with highly-doped semiconductive films. EIS was also employed to study reactively-sputtered TiO2 films on stainless steel type 304, which was substantially thicker than initial TiO2 coatings. The impedance spectra of TiO2-coated stainless steel exhibited several distinctions from its uncoated counterpart and were clearly dominated by the dielectric coating material. Film defect density was on the order of 1017 cm-3, which is several orders of magnitude lower than the bare steel and is more consistent with solid-state semiconductors. This research shows the potential of these coating materials to alter the corrosion behavior of the outer surface of a HLW storage canister. Although the initial single layered coatings had little effect on the corrosion and passivity of the stainless steel substrates, it is possible that with a thicker multi-layered coating system the substrate may be sufficiently isolated from the environment. Moreover, the thin single layer coatings were able to reduce corrosion of A36 steel, showing the promise of these coating

Mo/Si multilayers with enhanced TiO II- and RuO II-capping layers

Science.gov (United States)

Yulin, Sergiy; Benoit, Nicolas; Feigl, Torsten; Kaiser, Norbert; Fang, Ming; Chandhok, Manish

2008-03-01

The lifetime of Mo/Si multilayer-coated projection optics is one of the outstanding issues on the road of commercialization of extreme-ultraviolet lithography (EUVL). The application of Mo/Si multilayer optics in EUVL requires both sufficient radiation stability and also the highest possible normal-incidence reflectivity. A serious problem of conventional high-reflective Mo/Si multilayers capped by silicon is the considerable degradation of reflective properties due to carbonization and oxidation of the silicon surface layer under exposure by EUV radiation. In this study, we focus on titanium dioxide (TiO II) and ruthenium dioxide (RuO II) as promising capping layer materials for EUVL multilayer coatings. The multilayer designs as well as the deposition parameters of the Mo/Si systems with different capping layers were optimized in terms of maximum peak reflectivity at the wavelength of 13.5 nm and longterm stability under high-intensive irradiation. Optimized TiO II-capped Mo/Si multilayer mirrors with an initial reflectivity of 67.0% presented a reflectivity drop of 0.6% after an irradiation dose of 760 J/mm2. The reflectivity drop was explained by the partial oxidation of the silicon sub-layer. No reflectivity loss after similar irradiation dose was found for RuO II-capped Mo/Si multilayer mirrors having initial peak reflectivity of 66%. In this paper we present data on improved reflectivity of interface-engineered TiO II- and RuO II-capped Mo/Si multilayer mirrors due to the minimization of both interdiffusion processes inside the multilayer stack and absorption loss in the oxide layer. Reflectivities of 68.5% at the wavelength of 13.4 nm were achieved for both TiO II- and RuO II-capped Mo/Si multilayer mirrors.

Simple method for measuring reflectance of optical coatings

International Nuclear Information System (INIS)

Wen Gui Wang; Yi Sheng Chen

1995-01-01

The quality of optical coatings has an important effect on the performance of optical instrument. The last few years, the requirements for super low loss dielectric mirror coatings used in low gain laser systems such as free electron laser and the ring laser etc., have given an impetus to the development of the technology of precise reflectance measurement of optical coatings. A reliable and workable technique is to measure the light intensity decay time of optical resonant cavity. This paper describes a measuring method which is dependent on direct measurement of the light intensity decay time of a resonant cavity comprised of low loss optical components. According to the evolution of a luminous flux stored inside the cavity, this method guarantees not only a quick and precise reflectance measurements of low loss highly reflecting mirror coatings but also transmittance measurements of low loss antireflection coatings and is especially effective with super los loss highly reflecting mirror. From the round-trip path length of the cavity and the speed of light, the light intensity exponential decay time of an optical cavity is easy to obtain and the cavity losses can be deduced. An optical reflectance of low loss highly mirror coatings and antireflection coatings is precisely measured as well. This is highly significant for the discrimination of the coating surface characteristics, the improvement of the performance of optical instrument and the development of high technology

Uniformity of the soft-x-ray emissions from gold foils irradiated by OMEGA laser beams determined by a two-mirror normal-incidence microscope with multilayer coatings

International Nuclear Information System (INIS)

Seely, John F.; Boehly, Thomas; Pien, Gregory; Bradley, David

1998-01-01

A two-mirror normal-incidence microscope with multilayer coatings was used to image the soft-x-ray emissions from planar foils irradiated by OMEGA laser beams. The bandpass of the multilayer coatings was centered at a wavelength of 48.3 Angstrom (257-eV energy) and was 0.5 Angstrom wide. Five overlapping OMEGA beams, without beam smoothing, were typically incident on the gold foils. The total energy was 1500 J, and the focused intensity was 6x10 13 Wcm -2 . The 5.8x magnified images were recorded by a gated framing camera at various times during the 3-ns laser pulse. A pinhole camera imaged the x-ray emission in the energy range of >2 keV. On a spatial scale of 10 μm, it was found that the soft-x-ray images at 257 eV were quite uniform and featureless. In contrast, the hard-x-ray images in the energy range of >2 kev were highly nonuniform with numerous features of size 150 μm. copyright 1998 Optical Society of America

A multilayer innovative solution to improve the adhesion of nanocrystalline diamond coatings

Energy Technology Data Exchange (ETDEWEB)

Poulon-Quintin, A., E-mail: poulon@icmcb-bordeaux.cnrs.fr [CNRS, ICMCB, UPR 9048, F-33600 Pessac (France); Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac (France); Faure, C.; Teulé-Gay, L.; Manaud, J.P. [CNRS, ICMCB, UPR 9048, F-33600 Pessac (France); Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac (France)

2015-03-15

Highlights: • Improvement of the NCD adhesion on WC-12%Co substrates for tooling applications using a multi-interlayer additional system. • Reduction of the graphite layer thickness and continuity at the interface with the diamond. • Transmission electron microscopy study for a better understanding of the diffusion phenomena occurring at the interfaces. - Abstract: Nano-crystalline diamond (NCD) films grown under negative biased substrates by chemical vapor deposition (CVD) are widely used as surface overlay coating onto cermet WC-Co cutting tools to get better performances. To improve the diamond adhesion to the cermet substrate, suitable multi-layer systems have been added. They are composed of a cobalt diffusion barrier close to the substrate (single and sequenced nitrides layers) coated with a nucleation extra layer to improve the nucleus density of diamond during CVD processing. For all systems, before and after diamond deposition, transmission electron microscopy (TEM) has been performed for a better understanding of the diffusion phenomena occurring at the interfaces and to evaluate the presence of graphitic species at the interface with the diamond. Innovative multilayer system dedicated to the regulation of cobalt diffusion coated with a bilayer system optimized for the carbon diffusion control, is shown as an efficient solution to significantly reduce the graphite layer formation at the interface with the diamond down to 10 nm thick and to increase the adhesion of NCD diamond layer as scratch-tests confirm.

Lipid Multilayer Grating Arrays Integrated by Nanointaglio for Vapor Sensing by an Optical Nose

Directory of Open Access Journals (Sweden)

Troy W. Lowry

2015-08-01

Full Text Available Lipid multilayer gratings are recently invented nanomechanical sensor elements that are capable of transducing molecular binding to fluid lipid multilayers into optical signals in a label free manner due to shape changes in the lipid nanostructures. Here, we show that nanointaglio is suitable for the integration of chemically different lipid multilayer gratings into a sensor array capable of distinguishing vapors by means of an optical nose. Sensor arrays composed of six different lipid formulations are integrated onto a surface and their optical response to three different vapors (water, ethanol and acetone in air as well as pH under water is monitored as a function of time. Principal component analysis of the array response results in distinct clustering indicating the suitability of the arrays for distinguishing these analytes. Importantly, the nanointaglio process used here is capable of producing lipid gratings out of different materials with sufficiently uniform heights for the fabrication of an optical nose.

Lipid Multilayer Grating Arrays Integrated by Nanointaglio for Vapor Sensing by an Optical Nose

Science.gov (United States)

Lowry, Troy W.; Prommapan, Plengchart; Rainer, Quinn; Van Winkle, David; Lenhert, Steven

2015-01-01

Lipid multilayer gratings are recently invented nanomechanical sensor elements that are capable of transducing molecular binding to fluid lipid multilayers into optical signals in a label free manner due to shape changes in the lipid nanostructures. Here, we show that nanointaglio is suitable for the integration of chemically different lipid multilayer gratings into a sensor array capable of distinguishing vapors by means of an optical nose. Sensor arrays composed of six different lipid formulations are integrated onto a surface and their optical response to three different vapors (water, ethanol and acetone) in air as well as pH under water is monitored as a function of time. Principal component analysis of the array response results in distinct clustering indicating the suitability of the arrays for distinguishing these analytes. Importantly, the nanointaglio process used here is capable of producing lipid gratings out of different materials with sufficiently uniform heights for the fabrication of an optical nose. PMID:26308001

Multilayer As{sub 2}Se{sub 3}/GeS{sub 2} quarter wave structures for photonic applications

Energy Technology Data Exchange (ETDEWEB)

Todorov, R; Tasseva, J; Babeva, Tz; Petkov, K, E-mail: rossen@clf.bas.b [Institute of Optical Materials and Technologies ' Acad. J. Malinowski' , Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl.109, 1113 Sofia (Bulgaria)

2010-12-22

The optical properties of single layers from As{sub 2}Se{sub 3} and GeS{sub 2}, double-layered stack and quarter-wave multilayer structure consisting of alternating layers from both materials are investigated. For modelling of multilayer coating the thickness dependence of the refractive index of single coatings from both materials is studied. The particularities and scope of application of different spectrophotometric methods for calculation of optical parameters of thin chalcogenide layers are discussed for film thickness, d, in the range {lambda}/25-1.5{lambda} ({lambda} being the operating wavelength). Having acquired the knowledge of optical parameters (refractive index, n, and extinction coefficient, k) of the single layers, we designed and produced a one-dimensional photonic crystal with fundamental reflection band at {lambda} = 850 nm. It was shown that the photoinduced changes of the refractive index of thin chalcogenide films can be used for enhancement of the optical contrast of both materials.

Acousto-optic interaction in polyimide coated optical fibers with flexural waves

OpenAIRE

ALCUSA-SÁEZ, E. P.; Díez, A.; Rivera-Pérez, E.; Margulis, W.; Norin, L.; Andrés, M. V.

2017-01-01

Acousto-optic coupling in polyimide-coated single-mode optical fibers using flexural elastic waves is demonstrated. The effect of the polyimide coating on the acousto-optic interaction process is analyzed in detailed. Theoretical and experimental results are in good agreement. Although the elastic attenuation is significant, we show that acousto-optic coupling can be produced with a reasonably good efficiency. To our knowledge, it is the first experimental demonstration of acousto-optic coupl...

The NSLS-II Multilayer Laue Lens Deposition System

International Nuclear Information System (INIS)

Conley, R.; Bouet, N.; Biancarosa, J.; Shen, Q.; Boas, L.; Feraca, J.; Rosenbaum, L.

2009-01-01

The NSLS-II(1) program has a requirement for an unprecedented level of x-ray nanofocusing and has selected the wedged multilayer Laue lens(2,3) (MLL) as the optic of choice to meet this goal. In order to fabricate the MLL a deposition system is required that is capable of depositing depth-graded and laterally-graded multilayers with precise thickness control over many thousands of layers, with total film growth in one run up to 100 m thick or greater. This machine design expounds on the positive features of a rotary deposition system(4) constructed previously for MLLs and will contain multiple stationary, horizontally-oriented magnetron sources where a transport will move a substrate back and forth in a linear fashion over shaped apertures at well-defined velocities to affect a multilayer coating.

A hard X-ray telescope/concentrator design based on graded period multilayer coatings

DEFF Research Database (Denmark)

Christensen, Finn Erland; Joensen, K. D.; Gorenstein, P.

1995-01-01

It is shown that compact designs of multifocus, conical approximations to highly nested Wolter I telescopes, as well as single reflection concentrators, employing realistic graded period W/Si or Ni/C multilayer coatings, allow one to obtain more than 1000 cm2 of on-axis effective area at 40 ke...... that it is smaller than roughly 1 mm. The design can be realized with foils as thin (≤0.4 mm) as used for ASCA and SODART or with closed, slightly thicker (∼1.0 mm) mirror shells as used for JET-X and XMM. The effect of an increase of the inner radius is quantified on the effective area for multilayered mirrors up...

Crack Driving Forces in a Multilayered Coating System for Ceramic Matrix Composite Substrates

Science.gov (United States)

Ghosn, Louis J.; Zhu, Dongming; Miller, Robert A.

2005-01-01

The effects of the top coating thickness, modulus and shrinkage strains on the crack driving forces for a baseline multilayer Yttria-Stabilized-Zirconia/Mullite/Si thermal and environment barrier coating (TEBC) system for SiC/SiC ceramic matrix composite substrates are determined for gas turbine applications. The crack driving forces increase with increasing modulus, and a low modulus thermal barrier coating material (below 10 GPa) will have no cracking issues under the thermal gradient condition analyzed. Since top coating sintering increases the crack driving forces with time, highly sintering resistant coatings are desirable to maintain a low tensile modulus and maintain a low crack driving force with time. Finite element results demonstrated that an advanced TEBC system, such as ZrO2/HfO2, which possesses improved sintering resistance and high temperature stability, exhibited excellent durability. A multi-vertical cracked structure with fine columnar spacing is an ideal strain tolerant coating capable of reducing the crack driving forces to an acceptable level even with a high modulus of 50 GPa.

Coating strategy for enhancing illumination uniformity in a lithographic condenser

International Nuclear Information System (INIS)

Gaines, D.P.; Vernon, S.P.; Sommargren, G.E.; Kania, D.R.

1995-01-01

A three-element Koehler condenser system has been fabricated, characterized, and integrated into an EUV lithographic system. The multilayer coatings deposited on the optics were designed to provide optimal radiation transport efficiency and illumination uniformity. Extensive EUV characterization measurements performed on the individual optics and follow-on system measurements indicated that the condenser was operating close to design goals. Multilayer d-spacings were within 0.05 nm of specifications, and reflectances were approximately 60%. Illumination uniformity was better than ±10%. The broadband transport efficiency was 11%

Multilayer poly(3,4-ethylenedioxythiophene)-dexamethasone and poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate-carbon nanotubes coatings on glassy carbon microelectrode arrays for controlled drug release.

Science.gov (United States)

Castagnola, Elisa; Carli, Stefano; Vomero, Maria; Scarpellini, Alice; Prato, Mirko; Goshi, Noah; Fadiga, Luciano; Kassegne, Sam; Ricci, Davide

2017-07-13

The authors present an electrochemically controlled, drug releasing neural interface composed of a glassy carbon (GC) microelectrode array combined with a multilayer poly(3,4-ethylenedioxythiophene) (PEDOT) coating. The system integrates the high stability of the GC electrode substrate, ideal for electrical stimulation and electrochemical detection of neurotransmitters, with the on-demand drug-releasing capabilities of PEDOT-dexamethasone compound, through a mechanically stable interlayer of PEDOT-polystyrene sulfonate (PSS)-carbon nanotubes (CNT). The authors demonstrate that such interlayer improves both the mechanical and electrochemical properties of the neural interface, when compared with a single PEDOT-dexamethasone coating. Moreover, the multilayer coating is able to withstand 10 × 10 6 biphasic pulses and delamination test with negligible change to the impedance spectra. Cross-section scanning electron microscopy images support that the PEDOT-PSS-CNT interlayer significantly improves the adhesion between the GC substrate and PEDOT-dexamethasone coating, showing no discontinuities between the three well-interconnected layers. Furthermore, the multilayer coating has superior electrochemical properties, in terms of impedance and charge transfer capabilities as compared to a single layer of either PEDOT coating or the GC substrate alone. The authors verified the drug releasing capabilities of the PEDOT-dexamethasone layer when integrated into the multilayer interface through repeated stimulation protocols in vitro, and found a pharmacologically relevant release of dexamethasone.

Residual stress, mechanical and microstructure properties of multilayer Mo{sub 2}N/CrN coating produced by R.F Magnetron discharge

Energy Technology Data Exchange (ETDEWEB)

Bouaouina, B., E-mail: b.bouaouina@gmail.com [Department of physic, research unite UR-MPE, Boumerdes University 35000 (Algeria); Besnard, A. [Arts et Metiers ParisTech—LaBoMaP, 71250 Cluny (France); Abaidia, S.E. [Department of physic, research unite UR-MPE, Boumerdes University 35000 (Algeria); Haid, F. [CDTA, Plasma discharges Group, Baba hassen, Algers (Algeria)

2017-02-15

Highlights: • Depositing of crystallized molybdenum nitride and chromium nitride multilayer at room temperature. • Correlation between stress measurement and the shift of the XRD diffraction peak (1 1 1) of Mo{sub 2}N. • Studied the effect of the bi-layer thickness on the mechanical properties. - Abstract: We have investigated the effect of the period thickness of the multilayer Mo{sub 2}N/CrN deposited on Si substrate produced by reactive magnetron sputtering. Mo{sub 2}N presents a face centered cubic structure and CrN an orthorhombic one. The residual stress of the coatings was determined by the measurement of the substrate curvature. The microstructure of the multilayer was investigated from the X-ray diffraction and scanning electron microscopy (cross section images). The residual stresses resulting from the deposition of the different bi-layer thickness were measured and correlated to the structural properties of the coating as well as the nanoindentation analysis of the coating. The stresses are compressive and tensile for the individual Mo{sub 2}N and CrN layer respectively. The result shows that an increase of the multilayer coatings Mo{sub 2}N/CrN thicknesses induce an increase of the hardness and the elastic modulus, in the other hand the tensile stress increases. The shift of the XRD diffraction peak (1 1 1) of Mo{sub 2}N at high angle which means the reduction of the residual stress is in good agreement with the residual stresses measurements.

Multi-layer service function chaining scheduling based on auxiliary graph in IP over optical network

Science.gov (United States)

Li, Yixuan; Li, Hui; Liu, Yuze; Ji, Yuefeng

2017-10-01

Software Defined Optical Network (SDON) can be considered as extension of Software Defined Network (SDN) in optical networks. SDON offers a unified control plane and makes optical network an intelligent transport network with dynamic flexibility and service adaptability. For this reason, a comprehensive optical transmission service, able to achieve service differentiation all the way down to the optical transport layer, can be provided to service function chaining (SFC). IP over optical network, as a promising networking architecture to interconnect data centers, is the most widely used scenarios of SFC. In this paper, we offer a flexible and dynamic resource allocation method for diverse SFC service requests in the IP over optical network. To do so, we firstly propose the concept of optical service function (OSF) and a multi-layer SFC model. OSF represents the comprehensive optical transmission service (e.g., multicast, low latency, quality of service, etc.), which can be achieved in multi-layer SFC model. OSF can also be considered as a special SF. Secondly, we design a resource allocation algorithm, which we call OSF-oriented optical service scheduling algorithm. It is able to address multi-layer SFC optical service scheduling and provide comprehensive optical transmission service, while meeting multiple optical transmission requirements (e.g., bandwidth, latency, availability). Moreover, the algorithm exploits the concept of Auxiliary Graph. Finally, we compare our algorithm with the Baseline algorithm in simulation. And simulation results show that our algorithm achieves superior performance than Baseline algorithm in low traffic load condition.

Multi-layered electroless Ni-P coatings on powder-sintered Nd-Fe-B permanent magnet

International Nuclear Information System (INIS)

Chen Zhong; Ng, Alice; Yi Jianzhang; Chen Xingfu

2006-01-01

This paper has shown a successful protective coating scheme for powder-sintered Nd-Fe-B permanent magnet using multi-layered electroless nickel (EN) deposition. A low-phosphorus nickel layer is plated with an alkaline EN solution first, followed by a high-phosphorus nickel layer plated with an acidic solution. An additional topcoat by medium-phosphorus nickel on the high-phosphorus coating is also explored. It is shown that the high-phosphorus nickel layer coated in acidic solution provides the best corrosion protection because of its dense amorphous structure. The medium phosphorus topcoat is also dense and is able to provide reasonable corrosion resistance. The low-phosphorus layer itself does not have enough corrosion resistance; its main role is to provide an intermediate coating on the powder-sintered magnet. X-ray diffraction measurement shows that the low-phosphorus coating consists of nano-crystallines, and the high- and the medium-phosphorus coatings are dominated by amorphous structure. Microscopic observation and scratch test on these composite coatings demonstrate good adhesion between the magnet and the coatings. Remanence and coercivity of the plated magnet decrease with the applied coatings, but measured values are still very attractive for practical applications among known hard magnets

Low temperature sol-gel process for optical coatings based on magnesium fluoride and titanium dioxide; Niedertemperatur Sol-Gel Verfahren fuer optische Schichtsysteme auf Basis von Magnesiumfluorid und Titandioxid

Energy Technology Data Exchange (ETDEWEB)

Krueger, Hannes

2009-09-24

This work deals with the development of a low temperature sol-gel spincoating process for thin films with thicknesses in the nanometer range based on metal oxides and metal fluorides. Optical films such as anti-reflective (AR) or high reflective coatings are of much interest and consist of alternating dielectric layers of low and high refractive index materials. Regarding the general procedure for the metal fluorides a novel nonaqueous sol-gel synthesis starting from metal alkoxides and alcohol-dissolved HF was used. The coatings were dried and calcined at 100 C. The morphology of these films was characterised with REM, TEM and AFM. EDX and XPS were used to identify the chemical composition and ellipsometry and UV-vis spectroscopy to determine the optical properties of the films. This new process allows the preparation of homogeneous magnesium fluoride and titanium dioxide layers with low roughness (R{sub a} {<=} 1,9 nm) on silicon and quartz substrates. The magnesium fluoride layers are partially amorphous or microcrystalline with crystallite sizes from 2 nm to 10 nm. The titanium dioxide layers are predominantly amorphous. The thicknesses of the magnesium fluoride and titanium dioxide single layers were adjustable between 25 nm and 500 nm depending on the number of coating steps and on the concentration of the used sols. The magnesium fluoride layers had a refractive index of n{sub 500} = 1,36 and the titanium dioxide layers a refraction index of n{sub 500} = 2,05. For the first time, an alternating metal fluoride and oxide multilayer system was produced with a low temperature sol-gel method (consisting of magnesium fluoride and titanium dioxide). Based on the determined optical constants of the magnesium fluoride and titanium dioxide single layers, AR and HR multilayer systems were calculated and fabricated. The transmission spectra of the designs and the corresponding multilayer were in good agreement. Similar results were obtained with the reflection spectra

High-energy x-ray microscopy with multilayer reflectors (invited)

International Nuclear Information System (INIS)

Underwood, J.H.

1986-01-01

A knowledge of the spatial distribution of the x rays emitted by the hot plasma region is a key element in the study of the physical processes occurring in laser-produced plasmas and complements other diagnostics such as spectroscopy and temporal studies. X-ray microscopy with reflection microscopes offers the most direct means of obtaining this information. Until recently, the two types of microscopes that had been developed for this purpose, the Kirkpatrick--Baez and the Wolter, operated at relatively low energies (about 4--5 keV) and had very little spectral selectivity, relying on filters for coarse spectral resolution. With the development of x-ray reflecting multilayer mirrors, the energy response of such microscopes can be extended to 10 keV or higher, with good spectral selectivity. In addition, it is possible to reduce some of the optical aberrations to obtain improved spatial resolution. This paper describes some of the recent progress in making and evaluating x-ray reflectors, and outlines the optical design considerations for multilayer-coated microscopes. Results from a prototype multilayer K--B microscope are presented

Extraction of optical parameters of thin films from spectral measurements for design and optical performance of multilayer structures

International Nuclear Information System (INIS)

Muellerova, J.; Jurecka, S.; Kucerova, A.

2003-01-01

Optical parameters of a-Si:H and indium tin oxide (ITO) thin films deposited on glass substrates are determined from spectral measurements of reflectance and/or transmittance. It is shown how important the exact knowledge of optical parameters as well as thicknesses of the layers for the design and the optical performance of multilayer structures is. The model of the p-i-n based a:Si-H solar cell with ITO as transparent conductive oxide layer is used for illustrating. The modeling of the solar cell integral reflectance in the spectral region of (650-830) nm is used as a criterion to reverse engineering of a multilayer structure with suppressed reflectance losses. The reflectance of a solar cell is modelled and the simulation of the varying optical parameters of individual layers including their thicknesses is discussed. Besides this,the advantage of using an antireflective layer under ITO is discussed (Authors)

MULTILAYER COATINGS Ti/TiN, Cr/CrN AND W/WN DEPOSITED BY MAGNETRON SPUTTERING FOR IMPROVEMENT OF ADHESION TO BASE MATERIALS

Directory of Open Access Journals (Sweden)

Jakub Horník

2015-12-01

Full Text Available The paper deals with evaluation of single and multilayer layer PVD coatings based on Cr and Ti widely used in tool application. Additionally, W and WN based coating which are not so widespread were designed and deposited as functionally graded material. The coatings properties were evaluated from the point of view of hardness and adhesion. The hardness measuring was carried out using nanoindentation method. The scratch test was performed to test adhesion. Moreover, the presence of metallic interlayer in functionally graded materials further increases the coating adhesion by gradually approaching its composition to the substrate. Coatings consisting of W and WN have showed very good adhesion. With regard to the results of the scratch test, the multilayer coatings of CrN, TiN and WN have increased adhesion and can be assumed to have their protective function improved. Results will be appliedin development of functionally graded layers for functionally graded materials.

Coordinated Multi-layer Multi-domain Optical Network (COMMON) for Large-Scale Science Applications (COMMON)

Energy Technology Data Exchange (ETDEWEB)

Vokkarane, Vinod [University of Massachusetts

2013-09-01

We intend to implement a Coordinated Multi-layer Multi-domain Optical Network (COMMON) Framework for Large-scale Science Applications. In the COMMON project, specific problems to be addressed include 1) anycast/multicast/manycast request provisioning, 2) deployable OSCARS enhancements, 3) multi-layer, multi-domain quality of service (QoS), and 4) multi-layer, multidomain path survivability. In what follows, we outline the progress in the above categories (Year 1, 2, and 3 deliverables).

Thin film optical coatings for the ultraviolet spectral region

Science.gov (United States)

Torchio, P.; Albrand, G.; Alvisi, M.; Amra, C.; Rauf, H.; Cousin, B.; Otrio, G.

2017-11-01

The applications and innovations related to the ultraviolet field are today in strong growth. To satisfy these developments which go from biomedical to the large equipment like the Storage Ring Free Electron Laser, it is crucial to control with an extreme precision the optical performances, in using the substrates and the thin film materials impossible to circumvent in this spectral range. In particular, the reduction of the losses by electromagnetic diffusion, Joule effect absorption, or the behavior under UV luminous flows of power, resistance to surrounding particulate flows... become top priority which concerns a broad European and international community. Our laboratory has the theoretical, experimental and technological tools to design and fabricate numerous multilayer coatings with desirable optical properties in the visible and infrared spectral ranges. We have extended our expertise to the ultraviolet. We present here some results on high reflectivity multidielectric mirrors towards 250 nm in wavelength, produced by Ion Plating Deposition. The latter technique allows us to obtain surface treatments with low absorption and high resistance. We give in this study the UV transparent materials and the manufacturing technology which have been the best suited to meet requirements. Single UV layers were deposited and characterized. HfO2/SiO2 mirrors with a reflectance higher than 99% at 300 nm were obtained. Optical and non-optical characterizations such as UV spectrophotometric measurements, X-Ray Diffraction spectra, Scanning Electron Microscope and Atomic Force Microscope images were performed

Adhesive and tribocorrosive behavior of TiAlPtN/TiAlN/TiAl multilayers sputtered coatings over CoCrMo

Science.gov (United States)

Canto, C. E.; Andrade, E.; Rocha, M. F.; Alemón, B.; Flores, M.

2017-09-01

The tribocorrosion resistance and adherence of multilayer coatings of TiAlPtN/TiAlN/TiAl synthesized by PVD reactive magnetron sputtering over a CoCrMo alloy substrate in 10 periods of 30 min each were analyzed and compared to those of the substrate alone and to that of a TiAlPtN single layer coating of the same thickness. The objective of the present work was to create multilayers with different amounts of Pt in order to enhance the tribocorrosion resistance of a biomedical alloy of CoCrMo. Tribocorrosion tests were performed using Simulated Body Fluid (SBF) at typical body temperature with a tribometer in a pin on disk test. The elemental composition and thickness of the coating which behave better at the tribocorrosion tests were evaluated by means of RBS (Rutherford Backscattering Spectroscopy) IBA (Ion Beam Analysis) technique, using an alpha particles beam of 1.8 MeV, before and after the reciprocating motion in the tribocorrosion test. In order to simulate the elemental profile of the samples, the SIMNRA simulation computer code was used. Measurements of the adhesion of the coatings to the substrate were carried on by means of a scratch test using a tribometer. By taking micrographs of the produced tracks, the critical loads at which the coatings are fully separated from the substrate were determined. From these tests it was observed that a coating with 10 min of TiAlPtN in a TiAlPtN/TiAl period of 30 min in multilayers of 10 periods and with an average thickness of 145 nm for the TiAlPtN nanolayers had the best tribocorrosion resistance behavior, compared to that of the CoCrMo alloy. The RBS experiments showed a reduction of the thickness of the films along with some loss of the multilayer structure after the reciprocating motion. The adhesion tests indicated that the multilayer with the average TiAlPtN thickness of 145 nm displayed the highest critical load. These results indicate a high correlation between the adherence and the tribocorrosion behavior.

The Optical Society's 2016 topical meeting on optical interference coatings: introduction.

Science.gov (United States)

Ristau, Detlev; Li, Li; Sargent, Robert; Sytchkova, Anna

2017-02-01

This feature issue of Applied Optics is dedicated to the 13th Topical Meeting on Optical Interference Coatings, which was held June 19-24, 2016, in Tucson, Arizona, USA. The conference, taking place every three years, is a focal point for global technical interchange in the field of optical interference coatings and provides premier opportunities for people working in the field to present their new advances in research and development. Papers presented at the meeting covered a broad range of topics, including fundamental research on coating design theory, new materials, and deposition and characterization technologies, as well as the vast and growing number of applications in electronic displays, communication, optical instruments, high power and ultra-fast lasers, solar cells, space missions, gravitational wave detection, and many others.

Optical Properties of Plasmon Resonances with Ag/SiO2/Ag Multi-Layer Composite Nanoparticles

International Nuclear Information System (INIS)

Ye-Wan, Ma; Li-Hua, Zhang; Zhao-Wang, Wu; Jie, Zhang

2010-01-01

Optical properties of plasmon resonance with Ag/SiO 2 /Ag multi-layer nanoparticles are studied by numerical simulation based on Green's function theory. The results show that compared with single-layer Ag nanoparticles, the multi-layer nanoparticles exhibit several distinctive optical properties, e.g. with increasing the numbers of the multi-layer nanoparticles, the scattering efficiency red shifts, and the intensity of scattering enhances accordingly. It is interesting to find out that slicing an Ag-layer into multi-layers leads to stronger scattering intensity and more 'hot spots' or regions of stronger field enhancement. This property of plasmon resonance of surface Raman scattering has greatly broadened the application scope of Raman spectroscopy. The study of metal surface plasmon resonance characteristics is critical to the further understanding of surface enhanced Raman scattering as well as its applications. (fundamental areas of phenomenology (including applications))

Mechanical properties of multilayer Ni-Fe and Ni-Fe-Al2O3 nanocomposite coating

DEFF Research Database (Denmark)

Torabinejad, V.; Aliofkhazraei, M.; Rouhaghdam, A. Sabour

2017-01-01

properties and wear resistance of composite coatings were studied. The shear punch testing method was employed to evaluate the room temperature mechanical properties. It was shown that increasing the pulse frequency and decreasing the pulse duty cycle improved the mechanical properties of monolithic coatings......A sulfate-based electrolyte was used for synthesis of multilayer (ML) and monolithic Ni-Fe-Al2O3 coatings. The ML electrodeposits were achieved by consecutive alteration of duty cycle of pulsed current between two values of 20% and 90%. The influences of the ML microstructure on mechanical....... The electrodeposited ML coatings exhibited a pronounced improvement in microhardness, shear strength and wear resistance in comparison to the monolithic coatings. Pin-on-disk sliding wear tests revealed that the main mechanisms of wear are plastic deformation, fatigue crack of deformed layers and delamination....

Thin Films for X-ray Optics

Science.gov (United States)

Conley, Raymond

Focusing x-rays with refraction requires an entire array of lens instead of a single element, each contributing a minute amount of focusing to the system. In contrast to their visible light counterparts, diffractive optics require a certain depth along the optical axis in order to provide sufficient phase shift. Mirrors reflect only at very shallow angles. In order to increase the angle of incidence, contribution from constructive interference within many layers needs to be collected. This requires a multilayer coating. Thin films have become a central ingredient for many x-ray optics due to the ease of which material composition and thickness can be controlled. Chapter 1 starts with a short introduction and survey of the field of x-ray optics. This begins with an explanation of reflective multilayers. Focusing optics are presented next, including mirrors, zone plates, refractive lenses, and multilayer Laue lens (MLL). The strengths and weaknesses of each "species" of optic are briefly discussed, alongside fabrication issues and the ultimate performance for each. Practical considerations on the use of thin-films for x-ray optics fabrication span a wide array of topics including material systems selection and instrumentation design. Sputter deposition is utilized exclusively for the work included herein because this method of thin-film deposition allows a wide array of deposition parameters to be controlled. This chapter also includes a short description of two deposition systems I have designed. Chapter 2 covers a small sampling of some of my work on reflective multilayers, and outlines two of the deposition systems I have designed and built at the Advanced Photon Source. A three-stripe double multilayer monochromator is presented as a case study in order to detail specifications, fabrication, and performance of this prolific breed of x-ray optics. The APS Rotary Deposition System was the first deposition system in the world designed specifically for multilayer

Investigation of aperiodic W/C multi-layer mirror for X-ray optics

International Nuclear Information System (INIS)

Wang Zhanshan; Cheng Xinbin; Zhu Jingtao; Huang Qiushi; Zhang Zhong; Chen Lingyan

2011-01-01

Design, fabrication and characterization of aperiodic tungsten/carbon (W/C) multi-layer mirror were studied. W/C multi-layer was designed as a broad-angle reflective supermirror for Cu-Kα line (λ = 0.154 nm) in the grazing incident angular range (0.9-1.1 deg.) using simulated annealing algorithm. To deposit the W/C depth-graded multi-layer mirror accurately, we introduce an effective layer growth rate as a function of layer thickness. This method greatly improves the reflectivity curve compared to the conventional multi-layer mirror prepared with constant growth rate. The deposited multi-layer mirror exhibits an average reflectivity of 19% over the grazing incident angle range of 0.88-1.08 deg. which mainly coincides with the designed value. Furthermore, the physical mechanisms were discussed and the re-sputtering process of light-atom layers is accounted for the modification of layer thicknesses which leads to the effective growth rates. Using this calibration method, the aperiodic multi-layer mirrors can be better fabricated for X-ray optics.

Simulation of an electrolytic bath for electrodeposition of multilayer shielding coatings

Directory of Open Access Journals (Sweden)

E. A. Dolmatova

2015-10-01

Full Text Available In the work galvanic bath of Cu/(Ni+Cu multilayer shielding coatings formation from an acetate electrolyte containing 0,03 mol/L of CuAc2, 0,3 mol/L of NiAc2 and 1,66 mol/L of acetic acid. According to the results of polarization studies values of coatings deposition pulse mode current density have been chosen and current efficiency of copper and nickel during deposition of Cu-Ni alloy has been determined. To ensure a constant formulation of the electrolyte it has been proposed to use insoluble anodes made of stainless steel and continuous circulation of the electrolyte. The scheme of steams enabling the adjustment of the solution formulation with the use of an additional collecting vessel has been developed. The formulation of the correcting stream continuously fed into the collecting vessel has been calculated.

Sintering Characteristics of Multilayered Thermal Barrier Coatings Under Thermal Gradient and Isothermal High Temperature Annealing Conditions

Science.gov (United States)

Rai, Amarendra K.; Schmitt, Michael P.; Bhattacharya, Rabi; Zhu, Dongming; Wolfe, Douglas E.

2014-01-01

Pyrochlore oxides have most of the relevant attributes for use as next generation thermal barrier coatings such as phase stability, low sintering kinetics and low thermal conductivity. One of the issues with the pyrochlore oxides is their lower toughness and therefore higher erosion rate compared to the current state-of-the-art TBC material, yttria (6 to 8 wt%) stabilized zirconia (YSZ). In this work, sintering characteristics were investigated for novel multilayered coating consisted of alternating layers of pyrochlore oxide viz Gd2Zr2O7 and t' low k (rare earth oxide doped YSZ). Thermal gradient and isothermal high temperature (1316 C) annealing conditions were used to investigate sintering and cracking in these coatings. The results are then compared with that of relevant monolayered coatings and a baseline YSZ coating.

Improvement of mechanical and tribological properties in steel surfaces by using titanium-aluminum/titanium-aluminum nitride multilayered system

Energy Technology Data Exchange (ETDEWEB)

Ipaz, L., E-mail: leoipazc@gmail.com [Thin Films Group, Physics departament, Universidad del Valle, Calle 13 100-00, A.A. 25360, Cali (Colombia); Caicedo, J.C. [Thin Films Group, Physics departament, Universidad del Valle, Calle 13 100-00, A.A. 25360, Cali (Colombia); Esteve, J. [Department de Fisica Aplicada i Optica, Universitat de Barcelona, Catalunya (Spain); Espinoza-Beltran, F.J. [Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Queretaro, Libramiento Norponiente 2000, Fracc. Real de Juriquilla, C.P. 76230 (Mexico); Zambrano, G. [Thin Films Group, Physics departament, Universidad del Valle, Calle 13 100-00, A.A. 25360, Cali (Colombia)

2012-02-01

Improvement of mechanical and tribological properties on AISI D3 steel surfaces coated with [Ti-Al/Ti-Al-N]{sub n} multilayer systems deposited in various bilayer periods ({Lambda}) via magnetron co-sputtering pulsed d.c. method, from a metallic binary target; has been studied in this work exhaustively. The multilayer coatings were characterized in terms of structural, chemical, morphological, mechanical and tribological properties by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), scanning electron microscopy, nanoindentation, pin-on-disc and scratch tests, respectively. The failure mode mechanisms were studied by optical microscopy. Results from X-ray diffraction analysis revealed that the crystal structure of TiAl/TiAlN multilayer coatings has a tetragonal and FCC NaCl-type lattice structures for Ti-Al and Ti-Al-N, respectively, i.e., it was found to be non-isostructural multilayers. An enhancement of both hardness and elastic modulus up to 29 GPa and 260 GPa, respectively, was observed as the bilayer periods ({Lambda}) in the coatings were decreased. The sample with a bilayer period ({Lambda}) of 25 nm and bilayer number n = 100 showed the lowest friction coefficient ({approx}0.28) and the highest critical load (45 N), corresponding to 2.7 and 1.5 times better than those values for the coating deposited with n = 1, respectively. These results indicate an enhancement of mechanical, tribological and adhesion properties, comparing to the [Ti-Al/Ti-Al-N]{sub n} multilayer systems with 1 bilayer at 26%, 63% and 33%, respectively. This enhancement in hardness and toughness for multilayer coatings could be attributed to the different mechanisms for layer formation with nanometric thickness such as the novel Ti-Al/Ti-Al-N effect and the number of interfaces that act as obstacles for the crack deflection and dissipation of crack energy.

Investigation of optical properties of Cu/Ni multilayer nanowires embedded in etched ion-track template

Energy Technology Data Exchange (ETDEWEB)

Xie, Lu [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Yao, Huijun, E-mail: Yaohuijun@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Duan, Jinglai; Chen, Yonghui [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Lyu, Shuangbao [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Maaz, Khan [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Nanomaterials Research Group, Physics Division, PINSTECH, Nilore 45650, Islamabad (Pakistan); Mo, Dan [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Liu, Jie, E-mail: J.Liu@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Sun, Youmei; Hou, Mingdong [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

2016-12-01

Graphical abstract: The schematic diagram of measurement of extinction spectra of Cu/Ni multilayer nanowire arrays embedded in the template after removing the gold/copper substrate. - Highlights: • The optical properties of Cu/Ni multilayer nanowire arrays were first investigated by UV/Vis/NIR spectrometer and it was confirmed that the extinction peaks strongly related to the periodicity of the multilayer nanowire. • The Ni segment was thought as a kind of impurity which can change the surface electron distribution and thereby the extinction peaks of nanowire. • Current work supplied the clear layer thickness information of Cu and Ni in Cu/Ni multilayer nanowire with TEM and EDS line-scan profile analysis. - Abstract: For understanding the interaction between light and noble/magnetism multilayer nanowires, Cu/Ni multilayer nanowires are fabricated by a multi-potential step deposition technique in etched ion-track polycarbonate template. The component and the corresponding layer thickness of multilayer nanowire are confirmed by TEM and EDS line-scan analysis. By tailoring the nanowire diameter, the Cu layer thickness and the periodicity of the nanowire, the extinction spectral of nanowire arrays exhibit an extra sensitivity to the change of structural parameters. The resonance wavelength caused by surface plasmon resonance increases obviously with increasing the nanowire diameter, the Cu layer thickness and the periodicity. The observations in our work can be explained by the “impurity effect” and coupled effect and can also be optimized for developing optical devices based on multilayer nanowires.

Sol–gel derived solar selective coatings on SS 321 substrates for solar thermal applications

Energy Technology Data Exchange (ETDEWEB)

Subasri, R., E-mail: subasri@arci.res.in; Soma Raju, K.R.C.; Reddy, D.S.; Hebalkar, Neha Y.; Padmanabham, G.

2016-01-01

Sol–gel derived multilayered solar selective coatings were generated on AISI SS 321 substrates using Ag-TiO{sub 2} as the cermet layer, titania and silica as the dielectric layers with high and low refractive indices respectively. The phase compositions of the individual layers were independently confirmed using grazing angle incidence X-ray diffraction, which was corroborated by X-ray photoelectron spectroscopic analysis. Thickness of the layers was measured using variable angle spectroscopic ellipsometry. The solar absorbance was measured over the UV–Vis-NIR wavelength range. Thermal emissivity was determined using FTIR spectroscopic analysis. The durability of the coatings was ascertained using accelerated corrosion testing methods as well as by measuring the optical properties after thermal cycling experiments. The promising nature of hexavalent chrome-free, environmental friendly, multilayered solar selective coating was ascertained with respect to amenability to scale-up. - Highlights: • Sol–gel derived multilayered solar selective coatings developed on SS321 • Solar absorptance and thermal emittance at par with toxic chrome coating • Thermal stability and corrosion resistance of coatings studied • Coating performance found to be promising for large scale applications • Scale-up amenability investigated by coating generation on 1 m tubes.

Sol–gel derived solar selective coatings on SS 321 substrates for solar thermal applications

International Nuclear Information System (INIS)

Subasri, R.; Soma Raju, K.R.C.; Reddy, D.S.; Hebalkar, Neha Y.; Padmanabham, G.

2016-01-01

Sol–gel derived multilayered solar selective coatings were generated on AISI SS 321 substrates using Ag-TiO_2 as the cermet layer, titania and silica as the dielectric layers with high and low refractive indices respectively. The phase compositions of the individual layers were independently confirmed using grazing angle incidence X-ray diffraction, which was corroborated by X-ray photoelectron spectroscopic analysis. Thickness of the layers was measured using variable angle spectroscopic ellipsometry. The solar absorbance was measured over the UV–Vis-NIR wavelength range. Thermal emissivity was determined using FTIR spectroscopic analysis. The durability of the coatings was ascertained using accelerated corrosion testing methods as well as by measuring the optical properties after thermal cycling experiments. The promising nature of hexavalent chrome-free, environmental friendly, multilayered solar selective coating was ascertained with respect to amenability to scale-up. - Highlights: • Sol–gel derived multilayered solar selective coatings developed on SS321 • Solar absorptance and thermal emittance at par with toxic chrome coating • Thermal stability and corrosion resistance of coatings studied • Coating performance found to be promising for large scale applications • Scale-up amenability investigated by coating generation on 1 m tubes

Advanced coatings for next generation lithography

Science.gov (United States)

Naujok, P.; Yulin, S.; Kaiser, N.; Tünnermann, A.

2015-03-01

Beyond EUV lithography at 6.X nm wavelength has a potential to extend EUVL beyond the 11 nm node. To implement B-based mirrors and to enable their industrial application in lithography tools, a reflectivity level of > 70% has to be reached in near future. The authors will prove that transition from conventional La/B4C to promising LaN/B4C multilayer coatings leads to enhanced optical properties. Currently a near normal-incidence reflectivity of 58.1% @ 6.65 nm is achieved by LaN/B4C multilayer mirrors. The introduction of ultrathin diffusion barriers into the multilayer design to reach the targeted reflectivity of 70% was also tested. The optimization of multilayer design and deposition process for interface-engineered La/C/B4C multilayer mirrors resulted in peak reflectivity of 56.8% at the wavelength of 6.66 nm. In addition, the thermal stability of several selected multilayers was investigated and will be discussed.

Neutron optics with multilayer monochromators

International Nuclear Information System (INIS)

Saxena, A.M.; Majkrzak, C.F.

1984-01-01

A multilayer monochromator is made by depositing thin films of two materials in an alternating sequence on a glass substrate. This makes a multilayer periodic in a direction perpendicular to the plane of the films, with a d-spacing equal to the thickness of one bilayer. Neutrons of wavelength λ incident on a multilayer will be reflected at an angle phi given by the Bragg relation nλ = 2d sinphi, where n is the order of reflection. The use of thin-film multilayers for monochromating neutrons is discussed. Because of the low flux of neutrons, the samples have to be large, and the width of the incident beam can be as much as 2 cm. Multilayers made earlier were fabricated by resistive heating of the materials in a vacuum chamber. Because of geometrical constraints imposed by the size of the vacuum chamber, limits on the amount of material that can be loaded in a boat, and finite life of the boats, this method of preparation limits the length of a multilayer to ∼ 15 cm and the total number of bilayers in a multilayer to about 200. This paper discusses a thin-film deposition system using RF sputtering for depositing films

The adaptation of methods in multilayer optics for the calculation of specular neutron reflection

International Nuclear Information System (INIS)

Penfold, J.

1988-10-01

The adaptation of standard methods in multilayer optics to the calculation of specular neutron reflection is described. Their application is illustrated with examples which include a glass optical flat and a deuterated Langmuir-Blodgett film. (author)

Ultrahard Multilayer Coatings

International Nuclear Information System (INIS)

Chrzan, D.C.; Dugger, M.; Follstaedt, D.M.; Friedman, Lawrence H.; Friedmann, T.A.; Knapp, J.A.; McCarty, K.F.; Medlin, D.L.; Mirkarimi, P.B.; Missert, N.; Newcomer, P.P.; Sullivan, J.P.; Tallant, D.R.

1999-01-01

We have developed a new multilayer a-tC material that is thick stress-free, adherent, low friction, and with hardness and stiffness near that of diamond. The new a-tC material is deposited by J pulsed-laser deposition (PLD) at room temperature, and fully stress-relieved by a short thermal anneal at 600 ampersand deg;C. A thick multilayer is built up by repeated deposition and annealing steps. We measured 88 GPa hardness, 1100 GPa Young's modulus, and 0.1 friction coefficient (under high load). Significantly, these results are all well within the range reported for crystalline diamond. In fact, this material, if considered separate from crystalline diamond, is the 2nd hardest material known to man. Stress-free a-tC also has important advantages over thin film diamond; namely, it is smooth, processed at lower temperature, and can be grown on a much broader range of substrates. This breakthrough will enable a host of applications that we are actively pursuing in MEMs, sensors, LIGA, etc

The (PrS/HGF-pDNA) multilayer films for gene-eluting stent coating: Gene-protecting, anticoagulation, antibacterial properties, and in vivo antirestenosis evaluation.

Science.gov (United States)

Chang, Hao; Ren, Ke-feng; Zhang, He; Wang, Jin-lei; Wang, Bai-liang; Ji, Jian

2015-02-01

Vascular gene-eluting stents (GES) is a promising strategy for treatment of cardiovascular disease. Very recently, we have proved that the (protamine sulfate/plasmid DNA encoding hepatocyte growth factor) (PrS/HGF-pDNA) multilayer can serve as a powerful tool for enhancing competitiveness of endothelial cell over smooth muscle cell, which opens perspectives for the regulation of intercellular competitiveness in the field of interventional therapy. However, before the gene multilayer films could be used in vascular stents for real clinical application, the preservation of gene bioactivity during the industrial sterilization and the hemocompatibility of film should be taken into account. Actually, both are long been ignored issues in the field of gene coating for GES. In this study, we demonstrate that the (PrS/HGF-pDNA) multilayer film exhibits the good gene-protecting abilities, which is confirmed by using the industrial sterilizations (gamma irradiation and ethylene oxide) and a routine storage condition (dry state at 4°C for 30 days). Furthermore, hemocompatible measurements (such as platelet adhesion and whole blood coagulation) and antibacterial assays (bacteria adhesion and growth inhibition) indicate the good anticoagulation and antibacterial properties of the (PrS/HGF-pDNA) multilayer film. The in vivo preliminary data of angiography and histological analysis suggest that the (PrS/HGF-pDNA) multilayer coated stent can reduce the in-stent restenosis. This work reveals that the (PrS/HGF-pDNA) multilayer film could be a promising candidate as coating for GES, which is of great potential in future clinic application. © 2014 Wiley Periodicals, Inc.

Nitridation and contrast of B4C/La interfaces and X-ray multilayer optics

NARCIS (Netherlands)

Tsarfati, T.; van de Kruijs, Robbert Wilhelmus Elisabeth; Zoethout, E.; Bijkerk, Frederik

2010-01-01

Chemical diffusion and interlayer formation in thin layers and at interfaces is of increasing influence in nanoscopic devices such as nano-electronics, magneto-optical storage and multilayer X-ray optics. We show that with the nitridation of reactive B4C/La interfaces, both the chemical and optical

Efficiency calibration of the first multilayer-coated holographic ion-etched flight grating for a sounding rocket high-resolution spectrometer.

Science.gov (United States)

Kowalski, M P; Barbee, T W; Heidemann, K F; Gursky, H; Rife, J C; Hunter, W R; Fritz, G G; Cruddace, R G

1999-11-01

We have fabricated the four flight gratings for a sounding rocket high-resolution spectrometer using a holographic ion-etching technique. The gratings are spherical (4000-mm radius of curvature), large (160 mm x 90 mm), and have a laminar groove profile of high density (3600 grooves/mm). They have been coated with a high-reflectance multilayer of Mo/Si. Using an atomic force microscope, we examined the surface characteristics of the first grating before and after multilayer coating. The average roughness is approximately 3 A rms after coating. Using synchrotron radiation, we completed an efficiency calibration map over the wavelength range 225-245 A. At an angle of incidence of 5 degrees and a wavelength of 234 A, the average efficiency in the first inside order is 10.4 +/- 0.5%, and the derived groove efficiency is 34.8 +/- 1.6%. These values exceed all previously published results for a high-density grating.

Spectral tailoring of nanoscale EUV and soft x-ray multilayer optics

NARCIS (Netherlands)

Huang, Qiushi; Medvedev, Viacheslav; van de Kruijs, Robbert Wilhelmus Elisabeth; Yakshin, Andrey; Louis, Eric; Bijkerk, Frederik

2017-01-01

Extreme ultraviolet and soft X-ray (XUV) multilayer optics have experienced significant development over the past few years, particularly on controlling the spectral characteristics of light for advanced applications like EUV photolithography, space observation, and accelerator- or lab-based XUV

Roughness Influence On Macro- And Micro-Tribology Of Multi-Layered Hard Coatings On Carbon Fibre Polymer Composite

Directory of Open Access Journals (Sweden)

Lackner J.M.

2015-09-01

Full Text Available Goal of this work is the investigation of roughness influences on the abrasive wear behaviour of magnetron sputtered multi-layered, low-friction coatings on carbon-fibre reinforced polymers (CFRP. Higher coating roughness at similar CFRP quality was realized by higher deposition rates, leading to increased heat flux to the substrates during deposition. Thermal expansion of the epoxy matrix on the micro scale results in a wavy, wrinkled surface topography. Both in scratch and reciprocal sliding testing against alumina, the friction coefficients are lower for the smooth coatings, but their wear rate is higher due to low-cycle fatigue caused abrasion.

New developments in Ni/Ti multilayers

Energy Technology Data Exchange (ETDEWEB)

Anderson, I; Hoghoj, P [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

1997-04-01

It is now 20 years since super-mirrors were first used as a neutron optical element. Since then the field of multilayer neutron-optics has matured with multilayers finding their way to application in many neutron scattering instruments. However, there is still room for progress in terms of multilayer quality, performance and application. Along with work on multilayers for neutron polarisation Ni/Ti super-mirrors have been optimised. The state-of-the-art Ni/Ti super-mirror performance and the results obtained in two neutron-optics applications of Ni/Ti multilayers are presented. (author).

Scattering by a conducting elliptic cylinder with a multilayer dielectric coating

Science.gov (United States)

Caorsi, Salvatore; Pastorino, Matteo; Raffetto, Mirco

1997-11-01

A solution to the electromagnetic scattering of a transverse magnetic plane wave due to a perfectly conducting elliptic cylinder coated by a lossless, nonmagnetic, and elliptic multilayer dielectric is proposed. Despite the lack of orthogonality of the eigenfunctions of the field inside different layers, an efficient recursive procedure for the computation of the solution is devised. It is based on series expansions of the fields in terms of Mathieu functions and on a Galerkin approach. An outline of the procedure is given, and some numerical results, concerning both the field quantities and the radar cross section per unit length, are provided.

Low-emissivity coating of amorphous diamond-like carbon/Ag-alloy multilayer on glass

International Nuclear Information System (INIS)

Chiba, Kiyoshi; Takahashi, Toshiyuki; Kageyama, Takashi; Oda, Hironori

2005-01-01

Transparent low-emissivity (low-e) coatings comprising dielectrics of amorphous diamond-like carbon (DLC) and Ag-alloy films are investigated. All films have been prepared by dc magnetron sputtering. An index of refraction of the DLC film deposited in a gas mixture of Ar/H 2 (4%) shows n = 1.80 + 0.047i at 500 nm wavelength. A multilayer stack of DLC (70 nm thick)/Ag 87.5 Cu 12.5 -alloy (10 nm)/DLC (140 nm)/Ag 87.5 Cu 12.5 -alloy (10 nm)/DLC (70 nm) has revealed clear interference spectra with spectra selectivity. This coating performs low emittance less than 0.1 for black body radiation at 297 K, exhibiting a transparent heat mirror property embedded in DLC films

Multi-layer coatings for bipolar rechargeable batteries with enhanced terminal voltage

Science.gov (United States)

Farmer, Joseph C.; Kaschmitter, James; Pierce, Steve

2017-06-06

A method for producing a multi-layer bipolar coated cell according to one embodiment includes applying a first active cathode material above a substrate to form a first cathode; applying a first solid-phase ionically-conductive electrolyte material above the first cathode to form a first electrode separation layer; applying a first active anode material above the first electrode separation layer to form a first anode; applying an electrically conductive barrier layer above the first anode; applying a second active cathode material above the anode material to form a second cathode; applying a second solid-phase ionically-conductive electrolyte material above the second cathode to form a second electrode separation layer; applying a second active anode material above the second electrode separation layer to form a second anode; and applying a metal material above the second anode to form a metal coating section. In another embodiment, the anode is formed prior to the cathode. Cells are also disclosed.

Coating of silicon pore optics

DEFF Research Database (Denmark)

Cooper-Jensen, Carsten P.; Ackermann, M.; Christensen, Finn Erland

2009-01-01

For the International X-ray observatory (IXO), a mirror module with an effective area of 3 m2 at 1.25 keV and at least 0.65 m2 at 6 keV has to be realized. To achieve this goal, coated silicon pore optics has been developed over the last years. One of the challenges is to coat the Si plates...

Nanometric resolution in glow discharge optical emission spectroscopy and Rutherford backscattering spectrometry depth profiling of metal (Cr, Al) nitride multilayers

International Nuclear Information System (INIS)

Escobar Galindo, R.; Gago, R.; Fornies, E.; Munoz-Martin, A.; Climent Font, A.; Albella, J.M.

2006-01-01

In this work, we address the capability of glow discharge optical emission spectroscopy (GDOES) for fast and accurate depth profiling of multilayer nitride coatings down to the nanometer range. This is shown by resolving the particular case of CrN/AlN structures with individual thickness ranging from hundreds to few nanometers. In order to discriminate and identify artefacts in the GDOES depth profile due to the sputtering process, the layered structures were verified by Rutherford backscattering spectrometry (RBS) and scanning electron microscopy (SEM). The interfaces in the GDOES profiles for CrN/AlN structures are sharper than the ones measured for similar metal multilayers due to the lower sputtering rate of the nitrides. However, as a consequence of the crater shape, there is a linear degradation of the depth resolution with depth (approximately 40 nm/μm), saturating at a value of approximately half the thickness of the thinner layer. This limit is imposed by the simultaneous sputtering of consecutive layers. The ultimate GDOES depth resolution at the near surface region was estimated to be of 4-6 nm

Investigation of sol-gel antireflective coatings

International Nuclear Information System (INIS)

Schmid, A.; Guardalben, M.; Chipp, T.

1984-03-01

Very high power laser systems present material design challenges which often approach the inherent optical survival strength of components. Optical coatings in the UV region suffer from anomalously high absorption and scattering in the deposited layers. The losses caused by these effects are often unacceptable or, in the case of absorption, usually fatal to the absorbing coatings. Unfortunately, no metals exist that have high enough reflectivities in the UV to serve as uncoated mirrors as they normally do in the CO 2 region of the infrared. Adequate multilayer dielectric coatings are therefore critically important for the development and utilization of UV lasers. The same could be said for relfection suppressing antireflective coatings in that wavelength range. Antireflective properties of gradientindex designs have been rediscovered and their potential for resolving UV laser design difficulties has been vigorously tested. These antireflective properties have been attained on glass or fused silica surfaces by chemical surface treatments

Young’s modulus of multi-layer microcantilevers

Directory of Open Access Journals (Sweden)

Zhikang Deng

2017-12-01

Full Text Available A theoretical model for calculating the Young’s modulus of multi-layer microcantilevers with a coating is proposed, and validated by a three-dimensional (3D finite element (FE model using ANSYS parametric design language (APDL and atomic force microscopy (AFM characterization. Compared with typical theoretical models (Rayleigh-Ritz model, Euler-Bernoulli (E-B beam model and spring mass model, the proposed theoretical model can obtain Young’s modulus of multi-layer microcantilevers more precisely. Also, the influences of coating’s geometric dimensions on Young’s modulus and resonant frequency of microcantilevers are discussed. The thickness of coating has a great influence on Young’s modulus and resonant frequency of multi-layer microcantilevers, and the coating should be considered to calculate Young’s modulus more precisely, especially when fairly thicker coating is employed.

Preliminary investigation of changes in x-ray multilayer optics subjected to high radiation flux

International Nuclear Information System (INIS)

Hockaday, M.P.; Blake, R.L.; Grosso, J.S.; Selph, M.M.; Klein, M.M.; Matuska, W. Jr.; Palmer, M.A.; Liefeld, R.J.

1985-01-01

A variety of metal multilayers was exposed to high x-ray flux using Sandia National Laboratories' PROTO II machine in the gas puff mode. Fluxes incident on the multilayers above 700 MW/cm 2 in total radiation, in nominal 20 ns pulses, were realized. The neon hydrogen- and helium-like resonance lines were used to probe the x-ray reflectivity properties of the multilayers as they underwent change of state during the heating pulse. A fluorescer-fiber optic-streak camera system was used to monitor the changes in x-ray reflectivity as a function of time and irradiance. Preliminary results are presented for a W/C multilayer. Work in progress to model the experiment is discussed. 13 refs., 4 figs

Effects of coating on the optical trapping efficiency of microspheres via geometrical optics approximation.

Science.gov (United States)

Park, Bum Jun; Furst, Eric M

2014-09-23

We present the optical trapping forces that are generated when a single laser beam strongly focuses on a coated dielectric microsphere. On the basis of geometrical optics approximation (GOA), in which a particle intercepts all of the rays that make up a single laser beam, we calculate the trapping forces with varying coating thickness and refractive index values. To increase the optical trapping efficiency, the refractive index (n(b)) of the coating is selected such that n(a) < n(b) < n(c), where na and nc are the refractive indices of the medium and the core material, respectively. The thickness of the coating also increases trapping efficiency. Importantly, we find that trapping forces for the coated particles are predominantly determined by two rays: the incident ray and the first refracted ray to the medium.

A Magnetron Sputter Deposition System for the Development of Multilayer X-Ray Optics

Data.gov (United States)

National Aeronautics and Space Administration — The proposal objective is to establish the capability to deposit multilayer structures for X-ray, neutron, and EUV optic applications through the development of a...

Skin and cutaneous melanocytic lesion simulation in biomedical optics with multilayered phantoms

Energy Technology Data Exchange (ETDEWEB)

Urso, P [Department of Occupational and Environmental Health, Hospital L. Sacco Unit, University of Milan, Via G B Grassi, 74-20157 Milan (Italy); Lualdi, M [Medical Physics Unit, Istituto Nazionale per lo Studio e la Cura dei Tumori, Via Venezian 1-20133 Milan (Italy); Colombo, A [Medical Physics Unit, Istituto Nazionale per lo Studio e la Cura dei Tumori, Via Venezian 1-20133 Milan (Italy); Carrara, M [Medical Physics Unit, Istituto Nazionale per lo Studio e la Cura dei Tumori, Via Venezian 1-20133 Milan (Italy); Tomatis, S [Medical Physics Unit, Istituto Nazionale per lo Studio e la Cura dei Tumori, Via Venezian 1-20133 Milan (Italy); Marchesini, R [Medical Physics Unit, Istituto Nazionale per lo Studio e la Cura dei Tumori, Via Venezian 1-20133 Milan (Italy)

2007-05-21

The complex inner layered structure of skin influences the photon diffusion inside the cutaneous tissues and determines the reflectance spectra formation. Phantoms are very useful tools to understand the biophysical meaning of parameters involved in light propagation through the skin. To simulate the skin reflectance spectrum, we realized a multilayered skin-like phantom and a multilayered skin phantom with a melanoma-like phantom embedded inside. Materials used were Al{sub 2}O{sub 3} particles, melanin of sepia officinalis and a calibrator for haematology systems dispersed in transparent silicon. Components were optically characterized with indirect techniques. Reflectance phantom spectra were compared with average values of in vivo spectra acquired on a sample of 573 voluntary subjects and 132 pigmented lesions. The phantoms' reflectance spectra agreed with those measured in vivo, mimicking the optical behaviour of the human skin. Further, the phantoms were optically stable and easily manageable, and represented a valid resource in spectra formation comprehension, in diagnostic laser applications and simulation model implementation, such as the Monte Carlo code for non-homogeneous media. (note)

Skin and cutaneous melanocytic lesion simulation in biomedical optics with multilayered phantoms

International Nuclear Information System (INIS)

Urso, P; Lualdi, M; Colombo, A; Carrara, M; Tomatis, S; Marchesini, R

2007-01-01

The complex inner layered structure of skin influences the photon diffusion inside the cutaneous tissues and determines the reflectance spectra formation. Phantoms are very useful tools to understand the biophysical meaning of parameters involved in light propagation through the skin. To simulate the skin reflectance spectrum, we realized a multilayered skin-like phantom and a multilayered skin phantom with a melanoma-like phantom embedded inside. Materials used were Al 2 O 3 particles, melanin of sepia officinalis and a calibrator for haematology systems dispersed in transparent silicon. Components were optically characterized with indirect techniques. Reflectance phantom spectra were compared with average values of in vivo spectra acquired on a sample of 573 voluntary subjects and 132 pigmented lesions. The phantoms' reflectance spectra agreed with those measured in vivo, mimicking the optical behaviour of the human skin. Further, the phantoms were optically stable and easily manageable, and represented a valid resource in spectra formation comprehension, in diagnostic laser applications and simulation model implementation, such as the Monte Carlo code for non-homogeneous media. (note)

Functional photocatalytically active and scratch resistant antireflective coating based on TiO{sub 2} and SiO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Mazur, M., E-mail: michal.mazur@pwr.edu.pl [Wroclaw University of Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw (Poland); Wojcieszak, D.; Kaczmarek, D.; Domaradzki, J. [Wroclaw University of Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw (Poland); Song, S.; Gibson, D.; Placido, F. [Institute of Thin Films, Sensors & Imaging, University of the West of Scotland, Scottish Universities Physics Alliance, High Street, Paisley PA1 2BE (United Kingdom); Mazur, P. [University of Wroclaw, Institute of Experimental Physics, Max Born 9, 50-204 Wroclaw (Poland); Kalisz, M. [Motor Transport Institute, Centre for Material Testing and Mechatronics, Jagiellonska 80, 03-301 Warsaw (Poland); Poniedzialek, A. [Wroclaw University of Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw (Poland)

2016-09-01

Graphical abstract: - Highlights: • Designed multilayer was deposited by microwave assisted magnetron sputtering method. • AR coating in designed wavelength range had transmittance higher than 97%. • The AR multilayer was hydrophobic and photocatalytically active. • AR coating was scratch resistant. • Deposited multilayer had higher hardness than the glass substrate. - Abstract: Antireflection (AR) multilayer coating, based on combination of five TiO{sub 2} and SiO{sub 2} thin films, was deposited by microwave assisted reactive magnetron sputtering process on microscope glass substrates. In this work X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy and wettability measurements were used to characterize the structural and surface properties of the deposited coating. These studies revealed that prepared coating was amorphous with low surface roughness. Photocatalytic properties were determined based on phenol decomposition reaction. Measurements of optical properties showed that transmittance in the visible wavelength range was increased after the deposition of AR coating as-compared to bare glass substrate. The mechanical properties were determined on the basis of nano-indentation and scratch resistance tests. Performed research has shown that deposition of an additional thin 10 nm thick TiO{sub 2} thin film top layer, the prepared AR coating was photocatalytically active, hydrophobic, scratch resistant and had increased hardness as-compared to bare glass substrate. These results indicate that prepared AR multilayer could be used also as a self-cleaning and protective coating.

Solution Coating of Pharmaceutical Nanothin Films and Multilayer Nanocomposites with Controlled Morphology and Polymorphism.

Science.gov (United States)

Horstman, Elizabeth M; Kafle, Prapti; Zhang, Fengjiao; Zhang, Yifu; Kenis, Paul J A; Diao, Ying

2018-03-28

Nanosizing is rapidly emerging as an alternative approach to enhance solubility and thus the bioavailability of poorly aqueous soluble active pharmaceutical ingredients (APIs). Although numerous techniques have been developed to perform nanosizing of API crystals, precise control and modulation of their size in an energy and material efficient manner remains challenging. In this study, we present meniscus-guided solution coating as a new technique to produce pharmaceutical thin films of nanoscale thickness with controlled morphology. We demonstrate control of aspirin film thickness over more than 2 orders of magnitude, from 30 nm to 1.5 μm. By varying simple process parameters such as the coating speed and the solution concentration, the aspirin film morphology can also be modulated by accessing different coating regimes, namely the evaporation regime and the Landau-Levich regime. Using ellipticine-a poorly water-soluble anticancer drug-as another model compound, we discovered a new polymorph kinetically trapped during solution coating. Furthermore, the polymorphic outcome can be controlled by varying coating conditions. We further performed layer-by-layer coating of multilayer nanocomposites, with alternating thin films of ellipticine and a biocompatible polymer, which demonstrate the potential of additive manufacturing of multidrug-personalized dosage forms using this approach.

Electrochemical behavior of hydroxyapatite/TiN multi-layer coatings on Ti alloys

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun-Ju [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University (Korea, Republic of); Jeong, Yong-Hoon [Biomechanics and Tissue Engineering Laboratory, Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH (United States); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University (Korea, Republic of); Brantley, William A. [Division of Restorative Science and Prosthodontics, College of Dentistry, The Ohio State University, Columbus, OH (United States)

2014-12-01

The electrochemical behavior of hydroxyapatite (HA) and titanium nitride (TiN) multi-layer coatings on Ti–Nb–Zr alloys was investigated by a variety of surface analytical methods. The HA/TiN layers were deposited using a magnetron sputtering system. The HA target was made of human tooth-ash sintered at 1300 °C for 1 h and had an average Ca/P ratio of 1.9. From X-ray diffraction patterns, the Ti–29Nb–5Zr alloy was composed entirely of equiaxed β-phase exhibiting the principal (110) reflection, and the coating exhibited the (111) and (200) reflections for TiN and the (112) and (202) reflections for HA. At the coating surface the HA films consisted of granular particles, and the surface roughness was 4.22 nm. The thickness of the coating layers increased in the order of HA/TiN (lowest), TiN, and HA (highest). Potentiodynamic polarization measurements revealed that the corrosion current density was the lowest, and the corrosion potential and polarization resistance the highest, when the Ti–29Nb–5Zr surface was covered by the HA/TiN film, compared to solely HA or TiN films. - Highlights: • HA/TiN films were deposited by magnetron sputtering on a Ti–29Nb–5Zr biomedical alloy. • The corrosion current density for the HA/TiN films was lower than that of the non-coated alloy. • The polarization resistance of the HA/TiN films was higher than that of the non-coated alloy.

Electrochemical behavior of hydroxyapatite/TiN multi-layer coatings on Ti alloys

International Nuclear Information System (INIS)

Kim, Eun-Ju; Jeong, Yong-Hoon; Choe, Han-Cheol; Brantley, William A.

2014-01-01

The electrochemical behavior of hydroxyapatite (HA) and titanium nitride (TiN) multi-layer coatings on Ti–Nb–Zr alloys was investigated by a variety of surface analytical methods. The HA/TiN layers were deposited using a magnetron sputtering system. The HA target was made of human tooth-ash sintered at 1300 °C for 1 h and had an average Ca/P ratio of 1.9. From X-ray diffraction patterns, the Ti–29Nb–5Zr alloy was composed entirely of equiaxed β-phase exhibiting the principal (110) reflection, and the coating exhibited the (111) and (200) reflections for TiN and the (112) and (202) reflections for HA. At the coating surface the HA films consisted of granular particles, and the surface roughness was 4.22 nm. The thickness of the coating layers increased in the order of HA/TiN (lowest), TiN, and HA (highest). Potentiodynamic polarization measurements revealed that the corrosion current density was the lowest, and the corrosion potential and polarization resistance the highest, when the Ti–29Nb–5Zr surface was covered by the HA/TiN film, compared to solely HA or TiN films. - Highlights: • HA/TiN films were deposited by magnetron sputtering on a Ti–29Nb–5Zr biomedical alloy. • The corrosion current density for the HA/TiN films was lower than that of the non-coated alloy. • The polarization resistance of the HA/TiN films was higher than that of the non-coated alloy

Optimization of Ni-Based WC/Co/Cr Composite Coatings Produced by Multilayer Laser Cladding

Directory of Open Access Journals (Sweden)

Andrea Angelastro

2013-01-01

Full Text Available As a surface coating technique, laser cladding (LC has been developed for improving wear, corrosion, and fatigue properties of mechanical components. The main advantage of this process is the capability of introducing hard particles such as SiC, TiC, and WC as reinforcements in the metallic matrix such as Ni-based alloy, Co-based alloy, and Fe-based alloy to form ceramic-metal composite coatings, which have very high hardness and good wear resistance. In this paper, Ni-based alloy (Colmonoy 227-F and Tungsten Carbides/Cobalt/Chromium (WC/Co/Cr composite coatings were fabricated by the multilayer laser cladding technique (MLC. An optimization procedure was implemented to obtain the combination of process parameters that minimizes the porosity and produces good adhesion to a stainless steel substrate. The optimization procedure was worked out with a mathematical model that was supported by an experimental analysis, which studied the shape of the clad track generated by melting coaxially fed powders with a laser. Microstructural and microhardness analysis completed the set of test performed on the coatings.

The effect of ion irradiation and elevated temperature on the microstructure and the properties of C/W/C/B multilayer coating

Energy Technology Data Exchange (ETDEWEB)

Vlcak, Petr, E-mail: petr.vlcak@fs.cvut.cz

2016-03-01

Graphical abstract: - Highlights: • C/W/C/B multilayer PVD coating was treated by 45 keV nitrogen ion irradiation. • The effect of ion irradiation and elevated temperature on microstructure was analyzed. • Formation of new compounds and degradation of carbon fraction were observed. • The causes of the observed changes in surface properties were discussed. - Abstract: C/W/C/B multi-layer PVD coating with a layer period of 10 nm and 500 nm in thickness was irradiated with 45 keV N ions at fluence of 1 × 10{sup 17} cm{sup −2}. Ion irradiation was performed at room temperature or at an elevated temperature of 500 °C. The microstructure was investigated by X-ray diffraction, by X-ray photoelectron spectroscopy, and by Raman spectroscopy. The results showed that implanted N ions bond both with W atoms and with C atoms. N ion irradiation induced the formation of WC and WC{sub 1−x} phases. The energetic ions transformed the C bonds in defect sp{sup 2} and defect sp{sup 3} hybridizations, resulting in graphitization of the carbon fraction in the multilayer coating. Ion irradiation reduced the cohesive strength of the monolayers, reduced hardness of the C/W/C/B coating, increased its surface roughness and increased its friction coefficient. An elevated temperature during ion irradiation caused a better arrangement of the WC phase and further graphitization of the carbon fraction, in comparison with a coating treated by ion irradiation at room temperature. There is discussion of the causes of the observed changes in surface properties.

Multilayer CVD Diamond Coatings in the Machining of an Al6061-15 Vol % Al2O3 Composite

Directory of Open Access Journals (Sweden)

Mohammadmehdi Shabani

2017-10-01

Full Text Available Ceramic cutting inserts coated with ten-fold alternating micro- and nanocrystalline diamond (MCD/NCD layers grown by hot filament chemical vapor deposition (CVD were tested in the machining of an Al based metallic matrix composite (MMC containing 15 vol % Al2O3 particles. Inserts with total coating thicknesses of approximately 12 µm and 24 µm were produced and used in turning: cutting speed (v of 250 to 1000 m·min−1; depth of cut (DOC from 0.5 to 3 mm and feed (f between 0.1 and 0.4 mm·rev−1. The main cutting force increases linearly with DOC (ca. 294 N per mm and with feed (ca. 640 N per mm·rev−1. The thicker coatings work within the following limits: DOC up to 1.5 mm and maximum speeds of 750 m·min−1 for feeds up to 0.4 mm·rev−1. Flank wear is predominant but crater wear is also observed due to the negative tool normal rake. Layer-by-layer wear of the tool rake, and not total delamination from the substrate, evidenced one of the advantages of using a multilayer design. The MCD/NCD multilayer diamond coated indexable inserts have longer tool life than most CVD diamond systems and behave as well as most polycrystalline diamond (PCD tools.

Cr/B{sub 4}C multilayer mirrors: Study of interfaces and X-ray reflectance

Energy Technology Data Exchange (ETDEWEB)

Burcklen, C.; Meltchakov, E.; Jérome, A.; Rossi, S. de; Delmotte, F. [Laboratoire Charles Fabry, Institut d' Optique Graduate School, CNRS, Université Paris-Saclay, 91127 Palaiseau Cedex (France); Soufli, R. [Laboratoire Charles Fabry, Institut d' Optique Graduate School, CNRS, Université Paris-Saclay, 91127 Palaiseau Cedex (France); Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Dennetiere, D.; Polack, F.; Capitanio, B.; Thomasset, M. [Synchrotron SOLEIL, L' Orme des Merisiers, Saint Aubin, BP 48F-91192 Gif sur Yvette Cedex (France); Gullikson, E. [Center for X-ray Optics, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, California 94720 (United States)

2016-03-28

We present an experimental study of the effect of layer interfaces on the x-ray reflectance in Cr/B{sub 4}C multilayer interference coatings with layer thicknesses ranging from 0.7 nm to 5.4 nm. The multilayers were deposited by magnetron sputtering and by ion beam sputtering. Grazing incidence x-ray reflectometry, soft x-ray reflectometry, and transmission electron microscopy reveal asymmetric multilayer structures with a larger B{sub 4}C-on-Cr interface, which we modeled with a 1–1.5 nm thick interfacial layer. Reflectance measurements in the vicinity of the Cr L{sub 2,3} absorption edge demonstrate fine structure that is not predicted by simulations using the currently tabulated refractive index (optical constants) values for Cr.

Recyclability of PET/WPI/PE Multilayer Films by Removal of Whey Protein Isolate-Based Coatings with Enzymatic Detergents

Directory of Open Access Journals (Sweden)

Patrizia Cinelli

2016-06-01

Full Text Available Multilayer plastic films provide a range of properties, which cannot be obtained from monolayer films but, at present, their recyclability is an open issue and should be improved. Research to date has shown the possibility of using whey protein as a layer material with the property of acting as an excellent barrier against oxygen and moisture, replacing petrochemical non-recyclable materials. The innovative approach of the present research was to achieve the recyclability of the substrate films by separating them, with a simple process compatible with industrial procedures, in order to promote recycling processes leading to obtain high value products that will beneficially impact the packaging and food industries. Hence, polyethyleneterephthalate (PET/polyethylene (PE multi-layer film was prepared based on PET coated with a whey protein layer, and then the previous structure was laminated with PE. Whey proteins, constituting the coating, can be degraded by enzymes so that the coating films can be washed off from the plastic substrate layer. Enzyme types, dosage, time, and temperature optima, which are compatible with procedures adopted in industrial waste recycling, were determined for a highly-efficient process. The washing of samples based on PET/whey and PET/whey/PE were efficient when performed with enzymatic detergent containing protease enzymes, as an alternative to conventional detergents used in recycling facilities. Different types of enzymatic detergents tested presented positive results in removing the protein layer from the PET substrate and from the PET/whey/PE multilayer films at room temperature. These results attested to the possibility of organizing the pre-treatment of the whey-based multilayer film by washing with different available commercial enzymatic detergents in order to separate PET and PE, thus allowing a better recycling of the two different polymers. Mechanical properties of the plastic substrate, such as stress at

Recyclability of PET/WPI/PE Multilayer Films by Removal of Whey Protein Isolate-Based Coatings with Enzymatic Detergents

Science.gov (United States)

Cinelli, Patrizia; Schmid, Markus; Bugnicourt, Elodie; Coltelli, Maria Beatrice; Lazzeri, Andrea

2016-01-01

Multilayer plastic films provide a range of properties, which cannot be obtained from monolayer films but, at present, their recyclability is an open issue and should be improved. Research to date has shown the possibility of using whey protein as a layer material with the property of acting as an excellent barrier against oxygen and moisture, replacing petrochemical non-recyclable materials. The innovative approach of the present research was to achieve the recyclability of the substrate films by separating them, with a simple process compatible with industrial procedures, in order to promote recycling processes leading to obtain high value products that will beneficially impact the packaging and food industries. Hence, polyethyleneterephthalate (PET)/polyethylene (PE) multi-layer film was prepared based on PET coated with a whey protein layer, and then the previous structure was laminated with PE. Whey proteins, constituting the coating, can be degraded by enzymes so that the coating films can be washed off from the plastic substrate layer. Enzyme types, dosage, time, and temperature optima, which are compatible with procedures adopted in industrial waste recycling, were determined for a highly-efficient process. The washing of samples based on PET/whey and PET/whey/PE were efficient when performed with enzymatic detergent containing protease enzymes, as an alternative to conventional detergents used in recycling facilities. Different types of enzymatic detergents tested presented positive results in removing the protein layer from the PET substrate and from the PET/whey/PE multilayer films at room temperature. These results attested to the possibility of organizing the pre-treatment of the whey-based multilayer film by washing with different available commercial enzymatic detergents in order to separate PET and PE, thus allowing a better recycling of the two different polymers. Mechanical properties of the plastic substrate, such as stress at yield, stress and

Wear behaviour of wear-resistant adaptive nano-multilayered Ti-Al-Mo-N coatings

Science.gov (United States)

Sergevnin, V. S.; Blinkov, I. V.; Volkhonskii, A. O.; Belov, D. S.; Kuznetsov, D. V.; Gorshenkov, M. V.; Skryleva, E. A.

2016-12-01

Coating samples in the Ti-Al-Mo-N system were obtained by arc-PVD method at variable bias voltage Ub applied to the substrate, and the partial pressure of nitrogen P(N2) used as a reaction gas. The deposited coatings were characterized by a nanocrystalline structure with an average grain size of 30-40 nm and multilayered architecture with alternating layers of (Ti,Al)N nitride and Mo-containing phases with a thickness comparable to the grain size. Coatings of (Ti,Al)N-Mo-Mo2N and (Ti,Al)N-Mo2N compositions were obtained by changing deposition parameters. The obtained coatings had hardness of 40 GPa and the relative plastic deformation under microindentation up to 60%. (Ti,Al)N-Mo2N coatings demonstrated better physicomechanical characteristics, showing high resistance to crack formation and destruction through the plastic deformation mechanism without brittle fracturing, unlike (Ti,Al)N-Mo-Mo2N. The friction coefficient of the study coatings (against Al2O3 balls under dry condition using a pin-on-disc method) reached the values of 0.35 and 0.5 at 20 °C and 500 °C respectively, without noticeable wear within this temperature range. These tribological properties were achieved by forming MoO3 acting as a solid lubricant. At higher temperatures the deterioration in the tribological properties is due to the high rate of MoO3 sublimation from friction surfaces.

An in vivo study on the effect of coating stability on osteointegration performance of collagen/hyaluronic acid multilayer modified titanium implants.

Science.gov (United States)

Ao, Haiyong; Zong, Jiajia; Nie, Yanjiao; Wan, Yizao; Zheng, Xiebin

2018-03-01

Aseptic loosening of implant is one of the main causes of Ti-based implant failure. In our previous work, a novel stable collagen/hyaluronic acid (Col/HA) multilayer modified titanium coatings (TCs) was developed by layer-by-layer (LBL) covalent immobilization technique, which showed enhanced biological properties compared with TCs that were physically absorbed with Col/HA multilayer in vitro . In this study, a rabbit model with femur condyle defect was employed to compare the osteointegration performance of them. Results indicated that Col/HA multilayer with favourable stability could better facilitate osteogenesis around implants and bone-implant contact. The Col/HA multilayer covalent-immobilized TC may reduce aseptic loosening of implant.

Coated sphere scattering by geometric optics approximation.

Science.gov (United States)

Mengran, Zhai; Qieni, Lü; Hongxia, Zhang; Yinxin, Zhang

2014-10-01

A new geometric optics model has been developed for the calculation of light scattering by a coated sphere, and the analytic expression for scattering is presented according to whether rays hit the core or not. The ray of various geometric optics approximation (GOA) terms is parameterized by the number of reflections in the coating/core interface, the coating/medium interface, and the number of chords in the core, with the degeneracy path and repeated path terms considered for the rays striking the core, which simplifies the calculation. For the ray missing the core, the various GOA terms are dealt with by a homogeneous sphere. The scattering intensity of coated particles are calculated and then compared with those of Debye series and Aden-Kerker theory. The consistency of the results proves the validity of the method proposed in this work.

ZnO/Cu2S/ZnO Multilayer Films: Structure Optimization and Its Detail Data for Applications on Photoelectric and Photocatalytic Properties

Directory of Open Access Journals (Sweden)

Zhenxing Wang

2017-01-01

Full Text Available Monolayer Cu2S and ZnO, and three kinds of complex films, Cu2S/ZnO, ZnO/Cu2S, and ZnO/Cu2S/ZnO, were deposited on glass substrates by means of radio frequency (RF magnetron sputtering device. The impact of the thickness of ZnO and Cu2S on the whole transmittance, conductivity, and photocatalysis was investigated. The optical and electrical properties of the multilayer were studied by optical spectrometry and four point probes. Numerical simulation of the optical transmittance of the multilayer films has been carried out in order to guide the experimental work. The comprehensive performances of the multilayers as transparent conductive coatings were compared using the figure of merit. Compared with monolithic Cu2S and ZnO films, both the optical transmission property and photocatalytic performance of complex films such as Cu2S/ZnO and ZnO/Cu2S/ZnO change significantly.

Sol-gel optical coatings for lasers: Part 1

International Nuclear Information System (INIS)

Floch, H.G.; Belleville, P.F.; Priotton, J.J.

1995-01-01

Many manufacturers and users claim that optical coatings are best prepared by physical vapor deposition technology. Others believe that sol-gel technology is an effective and competitive alternative. This article, the first of three, emphasizes sol-gel thin-film history and relates it to high-power laser technology, chemistry of the sol-gel process, production of optical coatings and deposition techniques. The second and third articles describe the preparation and performance of antireflective and highly reflective sol-gel optical coatings, respectively, that have been developed for the 1.8-MJ/500-TW (351-nm) pulsed neodymium-glass laser. This powerful laser is to be used in France's Inertial Confinement Fusion (ICF) program. It will demonstrate, at the laboratory scale, ignition of deuterium-tritium fusion fuel

Metal-coated optical fibers for high temperature sensing applications

Science.gov (United States)

Fidelus, Janusz D.; Wysokiński, Karol; Stańczyk, Tomasz; Kołakowska, Agnieszka; Nasiłowski, Piotr; Lipiński, Stanisław; Tenderenda, Tadeusz; Nasiłowski, Tomasz

2017-10-01

An novel low-temperature method was used to enhance the corrosion resistance of copper or gold-coated optical fibers. A characterization of the elaborated materials and reports on selected studies such as cyclic temperature tests together with tensile tests is presented. Gold-coated optical fibers are proposed as a component of optical fiber sensors working in oxidizing atmospheres under temperatures exceeding 900 °C.

Stress analysis and microstructure of PVD monolayer TiN and multilayer TiN/(Ti,Al)N coatings

NARCIS (Netherlands)

Carvalho, NJM; Zoestbergen, E; Kooi, BJ; De Hosson, JTM

2003-01-01

Two PVD titanium nitride based coatings; monolayer TiN and multilayer resulting from the stacking of TiN and (Ti,Al)N layers were evaluated with respect to their stress state and microstructure. The TiN was deposited by triode evaporation ion plating, whereas the TiN/(Ti,AI)N was deposited using a

Optical properties of metallic multi-layer films

International Nuclear Information System (INIS)

Dimmich, R.

1991-09-01

Optical properties of multi-layer films consisting of alternating layers of two different metals are studied on the basis of the Maxwell equations and the Boltzmann transport theory. The influence of free-electron scattering at the film external surface and at the interfaces is taken into account and considered as a function of the electromagnetic field frequency and the structure modulation wavelength. Derived formulas for optical coefficients are valid at low frequencies, where the skin effect is nearly classical, as well as in the near-infrared, visible and ultraviolet spectral ranges, where the skin effect has the anomalous nature. It is shown that the obtained results are apparently dependent on the values of the scattering parameters. What is more, the oscillatory nature of analyzed spectra is observed, where the two oscillation periods may appear on certain conditions. The oscillations result from the electron surface and interface scattering and their amplitudes and periods depend on the boundary conditions for free-electron scattering. Finally, the application of the interference phenomenon in dielectric layers is proposed to obtain the enhancement of the non distinct details which can appear in optical spectra of metallic films. (author). 31 refs, 6 figs

Modifications of optical properties with ceramic coatings

International Nuclear Information System (INIS)

Besmann, T.M.; Abdel-Latif, A.I.

1990-01-01

Coatings of ceramic materials that exhibited high thermal absorptivities and emissivities were chemical vapor deposited on graphite and refractory metals. In this paper the coatings prepared were SiC and B 4 C, and the substrates used were graphite, molybdenum, titanium, and Nb-1Zr. The coatings are characterized with regard to adherence, optical properties, and response to potential harsh environments

The role of defects in laser damage of multilayer coatings

International Nuclear Information System (INIS)

Kozlowski, M.R.; Chow, R.

1993-01-01

Laser induced damage to optical coatings is generally a localized phenomenon associated with coating defects. The most common of the defect types are the well-known nodule defect. This paper reviews the use of experiments and modeling to understand the formation of these defects and their interaction with laser light. Of particular interest are efforts to identify which defects are most susceptible to laser damage. Also discussed are possible methods for stabilizing these defects (laser conditioning) or preventing their initiation (source stabilization, spatter particle trapping)

Elemental profiling of laser cladded multilayer coatings by laser induced breakdown spectroscopy and energy dispersive X-ray spectroscopy

Science.gov (United States)

Lednev, V. N.; Sdvizhenskii, P. A.; Filippov, M. N.; Grishin, M. Ya.; Filichkina, V. A.; Stavertiy, A. Ya.; Tretyakov, R. S.; Bunkin, A. F.; Pershin, S. M.

2017-09-01

Multilayer tungsten carbide wear resistant coatings were analyzed by laser induced breakdown spectroscopy (LIBS) and energy dispersive X-ray (EDX) spectroscopy. Coaxial laser cladding technique was utilized to produce tungsten carbide coating deposited on low alloy steel substrate with additional inconel 625 interlayer. EDX and LIBS techniques were used for elemental profiling of major components (Ni, W, C, Fe, etc.) in the coating. A good correlation between EDX and LIBS data was observed while LIBS provided additional information on light element distribution (carbon). A non-uniform distribution of tungsten carbide grains along coating depth was detected by both LIBS and EDX. In contrast, horizontal elemental profiling showed a uniform tungsten carbide particles distribution. Depth elemental profiling by layer-by-layer LIBS analysis was demonstrated to be an effective method for studying tungsten carbide grains distribution in wear resistant coating without any sample preparation.

Broader color gamut of color-modulating optical coating display based on indium tin oxide and phase change materials.

Science.gov (United States)

Ni, Zhigang; Mou, Shenghong; Zhou, Tong; Cheng, Zhiyuan

2018-05-01

A color-modulating optical coating display based on phase change materials (PCM) and indium tin oxide (ITO) is fabricated and analyzed. We demonstrate that altering the thickness of top-ITO in this PCM-based display device can effectively change color. The significant role of the top-ITO layer in the thin-film interference in this multilayer system is confirmed by experiment as well as simulation. The ternary-color modulation of devices with only 5 nano thin layer of phase change material is achieved. Furthermore, simulation work demonstrates that a stirringly broader color gamut can be obtained by introducing the control of the top-ITO thickness.

GOLD's coating and testing facilities for ISSIS-WSO

Science.gov (United States)

Larruquert, Juan I.; Méndez, José Antonio; Aznárez, José Antonio; Vidal-Dasilva, Manuela; García-Cortés, Sergio; Rodríguez-de Marcos, Luis; Fernández-Perea, Mónica

2011-09-01

ISSIS imager has been thought as an open purpose instrument within the World Space Observatory (WSO) international space mission. The highest priorities of ISSIS, an instrument to be developed by Spain, are to guarantee high spatial resolution and high sensitivity down to the far ultraviolet (FUV). The paper displays the capacities of GOLD for multilayer deposition and FUV reflectometry, among other metrologies, for ISSIS optical elements. Deposition of coatings for ISSIS-WSO will be carried out in a new UHV system with a 75-cm diameter deposition chamber. The purpose of the new laboratory is the deposition of coatings satisfying the constraints for FUV space optics. The first target coating to be developed in this new laboratory is Al protected with MgF2, with optimum reflectance down to ˜120 nm. GOLD's existing reflectometer is able to characterize flat pieces both by transmittance and reflectance, and the latter from near-normal to grazing incidence, in the range from 12 to 200 nm. Other metrologies that will be available at GOLD for ISSIS's coatings and filters include optical thickness of filters to assure parfocality, filter wedge, and coating and filter scattering.

Multilayered phantoms with tunable optical properties for a better understanding of light/tissue interactions

Science.gov (United States)

Roig, Blandine; Koenig, Anne; Perraut, François; Piot, Olivier; Vignoud, Séverine; Lavaud, Jonathan; Manfait, Michel; Dinten, Jean-Marc

2015-03-01

Light/tissue interactions, like diffuse reflectance, endogenous fluorescence and Raman scattering, are a powerful means for providing skin diagnosis. Instrument calibration is an important step. We thus developed multilayered phantoms for calibration of optical systems. These phantoms mimic the optical properties of biological tissues such as skin. Our final objective is to better understand light/tissue interactions especially in the case of confocal Raman spectroscopy. The phantom preparation procedure is described, including the employed method to obtain a stratified object. PDMS was chosen as the bulk material. TiO2 was used as light scattering agent. Dye and ink were adopted to mimic, respectively, oxy-hemoglobin and melanin absorption spectra. By varying the amount of the incorporated components, we created a material with tunable optical properties. Monolayer and multilayered phantoms were designed to allow several characterization methods. Among them, we can name: X-ray tomography for structural information; Diffuse Reflectance Spectroscopy (DRS) with a homemade fibered bundle system for optical characterization; and Raman depth profiling with a commercial confocal Raman microscope for structural information and for our final objective. For each technique, the obtained results are presented and correlated when possible. A few words are said on our final objective. Raman depth profiles of the multilayered phantoms are distorted by elastic scattering. The signal attenuation through each single layer is directly dependent on its own scattering property. Therefore, determining the optical properties, obtained here with DRS, is crucial to properly correct Raman depth profiles. Thus, it would be permitted to consider quantitative studies on skin for drug permeation follow-up or hydration assessment, for instance.

New multilayer coating using quaternary ammonium chitosan and κ-carrageenan in capillary electrophoresis: application in fast analysis of betaine and methionine.

Science.gov (United States)

Vitali, Luciano; Della Betta, Fabiana; Costa, Ana Carolina O; Vaz, Fernando Antonio Simas; Oliveira, Marcone Augusto Leal; Vistuba, Jacqueline Pereira; Fávere, Valfredo T; Micke, Gustavo A

2014-06-01

The aim of this study was to develop a new multilayer coating with crosslinked quaternary ammonium chitosan (hydroxypropyltrimethyl ammonium chloride chitosan; HACC) and κ-carrageenan for use in capillary electrophoresis. A new semi-permanent multilayer coating was formed using the procedure developed and the method does not require the presence of polymers in the background electrolyte (BGE). The new capillary multilayer coating showed a cathodic electroosmotic flow (EOF) of around 30×10(-9) m(2) V(-1) s(-1) which is pH-independent in the range of pH 2 to 10. The enhanced EOF at low pH obtained contributed significantly to the development of a fast method of separation. The multilayer coating was then applied in the development of a fast separation method to determine betaine and methionine in pharmaceutical formulations by capillary zone electrophoresis (CZE). The BGE used to determine the betaine and methionine concentrations was composed of 10 mmol L(-1) tris(hydroxymethyl) aminomethane, 40 mmol L(-1) phosphoric acid and 10% (v/v) ethanol, at pH 2.1. A fused-silica capillary of 32 cm (50 µm ID×375 µm OD) was used in the experiments and samples and standards were analyzed employing the short-end injection procedure (8.5 cm effective length). The instrumental analysis time of the optimized method was 1.53 min (approx. 39 runs per hour). The validation of the proposed method for the determination of betaine and methionine showed good linearity (R(2)>0.999), adequate limit of detection (LOD <8 mg L(-1)) for the concentration in the samples and inter-day precision values lower than 3.5% (peak area and time migration). The results for the quantification of the amino acids in the samples determined by the CZE-UV method developed were statistically equal to those obtained with the comparative LC-MS/MS method according to the paired t-test with a confidence level of 95%. Copyright © 2014 Elsevier B.V. All rights reserved.

Obtention and characterization of TiO2/TiN multilayers coatings

International Nuclear Information System (INIS)

Goncalves, Andre

2010-01-01

Nano science has emerged in recent years as one of the most important areas for future technological developments, especially in the area of electronic devices. Nanotechnology has an interdisciplinary character which includes knowledge from physics, chemistry, engineering, and biology. This technology is being used in the manufacture of microprocessors, pumps for dose of medicine, and coating materials, among others. The MOCVD technique has been used recently to obtain nanocrystalline coatings, and provide films of better quality than those obtained by conventional CVD or physical methods. Furthermore, the MOCVD technique presents itself as a competitive alternative because it is relatively inexpensive and easy to deploy compared to physical deposition methods. In this work multilayer coatings of TiO 2 /TiN were produced. During the experiment, the opening and closing of the valves of gases admission, requires from the operator manual ability to trigger the valve and controlling the deposition time, which creates the possibility of errors, leading directly into the thickness of each layer. Thus, the need of reducing the influence of the operator, and the possibility of using time intervals of less than a minute in the growths, created the opportunity to develop a computer program to manage the whole system. The software was developed using the 'State machine' concept for the process control and Hardware in the loop simulation. (author)

Advanced materials for multilayer mirrors for extreme ultraviolet solar astronomy.

Science.gov (United States)

Bogachev, S A; Chkhalo, N I; Kuzin, S V; Pariev, D E; Polkovnikov, V N; Salashchenko, N N; Shestov, S V; Zuev, S Y

2016-03-20

We provide an analysis of contemporary multilayer optics for extreme ultraviolet (EUV) solar astronomy in the wavelength ranges: λ=12.9-13.3  nm, λ=17-21  nm, λ=28-33  nm, and λ=58.4  nm. We found new material pairs, which will make new spaceborne experiments possible due to the high reflection efficiencies, spectral resolution, and long-term stabilities of the proposed multilayer coatings. In the spectral range λ=13  nm, Mo/Be multilayer mirrors were shown to demonstrate a better ratio of reflection efficiency and spectral resolution compared with the commonly used Mo/Si. In the spectral range λ=17-21  nm, a new multilayer structure Al/Si was proposed, which had higher spectral resolution along with comparable reflection efficiency compared with the commonly used Al/Zr multilayer structures. In the spectral range λ=30  nm, the Si/B4C/Mg/Cr multilayer structure turned out to best obey reflection efficiency and long-term stability. The B4C and Cr layers prevented mutual diffusion of the Si and Mg layers. For the spectral range λ=58  nm, a new multilayer Mo/Mg-based structure was developed; its reflection efficiency and long-term stability have been analyzed. We also investigated intrinsic stresses inherent for most of the multilayer structures and proposed possibilities for stress elimination.

Durable Corrosion Resistance of Copper Due to Multi-Layer Graphene

Directory of Open Access Journals (Sweden)

Abhishek Tiwari

2017-09-01

Full Text Available Ultra-thin graphene coating has been reported to provide considerable resistance against corrosion during short-term exposures, however, there is great variability in the corrosion resistance due to graphene coating in different studies. It may be possible to overcome the problem of hampered corrosion protection ability of graphene that is caused due to defective single layer graphene by applying multilayer graphene. Systematic electrochemical characterization showed that the multilayer graphene coating developed in the study provided significant corrosion resistance in a chloride solution and the corrosion resistance was sustained for long durations (~400 h, which is attributed to the multilayer graphene.

Improving the oxidation resistance and stability of Ag nanoparticles by coating with multilayered reduced graphene oxide

Science.gov (United States)

Li, Yahui; Zhang, Huayu; Wu, Bowen; Guo, Zhuo

2017-12-01

A kind of coating nanostructure, Ag nanoparticles coated with multilayered reduced graphene oxide (RGO), is fabricated by employing a three-step reduction method in an orderly manner, which is significantly different from the conventional structures that are simply depositing or doping with Ag nanoparticles on RGO via chemical reduction. The as-prepared nanostructure is investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected-area electronic diffraction (SEAD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The results show that the obtained Ag/RGO nanostructure is observed to be a perfect coating structure with well dispersed Ag particles, which is responsible for the remarkable oxidation resistance. The results of XPS spectra indicate the content of metallic Ag is far greater than that of Ag oxides despite of prolonged exposure to the air, which fully demonstrate the excellent stability of thus coating nanostructure.

Engineering tool for the qualification of optical coatings

Science.gov (United States)

Davi, M.; Perrin, D.; Lequime, M.; Doyle, D.

2017-11-01

For the needs of the European Space Agency, SESO is developing in cooperation with the Institut Fresnel an Engineering Tool for the Qualification of Optical Coatings. The goal is to develop a standard methodology for testing the behaviour and stability of optical coatings during the air to vacuum transition. The Engineering Tool is indeed designed to achieve in vacuum reflectance and transmittance measurements between 600 and 1700 nm. It is also designed to evaluate during the vacuum cycle partially the nature of the outgassing elements, using mass spectrometry. We will present in our paper the concept of this equipment and the associated test method. The preliminary characterizations will be done in June 2006 on reflective coatings, one anti reflective coating and dichroic filters.

Reflectivity quenching of ESR multilayer polymer film reflector in optically bonded scintillator arrays

Science.gov (United States)

Loignon-Houle, Francis; Pepin, Catherine M.; Charlebois, Serge A.; Lecomte, Roger

2017-04-01

The 3M-ESR multilayer polymer film is a widely used reflector in scintillation detector arrays. As specified in the datasheet and confirmed experimentally by measurements in air, it is highly reflective (> 98 %) over the entire visible spectrum (400-1000 nm) for all angles of incidence. Despite these outstanding characteristics, it was previously found that light crosstalk between pixels in a bonded LYSO scintillator array with ESR reflector can be as high as ∼30-35%. This unexplained light crosstalk motivated further investigation of ESR optical performance. Analytical simulation of a multilayer structure emulating the ESR reflector showed that the film becomes highly transparent to incident light at large angles when surrounded on both sides by materials of refractive index higher than air. Monte Carlo simulations indicate that a considerable fraction (∼25-35%) of scintillation photons are incident at these leaking angles in high aspect ratio LYSO scintillation crystals. The film transparency was investigated experimentally by measuring the scintillation light transmission through the ESR film sandwiched between a scintillation crystal and a photodetector with or without layers of silicone grease. Strong light leakage, up to nearly 30%, was measured through the reflector when coated on both sides with silicone, thus elucidating the major cause of light crosstalk in bonded arrays. The reflector transparency was confirmed experimentally for angles of incidence larger than 60 ° using a custom designed setup allowing illumination of the bonded ESR film at selected grazing angles. The unsuspected ESR film transparency can be beneficial for detector arrays exploiting light sharing schemes, but it is highly detrimental for scintillator arrays designed for individual pixel readout.

Multilayered analog optical differentiating device: performance analysis on structural parameters.

Science.gov (United States)

Wu, Wenhui; Jiang, Wei; Yang, Jiang; Gong, Shaoxiang; Ma, Yungui

2017-12-15

Analogy optical devices (AODs) able to do mathematical computations have recently gained strong research interest for their potential applications as accelerating hardware in traditional electronic computers. The performance of these wavefront-processing devices is primarily decided by the accuracy of the angular spectral engineering. In this Letter, we show that the multilayer technique could be a promising method to flexibly design AODs according to the input wavefront conditions. As examples, various Si-SiO 2 -based multilayer films are designed that can precisely perform the second-order differentiation for the input wavefronts of different Fourier spectrum widths. The minimum number and thickness uncertainty of sublayers for the device performance are discussed. A technique by rescaling the Fourier spectrum intensity has been proposed in order to further improve the practical feasibility. These results are thought to be instrumental for the development of AODs.

ATHENA optimized coating design

DEFF Research Database (Denmark)

Ferreira, Desiree Della Monica; Christensen, Finn Erland; Jakobsen, Anders Clemen

2012-01-01

The optimization of coating design for the ATHENA mission si described and the possibility of increasing the telescope effective area in the range between 0.1 and 10 keV is investigated. An independent computation of the on-axis effective area based on the mirror design of ATHENA is performed...... in order to review the current coating baseline. The performance of several material combinations, considering a simple bi-layer, simple multilayer and linear graded multilayer coatings are tested and simulation of the mirror performance considering both the optimized coating design and the coating...

Optical characterization of antirelaxation coatings

Science.gov (United States)

Tsvetkov, S.; Gateva, S.; Cartaleva, S.; Mariotti, E.; Nasyrov, K.

2018-03-01

Antirelaxation coatings (ARC) are used in optical cells containing alkali metal vapor to reduce the depolarization of alkali atoms after collisions with the cell walls. The long-lived ground state polarization is a basis for development of atomic clocks, magnetometers, quantum memory, slow light experiments, precision measurements of fundamental symmetries etc. In this work, a simple method for measuring the number of collisions of the alkali atoms with the cell walls without atomic spin randomization (Nasyrov et al., Proc. SPIE (2015)) was applied to characterize the AR properties of two PDMS coatings prepared from different solutions in ether (PDMS 2% and PDMS 5%). We observed influence of the light-induced atomic desorption (LIAD) on the AR properties of coatings.

High Transparent and Conductive TiO2/Ag/TiO2 Multilayer Electrode Films Deposited on Sapphire Substrate

Science.gov (United States)

Loka, Chadrasekhar; Moon, Sung Whan; Choi, YiSik; Lee, Kee-Sun

2018-03-01

Transparent conducting oxides attract intense interests due to its diverse industrial applications. In this study, we report sapphire substrate-based TiO2/Ag/TiO2 (TAT) multilayer structure of indium-free transparent conductive multilayer coatings. The TAT thin films were deposited at room temperature on sapphire substrates and a rigorous analysis has been presented on the electrical and optical properties of the films as a function of Ag thickness. The optical and electrical properties were mainly controlled by the Ag mid-layer thickness of the TAT tri-layer. The TAT films showed high luminous transmittance 84% at 550 nm along with noteworthy low electrical resistance 3.65 × 10-5 Ω-cm and sheet resistance of 3.77 Ω/square, which is better are than those of amorphous ITO films and any sapphire-based dielectric/metal/dielectric multilayer stack. The carrier concentration of the films was increased with respect to Ag thickness. We obtained highest Hackke's figure of merit 43.97 × 10-3 Ω-1 from the TAT multilayer thin film with a 16 nm thick Ag mid-layer.

Precision Optical Coatings for Large Space Telescope Mirrors

Science.gov (United States)

Sheikh, David

This proposal “Precision Optical Coatings for Large Space Telescope Mirrors” addresses the need to develop and advance the state-of-the-art in optical coating technology. NASA is considering large monolithic mirrors 1 to 8-meters in diameter for future telescopes such as HabEx and LUVOIR. Improved large area coating processes are needed to meet the future requirements of large astronomical mirrors. In this project, we will demonstrate a broadband reflective coating process for achieving high reflectivity from 90-nm to 2500-nm over a 2.3-meter diameter coating area. The coating process is scalable to larger mirrors, 6+ meters in diameter. We will use a battery-driven coating process to make an aluminum reflector, and a motion-controlled coating technology for depositing protective layers. We will advance the state-of-the-art for coating technology and manufacturing infrastructure, to meet the reflectance and wavefront requirements of both HabEx and LUVOIR. Specifically, we will combine the broadband reflective coating designs and processes developed at GSFC and JPL with large area manufacturing technologies developed at ZeCoat Corporation. Our primary objectives are to: Demonstrate an aluminum coating process to create uniform coatings over large areas with near-theoretical aluminum reflectance Demonstrate a motion-controlled coating process to apply very precise 2-nm to 5- nm thick protective/interference layers to large areas, Demonstrate a broadband coating system (90-nm to 2500-nm) over a 2.3-meter coating area and test it against the current coating specifications for LUVOIR/HabEx. We will perform simulated space-environment testing, and we expect to advance the TRL from 3 to >5 in 3-years.

Elasto-optics in double-coated optical fibers induced by axial strain and hydrostatic pressure.

Science.gov (United States)

Yang, Yu-Ching; Lee, Haw-Long; Chou, Huann-Ming

2002-04-01

Stresses, microbending loss, and refractive-index changes induced simultaneously by axial strain and hydrostatic pressure in double-coated optical fibers are analyzed. The lateral pressure and normal stresses in the optical fiber, primary coating, and secondary coating are derived. Also presented are the microbending loss and refractive-index changes in the glass fiber. The normal stresses are affected by axial strain, hydrostatic pressure, material properties, and thickness of the primary and secondary coatings. It is found that microbending loss decreases with increasing thickness, the Young's modulus, and the Poisson's ratio of the secondary coating but increases with the increasing Young's modulus and Poisson's ratio of the primary coating. Similarly, changes in refractive index in the glass fiber decrease with the increasing Young's modulus and Poisson's ratio of the secondary coating but increase with the increasing Young's modulus and Poisson's ratio of the primary coating. Therefore, to minimize microbending loss induced simultaneously by axial strain and hydrostatic pressure in the glass fiber, the polymeric coatings should be suitably selected. An optimal design procedure is also indicated.

The effect of irradiation process on the optical fiber coating

Science.gov (United States)

Wang, Zeyu; Xiao, Chun; Rong, Liang; Ji, Wei

2018-03-01

Protective fiber coating decides the mechanical strength of an optical fiber as well as its resistance against the influence of environment, especially in some special areas like irradiation atmospheres. According to the experiment in this paper, it was found that the tensile force and peeling force of resistant radiation optical fiber was improved because of the special optical fiber coating.

Microstructure and interfacial evaluation of Co-based alloy coating on copper by pulsed Nd:YAG multilayer laser cladding

International Nuclear Information System (INIS)

Yan Hua; Wang Aihua; Xu Kaidong; Wang Wenyan; Huang Zaowen

2010-01-01

Laser cladding defect-free coatings on copper is rather difficult. The purpose of this study is to fabricate high quality Co-based alloy coating on copper substrate by laser cladding. Powder preplacement with a thickness of 0.7 mm improves the absorptivity of copper substrate to laser effectively and generates defect-free coating. Microstructures, phase constitutions and wear properties are investigated by means of scanning electronic microscopy (SEM) with X-ray energy dispersive microanalysis (EDX), transmission electron microscopy (TEM) and X-ray diffraction (XRD), as well as dry sliding wear test. Experimental results show that α-Co solution, Cr 23 C 6 , Ni 17 W 3 and Cr 4 Ni 15 W are the main phases in the Co-based coating. The Ni-based solid solutions (α-Co, Ni) and (Ni, Cu) are formed at interface, which generate metallurgical bonding by diffusion between Co-based coating and copper substrate. The average microhardness of the coating is 478HV 0.1 . Wear resistance of copper is significantly improved by laser cladding Co-based alloy multilayer coating.

Nanomechanical Behavior of High Gas Barrier Multilayer Thin Films.

Science.gov (United States)

Humood, Mohammad; Chowdhury, Shahla; Song, Yixuan; Tzeng, Ping; Grunlan, Jaime C; Polycarpou, Andreas A

2016-05-04

Nanoindentation and nanoscratch experiments were performed on thin multilayer films manufactured using the layer-by-layer (LbL) assembly technique. These films are known to exhibit high gas barrier, but little is known about their durability, which is an important feature for various packaging applications (e.g., food and electronics). Films were prepared from bilayer and quadlayer sequences, with varying thickness and composition. In an effort to evaluate multilayer thin film surface and mechanical properties, and their resistance to failure and wear, a comprehensive range of experiments were conducted: low and high load indentation, low and high load scratch. Some of the thin films were found to have exceptional mechanical behavior and exhibit excellent scratch resistance. Specifically, nanobrick wall structures, comprising montmorillonite (MMT) clay and polyethylenimine (PEI) bilayers, are the most durable coatings. PEI/MMT films exhibit high hardness, large elastic modulus, high elastic recovery, low friction, low scratch depth, and a smooth surface. When combined with the low oxygen permeability and high optical transmission of these thin films, these excellent mechanical properties make them good candidates for hard coating surface-sensitive substrates, where polymers are required to sustain long-term surface aesthetics and quality.

Status of Optical Coatings for the National Ignition Facility

International Nuclear Information System (INIS)

Stolz, C J; Weinzapfel, C; Rogowski, G T; Smith, D; Rigatti, A; Oliver, J; Taniguchi, J; Gunten, M von; Bevis, R; Smith, M; Ivan, V

2001-01-01

Optical coatings are a crucial part of the pulse trapping and extraction in the NIF multipass amplifiers. Coatings also steer the 192 beams from four linear arrays to four converging cones entering the target chamber. There are a total of 1600 physical vapor deposited coatings on NIF consisting of 576 mirrors within the multipass cavity, 192 polarizers that work in tandem with a Pockels cell to create an optical switch, and 832 transport mirrors. These optics are of sufficient size so that they are not aperture-limiting for the 40-cm x 40 cm beams over an incident range of 0 to 56.4 degrees. These coatings must withstand laser fluences up to 25 J/cm 2 at 1053 nm (1 ω) and 3-ns pulse length and are the 1ω fluence-limiting component on NIF. The coatings must have a minimal impact on the beam wavefront and phase to maintain beam focusability, minimize scattered loss, and minimize nonlinear damage mechanisms. This is achieved by specifications ranging from 99.5% and >99% for mirrors and polarizers, respectively, and T>98% for polarizers

Multilayer supermirrors: broadband reflection coatings for the 15- to 100-keV range

DEFF Research Database (Denmark)

Joensen, K. D.; Gorenstein, P.; Christensen, Finn Erland

1994-01-01

reflectivity for X-rays. For hard X-rays (>= 15 keV), the absorption, however, is low enough that it is possible to design supermirrors with 10 - 70% reflectivity in a band approximately equals 3 times the width of the total reflection regime. Supermirrors of W/Si and Ni/C have been successfully fabricated...... and characterized. The measured X-ray reflectivities are well accounted for by the standard dynamical theories of multilayer reflection. Hard X-ray applications that could benefit from X-ray supermirror coatings include focusing and imaging instrumentation for astrophysics, and collimating and focusing device...

Sensitivity versus polarisation in multilayer optical thin film design

Directory of Open Access Journals (Sweden)

Efrem K. Ejigu

2012-07-01

Full Text Available The design of a polarised optical filter is more complicated than that of a filter where the polarisation effect does not exist (at a normal angle of incidence. An error in the optical parameters, such as the physical thickness or refractive index of a layer, results in a change in the spectral performance of the multilayer structure. The correlation between error sensitivity and the polarisation effect of light in structures designed at an oblique angle was investigated. To illustrate the correlation, a perpendicular (S and parallel (P polarised beam splitter, at 0.9818 µm central wavelength, designed by genetic algorithm, was used. The beam splitter changes its state of polarisation according to the error in thickness simultaneously induced in each of the layers. The error was calculated by optimising the original design. The observation of the change of the state of polarisation as a result of error sensitivity leads to a different method of designing pure S-polarised or P-polarised optical filters.

Improved wettability and adhesion of polylactic acid/chitosan coating for bio-based multilayer film development

Energy Technology Data Exchange (ETDEWEB)

Gartner, Hunter [School of Packaging, Michigan State University, East Lansing, Michigan (United States); Li, Yana [Mechanical Engineering College, Wuhan Polytechnic University (China); Almenar, Eva, E-mail: ealmenar@msu.edu [School of Packaging, Michigan State University, East Lansing, Michigan (United States)

2015-03-30

Graphical abstract: - Highlights: • Surface tension between PLA/CS blend solution and PLA film modified by MDI. • Better wettability between PLA/CS blend solution and PLA film by increasing MDI. • Increased breaking strength by increasing MDI due to the increased H-bonding. • Increased number of physical entanglements between PLA/CS coating and PLA film. • Development of a suitable bio-based multilayer film for food packaging applications. - Abstract: The objective of this study was to investigate the effect of methyldiphenyl diisocyanate (MDI) concentration (0, 0.2, 1, 2, and 3%) on the wettability and adhesion of blend solutions of poly(lactic acid) (PLA) and chitosan (CS) when coated on PLA film for development of a bio-based multi-layer film suitable for food packaging and other applications. Characterization was carried out by attenuated total reflectance infrared spectrometry (ATR-FTIR), contact angle (θ), mechanical adhesion pull-off testing, and scanning electron microscopy (SEM). The θ of the PLA/CS blend shifted to a lower value (41–35°) with increasing MDI concentration showing that the surface tension was modified between the PLA/CS blend solution and PLA film and better wettability was achieved. The increase in MDI also resulted in an increased breaking strength (228–303 kPa) due to the increased H-bonding resulting from the more urethane groups formed within the PLA/CS blend as shown by ATR-FTIR. The improved adhesion was also shown by the increased number of physical entanglements observed by SEM. It can be concluded that MDI can be used to improve wettability and adhesion between PLA/CS coating and PLA film.

Improved wettability and adhesion of polylactic acid/chitosan coating for bio-based multilayer film development

International Nuclear Information System (INIS)

Gartner, Hunter; Li, Yana; Almenar, Eva

2015-01-01

Graphical abstract: - Highlights: • Surface tension between PLA/CS blend solution and PLA film modified by MDI. • Better wettability between PLA/CS blend solution and PLA film by increasing MDI. • Increased breaking strength by increasing MDI due to the increased H-bonding. • Increased number of physical entanglements between PLA/CS coating and PLA film. • Development of a suitable bio-based multilayer film for food packaging applications. - Abstract: The objective of this study was to investigate the effect of methyldiphenyl diisocyanate (MDI) concentration (0, 0.2, 1, 2, and 3%) on the wettability and adhesion of blend solutions of poly(lactic acid) (PLA) and chitosan (CS) when coated on PLA film for development of a bio-based multi-layer film suitable for food packaging and other applications. Characterization was carried out by attenuated total reflectance infrared spectrometry (ATR-FTIR), contact angle (θ), mechanical adhesion pull-off testing, and scanning electron microscopy (SEM). The θ of the PLA/CS blend shifted to a lower value (41–35°) with increasing MDI concentration showing that the surface tension was modified between the PLA/CS blend solution and PLA film and better wettability was achieved. The increase in MDI also resulted in an increased breaking strength (228–303 kPa) due to the increased H-bonding resulting from the more urethane groups formed within the PLA/CS blend as shown by ATR-FTIR. The improved adhesion was also shown by the increased number of physical entanglements observed by SEM. It can be concluded that MDI can be used to improve wettability and adhesion between PLA/CS coating and PLA film

Deposition and characterisation of multilayer hard coatings. Ti/TiNδ/TiCxNy/(TiC) a-C:H/(Ti) a-C:H

International Nuclear Information System (INIS)

Burinprakhon, T.

2001-02-01

Multilayer hard coatings containing Ti, TiNδ, TiC x N y , (TiC m ) a-C:H, (TiC n ) a-C:H, and (Ti) a-C:H were deposited on commercially pure titanium substrates by using an asymmetric bipolar pulsed-dc reactive magnetron sputtering of a titanium target, with Ar, Ar+N 2 , Ar+N 2 +CH 4 , and Ar+CH 4 gas mixtures. The microstructures, elemental compositions and bonding states of the interlayers and the coating surfaces were studied by using cross-sectional transmission electron microscopy (XTEM), electron energy loss spectroscopy (EELS), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The microstructure development of the multilayer coating was strongly influenced by target poisoning. As a result of the complete poisoning of the titanium target during the deposition of TiNδ and TiC x N y interlayers, the a-C:H interlayers containing graded titanium and nitrogen contents were found to develop successively to the TiC x N y interlayer without the formation of near-stoichiometric TiC. The (TiC m ) a-C:H interlayer consisted of nano-particles of distorted fcc crystal structure embedded in the a-C:H matrix. The (TiC n ) a-C:H and (Ti) a-C:H top layers were found to be a-C:H matrix without nano-particles. In the (Ti) a-C:H top layer there was no measurable amount of Ti observed, regardless of the variation of CH 4 concentration between 37.5 and 60 % flow rate in Ar+-CH4 gas mixture. The top layer (Ti) a-C:H was found to contain approximately 10 atomic % nitrogen, due to N 2 contamination during deposition caused by low conductance of N 2 through the nominally closed valve of the mass flow controller. The change of the CH 4 concentration during deposition of the top layer (Ti) a-C:H, however, showed a strong influence on the hydrogen content. The comparison of the fluorescence background of the Raman spectra revealed that hydrogen-less (Ti) a-C:H was deposited at a CH 4 concentration of less than 50 % flow rate in Ar. The hardness

Multi-layered silicides coating for vanadium alloys for generation IV reactors

International Nuclear Information System (INIS)

Mathieu, S.; Chaia, N.; Vilasi, M.; Le Flem, M.

2012-01-01

The halide-activated pack-cementation technique was employed to fabricate a diffusion coating that is resistant both to isothermal and to cyclic oxidation in air at 650 degrees C on the surface of the V-4Cr-4Ti vanadium alloy that is a potential core component of future nuclear systems. A thermodynamic assessment determined the deposit conditions in terms of master alloy, activator, filler and temperature. The partial pressures of the main gaseous species (SiCl 4 , SiCl 2 and VCl 2 ) in the pack were calculated with the master alloy Si and the mixture VSi 2 + Si. The VSi 2 + Si master alloy was used to limit vanadium loss from the surface. The obtained coating consisted of multi-layered V x Si y silicides with an outer layer of VSi 2 . This silicide developed a protective layer of silica at 650 degrees C in air and was not susceptible to the pest phenomenon, unlike other refractory silicides (MoSi 2 , NbSi 2 ). We suggest that VSi 2 exhibits no risk of rapid degradation in the gas fast reactor (GFR) conditions. (authors)

A wideband optical monitor for a planetary-rotation coating-system

International Nuclear Information System (INIS)

Campanelli, M.B.; Smith, D.J.

1998-01-01

A substrate-specific, through-planet, wideband optical coating monitor is being developed to increase production yield and the understanding of physical vapor deposition (PVD) coatings fabricated in the Optical Manufacturing Laboratory at the University of Rochester's Laboratory for Laser Energetics. In-situ wideband optical monitoring of planetary rotation systems allows direct monitoring of large, expensive substrates with complex layering schemes. The optical monitor discussed here is under development for coating several large (e.g., 80.7 x 41.7 x 9.0 cm) polarizers for the National Ignition Facility. Wideband optical monitoring of the production substrates is used in concert with an array of crystal monitors for process control, film parameter evaluation, and error detection with associated design reoptimization. The geometry of a planetary rotation system, which produces good uniformity across large substrates, makes optical monitoring more difficult. Triggering and timing techniques for data acquisition become key to the process because the optical coating is available only intermittently for monitoring. Failure to properly consider the effects of the system dynamics during data retrieval and processing may result in significant decreases in the spectral data's reliability. Improved data accuracy allows better determination of film thicknesses, indices, and inhomogeneities and enables in-situ error detection for design reoptimization

Multifunctional zirconium nitride/copper multilayer coatings on medical grade 316L SS and titanium substrates for biomedical applications.

Science.gov (United States)

Kumar, D Dinesh; Kaliaraj, Gobi Saravanan

2018-01-01

Protecting from wear and corrosion of many medical devices in the biomedical field is an existing scientific challenge. Surface modification with multilayer ZrN/Cu coating was deposited on medical grade stainless steel (SS) and titanium substrates to enhance their surface properties. Structural results revealed that the ZrN/Cu coatings are highly crystalline and uniform microstructure on both the substrates. Dry and wet tribological measurements of the coated titanium substrate exhibit enhanced wear resistance and low friction coefficient due to the improved microstructure. Similarly, the corrosion resistance was exceptionally improved on titanium substrates, resulting from the high inertness of coating to the SBF electrolyte solution. Antibacterial activity and epifluorescence results signify the effective killing of pathogens by means of ion release killing as well as contact killing mechanisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

VUV Optics Development for the Elettra Storage Ring FEL

CERN Document Server

Guenster, Stefan

2004-01-01

Vacuum ultraviolet optical components for the storage ring FEL at Elettra are under continuous development in the European research consortium EUFELE. Target of the project is the progress to shorter lasing wavelengths in the VUV spectral range. The current status allows lasing with oxide mirror systems down to 190 nm. The main obstacles for the development of optical coatings for shorter wavelengths is the high energetic background of the synchrotron radiation impinging onto the front mirror in the laser cavity. Investigations in single layer systems and multilayer stacks of oxide or fluoride materials demonstrate that fluoride mirrors reach highest reflectivity values down to 140 nm, and oxide coatings possess a satisfactory resistance against the high energetic background irradiation. However, pure oxide multilayer stacks exhibit significant absorption below 190 nm and pure fluoride stacks suffer from strong degradation effects under synchrotron radiation. A solution could be hybrid systems, combining fluo...

Compositionally modulated multilayer diamond-like carbon coatings with AlTiSi multi-doping by reactive high power impulse magnetron sputtering

Science.gov (United States)

Dai, Wei; Gao, Xiang; Liu, Jingmao; Kwon, Se-Hun; Wang, Qimin

2017-12-01

Diamond-like carbon (DLC) coatings with AlTiSi multi-doping were prepared by a reactive high power impulse magnetron sputtering with using a gas mixture of Ar and C2H2 as precursor. The composition, microstructure, compressive stress, and mechanical property of the as-deposited DLC coatings were studied systemically by using SEM, XPS, TEM, Raman spectrum, stress-tester, and nanoindentation as a function of the Ar fraction. The results show that the doping concentrations of the Al, Ti and Si atoms increased as the Ar fraction increased. The doped Ti and Si preferred to bond with C while the doped Al mainly existed in oxidation state without bonding with C. As the doping concentrations increased, TiC carbide nanocrystals were formed in the DLC matrix. The microstructure of coatings changed from an amorphous feature dominant AlTiSi-DLC to a carbide nanocomposite AlTiSi-DLC with TiC nanoparticles embedding. In addition, the coatings exhibited the compositionally modulated multilayer consisting of alternate Al-rich layer and Al-poor layer due to the rotation of the substrate holder and the diffusion behavior of the doped Al which tended to separate from C and diffuse towards the DLC matrix surface owing to its weak interactions with C. The periodic Al-rich layer can effectively release the compressive stress of the coatings. On the other hand, the hard TiC nanoparticles were conducive to the hardness of the coatings. Consequently, the DLC coatings with relatively low residual stress and high hardness could be acquired successfully through AlTiSi multi-doping. It is believed that the AlCrSi multi-doping may be a good way for improving the comprehensive properties of the DLC coatings. In addition, we believe that the DLC coatings with Al-rich multilayered structure have a high oxidation resistance, which allows the DLC coatings application in high temperature environment.

Development of high-index optical coating for security holograms

Science.gov (United States)

Ahmed, Nadir A. G.

2000-10-01

Over the past few years security holograms have grown into a complex business to prevent counterfeiting of security cards, banknotes and the like. Rapid advances in holographic technology have led to a growing requirement for optical materials and coating methods to produce such holograms at reasonable costs. These materials have specific refractive indices and are used to fabricate semi- transparent holograms. The present paper describes a coating process to deposit optical coating on flexible films inside a vacuum web metallizer for the production of high quality semi-transparent holograms.

Determination and analysis of non-linear index profiles in electron-beam-deposited MgOAl2O3ZrO2 ternary composite thin-film optical coatings

International Nuclear Information System (INIS)

Sahoo, N.K.; Thakur, S.; Senthilkumar, M.; Das, N.C.

2005-01-01

Thickness-dependent index non-linearity in thin films has been a thought provoking as well as intriguing topic in the field of optical coatings. The characterization and analysis of such inhomogeneous index profiles pose several degrees of challenges to thin-film researchers depending upon the availability of relevant experimental and process-monitoring-related information. In the present work, a variety of novel experimental non-linear index profiles have been observed in thin films of MgOAl 2 O 3 ZrO 2 ternary composites in solid solution under various electron-beam deposition parameters. Analysis and derivation of these non-linear spectral index profiles have been carried out by an inverse-synthesis approach using a real-time optical monitoring signal and post-deposition transmittance and reflection spectra. Most of the non-linear index functions are observed to fit polynomial equations of order seven or eight very well. In this paper, the application of such a non-linear index function has also been demonstrated in designing electric-field-optimized high-damage-threshold multilayer coatings such as normal- and oblique-incidence edge filters and a broadband beam splitter for p-polarized light. Such designs can also advantageously maintain the microstructural stability of the multilayer structure due to the low stress factor of the non-linear ternary composite layers. (orig.)

Optically transparent, superhydrophobic, biocompatible thin film coatings and methods for producing same

Energy Technology Data Exchange (ETDEWEB)

Armstrong, Beth L.; Aytug, Tolga; Paranthaman, Mariappan Parans; Simpson, John T.; Hillesheim, Daniel A.; Trammell, Neil E.

2017-09-05

An optically transparent, hydrophobic coating, exhibiting an average contact angle of at least 100 degrees with a drop of water. The coating can be produced using low-cost, environmentally friendly components. Methods of preparing and using the optically transparent, hydrophobic coating.

Contact damage and fracture micromechanisms of multilayered TiN/CrN coatings at micro- and nano-length scales

International Nuclear Information System (INIS)

Roa, J.J.; Jiménez-Piqué, E.; Martínez, R.; Ramírez, G.; Tarragó, J.M.

2014-01-01

In this study, systematic nanomechanical and micromechanical studies have been conducted in three multilayer TiN/CrN systems with different bilayer periods (8, 19 and 25 nm). Additionally, experimental work has been performed on corresponding TiN and CrN single layers, for comparison purposes. The investigation includes the use of different indenter tip geometries as well as contact loading conditions (i.e. indentation/scratch) such to induce different stress field and damage scenarios within the films. The surface and subsurface damage under the different indentation imprints and scratch tracks have been observed by atomic force microscopy, field emission scanning electron microscopy and focused ion beam. Multilayer TiN/CrN coated systems are found to exhibit higher adhesion strength (under sliding contact load) and cracking resistance (under spherical indentation) than those coated with reference TiN and CrN monolayers. The main reason behind these findings is the effective development of microstructurally-driven deformation and cracking resistant micromechanisms: rotation of columnar grains (and associated distortion of bilayer period) and crack deflection of interlayer thickness length scale, respectively. - Highlights: • Nanomechanical and micromechanical study in TiN/CrN systems • TiN/CrN coated systems exhibit higher adhesion strength and cracking resistance. • Main deformation and cracking micromechanisms: columnar grain rotation and crack deflection

Contact damage and fracture micromechanisms of multilayered TiN/CrN coatings at micro- and nano-length scales

Energy Technology Data Exchange (ETDEWEB)

Roa, J.J., E-mail: joan.josep.roa@upc.edu [CIEFMA — Departament de Ciència dels Materials i Eng. Metallúrgica, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona (Spain); CRnE, Universitat Politècnica de Catalunya, C. Pasqual i Vila 15, 08028 Barcelona (Spain); Jiménez-Piqué, E. [CIEFMA — Departament de Ciència dels Materials i Eng. Metallúrgica, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona (Spain); CRnE, Universitat Politècnica de Catalunya, C. Pasqual i Vila 15, 08028 Barcelona (Spain); Martínez, R. [Centro de Ingeniería Avanzada de Superfícies, Asociación de la Industria Navarra — AIN, Crta. Pamplona, 1, Edificio AIN, 31191 Cordovilla (Spain); Ramírez, G. [CIEFMA — Departament de Ciència dels Materials i Eng. Metallúrgica, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona (Spain); Fundació CTM Centre Tecnològic, Avda. Bases de Manresa 1, 08243 Manresa (Spain); Tarragó, J.M. [CIEFMA — Departament de Ciència dels Materials i Eng. Metallúrgica, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona (Spain); CRnE, Universitat Politècnica de Catalunya, C. Pasqual i Vila 15, 08028 Barcelona (Spain); and others

2014-11-28

In this study, systematic nanomechanical and micromechanical studies have been conducted in three multilayer TiN/CrN systems with different bilayer periods (8, 19 and 25 nm). Additionally, experimental work has been performed on corresponding TiN and CrN single layers, for comparison purposes. The investigation includes the use of different indenter tip geometries as well as contact loading conditions (i.e. indentation/scratch) such to induce different stress field and damage scenarios within the films. The surface and subsurface damage under the different indentation imprints and scratch tracks have been observed by atomic force microscopy, field emission scanning electron microscopy and focused ion beam. Multilayer TiN/CrN coated systems are found to exhibit higher adhesion strength (under sliding contact load) and cracking resistance (under spherical indentation) than those coated with reference TiN and CrN monolayers. The main reason behind these findings is the effective development of microstructurally-driven deformation and cracking resistant micromechanisms: rotation of columnar grains (and associated distortion of bilayer period) and crack deflection of interlayer thickness length scale, respectively. - Highlights: • Nanomechanical and micromechanical study in TiN/CrN systems • TiN/CrN coated systems exhibit higher adhesion strength and cracking resistance. • Main deformation and cracking micromechanisms: columnar grain rotation and crack deflection.

Design and fabrication of anti-reflection coating on Gallium Phosphide, Zinc Selenide and Zinc Sulfide substrates for visible and infrared application

Directory of Open Access Journals (Sweden)

Mokrý P.

2013-05-01

Full Text Available Results of design and fabrication of a dual-band anti-reflection coating on a gallium phosphide (GaP, zinc selenide (ZnSe and zinc sulfide (ZnS substrates are presented. A multilayer stack structure of antireflection coatings made of zinc sulfide and yttrium fluoride (YF3 was theoretically designed for optical bands between 0.8 and 0.9 μm and between 9.5 and 10.5 μm. This stack was designed as efficient for these materials (GaP, ZnS, ZnSe together. Multilayer stack structure was deposited using thermal evaporation method. Theoretically predicted transmittance spectra were compared with transmitted spectra measured on coated substrates. Efficiency of anti-reflection coating is estimated and discrepancies are analyzed and discussed.

Tantalum-based multilayer coating on cobalt alloys in total hip and knee replacement

Energy Technology Data Exchange (ETDEWEB)

Balagna, C., E-mail: cristina.balagna@polito.it [Institute of Materials Engineering and Physics, Applied Science and Technology Department, Politecnico di Torino, Corso Duca degli Abruzzi 24,10129 Torino (Italy); Faga, M.G. [Istituto di Scienza e Tecnologia dei Materiali Ceramici, Consiglio Nazionale delle Ricerche, Strada delle Cacce 73, 10135 Torino (Italy); Spriano, S. [Institute of Materials Engineering and Physics, Applied Science and Technology Department, Politecnico di Torino, Corso Duca degli Abruzzi 24,10129 Torino (Italy)

2012-05-01

Cobalt-chromium-molybdenum (CoCrMo) alloys are widely used in total hip and knee joint replacement, due to high mechanical properties and resistance to wear and corrosion. They are able to form efficient artificial joints by means of coupling metal-on-polymer or metal-on-metal contacts. However, a high concentration of stress and direct friction between surfaces leads to the formation of polyethylene wear debris and the release of toxic metal ions into the human body, limiting, as a consequence, the lifetime of implants. The aim of this research is a surface modification of CoCrMo alloys in order to improve their biocompatibility and to decrease the release of metal ions and polyethylene debris. Thermal treatment in molten salts was the process employed for the deposition of tantalum-enriched coating. Tantalum and its compounds are considered biocompatible materials with low ion release and high corrosion resistance. Three different CoCrMo alloys were processed as substrates. An adherent coating of about 1 {mu}m of thickness, with a multilayer structure consisting of two tantalum carbides and metallic tantalum was deposited. The substrates and modified layers were characterized by means of structural, chemical and morphological analysis. Moreover nanoindentation, scratch and tribological tests were carried out in order to evaluate the mechanical behavior of the substrates and coating. The hardness of the coated samples increases more than double than the untreated alloys meanwhile the presence of the coating reduced the wear volume and rate of about one order of magnitude. - Highlights: Black-Right-Pointing-Pointer Thermal treatment in molten salts deposits a Ta-based coating on Co-based alloys. Black-Right-Pointing-Pointer Coating is composed by one or two tantalum carbides and/or metallic tantalum. Black-Right-Pointing-Pointer The coating structure depends on thermal temperature and substrates carbon content. Black-Right-Pointing-Pointer Coating is able to

Sensitivity to contamination of optical coatings

International Nuclear Information System (INIS)

Macleod, A.

1999-01-01

A simple theory is presented of the sensitivity to contamination of optical coatings, which permits prediction of performance degradation in the presence of small deposit s of absorbing material. Although a major objective is the ability to compare the sensitivities of different coating types, absolute values can be made possible by adopting a standard contamination layer consisting of a 1 Angstrom thickness of carbon. Results are quoted for a number of common thin-film coatings and filters and are sometimes surprising. The common high-reflectance coating is the quarterwave stack and, at its reference wavelength, it has very low sensitivity to contamination. Although minor constructional errors have little effect on the reflectance, they can seriously affect the contamination sensitivity. Further, the level of contamination determines the maximum reflectance it is possible to achieve, regardless of the number of layers in the coating. The admittance diagram helps in understanding the reasons for the very large variations in sensitivity between coatings with quite similar reflectance

Optimization of Broadband Optical Response of Multilayer Nanospheres

Science.gov (United States)

2012-07-27

D. Levit , P. Nordlander, and N. J. Halas, “Nanosphere-in-a-nanoshell: A simple nanomatryushka,” J. Phys. Chem. C 114, 7378–7383 (2010). #169722...metal nanoparticles coated with a dye j-aggregate monolayer,” Quantum Electron. 40, 246–248 (2010). 1. Introduction Nanoparticles with strong optical

Preliminary coating design and coating developments for ATHENA

DEFF Research Database (Denmark)

Jakobsen, Anders Clemen; Ferreira, Desiree Della Monica; Christensen, Finn Erland

2011-01-01

We present initial novel coating design for ATHENA. We make use of both simple bilayer coatings of Ir and B4C and more complex constant period multilayer coatings to enhance the effective area and cover the energy range from 0.1 to 10 keV. We also present the coating technology used...... for these designs and present test results from coatings....

Improved rate control for electron-beam evaporation and evaluation of optical performance improvements.

Science.gov (United States)

Gevelber, Michael; Xu, Bing; Smith, Douglas

2006-03-01

A new deposition-rate-control and electron-beam-gun (e-gun) strategy was developed that significantly reduces the growth-rate variations for e-beam-deposited SiO2 coatings. The resulting improvements in optical performance are evaluated for multilayer bandpass filters. The adverse effect of uneven silica-source depletion on coating spectral performances during long deposition runs is discussed.

X-ray photoelectron spectroscopy of nano-multilayered Zr-O/Al-O coatings deposited by cathodic vacuum arc plasma

International Nuclear Information System (INIS)

Zhitomirsky, V.N.; Kim, S.K.; Burstein, L.; Boxman, R.L.

2010-01-01

Nano-multilayered Zr-O/Al-O coatings with alternating Zr-O and Al-O layers having a bi-layer period of 6-7 nm and total coating thickness of 1.0-1.2 μm were deposited using a cathodic vacuum arc plasma process on rotating Si substrates. Plasmas generated from two cathodes, Zr and Al, were deposited simultaneously in a mixture of Ar and O 2 background gases. The Zr-O/Al-O coatings, as well as bulk ZrO 2 and Al 2 O 3 reference samples, were studied using X-ray photoelectron spectroscopy (XPS). The XPS spectra were analyzed on the surface and after sputtering with a 4 kV Ar + ion gun. High resolution angle resolved spectra were obtained at three take-off angles: 15 o , 45 o and 75 o relative to the sample surface. It was shown that preferential sputtering of oxygen took place during XPS of bulk reference ZrO 2 samples, producing ZrO and free Zr along with ZrO 2 in the XPS spectra. In contrast, no preferential sputtering was observed with Al 2 O 3 reference samples. The Zr-O/Al-O coatings contained a large amount of free metals along with their oxides. Free Zr and Al were observed in the coating spectra both before and after sputtering, and thus cannot be due solely to preferential sputtering. Transmission electron microscopy revealed that the Zr-O/Al-O coatings had a nano-multilayered structure with well distinguished alternating layers. However, both of the alternating layers of the coating contained of a mixture of aluminum and zirconium oxides and free Al and Zr metals. The concentration of Zr and Al changed periodically with distance normal to the coating surface: the Zr maximum coincided with the Al minimum and vice versa. However the concentration of Zr in both alternating layers was significantly larger than that of Al. Despite the large free metal concentration, the Knoop hardness, 21.5 GPa, was relatively high, which might be attributed to super-lattice formation or formation of a metal-oxide nanocomposite within the layers.

Investigation of multilayer X-ray optics for 6 keV to 20 keV energy range

Czech Academy of Sciences Publication Activity Database

Oberta, Peter; Platonov, Y.; Flechsig, U.

2012-01-01

Roč. 19, č. 5 (2012), s. 675-681 ISSN 0909-0495 Institutional research plan: CEZ:AV0Z10100522 Keywords : X-ray optics * multilayer * energy resolution Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.186, year: 2012 http://journals.iucr.org/s/issues/2012/05/00/issconts.html

Design of a high-efficiency grazing incidence monochromator with multilayer-coated laminar gratings for the 1-6 keV region

International Nuclear Information System (INIS)

Koike, Masato; Ishino, Masahiko; Sasai, Hiroyuki

2006-01-01

A grazing incidence objective monochromator consisting of a spherical mirror, a varied-line-spacing plane grating with multilayered coating, a movable plane multilayered mirror, and a fixed exit slit for the 1-6 keV region has been designed. The included angle at the grating was chosen to satisfy the grating equation and extended Bragg condition simultaneously. The aberration was corrected by means of a hybrid design method. A spectral resolving power of ∼600-∼6000 and a throughput of ∼2%-∼40% is expected for the monochromator when used in an undulator beamline

High color fidelity thin film multilayer systems for head-up display use

Science.gov (United States)

Tsou, Yi-Jen D.; Ho, Fang C.

1996-09-01

Head-up display is gaining increasing access in automotive vehicles for indication and position/navigation purposes. An optical combiner, which allows the driver to receive image information from outside and inside of the automobile, is the essential part of this display device. Two multilayer thin film combiner coating systems with distinctive polarization selectivity and broad band spectral neutrality are discussed. One of the coating systems was designed to be located at the lower portion of the windshield. The coating reduced the exterior glare by approximately 45% and provided about 70% average see-through transmittance in addition to the interior information display. The other coating system was designed to be integrated with the sunshield located at the upper portion of the windshield. The coating reflected the interior information display while reducing direct sunlight penetration to 25%. Color fidelity for both interior and exterior images were maintained in both systems. This facilitated the display of full-color maps. Both coating systems were absorptionless and environmentally durable. Designs, fabrication, and performance of these coating systems are addressed.

Optically transparent, superhydrophobic methyltrimethoxysilane based silica coatings without silylating reagent

International Nuclear Information System (INIS)

Kavale, Mahendra S.; Mahadik, D.B.; Parale, V.G.; Wagh, P.B.; Gupta, Satish C.; Rao, A.Venkateswara; Barshilia, Harish C.

2011-01-01

The superhydrophobic surfaces have drawn lot of interest, in both academic and industries because of optically transparent, adherent and self-cleaning behavior. Surface chemical composition and morphology plays an important role in determining the superhydrophobic nature of coating surface. Such concert of non-wettability can be achieved, using surface modifying reagents or co-precursor method in sol-gel process. Attempts have been made to increase the hydrophobicity and optical transparency of methyltrimethoxysilane (MTMS) based silica coatings using polymethylmethacrylate (PMMA) instead of formal routes like surface modification using silylating reagents. The optically transparent, superhydrophobic uniform coatings were obtained by simple dip coating method. The molar ratio of MTMS:MeOH:H 2 O was kept constant at 1:5.63:1.58, respectively with 0.5 M NH 4 F as a catalyst and the weight percent of PMMA varied from 1 to 8. The hydrophobicity of silica coatings was analyzed by FTIR and contact angle measurements. These substrates exhibited 91% optical transmittance as compared to glass and water drop contact angle as high as 171 ± 1 deg. The effect of humidity on hydrophobic nature of coating has been studied by exposing these films at relative humidity of 90% at constant temperature of 30 deg. C for a period of 45 days. The micro-structural studies carried out by transmission electron microscopy (TEM).

Spin coating and plasma process for 2.5D integrated photonics on multilayer polymers

International Nuclear Information System (INIS)

Zebda, A.; Camberlein, L.; Beche, B.; Gaviot, E.; Beche, E.; Duval, D.; Zyss, J.; Jezequel, G.; Solal, F.; Godet, C.

2008-01-01

Polymer spin coating, surface plasma treatment and selective UV-lithography processes have been developed to realize 2.5D photonic micro-resonators, made of disk- or ring-shaped upper rib waveguides, using common polymers such as SU8 (biphenol A ether glycidyl), PS233 (polymeric silane) and SOG (siloxane Spin on Glass). Both oxygen and argon plasma treatments, applied to PS233 and SOG before spin-coating the SU8, improve substantially the grip of multilayer devices (SU8 / PS233 or SU8 / SOG). Surface energy components derived from contact angle measurements have been used to optimize the processing conditions. In such integrated photonic devices, the both single-electromagnetic-modes called transverse electric (TE 00 ) and transverse magnetic (TM 00 ) have been excited in a SU8 micro-disk, with a single mode propagation strongly localized near the edge of the disk (i.e. the so called whispering gallery modes)

Oxidation protection of multilayer CVD SiC/B/SiC coatings for 3D C/SiC composite

International Nuclear Information System (INIS)

Liu Yongsheng; Cheng Laifei; Zhang Litong; Wu Shoujun; Li Duo; Xu Yongdong

2007-01-01

A CVD boron coating was introduced between two CVD SiC coating layers. EDS and XRD results showed that the CVD B coating was a boron crystal without other impurity elements. SEM results indicated that the CVD B coating was a flake-like or column-like crystal with a compact cross-section. The crack width in the CVD SiC coating deposited on CVD B is smaller than that in a CVD SiC coating deposited on CVD SiC coating. After oxidation at 700 deg. C and 1000 deg. C, XRD results indicated that the coating was covered by product B 2 O 3 or B 2 O 3 .xSiO 2 film. The cracks were sealed as observed by SEM. There was a large amount of flake-like material on hybrid coating surface after oxidation at 1300 deg. C. Oxidation weight loss and residual flexural strength results showed that hybrid SiC/B/SiC multilayer coating provided better oxidation protection for C/SiC composite than a three layer CVD SiC coating at temperatures from 700 deg. C to 1000 deg. C for 600 min, but worse oxidation protection above 1000 deg. C due to the large amount of volatilization of B 2 O 3 or B 2 O 3 .xSiO 2

Correlation of optical properties with the fractal microstructure of black molybdenum coatings

Energy Technology Data Exchange (ETDEWEB)

Barrera, Enrique; Gonzalez, Federico [Area de Energia, Division de Ciencias Basicas e Ingenieria, Universidad Autonoma Metropolitana-Iztapalapa, Apartado Postal 55-534, Mexico, D.F. 09340 (Mexico); Rodriguez, Eduardo [Area de Computacion y Sistemas, Division de Ciencias Basicas e Ingenieria, Universidad Autonoma Metropolitana-Iztapalapa, Apartado Postal 55-534, Mexico, D.F. 09340 (Mexico); Alvarez-Ramirez, Jose, E-mail: jjar@xanum.uam.mx [Area de Energia, Division de Ciencias Basicas e Ingenieria, Universidad Autonoma Metropolitana-Iztapalapa, Apartado Postal 55-534, Mexico, D.F. 09340 (Mexico)

2010-01-01

Coating is commonly used for improving the optical properties of surfaces for solar collector applications. The coating morphology depends on the deposition conditions, and this determines the final optical characteristics. Coating morphologies are irregular and of fractal nature, so a suitable approach for its characterization should use methods borrowed from fractal analysis. The aim of this work is to study the fractal characteristics of black molybdenum coatings on copper and to relate the fractal parameters to the optical properties. To this end, coating surfaces were prepared via immersion in a solution of ammonium paramolybdate for different deposition periods. The fractal analysis was carried out for SEM and AFM images of the coating surface and the fractal properties were obtained with a recently developed high-dimensional extension of the well-known detrended fluctuation analysis (DFA). The most salient parameter drawn from the application of the DFA is the Hurst index, a parameter related to the roughness of the coating surface, and the multifractality index, which is related to the non-linearity features of the coating morphology. The results showed that optical properties, including absorptance and emittance, are decreasing functions of the Hurst and multifractality indices. This suggests that coating surfaces with high absorptance and emittance values are related to complex coating morphologies conformed within a non-linear structure.

Fabrication of anticorrosive multilayer onto magnesium alloy substrates via spin-assisted layer-by-layer technique

Energy Technology Data Exchange (ETDEWEB)

Cai Kaiyong, E-mail: Kaiyong_cai@cqu.edu.cn [Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Sui Xiaojing; Hu Yan [Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Zhao Li [China National Centre for Biotechnology Development, No. 16, Xi Si Huan Zhong Lu, Haidian District, Beijing 100036 (China); Lai Min; Luo Zhong; Liu Peng; Yang Weihu [Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China)

2011-12-01

To improve the corrosion resistance of magnesium alloy, we reported a novel approach for the fabrication of anticorrosive multilayers onto AZ91D substrates. The multilayers were composed of poly(ethylene imine) (PEI), poly(styrene sulfonate) (PSS) and 8-hydroxyquinoline (8HQ). They were deposited onto AZ91D substrates via a spin-assisted layer-by-layer (LbL) technique. The multilayered structure was stabilized with glutaraldehyde (GA) as crossing linker. It was confirmed by Fourier transform infrared spectroscopy (FT-IR). Surface morphologies and elemental compositions of the formed anticorrosive multilayers were characterized with scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The corrosion performance of the multilayer coated AZ91D substrates was characterized by hydrogen evolution. The results of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements suggested that the multilayered coating improved the corrosion resistance of AZ91D substrates. In vitro study revealed that the multilayered coating was cytocompatible. The study provides a potential alternative for the fabrication of corrosion resistant magnesium alloy-based implants. Highlights: {yields} Corrosion protective multilayers have been constructed onto AZ91D substrates via layer by layer technique. {yields} The multilayered structured containing 8-hydroxyquinoline highly improves the corrosion resistance of AZ91D substrates. {yields} The novel multilayered coating is potentially important for developing corrosion resistant magnesium alloy-based implants.

Fabrication of anticorrosive multilayer onto magnesium alloy substrates via spin-assisted layer-by-layer technique

International Nuclear Information System (INIS)

Cai Kaiyong; Sui Xiaojing; Hu Yan; Zhao Li; Lai Min; Luo Zhong; Liu Peng; Yang Weihu

2011-01-01

To improve the corrosion resistance of magnesium alloy, we reported a novel approach for the fabrication of anticorrosive multilayers onto AZ91D substrates. The multilayers were composed of poly(ethylene imine) (PEI), poly(styrene sulfonate) (PSS) and 8-hydroxyquinoline (8HQ). They were deposited onto AZ91D substrates via a spin-assisted layer-by-layer (LbL) technique. The multilayered structure was stabilized with glutaraldehyde (GA) as crossing linker. It was confirmed by Fourier transform infrared spectroscopy (FT-IR). Surface morphologies and elemental compositions of the formed anticorrosive multilayers were characterized with scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The corrosion performance of the multilayer coated AZ91D substrates was characterized by hydrogen evolution. The results of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements suggested that the multilayered coating improved the corrosion resistance of AZ91D substrates. In vitro study revealed that the multilayered coating was cytocompatible. The study provides a potential alternative for the fabrication of corrosion resistant magnesium alloy-based implants. Highlights: → Corrosion protective multilayers have been constructed onto AZ91D substrates via layer by layer technique. → The multilayered structured containing 8-hydroxyquinoline highly improves the corrosion resistance of AZ91D substrates. → The novel multilayered coating is potentially important for developing corrosion resistant magnesium alloy-based implants.

In Vivo Expansion of Melanoma-Specific T Cells Using Microneedle Arrays Coated with Immune-Polyelectrolyte Multilayers.

Science.gov (United States)

Zeng, Qin; Gammon, Joshua M; Tostanoski, Lisa H; Chiu, Yu-Chieh; Jewell, Christopher M

2017-02-13

Microneedles (MNs) are micron-scale polymeric or metallic structures that offer distinct advantages for vaccines by efficiently targeting skin-resident immune cells, eliminating injection-associated pain, and improving patient compliance. These advantages, along with recent studies showing therapeutic benefits achieved using traditional intradermal injections in human cancer patients, suggest MN delivery might enhance cancer vaccines and immunotherapies. We recently developed a new class of polyelectrolyte multilayers based on the self-assembly of model peptide antigens and molecular toll-like receptor agonists (TLRa) into ultrathin, conformal coatings. Here, we reasoned that these immune polyelectrolyte multilayers (iPEMs) might be a useful platform for assembling cancer vaccine components on MN arrays for intradermal delivery from these substrates. Using conserved human melanoma antigens and a potent TLRa vaccine adjuvant, CpG, we show that iPEMs can be assembled on MNs in an automated fashion. These films, prepared with up to 128 layers, are approximately 200 nm thick but provide cancer vaccine cargo loading >225 μg/cm 2 . In cell culture, iPEM cargo released from MNs is internalized by primary dendritic cells, promotes activation of these cells, and expands T cells during coculture. In mice, application of iPEM-coated MNs results in the codelivery of tumor antigen and CpG through the skin, expanding tumor-specific T cells during initial MN applications and resulting in larger memory recall responses during a subsequent booster MN application. This study support MNs coated with PEMs built from tumor vaccine components as a well-defined, modular system for generating tumor-specific immune responses, enabling new approaches that can be explored in combination with checkpoint blockade or other combination cancer therapies.

Optical Fiber Sensors Based on Nanoparticle-Embedded Coatings

Directory of Open Access Journals (Sweden)

Aitor Urrutia

2015-01-01

Full Text Available The use of nanoparticles (NPs in scientific applications has attracted the attention of many researchers in the last few years. The use of NPs can help researchers to tune the physical characteristics of the sensing coating (thickness, roughness, specific area, refractive index, etc. leading to enhanced sensors with response time or sensitivity better than traditional sensing coatings. Additionally, NPs also offer other special properties that depend on their nanometric size, and this is also a source of new sensing applications. This review focuses on the current status of research in the use of NPs within coatings in optical fiber sensing. Most used sensing principles in fiber optics are briefly described and classified into several groups: absorbance-based sensors, interferometric sensors, fluorescence-based sensors, fiber grating sensors, and resonance-based sensors, among others. For each sensor group, specific examples of the utilization of NP-embedded coatings in their sensing structure are reported.

Optical phonons in PbTe/CdTe multilayer heterostructures

Energy Technology Data Exchange (ETDEWEB)

Novikova, N. N.; Yakovlev, V. A. [Russian Academy of Sciences, Institute for Spectroscopy (Russian Federation); Kucherenko, I. V., E-mail: kucheren@sci.lebedev.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Karczewski, G. [Polish Academy of Sciences, Institute of Physics (Poland); Aleshchenko, Yu. A.; Muratov, A. V.; Zavaritskaya, T. N.; Melnik, N. N. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

2015-05-15

The infrared reflection spectra of PbTe/CdTe multilayer nanostructures grown by molecular-beam epitaxy are measured in the frequency range of 20–5000 cm{sup −1} at room temperature. The thicknesses and high-frequency dielectric constants of the PbTe and CdTe layers and the frequencies of the transverse optical (TO) phonons in these structures are determined from dispersion analysis of the spectra. It is found that the samples under study are characterized by two TO phonon frequencies, equal to 28 and 47 cm{sup −1}. The first frequency is close to that of TO phonons in bulk PbTe, and the second is assigned to the optical mode in structurally distorted interface layers. The Raman-scattering spectra upon excitation with the radiation of an Ar{sup +} laser at 514.5 nm are measured at room and liquid-nitrogen temperatures. The weak line at 106 cm{sup −1} observed in these spectra is attributed to longitudinal optical phonons in the interface layers.

Reflective and antireflective coatings for the optical chain of the ASTRI SST-2M prototype

Science.gov (United States)

Bonnoli, Giacomo; Canestrari, Rodolfo; Catalano, Osvaldo; Pareschi, Giovanni; Perri, Luca; Stringhetti, Luca

2013-09-01

ASTRI is a Flagship Project of the Italian Ministry of Education, University and Research, led by the Italian National Institute of Astrophysics, INAF. One of the main aims of the ASTRI Project is the design, construction and on-field verification of a dual mirror (2M) end-to-end prototype for the Small Size Telescope (SST) envisaged to become part of the Cherenkov Telescope Array. The ASTRI SST-2M prototype is designed according to the Schwarzschild-Couder optical scheme, and adopts a camera based on Silicon Photo Multipliers (SiPM); it will be assembled at the INAF astronomical site of Serra La Nave on mount Etna (Catania, Italy) in the second half of 2014, and will start scientific validation phase soon after. With its 4m wide primary dish, the telescope will be sensitive to multi-TeV Very High Energy (VHE) gamma rays up to 100 TeV and above, with a point spread function of ~2 arcminutes and a wide (semiaperture 4.8°) corrected field of view. The peculiarities of the optical design and of the SiPM bandpass pushed towards specifically optimized choices in terms of reflective coatings for both the primary and the secondary mirror. Fully dielectric multi-layer coatings have been developed and tested as an option for the primary mirror, aiming to filter out the large Night Sky Background contamination at wavelengths λ>~700 nm. On the other hand, for the large monolithic secondary mirror a simpler design with quartz-overcoated aluminium has been optimized for incidences far from normality. The conformation of the ASTRI camera in turn pushed towards the design of a reimaging system based on thin pyramidal light guides, that could be optionally integrated in the focal surface, aiming to increase the fill factor. An anti-reflective coating optimized for a wide range of incident angles faraway from normality was specifically developed to enhance the UV-optical transparency of these elements. The issues, strategy, simulations and experimental results are thoroughly

Double-layer optical fiber coating analysis in MHD flow of an elastico-viscous fluid using wet-on-wet coating process

Directory of Open Access Journals (Sweden)

Zeeshan Khan

Full Text Available Modern optical fibers require a double-layer coating on the glass fiber in order to provide protection from signal attenuation and mechanical damage. The most important plastic resins used in wires and optical fibers are plastic polyvinyl chloride (PVC and low and high density polyethylene (LDPE/HDPE, nylon and Polysulfone. One of the most important things which affect the final product after processing is the design of the coating die. In the present study, double-layer optical fiber coating is performed using melt polymer satisfying Oldroyd 8-constant fluid model in a pressure type die with the effect of magneto-hydrodynamic (MHD. Wet-on-wet coating process is applied for double-layer optical fiber coating. The coating process in the coating die is modeled as a simple two-layer Couette flow of two immiscible fluids in an annulus with an assigned pressure gradient. Based on the assumptions of fully developed laminar and MHD flow, the Oldroyd 8-constant model of non-Newtonian fluid of two immiscible resin layers is modeled. The governing nonlinear equations are solved analytically by the new technique of Optimal Homotopy Asymptotic Method (OHAM. The convergence of the series solution is established. The results are also verified by the Adomian Decomposition Method (ADM. The effect of important parameters such as magnetic parameter Mi, the dilatant constant α, the Pseodoplastic constant β, the radii ratio δ, the pressure gradient Ω, the speed of fiber optics V, and the viscosity ratio κ on the velocity profiles, thickness of coated fiber optics, volume flow rate, and shear stress on the fiber optics are investigated. At the end the result of the present work is also compared with the experimental results already available in the literature by taking non-Newtonian parameters tends to zero. Keywords: Non-Newtonian fluid, Oldroyd 8-constant fluid, MHD flow, Double-layer fiber coating, OHAM, ADM, Wet-on-wet coating process

Single shot damage mechanism of Mo/Si multilayer optics under intense pulsed XUV-exposure

Czech Academy of Sciences Publication Activity Database

Khorsand, A.R.; Sobierajski, R.; Louis, E.; Bruijn, S.; van Hattum, E.D.; van de Kruijs, R.W.E.; Jurek, M.; Klinger, D.; Pelka, J. B.; Juha, Libor; Burian, Tomáš; Chalupský, Jaromír; Cihelka, Jaroslav; Hájková, Věra; Vyšín, Luděk; Jastrow, U.; Stojanovic, N.; Toleikis, S.; Wabnitz, H.; Tiedtke, K.; Sokolowski-Tinten, K.; Shymanovich, U.; Krzywinski, J.; Hau-Riege, S.; London, R.; Gleeson, A.; Gullikson, E.M.; Bijkerk, F.

2010-01-01

Roč. 18, č. 2 (2010), 700-712 ISSN 1094-4087 R&D Projects: GA AV ČR KAN300100702; GA MŠk LC510; GA MŠk(CZ) LC528; GA MŠk LA08024; GA AV ČR IAA400100701 Institutional research plan: CEZ:AV0Z10100523 Keywords : laser damage * thermal effects * multilayers * optical design and fabrication * free-electron lasers Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.749, year: 2010

Coating Thin Mirror Segments for Lightweight X-ray Optics

Science.gov (United States)

Chan, Kai-Wing; Sharpe, Marton V.; Zhang, William; Kolosc, Linette; Hong, Melinda; McClelland, Ryan; Hohl, Bruce R.; Saha, Timo; Mazzarellam, James

2013-01-01

Next generations lightweight, high resolution, high throughput optics for x-ray astronomy requires integration of very thin mirror segments into a lightweight telescope housing without distortion. Thin glass substrates with linear dimension of 200 mm and thickness as small as 0.4 mm can now be fabricated to a precision of a few arc-seconds for grazing incidence optics. Subsequent implementation requires a distortion-free deposition of metals such as iridium or platinum. These depositions, however, generally have high coating stresses that cause mirror distortion. In this paper, we discuss the coating stress on these thin glass mirrors and the effort to eliminate their induced distortion. It is shown that balancing the coating distortion either by coating films with tensile and compressive stresses, or on both sides of the mirrors is not sufficient. Heating the mirror in a moderately high temperature turns out to relax the coated films reasonably well to a precision of about a second of arc and therefore provide a practical solution to the coating problem.

Wedged multilayer Laue lens

International Nuclear Information System (INIS)

Conley, Ray; Liu Chian; Qian Jun; Kewish, Cameron M.; Macrander, Albert T.; Yan Hanfei; Maser, Joerg; Kang, Hyon Chol; Stephenson, G. Brian

2008-01-01

A multilayer Laue lens (MLL) is an x-ray focusing optic fabricated from a multilayer structure consisting of thousands of layers of two different materials produced by thin-film deposition. The sequence of layer thicknesses is controlled to satisfy the Fresnel zone plate law and the multilayer is sectioned to form the optic. An improved MLL geometry can be created by growing each layer with an in-plane thickness gradient to form a wedge, so that every interface makes the correct angle with the incident beam for symmetric Bragg diffraction. The ultimate hard x-ray focusing performance of a wedged MLL has been predicted to be significantly better than that of a nonwedged MLL, giving subnanometer resolution with high efficiency. Here, we describe a method to deposit the multilayer structure needed for an ideal wedged MLL and report our initial deposition results to produce these structures

ZnO/Cu/ZnO multilayer films: Structure optimization and investigation on photoelectric properties

International Nuclear Information System (INIS)

Liu Xiaoyu; Li Yingai; Liu Shi; Wu Honglin; Cui Haining

2012-01-01

A series of ZnO/Cu/ZnO multilayer films has been fabricated from zinc and copper metallic targets by simultaneous RF and DC magnetron sputtering. Numerical simulation of the optical properties of the multilayer films has been carried out in order to guide the experimental work. The influences of the ZnO and Cu layer thicknesses, and of O 2 /Ar ratio on the photoelectric and structural properties of the films were investigated. The optical and electrical properties of the multilayers were studied by optical spectrometry and four point probe measurements, respectively. The structural properties were investigated using X-ray diffraction. The performance of the multilayers as transparent conducting coatings was compared using a figure of merit. In experiments, the thickness of the ZnO layers was varied between 4 and 70 nm and those of Cu were between 8 and 37 nm. The O 2 /Ar ratios range from 1:5 to 2:1. Low sheet resistance and high transmittance were obtained when the film was prepared using an O 2 /Ar ratio of 1:4 and a thickness of ZnO (60 nm)/Cu (15 nm)/ZnO (60 nm). - Highlights: ► ZnO/Cu/ZnO films were fabricated from zinc and copper targets by sputtering. ► Transmittance reaches maximum when top and bottom ZnO thicknesses are nearly equal. ► Sheet resistance increases with increasing ZnO layer thickness. ► Variation in sheet resistance with oxygen/argon ratio is due to interface effect.

The electrochemical synthesis and corrosion behaviour of TiO2/poly(indole-co-aniline multilayer coating: Experimental and theoretical approach

Directory of Open Access Journals (Sweden)

Serap Toprak Döşlü

2018-01-01

Full Text Available The aim of this study was to protect stainless steel against corrosion via poly (indole-co-aniline with the help of titanium dioxide pre-coating. Different monomer ratios (1:1 and 1:9 were applied in order to determine the suitable chain composition to synthesize the copolymer in lithium perchlorate containing acetonitrile. The structures, morphologies, electrochemical properties and corrosion resistances of the mono and multi-layer coatings were investigated by Fourier-transform infrared spectra, scanning electron microscope, energy dispersive X-ray spectrometer, electrochemical impedance spectroscopy and anodic polarization. Furthermore the geometric structure and electronic properties of indole, aniline, and indole-co-aniline (dimmer molecules have been investigated by quantum calculations. The results indicated that corrosion protection of copolymers was increased via titanium dioxide pre-coating. The 1:1 copolymer coating showed better corrosion prevention than 1:9 coating. The correlation was determined between experimental and theoretical parameters.

Ni-P/Zn-Ni compositionally modulated multilayer coatings - Part 2: Corrosion and protection mechanisms

Science.gov (United States)

Bahadormanesh, Behrouz; Ghorbani, Mohammad

2018-06-01

The Ni-P/Zn-Ni compositionally modulated multilayer coatings CMMCs were electrodeposited from a single bath by switching the deposition current density. The corrosion resistance of the deposits was studied and compared with that of monolayers of Ni-P and Zn-Ni alloys via Tafel polarization, EIS and salt spray tests. Characterization of corrosion products by means of EDS and XRD revealed more details from the corrosion mechanism of the monolayers and multilayers. The corrosion current density of Ni-P/Zn-Ni CMMCs were around one tenth of Zn-Ni monolayer. The CMMC with incomplete layers performed lower polarization resistance and higher corrosion current density compared to the CMMC with complete layers. The electrical circuit that was proposed for modeling the corrosion process based on the EIS spectrum, proved that layering reduces the porosity and consequently improves the barrier properties. Although, layering of Zn-Ni layers with Ni-P deposits increased the time to red rust in salt spray test, the time for white rust formation decreased. The corrosion mechanism of both Zn-Ni and Ni-P (containing small amount of Zn) was preferential dissolution of Zn and the corrosion products were comprised of mainly Zn hydroxychloride and Zn hydroxycarbonate. Also, Ni and P did not take part in the corrosion products. Based on the electrochemical character of the layers and the morphology of the corroded surface, the corrosion mechanism of multilayers was discussed.

W/SiC X-ray multilayers optimized for use above 100 keV

DEFF Research Database (Denmark)

Windt, D.L.; Dongey, S.; Hailey, C.J.

2002-01-01

-derived optical constants, which we determined from reflectance-vs-incidence angle measurements also made using synchrotron radiation, in the range E=120 - 180 keV. We describe our experimental investigation in detail, compare the new W/SiC multilayers with both W/Si and W/B4C films that have been studied......We have developed a new depth-graded multilayer system comprising W and SiC layers, suitable for use as hard X-ray reflective coatings operating in the energy range 100 - 200 keV. Grazing incidence X-ray reflectance at E=8 keV was used to characterize the interface widths, as well as the temporal...... and thermal stability in both periodic and depth-graded W/SiC structures, while synchrotron radiation was used to measure the hard X-ray reflectance of a depth-graded multilayer designed specifically for use in the range Esimilar to150 - 170 keV. We have modeled the hard X-ray reflectance using newly...

W/SiC x-ray multilayers optimized for use above 100 keV

DEFF Research Database (Denmark)

Windt, D.L.; Donguy, S.; Hailey, C.J.

2003-01-01

optical constants, which we determined from reflectance versus incidence angle measurements also made using synchrotron radiation, in the range E = 120-180 keV. We describe our experimental investigation in detail, compare the new W/SiC multilayers with both W/Si and W/B4C films that have been studied......We have developed a new depth-graded multilayer system comprising W and SiC layers, suitable for use as hard x-ray reflective coatings operating in the energy range 100-200 keV. Grazing-incidence x-ray reflectance at E = 8 keV was used to characterize the interface widths, as well as the temporal...... and thermal stability in both periodic and depth-graded W/SiC structures, whereas synchrotron radiation was used to measure the hard x-ray reflectance of a depth-graded multilayer designed specifically for use in, the range Esimilar to150-170 keV. We have modeled the hard x-ray reflectance using newly derived...

Reference Architecture for Multi-Layer Software Defined Optical Data Center Networks

Directory of Open Access Journals (Sweden)

Casimer DeCusatis

2015-09-01

Full Text Available As cloud computing data centers grow larger and networking devices proliferate; many complex issues arise in the network management architecture. We propose a framework for multi-layer; multi-vendor optical network management using open standards-based software defined networking (SDN. Experimental results are demonstrated in a test bed consisting of three data centers interconnected by a 125 km metropolitan area network; running OpenStack with KVM and VMW are components. Use cases include inter-data center connectivity via a packet-optical metropolitan area network; intra-data center connectivity using an optical mesh network; and SDN coordination of networking equipment within and between multiple data centers. We create and demonstrate original software to implement virtual network slicing and affinity policy-as-a-service offerings. Enhancements to synchronous storage backup; cloud exchanges; and Fibre Channel over Ethernet topologies are also discussed.

Enhancement of surface mechanical properties by using TiN[BCN/BN] n/c-BN multilayer system

Science.gov (United States)

Moreno, H.; Caicedo, J. C.; Amaya, C.; Muñoz-Saldaña, J.; Yate, L.; Esteve, J.; Prieto, P.

2010-11-01

The aim of this work is to improve the mechanical properties of AISI 4140 steel substrates by using a TiN[BCN/BN] n/c-BN multilayer system as a protective coating. TiN[BCN/BN] n/c-BN multilayered coatings via reactive r.f. magnetron sputtering technique were grown, systematically varying the length period ( Λ) and the number of bilayers ( n) because one bilayer ( n = 1) represents two different layers ( tBCN + tBN), thus the total thickness of the coating and all other growth parameters were maintained constant. The coatings were characterized by Fourier transform infrared spectroscopy showing bands associated with h-BN bonds and c-BN stretching vibrations centered at 1400 cm -1 and 1100 cm -1, respectively. Coating composition and multilayer modulation were studied via secondary ion mass spectroscopy. Atomic force microscopy analysis revealed a reduction in grain size and roughness when the bilayer number ( n) increased and the bilayer period decreased. Finally, enhancement of mechanical properties was determined via nanoindentation measurements. The best behavior was obtained when the bilayer period ( Λ) was 80 nm ( n = 25), yielding the relative highest hardness (˜30 GPa) and elastic modulus (230 GPa). The values for the hardness and elastic modulus are 1.5 and 1.7 times greater than the coating with n = 1, respectively. The enhancement effects in multilayered coatings could be attributed to different mechanisms for layer formation with nanometric thickness due to the Hall-Petch effect; because this effect, originally used to explain increased hardness with decreasing grain size in bulk polycrystalline metals, has also been used to explain hardness enhancements in multilayered coatings taking into account the thickness reduction at individual single layers that make up the multilayered system. The Hall-Petch model based on dislocation motion within layered and across layer interfaces has been successfully applied to multilayered coatings to explain this

Enhancement of surface mechanical properties by using TiN[BCN/BN]n/c-BN multilayer system

International Nuclear Information System (INIS)

Moreno, H.; Caicedo, J.C.; Amaya, C.; Munoz-Saldana, J.; Yate, L.; Esteve, J.; Prieto, P.

2010-01-01

The aim of this work is to improve the mechanical properties of AISI 4140 steel substrates by using a TiN[BCN/BN] n /c-BN multilayer system as a protective coating. TiN[BCN/BN] n /c-BN multilayered coatings via reactive r.f. magnetron sputtering technique were grown, systematically varying the length period (Λ) and the number of bilayers (n) because one bilayer (n = 1) represents two different layers (t BCN + t BN ), thus the total thickness of the coating and all other growth parameters were maintained constant. The coatings were characterized by Fourier transform infrared spectroscopy showing bands associated with h-BN bonds and c-BN stretching vibrations centered at 1400 cm -1 and 1100 cm -1 , respectively. Coating composition and multilayer modulation were studied via secondary ion mass spectroscopy. Atomic force microscopy analysis revealed a reduction in grain size and roughness when the bilayer number (n) increased and the bilayer period decreased. Finally, enhancement of mechanical properties was determined via nanoindentation measurements. The best behavior was obtained when the bilayer period (Λ) was 80 nm (n = 25), yielding the relative highest hardness (∼30 GPa) and elastic modulus (230 GPa). The values for the hardness and elastic modulus are 1.5 and 1.7 times greater than the coating with n = 1, respectively. The enhancement effects in multilayered coatings could be attributed to different mechanisms for layer formation with nanometric thickness due to the Hall-Petch effect; because this effect, originally used to explain increased hardness with decreasing grain size in bulk polycrystalline metals, has also been used to explain hardness enhancements in multilayered coatings taking into account the thickness reduction at individual single layers that make up the multilayered system. The Hall-Petch model based on dislocation motion within layered and across layer interfaces has been successfully applied to multilayered coatings to explain this

New generation all-silica based optical elements for high power laser systems

Science.gov (United States)

Tolenis, T.; GrinevičiÅ«tÄ--, L.; Melninkaitis, A.; Selskis, A.; Buzelis, R.; MažulÄ--, L.; Drazdys, R.

2017-08-01

Laser resistance of optical elements is one of the major topics in photonics. Various routes have been taken to improve optical coatings, including, but not limited by, materials engineering and optimisation of electric field distribution in multilayers. During the decades of research, it was found, that high band-gap materials, such as silica, are highly resistant to laser light. Unfortunately, only the production of anti-reflection coatings of all-silica materials are presented to this day. A novel route will be presented in materials engineering, capable to manufacture high reflection optical elements using only SiO2 material and GLancing Angle Deposition (GLAD) method. The technique involves the deposition of columnar structure and tailoring the refractive index of silica material throughout the coating thickness. A numerous analysis indicate the superior properties of GLAD coatings when compared with standard methods for Bragg mirrors production. Several groups of optical components are presented including anti-reflection coatings and Bragg mirrors. Structural and optical characterisation of the method have been performed and compared with standard methods. All researches indicate the possibility of new generation coatings for high power laser systems.

Electrically driven ion separations and nanofiltration through membranes coated with polyelectrolyte multilayers

Science.gov (United States)

White, Nicholas

Polyelectrolyte multilayer (PEM) films deposited using the layer-by-layer (LBL) method are attractive for their simple deposition, tailorable nature, scalability, and charge or size-based selectivity for solutes. This dissertation explores ion separations in electrodialysis (ED) and solute removal through nanofiltration with PEMs deposited on polymer membranes. ED membranes typically exhibit modest selectivities between monovalent and divalent ions. In contrast, this work shows that K+/Mg 2+ ED selectivities reach values >1000 when using Nafion 115 cation-exchange membranes coated with multilayer poly(4-styrenesulfonate) (PSS)/protonated poly(allylamine) (PAH) films. For comparison, the corresponding K+ /Mg2+ selectivity of bare Nafion 115 is salt concentrations, the K+ transference number approaches unity and the K+/Mg2+ selectivity is >20,000, presumably because the applied current is below the limiting value for K+ and H+ transport is negligible at this high K+ concentration. The high selectivities of these membranes may enable electrodialysis applications such as purification of salts that contain divalent or trivalent ions. The high ED selectivities of (PAH/PSS)5PAH-coated Nafion membranes translate to separations with Li+/Co2+ and K +/La3+. Even with adsorption of only 3 polyelectrolyte layers, Nafion membranes exhibit a Li+/Co2+ selectivity >23. However, the resistance to monovalent-ion passage does not decrease significantly with fewer polyelectrolyte layers. At overlimiting currents, hydroxides from water splitting form insoluble metal hydroxides to foul the membrane. With 0.1 M source-phase salt concentrations, transference numbers for monovalent cations approach unity and selectivities are >5000 because the diffusion-limited K+ or Li+ currents exceed the applied current. However, ED selectivities gradually decline with time. Thus, future research should aim to increase membrane stability and limiting currents to fully exploit the remarkable selectivity

APPLYING PRINCIPAL COMPONENT ANALYSIS, MULTILAYER PERCEPTRON AND SELF-ORGANIZING MAPS FOR OPTICAL CHARACTER RECOGNITION

Directory of Open Access Journals (Sweden)

Khuat Thanh Tung

2016-11-01

Full Text Available Optical Character Recognition plays an important role in data storage and data mining when the number of documents stored as images is increasing. It is expected to find the ways to convert images of typewritten or printed text into machine-encoded text effectively in order to support for the process of information handling effectively. In this paper, therefore, the techniques which are being used to convert image into editable text in the computer such as principal component analysis, multilayer perceptron network, self-organizing maps, and improved multilayer neural network using principal component analysis are experimented. The obtained results indicated the effectiveness and feasibility of the proposed methods.

Ferroelectric properties of PZT/BFO multilayer thin films prepared using the sol-gel method.

Science.gov (United States)

Jo, Seo-Hyeon; Lee, Sung-Gap; Lee, Young-Hie

2012-01-05

In this study, Pb(Zr0.52Ti0.48)O3/BiFeO3 [PZT/BFO] multilayer thin films were fabricated using the spin-coating method on a Pt(200 nm)/Ti(10 nm)/SiO2(100 nm)/p-Si(100) substrate alternately using BFO and PZT metal alkoxide solutions. The coating-and-heating procedure was repeated several times to form the multilayer thin films. All PZT/BFO multilayer thin films show a void-free, uniform grain structure without the presence of rosette structures. The relative dielectric constant and dielectric loss of the six-coated PZT/BFO [PZT/BFO-6] thin film were approximately 405 and 0.03%, respectively. As the number of coatings increased, the remanent polarization and coercive field increased. The values for the BFO-6 multilayer thin film were 41.3 C/cm2 and 15.1 MV/cm, respectively. The leakage current density of the BFO-6 multilayer thin film at 5 V was 2.52 × 10-7 A/cm2.

Modelling single shot damage thresholds of multilayer optics for high-intensity short-wavelength radiation sources

NARCIS (Netherlands)

Loch, R.A.; Sobierajski, R.; Louis, Eric; Bosgra, J.; Bosgra, J.; Bijkerk, Frederik

2012-01-01

The single shot damage thresholds of multilayer optics for highintensity short-wavelength radiation sources are theoretically investigated, using a model developed on the basis of experimental data obtained at the FLASH and LCLS free electron lasers. We compare the radiation hardness of commonly

Magnesium Diboride thin Films, multilayers, and coatings for SRF cavities

Energy Technology Data Exchange (ETDEWEB)

Xi, Xiaoxing [Temple Univ., Philadelphia, PA (United States)

2017-08-17

Superconducting radio frequency (SRF) cavities currently use low-temperature superconductor niobium, and the Nb SRF cavities have approached the performance levels predicted theoretically. Compared to Nb, MgB₂ becomes superconducting at a much higher temperature and promises a better RF performance in terms of higher quality factor Q and higher acceleration capability. An MgB₂ SRF technology can significantly reduce the operating costs of particle accelerators when these potentials are realized. This project aimed to advance the development of an MgB₂ SRF technology. It had two main objectives: (1) materials issues of MgB₂ thin films and multilayers related to their applications in SRF cavities; and (2) coating single-cell cavities for testing at RF frequencies. The key technical thrust of the project is the deposition of high quality clean MgB₂ films and coatings by the hybrid physical-chemical vapor deposition (HPCVD) technique, which was developed in my group. We have achieved technical progress in each of the two areas. For the first objective, we have confirmed that MgB₂ thin film coatings can be used to effectively enhance the vortex penetration field of an SRF cavity. A vortex is a normal region in the shape of spaghetti that threads through a superconductor. Its existence is due to an applied magnetic field that is greater than a so-called lower critical field, H_c1. Once a vortex enters the superconductor, its movement leads to loss. This has been shown to be the reason for an SRF cavity to break down. Thus, enhancing the magnetic field for a vortex to enter the superconductor that forms the SRF cavity has be a goal of intense research. To this end, Gurevich proposed that a coating of thin superconductor layer can impede the vortex entrance. In this project, we have done two important experiment to test this concept. One, we showed that the enhancement of H_c1 can be

Magneto-optical and magnetic properties in a Co/Pd multilayered thin film

Energy Technology Data Exchange (ETDEWEB)

Nwokoye, Chidubem A. [Institute for Magnetics Research, Department of Electrical and Computer Engineering, The George Washington University, DC 20052 (United States); Naval Air Systems Command, Avionics, Sensors and E*Warfare Department, Patuxent River, MD 20670 (United States); Bennett, Lawrence H., E-mail: lbennett@gwu.edu [Institute for Magnetics Research, Department of Electrical and Computer Engineering, The George Washington University, DC 20052 (United States); Della Torre, Edward, E-mail: edt@gwu.edu [Institute for Magnetics Research, Department of Electrical and Computer Engineering, The George Washington University, DC 20052 (United States); Ghahremani, Mohammadreza [Institute for Magnetics Research, Department of Electrical and Computer Engineering, The George Washington University, DC 20052 (United States); Narducci, Frank A. [Naval Air Systems Command, Avionics, Sensors and E*Warfare Department, Patuxent River, MD 20670 (United States)

2017-01-01

The paper describes investigation of ferromagnetism at low temperatures. We explored the magneto-optical properties, influenced by photon–magnon interactions, of a ferromagnetic Co/Pd multilayered thin film below and above the magnon Bose–Einstein Condensation (BEC) temperature. Analyses of SQUID and MOKE low temperature experimental results reveal a noticeable phase transition in both magnetic and magneto-optical properties of the material at the BEC temperature. - Highlights: • The results show the effect of a non-zero chemical potential on the magnetization. • The MOKE and SQUID results show a phase transition point at the same temperature. • Magnon BEC is a major influence of the observed phase transition temperature.

Optimizations of Pt/SiC and W/Si multilayers for the Nuclear Spectroscopic Telescope Array

DEFF Research Database (Denmark)

Madsen, K. K.; Harrison, F. A.; Mao, P. H.

2009-01-01

function to control the shape of the desired effective area. The NuSTAR multilayers are depth graded with a power-law, di = a/(b + i)c, and we optimize over the total number of bi-layers, N, c, and the maximum bi-layer thickness, dmax. The result is a 10 mirror group design optimized for a flat even energy......The Nuclear Spectroscopic Telescope Array, NuSTAR, is a NASA funded Small Explorer Mission, SMEX, scheduled for launch in mid 2011. The spacecraft will fly two co-aligned conical approximation Wolter-I optics with a focal length of 10 meters. The mirrors will be deposited with Pt/SiC and W....../Si multilayers to provide a broad band reflectivity from 6 keV up to 78.4 keV. To optimize the mirror coating we use a Figure of Merit procedure developed for gazing incidence optics, which averages the effective area over the energy range, and combines an energy weighting function with an angular weighting...

Continuous blade coating for multi-layer large-area organic light-emitting diode and solar cell

Science.gov (United States)

Chen, Chun-Yu; Chang, Hao-Wen; Chang, Yu-Fan; Chang, Bo-Jie; Lin, Yuan-Sheng; Jian, Pei-Siou; Yeh, Han-Cheng; Chien, Hung-Ta; Chen, En-Chen; Chao, Yu-Chiang; Meng, Hsin-Fei; Zan, Hsiao-Wen; Lin, Hao-Wu; Horng, Sheng-Fu; Cheng, Yen-Ju; Yen, Feng-Wen; Lin, I.-Feng; Yang, Hsiu-Yuan; Huang, Kuo-Jui; Tseng, Mei-Rurng

2011-11-01

A continuous roll-to-roll compatible blade-coating method for multi-layers of general organic semiconductors is developed. Dissolution of the underlying film during coating is prevented by simultaneously applying heating from the bottom and gentle hot wind from the top. The solvent is immediately expelled and reflow inhibited. This method succeeds for polymers and small molecules. Uniformity is within 10% for 5 cm by 5 cm area with a mean value of tens of nanometers for both organic light-emitting diode (OLED) and solar cell structure with little material waste. For phosphorescent OLED 25 cd/A is achieved for green, 15 cd/A for orange, and 8 cd/A for blue. For fluorescent OLED 4.3 cd/A is achieved for blue, 9 cd/A for orange, and 6.9 cd/A for white. For OLED with 2 cm by 3 cm active area, the luminance variation is within 10%. Power conversion efficiency of 4.1% is achieved for polymer solar cell, similar to spin coating using the same materials. Very-low-cost and high-throughput fabrication of efficient organic devices is realized by the continuous blade-only method.

Failure Analysis of Multilayered Suspension Plasma-Sprayed Thermal Barrier Coatings for Gas Turbine Applications

Science.gov (United States)

Gupta, M.; Markocsan, N.; Rocchio-Heller, R.; Liu, J.; Li, X.-H.; Östergren, L.

2018-02-01

Improvement in the performance of thermal barrier coatings (TBCs) is one of the key objectives for further development of gas turbine applications. The material most commonly used as TBC topcoat is yttria-stabilized zirconia (YSZ). However, the usage of YSZ is limited by the operating temperature range which in turn restricts the engine efficiency. Materials such as pyrochlores, perovskites, rare earth garnets are suitable candidates which could replace YSZ as they exhibit lower thermal conductivity and higher phase stability at elevated temperatures. The objective of this work was to investigate different multilayered TBCs consisting of advanced topcoat materials fabricated by suspension plasma spraying (SPS). The investigated topcoat materials were YSZ, dysprosia-stabilized zirconia, gadolinium zirconate, and ceria-yttria-stabilized zirconia. All topcoats were deposited by TriplexPro-210TM plasma spray gun and radial injection of suspension. Lifetime of these samples was examined by thermal cyclic fatigue and thermal shock testing. Microstructure analysis of as-sprayed and failed specimens was performed with scanning electron microscope. The failure mechanisms in each case have been discussed in this article. The results show that SPS could be a promising route to produce multilayered TBCs for high-temperature applications.

Fiber Optic pH Sensor with Self-Assembled Polymer Multilayer Nanocoatings

OpenAIRE

Shao, Li-Yang; Yin, Ming-Jie; Tam, Hwa-Yaw; Albert, Jacques

2013-01-01

A fiber-optic pH sensor based on a tilted fiber Bragg grating (TFBG) with electrostatic self-assembly multilayer sensing film is presented. The pH sensitive polymeric film, poly(diallyldimethylammonium chloride) (PDDA) and poly(acrylic acid) (PAA) was deposited on the circumference of the TFBG with the layer-by-layer (LbL) electrostatic self-assembly technique. The PDDA/PAA film exhibits a reduction in refractive index by swelling in different pH solutions. This effect results in wavelength s...

The Impedance of Multi-layer Vacuum Chambers

CERN Document Server

Vos, L

2003-01-01

Many components of the LHC vacuum chamber have multi-layered walls : the copper coated cold beam screen, the titanium coated ceramic chamber of the dump kickers, the ceramic chamber of the injection kickers coated with copper stripes, only to name a few. Theories and computer programs are available for some time already to evaluate the impedance of these elements. Nevertheless, the algorithm developed in this paper is more convenient in its application and has been used extensively in the design phase of multi-layer LHC vacuum chamber elements. It is based on classical transmission line theory. Closed expressions are derived for simple layer configurations, while beam pipes involving many layers demand a chain calculation. The algorithm has been tested with a number of published examples and was verified with experimental data as well.

Ultra-short-period W/B₄C multilayers for x-ray optics-microstructure limits on reflectivity

Energy Technology Data Exchange (ETDEWEB)

Walton, Christopher Charles [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering

1997-12-01

Multilayer thin films are used as Bragg reflectors for soft x-rays in the energy range 50eV < E < 1000eV in many x-ray optics applications such as x-ray microscopes and telescopes, reducing optics for extreme ultraviolet (EUV) lithography, and x-ray polarizers and phase retarders. Applications often depend critically on reflectivity, which has not been systematically characterized for multilayer periods below 20Å. For this study, W/B₄C multilayers were fabricated by magnetron sputtering on Si(111), with periods from 48Å to as little as 4.7Å. The x-ray reflectivity measured at λ = 1.54Å and at 45° incidence (289 eV < E < 860 eV) was found to decrease sharply for multilayer periods less than 15-20Å. Examination by high-resolution transmission electron microscopy (HRTEM) showed an expansion of the thickness of the W-rich layers of 30-40% from the nominal values, consistent with intermixture of the two materials during sputter growth, and discontinuous W-rich layers for multilayer periods below about 15Å. The experimental data for the specular reflectivity in the hard and soft x-ray regimes and the diffuse scattering fit well to a model of multilayer roughness. The model is expressed as a power-law dependence of roughness on spatial frequency. Analysis of small-angle scattering in transmission from multilayers grown on freestanding Si₃N₄ membranes confirms the onset of discontinuity at periods between 14Å and 22Å. Spectroscopy studies by x-ray absorption (NEXAFS) and electron energy loss (EELS) at the boron K-edge (188eV) are consistent with changes in the average boron bonding environment, as the multilayer period decreases and the W-rich layers are increasingly thin and dispersed. A discrete W-rich phase is present for periods at least as small as 6.3Å.

Inorganic-organic nanocomposites for optical coatings

Science.gov (United States)

Schmidt, Helmut K.; Krug, Herbert; Sepeur-Zeitz, Bernhard; Geiter, Elisabeth

1997-10-01

The fabrication of nanoparticles by the sol-gel process and their use in polymeric or sol-gel-derived inorganic-organic composite matrices opens up interesting possibilities for designing new optical materials. Two different routes have been chosen for preparing optical nanocomposites: The first is the so-called 'in situ route,' where the nanoparticles are synthesized in a liquid mixture from Zr-alkoxides in a polymerizable system and diffractive gratings were produced by embossing uncured film. The second is the 'separate' preparation route, where a sterically stabilized dry nanoboehmite powder was completely redispersed in an epoxy group-containing matrix and hard coatings with optical quality on polycarbonate were prepared.

Optical Design of COATLI: A Diffraction-Limited Visible Imager with Fast Guiding and Active Optics Correction

Science.gov (United States)

Fuentes-Fernández, J.; Cuevas, S.; Watson, A. M.

2018-04-01

We present the optical design of COATLI, a two channel visible imager for a comercial 50 cm robotic telescope. COATLI will deliver diffraction-limited images (approximately 0.3 arcsec FWHM) in the riz bands, inside a 4.2 arcmin field, and seeing limited images (approximately 0.6 arcsec FWHM) in the B and g bands, inside a 5 arcmin field, by means of a tip-tilt mirror for fast guiding, and a deformable mirror for active optics, both located on two optically transferred pupil planes. The optical design is based on two collimator-camera systems plus a pupil transfer relay, using achromatic doublets of CaF2 and S-FTM16 and one triplet of N-BK7 and CaF2. We discuss the effciency, tolerancing, thermal behavior and ghosts. COATLI will be installed at the Observatorio Astronómico Nacional in Sierra San Pedro Mártir, Baja California, Mexico, in 2018.

Development of hybrid organic-inorganic optical coatings to prevent laser damage

International Nuclear Information System (INIS)

Compoint, Francois

2015-01-01

The optical devices (lents, mirrors, portholes...) that are set on the chains of the Laser Megajoule (LMJ) may be damaged by the high energy laser beam especially around the UV wavelength of 351 nm. The damages are micronic craters on the rear of the optics that grows exponentially after each laser shots. The study aims at developing some optical thin coatings on the rear of the optical substrates to prevent the growth of the damage by amortizing the laser shock wave, self-healing the craters that has appeared, or repairing the laser hole after the damage occurs. The thin coatings have been prepared by a sol-gel method by using silica precursor and a polydimethylsiloxane (PDMS) elastomer. The two species reacted together to get a hybrid organic-inorganic Ormosil (organically modified silica) material, by creating a silica network linked to the PDMS species with covalent and hydrogen bounds. The thin layers are obtained from the sol-gel solution by using a dip and spin coating method. The coatings have an excellent optical transmission around the UV (351 nm) wavelength. They also have some self-healing properties by using mechanical (viscoelastic) mechanism and chemical reversible hydrogen bounds action in the materials. The silica-PDMS coatings prove to be resistant to the laser beam at 351 nm, despite some optimizations that still need to be done to reach the sought laser damage threshold. (author) [fr

An Optically Driven Bistable Janus Rotor with Patterned Metal Coatings.

Science.gov (United States)

Zong, Yiwu; Liu, Jing; Liu, Rui; Guo, Honglian; Yang, Mingcheng; Li, Zhiyuan; Chen, Ke

2015-11-24

Bistable rotation is realized for a gold-coated Janus colloidal particle in an infrared optical trap. The metal coating on the Janus particles are patterned by sputtering gold on a monolayer of closely packed polystyrene particles. The Janus particle is observed to stably rotate in an optical trap. Both the direction and the rate of rotation can be experimentally controlled. Numerical calculations reveal that the bistable rotation is the result of spontaneous symmetry breaking induced by the uneven curvature of the coating patterns on the Janus sphere. Our results thus provide a simple method to construct large quantities of fully functional rotary motors for nano- or microdevices.

Structural, optical and electrical properties of silicon nanocrystals embedded in SixC1−x/SiC multilayer systems for photovoltaic applications

International Nuclear Information System (INIS)

López-Vidrier, J.; Hernández, S.; Samà, J.; Canino, M.; Allegrezza, M.; Bellettato, M.; Shukla, R.; Schnabel, M.; Löper, P.; López-Conesa, L.; Estradé, S.; Peiró, F.; Janz, S.; Garrido, B.

2013-01-01

Highlights: ► We study the structural, optical and electrical properties of Si x C 1−x /SiC multilayers with different Si excess. ► Multilayer structure is destroyed after annealing at 1100 °C. ► Energy filtered TEM confirmed the Si NC formation. ► Sample thickness values from optical simulations are in agreement with TEM observations. ► The crystallization degree of the NCs was evaluated by Raman scattering and R and T techniques. ► The system conductivity depends on the NC size. ► The presence of a defective oxycarbide layer on top did not allow for obtaining useful electrical information. -- Abstract: In this work we present a structural, optical and electrical characterization of Si x C 1−x /SiC multilayer systems with different silicon content. After the deposition process, an annealing treatment was carried out in order to induce the silicon nanocrystals formation. By means of energy-filtered transmission electron microscopy (EFTEM) we observed the structural morphology of the multilayers and the presence of crystallized silicon nanoprecipitates for samples annealed up to 1100 °C. We discuss the suitability of optical techniques such as Raman scattering and reflectance and transmittance (R and T) for the evaluation of the crystalline fraction of our samples at different silicon excess ranges. In addition, the combination of R and T measurements with simulation has proved to be a useful instrument to confirm the structural properties observed by EFTEM. Finally, we explore the origin of the extremely high current density revealed by electrical measurements, probably due to the presence of an undesired defective SiC y O z ternary compound layer, already supported by the structural and optical results. Nevertheless, the variation of the electrical measurements with the silicon amount indicates a small but significant contribution from the multilayers

Corrugated grating on organic multilayer Bragg reflector

Science.gov (United States)

Jaquet, Sylvain; Scharf, Toralf; Herzig, Hans Peter

2007-08-01

Polymeric multilayer Bragg structures are combined with diffractive gratings to produce artificial visual color effects. A particular effect is expected due to the angular reflection dependence of the multilayer Bragg structure and the dispersion caused by the grating. The combined effects can also be used to design particular filter functions and various resonant structures. The multilayer Bragg structure is fabricated by spin-coating of two different low-cost polymer materials in solution on a cleaned glass substrate. These polymers have a refractive index difference of about 0.15 and permit multilayer coatings without interlayer problems. Master gratings of different periods are realized by laser beam interference and replicated gratings are superimposed on the multilayer structure by soft embossing in a UV curing glue. The fabrication process requires only polymer materials. The obtained devices are stable and robust. Angular dependent reflection spectrums for the visible are measured. These results show that it is possible to obtain unexpected reflection effects. A rich variety of color spectra can be generated, which is not possible with a single grating. This can be explained by the coupling of transmission of grating orders and the Bragg reflection band. A simple model permits to explain some of the spectral vs angular dependence of reflected light.

Moosh: A Numerical Swiss Army Knife for the Optics of Multilayers in Octave/Matlab

Directory of Open Access Journals (Sweden)

Josselin Defrance

2016-04-01

Full Text Available The aim of Moosh is to provide a complete set of tools to compute all the optical properties of any multilayered structure: reflection, transmission, absorption spectra, as well as gaussian beam propagation or guided modes. It can be seen as a semi-analytic (making it light and fast solver for Maxwell’s equations in multilayers. It is written in Octave/Matlab, available on Github and based on scattering matrices, making it perfectly stable. This software is meant to be extremely easy to (reuse, and could prove useful in many research areas like photovoltaics, plasmonics and nanophotonics, as well as for educational purposes for the large number of physical phenomena it can illustrate.

The optical properties of boron carbide near boron K-edge inside periodical multilayers

Energy Technology Data Exchange (ETDEWEB)

Ksenzov, Dmitriy; Schlemper, Christoph; Pietsch, Ullrich [University of Siegen (Germany)

2010-07-01

Multilayer mirrors made for the use in the wavelength range near K-edge of boron (188 eV) are of great interest for X-ray fluorescence analysis of boron content in doped semiconductors, plasma diagnostics, astronomy and lithography. Moreover, multilayer mirrors composed by a metal and a low Z element like boron are used as optical elements in both the soft x-ray spectral range as well as at higher photon energies on 3rd generation synchrotron beamlines. Using an energy-resolved photon-in-photon-out method we reconstructed the optical data from energy dependence of both integrated peak intensity and FWHM of the 1st order ML Bragg peak measured at the UHV triple axis soft-x-ray reflectometer at BESSY II. The experiments clearly demonstrate that the peak shape of the ML Bragg peak is most sensitive to any kind of electronic excitation and recombination in solid. The soft-ray reflectivity can give detailed information for MLs with thickness up to several tens of nanometers. In addition, measurements close to a resonance edge probe the chemical state of the respective constituent accompanied with a high sensitivity of changes close to the sample surface.

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

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.

Modeling skin cooling using optical windows and cryogens during laser induced hyperthermia in a multilayer vascularized tissue

International Nuclear Information System (INIS)

Singh, Rupesh; Das, Koushik; Okajima, Junnosuke; Maruyama, Shigenao; Mishra, Subhash C.

2015-01-01

This article deals with the spatial and the temporal evolution of tissue temperature during skin surface cooled laser induced hyperthermia. Three different skin surface cooling methodologies viz., optical window contact cooling, cryogenic spray cooling and cryogen cooled optical window contact cooling are considered. Sapphire, yttrium aluminum garnet, lithium tantalate, and magnesium oxide doped lithium niobate are the considered optical windows. The cryogens considered are liquid CO_2 and R1234yf. Heat transfer in the multilayer skin tissue embedded with thermally significant blood vessels pairs is modeled using the Pennes and Weinbaum–Jiji bioheat equations. Weinbaum–Jiji bioheat equation is used for the vascularized tissue. Laser transport in the tissue is modeled using the radiative transfer equation. Axial and radial (skin surface) temperature distributions for different combinations of optical windows and cryogens are analyzed. Liquid CO_2 cooled yttrium aluminum garnet is found to be the best surface cooling mechanism. - Highlights: • Skin surface cooled laser induced hyperthermia is studied. • A multi-layer 2-D cylindrical tissue geometry is considered. • Both Pennes and Weinbaum–Jiji bioheat models are considered. • Laser transport in the tissue is modeled using discrete ordinate method. • Results for 4 optical windows and 2 cryogens for skin cooling are presented.

Epoxy-based broadband antireflection coating for millimeter-wave optics.

Science.gov (United States)

Rosen, Darin; Suzuki, Aritoki; Keating, Brian; Krantz, William; Lee, Adrian T; Quealy, Erin; Richards, Paul L; Siritanasak, Praween; Walker, William

2013-11-20

We have developed epoxy-based, broadband antireflection coatings for millimeter-wave astrophysics experiments with cryogenic optics. By using multiple-layer coatings where each layer steps in dielectric constant, we achieved low reflection over a wide bandwidth. We suppressed the reflection from an alumina disk to 10% over fractional bandwidths of 92% and 104% using two-layer and three-layer coatings, respectively. The dielectric constants of epoxies were tuned between 2.06 and 7.44 by mixing three types of epoxy and doping with strontium titanate powder required for the high dielectric mixtures. At 140 K, the band-integrated absorption loss in the coatings was suppressed to less than 1% for the two-layer coating, and below 10% for the three-layer coating.

Magneto-optical transitions in multilayer semiconductor nanocrystals

CERN Document Server

Climente, J; Jaskolski, W; Aliaga, J I

2003-01-01

Absorption spectra of chemically synthesized uniform and multilayer semiconductor nanocrystals in a magnetic field are investigated theoretically. The nanocrystals are modelled by spherical barrier/well potentials. The electron states are calculated within the effective mass model. A four-band k centre dot p Hamiltonian, accounting for the valence subband mixing, is used to obtain the hole states. The magneto-optical transition spectrum depends strongly on the size and composition of the nanocrystals. In the case of small uniform quantum dots, only the linear Zeeman splitting of the electron and hole energy levels is observed even for very strong magnetic fields. In larger nanocrystals, the quadratic magnetic interaction turns out to be important and the transition spectrum becomes complicated. The most complicated influence of the magnetic field is found in quantum dot-quantum well systems in which the lowest electron and hole states are localized in a thin spherical layer. It is shown that transitions that ...

Enhancement of surface mechanical properties by using TiN[BCN/BN]{sub n}/c-BN multilayer system

Energy Technology Data Exchange (ETDEWEB)

Moreno, H. [Laboratorio de Recubrimientos Duros, CDT-ASTIN SENA, Cali (Colombia); Caicedo, J.C., E-mail: Jcesarca@calima.univalle.edu.co [Grupo de Peliculas Delgadas, Universidad del Valle, Cali (Colombia); Amaya, C. [Grupo de Peliculas Delgadas, Universidad del Valle, Cali (Colombia); Munoz-Saldana, J. [Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Queretaro, Mexico (Mexico); Yate, L.; Esteve, J. [Department de Fisica Aplicada i Optica, Universitat de Barcelona, Catalunya (Spain); Prieto, P. [Grupo de Peliculas Delgadas, Universidad del Valle, Cali (Colombia); Centro de Excelencia en Nuevos Materiales, CENM, Cali (Colombia)

2010-11-15

The aim of this work is to improve the mechanical properties of AISI 4140 steel substrates by using a TiN[BCN/BN]{sub n}/c-BN multilayer system as a protective coating. TiN[BCN/BN]{sub n}/c-BN multilayered coatings via reactive r.f. magnetron sputtering technique were grown, systematically varying the length period ({Lambda}) and the number of bilayers (n) because one bilayer (n = 1) represents two different layers (t{sub BCN} + t{sub BN}), thus the total thickness of the coating and all other growth parameters were maintained constant. The coatings were characterized by Fourier transform infrared spectroscopy showing bands associated with h-BN bonds and c-BN stretching vibrations centered at 1400 cm{sup -1} and 1100 cm{sup -1}, respectively. Coating composition and multilayer modulation were studied via secondary ion mass spectroscopy. Atomic force microscopy analysis revealed a reduction in grain size and roughness when the bilayer number (n) increased and the bilayer period decreased. Finally, enhancement of mechanical properties was determined via nanoindentation measurements. The best behavior was obtained when the bilayer period ({Lambda}) was 80 nm (n = 25), yielding the relative highest hardness ({approx}30 GPa) and elastic modulus (230 GPa). The values for the hardness and elastic modulus are 1.5 and 1.7 times greater than the coating with n = 1, respectively. The enhancement effects in multilayered coatings could be attributed to different mechanisms for layer formation with nanometric thickness due to the Hall-Petch effect; because this effect, originally used to explain increased hardness with decreasing grain size in bulk polycrystalline metals, has also been used to explain hardness enhancements in multilayered coatings taking into account the thickness reduction at individual single layers that make up the multilayered system. The Hall-Petch model based on dislocation motion within layered and across layer interfaces has been successfully applied to

Design of a normal incidence multilayer imaging X-ray microscope

Science.gov (United States)

Shealy, David L.; Gabardi, David R.; Hoover, Richard B.; Walker, Arthur B. C., Jr.; Lindblom, Joakim F.

Normal incidence multilayer Cassegrain X-ray telescopes were flown on the Stanford/MSFC Rocket X-ray Spectroheliograph. These instruments produced high spatial resolution images of the sun and conclusively demonstrated that doubly reflecting multilayer X-ray optical systems are feasible. The images indicated that aplanatic imaging soft X-ray/EUV microscopes should be achievable using multilayer optics technology. A doubly reflecting normal incidence multilayer imaging X-ray microscope based on the Schwarzschild configuration has been designed. The design of the microscope and the results of the optical system ray trace analysis are discussed. High resolution aplanatic imaging X-ray microscopes using normal incidence multilayer X-ray mirrors should have many important applications in advanced X-ray astronomical instrumentation, X-ray lithography, biological, biomedical, metallurgical, and laser fusion research.

Thickness-dependent magneto-optical effects in hole-doped GaS and GaSe multilayers: a first-principles study

Science.gov (United States)

Li, Fei; Zhou, Xiaodong; Feng, Wanxiang; Fu, Botao; Yao, Yugui

2018-04-01

Recently, two-dimensional (2D) GaS and GaSe nanosheets were successfully fabricated and the measured electronic, mechanical, and optoelectronic properties are excellent. Here, using the first-principles density functional theory, we investigate the magnetic, optical, and magneto-optical (MO) Kerr and Faraday effects in hole-doped GaS and GaSe multilayers. GaS and GaSe monolayers (MLs) manifest ferromagnetic ground states by introducing even a small amount of hole doping, whereas the magnetism in GaS and GaSe multilayers are significantly different under hole doping. Our results show that ferromagnetic states can be easily established in GaS bilayers and trilayers under proper hole doping, however, most of GaSe multilayers are more favorable to nonmagnetic states. The magnetic moments in GaS multilayers are weakened remarkably with the increasing of thin film thickness and are negligible more than three MLs. This leads to the thickness dependence of MO Kerr and Faraday effects. Furthermore, the MO effects strongly depend on the doping concentration and therefore are electrically controllable by adjusting the number of holes via gate voltage. The substrate effects on the MO properties are also discussed. Combining the unique MO and other interesting physical properties make GaS and GaSe a superior 2D material platform for semiconductor MO and spintronic nanodevices.

Pixelated coatings and advanced IR coatings

Science.gov (United States)

Pradal, Fabien; Portier, Benjamin; Oussalah, Meihdi; Leplan, Hervé

2017-09-01

Reosc developed pixelated infrared coatings on detector. Reosc manufactured thick pixelated multilayer stacks on IR-focal plane arrays for bi-spectral imaging systems, demonstrating high filter performance, low crosstalk, and no deterioration of the device sensitivities. More recently, a 5-pixel filter matrix was designed and fabricated. Recent developments in pixelated coatings, shows that high performance infrared filters can be coated directly on detector for multispectral imaging. Next generation space instrument can benefit from this technology to reduce their weight and consumptions.

Using nanosphere lithography for fabrication of a multilayered system of ordered gold nanoparticles

Directory of Open Access Journals (Sweden)

V.I. Styopkin

2017-07-01

Full Text Available New modification of nanosphere lithography has been realized to obtain multilayered systems of ordered gold nanopartciles (NP. NP have been formed using vacuum deposition of 5…60-nm layer of gold on ionic etched multilayered regular coating consisted of several layers of 200-nm polystyrene spheres. Optical study shows that spectra of NP depend on their thickness and may be changed by heat treatment. Increasing the NP thickness within the 5…20-nm range leads to a shortwave displacement of the plasmon resonance peak position, while the longwave shift is observed in 20…60-nm range. Heat treatment of NP brings narrowing and displacement of spectral bands, rising the extinction. It has been supposed that variation of the NP shape is the most substantial factor for changes of optical properties in the 5…20 nm thickness region, while electromagnetic coupling between NP in different layers becomes more important for thicknesses larger than 40 nm. Optical properties inherent to the obtained system of NP can be tuned by changing the polystyrene spheres diameter, extent of etching, thickness of gold layer and with the heat treatment. It may be used in design of nanophotonic devices.

Carbon-coated Si nanoparticles/reduced graphene oxide multilayer anchored to nanostructured current collector as lithium-ion battery anode

Energy Technology Data Exchange (ETDEWEB)

Liu, Zhengjiao; Guo, Pengqian; Liu, Boli; Xie, Wenhe; Liu, Dequan; He, Deyan, E-mail: hedy@lzu.edu.cn

2017-02-28

Silicon is the most promising anode material for the next-generation lithium-ion batteries (LIBs). However, the large volume change during lithiation/delithiation and low intrinsic conductivity hamper its electrochemical performance. Here we report a well-designed LIB anode in which carbon-coated Si nanoparticles/reduced graphene oxide (Si/rGO) multilayer was anchored to nanostructured current collector with stable mechanical support and rapid electron conduction. Furthermore, we improved the integral stability of the electrode through introducing amorphous carbon. The designed anode exhibits superior cyclability, its specific capacity remains above 800 mAh g{sup −1} after 350 cycles at a current density of 2.0 A g{sup −1}. The excellent electrochemical performance can be attributed to the fact that the Si/rGO multilayer is reinforced by the nanostructured current collector and the formed amorphous carbon, which can maintain the structural and electrical integrities of the electrode.

Nanomechanical properties of TiCN and TiCN/Ti coatings on Ti prepared by Filtered Arc Deposition

International Nuclear Information System (INIS)

Sun, Yong; Lu, Cheng; Yu, Hailiang; Kiet Tieu, A.; Su, Lihong; Zhao, Yue; Zhu, Hongtao; Kong, Charlie

2015-01-01

Monolayer TiCN and multilayer TiCN/Ti coatings were deposited on the surface of Ti using the Filtered Arc Deposition System (FADS). Nanoindentation tests were performed on both coatings. The multilayer TiCN/Ti coating exhibited better ductility than the monolayer TiCN coating. The lattice constants of the coatings were characterized by X-ray diffraction. Transmission Electron Microscopy (TEM) was used to investigate the fracture behavior of the coatings. Inter-columnar, inclined and lateral cracks were found to be the dominant crack modes in the monolayer TiCN coatings while small bending crack and radial crack were the dominant crack modes in the multilayer TiCN/Ti coatings. The Finite Element Method (FEM) was used to simulate the indentation process. It was found that the Ti interlayer in the multilayer TiCN/Ti coating could efficiently suppress the fracture, which is responsible for the improved ductility of the multilayer TiCN/Ti coating

Progress at the ESRF multilayer facility

International Nuclear Information System (INIS)

Morawe, Ch; Peffen, J Ch; Friedrich, K; Osterhoff, M

2013-01-01

The ESRF multilayer (ML) deposition facility is fully operational since 2009. By the end of 2011, almost 50 ML projects were completed using the new machine, bringing the total number to 143 since 1998. Thanks to the new equipment and its improved performance the throughput could be significantly increased. The ESRF upgrade project caused strong demands for new ML optics, in particular dynamically bent KB focusing devices requiring very precise and steeply graded ML coatings. Thanks to this technology, the ESRF nano-imaging end-station ID22NI now provides the users with spot sizes of the order of 50×50 nm 2 at a photon flux of 10 12 ph/s. Among various in-house research and development activities the study of stress evolution during thin film and ML growth will be highlighted. Additional projects involving a PhD student and a PostDoc fellow cover the fields of wave optical simulations using curved MLs and the exposure of ML based monochromators to the white beam.

Time resolved Raman studies of laser induced damage in TiO2 optical coatings

International Nuclear Information System (INIS)

Exarhos, G.J.; Morse, P.L.

1984-10-01

Molecular information available from Raman scattering measurements of sputter deposited TiO 2 on silica substrates has been used to characterize crystalline phases, thickness, and surface homogeneity. A two laser technique is described for investigating transient molecular changes in both coating and substrate which result from pulsed 532 nm laser irradiation. Single layer and multilayer coatings of both anatase and rutile phases of TiO 2 have been probed by Raman spectroscopy immediately following the damage pulse (nanoseconds) and at longer times. Transient measurements are designed to follow surface transformation/relaxation phenomena; measurements at longer times characterize the equilibrium damage state

Identification of second harmonic optical effects from vaccine coated gold microparticles

International Nuclear Information System (INIS)

Jumah, N A; Ameer-Beg, S M; White, N S; Prasad, K V R; Bellhouse, B J

2004-01-01

This study investigates the optical effects observed from uncoated and protein vaccine coated gold microparticles while imaging with two-photon excitation in the Mie scattering regime. When observed with time correlated single photon counting fluorescence lifetime microscopy, the emission from the gold microparticles appeared as an intense instrument-limited temporal response. The intensity of the emission showed a second-order dependence on the laser power and frequency doubling of the emitted light was observed for fundamental light between 890 and 970 nm. The optical effect was attributed to two-photon induced second harmonic generation. The vaccine coated gold microparticles had a much weaker second harmonic signal than the uncoated gold microparticles. Chemical analysis of the surface of the gold microparticles revealed that the vaccine coating decreases the surface charge thereby diminishing the observed second harmonic signal. These optical properties can be exploited to identify both the location of the protein vaccine coating as well as the gold microparticles in vitro and potentially to investigate the vaccine delivery kinetics in vivo

Multilayer Markov Random Field models for change detection in optical remote sensing images

Science.gov (United States)

Benedek, Csaba; Shadaydeh, Maha; Kato, Zoltan; Szirányi, Tamás; Zerubia, Josiane

2015-09-01

In this paper, we give a comparative study on three Multilayer Markov Random Field (MRF) based solutions proposed for change detection in optical remote sensing images, called Multicue MRF, Conditional Mixed Markov model, and Fusion MRF. Our purposes are twofold. On one hand, we highlight the significance of the focused model family and we set them against various state-of-the-art approaches through a thematic analysis and quantitative tests. We discuss the advantages and drawbacks of class comparison vs. direct approaches, usage of training data, various targeted application fields and different ways of Ground Truth generation, meantime informing the Reader in which roles the Multilayer MRFs can be efficiently applied. On the other hand we also emphasize the differences between the three focused models at various levels, considering the model structures, feature extraction, layer interpretation, change concept definition, parameter tuning and performance. We provide qualitative and quantitative comparison results using principally a publicly available change detection database which contains aerial image pairs and Ground Truth change masks. We conclude that the discussed models are competitive against alternative state-of-the-art solutions, if one uses them as pre-processing filters in multitemporal optical image analysis. In addition, they cover together a large range of applications, considering the different usage options of the three approaches.

Performance of the Multi-Spectral Solar Telescope Array. III - Optical characteristics of the Ritchey-Chretien and Cassegrain telescopes

Science.gov (United States)

Hoover, Richard B.; Baker, Phillip C.; Hadaway, James B.; Johnson, R. B.; Peterson, Cynthia; Gabardi, David R.; Walker, Arthur B., Jr.; Lindblom, J. F.; Deforest, Craig; O'Neal, R. H.

1991-12-01

The Multi-Spectral Solar Telescope Array (MSSTA), which is a sounding-rocket-borne observatory for investigating the sun in the soft X-ray/EUV and FUV regimes of the electromagnetic spectrum, utilizes single reflection multilayer coated Herschelian telescopes for wavelengths below 100 A, and five doubly reflecting multilayer coated Ritchey-Chretien and two Cassegrain telescopes for selected wavelengths in the EUV region between 100 and 1000 A. The paper discusses the interferometric alignment, testing, focusing, visible light testing, and optical performance characteristics of the Ritchey-Chretien and Cassegrain telescopes of MSSTA. A schematic diagram of the MSSTA Ritchey-Chretien telescope is presented together with diagrams of the system autocollimation testing.

Development of a TiO2-coated optical fiber reactor for water decontamination

International Nuclear Information System (INIS)

Danion, A.

2004-09-01

The objective of this study was to built and to study a photo-reactor composed by TiO 2 -coated optical fibers for water decontamination. The physico-chemical characteristics and the optical properties of the TiO 2 coating were first studied. Then, the influences of different parameters as the coating thickness, the coating length and the coating volume were investigated both on the light transmission in the TiO 2 - coated fiber and on the photo-catalytic activity of the fiber for a model compound (malic acid). The photo-catalytic degradation of malic acid was optimized using the experimental design methodology allowing to build a multi-fiber reactor comprising 57 optical fibers. The photo-degradation of malic acid was conducted in the multi-fiber reactor and it was demonstrated that the multi-fiber reactor was more efficient than the single-fiber reactor at the same fibers density. Finally, the multi-fiber reactor was applied to the photo-degradation of a fungicide, called fenamidone, and a degradation pathway was proposed. (author)

ANTIREFLECTION MULTILAYER COATINGS WITH THIN METAL LAYERS

Directory of Open Access Journals (Sweden)

L. A. Gubanova

2016-03-01

Full Text Available The design of anti-reflective coatings for metal surfaces of Al, Ti, N,i Cr is proposed. The coatings have the form of alternating layers of dielectric/metal/dielectric with the number of cells up to15. The method of calculation of such coatings is proposed. We have calculated the coatings of the type [HfO2/Cr/HfO2]15, [ZrO2/Ti/Al2O3]15, [ZrO2/Cr/ZrO2]15. It is shown that the proposed interference coatings provide reduction of the residual reflectance of the metal several times (from 3.5 to 6.0 in a wide spectral range (300-1000 nm. The proposed coatings can be recommended as anti-reflective coatings for energy saving solar systems and batteries, and photovoltaic cells.

Anodization and Optical Appearance of Sputter Deposited Al-Zr Coatings

DEFF Research Database (Denmark)

Gudla, Visweswara Chakravarthy; Canulescu, Stela; Shabadi, Rajashekhara

2014-01-01

of the anodized layer. The microstructure of the coating is found to influence the appearance of anodized layer owing to the presence of completely or partially dissolved second phases during anodizing process. Oxidation status of the second phase particles in the coatings affected the light absorption......Anodized Al alloy components are extensively used in various applications like architectural, decorative and automobiles for corrosion protection and/or decorative optical appearance. However, tailoring the anodized layer for specific optical appearance is limited due to variation in composition...... and microstructure of the commercial alloys, and even more difficult with recycled alloys. Sputter coating methods promise to control the chemical composition of the Al alloy surfaces and eventually modify the microstructure of the surfaces with heat treatments thus enabling the freedom on the substrate quality...

A preferential coating technique for fabricating large, high quality optics

International Nuclear Information System (INIS)

Alcock, S.G.; Cockerton, S.

2010-01-01

A major challenge facing optic manufacturers is the fabrication of large mirrors (>1 m) with minimal residual slope errors (<0.5 μrad rms). We present a differential coating method with the potential to satisfy such exacting technical demands. Iterative cycles of measurement using the Diamond-NOM, followed by preferential deposition, were performed on a 1200 mm long, silicon mirror. The applied coatings were observed to reduce the optical slope and figure errors from 1.62 to 0.44 μrad rms, and from 208 to 13 nm rms, respectively. It is hoped that this research will lead to commercially available products, of direct benefit to the Synchrotron, Free Electron Laser, Astronomy, Space, and Laser communities, who all require state-of-the-art optics.

Magneto-optical fingerprints of distinct graphene multilayers using the giant infrared Kerr effect

Science.gov (United States)

Ellis, Chase T.; Stier, Andreas V.; Kim, Myoung-Hwan; Tischler, Joseph G.; Glaser, Evan R.; Myers-Ward, Rachael L.; Tedesco, Joseph L.; Eddy, Charles R.; Gaskill, D. Kurt; Cerne, John

2013-11-01

The remarkable electronic properties of graphene strongly depend on the thickness and geometry of graphene stacks. This wide range of electronic tunability is of fundamental interest and has many applications in newly proposed devices. Using the mid-infrared, magneto-optical Kerr effect, we detect and identify over 18 interband cyclotron resonances (CR) that are associated with ABA and ABC stacked multilayers as well as monolayers that coexist in graphene that is epitaxially grown on 4H-SiC. Moreover, the magnetic field and photon energy dependence of these features enable us to explore the band structure, electron-hole band asymmetries, and mechanisms that activate a CR response in the Kerr effect for various multilayers that coexist in a single sample. Surprisingly, we find that the magnitude of monolayer Kerr effect CRs is not temperature dependent. This unexpected result reveals new questions about the underlying physics that makes such an effect possible.

Preparation and characterization of carbon/SiC nanowire/Na-doped carbonated hydroxyapatite multilayer coating for carbon/carbon composites

International Nuclear Information System (INIS)

Leilei, Zhang; Hejun, Li; Kezhi, Li; Shouyang, Zhang; Qiangang, Fu; Yulei, Zhang; Jinhua, Lu; Wei, Li

2014-01-01

Highlights: • CSH coatings were prepared by combination of magnetron sputter ion plating, CVD and UECD. • Na + and CO 3 2− were developed to co-substitute hydroxyapatite. • SiC nanowires were introduced into Na-doped carbonated hydroxyapatite. • CSH coatings showed excellent cell activity and cell proliferation behavior. - Abstract: A carbon/SiC nanowire/Na-doped carbonated hydroxyapatite multilayer coating (CSH coating) was prepared on carbon/carbon composites using a combination method of magnetron sputter ion plating, chemical vapor deposition and ultrasound-assisted electrochemical deposition procedure. The morphology, microstructure and chemical composition of the coating were investigated by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The results showed that the CSH coating was consisted of three components: carbon layer, SiC nanowires and Na-doped carbonated hydroxyapatite. The carbon layer provided a dense and uniform surface structure for the growth of SiC nanowires. The SiC nanowires exhibited a porous structure, favoring the infiltration of Na-doped carbonated hydroxyapatite crystals. The Na-doped carbonated hydroxyapatite could infiltrate into the pores of SiC nanowires and finally cover the SiC nanowires entirely with a needle shape. The osteoblast-like MG63 cells were employed to assess the in vitro biocompatibility of the CSH coating. The MG63 cells favorably spread and grew well across the CSH coating surface with plenty of filopods and microvilli, exhibiting excellent cell activity. Moreover, the CSH coating elicited higher cell proliferation as compared to bare carbon/carbon composites. In conclusion, the CSH offers great potential as a coating material for future medical application in hard tissue replacement

Preparation and characterization of carbon/SiC nanowire/Na-doped carbonated hydroxyapatite multilayer coating for carbon/carbon composites

Energy Technology Data Exchange (ETDEWEB)

Leilei, Zhang, E-mail: zhangleilei1121@aliyun.com; Hejun, Li; Kezhi, Li; Shouyang, Zhang; Qiangang, Fu; Yulei, Zhang; Jinhua, Lu; Wei, Li

2014-09-15

Highlights: • CSH coatings were prepared by combination of magnetron sputter ion plating, CVD and UECD. • Na{sup +} and CO{sub 3}{sup 2−} were developed to co-substitute hydroxyapatite. • SiC nanowires were introduced into Na-doped carbonated hydroxyapatite. • CSH coatings showed excellent cell activity and cell proliferation behavior. - Abstract: A carbon/SiC nanowire/Na-doped carbonated hydroxyapatite multilayer coating (CSH coating) was prepared on carbon/carbon composites using a combination method of magnetron sputter ion plating, chemical vapor deposition and ultrasound-assisted electrochemical deposition procedure. The morphology, microstructure and chemical composition of the coating were investigated by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The results showed that the CSH coating was consisted of three components: carbon layer, SiC nanowires and Na-doped carbonated hydroxyapatite. The carbon layer provided a dense and uniform surface structure for the growth of SiC nanowires. The SiC nanowires exhibited a porous structure, favoring the infiltration of Na-doped carbonated hydroxyapatite crystals. The Na-doped carbonated hydroxyapatite could infiltrate into the pores of SiC nanowires and finally cover the SiC nanowires entirely with a needle shape. The osteoblast-like MG63 cells were employed to assess the in vitro biocompatibility of the CSH coating. The MG63 cells favorably spread and grew well across the CSH coating surface with plenty of filopods and microvilli, exhibiting excellent cell activity. Moreover, the CSH coating elicited higher cell proliferation as compared to bare carbon/carbon composites. In conclusion, the CSH offers great potential as a coating material for future medical application in hard tissue replacement.

Interfacial effects in multilayers

International Nuclear Information System (INIS)

Barbee, T.W. Jr.

1998-01-01

Interfacial structure and the atomic interactions between atoms at interfaces in multilayers or nano-laminates have significant impact on the physical properties of these materials. A technique for the experimental evaluation of interfacial structure and interfacial structure effects is presented and compared to experiment. In this paper the impact of interfacial structure on the performance of x-ray, soft x-ray and extreme ultra-violet multilayer optic structures is emphasized. The paper is concluded with summary of these results and an assessment of their implications relative to multilayer development and the study of buried interfaces in solids in general

[Method of multilayer assembly as alternative to antibacterial coverings of medicobiological implants].

Science.gov (United States)

Ospanova, A K; Omarova, R A; Abdurazakov, U A; Zhartybaev, R N; Iskakova, M K; Savdenbekova, B E; Amkhadova, M A

2016-01-01

Department of Traumatology and Orthopedics Almaty Kazakh Medical University of Continuing Education; 4. Moscow Regional Research Clinical Institute, Russia Resume: in this report we present the results on the use of the method of layer-by-layer (LbL) for obtaining antimicrobial coatings for biomedical implants. As the substrates were used silicon titanium implants and silicon plate. For the obtaining multilayer coatings on the surfaces of the samples were used as the polycation--chitosan and polyanion--carboxymethylcellulose sodium. On the surface multilayer were deposited antibacterial preparations: Triclosan-2,4,4'trichloro-2' hydroxyphenyl ether, silver ions and iodine. Microbiological studies were conducted on the museum strains: E. coli, Candida and Staf. Preliminary antibacterial studies on these microorganisms showed high activity multilayer coating containing triclosan.

Effects of fixture rotation on coating uniformity for high-performance optical filter fabrication

Science.gov (United States)

Rubin, Binyamin; George, Jason; Singhal, Riju

2018-04-01

Coating uniformity is critical in fabricating high-performance optical filters by various vacuum deposition methods. Simple and planetary rotation systems with shadow masks are used to achieve the required uniformity [J. B. Oliver and D. Talbot, Appl. Optics 45, 13, 3097 (2006); O. Lyngnes, K. Kraus, A. Ode and T. Erguder, in `Method for Designing Coating Thickness Uniformity Shadow Masks for Deposition Systems with a Planetary Fixture', 2014 Technical Conference Proceedings, Optical Coatings, August 13, 2014, DOI: 10.14332/svc14.proc.1817.]. In this work, we discuss the effect of rotation pattern and speed on thickness uniformity in an ion beam sputter deposition system. Numerical modeling is used to determine statistical distribution of random thickness errors in coating layers. The relationship between thickness tolerance and production yield are simulated theoretically and demonstrated experimentally. Production yields for different optical filters produced in an ion beam deposition system with planetary rotation are presented. Single-wavelength and broadband optical monitoring systems were used for endpoint monitoring during filter deposition. Limitations of thickness tolerances that can be achieved in systems with planetary rotation are shown. Paths for improving production yield in an ion beam deposition system are described.

Characterization of electron microscopes with binary pseudo-random multilayer test samples

Science.gov (United States)

Yashchuk, Valeriy V.; Conley, Raymond; Anderson, Erik H.; Barber, Samuel K.; Bouet, Nathalie; McKinney, Wayne R.; Takacs, Peter Z.; Voronov, Dmitriy L.

2011-09-01

Verification of the reliability of metrology data from high quality X-ray optics requires that adequate methods for test and calibration of the instruments be developed. For such verification for optical surface profilometers in the spatial frequency domain, a modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) gratings and arrays has been suggested [1,2] and proven to be an effective calibration method for a number of interferometric microscopes, a phase shifting Fizeau interferometer, and a scatterometer [5]. Here we describe the details of development of binary pseudo-random multilayer (BPRML) test samples suitable for characterization of scanning (SEM) and transmission (TEM) electron microscopes. We discuss the results of TEM measurements with the BPRML test samples fabricated from a WiSi 2/Si multilayer coating with pseudo-randomly distributed layers. In particular, we demonstrate that significant information about the metrological reliability of the TEM measurements can be extracted even when the fundamental frequency of the BPRML sample is smaller than the Nyquist frequency of the measurements. The measurements demonstrate a number of problems related to the interpretation of the SEM and TEM data. Note that similar BPRML test samples can be used to characterize X-ray microscopes. Corresponding work with X-ray microscopes is in progress.

Characterization of electron microscopes with binary pseudo-random multilayer test samples

International Nuclear Information System (INIS)

Yashchuk, Valeriy V.; Conley, Raymond; Anderson, Erik H.; Barber, Samuel K.; Bouet, Nathalie; McKinney, Wayne R.; Takacs, Peter Z.; Voronov, Dmitriy L.

2011-01-01

Verification of the reliability of metrology data from high quality X-ray optics requires that adequate methods for test and calibration of the instruments be developed. For such verification for optical surface profilometers in the spatial frequency domain, a modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) gratings and arrays has been suggested and proven to be an effective calibration method for a number of interferometric microscopes, a phase shifting Fizeau interferometer, and a scatterometer [5]. Here we describe the details of development of binary pseudo-random multilayer (BPRML) test samples suitable for characterization of scanning (SEM) and transmission (TEM) electron microscopes. We discuss the results of TEM measurements with the BPRML test samples fabricated from a WiSi 2 /Si multilayer coating with pseudo-randomly distributed layers. In particular, we demonstrate that significant information about the metrological reliability of the TEM measurements can be extracted even when the fundamental frequency of the BPRML sample is smaller than the Nyquist frequency of the measurements. The measurements demonstrate a number of problems related to the interpretation of the SEM and TEM data. Note that similar BPRML test samples can be used to characterize X-ray microscopes. Corresponding work with X-ray microscopes is in progress.

An acoustic metamaterial composed of multi-layer membrane-coated perforated plates for low-frequency sound insulation

Science.gov (United States)

Fan, Li; Chen, Zhe; Zhang, Shu-yi; Ding, Jin; Li, Xiao-juan; Zhang, Hui

2015-04-01

Insulating against low-frequency sound (below 500 Hz ) remains challenging despite the progress that has been achieved in sound insulation and absorption. In this work, an acoustic metamaterial based on membrane-coated perforated plates is presented for achieving sound insulation in a low-frequency range, even covering the lower audio frequency limit, 20 Hz . Theoretical analysis and finite element simulations demonstrate that this metamaterial can effectively block acoustic waves over a wide low-frequency band regardless of incident angles. Two mechanisms, non-resonance and monopolar resonance, operate in the metamaterial, resulting in a more powerful sound insulation ability than that achieved using periodically arranged multi-layer solid plates.

Low atomic number coating for XEUS silicon pore optics

Science.gov (United States)

Lumb, D. H.; Jensen, C. P.; Krumrey, M.; Cibik, L.; Christensen, F.; Collon, M.; Bavdaz, M.

2008-07-01

We describe a set of measurements on coated silicon substrates that are representative of the material to be used for the XEUS High Performance Pore Optics (HPO) technology. X-ray angular reflectance measurements at 2.8 and 8 keV, and energy scans of reflectance at a fixed angle representative of XEUS graze angles are presented. Reflectance is significantly enhanced for low energies when a low atomic number over-coating is applied. Modeling of the layer thicknesses and roughness is used to investigate the dependence on the layer thicknesses, metal and over coat material choices. We compare the low energy effective area increase that could be achieved with an optimized coating design.

Design and fabrication of heat resistant multilayers

International Nuclear Information System (INIS)

Thorne, J.M.; Knight, L.V.; Peterson, B.G.; Perkins, R.T.; Gray, K.J.

1986-01-01

Many promising applications of multilayer x-ray optical elements subject them to intense radiation. This paper discusses the selection of optimal pairs of materials to resist heat damage and presents simulations of multilayer performance under extreme heat loadings

Epoxy-based broadband anti-reflection coating for millimeter-wave optics

OpenAIRE

Rosen, Darin; Suzuki, Aritoki; Keating, Brian; Krantz, William; Lee, Adrian T.; Quealy, Erin; Richards, Paul L.; Siritanasak, Praween; Walker, William

2013-01-01

We have developed epoxy-based, broadband anti-reflection coatings for millimeter-wave astrophysics experiments with cryogenic optics. By using multiple-layer coatings where each layer steps in dielectric constant, we achieved low reflection over a wide bandwidth. We suppressed the reflection from an alumina disk to 10% over fractional bandwidths of 92% and 104% using two-layer and three-layer coatings, respectively. The dielectric constants of epoxies were tuned between 2.06 and 7.44 by mixin...

Hybrid Coatings as Transducer in Optical Biosensors

Czech Academy of Sciences Publication Activity Database

Rose, K.; Dzyadevych, S.; Fernandez-Lafuente, R.; Jaffrezic, N.; Kuncová, Gabriela; Matějec, Vlastimil; Scully, P.

2008-01-01

Roč. 5, č. 4 (2008), s. 491-496 ISSN 1547-0091 Grant - others:GRD1(XE) 2001-C40477 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z20670512 Keywords : optical sensor * fluorescence * hybrid coating Subject RIV: EI - Biotechnology ; Bionics Impact factor: 1.059, year: 2008

Fiber optic pH sensor with self-assembled polymer multilayer nanocoatings.

Science.gov (United States)

Shao, Li-Yang; Yin, Ming-Jie; Tam, Hwa-Yaw; Albert, Jacques

2013-01-24

A fiber-optic pH sensor based on a tilted fiber Bragg grating (TFBG) with electrostatic self-assembly multilayer sensing film is presented. The pH sensitive polymeric film, poly(diallyldimethylammonium chloride) (PDDA) and poly(acrylic acid) (PAA) was deposited on the circumference of the TFBG with the layer-by-layer (LbL) electrostatic self-assembly technique. The PDDA/PAA film exhibits a reduction in refractive index by swelling in different pH solutions. This effect results in wavelength shifts and transmission changes in the spectrum of the TFBG. The peak amplitude of the dominant spectral fringes over a certain window of the transmission spectrum, obtained by FFT analysis, has a near-linear pH sensitivity of 117 arbitrary unit (a.u.)/pH unit and an accuracy of ±1 a.u. (in the range of pH 4.66 to pH 6.02). The thickness and surface morphology of the sensing multilayer film were characterized to investigate their effects on the sensor's performance. The dynamic response of the sensor also has been studied (10 s rise time and 18 s fall time for a sensor with six bilayers of PDDA/PAA).

Multilayer optics for monochromatic high-resolution X-ray imaging diagnostic in a broad photon energy range from 2 keV to 22 keV

International Nuclear Information System (INIS)

Troussel, Ph.; Dennetiere, D.; Maroni, R.; Høghøj, P.; Hedacq, S.; Cibik, L.; Krumrey, M.

2014-01-01

The “Commissariat à l’énergie atomique et aux énergies alternatives” (CEA) studies and designs advanced X-ray diagnostics to probe dense plasmas produced at the future Laser MegaJoule (LMJ) facility. Mainly for X-ray imaging with high spatial resolution, different types of multilayer mirrors were developed to provide broadband X-ray reflectance at grazing incidence. These coatings are deposited on two toroidal mirror substrates that are then mounted into a Wolter-type geometry (working at a grazing angle of 0.45°) to realize an X-ray microscope. Non-periodic (depth graded) W/Si multilayer can be used in the broad photon energy range from 2 keV to 22 keV. A third flat mirror can be added for the spectral selection of the microscope. This mirror is coated with a Mo/Si multilayer for which the d-spacing varies in the longitudinal direction to satisfy the Bragg condition within the angular acceptance of the microscope and also to compensate the angular dispersion due to the field of the microscope. We present a study of such a so-called Göbel mirror which was optimized for photon energy of 10.35 keV. The three mirrors were coated using magnetron sputtering technology by Xenocs SA. The reflectance in the entire photon energy range was determined in the laboratory of the Physikalisch-Technische Bundesanstalt (PTB) at the synchrotron radiation facility BESSY II in Berlin

Multilayer optics for monochromatic high-resolution X-ray imaging diagnostic in a broad photon energy range from 2 keV to 22 keV

Energy Technology Data Exchange (ETDEWEB)

Troussel, Ph., E-mail: philippe.troussel@cea.fr [CEA, DAM, DIF, F-91297 Arpajon (France); Dennetiere, D. [Synchrotron Soleil, L’orme des Merisiers, 91190 Saint-Aubin (France); Maroni, R. [CEA, DAM, DIF, F-91297 Arpajon (France); Høghøj, P.; Hedacq, S. [Xenocs SA, 19, rue François Blumet, F-38360 Sassenage (France); Cibik, L.; Krumrey, M. [Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin (Germany)

2014-12-11

The “Commissariat à l’énergie atomique et aux énergies alternatives” (CEA) studies and designs advanced X-ray diagnostics to probe dense plasmas produced at the future Laser MegaJoule (LMJ) facility. Mainly for X-ray imaging with high spatial resolution, different types of multilayer mirrors were developed to provide broadband X-ray reflectance at grazing incidence. These coatings are deposited on two toroidal mirror substrates that are then mounted into a Wolter-type geometry (working at a grazing angle of 0.45°) to realize an X-ray microscope. Non-periodic (depth graded) W/Si multilayer can be used in the broad photon energy range from 2 keV to 22 keV. A third flat mirror can be added for the spectral selection of the microscope. This mirror is coated with a Mo/Si multilayer for which the d-spacing varies in the longitudinal direction to satisfy the Bragg condition within the angular acceptance of the microscope and also to compensate the angular dispersion due to the field of the microscope. We present a study of such a so-called Göbel mirror which was optimized for photon energy of 10.35 keV. The three mirrors were coated using magnetron sputtering technology by Xenocs SA. The reflectance in the entire photon energy range was determined in the laboratory of the Physikalisch-Technische Bundesanstalt (PTB) at the synchrotron radiation facility BESSY II in Berlin.

Multilayer optics for monochromatic high-resolution X-ray imaging diagnostic in a broad photon energy range from 2 keV to 22 keV

Science.gov (United States)

Troussel, Ph.; Dennetiere, D.; Maroni, R.; Høghøj, P.; Hedacq, S.; Cibik, L.; Krumrey, M.

2014-12-01

The "Commissariat à l'énergie atomique et aux énergies alternatives" (CEA) studies and designs advanced X-ray diagnostics to probe dense plasmas produced at the future Laser MegaJoule (LMJ) facility. Mainly for X-ray imaging with high spatial resolution, different types of multilayer mirrors were developed to provide broadband X-ray reflectance at grazing incidence. These coatings are deposited on two toroidal mirror substrates that are then mounted into a Wolter-type geometry (working at a grazing angle of 0.45°) to realize an X-ray microscope. Non-periodic (depth graded) W/Si multilayer can be used in the broad photon energy range from 2 keV to 22 keV. A third flat mirror can be added for the spectral selection of the microscope. This mirror is coated with a Mo/Si multilayer for which the d-spacing varies in the longitudinal direction to satisfy the Bragg condition within the angular acceptance of the microscope and also to compensate the angular dispersion due to the field of the microscope. We present a study of such a so-called Göbel mirror which was optimized for photon energy of 10.35 keV. The three mirrors were coated using magnetron sputtering technology by Xenocs SA. The reflectance in the entire photon energy range was determined in the laboratory of the Physikalisch-Technische Bundesanstalt (PTB) at the synchrotron radiation facility BESSY II in Berlin.

Design refinement of multilayer optical thin film devices with two optimization techniques

International Nuclear Information System (INIS)

Apparao, K.V.S.R.

1992-01-01

The design efficiency of two different optimization techniques of designing multilayer optical thin film devices is compared. Ten different devices of varying complexities are chosen as design examples for the comparison. The design refinement efficiency and the design parameter characteristics of all the sample designs obtained with the two techniques are compared. The results of the comparison demonstrate that the new method of design developed using damped least squares technique with indirect derivatives give superior and efficient designs compared to the method developed with direct derivatives. (author). 23 refs., 4 tabs., 14 figs

Design, conception, and metrology of Extreme Ultraviolet multilayers mirrors resistant environments of space and EUV sources

International Nuclear Information System (INIS)

Hecquet, Ch.

2009-03-01

The Extreme Ultraviolet Spectrum (EUV) wavelengths, which range between 13 nm and 40 nm, have many applications in science and technology. These have been developed for example in plasma physics (high order harmonics sources, X ray lasers). The work presented is about the design, the fabrication and the metrology of periodic multilayer mirrors. The main motivation of this study is to establish a cycle of development taking into account both the optical properties of reflective coatings (reflectivity, spectral selectivity, attenuation) and their behaviour under various environments. To improve the spectral selectivity, new multilayer periodic structures have been developed. They are characterized by a bimodal reflectance profile with adjustable attenuation. The effect of environment on the stability of performance is especially critical for the optical collection. The addition of material barriers has stabilized the performance of the peak reflectivity for over 200 h at 400 C deg. and it reduces the influence of other factors of instability on the reflectance. In addition, all structures have been fabricated successfully and evaluated in severe environments. (author)

Deposition and characterization of titania-silica optical multilayers by asymmetric bipolar pulsed dc sputtering of oxide targets

Energy Technology Data Exchange (ETDEWEB)

Sagdeo, P R; Shinde, D D; Misal, J S [Optics and Thin Film Laboratory, Autonagar, BARC-Vizag, Visakhapatnam -530012 (India); Kamble, N M; Tokas, R B; Biswas, A; Poswal, A K; Thakur, S; Bhattacharyya, D; Sahoo, N K; Sabharwal, S C, E-mail: nksahoo@barc.gov.i, E-mail: sahoonk@gmail.co [Spectroscopy Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

2010-02-03

Titania-silica (TiO{sub 2}/SiO{sub 2}) optical multilayer structures have been conventionally deposited by reactive sputtering of metallic targets. In order to overcome the problems of arcing, target poisoning and low deposition rates encountered there, the application of oxide targets was investigated in this work with asymmetric bipolar pulsed dc magnetron sputtering. In order to evaluate the usefulness of this deposition methodology, an electric field optimized Fabry Perot mirror for He-Cd laser ({lambda} = 441.6 nm) spectroscopy was deposited and characterized. For comparison, this mirror was also deposited by the reactive electron beam (EB) evaporation technique. The mirrors developed by the two complementary techniques were investigated for their microstructural and optical reflection properties invoking atomic force microscopy, ellipsometry, grazing incidence reflectometry and spectrophotometry. From these measurements the layer geometry, optical constants, mass density, topography, surface and interface roughness and disorder parameters were evaluated. The microstructural properties and spectral functional characteristics of the pulsed dc sputtered multilayer mirror were found to be distinctively superior to the EB deposited mirror. The knowledge gathered during this study has been utilized to develop a 21-layer high-pass edge filter for radio photoluminescence dosimetry.

Deposition and characterization of titania-silica optical multilayers by asymmetric bipolar pulsed dc sputtering of oxide targets

International Nuclear Information System (INIS)

Sagdeo, P R; Shinde, D D; Misal, J S; Kamble, N M; Tokas, R B; Biswas, A; Poswal, A K; Thakur, S; Bhattacharyya, D; Sahoo, N K; Sabharwal, S C

2010-01-01

Titania-silica (TiO 2 /SiO 2 ) optical multilayer structures have been conventionally deposited by reactive sputtering of metallic targets. In order to overcome the problems of arcing, target poisoning and low deposition rates encountered there, the application of oxide targets was investigated in this work with asymmetric bipolar pulsed dc magnetron sputtering. In order to evaluate the usefulness of this deposition methodology, an electric field optimized Fabry Perot mirror for He-Cd laser (λ = 441.6 nm) spectroscopy was deposited and characterized. For comparison, this mirror was also deposited by the reactive electron beam (EB) evaporation technique. The mirrors developed by the two complementary techniques were investigated for their microstructural and optical reflection properties invoking atomic force microscopy, ellipsometry, grazing incidence reflectometry and spectrophotometry. From these measurements the layer geometry, optical constants, mass density, topography, surface and interface roughness and disorder parameters were evaluated. The microstructural properties and spectral functional characteristics of the pulsed dc sputtered multilayer mirror were found to be distinctively superior to the EB deposited mirror. The knowledge gathered during this study has been utilized to develop a 21-layer high-pass edge filter for radio photoluminescence dosimetry.

Automated pharmaceutical tablet coating layer evaluation of optical coherence tomography images

International Nuclear Information System (INIS)

Markl, Daniel; Sacher, Stephan; Khinast, Johannes G; Hannesschläger, Günther; Leitner, Michael; Buchsbaum, Andreas

2015-01-01

Film coating of pharmaceutical tablets is often applied to influence the drug release behaviour. The coating characteristics such as thickness and uniformity are critical quality parameters, which need to be precisely controlled. Optical coherence tomography (OCT) shows not only high potential for off-line quality control of film-coated tablets but also for in-line monitoring of coating processes. However, an in-line quality control tool must be able to determine coating thickness measurements automatically and in real-time. This study proposes an automatic thickness evaluation algorithm for bi-convex tables, which provides about 1000 thickness measurements within 1 s. Beside the segmentation of the coating layer, optical distortions due to refraction of the beam by the air/coating interface are corrected. Moreover, during in-line monitoring the tablets might be in oblique orientation, which needs to be considered in the algorithm design. Experiments were conducted where the tablet was rotated to specified angles. Manual and automatic thickness measurements were compared for varying coating thicknesses, angles of rotations, and beam displacements (i.e. lateral displacement between successive depth scans). The automatic thickness determination algorithm provides highly accurate results up to an angle of rotation of 30°. The computation time was reduced to 0.53 s for 700 thickness measurements by introducing feasibility constraints in the algorithm. (paper)

Low atomic number coating for XEUS silicon pore optics

DEFF Research Database (Denmark)

Lumb, D.H.; Cooper-Jensen, Carsten P.; Krumrey, M.

2008-01-01

We describe a set of measurements on coated silicon substrates that are representative of the material to be used for the XEUS High Performance Pore Optics (HPO) technology. X-ray angular reflectance measurements at 2.8 and 8 keV, and energy scans of reflectance at a fixed angle representative...... of XEUS graze angles are presented. Reflectance is significantly enhanced for low energies when a low atomic number over-coating is applied. Modeling of the layer thicknesses and roughness is used to investigate the dependence on the layer thicknesses, metal and over coat material choices. We compare...

FDTD-based quantitative analysis of terahertz wave detection for multilayered structures.

Science.gov (United States)

Tu, Wanli; Zhong, Shuncong; Shen, Yaochun; Zhou, Qing; Yao, Ligang

2014-10-01

Experimental investigations have shown that terahertz pulsed imaging (TPI) is able to quantitatively characterize a range of multilayered media (e.g., biological issues, pharmaceutical tablet coatings, layered polymer composites, etc.). Advanced modeling of the interaction of terahertz radiation with a multilayered medium is required to enable the wide application of terahertz technology in a number of emerging fields, including nondestructive testing. Indeed, there have already been many theoretical analyses performed on the propagation of terahertz radiation in various multilayered media. However, to date, most of these studies used 1D or 2D models, and the dispersive nature of the dielectric layers was not considered or was simplified. In the present work, the theoretical framework of using terahertz waves for the quantitative characterization of multilayered media was established. A 3D model based on the finite difference time domain (FDTD) method is proposed. A batch of pharmaceutical tablets with a single coating layer of different coating thicknesses and different refractive indices was modeled. The reflected terahertz wave from such a sample was computed using the FDTD method, assuming that the incident terahertz wave is broadband, covering a frequency range up to 3.5 THz. The simulated results for all of the pharmaceutical-coated tablets considered were found to be in good agreement with the experimental results obtained using a commercial TPI system. In addition, we studied a three-layered medium to mimic the occurrence of defects in the sample.

The gridless plasma ion source (GIS) for plasma ion assisted optical coating

International Nuclear Information System (INIS)

You Dawei; Li Xiaoqian; Wang Yu; Lin Yongchang

2004-01-01

High-quality optical coating is a key technology for modern optics. Ion-assisted deposition technology was used to improve the vaporized coating in 1980's. The GIS (gridless ion source), which is an advanced plasma source for producing a high-quality optical coating in large area, can produce a large area uniformity>1000 mm (diameter), a high ion current density ∼0.5 mA/cm 2 , 20 eV-200 eV energetic plasma ions and can activate reactive gas and film atoms. Now we have developed a GIS system. The GIS and the plasma ion-assisted deposition technology are investigated to achieve a high-quality optical coating. The GIS is a high power and high current source with a power of 1 kW-7.5 kW, a current of 10 A- 70 A and an ion density of 200 μA/cm 2 -500 μA/cm 2 . Because of the special magnetic structure, the plasma-ion extraction efficiency has been improved to obtain a maximum ion density of 500 μA/cm 2 in the medium power (∼4 kW) level. The GIS applied is of a special cathode structure, so that the GIS operation can be maintained under a rather low power and the lifetime of cathode will be extended. The GIS has been installed in the LPSX-1200 type box coating system. The coated TiO 2 , SiO 2 films such as antireflective films with the system have the same performance reported by Leybold Co, 1992, along with a controllable refractive index and film structure. (authors)

Anomalously Weak Scattering in Metal-Semiconductor Multilayer Hyperbolic Metamaterials

Directory of Open Access Journals (Sweden)

Hao Shen

2015-05-01

Full Text Available In contrast to strong plasmonic scattering from metal particles or structures in metal films, we show that patterns of arbitrary shape fabricated out of multilayer hyperbolic metamaterials become invisible within a chosen band of optical frequencies. This is due to anomalously weak scattering when the in-plane permittivity of the multilayer hyperbolic metamaterials is tuned to match with the surrounding medium. This new phenomenon is described theoretically and demonstrated experimentally by optical characterization of various patterns in Au-Si multilayer hyperbolic metamaterials. This anomalously weak scattering is insensitive to pattern sizes, shapes, and incident angles, and has potential applications in scattering cross-section engineering, optical encryption, low-observable conductive probes, and optoelectric devices.

Optical properties of Lactuca and Taraxacum seed and fruit coats: Their role as light filters [phytochrome, photoblasty, fiber optics, transmission, spectra

International Nuclear Information System (INIS)

Widell, K.-O.; Vogelmann, T.C.

1985-01-01

The optical properties of seed and fruit coats were examined from several varieties of light-sensitive achenes. Taraxacum vulgare L. and Lactuca sativa L. cv. Grand Rapids achenes with dark fruit coats and L. sativa cvs Huvudsallat and Issallat with white fruit coats were examined. Transmission spectra varied among the different achenes: white fruit coats of Lactuca acted as neutral density filters between 450 and 780 nm, whereas Taraxacum transmitted 2–36% in this region. The ribbed fruit coat structure greatly affected transmission so that at different locations in the same coat, transmission varied between 20 to 80% at 660 and 730 nm. Fruit coats of Grand Rapids lettuce and Taraxacum transmitted more far-red than red light with T 660 /T 730 ratios of 0.8 and 0.4, respectively. The relationship between the optical properties of fruit coats and light-stimulated germination is discussed. (author)

Anti-wetting Cu/Cr coating with micro-posts array structure fabricated by electrochemical approaches

International Nuclear Information System (INIS)

Zhou, Yufeng; Hang, Tao; Li, Feng; Li, Ming

2013-01-01

Microposts structured Cu/Cr multilayer coating was prepared by a simple two-step approach combining electroless and electro deposition. Surface morphologies of the as-prepared Cu/Cr multilayer coating characterized by field emission scanning electron microscopy show that this multilayer coating exhibits micro-posts arrayed structure with a layer of Cr uniformly covering the circular conical surface of Cu micro-cones array. The wettability test shows that the contact angle of Cu/Cr multilayer surface with water drop can be greater than 140° by optimizing the electrodeposition time of Cr. The mechanism of hydrophobicity of both the micro-cones arrayed and micro-posts arrayed structures was briefly discussed by comparing two different wetting modes. Due to its good anti-wetting property and unique structure, the micro-posts arrayed Cu/Cr multilayer coating is expected for extensive practical applications.

Dynamic clustering scheme based on the coordination of management and control in multi-layer and multi-region intelligent optical network

Science.gov (United States)

Niu, Xiaoliang; Yuan, Fen; Huang, Shanguo; Guo, Bingli; Gu, Wanyi

2011-12-01

A Dynamic clustering scheme based on coordination of management and control is proposed to reduce network congestion rate and improve the blocking performance of hierarchical routing in Multi-layer and Multi-region intelligent optical network. Its implement relies on mobile agent (MA) technology, which has the advantages of efficiency, flexibility, functional and scalability. The paper's major contribution is to adjust dynamically domain when the performance of working network isn't in ideal status. And the incorporation of centralized NMS and distributed MA control technology migrate computing process to control plane node which releases the burden of NMS and improves process efficiently. Experiments are conducted on Multi-layer and multi-region Simulation Platform for Optical Network (MSPON) to assess the performance of the scheme.

Formation of blade and slot die coated small molecule multilayers for OLED applications studied theoretically and by XPS depth profiling

Science.gov (United States)

Peters, Katharina; Raupp, Sebastian; Hummel, Helga; Bruns, Michael; Scharfer, Philip; Schabel, Wilhelm

2016-06-01

Slot die coaters especially designed for low material consumption and doctor blades were used to process small molecule solutions for organic light-emitting diodes (OLEDs). Optimum process parameters were developed for the large-scale coating techniques to generate stable single and multiple layers only a few nanometers thick. Achieving a multilayer architecture for solution-processed OLEDs is the most challenging step. X-ray photoelectron spectroscopy sputter depth profiling was performed to determine defined interfaces between coated organic layers. Commercially available small molecules NPB (N,N'-Di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine) and BAlq (Bis(8-hdroxy-2methylquinoline)-(4-phenylphenoxy)aluminum), originally developed for vacuum deposition, were used as hole, respectively electron transport material. Defined double-layers were processed with both scalable coating methods using the orthogonal solvent approach. The use of non-orthogonal solvents resulted in complete intermixing of the material. The results are explained by calculations of solubilities and simulating drying and diffusion kinetics of the small molecule solutions.

Significant degradability enhancement in multilayer coating of polycaprolactone-bioactive glass/gelatin-bioactive glass on magnesium scaffold for tissue engineering applications

Science.gov (United States)

Yazdimamaghani, Mostafa; Razavi, Mehdi; Vashaee, Daryoosh; Pothineni, Venkata Raveendra; Rajadas, Jayakumar; Tayebi, Lobat

2015-05-01

Magnesium (Mg) is a promising candidate to be used in medical products especially as bone tissue engineering scaffolds. The main challenge for using Mg in biomedical applications is its high degradation rate in the body. For this reason, in this study, a multilayer polymeric layer composed of polycaprolactone (PCL) and gelatin (Gel) reinforced with bioactive glass (BaG) particles has been applied on the surface of Mg scaffolds. The materials characteristics of uncoated Mg scaffold, Mg scaffold coated only with PCL-BaG and Mg scaffold coated with PCL-BaG and Gel-BaG have been analyzed and compared in detail. Scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR) were utilized for microstructural studies. In vitro bioactivity and biodegradation evaluations were carried out by submerging the scaffolds in simulated body fluid (SBF) at pre-determined time points. The results demonstrated that Mg scaffold coated with PCL-BaG and Gel-BaG exhibited significant improvement in biodegradability.

High efficiency multilayer blazed gratings for EUV and soft X-rays: Recent developments

International Nuclear Information System (INIS)

Voronov, Dmitriy; Ahn, Minseung; Anderson, Erik; Cambie, Rossana; Chang, Chih-Hao; Goray, Leonid; Gullikson, Eric; Heilmann, Ralf; Salmassi, Farhad; Schattenburg, Mark; Warwick, Tony; Yashchuk, Valeriy; Padmore, Howard

2011-01-01

Multilayer coated blazed gratings with high groove density are the best candidates for use in high resolution EUV and soft x-ray spectroscopy. Theoretical analysis shows that such a grating can be potentially optimized for high dispersion and spectral resolution in a desired high diffraction order without significant loss of diffraction efficiency. In order to realize this potential, the grating fabrication process should provide a perfect triangular groove profile and an extremely smooth surface of the blazed facets. Here we report on recent progress achieved at the Advanced Light Source (ALS) in fabrication of high quality multilayer coated blazed gratings. The blazed gratings were fabricated using scanning beam interference lithography followed by wet anisotropic etching of silicon. A 200 nm period grating coated with a Mo/Si multilayer composed with 30 bi-layers demonstrated an absolute efficiency of 37.6percent in the 3rd diffraction order at 13.6 nm wavelength. The groove profile of the grating was thoroughly characterized with atomic force microscopy before and after the multilayer deposition. The obtained metrology data were used for simulation of the grating efficiency with the vector electromagnetic PCGrate-6.1 code. The simulations showed that smoothing of the grating profile during the multilayer deposition is the main reason for efficiency losses compared to the theoretical maximum. Investigation of the grating with cross-sectional transmission electron microscopy revealed a complex evolution of the groove profile in the course of the multilayer deposition. Impact of the shadowing and smoothing processes on growth of the multilayer on the surface of the sawtooth substrate is discussed.

Coloration of metallic and/or ceramic surfaces obtained by atomic layer deposited nano-coatings

Energy Technology Data Exchange (ETDEWEB)

Guzman, L., E-mail: luisg47@gmail.com [Fondazione Bruno Kessler (FBK), Centro Materiali e Microsistemi, Functional Materials & Photonic Structures Unit, via Sommarive 18, 38123 Trento (Italy); Vettoruzzo, F. [Ronda High Tech, via Vegri 83, 36010 Zane’, Vicenza (Italy); Laidani, N. [Fondazione Bruno Kessler (FBK), Centro Materiali e Microsistemi, Functional Materials & Photonic Structures Unit, via Sommarive 18, 38123 Trento (Italy)

2016-02-29

By depositing single layer coatings by means of physical vapor techniques, tailoring of their coloration is generally complex because a given color can be obtained only by very high composition control. Physical vapor deposition (PVD) processes are expensive and cannot be easily used for obtaining conformal coating on three-dimensional objects. Moreover PVD coatings exhibit intrinsic defects (columnar structures, pores) that affect their functional properties and applications such as barrier layers. Atomic layer deposition (ALD) technology delivers conformal coatings on different materials with very low defectiveness. A straightforward coloration can be obtained by a combination of two types of layers with different refraction index, deposited to high thickness precision. Computer simulation studies were performed to design the thickness and architecture of multilayer structures, to a total thickness of approximately 100 nm, suitable to modify the typical coloration of some materials, without altering their other physical and chemical properties. The most promising nano-layered structures were then deposited by ALD and tested with regard to their optical properties. Their total thicknesses were specified in such a way to be technically feasible and compatible with future industrial production. The materials employed in this study to build the optical coatings, are two oxides (Al{sub 2}O{sub 3}, TiO{sub 2}) deposited at 120 °C and two nitrides (AlN, TiN), which need a deposition temperature of 400 °C. The possibility of using such modern deposition technology for esthetic and decorative purposes, while maintaining the functional properties, opens perspectives of industrial applications. - Highlights: • Computer simulation is done to design multilayers made of Al{sub 2}O{sub 3}, TiO{sub 2}, AlN, and TiN. • Total thickness (< 120 nm) is specified to be compatible with industrial production. • The most promising nano-layered structures are then produced and

Coloration of metallic and/or ceramic surfaces obtained by atomic layer deposited nano-coatings

International Nuclear Information System (INIS)

Guzman, L.; Vettoruzzo, F.; Laidani, N.

2016-01-01

By depositing single layer coatings by means of physical vapor techniques, tailoring of their coloration is generally complex because a given color can be obtained only by very high composition control. Physical vapor deposition (PVD) processes are expensive and cannot be easily used for obtaining conformal coating on three-dimensional objects. Moreover PVD coatings exhibit intrinsic defects (columnar structures, pores) that affect their functional properties and applications such as barrier layers. Atomic layer deposition (ALD) technology delivers conformal coatings on different materials with very low defectiveness. A straightforward coloration can be obtained by a combination of two types of layers with different refraction index, deposited to high thickness precision. Computer simulation studies were performed to design the thickness and architecture of multilayer structures, to a total thickness of approximately 100 nm, suitable to modify the typical coloration of some materials, without altering their other physical and chemical properties. The most promising nano-layered structures were then deposited by ALD and tested with regard to their optical properties. Their total thicknesses were specified in such a way to be technically feasible and compatible with future industrial production. The materials employed in this study to build the optical coatings, are two oxides (Al_2O_3, TiO_2) deposited at 120 °C and two nitrides (AlN, TiN), which need a deposition temperature of 400 °C. The possibility of using such modern deposition technology for esthetic and decorative purposes, while maintaining the functional properties, opens perspectives of industrial applications. - Highlights: • Computer simulation is done to design multilayers made of Al_2O_3, TiO_2, AlN, and TiN. • Total thickness (< 120 nm) is specified to be compatible with industrial production. • The most promising nano-layered structures are then produced and optically tested. • An

Development of nanostructured PVD coatings for total knee replacement joints using HIPIMS

Science.gov (United States)

Sugumaran, Arunprabhu A.

The aim of this study was to develop thin film coatings for total knee replacement joints using high power impulse magnetron sputtering (HIPIMS). An industrial size four cathode magnetron sputtering system equipped with direct current (DC) and HIPIMS power supplies was used for this purpose. Initially, Plasma diagnostics were carried out using optical emission spectroscopy (OES) while sputtering Ti target in Ar + N2 atmosphere by utilizing various HIP IMS/conventional DCMS (henceforth UBM) source combinations by varying the process parameters such as coil current and N2 flow. Then, single layer titanium nitride (TiN) coating was deposited by varying the degree of HIPIMS utilisation and the process parameters such as bias voltage and coil current to thoroughly understand the effect of degree of HIPIMS utilisation on the microstructure, residual stress, texture, mechanical, tribological and corrosion properties of such coatings. The degree of HIPIMS utilisation was altered by increasing the number of HIPIMS targets used for the deposition. Four different source combinations were used for this purpose, as follows: 4 cathodes in conventional DCMS mode to deposit pure UBM coating, 1 HIPIMS + 3UBM and 2HIPIMS + 2UBM cathodes to deposit combined HIPIMS/UBM coatings and 2HIPIMS cathodes to deposit pure HIPIMS coatings. TiN/NbN, TiCN/NbCN and CrN/NbN multilayer coatings were deposited on CoCr alloy test buttons along with other (HSS, SS and Si) substrates since our intended application is on total knee replacement joints made of CoCr alloy. The knowledge gained by investigating the TiN (Ar + N[2]) plasma and the properties of TiN was used to determine the process parameters for depositing the multilayer coatings. X- ray diffraction (XRD) technique was used for calculating the texture, residual stress and bilayer thickness of the coatings. Nanoindentation method was used to determine the nano hardness of the coatings. The adhesion strength of the coatings was estimated by

Grazing incidence Fe-line telescopes using W/B4C multilayers

DEFF Research Database (Denmark)

Joensen, K. D.; Gorenstein, P.; Christensen, Finn Erland

1995-01-01

The loss of throughput observed at higher energies for traditional grazing-incidence X-ray telescopes coated with high-Z elements can be partly countered by employing multilayers on the outermost reflectors. Using 8-keV reflectivity data from a periodic W/B4C multilayer, the expected performance...

Multi-layered fabrication of large area PDMS flexible optical light guide sheets

Science.gov (United States)

Green, Robert; Knopf, George K.; Bordatchev, Evgueni V.

2017-02-01

Large area polydimethylsiloxane (PDMS) flexible optical light guide sheets can be used to create a variety of passive light harvesting and illumination systems for wearable technology, advanced indoor lighting, non-planar solar light collectors, customized signature lighting, and enhanced safety illumination for motorized vehicles. These thin optically transparent micro-patterned polymer sheets can be draped over a flat or arbitrarily curved surface. The light guiding behavior of the optical light guides depends on the geometry and spatial distribution of micro-optical structures, thickness and shape of the flexible sheet, refractive indices of the constituent layers, and the wavelength of the incident light. A scalable fabrication method that combines soft-lithography, closed thin cavity molding, partial curing, and centrifugal casting is described in this paper for building thin large area multi-layered PDMS optical light guide sheets. The proposed fabrication methodology enables the of internal micro-optical structures (MOSs) in the monolithic PDMS light guide by building the optical system layer-by-layer. Each PDMS layer in the optical light guide can have the similar, or a slightly different, indices of refraction that permit total internal reflection within the optical sheet. The individual molded layers may also be defect free or micro-patterned with microlens or reflecting micro-features. In addition, the bond between adjacent layers is ensured because each layer is only partially cured before the next functional layer is added. To illustrate the scalable build-by-layers fabrication method a three-layer mechanically flexible illuminator with an embedded LED strip is constructed and demonstrated.

Anodisation of sputter deposited aluminium–titanium coatings: Effect of microstructure on optical characteristics

DEFF Research Database (Denmark)

Aggerbeck, Martin; Junker-Holst, Andreas; Vestergaard Nielsen, Daniel

2014-01-01

Magnetron sputtered coatings of aluminium containing up to 18 wt.% titanium were deposited on aluminium substrates to study the effect of microstructure on the optical appearance of the anodised layer. The microstructure and morphology were studied using transmission electron microscopy (TEM), X......-ray diffraction (XRD), and glow discharge optical emission spectroscopy (GDOES), while the optical appearance was investigated using photospectrometry. The microstructure of the coatings was varied by heat treatment, resulting in the precipitation of Al3Ti phases. The reflectance of the anodised surfaces...

Optical measurement of microroughness of pigment coatings on rough substrates

Science.gov (United States)

Elton, N. J.

2009-02-01

The optical determination of rms roughness at the sub-wavelength scale by measurement of specular intensity as a function of wavelength or angle of incidence is well known. The method is normally used for specimens that are macroscopically flat. However, important industrial materials such as coated paper and paint consist of microscopically rough pigment coatings on a macroscopically rough substrate. Numerical modelling is used to assess the applicability and limitations of optical measurement of microroughness for such materials. Experimental results are presented for a range of paints on substrates of various macroroughness. Model and data are in fair agreement and show that the presence of substrate macroroughness always leads to an underestimation of microroughness. Generally, optical measurements of microroughness are only comparable for substrates of similar macroroughness and a limiting value exists above which measurements may not be meaningful.

Optical measurement of microroughness of pigment coatings on rough substrates

International Nuclear Information System (INIS)

Elton, N J

2009-01-01

The optical determination of rms roughness at the sub-wavelength scale by measurement of specular intensity as a function of wavelength or angle of incidence is well known. The method is normally used for specimens that are macroscopically flat. However, important industrial materials such as coated paper and paint consist of microscopically rough pigment coatings on a macroscopically rough substrate. Numerical modelling is used to assess the applicability and limitations of optical measurement of microroughness for such materials. Experimental results are presented for a range of paints on substrates of various macroroughness. Model and data are in fair agreement and show that the presence of substrate macroroughness always leads to an underestimation of microroughness. Generally, optical measurements of microroughness are only comparable for substrates of similar macroroughness and a limiting value exists above which measurements may not be meaningful

Multilayer ultra-high-temperature ceramic coatings

Science.gov (United States)

Loehman, Ronald E [Albuquerque, NM; Corral, Erica L [Tucson, AZ

2012-03-20

A coated carbon-carbon composite material with multiple ceramic layers to provide oxidation protection from ultra-high-temperatures, where if the carbon-carbon composite material is uninhibited with B.sub.4C particles, then the first layer on the composite material is selected from ZrB.sub.2 and HfB.sub.2, onto which is coated a layer of SiC coated and if the carbon-carbon composite material is inhibited with B.sub.4C particles, then protection can be achieved with a layer of SiC and a layer of either ZrB.sub.2 and HfB.sub.2 in any order.

Improved wettability and adhesion of polylactic acid/chitosan coating for bio-based multilayer film development

Science.gov (United States)

Gartner, Hunter; Li, Yana; Almenar, Eva

2015-03-01

The objective of this study was to investigate the effect of methyldiphenyl diisocyanate (MDI) concentration (0, 0.2, 1, 2, and 3%) on the wettability and adhesion of blend solutions of poly(lactic acid) (PLA) and chitosan (CS) when coated on PLA film for development of a bio-based multi-layer film suitable for food packaging and other applications. Characterization was carried out by attenuated total reflectance infrared spectrometry (ATR-FTIR), contact angle (θ), mechanical adhesion pull-off testing, and scanning electron microscopy (SEM). The θ of the PLA/CS blend shifted to a lower value (41-35°) with increasing MDI concentration showing that the surface tension was modified between the PLA/CS blend solution and PLA film and better wettability was achieved. The increase in MDI also resulted in an increased breaking strength (228-303 kPa) due to the increased H-bonding resulting from the more urethane groups formed within the PLA/CS blend as shown by ATR-FTIR. The improved adhesion was also shown by the increased number of physical entanglements observed by SEM. It can be concluded that MDI can be used to improve wettability and adhesion between PLA/CS coating and PLA film.

Finite-width plasmonic waveguides with hyperbolic multilayer cladding

DEFF Research Database (Denmark)

Babicheva, Viktoriia; Shalaginov, Mikhail Y.; Ishii, Satoshi

2015-01-01

Engineering plasmonic metamaterials with anisotropic optical dispersion enables us to tailor the properties of metamaterial-based waveguides. We investigate plasmonic waveguides with dielectric cores and multilayer metal-dielectric claddings with hyperbolic dispersion. Without using any homogeniz......Engineering plasmonic metamaterials with anisotropic optical dispersion enables us to tailor the properties of metamaterial-based waveguides. We investigate plasmonic waveguides with dielectric cores and multilayer metal-dielectric claddings with hyperbolic dispersion. Without using any...

Preparation and Electrochemical Properties of Graphene/Epoxy Resin Composite Coating

Science.gov (United States)

Liao, Zijun; Zhang, Tianchi; Qiao, Sen; Zhang, Luyihang

2017-11-01

The multilayer graphene powder as filler, epoxy modified silicone resin as film-forming agent, anticorrosion composite coating has been created using sand dispersion method, the electrochemical performance was compared with different content of graphene composite coating and pure epoxy resin coating. The open circuit potential (OCP), potentiodynamic polarization curves (Tafel Plot) and electrochemical impedance spectroscopy (EIS) were tested. The test results showed that the anti-corrosion performance of multilayer graphene added has improved greatly, and the content of the 5% best corrosion performance of graphene composite coating.

Significant degradability enhancement in multilayer coating of polycaprolactone-bioactive glass/gelatin-bioactive glass on magnesium scaffold for tissue engineering applications

Energy Technology Data Exchange (ETDEWEB)

Yazdimamaghani, Mostafa [School of Chemical Engineering, Oklahoma State University, Stillwater, OK 74078 (United States); School of Materials Science and Engineering, Helmerich Advanced Technology Research Center, Oklahoma State University, Tulsa, OK 74106 (United States); Razavi, Mehdi [School of Materials Science and Engineering, Helmerich Advanced Technology Research Center, Oklahoma State University, Tulsa, OK 74106 (United States); Vashaee, Daryoosh [Electrical and Computer Engineering Department, North Carolina State University, Raleigh, NC 27606 (United States); Pothineni, Venkata Raveendra [Biomaterials and Advanced Drug Delivery Laboratory, Stanford University, Palo Alto, CA 94305 (United States); Rajadas, Jayakumar [Biomaterials and Advanced Drug Delivery Laboratory, Stanford University, Palo Alto, CA 94305 (United States); Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Palo Alto, CA 94305 (United States); Stanford Cardiovascular Institute, Stanford University School of Medicine, Palo Alto, CA 94305 (United States); Tayebi, Lobat, E-mail: lobat.tayebi@marquette.edu [School of Materials Science and Engineering, Helmerich Advanced Technology Research Center, Oklahoma State University, Tulsa, OK 74106 (United States); Biomaterials and Advanced Drug Delivery Laboratory, Stanford University, Palo Alto, CA 94305 (United States); Department of Developmental Sciences, Marquette University School of Dentistry, Milwaukee, WI 53233 (United States)

2015-05-30

Highlights: • PCL-BaG/Gel-BaG coating was applied on the surface of Mg scaffolds. • Mg scaffold/PCL-BaG/Gel-BaG presented improved biodegradation resistance. • Mg scaffold coated with the PCL-BaG layer indicated better bioactivity. - Abstract: Magnesium (Mg) is a promising candidate to be used in medical products especially as bone tissue engineering scaffolds. The main challenge for using Mg in biomedical applications is its high degradation rate in the body. For this reason, in this study, a multilayer polymeric layer composed of polycaprolactone (PCL) and gelatin (Gel) reinforced with bioactive glass (BaG) particles has been applied on the surface of Mg scaffolds. The materials characteristics of uncoated Mg scaffold, Mg scaffold coated only with PCL-BaG and Mg scaffold coated with PCL-BaG and Gel-BaG have been analyzed and compared in detail. Scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR) were utilized for microstructural studies. In vitro bioactivity and biodegradation evaluations were carried out by submerging the scaffolds in simulated body fluid (SBF) at pre-determined time points. The results demonstrated that Mg scaffold coated with PCL-BaG and Gel-BaG exhibited significant improvement in biodegradability.

Significant degradability enhancement in multilayer coating of polycaprolactone-bioactive glass/gelatin-bioactive glass on magnesium scaffold for tissue engineering applications

International Nuclear Information System (INIS)

Yazdimamaghani, Mostafa; Razavi, Mehdi; Vashaee, Daryoosh; Pothineni, Venkata Raveendra; Rajadas, Jayakumar; Tayebi, Lobat

2015-01-01

Highlights: • PCL-BaG/Gel-BaG coating was applied on the surface of Mg scaffolds. • Mg scaffold/PCL-BaG/Gel-BaG presented improved biodegradation resistance. • Mg scaffold coated with the PCL-BaG layer indicated better bioactivity. - Abstract: Magnesium (Mg) is a promising candidate to be used in medical products especially as bone tissue engineering scaffolds. The main challenge for using Mg in biomedical applications is its high degradation rate in the body. For this reason, in this study, a multilayer polymeric layer composed of polycaprolactone (PCL) and gelatin (Gel) reinforced with bioactive glass (BaG) particles has been applied on the surface of Mg scaffolds. The materials characteristics of uncoated Mg scaffold, Mg scaffold coated only with PCL-BaG and Mg scaffold coated with PCL-BaG and Gel-BaG have been analyzed and compared in detail. Scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR) were utilized for microstructural studies. In vitro bioactivity and biodegradation evaluations were carried out by submerging the scaffolds in simulated body fluid (SBF) at pre-determined time points. The results demonstrated that Mg scaffold coated with PCL-BaG and Gel-BaG exhibited significant improvement in biodegradability

Dependences of the Al thickness and annealing temperature on the structural, optical and electrical properties in ZnO/Al multilayers

International Nuclear Information System (INIS)

Hu, Y.M.; Lin, C.W.; Huang, J.C.A.

2006-01-01

High-quality (0001) oriented ZnO (300 A) film and [ZnO(100 A)/Al(t Al )] 3 (t Al = 0.6, 1.7, 2.8 A) multilayers have been established at room temperature on Al 2 O 3 (0001) substrates by ion-beam sputtering. The structural, optical and electrical properties of multilayers as functions of both the Al thickness and annealing temperature are reported. We have verified that Al thickness and annealing temperature are the key factors to optimize transparency-conducting property in ZnO/Al multilayers. The optimum Al thickness and annealing temperature for ZnO/Al multilayer of 300 A thin is 1.7 A (about one Al atomic layer) and 400 deg. C, respectively, leading to the relatively lower resistivity (2.8 x 10 -3 Ω cm) and higher Hall mobility (10 cm 2 /V.s) without suppression of the visible transmittance (above 85%)