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Sample records for electrodeposited co-w-p amorphous

  1. Diffusion barrier characteristics and shear fracture behaviors of eutectic PbSn solder/electroless Co(W,P) samples

    International Nuclear Information System (INIS)

    Pan, Hung-Chun; Hsieh, Tsung-Eong

    2012-01-01

    Highlights: ► Diffusion barrier features, activation energies of IMC growth and mechanical behaviors of electroless Co(W,P)/PbSn joints. ► Amorphous Co(W,P) is a sacrificial- plus stuffed-type barrier while polycrystalline Co(W,P) is a sacrificial-type barrier. ► Ductile mode dominates the failure of Co(W,P)/PbSn joints. ► Phosphorus content of Co(W,P) is crucial to the barrier capability and microstructure evolution at Co(W,P)/PbSn interface. ► Diffusion barrier capability is governed by the nature of chemical bonds, rather than the crystallinity of materials. - Abstract: Diffusion barrier characteristics, activation energy (E a ) of IMC growth and bonding properties of amorphous and polycrystalline electroless Co(W,P) (termed as α-Co(W,P) and poly-Co(W,P)) to eutectic PbSn solder are presented. Intermetallic compound (IMC) spallation and an nano-crystalline P-rich layer were observed in PbSn/α-Co(W,P) samples subjected to liquid-state aging at 250 °C. In contrast, IMCs resided on the P-rich layer in PbSn/α-Co(W,P) samples subjected to solid-state aging at 150 °C. Thick IMCs neighboring to an amorphous W-rich layer was seen in PbSn/poly-Co(W,P) samples regardless of the aging type. α-Co(W,P) was found to be a sacrificial- plus stuffed-type barrier while poly-Co(W,P) is mainly a sacrificial-type barrier. The values of E a 's for PbSn/α-Co(W,P) and PbSn/poly-Co(W,P) systems were 338.6 and 167.5 kJ/mol, respectively. Shear test revealed the ductile mode dominates the failure in both α- and poly-Co(W,P) samples. Analytical results indicated the high P content in electroless layer might enhance the barrier capability but degrade the bonding strength.

  2. ZnTe Amorphous Semiconductor Nanowires Array Electrodeposited into Polycarbonate Membrane Thin Films

    International Nuclear Information System (INIS)

    Ohgai, T; Ikeda, T; Ohta, J

    2013-01-01

    ZnTe amorphous semiconductor nanowires array was electrodeposited into the nanochannels of ion-track etched polycarbonate membrane thin films from acidic aqueous solution at 313 K. ZnTe electrodeposits with Zn-rich composition was obtained over the wide range of cathode potential from −0.8 V to −1.1 V and the growth rate of ZnTe amorphous nanowires was around 3 nm.sec −1 at the cathode potential of −0.8 V. Cylindrical shape of the nanowires was precisely transferred from the nanochannels and the aspect ratio reached up to ca. 40. ZnTe amorphous phase electrodeposited at 313 K was crystallized by annealing at 683 K and the band gap energy of ZnTe crystalline phase reached up to ca. 2.13 eV.

  3. Electrodeposition of Amorphous Molybdenum Chalcogenides from Ionic Liquids and Their Activity for the Hydrogen Evolution Reaction.

    Science.gov (United States)

    Redman, Daniel W; Rose, Michael J; Stevenson, Keith J

    2017-09-19

    This work reports on the general electrodeposition mechanism of tetrachalcogenmetallates from 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. Both tetrathio- and tetraselenomolybdate underwent anodic electrodeposition and cathodic corrosion reactions as determined by UV-vis spectroelectrochemistry. Electrodeposition was carried out by cycling the potential between the anodic and cathodic regimes. This resulted in a film of densely packed nanoparticles of amorphous MoS x or MoSe x as determined by SEM, Raman, and XPS. The films were shown to have high activity for the hydrogen evolution reaction. The onset potential (J = 1 mA/cm 2 ) of the MoS x film was E = -0.208 V vs RHE, and that of MoSe x was E = -0.230 V vs RHE. The Tafel slope of MoS x was 42 mV/decade, and that of MoSe x was 59 mV/decade.

  4. Electrochemical evaluation of corrosion and tribocorrosion behaviour of amorphous and nanocrystalline cobalt–tungsten electrodeposited coatings

    Energy Technology Data Exchange (ETDEWEB)

    Fathollahzade, N.; Raeissi, K., E-mail: k_raeissi@cc.iut.ac.ir

    2014-11-14

    Amorphous and nanocrystalline Co–W coatings were electrodeposited on copper substrates from a citrate–ammonia bath. The coatings showed nodular surface morphologies, but a microcrack network was detected in the amorphous coating. However, a better corrosion resistance was achieved for the amorphous coating. During sliding under open circuit potential (OCP) condition, the potential of amorphous coating gradually became more active probably due to the widening of wear scar, and thus expansion of active area. The amorphous coatings showed a higher volume loss at OCP probably due to its lower microhardness. In anodic sliding, a sharp increase in current density was observed due to mass transport and depassivation effects. In all sliding conditions, the proportion of mass transport was higher than wear accelerated corrosion, which implied that the dissolution reaction of the coatings was mainly a mass-transport controlled process. The results also showed that the effect of sliding on degradation is more intense for the nanocrystalline coating. For both coatings, the formation of the superficial microcracks in the vicinity of wear scars indicating on a surface fatigue wear mechanism. - Highlights: • Mass-transport effect had higher proportion in tribocorrosion of Co–W coatings. • The major electrochemical-wear degradation was for the nanocrystalline coating. • The higher proportion of wear accelerated corrosion was for the amorphous coating. • Superficial microcracks were formed near scars due to the coatings brittleness.

  5. The effect of nickel electrodeposition on magnetic properties of CoFeSiB amorphous wire

    International Nuclear Information System (INIS)

    Atalay, F.E.

    2004-01-01

    Nickel films were electrodeposited on rapidly quenched amorphous wires from nitrate bath using a constant voltage. It was found that the pH of plating bath had a very strong effect on the formation of nickel films. The magnetic field, H, dependence of the impedance, of nickel plated (Co 0.94 Fe 0.06 ) 72.5 Si 12.5 B 15 wires have been investigated using a Hewlett-Packard 4294A impedance analyser with 42941A impedance probe. The best elecroplating condition and GMI response were obtained for the plated wire at pH 5 for 30 min plating time

  6. Electrodeposition at room temperature of amorphous silicon and germanium nanowires in ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Martineau, F; Namur, K; Mallet, J; Delavoie, F; Troyon, M; Molinari, M [Laboratoire de Microscopies et d' Etude de Nanostructures (LMEN EA3799), Universite de Reims Champagne Ardennes (URCA), Reims Cedex 2 (France); Endres, F, E-mail: michael.molinari@univ-reims.fr [Institute of Particle Technology, Chair of Interface Processes, Clausthal University of Technology, D-36678 Clausthal-Zellerfeld (Germany)

    2009-11-15

    The electrodeposition at room temperature of silicon and germanium nanowires from the air- and water-stable ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (P{sub 1,4}) containing SiCl{sub 4} as Si source or GeCl{sub 4} as Ge source is investigated by cyclic voltammetry. By using nanoporous polycarbonate membranes as templates, it is possible to reproducibly grow pure silicon and germanium nanowires of different diameters. The nanowires are composed of pure amorphous silicon or germanium. The nanowires have homogeneous cylindrical shape with a roughness of a few nanometres on the wire surfaces. The nanowires' diameters and lengths well match with the initial membrane characteristics. Preliminary photoluminescence experiments exhibit strong emission in the near infrared for the amorphous silicon nanowires.

  7. Cathodic electrodeposition of amorphous elemental selenium from an air- and water-stable ionic liquid.

    Science.gov (United States)

    Redman, Daniel W; Murugesan, Sankaran; Stevenson, Keith J

    2014-01-14

    Electrodeposition of selenium from 1-propyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide is reported. In situ UV-vis spectroelectrochemistry was used to investigate the reduction of diethyl selenite to form elemental selenium thin films from an ionic liquid-acetonitrile medium. Three reduction peaks of diethyl selenite were observed via cyclic voltammetry and are attributed to the stepwise reduction of the selenium precursor adsorbed on the electrode. The electrodeposition mechanism is influenced by both potential and time. Electrodeposition at -1.7 V vs Pt QRE resulted in the deposition of elemental selenium nanoparticles that with time coalesced to form a continuous film. At reduction potentials more negative than -1.7 V the morphology of the deposit changed significantly due to the reduction of elemental Se to Se(2-). In addition, p-type photoconductivity of the films was observed during the spectroelectrochemical measurements. X-ray diffraction and Raman spectroscopy confirmed that the deposited selenium films were amorphous. X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy confirm the films consisted of pure selenium with minor residual contamination from the precursor and ionic liquid.

  8. Metallic amorphous electrodeposited molybdenum coating from aqueous electrolyte: Structural, electrical and morphological properties under current density

    Energy Technology Data Exchange (ETDEWEB)

    Nemla, Fatima [LEPCM, Department of Physics, University of Batna (Algeria); Cherrad, Djellal, E-mail: cherradphisic@yahoo.fr [Laboratory for Developing New Materials and Their Characterizations, University of Setif (Algeria)

    2016-07-01

    Graphical abstract: - Highlights: • Although difficulties related to electrodeposition of Mo films, we have successfully coated onto a cooper substrate. • A good formation of bcc Mo phase and lattice parameter was very accurate. • It seems that electrical properties of our samples are good and suitable as back contact for thin film solar cells. • It seems that grain size, microstrain and dislocation density are all managed and correlated to retain the resistivity to a considerable minimum value. - Abstract: Molybdenum coatings are extensively utilized as back contact for CIGS-based solar cells. However, their electrodeposition from aqueous electrolyte still sophisticates, since long time, owing to the high reactivity with oxygen. In this study, we present a successful 30 min electrodeposition experiment of somewhat thick (∼0.98–2.9 μm) and of moderate surface roughness RMS (∼47–58 nm), metallic bright Mo coating from aqueous electrolyte containing molybdate ions. XRD analysis and Hall Effect measurements have been used to confirm the presence of Mo. The crystal structure of deposits was slightly amorphous in nature to body centred cubic structure (bcc) Mo (110), (211) and (220) face. Lattice parameters exhibit some weak fluctuated tensile stress when compared to the reference lattice parameter. Additionally, our calculated lattice parameters are in good agreement with some previous works from literature. Discussions on the grain growth prove that they are constrained by grain boundary energy not the thickness effect. Further discussions were made on the electrical resistivity and surface morphology. Resonance scattering of Fermi electrons are expected to contribute towards the variation in the film resistivity through the carrier mobility limitation. However, studied samples might be qualified as candidates for solar cell application.

  9. Control and optimization of baths for electrodeposition of Co-Mo-B amorphous alloys

    Directory of Open Access Journals (Sweden)

    S. Prasad

    2000-12-01

    Full Text Available Optimization and control of an electrodeposition process for depositing boron-containing amorphous metallic layer of cobalt-molybdenum alloy onto a cathode from an electrolytic bath having cobalt sulfate, sodium molybdate, boron phosphate, sodium citrate, 1-dodecylsulfate-Na, ammonium sulfate and ammonia or sulfuric acid for pH adjustments has been studied. Detailed studies on bath composition, pH, temperature, mechanical agitation and cathode current density have led to optimum conditions for obtaining satisfactory alloy deposits. These alloys were found to have interesting properties such as high hardness, corrosion resistance, wear resistance and also sufficient ductility. A voltammetric method for automatic monitoring and control of the process has been proposed.

  10. Electrodeposited porous and amorphous copper oxide film for application in supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Patake, V.D. [Thin Film Physics Laboratory, Department of Physics, Shivaji University, Kolhapur 416004, (M.S.) (India); Joshi, S.S. [Clean Energy Research Center, Korea Institute of Science and Technology, Cheongryang, Seoul 130-650 (Korea, Republic of); Lokhande, C.D. [Thin Film Physics Laboratory, Department of Physics, Shivaji University, Kolhapur 416004, (M.S.) (India); Clean Energy Research Center, Korea Institute of Science and Technology, Cheongryang, Seoul 130-650 (Korea, Republic of)], E-mail: l_chandrakant@yahoo.com; Joo, Oh-Shim [Clean Energy Research Center, Korea Institute of Science and Technology, Cheongryang, Seoul 130-650 (Korea, Republic of)], E-mail: joocat@kist.rre.kr

    2009-03-15

    In present study, the porous amorphous copper oxide thin films have been deposited from alkaline sulphate bath. The cathodic electrodeposition method was employed to deposit copper oxide film at room temperature on stainless steel substrate. Their structural and surface morphological properties were investigated by means of X-ray diffraction (XRD) and scanning electron micrograph (SEM), respectively. To propose this as a new material for possible application in the supercapacitor, its electrochemical properties have been studied in aqueous 1 M Na{sub 2}SO{sub 4} electrolyte using cyclic voltammetry. The structural analysis from XRD pattern showed the formation of amorphous copper oxide film on the substrate. The surface morphological studies from scanning electron micrographs revealed the formation of porous cauliflower-like copper oxide film. The cyclic voltammetric curves showed symmetric nature and increase in capacitance with increase in film thickness. The maximum specific capacitance of 36 F g{sup -1} was exhibited for the 0.6959 mg cm{sup -2} film thickness. This shows that low-cost copper oxide electrode will be a potential application in supercapacitor.

  11. Deformation behavior of an electrodeposited nano-Ni/amorphous Fe78Si9B13 laminated composite sheet

    Directory of Open Access Journals (Sweden)

    Zhang Kaifeng

    2015-01-01

    Full Text Available A nano-Ni/amorphous Fe78Si9B13 composite sheet was prepared in the form of three-ply (Ni-Fe78Si9B13-Ni laminated structure by an electrodeposition method. The average grain size of Ni layers is about 50 nm. The interface of laminated composite was investigated with SEM equipped with energy dispersive scanning (EDS and line analysis technique. The laminated composite has a good interfacial bonding between amorphous layer and nano-Ni layers due to the mutual diffusion of atoms in Fe78Si9B13 and Ni layers during the process of electrodeposition. A maximum elongation of 115.5% was obtained when the volume fraction of nano-Ni layers (VNi was 0.77, which is greatly higher than that of monolithic amorphous Fe78Si9B13 ribbon (36.3% tested under the same conditions. Bulging tests were carried out to evaluate plastic forming properties of the Fe78Si9B13/Ni laminated composite. Under the condition of 450 °C, 4.0 MPa and 30 min, a good bulging part with the relative bulging height (RBH of 0.4 was obtained.

  12. Controlling electrodeposited ultrathin amorphous Fe hydroxides film on V-doped nickel sulfide nanowires as efficient electrocatalyst for water oxidation

    Science.gov (United States)

    Shang, Xiao; Yan, Kai-Li; Lu, Shan-Shan; Dong, Bin; Gao, Wen-Kun; Chi, Jing-Qi; Liu, Zi-Zhang; Chai, Yong-Ming; Liu, Chen-Guang

    2017-09-01

    Developing cost-effective electrocatalysts with both high activity and stability remains challenging for oxygen evolution reaction (OER) in water electrolysis. Herein, based on V-doped nickel sulfide nanowire on nickel foam (NiVS/NF), we further conduct controllable electrodeposition of Fe hydroxides film on NiVS/NF (eFe/NiVS/NF) to further improve OER performance and stability. For comparison, ultrafast chemical deposition of Fe hydroxides on NiVS/NF (uFe/NiVS/NF) is also utilized. V-doping of NiVS/NF may introduce more active sites for OER, and nanowire structure can expose abundant active sites and facilitate mass transport. Both of the two depositions generate amorphous Fe hydroxides film covering on the surface of nanowires and lead to enhanced OER activities. Furthermore, electrodeposition strategy realizes uniform Fe hydroxides film on eFe/NiVS/NF confirmed by superior OER activity of eFe/NiVS/NF than uFe/NiVS/NF with relatively enhanced stability. The OER activity of eFe/NiVS/NF depends on various electrodepositon time, and the optimal time (15 s) is obtained with maximum OER activity. Therefore, the controllable electrodeposition of Fe may provide an efficient and simple strategy to enhance the OER properties of electrocatalysts.

  13. Electrodeposition of amorphous Ni-P coatings onto Nd-Fe-B permanent magnet substrates

    Energy Technology Data Exchange (ETDEWEB)

    Ma, C.B [Department of Chemistry, Yuquan campus, Zhejiang University, Hangzhou 310027 (China); Cao, F.H [Department of Chemistry, Yuquan campus, Zhejiang University, Hangzhou 310027 (China); Zhang, Z. [Department of Chemistry, Yuquan campus, Zhejiang University, Hangzhou 310027 (China)]. E-mail: eaglezzy@zjuem.zju.edu.cn; Zhang, J.Q [Department of Chemistry, Yuquan campus, Zhejiang University, Hangzhou 310027 (China); State Key Laboratory for Corrosion and Protection of Metals, Institute of Metal Research, The Chinese Academy of Sciences, Shenyang 110016 (China)

    2006-12-15

    Decorative and protective Ni-P amorphous coatings were electroplated onto NdFeB permanent magnet from an ortho-phosphorous acid contained bath. The influences of the main electroplating technological parameters including current density, bath pH, bath temperature and H{sub 3}PO{sub 3} on the structure and chemical composition of Ni-P coatings were investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques in conjunction with X-ray diffraction (XRD), scanning transmission electron microscopy (SEM) and X-ray energy-dispersive spectrometry (EDX). The optimized amorphous Ni-P coated NdFeB can stand for ca. 180 h against neutral 3.0 wt.% NaCl salt spray without any pitting corrosion. Meanwhile, the results also showed that large phosphorous content is the precondition for Ni-P coatings to possess the amorphous structure, but too much high phosphorous content can damage the amorphous structure due to the separation of superfluous P from Ni{sub 2}P/Ni{sub 3}P and the resultant formation of multi-phase coatings (such as Ni{sub 2}P-P)

  14. Amorphous Al–Mn coating on NdFeB magnets: Electrodeposition from AlCl3–EMIC–MnCl2 ionic liquid and its corrosion behavior

    International Nuclear Information System (INIS)

    Chen Jing; Xu Bajin; Ling Guoping

    2012-01-01

    Amorphous Al–Mn coating was electrodeposited on NdFeB magnets from AlCl 3 –EMIC–MnCl 2 ionic liquid with the pretreatment of anodic electrolytic etching in AlCl 3 –EMIC ionic liquid at room temperature. The microstructure, composition and phase constituents of the coatings were investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The corrosion resistance of the coatings was tested by means of potentiodynamic polarization and immersion test in 3.5 wt. % NaCl solution. The results show that anodic electrolytic etching in AlCl 3 –EMIC ionic liquid is a satisfactory pretreatment to remove the surface oxide film and favor the adhesion of the Al–Mn alloy coating to the NdFeB substrate. The amorphous Al–Mn alloy coating provides sacrificial anodic protection for NdFeB. It exhibited good corrosion resistance and significantly reduced the corrosion current density of NdFeB by three orders of magnitude at potentiodynamic polarization. - Highlights: ► Amorphous Al–Mn alloy coating was electrodeposited on NdFeB magnet from ionic liquid. ► To remove the surface oxides of NdFeB, anodic etching pretreatment is used. ► The deposited Al–Mn alloy coating shows high adhesion to the NdFeB substrate. ► Corrosion tests show that amorphous Al–Mn alloy coating is anodic coating for NdFeB magnet.

  15. Amorphous Al-Mn coating on NdFeB magnets: Electrodeposition from AlCl{sub 3}-EMIC-MnCl{sub 2} ionic liquid and its corrosion behavior

    Energy Technology Data Exchange (ETDEWEB)

    Chen Jing; Xu Bajin [Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Ling Guoping, E-mail: linggp@zju.edu.cn [Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China)

    2012-06-15

    Amorphous Al-Mn coating was electrodeposited on NdFeB magnets from AlCl{sub 3}-EMIC-MnCl{sub 2} ionic liquid with the pretreatment of anodic electrolytic etching in AlCl{sub 3}-EMIC ionic liquid at room temperature. The microstructure, composition and phase constituents of the coatings were investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The corrosion resistance of the coatings was tested by means of potentiodynamic polarization and immersion test in 3.5 wt. % NaCl solution. The results show that anodic electrolytic etching in AlCl{sub 3}-EMIC ionic liquid is a satisfactory pretreatment to remove the surface oxide film and favor the adhesion of the Al-Mn alloy coating to the NdFeB substrate. The amorphous Al-Mn alloy coating provides sacrificial anodic protection for NdFeB. It exhibited good corrosion resistance and significantly reduced the corrosion current density of NdFeB by three orders of magnitude at potentiodynamic polarization. - Highlights: Black-Right-Pointing-Pointer Amorphous Al-Mn alloy coating was electrodeposited on NdFeB magnet from ionic liquid. Black-Right-Pointing-Pointer To remove the surface oxides of NdFeB, anodic etching pretreatment is used. Black-Right-Pointing-Pointer The deposited Al-Mn alloy coating shows high adhesion to the NdFeB substrate. Black-Right-Pointing-Pointer Corrosion tests show that amorphous Al-Mn alloy coating is anodic coating for NdFeB magnet.

  16. Electro-Deposition Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The electro-deposition laboratory can electro-deposit various coatings onto small test samples and bench level prototypes. This facility provides the foundation for...

  17. Moessbauer study of amorphous Fe-P alloys

    International Nuclear Information System (INIS)

    Takacs, L.; Toth-Kadar, E.

    1981-01-01

    Preliminary Moessbauer results are represented on electrodeposited Fe-P amorphous alloys. Very broad hyperfine field distributions and relatively large isomer shifts have been found. Problems worth of further investigation are discussed in details. (author)

  18. Electrodeposition of Radium

    International Nuclear Information System (INIS)

    Crespo, M.T.; Jimenez, A.S.

    1996-01-01

    A study of different electrodeposition methods of radium for its measurement by alpha-spectrometry is presented. The recommended procedure uses an aqueous solution of ammonium oxalate and nitric acid in the presence of microgram amounts of platinum as electrolyte

  19. Phase-Change Memory Properties of Electrodeposited Ge-Sb-Te Thin Film

    Science.gov (United States)

    Huang, Ruomeng; Kissling, Gabriela P.; Jolleys, Andrew; Bartlett, Philip N.; Hector, Andrew L.; Levason, William; Reid, Gillian; De Groot, C. H. `Kees'

    2015-11-01

    We report the properties of a series of electrodeposited Ge-Sb-Te alloys with various compositions. It is shown that the Sb/Ge ratio can be varied in a controlled way by changing the electrodeposition potential. This method opens up the prospect of depositing Ge-Sb-Te super-lattice structures by electrodeposition. Material and electrical characteristics of various compositions have been investigated in detail, showing up to three orders of magnitude resistance ratio between the amorphous and crystalline states and endurance up to 1000 cycles.

  20. Characterisation of electrodeposited and heat-treated Ni-Mo-P coatings

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Regis L.; Casciano, Paulo N.S.; Correia, Adriana N.; Lima-Neto, Pedro de, E-mail: pln@ufc.br [Departamento de Quimica Analitica e Fisico-Quimica, Universidade Federal do Ceara, Fortaleza, CE (Brazil)

    2012-07-01

    The electrodeposition, hardness and corrosion resistance properties of Ni-Mo-P coatings were investigated. Characterisations of the electrodeposited coatings were carried out using scanning electron microscopy, X-ray diffraction and energy dispersive X-ray analysis techniques. Corrosion tests were performed at room temperature in 10-1 mol dm-3 NaCl solutions and by potentiodynamic linear polarisation. Amorphous Ni-Mo-P coatings were successfully obtained by electrodeposition using direct current. The coating composition showed to be dependent on the bath composition, current density and bath temperature. Both P and Mo contents contribute for the hardness properties of the Ni-Mo-P coatings and the absence of cracks is a requirement to produce electrodeposited Ni-Mo-P coatings with good hardness properties. The hardness values increase with heat-treatment temperature due to the precipitation of Ni, Ni{sub 3}P and NiMo phases during the heat treatment. The corrosion resistance of the electrodeposited Ni-Mo-P amorphous coatings increases with P content in the layer. Among the electrodeposited Ni-Mo-P amorphous coatings, Ni{sub 78}Mo{sub 10}P{sub 12} presented the best hardness and corrosion-resistance properties. The results showed that the addition of P is beneficial for the hardness and corrosion resistance properties of the Ni-Mo-based coatings. (author)

  1. Electrodeposition of germanium from supercritical fluids.

    Science.gov (United States)

    Ke, Jie; Bartlett, Philip N; Cook, David; Easun, Timothy L; George, Michael W; Levason, William; Reid, Gillian; Smith, David; Su, Wenta; Zhang, Wenjian

    2012-01-28

    Several Ge(II) and Ge(IV) compounds were investigated as possible reagents for the electrodeposition of Ge from liquid CH(3)CN and CH(2)F(2) and supercritical CO(2) containing as a co-solvent CH(3)CN (scCO(2)) and supercritical CH(2)F(2) (scCH(2)F(2)). For Ge(II) reagents the most promising results were obtained using [NBu(n)(4)][GeCl(3)]. However the reproducibility was poor and the reduction currents were significantly less than the estimated mass transport limited values. Deposition of Ge containing films was possible at high cathodic potential from [NBu(n)(4)][GeCl(3)] in liquid CH(3)CN and supercritical CO(2) containing CH(3)CN but in all cases they were heavily contaminated by C, O, F and Cl. Much more promising results were obtained using GeCl(4) in liquid CH(2)F(2) and supercritical CH(2)F(2). In this case the reduction currents were consistent with mass transport limited reduction and bulk electrodeposition produced amorphous films of Ge. Characterisation by XPS showed the presence of low levels of O, F and C, XPS confirmed the presence of Ge together with germanium oxides, and Raman spectroscopy showed that the as deposited amorphous Ge could be crystallised by the laser used in obtaining the Raman measurements.

  2. Recent Advances in Superhydrophobic Electrodeposits

    Directory of Open Access Journals (Sweden)

    Jason Tam

    2016-03-01

    Full Text Available In this review, we present an extensive summary of research on superhydrophobic electrodeposits reported in the literature over the past decade. As a synthesis technique, electrodeposition is a simple and scalable process to produce non-wetting metal surfaces. There are three main categories of superhydrophobic surfaces made by electrodeposition: (i electrodeposits that are inherently non-wetting due to hierarchical roughness generated from the process; (ii electrodeposits with plated surface roughness that are further modified with low surface energy material; (iii composite electrodeposits with co-deposited inert and hydrophobic particles. A recently developed strategy to improve the durability during the application of superhydrophobic electrodeposits by controlling the microstructure of the metal matrix and the co-deposition of hydrophobic ceramic particles will also be addressed.

  3. Microstructure development in zinc oxide nanowires and iron oxohydroxide nanotubes by cathodic electrodeposition in nanopores

    NARCIS (Netherlands)

    Maas, M.G.; Rodijk, E.J.B.; Maijenburg, A.W.; Blank, David H.A.; ten Elshof, Johan E.

    2011-01-01

    The cathodic electrodeposition of crystalline ZnO nanowires and amorphous FeO(OH) nanotubes in polycarbonate track-etched membranes with pore diameters of 50–200 nm is reported. Nitrate was used as a sacrificial precursor for the electrochemical generation of hydroxyl ions that raised the pH of the

  4. Fabricating Copper Nanotubes by Electrodeposition

    Science.gov (United States)

    Yang, E. H.; Ramsey, Christopher; Bae, Youngsam; Choi, Daniel

    2009-01-01

    Copper tubes having diameters between about 100 and about 200 nm have been fabricated by electrodeposition of copper into the pores of alumina nanopore membranes. Copper nanotubes are under consideration as alternatives to copper nanorods and nanowires for applications involving thermal and/or electrical contacts, wherein the greater specific areas of nanotubes could afford lower effective thermal and/or electrical resistivities. Heretofore, copper nanorods and nanowires have been fabricated by a combination of electrodeposition and a conventional expensive lithographic process. The present electrodeposition-based process for fabricating copper nanotubes costs less and enables production of copper nanotubes at greater rate.

  5. Surface-Activated Amorphous Alloy Fuel Electrodes for Methanol Fuel Cell

    OpenAIRE

    Asahi, Kawashima; Koji, Hashimoto; The Research Institute for Iron, Steel and Other Metals; The Research Institute for Iron, Steel and Other Metals

    1983-01-01

    Amorphous alloy electrodes for electrochemical oxidation of methanol and its derivatives were obtained by the surface activation treatment consisting of electrodeposition of zinc on as-quenched amorphous alloy substrates, heating at 200-300℃ for 30 min, and subsequently leaching of zinc in an alkaline solution. The surface activation treatment provided a new method for the preparation of a large surface area on the amorphous alloys. The best result for oxidation of methanol, sodium formate an...

  6. Amorphous nanophotonics

    CERN Document Server

    Scharf, Toralf

    2013-01-01

    This book represents the first comprehensive overview over amorphous nano-optical and nano-photonic systems. Nanophotonics is a burgeoning branch of optics that enables many applications by steering the mould of light on length scales smaller than the wavelength with devoted nanostructures. Amorphous nanophotonics exploits self-organization mechanisms based on bottom-up approaches to fabricate nanooptical systems. The resulting structures presented in the book are characterized by a deterministic unit cell with tailored geometries; but their spatial arrangement is not controlled. Instead of periodic, the structures appear either amorphous or random. The aim of this book is to discuss all aspects related to observable effects in amorphous nanophotonic material and aspects related to their design, fabrication, characterization and integration into applications. The book has an interdisciplinary nature with contributions from scientists in physics, chemistry and materials sciences and sheds light on the topic fr...

  7. Efficient production of ultrapure manganese oxides via electrodeposition.

    Science.gov (United States)

    Cheney, Marcos A; Joo, Sang Woo; Banerjee, Arghya; Min, Bong-Ki

    2012-08-01

    A new process for the production of electrolytic amorphous nanomanganese oxides (EAMD) with uniform size and morphology is described. EAMD are produced for the first time by cathodic deposition from a basic aqueous solution of potassium permanganate at a constant temperature of 16°C. The synthesized materials are characterized by XRD, SEM, TEM, and HRTEM. The materials produced at 5.0 V at constant temperature are amorphous with homogeneous size and morphology with an average particle size around 20 nm, which appears to be much lesser than the previously reported anodic EAMD. A potentiostatic electrodeposition with much lesser deposition rate (with respect to previously reported anodic depositions) is considered to be the reason behind the very low and homogenous particle size distribution due to the lesser agglomeration of our as-synthesized nanoparticles. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Niobium electrodeposition from molten fluorides

    International Nuclear Information System (INIS)

    Sartori, A.F.

    1987-01-01

    Niobium electrodeposition from molten alkali fluorides has been studied aiming the application of this technic to the processes of electrorefining and galvanotechnic of this metal. The effects of current density, temperature, niobium concentration in the bath, electrolysis time, substrate nature, ratio between anodic and cathodic areas, electrodes separation and the purity of anodes were investigated in relation to the cathodic current efficiency, electrorefining, electroplating and properties of the deposit and the electrolytic solution. The work also gives the results of the conctruction and operation of a pilot plant for refractory metals electrodeposition and shows the electrorefining and electroplating compared to those obtained at the laboratory scale. (author) [pt

  9. Amorphous superconductors

    International Nuclear Information System (INIS)

    Missell, F.P.

    1985-01-01

    We describe briefly the strong coupling superconductivity observed in amorphous alloys based upon simple metals. For transition metal alloys we discuss the behavior of the superconducting transition temperature T c , the upper critical field H (sub)c2 and the critical current J c . A survey of current problems is presented. (author) [pt

  10. Electrodeposition of rhenium-tin nanowires

    International Nuclear Information System (INIS)

    Naor-Pomerantz, Adi; Eliaz, Noam; Gileadi, Eliezer

    2011-01-01

    Highlights: → Rhenium-tin nanowires were formed electrochemically, without using a template. → The nanowires consisted of a crystalline-Sn-core/amorphous-Re-shell structure. → The effects of bath composition and operating conditions were investigated. → A mechanism is suggested for the formation of the core/shell structure. → The nanowires may be attractive for a variety of applications. - Abstract: Rhenium (Re) is a refractory metal which exhibits an extraordinary combination of properties. Thus, nanowires and other nanostructures of Re-alloys may possess unique properties resulting from both Re chemistry and the nanometer scale, and become attractive for a variety of applications, such as in catalysis, photovoltaic cells, and microelectronics. Rhenium-tin coatings, consisting of nanowires with a core/shell structure, were electrodeposited on copper substrates under galvanostatic or potentiostatic conditions. The effects of bath composition and operating conditions were investigated, and the chemistry and structure of the coatings were studied by a variety of analytical tools. A Re-content as high as 77 at.% or a Faradaic efficiency as high as 46% were attained. Ranges of Sn-to-Re in the plating bath, applied current density and applied potential, within which the nanowires could be formed, were determined. A mechanism was suggested, according to which Sn nanowires were first grown on top of Sn micro-particles, and then the Sn nanowires reduced the perrhenate chemically, thus forming a core made of crystalline Sn-rich phase, and a shell made of amorphous Re-rich phase. The absence of mutual solubility of Re and Sn may be the driving force for this phase separation.

  11. DC electrodeposition of NiGa alloy nanowires in AAO template

    Energy Technology Data Exchange (ETDEWEB)

    Maleki, K. [Nanomaterials Group, Department of Materials Engineering, Tarbiat Modares University, Iran, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of); Sanjabi, S., E-mail: sanjabi@modares.ac.ir [Nanomaterials Group, Department of Materials Engineering, Tarbiat Modares University, Iran, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of); Alemipour, Z. [Department of Physics, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)

    2015-12-01

    NiGa alloy nanowires were electrodeposited from an acidic sulfate bath into nanoporous anodized alumina oxide (AAO). This template was fabricated by two-step anodizing. The effects of bath composition and current density were explored on the Ga content of electrodeposited nanowires. The Ga content in the deposits was increased by increasing both Ga in the bath composition and electrodepositing current density. The NiGa alloy nanowires were synthesized for Ga content up to 2–4% without significant improving the magnetic properties. Above this threshold Ga clusters were formed and decreased the magnetic properties of the nanowires. For Ga content of the alloy above 30%, the wires were too short and incomplete. X-ray diffraction patterns reveal that the significant increase of Ga content in the nanowires, changes the FCC crystal structure of Ni to an amorphous phase. It also causes a sizeable increase in the Ga cluster size; these both lead to a significant reduction in the coercivity and the magnetization respectively. - Highlights: • NiGa alloy nanowires were electrodeposited from acidic sulphate baths into nanoporous anodized alumina oxide (AAO) template. • The Ga content was increased by increasing the Ga in the bath composition and electrodeposition current density. • The magnetic parameters such as coercivity and magnetization were not changed for the alloy nanowire with Ga content less than 4%.

  12. Structural characterization of electrodeposited boron

    Indian Academy of Sciences (India)

    Structural characterization of electrodeposited boron was carried out by using transmission electron microscopy and Raman spectroscopy. Electron diffraction and phase contrast imaging were carried out by using transmission electron microscopy. Phase identification was done based on the analysis of electron diffraction ...

  13. ELECTRODEPOSITION OF NICKEL ON URANIUM

    Science.gov (United States)

    Gray, A.G.

    1958-08-26

    A method is described for preparing uranium objects prior to nickel electroplating. The process consiats in treating the surface of the uranium with molten ferric chloride hexahydrate, at a slightiy elevated temperature. This treatment etches the metal surface providing a structure suitable for the application of adherent electrodeposits and at the same time plates the surface with a thin protective film of iron.

  14. Electrodeposition of engineering alloy coatings

    DEFF Research Database (Denmark)

    Christoffersen, Lasse

    Nickel based electrodeposited alloys were investigated with respect to their deposition process, heat treatment, hardness, corrosion resistance and combined wear-corrosion resistance. The investigated alloys were Ni-B, Ni-P and Ni-W, which are not fully developed for industrial utilisation...... are written in brackets). Temperature and especially pH influenced the cathodic efficiency of the electrodeposition processes for Ni-W and Ni-P. Mass balance problems of the development alloy processes are identified.Heat treatment for one hour at approx. 350°C, 400°C and 600°C of electrodeposited Ni-B, Ni......-P and Ni-W, respectively, resulted in hardness values of approx. 1000 HV0.1 in the case of Ni-P(6), approx. 1100 HV0.1 in the case of Ni-W(40-53) and approx. 1300 HV0.1 in the case of Ni-B(5). Cracks, which emerged during electrodeposition and heat treatment, were observed on Ni-W and Ni-B.The corrosion...

  15. Electrodeposition: Principles, Applications and Methods

    International Nuclear Information System (INIS)

    Nur Ubaidah Saidin; Ying, K.K.; Khuan, N.I.

    2011-01-01

    Electrodeposition technique has been around for a very long time. It is a process of coating a thin layer of one metal on top of a different metal to modify its surface properties, by donating electrons to the ions in a solution. This bottom-up fabrication technique is versatile and can be applied to a wide range of potential applications. Electrodeposition is gaining popularity in recent years due to its capability in fabricating one-dimensional nano structures such as nano rods, nao wires and nano tubes. In this paper, we present an overview on the fabrication and characterization of high aspect ratio nano structures prepared using the nano electrochemical deposition system set up in our laboratory. (author)

  16. Radiation amorphization of materials

    International Nuclear Information System (INIS)

    Neklyudov, I.M.; Chernyaeva, T.P.

    1993-01-01

    The results of experimental and theoretical research on radiation amorphization are presented in this analytical review. Mechanism and driving forces of radiation amorphization are described, kinetic and thermodynamic conditions of amorphization are formulated. Compositional criteria of radiation amorphization are presented, that allow to predict irradiation behaviour of materials, their tendency to radiation amorphization. Mechanism of transition from crystalline state to amorphous state are considered depending on dose, temperature, structure of primary radiation damage and flux level. (author). 134 refs., 4 tab., 25 fig

  17. Crystallization of Electrodeposited Germanium Thin Film on Silicon (100).

    Science.gov (United States)

    Abidin, Mastura Shafinaz Zainal; Matsumura, Ryo; Anisuzzaman, Mohammad; Park, Jong-Hyeok; Muta, Shunpei; Mahmood, Mohamad Rusop; Sadoh, Taizoh; Hashim, Abdul Manaf

    2013-11-06

    We report the crystallization of electrodeposited germanium (Ge) thin films on n-silicon (Si) (100) by rapid melting process. The electrodeposition was carried out in germanium (IV) chloride: propylene glycol (GeCl₄:C₃H₈O₂) electrolyte with constant current of 50 mA for 30 min. The measured Raman spectra and electron backscattering diffraction (EBSD) images show that the as-deposited Ge thin film was amorphous. The crystallization of deposited Ge was achieved by rapid thermal annealing (RTA) at 980 °C for 1 s. The EBSD images confirm that the orientations of the annealed Ge are similar to that of the Si substrate. The highly intense peak of Raman spectra at 300 cm -1 corresponding to Ge-Ge vibration mode was observed, indicating good crystal quality of Ge. An additional sub peak near to 390 cm -1 corresponding to the Si-Ge vibration mode was also observed, indicating the Ge-Si mixing at Ge/Si interface. Auger electron spectroscopy (AES) reveals that the intermixing depth was around 60 nm. The calculated Si fraction from Raman spectra was found to be in good agreement with the value estimated from Ge-Si equilibrium phase diagram. The proposed technique is expected to be an effective way to crystallize Ge films for various device applications as well as to create strain at the Ge-Si interface for enhancement of mobility.

  18. Crystallization of Electrodeposited Germanium Thin Film on Silicon (100

    Directory of Open Access Journals (Sweden)

    Abdul Manaf Hashim

    2013-11-01

    Full Text Available We report the crystallization of electrodeposited germanium (Ge thin films on n-silicon (Si (100 by rapid melting process. The electrodeposition was carried out in germanium (IV chloride: propylene glycol (GeCl4:C3H8O2 electrolyte with constant current of 50 mA for 30 min. The measured Raman spectra and electron backscattering diffraction (EBSD images show that the as-deposited Ge thin film was amorphous. The crystallization of deposited Ge was achieved by rapid thermal annealing (RTA at 980 °C for 1 s. The EBSD images confirm that the orientations of the annealed Ge are similar to that of the Si substrate. The highly intense peak of Raman spectra at 300 cm−1 corresponding to Ge-Ge vibration mode was observed, indicating good crystal quality of Ge. An additional sub peak near to 390 cm−1 corresponding to the Si-Ge vibration mode was also observed, indicating the Ge-Si mixing at Ge/Si interface. Auger electron spectroscopy (AES reveals that the intermixing depth was around 60 nm. The calculated Si fraction from Raman spectra was found to be in good agreement with the value estimated from Ge-Si equilibrium phase diagram. The proposed technique is expected to be an effective way to crystallize Ge films for various device applications as well as to create strain at the Ge-Si interface for enhancement of mobility.

  19. Oriented hydroxyapatite single crystals produced by the electrodeposition method

    Energy Technology Data Exchange (ETDEWEB)

    Santos, E.A. dos, E-mail: euler@ufs.br [INSA - Groupe Ingenierie des Surfaces, 24, Bld de la Victoire, 67084 Strasbourg (France); IPCMS - Departement de Surfaces et Interfaces, 23, rue du Loess, BP 43, 67034 Strasbourg (France); Moldovan, M.S. [INSA - Groupe Ingenierie des Surfaces, 24, Bld de la Victoire, 67084 Strasbourg (France); IPCMS - Departement de Surfaces et Interfaces, 23, rue du Loess, BP 43, 67034 Strasbourg (France); Jacomine, L. [INSA - Groupe Ingenierie des Surfaces, 24, Bld de la Victoire, 67084 Strasbourg (France); Mateescu, M. [IS2M - Equipe Interaction Surface-Matiere Vivant, 15, rue Jean Starcky, BP 2488, 68057 Mulhouse (France); Werckmann, J. [IPCMS - Departement de Surfaces et Interfaces, 23, rue du Loess, BP 43, 67034 Strasbourg (France); Anselme, K. [IS2M - Equipe Interaction Surface-Matiere Vivant, 15, rue Jean Starcky, BP 2488, 68057 Mulhouse (France); Mille, P.; Pelletier, H. [INSA - Groupe Ingenierie des Surfaces, 24, Bld de la Victoire, 67084 Strasbourg (France)

    2010-05-25

    We propose here the use of cathodic electrodeposition as tool to fabricate implant coatings consisting in nano/micro single crystals of hydroxyapatite (HA), preferentially orientated along the c-axis. Coating characterization is the base of this work, where we discuss the mechanisms related to the deposition of oriented hydroxyapatite thin films. It is shown that when deposited on titanium alloys, the HA coating is constituted by two distinct regions with different morphologies: at a distance of few microns from the substrate, large HA single crystals are oriented along the c-axis and appear to grow up from a base material, consisting in an amorphous HA. This organized system has a great importance for cell investigation once the variables involved in the cell/surface interaction are reduced. The use of such systems could give a new insight on the effect of particular HA orientation on the osteoblast cells.

  20. Indium doped zinc oxide thin films obtained by electrodeposition

    International Nuclear Information System (INIS)

    Machado, G.; Guerra, D.N.; Leinen, D.; Ramos-Barrado, J.R.; Marotti, R.E.; Dalchiele, E.A.

    2005-01-01

    Indium doped ZnO thin films were obtained by co-electrodeposition (precursor and dopant) from aqueous solution. XRD analysis showed typical patterns of the hexagonal ZnO structure for both doped and undoped films. No diffraction peaks of any other structure such as In 2 O 3 or In(OH) 3 were found. The incorporation of In into the ZnO film was verified by both EDS and XPS measurements. The bandgap energy of the films varied from 3.27 eV to 3.42 eV, increasing with the In concentration in the solution. This dependence was stronger for the less cathodic potentials. The incorporation of In into the film occurs as both, an In donor state in the ZnO grains and as an amorphous In 2 O 3 at the grain boundaries

  1. Long Silver Nanowires Synthesis by Pulsed Electrodeposition

    Directory of Open Access Journals (Sweden)

    M.R. Batevandi

    2015-09-01

    Full Text Available Silver nanowires were pulse electrodeposited into nanopore anodic alumina oxide templates. The effects of continuous and pulse electrodeposition waveform on the microstructure properties of the nanowire arrays were studied. It is seen that the microstructure of nanowire is depend to pulse condition. The off time duration of pulse waveform enables to control the growth direction of Ag nanowires.

  2. Cationic electrodepositable coating composition comprising lignin

    Science.gov (United States)

    Fenn, David; Bowman, Mark P; Zawacky, Steven R; Van Buskirk, Ellor J; Kamarchik, Peter

    2013-07-30

    A cationic electrodepositable coating composition is disclosed. The present invention in directed to a cationic electrodepositable coating composition comprising a lignin-containing cationic salt resin, that comprises (A) the reaction product of: lignin, an amine, and a carbonyl compound; (B) the reaction product of lignin, epichlorohydrin, and an amine; or (C) combinations thereof.

  3. Electrochemical corrosion measurements on noble electrodeposits

    DEFF Research Database (Denmark)

    Christoffersen, Lasse; Maahn, Ernst Emanuel

    1998-01-01

    Novel electrodeposits are compared with hard chrome and electroless Ni-P with respect to production, corrosion resistance and hardness.......Novel electrodeposits are compared with hard chrome and electroless Ni-P with respect to production, corrosion resistance and hardness....

  4. Theory and practice of metal electrodeposition

    CERN Document Server

    Gamburg, Yuliy D

    2011-01-01

    fills the gap between modern developments in electrochemistry and outdated information on metals electrodeposition currently available in competing titles essential information on the theoretical and practical electrochemistry necessary to investigate modern metal deposition is provided part of the growing literature on electrodeposition

  5. Studies on electrodeposition and characterization of the Ni–W–Fe alloys coatings

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Aldrighi Luiz M.; Costa, Josiane D.; Sousa, Mikarla B. de; Alves, José Jailson N. [Department of Chemical Engineering, Federal University of Campina Grande, Av. Aprígio Veloso, 882, 58429-970 Campina Grande (Brazil); Campos, Ana Regina N.; Santana, Renato Alexandre C. [Department of Education, Federal University of Campina Grande, R. Olho da Água da Bica, S. N., 58175-000 Cuité-Pb (Brazil); Prasad, Shiva, E-mail: prasad@deq.ufcg.edu.br [Department of Education, Federal University of Campina Grande, R. Olho da Água da Bica, S. N., 58175-000 Cuité-Pb (Brazil)

    2015-01-15

    Highlights: • Ni–W–Fe alloy resistant to corrosion has been obtained by electrodeposition. • Optimal temperature and current density for Ni–W–Fe alloy electrodeposition has been found. • Experimental design has been used as optimization tool. • Amorphous Ni–W–Fe alloy has been obtained. - Abstract: Corrosion has been responsible for industrial maintenance cost as well as for industrial accidents. A key to prevent corrosion is to develop advanced materials with highly anti-corrosive properties. The electrodeposition has been one of the most important techniques for obtaining these materials. The objective of this work is to develop and optimize the parameters to obtain a new Ni–W–Fe alloy with high resistance to corrosion. A factorial design 2{sup 2} with 2 center points was used to find the optimal current density and bath temperature for Ni–W–Fe electrodeposition. The influence of such variables on the cathodic current efficiency and polarization resistance were obtained. The alloys obtained with the highest current density (125 mA/cm{sup 2}) and the highest bath temperature (70 °C) had the best anticorrosive properties, which are superior to anticorrosive properties of Ni–W–Fe available in the literature. The obtained alloys had the highest tungsten content compared with other alloys studied of about 46 wt.%. The highest cathodic current efficiency was 34% for the alloy with a chemical composition of 3 wt.% Fe, 29 wt.% W and 68 wt.% Ni.

  6. Surfactant assisted electrodeposition of MnO{sub 2} thin films: Improved supercapacitive properties

    Energy Technology Data Exchange (ETDEWEB)

    Dubal, D.P. [Thin Film Physics Laboratory, Department of Physics, Shivaji University, Kolhapur 416004 (M.S.) (India); School of Materials Science and Engineering, Gwangju Institute of Science and Technology, 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of); Kim, W.B. [School of Materials Science and Engineering, Gwangju Institute of Science and Technology, 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of); Lokhande, C.D., E-mail: l_chandrakant@yahoo.com [Thin Film Physics Laboratory, Department of Physics, Shivaji University, Kolhapur 416004 (M.S.) (India)

    2011-10-13

    Highlights: > Effect of Triton X-100 on physico-chemical properties of MnO{sub 2} films. > High supercapacitance of 345 F g{sup -1}. > Charge-discharge, impedance spectroscopy. - Abstract: In order to obtain a high specific capacitance, MnO{sub 2} thin films have been electrodeposited in the presence of a neutral surfactant (Triton X-100). These films were further characterized by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM) and contact angle measurement. The XRD studies revealed that the electrodeposited MnO{sub 2} films are amorphous and addition of Triton X-100 does not change its amorphous nature. The electrodeposited films of MnO{sub 2} in the presence of the Triton X-100 possess greater porosity and hence greater surface area in relation to the films prepared in the absence of the surfactant. Wettability test showed that the MnO{sub 2} film becomes superhydrophilic from hydrophilic due to Triton X-100. Supercapacitance properties of MnO{sub 2} thin films studied by cyclic voltammetry, galvanostatic charge-discharge cycling and impedance spectroscopy showed maximum supercapacitance for MnO{sub 2} films deposited in presence of Triton X-100 is 345 F g{sup -1}.

  7. Surfactant assisted electrodeposition of MnO2 thin films: Improved supercapacitive properties

    International Nuclear Information System (INIS)

    Dubal, D.P.; Kim, W.B.; Lokhande, C.D.

    2011-01-01

    Highlights: → Effect of Triton X-100 on physico-chemical properties of MnO 2 films. → High supercapacitance of 345 F g -1 . → Charge-discharge, impedance spectroscopy. - Abstract: In order to obtain a high specific capacitance, MnO 2 thin films have been electrodeposited in the presence of a neutral surfactant (Triton X-100). These films were further characterized by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM) and contact angle measurement. The XRD studies revealed that the electrodeposited MnO 2 films are amorphous and addition of Triton X-100 does not change its amorphous nature. The electrodeposited films of MnO 2 in the presence of the Triton X-100 possess greater porosity and hence greater surface area in relation to the films prepared in the absence of the surfactant. Wettability test showed that the MnO 2 film becomes superhydrophilic from hydrophilic due to Triton X-100. Supercapacitance properties of MnO 2 thin films studied by cyclic voltammetry, galvanostatic charge-discharge cycling and impedance spectroscopy showed maximum supercapacitance for MnO 2 films deposited in presence of Triton X-100 is 345 F g -1 .

  8. Thermodynamics of gallium arsenide electrodeposition

    International Nuclear Information System (INIS)

    Perrault, G.G.

    1986-01-01

    Gallium Arsenide is well known as a very interesting compound for photoelectrical devices. Up to now, it has been prepared mostly by high temperature technology, and the authors considered that it might be of interest to set up an electrodeposition technique suitable to prepare thin layers of this compound. A reaction sequence similar to the one observed for Cadmium Sulfide or Cadmium Telluride could be considered. In these cases, the metal chalcogenide is obtained from the precipitation of the metal ions dissolved in the solutions by the reduction product of the metalloidic compound

  9. Structure investigations of electrodeposited nickel

    International Nuclear Information System (INIS)

    Vertes, A.; Czako-Nagy, I.; Lakatos-Varsanyi, M.; Brauer, G.; Leidheiser, H. Jr

    1981-01-01

    Electrodeposited nickel samples were investigated by positron annihilation (lifetime and Doppler-broadening), Moessbauer effect and X-ray diffraction measurements. Two-component positron lifetime spectra were obtained. The first component is thought to result from bulk annihilation and trapping at single trapping centres (TC), their concentrations are obtained from the trapping model. The second one possibly denotes annihilation at voids, the number of which is dependent on the stress in the deposit. The Moessbauer results show differences in the magnetic orientation in the three samples examined. (author)

  10. Concerted Electrodeposition and Alloying of Antimony on Indium Electrodes for Selective Formation of Crystalline Indium Antimonide.

    Science.gov (United States)

    Fahrenkrug, Eli; Rafson, Jessica; Lancaster, Mitchell; Maldonado, Stephen

    2017-09-19

    The direct preparation of crystalline indium antimonide (InSb) by the electrodeposition of antimony (Sb) onto indium (In) working electrodes has been demonstrated. When Sb is electrodeposited from dilute aqueous electrolytes containing dissolved Sb 2 O 3 , an alloying reaction is possible between Sb and In if any surface oxide films are first thoroughly removed from the electrode. The presented Raman spectra detail the interplay between the formation of crystalline InSb and the accumulation of Sb as either amorphous or crystalline aggregates on the electrode surface as a function of time, temperature, potential, and electrolyte composition. Electron and optical microscopies confirm that under a range of conditions, the preparation of a uniform and phase-pure InSb film is possible. The cumulative results highlight this methodology as a simple yet potent strategy for the synthesis of intermetallic compounds of interest.

  11. Amorphous metal composites

    International Nuclear Information System (INIS)

    Byrne, M.A.; Lupinski, J.H.

    1984-01-01

    This patent discloses an improved amorphous metal composite and process of making the composite. The amorphous metal composite comprises amorphous metal (e.g. iron) and a low molecular weight thermosetting polymer binder. The process comprises placing an amorphous metal in particulate form and a thermosetting polymer binder powder into a container, mixing these materials, and applying heat and pressure to convert the mixture into an amorphous metal composite

  12. Preparation of 235U target by electrodeposition

    International Nuclear Information System (INIS)

    Chen Qiping; Zhong Wenbin; Li Yougen

    2004-12-01

    A target for the production of fission 99 Mo in a nuclear reactor is composed of an enclosed, cylindrical vessel. Preferable vessel is comprised of stainless steel, having a thin, continuous, uniform layer of 235 U integrally bonded to its inner walls. Two processes are introduced for electrodepositing uranium on to the inner walls of the vessel. One processes is electrodepositing UO 2 from UO 2 (NO 3 ) 2 -(NH 4 ) 2 CO 4 ·H 2 O solution; the other is electrodepositing pure uranium metal from molten salt. Its plating efficiency and plating quantity from a molten bath is higher than UO 2 from the aqueous system. (authors)

  13. Structure characterization of nanocrystalline Ni–W alloys obtained by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Indyka, P., E-mail: paulina.indyka@uj.edu.pl [Jagiellonian University, Faculty of Chemistry, 3 Ingardena St., 30-059 Krakow (Poland); Beltowska-Lehman, E.; Tarkowski, L.; Bigos, A. [Institute of Metallurgy and Materials Science, Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow (Poland); García-Lecina, E. [Surface Finishing Department, CIDETEC-IK4 – Centre for Electrochemical Technologies, P° Miramón 196, 20009 Donostia-San Sebastián (Spain)

    2014-03-25

    Highlights: • Ni–W alloy coatings were electrodeposited from an aqueous electrolyte solutions. • The microstructure was studied with respect to electrodeposition process parameters. • We report optimal plating conditions for crack-free, nanocrystalline Ni–W coatings. • Crystalline Ni–W coatings exhibited the phase structure of an α-Ni(W) solid solution. • Coatings revealed tensile residual stresses and weakly pronounced 〈1 1 0〉 fiber texture. -- Abstract: Ni–W coatings of different tungsten content (2–50 wt%) were electrodeposited on a steel substrates from an aqueous complex sulfate–citrate galvanic baths, under controlled hydrodynamic conditions in a Rotating Disk Electrode (RDE) system. The optimum conditions for the electrodeposition of crack-free, homogeneous nanocrystalline Ni–W coatings were determined on the basis of the microstructure investigation results. The XRD structural characterizations of Ni–W alloy coatings obtained under different experimental conditions were complemented by SEM and TEM analysis. Results of the study revealed that the main factor influencing the microstructure formation of the Ni–W coatings is the chemical composition of an electrolyte solution. X-ray and electron diffraction patterns of all nanocrystalline Ni–W coatings revealed mainly the fcc phase structure of an α-Ni(W) solid solution with a lattice parameter increased along with tungsten content. The use of additives in the plating bath resulted in the formation of equiaxial/quasifibrous, nanocrystalline Ni–W grains of an average size of about 10 nm. The coatings were characterized by relatively high tensile residual stresses (500–1000 MPa), depending on the electrodeposition conditions. Ni–W coatings exhibited weakly pronounced fiber type 〈1 1 0〉 crystallographic texture, consistent with the symmetry of the plating process. Coatings of the highest tungsten content 50 wt% were found to be amorphous.

  14. The electrodeposition of niobium on tungsten

    International Nuclear Information System (INIS)

    Taylor, R.G.

    1977-03-01

    The electrodeposition of niobium on a tungsten substrate has been demonstrated by electrolysis of an alkali metal fluoride melt. The deposit produced was non-porous, coherent and formed a good bond to the substrate. (author)

  15. Electrodeposition and surface finishing fundamentals and applications

    CERN Document Server

    Djokic, Stojan

    2014-01-01

    This volume of Modern Aspects of Electrochemistry has contributions from significant individuals in electrochemistry. This 7 chapter book discusses electrodeposition and the characterization of alloys and composite materials, the mechanistic aspects of lead electrodeposition, electrophoretic deposition of ceramic materials onto metal surfaces and the fundamentals of metal oxides for energy conversion and storage technologies. This volume also has a chapter devoted to the anodization of aluminum, electrochemical aspects of chemical and mechanical polishing, and surface treatments prior to metal

  16. Electrodeposited nanoparticles: properties and photocatalytic applications

    OpenAIRE

    Sheridan, Eoin E.

    2009-01-01

    The work presented in this thesis reports on fundamental studies into electrodeposition of gold and silver nanoparticulate spheroids on a conducting substrate, Fluorine-doped tin-oxide, and the manipulation of the electrodeposition conditions in order to influence and control the size and surface concentration of spheroids. Methods to control the deposition included chemical modification of the surface with an adsorbed monolayer of 3-aminopropyldimethylmethoxysilane, and manipulation of...

  17. Texture and microstructure evolution in nickel electrodeposited from an additive-free Watts electrolyte

    DEFF Research Database (Denmark)

    Alimadadi, Hossein; da Silva Fanta, Alice Bastos; Kasama, Takeshi

    2016-01-01

    Nickel layers with 〈100〉, 〈210〉, 〈110〉 and 〈211〉 fiber textures were electrodeposited from additive-free Watts type electrolytes by adjusting both the pH and the applied current density. Quantitative crystallographic texture analysis by XRD was supplemented by micro-texture analysis applying EBSD....... While XRD results correspond to absorption-weighted averages over the top part of the layer, EBSD on the cross section allowed studying the texture evolution as a function of distance to the substrate. Although layer growth started on amorphous substrates, implying that nucleation occurs unbiased...

  18. Challenges of sample preparation for cross sectional EBSD analysis of electrodeposited nickel films

    DEFF Research Database (Denmark)

    Alimadadi, Hossein; Pantleon, Karen

    2009-01-01

    Thorough microstructure and crystallographic orientation analysis of thin films by means of electron backscatter diffraction requires cross section preparation of the film-substrate compound. During careful preparation, changes of the rather non-stable as-deposited microstructure must be avoided....... Different procedures for sample preparation including mechanical grinding and polishing, electropolishing and focused ion beam milling have been applied to a nickel film electrodeposited on top of an amorphous Ni-P layer on a Cu-substrate. Reliable EBSD analysis of the whole cross section can be obtained...

  19. Magnetic and Structural Properties of Electrodeposited Iron on Copper and Silver

    International Nuclear Information System (INIS)

    Koempe, K.; Kuehl, E.; Nagorny, K.

    2002-01-01

    Electrodeposition of iron on copper or silver leads to the formation of bcc-iron or amorphous iron. Thermal annealing usually results in soluted iron (also γ-iron and clusters) in copper. On silver the insolubility of iron never causes the formation of bcc-iron. Instead on copper as well as on silver fcc-iron states are formed, especially at relatively low temperatures with short times of annealing. Moessbauer spectroscopy accompanied by X-ray diffraction (XRD) and vibrating sample magnetometry (VSM) are applied for characterisation of the iron states.

  20. Apparatus for eliminating electrodeposition of radioactive nuclide

    International Nuclear Information System (INIS)

    Inomata, Ichiro; Ishibe, Tadao; Matsunaga, Masaaki; Konuki, Ryoichi; Suzuki, Kazunori; Watanabe, Minoru; Tomoshige, Shozo; Kondo, Kozo.

    1990-01-01

    In a conventional device for eliminating by radioactive nuclides electrodeposition, a liquid containing radioactive nuclides is electrolyzed under a presence of non-radioactive heavy metals and removing radioactive nuclides by electrodepositing them together with the heavy metals. Two anode plates are opposed in an electrolysis vessel of this device. A plurality (4 to 6) of cathode plates are arranged between the anodes in parallel with them and the cathode surfaces opposed to the anodes are insulated. Further, such a plurality of cathode plates are grouped into respective units. Alternatively, the anode plate is made of platinum-plated titanium material and the cathode plate is made of stainless steel. In the thus constituted electrodeposition eliminating device, since the cathode surface directed to the anodes on both ends are insulated, all of electric current from the anode reach the core cathode after flowing around the cathodes at both ends. As a result, there is no substantial difference in the flowing length of the electrolyzing current to each of the cathodes and these is neither difference in the electrodeposition amount. The electrodeposited products are adhered uniformly and densely to the electrodes and, simultaneously, Co-60 and Mn-54, etc. are also electrodeposited. (I.S.)

  1. Stable lithium electrodeposition in liquid and nanoporous solid electrolytes

    KAUST Repository

    Lu, Yingying; Tu, Zhengyuan; Archer, Lynden A.

    2014-01-01

    of these metals and their inability to form uniform electrodeposits on surfaces with inevitable defects. We report on electrodeposition of lithium in simple liquid electrolytes and in nanoporous solids infused with liquid electrolytes. We find that simple liquid

  2. Theory of amorphous ices.

    Science.gov (United States)

    Limmer, David T; Chandler, David

    2014-07-01

    We derive a phase diagram for amorphous solids and liquid supercooled water and explain why the amorphous solids of water exist in several different forms. Application of large-deviation theory allows us to prepare such phases in computer simulations. Along with nonequilibrium transitions between the ergodic liquid and two distinct amorphous solids, we establish coexistence between these two amorphous solids. The phase diagram we predict includes a nonequilibrium triple point where two amorphous phases and the liquid coexist. Whereas the amorphous solids are long-lived and slowly aging glasses, their melting can lead quickly to the formation of crystalline ice. Further, melting of the higher density amorphous solid at low pressures takes place in steps, transitioning to the lower-density glass before accessing a nonequilibrium liquid from which ice coarsens.

  3. Structural characterization of Fe−Pd nanowires grown by electrodeposition using an acid electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Domenichini, P. [Instituto Balseiro, Universidad Nacional de Cuyo, Av. Bustillo 9500, 8400 San Carlos de Bariloche (Argentina); Condó, A.M. [Instituto Balseiro, Universidad Nacional de Cuyo, Av. Bustillo 9500, 8400 San Carlos de Bariloche (Argentina); Centro Atómico Bariloche, Comisión Nacional de Energía Atómica, Av. Bustillo 9500, 8400 San Carlos de Bariloche (Argentina); Haberkorn, N., E-mail: nhaberk@cab.cnea.gov.ar [Instituto Balseiro, Universidad Nacional de Cuyo, Av. Bustillo 9500, 8400 San Carlos de Bariloche (Argentina); Centro Atómico Bariloche, Comisión Nacional de Energía Atómica, Av. Bustillo 9500, 8400 San Carlos de Bariloche (Argentina)

    2016-07-01

    Fe{sub 70}Pd{sub 30} nanostructures have potential application in actuators due to their conventional and magnetic shape memory. Here, we report the microstructure of electrodeposition grown Fe−Pd nanowires in which the process was confined to polycarbonate membranes with a nominal pore diameter of 200 nm. We used an acid electrolyte (pH ≈ 5) in which the solution was stabilized with sulfosalicylic acid. The average chemical concentration of the nanowires can be systematically shifted from rich palladium to rich iron by changing the growth potential. The study of the microstructure by transmission electron microscopy indicates high chemical inhomogeneities due to phase coexistence between rich palladium regions (with FCC structure) and rich iron regions. The latter present a combination of BCC and amorphous phases. The average chemical composition of the nanowires can be better adjusted by using a low frequency square wave voltage excitation (alternating rich Pd and rich Fe regions). However, independently of the growth process, the nanowires morphology collapses after thermal annealing. This could be ascribed to fragile grain boundaries due to the presence of amorphous hydroxides and chemical impurities produced during the electrochemical process. - Highlights: • Synthesis of Fe−Pd nanowires by electrodeposition is reported. • Structural characterization of the nanowires by transmission electron microscopy. • The synthesis of nanowires with austenitic phase is limited by fragile grain boundaries.

  4. The chemistry and structure of nickel–tungsten coatings obtained by pulse galvanostatic electrodeposition

    International Nuclear Information System (INIS)

    Argañaraz, M.P. Quiroga; Ribotta, S.B.; Folquer, M.E.; Zelaya, E.; Llorente, C.; Ramallo-López, J.M.; Benítez, G.; Rubert, A.; Gassa, L.M.; Vela, M.E.; Salvarezza, R.C.

    2012-01-01

    A detailed characterization of electrodeposited Ni-W coatings prepared by pulse electrodeposition on steel and copper substrates is presented. The coatings were obtained at high current pulse frequency and show high microhardness and absence of brittleness. The surface of the coating consists of nanometer sized crystals forming a cauliflower-like structure protected by a mixture of nickel and tungsten oxides. The cauliflower structure is preserved into the bulk coating that exhibits an average composition ≈70 at% Ni-30 at% W. Different phases are observed in the bulk structure: a W-rich amorphous phase (≈40%) and Ni-rich crystalline phases (≈60%). The crystalline phases consist of crystalline domains ≈7 nm in size of Ni(W) (fcc) solid solution (12 at% W content) and a minor Ni 4 W component (less than 10%). The amorphous phase exhibits a less compact Ni-W structure where some amount of C could also be present. Oxidized W species cannot be detected in the bulk coating, thus discarding the presence of significant amounts of tungsten carbide, tungstates or citrate–tungsten complexes. Our results shed light on controversial points related to the chemical composition and demonstrate the complex structure of this system.

  5. Electrodeposited Silver Nanoparticles Patterned Hexagonally for SERS

    International Nuclear Information System (INIS)

    Gu, Geun Hoi; Lee, Sue Yeone; Suh, Jung Sang

    2010-01-01

    We have fabricated hexagonally patterned silver nanoparticles for surface-enhanced Raman scattering (SERS) by electrodepositing silver on the surface of an aluminum plate prepared by completely removing the oxide from anodic aluminum oxide (AAO) templates. Even after completely removing the oxide, well-ordered hexagonal patterns, similar to the shape of graphene, remained on the surface of the aluminum plate. The borders of the hexagonal pattern protruded up to form sorts of nano-mountains at both the sides and apexes of the hexagon, with the apexes protruding even more significantly than the sides. The aluminum plate prepared by completely removing the oxide has been used in the preparation of SERS substrates by sputter-coating of gold or silver on it. Instead of sputter-coating, here we have electro-deposited silver on the aluminum plate. When silver was electro-deposited on the plate, silver nanoparticles were made along the hexagonal margins.

  6. Quantitative texture analysis of electrodeposited line patterns

    DEFF Research Database (Denmark)

    Pantleon, Karen; Somers, Marcel A.J.

    2005-01-01

    Free-standing line patterns of Cu and Ni were manufactured by electrochemical deposition into lithographically prepared patterns. Electrodeposition was carried out on top of a highly oriented Au-layer physically vapor deposited on glass. Quantitative texture analysis carried out by means of x......-ray diffraction for both the substrate layer and the electrodeposits yielded experimental evidence for epitaxy between Cu and Au. An orientation relation between film and substrate was discussed with respect to various concepts of epitaxy. While the conventional mode of epitaxy fails for the Cu...

  7. Electrochemical synthesis, structure and phase composition of nano structured amorphous thin layers of NiW and Ni-Mo

    International Nuclear Information System (INIS)

    Vitina, I.; Lubane, M.; Belmane, V.; Rubene, V.; Krumina, A.

    2006-01-01

    Full text: Nano structured Ni-W thin layers containing W 6-37 wt.% were electrodeposited on a copper substratum. The W content in the layer changes, and it is determined by the electrolyte pH in the range 8.0-9.6 and the cathode current density in the range 1.0-10.0 A/dm 2 . The atomic composition and thermal stability of structure of the electrodeposited thin layers depend for the most part on the conditions of the electrodeposition and less on the W content in the layer. Cracking of the Ni-W layers electrodeposited at the electrolyte pH 8.5 and containing 34-37 wt.% W and 8.5 wt.% W was observed. The cracking increases at heating at 400 deg C for 50 h. On the contrary, no cracking of the Ni-W layer electrodeposited at the electrolyte pH 9.0 and containing 25 wt.% W was observed. The atomic composition of the layer remains practically unchanged at heating at 400 deg C for 50 h. The layer binds oxygen up to 7 wt.%. According to X-ray diffraction, in spite of the W content 35-37 wt.% in the layer, nano structured layers rather than amorphous layers were obtained which at heating at 400 deg C depending on the W content crystallises as Ni or intermetallic compounds Ni x W y if the W content is approx. 25 wt.%. Amorphous Ni-Mo alloys containing 35-52 wt.% Mo was electrodeposited on copper substratum at the cathode current densities of 0.5-1.5 A/dm2 and the electrolyte pH 6.8-8.6. Formation of thin layer (∼1-2μm) of X-ray amorphous Ni-Mo alloy, the Mo content, the characteristics of structure depend on the electrodeposition process, the electrolyte pH, and the cathode current density. The Ni-Mo layer deposited at the electrolyte pH above 8.6 and below average 6.8 had a nanocrystalline structure rather than characteristics of amorphous structure. Ni- W and Ni-Mo alloys were electrodeposited from citrate electrolyte not containing ammonium ions

  8. Hydroxyapatite electrodeposition on anodized titanium nanotubes for orthopedic applications

    Science.gov (United States)

    Parcharoen, Yardnapar; Kajitvichyanukul, Puangrat; Sirivisoot, Sirinrath; Termsuksawad, Preecha

    2014-08-01

    Nanotubes modification for orthopedic implants has shown interesting biological performances (such as improving cell adhesion, cell differentiation, and enhancing osseointegration). The purpose of this study is to investigate effect of titanium dioxide (TiO2) nanotube feature on performance of hydroxyapatite-coated titanium (Ti) bone implants. TiO2 nanotubes were prepared by anodization using ammonium fluoride electrolyte (NH4F) with and without modifiers (PEG400 and Glycerol) at various potential forms, and times. After anodization, the nanotubes were subsequently annealed. TiO2 nanotubes were characterized by scanning electron microscope and X-ray diffractometer. The amorphous to anatase transformation due to annealing was observed. Smooth and highly organized TiO2 nanotubes were found when high viscous electrolyte, NH4F in glycerol, was used. Negative voltage (-4 V) during anodization was confirmed to increase nanotube thickness. Length of the TiO2 nanotubes was significantly increased by times. The TiO2 nanotube was electrodeposited with hydroxyapatite (HA) and its adhesion was estimated by adhesive tape test. The result showed that nanotubes with the tube length of 560 nm showed excellent adhesion. The coated HA were tested for biological test by live/dead cell straining. HA coated on TiO2 nanotubes showed higher cells density, higher live cells, and more spreading of MC3T3-E1 cells than that growing on titanium plate surface.

  9. Electrodeposition of zinc--nickel alloys coatings

    Energy Technology Data Exchange (ETDEWEB)

    Dini, J W; Johnson, H R

    1977-10-01

    One possible substitute for cadmium in some applications is a zinc--nickel alloy deposit. Previous work by others showed that electrodeposited zinc--nickel coatings containing about 85 percent zinc and 15 percent nickel provided noticeably better corrosion resistance than pure zinc. Present work which supports this finding also shows that the corrosion resistance of the alloy deposit compares favorably with cadmium.

  10. Synthesis of shape memory alloys using electrodeposition

    Science.gov (United States)

    Hymer, Timothy Roy

    Shape memory alloys are used in a variety of applications. The area of micro-electro-mechanical systems (MEMS) is a developing field for thin film shape memory alloys for making actuators, valves and pumps. Until recently thin film shape memory alloys could only be made by rapid solidification or sputtering techniques which have the disadvantage of being "line of sight". At the University of Missouri-Rolla, electrolytic techniques have been developed that allow the production of shape memory alloys in thin film form. The advantages of this techniques are in-situ, non "line of sight" and the ability to make differing properties of the shape memory alloys from one bath. This research focused on the electrodeposition of In-Cd shape memory alloys. The primary objective was to characterize the electrodeposited shape memory effect for an electrodeposited shape memory alloy. The effect of various operating parameters such as peak current density, temperature, pulsing, substrate and agitation were investigated and discussed. The electrodeposited alloys were characterized by relative shape memory effect, phase transformation, morphology and phases present. Further tests were performed to optimize the shape memory by the use of a statistically designed experiment. An optimized shape memory effect for an In-Cd alloy is reported for the conditions of the experiments.

  11. Defect structure of electrodeposited chromium layers

    International Nuclear Information System (INIS)

    Marek, T.; Suevegh, K.; Vertes, A.; El-Sharif, M.; McDougall, J.; Chisolm, C.U.

    2000-01-01

    Positron annihilation spectroscopy was applied to study the effects of pre-treatment and composition of substrates on the quality and defect structure of electrodeposited thick chromium coatings. The results show that both parameters are important, and a scenario is proposed why the mechanically polished substrate gives more defective film than the electro polished one.

  12. Defect structure of electrodeposited chromium layers

    Energy Technology Data Exchange (ETDEWEB)

    Marek, T. E-mail: marek@para.chem.elte.hu; Suevegh, K.; Vertes, A.; El-Sharif, M.; McDougall, J.; Chisolm, C.U

    2000-06-01

    Positron annihilation spectroscopy was applied to study the effects of pre-treatment and composition of substrates on the quality and defect structure of electrodeposited thick chromium coatings. The results show that both parameters are important, and a scenario is proposed why the mechanically polished substrate gives more defective film than the electro polished one.

  13. On texture formation of chromium electrodeposits

    DEFF Research Database (Denmark)

    Nielsen, Christian Bergenstof; Leisner, Peter; Horsewell, Andy

    1998-01-01

    The microstructure, texture and hardness of electrodeposited hard, direct current (DC) chromium and pulsed reversed chromium has been investigated. These investigations suggest that the growth and texture of hard chromium is controlled by inhibition processes and reactions. Further, it has been...

  14. Amorphous iron (II) carbonate

    DEFF Research Database (Denmark)

    Sel, Ozlem; Radha, A.V.; Dideriksen, Knud

    2012-01-01

    Abstract The synthesis, characterization and crystallization energetics of amorphous iron (II) carbonate (AFC) are reported. AFC may form as a precursor for siderite (FeCO3). The enthalpy of crystallization (DHcrys) of AFC is similar to that of amorphous magnesium carbonate (AMC) and more...

  15. Hydrogen in amorphous silicon

    International Nuclear Information System (INIS)

    Peercy, P.S.

    1980-01-01

    The structural aspects of amorphous silicon and the role of hydrogen in this structure are reviewed with emphasis on ion implantation studies. In amorphous silicon produced by Si ion implantation of crystalline silicon, the material reconstructs into a metastable amorphous structure which has optical and electrical properties qualitatively similar to the corresponding properties in high-purity evaporated amorphous silicon. Hydrogen studies further indicate that these structures will accomodate less than or equal to 5 at.% hydrogen and this hydrogen is bonded predominantly in a monohydride (SiH 1 ) site. Larger hydrogen concentrations than this can be achieved under certain conditions, but the excess hydrogen may be attributed to defects and voids in the material. Similarly, glow discharge or sputter deposited amorphous silicon has more desirable electrical and optical properties when the material is prepared with low hydrogen concentration and monohydride bonding. Results of structural studies and hydrogen incorporation in amorphous silicon were discussed relative to the different models proposed for amorphous silicon

  16. Amorphization within the tablet

    DEFF Research Database (Denmark)

    Doreth, Maria; Hussein, Murtadha Abdul; Priemel, Petra A.

    2017-01-01

    , the feasibility of microwave irradiation to prepare amorphous solid dispersions (glass solutions) in situ was investigated. Indomethacin (IND) and polyvinylpyrrolidone K12 (PVP) were tableted at a 1:2 (w/w) ratio. In order to study the influence of moisture content and energy input on the degree of amorphization......, tablet formulations were stored at different relative humidity (32, 43 and 54% RH) and subsequently microwaved using nine different power-time combinations up to a maximum energy input of 90 kJ. XRPD results showed that up to 80% (w/w) of IND could be amorphized within the tablet. mDSC measurements...

  17. Physics of amorphous metals

    CERN Document Server

    Kovalenko, Nikolai P; Krey, Uwe

    2008-01-01

    The discovery of bulk metallic glasses has led to a large increase in the industrial importance of amorphous metals, and this is expected to continue. This book is the first to describe the theoretical physics of amorphous metals, including the important theoretical development of the last 20 years.The renowned authors stress the universal aspects in their description of the phonon or magnon low-energy excitations in the amorphous metals, e.g. concerning the remarkable consequences of the properties of these excitations for the thermodynamics at low and intermediate temperatures. Tunneling

  18. The mechanism of cathodic electrodeposition of epoxy coatings and the corrosion behaviour of the electrodeposited

    Directory of Open Access Journals (Sweden)

    VESNA B. MISKOVIC-STANKOVIC

    2002-05-01

    Full Text Available The model of organic film growth on a cathode during electrodeposition process proposes the current density-time and film thickness-time relationships and enables the evaluation of the rate contants for the electrochemical reaction of OH– ion evolution and for the chemical reaction of organic film deposition. The dependences of film thickness and rate constants on the applied voltage, bath temperature and resin concentration in the electrodeposition bath have also been obtained. The deposition parameters have a great effect on the cathodic electrodeposition process and on the protective properties of the obtained electrodeposited coatings. From the time dependences of the pore resistance, coating capacitance and relative permittivity, obtained from impedance measurements, the effect of applied voltage, bath temperature and resin concentration on the protective properties of electrodeposited coatings has been shown. Using electrochemical impedance spectroscopy, thermogravimetric analysis, gravimetric liquid sorption experiments, differential scanning calorimetry and optical miscroscopy, the corrosion stability of epoxy coatings was investigated. A mechanism for the penetration of electrolyte through an organic coating has been suggested and the shape and dimensions of the conducting macropores have been determined. It was shown that conduction through a coating depends only on the conduction through the macropores, although the quantity of electrolyte in the micropores of the polymer net is about one order of magnitude greater than that inside the conducting macropores.

  19. Nanocrystalline Ni-Co Alloy Synthesis by High Speed Electrodeposition

    OpenAIRE

    Idris, Jamaliah; Christian, Chukwuekezie; Gaius, Eyu

    2013-01-01

    Electrodeposition of nanocrystals is economically and technologically viable production path for the synthesis of pure metals and alloys both in coatings and bulk form. The study presents nanocrystalline Ni-Co alloy synthesis by high speed electrodeposition. Nanocrystalline Ni-Co alloys coatings were prepared by direct current (DC) and deposited directly on steel and aluminum substrates without any pretreatment, using high speed electrodeposition method. The influence of the electrolysis par...

  20. Positrons in amorphous alloys

    International Nuclear Information System (INIS)

    Moser, Pierre.

    1981-07-01

    Positron annihilation techniques give interesting informations about ''empty spaces'' in amorphous alloys. The results of an extensive research work on the properties of either pre-existing or irradiation induced ''empty spaces'' in four amorphous alloys are presented. The pre-existing empty spaces appear to be small vacancy-like defects. The irradiation induced defects are ''close pairs'' with widely distributed configurations. There is a strong interaction between vacancy like and interstitial like components. A model is proposed, which explains the radiation resistance mechanism of the amorphous alloys. An extensive joint research work to study four amorphous alloys, Fe 80 B 20 ,Fe 40 Ni 40 P 14 B 6 , Cu 50 Ti 50 , Pd 80 Si 20 , is summarized

  1. Electrodeposition of Actinide and Lanthanide Elements

    International Nuclear Information System (INIS)

    Baerring, N.E.

    1966-02-01

    Some deposition parameters for the quantitative electrodeposition of hydrolysis products of plutonium were qualitatively studied at trace concentrations of plutonium. The hydrogen ion concentration, the current and the electrolysis time proved to be the determining factors in the quantitative electrolytic precipitation of plutonium, while other factors such as cathode material, the pretreatment of the cathode surface, the nature of the electrolytic anion, and the oxidation state of plutonium in the starting solution were found to be of less importance. The conditions selected for quantitative electrodeposition of plutonium from slightly acid nitrate solutions on a stainless steel cathode were successfully tried also with uranium, neptunium, americium, cerium and thulium. Details of a procedure used for plating mg amounts of plutonium and neptunium on small stainless steel cylinders are also given

  2. Electrodeposition of nickel nano wire arrays

    International Nuclear Information System (INIS)

    Nur Ubaidah Saidin; Kok Kuan Ying; Ng Inn Khuan; Nurazila Mat Zali; Siti Salwa Zainal Abidin

    2010-01-01

    Synthesis, characterization and assembly of one-dimensional nickel nano wires prepared by template directed electrodeposition are discussed in this paper. Parallel arrays of high aspect ratio nickel nano wires were electrodeposited using electrolytes with different cations and pH. The nano wires were characterized using X-ray diffractometry and scanning electron microscopy. It was found that the orientations of the electro deposited Ni nano wires were governed by the deposition current and the electrolyte conditions. Free standing nickel nano wires can be obtained by dissolving the template. Due to the magnetic nature of the nano wires, magnetic alignment was employed to assemble and position the free standing nano wires in the device structure. (author)

  3. Electrodeposition of Actinide and Lanthanide Elements

    Energy Technology Data Exchange (ETDEWEB)

    Baerring, N E

    1966-02-15

    Some deposition parameters for the quantitative electrodeposition of hydrolysis products of plutonium were qualitatively studied at trace concentrations of plutonium. The hydrogen ion concentration, the current and the electrolysis time proved to be the determining factors in the quantitative electrolytic precipitation of plutonium, while other factors such as cathode material, the pretreatment of the cathode surface, the nature of the electrolytic anion, and the oxidation state of plutonium in the starting solution were found to be of less importance. The conditions selected for quantitative electrodeposition of plutonium from slightly acid nitrate solutions on a stainless steel cathode were successfully tried also with uranium, neptunium, americium, cerium and thulium. Details of a procedure used for plating mg amounts of plutonium and neptunium on small stainless steel cylinders are also given.

  4. Superplasticity of amorphous alloy

    International Nuclear Information System (INIS)

    Levin, Yu.B.; Likhachev, V.L.; Sen'kov, O.N.

    1988-01-01

    Results of mechanical tests of Co 57 Ni 10 Fe 5 Si 11 B 17 amorphous alloy are presented and the effect of crystallization, occurring during deformation process, on plastic low characteristics is investiagted. Superplasticity of amorphous tape is investigated. It is shown, that this effect occurs only when during deformation the crystallization takes place. Process model, based on the usage disclination concepts about glass nature, is suggested

  5. Phosphorus introduction mechanism in electrodeposited cobalt films

    International Nuclear Information System (INIS)

    Kravtchenko, Jean-Francois

    1973-01-01

    The cathodic reduction of hypophosphite, phosphite and phosphate ions was studied using chrono-potentiometry and voltammetry. Then cobalt was deposited at constant current from a bath containing one of these three compounds. The current, while giving an electrodeposition of cobalt, also enhances at the same time a chemical deposition of cobalt. It is shown that high coercive forces in cobalt films are much more related to this chemical deposition than to the simple fact that the films contain some phosphorus. (author) [fr

  6. The Electrodeposition of Rhenium and Its Alloys

    Science.gov (United States)

    2015-09-18

    did not have benefit. A combination of vanillin, sodium lauryl sulfate, and gelatin , and equal concentrations of Ni2+ and ReO4 - yielded a coating...substrate, thus facilitating good bonding between the coating and substrate. Similar phenomenon would occur between a silver substrate and...electrodeposited metal coating. Historically, this is why most successful electroplating process used copper, brass (copper-zinc alloy), and silver as substrates

  7. Electrodepositions on Tantalum in Alkali Halide Melts

    DEFF Research Database (Denmark)

    Barner, Jens H. Von; Jensen, Annemette Hindhede; Christensen, Erik

    2013-01-01

    Surface layers of tantalum metal were electrodeposited on steel from K2TaF7-LiF-NaF-KF melts. With careful control of the oxide contents dense and adherent deposits could be obtained by pulse plating. In NaCl-KCl-NaF-Na2CO3 and NaCl-KCl-Na2CO3 melts carbonate ions seems to be reduced to carbon in...

  8. Electrodepositions on Tantalum in alkali halide melts

    DEFF Research Database (Denmark)

    Barner, Jens H. Von; Jensen, Annemette Hindhede; Christensen, Erik

    2012-01-01

    Surface layers of tantalum metal were electrodeposited on steel from K 2TaF7-LiF-NaF-KF melts. With careful control of the oxide contents dense and adherent deposits could be obtained by pulse plating. In NaCl-KCl-NaF-Na2CO3 and NaCl-KCl-Na2CO 3 melts carbonate ions seems to be reduced to carbon ...

  9. Acidic aqueous uranium electrodeposition for target fabrication

    International Nuclear Information System (INIS)

    Saliba-Silva, A.M.; Oliveira, E.T.; Garcia, R.H.L.; Durazzo, M.

    2013-01-01

    Direct irradiation of targets inside nuclear research or multiple purpose reactors is a common route to produce 99 Mo- 99m Tc radioisotopes. The electroplating of low enriched uranium over nickel substrate might be a potential alternative to produce targets of 235 U. The electrochemistry of uranium at low temperature might be beneficial for an alternative route to produce 99 Mo irradiation LEU targets. Electrodeposition of uranium can be made using ionic and aqueous solutions producing uranium oxide deposits. The performance of uranium electrodeposition is relatively low because a big competition with H 2 evolution happens inside the window of electrochemical reduction potential. This work explores possibilities of electroplating uranium as UO 2 2+ (Uranium-VI) in order to achieve electroplating uranium in a sufficient amount to be commercially irradiated in the future Brazilian RMB reactor. Electroplated nickel substrate was followed by cathodic current electrodeposition from aqueous UO 2 (NO 3 ) 2 solution. EIS tests and modeling showed that a film formed differently in the three tested cathodic potentials. At the lower level, (-1.8V) there was an indication of a double film formation, one overlaying the other with ionic mass diffusion impaired at the interface with nickel substrate as showed by the relatively lower admittance of Warburg component. (author)

  10. In vitro precipitation of electrodeposited calcium-deficient hydroxyapatite coatings on Ti6Al4V substrate

    International Nuclear Information System (INIS)

    Dumelie, N.; Benhayoune, H.; Richard, D.; Laurent-Maquin, D.; Balossier, G.

    2008-01-01

    In this study, electrodeposited calcium phosphate coatings were characterized by X-ray diffraction, using a scanning electron microscope equipped with an EDAX detector, before and after immersion in DMEM (Dulbecco's Modified Eagle Medium). After 1, 7, 14, and 21 days of immersion, the calcium and phosphate contents in solution were measured by inductively coupled plasma atomic emission spectrometry (ICP-AES). The results indicated that precipitation of the coating occurred. Before immersion in DMEM, the electrodeposited coating was a mixed crystalline and amorphous calcium-deficient hydroxyapatite with a Ca/P atomic ratio of about 1.5, but during the immersion period these phases rapidly disappeared and were followed by the precipitation of a crystalline apatite with a Ca/P atomic ratio near 1.65. On the basis of these results, we conclude that an electrodeposited calcium phosphate coating on roughened titanium alloy substrate may act as a precursor for newly precipitated calcium phosphate in in vitro experiments independent of cellular activities

  11. Fabrication, morphological, structural and magnetic properties of electrodeposited Fe{sub 3}Pt nanowires and nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Khan, U. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Adeela, N. [Centre for High Energy Physics, University of the Punjab, Lahore 54000 (Pakistan); Li, Wenjing; Irfan, M.; Javed, K.; Riaz, S. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Han, X.F., E-mail: xfhan@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2017-02-15

    Highly ordered Fe{sub 3}Pt nanowires (NWs) and nanotubes (NTs) embedded in anodic aluminum oxide (AAO) template have been fabricated by dc electrodeposition method. Response of heat treatment on structural and magnetic properties of the samples has been studied with and without the presence of magnetic field (1 T). X-Ray Diffraction analysis shows chemically ordered L1{sub 2} face centered cubic (FCC) as the dominant phase for Fe{sub 3}Pt NWs and heat treatment improves crystallinity with retained its phase. Whereas, Fe{sub 3}Pt NTs show amorphous behavior with and without magnetic field annealing. Furthermore, magnetic properties of the samples have been investigated by vibrating sample magnetometer (VSM). Magnetic parameters of Fe{sub 3}Pt including magnetic coercivity, saturation magnetization, squareness and shape of MH-loops have been investigated as a result of simple and MF annealing. - Highlights: • Fe{sub 3}Pt NWs and NTs embedded into anodic alumina templates have been synthesized by dc electrodeposition method. • Structural analysis (XRD) confirmed the formation of fcc structure. • Magnetic properties have been measured as a function of simple and magnetic field annealing.

  12. Electrodeposition of Al-Mn alloy on AZ31B magnesium alloy in molten salts

    International Nuclear Information System (INIS)

    Zhang Jifu; Yan Chuanwei; Wang Fuhui

    2009-01-01

    The Al-Mn alloy coatings were electrodeposited on AZ31B Mg alloy in AlCl 3 -NaCl-KCl-MnCl 2 molten salts at 170 deg. C aiming to improve the corrosion resistance. However, in order to prevent AZ31B Mg alloy from corrosion during electrodeposition in molten salts and to ensure excellent adhesion of coatings to the substrate, AZ31B Mg alloy should be pre-plated with a thin zinc layer as intermediate layer. Then the microstructure, composition and phase constituents of the coatings were investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD). It was indicated that, by adjusting the MnCl 2 content in the molten salts from 0.5 wt% to 2 wt%, the Mn content in the alloy coating was increased and the phase constituents were changed from f.c.c Al-Mn solid solution to amorphous phase. The corrosion resistance of the coatings was evaluated by potentiodynamic polarization measurements in 3.5% NaCl solution. It was confirmed that the Al-Mn alloy coatings exhibited good corrosion resistance with a chear passive region and significantly reduced corrosion current density at anodic potentiodynamic polarization. The corrosion resistance of the alloy coatings was also related with the microstructure and Mn content of the coatings.

  13. Hydroxyapatite electrodeposition on anodized titanium nanotubes for orthopedic applications

    Energy Technology Data Exchange (ETDEWEB)

    Parcharoen, Yardnapar [Department of Biological Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand); Kajitvichyanukul, Puangrat [Center of Excellence on Environmental Research and Innovation, Faculty of Engineering, Naresuan University, Phitsanulok (Thailand); Sirivisoot, Sirinrath [Department of Biological Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand); Termsuksawad, Preecha, E-mail: preecha.ter@kmutt.ac.th [Division of Materials Technology, School of Energy, Environment and Materials, King Mongkut' s University of Technology Thonburi, 126 Pracha Uthit Rd., Bang Mod, ThungKhru, Bangkok 10140 (Thailand)

    2014-08-30

    Highlights: • We found that different anodization time of titanium significantly effects on nanotube length which further impacts adhesion strength of hydroxyapatite coating layers. • Adhesion strength of Hydroxyapatite (HA) coated on titanium dioxide nanotubes is better than that of HA coated on titanium plate. • Hydroxyapatite coated on titanium dioxide nanotubes showed higher cell density and better spreading of MC3T3-E1 cells (bone-forming cells) than that coated on titanium plate surface. - Abstract: Nanotubes modification for orthopedic implants has shown interesting biological performances (such as improving cell adhesion, cell differentiation, and enhancing osseointegration). The purpose of this study is to investigate effect of titanium dioxide (TiO{sub 2}) nanotube feature on performance of hydroxyapatite-coated titanium (Ti) bone implants. TiO{sub 2} nanotubes were prepared by anodization using ammonium fluoride electrolyte (NH{sub 4}F) with and without modifiers (PEG400 and Glycerol) at various potential forms, and times. After anodization, the nanotubes were subsequently annealed. TiO{sub 2} nanotubes were characterized by scanning electron microscope and X-ray diffractometer. The amorphous to anatase transformation due to annealing was observed. Smooth and highly organized TiO{sub 2} nanotubes were found when high viscous electrolyte, NH{sub 4}F in glycerol, was used. Negative voltage (−4 V) during anodization was confirmed to increase nanotube thickness. Length of the TiO{sub 2} nanotubes was significantly increased by times. The TiO{sub 2} nanotube was electrodeposited with hydroxyapatite (HA) and its adhesion was estimated by adhesive tape test. The result showed that nanotubes with the tube length of 560 nm showed excellent adhesion. The coated HA were tested for biological test by live/dead cell straining. HA coated on TiO{sub 2} nanotubes showed higher cells density, higher live cells, and more spreading of MC3T3-E1 cells than that

  14. Templated electrodeposition of functional nanostructures: nanowires, nanotubes and nanocubes

    NARCIS (Netherlands)

    Maijenburg, A.W.

    2014-01-01

    This thesis is entitled “Templated electrodeposition of functional nanostructures: nanowires, nanotubes and nanocubes”. Templated electrodeposition is the synthesis technique that was used throughout this thesis, and it comprises the use of a template with specific shape and dimensions for the

  15. Electrodeposition route to synthesize cigs films – an economical way ...

    African Journals Online (AJOL)

    Electrodeposition route to synthesize cigs films – an economical way to harness solar energy. ... for solar cells, how the charge separation in this nano scale photovoltaic (PV) materials occurs which help in absorption of radiation, and the electro-deposition route, a low cost one, produces thin film solar cells are analyzed.

  16. Conductance quantization in magnetic nanowires electrodeposited in nanopores

    DEFF Research Database (Denmark)

    Elhoussine, F.; Mátéfi-Tempfli, Stefan; Encinas, A.

    2002-01-01

    Magnetic nanocontacts have been prepared by a templating method that involves the electrodeposition of Ni within the pores of track-etched polymer membranes. The nanocontacts are made at the extremity of a single Ni nanowire either inside or outside the pores. The method is simple, flexible...... degeneracy. Our fabrication method enables future investigation of ballistic spin transport phenomena in electrodeposited magnetic nanocontacts....

  17. Electrodeposition of Al-Ta alloys in NaCl-KCl-AlCl{sub 3} molten salt containing TaCl{sub 5}

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Kazuki; Matsushima, Hisayoshi; Ueda, Mikito, E-mail: mikito@eng.hokudai.ac.jp

    2016-12-01

    Highlights: • Electrodeposition of Al-Ta alloys in an AlCl{sub 3}-NaCl-KCl-TaCl{sub 5} melt was carried out. • We were obtained 72 at% Ta-Al alloy at 0.3 V. • Amorphous Ta-Al was formed in high Ta concentration. - Abstract: To form Al-Ta alloys for high temperature oxidation resistance components, molten salt electrolysis was carried out in an AlCl{sub 3}-NaCl-KCl melt containing TaCl{sub 5} at 423 K. The voltammogram showed two cathodic waves at 0.45 V and 0.7 V vs. Al/Al(III), which may correspond to reduction from Ta(V) to Ta(III) and from Ta(III) to tantalum metal, respectively. Electrodeposits of Al and Ta were obtained in the range from −0.05 to 0.3 V and the highest concentration of Ta in the electrodeposit was 72 at% at 0.3 V. With increasing Ta content in the alloy, the morphology of the electrodeposits became powdery and the particle size smaller.

  18. Characterization and corrosion resistance of anodic electrodeposited titanium oxide/phosphate films on Ti-20Nb-10Zr-5Ta bioalloy

    Energy Technology Data Exchange (ETDEWEB)

    Popa, Monica; Vasilescu, Cora; Drob, Silviu I.; Osiceanu, Petre; Anastasescu, Mihai; Calderon-Moreno, Jose M., E-mail: josecalderonmoreno@yahoo.com [Institute of Physical Chemistry ' Ilie Murgulescu' of the Romanian Academy, Bucharest (Romania)

    2013-07-15

    In this work, the anodic galvanostatic electrodeposition of an oxidation film containing phosphates on Ti-20Nb-10Zr-5Ta alloy from orthophosphoric acid solution is presented. Its composition was determined by X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman micro-spectroscopy, and its topography by atomic force microscopy (AFM). The corrosion resistance of the coated alloy in simulated human fluid (by linear polarization method and monitoring of open circuit potentials, corresponding open circuit potential gradients) as well as the characterization of the coating (by Raman spectroscopy and depth profile X-ray photoelectron spectroscopy (XPS)) deposited in a period of 300 h soaking in simulated human body fluid were studied. The electrodeposited film was composed of amorphous titanium dioxide and contained phosphate groups. The corrosion resistance of the coated Ti-20Nb-10Zr-5Ta alloy in neutral and alkaline Ringer's solutions was higher than that of the bare alloy due to the protective properties of the electrodeposited film. The corrosion parameters improved over time as result of the thickening of the surface film by the deposition from the physiological solution. The deposited coating presented a variable composition in depth: at the deeper layer nucleated nanocrystalline hydroxyapatite and at the outer layer amorphous calcium phosphate. (author)

  19. Characterization and corrosion resistance of anodic electrodeposited titanium oxide/phosphate films on Ti-20Nb-10Zr-5Ta bioalloy

    International Nuclear Information System (INIS)

    Popa, Monica; Vasilescu, Cora; Drob, Silviu I.; Osiceanu, Petre; Anastasescu, Mihai; Calderon-Moreno, Jose M.

    2013-01-01

    In this work, the anodic galvanostatic electrodeposition of an oxidation film containing phosphates on Ti-20Nb-10Zr-5Ta alloy from orthophosphoric acid solution is presented. Its composition was determined by X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman micro-spectroscopy, and its topography by atomic force microscopy (AFM). The corrosion resistance of the coated alloy in simulated human fluid (by linear polarization method and monitoring of open circuit potentials, corresponding open circuit potential gradients) as well as the characterization of the coating (by Raman spectroscopy and depth profile X-ray photoelectron spectroscopy (XPS)) deposited in a period of 300 h soaking in simulated human body fluid were studied. The electrodeposited film was composed of amorphous titanium dioxide and contained phosphate groups. The corrosion resistance of the coated Ti-20Nb-10Zr-5Ta alloy in neutral and alkaline Ringer's solutions was higher than that of the bare alloy due to the protective properties of the electrodeposited film. The corrosion parameters improved over time as result of the thickening of the surface film by the deposition from the physiological solution. The deposited coating presented a variable composition in depth: at the deeper layer nucleated nanocrystalline hydroxyapatite and at the outer layer amorphous calcium phosphate. (author)

  20. Deuterium retention in molten salt electrodeposition tungsten coatings

    International Nuclear Information System (INIS)

    Zhou, Hai-Shan; Xu, Yu-Ping; Sun, Ning-Bo; Zhang, Ying-Chun; Oya, Yasuhisa; Zhao, Ming-Zhong; Mao, Hong-Min; Ding, Fang; Liu, Feng; Luo, Guang-Nan

    2016-01-01

    Highlights: • We investigate D retention in electrodeposition W coatings. • W coatings are exposed to D plasmas in the EAST tokamak. • A cathodic current density dependence on D retention is found. • Electrodeposition W exhibits lower D retention than VPS-W. - Abstract: Molten salt electrodeposition is a promising technology to manufacture the first wall of a fusion reactor. Deuterium (D) retention behavior in molten salt electrodeposition tungsten (W) coatings has been investigated by D-plasma exposure in the EAST tokamak and D-ion implantation in an ion beam facility. Tokamak exposure experiments demonstrate that coatings prepared with lower current density exhibit less D retention and milder surface damage. Deuterium-ion implantation experiments indicate the D retention in the molten salt electrodeposition W is less than that in vacuum plasma spraying W and polycrystalline W.

  1. Deuterium retention in molten salt electrodeposition tungsten coatings

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Hai-Shan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Xu, Yu-Ping [Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Sun, Ning-Bo; Zhang, Ying-Chun [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing (China); Oya, Yasuhisa [Radioscience Research Laboratory, Faculty of Science, Shizuoka University, Shizuoka (Japan); Zhao, Ming-Zhong [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Mao, Hong-Min [Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Ding, Fang; Liu, Feng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Luo, Guang-Nan, E-mail: gnluo@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Hefei Center for Physical Science and Technology, Hefei (China); Hefei Science Center of Chinese Academy of Science, Hefei (China)

    2016-12-15

    Highlights: • We investigate D retention in electrodeposition W coatings. • W coatings are exposed to D plasmas in the EAST tokamak. • A cathodic current density dependence on D retention is found. • Electrodeposition W exhibits lower D retention than VPS-W. - Abstract: Molten salt electrodeposition is a promising technology to manufacture the first wall of a fusion reactor. Deuterium (D) retention behavior in molten salt electrodeposition tungsten (W) coatings has been investigated by D-plasma exposure in the EAST tokamak and D-ion implantation in an ion beam facility. Tokamak exposure experiments demonstrate that coatings prepared with lower current density exhibit less D retention and milder surface damage. Deuterium-ion implantation experiments indicate the D retention in the molten salt electrodeposition W is less than that in vacuum plasma spraying W and polycrystalline W.

  2. Structural amorphous steels

    International Nuclear Information System (INIS)

    Lu, Z.P.; Liu, C.T.; Porter, W.D.; Thompson, J.R.

    2004-01-01

    Recent advancement in bulk metallic glasses, whose properties are usually superior to their crystalline counterparts, has stimulated great interest in fabricating bulk amorphous steels. While a great deal of effort has been devoted to this field, the fabrication of structural amorphous steels with large cross sections has remained an alchemist's dream because of the limited glass-forming ability (GFA) of these materials. Here we report the discovery of structural amorphous steels that can be cast into glasses with large cross-section sizes using conventional drop-casting methods. These new steels showed interesting physical, magnetic, and mechanical properties, along with high thermal stability. The underlying mechanisms for the superior GFA of these materials are discussed

  3. Architectural Growth of Cu Nanoparticles Through Electrodeposition

    Directory of Open Access Journals (Sweden)

    Cheng Ching-Yuan

    2009-01-01

    Full Text Available Abstract Cu particles with different architectures such as pyramid, cube, and multipod have been successfully fabricated on the surface of Au films, which is the polycrystalline Au substrate with (111 domains, using the electrodeposition technique in the presence of the surface-capping reagents of dodecylbenzene sulfonic acid and poly(vinylpyrrolidone. Further, the growth evolution of pyramidal Cu nanoparticles was observed for the first time. We believe that our method might open new possibilities for fabricating nanomaterials of non-noble transition metals with various novel architectures, which can then potentially be utilized in applications such as biosensors, catalysis, photovoltaic cells, and electronic nanodevices.

  4. Electrodeposition of nickel particles and their characterization

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, G. T. [Centro de Investigacion en Quimica Aplicada, Laboratorio de Microscopia. Blvd. Enrique Reyna No. 140, Saltillo 25253, Coahuila (Mexico); Zavala, G.; Videa, M. [ITESM, Campus Monterrey, Depto. de Fisica, Av. Garza Sada 2501 Sur, Monterrey 64849, N. L. (Mexico)], e-mail: gtadeo@ciqa.mx

    2009-07-01

    Electrodeposition of nickel particles on ITO substrates is achieved by current pulse reduction. A comparison between potential pulse and current pulse experiments presents differences in particle size and particle size distribution. The latter shows smaller particle size dispersion than what is found with potential pulses. Characterization of the particles carried out by Atomic Force Microscopy shows particles with average sizes between 100 to 300 nm. Magnetic characterization by Magnetic Force Microscopy and SQUID shows that particles of {approx} 300 nm were ferromagnetic with a coercive field of 200 Oe and a saturation magnetization of 40 x 10{sup -6} emu at 300 K. (Author)

  5. Residual stress in Ni-W electrodeposits

    DEFF Research Database (Denmark)

    Mizushima, Io; Tang, Peter Torben; Hansen, Hans Nørgaard

    2006-01-01

    In the present work, the residual stress in Ni–W layers electrodeposited from electrolytes based on NiSO4 and Na2WO4, is investigated. Citrate, glycine and triethanolamine were used as complexing agents, enabling complex formation between the nickel ion and tungstate. The results show that the type...... of complexing agent and the current efficiency have an influence on the residual stress. In all cases, an increase in tensile stress in the deposit with time after deposition was observed. Pulse plating could improve the stress level for the electrolyte containing equal amounts of citrate...

  6. Electrodeposited zinc/nickel coatings. A review

    Energy Technology Data Exchange (ETDEWEB)

    Shoeib, Madiha A. [Central Metallurgical Research and Development Institute (CMRDI), Helwan, Cairo (Egypt). Surface Coating Dept.

    2011-10-15

    In recent years, the use of electrodeposited zinc-nickel coatings has significantly increased, mainly because of their superior corrosion resistance as compared with zinc. An additional strength of the process is that the proportion of the two metals, and thus the coating properties, can be varied. Initially, these alloy deposits were relatively brittle, with a tendency to crack-formation. More recently, ductile coatings have been developed. Now, as in the past, the emphasis has been on the cathodic corrosion protection which these coatings provide. Their properties can be further enhanced by post-treatment where additional developments have taken place. (orig.)

  7. Structure of amorphous sulfur

    CSIR Research Space (South Africa)

    Eichinger, BE

    2001-06-01

    Full Text Available The lambda-transition of elemental sulfur occurring at about 159°C has long been associated with the conversion of cyclic S8 rings (c-S8) to amorphous polymer (a-S) via a ring opening polymerization. It is demonstrated, with the use of both density...

  8. Neutron reflectivity of electrodeposited thin magnetic films

    International Nuclear Information System (INIS)

    Cooper, Joshaniel F.K.; Vyas, Kunal N.; Steinke, Nina-J.; Love, David M.; Kinane, Christian J.; Barnes, Crispin H.W.

    2014-01-01

    Highlights: • Electrodeposited magnetic bi-layers were measured by polarised neutron reflectivity. • When growing a CoNiCu alloy from a single bath a Cu rich region is initially formed. • This Cu rich region is formed in the first layer but not subsequent ones. • Ni deposition is inhibited in thin film growth and Co deposits anomalously. • Alloy magnetism and neutron scattering length give a self-consistent model. - Abstract: We present a polarised neutron reflectivity (PNR) study of magnetic/non-magnetic (CoNiCu/Cu) thin films grown by single bath electrodeposition. We find that the composition is neither homogeneous with time, nor consistent with bulk values. Instead an initial, non-magnetic copper rich layer is formed, around 2 nm thick. This layer is formed by the deposition of the dilute, but rapidly diffusing, Cu 2+ ions near the electrode surface at the start of growth, before the region is depleted and the deposition becomes mass transport limited. After the region has been depleted, by growth etc., this layer does not form and thus may be prevented by growing a copper buffer layer immediately preceding the magnetic layer growth. As has been previously found, cobalt deposits anomalously compared to nickel, and even inhibits Ni deposition in thin films. The layer magnetisation and average neutron scattering length are fitted independently but both depend upon the alloy composition. Thus these parameters can be used to check for model self-consistency, increasing confidence in the derived composition

  9. Gas Sensors Based on Electrodeposited Polymers

    Directory of Open Access Journals (Sweden)

    Boris Lakard

    2015-07-01

    Full Text Available Electrochemically deposited polymers, also called “synthetic metals”, have emerged as potential candidates for chemical sensing due to their interesting and tunable chemical, electrical, and structural properties. In particular, most of these polymers (including polypyrrole, polyaniline, polythiophene and their derivatives can be used as the sensitive layer of conductimetric gas sensors because of their conducting properties. An important advantage of polymer-based gas sensors is their efficiency at room temperature. This characteristic is interesting since most of the commercially-available sensors, usually based on metal oxides, work at high temperatures (300–400 °C. Consequently, polymer-based gas sensors are playing a growing role in the improvement of public health and environment control because they can lead to gas sensors operating with rapid detection, high sensitivity, small size, and specificity in atmospheric conditions. In this review, the recent advances in electrodeposited polymer-based gas sensors are summarized and discussed. It is shown that the sensing characteristics of electrodeposited polymers can be improved by chemical functionalization, nanostructuration, or mixing with other functional materials to form composites or hybrid materials.

  10. Preparation of uranium electrodeposited target in aqueous system

    International Nuclear Information System (INIS)

    Chen Qiping; Li Yougen; Zhong Wenbin

    2006-03-01

    The main factors affecting uranium electrodeposition were tested and discussed. In the primary experiment about preparation of uranium isotopic target by electrodeposition, a stainless steel disk has been chosen as the target material, the electrolytic bath is comprised of UO 2 (NO 3 ) 2 and (NH 4 ) 2 C 2 O 4 , which has been adjusted to a pH of 2-3. Composition of the lost electrolytic bath was analysed by spectrophotometer. The thickness of resulting film is about 8-10 mg/cm 2 , the target having a thin, continuous, uniform layer of uranium, and its electrodeposited rate is more than 80%. (authors)

  11. Preliminary results about Electrodeposition of Cobalt at laboratory level

    International Nuclear Information System (INIS)

    Cornejo, N.

    1992-01-01

    As of an organic compound, an extraction and Cobalt electrodeposition method had been developed as a part of fabrication aim of a sealed radioactive source with objective to the construction of density meter prototype. It was performed preliminary test of electrodeposition in the laboratory level in a simple cell. The used electrolyte had been a sulphate solution obtained by extraction of an organic solution. It is obtained a Co film by electrodeposition at 55 o C temperature and with an approximately Co concentration in 70 g/lt. (Author) 3 refs., 1 fig., 1 tab

  12. The preparation and thermoelectric properties of molten salt electrodeposited boron wafers

    International Nuclear Information System (INIS)

    Kumashiro, Y.; Ozaki, S.; Sato, K.; Kataoka, Y.; Hirata, K.; Yokoyama, T.; Nagatani, S.; Kajiyama, K.

    2004-01-01

    We have prepared electrodeposited boron wafer by molten salts with KBF 4 -KF at 680 deg. C using graphite crucible for anode and silicon wafer and nickel plate for cathodes. Experiments were performed by various molar ratios KBF 4 /KF and current densities. Amorphous p-type boron wafers with purity 87% was deposited on nickel plate for 1 h. Thermal diffusivity by ring-flash method and heat capacity by DSC method produced thermal conductivity showing amorphous behavior in the entire temperature range. The systematical results on thermoelectric properties were obtained for the wafers prepared with KBF 4 -KF (66-34 mol%) under various current densities in the range 1-2 A/cm 2 . The temperature dependencies of electrical conductivity showed thermal activated type with activation energy of 0.5 eV. Thermoelectric power tended to increase with increasing temperature up to high temperatures with high values of (1-10) mV/K. Thermoelectric figure-of-merit was 10 -4 /K at high temperatures. Estimated efficiency of thermoelectric energy conversion would be calculated to be 4-5%

  13. Electrodeposition of gallium and zinc onto aluminium. Influence of the electrodeposited metals on the activation process

    International Nuclear Information System (INIS)

    Flamini, D.O.; Saidman, S.B.; Bessone, J.B.

    2007-01-01

    The electrodeposition of gallium and/or zinc on aluminium, aluminium-zinc alloy and vitreous carbon electrodes in chloride solutions is analysed. The electrodissolution of the formed interfaces is also described and discussed. For this purpose, potentiodynamic and potentiostatic techniques and open circuit potential measurements were employed and surface characterisation was performed by scanning electron microscopy and energy dispersive X-ray analysis. The presence of zinc, electrodeposited from the solution or as an alloying component, facilitates gallium enrichment at the interface and improves the wetting on the aluminium oxide. These conditions ensure the formation of a surface Ga-Al amalgam. As a result, the dissolution process occurs at potentials which are more active than those observed for aluminium or aluminium-zinc alloy in halide solutions

  14. Electrodeposition of gallium and zinc onto aluminium. Influence of the electrodeposited metals on the activation process

    Energy Technology Data Exchange (ETDEWEB)

    Flamini, D.O. [Instituto de Ingenieria Electroquimica y Corrosion (INIEC), Departamento de Ingenieria Quimica, Universidad Nacional del Sur, Av. Alem 1253, 8000 Bahia Blanca (Argentina); Saidman, S.B. [Instituto de Ingenieria Electroquimica y Corrosion (INIEC), Departamento de Ingenieria Quimica, Universidad Nacional del Sur, Av. Alem 1253, 8000 Bahia Blanca (Argentina)], E-mail: ssaidman@criba.edu.ar; Bessone, J.B. [Instituto de Ingenieria Electroquimica y Corrosion (INIEC), Departamento de Ingenieria Quimica, Universidad Nacional del Sur, Av. Alem 1253, 8000 Bahia Blanca (Argentina)

    2007-07-31

    The electrodeposition of gallium and/or zinc on aluminium, aluminium-zinc alloy and vitreous carbon electrodes in chloride solutions is analysed. The electrodissolution of the formed interfaces is also described and discussed. For this purpose, potentiodynamic and potentiostatic techniques and open circuit potential measurements were employed and surface characterisation was performed by scanning electron microscopy and energy dispersive X-ray analysis. The presence of zinc, electrodeposited from the solution or as an alloying component, facilitates gallium enrichment at the interface and improves the wetting on the aluminium oxide. These conditions ensure the formation of a surface Ga-Al amalgam. As a result, the dissolution process occurs at potentials which are more active than those observed for aluminium or aluminium-zinc alloy in halide solutions.

  15. A Study on the Effect of Electrodeposition Parameters on the Morphology of Porous Nickel Electrodeposits

    Science.gov (United States)

    Sengupta, Srijan; Patra, Arghya; Jena, Sambedan; Das, Karabi; Das, Siddhartha

    2018-03-01

    In this study, the electrodeposition of nickel foam by dynamic hydrogen bubble-template method is optimized, and the effects of key deposition parameters (applied voltage and deposition time) and bath composition (concentration of Ni2+, pH of the bath, and roles of Cl- and SO4 2- ions) on pore size, distribution, and morphology and crystal structure are studied. Nickel deposit from 0.1 M NiCl2 bath concentration is able to produce the honeycomb-like structure with regular-sized holes. Honeycomb-like structure with cauliflower morphology is deposited at higher applied voltages of 7, 8, and 9 V; and a critical time (>3 minutes) is required for the development of the foamy structure. Compressive residual stresses are developed in the porous electrodeposits after 30 seconds of deposition time (-189.0 MPa), and the nature of the residual stress remains compressive upto 10 minutes of deposition time (-1098.6 MPa). Effect of pH is more pronounced in a chloride bath compared with a sulfate bath. The increasing nature of pore size in nickel electrodeposits plated from a chloride bath (varying from 21 to 48 μm), and the constant pore size (in the range of 22 to 24 μm) in deposits plated from a sulfate bath, can be ascribed to the striking difference in the magnitude of the corresponding current-time profiles.

  16. Amorphous silicon radiation detectors

    Science.gov (United States)

    Street, Robert A.; Perez-Mendez, Victor; Kaplan, Selig N.

    1992-01-01

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification.

  17. Electrodeposition route to synthesize cigs films – an economical way ...

    African Journals Online (AJOL)

    user

    Unlike binary conductors CIGS film preparation needs highly ... This argument also holds well in forming a hetero-junction partner CdS ..... successfully electrodeposited onto indium tin oxide substrate and it is recently reported (Li et al., 2010).

  18. Bulk Copper Electrodeposition on Gold Imaged by In Situ STM

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Bech-Nielsen, Gregers; Møller, Per

    1996-01-01

    Electrochemical measurements were carried out simultaneously with acquisition of in situ STM images of copper electrodeposition at low cathodic overpotentials and subsequent dissolution from the underlying polycrystalline gold surfaces. The morphologies of the copper deposits were examined...

  19. Nanocrystalline Ni-Co Alloy Synthesis by High Speed Electrodeposition

    Directory of Open Access Journals (Sweden)

    Jamaliah Idris

    2013-01-01

    Full Text Available Electrodeposition of nanocrystals is economically and technologically viable production path for the synthesis of pure metals and alloys both in coatings and bulk form. The study presents nanocrystalline Ni-Co alloy synthesis by high speed electrodeposition. Nanocrystalline Ni-Co alloys coatings were prepared by direct current (DC and deposited directly on steel and aluminum substrates without any pretreatment, using high speed electrodeposition method. The influence of the electrolysis parameters, such as cathodic current density and temperature at constant pH, on electrodeposition and microstructure of Ni-Co alloys were examined. A homogeneous surface morphology was obtained at all current densities of the plated samples, and it was evident that the current density and temperature affect the coating thickness of Ni-Co alloy coatings.

  20. Effect of condensation product on electrodeposition of zinc on mild ...

    Indian Academy of Sciences (India)

    WINTEC

    Abstract. Electrodeposition of zinc on steel was obtained from acid chloride bath containing condensation products (CP) of 3,4 ..... nucleation number and hence smaller grain size. The ... thesis, Bangalore University, Bangalore. Venkatesha ...

  1. Templated electrodeposition of functional nanostructures: nanowires, nanotubes and nanocubes

    OpenAIRE

    Maijenburg, A.W.

    2014-01-01

    This thesis is entitled “Templated electrodeposition of functional nanostructures: nanowires, nanotubes and nanocubes”. Templated electrodeposition is the synthesis technique that was used throughout this thesis, and it comprises the use of a template with specific shape and dimensions for the formation of different types of nanostructures. Throughout this thesis, three different nanostructures were made: nanowires (Chapters 2 to 6), nanotubes (Chapters 2 and 5) and nanocubes (Chapters 7 and ...

  2. Structural defects in electrodeposited Ni studied by positron annihilation

    International Nuclear Information System (INIS)

    Vertes, A.; Szeles, C.; Czako-Nagy, I.; Lakatos-Varsanyi, M.

    1982-01-01

    Structural investigation of electrodeposited Ni was carried out by positron annihilation (PA) technique. Additional Moessbauer effect and X-ray diffraction measurements were also performed. The samples were produced under different plating conditions resulting in stress in the range -100 to +600 N/mm 2 . From the positron lifetime measurements it seems that the defect pattern of electrodeposited Ni samples might be substantially different from sample to sample with different deposition and plating conditions. (Auth.)

  3. Electrodeposition of nanostructured Sn-Zn coatings

    Science.gov (United States)

    Salhi, Y.; Cherrouf, S.; Cherkaoui, M.; Abdelouahdi, K.

    2016-03-01

    The electrodeposition of Sn-Zn coating at ambient temperature was investigated. The bath consists of metal salts SnCl2·2H2O and ZnSO4·7H2O and sodium citrate (NaC6H5Na3O7·2H2O) as complexing agent. To prevent precipitation, the pH is fixed at 5. Reducing tin and zinc through Sncit2- and ZnHcit- complex respectively is confirmed by the presence of two cathodic peaks on the voltammogram. The kinetic of tin (II) reduction process is limited by the SnCit2- dissociation. The SEM and TEM observations have showed that the coating consists of a uniform Sn-Zn layer composed of fine grains on which tin aggregates grow up. XRD revealed peaks corresponding to the hexagonal Zn phase and the tetragonal β-Sn phase.

  4. Separation and electrodeposited of 210 Po

    International Nuclear Information System (INIS)

    Ordonez R, E.; Iturbe G, J.L.

    1991-12-01

    Presently work it was determined the selective separation of the 210 Po that is in an uraniferous mineral, by means of acid leaching of the mineral and the purification was carried out by means of partition chromatography whose stationary phase is 2-ethylhexyl phosphoric acid (D 2 EHPA), it has been possible to isolate the 210 Po of the rest of the radioactive elements that conform the family 4 N +2 , the optimal elutriation conditions of this element were settled down of manner of not dragging other radioelements. Another of the achievements presented in this communication has been the electrodeposition of this element has more than enough stainless steel discs with a superior yield to 95%. (Author)

  5. Methods of amorphization and investigation of the amorphous state

    OpenAIRE

    EINFALT, TOMAŽ; PLANINŠEK, ODON; HROVAT, KLEMEN

    2013-01-01

    The amorphous form of pharmaceutical materials represents the most energetic solid state of a material. It provides advantages in terms of dissolution rate and bioavailability. This review presents the methods of solid-state amorphization described in literature (supercooling of liquids, milling, lyophilization, spray drying, dehydration of crystalline hydrates), with the emphasis on milling. Furthermore, we describe how amorphous state of pharmaceuticals differ depending on method of prepara...

  6. Method of recovering phosphoric acid type decontaminating electrolytes by electrodeposition

    International Nuclear Information System (INIS)

    Sasaki, Takashi; Wada, Koichi; Kobayashi, Toshio.

    1985-01-01

    Purpose: To recoving phosphoric acid type highly concentrated decontaminating liquid used for the electrolytic decontamination of contaminated equipments, components, etc in nuclear power plants or the like through electrodeposition by diaphragm electrolysis. Method: Before supplying phosphoric acid decontaminating liquid at high concentration used in the electrolytic decontaminating step to an electrodeposition recovering tank, phosphoric acid in the decontaminating electrolyte is extracted with solvents and decomposed liquid extracts (electrolyte reduced with the phosphoric acid component) are supplied to the cathode chamber of the electrodeposition recovering tank, where phosphoric acid is back-extracted with water from the solvents after extraction of phosphoric acid. Then, the back-extracted liquids (aqueous phosphoric acid solution scarcely containing metal ions) are sent to the anode chamber of the electrodeposition recovering tank. Metal ions in the liquid are captured by electrodeposition in the cathode chamber, as well as phosphoric acid in the liquids is concentrated to the initial concentration of the electrolyte in the anode chamber for reuse as the decontaminating electrolyte. As the phosphoric acid extracting agent used in the electrodeposition recovering step for the decontaminating electrolyte, water-insoluble and non-combustible tributyl phosphate (TBP) is most effective. (Horiuchi, T.)

  7. Electrodeposition of amine-terminatedpoly(ethylene glycol) to titanium surface

    International Nuclear Information System (INIS)

    Tanaka, Yuta; Doi, Hisashi; Iwasaki, Yasuhiko; Hiromoto, Sachiko; Yoneyama, Takayuki; Asami, Katsuhiko; Imai, Hachiro; Hanawa, Takao

    2007-01-01

    The immobilization of poly(ethylene glycol), PEG, to a solid surface is useful to functionalize the surface, e.g., to prevent the adsorption of proteins. No successful one-stage technique for the immobilization of PEG to base metals has ever been developed. In this study, PEG in which both terminals or one terminal had been modified with amine bases was immobilized onto a titanium surface using electrodeposition. PEG was dissolved in a NaCl solution, and electrodeposition was carried out at 310 K with - 5 V for 300 min. The thickness of the deposited PEG layer was evaluated using ellipsometry, and the bonding manner of PEG to the titanium surface was characterized using X-ray photoelectron spectroscopy after electrodeposition. The results indicated that a certain amount of PEG was adsorbed on titanium through both electrodeposition and immersion when PEG was terminated by amine. However, terminated amines existed at the surface of titanium and were combined with titanium oxide as N-HO by electrodeposition, while amines randomly existed in the molecule and showed an ionic bond with titanium oxide by immersion. The electrodeposition of PEG was effective for the inhibition of albumin adsorption. This process is useful for materials that have electroconductivity and a complex morphology

  8. The Stabilization of Amorphous Zopiclone in an Amorphous Solid Dispersion.

    Science.gov (United States)

    Milne, Marnus; Liebenberg, Wilna; Aucamp, Marique

    2015-10-01

    Zopiclone is a poorly soluble psychotherapeutic agent. The aim of this study was to prepare and characterize an amorphous form of zopiclone as well as the characterization and performance of a stable amorphous solid dispersion. The amorphous form was prepared by the well-known method of quench-cooling of the melt. The solid dispersion was prepared by a solvent evaporation method of zopiclone, polyvinylpyrrolidone-25 (PVP-25), and methanol, followed by freeze-drying. The physico-chemical properties and stability of amorphous zopiclone and the solid dispersion was studied using differential scanning calorimetry (DSC), infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), hot-stage microscopy (HSM), X-ray diffractometry (XRD), solubility, and dissolution studies. The zopiclone amorphous solid-state form was determined to be a fragile glass; it was concluded that the stability of the amorphous form is influenced by both temperature and water. Exposure of amorphous zopiclone to moisture results in rapid transformation of the amorphous form to the crystalline dihydrated form. In comparison, the amorphous solid dispersion proved to be more stable with increased aqueous solubility.

  9. Ion implantation and amorphous metals

    International Nuclear Information System (INIS)

    Hohmuth, K.; Rauschenbach, B.

    1981-01-01

    This review deals with ion implantation of metals in the high concentration range for preparing amorphous layers (>= 10 at%, implantation doses > 10 16 ions/cm 2 ). Different models are described concerning formation of amorphous phases of metals by ion implantation and experimental results are given. The study of amorphous phases has been carried out by the aid of Rutherford backscattering combined with the channeling technique and using transmission electron microscopy. The structure of amorphous metals prepared by ion implantation has been discussed. It was concluded that amorphous metal-metalloid compounds can be described by a dense-random-packing structure with a great portion of metal atoms. Ion implantation has been compared with other techniques for preparing amorphous metals and the adventages have been outlined

  10. Formation of nanocrystalline phases during decomposition of amorphous Ni-P alloys by continuous linear heating

    Energy Technology Data Exchange (ETDEWEB)

    Revesz, A.; Lendvai, J. [Eoetvoes Lorand Tudomanyegyeten, Budapest (Hungary). Dept. for General Physics; Cziraki, A. [Eoetvoes Univ. (Hungary). Dept. of Solid State Physics; Liebermann, H.H. [Honeywell Amorphous Metals, Morristown, NJ (United States); Bakonyi, I. [Hungarian Academy of Sciences (Hungary). Research Inst. for Solid State Physics and Optics

    2001-05-01

    Differential scanning calorimetry (DSC), powder diffraction and high-resolution X-ray diffraction (XRD), and transmission electron microscopy (TEM) investigations have been performed on melt-quenched amorphous Ni-P alloys with compositions of 18 to 22 at.% P. The calorimetric results revealed different crystallization routes during linear heating below, at and above the eutectic point (19 at.% P) but with the same general transformation scheme as reported previously for electrodeposited and electroless Ni-P amorphous alloys. The composition dependence of the activation energy of the crystallization and the heats evolved during the structural transformations were determined from DSC measurements. The average grain size was derived from XRD line broadening and important information on the crystallization products and their microstructure could be revealed also from the TEM studies. All these findings will have special significance when analysing the results of isothermal annealing experiments to be described in a forthcoming paper. (orig.)

  11. Origins of amorphous interstellar grains

    International Nuclear Information System (INIS)

    Hasegawa, H.

    1984-01-01

    The existence of amorphous interstellar grains has been suggested from infrared observations. Some carbon stars show the far infrared emission with a lambda -1 wavelength dependence. Far infrared emission supposed to be due to silicate grains often show the lambda -1 wavelength dependence. Mid infrared spectra around 10 μm have broad structure. These may be due to the amorphous silicate grains. The condition that the condensed grains from the cosmic gas are amorphous is discussed. (author)

  12. Amorphous silicon based particle detectors

    OpenAIRE

    Wyrsch, N.; Franco, A.; Riesen, Y.; Despeisse, M.; Dunand, S.; Powolny, F.; Jarron, P.; Ballif, C.

    2012-01-01

    Radiation hard monolithic particle sensors can be fabricated by a vertical integration of amorphous silicon particle sensors on top of CMOS readout chip. Two types of such particle sensors are presented here using either thick diodes or microchannel plates. The first type based on amorphous silicon diodes exhibits high spatial resolution due to the short lateral carrier collection. Combination of an amorphous silicon thick diode with microstrip detector geometries permits to achieve micromete...

  13. Amorphous drugs and dosage forms

    DEFF Research Database (Denmark)

    Grohganz, Holger; Löbmann, K.; Priemel, P.

    2013-01-01

    The transformation to an amorphous form is one of the most promising approaches to address the low solubility of drug compounds, the latter being an increasing challenge in the development of new drug candidates. However, amorphous forms are high energy solids and tend to recry stallize. New...... formulation principles are needed to ensure the stability of amorphous drug forms. The formation of solid dispersions is still the most investigated approach, but additional approaches are desirable to overcome the shortcomings of solid dispersions. Spatial separation by either coating or the use of micro-containers...... before single molecules are available for the formation of crystal nuclei, thus stabilizing the amorphous form....

  14. Kinetics of Ni–Mo electrodeposition from Ni-rich citrate baths

    International Nuclear Information System (INIS)

    Beltowska-Lehman, E.; Indyka, P.

    2012-01-01

    The kinetics of Ni–Mo alloy electrodeposition on steel substrates from an aqueous citrate–ammonia complex baths has been investigated by means of steady-state polarisation measurements in a system with a rotating disc electrode (RDE). Partial current densities for discharge of Ni(II) and Mo(VI) ions and hydrogen evolution as a function of molybdate concentration in the bath, cathode potentials and the rate of mass transport were determined. It has been shown that – under all investigated conditions – Ni–Mo alloy deposition is more favourable than pure nickel and the cathodic process is strongly influenced by the Mo(VI) content in the solution. The Ni(II) electroreduction rate initially increases, as the cathode potential shifts towards more negative values and the concentration of molybdate grows in the solution. However, for the highest examined MoO 4 2− content, a considerable decrease in the rate of the process is subsequently observed at certain limit potentials, the values of which depend on molybdate concentration and hydrodynamic conditions. This effect, related to the formation of intermediate molybdenum oxides (characterised by very low overvoltage for hydrogen evolution), becomes less pronounced when the RDE rotation speed is increased. Hydrogen evolution is strongly associated with molybdenum deposition. An increase of the molybdate ions concentration in the bath, as well as an increase in the rate of mass transport, leads to an increase in Mo content in deposits and to the reduction of current efficiency. The Ni–Mo coatings electrodeposited from the designed bath (with the current efficiency of about 70%) containing about 30 wt.% Mo, are characterised by a shiny-grey appearance and good adhesion to the steel substrate. They are characterised by column growth and amorphous microstructure with randomly distributed nanocrystallites of the MoNi 4 intermetallic phase.

  15. Al–Mn coating electrodeposited from ionic liquid on NdFeB magnet with high hardness and corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Jingjing; Xu, Bajin; Ling, Guoping, E-mail: linggp@zju.edu.cn

    2014-06-01

    Al–Mn coatings were electrodeposited on sintered NdFeB permanent magnet in MnCl{sub 2}–AlCl{sub 3}–1-ethyl-3-methylim-idazolium chloride (MnCl{sub 2}–AlCl{sub 3}–EMIC) ionic liquid at room temperature. The coatings were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The adhesion strength of the coating on NdFeB substrate was evaluated by thermal shock and scratch test. The hardness and corrosion behavior of Al–Mn coating were measured by a Knoop microhardness tester, immersion test and neutral salt spray test respectively. The results showed that the amorphous structure of the deposits was obtained at the current density of 6 mA/cm{sup 2}, while higher current densities resulted in a mixed structure of amorphous and crystalline. The Al–Mn coating showed excellent adhesion strength on NdFeB substrate with the thermal shock test over 30 cycles and L{sub c} > 80 N. The hardness of Al–Mn coating was up to 5.4 GPa. The amorphous Al–Mn coating showed an anodic sacrificial protection with a low corrosion rate for NdFeB. Meanwhile, the magnetic properties measured by an AMT-4 magnetic measurement device showed that Al–Mn coating did not deteriorate the magnetic property of NdFeB.

  16. Al–Mn coating electrodeposited from ionic liquid on NdFeB magnet with high hardness and corrosion resistance

    International Nuclear Information System (INIS)

    Ding, Jingjing; Xu, Bajin; Ling, Guoping

    2014-01-01

    Al–Mn coatings were electrodeposited on sintered NdFeB permanent magnet in MnCl 2 –AlCl 3 –1-ethyl-3-methylim-idazolium chloride (MnCl 2 –AlCl 3 –EMIC) ionic liquid at room temperature. The coatings were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The adhesion strength of the coating on NdFeB substrate was evaluated by thermal shock and scratch test. The hardness and corrosion behavior of Al–Mn coating were measured by a Knoop microhardness tester, immersion test and neutral salt spray test respectively. The results showed that the amorphous structure of the deposits was obtained at the current density of 6 mA/cm 2 , while higher current densities resulted in a mixed structure of amorphous and crystalline. The Al–Mn coating showed excellent adhesion strength on NdFeB substrate with the thermal shock test over 30 cycles and L c > 80 N. The hardness of Al–Mn coating was up to 5.4 GPa. The amorphous Al–Mn coating showed an anodic sacrificial protection with a low corrosion rate for NdFeB. Meanwhile, the magnetic properties measured by an AMT-4 magnetic measurement device showed that Al–Mn coating did not deteriorate the magnetic property of NdFeB.

  17. Phosphate tuned copper electrodeposition and promoted formic acid selectivity for carbon dioxide reduction

    DEFF Research Database (Denmark)

    Zhao, Jian; Sun, Libo; Canepa, Silvia

    2017-01-01

    Fabrication of catalytically active electrodes by electrodeposition is attractive due to its in situ nature, easy controllability, and large-scale operation capability. Most recently, modifying the electrodes with phosphate ligands through electrodepositing electrode materials has shown promising...

  18. Amorphous silicon ionizing particle detectors

    Science.gov (United States)

    Street, Robert A.; Mendez, Victor P.; Kaplan, Selig N.

    1988-01-01

    Amorphous silicon ionizing particle detectors having a hydrogenated amorphous silicon (a--Si:H) thin film deposited via plasma assisted chemical vapor deposition techniques are utilized to detect the presence, position and counting of high energy ionizing particles, such as electrons, x-rays, alpha particles, beta particles and gamma radiation.

  19. Preparation and characterization of electrodeposited cobalt nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Irshad, M. I., E-mail: imrancssp@gmail.com; Mohamed, N. M., E-mail: noranimuti-mohamed@petronas.com.my [Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, 31750 PERAK (Malaysia); Ahmad, F., E-mail: faizahmad@petronas.com.my; Abdullah, M. Z., E-mail: zaki-abdullah@petronas.com.my [Department of Mechanical Engineering, Universiti Teknologi PETRONAS, 31750 PERAK (Malaysia)

    2014-10-24

    Electrochemical deposition technique has been used to deposit cobalt nanowires into the nano sized channels of Anodized Aluminium Oxide (AAO) templates. CoCl{sub 2}Ðœ‡6H2O salt solution was used, which was buffered with H{sub 3}BO{sub 3} and acidified by dilute H{sub 2}SO{sub 4} to increase the plating life and control pH of the solution. Thin film of copper around 150 nm thick on one side of AAO template coated by e-beam evaporation system served as cathode to create electrical contact. FESEM analysis shows that the as-deposited nanowires are highly aligned, parallel to one another and have high aspect ratio with a reasonably high pore-filing factor. The TEM results show that electrodeposited cobalt nanowires are crystalline in nature. The Hysteresis loop shows the magnetization properties for in and out of plane configuration. The in plane saturation magnetization (Ms) is lower than out of plane configuration because of the easy axis of magnetization is perpendicular to nanowire axis. These magnetic nanowires could be utilized for applications such as spintronic devices, high density magnetic storage, and magnetic sensor applications.

  20. Preparation and characterization of electrodeposited cobalt nanowires

    International Nuclear Information System (INIS)

    Irshad, M. I.; Mohamed, N. M.; Ahmad, F.; Abdullah, M. Z.

    2014-01-01

    Electrochemical deposition technique has been used to deposit cobalt nanowires into the nano sized channels of Anodized Aluminium Oxide (AAO) templates. CoCl 2 Ðœ‡6H2O salt solution was used, which was buffered with H 3 BO 3 and acidified by dilute H 2 SO 4 to increase the plating life and control pH of the solution. Thin film of copper around 150 nm thick on one side of AAO template coated by e-beam evaporation system served as cathode to create electrical contact. FESEM analysis shows that the as-deposited nanowires are highly aligned, parallel to one another and have high aspect ratio with a reasonably high pore-filing factor. The TEM results show that electrodeposited cobalt nanowires are crystalline in nature. The Hysteresis loop shows the magnetization properties for in and out of plane configuration. The in plane saturation magnetization (Ms) is lower than out of plane configuration because of the easy axis of magnetization is perpendicular to nanowire axis. These magnetic nanowires could be utilized for applications such as spintronic devices, high density magnetic storage, and magnetic sensor applications

  1. Electrodeposition of thin Pd-Ag films

    International Nuclear Information System (INIS)

    Hasler, P.; Allmendinger, T.

    1993-01-01

    Thin Pd-Ag layers were electroplated preferably on brass and on nickel substrates using a two-compartment cell separated by an anion exchange membrane. The weakly alkaline electrolyte contained glycine-glycinate as the major complexing agents. The plating experiments were usually carried out without stirring, at different potentials and temperatures and in the absence or in the presence of sodium benzaldehyde-2,4-disulphonate (BDS). The samples were characterized by scanning electron microscopy and light microscopy. Their compositions were determined analytically by the inductively coupled plasma technique. In addition, the film porosity was tested. Electrodeposition in almost limiting current conditions for both components and without simultaneous hydrogen evolution led to deposits with compositions being in good agreement with the molar metal ratio in the electrolyte (77:23). The best results were achieved between 0 and -50 mV with respect to a reversible hydrogen electrode at 0 C in the presence of BDS. These deposits were bright, had good adherence and exhibited no pores at a film thickness of 1.2 μm. At too negative potentials, the deposits became black and powdery. (orig.)

  2. Preparation of uranium electrodeposited target in aqueous system

    Energy Technology Data Exchange (ETDEWEB)

    Qiping, Chen; Yougen, Li; Wenbin, Zhong [China Academy of Engineering Physics, Mianyang (China). Inst. of Nuclear Physics and Chemistry

    2006-03-15

    The main factors affecting uranium electrodeposition were tested and discussed. In the primary experiment about preparation of uranium isotopic target by electrodeposition, a stainless steel disk has been chosen as the target material, the electrolytic bath is comprised of UO{sub 2}(NO{sub 3}){sub 2} and (NH{sub 4}){sub 2}C{sub 2}O{sub 4}, which has been adjusted to a pH of 2-3. Composition of the lost electrolytic bath was analysed by spectrophotometer. The thickness of resulting film is about 8-10 mg/cm{sup 2}, the target having a thin, continuous, uniform layer of uranium, and its electrodeposited rate is more than 80%. (authors)

  3. Use of carriers for to electrodeposited radium 226

    International Nuclear Information System (INIS)

    Iturbe, J.L.

    1991-10-01

    The form of the energy distribution of a monoenergetic alpha particle starting from some emitting source of these particles, it depends on the quantity of material that its cross before being detected. Some authors deposit to the radium-226 by means of direct evaporation of the solution on metallic supports, on millipore paper and by electrodeposition. Some other ones place the radium solution in scintillation liquid, to quantify it by this technique. The objective of the present work is using carriers with the same oxidation state of the radium, that is to say of 2 + , for treating to be electrodeposited to the radium-226 with the biggest possible percentage for later use the alpha spectroscopy technique to quantify it. The carriers that have been used until its they are barium and zinc in form of barium chloride, zinc nitrate and zinc sulfate. The first results indicate that with the zinc solution a yield of 40% of electrodeposited radium has been reached. (Author)

  4. Microstructure and surface mechanical properties of pulse electrodeposited nickel

    Energy Technology Data Exchange (ETDEWEB)

    Ul-Hamid, A., E-mail: anwar@kfupm.edu.sa [Center of Research Excellence in Corrosion (CoRE-C), Research Institute, King Fahd University of Petroleum and Minerals, P.O. Box 1073, Dhahran 31261 (Saudi Arabia); Dafalla, H.; Quddus, A.; Saricimen, H.; Al-Hadhrami, L.M. [Center of Research Excellence in Corrosion (CoRE-C), Research Institute, King Fahd University of Petroleum and Minerals, P.O. Box 1073, Dhahran 31261 (Saudi Arabia)

    2011-09-01

    The surface of carbon steel was modified by electrochemical deposition of Ni in a standard Watt's bath using dc and pulse plating electrodeposition. The aim was to compare the microstructure and surface mechanical properties of the deposit obtained by both techniques. Materials characterization was conducted using field emission scanning electron microscope fitted with scanning transmission electron detector, atomic force microscope and X-ray diffractometer. Nanoindentation hardness, elastic modulus, adhesion, coefficients of friction and wear rates were determined for both dc and pulse electrodeposits. Experimental results indicate that pulse electrodeposition produced finer Ni grains compared to dc plating. Size of Ni grains increased with deposition. Both dc and pulse deposition resulted in grain growth in preferred (2 0 0) orientation. However, presence of Ni (1 1 1) grains increased in deposits produced by pulse deposition. Pulse plated Ni exhibited higher hardness, creep and coefficient of friction and lower modulus of elasticity compared to dc plated Ni.

  5. Electrodeposition of Metal on GaAs Nanowires

    Science.gov (United States)

    Liu, Chao; Einabad, Omid; Watkins, Simon; Kavanagh, Karen

    2010-10-01

    Copper (Cu) electrical contacts to freestanding gallium arsenide (GaAs) nanowires have been fabricated via electrodeposition. The nanowires are zincblende (111) oriented grown epitaxially on n-type Si-doped GaAs (111)B substrates by gold-catalyzed Vapor Liquid Solid (VLS) growth in a metal organic vapour phase epitaxy (MOVPE) reactor. The epitaxial electrodeposition process, based on previous work with bulk GaAs substrates, consists of a substrate oxide pre-etch in dilute ammonium-hydroxide carried out prior to galvanostatic electrodeposition in a pure Cu sulphate aqueous electrolyte at 20-60^oC. For GaAs nanowires, we find that Cu or Fe has a preference for growth on the gold catalyst avoiding the sidewalls. After removing gold, both metals still prefer to grow only on top of the nanowire, which has the largest potential field.

  6. Ultrasonic electrodeposition of silver nanoparticles on dielectric silica spheres

    International Nuclear Information System (INIS)

    Tang Shaochun; Tang Yuefeng; Gao Feng; Liu Zhiguo; Meng Xiangkang

    2007-01-01

    In the present study, a facile and one-step ultrasonic electrodeposition method is first applied to controllably coat colloidal silica spheres with silver nanoparticles. This method is additive-free and very direct, because processes necessary in many other approaches, such as pretreatment of the silica sphere surface and pre-preparation of silver nanoparticles, are not involved in it. Furthermore, it makes possible the coating of dielectric substrates with metal through an electrodeposition route. Under appropriate conditions, silver nanoparticles with sizes of 8-10 nm in diameter can be relatively homogeneously deposited onto the surface of preformed colloidal silica spheres. Silver particles with different sizes and dispersive uniformity on silica sphere surfaces can also be obtained by adjusting the current density (I), the concentration of electrolyte (C) and the electrolysis time (t). The possible ultrasonic electrodeposition mechanism is also suggested according to the experimental results

  7. Electrodeposition of polyfluorene on a carbon nanotube electrode

    International Nuclear Information System (INIS)

    Valentini, L; Mengoni, F; Mattiello, L; Kenny, J M

    2007-01-01

    Electrophoretically deposited single-walled carbon nanotube (SWCNT) films on a transparent conducting surface are used as electrodes for the electrodeposition of a π-conjugated polymer formed by the oxidative coupling of fluorene units. This method provides a uniform coverage of the conducting surface with respect to SWCNTs chemically assembled on a gold substrate. Electron microscopy reveals the formation of a polymer-SWCNT nanostructure which imparts distinct electrical properties from those of the polymer electrodeposited on the neat electrode. By combining the attractive properties of SWCNTs and polyfluorene, these nanocomposites open up new opportunities to achieve electrical contacts in nano- to micro-devices

  8. Morphology selection for cupric oxide thin films by electrodeposition.

    Science.gov (United States)

    Dhanasekaran, V; Mahalingam, T; Chandramohan, R

    2011-10-01

    Polycrystalline cupric oxide thin films were deposited using alkaline solution bath employing cathodic electrodeposition method. The thin films were electrodeposited at various solution pH. The surface morphology and elemental analyzes of the films were studied using scanning electron microscopy (SEM) and energy dispersive X-ray analysis, respectively. SEM studies revealed that the surface morphology could be tailored suitably by adjusting the pH value during deposition. Mesh average on multiple lattice mode atomic force microscopy image was obtained and reported. Copyright © 2011 Wiley-Liss, Inc.

  9. Effect of pretreatments on electrodeposited epoxy coatings for electronic industries

    Directory of Open Access Journals (Sweden)

    Sironmani Palraj

    2016-02-01

    Full Text Available Waterborne epoxy coatings were prepared on aluminium (Al surfaces by cathodic electro-deposition on the pretreated surface of pickling, phosphating, chromating and anodizing. The electro-deposition experiments were done at two different voltages, 15 V and 25 V at room temperature in 10% epoxy coating formulations. Corrosion and thermal behavior of these coatings were investigated using electrochemical impedance spectroscopy (EIS and thermo gravimetric analysis (TGA. The coating exhibits better corrosion resistance in anodized Al surface than the other. But, TGA studies show that the thermal stability is higher in anodized and chromated Al surfaces. The surface morphology of these coatings were analyzed by SEM and AFM studies.

  10. Morphological and magnetic properties of cobalt nanoclusters electrodeposited onto HOPG

    International Nuclear Information System (INIS)

    Rivera, M.; Rios-Reyes, C.H.; Mendoza-Huizar, L.H.

    2008-01-01

    In this work, the morphological and magnetic properties of cobalt nanoclusters obtained from two different sulphate electrolyte solutions were studied. The aggregates were electrodeposited onto highly oriented pyrolytic graphite electrodes in overpotential conditions, in order to investigate the cationic influence on the final properties of the aggregates. In both cases, scanning electron microscopy and atomic force microscopy showed random isolated clusters on the electrode surface, where size variations were determined by the electrolyte solution. By using magnetic force microscopy, the distribution of the electrodeposited magnetic material was more clearly observed which gave some insights on the growth mechanism of these aggregates.

  11. Microstructure stability of silver electrodeposits at room temperature

    International Nuclear Information System (INIS)

    Hansen, Karsten; Pantleon, Karen

    2008-01-01

    In situ quantitative X-ray diffraction analysis was used to investigate the kinetics of microstructure evolution at room temperature (self-annealing) in an electrodeposited silver layer. As a function of time at room temperature the as-deposited nanocrystalline microstructure evolved considerably: orientation-dependent grain growth and changes of the preferred grain orientation occurred. It is demonstrated for the first time that self-annealing occurs for electrodeposited silver layers and, hence, is not a unique feature of copper as often suggested

  12. Crystallization inhibitors for amorphous oxides

    International Nuclear Information System (INIS)

    Reznitskij, L.A.; Filippova, S.E.

    1993-01-01

    Data for the last 10 years, in which experimental results of studying the temperature stabilization of x-ray amorphous oxides (including R 3 Fe 5 O 12 R-rare earths, ZrO 2 , In 2 O 3 , Sc 2 O 3 ) and their solid solution are presented, are generalized. Processes of amorphous oxide crystallization with the production of simple oxides, solid solutions and chemical compounds with different polyhedral structure, are investigated. Energy and crystallochemical criteria for selecting the doping inhibitor-components stabilizing the amorphous state are ascertained, temperatures and enthalpies of amorpous oxide crystallization are determined, examination of certain provisions of iso,orphous miscibility theory is conducted

  13. Electrodeposited silk coatings for functionalized implant applications

    Science.gov (United States)

    Elia, Roberto

    The mechanical and morphological properties of titanium as well as its biocompatibility and osteoinductive characteristics have made it the material of choice for dental implant systems. Although the success rate of titanium implants exceeds 90% in healthy individuals, a large subset of the population has one or more risk factors that inhibit implant integration. Treatments and coatings have been developed to improve clinical outcomes via introduction of appropriate surface topography, texture and roughness or incorporation of bioactive molecules. It is essential that the coatings and associated deposition techniques are controllable and reproducible. Currently, methods of depositing functional coatings are dictated by numerous parameters (temperature, particle size distribution, pH and voltage), which result in variable coating thickness, strength, porosity and weight, and hinder or preclude biomolecule incorporation. Silk is a highly versatile protein with a unique combination of mechanical and physical properties, including tunable degradation, biocompatibility, drug stabilizing capabilities and mechanical properties. Most recently an electrogelation technique was developed which allows for the deposition of gels which dry seamlessly over the contoured topography of the conductive substrate. In this work we examine the potential use of silk electrogels as mechanically robust implant coatings capable of sequestering and releasing therapeutic agents. Electrodeposition of silk electrogels formed in uniform electric fields was characterized with respect to field intensity and deposition time. Gel formation kinetics were used to derive functions which allowed for the prediction of coating deposition over a range of process and solution parameters. Silk electrogel growth orientation was shown to be influenced by the applied electric field. Coatings were reproducible and tunable via intrinsic silk solution properties and extrinsic process parameters. Adhesion was

  14. Kinetically Controlled Two-Step Amorphization and Amorphous-Amorphous Transition in Ice

    Science.gov (United States)

    Lin, Chuanlong; Yong, Xue; Tse, John S.; Smith, Jesse S.; Sinogeikin, Stanislav V.; Kenney-Benson, Curtis; Shen, Guoyin

    2017-09-01

    We report the results of in situ structural characterization of the amorphization of crystalline ice Ih under compression and the relaxation of high-density amorphous (HDA) ice under decompression at temperatures between 96 and 160 K by synchrotron x-ray diffraction. The results show that ice Ih transforms to an intermediate crystalline phase at 100 K prior to complete amorphization, which is supported by molecular dynamics calculations. The phase transition pathways show clear temperature dependence: direct amorphization without an intermediate phase is observed at 133 K, while at 145 K a direct Ih-to-IX transformation is observed; decompression of HDA shows a transition to low-density amorphous ice at 96 K and ˜1 Pa , to ice Ic at 135 K and to ice IX at 145 K. These observations show that the amorphization of compressed ice Ih and the recrystallization of decompressed HDA are strongly dependent on temperature and controlled by kinetic barriers. Pressure-induced amorphous ice is an intermediate state in the phase transition from the connected H-bond water network in low pressure ices to the independent and interpenetrating H-bond network of high-pressure ices.

  15. HER Catalytic Activity of Electrodeposited Ni-P Nanowires under the Influence of Magnetic Field

    Directory of Open Access Journals (Sweden)

    Hung-Bin Lee

    2013-01-01

    Full Text Available Nickel alloy electrodes both in plane and nanowire morphologies were fabricated by electrodeposition in sulfamate bath. With the increasing concentration of phosphorous acid in the electrolyte, the P content in the deposition increased accordingly. In the meantime, the grain refined and even became amorphous in microstructure as the P content was raised. For the nanowire electrode, vibrating sample magnetometer (VSM measurement showed that its coercivity was anisotropic and decreased with P-content. In addition, the easy axis for magnetization of the electrode was parallel to the axial direction of nanowire. The electrocatalytic activity measurement of the electrode in 0.5 M H2SO4 electrolyte showed that the nanowire electrode had higher activity than the plane one, and the alloying of P in Ni electrode raised its hydrogen evolution reaction (HER performance. The enhanced performance of nanowire electrode was attributed to the smaller and more uniform hydrogen bubbles generated in HER reaction. Finally, the applied magnetic field (3.2 T improved significantly the HER activity of Ni but not Ni-P electrode. By using nanowire morphology and applying magnetic field, the current density at −0.75 V HER stability test of the Ni electrode increased fourfold more than its plane counterpart.

  16. Amorphous Ti-Zr

    International Nuclear Information System (INIS)

    Rabinkin, A.; Liebermann, H.; Pounds, S.; Taylor, T.

    1991-01-01

    This paper is the first report on processing, properties and potential application of amorphous titanium/zirconium-base alloys produced in the form of a good quality continuous and ductile ribbon having up to 12.5 mm width. To date, the majority of titanium brazing is accomplished using cooper and aluminum-base brazing filler metals. The brazements produced with these filler metals have rather low (∼300 degrees C) service temperature, thus impeding progress in aircraft and other technologies and industries. The attempt to develop a generation of high temperature brazing filler metals was made in the late sixties-early seventies studies in detail were a large number of Ti-, Zr-Ti-Zr, Ti-V and Zr-V-Ti based alloys. The majority of these alloys has copper and nickel as melting temperature depressants. The presence of nickel and copper converts them into eutectic alloys having [Ti(Zr)] [Cu(Ni)], intermetallic phases as major structural constituents. This, in turn, results in high alloy brittleness and poor, if any, processability by means of conventional, i.e. melting-ingot casting-deformation technology. In spite of good wettability and high joint strength achieved in dozens of promising alloys, only Ti-15Cu-15Ni is now widely used as a brazing filler metal for high service temperature. Up until now this material could not be produced as a homogeneous foil and is instead applied as a clad strip consisting of three separate metallic layers

  17. Anomalous magnetoresistance in amorphous metals

    International Nuclear Information System (INIS)

    Kuz'menko, V.M.; Vladychkin, A.N.; Mel'nikov, V.I.; Sudovtsev, A.I.

    1984-01-01

    The magnetoresistance of amorphous Bi, Ca, V and Yb films is investigated in fields up to 4 T at low temperatures. For all metals the magnetoresistance is positive, sharply decreases with growth of temperature and depends anomalously on the magnetic field strength. For amorphous superconductors the results agree satisfactorily with the theory of anomalous magnetoresistance in which allowance is made for scattering of electrons by the superconducting fluctuations

  18. Morphological instability during steady electrodeposition at overlimiting currents

    DEFF Research Database (Denmark)

    Nielsen, Christoffer Peder; Bruus, Henrik

    2015-01-01

    We present a linear stability analysis of a planar metal electrode during steady electrodeposition. We extend the previous work of Sundstrom and Bark by accounting for the extended space-charge density, which develops at the cathode once the applied voltage exceeds a few thermal voltages...

  19. Cathodic electrodeposition of ceramic and organoceramic materials. Fundamental aspects.

    Science.gov (United States)

    Zhitomirsky, I

    2002-03-29

    Electrodeposition of ceramic materials can be performed by electrophoretic (EPD) or electrolytic (ELD) deposition. Electrophoretic deposition is achieved via motion of charged particles towards an electrode under an applied electric field. Electrolytic deposition produces colloidal particles in cathodic reactions for subsequent deposition. Various electrochemical strategies and deposition mechanisms have been developed for electrodeposition of ceramic and organoceramic films, and are discussed in the present article. Electrode-position of ceramic and organoceramic materials includes mass transport, accumulation of particles near the electrode and their coagulation to form a cathodic deposit. Various types of interparticle forces that govern colloidal stability in the absence and presence of processing additives are discussed. Novel theoretical contributions towards an interpretation of particle coagulation near the electrode surface are reviewed. Background information is given on the methods of particle charging, stabilization of colloids in aqueous and non-aqueous media, electrophoretic mobility of ceramic particles and polyelectrolytes, and electrode reactions. This review also covers recent developments in the electrodeposition of ceramic and organoceramic materials.

  20. Identification of an anomalous phase in Ni–W electrodeposits

    DEFF Research Database (Denmark)

    Mizushima, Io; Tang, Peter Torben; Somers, Marcel A. J.

    2008-01-01

    In the present work Ni–W layers electrodeposited from electrolytes based on NiSO4, Na2WO4, citrate, glycine and triethanolamine are characterized with glow discharge optical emission spectroscopy (GD-OES) and X-ray diffraction analysis (XRD). XRD showed the occurrence of an anomalous phase...

  1. Textural and morphological studies on zinc-iron alloy electrodeposits

    Indian Academy of Sciences (India)

    Zinc-iron alloy electrodeposits have industrial significance, since they provide better corrosion resistance and with improved mechanical properties when compared to pure zinc coatings. This is due to the unique phase structure of the alloy formed. But this deposition belongs to anomalous deposition, where the ...

  2. Electrodeposited Cu2ZnSnS4 thin films

    CSIR Research Space (South Africa)

    Valdes, M

    2014-05-01

    Full Text Available Cu(sub2)ZnSnS(sub4)(CZTS) thin films have been prepared using Electrochemical Atomic Layer Deposition (EC-ALD)and also by one-step conventional constant potential electrodeposition. Optimal deposition conditionswere investigated using cyclic...

  3. Stable lithium electrodeposition in salt-reinforced electrolytes

    KAUST Repository

    Lu, Yingying; Tu, Zhengyuan; Shu, Jonathan; Archer, Lynden A.

    2015-01-01

    © 2015 Elsevier B.V. Development of high-energy lithium-based batteries that are safe remains a challenge due to the non-uniform lithium electrodeposition during repeated charge and discharge cycles. We report on the effectiveness of lithium bromide

  4. The fabrication of short metallic nanotubes by templated electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Chienwen, Huang; Hao Yaowu, E-mail: yhao@uta.ed [Department of Materials Science and Engineering, University of Texas at Arlington, Arlington, TX 76051 (United States)

    2009-11-04

    Template-based electrochemical synthesis has widely been used to produce metal nanowires and nanorods. Commercially available filtration membranes, such as anodic aluminum oxide (AAO) and polycarbonate track etch membranes, have commonly been utilized as hard templates for this purpose. In this process, a thick metal film is usually sputtered or vacuum evaporated onto one side of the membrane to block the pores and serve as the working electrode for the subsequent electrodeposition. Here, we show that during the deposition of the metal electrode for AAO membranes, the electrode metal diffuses into the pores and is deposited on the pore walls which leads to preferential electrodeposition of metal on the walls and therefore forms metal tubes. This phenomenon has been utilized to fabricate short nanotubes by carefully controlling the electrodeposition conditions. The process is a straightforward method for any electroplatable materials to form nanoscale tubular structures. The effects of working electrodes and electrodeposition conditions on the formation of tubular structures are discussed in detail. A new mechanism based on this simple fact is proposed to explain the formation of Ni tubes by Ni-Cu co-deposition. Also, we demonstrate how to distinguish magnetic nanotubes from nanorods by a simple magnetic measurement.

  5. The fabrication of short metallic nanotubes by templated electrodeposition

    International Nuclear Information System (INIS)

    Huang Chienwen; Hao Yaowu

    2009-01-01

    Template-based electrochemical synthesis has widely been used to produce metal nanowires and nanorods. Commercially available filtration membranes, such as anodic aluminum oxide (AAO) and polycarbonate track etch membranes, have commonly been utilized as hard templates for this purpose. In this process, a thick metal film is usually sputtered or vacuum evaporated onto one side of the membrane to block the pores and serve as the working electrode for the subsequent electrodeposition. Here, we show that during the deposition of the metal electrode for AAO membranes, the electrode metal diffuses into the pores and is deposited on the pore walls which leads to preferential electrodeposition of metal on the walls and therefore forms metal tubes. This phenomenon has been utilized to fabricate short nanotubes by carefully controlling the electrodeposition conditions. The process is a straightforward method for any electroplatable materials to form nanoscale tubular structures. The effects of working electrodes and electrodeposition conditions on the formation of tubular structures are discussed in detail. A new mechanism based on this simple fact is proposed to explain the formation of Ni tubes by Ni-Cu co-deposition. Also, we demonstrate how to distinguish magnetic nanotubes from nanorods by a simple magnetic measurement.

  6. Effect of electrodeposition potential on composition and morphology ...

    Indian Academy of Sciences (India)

    The underpotential deposition mechanism of Cu–Se and In–Se phases was observed in ... Thin films; cyclic voltammetry; CuInGaSe (CIGS); solar cell; electrodeposition. 1. ... trode was a Pt spiral wire and the working electrode was. 735 ...

  7. Metal-organic framework templated electrodeposition of functional gold nanostructures

    International Nuclear Information System (INIS)

    Worrall, Stephen D.; Bissett, Mark A.; Hill, Patrick I.; Rooney, Aidan P.; Haigh, Sarah J.; Attfield, Martin P.; Dryfe, Robert A.W.

    2016-01-01

    Highlights: • Electrodeposition of anisotropic Au nanostructures templated by HKUST-1. • Au nanostructures replicate ∼1.4 nm pore spaces of HKUST-1. • Encapsulated Au nanostructures active as SERS substrate for 4-fluorothiophenol. - Abstract: Utilizing a pair of quick, scalable electrochemical processes, the permanently porous MOF HKUST-1 was electrochemically grown on a copper electrode and this HKUST-1-coated electrode was used to template electrodeposition of a gold nanostructure within the pore network of the MOF. Transmission electron microscopy demonstrates that a proportion of the gold nanostructures exhibit structural features replicating the pore space of this ∼1.4 nm maximum pore diameter MOF, as well as regions that are larger in size. Scanning electron microscopy shows that the electrodeposited gold nanostructure, produced under certain conditions of synthesis and template removal, is sufficiently inter-grown and mechanically robust to retain the octahedral morphology of the HKUST-1 template crystals. The functionality of the gold nanostructure within the crystalline HKUST-1 was demonstrated through the surface enhanced Raman spectroscopic (SERS) detection of 4-fluorothiophenol at concentrations as low as 1 μM. The reported process is confirmed as a viable electrodeposition method for obtaining functional, accessible metal nanostructures encapsulated within MOF crystals.

  8. Stable lithium electrodeposition in liquid and nanoporous solid electrolytes

    KAUST Repository

    Lu, Yingying

    2014-08-10

    Rechargeable lithium, sodium and aluminium metal-based batteries are among the most versatile platforms for high-energy, cost-effective electrochemical energy storage. Non-uniform metal deposition and dendrite formation on the negative electrode during repeated cycles of charge and discharge are major hurdles to commercialization of energy-storage devices based on each of these chemistries. A long-held view is that unstable electrodeposition is a consequence of inherent characteristics of these metals and their inability to form uniform electrodeposits on surfaces with inevitable defects. We report on electrodeposition of lithium in simple liquid electrolytes and in nanoporous solids infused with liquid electrolytes. We find that simple liquid electrolytes reinforced with halogenated salt blends exhibit stable long-term cycling at room temperature, often with no signs of deposition instabilities over hundreds of cycles of charge and discharge and thousands of operating hours. We rationalize these observations with the help of surface energy data for the electrolyte/lithium interface and impedance analysis of the interface during different stages of cell operation. Our findings provide support for an important recent theoretical prediction that the surface mobility of lithium is significantly enhanced in the presence of lithium halide salts. Our results also show that a high electrolyte modulus is unnecessary for stable electrodeposition of lithium.

  9. Order/disorder in electrodeposited aluminum-titanium alloys

    Directory of Open Access Journals (Sweden)

    Stafford G.R.

    2003-01-01

    Full Text Available The composition, morphology, and crystallographic microstructure of Al-Ti alloys electrodeposited from two different chloroaluminate molten salt electrolytes were examined. Alloys containing up to 28 % atomic fraction Ti were electrodeposited at 150 °C from 2:1 AlCl3-NaCl with controlled additions of Ti2+. The apparent limit on alloy composition is proposed to be due to a mechanism by which Al3Ti forms through the reductive decomposition of [Ti(AlCl43]-. The composition of Al-Ti alloys electrodeposited from the AlCl3-EtMeImCl melt at 80 °C is limited by the diffusion of Ti2+ to the electrode surface. Alloys containing up to 18.4 % atomic fraction Ti are only obtainable at high Ti2+ concentrations in the melt and low current densities. Alloys electrodeposited from the higher temperature melt have an ordered L12 crystal structure while alloys of similar composition but deposited at lower temperature are disordered fcc. The appearance of antiphase boundaries in the ordered alloys suggests that the deposit may be disordered initially and then orders in the solid state, subsequent to the charge transfer step and adatom incorporation into the lattice. This is very similar to the disorder-trapping observed in rapidly solidified alloys. The measured domain size is consistent with a mechanism of diffusion-controlled doman growth at the examined deposition temperatures and times.

  10. Moessbauer and X-ray Diffraction Investigations of Sn-containing Binary and Ternary Electrodeposited Alloys from a Gluconate Bath

    International Nuclear Information System (INIS)

    Kuzmann, E.; Stichleutner, S.; Homonnay, Z.; Vertes, A.; Doyle, O.; Chisholm, C.U.; El-Sharif, M.

    2005-01-01

    Constant current technique was applied to electrodeposit tin-containing coatings such as tin-cobalt (Sn-Co), tin-iron (Sn-Fe) and a novel tin-cobalt-iron (Sn-Co-Fe) from a gluconate bath. The effect of plating parameters (current density, deposition time at an electrolyte temperature of 60 deg. C and pH=7.0) on phase composition, crystal structure and magnetic anisotropy of alloy deposits has been investigated mainly by 57Fe CEMS, 119Sn CEMS and transmission Moessbauer Spectroscopy as well as XRD. 57Fe and 119Sn CEM spectra and XRD reflect that the dominant phases of the deposits are orthorhombic Co3Sn2, tetragonal FeSn2 or amorphous Fe-Sn and amorphous Sn-Co-Fe in Sn-Co, Sn-Fe and Sn-Co-Fe coatings, respectively. Furthermore, the relative area of the 2nd and 5th lines of the sextets representing the magnetic iron containing phases decreases continuously with increasing current density in all Fe-containing deposits. At the same time, no essential change in the magnetic anisotropy can be found with the plating time. 119Sn spectra reveal the presence of small amount of β-Sn besides the main phases in Sn-Fe and in the Sn-Co coatings. Magnetically split 119Sn spectra reflecting transferred hyperfine field were observed in the case of Co-Sn-Fe coatings

  11. Moessbauer and X-ray Diffraction Investigations of Sn-containing Binary and Ternary Electrodeposited Alloys from a Gluconate Bath

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmann, E; Stichleutner, S; Homonnay, Z; Vertes, A [Department of Nulear Chemistry, Hungarian Academy of Sciences, Eoetvoes University, Budapest (Hungary); Research Group for Nuclear Methods in Structural Chemistry, Hungarian Academy of Sciences, Eoetvoes University, Budapest (Hungary); Doyle, O; Chisholm, C U; El-Sharif, M [Glasgow Caledonian University, Glasgow, Scotland (United Kingdom)

    2005-04-26

    Constant current technique was applied to electrodeposit tin-containing coatings such as tin-cobalt (Sn-Co), tin-iron (Sn-Fe) and a novel tin-cobalt-iron (Sn-Co-Fe) from a gluconate bath. The effect of plating parameters (current density, deposition time at an electrolyte temperature of 60 deg. C and pH=7.0) on phase composition, crystal structure and magnetic anisotropy of alloy deposits has been investigated mainly by 57Fe CEMS, 119Sn CEMS and transmission Moessbauer Spectroscopy as well as XRD. 57Fe and 119Sn CEM spectra and XRD reflect that the dominant phases of the deposits are orthorhombic Co3Sn2, tetragonal FeSn2 or amorphous Fe-Sn and amorphous Sn-Co-Fe in Sn-Co, Sn-Fe and Sn-Co-Fe coatings, respectively. Furthermore, the relative area of the 2nd and 5th lines of the sextets representing the magnetic iron containing phases decreases continuously with increasing current density in all Fe-containing deposits. At the same time, no essential change in the magnetic anisotropy can be found with the plating time. 119Sn spectra reveal the presence of small amount of {beta}-Sn besides the main phases in Sn-Fe and in the Sn-Co coatings. Magnetically split 119Sn spectra reflecting transferred hyperfine field were observed in the case of Co-Sn-Fe coatings.

  12. Electrochemically synthesized amorphous and crystalline nanowires: dissimilar nanomechanical behavior in comparison with homologous flat films

    Science.gov (United States)

    Zeeshan, M. A.; Esqué-de Los Ojos, D.; Castro-Hartmann, P.; Guerrero, M.; Nogués, J.; Suriñach, S.; Baró, M. D.; Nelson, B. J.; Pané, S.; Pellicer, E.; Sort, J.

    2016-01-01

    The effects of constrained sample dimensions on the mechanical behavior of crystalline materials have been extensively investigated. However, there is no clear understanding of these effects in nano-sized amorphous samples. Herein, nanoindentation together with finite element simulations are used to compare the properties of crystalline and glassy CoNi(Re)P electrodeposited nanowires (φ ~ 100 nm) with films (3 μm thick) of analogous composition and structure. The results reveal that amorphous nanowires exhibit a larger hardness, lower Young's modulus and higher plasticity index than glassy films. Conversely, the very large hardness and higher Young's modulus of crystalline nanowires are accompanied by a decrease in plasticity with respect to the homologous crystalline films. Remarkably, proper interpretation of the mechanical properties of the nanowires requires taking the curved geometry of the indented surface and sink-in effects into account. These findings are of high relevance for optimizing the performance of new, mechanically-robust, nanoscale materials for increasingly complex miniaturized devices.The effects of constrained sample dimensions on the mechanical behavior of crystalline materials have been extensively investigated. However, there is no clear understanding of these effects in nano-sized amorphous samples. Herein, nanoindentation together with finite element simulations are used to compare the properties of crystalline and glassy CoNi(Re)P electrodeposited nanowires (φ ~ 100 nm) with films (3 μm thick) of analogous composition and structure. The results reveal that amorphous nanowires exhibit a larger hardness, lower Young's modulus and higher plasticity index than glassy films. Conversely, the very large hardness and higher Young's modulus of crystalline nanowires are accompanied by a decrease in plasticity with respect to the homologous crystalline films. Remarkably, proper interpretation of the mechanical properties of the nanowires

  13. Fundamentals of amorphous solids structure and properties

    CERN Document Server

    Stachurski, Zbigniew H

    2014-01-01

    Long awaited, this textbook fills the gap for convincing concepts to describe amorphous solids. Adopting a unique approach, the author develops a framework that lays the foundations for a theory of amorphousness. He unravels the scientific mysteries surrounding the topic, replacing rather vague notions of amorphous materials as disordered crystalline solids with the well-founded concept of ideal amorphous solids. A classification of amorphous materials into inorganic glasses, organic glasses, glassy metallic alloys, and thin films sets the scene for the development of the model of ideal amorph

  14. Electrodeposited Pt for cost-efficient and flexible dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Kim, Seok-Soon; Nah, Yoon-Chae; Noh, Yong-Young; Jo, Jang; Kim, Dong-Yu

    2006-01-01

    Pt electrodes were prepared by direct and pulse current electrodeposition for use as counter electrodes in dye-sensitized solar cells. Scanning electron microscope and transmission electron microscope images confirmed the formation of uniform Pt nanoclusters of ∼40 nm composed of 3 nm nanoparticles, when the pulse current electrodeposition method was used, as opposed to the dendritic growth of Pt by the results from direct current electrodeposition. By applying pulse electrodeposited Pt which has a 1.86 times higher surface area compared to direct current electrodeposited Pt, short-circuit current and conversion efficiency were increased from 10.34 to 14.11 mA/cm 2 and from 3.68 to 5.03%, respectively. In addition, a flexible solar cell with a pulse current electrodeposited Pt counter electrode with a conversion efficiency of 0.86% was demonstrated

  15. Amorphous titanium-oxide supercapacitors

    OpenAIRE

    Fukuhara, Mikio; Kuroda, Tomoyuki; Hasegawa, Fumihiko

    2016-01-01

    The electric capacitance of an amorphous TiO2-x surface increases proportionally to the negative sixth power of the convex diameter d. This occurs because of the van der Waals attraction on the amorphous surface of up to 7?mF/cm2, accompanied by extreme enhanced electron trapping resulting from both the quantum-size effect and an offset effect from positive charges at oxygen-vacancy sites. Here we show that a supercapacitor, constructed with a distributed constant-equipment circuit of large r...

  16. Electrocatalysis of the hydrogen evolution reaction by rhenium oxides electrodeposited by pulsed-current

    International Nuclear Information System (INIS)

    Vargas-Uscategui, Alejandro; Mosquera, Edgar; Chornik, Boris; Cifuentes, Luis

    2015-01-01

    Highlights: • Rhenium oxides were produced by means of pulsed current electrodeposition over ITO. • The electrocatalytic behavior of rhenium oxides electrodeposited over ITO was studied. • Electrodeposited rhenium oxides showed electrocatalytic behavior increasing the rate of the hydrogen evolution reaction. • The electrocatalysis behavior was explained considering the relative abundance of Re species on the surface of the electrodeposited material. - Abstract: Rhenium oxides are materials of interest for applications in the catalysis of reactions such as those occurring in fuel cells and photoelectrochemical cells. This research work was devoted to the production of rhenium oxide by means of pulsed current electrodeposition for the electrocatalysis of the hydrogen evolution reaction (HER). Rhenium oxides were electrodeposited over a transparent conductive oxide substrate (Indium Tin-doped Oxide – ITO) in an alkaline aqueous electrolyte. The electrodeposition process allowed the production of rhenium oxides islands (200–600 nm) with the presence of three oxidized rhenium species: Re"I"V associated to ReO_2, Re"V"I associated to ReO_3 and Re"V"I"I associated to H(ReO_4)H_2O. Electrodeposited rhenium oxides showed electrocatalytic behavior over the HER and an increase of one order of magnitude of the exchange current density was observed compared to the reaction taking place on the bare substrate. The electrocatalytic behavior varied with the morphology and relative abundance of oxidized rhenium species in the electrodeposits. Finally, two mechanisms of electrocatalysis were proposed to explain experimental results.

  17. Influence of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) on zinc electrodeposition

    International Nuclear Information System (INIS)

    Lehr, I.L.; Saidman, S.B.

    2012-01-01

    This work is a study of the electrodeposition of zinc onto SAE 4140 steel electrodes using solutions containing zinc sulfate and bis(2-ethylhexyl) sodium sulfosuccinate (AOT). The influence of different parameters such as electrolyte concentration, electrodeposition time and temperature on the morphology of the electrodeposits was analyzed. The deposits were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction. The variation of open circuit potential over time in chloride solutions was also evaluated. The nucleation-growth process and consequently the morphology of the electrodeposits are modified in the presence of AOT. The surfactant induces the formation of a porous deposit.

  18. Influence of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) on zinc electrodeposition

    Science.gov (United States)

    Lehr, I. L.; Saidman, S. B.

    2012-03-01

    This work is a study of the electrodeposition of zinc onto SAE 4140 steel electrodes using solutions containing zinc sulfate and bis(2-ethylhexyl) sodium sulfosuccinate (AOT). The influence of different parameters such as electrolyte concentration, electrodeposition time and temperature on the morphology of the electrodeposits was analyzed. The deposits were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction. The variation of open circuit potential over time in chloride solutions was also evaluated. The nucleation-growth process and consequently the morphology of the electrodeposits are modified in the presence of AOT. The surfactant induces the formation of a porous deposit.

  19. Fabrication of mesoporous cerium dioxide films by cathodic electrodeposition.

    Science.gov (United States)

    Kim, Young-Soo; Lee, Jin-Kyu; Ahn, Jae-Hoon; Park, Eun-Kyung; Kim, Gil-Pyo; Baeck, Sung-Hyeon

    2007-11-01

    Mesoporous cerium dioxide (Ceria, CeO2) thin films have been successfully electrodeposited onto ITO-coated glass substrates from an aqueous solution of cerium nitrate using CTAB (Cetyltrimethylammonium Bromide) as a templating agent. The synthesized films underwent detailed characterizations. The crystallinity of synthesized CeO2 film was confirmed by XRD analysis and HR-TEM analysis, and surface morphology was investigated by SEM analysis. The presence of mesoporosity in fabricated films was confirmed by TEM and small angle X-ray analysis. As-synthesized film was observed from XRD analysis and HR-TEM image to have well-crystallized structure of cubic phase CeO2. Transmission electron microscopy and small angle X-ray analysis revealed the presence of uniform mesoporosity with a well-ordered lamellar phase in the CeO2 films electrodeposited with CTAB templating.

  20. Electro-deposition of nickel, on reactor seal discs

    International Nuclear Information System (INIS)

    Vernekar, R.B.; Bhide, G.K.

    1977-01-01

    The effect of plating variables, acidity, current density and temperature on hardness of nickel deposited from purified nickel sulfamate bath has been investigated and optimum conditions for electrodeposition of nickel plating of hardness 160-170 VHN on reactor seal discs are established. Sodium lauryl sulfate was added as a wetting agent to the bath to overcome pitting tendency of the deposit. Factors affecting hydrogen absorption by electrodeposited nickel are also discussed. It is observed that : (1) at a pH 3.5 - 4.0 the decomposition rate of sulfamate salt is almost negligible and is the best value for bath operation, (2) at 15 A/dm 2 the hardness value is consistently around 160-170 VHN, (3) the temperatures less than 50 0 C give harder deposits and the bath is best operated at temperature 50-60 0 C and (4) annealing of the plated discs substantially reduces the hardness. (M.G.B.)

  1. Chirality of magneto-electrodeposited metal film electrodes

    International Nuclear Information System (INIS)

    Mogi, Iwao; Watanabe, Kazuo

    2008-01-01

    The chiral electrode behaviors of magneto-electrodeposited (MED) Ag and Cu films were examined for the electrochemical reactions of D-glucose, L-glucose and L-cysteine. The Ag and Cu films were electrodeposited under a magnetic field of 2 T parallel (+2 T) or antiparallel (-2 T) to the faradaic current. For MED films of both Ag and Cu, the oxidation current of L-glucose was larger than that of D-glucose on the +2 T-film electrodes, and the results were opposite on the - 2 T-film electrodes. These facts demonstrate that the MED metal films possess the ability of chiral recognition for D- and L-glucoses. The MED Ag film electrodes also exhibited chiral behavior for the oxidation of L-cysteine

  2. The properties of electrodeposited Zn-Co coatings

    Science.gov (United States)

    Mahieu, J.; de Wit, K.; de Cooman, B. C.; de Boeck, A.

    1999-10-01

    The possibility of increasing the corrosion resistance of automotive sheet steel by electrodepositing with Zn-Co alloy coatings was investigated. Process variables during electrodeposition such as current density, electrolyte flow rate, and pH were varied in order to examine their influence on the electroplating process. Cobalt contents varying from 0.2 to 7 wt% were easily obtained. The influence of these process parameters on the characteristics of the coating could be related to the hydroxide suppression mechanism for anomalous codeposition. The structure and the morphology of the coatings were determined using SEM and XRD analysis. Application properties important for coating systems used in the automotive industry, such as friction behavior, adhesion, and corrosion behavior, were investigated on coatings with varying cobalt content. The corrosion resistance of the Zn-Co alloy layers was found to be better than that of pure zinc coatings.

  3. Silver electrodeposition on nanostructured gold: from nanodots to nanoripples

    International Nuclear Information System (INIS)

    Claro, P C dos Santos; Fonticelli, M; BenItez, G; Azzaroni, O; Schilardi, P L; Luque, N B; Leiva, E; Salvarezza, R C

    2006-01-01

    Silver nanodots and nanoripples have been grown on nanocavity-patterned polycrystalline Au templates by controlled electrodeposition. The initial step is the growth of a first continuous Ag monolayer followed by preferential deposition at nanocavities. The Ag-coated nanocavities act as preferred sites for instantaneous nucleation and growth of the three-dimensional metallic centres. By controlling the amount of deposited Ag, dots of ∼50 nm average size and ∼4 nm average height can be grown with spatial and size distributions dictated by the template. The dots are in a metastable state. Further Ag deposition drives the dot surface structure to nanoripple formation. Results show that electrodeposition on nanopatterned electrodes can be used to prepare a high density of nanostructures with a narrow size distribution and spatial order

  4. Electrodepositing of Au on hollow PS micro-spheres

    International Nuclear Information System (INIS)

    Sun Jingyuan; Zhang Yunwang; Du Kai; Wan Xiaobo; Xiao Jiang; Zhang Wei; Zhang Lin; Chen Jing

    2010-01-01

    Using the self-regulating new micro-sphere electrodepositing device, the techniques of electrodepositing gold on hollow PS micro-spheres were established. The experiment was carried out under the following conditions: voltage was about 0.7 ∼ 0.8 V, current density was 2.0 mA · cm -2 , the temperature was 45 degree C, cathode rotating rate was 250 r · min -1 , flow rate of the solution was 7 mL · min -1 · cm -2 . Hollow gold-plated micro-spheres were prepared with well spherical symmetry, uniform thickness and surface smoothness under 500 nm. The speed of the gold depositing was 6 μm · h -1 . (authors)

  5. Production of amorphous alloys by ion implantation

    International Nuclear Information System (INIS)

    Grant, W.A.; Chadderton, L.T.; Johnson, E.

    1978-01-01

    Recent data are reported on the use of ion implantation to produce amorphous metallic alloys. In particular data on the dose dependence of the crystalline to amorphous transition induced by P + implantation of nickel is presented. (Auth.)

  6. Amorphous nanoparticles — Experiments and computer simulations

    International Nuclear Information System (INIS)

    Hoang, Vo Van; Ganguli, Dibyendu

    2012-01-01

    The data obtained by both experiments and computer simulations concerning the amorphous nanoparticles for decades including methods of synthesis, characterization, structural properties, atomic mechanism of a glass formation in nanoparticles, crystallization of the amorphous nanoparticles, physico-chemical properties (i.e. catalytic, optical, thermodynamic, magnetic, bioactivity and other properties) and various applications in science and technology have been reviewed. Amorphous nanoparticles coated with different surfactants are also reviewed as an extension in this direction. Much attention is paid to the pressure-induced polyamorphism of the amorphous nanoparticles or amorphization of the nanocrystalline counterparts. We also introduce here nanocomposites and nanofluids containing amorphous nanoparticles. Overall, amorphous nanoparticles exhibit a disordered structure different from that of corresponding bulks or from that of the nanocrystalline counterparts. Therefore, amorphous nanoparticles can have unique physico-chemical properties differed from those of the crystalline counterparts leading to their potential applications in science and technology.

  7. Processing and properties of electrodeposited layered surface coatings

    DEFF Research Database (Denmark)

    Horsewell, Andy

    1998-01-01

    Hard chromium, produced by conventional dir ect curl ent (DC) electrodeposition, cannot be deposited to thicknesses gl enter than about 5 mu m because of the buildup of processing stresses which cause channel cracks in the coating. Much thicker chromium coatings map be produced by depositing a la...... geometry is almost always analogous to bending, and fracture resistance is provided through deviation of the channel crack by weak interfaces, resulting in 'terrace cracking'....

  8. Electrodeposition of uranium in stirred liquid cadmium cathode

    International Nuclear Information System (INIS)

    Koyama, T.; Tanaka, H.

    1997-01-01

    The electrodeposition of U in a liquid Cd cathode was known to be hampered by the formation of dendritic U on the Cd surface. Electrotransports of uranium to the stirred liquid Cd cathode were carried out at 773 K for different cathode current densities and different Reynolds number of stirring. The maximum amount of U taken in the liquid Cd cathode without forming dendrites was found to increase with an increasing Reynolds number of stirring and decrease with increasing cathode current density. (orig.)

  9. Quantum conductance in electrodeposited nanocontacts and magnetoresistance measurements

    DEFF Research Database (Denmark)

    Elhoussine, F.; Encinas, A.; Mátéfi-Tempfli, Stefan

    2003-01-01

    The conductance and magnetoresistance measurements in magnetic Ni-Ni and Co-Ni nanocontacts prepared by electrodeposition within the pores of a track of track-etched polymer membrane were discussed. At room temperature, Ni-Ni constrictions were found to show broad quantization plateaus of conduct...... of conductance during their dissolution in units of e/h, as expected for ferromagnetic ballistic nanocontacts. The measurement of the positive and negative magnetoresistance in Co-Ni nanocontacts was also elaborated....

  10. Possible origin of superior corrosion resistance for electrodeposited nanocrystalline Ni

    International Nuclear Information System (INIS)

    Roy, I.; Yang, H.W.; Dinh, L.; Lund, I.; Earthman, J.C.; Mohamed, F.A.

    2008-01-01

    We present here for the first time observations that grain boundaries in electrodeposited (ED) nanocrystalline (nc) Ni are predominantly of Σ3 character. The results presented are based on orientation imaging microscopy (OIM) performed to produce electron backscatter diffraction (EBSD) maps. This large volume fraction of coherent low sigma coincidence site lattice (CSL) boundaries appears to be consistent with the superior corrosion resistance of ED nc-Ni in comparison with its coarse-grained counterpart

  11. Electrodeposition of epitaxial CdSe on (111) gallium arsenide

    Energy Technology Data Exchange (ETDEWEB)

    Cachet, H.; Cortes, R.; Froment, M. [Universite Pierre et Marie Curie, Paris (France). Phys. des Liquides et Electrochimie; Etcheberry, A. [Institut Lavoisier (IREM) UMR CNRS C0173, Universite de Versailles- St Quentin en Yvelynes, 45 Avenue des Etats Unis, 78035, Versailles (France)

    2000-02-21

    Epitaxial growth of CdSe has been achieved on GaAs(111) by electrodeposition from an aqueous electrolyte. The structure of the film corresponds to the cubic modification of CdSe. The quality of epitaxy has been investigated by reflection high energy electron diffraction, transmission electron microscopy and X-ray diffraction techniques. By XPS measurements the chemistry of the CdSe/GaAs interface and the composition of CdSe are determined. (orig.)

  12. Electrodeposition of niobium and titanium in molten salts

    International Nuclear Information System (INIS)

    Sartori, A.F.; Chagas, H.C.

    1988-01-01

    The electrodeposition of niobium and titanium in molten fluorides from the additions of fluorine niobates and fluorine titanates of potassium is described in laboratory and pilot scale. The temperature influence, the current density and the time deposition over the current efficiency, the deposits structure and the deposits purity are studied. The conditions for niobium coating over copper and carbon steel and for titanium coating over carbon steel are also presented. (C.G.C.) [pt

  13. Amorphous titanium-oxide supercapacitors

    Science.gov (United States)

    Fukuhara, Mikio; Kuroda, Tomoyuki; Hasegawa, Fumihiko

    2016-10-01

    The electric capacitance of an amorphous TiO2-x surface increases proportionally to the negative sixth power of the convex diameter d. This occurs because of the van der Waals attraction on the amorphous surface of up to 7 mF/cm2, accompanied by extreme enhanced electron trapping resulting from both the quantum-size effect and an offset effect from positive charges at oxygen-vacancy sites. Here we show that a supercapacitor, constructed with a distributed constant-equipment circuit of large resistance and small capacitance on the amorphous TiO2-x surface, illuminated a red LED for 37 ms after it was charged with 1 mA at 10 V. The fabricated device showed no dielectric breakdown up to 1,100 V. Based on this approach, further advances in the development of amorphous titanium-dioxide supercapacitors might be attained by integrating oxide ribbons with a micro-electro mechanical system.

  14. Radiation tolerance of amorphous semiconductors

    International Nuclear Information System (INIS)

    Nicolaides, R.V.; DeFeo, S.; Doremus, L.W.

    1976-01-01

    In an attempt to determine the threshold radiation damage in amorphous semiconductors, radiation tests were performed on amorphous semiconductor thin film materials and on threshold and memory devices. The influence of flash x-rays and neutron radiation upon the switching voltages, on- and off-state characteristics, dielectric response, optical transmission, absorption band edge and photoconductivity were measured prior to, during and following irradiation. These extensive tests showed the high radiation tolerance of amorphous semiconductor materials. Electrical and optical properties, other than photoconductivity, have a neutron radiation tolerance threshold above 10 17 nvt in the steady state and 10 14 nvt in short (50 μsec to 16 msec) pulses. Photoconductivity increases by 1 1 / 2 orders of magnitude at the level of 10 14 nvt (short pulses of 50 μsec). Super flash x-rays up to 5000 rads (Si), 20 nsec, do not initiate switching in off-state samples which are voltage biased up to 90 percent of the threshold voltage. Both memory and threshold amorphous devices are capable of switching on and off during nuclear radiation transients at least as high as 2 x 10 14 nvt in 50 μsec pulses

  15. Amorphous metal matrix composite ribbons

    International Nuclear Information System (INIS)

    Barczy, P.; Szigeti, F.

    1998-01-01

    Composite ribbons with amorphous matrix and ceramic (SiC, WC, MoB) particles were produced by modified planar melt flow casting methods. Weldability, abrasive wear and wood sanding examinations were carried out in order to find optimal material and technology for elevated wear resistance and sanding durability. The correlation between structure and composite properties is discussed. (author)

  16. Fracture Phenomena in Amorphous Selenium

    DEFF Research Database (Denmark)

    Lindegaard-Andersen, Asger; Dahle, Birgit

    1966-01-01

    Fracture surfaces of amorphous selenium broken in flexure at room temperature have been studied. The fracture velocity was found to vary in different regions of the fracture surface. Peculiar features were observed in a transition zone between fast and slower fracture. In this zone cleavage steps...

  17. Model for amorphous aggregation processes

    Science.gov (United States)

    Stranks, Samuel D.; Ecroyd, Heath; van Sluyter, Steven; Waters, Elizabeth J.; Carver, John A.; von Smekal, Lorenz

    2009-11-01

    The amorphous aggregation of proteins is associated with many phenomena, ranging from the formation of protein wine haze to the development of cataract in the eye lens and the precipitation of recombinant proteins during their expression and purification. While much literature exists describing models for linear protein aggregation, such as amyloid fibril formation, there are few reports of models which address amorphous aggregation. Here, we propose a model to describe the amorphous aggregation of proteins which is also more widely applicable to other situations where a similar process occurs, such as in the formation of colloids and nanoclusters. As first applications of the model, we have tested it against experimental turbidimetry data of three proteins relevant to the wine industry and biochemistry, namely, thaumatin, a thaumatinlike protein, and α -lactalbumin. The model is very robust and describes amorphous experimental data to a high degree of accuracy. Details about the aggregation process, such as shape parameters of the aggregates and rate constants, can also be extracted.

  18. Electrodeposition of quaternary alloys in the presence of magnetic field

    Science.gov (United States)

    2010-01-01

    Electrodeposition of Ni-Co-Fe-Zn alloys was done in a chloride ion solution with the presence and absence of a Permanent Parallel Magnetic Field (PPMF). The PPMF was applied parallel to the cathode surface. The deposition profile was monitored chronoamperometrically. It was found that the electrodeposition current was enhanced in the presence of PPMF (9 T) compared to without PPMF. The percentage of current enhancement (Γ%) was increased in the presence of PPMF, with results of Γ% = 11.9%, 16.7% and 18.5% at -1.1, -1.2 and -1.3 V respectively for a 2400 sec duration. In chronoamperometry, the Composition Reference Line (CRL) for Ni was around 57%, although the nobler metals (i.e. Ni, Co) showed anomalous behaviour in the presence of Zn and Fe. The anomalous behaviour of the Ni-Co-Fe-Zn electrodeposition was shown by the Energy Dispersive X-Ray (EDX) results. From Atomic Force Microscopy (AFM) measurements, it was found that the surface roughness of the Ni-Co-Fe-Zn alloy films decreased in the presence of a PPMF. PMID:20604934

  19. 2010 ELECTRODEPOSITION GORDON RESEARCH CONFERENCE, AUGUST 1-6, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Peter Searson

    2010-08-06

    The 2010 Gordon Conference on Electrodeposition will present cutting-edge research on electrodeposition with emphasis on (i) advances in basic science, (ii) developments in next-generation technologies, and (iii) new and emerging areas. The Conference will feature a wide range of topics, from atomic scale processes, nucleation and growth, thin film deposition, and electrocrystallization, to applications of electrodeposition in devices including microelectronics, solar energy, and power sources. The Conference will bring together investigators from a wide range of scientific disciplines, including chemical engineering, materials science and engineering, physics, and chemistry. The Conference will feature invited speakers at the forefront of the field, and a late-breaking news session that will provide the opportunity for graduate students, post-docs, and junior faculty to participate. The collegial atmosphere of this Conference, with scientific talks and poster sessions, as well as opportunities for informal gatherings in the afternoons and evenings, provides an avenue for scientists from different disciplines to discuss current issues and promotes cross-disciplinary collaborations in the various research areas represented. The Conference will be held at Colby-Sawyer College, located in the Mt. Kearsarge-Lake Sunapee Region of New Hampshire. The surrounding mountains, forests, and lakes provide a beautiful setting for this conference. The attendance is limited so early application is strongly advised.

  20. Super Nonlinear Electrodeposition-Diffusion-Controlled Thin-Film Selector.

    Science.gov (United States)

    Ji, Xinglong; Song, Li; He, Wei; Huang, Kejie; Yan, Zhiyuan; Zhong, Shuai; Zhang, Yishu; Zhao, Rong

    2018-03-28

    Selector elements with high nonlinearity are an indispensable part in constructing high density, large-scale, 3D stackable emerging nonvolatile memory and neuromorphic network. Although significant efforts have been devoted to developing novel thin-film selectors, it remains a great challenge in achieving good switching performance in the selectors to satisfy the stringent electrical criteria of diverse memory elements. In this work, we utilized high-defect-density chalcogenide glass (Ge 2 Sb 2 Te 5 ) in conjunction with high mobility Ag element (Ag-GST) to achieve a super nonlinear selective switching. A novel electrodeposition-diffusion dynamic selector based on Ag-GST exhibits superior selecting performance including excellent nonlinearity (<5 mV/dev), ultra-low leakage (<10 fA), and bidirectional operation. With the solid microstructure evidence and dynamic analyses, we attributed the selective switching to the competition between the electrodeposition and diffusion of Ag atoms in the glassy GST matrix under electric field. A switching model is proposed, and the in-depth understanding of the selective switching mechanism offers an insight of switching dynamics for the electrodeposition-diffusion-controlled thin-film selector. This work opens a new direction of selector designs by combining high mobility elements and high-defect-density chalcogenide glasses, which can be extended to other materials with similar properties.

  1. The effect of cysteine on electrodeposition of gold nanoparticle

    International Nuclear Information System (INIS)

    Dolati, A.; Imanieh, I.; Salehi, F.; Farahani, M.

    2011-01-01

    Highlights: → Cysteine was found as an appropriate additive for electrodeposition of gold nanoparticles. → The deposition mechanism of gold nanoparticle was determined as instantaneous nucleation. → Oxygen reduction on the gold nanoparticle surface was eight times greater than that on the conventional gold deposits. - Abstract: The most applications of gold nanoparticles are in the photo-electronical accessories and bio-chemical sensors. Chloride solution with cysteine additive was used as electrolyte in gold nanoparticles electrodeposition. The nucleation and growing mechanism were studied by electrochemical techniques such as cyclic voltammetry and chronoamperometry, in order to obtain a suitable nano structure. The deposition mechanism was determined as instantaneous nucleation and the dimension of particles was controlled in nanometric particle size range. Atomic Force Microscope was used to evaluate the effect of cysteine on the morphology and topography of gold nanoparticles. Finally the catalytic property of gold nanoparticle electrodeposited was studied in KOH solution, where oxygen reduction on the gold nanoparticle surface was eight times greater than that on the conventional gold deposits.

  2. SILVER RECYCLING FROM PHOTO-PROCESSING WASTE USING ELECTRODEPOSITION METHOD

    Directory of Open Access Journals (Sweden)

    Mochammad Feri Hadiyanto

    2010-06-01

    Full Text Available Silver electrodeposition of photo-processing waste and without addition of KCN 1,0 M has been studied for silver recycling. Photo procesing waste containing silver in form of [Ag(S2O32]3- was electrolysed at constant potential and faradic efficiency was determined at various of electrolysis times. Electrolysis of 100 mL photo processing waste without addition of KCN 1,0 M was carried out at constant potential 1.20 Volt, while electrolysis 100 mL photo procesing waste with addition of 10 mL KCN 1,0 M electrolysis was done at 1.30 Volt.The results showed that for silver electrodeposition from photo processing waste with addition of KCN 1,0 M was more favorable with faradic efficiency respectively were 93,16; 87,02; 74,74 and 78,35% for 30; 60; 90 and 120 minutes of electrolysis.   Keywords: Silver extraction, electrodeposition, photo-processing waste

  3. Atomistic minimal model for estimating profile of electrodeposited nanopatterns

    Science.gov (United States)

    Asgharpour Hassankiadeh, Somayeh; Sadeghi, Ali

    2018-06-01

    We develop a computationally efficient and methodologically simple approach to realize molecular dynamics simulations of electrodeposition. Our minimal model takes into account the nontrivial electric field due a sharp electrode tip to perform simulations of the controllable coating of a thin layer on a surface with an atomic precision. On the atomic scale a highly site-selective electrodeposition of ions and charged particles by means of the sharp tip of a scanning probe microscope is possible. A better understanding of the microscopic process, obtained mainly from atomistic simulations, helps us to enhance the quality of this nanopatterning technique and to make it applicable in fabrication of nanowires and nanocontacts. In the limit of screened inter-particle interactions, it is feasible to run very fast simulations of the electrodeposition process within the framework of the proposed model and thus to investigate how the shape of the overlayer depends on the tip-sample geometry and dielectric properties, electrolyte viscosity, etc. Our calculation results reveal that the sharpness of the profile of a nano-scale deposited overlayer is dictated by the normal-to-sample surface component of the electric field underneath the tip.

  4. Stable lithium electrodeposition in salt-reinforced electrolytes

    KAUST Repository

    Lu, Yingying

    2015-04-01

    © 2015 Elsevier B.V. Development of high-energy lithium-based batteries that are safe remains a challenge due to the non-uniform lithium electrodeposition during repeated charge and discharge cycles. We report on the effectiveness of lithium bromide (LiBr) salt additives in a common liquid electrolyte (i.e. propylene carbonate (PC)) on the stability of lithium electrodeposition. From galvanostatic cycling measurements, we find that the presence of LiBr in PC provides more than 20-fold enhancement in cell lifetime over the control LiTFSI/PC electrolyte. Batteries containing 30 mol% LiBr additive in the electrolytes are able to cycle stably for at least 1.8 months with no observations of cell failure. From galvanostatic polarization measurements, an electrolyte containing 30 mol% LiBr shows a maximum improvement in lifetime. The formation of uneven lithium electrodeposits is significantly suppressed by the Br-containing SEI layers, evidenced by impedance spectra, post-mortem SEM and XPS analyses. The study also concludes that good solubility of halogenated salts is not necessary for achieving the observed improvements in cell lifetime.

  5. Electrodeposited cadmium selenide films for solar cells; Electrodeposition de couches minces de CdSe: Application a la conversion photovoltaique

    Energy Technology Data Exchange (ETDEWEB)

    Bnamar, E.; Rami, M.; Fahoume, M.; Chraibi, F.; Ennaoui, A. [Universite Mohammed 5, Rabat (Morocco). Faculte des Sciences; Fahoume, M. [Universite Ibn Tofail, Faculte des Sciences, Kenitra (Morocco)

    1998-01-01

    Solar cells based on II-IV semiconductors are among the leading candidates for low-cost photovoltaic conversion of solar energy due to their high absorption coefficients and therefore the low materials consumption for their production. The synthesis of polycrystalline Cd Se thin films by cathodic electrodeposition on conducting substrates is described in this paper. Electrodeposition involves potentiostatic reduction from an acid aqueous bath. The influence of bath temperature and deposition potential on the crystallinity is discussed. For optimized deposition parameters, the XRD patterns reveal cubic and hexagonal Cd Se. Electron probe microanalysis shows an excess of Se in the samples. Photoelectrochemical studies of the films in aqueous polysulfide allowed us to determine the photovoltaic properties e.g.: semiconducting type, short-circuit current, open circuit voltage and fill factor. (authors) 5 refs.

  6. Controllable wettability and morphology of electrodeposited surfaces on zinc substrates

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Binyan; Lu, Shixiang, E-mail: shixianglu@bit.edu.cn; Xu, Wenguo, E-mail: wenguoxu60@bit.edu.cn; Cheng, Yuanyuan

    2016-01-01

    Graphical abstract: Superhydrophobic surfaces combining hierarchical micro/nanostructures were fabricated on zinc substrates by etching, electrodeposition of ZnO coatings and annealing. Such superhydrophobic surfaces offer possibilities for chemical, biological, electronic and microfluidic applications. - Highlights: • Superhydrophobic surface was fabricated via electrodeposition of ZnO and annealing. • The ZnO hierarchical micro/nanostructures contribute to the surface superhydrophobicity. • Surface wettability and morphology can be controlled by varying process conditions. • The anti-icing properties and reversible wetting behaviors of the ZnO coatings were studied. - Abstract: Superhydrophobic surfaces combining hierarchical micro/nanostructures were fabricated on zinc substrates by etching in hydrochloric acid solution, electrodeposition of ZnO coatings and subsequent thermal annealing. The optimal coatings were electrodeposited at −1.25 V for 900 s on the etched zinc substrates and then annealed at 200 °C for 60 min, which could achieve a maximum water contact angle of 170 ± 2° and an ultra-low sliding angle of approximately 0°. By conducting SEM and water CA analysis, we found that the morphology and wettability of prepared samples were controllable by the fabrication process. Interestingly, even without any additional modification, the samples prepared under different electrodeposition conditions (including Zn(CH{sub 3}COO){sub 2} concentration from 5 mM to 40 mM and deposition time from 300 s to 1500 s) exhibited superhydrophobic character. The influences of the Zn(CH{sub 3}COO){sub 2} concentration, deposition time, annealing temperature and annealing time on the wetting behaviors were also discussed in detail. Such superhydrophobic surfaces possess long-term stability, and good corrosion resistance as well as self-cleaning ability. In addition, the anti-icing properties of the ZnO films were investigated. These surfaces could be rapidly and

  7. Controllable wettability and morphology of electrodeposited surfaces on zinc substrates

    International Nuclear Information System (INIS)

    Zhang, Binyan; Lu, Shixiang; Xu, Wenguo; Cheng, Yuanyuan

    2016-01-01

    Graphical abstract: Superhydrophobic surfaces combining hierarchical micro/nanostructures were fabricated on zinc substrates by etching, electrodeposition of ZnO coatings and annealing. Such superhydrophobic surfaces offer possibilities for chemical, biological, electronic and microfluidic applications. - Highlights: • Superhydrophobic surface was fabricated via electrodeposition of ZnO and annealing. • The ZnO hierarchical micro/nanostructures contribute to the surface superhydrophobicity. • Surface wettability and morphology can be controlled by varying process conditions. • The anti-icing properties and reversible wetting behaviors of the ZnO coatings were studied. - Abstract: Superhydrophobic surfaces combining hierarchical micro/nanostructures were fabricated on zinc substrates by etching in hydrochloric acid solution, electrodeposition of ZnO coatings and subsequent thermal annealing. The optimal coatings were electrodeposited at −1.25 V for 900 s on the etched zinc substrates and then annealed at 200 °C for 60 min, which could achieve a maximum water contact angle of 170 ± 2° and an ultra-low sliding angle of approximately 0°. By conducting SEM and water CA analysis, we found that the morphology and wettability of prepared samples were controllable by the fabrication process. Interestingly, even without any additional modification, the samples prepared under different electrodeposition conditions (including Zn(CH_3COO)_2 concentration from 5 mM to 40 mM and deposition time from 300 s to 1500 s) exhibited superhydrophobic character. The influences of the Zn(CH_3COO)_2 concentration, deposition time, annealing temperature and annealing time on the wetting behaviors were also discussed in detail. Such superhydrophobic surfaces possess long-term stability, and good corrosion resistance as well as self-cleaning ability. In addition, the anti-icing properties of the ZnO films were investigated. These surfaces could be rapidly and reversibly switched

  8. Silver-zinc electrodeposition from a thiourea solution with added EDTA or HEDTA

    International Nuclear Information System (INIS)

    Oliveira, G.M. de; Carlos, I.A.

    2009-01-01

    This paper shows the study of silver-zinc electrodeposition from a thiourea solution with added (ethylenedinitrilo)tetraacetic acid (EDTA), disodium salt and N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA), trisodium salt. Voltammetric results indicated that silver-zinc alloy can be obtained applying overpotential higher than 0.495 V, in Tu solution containing 1.0 x 10 -1 mol L -1 Zn(NO 3 ) 2 + 2.5 x 10 -2 mol L -1 AgNO 3 . This was due to silver(I) ion complexation with thiourea, which shifted the silver deposition potential to more negative value and due to silver-zinc alloy deposition, which occurred at potentials more positive than the potential to zinc deposition alone. EDTA or HEDTA did not significantly affect the silver and zinc deposition potentials, but decreased the current density for silver-zinc deposition. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses of the silver-zinc deposits showed that the morphology and composition changed as a function of the conditions of deposition, viz, deposition potential (E d ), deposition charge density (q d ) and solution composition (silver, EDTA and HEDTA concentrations). EDS analysis of the deposits showed sulphur (S) incorporated into the silver-zinc deposit, while SEM images showed that this sulphur content seemed to improve the silver-zinc morphology, as did the presence of EDTA and HEDTA in the solution, which enhanced the sulphur incorporation into the silver-zinc deposit. X-ray diffraction (XRD) analysis of the silver-zinc deposit showed that it was amorphous, irrespective of its composition and morphology

  9. Alloy formation during chromium electrodeposition at niobium cathode in molten salts

    International Nuclear Information System (INIS)

    Kuznetsov, S.A.; Glagolevskaya, A.L.

    1993-01-01

    Alloy formation during electrodeposition of chromium at niobium cathode is studied in salt melts. It is shown that during chromium electrodeposition at niobium support intermetallic compound Cr 2 Nb is formed. Thermodynamic characteristics of Cr 0.66 Nb 0.33 alloy are determined. 10 refs., 1 fig

  10. Electrodeposition of Zn-Co and Zn-Co-Fe alloys from acidic chloride electrolytes

    NARCIS (Netherlands)

    Lodhi, Z.F.; Mol, J.M.C.; Hovestad, A.; Terryn, H.; Wit, J.H.W. de

    2007-01-01

    The electrodeposition operating conditions for Zn-Co and Zn-Co-Fe alloys from chloride baths were studied. The electrodeposition was performed on a high strength steel substrate, under galvanostatic conditions, for a range of current densities at varying Co2+ and Fe2+ bath concentrations and at

  11. Amorphous metal based nanoelectromechanical switch

    KAUST Repository

    Mayet, Abdulilah M.; Smith, Casey; Hussain, Muhammad Mustafa

    2013-01-01

    Nanoelectromechanical (NEM) switch is an interesting ultra-low power option which can operate in the harsh environment and can be a complementary element in complex digital circuitry. Although significant advancement is happening in this field, report on ultra-low voltage (pull-in) switch which offers high switching speed and area efficiency is yet to be made. One key challenge to achieve such characteristics is to fabricate nano-scale switches with amorphous metal so the shape and dimensional integrity are maintained to achieve the desired performance. Therefore, we report a tungsten alloy based amorphous metal with fabrication process development of laterally actuated dual gated NEM switches with 100 nm width and 200 nm air-gap to result in <5 volts of actuation voltage (Vpull-in). © 2013 IEEE.

  12. Amorphous metal based nanoelectromechanical switch

    KAUST Repository

    Mayet, Abdulilah M.

    2013-04-01

    Nanoelectromechanical (NEM) switch is an interesting ultra-low power option which can operate in the harsh environment and can be a complementary element in complex digital circuitry. Although significant advancement is happening in this field, report on ultra-low voltage (pull-in) switch which offers high switching speed and area efficiency is yet to be made. One key challenge to achieve such characteristics is to fabricate nano-scale switches with amorphous metal so the shape and dimensional integrity are maintained to achieve the desired performance. Therefore, we report a tungsten alloy based amorphous metal with fabrication process development of laterally actuated dual gated NEM switches with 100 nm width and 200 nm air-gap to result in <5 volts of actuation voltage (Vpull-in). © 2013 IEEE.

  13. Influences of magnetic field on the fractal morphology in copper electrodeposition

    Science.gov (United States)

    Sudibyo; How, M. B.; Aziz, N.

    2018-01-01

    Copper magneto-electrodeposition (MED) is used decrease roughening in the copper electrodeposition process. This technology plays a vital role in electrodeposition process to synthesize metal alloy, thin film, multilayer, nanowires, multilayer nanowires, dot array and nano contacts. The effects of magnetic fields on copper electrodeposition are investigated in terms of variations in the magnetic field strength and the electrolyte concentration. Based on the experimental results, the mere presence of magnetic field would result in a compact deposit. As the magnetic field strength is increased, the deposit grows denser. The increment in concentration also leads to the increase the deposited size. The SEM image analysis showed that the magnetic field has a significant effect on the surface morphology of electrodeposits.

  14. Morphology of uranium electrodeposits on cathode in electrorefining process: A phase-field simulation

    International Nuclear Information System (INIS)

    Shibuta, Yasushi; Sato, Takumi; Suzuki, Toshio; Ohta, Hirokazu; Kurata, Masaki

    2013-01-01

    Morphology of uranium electrodeposits on cathode with respect to applied voltage, zirconium concentration in the molten salt and the size of primary deposit during pyroprocessing is systematically investigated by the phase-field simulation. It is found that there is a threshold zirconium concentration in the molten salt demarcating planar and cellular/needle-like electrodeposits, which agrees with experimental results. In addition, the effect of size of primary deposits on the morphology of electrodeposits is examined. It is then confirmed that cellular/needle-like electrodeposits are formed from large primary deposits at all applied voltages considered, whereas both the planar and cellular/needle-like electrodeposits are formed from the primary deposits of 10 μm and less

  15. Transient photoconductivity in amorphous semiconductors

    International Nuclear Information System (INIS)

    Mpawenayo, P.

    1997-07-01

    Localized states in amorphous semiconductors are divided in disorder induced shallow trap levels and dangling bonds deep states. Dangling bonds are assumed here to be either neutral or charged and their energy distribution is a single gaussian. Here, it is shown analytically that transient photocurrent in amorphous semiconductors is fully controlled by charge carriers transitions between localized states for one part and tunneling hopping carriers on the other. Localized dangling bonds deep states act as non radiative recombination centres, while hopping tunnelling is assisted by the Coulomb interaction between defects sites. The half-width of defects distribution is the disorder parameter that determines the carrier hopping time between defects sites. The macroscopic time that explains the long decay response times observed will all types of amorphous semiconductors is duly thought to be temperature dependent. Basic equations developed by Longeaud and Kleider are solved for the general case of a semiconductor after photo-generation. It turns out that the transient photoconductivity decay has two components; one with short response times from carriers trap-release transitions between shallow levels and extended states and a hopping component made of inter-dependent exponentials whose time constants span in larger ranges depending on disorder. The photoconductivity hopping component appears as an additional term to be added to photocurrents derived from existing models. The results of the present study explain and complete the power law decay derived in the multiple trapping models developed 20 years ago only in the approximation of the short response time regime. The long response time regime is described by the hopping macroscopic time. The present model is verified for all samples of amorphous semiconductors known so far. Finally, it is proposed to improved the modulated photoconductivity calculation techniques by including the long-lasting hopping dark documents

  16. Magnetic excitations in amorphous ferromagnets

    International Nuclear Information System (INIS)

    Continentino, M.A.

    The propagation of magnetic excitations in amorphous ferromagnets is studied from the point of view of the theory of random frequency modulation. It is shown that the spin waves in the hydrodynamic limit are well described by perturbation theory while the roton-like magnetic excitations with wavevector about the peak in the structure factor are not. A criterion of validity of perturbation theory is found which is identical to a narrowing condition in magnetic resonance. (author) [pt

  17. Colloidal Photoluminescent Amorphous Porous Silicon, Methods Of Making Colloidal Photoluminescent Amorphous Porous Silicon, And Methods Of Using Colloidal Photoluminescent Amorphous Porous Silicon

    KAUST Repository

    Chaieb, Sahraoui

    2015-04-09

    Embodiments of the present disclosure provide for a colloidal photoluminescent amorphous porous silicon particle suspension, methods of making a colloidal photoluminescent amorphous porous silicon particle suspension, methods of using a colloidal photoluminescent amorphous porous silicon particle suspension, and the like.

  18. Colloidal Photoluminescent Amorphous Porous Silicon, Methods Of Making Colloidal Photoluminescent Amorphous Porous Silicon, And Methods Of Using Colloidal Photoluminescent Amorphous Porous Silicon

    KAUST Repository

    Chaieb, Saharoui; Mughal, Asad Jahangir

    2015-01-01

    Embodiments of the present disclosure provide for a colloidal photoluminescent amorphous porous silicon particle suspension, methods of making a colloidal photoluminescent amorphous porous silicon particle suspension, methods of using a colloidal photoluminescent amorphous porous silicon particle suspension, and the like.

  19. Electrodeposition of gold templated by patterned thiol monolayers

    Energy Technology Data Exchange (ETDEWEB)

    She, Zhe [EaStCHEM School of Chemistry, University of St. Andrews, KY16 9ST (United Kingdom); Di Falco, Andrea [SUPA, School of Physics and Astronomy, University of St. Andrews, KY16 9SS (United Kingdom); Hähner, Georg [EaStCHEM School of Chemistry, University of St. Andrews, KY16 9ST (United Kingdom); Buck, Manfred, E-mail: mb45@st-andrews.ac.uk [EaStCHEM School of Chemistry, University of St. Andrews, KY16 9ST (United Kingdom)

    2016-06-15

    Graphical abstract: - Highlights: • First demonstration of electrodeposition/lift-off of gold using thiol monolayers. • Microelectrode structures with large length to width ratio were generated. • Performance of two different patterning techniques was investigated. • Conditions for achieving good contrast in the electrodeposition were established. - Abstract: The electrochemical deposition of Au onto Au substrates modified by self-assembled monolayers (SAMs) was studied by linear sweep voltammetry (LSV), atomic force microscopy (AFM) and scanning electron microscopy (SEM). Patterned SAMs exhibiting electrochemical contrast were prepared by two different methods. One used microcontact printing (μCP) to generate a binary SAM of ω-(4′-methyl-biphenyl-4-yl)-propane thiol (CH{sub 3}-C{sub 6}H{sub 4}-C{sub 6}H{sub 4}-(CH{sub 2}){sub 3}-SH, MBP3) and octadecane thiol (CH{sub 3}(CH{sub 2}){sub 17}SH, ODT). Templated by the SAM, a gold microelectrode structure was electrodeposited featuring a line 15 μm wide and 3 mm long. After transfer to an epoxy substrate the structure proved to be electrically conductive across the full length. The other patterning method applied electron beam lithography (EBL) where electrochemical contrast was achieved by crosslinking molecules in a single component SAM of MBP3. An electron dose above 250 mC/cm{sup 2} results in a high deposition contrast. The choice of parameters for the deposition/lift-off process is found to be more critical for Au compared to Cu studied previously. The origin of the differences and implications for nanoscale patterning are discussed.

  20. Zn–Mn alloy coatings from acidic chloride bath: Effect of deposition conditions on the Zn–Mn electrodeposition-morphological and structural characterization

    Energy Technology Data Exchange (ETDEWEB)

    Loukil, N., E-mail: nloukil87@gmail.com; Feki, M.

    2017-07-15

    Highlights: • Zn-Mn co-deposition from an additives-free chloride bath is possible. • Effect of Mn{sup 2+} ion concentration and current density on Zn-Mn electrodeposition and particularly Mn content into Zn-Mn deposits were investigated. • A dimensionless graph model was used to analyze the effect of Mn{sup 2+} ion concentration as well as the applied potential on Zn-Mn nucleation process. • Effect of current density on the morphology and structure of Zn-Mn alloys deposits. • A transition from crystalline to amorphous structure may occur in the Mn alloy electrodeposits at high current densities. - Abstract: Zn–Mn alloy electrodeposition on steel electrode in chloride bath was investigated using cyclic voltammetric, chronopotentiometric and chronoamperometric techniques. Cyclic voltammetries (CV) reveal a deep understanding of electrochemical behaviors of each metal Zn, Mn, proton discharge and Zn–Mn co-deposition. The electrochemical results show that with increasing Mn{sup 2+} ions concentration in the electrolytic bath, Mn{sup 2+} reduction occurs at lower over-potential leading to an enhancement of Mn content into the Zn–Mn deposits. A dimensionless graph model was used to analyze the effect of Mn{sup 2+} ions concentration on Zn–Mn nucleation process. It was found that the nucleation process is not extremely affected by Mn{sup 2+} concentration. Nevertheless, it significantly depends on the applied potential. Several parameters such as Mn{sup 2+} ions concentration, current density and stirring were investigated with regard to the Mn content into the final Zn–Mn coatings. It was found that the Mn content increases with increasing the applied current density j{sub imp} and Mn{sup 2+} ions concentration in the electrolytic bath. However, stirring of the solution decreases the Mn content in the Zn–Mn coatings. The phase structure and surface morphology of Zn–Mn deposits are characterized by means of X-ray diffraction analysis and Scanning

  1. Microgravimetric Studies of Selenium Electrodeposition Onto Different Substrates

    Directory of Open Access Journals (Sweden)

    Kowalik R.

    2014-10-01

    Full Text Available The mechanism of selenium electrodeposition from sulfuric acid solution on different substrates was studied with the electrochemical techniques. The cyclic voltammetry was combined with the quartz crystal microbalance technique to analyze selenium deposition process. The electrochemical reduction of selenous acid on gold, silver and copper electrodes was investigated. It was found that reduction of selenous acid is a very complex process and it strongly depends from the applied substrate. The voltammetric measurements indicate the range of potentials in which the process of reduction of selenous acids on the applied substrate is possible. Additionally, the microgravimetric data confirm the deposition of selenium and they reveal the mechanism of the deposition process.

  2. Synthesis of tin oxide nanoparticle film by cathodic electrodeposition.

    Science.gov (United States)

    Kim, Seok; Lee, Hochun; Park, Chang Min; Jung, Yongju

    2012-02-01

    Three-dimensional SnO2 nanoparticle films were deposited onto a copper substrate by cathodic electrodeposition in a nitric acid solution. A new formation mechanism for SnO2 films is proposed based on the oxidation of Sn2+ ion to Sn4+ ion by NO+ ion and the hydrolysis of Sn4+. The particle size of SnO2 was controlled by deposition potential. The SnO2 showed excellent charge capacity (729 mAh/g) at a 0.2 C rate and high rate capability (460 mAh/g) at a 5 C rate.

  3. Zinc-nickel alloy electrodeposits for water electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Sheela, G.; Pushpavanam, Malathy; Pushpavanam, S. [Central Electrochemical Research Inst., Karaikudi (India)

    2002-06-01

    Electrodeposited zinc-nickel alloys of various compositions were prepared. A suitable electrolyte and conditions to produce alloys of various compositions were identified. Alloys produced on electroformed nickel foils were etched in caustic to leach out zinc and to produce the Raney type, porous electro catalytic surface for hydrogen evolution. The electrodes were examined by polarisation measurements, to evaluate their Tafel parameters, cyclic voltammetry, to test the change in surface properties on repeated cycling, scanning electron microscopy to identify their microstructure and X-ray diffraction. The catalytic activity as well as the life of the electrode produced from 50% zinc alloy was found to be better than others. (Author)

  4. Electrodeposition of Asphaltenes. 2. Effect of Resins and Additives

    DEFF Research Database (Denmark)

    Khvostichenko, Daria S; Andersen, Simon Ivar

    2010-01-01

    Electrodeposition of asphaltenes from oil/heptane, asphaltene/heptane, and asphaltene/heptane/additive mixtures has been investigated. Toluene, native petroleum resins, and a synthetic asphaltene dispersant, p-nonylphenol, were used as additives. The addition of these components led to partial...... dissolution of asphaltenes in heptane. The charge of asphaltenic particles was found to be negative in oil/heptane mixtures and positive in asphaltene/heptane mixtures. In asphaltene/heptane/toluene systems, the charge of the deposit varied from positive to neutral to negative, depending upon the method...

  5. The electrodeposition of thorium in natural materials for alpha spectrometry

    International Nuclear Information System (INIS)

    Roman, D.

    1980-01-01

    A technique has been developed for the electrodeposition of thorium on stainless steel planchettes following standard radiochemical separation and uptake in acetate buffer. The method has been used on over 130 samples including calcrete, clay, granite and shell matrices. To assess the efficiency at ultra low levels, three solutions of carrier free 228 Th ( -7 μg in 5 ml electrolyte) and four solutions of 229 Th (4.4x10 -4 μg in 5 ml) were studied. The efficiencies of the former averaged 66 per cent; those of the 229 Th varied from 41 to 91%. (author)

  6. 2008 Gordon Research Conference on Electrodeposition [Conference summary report

    Energy Technology Data Exchange (ETDEWEB)

    Moffat, Thomas P.; Gray, Nancy Ryan

    2009-01-01

    Electrodeposition melds key aspects of electrochemistry and materials science. In the last decade the advent of a variety of remarkable in situ characterization methods combined with the ever expanding application of wet chemical processing in high end technological endeavors has transformed the nature of the field. The 'old black magic' is giving way to the rigors of science as the electrodeposition process plays a central role in the fabrication of state-of-the-art ULSI and MEMS devices as well as being a key tool in the fabrication of novel materials and nanostructures. This year the conference will consider several timely issues such as how electrodeposition can contribute to the effective production of energy conversion devices, ranging from solar collectors to fuel cell electrocatalysts. Likewise, the challenge of building contacts and interconnects for next generation electronics will be examined over length scales ranging from individual atoms or molecules to chip stacking. Electrochemical fabrication of magnetic materials and devices as well as composite materials will also be discussed. Nucleation and growth phenomena underlie all aspect of electrochemical deposition and this year's meeting will consider the effect of both adsorbates and stress state on morphological evolution during thin film growth. A variety of new measurement methods for studying the growing electrode/electrolyte interface will also be detailed. In addition to the scheduled talks a session of short talks on late breaking news will be held Wednesday evening. There will also be at least two lively poster sessions that are essential elements of the conference and to which all attendees are encouraged to contribute. This will be 7th Electrodeposition GRC and based on past experience it is the premier 'mixing bowl' where young investigators and international experts have an extended opportunity to interact in a fun and collegial atmosphere. The afternoons provide

  7. Zinc Electrodeposition from Chloride Solutions onto Glassy Carbon Electrode

    OpenAIRE

    Mendoza-Huízar, Luis Humberto; Rios-Reyes, Clara Hilda; Gómez-Villegas, María Guadalupe

    2009-01-01

    An electrochemical study of zinc deposition was carried out in baths containing 0.5 M ZnCl2 and 0.4 M H3BO3. From the voltammetric study it was found that, in our experimental conditions, zinc electrodeposition is quasi-reversible and occurs under charge transfer control. The average coefficient diffusion calculated was D = 7.14 × 10-6 cm²s-1 while the standard constant at electrode charge was 8.78 × 10-3 cms-1. The nucleation and growth parameters determined from the potentiostatic study sho...

  8. High-temperature ductility of electro-deposited nickel

    Science.gov (United States)

    Dini, J. W.; Johnson, H. R.

    1977-01-01

    Work done during the past several months on high temperature ductility of electrodeposited nickel is summarized. Data are presented which show that earlier measurements made at NASA-Langley erred on the low side, that strain rate has a marked influence on high temperature ductility, and that codeposition of a small amount of manganese helps to improve high temperature ductility. Influences of a number of other factors on nickel properties were also investigated. They included plating solution temperature, current density, agitation, and elimination of the wetting agent from the plating solution. Repair of a large nozzle section by nickel plating is described.

  9. Characterization of nickel nanocones routed by electrodeposition without any template.

    Science.gov (United States)

    Hang, Tao; Li, Ming; Fei, Qin; Mao, Dali

    2008-01-23

    This work reports the synthesis of Ni nanocones by a one-step electrodeposition method without any template. With the addition of ethylenediamine dihydrochloride (EDA·2HCl) in the nickel plating solution, the novel Ni conical structure can be easily deposited onto different metal surfaces. The as-prepared nickel nanocones grow preferentially along [Formula: see text] directions with very sharp tips. The conical structures are single crystalline without any disruption of the lattice planes. In addition, the Ni nanocone structure is demonstrated to show magnetocrystalline anisotropy and enhance the magnetic properties when compared with other Ni nanostructures.

  10. Electrodeposition and properties of Zn-Ni-CNT composite coatings

    International Nuclear Information System (INIS)

    Praveen, B.M.; Venkatesha, T.V.

    2009-01-01

    Zn-Ni-CNT composite coatings were prepared by electrodeposition from a sulphate bath. The effect of CNTs on the corrosion behavior, wear resistance and hardness of the composite coatings was investigated. Their corrosion properties were evaluated by polarization, impedance, weight loss and salt spray tests. The CNT particles inclusion improved the corrosion resistance, hardness and wear resistance of the coating. The grain size of the composite coating was smaller than that of a pure Zn-Ni coating with the same Zn/Ni ratio. Scanning electron microscope images and X-ray diffraction patterns of coating revealed its fine-grain nature.

  11. Amorphization of ceramics by ion beams

    International Nuclear Information System (INIS)

    McHargue, C.J.; Farlow, G.C.; White, C.W.; Williams, J.M.; Appleton, B.R.; Naramoto, H.

    1984-01-01

    The influence of the implantation parameters fluence, substrate temperature, and chemical species on the formation of amorphous phases in Al 2 O 3 and α-SiC was studied. At 300 0 K, fluences in excess of 10 17 ions.cm -2 were generally required to amorphize Al 2 O 3 ; however, implantation of zirconium formed the amorphous phase at a fluence of 4 x 10 16 Zr.cm -2 . At 77 0 K, the threshold fluence was lowered to about 2 x 10 15 Cr.cm -2 . Single crystals of α-SiC were amorphized at 300 0 K by a fluence of 2 x 10 14 Cr.cm -2 or 1 x 10 15 N.cm -2 . Implantation at 1023 0 K did not produce the amorphous phase in SiC. The micro-indentation hardness of the amorphous material was about 60% of that of the crystalline counterpart

  12. Hydrogen in disordered and amorphous solids

    International Nuclear Information System (INIS)

    Bambakidis, G; Bowman, R.C.

    1986-01-01

    This book presents information on the following topoics: elements of the theory of amorphous semiconductors; electronic structure of alpha-SiH; fluctuation induced gap states in amorphous hydrogenated silicon; hydrogen on semiconductor surfaces; the influence of hydrogen on the defects and instabilities in hydrogenated amorphous silicon; deuteron magnetic resonance in some amorphous semiconductors; formation of amorphous metals by solid state reactions of hydrogen with an intermetallic compound; NMR studies of the hydrides of disordered and amorphous alloys; neutron vibrational spectroscopy of disordered metal-hydrogen system; dynamical disorder of hydrogen in LaNi /SUB 5-y/ M /SUB y/ hydrides studied by quasi-elastic neutron scattering; recent studies of intermetallic hydrides; tritium in Pd and Pd /SUB 0.80/ Sg /SUB 0.20/ ; and determination of hydrogen concentration in thin films of absorbing materials

  13. The influence of structural changes on electrical and magnetic characteristics of amorphous powder of the nixmoy alloy

    Directory of Open Access Journals (Sweden)

    Ribić-Zelenović Lenka

    2006-01-01

    Full Text Available Nickel and molybdenum alloy powder was electrodeposited on a titanium cathode from a NiSO4⋅7H2O and (NH46 Mo7O24⋅4H2O ammonium solution. The desired chemical composition, structure, size and shape of particles in the powder samples were achieved by an appropriate choice of electrolysis parameters (current density, composition and temperature of the solution, cathode material and electrolysis duration. Metal coatings form in the current density range 15 mA cm-2electrodeposition. The molybdenum content in the powder increases with the increase of current density (in the low current density range, while in the higher current density range the molybdenum content in the alloy decreases with the increase of the current density of deposition. Smaller sized particles form at higher current density. X-ray analysis, differential scanning calorimetric and measurements of the temperature dependence of electric resistance and magnetic permeability of the powder samples were all used to establish a predominantly amorphous structure of the powder samples formed at the current density of j≥70mA cm-2. The crystalline particle content in the powder samples increases with the decrease of the current density of deposition. Powder heating causes structural changes. The process of thermal stabilization of nickel and molybdenum amorphous powders takes place in the temperature interval from 463K to 573K and causes a decrease in electrical resistance and increase in magnetic permeability. The crystallization temperature depends on the value of current density of powder electrodeposition. Powder formed at j=180 mA cm-2 begins to crystallize at 573K, while the powder deposited at j=50 mA cm-2 begins to crystallize at 673K. Crystallization of the powder causes a decrease in electric resistivity and magnetic

  14. Material reliability of Ni alloy electrodeposition for steam generator tube repair

    International Nuclear Information System (INIS)

    Kim, Dong Jin; Kim, Myong Jin; Kim, Joung Soo; Kim, Hong Pyo

    2007-01-01

    Due to the occasional occurrences of Stress Corrosion Cracking (SCC) in steam generator tubing (Alloy 600), degraded tubes are removed from service by plugging or are repaired for re-use. Since electrodeposition inside a tube dose not entail parent tube deformation, residual stress in the tube can be minimized. In this work, tube restoration via electrodeposition inside a steam generator tubing was performed after developing the following: an anode probe to be installed inside a tube, a degreasing condition to remove dirt and grease, an activation condition for surface oxide elimination, a tightly adhered strike layer forming condition between the electroforming layer and the Alloy 600 tube, and the condition for an electroforming layer. The reliability of the electrodeposited material, with a variation of material properties, was evaluated as a function of the electrodeposit position in the vertical direction of a tube using the developed anode. It has been noted that the variation of the material properties along the electrodeposit length was acceptable in a process margin. To improve the reliability of a material property, the causes of the variation occurrence were presumed, and an attempt to minimize the variation has been made. A Ni alloy electrodeposition process is suggested as a Primary Water Stress Corrosion Cracking (PWSCC) mitigation method for various components, including steam generator tubes. The Ni alloy electrodeposit formed inside a tube by using the installed assembly shows proper material properties as well as an excellent SCC resistance

  15. Amorphous silicon based radiation detectors

    International Nuclear Information System (INIS)

    Perez-Mendez, V.; Cho, G.; Drewery, J.; Jing, T.; Kaplan, S.N.; Qureshi, S.; Wildermuth, D.; Fujieda, I.; Street, R.A.

    1991-07-01

    We describe the characteristics of thin(1 μm) and thick (>30μm) hydrogenated amorphous silicon p-i-n diodes which are optimized for detecting and recording the spatial distribution of charged particles, x-rays and γ rays. For x-ray, γ ray, and charged particle detection we can use thin p-i-n photosensitive diode arrays coupled to evaporated layers of suitable scintillators. For direct detection of charged particles with high resistance to radiation damage, we use the thick p-i-n diode arrays. 13 refs., 7 figs

  16. Inelastic scattering from amorphous solids

    International Nuclear Information System (INIS)

    Price, D.L.

    1985-08-01

    The potential of inelastic neutron scattering techniques for surveying various aspects of the dynamics of amorphous solids is briefly reviewed. The recent use of the Intense Pulsed Neutron Source to provide detailed information on the optical vibrations of glasses is discussed in more detail. The density of states represents an averaged quantity which gives information about the general characteristics of the structure and bonding. More extensive information can be obtained by studying the detailed wavevector dependence of the dynamic structure factor. 15 refs., 7 figs

  17. Influence of titanium oxide films on copper nucleation during electrodeposition

    International Nuclear Information System (INIS)

    Chang, Hyun K.; Choe, Byung-Hak; Lee, Jong K.

    2005-01-01

    Copper electrodeposition has an important industrial role because of various interconnects used in electronic devices such as printed wire boards. With an increasing trend in device miniaturization, in demand are void-free, thin copper foils of 10 μm thick or less with a very low surface profile. In accordance, nucleation kinetics of copper was studied with titanium cathodes that were covered with thin, passive oxide films of 2-3 nm. Such an insulating oxide layer with a band gap of 3 eV is supposed to nearly block charge transfer from the cathode to the electrolyte. However, significant nucleation rates of copper were observed. Pipe tunneling mechanism along a dislocation core is reasoned to account for the high nucleation kinetics. A dislocation core is proposed to be a high electron tunneling path with a reduced energy barrier and a reduced barrier thickness. In supporting the pipe tunneling mechanism, both 'in situ' and 'ex situ' scratch tests were performed to introduce extra dislocations into the cathode surface, that is, more high charge paths via tunneling, before electrodeposition

  18. Molybdenum carbide coating electrodeposited from molten fluoride bath

    International Nuclear Information System (INIS)

    Topor, D.C.; Selman, J.R.

    1987-01-01

    Molybdenum carbide has been recently considered as a candidate material for the protection of common steel-based substrates in high-temperature high-sulfur activity applications. Methods to produce coatings of materials such as Mo/sub 2/C are scarce and only the electrodeposition from molten salts can yield dense, pore-free layers on various metallic profiles. Recently Stern reported the deposition of a Mo/sub 2/C coating on nickel substrate form, FLINAK + K/sub 2/MoCl/sub 6/ + Na/sub 2/CO/sub 3/ mixture at 850 0 C. Electrodeposition of Mo/sub 2/C on a cathode surface proceeds according to a rather complicated mechanism which may involve simultaneous reduction of carbonate to C, of molybdate to Mo and a subsequent chemical reaction between both species. The deposit grows further as a coherent coating. Reduction of CO/sub 2/ or carbonate to carbon in a fused salt medium could follow different paths but Li/sup +/ ions or other highly polarizing ions must be present. A similar situation in which a polyatomic anion discharges at the cathode is encountered when molybdates are used as source of molybdenum. In fluoride melts the chemistry of Mo(VI) species is considered to be much simpler due to the hard fluoride ions. These ions form strong complexes with molybdenum and the resulting solution is more stable

  19. Electrodeposition properties of modified cational epoxy resin-type photoresist

    International Nuclear Information System (INIS)

    Yong He; Yunlong Zhang; Feipeng Wu; Miaozhen Li; Erjian Wang

    1999-01-01

    Multi-component cationic epoxy and acrylic resin system for ED photoresist was used in this work, since they can provide better storage stability for ED emulsion and better physical and chemical properties of deposited film than one-component system. The cationic main resin (AE) was prepared from amine modified epoxy resins and then treated with acetic acid. The amination degree was controlled as required. The synthetic procedure of cationic main resins is described in scheme I. The ED photoresist (AME) is composed of cationic main resin (AE) and nonionic multifunctional acrylic crosslinkers (PETA), in combination with suitable photo-initiator. They can easily be dispersed in deionized water to form a stable ED emulsion. The exposed part of deposited film upon UV irradiation occurs crosslinking to produce an insoluble semi-penetrating network and the unexposed part remains good solubility in the acidic water solution. It is readily utilized for fabrication of fine micropattern. The electrodeposition are carried out on Cu plate at room temperature. To evaluate the electrodeposition properties of ED photoresist (AME), the different influences are examined

  20. A MEMS lamination technology based on sequential multilayer electrodeposition

    International Nuclear Information System (INIS)

    Kim, Minsoo; Kim, Jooncheol; Herrault, Florian; Schafer, Richard; Allen, Mark G

    2013-01-01

    A MEMS lamination technology based on sequential multilayer electrodeposition is presented. The process comprises three main steps: (1) automated sequential electrodeposition of permalloy (Ni 80 Fe 20 ) structural and copper sacrificial layers to form multilayer structures of significant total thickness; (2) fabrication of polymeric anchor structures through the thickness of the multilayer structures and (3) selective removal of copper. The resulting structure is a set of air-insulated permalloy laminations, the separation of which is sustained by insulating polymeric anchor structures. Individual laminations have precisely controllable thicknesses ranging from 500 nm to 5 µm, and each lamination layer is electrically isolated from adjacent layers by narrow air gaps of similar scale. In addition to air, interlamination insulators based on polymers are investigated. Interlamination air gaps with very high aspect ratio (>1:100) can be filled with polyvinylalcohol and polydimethylsiloxane. The laminated structures are characterized using scanning electron microscopy and atomic force microscopy to directly examine properties such as the roughness and the thickness uniformity of the layers. In addition, the quality of the electrical insulation between the laminations is evaluated by quantifying the eddy current within the sample as a function of frequency. Fabricated laminations are comprised of uniform, smooth (surface roughness <100 nm) layers with effective electrical insulation for all layer thicknesses and insulator approaches studied. Such highly laminated structures have potential uses ranging from energy conversion to applications where composite materials with highly anisotropic mechanical or thermal properties are required. (paper)

  1. Microscopic and magnetic properties of template assisted electrodeposited iron nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Irshad, M. I., E-mail: imrancssp@gmail.com; Mohamed, N. M., E-mail: noranimuti-mohamed@petronas.com.my; Yar, A., E-mail: asfandyarhargan@gmail.com [Department of Fundamental & Applied Sciences, Universiti Teknologi PETRONAS, 31750 PERAK (Malaysia); Ahmad, F., E-mail: faizahmad@petronas.com.my; Abdullah, M. Z., E-mail: zaki-abdullah@petronas.com.my [Department of Mechanical Engineering, Universiti Teknologi PETRONAS, 31750 PERAK (Malaysia)

    2015-07-22

    Nanowires of magnetic materials such as Iron, nickel, cobalt, and alloys of them are one of the most widely investigated structures because of their possible applications in high density magnetic recording media, sensor elements, and building blocks in biological transport systems. In this work, Iron nanowires have been prepared by electrodeposition technique using Anodized Aluminium Oxide (AAO) templates. The electrolyte used consisted of FeSO{sub 4.}6H{sub 2}O buffered with H{sub 3}BO{sub 3} and acidized by dilute H{sub 2}SO{sub 4}. FESEM analysis shows that the asdeposited nanowires are parallel to one another and have high aspect ratio with a reasonably high pore-filing factor. To fabricate the working electrode, a thin film of copper (∼ 220 nm thick) was coated on back side of AAO template by e-beam evaporation system to create electrical contact with the external circuit. The TEM results show that electrodeposited nanowires have diameter around 100 nm and are polycrystalline in structure. Magnetic properties show the existence of anisotropy for in and out of plane configuration. These nanowires have potential applications in magnetic data storage, catalysis and magnetic sensor applications.

  2. II. Electrodeposition/removal of nickel in a spouted electrochemical reactor.

    Science.gov (United States)

    Grimshaw, Pengpeng; Calo, Joseph M; Shirvanian, Pezhman A; Hradil, George

    2011-08-17

    An investigation is presented of nickel electrodeposition from acidic solutions in a cylindrical spouted electrochemical reactor. The effects of solution pH, temperature, and applied current on nickel removal/recovery rate, current efficiency, and corrosion rate of deposited nickel on the cathodic particles were explored under galvanostatic operation. Nitrogen sparging was used to decrease the dissolved oxygen concentration in the electrolyte in order to reduce the nickel corrosion rate, thereby increasing the nickel electrowinning rate and current efficiency. A numerical model of electrodeposition, including corrosion and mass transfer in the particulate cathode moving bed, is presented that describes the behavior of the experimental net nickel electrodeposition data quite well.

  3. Stability of Electrodeposition at Solid-Solid Interfaces and Implications for Metal Anodes

    Science.gov (United States)

    Ahmad, Zeeshan; Viswanathan, Venkatasubramanian

    2017-08-01

    We generalize the conditions for stable electrodeposition at isotropic solid-solid interfaces using a kinetic model which incorporates the effects of stresses and surface tension at the interface. We develop a stability diagram that shows two regimes of stability: a previously known pressure-driven mechanism and a new density-driven stability mechanism that is governed by the relative density of metal in the two phases. We show that inorganic solids and solid polymers generally do not lead to stable electrodeposition, and provide design guidelines for achieving stable electrodeposition.

  4. Electrodeposition of Iridium Oxide by Cyclic Voltammetry: Application of Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Kakooei Saeid

    2014-07-01

    Full Text Available The effects of scan rate, temperature, and number of cycles on the coating thickness of IrOX electrodeposited on a stainless steel substrate by cyclic voltammetry were investigated in a statistical system. The central composite design, combined with response surface methodology, was used to study condition of electrodeposition. All fabricated electrodes were characterized using electrochemical methods. Field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy were performed for IrOX film characterization. Results showed that scan rate significantly affects the thickness of the electrodeposited layer. Also, the number of cycles has a greater effect than temperature on the IrOX thickness.

  5. Magnetic properties of CoP alloys electrodeposited at room temperature

    International Nuclear Information System (INIS)

    Lucas, I.; Perez, L.; Aroca, C.; Sanchez, P.; Lopez, E.; Sanchez, M.C.

    2005-01-01

    CoP alloys have been electrodeposited at room temperature from electrolytes with different pH values and their magnetic properties have been studied. Cracks and fractures appear when using stiff substrates, showing that high internal stresses, due to hydrogen evolution, are involved in the electrodeposition process. Samples electrodeposited onto flexible substrates do not show cracks on the surface. We also report an increment in the coercivity of the alloys when the pH of the electrolyte decreases, and therefore, the hydrogen evolution and the internal stresses increase

  6. A Study on Zinc-Iron Alloy Electrodeposition from a Chloride Electrolyte

    DEFF Research Database (Denmark)

    Jensen, Jens Dahl

    1998-01-01

    The electrodeposition of zinc-iron alloys from a chloride-based electrolyte has been studied using electrochemical polarisation techniques, Auger Electron Spectroscopy (AES), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDXA) and Computer Assisted Pulse Plating (CAPP...... this system ideal for production of compositional modulated alloy (CMA) electrodeposits. Chloride content, pH and agitation of the electrolyte have been observed to have a strong influence on the reaction at the cathode surface, just as the use of pulse reversal current during electrodeposition. A theory...

  7. Mössbauer and X-ray Diffraction Investigations of Sn-containing Binary and Ternary Electrodeposited Alloys from a Gluconate Bath

    Science.gov (United States)

    Kuzmann, E.; Stichleutner, S.; Doyle, O.; Chisholm, C. U.; El-Sharif, M.; Homonnay, Z.; Vértes, A.

    2005-04-01

    Constant current technique was applied to electrodeposit tin-containing coatings such as tin-cobalt (Sn-Co), tin-iron (Sn-Fe) and a novel tin-cobalt-iron (Sn-Co-Fe) from a gluconate bath. The effect of plating parameters (current density, deposition time at an electrolyte temperature of 60°C and pH=7.0) on phase composition, crystal structure and magnetic anisotropy of alloy deposits has been investigated mainly by 57Fe CEMS, 119Sn CEMS and transmission Mössbauer Spectroscopy as well as XRD. 57Fe and 119Sn CEM spectra and XRD reflect that the dominant phases of the deposits are orthorhombic Co3Sn2, tetragonal FeSn2 or amorphous Fe-Sn and amorphous Sn-Co-Fe in Sn-Co, Sn-Fe and Sn-Co-Fe coatings, respectively. Furthermore, the relative area of the 2nd and 5th lines of the sextets representing the magnetic iron containing phases decreases continuously with increasing current density in all Fe-containing deposits. At the same time, no essential change in the magnetic anisotropy can be found with the plating time. 119Sn spectra reveal the presence of small amount of β-Sn besides the main phases in Sn-Fe and in the Sn-Co coatings. Magnetically split 119Sn spectra reflecting transferred hyperfine field were observed in the case of Co-Sn-Fe coatings.

  8. Electrodeposition of Zn and Cu–Zn alloy from ZnO/CuO precursors in deep eutectic solvent

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Xueliang [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Zou, Xingli, E-mail: xinglizou@shu.edu.cn [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Lu, Xionggang, E-mail: luxg@shu.edu.cn [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Lu, Changyuan; Cheng, Hongwei; Xu, Qian [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Zhou, Zhongfu [State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Institute of Mathematics and Physics, Aberystwyth University, Aberystwyth SY23 3BZ (United Kingdom)

    2016-11-01

    Graphical abstract: Micro/nanostructured Zn and Cu–Zn alloy films have been electrodeposited directly from ZnO/CuO precursors in ChCl/urea-based DES, the typical nucleation-growth mechanism and the micro/nanostructures-formation process are determined. Display Omitted - Highlights: • Micro/nanostructured Zn films have been electrodeposited directly from ZnO precursor in deep eutectic solvent (DES). • The morphology of the Zn electrodeposits depends on the cathodic potential and temperature. • The electrodeposited Zn films exhibit homogeneous morphologies with controllable particle sizes and improved corrosion resistance. • Cu–Zn alloy films have also been electrodeposited directly from their metal oxides precursors in DES. - Abstract: The electrodeposition of Zn and Cu–Zn alloy has been investigated in choline chloride (ChCl)/urea (1:2 molar ratio) based deep eutectic solvent (DES). Cyclic voltammetry study demonstrates that the reduction of Zn(II) to Zn is a diffusion-controlled quasi-reversible, one-step, two electrons transfer process. Chronoamperometric investigation indicates that the electrodeposition of Zn on a Cu electrode typically involves three-dimensional instantaneous nucleation with diffusion-controlled growth process. Micro/nanostructured Zn films can be obtained by controlling the electrodeposition potential and temperature. The electrodeposited Zn crystals preferentially orient parallel to the (101) plane. The Zn films electrodeposited under more positive potentials and low temperatures exhibit improved corrosion resistance in 3 wt% NaCl solution. In addition, Cu–Zn alloy films have also been electrodeposited directly from CuO–ZnO precursors in ChCl/urea-based DES. The XRD analysis indicates that the phase composition of the electrodeposited Cu–Zn alloy depends on the electrodeposition potential.

  9. Photoexcitation-induced processes in amorphous semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Jai [School of Engineering and Logistics, Charles Darwin University, Darwin, NT 0909 (Australia)]. E-mail: jai.singh@cdu.edu.au

    2005-07-30

    Theories for the mechanism of photo-induced processes of photodarkening (PD), volume expansion (VE) in amorphous chalcogenides are presented. Rates of spontaneous emission of photons by radiative recombination of excitons in amorphous semiconductors are also calculated and applied to study the excitonic photoluminescence in a-Si:H. Results are compared with previous theories.

  10. Analytical theory of noncollinear amorphous metallic magnetism

    International Nuclear Information System (INIS)

    Kakehashi, Y.; Uchida, T.

    2001-01-01

    Analytical theory of noncollinear magnetism in amorphous metals is proposed on the basis of the Gaussian model for the distribution of the interatomic distance and the saddle-point approximation. The theory removes the numerical difficulty in the previous theory based on the Monte-Carlo sampling method, and reasonably describes the magnetic properties of amorphous transition metals

  11. Challenges in amorphous silicon solar cell technology

    NARCIS (Netherlands)

    Swaaij, van R.A.C.M.M.; Zeman, M.; Korevaar, B.A.; Smit, C.; Metselaar, J.W.; Sanden, van de M.C.M.

    2000-01-01

    Hydrogenated amorphous silicon is nowadays extensively used for a range of devices, amongst others solar cells, Solar cell technology has matured over the last two decades and resulted in conversion efficiencies in excess of 15%. In this paper the operation of amorphous silicon solar cells is

  12. Photoconductivity of amorphous silicon-rigorous modelling

    International Nuclear Information System (INIS)

    Brada, P.; Schauer, F.

    1991-01-01

    It is our great pleasure to express our gratitude to Prof. Grigorovici, the pioneer of the exciting field of amorphous state by our modest contribution to this area. In this paper are presented the outline of the rigorous modelling program of the steady-state photoconductivity in amorphous silicon and related materials. (Author)

  13. Colors and the evolution of amorphous galaxies

    International Nuclear Information System (INIS)

    Gallagher, J.S. III; Hunter, D.A.

    1987-01-01

    UBVRI and H-alpha photometric observations are presented for 16 amorphous galaxies and a comparison sample of Magellanic irregular (Im) and Sc spiral galaxies. These data are analyzed in terms of star-formation rates and histories in amorphous galaxies. Amorphous galaxies have mean global colors and star-formation rates per unit area that are similar to those in giant Im systems, despite differences in spatial distributions of star-forming centers in these two galactic structural classes. Amorphous galaxies differ from giant Im systems in having somewhat wider scatter in relationships between B - V and U - B colors, and between U - B and L(H-alpha)/L(B). This scatter is interpreted as resulting from rapid variations in star-formation rates during the recent past, which could be a natural consequence of the concentration of star-forming activity into centrally located, supergiant young stellar complexes in many amorphous galaxies. While the unusual spatial distribution and intensity of star formation in some amorphous galaxies is due to interactions with other galaxies, several amorphous galaxies are relatively isolated and thus the processes must be internal. The ultimate evolutionary fate of rapidly evolving amorphous galaxies remains unknown. 77 references

  14. Photoexcitation-induced processes in amorphous semiconductors

    International Nuclear Information System (INIS)

    Singh, Jai

    2005-01-01

    Theories for the mechanism of photo-induced processes of photodarkening (PD), volume expansion (VE) in amorphous chalcogenides are presented. Rates of spontaneous emission of photons by radiative recombination of excitons in amorphous semiconductors are also calculated and applied to study the excitonic photoluminescence in a-Si:H. Results are compared with previous theories

  15. Neutron irradiation induced amorphization of silicon carbide

    International Nuclear Information System (INIS)

    Snead, L.L.; Hay, J.C.

    1998-01-01

    This paper provides the first known observation of silicon carbide fully amorphized under neutron irradiation. Both high purity single crystal hcp and high purity, highly faulted (cubic) chemically vapor deposited (CVD) SiC were irradiated at approximately 60 C to a total fast neutron fluence of 2.6 x 10 25 n/m 2 . Amorphization was seen in both materials, as evidenced by TEM, electron diffraction, and x-ray diffraction techniques. Physical properties for the amorphized single crystal material are reported including large changes in density (-10.8%), elastic modulus as measured using a nanoindentation technique (-45%), hardness as measured by nanoindentation (-45%), and standard Vickers hardness (-24%). Similar property changes are observed for the critical temperature for amorphization at this neutron dose and flux, above which amorphization is not possible, is estimated to be greater than 130 C

  16. Structure, thermodynamics, and crystallization of amorphous hafnia

    International Nuclear Information System (INIS)

    Luo, Xuhui; Demkov, Alexander A.

    2015-01-01

    We investigate theoretically amorphous hafnia using the first principles melt and quench method. We identify two types of amorphous structures of hafnia. Type I and type II are related to tetragonal and monoclinic hafnia, respectively. We find type II structure to show stronger disorder than type I. Using the phonon density of states, we calculate the specific heat capacity for type II amorphous hafnia. Using the nudged elastic band method, we show that the averaged transition barrier between the type II amorphous hafnia and monoclinic phase is approximately 0.09 eV/HfO 2 . The crystallization temperature is estimated to be 421 K. The calculations suggest an explanation for the low thermal stability of amorphous hafnia

  17. One-step electrodeposition process of CuInSe2: Deposition time effect

    Indian Academy of Sciences (India)

    Administrator

    CuInSe2 thin films were prepared by one-step electrodeposition process using a simplified two- electrodes system. ... homojunctions or heterojunctions (Rincon et al 1983). Efficiency of ... deposition times onto indium thin oxide (ITO)-covered.

  18. Nucleation and growth mechanism of Co–Pt alloy nanowires electrodeposited within alumina template

    Energy Technology Data Exchange (ETDEWEB)

    Srivastav, Ajeet K., E-mail: srivastav.ajeet.kumar@gmail.com, E-mail: mm09d004@smail.iitm.ac.in [Indian Institute of Technology Madras, Department of Metallurgical and Materials Engineering (India); Shekhar, Rajiv [Indian Institute of Technology Kanpur, Department of Materials Science and Engineering (India)

    2015-01-15

    Co–Pt alloy nanowires were electrodeposited by direct current electrodeposition within nanoporous alumina templates with varying deposition potentials. The effect of deposition potential on nucleation and growth mechanisms during electrodeposition of Co–Pt alloy nanowires was investigated. The less negative deposition potential (−0.9 V) favours the instantaneous nucleation mechanism. The positive deviation from theoretical instantaneous and progressive nucleation mechanisms occurs at higher negative deposition potentials. The hysteresis behaviour and magnetic properties of electrodeposited Co–Pt alloy nanowires altered with varying deposition potential. The easy magnetization direction was in direction perpendicular to the wire axis. The deposition potential dependent change in hysteresis behaviour with increased coercivity and scattered remanence ratio was observed. This is attributed to better crystallinity with reduced defect density and hydrogen evolution causing structural changes at more negative deposition potentials.

  19. Interfacial electronic structure of electrodeposited Ag nanoparticles on iron oxide nanorice particles

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Young Ku [Dept. of Chemistry, Yeungnam University, Gyeongsan (Korea, Republic of)

    2016-12-15

    A bimetallic hybrid nanostructure of uni- formly electrodeposited Ag NPs on an Fe oxide nanorice particle template was developed. Figure 6 schematically illustrates uniform electrodeposition of Ag NPs on Fe oxide nanorice supported on a Si substrate. According to Ar + ion depth-probling XPS spectra, the electrodeposited Ag NPs are metallic, and the Fe oxide nanorice particles consist of a metallic shell covered by ultrathin FeOOH or Fe 2 O 3 shells. When the template was functionalized with 1,4-diisocyanobenzene, one terminal NC group was bridge- bonded as in the N C form on the Fe surface. The newly developed selective facial electrodeposition method will be very useful for facial fabrication of bimetallic hybrid systems for diverse application areas.

  20. Development of plastic elongation in nanocrystalline and amorphous Ni–W dual phase alloys by brushing technique

    International Nuclear Information System (INIS)

    Nakayama, S.; Adachi, H.; Yamasaki, T.

    2015-01-01

    Highlights: • A novel agitation technique called the brushing technique is proposed. • A homogeneous material can be obtained with the brushing technique. • The brushed material exhibits large plastic elongation with work hardening. - Abstract: A novel agitation technique, referred to as the “brushing technique” is proposed to treat the surface of a Ni–W alloy film during electrodeposition. This technique was developed to directly remove hydrogen bubbles on the film surface and to apply Ni ions to the interfacial layer with the substrate. The intrinsic mechanical properties of the Ni–W electrodeposits are then evaluated with respect to application. High resolution transmission electron microscopy observations revealed that both treated and untreated films have nanocrystallites of approximately 5 nm in diameter and an amorphous phase. There was a compositional difference of about. 1.4 at% W between the face side and the reverse side of the film that was not subjected to the brushing technique, whereas this difference was absent in the film subjected to the brushing technique. In addition, the brushing technique reduced the surface roughness of the film and decreased the number of defects. As a result, a large plastic strain of about. 2.9% was observed with work hardening under tensile testing

  1. Locomotion of Amorphous Surface Robots

    Science.gov (United States)

    Bradley, Arthur T. (Inventor)

    2018-01-01

    An amorphous robot includes a compartmented bladder containing fluid, a valve assembly, and an outer layer encapsulating the bladder and valve assembly. The valve assembly draws fluid from a compartment(s) and discharges the drawn fluid into a designated compartment to displace the designated compartment with respect to the surface. Another embodiment includes elements each having a variable property, an outer layer that encapsulates the elements, and a control unit. The control unit energizes a designated element to change its variable property, thereby moving the designated element. The elements may be electromagnetic spheres with a variable polarity or shape memory polymers with changing shape and/or size. Yet another embodiment includes an elongated flexible tube filled with ferrofluid, a moveable electromagnet, an actuator, and a control unit. The control unit energizes the electromagnet and moves the electromagnet via the actuator to magnetize the ferrofluid and lengthen the flexible tube.

  2. Regulating the electrodeposition of zinc and cadmium coatings with mixtures of o-oxyazomethyne derivatives

    International Nuclear Information System (INIS)

    Grigor'ev, V.P.; Shpan'ko, S.P.; Dymnikova, O.V.; Popov, L.D.

    2000-01-01

    The results of electrodeposition of zinc and cadmium metals from the sulfate electrolyte in presence of the organic compounds of the oxyazomethine reaction series are described. It is shown that the current dependences retardation coefficient and cathode polarization of electrodeposited zinc and cadmium are described by equations, following from the principle of the reaction and activation free energy linearity. The character of these dependence for the negatively charged zinc and positively charged cadmium cathodes is similar [ru

  3. Dendrite-Free Electrodeposition and Reoxidation of Lithium-Sodium Alloy for Metal-Anode Battery

    Science.gov (United States)

    2011-11-01

    Dendrite-Free Electrodeposition and Reoxidation of Lithium-Sodium Alloy for Metal-Anode Battery Johanna K. Star 1 , Yi Ding 2 , and Paul A. Kohl ,1, * 1...Journal Article 3. DATES COVERED 01-11-2011 to 01-11-2011 4. TITLE AND SUBTITLE DENDRITE-FREE ELECTRODEPOSITION AND REOXIDATION OF LITHIUM-SODIUM...can short circuit the anode and cathode . Anode- cathode short circuits are especially dangerous when a flammable organic solvent is used as the

  4. Vapour and electro-deposited metal films on copper: structure and reactivity

    OpenAIRE

    McEvoy, Thomas F.

    2004-01-01

    The systems studied involve deposition of metals of a larger atomic diameter on a Cu{100} single crystal surface under vacuum and determining the structures formed along with the effect on the Cu{100} substrate. Cu microelectrodes were fabricated and characterised with Indium electrodeposited on the electrode surface. The In on Cu{ 100} growth mode is compared with the growth mode of electrodeposited Indium on Cu microelectrodes. The Cu{100}/In system has been studied for the In coverage ...

  5. Influence of lead ions on the macromorphology of electrodeposited zinc

    Energy Technology Data Exchange (ETDEWEB)

    Tsuda, Tetsuaki [Univ. of California, Berkeley, CA (United States); Tobias, Charles W. [Univ. of California, Berkeley, CA (United States)

    1981-09-01

    The morphology of zinc as it is electrodeposited from acid solutions demonstrates a remarkable imprint of electrolyte flow conditions. The development of macromorphology of zinc deposits has been investigated under galvanostatic conditions on a rotating plantinum disk electrode by use of photomacrography, scanning electron microscopy, electron probe microanalysis and Auger microprobe analysis. Logarithmic spiral markings, which reflect the hydrodynamic flow on a rotating disk, appear in a certain region of current density well below the limiting current density. Morphological observations revealed the major influence of trace lead ions on the amplifications of surface roughness through coalescence and preferred growth of initial protrusions. Results obtained from ultra-pure electrolyte suggest preferred crystal growth towards well-mixed orientation in the concentration field caused by slight differences in crystallization overpotential. A qualitative model involving a coupling mechanism between the evolving surface roughness and instability phenomena in the boundary layer is advanced to explain the formation of spiral patterns.

  6. Studies on zinc nodules electrodeposited from acid electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Rolfe [Univ. of California, Berkeley, CA (United States); Tobias, Charles W. [Univ. of California, Berkeley, CA (United States)

    1984-12-01

    The development of morphology of electrodeposited zinc was investigated by studying the initial stages of deposition. Zinc was deposited galvanostatically from 1.0 M ZnCl2 electrolyte (0.7 < pH < 4.6) on rotating disc electrodes at current densities from 5 to 130 ma/cm2. Pine glassy carbon, Union Carbide pyrolytic graphite, Gould pyrolytic graphite, Exxon graphite loaded polymer, and platinum substrates were used. The number densities of nodules (diameter greater than 1 μm), typically encountered during incipient morphological development, were measured using scanning electron microscopy and image analysis. Nodule densities up to 7 x 104 nodules/mm2 were measured.

  7. Zinc electrodeposition from alkaline zincate solution by pulsating overpotentials

    Directory of Open Access Journals (Sweden)

    MILOS V. SIMICIC

    2000-09-01

    Full Text Available It is well known that smooth zinc deposits cannot be obtained from alkaline zincate using constant overpotential and current rate. During prolonged metal deposition, spongy and dendritic deposits are formed. It has been shown that the deposits are less agglomerated in the case of square-wave pulsating overpotentials regime than the ones obtained in case of constant overpotential regime. This is explained in a semiquantitative way by two phenomena: selective anodic dissolution during overpotentials “off” period and decreasing diffusion control. These effects is more pronounced at higher pause-to-pulse ratio. Increasing the pause-to-pulse ratio causes a reduction of the ratio between diffusion and activation overpotential, resulting in a more compact deposit. Confirmation of the proposed semiquantitative mathematical model was obtained by zinc electrodeposition onto a copper wire from a 0.1 M zincate solution in 1.0 M KOH at room temperature.

  8. Potentiostatic current and galvanostatic potential oscillations during electrodeposition of cadmium.

    Science.gov (United States)

    López-Sauri, D A; Veleva, L; Pérez-Ángel, G

    2015-09-14

    Cathodic current and potential oscillations were observed during electrodeposition of cadmium from a cyanide electrolyte on a vertical platinum electrode, in potentiostatic and galvanostatic experiments. Electrochemical impedance spectroscopy experiments revealed a region of negative real impedance in a range of non-zero frequencies, in the second descending branch with a positive slope of the N-shape current-potential curve. This kind of dynamical behaviour is characteristic of the HN-NDR oscillators (oscillators with the N-Shape current-potential curve and hidden negative differential resistance). The oscillations could be mainly attributed to the changes in the real active cathodic area, due to the adsorption of hydrogen molecules and their detachment from the surface. The instabilities of the electrochemical processes were characterized by time series, Fast Fourier Transforms and 2-D phase portraits showing quasi-periodic oscillations.

  9. Nanocrystalline electrodeposited Ni-Mo-C cathodes for hydrogen production

    International Nuclear Information System (INIS)

    Hashimoto, K.; Sasaki, T.; Meguro, S.; Asami, K.

    2004-01-01

    Tailoring active nickel alloy cathodes for hydrogen evolution in a hot concentrated hydroxide solution was attempted by electrodeposition. The carbon addition to Ni-Mo alloys decreased the nanocrystalline grain size and remarkably enhanced the activity for hydrogen evolution, changing the mechanism of hydrogen evolution. The Tafel slope of hydrogen evolution was about 35 mV per decade. This suggested that the rate-determining step is desorption of adsorbed hydrogen atoms by recombination. As was distinct from the binary Ni-Mo alloys, after open circuit immersion, the overpotential, that is, the activity of nanocrystalline Ni-Mo-C alloys for hydrogen evolution was not changed, indicating the sufficient durability in the practical electrolysis

  10. Tin electrodeposition from sulfate solution containing a benzimidazolone derivative

    Directory of Open Access Journals (Sweden)

    Said BAKKALI

    2016-11-01

    Full Text Available Tin electrodeposition in an acidic medium in the presence of N,N’-1,3-bis-[N-3-(6-deoxy-3-O-methyl-D-glucopyranose-6-yl-2-oxobenzimidazol-1-yl]-2-tetradecyloxypropane as an additive was investigated in this work. The adequate current density and the appropriate additive concentration were determined by gravimetric measurements. Chronopotentiometric curves showed that the presence of the additive caused an increase in the overpotential of tin reduction. The investigations by cyclic voltammetry technique revealed that, in the presence and in absence of the additive, there were two peaks, one in the cathodic side attributed to the reduction of Sn2+ and the other one in the anodic side assigned to the oxidation of tin previously formed during the cathodic scan. The surface morphology of the tin deposits was studied by scanning electron microscopy (SEM and XRD.

  11. Electrodeposited highly-ordered manganese oxide nanowire arrays for supercapacitors

    Science.gov (United States)

    Liu, Haifeng; Lu, Bingqiang; Wei, Shuiqiang; Bao, Mi; Wen, Yanxuan; Wang, Fan

    2012-07-01

    Large arrays of well-aligned Mn oxide nanowires were prepared by electrodeposition using anodic aluminum oxide templates. The sizes of nanowires were tuned by varying the electrotype solution involved and the MnO2 nanowires with 10 μm in length were obtained in a neutral KMnO4 bath for 1 h. MnO2 nanowire arrays grown on conductor substance save the tedious electrode-making process, and electrochemical characterization demonstrates that the MnO2 nanowire arrays electrode has good capacitive behavior. Due to the limited mass transportation in narrow spacing, the spacing effects between the neighbor nanowires have show great influence to the electrochemical performance.

  12. Nanostructured Electrolytes for Stable Lithium Electrodeposition in Secondary Batteries

    KAUST Repository

    Tu, Zhengyuan

    2015-11-17

    © 2015 American Chemical Society. ConspectusSecondary batteries based on lithium are the most important energy storage technology for contemporary portable devices. The lithium ion battery (LIB) in widespread commercial use today is a compromise technology. It compromises high energy, high power, and design flexibility for long cell operating lifetimes and safety. Materials science, transport phenomena, and electrochemistry in the electrodes and electrolyte that constitute such batteries are areas of active study worldwide because significant improvements in storage capacity and cell lifetime are required to meet new demands, including the electrification of transportation and for powering emerging autonomous aircraft and robotics technologies. By replacing the carbonaceous host material used as the anode in an LIB with metallic lithium, rechargeable lithium metal batteries (LMBs) with higher storage capacity and compatibility with low-cost, high-energy, unlithiated cathodes such as sulfur, manganese dioxide, carbon dioxide, and oxygen become possible. Large-scale, commercial deployment of LMBs are today limited by safety concerns associated with unstable electrodeposition and lithium dendrite formation during cell recharge. LMBs are also limited by low cell operating lifetimes due to parasitic chemical reactions between the electrode and electrolyte. These concerns are greater in rechargeable batteries that utilize other, more earth abundant metals such as sodium and to some extent even aluminum.Inspired by early theoretical works, various strategies have been proposed for alleviating dendrite proliferation in LMBs. A commonly held view among these early studies is that a high modulus, solid-state electrolyte that facilitates fast ion transport, is nonflammable, and presents a strong-enough physical barrier to dendrite growth is a requirement for any commercial LMB. Unfortunately, poor room-temperature ionic conductivity, challenging processing, and the high cost

  13. Nanostructured electrolytes for stable lithium electrodeposition in secondary batteries.

    Science.gov (United States)

    Tu, Zhengyuan; Nath, Pooja; Lu, Yingying; Tikekar, Mukul D; Archer, Lynden A

    2015-11-17

    Secondary batteries based on lithium are the most important energy storage technology for contemporary portable devices. The lithium ion battery (LIB) in widespread commercial use today is a compromise technology. It compromises high energy, high power, and design flexibility for long cell operating lifetimes and safety. Materials science, transport phenomena, and electrochemistry in the electrodes and electrolyte that constitute such batteries are areas of active study worldwide because significant improvements in storage capacity and cell lifetime are required to meet new demands, including the electrification of transportation and for powering emerging autonomous aircraft and robotics technologies. By replacing the carbonaceous host material used as the anode in an LIB with metallic lithium, rechargeable lithium metal batteries (LMBs) with higher storage capacity and compatibility with low-cost, high-energy, unlithiated cathodes such as sulfur, manganese dioxide, carbon dioxide, and oxygen become possible. Large-scale, commercial deployment of LMBs are today limited by safety concerns associated with unstable electrodeposition and lithium dendrite formation during cell recharge. LMBs are also limited by low cell operating lifetimes due to parasitic chemical reactions between the electrode and electrolyte. These concerns are greater in rechargeable batteries that utilize other, more earth abundant metals such as sodium and to some extent even aluminum. Inspired by early theoretical works, various strategies have been proposed for alleviating dendrite proliferation in LMBs. A commonly held view among these early studies is that a high modulus, solid-state electrolyte that facilitates fast ion transport, is nonflammable, and presents a strong-enough physical barrier to dendrite growth is a requirement for any commercial LMB. Unfortunately, poor room-temperature ionic conductivity, challenging processing, and the high cost of ceramic electrolytes that meet the

  14. Electrodeposition of silver nanoparticle arrays on transparent conductive oxides

    International Nuclear Information System (INIS)

    Zhang, Dezhong; Tang, Yang; Jiang, Fuguo; Han, Zhihua; Chen, Jie

    2016-01-01

    Highlights: • The sliver nanoparticles' size and the distance between nanoparticles are tunable. - Abstract: In this paper, we present a facile method for the preparation of silver nanoparticles on aluminum-doped zinc oxide (AZO) via electrodeposition techniques at room temperature. The morphology and structure of silver nanoparticles are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), respectively. Due to localized surface plasmon resonances, as-prepared silver nanoparticles on AZO glass exhibited different reflectivity in contrast with bare AZO glass. The weighted reflection of AZO substrate increased from 10.2% to 12.8%. The high reflection property of silver nanoparticle arrays on AZO substrate might be applicable for thin film solar cells and other optoelectronics applications.

  15. Electrodeposition of silver nanoparticle arrays on transparent conductive oxides

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Dezhong; Tang, Yang, E-mail: tangyang@nicenergy.com; Jiang, Fuguo; Han, Zhihua; Chen, Jie

    2016-04-30

    Highlights: • The sliver nanoparticles' size and the distance between nanoparticles are tunable. - Abstract: In this paper, we present a facile method for the preparation of silver nanoparticles on aluminum-doped zinc oxide (AZO) via electrodeposition techniques at room temperature. The morphology and structure of silver nanoparticles are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), respectively. Due to localized surface plasmon resonances, as-prepared silver nanoparticles on AZO glass exhibited different reflectivity in contrast with bare AZO glass. The weighted reflection of AZO substrate increased from 10.2% to 12.8%. The high reflection property of silver nanoparticle arrays on AZO substrate might be applicable for thin film solar cells and other optoelectronics applications.

  16. Nonequilibrium fluctuations in micro-MHD effects on electrodeposition

    International Nuclear Information System (INIS)

    Aogaki, Ryoichi; Morimoto, Ryoichi; Asanuma, Miki

    2010-01-01

    In copper electrodeposition under a magnetic field parallel to electrode surface, different roles of two kinds of nonequilibrium fluctuations for micro-magnetohydrodynamic (MHD) effects are discussed; symmetrical fluctuations are accompanied by the suppression of three dimensional (3D) nucleation by micro-MHD flows (the 1st micro-MHD effect), whereas asymmetrical fluctuations controlling 2D nucleation yield secondary nodules by larger micro-MHD flows (the 2nd micro-MHD effect). Though the 3D nucleation with symmetrical fluctuations is always suppressed by the micro-MHD flows, due to the change in the rate-determining step from electron transfer to mass transfer, the 2D nucleation with asymmetrical fluctuations newly turns unstable, generating larger micro-MHD flows. As a result, round semi-spherical deposits, i.e., secondary nodules are yielded. Using computer simulation, the mechanism of the 2nd micro-MHD effect is validated.

  17. Characterisation of a thiosulphate-sulphite gold electrodeposition process

    International Nuclear Information System (INIS)

    J-Liew, M.; Sobri, S.; Roy, S.

    2005-01-01

    Electrodeposition of soft gold is an important process in the fabrication of micro devices for electronics, optics etc. Traditional gold electroplating is based on a gold cyanide process which is not applicable for the stringent requirements in state of the art micro device manufacture. Newcastle University has been involved in the development of an industrial process based on a mixed ligand electrolyte-the gold thiosulphate-sulphite system. Here we present methods for the formulation of this electrolyte in the laboratory which ensure bath stability and process compatibility. In addition, we have carried out spectrophotometry to elucidate the possible reasons of its chemical stability. Standard rotating disk and cyclic voltammetry has been carried out to determine the electrochemical behaviour of the gold thiosulphate-sulphite system. The changes in electrochemical behaviour as the bath ages are also discussed

  18. Electrical conductivity of chromate conversion coating on electrodeposited zinc

    International Nuclear Information System (INIS)

    Tencer, Michal

    2006-01-01

    For certain applications of galvanized steel protected with conversion coatings it is important that the surface is electrically conductive. This is especially important with mating surfaces for electromagnetic compatibility. This paper addresses electrical conductivity of chromate conversion coatings. A cross-matrix study using different zinc plating techniques by different labs showed that the main deciding factor is the type of zinc-plating bath used rather than the subsequent chromating process. Thus, chromated zinc plate electrodeposited from cyanide baths is non-conductive while that from alkaline (non-cyanide) and acid baths is conductive, even though the plate from all the bath types is conductive before conversion coating. The results correlate well with the microscopic structure of the surfaces as observed with scanning electron microscopy (SEM) and could be further corroborated and rationalized using EDX and Auger spectroscopies

  19. Insights into pulsed electrodeposition of GMR multilayered nanowires

    International Nuclear Information System (INIS)

    Pullini, D.; Busquets, D.; Ruotolo, A.; Innocenti, G.; Amigo, V.

    2007-01-01

    In this work, Co/Cu nanowires are fabricated by pulsed electrodeposition from a single bath solution containing both Co and Cu ions. Alternate Co and Cu layers are deposited into the nanopores of track etched polycarbonate templates. Although the feasibility of this process is generally recognized, some important issues such as process reproducibility and how structural defects affect the nanowires arrays' sensing performances are still open; conditions necessary to turn a this made system into a magnetic field sensor. The present work aims at pushing forward knowledge concerning the nanowires fabrication and defining the best growth parameters; in particular, a tight control of the growth process parameters such as single metal deposition potentials and single cycle deposition durations have been carried out for nanowires of 80 nm diameter and correlated to the system magneto-electric response

  20. Iron Fibers Arrays Prepared by Electrodepositing in Reverse Liquid Crystalline

    Institute of Scientific and Technical Information of China (English)

    ZHAO Suling; LIN Dong; GUAN Jianguo; ZHANG Lianmeng

    2006-01-01

    Ordered iron fiber arrays were electrodeposited on the surface of zinc foils using "FeSO4 solution-sodium caprylate-Decanol" 3-component reverse hexagonal liquid crystal as soft templates. The structure of the soft templates and the synthesized iron fibers were characterized by polarizing microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray microanalysis etc. The experimental results show that the synthesized iron fibers with α crystal phase grew up in the form of fiber clusters of about 200 nm along the direction perpendicular to the cathode surface. Each cluster was composed of several tens of fibers. The fibers had almost the same length of more than 10 μm with a diameter of about 50 nm.

  1. Mechanical Properties of Electrolyte Jet Electrodeposited Nickel Foam

    Directory of Open Access Journals (Sweden)

    Jinsong Chen

    2013-07-01

    Full Text Available Principles of the preparation of nickel foam by electrolyte jet electrodeposition were introduced, Nickel foam samples with different porosity were fabricated. Effect of different porosity on microhardness and uniaxial tensile properties of nickel foam was discussed. The results show that the microhardness of nickel foam is 320~400 HV, lower than entitative metal clearly. The lower the porosity of nickel foam, the higher the microhardness is. During the process of uniaxial tensile, nickel foam is characterized by three distinct regions, e.g. elastic deforming region, plastic plateau region and densification region. The higher the porosity of nickel foam, the lower the plastic plateau and the poorer the strength of nickel foam, accordingly

  2. Pulse electrodeposition of Fe-Ni-Cr alloys

    International Nuclear Information System (INIS)

    Adelkhani, H.

    2000-01-01

    Pulse Electroplating is a relativity new technique in electrodeposition of pure metals and alloys which has resulted in a number of improvement over the traditional direct current method. Among these are a better composition control, lower porosity, reduction of internal stresses and hydrogen content as well as other impurities. In this work Pulse plating of Fe-Ni-Cr alloys has been investigated by using a series of planned experiments. A domain of Pulse parameters, such a pulse frequency, pulse duration, current density and batch condition such as Ph, temperature and has been defined where the coating quality is optimal. The result obtained were Compared with those of D C electroplating and finally a number of recommendations are made for future works towards a semi-industrial process

  3. Cathodic processes during ruthenium electrodeposition from a chloride melt

    International Nuclear Information System (INIS)

    Sokol'skij, D.V.

    1985-01-01

    Cathodic processes occurring during the electrolysis of chloride melts in the presence of oxygen-containing impurities were studied. The experiments were carried out at 500, 550 600 and 680 deg C, ruthenium ions concentration in KCl-NaCl-CsCl eutectic melt being 0.4-1.5 mol% and BaO additions 4.8x10 -2 mol%. Temperature dependence of Ru(3) ion diffusion coefficient in the chloride melt (lg D=3.25-1508/T+-0.02) and activation energy of the diffusion process (6.9 k cal/mol) were determined. It is shown that changes of the shape of E, t-curve and the deviation of values determined in the cause of chronopotentiometric investigations from the corresponding values of reversable processes are related in many respects to the participation of oxygen-containing compounds in the cathodic process. Irreversibility of the cathodic process is also connected with metal crystallization during electrodeposition

  4. Effect of Deposition Time on the Photoelectrochemical Properties of Cupric Oxide Thin Films Synthesized via Electrodeposition Method

    Directory of Open Access Journals (Sweden)

    Yaw Chong Siang

    2016-01-01

    Full Text Available The main aim of this study was to investigate the effect of deposition time on the physicochemical and photoelectrochemical properties of cupric oxide (CuO thin films synthesized via electrodeposition method. Firstly, the electrodeposition of amorphous CuO films on fluorine-doped tin oxide (FTO working electrodes with varying deposition time between 5 and 30 min was carried out, followed by annealing treatment at 500 °C. Resultant nanocrystalline CuO thin films were characterised using field emission-scanning electron microscopy (FE-SEM, photocurrent density, and photoluminescence measurements. Through FE-SEM analysis, it was observed that the surface of thin films was composed of irregular-sized CuO nanocrystals. A smaller CuO nanocrystals size will lead to a higher photoactivity due to the increase in overall catalytic surface area. In addition, the smaller CuO nanocrystals size will prolongs the electron-hole recombination rate due to the increase in copious amount of surface defects. From this study, it was revealed that the relationship between deposition time and CuO film thickness was non-linear. This could be due to the detachment of CuO thin films from the FTO surface at an increasing amount of CuO mass being deposited. It was observed that the amount of light absorbed by CuO thin films increased with film thickness until a certain extent whereby, any further increase in the film thickness will result in a reduction of light photon penetration. Therefore, the CuO nanocrystals size and film thickness have to be compromised in order to yield a higher catalytic surface area and a lower rate of surface charge recombination. Finally, it was found that the deposition time of 15 min resulted in an average CuO nanocrystals size of 73.7 nm, optimum film thickness of 0.73 μm, and corresponding photocurrent density of 0.23 mA/cm2 at the potential bias of - 0.3 V (versus Ag/AgCl. The PL spectra for the deposition time of 15 min has the lowest

  5. Growth of uranyl hydroxide nanowires and nanotubes with electrodeposition method

    International Nuclear Information System (INIS)

    Wang Lin; Yuan Liyong; Chai Zhifang; Shi Weiqun

    2013-01-01

    Actinides nanomaterials have great potential applications in fabrication of novel nuclear fuel and spent fuel reprocessing in advanced nuclear energy system. However, the relative research so far still lacks systematic investigation on the synthetic methods for actinides nanomaterials. In this work, we use track-etched membranes as hard templates to synthesize uranium based nanomaterials with novel structures by electrodeposition method. Through electrochemical behavior investigations and subsequent product characterizations such as energy dispersive spectrometer (EDS), fourier transform infrared spectroscopy (FTIR), the chemical composition of deposition products have been confirmed as the uranyl hydroxide. More importantly, accurate control of morphology and structures (nanowires and nanotubes) could be achieved by carefully adjusting the growth parameters such as deposition time and deposition current density. It was found that the preferred morphology of electrodeposition products is nanowire when a low current density was applied, whereas nanotubes could be formed only under conditions of high current density and the short deposition time. The mechanism for the formation of nanowires in track-etched membranes is based on the precipitation of uranyl hydroxide from uranyl nitrate solution, according to the previous researches about obtaining nanostructures of hydroxides from nitrate salt solutions. And we have concluded that the formation of nanotubes is attributed to the hydrogen bubbles generated by water electrolysis under the condition of over-potential electro-reduction. The conveying of hydrogen bubbles plays the role of dynamic template which can prevent the complete filling of uranyl hydroxide in the channels. Additionally, we transform the chemical composition of deposition products from uranyl hydroxide to triuranium octoxide by calcining them at 500 and 800 degree centigrade, respectively, and SEM results show the morphologies of nanowires and

  6. Crystalline to amorphous transformation in silicon

    International Nuclear Information System (INIS)

    Cheruvu, S.M.

    1982-09-01

    In the present investigation, an attempt was made to understand the fundamental mechanism of crystalline-to-amorphous transformation in arsenic implanted silicon using high resolution electron microscopy. A comparison of the gradual disappearance of simulated lattice fringes with increasing Frenkel pair concentration with the experimental observation of sharp interfaces between crystalline and amorphous regions was carried out leading to the conclusion that when the defect concentration reaches a critical value, the crystal does relax to an amorphous state. Optical diffraction experiments using atomic models also supported this hypothesis. Both crystalline and amorphous zones were found to co-exist with sharp interfaces at the atomic level. Growth of the amorphous fraction depends on the temperature, dose rate and the mass of the implanted ion. Preliminary results of high energy electron irradiation experiments at 1.2 MeV also suggested that clustering of point defects occurs near room temperature. An observation in a high resolution image of a small amorphous zone centered at the core of a dislocation is presented as evidence that the nucleation of an amorphous phase is heterogeneous in nature involving clustering or segregation of point defects near existing defects

  7. Preliminary study on auto-electrodeposition of copper, cadmium, nickel, and cobalt in acid and glycerol medium

    Directory of Open Access Journals (Sweden)

    S.G. Viswanath

    2013-12-01

    Full Text Available Electrodeposition can be carried out even without corresponding metal ions in the solution, but the respective metal electrode acts as anode. This process is called auto-electrodeposition. It occurs under similar conditions applied for electrowinning or electrodeposition. The electrochemical mechanism of electrowinning and autoelectrodeposition is suggested. Hydroxyl ions play very important role in this process. In this process, a black loss deposit is formed on the anode metal. The autoelectrodeposition is combination of electrodissolution process and electrowinning process.

  8. Effect of Electrodeposition Potential on Composition of CuIn1−xGaxSe2 Absorber Layer for Solar Cell by One-Step Electrodeposition

    OpenAIRE

    You, Rui-Wei; Lew, Kar-Kit; Fu, Yen-Pei

    2014-01-01

    CIGS polycrystalline thin films were successfully fabricated by one-step cathodic electrodeposition on Mo-coated glass. In this study, we applied a galvanometry mode with three-electrode potentiostatic systems to produce a constant concentration electroplating solution, which were composed of CuCl2, InCl3, GaCl3, and SeO2. Then these as-electrodeposited films were annealed in argon atmosphere and characterized by X-ray diffraction. The results revealed that annealing treatment significantly i...

  9. Photonic crystals, amorphous materials, and quasicrystals.

    Science.gov (United States)

    Edagawa, Keiichi

    2014-06-01

    Photonic crystals consist of artificial periodic structures of dielectrics, which have attracted much attention because of their wide range of potential applications in the field of optics. We may also fabricate artificial amorphous or quasicrystalline structures of dielectrics, i.e. photonic amorphous materials or photonic quasicrystals. So far, both theoretical and experimental studies have been conducted to reveal the characteristic features of their optical properties, as compared with those of conventional photonic crystals. In this article, we review these studies and discuss various aspects of photonic amorphous materials and photonic quasicrystals, including photonic band gap formation, light propagation properties, and characteristic photonic states.

  10. Synthesis of amorphous acid iron phosphate nanoparticles

    International Nuclear Information System (INIS)

    Palacios, E.; Leret, P.; Fernández, J. F.; Aza, A. H. De; Rodríguez, M. A.

    2012-01-01

    A simple method to precipitate nanoparticles of iron phosphate with acid character has been developed in which the control of pH allows to obtain amorphous nanoparticles. The acid aging of the precipitated amorphous nanoparticles favored the P–O bond strength that contributes to the surface reordering, the surface roughness and the increase of the phosphate acid character. The thermal behavior of the acid iron phosphate nanoparticles has been also studied and the phosphate polymerization at 400 °C produces strong compacts of amorphous nanoparticles with interconnected porosity.

  11. Structure of a new dense amorphous ice

    International Nuclear Information System (INIS)

    Finney, J.L.; Bowron, D.T.; Soper, A.K.; Loerting, T.; Mayer, E.; Hallbrucker, A.

    2002-01-01

    The detailed structure of a new dense amorphous ice, VHDA, is determined by isotope substitution neutron diffraction. Its structure is characterized by a doubled occupancy of the stabilizing interstitial location that was found in high density amorphous ice, HDA. As would be expected for a thermally activated unlocking of the stabilizing 'interstitial', the transition from VHDA to LDA (low-density amorphous ice) is very sharp. Although its higher density makes VHDA a better candidate than HDA for a physical manifestation of the second putative liquid phase of water, as for the HDA case, the VHDA to LDA transition also appears to be kinetically controlled

  12. Peculiarities of Vibration Characteristics of Amorphous Ices

    Science.gov (United States)

    Gets, Kirill V.; Subbotin, Oleg S.; Belosludov, Vladimir R.

    2012-03-01

    Dynamic properties of low (LDA), high (HDA) and very high (VHDA) density amorphous ices were investigated within the approach based on Lattice Dynamics simulations. In this approach, we assume that the short-range molecular order mainly determines the dynamic and thermodynamic properties of amorphous ices. Simulation cell of 512 water molecules with periodical boundary conditions and disordering allows us to study dynamical properties and dispersion curves in the Brillouin zone of pseudo-crystal. Existence of collective phenomena in amorphous ices which is usual for crystals but anomalous for disordered phase was confirmed in our simulations. Molecule amplitudes of delocalized (collective) as well as localized vibrations have been considered.

  13. X-ray in-situ study of copper electrodeposition on UHV prepared GaAs(001) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gruender, Yvonne

    2008-06-02

    For this work a unique setup for in-situ electrochemical studies was employed and improved. This setup permits UHV preparation of the GaAs(001) surface with a defined surface termination (arsenic-rich or gallium-rich) and its characterization by SXRD in UHV, under ambient pressure in inert gas and in electrolyte under potential control without passing through air. The GaAs(001) surfaces were capped by amorphous arsenic. This permitted to ship them through ambient air. Afterwards smooth well defined GaAs(001) surfaces could be recovered by thermal annealing in UHV. A first investigation of the arsenic capped sample was done by atomic force microscopy (AFM) and Surface X-Ray Diffraction (SXRD). The non bulk like termination of the arsenic buried GaAs(001) surface was revealed. For the electrochemical metal deposition, arsenic terminated (2 x 4) reconstructed and gallium terminated (4 x 2) reconstructed GaAs(001) surfaces were employed. These surfaces were characterized by STM, LEED and a first time by SXRD. The surfaces are smooth, however, a higher degree of disorder than for MBE prepared reconstructed GaAs(001) is found. After exposure of the sample to nitrogen, the surfaces were then again studied by SXRD. These two steps characterizing the bare GaAs(001) surfaces permitted us to get a better knowledge of the starting surface and its influence on the later electrodeposited copper. At ambient pressure both reconstructions are lifted, but the surface is not bulk-like terminated as can be deduced from the crystal truncation rods. Epitaxial copper clusters grow upon electrodeposition on the UHV prepared GaAs(001) surface. The copper lattice is rotated and inclined with respect to the GaAs substrate lattice, leading to eight symmetry equivalent domains. The influence of the surface termination as well as the nucleation potential on the structure of the electrodeposited copper were investigated. The tilt and rotation angles do not depend on the deposition potential but

  14. Corrosion resistant amorphous metals and methods of forming corrosion resistant amorphous metals

    Science.gov (United States)

    Farmer, Joseph C [Tracy, CA; Wong, Frank M. G. [Livermore, CA; Haslam, Jeffery J [Livermore, CA; Yang, Nancy [Lafayette, CA; Lavernia, Enrique J [Davis, CA; Blue, Craig A [Knoxville, TN; Graeve, Olivia A [Reno, NV; Bayles, Robert [Annandale, VA; Perepezko, John H [Madison, WI; Kaufman, Larry [Brookline, MA; Schoenung, Julie [Davis, CA; Ajdelsztajn, Leo [Walnut Creek, CA

    2009-11-17

    A system for coating a surface comprises providing a source of amorphous metal, providing ceramic particles, and applying the amorphous metal and the ceramic particles to the surface by a spray. The coating comprises a composite material made of amorphous metal that contains one or more of the following elements in the specified range of composition: yttrium (.gtoreq.1 atomic %), chromium (14 to 18 atomic %), molybdenum (.gtoreq.7 atomic %), tungsten (.gtoreq.1 atomic %), boron (.ltoreq.5 atomic %), or carbon (.gtoreq.4 atomic %).

  15. Electrodeposited Ni-W magnetic thin films with columnar nanocrystallites

    International Nuclear Information System (INIS)

    Sulitanu, N.; Brinza, F.

    2002-01-01

    Nanocrystalline Ni-W thin films (140 nm) containing from zero to 18 wt % W were electrolytically prepared and structural and magnetic characterized. XRD, SEM and TEM investigations have revealed that all segregated Ni columns are fcc-type whose [111] axis is oriented perpendicular to the film plane and have 140 nm in height and 6-27 nm in diameter. Depending on film composition, two types of nanostructures were observed: (a) single-phase nanostructure ( i nterphases , namely W enriched particles boundaries, and (b) two-phase nanostructure (7-18 wt %) in which a second Ni-W amorphous phase or even amorphous-disordered mixture separates the magnetic columnar Ni nanocrystallites (d = 6-14 nm). The columnar crystallites have an easy magnetization direction along their long axis mainly due to the in-plane internal biaxial stresses. Magnetic characteristics of prepared thin films are presented. (Authors)

  16. Surface magnetic structures in amorphous ferromagnetic microwires

    Energy Technology Data Exchange (ETDEWEB)

    Usov, N.A., E-mail: usov@obninsk.ru [National University of Science and Technology «MISIS», 119049 Moscow (Russian Federation); Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences, IZMIRAN, 108840 Troitsk, Moscow (Russian Federation); Serebryakova, O.N.; Gudoshnikov, S.A. [National University of Science and Technology «MISIS», 119049 Moscow (Russian Federation); Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences, IZMIRAN, 108840 Troitsk, Moscow (Russian Federation); Tarasov, V.P. [National University of Science and Technology «MISIS», 119049 Moscow (Russian Federation)

    2017-05-01

    The spatial period of magnetization perturbations that occur near the surface of magnetic nanotube or nanowire under the influence of surface magnetic anisotropy is determined by means of numerical simulation as a function of the sample geometry and material parameters. The surface magnetization distribution obtained is then used to estimate the period of the surface magnetic texture in amorphous microwire of several micrometers in diameter by means of appropriate variational procedure. The period of the surface magnetic texture in amorphous microwire is found to be significantly smaller than the wire diameter. - Highlights: • Magnetic structure may arise near the magnetic nanotube surface under the influence of surface magnetic anisotropy. • The period of the surface magnetization pattern is calculated as a function of the sample geometry. • Similar magnetic structure may exist in amorphous microwire of several micrometers in diameter. • The period of the surface magnetic structure in amorphous wire is found to be significantly smaller than the wire diameter.

  17. Amorphous uranium alloy and use thereof

    International Nuclear Information System (INIS)

    Gambino, R.J.; McElfresh, M.W.; McGuire, T.R.; Plaskett, T.S.

    1991-01-01

    An amorphous alloy containing uranium and a member selected from the group N, P, As, Sb, Bi, S, Se, Te, Po and mixtures thereof; and use thereof for storage medium, light modulator or optical isolator. (author) figs

  18. Magnetomechanical coupling in thermal amorphous solids

    Science.gov (United States)

    Hentschel, H. George E.; Ilyin, Valery; Mondal, Chandana; Procaccia, Itamar

    2018-05-01

    Standard approaches to magnetomechanical interactions in thermal magnetic crystalline solids involve Landau functionals in which the lattice anisotropy and the resulting magnetization easy axes are taken explicitly into account. In glassy systems one needs to develop a theory in which the amorphous structure precludes the existence of an easy axis, and in which the constituent particles are free to respond to their local amorphous surroundings and the resulting forces. We present a theory of all the mixed responses of an amorphous solid to mechanical strains and magnetic fields. Atomistic models are proposed in which we test the predictions of magnetostriction for both bulk and nanofilm amorphous samples in the paramagnetic phase. The application to nanofilms with emergent self-affine free interfaces requires a careful definition of the film "width" and its change due to the magnetostriction effect.

  19. Electro-deposition of Pd on carbon paper and Ni foam via surface limited redox-replacement reaction for oxygen reduction reaction

    CSIR Research Space (South Africa)

    Modibedi, RM

    2014-05-01

    Full Text Available Pd nanostructured catalysts were electrodeposited by surface-limited redox replacement reactions usingthe electrochemical atomic layer deposition technique. Carbon paper and Ni foam were used as substratesfor the electrodeposition of the metal...

  20. Using containerless methods to develop amorphous pharmaceuticals.

    Science.gov (United States)

    Weber, J K R; Benmore, C J; Suthar, K J; Tamalonis, A J; Alderman, O L G; Sendelbach, S; Kondev, V; Yarger, J; Rey, C A; Byrn, S R

    2017-01-01

    Many pipeline drugs have low solubility in their crystalline state and require compounding in special dosage forms to increase bioavailability for oral administration. The use of amorphous formulations increases solubility and uptake of active pharmaceutical ingredients. These forms are rapidly gaining commercial importance for both pre-clinical and clinical use. Synthesis of amorphous drugs was performed using an acoustic levitation containerless processing method and spray drying. The structure of the products was investigated using in-situ high energy X-ray diffraction. Selected solvents for processing drugs were investigated using acoustic levitation. The stability of amorphous samples was measured using X-ray diffraction. Samples processed using both spray drying and containerless synthesis were compared. We review methods for making amorphous pharmaceuticals and present data on materials made by containerless processing and spray drying. It was shown that containerless processing using acoustic levitation can be used to make phase-pure forms of drugs that are known to be difficult to amorphize. The stability and structure of the materials was investigated in the context of developing and making clinically useful formulations. Amorphous compounds are emerging as an important component of drug development and for the oral delivery of drugs with low solubility. Containerless techniques can be used to efficiently synthesize small quantities of pure amorphous forms that are potentially useful in pre-clinical trials and for use in the optimization of clinical products. Developing new pharmaceutical products is an essential enterprise to improve patient outcomes. The development and application of amorphous pharmaceuticals to increase absorption is rapidly gaining importance and it provides opportunities for breakthrough research on new drugs. There is an urgent need to solve problems associated with making formulations that are both stable and that provide high

  1. Amorphization Mechanism of Icosahedral Platinum Clusters

    International Nuclear Information System (INIS)

    Apra, Edoardo; Baletto, Francesca; Ferrando, Riccardo; Fortunelli, Alessandro

    2004-01-01

    The amorphization mechanism of high-symmetry pt nanoclusters is investigated by a combination of Molecular Dynamics simulations and Density Functional calculations. A general mechanism for amorphization, involving rosette-like structural transformations at fivefold vertices, is proposed. IN the tosette, a fivefold vertex is transformed into a hexagonal ring. We show that for icosahedral Pt nanoclusters, this transformation is associated with an energy gain, so that their most favorable structures have a low symmetry even at icosahedral magic numbers

  2. Immobilization technology for krypton in amorphous zeolite

    International Nuclear Information System (INIS)

    Takusagawa, Atsushi; Ishiyama, Keiichi

    1989-01-01

    Radioactive krypton recovered from the offgas of a reprocessing plant requires long-term storage on the order of 100 years. Immobilization technology for krypton into amorphous zeolite 5A is considered one of the best methods for long-term storage. In this report, conditions for immobilization treatment and stability of amorphous zeolite 5A loaded krypton against heat, radiation and water are discussed, and a treatment system using this technology is described. (author)

  3. A Magnetic Sensor with Amorphous Wire

    Directory of Open Access Journals (Sweden)

    Dongfeng He

    2014-06-01

    Full Text Available Using a FeCoSiB amorphous wire and a coil wrapped around it, we have developed a sensitive magnetic sensor. When a 5 mm long amorphous wire with the diameter of 0.1 mm was used, the magnetic field noise spectrum of the sensor was about 30 pT/ÖHz above 30 Hz. To show the sensitivity and the spatial resolution, the magnetic field of a thousand Japanese yen was scanned with the magnetic sensor.

  4. Effect of Electrodeposition Potential on Composition of CuIn1−xGaxSe2 Absorber Layer for Solar Cell by One-Step Electrodeposition

    Directory of Open Access Journals (Sweden)

    Rui-Wei You

    2014-01-01

    Full Text Available CIGS polycrystalline thin films were successfully fabricated by one-step cathodic electrodeposition on Mo-coated glass. In this study, we applied a galvanometry mode with three-electrode potentiostatic systems to produce a constant concentration electroplating solution, which were composed of CuCl2, InCl3, GaCl3, and SeO2. Then these as-electrodeposited films were annealed in argon atmosphere and characterized by X-ray diffraction. The results revealed that annealing treatment significantly improved the crystallinity of electrodeposited films and formed CIGS chalcopyrite structure, but at low applied deposition voltage (−950 mV versus SCE there appeared second phase. The cross-section morphology revealed that applied voltage at −1350 mV versus SCE has uniform deposition, and higher applied voltage made grain more unobvious. The deposition rate and current density are proportional to deposition potential, and hydrogen was generated apparently when applying potential beyond −1750 mV versus SCE. It was found that the CIGS compound did not match exact stoichiometry of Cu : In : Ga : Se =1 : x : 1-x : 2. This result suggests the possibility of controlling the property of thin films by varying the applied potential during electrodeposition.

  5. The effect of different component ratios in block polymers and processing conditions on electrodeposition efficiency onto titanium

    Energy Technology Data Exchange (ETDEWEB)

    Fukuhara, Yusuke; Kyuzo, Megumi [Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Tsutsumi, Yusuke [Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan); Nagai, Akiko [Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan); Chen, Peng [Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan); Hanawa, Takao, E-mail: hanawa.met@tmd.ac.jp [Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan)

    2015-11-15

    Graphical abstract: - Highlights: • MPC polymers with an ability of electrodeposition were synthesized. • MPC polymers were immobilized on titanium substrates by electrodeposition. • Immobilization by electrodeposition of MPC polymer decreased water contact angle and protein adsorption. • Length of MPC unit and electrodeposition time did not influence water contact angle and protein adsorption. - Abstract: 2-Methacryloyloxyethyl phosphorylcholine (MPC) polymers for electrodeposition to titanium surfaces were synthesized. The polymers were block-type copolymers composed of a poly(MPC) segment and a poly(2-aminoethylmethacrylate (AEMA)) segment, which could electronically adsorb to a titanium oxide film on the titanium surface. The polymer was synthesized as expected by nuclear magnetic resonance and gel permeation chromatography. In a 0.26 mmol L{sup −1} PMbA solution adjusted to pH 11, −3.0 V (vs. an Ag/AgCl electrode) was applied to a titanium substrate for 300 s. We evaluated the effects of the molecular structure of poly(MPC-block-AEMA) (PMbA) with a different polymerization degree of MPC unit, whereas the polymerization degree of the AEMA units was fixed. The 15-min electrodeposition of PMbA100 was the most efficient condition in this study. On the other hand, the results of the water contact angle and the amount of adsorbed protein did not change, even when altering the MPC unit number and electrodeposition time. This indicates that the immobilization by electrodeposition of PMbA is important for the inhibition of protein adsorption, while the polymerization degree of the MPC unit and the electrodeposition time do not influence them. This study will enhance the understanding of effective polymer structures for electrodeposition and electrodeposition conditions.

  6. Iron oxide nanotubes synthesized via template-based electrodeposition

    Science.gov (United States)

    Lim, Jin-Hee; Min, Seong-Gi; Malkinski, Leszek; Wiley, John B.

    2014-04-01

    Considerable effort has been invested in the development of synthetic methods for the preparation iron oxide nanostructures for applications in nanotechnology. While a variety of structures have been reported, only a few studies have focused on iron oxide nanotubes. Here, we present details on the synthesis and characterization of iron oxide nanotubes along with a proposed mechanism for FeOOH tube formation. The FeOOH nanotubes, fabricated via a template-based electrodeposition method, are found to exhibit a unique inner-surface. Heat treatment of these tubes under oxidizing or reducing atmospheres can produce either hematite (α-Fe2O3) or magnetite (Fe3O4) structures, respectively. Hematite nanotubes are composed of small nanoparticles less than 20 nm in diameter and the magnetization curves and FC-ZFC curves show superparamagnetic properties without the Morin transition. In the case of magnetite nanotubes, which consist of slightly larger nanoparticles, magnetization curves show ferromagnetism with weak coercivity at room temperature, while FC-ZFC curves exhibit the Verwey transition at 125 K.Considerable effort has been invested in the development of synthetic methods for the preparation iron oxide nanostructures for applications in nanotechnology. While a variety of structures have been reported, only a few studies have focused on iron oxide nanotubes. Here, we present details on the synthesis and characterization of iron oxide nanotubes along with a proposed mechanism for FeOOH tube formation. The FeOOH nanotubes, fabricated via a template-based electrodeposition method, are found to exhibit a unique inner-surface. Heat treatment of these tubes under oxidizing or reducing atmospheres can produce either hematite (α-Fe2O3) or magnetite (Fe3O4) structures, respectively. Hematite nanotubes are composed of small nanoparticles less than 20 nm in diameter and the magnetization curves and FC-ZFC curves show superparamagnetic properties without the Morin transition

  7. Cyclic Voltammetric Study of High Speed Silver Electrodeposition and Dissolution in Low Cyanide Solutions

    Directory of Open Access Journals (Sweden)

    Bo Zheng

    2016-01-01

    Full Text Available The electrochemical processes in solutions with a much lower amount of free cyanide (<10 g/L KCN than the conventional alkaline silver electrolytes were first explored by using cyclic voltammetry. The electrochemical behavior and the effect of KAg(CN2, KCN, and KNO3 electrolytes and solution pH on the electrodeposition and dissolution processes were investigated. Moreover, suitable working conditions for high speed, low cyanide silver electrodeposition were also proposed. Both silver and cyanide ions concentration had significant effects on the electrode polarization and deposition rate. The onset potential of silver electrodeposition could be shifted to more positive values by using solutions containing higher silver and lower KCN concentration. Higher silver concentration also led to higher deposition rate. Besides maintaining high conductivity of the solution, KNO3 might help reduce the operating current density required for silver electrodeposition at high silver concentration albeit at the expense of slowing down the electrodeposition rate. The silver dissolution consists of a limiting step and the reaction rate depends on the amount of free cyanide ions. The surface and material characteristics of Ag films deposited by low cyanide solution are also compared with those deposited by conventional high cyanide solution.

  8. Physical and electrochemical properties of ZnO films fabricated from highly cathodic electrodeposition potentials

    Science.gov (United States)

    Ismail, Abdul Hadi; Abdullah, Abdul Halim; Sulaiman, Yusran

    2017-03-01

    The physical and electrochemical properties of zinc oxide (ZnO) film electrode that were prepared electrochemically were studied. ZnO was electrodeposited on ITO glass substrate by applying three different highly cathodic potentials (-1.3 V, -1.5 V, -1.7 V) in a solution containing 70 mM of Zn(NO3)2.xH2O and 0.1 M KCl with bath temperatures of 70 °C and 80 °C. The presence of ZnO was asserted from XRD analysis where the corresponding peaks in the spectra were assigned. SEM images revealed the plate-like hexagonal morphology of ZnO which is in agreement with the XRD analysis. The areal capacitance of the ZnO was observed to increase when the applied electrodeposition potential is increased from -1.3 V to -1.5 V. However, the areal capacitance is found to decrease when the applied electrodeposition potential is further increased to -1.7 V. The resistance of charge transfer (Rct) of the ZnO decreased when the applied electrodeposition potential varies from -1.3 V to -1.7 V due to the decreased particle size of ZnO when more cathodic electrodeposition potential is applied.

  9. Correlation between crystallographic texture, microstructure and magnetic properties of pulse electrodeposited nanocrystalline Nickel–Cobalt alloys

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Amit; Chhangani, Sumit; Madhavan, R.; Suwas, Satyam, E-mail: satyamsuwas@materials.iisc.ernet.in

    2017-07-15

    Highlights: • Nano-crystalline Ni–Co materials with varying composition has been deposited by pulse electrodeposition. • Overall weakening of <1 1 1> texture and strengthening of <2 0 0> fibre texture is observed with increasing cobalt content. • Higher thermal stability of Ni–70Co is interpreted in terms of low mobility twins and texture. • A clear transition from soft to hard magnetic character is observed with an increase cobalt content. - Abstract: This paper reports the evolution of microstructure and texture in Nickel–Cobalt electrodeposits fabricated by pulse electrodeposition (PED) technique and the correlation of these attributes with the magnetic properties. The structural and microstructural investigation using X-ray diffraction and transmission electron microscopic studies indicate the presence of nanocrystalline grains and nano-twins in the electrodeposits. Convoluted Multiple Whole profile fitting reveals an increase in dislocation density and twin density with increasing cobalt content in the as-deposited samples. Strengthening of <1 1 1> fibre texture and weakening of <2 0 0> fibre texture with increasing cobalt concentration has been observed with X-ray texture analysis. A corresponding significant increase in the saturation magnetization and coercivity observed with increasing cobalt content. A significant improvement in the soft magnetic character in the electrodeposits in terms of increase in saturation magnetization and decrease in coercivity has been observed with thermal annealing.

  10. Utilization of electrodeposition for electrothermal atomic absorption spectrometry determination of gold

    International Nuclear Information System (INIS)

    Konecna, Marie; Komarek, Josef

    2007-01-01

    Gold was determined by electrothermal atomic absorption spectrometry after electrochemical preconcentration on the graphite ridge probe used as a working electrode and sample support. The probe surface was electrochemically modified with Pd, Re and the mixture of both. The electrolysis of gold was performed under galvanostatic control at 0.5 mA. Maximum pyrolysis temperature for the probe surface modified with Pd was 1200 deg. C, with Re 1300 deg. C. The relative standard deviation for the determination of 2 μg l -1 Au was not higher than 5.6% (n = 8) for 2 min electrodeposition. The sensitivity of gold determination was reproducible for 300 electrodeposition and atomization cycles. When the probe surface was modified with a mixture of Pd and Re the detection limit was 31 ng l -1 for 2 min electrodeposition, 3.7 ng l -1 for 30 min, 1.5 ng l -1 for 1 h and 0.4 ng l -1 for 4 h electrodeposition, respectively. The procedure was applied to the determination of gold in river water samples. The relative standard deviation for the determination of 2.5 ng l -1 Au at 4 h electrodeposition time at 0.5 mA was 7.5%

  11. Electrodeposited Ni-B coatings: Formation and evaluation of hardness and wear resistance

    International Nuclear Information System (INIS)

    Krishnaveni, K.; Sankara Narayanan, T.S.N.; Seshadri, S.K.

    2006-01-01

    The formation of electrodeposited Ni-B alloy coatings using a dimethylamine borane (DMAB) modified Watt's nickel bath and evaluation of their structural characteristics, hardness and wear resistance are discussed. The boron content in the electrodeposited Ni-B alloy coating is determined by the ratio of rate of reduction of nickel and rate of decomposition of DMAB. The boron content of the electrodeposited Ni-B coating decreases as the current density increased from 0.4 to 4 A dm -2 . XRD diffraction pattern of electrodeposited Ni-B coatings in their as-plated condition exhibits the presence of Ni (1 1 1) (2 0 0) and (2 2 0) reflections with (1 1 1) texture. Heat treatment at 400 deg. C for 1 h has resulted in the formation of nickel boride phases, which results in an increase in hardness and wear resistance. The mechanism of wear in electrodeposited Ni-B coatings is intensive plastic deformation of the coating due to the ploughing action of the hard counter disk

  12. Magnetic signature of granular superconductivity in electrodeposited Pb nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Riminucci, Alberto, E-mail: a.riminucci@bo.ismn.cnr.it [CNR, Institute for Nanostructured Materials, Via Gobetti 101, 40129 Bologna (Italy); H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Schwarzacher, Walther [H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom)

    2014-06-14

    Nanocrystalline freestanding Pb nanowires ∼200 nm in diameter were fabricated by electrodeposition into track etched polycarbonate membranes in order to study their superconducting properties. Their superconducting critical temperature, as determined by measuring the Meissner effect, was the same as for bulk Pb, but their critical field was greatly enhanced up to ∼3000 Oe. By assuming the wires consisted of spherical superconducting grains, an estimated grain size r = 60 ± 25 nm was obtained from the magnetization measured as a function of the applied magnetic field at a fixed temperature. An independent estimate for r = 47 ± 12 nm, in good agreement with the previous one, was obtained from the magnetization measured as a function of temperature at a fixed applied magnetic field. Transmission electron microscopy was used to characterize grain size at the wire edges, where a grain size in agreement with the magnetic studies was observed.

  13. Triboelectric-generator-driven pulse electrodeposition for micropatterning.

    Science.gov (United States)

    Zhu, Guang; Pan, Caofeng; Guo, Wenxi; Chen, Chih-Yen; Zhou, Yusheng; Yu, Ruomeng; Wang, Zhong Lin

    2012-09-12

    By converting ambient energy into electricity, energy harvesting is capable of at least offsetting, or even replacing, the reliance of small portable electronics on traditional power supplies, such as batteries. Here we demonstrate a novel and simple generator with extremely low cost for efficiently harvesting mechanical energy that is typically present in the form of vibrations and random displacements/deformation. Owing to the coupling of contact charging and electrostatic induction, electric generation was achieved with a cycled process of contact and separation between two polymer films. A detailed theory is developed for understanding the proposed mechanism. The instantaneous electric power density reached as high as 31.2 mW/cm(3) at a maximum open circuit voltage of 110 V. Furthermore, the generator was successfully used without electric storage as a direct power source for pulse electrodeposition (PED) of micro/nanocrystalline silver structure. The cathodic current efficiency reached up to 86.6%. Not only does this work present a new type of generator that is featured by simple fabrication, large electric output, excellent robustness, and extremely low cost, but also extends the application of energy-harvesting technology to the field of electrochemistry with further utilizations including, but not limited to, pollutant degradation, corrosion protection, and water splitting.

  14. Electrodeposition of uranium and transuranic metals (Pu) on solid cathode

    International Nuclear Information System (INIS)

    Laplace, A. F.; Lacquement, J.; Willitt, J. L.; Finch, R. A.; Fletcher, G. A.; Williamson, M. A.

    2008-01-01

    The results from a study of U and Pu metal electrodeposition from molten eutectic LiCl-KCl on a solid inert cathode are presented. This study has been conducted using ∼ to 50 g of U-Pu together with rare earths (mostly Nd) and 1.5 kg of salt. The introduction of a three-electrode probe with an Ag/AgCl reference electrode has allowed voltammetric measurement during electrolysis and control of the cathode potential versus the reference. Cyclic and square-wave voltammetric measurements proved to be very useful tools for monitoring the electrolysis as well as selecting the cathode versus reference potential to maximize the separation between actinides and rare earths. The voltammetric data also highlighted the occurrence of back reactions between the cathode deposit and oxidizing equivalents formed at the anode that remained in the molten salt electrolyte. Any further electrolysis test needs to be conducted continuously and followed by immediate removal of the cathode to minimize those back reactions. (authors)

  15. Electrochemical behavior of CIGS electrodeposition for applications to photovoltaic cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyunju; Ji, Changwook; Kim, Yangdo; Hwang, Yoonhwae [Pusan National University, Busan (Korea, Republic of); Lee, Jaeho [Hongik University, Seoul (Korea, Republic of); Jo, Ilguk [Colorado School of Mines, Golden, CO (United States); Kim, Hyoungchan [Korea Institute of Industrial Technology, Busan (Korea, Republic of)

    2014-04-15

    The electrodeposition mechanism of Cu(In,Ga)Se{sub 2} (CIGS) thin films on ITO substrates was examined by using cyclic voltammetry (CV). The CV study was performed in unitary In, binary In-Se, ternary Cu-In-Se, and quaternary Cu-In-Ga-Se systems. CV of the Cu-In-Ga-Se system revealed a reduction peak at -0.6 V with the addition of GaCl{sub 3} and showed that the current density was affected significantly by the concentrations of GaCl{sub 3} and InCl{sub 3}. This is probably due to the adsorption-site competition between In{sup 3+} and Ga{sup 3+} on the electrode surface. Energy dispersive X-ray spectroscopy confirmed the CV results. The composition of Ga in the CIGS films increased with increasing concentration of GaCl{sub 3} in the electrolyte whereas the composition of In decreased sharply. The as-deposited films were annealed at 500 .deg. C in a N{sub 2} atmosphere for crystallization. XRD revealed three major peaks corresponding to the (112), (220) and (312) planes of CIGS chalcopyrite respectively. On the other hand, a secondary phase, such as In{sub 4}Se{sub 3}, was observed in the CIGS films containing a high In composition.

  16. Electrodeposition of hybrid ZnO/organic dye films

    Energy Technology Data Exchange (ETDEWEB)

    Moya, Monica; Mari, Bernabe; Mollar, Miquel [Department de Fisica Aplicada-IDF, Universitat Politecnica de Valencia, Cami de Vera s/n, 46022 Valencia (Spain)

    2011-06-15

    The viability of the electrodeposition as a suitable technique for preparing new porous hybrid materials has been tested in this paper. Hybrid ZnO films with two different organic dyes: Eosin-Y and Tetrasulphonated-Cu-phtalocyanine were prepared. Their physical and chemical properties as well as their dependence on the growth conditions were investigated. It is found that the type of dye has a big influence on the morphology and porosity of hybrid films. Open and connected pores are created in hybrid ZnO/Eosin-Y films while both open and closed pores coexist in hybrid ZnO/Tetrasulfonated-Cu-phthalocyanine. As one of the promising applications of hybrid materials is photovoltaic conversion of sunlight, photoelectrochemical characterization of hybrid films is also reported. Photocurrent generation owing to both contributions ZnO and Eosin-Y is observed in ZnO/Eosin-Y films but no photocurrent has been observed in ZnO/Tetrasulfonated-Cu-phthalocyanine films. SEM micrographs of hybrid ZnO films grown in aqueous bath; (Left) ZnO/Eosin-Y films grown at 70 C, -0.9 V (Right) ZnO/Ts-CuPc films grown at 70 C, -0.9 V. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Surface and electrochemical characterization of electrodeposited PtRu alloys

    Science.gov (United States)

    Richarz, Frank; Wohlmann, Bernd; Vogel, Ulrich; Hoffschulz, Henning; Wandelt, Klaus

    1995-07-01

    PtRu alloys of different compositions were electrodeposited on Au. Twelve alloys between 0% and 100% Pt were characterized with surface sensitive spectroscopies (XPS, LEIS) after transfer from an electrochemical cell to an ultra high vaccum chamber without contact to air. The composition of the thus prepared alloys showed a linear dependence on the concentrations of the deposition solution, but was Pt-enriched both in the bulk and (even more so) at the surface. During the electrochemical reduction of the metal cations, sulfur from the supporting electrolyte 1N H 2SO 4 was found to be incorporated into the electrodes. Cyclic voltammetry was used for the determination of the electrocatalytic activity of the electrodes for the oxidation of carbon monoxide. The highest activity for this oxidation as measured by the (peak) potential of the CO oxidation cyclovoltammograms was found for a surface concentration of ˜ 50%Pt. The asymmetry of this "activity curve" (oxidation potential versus Pt surface concentration) is tentatively explained in terms of a surface structural phase separation.

  18. Kinetics of ethanol electrooxidation at Pd electrodeposited on Ti

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jianping; Ye, Jianqing; Tong, Yexiang [School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Xu, Changwei [School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Department of Chemistry and Institute of Nanochemistry, Jinan University, Guangzhou 510632 (China); Jiang, San Ping [School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2007-09-15

    Pd nanoparticles dispersed well on Ti were successfully prepared by the electrodeposition method used in this study. The results show that Pd has no activity for ethanol oxidation in acid media and is a good electrocatalyst for ethanol oxidation in alkaline media when the OH{sup -} concentration is greater than 0.001 M. The pH and ethanol concentration affects the ethanol oxidation. The reaction orders for OH{sup -} and ethanol are 0.2 and 1. The anodic transfer coefficient ({alpha}) is 0.1. The diffusion coefficient (D) of ethanol is calculated as 9.3 x 10{sup -5} cm{sup 2} s{sup -1} (298 K) when the concentration of KOH and ethanol is both 1.0 M. The overall rate equation for ethanol oxidation on Pd/Ti electrode in alkaline media is given as j=1.4 x 10{sup -4}C{sub KOH}{sup 0.2}C{sub ethanol} exp ((0.28F)/(RT){eta}). (author)

  19. Structural and electrical properties of CZTS thin films by electrodeposition

    Science.gov (United States)

    Rao, M. C.; Basha, Sk. Shahenoor

    2018-06-01

    CZTS (Cu2ZnSnS4) thin films were coated on ITO glass substrates by single bath electrodeposition technique. The prepared films were subsequently characterized by XRD, SEM, FTIR, UV-visible spectroscopy and Raman studies. The thickness of the thin films was measured by wedge method. X-ray diffraction studies revealed the formation of polycrystalline phase. The morphological surface of the prepared thin films was examined by SEM and AFM and showed the presence of microcrystals on the surface of the samples. The elemental analysis and their compositional ratios present in the samples were confirmed by the energy dispersive X-ray analysis. Functional groups and the position of band structure involved in the materials were confirmed by FTIR. Optical absorption studies were performed on the prepared thin films in the wavelength ranging from 300 to 1000 nm and the energy bandgap values were found to be in the range from 1.39 to 1.60 eV. Raman spectral peak which was observed at 360 cm-1 correspond to kesterite phase, was formed due to the vibration of the molecules. Electrical measurements confirmed the nature of the thin film depending on the charge concentration present in the samples.

  20. Electrodeposition and Corrosion Resistance of Ni-Graphene Composite Coatings

    Science.gov (United States)

    Szeptycka, Benigna; Gajewska-Midzialek, Anna; Babul, Tomasz

    2016-08-01

    The research on the graphene application for the electrodeposition of nickel composite coatings was conducted. The study assessed an important role of graphene in an increased corrosion resistance of these coatings. Watts-type nickel plating bath with low concentration of nickel ions, organic addition agents, and graphene as dispersed particles were used for deposition of the composite coatings nickel-graphene. The results of investigations of composite coatings nickel-graphene deposited from the bath containing 0.33, 0.5, and 1 g/dm3 graphene and one surface-active substance were shown. The contents of particles in coatings, the surface morphology, the cross-sectional structures of the coated samples, and their thickness and the internal stresses were studied. Voltammetric method was used for examination of the corrosion resistance of samples of composite coatings in 0.5 M NaCl. The obtained results suggest that the content of incorporated graphene particles increases with an increasing amount of graphene in plating bath. The application of organic compounds was advantageous because it caused compressive stresses in the deposited coatings. All of the nickel-graphene composite layers had better corrosion resistance than the nickel coating.

  1. Electrodeposition of bismuth alloys by the controlled potential method

    International Nuclear Information System (INIS)

    Lopez Alvarez, F.A.

    1993-01-01

    We worked with the electrodeposition of three bismuth alloys, the composition of the first electrolyte was: 0.3 g/l. Bi; 20 g/l. Ni; and the conditions were pH = 5.2 - 5.6; T = 25 Centigrade degrees; current density 0.3 A / dm 2 - 6.6 A / dm 2 . Following alloy was between Bi - Pb, composition of the electrolyte was 3.18 g/l. Bi (metallic); 31.81 g/l. Pb (Pb(NO 3 ) 2 ) pH : 1; T = 20 Centigrade degrees; current density 10.20 A/dm 2 . The third electrolyte was Bi-Cu, its composition was: 20.89 g/l. Bi; (metallic) 63.54 g/l Cu (Cu(NO 3 ) 2 ) pH : 1.5 - 1.8; T = 25-30 Centigrade degrees; current density 1-2 A/dm 2 . The best results were obtained with the third electrolyte. The purpose of this work was to experiment with different parameters like temperature, pH and the electrolyte concentration to obtain a bismuth alloy. (Author)

  2. Effects of the amorphization on hysteresis loops of the amorphous spin-1/2 Ising system

    International Nuclear Information System (INIS)

    Essaoudi, I.; Ainane, A.; Saber, M.; Miguel, J.J. de

    2009-01-01

    We examine the effects of the amorphization on the hysteresis loops of the amorphous spin-1/2 Ising system using the effective field theory within a probability distribution technique that accounts for the self-spin correlation functions. The magnetization, the transverse and longitudinal susceptibilities, and pyromagnetic coefficient are also studied in detail

  3. Ab initio simulation of amorphous silicon

    International Nuclear Information System (INIS)

    Cooper, N.C.; McKenzie, D.R.; Goringe, C.M.

    1999-01-01

    Full text: A first-principles Car-Parrinello molecular dynamics simulation of amorphous silicon is presented. Density Functional Theory is used to describe the forces between the atoms in a 64 atom supercell which is periodically repeated throughout space in order to generate an infinite network of atoms (a good approximation to a real solid). A quench from the liquid phase is used to achieve a quenched amorphous structure, which is subjected to an annealing cycle to improve its stability. The final, annealed network is in better agreement with experiment than any previous simulation of amorphous silicon. Significantly, the predicted average first-coordination numbers of 3.56 and 3.84 for the quenched and annealed structures from this simulation agree very closely with the experimental values of 3.55 and 3.90 respectively, whereas all previous simulations yielded first coordination numbers greater than 4. This improved agreement in coordination numbers is important because it supports the experimental finding that dangling bonds (which are associated with under-coordinated atoms) are more prevalent than floating bonds (the strained, longer bond of a five coordinate atom) in pure amorphous silicon. Finally, the effect of adding hydrogen to amorphous silicon was investigated by specifically placing hydrogen atoms at the likely defect sites. After a structural relaxation to optimise the positions of these hydrogen atoms, the localised electronic states associated with these defects are absent. Thus hydrogen is responsible for removing these defect states (which are able to trap carriers) from the edge of the band gap of the amorphous silicon. These results confirm the widely held ideas about the effect of hydrogen in producing remarkable improvements in the electronic properties of amorphous silicon

  4. Iron-based amorphous alloys and methods of synthesizing iron-based amorphous alloys

    Science.gov (United States)

    Saw, Cheng Kiong; Bauer, William A.; Choi, Jor-Shan; Day, Dan; Farmer, Joseph C.

    2016-05-03

    A method according to one embodiment includes combining an amorphous iron-based alloy and at least one metal selected from a group consisting of molybdenum, chromium, tungsten, boron, gadolinium, nickel phosphorous, yttrium, and alloys thereof to form a mixture, wherein the at least one metal is present in the mixture from about 5 atomic percent (at %) to about 55 at %; and ball milling the mixture at least until an amorphous alloy of the iron-based alloy and the at least one metal is formed. Several amorphous iron-based metal alloys are also presented, including corrosion-resistant amorphous iron-based metal alloys and radiation-shielding amorphous iron-based metal alloys.

  5. Electrodeposition and characterization of Fe–Mo alloys as cathodes for hydrogen evolution in the process of chlorate

    Directory of Open Access Journals (Sweden)

    B. N. GRGUR

    2005-06-01

    Full Text Available Fe–Mo alloys were electrodeposited from a pyrophosphate bath using a single diode rectified AC current. Their composition and morphology were investigated by SEM, optical microscopy and EDS, in order to determine the influence of the deposition conditions on the morphology and composition of these alloys. It was shown that the electrodeposition parameters, such as: chemical bath composition and current density, influenced both the composition of the Fe–Mo alloys and the current efficiency for their deposition, while the micro and macro-morphology did not change significantly with changing conditions of alloy electrodeposition. It was found that the electrodeposited Fe–Mo alloys possessed a 0.15 V to 0.30 V lower overvoltage than mild steel for hydrogen evolution in an electrolyte commonly used in commercial chlorate production, depending on the alloy composition, i.e., the conditions of alloy electrodeposition.

  6. Interpretation of microstructure evolution during self-annealing and thermal annealing of nanocrystalline electrodeposits-A comparative study

    International Nuclear Information System (INIS)

    Pantleon, Karen; Somers, Marcel A.J.

    2010-01-01

    Electrodeposition results in a non-equilibrium state of the as-deposited nanocrystalline microstructure, which evolves towards an energetically more favorable state as a function of time and/or temperature upon deposition. Real-time investigation of the evolving microstructure in copper, silver and nickel electrodeposits was achieved by time-resolved X-ray diffraction line profile analysis and crystallographic texture analysis during room temperature storage and during isothermal annealing at elevated temperatures. These in-situ studies with unique time resolution allowed quantification of the self-annealing kinetics of copper and silver electrodeposits as well as the annealing kinetics of electrodeposited nickel. Similarities and characteristic differences of the kinetics and mechanisms of microstructure evolution in the various electrodeposits are discussed and the experimental results are attempted to be interpreted in terms of recovery, recrystallization and grain growth.

  7. Electrodeposition as an alternate method for preparation of environmental samples for iodide by AMS

    Energy Technology Data Exchange (ETDEWEB)

    Adamic, M.L., E-mail: Mary.Adamic@inl.gov [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83402 (United States); Lister, T.E.; Dufek, E.J.; Jenson, D.D.; Olson, J.E. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83402 (United States); Vockenhuber, C. [Laboratory of Ion Beam Physics, ETH Zurich, Otto-Stern-Weg 5, 8093 Zurich (Switzerland); Watrous, M.G. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83402 (United States)

    2015-10-15

    This paper presents an evaluation of an alternate method for preparing environmental samples for {sup 129}I analysis by accelerator mass spectrometry (AMS) at Idaho National Laboratory. The optimal sample preparation method is characterized by ease of preparation, capability of processing very small quantities of iodide, and ease of loading into a cathode. Electrodeposition of iodide on a silver wire was evaluated using these criteria. This study indicates that the electrochemically-formed silver iodide deposits produce ion currents similar to those from precipitated silver iodide for the same sample mass. Precipitated silver iodide samples are usually mixed with niobium or silver powder prior to loading in a cathode. Using electrodeposition, the silver is already mixed with the sample and can simply be picked up with tweezers, placed in the sample die, and pressed into a cathode. The major advantage of this method is that the silver wire/electrodeposited silver iodide is much easier to load into a cathode.

  8. The Technology and Properties of Digital Double Pulse Electrodepositing Ni-HA Composite Coating of Bioceramics

    Institute of Scientific and Technical Information of China (English)

    DONG He-yan; WANG Zhou; SHI Gu-guizhi; FU Chuan-qi; CHEN Wei-rong; JIN Zhong-hong; LI Yan

    2004-01-01

    This article discusses and analyses the technology, the surface image, microstructure and ability of digital double pulse electrodepositing Ni-HA composite coatings of bioceramics made on 1Crl8Ni9Ti substrate by SEM ,XRD and so on. The results shows that ( 1 ) the HA particles exit in substrate uniformly; (2) XRD result shows that there are HA peaks at 78. 023 ° ,43. 246°and 73. 120°differently; (3) The microhardnees of the composite coatings is increased with the rise of content of HA particles, and on the same conditions the microhardnees value is greater than that of common non-pulse electrodepositing Ni-HA composite coatings of bioceramics. (4) The grain size of digital double pulse electrodepositing Ni-HA composite coatings of bioceramics is much thinner than that of common D. C.

  9. Electrodeposition of milligram amounts of uranium on electropolished stainless steel disks

    International Nuclear Information System (INIS)

    Aggarwal, S.K.; Shah, P.M.; Duggal, R.K.; Jain, H.C.

    1991-01-01

    Investigations have been carried out for the electrodeposition of milligram amounts of uranium on electropolished stainless steel disks with an objective of preparing good quality sources for α-spectrometric studies on uranium. The parameters studied include the vatiation of electrodeposition yield as a function of voltage, time, distance between the cathode and anode, and the volume of 0.2M ammonium oxalate solution. The conditions selected for preparing good quality sources with nearly 100% yield were: electrodeposition voltage 25 V, time of deposition 15 min, volume of 0.2M ammonium oxalate solution in the cell 4 ml and a distance of 2 cm between the cathode and anode. The sources prepared using this method have been used successfully for the α-spectrometric determination of 234 U/ 238 U ratios in uranium samples. (author) 6 refs.; 4 figs

  10. Electrodeposition as an alternate method for preparation of environmental samples for iodide by AMS

    International Nuclear Information System (INIS)

    Adamic, M.L.; Lister, T.E.; Dufek, E.J.; Jenson, D.D.; Olson, J.E.; Vockenhuber, C.; Watrous, M.G.

    2015-01-01

    This paper presents an evaluation of an alternate method for preparing environmental samples for "1"2"9I analysis by accelerator mass spectrometry (AMS) at Idaho National Laboratory. The optimal sample preparation method is characterized by ease of preparation, capability of processing very small quantities of iodide, and ease of loading into a cathode. Electrodeposition of iodide on a silver wire was evaluated using these criteria. This study indicates that the electrochemically-formed silver iodide deposits produce ion currents similar to those from precipitated silver iodide for the same sample mass. Precipitated silver iodide samples are usually mixed with niobium or silver powder prior to loading in a cathode. Using electrodeposition, the silver is already mixed with the sample and can simply be picked up with tweezers, placed in the sample die, and pressed into a cathode. The major advantage of this method is that the silver wire/electrodeposited silver iodide is much easier to load into a cathode.

  11. Studying the initial stages of film electrodeposition of magnetic cobalt-tungsten alloys

    International Nuclear Information System (INIS)

    Rachinskas, V.S.; Orlovskaya, L.V.; Parfenov, V.A.; Yasulajtene, V.V.

    1996-01-01

    Initial stages of magnetic film electrodeposition by recording potentiodynamic polarization and j c ,t-curves, determination of surface structure of electrolytically deposited films by the method of XPS and study of thin coating properties have been considered. It is shown that at initial stage of electrodeposition of magnetic Co-W-films a sharp decrease in cathode process rate and formation of Co(OH) 2 , WO 3 and/or WO 4 2- occur on Cu-cathode surface. Electrodeposition of metallic magnetic Co-W-alloy, consisting of Co, W and containing basic compounds of co-deposited metals, takes place after a certain time period depending on deposition E c . 6 refs.; 3 figs

  12. Liquid Membrane System for Extraction and Electrodeposition of Lead(II During Electrodialysis

    Directory of Open Access Journals (Sweden)

    Sadyrbaeva Tatiana

    2017-05-01

    Full Text Available A novel method for lead(II removal from aqueous acidic solutions is presented. The method involves electrodialysis through bulk liquid membranes accompanied by electrodeposition of metal from the cathodic solution. Solutions of di(2-ethylhexylphosphoric acid with admixtures of tri-n-octylamine in 1,2-dichloroethane were used as the liquid membranes. The effects of the main electrodialysis parameters as well as of the composition of the liquid membranes and aqueous solutions on the lead(II transport rate are studied. The optimal conditions are determined. A possibility of effective single-stage transfer of lead(II through the liquid membrane into dilute solutions of perchloric, nitric and acetic acids is demonstrated. Dense and adherent lead electrodeposits are obtained from perchloric acid solutions. Maximum extraction degree of 93 % and electrodeposition degree of ~60 % are obtained during 5 h of electrodialysis.

  13. Composition control of tin-zinc electrodeposits through means of experimental strategies

    International Nuclear Information System (INIS)

    Dubent, S.; De Petris-Wery, M.; Saurat, M.; Ayedi, H.F.

    2007-01-01

    Tin-zinc coatings offer excellent corrosion protection and do not suffer the drawback of the voluminous white corrosion product of pure zinc or high zinc alloy coatings. The aim of this study was to determine the suitable electroplating conditions (i.e. electrolyte composition and cathode current density) to produce 70Sn-30Zn electrodeposits. Thus, a fractional factorial design (FFD) was carried out to evaluate the effects of experimental parameters (Zn II concentration, Sn IV concentration, pH and current density) on the Zn content of the electrodeposit. On the other hand, the electrodeposits were characterised by glow discharge optical emission spectroscopy (GDOES) and scanning electron microscopy (SEM). Correlation between operating conditions, composition and morphology was attempted

  14. Electrodeposition of Manganese-Nickel Oxide Films on a Graphite Sheet for Electrochemical Capacitor Applications

    Directory of Open Access Journals (Sweden)

    Hae-Min Lee

    2014-01-01

    Full Text Available Manganese-nickel (Mn-Ni oxide films were electrodeposited on a graphite sheet in a bath consisting of manganese acetate and nickel chloride, and the structural, morphological, and electrochemical properties of these films were investigated. The electrodeposited Mn-Ni oxide films had porous structures covered with nanofibers. The X-ray diffractometer pattern revealed the presence of separate manganese oxide (g-MnO2 and nickel oxide (NiO in the films. The electrodeposited Mn-Ni oxide electrode exhibited a specific capacitance of 424 F/g in Na2SO4 electrolyte. This electrode maintained 86% of its initial specific capacitance over 2000 cycles of the charge-discharge operation, showing good cycling stability.

  15. Effects of highly ordered TiO2 nanotube substrates on the nucleation of Cu electrodeposits.

    Science.gov (United States)

    Ryu, Won Hee; Park, Chan Jin; Kwon, Hyuk Sang

    2010-05-01

    We investigated the effects of TiO2 nanotube substrates on the nucleation density of Cu during electrodeposition in a solution of CuSO4 and H2SO4 at 50 degrees C compared with those of pure Ti and micro-porous TiO2 substrates. During electrodeposition, the density of Cu nuclei on the TiO2 nanotube substrate increased and the average size of Cu nuclei decreased with increasing anodizing voltage and time for the synthesis of the substrate. In addition, the nucleation density of Cu electrodeposits on the highly ordered TiO2 nanotube substrate was much higher than that on pure Ti and micro-porous TiO2 substrates.

  16. Use of carriers for to electrodeposited radium 226; Utilizacion de portadores para electrodepositar radio 226

    Energy Technology Data Exchange (ETDEWEB)

    Iturbe, J.L

    1991-10-15

    The form of the energy distribution of a monoenergetic alpha particle starting from some emitting source of these particles, it depends on the quantity of material that its cross before being detected. Some authors deposit to the radium-226 by means of direct evaporation of the solution on metallic supports, on millipore paper and by electrodeposition. Some other ones place the radium solution in scintillation liquid, to quantify it by this technique. The objective of the present work is using carriers with the same oxidation state of the radium, that is to say of 2{sup +}, for treating to be electrodeposited to the radium-226 with the biggest possible percentage for later use the alpha spectroscopy technique to quantify it. The carriers that have been used until its they are barium and zinc in form of barium chloride, zinc nitrate and zinc sulfate. The first results indicate that with the zinc solution a yield of 40% of electrodeposited radium has been reached. (Author)

  17. Stress control in electrodeposited CoFe films—Experimental study and analytical model

    International Nuclear Information System (INIS)

    Brankovic, Stanko R.; Kagajwala, Burhanuddin; George, Jinnie; Majkic, Goran; Stafford, Gery; Ruchhoeft, Paul

    2012-01-01

    Work investigating the effect of saccharin as an additive on growth stress and structure of electrodeposited CoFe films is presented. The saccharin concentrations were in the range between 0 g L −1 and 1.5 g L −1 . The stress measurements are performed in situ during electrodeposition of CoFe films using cantilever-bending method (curvature measurements). The structure of CoFe films was studied by transmission electron microscopy and X-ray diffraction. Results show that growth stress is a decreasing function of saccharin concentration. No appreciable change in composition, grain size, orientation or texture of CoFe films are observed with increasing saccharin content in solution. The growth stress dependence on saccharin concentration is discussed within the framework of analytical model, which directly links the observed stress decrease with the apparent saccharin coverage of the CoFe film surface during the electrodeposition process.

  18. Aluminium Electrodeposition from Ionic Liquid: Effect of Deposition Temperature and Sonication †

    Directory of Open Access Journals (Sweden)

    Enrico Berretti

    2016-08-01

    Full Text Available Since their discovery, ionic liquids (ILs have attracted a wide interest for their potential use as a medium for many chemical processes, in particular electrochemistry. As electrochemical media they allow the electrodeposition of elements that are impossible to reduce in aqueous media. We have investigated the electrodeposition of aluminium from 1-butyl-3-methyl-imidazolium chloride ((BmimCl/AlCl3 (40/60 mol % as concerns the effect of deposition parameters on the quality of the deposits. Thick (20 μm aluminium coatings were electrodeposited on brass substrates at different temperatures and mixing conditions (mechanical stirring and sonication. These coatings were investigated by means of scanning electron microscope, roughness measurements, and X-ray diffraction to assess the morphology and the phase composition. Finally, electrochemical corrosion tests were carried out with the intent to correlate the deposition parameters to the anti-corrosion properties.

  19. The Structure of Liquid and Amorphous Hafnia

    Directory of Open Access Journals (Sweden)

    Leighanne C. Gallington

    2017-11-01

    Full Text Available Understanding the atomic structure of amorphous solids is important in predicting and tuning their macroscopic behavior. Here, we use a combination of high-energy X-ray diffraction, neutron diffraction, and molecular dynamics simulations to benchmark the atomic interactions in the high temperature stable liquid and low-density amorphous solid states of hafnia. The diffraction results reveal an average Hf–O coordination number of ~7 exists in both the liquid and amorphous nanoparticle forms studied. The measured pair distribution functions are compared to those generated from several simulation models in the literature. We have also performed ab initio and classical molecular dynamics simulations that show density has a strong effect on the polyhedral connectivity. The liquid shows a broad distribution of Hf–Hf interactions, while the formation of low-density amorphous nanoclusters can reproduce the sharp split peak in the Hf–Hf partial pair distribution function observed in experiment. The agglomeration of amorphous nanoparticles condensed from the gas phase is associated with the formation of both edge-sharing and corner-sharing HfO6,7 polyhedra resembling that observed in the monoclinic phase.

  20. Amorphous silicon detectors in positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Conti, M. (Istituto Nazionale di Fisica Nucleare, Pisa (Italy) Lawrence Berkeley Lab., CA (USA)); Perez-Mendez, V. (Lawrence Berkeley Lab., CA (USA))

    1989-12-01

    The physics of the detection process is studied and the performances of different Positron Emission Tomography (PET) system are evaluated by theoretical calculation and/or Monte Carlo Simulation (using the EGS code) in this paper, whose table of contents can be summarized as follows: a brief introduction to amorphous silicon detectors and some useful equation is presented; a Tantalum/Amorphous Silicon PET project is studied and the efficiency of the systems is studied by Monte Carlo Simulation; two similar CsI/Amorphous Silicon PET projects are presented and their efficiency and spatial resolution are studied by Monte Carlo Simulation, light yield and time characteristics of the scintillation light are discussed for different scintillators; some experimental result on light yield measurements are presented; a Xenon/Amorphous Silicon PET is presented, the physical mechanism of scintillation in Xenon is explained, a theoretical estimation of total light yield in Xenon and the resulting efficiency is discussed altogether with some consideration of the time resolution of the system; the amorphous silicon integrated electronics is presented, total noise and time resolution are evaluated in each of our applications; the merit parameters {epsilon}{sup 2}{tau}'s are evaluated and compared with other PET systems and conclusions are drawn; and a complete reference list for Xenon scintillation light physics and its applications is presented altogether with the listing of the developed simulation programs.

  1. Amorphous silicon detectors in positron emission tomography

    International Nuclear Information System (INIS)

    Conti, M.; Perez-Mendez, V.

    1989-12-01

    The physics of the detection process is studied and the performances of different Positron Emission Tomography (PET) system are evaluated by theoretical calculation and/or Monte Carlo Simulation (using the EGS code) in this paper, whose table of contents can be summarized as follows: a brief introduction to amorphous silicon detectors and some useful equation is presented; a Tantalum/Amorphous Silicon PET project is studied and the efficiency of the systems is studied by Monte Carlo Simulation; two similar CsI/Amorphous Silicon PET projects are presented and their efficiency and spatial resolution are studied by Monte Carlo Simulation, light yield and time characteristics of the scintillation light are discussed for different scintillators; some experimental result on light yield measurements are presented; a Xenon/Amorphous Silicon PET is presented, the physical mechanism of scintillation in Xenon is explained, a theoretical estimation of total light yield in Xenon and the resulting efficiency is discussed altogether with some consideration of the time resolution of the system; the amorphous silicon integrated electronics is presented, total noise and time resolution are evaluated in each of our applications; the merit parameters ε 2 τ's are evaluated and compared with other PET systems and conclusions are drawn; and a complete reference list for Xenon scintillation light physics and its applications is presented altogether with the listing of the developed simulation programs

  2. Amorphous Diamond MEMS and Sensors

    Energy Technology Data Exchange (ETDEWEB)

    SULLIVAN, JOHN P.; FRIEDMANN, THOMAS A.; ASHBY, CAROL I.; DE BOER, MAARTEN P.; SCHUBERT, W. KENT; SHUL, RANDY J.; HOHLFELDER, ROBERT J.; LAVAN, D.A.

    2002-06-01

    This report describes a new microsystems technology for the creation of microsensors and microelectromechanical systems (MEMS) using stress-free amorphous diamond (aD) films. Stress-free aD is a new material that has mechanical properties close to that of crystalline diamond, and the material is particularly promising for the development of high sensitivity microsensors and rugged and reliable MEMS. Some of the unique properties of aD include the ability to easily tailor film stress from compressive to slightly tensile, hardness and stiffness 80-90% that of crystalline diamond, very high wear resistance, a hydrophobic surface, extreme chemical inertness, chemical compatibility with silicon, controllable electrical conductivity from insulating to conducting, and biocompatibility. A variety of MEMS structures were fabricated from this material and evaluated. These structures included electrostatically-actuated comb drives, micro-tensile test structures, singly- and doubly-clamped beams, and friction and wear test structures. It was found that surface micromachined MEMS could be fabricated in this material easily and that the hydrophobic surface of the film enabled the release of structures without the need for special drying procedures or the use of applied hydrophobic coatings. Measurements using these structures revealed that aD has a Young's modulus of {approx}650 GPa, a tensile fracture strength of 8 GPa, and a fracture toughness of 8 MPa{center_dot}m {sup 1/2}. These results suggest that this material may be suitable in applications where stiction or wear is an issue. Flexural plate wave (FPW) microsensors were also fabricated from aD. These devices use membranes of aD as thin as {approx}100 nm. The performance of the aD FPW sensors was evaluated for the detection of volatile organic compounds using ethyl cellulose as the sensor coating. For comparable membrane thicknesses, the aD sensors showed better performance than silicon nitride based sensors. Greater

  3. Microstructure and tribological property of nanocrystalline Co–W alloy coating produced by dual-pulse electrodeposition

    International Nuclear Information System (INIS)

    Su Fenghua; Huang Ping

    2012-01-01

    Highlights: ► The nanocrystalline Co–W alloy coating were produced by dual-pulse electrodeposition from aqueous bath with cobalt sulfate and sodium tungstate. ► The correlation between the electrodeposition condition, the microstructure and alloy composition, and the hardness and tribological properties of electrodeposited Co–W alloy coatings were established. ► By careful control of the electrodeposition condition and the bath composition, the Co–W alloy coating excellent performance of microhardness and tribological properties, can exhibit excellent performances of microhardness and tribological properties. - Abstract: The nanocrystalline Co–W alloy coatings were produced by dual-pulse electrodeposition from aqueous bath with cobalt sulfate and sodium tungstate (Na 2 WO 4 ). Influence of the current density and Na 2 WO 4 concentration in bath on the microstructure, morphology and hardness of the Co–W alloy coatings were investigated using an X-ray diffraction, a scanning electronic microscope and a Vickers hardness tester, respectively. In addition, the friction and wear properties of the Co–W alloy coating electrodeposited under different condition were evaluated with a ball-on-disk UMT-3MT tribometer. The correlation between the electrodeposition condition, the microstructure and alloy composition, and the hardness and tribological properties of the deposited Co–W alloy coatings were discussed in detail. The results showed that the microhardness of the deposited Co–W alloy coating was significantly affected by its average grain size, W content and crystal orientation. Smaller grain size, higher W content and strong hcp (1 0 0) orientation favor the improvement of the hardness for Co–W alloy coatings. The deposited Co–W alloy coating could obtain the maximum microhardness over 1000 kgf mm −2 by careful control of the electrodeposition conditions. The tribological properties of the electrodeposited Co–W alloy coating were greatly

  4. Microstructure and corrosion behavior of electrodeposited nano-crystalline nickel coating on AZ91 Mg alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zarebidaki, Arman, E-mail: arman.zare@iauyazd.ac.ir; Mahmoudikohani, Hassan, E-mail: hassanmahmoudi.k@gmail.com; Aboutalebi, Mohammad-Reza

    2014-12-05

    Highlights: • Activation, zincating, and Cu electrodeposition were used as pretreatment processes for electrodeposition of nickel coatings. • Nano-crystalline nickel coatings were successfully electrodeposited onto the AZ91 Mg alloys. • Effect of nickel electrodeposited coating on the corrosion resistance of AZ91 Mg alloy has been studied. - Abstract: In order to enhance the corrosion resistance, nickel coating was electrodeposited onto AZ91 Mg alloy. Activation, zincating, and Cu electrodeposition used as pretreatment processes for better adhesion and corrosion performance of the nickel over layer. The corrosion properties of the AZ91 Mg alloy, nickel electroplated AZ91 Mg alloy, and pure nickel was assessed via polarization and electrochemical impedance spectroscopy (EIS) methods in 3.5 wt% NaCl solution. Moreover, the structure of the coating was investigated by means of X-ray diffraction, whereas specimen’s morphology and elemental composition were analyzed using scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS). Measurements revealed that the coating has a nano-crystalline structure with the grain size of 95 nm. Corrosion results showed superior corrosion resistance for the coated AZ91 Mg alloy as the corrosion current density decreased from 2.5 × 10{sup −4} A cm{sup −2}, for the uncoated sample, to 1.5 × 10{sup −5} A cm{sup −2}, for coated specimen and the corrosion potential increased from −1.55 V to −0.98 V (vs. Ag/AgCl) at the same condition.

  5. Evolution of the microstructure in nanocrystalline copper electrodeposits during room temperature storage

    DEFF Research Database (Denmark)

    Pantleon, Karen; Somers, Marcel A. J.

    2007-01-01

    The microstructure evolution in copper electrodeposits at room temperature (self-annealing) was investigated by means of X-ray diffraction analysis and simultaneous measurement of the electrical resistivity as a function of time. In-situ studies were started immediately after electrodeposition......, crystallographic texture changes by multiple twinning and a decrease of the electrical resistivity occurred as a function of time at room temperature. The kinetics of self-annealing is strongly affected by the layer thickness: the thinner the layer the slower is the microstructure evolution and self-annealing...

  6. Near boundary acoustic streaming in Ni-Fe alloy electrodeposition control

    DEFF Research Database (Denmark)

    Pocwiardowski, Pawel; Lasota, H.; Ravn, Christian

    2005-01-01

    Alloy electrodeposition is strongly influenced by diffusion layer phenomena affecting the ion concentration distribution in a different way for each component. This paper presents the method of acoustic agitation leading to controlled uniform electrodeposition of alloys. The method consists...... in generating acoustic flow perpendicular to the surface in the field of an acoustic standing wave parallel to the plated substrate - so called modified Rayleigh streaming. The result showed that the near boundary streaming offers controlled mass transportation in the micrometer thick layer close to the cathode...

  7. Electrodeposition of near stoichiometric CuInSe2 thin films for photovoltaic applications

    Science.gov (United States)

    Chandran, Ramkumar; Mallik, Archana

    2018-03-01

    This work investigates on the single step electrodeposition of quality CuInSe2 (CIS) thin film absorber layer for photovoltaics applications. The electrodeposition was carried using an aqueous acidic solution with a pH of 2.25. The deposition was carried using a three electrode system in potentiostatic conditions for 50 minutes. The as-deposited and nitrogen (N2) annealed films were characterized using XRD, FE-SEM and Raman spectroscopy. It has been observed that the SDS has the tendency to suppress the copper selenide (CuxSe) secondary phase which is detrimental to the device performance.

  8. Controllable growth and magnetic properties of nickel nanoclusters electrodeposited on the ZnO nanorod template

    International Nuclear Information System (INIS)

    Tang Yang; Zhao Dongxu; Shen Dezhen; Zhang Jiying; Wang Xiaohua

    2009-01-01

    The ZnO nanorods were used as a template to fabricate nickel nanoclusters by electrodeposition. The ZnO nanorod arrays act as a nano-semiconductor electrode for depositing metallic and magnetic nickel nanoclusters. The growth sites of Ni nanoclusters could be controlled by adjusting the applied potential. Under -1.15 V the Ni nanoclusters could be grown on the tips of ZnO nanorods. On increasing the potential to be more negative the ZnO nanorods were covered by Ni nanoclusters. The magnetic properties of the electrodeposited Ni nanoclusters also evolved with the applied potentials.

  9. Controllable growth and magnetic properties of nickel nanoclusters electrodeposited on the ZnO nanorod template

    Energy Technology Data Exchange (ETDEWEB)

    Tang Yang; Zhao Dongxu; Shen Dezhen; Zhang Jiying [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 16 East Nan-Hu Road, Open Economic Zone, Changchun 130033 (China); Wang Xiaohua, E-mail: dxzhao2000@yahoo.com.c [National Key Laboratory of High Power Semiconductor Laser, Changchun University of Science and Technology, 7089 WeiXing Road, ChangChun 130022 (China)

    2009-12-09

    The ZnO nanorods were used as a template to fabricate nickel nanoclusters by electrodeposition. The ZnO nanorod arrays act as a nano-semiconductor electrode for depositing metallic and magnetic nickel nanoclusters. The growth sites of Ni nanoclusters could be controlled by adjusting the applied potential. Under -1.15 V the Ni nanoclusters could be grown on the tips of ZnO nanorods. On increasing the potential to be more negative the ZnO nanorods were covered by Ni nanoclusters. The magnetic properties of the electrodeposited Ni nanoclusters also evolved with the applied potentials.

  10. Depth profile analysis of electrodeposited nanoscale multilayers by Secondary Neutral Mass Spectrometry (SNMS)

    International Nuclear Information System (INIS)

    Katona, G.L.; Berenyi, Z.; Vad, K.; Peter, L.

    2006-01-01

    Complete text of publication follows. Nanoscale multilayers have been in the focus of research since the discovery of the giant magnetoresistance (GMR) effect in this family of nanostructures. The first observation of GMR on sputtered magnetic/non-magnetic multilayers was followed by the detection of the same effect in electrodeposited Co-Ni-Cu/Cu multilayers within half a decade. Electrodeposition has long been considered as an inexpensive alternative of the high-vacuum methods to produce multilayers with GMR, although the GMR effect observed for electrodeposited multilayers is usually inferior to multilayers produced by physical methods. Electrochemistry appears to be an exclusive technology to produce multilayered nanowires by using porous templates. In spite of the large number of papers about the multilayers themselves, data on the depth profile of electrodeposited multilayer samples are very scarce. It has long been known that the simultaneous electrodeposition of the iron group metals takes place in the so-called anomalous manner. The diagnostic criterion of the anomalous codeposition is that the metallic component of lower standard potential (the Co in the case of Ni/Co) can be discharged together with the more noble one (Ni) at potentials where the less noble component (Co) alone cannot be deposited onto a substrate composed of the parent metal; moreover, the less noble metal (Co) is deposited preferentially. We have investigated the composition gradient along the growth direction of electrodeposited Co/Cu and CoNiCu/Cu multilayers films using SNMS. Samples were electrodeposited using the single bath method. Commercial Cu sheets and an Cr/Cu layer evaporated onto Si (111) surface were used as substrates with high and low roughness, respectively. The depth profiles of the samples were recorded using SNMS (INA-X, Specs GmbH, Berlin) in the Direct Bombardment Mode. Depth profile analysis of electrodeposited magnetic/nonmagnetic layered structures on

  11. Effect of mass density on surface morphology of electrodeposited manganese oxide films

    Science.gov (United States)

    Singh, Avtar; Kumar, Davinder; Thakur, Anup; Kaur, Raminder

    2018-05-01

    This work focus on high surface area morphology of manganese oxide films which are currently required for electrochemical capacitor electrode to enhance their performance. Electrodeposition of manganese oxide films was carried out using Chronoamperometry for different deposition time ranging from 30 to 120 sec. Cronoamperomertic I-T integrated data have been used to analyze active mass of all electrodeposited films. Morphological study of the deposited films with different mass was carried out through scanning electron microscopy. Film deposited for 30 sec time show highest porous morphology than others. Manganese oxide films with high porosity are suitable for electrochemical capacitor electrode.

  12. Mechanisms of Current Transfer in Electrodeposited Layers of Submicron Semiconductor Particles

    Science.gov (United States)

    Zhukov, N. D.; Mosiyash, D. S.; Sinev, I. V.; Khazanov, A. A.; Smirnov, A. V.; Lapshin, I. V.

    2017-12-01

    Current-voltage ( I- V) characteristics of conductance in multigrain layers of submicron particles of silicon, gallium arsenide, indium arsenide, and indium antimonide have been studied. Nanoparticles of all semiconductors were obtained by processing initial single crystals in a ball mill and applied after sedimentation onto substrates by means of electrodeposition. Detailed analysis of the I- V curves of electrodeposited layers shows that their behavior is determined by the mechanism of intergranular tunneling emission from near-surface electron states of submicron particles. Parameters of this emission process have been determined. The proposed multigrain semiconductor structures can be used in gas sensors, optical detectors, IR imagers, etc.

  13. Surface crack nucleation and propagation in electrodeposited nanocrystalline Ni-P alloy during high cycle fatigue

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Shigeaki; Kamata, Akiyuki [Department of Mechanical Engineering, Faculty of Engineering, Ashikaga Institute of Technology, 268-1 Omae, Ashikaga, Tochigi 326-8558 (Japan); Watanabe, Tadao, E-mail: skoba@ashitech.ac.j [Key Laboratory for Anisotropy and Texture of Materials, Northeastern University, Shenyang, 110004 (China)

    2010-07-01

    The morphology of specimen surface after fatigue fracture was evaluated in connection with grain orientation distribution and grain boundary microstructure to reveal a mechanism of fatigue fracture in nanocrystalline materials. The electrodeposited and sharply {l_brace}001{r_brace} textured Ni -2.0 mass% P alloy with the average grain size of ca. 45 nm and high fractions of low-angle and {Sigma}3 boundaries showed 2 times higher fatigue limit than electrodeposited microcrystalline Ni polycrystal. The surface features of fatigued specimen were classified into two different types of morphologies characterized as brittle fracture at the central area and as ductile fracture at the surrounding area.

  14. Electrodeposition of lead on ITO electrode: influence of copper as an additive

    International Nuclear Information System (INIS)

    Avellaneda, Cesar O.; Napolitano, Marcos A.; Kaibara, Evandro K.; Bulhoes, Luis O.S.

    2005-01-01

    The reversible electrodeposition of metallic lead onto indium-tin oxide coated glass (ITO) was investigated and the influence of Cu(NO 3 ) 2 ·3H 2 O as additive was evaluated. The presence of Cu 2+ in the electrolytic solution produces a higher variation in the optical transmissivity. The optical response of the system changes from 85 to 10% relative to the ITO coated substrate. The kinetics of the electroreduction process of the Pb 2+ and Cu 2+ from the electrolytes has been determined by electrochemical impedance spectroscopy (EIS) at different electrodeposition potentials. This system may be a promising candidate for electrochromic materials

  15. Characterisation of electrodeposited polycrystalline uranium dioxide thin films on nickel foil for industrial applications

    International Nuclear Information System (INIS)

    Adamska, A.M.; Bright, E. Lawrence; Sutcliffe, J.; Liu, W.; Payton, O.D.; Picco, L.; Scott, T.B.

    2015-01-01

    Polycrystalline uranium dioxide thin films were grown on nickel substrates via aqueous electrodeposition of a precursor uranyl salt. The arising semiconducting uranium dioxide thin films exhibited a tower-like morphology, which may be suitable for future application in 3D solar cell applications. The thickness of the homogenous, tower-like films reached 350 nm. Longer deposition times led to the formation of thicker (up to 1.5 μm) and highly porous films. - Highlights: • Electrodeposition of polycrystalline UO_2 thin films • Tower-like morphology for 3D solar cell applications • Novel technique for separation of heavy elements from radioactive waste streams

  16. Fabrication and application of amorphous semiconductor devices

    International Nuclear Information System (INIS)

    Kumurdjian, Pierre.

    1976-01-01

    This invention concerns the design and manufacture of elecric switching or memorisation components with amorphous semiconductors. As is known some compounds, particularly the chalcogenides, have a resistivity of the semiconductor type in the amorphous solid state. These materials are obtained by the high temperature homogeneisation of several single elements such as tellurium, arsenic, germanium and sulphur, followed by water or air quenching. In particular these compounds have useful switching and memorisation properties. In particular they have the characteristic of not suffering deterioration when placed in an environment subjected to nuclear radiations. In order to know more about the nature and properties of these amorphous semiconductors the French patent No. 71 28048 of 30 June 1971 may be consulted with advantage [fr

  17. Relaxation processes during amorphous metal alloys heating

    International Nuclear Information System (INIS)

    Malinochka, E.Ya.; Durachenko, A.M.; Borisov, V.T.

    1982-01-01

    Behaviour of Te+15 at.%Ge and Fe+13 at.%P+7 at.%C amorphous metal alloys during heating has been studied using the method of differential scanning calorimetry (DSC) as the most convenient one for determination of the value of heat effects, activation energies, temperature ranges of relaxation processes. Thermal effects corresponding to high-temperature relaxation processes taking place during amorphous metal alloys (AMA) heating are detected. The change of ratio of relaxation peaks values on DSC curves as a result of AMA heat treatment can be explained by the presence of a number of levels of inner energy in amorphous system, separated with potential barriers, the heights of which correspond to certain activation energies of relaxation processes

  18. Heavy ions amorphous semiconductors irradiation study

    International Nuclear Information System (INIS)

    Benmalek, M.

    1978-01-01

    The behavior of amorphous semiconductors (germanium and germanium and arsenic tellurides) under ion bombardment at energies up to 2 MeV was studied. The irradiation induced modifications were followed using electrical parameter changes (resistivity and activation energy) and by means of the transmission electron microscopy observations. The electrical conductivity enhancement of the irradiated samples was interpreted using the late conduction theories in amorphous compounds. In amorphous germanium, Electron Microscopy showed the formations of 'globules', these defects are similar to voids observed in irradiated metals. The displacement cascade theory was used for the interpretation of the irradiation induced defects formation and a coalescence mechanism of growth was pointed out for the vacancy agglomeration [fr

  19. Formation of amorphous layers by irradiation

    International Nuclear Information System (INIS)

    Bourgoin, J.C.

    1979-01-01

    When an ordered solid is irradiated with heavy energy particles, disorder is produced. When the irradiation dose exceeds a so-called critical dose, the irradiated area of the solid becomes uniformly disordered. Mention is first made of the nature, concentration and distribution of the defects created by a heavy energy particle. The description is then given -solely with respect to semiconductors- of the effect of the various parameters on the critical dose energy and nature of the ion, nature and temperature of the solid, irradiation flux. The physical properties (electronic and thermodynamic types) and the uniformly disordered areas are briefly discussed and these properties are compared with those of amorphous semiconductor layers fabricated by evaporation. It is concluded that the evaporated and irradiated layers are similar in nature. It is suggested that the transformation of an irradiated crystalline area into an amorphous one occurs when the Gibbs energy of the crystal become greater than the Gibbs energy of the amorphous one [fr

  20. Analysis of an ideal amorphous solid

    International Nuclear Information System (INIS)

    To, L.T.; Stachurski, Z.H.

    2004-01-01

    Full text: In geometrical terms, amorphous solids are fundamentally different from crystalline solids in that they can not be constructed by the crystallographic method of translation of the basis along a lattice. Therefore, to study amorphous structures we must invoke concepts and use measures different to those used for ordered structures. Nevertheless, an ideal amorphous solid must share together with the ideal crystalline solid in the same definition of the term 'ideal'. In both cases it must be a perfect body, in which perfection is carried through in every detail to an unlimited (infinite) size without fault or defect. The latest results on this research will be presented. To qualify for a solid, rigid body, close packing of the spheres is required. For an ideal amorphous solids composed of hard spheres of identical size, we impose a stricter condition for the packing, namely, to be such that all spheres are in fixed positions (no loose spheres). To define the ideal solid, we must define what we mean by a perfect amorphous structure. Here, perfection is defined by, first the definition of imperfections, and next by the requirement of absence of imperfections of any kind. We envisage two types of defects: (i) geometrical, and (ii) statistical. Geometrical defects are: a sphere of different size, a loose sphere, and a vacancy. A statistical defect is defined with respect to two statistical functions: Ψ(N C ), and Φ(S β ). The former describes the probability of a given sphere having nc number of touching contacts, and the latter describes the disposition of the contacts on the surface of the sphere. Defects relating to the two functions will be described. The results for the functions, Ψ(N C ), and Φ(S β ), for the corresponding radial distribution function, and so called blocking number will be presented from simulations of an ideal amorphous solid

  1. Definition and properties of ideal amorphous structures

    International Nuclear Information System (INIS)

    Stachurski, Z.H.

    2002-01-01

    Full text: Amorphous structure is usually defined by what it is not (ie, no crystalline peaks in XRS, no bond correlation in NMR), rather than by what it is. The interest in defining the structure of non-crystalline materials is long standing; packing geometry of spheres, molecular structure of glassy SiO 2 , or the structure of atactic polymers are prime examples. The earliest definitions of amorphous structure were in terms of a microcrystallite model of Valenkov, or continuous random network by Zachariasen. The random close packing of spheres of equal size, and an amorphous structure, composed of freely jointed linear chains of hard spheres, has been described mathematically in terms of a linear homogeneous Poisson process. This paper aims to describe some geometrical, kinematic, and topological properties of these two ideal amorphous structures, which belong to the same amorphous class. The geometry of packing is elucidated, and the use of Voronoi tessellation method for measuring the structures is described. The ideal amorphous solid has no symmetry elements; its volume can not be divided into identical unit cells. However, there is a volume element small enough to allow the distinction of its nanoscopic inhomogeneities, and sufficiently large enough to represent, accurately the overall behaviour. We define this volume element, the representative volume element. Suitable boundary conditions must be prescribed for a choice of RVE, and satisfy certain requirements. Topologically, a catchment region on the Born-Oppenheimer potential energy surface over nuclear configuration space, is defined by Mezey and Bader as an energetically stable geometry of the open region of R 3 traversed by all the trajectories which terminate at a local maximum. Two topological properties will be described: (i) the boundaries of the catchment region as a direct geometrical correspondence to the Voronoi polyhedron for a given atom in a given structure, and (ii) the constriction points

  2. Microstructure and properties of manganese dioxide films prepared by electrodeposition

    International Nuclear Information System (INIS)

    Jacob, G. Moses; Zhitomirsky, I.

    2008-01-01

    Nanostructured manganese dioxide films were obtained by galvanostatic, pulse and reverse pulse electrodeposition from 0.01 to 0.1 M KMnO 4 solutions. The deposition yield was investigated by in situ monitoring the deposit mass using a quartz crystal microbalance (QCM). Obtained films were studied by electron microscopy, X-ray diffraction analysis, energy dispersive spectroscopy, thermogravimetric and differential thermal analysis. The QCM and electron microscopy data were utilized for the investigation of deposition kinetics and film formation mechanism. It was shown that the deposition rate and film microstructure could be changed by variation of deposition conditions. The method allowed the fabrication of dense or porous films. The thickness of dense films was limited to ∼0.1 μm due to the insulating properties of manganese dioxide and film cracking, attributed to drying shrinkage. Porous and crack-free 1-2 μm films were obtained using galvanostatic or reverse pulse deposition from 0.02 M KMnO 4 solutions. It was shown that film porosity is beneficial for the charge transfer during deposition and crack prevention in thick films. Moreover, porous nanostructured films showed good capacitive behavior for applications in electrochemical supercapacitors. The porous nanostructured films prepared in the reverse pulse regime showed higher specific capacitance (SC) compared to the SC of the galvanostatic films. The highest SC of 279 F/g in a voltage window of 1 V was obtained in 0.1 M Na 2 SO 4 solutions at a scan rate of 2 mV/s

  3. Amorphous ice. A microporous solid: astrophysical implications

    International Nuclear Information System (INIS)

    Mayer, E.; Pletzer, R.

    1987-01-01

    Vapour deposited amorphous ice, investigated by N 2 -adsorption at 77 K, was found to be a microporous solid. Micropore volumes between 0.21 and 0.12 cm 3 /g were determined by comparison plots and Dubinin-Radushkevich plots. Warming of the adsorbent to 113 K caused sintering and reduction of apparent surface area by about an order of magnitude; in the presence of adsorbed gas, large amounts of gas were enclosed in the solid. The influence of micropores on the H 2 recombination rate on amorphous ice in interstellar dust and on adsorption of volatile gases in comets is discussed briefly

  4. Amorphous Alloy: Promising Precursor to Form Nanoflowerpot

    Directory of Open Access Journals (Sweden)

    Guo Lan

    2014-01-01

    Full Text Available Nanoporous copper is fabricated by dealloying the amorphous Ti2Cu alloy in 0.03 M HF electrolyte. The pore and ligament sizes of the nanoporous copper can be readily tailored by controlling the dealloying time. The as-prepared nanoporous copper provides fine and uniform nanoflowerpots to grow highly dispersed Au nanoflowers. The blooming Au nanoflowers in the nanoporous copper flowerpots exhibit both high catalytic activity and stability towards the oxidation of glucose, indicating that the amorphous alloys are ideal precursors to form nanoflowerpot which can grow functional nanoflowers.

  5. Short range order in amorphous polycondensates

    Energy Technology Data Exchange (ETDEWEB)

    Lamers, C.; Richter, D.; Schweika, W. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Festkoerperforschung; Batoulis, J.; Sommer, K. [Bayer AG, Leverkusen (Germany); Cable, J.W. [Oak Ridge National Lab., TN (United States); Shapiro, S.M. [Brookhaven National Lab., Upton, NY (United States)

    1992-12-01

    The static coherent structure factors S(Q) of the polymer glass Bisphenol-A-Polycarbonate and its chemical variation Bisphenol-A- Polyctherkctone- both in differently deuterated versions- have been measured by spin polarized neutron scattering. The method of spin polarization analysis provided an experimental separation of coherent and incoherent scattering and a reliable intensity calibration. Results are compared to structure factors calculated for model structures which were obtained by ``amorphous cell`` computer simulations. In general reasonable agreement is found between experiment and simulation; however, certain discrepancies hint at an insufficient structural relaxation in the amorphous cell method. 15 refs, 1 fig, 1 tab.

  6. Phonon excitations in multicomponent amorphous solids

    International Nuclear Information System (INIS)

    Vakarchuk, I.A.; Migal', V.M.; Tkachuk, V.M.

    1988-01-01

    The method of two-time temperature-dependent Green's functions is used to investigate phonon excitations in multicomponent amorphous solids. The equation obtained for the energy spectrum of the phonon excitations takes into account the damping associated with scattering of phonons by structure fluctuations. The quasicrystal approximation is considered, and as an example explicit expressions are obtained for the case of a two-component amorphous solid for the frequencies of the acoustical and optical modes and for the longitudinal and transverse velocities of sound. The damping is investigated

  7. Paramagnetic defects in hydrogenated amorphous carbon powders

    International Nuclear Information System (INIS)

    Keeble, D J; Robb, K M; Smith, G M; Mkami, H El; Rodil, S E; Robertson, J

    2003-01-01

    Hydrogenated amorphous carbon materials typically contain high concentrations of paramagnetic defects, the density of which can be quantified by electron paramagnetic resonance (EPR). In this work EPR measurements near 9.5, 94, and 189 GHz have been performed on polymeric and diamond-like hydrogenated amorphous carbon (a-C:H) powder samples. A similar single resonance line was observed at all frequencies for the two forms of a-C:H studied. No contributions to the spectrum from centres with resolved anisotropic g-values as reported earlier were detected. An increase in linewidth with microwave frequency was observed. Possible contributions to this frequency dependence are discussed

  8. Porosity and mechanical properties of amorphous alloys

    International Nuclear Information System (INIS)

    Betekhtin, V.I.; Kadomtsev, A.G.; Amosova, O.V.

    2003-01-01

    The obtained experimental data on the effect of the inherent submicroporosity and its change under impact of high hydrostatic pressure or annealing on the strength, microdestruction, embrittlement temperature, the first crystallization stage and peculiarities of the surface crystallization of the amorphous alloys are analyzed. The conclusion is made on the basis of the studies on the peculiarities of the voluminous and surface crystallization of the Fe 56 Co 24 Si 5 B 15 , Fe 78 Ni 2 Si 8 B 12 , Fe 85 B 15 , Fe 58 Ni 20 Si 9 B 13 amorphous alloys that the increase in the inherent submicroporosity is one of the essential factors facilitating crystallization [ru

  9. Amorphous Phase Mediated Crystallization: Fundamentals of Biomineralization

    Directory of Open Access Journals (Sweden)

    Wenjing Jin

    2018-01-01

    Full Text Available Many biomineralization systems start from transient amorphous precursor phases, but the exact crystallization pathways and mechanisms remain largely unknown. The study of a well-defined biomimetic crystallization system is key for elucidating the possible mechanisms of biomineralization and monitoring the detailed crystallization pathways. In this review, we focus on amorphous phase mediated crystallization (APMC pathways and their crystallization mechanisms in bio- and biomimetic-mineralization systems. The fundamental questions of biomineralization as well as the advantages and limitations of biomimetic model systems are discussed. This review could provide a full landscape of APMC systems for biomineralization and inspire new experiments aimed at some unresolved issues for understanding biomineralization.

  10. Ion bombardment and disorder in amorphous silicon

    International Nuclear Information System (INIS)

    Sidhu, L.S.; Gaspari, F.; Zukotynski, S.

    1997-01-01

    The effect of ion bombardment during growth on the structural and optical properties of amorphous silicon are presented. Two series of films were deposited under electrically grounded and positively biased substrate conditions. The biased samples displayed lower growth rates and increased hydrogen content relative to grounded counterparts. The film structure was examined using Raman spectroscopy. The transverse optic like phonon band position was used as a parameter to characterize network order. Biased samples displayed an increased order of the amorphous network relative to grounded samples. Furthermore, biased samples exhibited a larger optical gap. These results are correlated and attributed to reduced ion bombardment effects

  11. Thermal conductivity of sputtered amorphous Ge films

    International Nuclear Information System (INIS)

    Zhan, Tianzhuo; Xu, Yibin; Goto, Masahiro; Tanaka, Yoshihisa; Kato, Ryozo; Sasaki, Michiko; Kagawa, Yutaka

    2014-01-01

    We measured the thermal conductivity of amorphous Ge films prepared by magnetron sputtering. The thermal conductivity was significantly higher than the value predicted by the minimum thermal conductivity model and increased with deposition temperature. We found that variations in sound velocity and Ge film density were not the main factors in the high thermal conductivity. Fast Fourier transform patterns of transmission electron micrographs revealed that short-range order in the Ge films was responsible for their high thermal conductivity. The results provide experimental evidences to understand the underlying nature of the variation of phonon mean free path in amorphous solids

  12. Irradiation induced crystalline to amorphous transition

    International Nuclear Information System (INIS)

    Bourgoin, J.

    1980-01-01

    Irradiation of a crystalline solid with energetic heavy particles results in cascades of defects which, with increasing dose, overlap and form a continuous disordered layer. In semiconductors the physical properties of such disordered layers are found to be similar to those of amorphous layers produced by evaporation. It is shown in the case of silicon, that the transition from a disordered crystalline (X) layer to an amorphous (α) layer occurs when the Gibbs energy of the X phase and of the defects it contains becomes larger than the Gibbs energy of the α phase. (author)

  13. Magnetotransport and magnetization reversal of electrodeposited multilayer nanowires

    Science.gov (United States)

    Tang, Xueti

    2007-12-01

    Electrodeposited magnetic multilayer nanowires are ideal materials to study nanoscale magnetism and the giant magnetoresistance (GMR) in the current-perpendicular-to-plane (CPP) geometry. This is because the diameter of each nanowire is uniform, the surface of the nanowire is smooth, and the thickness of both the magnetic and non-magnetic layers can be varied to either larger or smaller than the spin diffusion length which is an important parameter in magnetotransport study. In addition, the aspect ratio (layer-thickness/diameter) that is related to shape anisotropy can be varied for magnetization reversal study. There has been little understanding in the magnetization reversal mechanism of multilayer nanowires, which is complicated due to the dipolar interactions between magnetic layers in each nanowire and between nanowires. The objective of this work is to study the magnetization reversal mechanism of multilayer nanowires using a vibrating sample magnetometer (VSM), where various dipolar interactions are taken into account. Although multilayer nanowires are ideal for the study of the CPP-GMR effect, there remains technical difficulty in making an electrical contact with individual nanowires for the CPP-GMR measurements. In this work, a point-contact method using a conductive plunger tip was developed in-house, that enabled us to measure the CPP-GMR of selected multilayer nanowires in an array of vertically aligned nanowires in each sample. To examine the CPP-GMR and compare the results with theoretical models, the CPP-GMR data were systematically obtained from samples with various magnetic and non-magnetic layer thicknesses. It was found from VSM measurement that the magnetization reversal mode in electrodeposited CoNi/Cu multilayer nanowires depends on the shape and thickness of the CoNi layers where the mode in rod-shaped thick CoNi layers is different from that in disk-shaped thin CoNi layers. The reversal mode in coherent rotation or curling was determined

  14. Inverted amorphous silicon solar cell utilizing cermet layers

    Science.gov (United States)

    Hanak, Joseph J.

    1979-01-01

    An amorphous silicon solar cell incorporating a transparent high work function metal cermet incident to solar radiation and a thick film cermet contacting the amorphous silicon opposite to said incident surface.

  15. Amorphization of metals by ion implantation and ion beam mixing

    International Nuclear Information System (INIS)

    Rauschenbach, B.; Heera, V.

    1988-01-01

    Amorphous metallic systems can be formed either by high-fluence ion implantation of glassforming species or by irradiation of layered metal systems with inert gas ions. Both techniques and experimental examples are presented. Empirical rules are discussed which predict whether a given system can be transformed into an amorphous phase. Influence of temperature, implantation dose and pre-existing crystalline metal composition on amorphization is considered. Examples are given of the implantation induced amorphous structure, recrystallization and formation of quasicrystalline structures. (author)

  16. Vibrational spectra for hydrogenated amorphous semiconductors

    International Nuclear Information System (INIS)

    Kamitakahara, W.A.; Bouchard, A.M.; Biswas, R.; Gompf, F.; Suck, J.B.

    1990-01-01

    Hydrogen vibration spectra have been measured by neutron scattering for several amorphous semiconductor materials, including a-Ge:H and a-SiC:H samples containing about 10 at. % H. The data for a-Ge:H are compared in detail with the results of realistic computer simulations

  17. Film adhesion in amorphous silicon solar cells

    Indian Academy of Sciences (India)

    TECS

    Film adhesion in amorphous silicon solar cells. A R M YUSOFF*, M N SYAHRUL and K HENKEL. Malaysia Energy Centre, 8th Floor, North Wing, Sapura @ Mines, 7, Jalan Tasik, The Mines Resort City,. 43300 Seri Kembangan, Selangor Darul Ehsan. MS received 11 April 2007. Abstract. A major issue encountered ...

  18. Characterization of amorphous and nanocrystalline carbon films

    International Nuclear Information System (INIS)

    Chu, Paul K.; Li Liuhe

    2006-01-01

    Amorphous and nanocrystalline carbon films possess special chemical and physical properties such as high chemical inertness, diamond-like properties, and favorable tribological proprieties. The materials usually consist of graphite and diamond microstructures and thus possess properties that lie between the two. Amorphous and nanocrystalline carbon films can exist in different kinds of matrices and are usually doped with a large amount of hydrogen. Thus, carbon films can be classified as polymer-like, diamond-like, or graphite-like based on the main binding framework. In order to characterize the structure, either direct bonding characterization methods or the indirect bonding characterization methods are employed. Examples of techniques utilized to identify the chemical bonds and microstructure of amorphous and nanocrystalline carbon films include optical characterization methods such as Raman spectroscopy, Ultra-violet (UV) Raman spectroscopy, and infrared spectroscopy, electron spectroscopic and microscopic methods such as scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy, transmission electron microscopy, and electron energy loss spectroscopy, surface morphology characterization techniques such as scanning probe microscopy (SPM) as well as other characterization methods such as X-ray reflectivity and nuclear magnetic resonance. In this review, the structures of various types of amorphous carbon films and common characterization techniques are described

  19. Amorphous calcium carbonate particles form coral skeletons

    Science.gov (United States)

    Mass, Tali; Giuffre, Anthony J.; Sun, Chang-Yu; Stifler, Cayla A.; Frazier, Matthew J.; Neder, Maayan; Tamura, Nobumichi; Stan, Camelia V.; Marcus, Matthew A.; Gilbert, Pupa U. P. A.

    2017-09-01

    Do corals form their skeletons by precipitation from solution or by attachment of amorphous precursor particles as observed in other minerals and biominerals? The classical model assumes precipitation in contrast with observed “vital effects,” that is, deviations from elemental and isotopic compositions at thermodynamic equilibrium. Here, we show direct spectromicroscopy evidence in Stylophora pistillata corals that two amorphous precursors exist, one hydrated and one anhydrous amorphous calcium carbonate (ACC); that these are formed in the tissue as 400-nm particles; and that they attach to the surface of coral skeletons, remain amorphous for hours, and finally, crystallize into aragonite (CaCO3). We show in both coral and synthetic aragonite spherulites that crystal growth by attachment of ACC particles is more than 100 times faster than ion-by-ion growth from solution. Fast growth provides a distinct physiological advantage to corals in the rigors of the reef, a crowded and fiercely competitive ecosystem. Corals are affected by warming-induced bleaching and postmortem dissolution, but the finding here that ACC particles are formed inside tissue may make coral skeleton formation less susceptible to ocean acidification than previously assumed. If this is how other corals form their skeletons, perhaps this is how a few corals survived past CO2 increases, such as the Paleocene-Eocene Thermal Maximum that occurred 56 Mya.

  20. Noise and degradation of amorphous silicon devices

    NARCIS (Netherlands)

    Bakker, J.P.R.

    2003-01-01

    Electrical noise measurements are reported on two devices of the disordered semiconductor hydrogenated amorphous silicon (a-Si:H). The material is applied in sandwich structures and in thin-film transistors (TFTs). In a sandwich configuration of an intrinsic layer and two thin doped layers, the

  1. Radiative recombination of excitons in amorphous semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Jai [School of Engineering and Logistics, Faculty Technology, B-41, Charles Darwin University, Darwin, NT 0909 (Australia)]. E-mail: jai.singh@cdu.edu.au

    2005-04-15

    A theory for calculating the radiative lifetime of excitons in amorphous semiconductors is presented. Four possibilities of excitonic radiative recombination are considered and the corresponding rates are derived at thermal equilibrium. The radiative lifetime is calculated from the inverse of the maximum rate for all the four possibilities. Results agree very well with experiments.

  2. Bulk amorphous Mg-based alloys

    DEFF Research Database (Denmark)

    Pryds, Nini

    2004-01-01

    are discussed in this paper. On the basis of these measurements phase diagrams of the different systems were constructed. Finally, it is demonstrated that when pressing the bulk amorphous alloy onto a metallic dies at temperatures within the supercooled liquid region, the alloy faithfully replicates the surface...

  3. Anodic electrochemical treatment of amorphous alloys

    International Nuclear Information System (INIS)

    Isaev, N.I.; Yakovlev, V.B.; Osipov, Eh.K.; Isaev, A.V.; Trofimova, E.A.; Vasil'ev, V.Yu.

    1983-01-01

    The aim of the investigation is to reveal peculiarities of the process of anodic oxidation and properties of anode oxide films, formed on the surface of amorphous alloys. Amorphous alloys on the base of rectifying metals of Zr-Ni, Zr-Cu-Ni, Zr-Al-Ni, Zr-Cu-Sn, Zr-Al, Zr-Mo systems are studied. Electrolytes which do not dissolve or weakly dissolve oxide film, such as boric acid electrolyte (40-45 g/l H 3 BO 3 and 18 cm 3 /l of the 25% aqueous NH 4 OH solution) and 20% H 2 SO 4 solution, are used for oxidation. Results of investigations, carried out on amorphous alloys, contaning noticeable quantities of non-rectifying components - Cu, Ni, Sn, Fe, Mo etc - have shown that non-rectifying components harden a process of anodic oxidation and decrease the current efficiency. Amorphous alloys, containing only rectifying components are oxidated in anodic way, the regularities of film growth being similar to those obtained for crystalline materials

  4. Amorphous bimetallic alloys prepared by steam condensation

    International Nuclear Information System (INIS)

    Drago, V.

    1988-01-01

    Amorphous alloys of MnSn are prepared by steam condensation, in a substratum with a temperature near of the liquid helium. The magnetic and paramagnetic hyperfine spectrum and the ordination temperature by Moessbauer effect 119Sn are measured. A diagram of magnetic phase is proposed, basing on the measures of Moessbauer effect. (C.G.C.) [pt

  5. Structural morphology of amorphous conducting carbon film

    Indian Academy of Sciences (India)

    Unknown

    moves from low preparation temperature to high preparation temperature. The amorphous .... nm and the interac- tion between the pi-electron clouds of the two layers re- .... sp2 configuration forms to minimize stress and making. C900 films ...

  6. Trap level spectroscopy in amorphous semiconductors

    CERN Document Server

    Mikla, Victor V

    2010-01-01

    Although amorphous semiconductors have been studied for over four decades, many of their properties are not fully understood. This book discusses not only the most common spectroscopic techniques but also describes their advantages and disadvantages.Provides information on the most used spectroscopic techniquesDiscusses the advantages and disadvantages of each technique

  7. Radiative recombination of excitons in amorphous semiconductors

    International Nuclear Information System (INIS)

    Singh, Jai

    2005-01-01

    A theory for calculating the radiative lifetime of excitons in amorphous semiconductors is presented. Four possibilities of excitonic radiative recombination are considered and the corresponding rates are derived at thermal equilibrium. The radiative lifetime is calculated from the inverse of the maximum rate for all the four possibilities. Results agree very well with experiments

  8. Templated electrodeposition of Ag7NO11 nanowires with very high oxidation states of silver

    NARCIS (Netherlands)

    Rodijk, E.J.B.; Maijenburg, A.W.; Maas, M.G.; Blank, David H.A.; ten Elshof, Johan E.

    2011-01-01

    The templated electrodeposition of 200 nm diameter nanowires of the argentic oxynitrate Ag(Ag3O4)2NO3 phase is reported. Their high surface-to-volume ratio and the high average oxidation state of Ag make these wires promising candidates for nanoscale redox processes in which both a high volumetric

  9. Nucleation, aggregative growth and detachment of metal nanoparticles during electrodeposition at electrode surfaces

    NARCIS (Netherlands)

    Lai, Stanley; Lazenby, R.A.; Kirkman, P.M.; Unwin, P.R.

    2015-01-01

    The nucleation and growth of metal nanoparticles (NPs) on surfaces is of considerable interest with regard to creating functional interfaces with myriad applications. Yet, key features of these processes remain elusive and are undergoing revision. Here, the mechanism of the electrodeposition of

  10. Potentiostatic electro-deposition of 241Am using room temperature ionic liquids

    International Nuclear Information System (INIS)

    Sankhe, R.H.; Mirashi, N.N.; Arijit Sengupta; Murali, M.S.

    2015-01-01

    An attempt was made for the potentiostatic electrodeposition of 241 Am using six different room temperature ionic liquids (RTILs). Effect of electrodeposition time on the % of electrodeposition of 241 Am, pH change of the solution and the temperature change of the systems were investigated. It was observed that for water immiscible RTILs, the least viscous RTIL gave the best yield (when mixed with iso-propanol), while for water miscible RTILs, reverse trend was observed (when mixed with water). Out of all water immiscible RTILs under consideration for the present case, the octyl-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)imide (C 8 mpyNTf 2 ) in isopropanol was found to yield almost quantitative (99.6 %) electrodeposition of 241 Am within 45 min whereas the most effective system was found to be C 8 mimBr with ∼90 % of 241 Am deposited on the electrode for water miscible RTILs. To the best of our knowledge, this is the first approach ever been reported in the literature. (author)

  11. A study on corrosion resistance of electrodeposited Zn-base alloy steel sheet

    International Nuclear Information System (INIS)

    Park, Hyun Soon

    1986-01-01

    Effects of electrodeposits of Zn-Ni or Zn-Co alloy with small amounts of Mo or W in sulphate bath on the corrosion resistance of plated steel sheet were studied. 1) The electrodeposition of Zn-Ni and Zn-Co alloy shows both anomalous codeposition behavior. The grade of anomalous codeposition of Zn-Co alloy rises with adding Mo or W in bath. 2) The Ni content in Zn-Ni deposits increases with decreasing cathode current density and with increasing bath temperature. 3) In case of electroplating of Zn-Co, the increase of cathodic current density of bath bring on increasing of the Co content, but on decreasing of the Mo content in deposits. And rising bath temperature increases both Co and Mo deposits. 4) The corrosion resistance of the Zn-Ni electrodeposited steel sheet is shown a maximum at the Ni content of 10-17%. The structure of Zn-Ni of these composition range was finegrained γ-phase. 5) The corrosion resistance of the Zn-Co electrodeposited steel sheet is improved with increasing Co content. The corrosion resistance of the Zn-Co-Mo or Zn-Co-W deposits electroplated by proper plating conditions was improved much more than that of Zn-Co deposits. (Author)

  12. Electrodeposition Techniques for the Preparation of Beta-Sprectroscopy Sources of Rare-Earth Elements

    DEFF Research Database (Denmark)

    Hansen, P. Gregers; Høgh, J.; Nielsen, H. L.

    1964-01-01

    Thin, uniform radioactive deposits of rare earths and related elements can be prepared by cathodic electrodeposition of their hydroxides. The main theoretical and experimental features of this process are reviewed and plating cell design and the choice of conditions are described together...

  13. Effect of weak magnetic field on the grain size of electrodeposited nickel

    International Nuclear Information System (INIS)

    Ansari, M.S.; Gul, N.

    2007-01-01

    Effect of weak magnetic field on the electro-deposition of nickel onto copper electrode has been investigated. The working conditions were optimized through adjustment of cathodic current density (CCD), deposition time, bath temperature and pH of the medium. For electro-deposition in the absence of magnetic field, the optimum conditions comprised of pH = 4.0+- 0.5, average CCD = 22.5 +- 0.5 mA cm/sup -2/ and bath temperature in the range from 25 to 30 degree C. The same conditions were maintained for the electrodeposition while applying magnetic field of 0.75 kG. The morphological features of the Ni-deposits on copper cathode were compared for the two cases. The applied magnetic field not only enhanced the amount of nickel deposition but also improved the quality of the deposit. Surface morphology of the electro-deposited nickel has been monitored using scanning electron microscopy (SEM); the preliminary investigation has shown that the grain size decreased with the applied magnetic field case. One possible explanation to this behavior is the convection flow of cations close to the electrode surface induced by the Lorentz force which also influences the ion-migration. (author)

  14. III. Co-electrodeposition/removal of copper and nickel in a spouted electrochemical reactor.

    Science.gov (United States)

    Grimshaw, Pengpeng; Calo, Joseph M; Hradil, George

    2011-07-11

    Results are presented of an investigation of co-electrodeposition of copper and nickel from acidic solution mixtures in a cylindrical spouted electrochemical reactor. The effects of solution pH, temperature, and applied current on metal removal/recovery rate, current efficiency, and corrosion of the deposited metals from the cathodic particles were examined under galvanostatic operation. The quantitative and qualitative behavior of co-electrodeposition of the two metals from their mixtures differs significantly from that of the individual single metal solutions. This is primarily attributed to the metal displacement reaction between Ni(0) and Cu(2+). This reaction effectively reduces copper corrosion, and amplifies that for nickel (at least at high concentrations). It also amplifies the separation of the deposition regimes of the two metals in time, which indicates that the recovery of each metal as a relatively pure deposit from the mixture is possible. It was also shown that nitrogen sparging considerably increases the observed net electrodeposition rates for both metals - considerably more so than from solutions with just the single metals alone. A numerical model of co-electrodeposition, corrosion, metal displacement, and mass transfer in the cylindrical spouted electrochemical reactor is presented that describes the behavior of the experimental copper and nickel removal data quite well.

  15. A novel polymeric leveller for the electrodeposition of copper from acidic sulphate bath: A spectroelectrochemical investigation

    International Nuclear Information System (INIS)

    Bozzini, Benedetto; D'Urzo, Lucia; Mele, Claudio

    2007-01-01

    The electrodeposition of copper has recently become a 'hot topic' due to its extensive application to the fabrication of interconnects in the integrated circuits (IC) manufacturing process. However, the proper composition of the electrochemical deposition (ECD) bath, and in particular the selection of the levelling agent, represents one of the crucial factors for an effective transition of Cu ECD towards the most advanced technology nodes. In this paper we report on the electrodeposition of Cu from acidic sulphate baths containing a potential innovative polymeric leveller: a benzyl-phenyl modified polyethyleneimine (BPPEI). This investigation was carried out by: (i) cyclic voltammetry (CV) at a rotating-disk electrode, (ii) in situ surface-enhanced Raman spectroscopy (SERS) during electrodeposition and (iii) scanning electron microscopy (SEM). CV results show that BPPEI acts as an inhibitor of the electrodeposition process, since it reduces the exchange current density and increases the cathodic Tafel slope. Mass transport limitations to the Cu(II) reduction process are essentially unaffected by the presence of BPPEI. SERS spectra show that BPPEI is adsorbed at the growing Cu cathode at all potentials of interest for electroplating. SEM micrographs prove that BPPEI acts as an efficient grain-refiner and suppressor of unstable 3D growth. Cathodic reactivity of BPPEI was proved by the analysis of CV features and potential-dependent SERS spectral changes

  16. A pH Sensor Based on a Stainless Steel Electrode Electrodeposited with Iridium Oxide

    Science.gov (United States)

    Martinez, C. C. M.; Madrid, R. E.; Felice, C. J.

    2009-01-01

    A simple procedure to make an iridium oxide (IrO[subscript 2]) electrodeposited pH sensor, that can be used in a chemical, biomedical, or materials laboratory, is presented here. Some exercises, based on this sensor, that can be used to teach important concepts in the field of biomedical, biochemical, tissue, or materials engineering, are also…

  17. Alternate method of source preparation for alpha spectrometry: No electrodeposition, no hydrofluoric acid

    International Nuclear Information System (INIS)

    Kurosaki, Hiromu; Mueller, Rebecca J.; Lambert, Susan B.; Rao, Govind R.

    2016-01-01

    An alternate method of preparing actinide alpha counting sources was developed in place of electrodeposition or lanthanide fluoride micro-precipitation. The method uses lanthanide hydroxide micro-precipitation to avoid the use of hazardous hydrofluoric acid. Lastly, it provides a quicker, simpler, and safer way of preparing actinide alpha counting sources in routine, production-type laboratories that process many samples daily.

  18. Thermal stability of electrodeposited Ni and Ni-Co layers; an EBSD-study

    DEFF Research Database (Denmark)

    Rasmussen, Anette Alsted; Gholinia, A.; Trimby, P.W.

    2004-01-01

    The influence of heat treatment on the microstructure and the microtexture of electrodeposited Ni and Ni-Co layers was investigated with Electron Backscatter Diffraction (EBSD) with high resolution. Samples were annealed for 1 hour at 523 K and 673 K, the temperature region wherein...

  19. Nanoindentation and micro-mechanical fracture toughness of electrodeposited nanocrystalline Ni-W alloy films

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, D.E.J., E-mail: david.armstrong@materials.ox.ac.uk [Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH (United Kingdom); Haseeb, A.S.M.A. [Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Roberts, S.G.; Wilkinson, A.J. [Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH (United Kingdom); Bade, K. [Institut fuer Mikrostrukturtechnik (IMT), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2012-04-30

    Nanocrystalline nickel-tungsten alloys have great potential in the fabrication of components for microelectromechanical systems. Here the fracture toughness of Ni-12.7 at.%W alloy micro-cantilever beams was investigated. Micro-cantilevers were fabricated by UV lithography and electrodeposition and notched by focused ion beam machining. Load was applied using a nanoindenter and fracture toughness was calculated from the fracture load. Fracture toughness of the Ni-12.7 at.%W was in the range of 1.49-5.14 MPa {radical}m. This is higher than the fracture toughness of Si (another important microelectromechanical systems material), but considerably lower than that of electrodeposited nickel and other nickel based alloys. - Highlights: Black-Right-Pointing-Pointer Micro-scale cantilevers manufactured by electro-deposition and focused ion beam machining. Black-Right-Pointing-Pointer Nanoindenter used to perform micro-scale fracture test on Ni-13at%W micro-cantilevers. Black-Right-Pointing-Pointer Calculation of fracture toughness of electrodeposited Ni-13at%W thin films. Black-Right-Pointing-Pointer Fracture toughness values lower than that of nanocrystalline nickel.

  20. Electrodeposition of antimony, tellurium and their alloys from molten acetamide mixtures

    NARCIS (Netherlands)

    Nguyen, H.P.; Peng, X.; Murugan, G.; Vullers, R.J.M.; Vereecken, P.M.; Fransaer, J.

    2013-01-01

    We examine the electrodeposition of antimony (Sb), tellurium (Te) and their alloys from molten mixtures of acetamide - antimony chloride and tellurium chloride. The binary mixtures of acetamide with SbCl3 and TeCl 4 exhibit eutectic formation with large depressions of freezing points to below room

  1. High Pt utilization PEMFC electrode obtained by alternative ion-exchange/electrodeposition.

    Science.gov (United States)

    Chen, Siguo; Wei, Zidong; Li, Hua; Li, Li

    2010-12-14

    High Pt utilization PEMFC electrodes were prepared by an alternative ion-exchange/electrodeposition (AIEE) technique. The results demonstrated that the MEA employing an AIEE electrode with a Pt loading of 0.014 mg Pt cm(-2) exhibits performance approximately 2.2 times larger than that employing a conventional Nafion-bonded Pt/C electrode with a same Pt loading.

  2. Alternate method of source preparation for alpha spectrometry: no electrodeposition, no hydrofluoric acid

    International Nuclear Information System (INIS)

    Hiromu Kurosaki; Lambert, S.B.; Rao, G.R.; Mueller, R.J.

    2017-01-01

    An alternate method of preparing actinide alpha counting sources was developed in place of electrodeposition or lanthanide fluoride micro-precipitation. The method uses lanthanide hydroxide micro-precipitation to avoid the use of hazardous hydrofluoric acid. It provides a quicker, simpler, and safer way of preparing actinide alpha counting sources in routine, production-type laboratories that process many samples daily. (author)

  3. Nanoindentation and micro-mechanical fracture toughness of electrodeposited nanocrystalline Ni–W alloy films

    International Nuclear Information System (INIS)

    Armstrong, D.E.J.; Haseeb, A.S.M.A.; Roberts, S.G.; Wilkinson, A.J.; Bade, K.

    2012-01-01

    Nanocrystalline nickel–tungsten alloys have great potential in the fabrication of components for microelectromechanical systems. Here the fracture toughness of Ni–12.7 at.%W alloy micro-cantilever beams was investigated. Micro-cantilevers were fabricated by UV lithography and electrodeposition and notched by focused ion beam machining. Load was applied using a nanoindenter and fracture toughness was calculated from the fracture load. Fracture toughness of the Ni–12.7 at.%W was in the range of 1.49–5.14 MPa √m. This is higher than the fracture toughness of Si (another important microelectromechanical systems material), but considerably lower than that of electrodeposited nickel and other nickel based alloys. - Highlights: ► Micro-scale cantilevers manufactured by electro-deposition and focused ion beam machining. ► Nanoindenter used to perform micro-scale fracture test on Ni-13at%W micro-cantilevers. ► Calculation of fracture toughness of electrodeposited Ni-13at%W thin films. ► Fracture toughness values lower than that of nanocrystalline nickel.

  4. Electrodeposition in capillaries: Bottom-up micro and nanopatterning of functional materials on conductive substrates

    NARCIS (Netherlands)

    George, A.; Maijenburg, A.W.; Maas, M.G.; Blank, David H.A.; ten Elshof, Johan E.

    2011-01-01

    A cost-effective and versatile methodology for bottom-up patterned growth of inorganic and metallic materials on the micro- and nanoscale is presented. Pulsed electrodeposition was employed to deposit arbitrary patterns of Ni, ZnO, and FeO(OH) of high quality, with lateral feature sizes down to

  5. Microstructure and micromechanical properties of electrodeposited Zn–Mo coatings on steel

    Energy Technology Data Exchange (ETDEWEB)

    Kazimierczak, Honorata, E-mail: h.kazimierczak@imim.pl [Institute of Metallurgy and Material Science, Polish Academy of Sciences, 30-059 Krakow, Reymonta 25 (Poland); Ozga, Piotr [Institute of Metallurgy and Material Science, Polish Academy of Sciences, 30-059 Krakow, Reymonta 25 (Poland); Berent, Katarzyna [Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, 30-059 Krakow, Mickiewicza Av. 30 (Poland); Kot, Marcin [Faculty of Mechanical Engineering and Robotics, AGH University of Science and Technology, 30-059 Krakow, Mickiewicza Av. 30 (Poland)

    2015-07-05

    Highlights: • The conditions for electrodeposition of uniform and compact Zn–Mo coatings have been studied. • Zn–Mo coatings microstructure can be controlled by the molybdenum content. • Surface roughness can be controlled by the content of Mo in coatings. • The value of microhardness grows gradually with the increase of Mo content up to 3 wt.%. - Abstract: The aim of the work was to characterise the new coating material based on zinc with the addition of molybdenum, electrodeposited on steel substrate from nontoxic, citrate based electrolytes. The surface composition of deposits was ascertained by chemical analysis (WDXRF). The morphology of coatings was studied by SEM. The surface morphology and roughness of Zn–Mo coatings on steel was investigated by AFM. The microhardness and Young modulus were determined by indentation technique, whereas the coating adhesion to the substrate was examined by means of scratch test. The optimal ranges of electrodeposition parameters, enabling the preparation of good quality coatings (i.e. uniform, compact, with good adhesion to the substrate), was specified. The morphology of deposits depends significantly on the content of molybdenum and on the thickness of electrodeposited layer. The microhardness of Zn–Mo coating increases with the increase of molybdenum content up to 3 wt.% and then reaches about 3.5 GPa, which is almost five times that of the value of the microhardness of the Zn coating studied.

  6. Magnetic vortex state and multi-domain pattern in electrodeposited hemispherical nanogranular nickel films

    International Nuclear Information System (INIS)

    Samardak, Alexander; Sukovatitsina, Ekaterina; Ognev, Alexey; Stebliy, Maksim; Davydenko, Alexander; Chebotkevich, Ludmila; Keun Kim, Young; Nasirpouri, Forough; Janjan, Seyed-Mehdi; Nasirpouri, Farzad

    2014-01-01

    Magnetic states of nickel nanogranular films were studied in two distinct structures of individual and agglomerated granules electrodeposited on n-type Si(1 1 1) surface from a modified Watts bath at a low pH of 2. Magnetic force microscopy and micromagnetic simulations revealed three-dimensional out-of-plane magnetic vortex states in stand-alone hemispherical granules and their arrays, and multi-domain patterns in large agglomerates and integrated films. Once the granules coalesce into small chains or clusters, the coercivity values increased due to the reduction of inter-granular spacing and strengthening of the magnetostatic interaction. Further growth leads to the formation of a continuous granulated film which strongly affected the coercivity and remanence. This was characterized by the domain wall nucleation and propagation leading to a stripe domain pattern. Magnetoresistance measurements as a function of external magnetic field are indicative of anisotropic magnetoresistance (AMR) for the continuous films electrodeposited on Si substrate. - Highlights: • Magnetic states of electrodeposited nickel in isolated spherical and agglomerated nanogranules, and a continuous film. • Preferential magnetization reversal mechanism in isolated granules is vortex state. • Micromagnetic simulations confirm the three-dimensional vortex. • Transition between the vortex state and multi-domain magnetic pattern causes a significant decrease in the coercive force. • Continuous nickel films electrodeposited on silicon substrate exhibit AMR whose magnitude increases with the film thickness

  7. Reuse of Expired Cefort Drug in Nickel Electrodeposition From Watts Bath

    Directory of Open Access Journals (Sweden)

    Delia-Andrada Duca

    2017-06-01

    Full Text Available This paper demonstrates the possibility to use ceftriaxone (CEFTR active compound from expired Cefort as additive in nickel electrodeposition from Watts baths. Electrochemical behaviour and the influence of CEFTR on nickel electroplating were studied by electrochemical methods. Experimental data recommends CEFTR as additive in nickel electroplating from Watts baths.

  8. Method for electrodeposition of nickel--chromium alloys and coating of uranium

    International Nuclear Information System (INIS)

    Stromatt, R.W.; Lundquist, J.R.

    1975-01-01

    High-quality electrodeposits of nickel-chromium binary alloys in which the percentage of chromium is controlled can be obtained by the addition of a complexing agent such as ethylenediaminetetraacetic disodium salt to the plating solution. The nickel-chromium alloys were found to provide an excellent hydrogen barrier for the protection of uranium fuel elements. (U.S.)

  9. Anticorrosion protection of carbon steel by electrodeposition of niobium in melted fluorides

    International Nuclear Information System (INIS)

    Almeida, M.E. de; Robin, A.

    1990-01-01

    The results about niobium electrodeposition over carbon steel from K sub(2) Nb F sub(7) solutions, on LiF-Na F-KF eutetic at 750 sup(0)C and over the corrosion resistance of obtainment deposit from acid media are presented. (author)

  10. Cr-Ni ALLOY ELECTRODEPOSITION AND COMPARISON WITH CONVENTIONAL PURE Cr COATING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    M. Moniruzzaman

    2012-12-01

    Full Text Available Cr coating is widely used as the outer surface of precision parts due to its attractive appearance and superior corrosion resistance properties. It is obtained by electrodeposition via a conventional bath with hexavalent Cr ions. This manufacturing technique has many drawbacks, such as very low efficiency and high operating temperature and it is hazardous to health. In this work, we studied a Cr-Ni alloy deposition technique and compared the alloy coating properties to those with conventional Cr coating. Sequential two-step alloy electrodeposition was also compared. We took varying concentrations of Cr, Ni and complexing agents for the electrodeposition of Cr-Ni alloy and sequential Cr-Ni alloy coating on mild steel. Operating parameters, i.e. current density and temperature, were varied to examine their effects on the coating properties. The coatings thus obtained were characterized by visual observation, corrosion test, microhardness measurement, morphology and chemical analysis. The Cr-Ni alloy coating was found to be more corrosion resistant in 5% NaCl solution and harder than the pure Cr coating obtained by conventional electrodeposition. Toxic gas was produced in a much lower extent in the alloy coating than the conventional Cr coating technique. Again, the two-step Cr-Ni alloy coating was found better in terms of corrosion resistance as well as hardness compared to the Cr-Ni alloy coating. The process was also found to be much more environmentally friendly.

  11. Preparation of /sup 237/Np samples by electrodeposition and its determination by alpha spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mertzig, W; Matsuda, H T; Araujo, B.F. de; Araujo, J.A. de [Instituto de Pesquisas Energeticas e Nucleares, Sao Paulo (Brazil). Centro de Engenharia Quimica

    1980-01-01

    An analytical method followed by alpha spectrometry was developed for the determination of trace amounts of actinides. A technique for quantitative electrodeposition of /sup 237/Np, under optimal conditions, using a carrier, is presented. This method will be applied for the control of trace amounts of /sup 237/Np in the solutions from the reprocessing (Purex process) of irradiated uranium.

  12. Whisker and Hillock formation on Sn, Sn-Cu and Sn-Pb electrodeposits

    International Nuclear Information System (INIS)

    Boettinger, W.J.; Johnson, C.E.; Bendersky, L.A.; Moon, K.-W.; Williams, M.E.; Stafford, G.R.

    2005-01-01

    High purity bright Sn, Sn-Cu and Sn-Pb layers, 3, 7 and 16 μm thick were electrodeposited on phosphor bronze cantilever beams in a rotating disk apparatus. Beam deflection measurements within 15 min of plating proved that all electrodeposits had in-plane compressive stress. In several days, the surfaces of the Sn-Cu deposits, which have the highest compressive stress, develop 50 μm contorted hillocks and 200 μm whiskers, pure Sn deposits develop 20 μm compact conical hillocks, and Sn-Pb deposits, which have the lowest compressive stress, remain unchanged. The differences between the initial compressive stresses for each alloy and pure Sn is due to the rapid precipitation of Cu 6 Sn 5 or Pb particles, respectively, within supersaturated Sn grains produced by electrodeposition. Over longer time, analysis of beam deflection measurements indicates that the compressive stress is augmented by the formation of Cu 6 Sn 5 on the bronze/Sn interface, while creep of the electrodeposit tends to decrease the compressive stress. Uniform creep occurs for Sn-Pb because it has an equi-axed grain structure. Localized creep in the form of hillocks and whiskers occurs for Sn and Sn-Cu because both have columnar structures. Compact hillocks form for the Sn deposits because the columnar grain boundaries are mobile. Contorted hillocks and whiskers form for the Sn-Cu deposits because the columnar grain boundary motion is impeded

  13. Electrodeposition and Properties of Copper Layer on NdFeB Device

    Directory of Open Access Journals (Sweden)

    LI Yue

    2017-06-01

    Full Text Available To decrease the impact of the regular Ni/Cu/Ni coating on the magnetic performance of sintered NdFeB device, alkaline system of HEDP complexing agent was applied to directly electro-deposit copper layer on NdFeB matrix, then nickel layer was electrodeposited on the copper layer and Cu/Ni coating was finally obtained to replace the regular Ni/Cu/Ni coating. The influence of concentration of HEDP complexing agent on deposition course was tested by electrochemical testing; morphology of copper layer was characterized by SEM, XRD and TEM; the binding force of copper layer and the thermal reduction of magnetic of NdFeB caused by electrodeposited coating were respectively explored through the thermal cycle test and thermal demagnetization test. The results show that the concentration of HEDP has great impact on the deposition overpotential of copper. In the initial electrodepositing stage, copper particles precipitate at the grain boundaries of NdFeB magnets with a preferred (111 orientation. The copper layer is compact and has enough binding force with the NdFeB matrix to meet the requirements in SJ 1282-1977. Furthermore, the thermal demagnetization loss rate of the sintered NdFeB with the protection of Cu/Ni coating is significantly less than that with the protection of Ni/Cu/Ni coating.

  14. Properties of ternary NiFeW alloy coating by jet electrodeposition

    Indian Academy of Sciences (India)

    In this paper, ternary NiFeW alloy coatings were prepared by jet electrodeposition, and the effects of lord salt concentration, jet speed, current density and temperature on the properties of the coatings, including the composition, microhardness, surface morphology, structure and corrosion resistance, were investigated.

  15. Electrodeposition and corrosion properties of zn-co and zn-co-fe alloy coatings

    NARCIS (Netherlands)

    Mol, J.M.C.; Lodhi, Z.F.; Hovestad, A.; Hoen-Velterop, L. 't; Terryn, H.; Wit, J.H.W. de

    2010-01-01

    Cadmium (Cd) has been extensively used as an excellent corrosion protective coating for steel components in aerospace, automotive, electrical and fasteners industries. However, Cd is banned due to its toxic nature and strict environmental regulations. In this study, the electrodeposition mechanism

  16. Electrodeposition and corrosion properties of Zn-Co and Zn-Co-Fe alloy coatings

    NARCIS (Netherlands)

    Mol, J.M.C.; Lodhi, Z.F.; Hovestad, A.; Hoen-Velterop, L. 't; Terryn, H.; Wit, J.H.W. de

    2011-01-01

    Cadmium (Cd) has been extensively used as an excellent corrosion protective coating for steel components in aerospace, automotive, electrical and fasteners industries. However, Cd is banned due to its toxic nature and strict environmental regulations. In this study, the electrodeposition mechanism

  17. Hybrid helical magnetic microrobots obtained by 3D template-assisted electrodeposition.

    Science.gov (United States)

    Zeeshan, Muhammad A; Grisch, Roman; Pellicer, Eva; Sivaraman, Kartik M; Peyer, Kathrin E; Sort, Jordi; Özkale, Berna; Sakar, Mahmut S; Nelson, Bradley J; Pané, Salvador

    2014-04-09

    Hybrid helical magnetic microrobots are achieved by sequential electrodeposition of a CoNi alloy and PPy inside a photoresist template patterned by 3D laser lithography. A controlled actuation of the microrobots by a rotating magnetic field is demonstrated in a fluidic environment. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Electrodeposition of enzymes-integrated mesoporous composite films by interfacial templating: A paradigm for electrochemical biosensors

    International Nuclear Information System (INIS)

    Wang, Dongming; Tan, Yiwei

    2014-01-01

    The development of nanostructured electrodes for electrochemical biosensors is of significant interest for modern detection, portable devices, and enhanced performance. However, development of such sensors still remains challenging due to the time-consuming, detriment-to-nature, and costly modifications of both electrodes and enzymes. In this work, we report a simple one-step approach to fabricating high-performance, direct electron transfer (DET) based nanoporous enzyme-embedded electrodes by electrodeposition coupled with recent progress in potential-controlled interfacial surfactant assemblies. In contrast to those previously electrodeposited mesoporous materials that are not bioactive, we imparted the biofunctionality to electrodeposited mesoporous thin films by means of the amphiphilic phospholipid templates strongly interacting with enzymes. Thus, phospholipid-templated mesoporous ZnO films covalently inlaid with the pristine enzymes were prepared by simple one-step electrodeposition. We further demonstrate two examples of such hybrid film electrodes embedded with alcohol dehydrogenase (ADH) and glucose oxidase (GOx), which are effectively employed as electrochemical biosensors for amperometric sensing of ethanol and glucose without using any electron relays. The favorable mass transport and large contact surface area provided by nanopores play an important role in improving the performance of these two biosensors, such as excellent sensitivities, low detection limits, and fast response. The matrix mesoporous films acting as effective electronic bridges are responsible for DET between enzyme molecules and metal electrode

  19. Hydrodynamic voltammetric studies of the oxygen reduction at gold nanoparticles-electrodeposited gold electrodes

    International Nuclear Information System (INIS)

    El-Deab, Mohamed S.; Ohsaka, Takeo

    2002-01-01

    The electrocatalytic reduction of oxygen at Au nanoparticles-electrodeposited Au electrodes has been studied using rotating disk electrode (RDE) voltammetry in 0.5 M H 2 SO 4 . Upon analyzing and comparison of the limiting currents data obtained at various rotation speeds of this RDE with those obtained at the bulk Au electrode, an effective value of the number of electrons, n, involved in the electrochemical reduction of O 2 was estimated to be ca. 4 for the former electrode and ca. 3 for the bulk Au electrode at the same potential of -350 mV versus Ag/AgCl/KCl(sat.). This indicates the higher possibility of further reduction and decomposition of H 2 O 2 at Au nanoparticles-electrodeposited Au electrode in this acidic medium. The reductive desorption of the self-assembled monolayer of cysteine, which was formed on the Au nanoparticles-electrodeposited Au electrode, was used to monitor the change of the specific activity of the bulk Au electrode upon the electrodeposition of the Au nanoparticles

  20. Development of silver-gas diffusion electrodes for the oxygen reduction reaction by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Salomé, Sónia; Rego, Rosa; Oliveira, M. Cristina, E-mail: mcris@utad.pt

    2013-12-16

    Silver-gas diffusion electrodes (Ag-GDE) were prepared by direct deposition of the catalyst onto a carbon paper support by electrodeposition. This deposition technique, under potentiostatic and galvanostatic mode, allows the production of well dispersed ultra-low Ag loading levels. The catalytic activity of the prepared materials towards the oxygen reduction reaction (ORR) was investigated in the alkaline solution and its tolerance to methanol was evaluated. Based on an Ag-ink prepared from the electrodeposit material and RDE experiments, it was concluded that the ORR occurs via a four-electron pathway on the Ag electrodeposit. The combination of reasonably high catalytic activity, efficiency, low price, facile and green synthesis makes the electrodeposited Ag-GDE attractive for the ORR in alkaline fuel cells. - Highlights: • A facile and simple way to successfully prepare catalyzed gas diffusion electrodes. • Ultra-low loadings of Ag-GDEs can be achieved. • Good tolerance to methanol and a high mass activity (3.14 mA{sub Ag} mg{sup −1}). • ORR occurs via a four-electron pathway.

  1. [Comparison of fibroblastic cell compatibility of type I collagen-immobilized titanium between electrodeposition and immersion].

    Science.gov (United States)

    Kyuragi, Takeru

    2014-03-01

    Titanium is widely used for medical implants. While many techniques for surface modification have been studied for optimizing its biocompatibility with hard tissues, little work has been undertaken to explore ways of maximizing its biocompatibility with soft tissues. We investigated cell attachment to titanium surfaces modified with bovine Type I collagen immobilized by either electrodeposition or a conventional immersion technique. The apparent thickness and durability of the immobilized collagen layer were evaluated prior to incubation of the collagen-immobilized titanium surfaces with NIH/3T3 mouse embryonic fibroblasts. The initial cell attachment and expression of actin and vinculin were evaluated. We determined that the immobilized collagen layer was much thicker and more durable when placed using the electrodeposition technique than the immersion technique. Both protocols produced materials that promoted better cell attachment, growth and structural protein expression than titanium alone. However, electrodeposition was ultimately superior to immersion because it is quicker to perform and produces a more durable collagen coating. We conclude that electrodeposition is an effective technique for immobilizing type I collagen on titanium surfaces, thus improving their cytocompatibility with fibroblasts.

  2. Numerical insights into the early stages of nanoscale electrodeposition: nanocluster surface diffusion and aggregative growth

    DEFF Research Database (Denmark)

    Mamme, Mesfin Haile; Kohn, Christoph; Deconinck, Johan

    2018-01-01

    Fundamental understanding of the early stages of electrodeposition at the nanoscale is key to address the challenges in a wide range of applications. Despite having been studied for decades, a comprehensive understanding of the whole process is still out of reach. In this work, we introduce a nov...

  3. Electrodeposition of BaCO3 coatings on stainless steel substrates ...

    Indian Academy of Sciences (India)

    Administrator

    Dedicated to the memory of the late Professor S K Rangarajan. *For correspondence. Electrodeposition of BaCO3 coatings on stainless steel substrates: Oriented growth ... orientation by an interfacial molecular recognition mechanism. BaCO3 has important applications in paint, ceramic, and paper industries. Also it is used ...

  4. Microstructure and thermal stability of nickel layers electrodeposited from an additive-free sulphamate-based electrolyte

    DEFF Research Database (Denmark)

    Rasmussen, Anette Alsted; Møller, Per; Somers, Marcel A. J.

    2006-01-01

    and scanning electron microscopy and X-ray diffraction; the Vickers hardness was measured in cross sections. The present is meant as a reference for forthcoming articles on the investigation of various strengthening mechanisms on the microstructure, hardness and thermal stability of Ni (alloys) electrodeposits.......The influences of the current density and the temperature on the microstructure and hardness of Ni layers electrodeposited from an additive-free sulphamate bath were investigated. The microstructure and thermal stability of the electrodeposits was investigated with a combination of transmission...

  5. Crystallization of biogenic hydrous amorphous silica

    Science.gov (United States)

    Kyono, A.; Yokooji, M.; Chiba, T.; Tamura, T.; Tuji, A.

    2017-12-01

    Diatom, Nitzschia cf. frustulum, collected from Lake Yogo, Siga prefecture, Japan was cultured in laboratory. Organic components of the diatom cell were removed by washing with acetone and sodium hypochlorite. The remaining frustules were studied by SEM-EDX, FTIR spectroscopy, and synchrotron X-ray diffraction. The results showed that the spindle-shaped morphology of diatom frustule was composed of hydrous amorphous silica. Pressure induced phase transformation of the diatom frustule was investigated by in situ Raman spectroscopic analysis. With exposure to 0.3 GPa at 100 oC, Raman band corresponding to quartz occurred at ν = 465 cm-1. In addition, Raman bands known as a characteristic Raman pattern of moganite was also observed at 501 cm-1. From the integral ratio of Raman bands, the moganite content in the probed area was estimated to be approximately 50 wt%. With the pressure and temperature effect, the initial morphology of diatom frustule was completely lost and totally changed to a characteristic spherical particle with a diameter of about 2 mm. With keeping the compression of 5.7 GPa at 100 oC, a Raman band assignable to coesite appeared at 538 cm-1. That is, with the compression and heating, the hydrous amorphous silica can be readily crystallized into quartz, moganite, and coesite. The first-principles calculations revealed that a disiloxane molecule stabilized in a trans configuration is twisted 60o and changed into the cis configuration with a close approach of water molecule. It is therefore a reasonable assumption that during crystallization of hydrous amorphous silica, the Si-O-Si bridging unit with the cis configuration would survive as a structural defect and then crystallized into moganite by keeping the geometry. This hypothesis is adaptable to the phase transformation from hydrous amorphous silica to coesite as well, because coesite has the four-membered rings and easily formed from the hydrous amorphous silica under high pressure and high

  6. Otimização do banho eletrolítico da liga Fe-W-B resistente à corrosão Optimization of the electrolytic bath for electrodeposition of corrosion resistant Fe-W-B alloys

    Directory of Open Access Journals (Sweden)

    Renato Alexandre Costa de Santana

    2007-04-01

    Full Text Available A study on optimization of bath parameters for electrodeposition of Fe-W-B alloys from plating baths containing ammonia and citrate is reported. A 2³ full factorial design was successfully employed for experimental design analysis of the results. The corrosion resistance and amorphous character were evaluated. The bath conditions obtained for depositing the alloy with good corrosion resistance were: 0.01 M iron sulfate, 0.10 M sodium tungstate and 0.60 M ammonium citrate. The alloy was deposited at 12% current efficiency. The alloy obtained had Ecorr -0.841 V and Rp 1.463 x 10(4 Ohm cm². The deposit obtained under these conditions had an amorphous character and no microcracks were observed on its surface. Besides this, the bath conditions obtained for depositing the alloy with the highest deposition efficiency were: 0.09 M iron sulfate, 0.30 M sodium tungstate and 0.50 M ammonium citrate. The alloy was deposited at 50% current efficiency, with an average composition of 34 wt% W, 66 wt% Fe and traces of boron. The alloy obtained had Ecorr -0.800 V and Rp 1.895 x 10³ Ohm cm². Electrochemical corrosion tests verified that the Fe-W-B alloy deposited under both conditions had better corrosion resistance than Fe-Mo-B.

  7. Copper electrodeposition from an acidic plating bath containing accelerating and inhibiting organic additives

    International Nuclear Information System (INIS)

    Pasquale, M.A.; Gassa, L.M.; Arvia, A.J.

    2008-01-01

    Copper electrodeposition on copper from still plating solutions of different compositions was investigated utilising electrochemical impedance spectroscopy (EIS), cyclic voltammetry, and scanning electron microscopy (SEM). An acid copper sulphate plating base solution was employed either with or without sodium chloride in the presence of a single additive, either polyethylene glycol (PEG) or 3-mercapto-2-propanesulphonic acid (MPSA), and their mixture. Thallium underpotential deposition/anodic stripping was employed to determine the adsorption capability of additives on copper. In the absence of chloride ions, MPSA shows a moderate adsorption on copper, whereas PEG is slightly adsorbed. At low cathodic overpotentials, the simultaneous presence of MPSA and chloride ions accelerates copper electrodeposition through the formation of an MPSA-chloride ion complex in the solution, particularly for about 220 μM sodium chloride. The reverse effect occurs in PEG-sodium chloride plating solutions. In this case, from EIS data the formation of a film that interferes with copper electrodeposition can be inferred. At higher cathodic overpotentials, when copper electrodeposition is under mass transport control, the cathode coverage by a PEG-copper chloride-mediated film becomes either partially or completely detached as the concentration of chloride ions at the negatively charged copper surface diminishes. The copper cathode grain topography at the μm scale depends on the cathodic overpotential, plating solution composition and average current density. Available data about the solution constituents and their adsorption on copper make it possible to propose a likely complex mechanism to understand copper electrodeposition from these media, including the accelerating effect of MPSA and the dynamics of PEG-copper chloride complex adsorbate interfering with the surface mobility of depositing copper ad-ions/ad-atoms

  8. The effect of the electrode material on the electrodeposition of zinc from deep eutectic solvents

    International Nuclear Information System (INIS)

    Vieira, L.; Schennach, R.; Gollas, B.

    2016-01-01

    Highlights: • Mechanistic insight into zinc electrodeposition from deep eutectic solvents. • Overpotential for hydrogen evolution affects the electrodeposition of zinc. • Electrodeposited zinc forms surface alloys on Cu, Au, and Pt. • In situ PM-IRRAS of a ZnCl_2 containing deep eutectic solvent on glassy carbon. - Abstract: The voltammetric behaviour of the ZnCl_2 containing deep eutectic solvent choline chloride/ethylene glycol 1:2 was investigated on glassy carbon, stainless steel, Au, Pt, Cu, and Zn electrodes. While cyclic voltammetry on glassy carbon and stainless steel showed a cathodic peak for zinc electrodeposition only in the anodic reverse sweep, a cathodic peak was found also in the cathodic forward sweep on Au, Pt, Cu, and Zn. This behaviour is in agreement with the proposed mechanism of zinc deposition from an intermediate species Z, whose formation depends on the cathodic reduction potential of the solvent. The voltammetric reduction of the electrolyte involves hydrogen evolution and as a result the formation of Z and its reduction to zinc depend on the hydrogen overpotential for each electrode material. On Au, Pt, and Cu also the anodic stripping was different from that on glassy carbon and steel due to the formation of surface zinc alloys with the three former metals. The morphology of the zinc layers on Cu has been characterised by scanning electron microscopy and focussed ion beam. X-ray diffraction confirmed the presence of crystalline zinc and a Cu_4Zn phase. Spectroelectrochemistry by means of polarization modulation reflection-absorption spectroscopy (PM-IRRAS) on a glassy carbon electrode in the ZnCl_2 containing deep eutectic solvent showed characteristic potential dependent changes. The variation of band intensities at different applied potentials correlate with the voltammetry and suggest the formation of a compact blocking layer on the electrode surface, which inhibits the electrodeposition of zinc at sufficiently negative

  9. Synthesizing the Nanocrytalline Cobalt-Iron Coating Through The Electrodeposition Process With Different Time Deposition

    Science.gov (United States)

    Rozlin Nik Masdek, Nik; Sorfian Hafiz Mansor, Mohd; Salleh, Zuraidah; Hyie, Koay Mei

    2018-03-01

    In the engineering world, electrodeposition or electroplating has become the most popular method of surface coating in improving corrosion behavior and mechanical properties of material. Therefore in this study, CoFe nanoparticle protective coating has been synthesized on the mild steel washer using electrodeposition method. The electrodeposition was conducted in the acidic environment with the pH value range from 1 to 2 with the controlled temperature of 50°C. The influence of deposition time (30, 60, 90 minutes) towards characteristic and properties such as particle size, surface morphology, corrosion behavior, and microhardness were studied in this investigation. Several results can be obtained by doing this experiment and testing. First, the surface morphology of Cobalt Iron (CoFe) on the electrodeposited mild steel washer are obtained. In addition, the microhardness of the mild steel washer due to the different deposition time are determined. Next, the observation on the difference in the grain size of CoFe that has been electrodeposited on the mild steel plate is made. Last but not least, the corrosion behavior was investigated. CoFe nanoparticles deposited for 30 minutes produced the smallest particle size and the highest microhardness of 86.17 and 236.84 HV respectively. The CoFe nanoparticles also exhibit the slowest corrosion rate at 30 minutes as compared to others. The crystalline size also increases when the time deposition is increased. The sample with 30 minute depositon time indicate the smallest crystalline size which is 15nm. The decrement of deposition time plays an important role in synthesizing CoFe nanoparticles with good corrosion resistance and microhardness. CoFe nanoparticles obtained at 30 minutes shows high corrosion resistance compared to others. In a nutshell, it was observed that the decrement of deposition time improved mechanical and corrosion properties of CoFe nanoparticles.

  10. Amorphous-crystalline transition in thermoelectric NbO2

    International Nuclear Information System (INIS)

    Music, Denis; Chen, Yen-Ting; Bliem, Pascal; Geyer, Richard W

    2015-01-01

    Density functional theory was employed to design enhanced amorphous NbO 2 thermoelectrics. The covalent-ionic nature of Nb–O bonding is identical in amorphous NbO 2 and its crystalline counterpart. However, the Anderson localisation occurs in amorphous NbO 2 , which may affect the transport properties. We calculate a multifold increase in the absolute Seebeck coefficient for the amorphous state. These predictions were critically appraised by measuring the Seebeck coefficient of sputtered amorphous and crystalline NbO 2 thin films with the identical short-range order. The first-order phase transition occurs at approximately 550 °C, but amorphous NbO 2 possesses enhanced transport properties at all temperatures. Amorphous NbO 2 , reaching  −173 μV K −1 , exhibits up to a 29% larger absolute Seebeck coefficient value, thereby validating the predictions. (paper)

  11. Emerging trends in the stabilization of amorphous drugs.

    Science.gov (United States)

    Laitinen, Riikka; Löbmann, Korbinian; Strachan, Clare J; Grohganz, Holger; Rades, Thomas

    2013-08-30

    The number of active pharmaceutical substances having high therapeutic potential but low water solubility is constantly increasing, making it difficult to formulate these compounds as oral dosage forms. The solubility and dissolution rate, and thus potentially the bioavailability, of these poorly water-soluble drugs can be increased by the formation of stabilized amorphous forms. Currently, formulation as solid polymer dispersions is the preferred method to enhance drug dissolution and to stabilize the amorphous form of a drug. The purpose of this review is to highlight emerging alternative methods to amorphous polymer dispersions for stabilizing the amorphous form of drugs. First, an overview of the properties and stabilization mechanisms of amorphous forms is provided. Subsequently, formulation approaches such as the preparation of co-amorphous small-molecule mixtures and the use of mesoporous silicon and silica-based carriers are presented as potential means to increase the stability of amorphous pharmaceuticals. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Research Progress on Fe-based Amorphous Coatings

    Directory of Open Access Journals (Sweden)

    LIANG Xiu-bing

    2017-09-01

    Full Text Available The latest research progresses on Fe-based amorphous coatings were reviewed. The typical alloy system and the classification of Fe-based amorphous coatings were clarified. The status, progress and development of the Fe-based amorphous coatings prepared by thermal spray processing and laser cladding process were discussed. The main mechanical properties and potential applications of the Fe-based amorphous coatings were also described. Furthermore, based on the main problems mentioned above, the future development of the Fe-based amorphous coatings was discussed, including the exploitation preparation technologies of high amorphous content of the Fe-based coatings, the development of the low cost and high performance Fe-based coating alloys system, the broadening application of Fe-based amorphous coatings, and so on.

  13. SURFACE MODIFICATION OF SEMICONDUCTOR THIN FILM OF TiO2 ON GRAPHITE SUBSTRATE BY Cu-ELECTRODEPOSITION

    Directory of Open Access Journals (Sweden)

    Fitria Rahmawati

    2010-06-01

    Full Text Available Surface modification of graphite/TiO2 has been done by mean of Cu electrodeposition. This research aims to study the effect of Cu electrodeposition on photocatalytic enhancing of TiO2. Electrodeposition has been done using CuSO4 0,4 M as the electrolyte at controlled current. The XRD pattern of modified TiO2 thin film on graphite substrate exhibited new peaks at 2θ= 43-44o and 2θ= 50-51o that have been identified as Cu with crystal cubic system, face-centered crystal lattice and crystallite size of 26-30 nm. CTABr still remains in the material as impurities. Meanwhile, based on morphological analysis, Cu particles are dissipated in the pore of thin film. Graphite/TiO2/Cu has higher photoconversion efficiency than graphite/TiO2.   Keywords: semiconductor, graphite/TiO2, Cu electrodeposition

  14. Tuning the electrodeposition parameters of silver to yield micro/nano structures from room temperature protic ionic liquids

    International Nuclear Information System (INIS)

    Suryanto, Bryan H.R.; Gunawan, Christian A.; Lu Xunyu; Zhao Chuan

    2012-01-01

    Controlled electrodeposition of silver onto glassy carbon, gold and indium tin oxide-coated glass substrates has been achieved from three room temperature protic ionic liquids (PILs), ethylammonium nitrate, triethylammonium methylsulfonate, and bis(2-methoxyethyl)ammonium acetate. Cyclic voltammetric, chronoamperometric, together with microscopic and X-ray techniques reveal that micro/nanostructured Ag thin films of controlled morphology, size, density, and uniformity can be achieved by tuning the electrodeposition parameters such as potential, time, types of PILs, substrate materials, and ionic liquid viscosity by altering the water content. Chronoamperometric results provide direct evidence that electrodeposition of Ag in protic ionic liquids takes place through a progressive nucleation and diffusion-controlled 3D growth mechanism. The as prepared Ag micro/nanoparticles have been employed as electrocatalysts for oxygen reduction reaction and exhibit excellent catalytic activity. The study provides promise for using protic ionic liquids as alternative electrolytes to conventional aprotic ionic liquids for electrodeposition of metals and nanostructured electrocatalysts.

  15. Influence of citrate ions as complexing agent for electrodeposition of CuInSe{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chraibi, F. [Universite Libre de Bruxelles (Belgium). Service de Sciences des Materiaux et Electrochimie; Universite Mohammed 5, Rabat (Morocco). Dept. de Physique; Fahoume, M.; Ennaoui, A. [Universite Mohammed 5, Rabat (Morocco). Dept. de Physique; Delplancke, J.L. [Universite Libre de Bruxelles (Belgium). Service de Sciences des Materiaux et Electrochimie

    2001-08-16

    The preparation of CuInSe{sub 2} thin films by electrodeposition is studied. The effect of sodium citrate (Na{sub 3}C{sub 6}H{sub 5}O{sub 7}) as complexing agent on the electrodeposition of pure copper, indium, selenium and of their ternary alloy is emphasized. Cathodic shifts of the copper and selenium electrodeposition potentials with increasing citrate concentration are observed. On the contrary, the presence of citrate in the electrolyte does not change the indium electrodeposition potential but improves its crystallinity. The surface morphology and the composition of the deposited films are characterized by scanning electron microscopy (SEM). The texture of the deposits and their compositions are analyzed by X-ray diffraction. The formation of CuInSe{sub 2} films with a chalcopyrite structure and good stoichiometry is observed. (orig.)

  16. Particle size dependence on oxygen reduction reaction activity of electrodeposited TaOx catalysts in acidic media

    KAUST Repository

    Seo, J.; Cha, Dong Kyu; Takanabe, Kazuhiro; Kubota, J.; Domen, K.

    2013-01-01

    The size dependence of the oxygen reduction reaction activity was studied for TaOx nanoparticles electrodeposited on carbon black for application to polymer electrolyte fuel cells (PEFCs). Compared with a commercial Ta2O5 material, the ultrafine

  17. Wear Resistant Amorphous and Nanocomposite Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Racek, O

    2008-03-26

    Glass forming materials (critical cooling rate <10{sup 4}K.s{sup -1}) are promising for their high corrosion and wear resistance. During rapid cooling, the materials form an amorphous structure that transforms to nanocrystalline during a process of devitrification. High hardness (HV 1690) can be achieved through a controlled crystallization. Thermal spray process has been used to apply coatings, which preserves the amorphous/nanocomposite structure due to a high cooling rate of the feedstock particles during the impact on a substrate. Wear properties have been studied with respect to process conditions and feedstock material properties. Application specific properties such as sliding wear resistance have been correlated with laboratory tests based on instrumented indentation and scratch tests.

  18. Compaction of amorphous iron–boron powder

    DEFF Research Database (Denmark)

    Hendriksen, Peter Vang; Mørup, Steen; Koch, Christian

    1993-01-01

    Large scale practical use of bulk amorphous alloys requires the capability of molding the material to a desired design, for instance by compaction of an amorphous powder. This is a difficult task because the sintering temperature is limited by the crystallization temperature of the alloy.1 Here we......, should facilitate a compaction. The passivation layer, however, impedes a compaction. Isostatic pressing at 540 K at a pressure of 200 MPa clearly illustrated this; pellets pressed from passivated powder were much more brittle than pellets pressed from unpassivated powder. The density of the pellets...... was very low ([approximately-equal-to]25% of the density of bulk FeB). We have designed a die for uniaxial pressing in which the compaction can be performed without exposing the powder to air and have obtained densities larger than 60% of that of bulk FeB. We have reported studies of the dependence...

  19. Study of an amorphous alloy core transformer

    Science.gov (United States)

    Nafalski, A.; Frost, D. C.

    1994-05-01

    Amorphous core transformers (ACT) have become a technological and commercial reality and there are an estimated 400,000 units installed worldwide [1]. Their applications reflect changes in buying practices, where the efficiency evaluation is an important factor in the purchasing decision for distribution transformers. Use of the total ownership cost (TOC) concept facilities the selection of a transformer on the basis of its performance. This concept is used in this paper to investigate the feasibility of applying a distribution ACT in Western Australian (WA). A 10 kVA ACT, evaluated by the TOC method, was compared with a traditional silicon iron core transformer of the same rating. The cost of amorphous metal (relative to alternative materials), the distribution load profile, and the values of capitalised loss costs are factors which affect the cost effectiveness of ACTs.

  20. Nature of amorphous polymorphism of water

    International Nuclear Information System (INIS)

    Koza, M.M.; Schober, H.; Hansen, T.; Geil, B.; Winkel, K.; Koehler, C.; Scheuermann, M.; Czeschka, F.

    2005-01-01

    We report elastic and inelastic neutron scattering experiments on different amorphous ice modifications. It is shown that an amorphous structure (HDA ' ) indiscernible from the high-density phase (HDA), obtained by compression of crystalline ice, can be formed from the very high-density phase (vHDA) as an intermediate stage of the transition of vHDA into its low-density modification (LDA ' ). Both HDA and HDA ' exhibit comparable small-angle scattering signals characterizing them as structures heterogeneous on a length scale of a few nanometers. The homogeneous structures are the initial and final transition stages vHDA and LDA ' , respectively. Despite their apparent structural identity on a local scale, HDA and HDA ' differ in their transition kinetics explored by in situ experiments. The activation energy of the vHDA-to-LDA ' transition is at least 20 kJ/mol higher than the activation energy of the HDA-to-LDA transition

  1. Determination of boron in amorphous alloys

    Energy Technology Data Exchange (ETDEWEB)

    Grazhulene, S.S.; Grossman, O.V.; Kuntscher, K.K.; Malygina, L.I.; Muller, E.N.; Telegin, G.F.

    1985-10-01

    In the determination of boron in amorphous alloys containingFe, Co, B, Si, Ni, and P having unusal magnetic and electrical properties, precise analysis and rapid analysis are necessary. To improve the metrological properties of the existing procedure, to find a rapid determination of boron in amorphous alloys, and to verify the accuracy of the results, in the present work the optimization of the photometric determination after extraction of the BF/sup -//sub 4/ ion pair with methylene blue has been studied, and a boron determination by flame photometry using selective methylation has been developed. The determination of boron by the flame photometric and spectrophotometric methods is shown. When a highly precise determination is needed, the spectrophotometric procedure can be used. This procedure is distinguished by its labor intensity and duration. When the need for reproducibility is less severe, the rapid flame photometric procedure is best.

  2. Mg amorphous alloys for biodegradable implants

    International Nuclear Information System (INIS)

    Danez, G.P.; Koga, G.Y.; Tonucci, S.; Bolfarini, C.; Kiminami, C.S.; Botta Filho, W.J.

    2010-01-01

    The use of implants made from amorphous alloys magnesium-based with additions of zinc and calcium are promising. Properties such as biocompatibility, low density, high mechanical strength, low modulus (as compared to alloys such as stainless steel and titanium), corrosion resistance and wear resistance make it attractive for use in implants. Moreover, the by-products of corrosion and wear are not toxic and may contribute to fixation. Aiming to understand the tendency of this amorphous ternary (Mg-Zn-Ca) and expand the information about this system, this work involved the use of the topological criterion of instability (λ) and the criterion of electronegativity (Δe) to the choice of compositions. The alloys were processed into wedge-shaped and analyzed structurally and in X-ray diffraction and scanning electron microscopy. (author)

  3. Annealing behavior of high permeability amorphous alloys

    International Nuclear Information System (INIS)

    Rabenberg, L.

    1980-06-01

    Effects of low temperature annealing on the magnetic properties of the amorphous alloy Co 71 4 Fe 4 6 Si 9 6 B 14 4 were investigated. Annealing this alloy below 400 0 C results in magnetic hardening; annealing above 400 0 C but below the crystallization temperature results in magnetic softening. Above the crystallization temperature the alloy hardens drastically and irreversibly. Conventional and high resolution transmission electron microscopy were used to show that the magnetic property changes at low temperatures occur while the alloy is truly amorphous. By imaging the magnetic microstructures, Lorentz electron microscopy has been able to detect the presence of microscopic inhomogeneities in this alloy. The low temperature annealing behavior of this alloy has been explained in terms of atomic pair ordering in the presence of the internal molecular field. Lorentz electron microscopy has been used to confirm this explanation

  4. Posterior amorphous corneal dystrophy: case report

    OpenAIRE

    Oliveira, Lauro Augusto de [UNIFESP; Vieira, Luiz Antônio [UNIFESP; Freitas, Denise de [UNIFESP; Sousa, Luciene Barbosa de [UNIFESP

    2006-01-01

    O objetivo deste trabalho é alertar o oftalmologista da possibilidade de se deparar com casos raros de distrofias corneanas. Neste caso correlacionamos os achados clínicos da distrofia amorfa posterior com refração, topografia e biomicroscopia ultra-sônica.The purpose of this paper is to warn the ophthalmologist about the possibility of facing rare cases of corneal dystrophies. Clinical findings of a case of posterior amorphous dystrophy were correlated with refraction, topography, and ultras...

  5. Metastable states in amorphous chalcogenide semiconductors

    CERN Document Server

    Mikla, Victor I

    2009-01-01

    This book addresses an interesting and technologically important class of materials, the amorphous chalcogenide semiconductors. Experimental results on the structural and electronic metastable states in Se-rich chalcogenides are presented. Special attention is paid to the states in the mobility gap and their sensitivity to various factors such as irradiation, annealing and composition. Photoinduced changes of structure and physical properties are also considered and structural transformation at photocrystallization is studied in detail. Finally, the authors discuss potential applications of th

  6. Characterization of diamond amorphized by ion implantation

    International Nuclear Information System (INIS)

    Allen, W.R.; Lee, E.H.

    1992-01-01

    Single crystal diamond has been implanted at 1 MeV with 2 x 10 20 Ar/m 2 . Rutherford backscattering spectrometry in a channeled geometry revealed a broad amorphized region underlying a thin, partially crystalline layer. Raman spectroscopy disclosed modifications in the bonding characteristic of the appearance of non-diamond carbon. The complementary nature of the two analysis techniques is demonstrated. The Knoop hardness of the implanted diamond was reduced by implantation

  7. Nanopillar arrays of amorphous carbon nitride

    Science.gov (United States)

    Sai Krishna, Katla; Pavan Kumar, B. V. V. S.; Eswaramoorthy, Muthusamy

    2011-07-01

    Nanopillar arrays of amorphous carbon nitride have been prepared using anodic aluminum oxide (AAO) membrane as a template. The amine groups present on the surface of these nanopillars were exploited for functionalization with oleic acid in order to stabilize the nanostructure at the aqueous-organic interface and also for the immobilization of metal nanoparticles and protein. These immobilised nanoparticles were found to have good catalytic activity.

  8. Structural and optical properties of electrodeposited molybdenum oxide thin films

    International Nuclear Information System (INIS)

    Patil, R.S.; Uplane, M.D.; Patil, P.S.

    2006-01-01

    Electrosynthesis of Mo(IV) oxide thin films on F-doped SnO 2 conducting glass (10-20/Ω/□) substrates were carried from aqueous alkaline solution of ammonium molybdate at room temperature. The physical characterization of as-deposited films carried by thermogravimetric/differential thermogravimetric analysis (TGA/DTA), infrared spectroscopy and X-ray diffraction (XRD) showed the formation of hydrous and amorphous MoO 2 . Scanning electron microscopy (SEM) revealed a smooth but cracked surface with multi-layered growth. Annealing of these films in dry argon at 450 deg. C for 1 h resulted into polycrystalline MoO 2 with crystallites aligned perpendicular to the substrate. Optical absorption study indicated a direct band gap of 2.83 eV. The band gap variation consistent with Moss rule and band gap narrowing upon crystallization was observed. Structure tailoring of as-deposited thin films by thermal oxidation in ambient air to obtain electrochromic Mo(VI) oxide thin films was exploited for the first time by this novel route. The results of this study will be reported elsewhere

  9. Fluctuation microscopy analysis of amorphous silicon models

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, J.M., E-mail: jmgibson@fsu.edu [Northeastern University, Department of Physics, Boston MA 02115 (United States); FAMU/FSU Joint College of Engineering, 225 Pottsdamer Street, Tallahassee, FL 32310 (United States); Treacy, M.M.J. [Arizona State University, Department of Physics, Tempe AZ 85287 (United States)

    2017-05-15

    Highlights: • Studied competing computer models for amorphous silicon and simulated fluctuation microscopy data. • Show that only paracrystalline/random network composite can fit published data. • Specifically show that pure random network or random network with void models do not fit available data. • Identify a new means to measure volume fraction of ordered material. • Identify unreported limitations of the Debye model for simulating fluctuation microscopy data. - Abstract: Using computer-generated models we discuss the use of fluctuation electron microscopy (FEM) to identify the structure of amorphous silicon. We show that a combination of variable resolution FEM to measure the correlation length, with correlograph analysis to obtain the structural motif, can pin down structural correlations. We introduce the method of correlograph variance as a promising means of independently measuring the volume fraction of a paracrystalline composite. From comparisons with published data, we affirm that only a composite material of paracrystalline and continuous random network that is substantially paracrystalline could explain the existing experimental data, and point the way to more precise measurements on amorphous semiconductors. The results are of general interest for other classes of disordered materials.

  10. Amorphous silicon as high index photonic material

    Science.gov (United States)

    Lipka, T.; Harke, A.; Horn, O.; Amthor, J.; Müller, J.

    2009-05-01

    Silicon-on-Insulator (SOI) photonics has become an attractive research topic within the area of integrated optics. This paper aims to fabricate SOI-structures for optical communication applications with lower costs compared to standard fabrication processes as well as to provide a higher flexibility with respect to waveguide and substrate material choice. Amorphous silicon is deposited on thermal oxidized silicon wafers with plasma-enhanced chemical vapor deposition (PECVD). The material is optimized in terms of optical light transmission and refractive index. Different a-Si:H waveguides with low propagation losses are presented. The waveguides were processed with CMOS-compatible fabrication technologies and standard DUV-lithography enabling high volume production. To overcome the large mode-field diameter mismatch between incoupling fiber and sub-μm waveguides three dimensional, amorphous silicon tapers were fabricated with a KOH etched shadow mask for patterning. Using ellipsometric and Raman spectroscopic measurements the material properties as refractive index, layer thickness, crystallinity and material composition were analyzed. Rapid thermal annealing (RTA) experiments of amorphous thin films and rib waveguides were performed aiming to tune the refractive index of the deposited a-Si:H waveguide core layer after deposition.

  11. Irradiation-induced amorphization process in graphite

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Hiroaki [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1996-04-01

    Effects of the element process of irradiation damage on irradiation-induced amorphization processes of graphite was studied. High orientation thermal decomposed graphite was cut about 100 nm width and used as samples. The irradiation experiments are carried out under the conditions of electronic energy of 100-400 KeV, ion energy of 200-600 KeV, ionic species Xe, Ar, Ne, C and He and the irradiation temperature at from room temperature to 900 K. The critical dose ({phi}a) increases exponentially with increasing irradiation temperature. The displacement threshold energy of graphite on c-axis direction was 27 eV and {phi}a{sup e} = 0.5 dpa. dpa is the average number of displacement to atom. The critical dose of ion irradiation ({phi}a{sup i}) was 0.2 dpa at room temperature, and amorphous graphite was produced by less than half of dose of electronic irradiation. Amorphization of graphite depending upon temperature is discussed. (S.Y.)

  12. Formation of iron disilicide on amorphous silicon

    Science.gov (United States)

    Erlesand, U.; Östling, M.; Bodén, K.

    1991-11-01

    Thin films of iron disilicide, β-FeSi 2 were formed on both amorphous silicon and on crystalline silicon. The β-phase is reported to be semiconducting with a direct band-gap of about 0.85-0.89 eV. This phase is known to form via a nucleation-controlled growth process on crystalline silicon and as a consequence a rather rough silicon/silicide interface is usually formed. In order to improve the interface a bilayer structure of amorphous silicon and iron was sequentially deposited on Czochralski silicon in an e-gun evaporation system. Secondary ion mass spectrometry profiling (SIMS) and scanning electron micrographs revealed an improvement of the interface sharpness. Rutherford backscattering spectrometry (RBS) and X-ray diffractiometry showed β-FeSi 2 formation already at 525°C. It was also observed that the silicide growth was diffusion-controlled, similar to what has been reported for example in the formation of NiSi 2 for the reaction of nickel on amorphous silicon. The kinetics of the FeSi 2 formation in the temperature range 525-625°C was studied by RBS and the activation energy was found to be 1.5 ± 0.1 eV.

  13. Inelastic neutron scattering of amorphous ice

    International Nuclear Information System (INIS)

    Fukazawa, Hiroshi; Ikeda, Susumu; Suzuki, Yoshiharu

    2001-01-01

    We measured the inelastic neutron scattering from high-density amorphous (HDA) and low-density amorphous (LDA) ice produced by pressurizing and releasing the pressure. We found a clear difference between the intermolecular vibrations in HDA and those in LDA ice: LDA ice has peaks at 22 and 33 meV, which are also seen in the spectrum of lattice vibrations in ice crystal, but the spectrum of HDA ice does not have these peaks. The excitation energy of librational vibrations in HDA ice is 10 meV lower than that in LDA ice. These results imply that HDA ice includes 2- and 5-coordinated hydrogen bonds that are created by breakage of hydrogen bonds and migration of water molecules into the interstitial site, while LDA ice contains mainly 4-coordinated hydrogen bonds and large cavities. Furthermore, we report the dynamical structure factor in the amorphous ice and show that LDA ice is more closely related to the ice crystal structure than to HDA ice. (author)

  14. Fluctuation microscopy analysis of amorphous silicon models

    International Nuclear Information System (INIS)

    Gibson, J.M.; Treacy, M.M.J.

    2017-01-01

    Highlights: • Studied competing computer models for amorphous silicon and simulated fluctuation microscopy data. • Show that only paracrystalline/random network composite can fit published data. • Specifically show that pure random network or random network with void models do not fit available data. • Identify a new means to measure volume fraction of ordered material. • Identify unreported limitations of the Debye model for simulating fluctuation microscopy data. - Abstract: Using computer-generated models we discuss the use of fluctuation electron microscopy (FEM) to identify the structure of amorphous silicon. We show that a combination of variable resolution FEM to measure the correlation length, with correlograph analysis to obtain the structural motif, can pin down structural correlations. We introduce the method of correlograph variance as a promising means of independently measuring the volume fraction of a paracrystalline composite. From comparisons with published data, we affirm that only a composite material of paracrystalline and continuous random network that is substantially paracrystalline could explain the existing experimental data, and point the way to more precise measurements on amorphous semiconductors. The results are of general interest for other classes of disordered materials.

  15. Characterization of Amorphous and Co-Amorphous Simvastatin Formulations Prepared by Spray Drying

    Directory of Open Access Journals (Sweden)

    Goedele Craye

    2015-12-01

    Full Text Available In this study, spray drying from aqueous solutions, using the surface-active agent sodium lauryl sulfate (SLS as a solubilizer, was explored as a production method for co-amorphous simvastatin–lysine (SVS-LYS at 1:1 molar mixtures, which previously have been observed to form a co-amorphous mixture upon ball milling. In addition, a spray-dried formulation of SVS without LYS was prepared. Energy-dispersive X-ray spectroscopy (EDS revealed that SLS coated the SVS and SVS-LYS particles upon spray drying. X-ray powder diffraction (XRPD and differential scanning calorimetry (DSC showed that in the spray-dried formulations the remaining crystallinity originated from SLS only. The best dissolution properties and a “spring and parachute” effect were found for SVS spray-dried from a 5% SLS solution without LYS. Despite the presence of at least partially crystalline SLS in the mixtures, all the studied formulations were able to significantly extend the stability of amorphous SVS compared to previous co-amorphous formulations of SVS. The best stability (at least 12 months in dry conditions was observed when SLS was spray-dried with SVS (and LYS. In conclusion, spray drying of SVS and LYS from aqueous surfactant solutions was able to produce formulations with improved physical stability for amorphous SVS.

  16. Characterization of Amorphous and Co-Amorphous Simvastatin Formulations Prepared by Spray Drying.

    Science.gov (United States)

    Craye, Goedele; Löbmann, Korbinian; Grohganz, Holger; Rades, Thomas; Laitinen, Riikka

    2015-12-03

    In this study, spray drying from aqueous solutions, using the surface-active agent sodium lauryl sulfate (SLS) as a solubilizer, was explored as a production method for co-amorphous simvastatin-lysine (SVS-LYS) at 1:1 molar mixtures, which previously have been observed to form a co-amorphous mixture upon ball milling. In addition, a spray-dried formulation of SVS without LYS was prepared. Energy-dispersive X-ray spectroscopy (EDS) revealed that SLS coated the SVS and SVS-LYS particles upon spray drying. X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC) showed that in the spray-dried formulations the remaining crystallinity originated from SLS only. The best dissolution properties and a "spring and parachute" effect were found for SVS spray-dried from a 5% SLS solution without LYS. Despite the presence of at least partially crystalline SLS in the mixtures, all the studied formulations were able to significantly extend the stability of amorphous SVS compared to previous co-amorphous formulations of SVS. The best stability (at least 12 months in dry conditions) was observed when SLS was spray-dried with SVS (and LYS). In conclusion, spray drying of SVS and LYS from aqueous surfactant solutions was able to produce formulations with improved physical stability for amorphous SVS.

  17. High Discharge Rate Electrodeposited Zinc Electrode for Use in Alkaline Microbattery

    Directory of Open Access Journals (Sweden)

    A. L. Nor Hairin

    2012-01-01

    Full Text Available High discharge rate zinc electrode is prepared from electrodeposition process. The electrolytic bath consists of zinc chloride as the metal source and ammonium chloride as the supporting electrolyte. The concentration of the supporting electrolyte is varied from zero until 4 M, while the concentration of zinc chloride is fixed at 2 M. The aim is to produce a porous zinc coating with an enhanced and intimate interfacial area per unit volume. These characteristics shall contribute towards reduced ohmic losses, improved active material utilization, and subsequently producing high rate capacity electrochemical cell. Nitrogen physisorption at 77 K is used to measure the BET surface area and pore volume density of the zinc electrodeposits. The electrodeposited zinc electrodes are then fabricated into alkaline zinc-air microbattery measuring 1 cm2 area x ca. 305 µm thick. The use of inorganic MCM-41 membrane separator enables the fabrication of a compact cell design. The quality of the electrodeposited zinc electrodes is gauged directly from the electrochemical performance of zinc-air cell. Zinc electrodeposits prepared from electrolytic bath of 2 M NH4Cl produces the highest discharge capacity.ABSTRAK: Elektrod zink dengan kadar discas tinggi telah dihasilkan dengan proses saduran elektrokimia. Takungan elektrolit terdiri daripada zink klorida sebagai sumber logam dan ammonium klorida sebagai elektrolit sokongan. Kepekatan elektrolit sokongan diubah daripada sifar hingga 4 M, sementara kepekatan zink klorida ditetapkan pada 2 M. Ini bertujuan untuk mendapatkan saduran zink yang poros dengan luas permukaan per unit isipadu dan sentuhan antaramuka yang dipertingkatkan. Ciri-ciri ini akan menyumbang terhadap pengurangan kehilangan disebabkan kerintangan, pertambahan dalam gunapakai bahan aktif dan akhirnya menghasilkan sel elektrokimia berprestasi tinggi. Physisorpsi nitrogen pada 77 K telah digunakan untuk mengukur luas permukaan BET dan isipadu liang

  18. Cutting the Gordian Knot of electrodeposition via controlled cathodic corrosion enabling the production of supported metal nanoparticles below 5 nm

    OpenAIRE

    Vanrenterghem, B.; Bele, M.; Zepeda, F.R.; Sala, M.; Hodnik, N.; Breugelmans, Tom

    2018-01-01

    Abstract: In the past decades, there has been an ongoing search for tailor-made active metal nanoparticles for the use as electrocatalysts. An upcoming versatile and green method for the synthesis of nanoparticles is electrodeposition. However, the state-of-the-art electrodeposited metal particle sizes are in the range of 50200 nm. Production of high surface area metallic electrocatalysts with small particle sizes is a serious limitation of electrodeposition, i.e., the Gordian Knot. In this a...

  19. Amorphous surface layer versus transient amorphous precursor phase in bone - A case study investigated by solid-state NMR spectroscopy.

    Science.gov (United States)

    Von Euw, Stanislas; Ajili, Widad; Chan-Chang, Tsou-Hsi-Camille; Delices, Annette; Laurent, Guillaume; Babonneau, Florence; Nassif, Nadine; Azaïs, Thierry

    2017-09-01

    The presence of an amorphous surface layer that coats a crystalline core has been proposed for many biominerals, including bone mineral. In parallel, transient amorphous precursor phases have been proposed in various biomineralization processes, including bone biomineralization. Here we propose a methodology to investigate the origin of these amorphous environments taking the bone tissue as a key example. This study relies on the investigation of a bone tissue sample and its comparison with synthetic calcium phosphate samples, including a stoichiometric apatite, an amorphous calcium phosphate sample, and two different biomimetic apatites. To reveal if the amorphous environments in bone originate from an amorphous surface layer or a transient amorphous precursor phase, a combined solid-state nuclear magnetic resonance (NMR) experiment has been used. The latter consists of a double cross polarization 1 H→ 31 P→ 1 H pulse sequence followed by a 1 H magnetization exchange pulse sequence. The presence of an amorphous surface layer has been investigated through the study of the biomimetic apatites; while the presence of a transient amorphous precursor phase in the form of amorphous calcium phosphate particles has been mimicked with the help of a physical mixture of stoichiometric apatite and amorphous calcium phosphate. The NMR results show that the amorphous and the crystalline environments detected in our bone tissue sample belong to the same particle. The presence of an amorphous surface layer that coats the apatitic core of bone apatite particles has been unambiguously confirmed, and it is certain that this amorphous surface layer has strong implication on bone tissue biogenesis and regeneration. Questions still persist on the structural organization of bone and biomimetic apatites. The existing model proposes a core/shell structure, with an amorphous surface layer coating a crystalline bulk. The accuracy of this model is still debated because amorphous calcium

  20. Non-Cyanide Electrodeposited Ag–PTFE Composite Coating Using Direct or Pulsed Current Deposition

    Directory of Open Access Journals (Sweden)

    Raymond Sieh

    2016-07-01

    Full Text Available The effects of FC-4 cationic surfactant on electrodeposited Ag–PTFE composite coating using direct or pulsed currents were studied using scanning electron microscope (SEM, energy dispersive X-ray (EDS, optical microscope, and a linear tribometer. FC-4:PTFE in various ratios were added to a non-cyanide succinimide silver complex bath. Direct or pulsed current method was used at a constant current density to enable comparison between both methods. A high incorporation rate of PTFE was successfully achieved, with pulsed current being highly useful in increasing the amount of PTFE in the composite coating. The study of coating wear under sliding showed that a large majority of the electrodeposited coatings still managed to adhere to the substrate, even after 10 wear cycles of sliding tests. Performance improvements were achieved on all the samples with a coefficient of friction (CoF between 0.06 and 0.12.

  1. Variation of magnetoimpedance of electrodeposited NiFe/Cu with deposition current density

    Science.gov (United States)

    Mishra, A. C.; Jha, A. K.

    2017-12-01

    An investigation about influence of deposition current density on electrodeposited magnetic film is reported in this paper. Ferromagnetic NiFe thin films were electrodeposited on copper wires of 100 μm diameter for various electrdepostion current densities ranging from 10 to 60 mA/cm2 maintaining equal thickness in all films. The composition of deposited film varied with deposition current density and in particular, a composition of Ni79Fe21 was achieved for a current density of 20 mA/cm2. The surface microstructure of the film deposited at the current density of 20 mA/cm2 was found to have excellent smoothness. The coercivity of the film was lowest and highest value of magnetoimpedance was measured for this film. The influence of current density on film composition and hence magnetic properties was attributed to the change of deposition mechanism.

  2. Microgravity effects on electrodeposition of metals and metal-cermet mixtures

    Science.gov (United States)

    Maybee, George W.; Riley, Clyde; Coble, H. Dwain

    1987-01-01

    An experimental system, designed to investigate the potential advantages of electrodeposition in microgravity, is being developed by the McDonnell Douglas Astronautics Company-Huntsville Division and the University of Alabama in Huntsville. It is intended to fly as an Orbiter payload when NASA resumes STS operations. The system will provide power, thermal conditioning, command and control for the production of electrodeposits; system performance data will be recorded for post-flight analysis. Plated metal surfaces will be created using simple electrolytic cells with pure metal electrodes immersed in aqueous electrolytic solutions. Crystalline structure and other properties will be analyzed to identify differences between samples produced in flight and those obtained from ground-based operations.

  3. Surface Engineering of Triboelectric Nanogenerator with an Electrodeposited Gold Nanoflower Structure.

    Science.gov (United States)

    Park, Sang-Jae; Seol, Myeong-Lok; Jeon, Seung-Bae; Kim, Daewon; Lee, Dongil; Choi, Yang-Kyu

    2015-09-14

    A triboelectric nanogenerator composed of gold nanoflowers is demonstrated. The proposed triboelectric nanogenerator creates electricity by contact-separation-based electrification between an anodic metal and a cathodic polymer. For the improvement of output power via the enlargement of the effective surface area in the anodic metal, gold nanoflowers that produce a hierarchical morphology at a micro-to-nano scale by electrodeposition are utilized. The hierarchical morphology is controlled by the applied voltage and deposition time. Even though the triboelectric coefficient of gold is inferior to those of other metals, gold is very attractive to make a flower-like structure by electrodeposition. Moreover, gold is stable against oxidation by oxygen in air. From a reliability and practicality point of view, the aforementioned stability against oxidation is preferred.

  4. A process for electrodeposition of layers of niobium, vanadium, molybdenum or tungsten, or of their alloys

    International Nuclear Information System (INIS)

    Diepers, H.; Schmidt, O.

    1977-01-01

    An improvement is proposed for the process for electrodeposition of layers of niobium, vanadium, molybdenum or tungsten or of their alloys from molten-salt electrolytes (fluorid melts) which is to increase the quality of layers in order to obtain regular thickness and smooth surfaces. According to the invention, a pre-separation is executed on an auxiliary cathode before the (preheated) cathode is immersed. The cathode is only charged for separation after the adjustment of a constant anode potential. It is an advantage that the auxiliary cathode is mechanically and electrically connected with the cathode. As an electrolyte, a mixture of niobium fluorides and a eustetic mixture of potassium fluorides, sodium fluorides and lithium fluorides are particularly suitable for the electrodeposition of miobium. (UWI) [de

  5. Electrodeposition of zinc-doped silane films for corrosion protection of mild steels

    International Nuclear Information System (INIS)

    Wu Liankui; Hu Jiming; Zhang Jianqing

    2012-01-01

    Highlights: ► Metallic zinc is doped into organosilane films by one-step electrodeposition. ► The composite films exhibit the improved corrosion resistance of mild steels. ► Zinc-doping provides additional cathodic protection to the mild steels. - Abstract: Organosilane/zinc composite films are prepared by one-step electrodeposition onto cold-rolled steels for corrosion protection. Electrochemical impedance spectroscopy measurement, bulk solution immersion and wet heat tests all show that the composite films have improved corrosion performance. X-ray photoelectron spectroscopy measurement suggests the successful encapsulation of metallic zinc. The embedding of metallic zinc results in negative shift in open-circuit potential of the film-covered electrodes. Such cathodic protection effect given by the metallic zinc provides the improved corrosion resistance of the composite films.

  6. A basic study on electrodeposition of metal halogen mixture in fluoride/chloride molten salts

    International Nuclear Information System (INIS)

    Shim, Z. H.; Kang, Y. H.; Hwang, S. C.; Woo, M. S.; Yoo, J. H.

    2001-01-01

    The electrodeposition experiments of metal mixture composed of U, Y, Gd, Nd and Ce were carried out in the KCl-LiCl and LiF-NaF-KF (FLINAK) eutectic melts at 500 .deg. C and 600 .deg. C, respectively. Uranium was major component in the cathode deposits, and the separation factors of uranium with respect to the rare earths (REs) are nearly same in both electrolytes. REs content in the cathode deposits increased sharply below -1.9V which is the decomposition voltage of the halogen compounds of REs. The current efficiency for electrodeposition of metals was inversely in proportion to the applied voltage in the range of -1.0 V to -1.9 V(vs. S.S. 304 or Ni)

  7. Magnetic transition phase diagram of cobalt clusters electrodeposited on HOPG: Experimental and micromagnetic modelling study

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, M., E-mail: mrivera@fisica.unam.m [Imperial College London, Department of Chemistry, South Kensington Campus, London SW7 2AZ (United Kingdom); Rios-Reyes, C.H. [Universidad Autonoma Metropolitana-Azcapotzalco, Departamento de Materiales, Av. San Pablo 180, Col. Reynosa Tamaulipas, C.P. 02200, Mexico D.F. (Mexico); Universidad Autonoma del Estado de Hidalgo, Centro de Investigaciones Quimicas, Mineral de la Reforma, Hidalgo, C.P. 42181 (Mexico); Mendoza-Huizar, L.H. [Universidad Autonoma del Estado de Hidalgo, Centro de Investigaciones Quimicas, Mineral de la Reforma, Hidalgo, C.P. 42181 (Mexico)

    2011-04-15

    The magnetic transition from mono- to multidomain magnetic states of cobalt clusters electrodeposited on highly oriented pyrolytic graphite electrodes was studied experimentally using Magnetic Force Microscopy. From these images, it was found that the critical size of the magnetic transition is dominated by the height rather than the diameter of the aggregate. This experimental behavior was found to be consistent with a theoretical single-domain ferromagnetic model that states that a critical height limits the monodomain state. By analyzing the clusters magnetic states as a function of their dimensions, magnetic exchange constant and anisotropy value were obtained and used to calculate other magnetic properties such as the exchange length, magnetic wall thickness, etc. Finally, a micromagnetic simulation study correctly predicted the experimental magnetic transition phase diagram. - Research highlights: > Electrodeposition of cobalt clusters. > Mono to multidomain magnetic transition. > Magnetic phase diagram.

  8. Magnetic transition phase diagram of cobalt clusters electrodeposited on HOPG: Experimental and micromagnetic modelling study

    International Nuclear Information System (INIS)

    Rivera, M.; Rios-Reyes, C.H.; Mendoza-Huizar, L.H.

    2011-01-01

    The magnetic transition from mono- to multidomain magnetic states of cobalt clusters electrodeposited on highly oriented pyrolytic graphite electrodes was studied experimentally using Magnetic Force Microscopy. From these images, it was found that the critical size of the magnetic transition is dominated by the height rather than the diameter of the aggregate. This experimental behavior was found to be consistent with a theoretical single-domain ferromagnetic model that states that a critical height limits the monodomain state. By analyzing the clusters magnetic states as a function of their dimensions, magnetic exchange constant and anisotropy value were obtained and used to calculate other magnetic properties such as the exchange length, magnetic wall thickness, etc. Finally, a micromagnetic simulation study correctly predicted the experimental magnetic transition phase diagram. - Research highlights: → Electrodeposition of cobalt clusters. →Mono to multidomain magnetic transition. → Magnetic phase diagram.

  9. The Cu2ZnSnSe4 thin films solar cells synthesized by electrodeposition route

    Science.gov (United States)

    Li, Ji; Ma, Tuteng; Wei, Ming; Liu, Weifeng; Jiang, Guoshun; Zhu, Changfei

    2012-06-01

    An electrodeposition route for preparing Cu2ZnSnSe4 thin films for thin film solar cell absorber layers is demonstrated. The Cu2ZnSnSe4 thin films are prepared by co-electrodeposition Cu-Zn-Sn metallic precursor and subsequently annealing in element selenium atmosphere. The structure, composition and optical properties of the films were investigated by X-ray diffraction (XRD), Raman spectrometry, energy dispersive spectrometry (EDS) and UV-VIS absorption spectroscopy. The Cu2ZnSnSe4 thin film with high crystalline quality was obtained, the band gap and absorption coefficient were 1.0 eV and 10-4 cm-1, which is quite suitable for solar cells fabrication. A solar cell with the structure of ZnO:Al/i-ZnO/CdS/Cu2ZnSnSe4/Mo/glass was fabricated and achieved an conversion efficiency of 1.7%.

  10. X-ray diffraction investigation of self-annealing in nanocrystalline copper electrodeposits

    DEFF Research Database (Denmark)

    Pantleon, Karen; Somers, Marcel A. J.

    2006-01-01

    X-ray diffraction analysis and electrical resistivity measurements were conducted simultaneously for in-situ examination of self-annealing in copper electrodeposits. Considerable growth of the as-deposited nano-sized crystallites occurs with time and the crystallographic texture changes by multip...... twinning during self-annealing. The kinetics of self-annealing depends on the layer thickness as well as on the orientation and/or the size of the as-deposited crystallites. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.......X-ray diffraction analysis and electrical resistivity measurements were conducted simultaneously for in-situ examination of self-annealing in copper electrodeposits. Considerable growth of the as-deposited nano-sized crystallites occurs with time and the crystallographic texture changes by multiple...

  11. The mechanism of electrodeposition of bismuth sulfide and cadmium sulfide from dimethylsulfoxide and diethylene glycol solution

    International Nuclear Information System (INIS)

    Gilbert, C.M.; Baranski, A.S.; Fawcett, W.R.

    1985-01-01

    The kinetics of the electrodeposition of Bi 2 S 3 on an electrode covered with a coherent layer of Bi 2 S 3 was examined by analysis of the Tafel plots for different solution compositions and at different temperatures in two nonaqueous solvents, dimethylsulfoxide (DMSO) and diethylene glycol (DEG). The results were compared with those obtained for the electrodeposition of CdS on CdS under similar conditions. In both cases, it was found that the rate-determining step was an irreversible electron transfer. The rate of the reaction was independent of the metal ion concentration, but electrochemical orders with respect to S 8 of 0.7 in DMSO and 1.0 in DEG were found. Several mechanisms explaining these results are proposed and discussed

  12. Optical properties of zinc oxide-based ternary compounds synthesized by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Cembrero, J. [Departament d' Enginyeria Mecanica i Materials, Universitat Politecnica de Valencia, Cami de Vera s/n, 46022 Valencia (Spain); Mollar, M.; Tortosa, M. [Departament de Fisica Aplicada, Universitat Politecnica de Valencia, Cami de Vera s/n, 46022 Valencia (Spain); Mari, B.

    2008-07-01

    Structure, morphology and optical properties of ZnO thin films grown by electrodeposition under different conditions changing both solvent (water or dimethylsulfoxide) and substrate (polycrystalline FTO or monocrystalline GaN) are reported. The results point out the advantage of using dimethylsulfoxide when uniform, oriented and highly transparent films are required. On the other hand electrodeposition in aqueous bath produces perfectly defined hexagonal ZnO columns which can be fully oriented by chosing a suitable substrate. Photoluminescence has only been observed for ZnO films grown in aqueous bath. Ternary compounds as ZnMO (M=Cd,Co,Mn) with a controlled ratio between both cations, and morphology and structure like binary ZnO can be easily obtained from dimethylsulfoxide. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Impact of anode substrates on electrodeposited zinc over cycling in zinc-anode rechargeable alkaline batteries

    International Nuclear Information System (INIS)

    Wei, Xia; Desai, Divyaraj; Yadav, Gautam G.; Turney, Damon E.; Couzis, Alexander; Banerjee, Sanjoy

    2016-01-01

    Electrochemical behavior of Ag, Bi, Cu, Fe, Ni and Sn substrates on zinc deposition was evaluated over battery cycling by cyclic voltammetry and electrochemical impedance spectroscopy. The effect of Bi, Cu, Ni, and Sn substrates on zinc electrodeposition during battery cycling was investigated using scanning electron microscopy and X-ray diffraction. The corrosion behavior of each metal in 9 M KOH and the corrosion rates of zinc plated on each substrate were analyzed by Tafel extrapolation method from the potentiodynamic polarization curves and electrochemical impedance spectroscopy. Although the charge-transfer resistance (R_c_t) of zinc electrodeposition is lowest on Sn, Sn eventually corrodes on cycling in alkaline media. Use of Ni as a substrate causes zinc to deteriorate on account of rapid hydrogen evolution. Bi and Cu substrates are more suitable for use as current collectors in zinc-anode alkaline rechargeable batteries because of their low corrosion rate and compact zinc deposition over battery cycling.

  14. Electrodeposited gold nanoparticles on carbon nanotube-textile: Anode material for glucose alkaline fuel cells

    KAUST Repository

    Pasta, Mauro; Hu, Liangbing; La Mantia, Fabio; Cui, Yi

    2012-01-01

    In the present paper we propose a new anode material for glucose-gluconate direct oxidation fuel cells prepared by electrodepositing gold nanoparticles onto a conductive textile made by conformally coating single walled carbon nanotubes (SWNT) on a polyester textile substrate. The electrodeposition conditions were optimized in order to achieve a uniform distribution of gold nanoparticles in the 3D porous structure of the textile. On the basis of previously reported studies, the reaction conditions (pH, electrolyte composition and glucose concentration) were tuned in order to achieve the highest oxidation rate, selectively oxidizing glucose to gluconate. The electrochemical characterization was carried out by means of cyclic voltammetry. © 2012 Elsevier B.V. All rights reserved.

  15. Effect of plasma nitriding on electrodeposited Ni–Al composite coating

    DEFF Research Database (Denmark)

    Daemi, N.; Mahboubi, F.; Alimadadi, Hossein

    2011-01-01

    In this study plasma nitriding is applied on nickel–aluminum composite coating, deposited on steel substrate. Ni–Al composite layers were fabricated by electro-deposition process in Watt’s bath containing Al particles. Electrodeposited specimens were subjected to plasma atmosphere comprising of N2......–20% H2, at 500°C, for 5h. The surface morphology investigated, using a scanning electron microscope (SEM) and the surface roughness was measured by use of contact method. Chemical composition was analyzed by X-ray fluorescence spectroscopy and formation of AlN phase was confirmed by X-ray diffraction....... The corrosion resistance of composite coatings was measured by potentiodynamic polarization in 3.5% NaCl solution. The obtained results show that plasma nitriding process leads to an increase in microhardness and corrosion resistance, simultaneously....

  16. Direct fabrication of gas diffusion cathode by pulse electrodeposition for proton exchange membrane water electrolysis

    Science.gov (United States)

    Park, Hyanjoo; Choe, Seunghoe; Kim, Hoyoung; Kim, Dong-Kwon; Cho, GeonHee; Park, YoonSu; Jang, Jong Hyun; Ha, Don-Hyung; Ahn, Sang Hyun; Kim, Soo-Kil

    2018-06-01

    Pt catalysts for water electrolysis were prepared on carbon paper by using both direct current and pulse electrodeposition. Controlling the mass transfer of Pt precursor in the electrolyte by varying the deposition potential enables the formation of various Pt particle shapes such as flower-like and polyhedral particles. Further control of the deposition parameters for pulse electrodeposition resulted in changes to the particle size and density. In particular, the upper potential of pulse was found to be the critical parameter controlling the morphology of the particles and their catalytic activity. In addition to the typical electrochemical measurements, Pt samples deposited on carbon paper were used as cathodes for a proton exchange membrane water electrolyser. This single cell test revealed that our Pt particle samples have exceptional mass activity while being cost effective.

  17. Fabrication and magnetization measurement of Ni thin films on silicon substrate by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Tang Yang [Key Laboratory of Excited State Process, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 16 East Nan-Hu Road, Open Economic Zone, Changchun 130033 (China); Graduate School of the Chinese Academy of Sciences (China); Zhao Dongxu [Key Laboratory of Excited State Process, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 16 East Nan-Hu Road, Open Economic Zone, Changchun 130033 (China)], E-mail: dxzhao2000@yahoo.com.cn; Shen Dezhen; Zhang Jiying; Li Binghui; Lu Youming; Fan Xiwu [Key Laboratory of Excited State Process, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 16 East Nan-Hu Road, Open Economic Zone, Changchun 130033 (China)

    2008-02-29

    Ni thin films were electrodeposited on n-Si (100) substrate from the electrolytes containing Ni(CH{sub 3}COO){sub 2} and CH{sub 3}COONH{sub 4} at room temperature. The scanning electron microscope images of the films reveals the uniform distribution of the nickel all over the substrate surface, which illustrates that the fine Ni films on large scales could be obtained through the method of electrodeposition. Vibrating sample magnetometer measurement with the applied field parallel to the surface shows obvious hysteresis loops of the magnetic thin films. The morphology and magnetism of the Ni thin films evolves with the deposition time increasing. The effect of deposition conditions on the properties of the Ni thin films is investigated.

  18. Role of anisotropy in determining stability of electrodeposition at solid-solid interfaces

    Science.gov (United States)

    Ahmad, Zeeshan; Viswanathan, Venkatasubramanian

    2017-10-01

    We investigate the stability of electrodeposition at solid-solid interfaces for materials exhibiting an anisotropic mechanical response. The stability of electrodeposition or resistance to the formation of dendrites is studied within a linear stability analysis. The deformation and stress equations are solved using the Stroh formalism and faithfully recover the boundary conditions at the interface. The stability parameter is used to quantify the stability of different solid-solid interfaces incorporating the full anisotropy of the elastic tensor of the two materials. Results show a high degree of variability in the stability parameter depending on the crystallographic orientation of the solids in contact, and point to opportunities for exploiting this effect in developing Li metal anodes.

  19. Development of carbon nanotubes reinforced hydroxyapatite composite coatings on titanium by electrodeposition method

    International Nuclear Information System (INIS)

    Gopi, D.; Shinyjoy, E.; Sekar, M.; Surendiran, M.; Kavitha, L.; Sampath Kumar, T.S.

    2013-01-01

    Highlights: •Successful development of CNTs reinforced HAP coating on Ti by electrodeposition. •CNTs as a reinforcing material imparts strength and toughness to HAP. •Incorporating CNTs improves crystallinity, morphology, biological properties of HAP. •CNTs–HAP coating on Ti is bioresistive, better candidate for implant applications. -- Abstract: Carbon nanotubes (CNTs) are outstanding reinforcement material for imparting strength and toughness to brittle hydroxyapatite (HAP). This work reports the electrodeposition of CNTs reinforced HAP on titanium substrate at −1.4 V vs. SCE during 30 min with the functionalised CNTs concentration ranging from 0 to 2 wt.%. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDX), high resolution transmission electron microscopy (HRTEM), mechanical and biological studies were used to characterise the coatings. Also, the corrosion resistance of the coatings was evaluated by electrochemical techniques in simulated body fluid (SBF) solution

  20. An electrodeposition method for the preparation of actinides and Ra samples for α spectrometry

    International Nuclear Information System (INIS)

    Garcia-Tenorio, R.; Garcia-Leon, M.; Madurga, G.; Piazza, C.

    1986-01-01

    As it is confirmed in this work, electrodeposition of α radionuclides gives a simple method for preparing α samples of high spectrometric quality, compared to those prepared by evaporation. Then we give the methods for electrodepositon or α emitters use in our Department. Actinides α emitters are electroplated from a 1% H 2 SO 4 medium with a recovery of about 90%. The samples of Ra are prepared by electrodeposition from a HCl + CH 3 -COONH 4 medium at pH approx.= 5. In this case the recovery reaches a value that ranges from 70 to 90%. For these measurements a Si surface barrier detector has been used. Some of its features are discussed in the text. (author)

  1. Rocking disc electro-deposition of copper films on Mo/MoSe{sub 2} substrates

    Energy Technology Data Exchange (ETDEWEB)

    Cummings, Charles Y.; Frith, Paul E. [Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Zoppi, Guillaume; Forbes, Ian [Northumbria Photovoltaics Applications Centre, Northumbria University, NE1 8ST (United Kingdom); Rogers, Keith D. [Cranfield Health, Cranfield University, Shrivenham Campus, Swindon, SN6 8LA (United Kingdom); Lane, David W. [Department of Applied Science, Security and Resilience, Cranfield University, Shrivenham, Swindon, SN6 8LA (United Kingdom); Marken, Frank, E-mail: F.Marken@bath.ac.uk [Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)

    2011-08-31

    A novel electro-deposition method based on a rocking disc system with {pi}/3 amplitude and variable frequency is introduced. Uniform copper films were deposited from a 0.1 M CuSO{sub 4}/3.0 M NaOH/0.2 M sorbitol bath directly onto 12.1 cm{sup 2} Mo/MoSe{sub 2} substrates with X-ray diffraction showing a thickness variation of {+-}5% over this area. Investigation of the mass transport conditions suggests (i) uniform diffusion over the sample, (ii) a rate of mass transport proportional to the square root of the rocking rate, and (iii) turbulent conditions, which are able to dislodge gas bubbles during electro-deposition.

  2. Electrodeposition and Characterization of Nanocrystalline Ni-Mo Catalysts for Hydrogen Production

    Directory of Open Access Journals (Sweden)

    J. Halim

    2012-01-01

    Full Text Available Ni-Mo nanocrystalline deposits (7–43 nm with a nodular morphology were prepared by electrodeposition using direct current from citrate-ammonia solutions. They exhibited a single Ni-Mo solid solution phase. The size of the nodules increased as electroplating current density increased. The molybdenum content—estimated using EDX analysis—in the deposits decreased from about 31 to 11 wt% as the current density increased from 5 to 80 mA·cm−2. The highest microhardness value (285 Hv corresponded to nanodeposits with 23% Mo. The highest corrosion resistance accompanied by relatively high hardness was detected for electrodeposits containing 15% Mo. Mo content values between 11 and 15% are recommended for obtaining better electrocatalytic activity for HER.

  3. Electrocatalytic reduction of carbon dioxide on electrodeposited tin-based surfaces

    Science.gov (United States)

    Alba, Bianca Christina S.; Camayang, John Carl A.; Mopon, Marlon L.; del Rosario, Julie Anne D.

    2017-08-01

    The electrocatalytic reduction of carbon dioxide to small organic molecular compounds provides a means of generating alternative fuel source while suppressing climate change. Suitable catalysts, however, are necessary to optimize its reaction kinetics towards more valuable products. Consequently, in this study, electrodeposited Sn electrodes have been developed as catalysts for CO2 electroreduction. Deposition potential was varied to produce different Sn catalysts. SEM showed varying morphologies and increasing amount as the applied potential becomes more negative. Cyclic voltammetry and chronoamperometry showed that the activity and stability of the catalysts towards CO2 reduction depend on the morphology and presence of tin oxides. These results provide a better understanding on the performance of electrodeposited Sn-based surfaces as catalysts for CO2 reduction.

  4. Cathodic electrodeposition of CuInSe sub 2 thin films

    Energy Technology Data Exchange (ETDEWEB)

    Guillen, C; Galiano, E; Herrero, J [Inst. de Energias Renovables (CIEMAT), Madrid (Spain)

    1991-01-01

    In order to study the preparation process of CuInSe{sub 2} thin films by a one-step electrodeposition method, thin films of the compound were prepared from aqueous citric acid (C{sub 6}H{sub 8}O{sub 7} . H{sub 2}O) plating baths onto titanium substrates. During electrodeposition, the bath composition and deposition potential were changed to obtain stoichiometric thin films. In general, close to stoichiometry, layers rich in selenium were observed, and this excess of selenium was removed after heat treatment. Best quality films were obtained after annealing at 400deg C during 15 min. X-ray diffraction showed the formation of CuInSe{sub 2} films, the chalcopyrite structure, at heating treatment temperatures higher than 350deg C. Optical measurements showed that the band gap of the deposited material was 0.99 eV. (orig.).

  5. Nanoporous PdCo Catalyst for Microfuel Cells: Electrodeposition and Dealloying

    Directory of Open Access Journals (Sweden)

    Satoshi Tominaka

    2011-01-01

    Full Text Available PdCo alloy is a promising catalyst for oxygen reduction reaction of direct methanol fuel cells because of its high activity and the tolerance to methanol. We have applied this catalyst in order to realize on-chip fuel cell which is a membraneless design. The novel design made the fuel cells to be flexible and integratable with other microdevices. Here, we summarize our recent research on the synthesis of nanostructured PdCo catalyst by electrochemical methods, which enable us to deposit the alloy onto microelectrodes of the on-chip fuel cells. First, the electrodeposition of PdCo is discussed in detail, and then, dealloying for introducing nanopores into the electrodeposits is described. Finally, electrochemical response and activities are fully discussed.

  6. Electrodeposition of high-density lithium vanadate nanowires for lithium-ion battery

    Science.gov (United States)

    Hua, Kang; Li, Xiujuan; Fang, Dong; Yi, Jianhong; Bao, Rui; Luo, Zhiping

    2018-07-01

    Lithium vanadate nanowires have been electrodeposited onto a titanium (Ti) foil by a direct current electrodeposition without template. The morphology, crystal structure, and the effects of deposition voltage, temperature and time on the prepared samples were tested and presented. The as-prepared lithium vanadate nanowires/Ti composite can be used as electrode for lithium-ion battery. Electrochemical measurements showed that the electrode displayed a specific discharge capacitance as high as 235.1 mAh g-1 after 100 cycles at a current density of 30 mA g-1. This research provides a new pathway to explore high tap density vanadates nanowires on metals with enhanced electrochemical performance.

  7. Effect of annealing temperature on the PEC performance of electrodeposited copper oxides

    Science.gov (United States)

    Marathey, Priyanka; Pati, Ranjan; Mukhopadhyay, Indrajit; Ray, Abhijit

    2018-05-01

    In this work, we have deposited Cu2O film on fluorine doped tin oxide (FTO) substrate by electrodeposition. Pure CuO phase has been obtained by annealing the electrodeposited Cu2O film at optimized temperature (500°C) for two hours in air. Copper(I) oxide films showed good photo response with a current density of 0.54mA/cm2 at 0 V vs RHE. It is evident from UV-Visible spectroscopic analysis that the bandgap of Cu(I) and Cu(II) oxides differs from each other resulting in significant change in photo current for these two phases, observed in the PEC study. However CuO film showed better stability as compared to Cu2O film.

  8. Electrochemical Properties of Graphene-vanadium Oxide Composite Prepared by Electro-deposition for Electrochemical Capacitors

    International Nuclear Information System (INIS)

    Jeong, Heeyoung; Jeong, Sang Mun

    2015-01-01

    The nanostructural graphene/vanadium oxide (graphene/V 2 O 5 ) composite with enhanced capacitance was synthesized by the electro-deposition in 0.5 M VOSO 4 solution. The morphology of composites was characterized using scanning electron microscopy (SEM), x-ray diffraction pattern (XRD), and x-ray photoelectron spectroscopy (XPS). The oxidation states of the electro-deposited vanadium oxide was found to be V 5+ and V 4+ . The morphology of the prepared graphene/V 2 O 5 composite exhibits a netlike nano-structure with V 2 O 5 nanorods in about 100 nm diameter, which could lead a better contact between electrolyte an electrode. The composite with a deposition time of 4,000 s exhibits the specific capacitance of 854 mF/cm 2 at a scan rate of 20 mV/s and the capacitance retention of 53% after 1000 CV cycles

  9. Surfactant-free electrodeposition of reduced graphene oxide/copper composite coatings with enhanced wear resistance

    Science.gov (United States)

    Mai, Y. J.; Zhou, M. P.; Ling, H. J.; Chen, F. X.; Lian, W. Q.; Jie, X. H.

    2018-03-01

    How to uniformly disperse graphene sheets into the electrolyte is one of the main challenges to synthesize graphene enhanced nanocomposites by electrodeposition. A surfactant-free colloidal solution comprised of copper (II)-ethylene diamine tetra acetic acid ([CuIIEDTA]2-) complexes and graphene oxide (GO) sheets is proposed to electrodeposit reduced graphene oxide/copper (RGO/Cu) composite coatings. Anionic [CuIIEDTA]2- complexes stably coexist with negatively charged GO sheets due to the electrostatic repulsion between them, facilitating the electrochemical reduction and uniform dispersion of GO sheets into the copper matrix. The RGO/Cu composite coatings are well characterized by XRD, Raman, SEM and XPS. Their tribological behavior as a function of RGO content in composite coatings and normal loads are investigated. Also the chemical composition and topography of the wear tracks for the composite coatings are analyzed to deduce the lubricating and anti-wear mechanism of RGO/Cu composite coatings.

  10. Effect of parameters on the electrodeposition of Ni-TiO2 nanocomposite coatings

    International Nuclear Information System (INIS)

    Le Thi Phuong Thao; Nguyen Duc Hung; Nguyen Duy Ket

    2013-01-01

    The Ni-TiO 2 composite was formed from nickel chloride solution by coelectrodeposition. Effect of stirring rate, current density, kind of current, electrodeposition time and concentration of TiO 2 in the solution on the codeposition of the particle in the nanocomposite coating was investigated. The composition of coating was characterized with energy dispersive analyzer system (EDX). Results showed that, the amount of nano-TiO 2 embedded in coatings depended on these factors. When the amount of nanoparticles in bath of electrochemical was 6 g/1, the codeposition of the TiO 2 particle in the matrix reached 10.53% at current density 3 A/dm 2 , stirring rate of 600 rpm and 20 minutes electrodeposition. (author)

  11. Facile Fabrication of Durable Copper-Based Superhydrophobic Surfaces via Electrodeposition.

    Science.gov (United States)

    Jain, R; Pitchumani, R

    2018-03-13

    Superhydrophobic surfaces have myriad industrial applications, yet their practical utilization has been limited by their poor mechanical durability and longevity. We present a low-cost, facile process to develop superhydrophobic copper-based coatings via an electrodeposition route, that addresses this limitation. Through electrodeposition, a stable, multiscale, cauliflower shaped fractal morphology was obtained and upon modification by stearic acid, the prepared coatings show extreme water repellency with contact angle of 162 ± 2° and roll-off angle of about 3°. Systematic studies are presented on coatings fabricated under different processing conditions to demonstrate good durability, mechanical and underwater stability, corrosion resistance, and self-cleaning effect. The study also presents an approach for rejuvenation of slippery superhydrophobic nature (roll-off angle <10°) on the surfaces after long-term water immersion. The presented process can be scaled to larger, durable coatings with controllable wettability for diverse applications.

  12. Diffusion and segregation of substrate copper in electrodeposited Ni-Fe thin films

    International Nuclear Information System (INIS)

    Ahadian, M.M.; Iraji zad, A.; Nouri, E.; Ranjbar, M.; Dolati, A.

    2007-01-01

    The Cu surface segregation is investigated in the electrodeposited Ni-Fe layers using X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), secondary ion mass spectroscopy (SIMS) and atomic force microscopy (AFM). The results indicate that Cu segregation and accumulation take place in areated and deareated baths and the amount of segregated copper increases after air exposure. This phenomenon is explained by lower interfacial tension of the Cu in comparison with Ni and Fe. Our results reveal more surface segregation in the electrodeposit than vacuum reported results. This should be due to interface charging and higher surface diffusion in applied potential. The effect of interface charging on the interfacial tension is discussed based on Lippmann equation. Increasing of the Cu accumulation after air exposure is related to selective oxidation in alloys and higher tendency of Cu to surface oxidation

  13. Microstructural effects on the magnetic and magneto-transport properties of electrodeposited Ni nanowire arrays

    International Nuclear Information System (INIS)

    Chen, Shu-Fang; Wei, Hao Han; Liu, Chuan-Pu; Hsu, C Y; Huang, J C A

    2010-01-01

    The magnetic and magneto-transport properties of Ni nanowire (NW) arrays, fabricated by electrodeposition in anodic-aluminum-oxide (AAO) templates, have been investigated. The AAO pores have diameters ranging from 35 to 75 nm, and the crystallinity of the Ni NW arrays could change from poly-crystalline to single-crystalline with the [111] and [110] orientations based on the electrodeposition potential. Notably, double switching magnetization loops and double-peaked magnetoresistance curves were observed in [110]-oriented NWs. The crystalline orientation of the Ni NW arrays is found to influence the corresponding magnetic and magneto-transport properties significantly. These magnetic behaviors are dominated by the competition between the magneto-crystalline and shape anisotropy.

  14. Gold Nanostructures for Surface-Enhanced Raman Spectroscopy, Prepared by Electrodeposition in Porous Silicon

    Directory of Open Access Journals (Sweden)

    Yukio H. Ogata

    2011-04-01

    Full Text Available Electrodeposition of gold into porous silicon was investigated. In the present study, porous silicon with ~100 nm in pore diameter, so-called medium-sized pores, was used as template electrode for gold electrodeposition. The growth behavior of gold deposits was studied by scanning electron microscope observation of the gold deposited porous silicon. Gold nanorod arrays with different rod lengths were prepared, and their surface-enhanced Raman scattering properties were investigated. We found that the absorption peak due to the surface plasmon resonance can be tuned by changing the length of the nanorods. The optimum length of the gold nanorods was ~600 nm for surface-enhanced Raman spectroscopy using a He-Ne laser. The reason why the optimum length of the gold nanorods was 600 nm was discussed by considering the relationship between the absorption peak of surface plasmon resonance and the wavelength of the incident laser for Raman scattering.

  15. Electrodeposited gold nanoparticles on carbon nanotube-textile: Anode material for glucose alkaline fuel cells

    KAUST Repository

    Pasta, Mauro

    2012-06-01

    In the present paper we propose a new anode material for glucose-gluconate direct oxidation fuel cells prepared by electrodepositing gold nanoparticles onto a conductive textile made by conformally coating single walled carbon nanotubes (SWNT) on a polyester textile substrate. The electrodeposition conditions were optimized in order to achieve a uniform distribution of gold nanoparticles in the 3D porous structure of the textile. On the basis of previously reported studies, the reaction conditions (pH, electrolyte composition and glucose concentration) were tuned in order to achieve the highest oxidation rate, selectively oxidizing glucose to gluconate. The electrochemical characterization was carried out by means of cyclic voltammetry. © 2012 Elsevier B.V. All rights reserved.

  16. Multistage electrodeposition of supported platinum-based nanostructured systems for electrocatalytic applications

    CSIR Research Space (South Africa)

    Mkwizu, TS

    2011-05-01

    Full Text Available .R. Modibedi and Mkhulu K. Mathe* *kmathe@csir.co.za 219th ECS Meeting, 1 ? 6 May, 2011, Montreal, Canada Multistage Electrodeposition of Supported Platinum-based Nanostructured Systems for Electrocatalytic Applications Overview ? Acknowledgements... of constituent elements of the given electrode surface. ? Applications areas: Fuel cells, electrochemical sensors, electrolyzers Introduction e- A B 5 Introduction Atomic-level processes during electrocatalysis www...

  17. Electrodeposited Reduced Graphene Oxide Films on Stainless Steel, Copper, and Aluminum for Corrosion Protection Enhancement

    OpenAIRE

    Abdulkareem Mohammed Ali Al-Sammarraie; Mazin Hasan Raheema

    2017-01-01

    The enhancement of corrosion protection of metals and alloys by coating with simple, low cost, and highly adhered layer is still a main goal of many workers. In this research graphite flakes converted into graphene oxide using modified Hammers method and then reduced graphene oxide was electrodeposited on stainless steel 316, copper, and aluminum for corrosion protection application in seawater at four temperatures, namely, 20, 30, 40, and 50°C. All corrosion measurements, kinetics, and therm...

  18. Kinetic study and growth behavior of template-based electrodeposited platinum nanotubes controlled by overpotential

    Energy Technology Data Exchange (ETDEWEB)

    Yousefi, E. [Department of Materials Science and Engineering, Sharif University of Technology, Azadi Ave., P.O.Box 11155-9466, Tehran (Iran, Islamic Republic of); Dolati, A., E-mail: dolati@sharif.edu [Department of Materials Science and Engineering, Sharif University of Technology, Azadi Ave., P.O.Box 11155-9466, Tehran (Iran, Islamic Republic of); Imanieh, I. [Department of Materials Science and Engineering, Sharif University of Technology, Azadi Ave., P.O.Box 11155-9466, Tehran (Iran, Islamic Republic of); Yashiro, H.; Kure-Chu, S.-Z. [Department of Chemistry and Bioengineering, Faculty of Engineering, Iwate University, 4-3-5 Ueda, Morioka, Iwate, 020-8551 (Japan)

    2017-02-01

    Platinum nanotubes (PtNTs) are fabricated by potentiostatic electrodeposition at various overpotentials (−200 up to −400 mV versus SCE) in polycarbonate templates (PCTs) with pore diameter of 200 nm in a solution containing 5 mM H{sub 2}PtCl{sub 6} and 0.1 M H{sub 2}SO{sub 4}. The synthesized PtNTs are characterized by field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The electrochemical growth mechanism within nanoscopic pores and the relationship between morphological variations and kinetic parameters are investigated for the first time. It is shown that more porous structure of nanotubes forms at high overpotentials possibly due to preferably nucleation. The kinetics of electrodeposition process is studied by electrochemical techniques such as voltammetry and chronoamperometry. The linear diffusion coefficient at the early stage of the deposition and the radial diffusion coefficients at steady state regime are calculated as D = 8.39 × 10{sup −5} and 2.33–13.26 × 10{sup −8} cm{sup 2}/s, respectively. The synthesized PtNT electrode is tested as electrocatalyst for hydrogen peroxide oxidation in phosphate buffer solution (PBS) and shows a sensitivity as high as 2.89 mA per 1 μM that is an indication to its enlarged electrochemical surface area. - Highlights: • PtNT is electrodeposited in a 3-aminopropyltrimethoxysilane-modified PCT. • The electrochemical growth mechanism within nanoscopic pores is discussed. • The kinetics of PtNT electrodeposition is studied based on models for UME arrays. • Relationship between morphological variations vs. kinetic parameters is studied.

  19. II. Electrodeposition/removal of nickel in a spouted electrochemical reactor

    OpenAIRE

    Grimshaw, Pengpeng; Calo, Joseph M.; Shirvanian, Pezhman A.; Hradil, George

    2011-01-01

    An investigation is presented of nickel electrodeposition from acidic solutions in a cylindrical spouted electrochemical reactor. The effects of solution pH, temperature, and applied current on nickel removal/recovery rate, current efficiency, and corrosion rate of deposited nickel on the cathodic particles were explored under galvanostatic operation. Nitrogen sparging was used to decrease the dissolved oxygen concentration in the electrolyte in order to reduce the nickel corrosion rate, ther...

  20. A hybrid multiscale kinetic Monte Carlo method for simulation of copper electrodeposition

    International Nuclear Information System (INIS)

    Zheng Zheming; Stephens, Ryan M.; Braatz, Richard D.; Alkire, Richard C.; Petzold, Linda R.

    2008-01-01

    A hybrid multiscale kinetic Monte Carlo (HMKMC) method for speeding up the simulation of copper electrodeposition is presented. The fast diffusion events are simulated deterministically with a heterogeneous diffusion model which considers site-blocking effects of additives. Chemical reactions are simulated by an accelerated (tau-leaping) method for discrete stochastic simulation which adaptively selects exact discrete stochastic simulation for the appropriate reaction whenever that is necessary. The HMKMC method is seen to be accurate and highly efficient