WorldWideScience

Sample records for ternary alloy nanoclusters

  1. TERNARY ALLOYS OF URANIUM, COLUMBIUM, AND ZIRCONIUM

    Science.gov (United States)

    Foote, F.G.

    1960-08-01

    Ternary alloys of uranium are described which are useful as neutron- reflecting materials in a fast neutron reactor. They are especially resistant to corrosion caused by oxidative processes of gascous or aqueous origin and comprise uranium as the predominant metal with zirconiunn and niobium wherein the total content of the minor alloying elements is between 2 and 8% by weight.

  2. Nanocluster irradiation evolution in Fe-9%Cr ODS and ferritic-martensitic alloys

    Science.gov (United States)

    Swenson, M. J.; Wharry, J. P.

    2017-12-01

    The objective of this study is to evaluate the influence of dose rate and cascade morphology on nanocluster evolution in a model Fe-9%Cr oxide dispersion strengthened steel and the commercial ferritic/martensitic (F/M) alloys HCM12A and HT9. We present a large, systematic data set spanning the three alloys, three irradiating particle types, four orders of magnitude in dose rate, and doses ranging 1-100 displacements per atom over 400-500 °C. Nanoclusters are characterized using atom probe tomography. ODS oxide nanoclusters experience partial dissolution after irradiation due to inverse Ostwald ripening, while F/M nanoclusters undergo Ostwald ripening. Damage cascade morphology is indicative of nanocluster number density evolution. Finally, the effects of dose rate on nanocluster morphology provide evidence for a temperature dilation theory, which purports that a negative temperature shift is necessary for higher dose rate irradiations to emulate nanocluster evolution in lower dose rate irradiations.

  3. Tracer diffusion in ternary alloys

    International Nuclear Information System (INIS)

    Tahir-Kheli, R.A.

    1985-07-01

    An intuitive extension of the theory for diffusion in dynamic binary alloys given in the preceding paper is presented. This theory has also received an independent derivation, based on more formal procedures, by Holdsworth and Elliott. We present Monte Carlo estimates for diffusion correlation factors, fsup(A), fsup(B), and fsup(C) and compare them with the theory. The agreement between the theoretical results and the Monte Carlo estimates for the correlation factors of the slow particles, i.e., fsup(C) and fsup(B), is found to be generally good. In contrast, for the correlation factor, fsup(A), referring to the diffusion coefficient of fast particles in the system, the theoretical results are found to be systematically lower by a small but resolvable margin. It is suggested that this is occasioned by the neglect of spatial constraints on the scattering of coupled tracer-background particle field pairs. (author)

  4. Pt, Co–Pt and Fe–Pt alloy nanoclusters encapsulated in virus capsids

    International Nuclear Information System (INIS)

    Okuda, M; Eloi, J-C; Jones, S E Ward; Schwarzacher, W; Verwegen, M; Cornelissen, J J L M

    2016-01-01

    Nanostructured Pt-based alloys show great promise, not only for catalysis but also in medical and magnetic applications. To extend the properties of this class of materials, we have developed a means of synthesizing Pt and Pt-based alloy nanoclusters in the capsid of a virus. Pure Pt and Pt-alloy nanoclusters are formed through the chemical reduction of [PtCl 4 ] − by NaBH 4 with/without additional metal ions (Co or Fe). The opening and closing of the ion channels in the virus capsid were controlled by changing the pH and ionic strength of the solution. The size of the nanoclusters is limited to 18 nm by the internal diameter of the capsid. Their magnetic properties suggest potential applications in hyperthermia for the Co–Pt and Fe–Pt magnetic alloy nanoclusters. This study introduces a new way to fabricate size-restricted nanoclusters using virus capsid. (paper)

  5. Collective and tracer diffusion kinetics in the ternary random alloy

    International Nuclear Information System (INIS)

    Belova, I.V.; Murch, G.E.; Allnatt, A.R.

    2002-01-01

    In this study, collective and tracer diffusion kinetics is addressed for the ternary random alloy. A formal solution from the self-consistent theory of Moleko et al (Moleko L K, Allnatt A R and Allnatt E L 1989 Phil. Mag. A 59 141) is derived for collective diffusion and compared with the corresponding solution for the binary random alloy. Tracer diffusion in the ternary alloy is treated from the perspective of a special case of the quaternary random alloy. Results from Monte Carlo calculations for tracer and collective correlation factors (for the bcc ternary random alloy) are found to be in excellent agreement with this self-consistent theory but in only semi-quantitative agreement with the earlier theory of Manning (Manning J R 1971 Phys. Rev. B 4 1111). (author)

  6. Polymer stabilized Ni-Ag and Ni-Fe alloy nanoclusters: Structural and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Kabir, L.; Mandal, A.R. [Department of Physics, Visva-Bharati, Santiniketan-731 235 (India); Mandal, S.K., E-mail: sk_mandal@hotmail.co [Department of Physics, Visva-Bharati, Santiniketan-731 235 (India)

    2010-04-15

    We report here the structural and magnetic behaviors of nickel-silver (Ni-Ag) and nickel-iron (Ni-Fe) nanoclusters stabilized with polymer (polypyrrole). High resolution transmission electron microscopy (HRTEM) indicates Ni-Ag nanoclusters to stabilize in core-shell configuration while that of Ni-Fe nanoclusters in a mixed type of geometry. Structural characterizations by X-ray diffraction (XRD) reveal the possibility of alloying in such bimetallic nanoclusters to some extent even at temperatures much lower than that of bulk alloying. Electron paramagnetic resonance (EPR) spectra clearly reveal two different absorption behaviors: one is ascribed to non-isolated Ni{sup 2+} clusters surrounded by either silver or iron giving rise to a broad signal, other (very narrow signal) being due to the isolated superparamagnetic Ni{sup 2+} clusters or bimetallic alloy nanoclusters. Results obtained for Ni-Ag and Ni-Fe nanoclusters have been further compared with the behavior exhibited by pure Ni nanoclusters in polypyrrole host. Temperature dependent studies (at 300 and 77 K) of EPR parameters, e.g. linewidth, g-value, line shape and signal intensity indicating the significant influence of surrounding paramagnetic silver or ferromagnetic iron within polymer host on the EPR spectra have been presented.

  7. Polymer stabilized Ni-Ag and Ni-Fe alloy nanoclusters: Structural and magnetic properties

    Science.gov (United States)

    Kabir, L.; Mandal, A. R.; Mandal, S. K.

    2010-04-01

    We report here the structural and magnetic behaviors of nickel-silver (Ni-Ag) and nickel-iron (Ni-Fe) nanoclusters stabilized with polymer (polypyrrole). High resolution transmission electron microscopy (HRTEM) indicates Ni-Ag nanoclusters to stabilize in core-shell configuration while that of Ni-Fe nanoclusters in a mixed type of geometry. Structural characterizations by X-ray diffraction (XRD) reveal the possibility of alloying in such bimetallic nanoclusters to some extent even at temperatures much lower than that of bulk alloying. Electron paramagnetic resonance (EPR) spectra clearly reveal two different absorption behaviors: one is ascribed to non-isolated Ni 2+ clusters surrounded by either silver or iron giving rise to a broad signal, other (very narrow signal) being due to the isolated superparamagnetic Ni 2+ clusters or bimetallic alloy nanoclusters. Results obtained for Ni-Ag and Ni-Fe nanoclusters have been further compared with the behavior exhibited by pure Ni nanoclusters in polypyrrole host. Temperature dependent studies (at 300 and 77 K) of EPR parameters, e.g. linewidth, g-value, line shape and signal intensity indicating the significant influence of surrounding paramagnetic silver or ferromagnetic iron within polymer host on the EPR spectra have been presented.

  8. Polymer stabilized Ni-Ag and Ni-Fe alloy nanoclusters: Structural and magnetic properties

    International Nuclear Information System (INIS)

    Kabir, L.; Mandal, A.R.; Mandal, S.K.

    2010-01-01

    We report here the structural and magnetic behaviors of nickel-silver (Ni-Ag) and nickel-iron (Ni-Fe) nanoclusters stabilized with polymer (polypyrrole). High resolution transmission electron microscopy (HRTEM) indicates Ni-Ag nanoclusters to stabilize in core-shell configuration while that of Ni-Fe nanoclusters in a mixed type of geometry. Structural characterizations by X-ray diffraction (XRD) reveal the possibility of alloying in such bimetallic nanoclusters to some extent even at temperatures much lower than that of bulk alloying. Electron paramagnetic resonance (EPR) spectra clearly reveal two different absorption behaviors: one is ascribed to non-isolated Ni 2+ clusters surrounded by either silver or iron giving rise to a broad signal, other (very narrow signal) being due to the isolated superparamagnetic Ni 2+ clusters or bimetallic alloy nanoclusters. Results obtained for Ni-Ag and Ni-Fe nanoclusters have been further compared with the behavior exhibited by pure Ni nanoclusters in polypyrrole host. Temperature dependent studies (at 300 and 77 K) of EPR parameters, e.g. linewidth, g-value, line shape and signal intensity indicating the significant influence of surrounding paramagnetic silver or ferromagnetic iron within polymer host on the EPR spectra have been presented.

  9. Synthesis and Optical Properties of Au-Ag Alloy Nanoclusters with Controlled Composition

    Directory of Open Access Journals (Sweden)

    J. F. Sánchez-Ramírez

    2008-01-01

    Full Text Available Colloidal solid-solution-like Au-Ag alloy nanoclusters of different compositions were synthesized through citrate reduction of mixed metal ions of low concentrations, without using any other protective or capping agents. Optical absorption of the alloy nanoclusters was studied both theoretically and experimentally. The position of the surface plasmon resonance (SPR absorption band of the nanoclusters could be tuned from 419 nm to 521 nm through the variation of their composition. Considering effective dielectric constant of the alloy, optical absorption spectra for the nanoclusters were calculated using Mie theory, and compared with the experimentally obtained spectra. Theoretically obtained optical spectra well resembled the experimental spectra when the true size distribution of the nanoparticles was considered. High-resolution transmission electron microscopy (HREM, high-angle annular dark field (HAADF imaging, and energy dispersive spectroscopy (EDS revealed the true alloy nature of the nanoparticles with nominal composition being preserved. The synthesis technique can be extended to other bimetallic alloy nanoclusters containing Ag.

  10. Segregation in ternary alloys: an interplay of driving forces

    International Nuclear Information System (INIS)

    Luyten, J.; Helfensteyn, S.; Creemers, C.

    2003-01-01

    Monte Carlo (MC) simulations combined with the constant bond energy (CBE) model are set up to explore and understand the general segregation behaviour in ternary alloys as a function of composition and more in particular the segregation to Cu-Ni-Al (1 0 0) surfaces. Besides its simplicity, allowing swift simulations, which are necessary for a first general survey over all possible compositions, one of the advantages of the CBE model lies in the possibility to clearly identify the different driving forces for segregation. All simulations are performed in the Grand Canonical Ensemble, using a new algorithm to determine the chemical potential of the components. Notwithstanding the simplicity of the CBE model, one extra feature is evidenced: depending on the values of the interatomic interaction parameters, in some regions of the ternary diagram, a single solid solution becomes thermodynamically unstable, leading to demixing into two conjugate phases. The simulations are first done for three hypothetical systems that are however representative for real alloy systems. The three systems are characterised by different sets of interatomic interaction parameters. These extensive simulations over the entire composition range of the ternary alloy yield a 'topographical' segregation map, showing distinct regions where different species segregate. These distinct domains originate from a variable interplay between the driving forces for segregation and attractive/repulsive interactions in the bulk of the alloy. The results on these hypothetical systems are very helpful for a better understanding of the segregation behaviour in Cu-Ni-Al and other ternary alloys

  11. Plutonium microstructures. Part 2. Binary and ternary alloys

    International Nuclear Information System (INIS)

    Cramer, E.M.; Bergin, J.B.

    1983-12-01

    This report is the second of three parts that exhibit illustrations of inclusions in plutonium metal from inherent and tramp impurities, of intermetallic and nonmetallic constituents from alloy additions, and of the effects of thermal and mechanical treatments. This part includes illustrations of the microstructures in binary cast alloys and a few selected ternary alloys that result from measured additions of diluent elements, and of the microconstituents that are characteristic of phase fields in extended alloy systems. Microhardness data are given and the etchant used in the preparation of each sample is described

  12. Susceptibility of ternary aluminum alloys to cracking during solidification

    International Nuclear Information System (INIS)

    Liu, Jiangwei; Kou, Sindo

    2017-01-01

    The crack susceptibility map of a ternary Al alloy system provides useful information about which alloy compositions are most susceptible to cracking and thus should be avoided by using a filler metal with a significantly different composition. In the present study the crack susceptibility maps of ternary Al alloy systems were calculated based on the maximum |dT/d(f S ) 1/2 | as an index for the crack susceptibility, where T is temperature and f S fraction solid. Due to the complexity associated with ternary alloy solidification, commercial thermodynamic software Pandat and Al database PanAluminum, instead of analytical equations, were used to calculate f S as a function of T and hence the maximum |dT/d(f S ) 1/2 | for ternary Al-Mg-Si, Al-Cu-Mg and Al-Cu-Si alloy systems. A crack susceptibility map covering 121 alloy compositions was constructed for each of the three ternary alloy systems at each of the following three levels of back diffusion: no back diffusion, back diffusion under a 100 °C/s cooling rate, and back diffusion under 20° C/s. The location of the region of high crack susceptibility, which is the most important part of the map, was shown in each of the nine calculated maps. These locations were compared with those observed in crack susceptibility tests by previous investigators. With back diffusion considered, either under 20 or 100 °C/s, the agreement between the calculated and observed maps was good especially for Al-Mg-Si and Al-Cu-Mg. Thus, the maximum |dT/d(f S ) 1/2 | can be used as a crack susceptibility index to construct crack susceptibility maps for ternary Al alloys and to evaluate the effect of back diffusion on their crack susceptibility. - Graphical abstract: The crack susceptibility map of a ternary alloy system indicates the composition range most susceptible to cracking, which should be avoided in welding or casting. The crack susceptibility maps of ternary Al alloy systems Al-Mg-Si, Al-Cu-Mg and Al-Cu-Si were calculated based

  13. Experimental Investigation of Ternary Alloys for Fusion Breeding Blankets

    Energy Technology Data Exchange (ETDEWEB)

    Choi, B. William [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Chiu, Ing L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-26

    Future fusion power plants based on the deuterium-tritium (DT) fuel cycle will be required to breed the T fuel via neutron reactions with lithium, which will be incorporated in a breeding blanket that surrounds the fusion source. Recent work by LLNL proposed the used of liquid Li as the breeder in an inertial fusion energy (IFE) power plant. Subsequently, an LDRD was initiated to develop alternatives ternary alloy liquid metal breeders that have reduced chemical reactivity with water and air compared to pure Li. Part of the work plan was to experimentally investigate the phase diagrams of ternary alloys. Of particular interest was measurement of the melt temperature, which must be low enough to be compatible with the temperature limits of the steel used in the construction of the chamber and heat transfer system.

  14. Ternary equilibria in bismuth--indium--lead alloys

    International Nuclear Information System (INIS)

    Liao, K.C.; Johnson, D.L.; Nelson, R.C.

    1975-01-01

    The liquidus surface is characterized by three binary equilibria. One binary extends from the Pb--Bi peritectic to the Pb--In peritectic. The other two extend from In--Bi eutectics, merge at 50 at. percent Bi and 30 at. percent Pb, and end at the Bi--Pb eutectic. Based on analysis of ternary liquidus contours and vertical sections, it is suggested that solidification for high lead and very high indium alloys occurs from two-phase equilibria. Solidification from all other alloys occurs from three-phase equilibria. Four-phase solidification does not occur in this system

  15. Kinetics of radiation-induced segregation in ternary alloys

    International Nuclear Information System (INIS)

    Lam, N.O.; Kumar, A.; Wiedersich, H.

    1982-01-01

    Model calculations of radiation-induced segregation in ternary alloys have been performed, using a simple theory. The theoretical model describes the coupling between the fluxes of radiation-induced defects and alloying elements in an alloy A-B-C by partitioning the defect fluxes into those occurring via A-, B-, and C-atoms, and the atom fluxes into those taking place via vacancies and interstitials. The defect and atom fluxes can be expressed in terms of concentrations and concentration gradients of all the species present. With reasonable simplifications, the radiation-induced segregation problem can be cast into a system of four coupled partial-differential equations, which can be solved numerically for appropriate initial and boundary conditions. Model calculations have been performed for ternary solid solutions intended to be representative of Fe-Cr-Ni and Ni-Al-Si alloys under various irradiation conditions. The dependence of segregation on both the alloy properties and the irradiation variables, e.g., temperature and displacement rate, was calculated. The sample calculations are in good qualitative agreement with the general trends of radiation-induced segregation observed experimentally

  16. Ternary ceramic alloys of Zr-Ce-Hf oxides

    Science.gov (United States)

    Becher, P.F.; Funkenbusch, E.F.

    1990-11-20

    A ternary ceramic alloy is described which produces toughening of zirconia and zirconia composites through the stress transformation from tetragonal phase to monoclinic phase. This alloy, having the general formula Ce[sub x]Hf[sub y]Zr[sub 1[minus]x[minus]y]O[sub 2], is produced through the addition of appropriate amounts of ceria and hafnia to the zirconia. Typically, improved toughness is achieved with about 5 to about 15 mol % ceria and up to about 40 mol % hafnia. The preparation of alloys of these compositions are given together with data as to the densities, tetragonal phase content, hardness and fracture toughness. The alloys are useful in preparing zirconia bodies as well as reinforcing ceramic composites. 1 fig.

  17. Superconducting properties of a copper-ternary alloy

    International Nuclear Information System (INIS)

    Sharma, R.G.; Aleksivskii, N.E.

    1975-01-01

    The superconducting properties of a copper-ternary alloy of the type Cu 93 Nb 5 Sn 2 , subjected to a variety of mechanical and heat treatments, are discussed. The as-cast alloy does not turn superconducting down to 4.5K; but the cold-work and subsequent prescribed heat treatments are found to raise the transition temperature Tsub(c) to values as high as 18.1K and the critical current density Jsub(c) (of the Nb 3 Sn formed during annealing) to a value of 3.6x10 5 Acm -2 (at 4.2K and 30kOe). Various possibilities to improve Jsub(c) of this alloy to still higher values are discussed. The as-cast alloy is ductile, easy to draw, and economical from a technical point of view, and the annealed wires and strips are flexible enough for winding. (author)

  18. The role of minor alloying elements on the stability and dispersion of yttria nanoclusters in nanostructured ferritic alloys: An ab initio study

    International Nuclear Information System (INIS)

    Murali, D.; Panigrahi, B.K.; Valsakumar, M.C.; Chandra, Sharat; Sundar, C.S.; Raj, Baldev

    2010-01-01

    Nanostructured ferritic alloys derive their strength from the dispersion of oxide nanoclusters in the ferritic matrix. We have explored the relative role of minor alloying elements like Ti and Zr on the stability of nanoclusters of vacancy-Y-Ti-O by density functional theory calculations and shown that the binding energy of these clusters increases when we replace Ti with Zr. This could imply faster nucleation of the nanoclusters which, in turn, may lead to finer dispersion of nanoclusters resulting in improved performance of ferritic alloys. Further, we show a core/shell structure for these nanoclusters in which the core is enriched in Y, O, Ti while the shell is enriched in Cr.

  19. Ternary alloy nanocatalysts for hydrogen evolution reaction

    Indian Academy of Sciences (India)

    CuFeNi (A1), CuFe2Ni (A2) and CuFeNi2 (A3) were successfully synthesized using microemulsion. It is to be noted that synthesis of nanocrystallineternary alloys with precise composition is a big challenge which can be overcome by choosing an appropriate microemulsion system. High electrocatalytic activity towards HER ...

  20. Electronic structure and phase equilibria in ternary substitutional alloys

    International Nuclear Information System (INIS)

    Traiber, A.J.S.; Allen, S.M.; Waterstrat, R.M.

    1996-01-01

    A reliable, consistent scheme to study phase equilibria in ternary substitutional alloys based on the tight-binding approximation is presented. With electronic parameters from linear muffin-tin orbital calculations, the computed density of states and band structures compare well with those from more accurate abinitio calculations. Disordered alloys are studied within the tight-binding coherent-potential approximation extended to alloys; energetics of ordered systems are obtained through effective pair interactions computed with the general perturbation method; and partially ordered alloys are studied with a novel simplification of the molecular coherent-potential approximation combined with the general perturbation method. The formalism is applied to bcc-based Zr-Ru-Pd alloys which are promising candidates for medical implant devices. Using energetics obtained from the above scheme, we apply the cluster- variation method to study phase equilibria for particular pseudo- binary alloys and show that results are consistent with observed behavior of electronic specific heat coefficient with composition for Zr 0.5 (Ru, Pd) 0.5

  1. Investigation of transient photoresponse of WSSe ternary alloy crystals

    Science.gov (United States)

    Chauhan, Payal; Solanki, G. K.; Tannarana, Mohit; Pataniya, Pratik; Patel, K. D.; Pathak, V. M.

    2018-05-01

    Transition metal chalcogenides have been studied intensively in recent time due to their tunability of electronic properties by compositional change, alloying and by transforming bulk material into crystalline 2D structure. These changes lead to the development of verities of next generation opto-electronic device applications such as solar cells, FETs and flexible detectors etc. In present work, we report growth and characterization of crystalline ternary alloy WSSe by direct vapour transport technique. A photodetector is constructed using grown crystals to study its transient photoresponse under polychromatic radiation. The WSSe crystals are mechanically exfoliated to thickness of 3 µm and the lateral dimension of prepared sample is 2.25 mm2. The time-resolved photoresponse is studied under polychromatic illumination of power density ranging from 10 to 40 mW/cm2. The photo response is also studied under different bias voltages ranging from 0.1 V to 0.5 V. The typical photodetector parameters i.e. photocurrent, rise and fall time, responsivity and sensitivity are evaluated and discussed in light of the ternary alloy composition.

  2. Corrosion and wear protective composition modulated alloy coatings based on ternary Ni-P-X alloys

    DEFF Research Database (Denmark)

    Leisner, P.; Benzon, M. E.; Christoffersen, Lasse

    1996-01-01

    Scattered reporting in the litterature describes a number of ternary Ni-P-X alloyes (where X can be Co, Cr, Cu, Mo, Pd, Re or W) with promising corrosin and wear protective performance. Based on a systematic study of Ni-P-X alloys it is the intention to produce coatings with improved corrosion...... and wear performance compared with conventional coatings like electroless nickel, hard chromioum and anodised aluminium....

  3. Deformation behaviour of a new magnesium ternary alloy

    Science.gov (United States)

    Guglielmi, P.; Kaya, A. Arslan; Sorgente, D.; Palumbo, G.

    2018-05-01

    Magnesium based alloys are yet to fill a greater niche especially in the automotive and aeronautical industry. In fact, such alloys have a big weight saving potential, together with good damping characteristics. However, nowadays about 90% of Magnesium products are produced by casting, mainly using two alloy systems, namely Mg-Al-Zn (AZ91D) and Mg-Al (AM50, AM60). Now the emphasis, especially after having achieved considerable success in creep resistance and understanding of the deformation behaviour of Magnesium, has been shifted towards wrought alloys; AZ31, in this case, is the most popular. In this work a multi-element Magnesium alloy, developed to improve the deformation capacity of such a lightweight material, has been investigated and compared to a commercial AZ31B. The possibility of adopting such a multi-element Magnesium alloy for manufacturing components via unconventional sheet forming (such as superplastic forming, warm hydroforming, incremental forming) has been proved in the present work focusing the attention on the superplastic field. Free inflation tests were thus conducted at 450°C setting constant pressure to investigate the superplastic behaviour (in terms of dome height and strain rate sensitivity index) of both the multi-element Magnesium alloy (Mg-2Zn-Ce) and the commercial one (AZ31B). To enhance information on the thickness distribution and investigate the microstructure evolution, metallographic analyses on the samples used to carry out free inflation tests were also performed. The developed ternary alloy manifested quite a good deformation behaviour (high strain rate sensitivity index), even being tested in the as cast condition; in addition a limited grain coarsening was observed in the specimens after deformation.

  4. Ternary alloying study of MoSi2

    International Nuclear Information System (INIS)

    Yi, D.; Li, C.; Akselsen, O.M.; Ulvensoen, J.H.

    1998-01-01

    Ternary alloying of MoSi 2 with adding a series of transition elements was investigated by X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS). Iron, Co, Ni, Cr, V, Ti, and Nb were chosen as alloying elements according to the AB 2 structure map or the atomic size factor. The studied MoSi 2 base alloys were prepared by the arc melting process from high-purity metals. The EDS analysis showed that Fe, Co, and Ni have no solid solubility in as-cast MoSi 2 , while Cr, V, Ti, and Nb exhibit limited solid solubilities, which were determined to be 1.4 ± 0.7, 1.4 ± 0.4, 0.4 ± 0.1, and 0.8 ± 0.1. Microstructural characterization indicated that Mo-Si-M VIII (M VIII = Fe, Co, Ni) and Mo-Si-Cr alloys have a two-phase as-cast microstructure, i.e., MoSi 2 matrix and the second-phase FeSi 2 , CoSi, NiSi 2 , and CrSi 2 , respectively. In as-cast Mo-Si-V, Mo-Si-Ti, and Mo-Si-Nb alloys, besides MoSi 2 and C40 phases, the third phases were observed, which have been identified to be (Mo, V) 5 Si 3 , TiSi 2 , and (Mo, Nb) 5 Si 3

  5. Radiation-induced segregation in binary and ternary alloys

    International Nuclear Information System (INIS)

    Okamoto, P.R.; Rehn, L.E.

    1979-01-01

    A review is given of our current knowledge of radiation-induced segregation of major and minor elements in simple binary and ternary alloys as derived from experimental techniques such as Auger electron spectroscopy, secondary-ion mass spectroscopy, ion-backscattering, infrared emissivity measurements and transmission electron microscopy. Measurements of the temperature, dose and dose-rate dependences as well as of the effects of such materials variables as solute solubility, solute misfit and initial solute concentration has proved particularly valuable in understanding the mechanisms of segregation. The interpretation of these data in terms of current theoretical models which link solute segregation behavior to defect-solute binding interactions and/or to the relative diffusion rates of solute and solvent atoms the interstitial and vacancy migration mechanisms has, in general, been fairly successful and has provided considerable insight into the highly interrelated phenomena of solute-defect trapping, solute segregation, phase stability and void swelling. Specific examples in selected fcc, bcc and hcp alloy systems are discussed with particular emphasis given to the effects of radiation-induced segregation on the phase stability of single-phase and two-phase binary alloys and simple Fe-Cr-Ni alloys. (Auth.)

  6. Secondary ordering in ternary alloy CuMnPt6

    International Nuclear Information System (INIS)

    Takahashi, Miwako; Das, Ananda Kumar; Nakamura, Reo; Ohshima, Ken-ichi; Iwasaki, Hiroshi; Shishido, Toetsu

    2006-01-01

    Using the pulsed-neutron diffraction technique, we performed in situ measurements of structural ordering in the ternary alloy CuMnPt 6 . The diffraction patterns at various temperatures give a direct observation of a double-step ordering: disorder to Cu 3 Au type order as an ordering within the fundamental face-centered cubic lattice to subdivide the lattice into two sublattices formed by face-centered sites (first sublattice) and corner sites (second sublattice) at 968degC; and Cu 3 Au type order to ABC 6 type order as an ordering within the second to subdivide the lattice further into two sublattices formed by alternating (111) planes at 746degC. The order parameters for the ABC 6 type structure experimentally estimated by the method of static concentration waves indicate that the primary ordering developed almost completely, but the secondary ordering remained incomplete. (author)

  7. Special quasirandom structures for binary/ternary group IV random alloys

    KAUST Repository

    Chroneos, Alexander I.; Jiang, Chao; Grimes, Robin W.; Schwingenschlö gl, Udo

    2010-01-01

    Simulation of defect interactions in binary/ternary group IV semiconductor alloys at the density functional theory level is difficult due to the random distribution of the constituent atoms. The special quasirandom structures approach is a

  8. Effect of ternary alloying elements on the shape memory behavior of Ti-Ta alloys

    International Nuclear Information System (INIS)

    Buenconsejo, Pio John S.; Kim, Hee Young; Miyazaki, Shuichi

    2009-01-01

    The effect of ternary alloying elements (X = V, Cr, Fe, Zr, Hf, Mo, Sn, Al) on the shape memory behavior of Ti-30Ta-X alloys was investigated. All the alloying elements decreased the martensitic transformation temperatures. The decrease in the martensitic transformation start (M s ) temperature due to alloying was affected by the atomic size and number of valence electrons of the alloying element. A larger number of valence electrons and a smaller atomic radius of an alloying element decreased the M s more strongly. The effect of the alloying elements on suppressing the aging effect on the shape memory behavior was also investigated. It was found that the additions of Sn and Al to Ti-Ta were effective in suppressing the effect of aging on the shape memory behavior, since they strongly suppress the formation of ω phase during aging treatment. For this reason the Ti-30Ta-1Al and Ti-30Ta-1Sn alloys exhibited a stable high-temperature shape memory effect during thermal cycling.

  9. Atomic-scale properties of Ni-based FCC ternary, and quaternary alloys

    International Nuclear Information System (INIS)

    Tamm, Artur; Aabloo, Alvo; Klintenberg, Mattias; Stocks, Malcolm; Caro, Alfredo

    2015-01-01

    The aim of this study is to characterize some atomic-scale properties of Ni-based FCC multicomponent alloys. For this purpose, we use Monte Carlo method combined with density functional theory calculations to study short-range order (SRO), atomic displacements, electronic density of states, and magnetic moments in equimolar ternary NiCrCo, and quaternary NiCrCoFe alloys. According to our study, the salient features for the ternary alloy are a negative SRO parameter between Ni–Cr and a positive between Cr–Cr pairs as well as a weakly magnetic state. For the quaternary alloy we predict negative SRO parameter for Ni–Cr and Ni–Fe pairs and positive for Cr–Cr and Fe–Fe pairs. Atomic displacements for both ternary and quaternary alloys are negligible. In contrast to the ternary, the quaternary alloy shows a complex magnetic structure. The electronic structure of the ternary and quaternary alloys shows differences near the Fermi energy between a random solid solution and the predicted structure with SRO. Despite that, the calculated EXAFS spectra does not show enough contrast to discriminate between random and ordered structures. The predicted SRO has an impact on point-defect energetics, electron–phonon coupling and thermodynamic functions and thus, SRO should not be neglected when studying properties of these two alloys

  10. Effect of ternary alloying elements on microstructure and mechanical property of Nb-Si based refractory intermetallic alloy

    International Nuclear Information System (INIS)

    Kim, W.Y.; Kim, H.S.; Kim, S.K.; Ra, T.Y.; Kim, M.S.

    2005-01-01

    Microstructure and mechanical property at room temperature and at 1773 K of Nb-Si based refractory intermetallic alloys were investigated in terms of compression and fracture toughness test. Mo and V were chosen as ternary alloying elements because of their high melting points, atomic sizes smaller than Nb. Both ternary alloying elements were found to have a significant role in modifying the microstructure from dispersed structure to eutectic-like structure in Nb solid solution/Nb 5 Si 3 intermetallic composites. The 0.2% offset yield strength at room temperature increased with increasing content of ternary elements in Nb solid solution and volume fraction of Nb 5 Si 3 . At 1773 K, Mo addition has a positive role in increasing the yield strength. On the other hand, V addition has a role in decreasing the yield strength. The fracture toughness of ternary alloys was superior to binary alloys. Details will be discussed in correlation with ternary alloying, volume fraction of constituent phase, and the microstructure. (orig.)

  11. Effect of cold rolling on the formation and distribution of nanoclusters during pre-aging in an Al–Mg–Si alloy

    International Nuclear Information System (INIS)

    Serizawa, A.; Sato, T.; Miller, M.K.

    2013-01-01

    The effect of high densities of dislocations on the formation behavior of two types of nano-scale clusters (nanoclusters), which are formed at room temperature or during pre-aging at ∼373 K in an Al–Mg–Si alloy, was investigated by atom probe tomography. Cold rolling was applied to modify the formation behavior and/or the characteristics of the nanoclusters and also the precipitation sequence, which involve both nanoclusters and a strengthening phase to improve the bake-hardening response. Nanoclusters formed during pre-aging tended to form along the dislocations. Cold rolling accelerated the preferential formation of the nanoclusters, whereas the number density of the nanoclusters decreased by cold rolling before pre-aging. However, the number density of the nanoclusters was considerably higher than that of the β″ phase. Cold rolling before pre-aging enhanced the age-hardenability the most compared with other processes such as the contemporary pre-aging process. It is considered that the nanoclusters along dislocations lead to the preferential transformation to the β″ phase and then the rapid growth of the β″ phase. The nanoclusters formed on dislocations are effective in improving the bake-hardening response for the duration of the bake-hardening process. The kinetics and the distribution of the nanoclusters were found to be affected by the dislocations which were induced by cold rolling.

  12. Physical Properties Of Some Pd-Au-Ag Ternary Alloys: A Md Study

    International Nuclear Information System (INIS)

    Aydin, G.

    2010-01-01

    Mechanical properties of palladium (Pd), gold (Au) and silver (Ag) and their ternary alloys in the following concentrations (Au 5 0Ag 2 5Pd 2 5, Au 4 0Ag 2 0Pd 4 0) are studied by using by using molecular dynamics with Quantum Sutton-Chen (Q-SC) potential. Cell constants, densities, enthalpies, elastic constants and heat capacities are investigated. Calculations are performed in the solid phase. Rafii-Tabar combination rules are used and it is showed that these combination rules are valid for ternary alloys also. Additionally, temperature dependence of mechanical properties of alloys are investigated.

  13. New method for the simultaneous condensation of complete ternary alloy systems under ultrahigh vacuum conditions

    International Nuclear Information System (INIS)

    Mehrtens, A.; Moske, M.; Samwer, K.

    1988-01-01

    An ultrahigh vacuum apparatus is described for the simultaneous condensation of complete ternary alloy systems. Three singly controlled electron beam evaporation sources provide a constant evaporation rate of the different elements. A specially designed rotating mask guarantees a concentration gradient on the substrate according to a ternary phase diagram. The conversion of the actual concentration profile into a standard ternary phase diagram is done by simple computer calculations. They involve corrections for the beam characteristics of the evaporation sources and for the rotating mask. As an example, measurements for the Zr--Cu--Co system are given. The concentration range for the amorphous phase is compared with thermodynamic predictions using Miedema's parameter

  14. Effect on strength of ternary alloying additions in L12 intermetallics

    International Nuclear Information System (INIS)

    Wu Yuanpang.

    1991-01-01

    The thermodynamic properties of {111} antiphase boundaries (APBs) as well as the site preference of ternary additions in an A 3 B intermetallic with L1 2 structure are studied, using a thermodynamic model. A survey of the results from a variety of ternary alloying additions to Ni 3 Al has shown that there is a conflict in the actual role which solid solution strengthening plays in the athermal increment of yield strength. For instance, a good quantitative agreement with linear concentration law is observed only in alloys with stoichiometric compositions but not in the general case of non-stoichiometric alloys. In the light of the possibility that micro-segregation could explain the experimental discrepancy, the author extends the binary solid solution strengthening theory to the ternary system in an L1 2 structure for the four real systems of Ni-Al-Si, Ni-Al-Ti, Ni-Al-Hf, and Ni-Al-V. It is found that ternary site preference plays an important role in the ternary solid solution strengthening theory with L1 2 structure. Good quantitative agreement was found between the calculated and experimentally measured strength for both stoichiometric and nonstoichiometric alloys

  15. First-principles study of ternary bcc alloys using special quasi-random structures

    International Nuclear Information System (INIS)

    Jiang Chao

    2009-01-01

    Using a combination of exhaustive enumeration and Monte Carlo simulated annealing, we have developed special quasi-random structures (SQSs) for ternary body-centered cubic (bcc) alloys with compositions of A 1 B 1 C 1 , A 2 B 1 C 1 , A 6 B 1 C 1 and A 2 B 3 C 3 , respectively. The structures possess local pair and multisite correlation functions that closely mimic those of the random bcc alloy. We employed the SQSs to predict the mixing enthalpies, nearest neighbor bond length distributions and electronic density of states of bcc Mo-Nb-Ta and Mo-Nb-V solid solutions. Our convergence tests indicate that even small-sized SQSs can give reliable results. Based on the SQS energetics, the predicting powers of the existing empirical ternary extrapolation models were assessed. The present results suggest that it is important to take into account the ternary interaction parameter in order to accurately describe the thermodynamic behaviors of ternary alloys. The proposed SQSs are quite general and can be applied to other ternary bcc alloys.

  16. Deviations from Vegard’s law in ternary III-V alloys

    KAUST Repository

    Murphy, S. T.

    2010-08-03

    Vegard’s law states that, at a constant temperature, the volume of an alloy can be determined from a linear interpolation of its constituent’s volumes. Deviations from this description occur such that volumes are both greater and smaller than the linear relationship would predict. Here we use special quasirandom structures and density functional theory to investigate such deviations for MxN1−xAs ternary alloys, where M and N are group III species (B, Al, Ga, and In). Our simulations predict a tendency, with the exception of AlxGa1−xAs, for the volume of the ternary alloys to be smaller than that determined from the linear interpolation of the volumes of the MAs and BAs binary alloys. Importantly, we establish a simple relationship linking the relative size of the group III atoms in the alloy and the predicted magnitude of the deviation from Vegard’s law.

  17. Liquid demixing and microstructure formation in ternary Al-Sn-Cu alloys

    Energy Technology Data Exchange (ETDEWEB)

    Mirkovic, D.; Groebner, J. [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Strasse 42, D-38678 Clausthal-Zellerfeld (Germany); Schmid-Fetzer, R. [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Strasse 42, D-38678 Clausthal-Zellerfeld (Germany)], E-mail: schmid-fetzer@tu-clausthal.de

    2008-07-25

    The complex features of the Al-Sn-Cu phase diagram, dominated by ternary liquid demixing, are revealed by a combination of thermodynamic modeling and experimental studies. Nine ternary alloys were selected to cover all essential features involving the liquidus surface and the invariant solidification reactions. These were analyzed by differential thermal analysis as well as microstructural and local chemical analysis of solidified microstructures. Three different monotectic invariant reactions occur in this system. Small changes in alloy composition may produce distinctly different microstructures with primary crystallization and secondary demixing or vice versa.

  18. The novel eutectic microstructures of Si-Mn-P ternary alloy

    International Nuclear Information System (INIS)

    Wu Yaping; Liu Xiangfa

    2010-01-01

    The microstructures of Si-Mn-P alloy manufactured by the technique of combining phosphorus transportation and alloy melting were investigated using electron probe micro-analyzer (EPMA). The phase compositions were determined by energy spectrum and the varieties of eutectic morphologies were discussed. It is found that there is no ternary compound but Si, MnP and MnSi 1.75-x could appear when the Si-Mn-P alloy's composition is proper. Microstructure is greatly refined by rapid solidification technique and the amount of eutectic phases change with faster cooling rates. Moreover, primary Si or MnP are surrounded firstly by the binary eutectic (Si + MnP) and then the ternary eutectic (Si + MnSi 1.75-x + MnP) which also exhibit binary structures due to divorced eutectic determined by the particularity of some Si-Mn-P alloys.

  19. Corrosion Characteristics of Ti-29Nb-xHf Ternary Alloy for Biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Pak, Sun Young; Choi, Han Chul [Chosun Univ., Kwangju (Korea, Republic of)

    2015-12-15

    The Cp-Ti and Ti-6Al-4V alloys were widely used for dental materials due to their mechanical properties and good corrosion resistance. However, Cp-Ti was known as bio-inert materials, Ti-6Al-4V alloy has a problem such as high Young modulus, potential loss of the surrounding bone, and to the release of potentially toxic ions from the alloy. To overcome this problem, Ti alloys containing Nb and Hf elements have been used for biomaterials due to low toxicity and high corrosion resistance. Especially, alloying element of Nb was known as β phase stabilizer. The β phase alloy was widely used to replace currently used implant materials. The corrosion resistances of Ti-29Nb-xHf ternary alloys were dependent on Hf content in oral environment solution.

  20. Deviations from Vegard’s law in ternary III-V alloys

    KAUST Repository

    Murphy, S. T.; Chroneos, Alexander; Grimes, R. W.; Jiang, C.; Schwingenschlö gl, Udo

    2010-01-01

    the linear relationship would predict. Here we use special quasirandom structures and density functional theory to investigate such deviations for MxN1−xAs ternary alloys, where M and N are group III species (B, Al, Ga, and In). Our simulations predict a

  1. 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.

  2. Organic alloy systems suitable for the investigation of regular binary and ternary eutectic growth

    Science.gov (United States)

    Sturz, L.; Witusiewicz, V. T.; Hecht, U.; Rex, S.

    2004-09-01

    Transparent organic alloys showing a plastic crystal phase were investigated experimentally using differential scanning calorimetry and directional solidification with respect to find a suitable model system for regular ternary eutectic growth. The temperature, enthalpy and entropy of phase transitions have been determined for a number of pure substances. A distinction of substances with and without plastic crystal phases was made from their entropy of melting. Binary phase diagrams were determined for selected plastic crystal alloys with the aim to identify eutectic reactions. Examples for lamellar and rod-like eutectic solidification microstructures in binary systems are given. The system (D)Camphor-Neopentylglycol-Succinonitrile is identified as a system that exhibits, among others, univariant and a nonvariant eutectic reaction. The ternary eutectic alloy close to the nonvariant eutectic composition solidifies with a partially faceted solid-liquid interface. However, by adding a small amount of Amino-Methyl-Propanediol (AMPD), the temperature of the nonvariant eutectic reaction and of the solid state transformation from plastic to crystalline state are shifted such, that regular eutectic growth with three distinct nonfaceted phases is observed in univariant eutectic reaction for the first time. The ternary phase diagram and examples for eutectic microstructures in the ternary and the quaternary eutectic alloy are given.

  3. Superconductivity and specific heat measurements in V--Nb--Ta ternary alloys

    International Nuclear Information System (INIS)

    Wang, R.Y.P.

    1977-01-01

    The correlation between the superconducting transition temperature T/sub c/ with electronic specific heat coefficient γ and Debye temperature theta/sub D/ in some isoelectronic ternary V--Nb--Ta alloys is investigated. It has been known that the variation of theta/sub D/ with concentration in both V--Nb and V--Ta systems is clearly of the same curvature as that of T/sub c/ and γ. In Ta--Nb alloys, however, over most of the concentration range theta/sub D/ seems to have a slight negative curvature while T/sub c/ and γ curve upwards. (But beyond approx. 80 at. % Nb theta/sub D/ rises rapidly to the pure Nb value.) By choosing alloys along a line connecting Ta and V 25 --Nb 75 which is close to the Nb--Ta side of the Gibb's triangle the extent to which the Nb--Ta type of behavior persists in this ternary system can be estimated. A model proposed by Miedema that takes into account the variation of properties caused by possible charge transfer among constituent atoms in an alloy has been found to apply almost quantitatively for nearly all binary alloy systems whose experimental data are available, including those for which Hopfield's method fails. A previous test of the extension of Miedema's empirical model into ternary alloys shows qualitatively correct behavior for intra-row Zr/sub x/Nb/sub 1-2x/Mo/sub x/ alloys. The good agreement between the predicted values of γ and T/sub c/ and the experimental values in the inter-row ternary V--Nb--Ta system studied here gives another and better test of the application of Miedema's model

  4. Wetting Behavior of Ternary Au-Ge-X (X = Sb, Sn) Alloys on Cu and Ni

    Science.gov (United States)

    Jin, S.; Valenza, F.; Novakovic, R.; Leinenbach, C.

    2013-06-01

    Au-Ge-based alloys are potential substitutes for Pb-rich solders currently used for high-temperature applications. In the present work, the wetting behavior of two Au-Ge-X (X = Sb, Sn) ternary alloys, i.e., Au-15Ge-17Sb and Au-13.7 Ge-15.3Sn (at.%), in contact with Cu and Ni substrates has been investigated. Au-13.7Ge-15.3Sn alloy showed complete wetting on both Cu and Ni substrates. Total spreading of Au-15Ge-17Sb alloy on Cu was also observed, while the final contact angle of this alloy on Ni was about 29°. Pronounced dissolution of Cu substrates into the solder alloys investigated was detected, while the formation of Ni-Ge intermetallic compounds at the interface of both solder/Ni systems suppressed the dissolution of Ni into the solder.

  5. Hydrogen storage in binary and ternary Mg-based alloys: A comprehensive experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Kalisvaart, W.P.; Harrower, C.T.; Haagsma, J.; Zahiri, B.; Luber, E.J.; Ophus, C.; Mitlin, D. [Chemical and Materials Engineering, University of Alberta and National Research Council Canada, National Institute for Nanotechnology, T6G 2V4, Edmonton, Alberta (Canada); Poirier, E.; Fritzsche, H. [National Research Council Canada, SIMS, Canadian Neutron Beam Centre, Chalk River Laboratories, Chalk River, Ontario, K0J 1J0 (Canada)

    2010-03-15

    This study focused on hydrogen sorption properties of 1.5 {mu}m thick Mg-based films with Al, Fe and Ti as alloying elements. The binary alloys are used to establish as baseline case for the ternary Mg-Al-Ti, Mg-Fe-Ti and Mg-Al-Fe compositions. We show that the ternary alloys in particular display remarkable sorption behavior: at 200 C the films are capable of absorbing 4-6 wt% hydrogen in seconds, and desorbing in minutes. Furthermore, this sorption behavior is stable over cycling for the Mg-Al-Ti and Mg-Fe-Ti alloys. Even after 100 absorption/desorption cycles, no degradation in capacity or kinetics is observed. For Mg-Al-Fe, the properties are clearly worse compared to the other ternary combinations. These differences are explained by considering the properties of all the different phases present during cycling in terms of their hydrogen affinity and catalytic activity. Based on these considerations, some general design principles for Mg-based hydrogen storage alloys are suggested. (author)

  6. Ternary diffusion in Cu-rich fcc Cu–Al–Si alloys at 1073 K

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Dandan [School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Zhang, Lijun [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Du, Yong, E-mail: yongducalphad@gmail.com [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Xu, Honghui [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Jin, Zhanpeng [School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083 (China)

    2013-07-25

    Highlights: •Interdiffusivities in Cu-rich fcc Cu–Al–Si alloys at 1073 K were determined. •The present results were compared with experimental data in boundary binary systems. •The present results were validated by thermodynamic constraints and Fick’s law. •The sign of ternary cross diffusivities was predicted in terms of thermodynamics. -- Abstract: Utilizing six groups of bulk diffusion couples and with electron probe microanalysis technique, the composition dependence of ternary interdiffusion coefficients in Cu-rich fcc Cu–Al–Si alloys at 1073 K were determined by the Matano-Kirkaldy method. Using a three-dimensional representation, the obtained main ternary diffusion coefficients were found to be consistent with the experimental data in boundary binaries available in the literature. The reliability of the obtained interdiffusivities was further validated by thermodynamic constraints as well as by Fick’s second law applied to numerical simulation. The sign of the ternary cross diffusivities in fcc Cu–Al–Si alloys, which shows a noticeable effect on microstructure, was also successfully predicted in terms of thermodynamics.

  7. Ternary diffusion in Cu-rich fcc Cu–Al–Si alloys at 1073 K

    International Nuclear Information System (INIS)

    Liu, Dandan; Zhang, Lijun; Du, Yong; Xu, Honghui; Jin, Zhanpeng

    2013-01-01

    Highlights: •Interdiffusivities in Cu-rich fcc Cu–Al–Si alloys at 1073 K were determined. •The present results were compared with experimental data in boundary binary systems. •The present results were validated by thermodynamic constraints and Fick’s law. •The sign of ternary cross diffusivities was predicted in terms of thermodynamics. -- Abstract: Utilizing six groups of bulk diffusion couples and with electron probe microanalysis technique, the composition dependence of ternary interdiffusion coefficients in Cu-rich fcc Cu–Al–Si alloys at 1073 K were determined by the Matano-Kirkaldy method. Using a three-dimensional representation, the obtained main ternary diffusion coefficients were found to be consistent with the experimental data in boundary binaries available in the literature. The reliability of the obtained interdiffusivities was further validated by thermodynamic constraints as well as by Fick’s second law applied to numerical simulation. The sign of the ternary cross diffusivities in fcc Cu–Al–Si alloys, which shows a noticeable effect on microstructure, was also successfully predicted in terms of thermodynamics

  8. New ternary ordered structures in CuMPt6 (M=3d elements) alloys

    International Nuclear Information System (INIS)

    Das, Ananda Kumar; Nakamura, Reo; Takahashi, Miwako; Ohshima, Ken-ichi; Iwasaki, Hiroshi; Shishido, Toetsu

    2006-01-01

    X-ray and electron diffraction measurements were performed to investigate the structure and ordering behaviour of the ternary alloys CuMPt 6 (M=Ti, V, Cr, Mn, Fe, Co, and Ni). X-ray polycrystalline diffraction patterns of all the speciments quenched from 1000degC have shown that a single phase is formed at this stoichiometric composition. The alloys with M=Cr, Mn, Co, and Ni have the face-centred cubic (fcc) structure, while in the alloys with M=Ti, V, and Fe ordering has occurred and the structure is of the Cu 3 Au type. On annealing at lower temperatures ordering has been induced in the alloys with M=Cr, Mn, and Co and the structure is of the Cu 3 Au type, though the ordering in the last alloy has remained incomplete. Detailed X-ray diffraction measurements on single crystals of the CuMnPt 6 alloy have revealed that further ordering takes place and structure changes from the Cu 3 Au type into the cubic ABC 6 type with the unit cell as large 2 x 2 x 2 as the fcc unit cell, a new observation of the double-step ordering in the ternary fcc alloy. The corresponding transition temperatures are T c =970(±5)degC and T cl =750(±5)degC. (author)

  9. Microstructural response of an Al-modified Ni-Cr-Fe ternary alloy during thermal processing

    Energy Technology Data Exchange (ETDEWEB)

    Akinlade, D.A. [Department of Mechanical and Manufacturing Engineering, University of Manitoba, Winnipeg, MB (Canada)], E-mail: dotun172@yahoo.co.uk; Caley, W.F. [Department of Process Engineering and Applied Science, Dalhousie University, Halifax, NS (Canada); Richards, N.L.; Chaturvedi, M.C. [Department of Mechanical and Manufacturing Engineering, University of Manitoba, Winnipeg, MB (Canada)

    2008-07-15

    A thermodynamic package was used to predict the phase transformations that occurred during thermal processing of a superalloy based on the composition of a ternary Ni-Cr-Fe alloy. The effect of the addition of 6 w/o Al on phase transformation in the material sintered were estimated and compared with results obtained experimentally by X-ray diffraction and metallography, while the transformation temperature of the modified alloy was corroborated by differential scanning calorimetry (DSC). Mechanical property of the alloy was estimated in terms of Vickers hardness. These results suggest that despite potential problems encountered in high-temperature powder processing of superalloys that often tend to influence the feasibility of using thermodynamic predictions to model such alloy systems, the software and predictions used in this study offer a way to simulate both design and characterisation of the experimental alloy.

  10. Nanotubular surface and morphology of Ti-binary and Ti-ternary alloys for biocompatibility

    International Nuclear Information System (INIS)

    Choe, Han-Cheol

    2011-01-01

    The nanotubular surface of Ti-binary and Ti-ternary alloys for biomaterials has been investigated using various methods of surface characterization. Binary Ti-xNb (x = 10, 20, 30, and 40 wt.%) and ternary Ti-30Ta-xNb (x = 3, 7 and 15 wt.%) alloys were prepared by using the high-purity sponges; Ti, Ta and Zr spheres. The nanotube on the alloy surface was formed in 1.0 M H 3 PO 4 with small additions of NaF (0.5 and 0.8 wt.%), using a potentiostat. For cell proliferation, an MC3T3-E1 mouse osteoblast was used. The surface characteristics were investigated using field-emission scanning electron microscope, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy. Binary Ti-xZr alloys had a lamellar and a needle-like structure, whereas, ternary Ti-30Ta-xZr alloys had equiaxed grains with a lamellar martensitic α' structure. The thickness of the needle-like laths of the α-phase increased as the Zr content increased. The nanotubes formed on the α phase and β phase showed a different size and shape appearance with Zr content. As the Zr content increased from 3 to 40 wt.%, the diameter of the nanotubes in Ti-xZr and Ti-30Ta-xZr alloy decreased from 200 nm to 50 nm. The nanotubular Ti-30Ta-15Zr alloy surface with a diameter of 50 nm provided a good osseointegration; cell proliferation, migration and differentiation.

  11. Metastable Phase Separation and Concomitant Solute Redistribution of Liquid Fe-Cu-Sn Ternary Alloy

    International Nuclear Information System (INIS)

    Xiao-Mei, Zhang; Wei-Li, Wang; Ying, Ruan; Bing-Bo, Wei

    2010-01-01

    Liquid Fe-Cu-Sn ternary alloys with lower Sn contents are usually assumed to display a peritectic-type solidification process under equilibrium condition. Here we show that liquid Fe 47.5 Cu 47.5 Sn 5 ternary alloy exhibits a metastable immiscibility gap in the undercooling range of 51–329 K (0.19T L ). Macroscopic phase separation occurs once undercooling exceeds 196 K and causes the formation of a floating Fe-rich zone and a descending Cu-rich zone. Solute redistribution induces the depletion of Sn concentration in the Fe-rich zone and its enrichment in the Cu-rich zone. The primary Fe phase grows dendritically and its growth velocity increases with undercooling until the appearance of notable macrosegregation, but will decrease if undercooling further increases beyond 236 K. The microsegregation degrees of both solutes in Fe and Cu phases vary only slightly with undercooling. (condensed matter: structure, mechanical and thermal properties)

  12. Neutronics and activation analysis of lithium-based ternary alloys in IFE blankets

    Energy Technology Data Exchange (ETDEWEB)

    Jolodosky, Alejandra, E-mail: aleja311@berkeley.edu [University of California Berkeley, Berkeley, CA 94706 (United States); Kramer, Kevin [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA (United States); Meier, Wayne; DeMuth, James; Reyes, Susana [TerraPower, Bellevue, WA 98005 (United States); Fratoni, Massimiliano [University of California Berkeley, Berkeley, CA 94706 (United States)

    2016-06-15

    Highlights: • Monte Carlo calculations were performed on numerous lithium ternary alloys. • Elements with high neutron multiplication performed well with low absorbers. • Enriching lithium decreases minimum lithium concentration of alloys by 60% or more. • Alloys that performed well neutronically were selected for activation calculations. • Alloys activated, except LiBaBi, do not pose major environmental or safety concerns. - Abstract: An attractive feature of using liquid lithium as the breeder and coolant in fusion blankets is that it has very high tritium solubility and results in very low levels of tritium permeation throughout the facility infrastructure. However, lithium metal vigorously reacts with air and water and presents plant safety concerns. The Lawrence Livermore National Laboratory is carrying an effort to develop a lithium-based ternary alloy that maintains the beneficial properties of lithium (e.g. high tritium breeding and solubility) and at the same time reduces overall flammability concerns. This study evaluates the neutronics performance of lithium-based alloys in the blanket of an inertial fusion energy chamber in order to inform such development. 3-D Monte Carlo calculations were performed to evaluate two main neutronics performance parameters for the blanket: tritium breeding ratio (TBR), and the fusion energy multiplication factor (EMF). It was found that elements that exhibit low absorption cross sections and higher q-values such as Pb, Sn, and Sr, perform well with those that have high neutron multiplication such as Pb and Bi. These elements meet TBR constrains ranging from 1.02 to 1.1. However, most alloys do not reach EMFs greater than 1.15. Additionally, it was found that enriching lithium with {sup 6}Li significantly increases the TBR and decreases the minimum lithium concentration by more than 60%. The amount of enrichment depends on how much total lithium is in the alloy to begin with. Alloys that performed well in the TBR

  13. Microstructural evolution of ternary Ag33Cu42Ge25 eutectic alloy inside ultrasonic field

    Directory of Open Access Journals (Sweden)

    Wei Zhai

    2014-12-01

    Full Text Available Ultrasonic field with a frequency of 20 kHz is introduced into the solidification process of ternary Ag33Cu42Ge25 eutectic alloy from the sample bottom to its top. The ultrasound stimulates the nucleation of alloy melt and prevents its bulk undercooling. At low ultrasound power of 250 W, the primary ε2 phase in the whole alloy sample grows into non-faceted equiaxed grains, which differs to its faceted morphology of long strip under static condition. The pseudobinary (Ag+ε2 eutectic transits from dendrite shape grain composed of rod type eutectic to equiaxed chrysanthemus shape formed by lamellar structure. By contrast, the ultrasound produces no obvious variation in the morphology of ternary (Ag+Ge+ε2 eutectic except a coarsening effect. When ultrasound power rises to 500 W, divorced ternary (Ag+Ge+ε2 eutectic forms at the sample bottom. However, in the upper part, the ultrasonic energy weakens, and it only brings about prominent refining effect to primary ε2 phase. The microstructural evolution mechanism is investigated on the cavitation, acoustic streaming and acoustic attenuation.

  14. Special quasirandom structures for binary/ternary group IV random alloys

    KAUST Repository

    Chroneos, Alexander I.

    2010-06-01

    Simulation of defect interactions in binary/ternary group IV semiconductor alloys at the density functional theory level is difficult due to the random distribution of the constituent atoms. The special quasirandom structures approach is a computationally efficient way to describe the random nature. We systematically study the efficacy of the methodology and generate a number of special quasirandom cells for future use. In order to demonstrate the applicability of the technique, the electronic structures of E centers in Si1-xGex and Si1-x -yGexSny alloys are discussed for a range of nearest neighbor environments. © 2010 Elsevier B.V. All rights reserved.

  15. E centers in ternary Si1−x−yGexSny random alloys

    KAUST Repository

    Chroneos, Alexander

    2009-09-14

    Density functional theory calculations are used to study the association of arsenic (As) atoms to lattice vacancies and the formation of As-vacancy pairs, known as E centers, in the random Si0.375Ge0.5Sn0.125 alloy. The local environments are described by 32-atom special quasirandom structures that represent random Si1−x−yGexSny alloys. It is predicted that the nearest-neighbor environment will exert a strong influence on the stability of E centers in ternary Si0.375Ge0.5Sn0.125.

  16. E centers in ternary Si1−x−yGexSny random alloys

    KAUST Repository

    Chroneos, Alexander; Bracht, H.; Grimes, R. W.; Jiang, C.; Schwingenschlö gl, Udo

    2009-01-01

    Density functional theory calculations are used to study the association of arsenic (As) atoms to lattice vacancies and the formation of As-vacancy pairs, known as E centers, in the random Si0.375Ge0.5Sn0.125 alloy. The local environments are described by 32-atom special quasirandom structures that represent random Si1−x−yGexSny alloys. It is predicted that the nearest-neighbor environment will exert a strong influence on the stability of E centers in ternary Si0.375Ge0.5Sn0.125.

  17. Hydrogen storage in binary and ternary Mg-based alloys. A comprehensive experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Kalisvaart, W.P.; Harrower, C.T.; Haagsma, J.; Zahiri, B.; Luber, E.J.; Ophus, C.; Miltin, D. [Alberta Univ., Edmonton (Canada); Poirier, E.; Fritzsche, H. [Canadian Neutron Beam Centre, Chalk River, ON (Canada)

    2010-07-01

    This study focuses on hydrogen sorption properties of cosputtered 1.5 micrometer thick Mg-based films with Al, Fe and Ti as alloying elements. We show that ternary Mg-Al-Ti and Mg-Fe-Ti alloys in particular display remarkable sorption behavior: at 200 C, the films are capable of absorbing 4-6 wt.% hydrogen in seconds, and desorbing in minutes. Furthermore, this sorption behavior is stable for over 100 ab- and desorption cycles for Mg-Al-Ti and Mg-Fe-Ti alloys. No degradation in capacity or kinetics is observed. Based on these observations, some general design principles for Mg-based hydrogen storage alloys are suggested. For Mg-Fe-Ti, encouraging preliminary results on multilayered systems are also presented. (orig.)

  18. Electrochemical studies on electroless ternary and quaternary Ni-P based alloys

    International Nuclear Information System (INIS)

    Balaraju, J.N.; Selvi, V. Ezhil; Grips, V.K. William; Rajam, K.S.

    2006-01-01

    The autocatalytic (electroless) deposition of Ni-P based alloys is a well-known commercial process that has found numerous applications because of their excellent anticorrosive, wear, magnetic, solderable properties, etc. It is a barrier coating, protecting the substrate by sealing it off from the corrosive environments, rather than by sacrificial action. The corrosion resistance varies with the phosphorus content of the deposit: relatively high for a high-phosphorus electroless nickel deposit but low for a low-phosphorus electroless nickel deposit. In the present investigation ternary Ni-W-P alloy films were prepared using alkaline citrate-based bath. Quaternary Ni-W-Cu-P films were deposited by the addition of 3 mM copper ions in ternary Ni-W-P bath. X-ray diffraction (XRD) studies indicated that all the deposits were nanocrystalline, i.e. 1.2, 2.1 and 6.0 nm, respectively, for binary, ternary and quaternary alloys. Corrosion resistance of the films was evaluated in 3.5% sodium chloride solution in non-deaerated and deaerated conditions by potentiodynamic polarization and electrochemical impedance (EIS) methods. Lower corrosion current density values were obtained for the coatings tested in deaerated condition. EIS studies showed that higher charge transfer resistance values were obtained for binary Ni-P coatings compared to ternary or quaternary coatings. For all the coatings a gradual increase in the anodic current density had been observed beyond 740 mV. In deaerated condition all the reported coatings exhibited a narrow passive region and all the values of E p , E tp and i pass were very close showing no major changes in the electrochemical behavior. In the non-deaerated conditions no passivation behavior had been observed for all these coatings

  19. Ion beam modifications of near-surface compositions in ternary alloys

    International Nuclear Information System (INIS)

    Lam, N.Q.; Tang, S.; Yacout, A.M.; Rehn, L.E.; Stubbins, J.F.

    1990-11-01

    Changes in the surface and subsurface compositions of ternary alloys during elevated-temperature sputtering with inert-gas ions were investigated. Theoretically, a comprehensive kinetic model which includes all the basic processes, such as preferential sputtering, displacement mixing, Gibbsian segregation, radiation-enhanced diffusion and radiation-induced segregation, was developed. This phenomenological approach enabled to predict the effects of each individual process or of a combination of processes on the compositional modification in model alloys. Experimentally, measurements of compositional changes at the surface of a Ag-40at%Au -- 20at%Cu alloy during 3-keV Ne + bombardment at various temperatures were made, using ion scattering spectroscopy. These measurements were interpreted on the basis of the results of theoretical modeling. 8 refs., 2 figs

  20. Development of aluminum (Al5083)-clad ternary Ag-In-Cd alloy for JSNS decoupled moderator

    International Nuclear Information System (INIS)

    Teshigawara, M.; Harada, M.; Saito, S.; Oikawa, K.; Maekawa, F.; Futakawa, M.; Kikuchi, K.; Kato, T.; Ikeda, Y.; Naoe, T.; Koyama, T.; Ooi, T.; Zherebtsov, S.; Kawai, M.; Kurishita, H.; Konashi, K.

    2006-01-01

    To develop Ag (silver)-In (indium)-Cd (cadmium) alloy decoupler, a method is needed to bond the decoupler between Al alloy (Al5083) and the ternary Ag-In-Cd alloy. We found that a better HIP condition was temperature, pressure and holding time at 803 K, 100 MPa and 10 min. for small test pieces (φ22 mm in dia. x 6 mm in height). Hardened layer due to the formation of AlAg 2 was found in the bonding layer, however, the rupture strength of the bonding layer is more than 30 MPa, the calculated design stress. Bonding tests of a large size piece (200 x 200 x 30 mm 3 ), which simulated the real scale, were also performed according to the results of small size tests. The result also gave good bonding and enough required-mechanical-strength

  1. Investigations of binary and ternary phase change alloys for future memory applications

    International Nuclear Information System (INIS)

    Rausch, Pascal

    2012-01-01

    The understanding of phase change materials is of great importance because it enables us to predict properties and tailor alloys which might be even better suitable to tackle challenges of future memory applications. Within this thesis two topics have been approached: on the one hand the understanding of the alloy In 3 Sb 1 Te 2 and on the other hand the so called resistivity drift of amorphous Ge-Sn-Te phase change materials. The main topic covers an in depth discussion of the ternary alloy In 3 Sb 1 Te 2 . At first glance, this alloy does not fit into the established concepts of phase alloys: e.g. the existence of resonant bonding in the crystalline phase is not obvious and the number of p-electrons is very low compared to other phase change alloys. Furthermore amorphous phase change alloys with high indium content are usually not discussed in literature, an exception being the recent work by Spreafico et al. on InGeTe 2 . For the first time a complete description of In 3 Sb 1 Te 2 alloy is given in this work for the crystalline phase, amorphous phase and crystallization process. In addition comparisons are drawn to typical phase change materials like Ge 2 Sb 2 Te 5 /GeTe or prototype systems like AgInTe 2 and InTe. The second topic of this thesis deals with the issue of resistivity drift, i.e. the increase of resistivity of amorphous phase change alloys with aging. This drift effect greatly hampers the introduction of multilevel phase change memory devices into the market. Recently a systematic decrease of drift coefficient with stoichiometry has been observed in our group going from GeTe over Ge 3 Sn 1 Te 4 to Ge 2 Sn 2 Te 4 . These alloys are investigated with respect to constraint theory.

  2. Robust tribo-mechanical and hot corrosion resistance of ultra-refractory Ta-Hf-C ternary alloy films.

    Science.gov (United States)

    Yate, Luis; Coy, L Emerson; Aperador, Willian

    2017-06-08

    In this work we report the hot corrosion properties of binary and ternary films of the Ta-Hf-C system in V 2 O 5 -Na 2 SO 4 (50%wt.-50%wt.) molten salts at 700 °C deposited on AISI D3 steel substrates. Additionally, the mechanical and nanowear properties of the films were studied. The results show that the ternary alloys consist of solid solutions of the TaC and HfC binary carbides. The ternary alloy films have higher hardness and elastic recoveries, reaching 26.2 GPa and 87%, respectively, and lower nanowear when compared to the binary films. The corrosion rates of the ternary alloys have a superior behavior compared to the binary films, with corrosion rates as low as 0.058 μm/year. The combination and tunability of high hardness, elastic recovery, low nanowear and an excellent resistance to high temperature corrosion demonstrates the potential of the ternary Ta-Hf-C alloy films for applications in extreme conditions.

  3. Phase diagrams of the ternary alloy with a single-ion anisotropy in the mean-field approximation

    International Nuclear Information System (INIS)

    Dely, J.; Bobak, A.

    2006-01-01

    The phase diagram of the AB p C 1-p ternary alloy consisting of Ising spins S A =32, S B =2, and S C =52 is investigated by the use of a mean-field theory based on the Bogoliubov inequality for the Gibbs free energy. The effect of the single-ion anisotropy on the phase diagrams is discussed by changing values of the parameters in the model Hamiltonian and comparison is made with the recently reported finite-temperature phase diagrams for the ternary alloy having spin S B =1

  4. Properties of mechanically alloyed Mg-Ni-Ti ternary hydrogen storage alloys for Ni-MH batteries

    Science.gov (United States)

    Ruggeri, Stéphane; Roué, Lionel; Huot, Jacques; Schulz, Robert; Aymard, Luc; Tarascon, Jean-Marie

    MgNiTi x, Mg 1- xTi xNi and MgNi 1- xTi x (with x varying from 0 to 0.5) alloys have been prepared by high energy ball milling and tested as hydrogen storage electrodes. The initial discharge capacities of the Mg-Ni-Ti ternary alloys are inferior to the MgNi electrode capacity. However, an exception is observed with MgNi 0.95Ti 0.05, which has an initial discharge capacity of 575 mAh/g compared to 522 mAh/g for the MgNi electrode. The Mg-Ni-Ti ternary alloys show improved cycle life compared to Mg-Ni binary alloys with the same Mg/Ni atomic ratio. The best cycle life is observed with Mg 0.5Ti 0.5Ni electrode which retains 75% of initial capacity after 10 cycles in comparison to 39% for MgNi electrodes, in addition to improved high-rate dischargeability (HRD). According to the XPS analysis, the cycle life improvement of the Mg 0.5Ti 0.5Ni electrode can be related to the formation of TiO 2 which limits Mg(OH) 2 formation. The anodic polarization curve of Mg 0.5Ti 0.5Ni electrode shows that the current related to the active/passive transition is much less important and that the passive region is more extended than for the MgNi electrode but the corrosion of the electrode is still significant. This suggests that the cycle life improvement would be also associated with a decrease of the particle pulverization upon cycling.

  5. Internal friction of Ti-Ni-Cu ternary shape memory alloys

    International Nuclear Information System (INIS)

    Yoshida, I.; Monma, D.; Iino, K.; Ono, T.; Otsuka, K.; Asai, M.

    2004-01-01

    Low frequency internal friction was measured on three specimens of Ti-Ni-Cu ternary alloys, the Cu content varying from 10 to 20 at.%, while Ti content was fixed at 50 at.%. The internal friction spectrum consists mainly of two peaks, a sharper one associated with the B2-B19 transformation and the other one at around 250 K, which is much broader and higher than the former. The peak height of the latter is 0.2 for the specimen containing 20% Cu, which shows that this alloy can be an excellent high damping material. Transformation behavior was studied by electrical resistivity, thermopower and DSC measurements, and was compared with the result of internal friction measurements. Solution treatment at higher temperatures lowers the internal friction peak markedly. Scanning electron microscopy observation reveals that the behaviors of precipitates are different for different solution treatment temperature, suggesting that the precipitation behavior is crucial in the damping properties

  6. Influence of indium clustering on the band structure of semiconducting ternary and quaternarynitride alloys

    DEFF Research Database (Denmark)

    Gorczyca,, I.; Łepkowski, S. P.; Suski, T.

    2009-01-01

    smaller when the In atoms are clustered than when they are uniformly distributed. An explanation of this phenomenon is proposed on the basis of an analysis of the density of states and the bond lengths, performed in detail for ternary alloys. Results for the band gaps of InxGayAl1-x-yN quaternary alloys...... and atomic arrangements are examined. Particular attention is paid to the magnitude of and trends in bowing of the band gaps. Indium composition fluctuation (clustering) is simulated by different distributions of In atoms and it is shown that it strongly influences the band gaps. The gaps are considerably...... show a similar trend. It is suggested that the large variation in the band gaps determined on samples grown in different laboratories is caused by different degrees of In clustering....

  7. Swelling of austenitic iron-nickelchromium ternary alloys during fast neutron irradiation

    International Nuclear Information System (INIS)

    Garner, F.A.; Brager, H.R.

    1984-01-01

    Swelling data are now available for 15 iron-nickel-chromium ternary alloys irradiated to exposures as high as 110 displacements per atom (dpa) in Experimental Breeder Reactor-II (EBR-II) between 400 and 650 0 C. These data confirm trends observed at lower exposure levels and extend the generality of earlier conclusions to cover a broader range of composition and temperature. It appears that all austenitic iron-nickel-chromium ternary alloys eventually approach an intrinsic swelling rate of about1%/dpa over a range of temperature even wider than studied in this experiment. The duration of the transient regime that precedes the attainment of this rate is quite sensitive to nickel and chromium content, however. At nickel and chromium levels typical of 300 series steels, swelling does not saturate at engineering-relevant levels. However, there appears to be a tendency toward saturation that increases with declining temperature, increasing nickel and decreasing chromium levels. Comparisons of these results are made with those of similar studies conducted with charged particles. Conclusions are then drawn concerning the validity of charged particle simulation studies to determine the compositional and temperature dependence of swelling

  8. The band gap of II-Vi ternary alloys in a tight-binding description

    Energy Technology Data Exchange (ETDEWEB)

    Olguin, Daniel; Blanquero, Rafael [Instituto Politecnico Nacional, Mexico, D.F (Mexico); De Coss, Romeo [Instituto Politecnico Nacional, Yucatan (Mexico)

    2001-02-01

    We present tight-binding calculations for the band gap of II-Vi pseudobinary ternary alloys. We use an sp{sup 3} s* tight-binding Hamiltonian which include spin-orbit coupling. The band gap composition dependence is calculated using a extended version of the virtual crystal approximation, which introduce an empirical correction factor that takes into account the non-linear dependence of the band gap with the composition. The results compare quite well with the experimental data, both for the ternary alloys with wide band gap and for the narrow band gap ones. [Spanish] Presentamos el calculo de la banda de energia prohibida de aleaciones ternarias de compuestos II-VI. El calculo, que incluye interaccion espin-orbita, se hace con el metodo de enlace fuerte, utilizando una base ortogonal de cinco orbitales atomicos por atomo (sp{sup 3} s*), en conjunto con la aproximacion del cristal virtual. En la aproximacion del cristal virtual, incluimos un factor de correccion que toma en cuenta la no linealidad de la banda de energia prohibida como funcion de la concentracion. Con esta correccion nuestros resultados reproducen aceptablemente los datos experimentales hallados en la literatura.

  9. Thermodynamic and kinetic aspects on the selective surface oxidation of binary, ternary and quarternary model alloys

    International Nuclear Information System (INIS)

    Swaminathan, Srinivasan; Spiegel, Michael

    2007-01-01

    Segregation and selective oxidation phenomena of minor alloying elements during annealing of steel sheets lead to the formation of bare spots after hot dip galvanizing. In order to understand the influence of common alloying elements on the surface chemistry after annealing, model alloys of binary (Fe-2Si, Fe-2Mn and Fe-0.8Cr), ternary (Fe-2Mn-2Si, Fe-2Mn-0.8Cr and Fe-2Si-0.8Cr) and quarternary (Fe-2Mn-2Si-0.8Cr) systems were investigated. The specimens were annealed for 60 s at 820 deg. C in N 2 -5% H 2 gas atmospheres with different dew points -80 and -40 deg. C, respectively. Surface chemistry of the annealed specimens was obtained by using X-ray photoelectron spectroscopy (XPS). The field emission scanning electron microscopy (FE-SEM) was used to view surface morphology. At low dew point -80 deg. C, apart from the thermodynamical calculations such as solubility product of oxides and their critical solute concentrations, kinetics play a decisive role on the selective oxidation, i.e. oxygen competition. As expected, the amount of external selective oxidation of alloying elements are well pronounced at higher dew point -40 deg. C. An attempt has been made to explain the dominant process of Si and Mn on Cr-oxidation and segregation. It is observed that annealing of quarternary system at higher dew point shifts the Cr-oxidation from external to internal

  10. The thermodynamic stability induced by solute co-segregation in nanocrystalline ternary alloys

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Tao; Chen, Zheng; Zhang, Jinyong; Zhang, Ping [China Univ. of Mining and Technology, Xuzhou (China). School of Mateial Science and Engineering; Yang, Xiaoqin [China Univ. of Mining and Technology, Xuzhou (China). School of Chemical Engineering and Technology

    2017-06-15

    The grain growth and thermodynamic stability induced by solute co-segregation in ternary alloys are presented. Grain growth behavior of the single-phase supersaturated grains prepared in Ni-Fe-Pb alloy melt at different undercoolings was investigated by performing isothermal annealings at T = 400 C-800 C. Combining the multicomponent Gibbs adsorption equation and Guttmann's grain boundary segregation model, an empirical relation for isothermal grain growth was derived. By application of the model to grain growth in Ni-Fe-Pb, Fe-Cr-Zr and Fe-Ni-Zr alloys, it was predicted that driving grain boundary energy to zero is possible in alloys due to the co-segregation induced by the interactive effect between the solutes Fe/Pb, Zr/Ni and Zr/Cr. A non-linear relationship rather than a simple linear relation between 1/D* (D* the metastable equilibrium grain size) and ln(T) was predicted due to the interactive effect.

  11. Microstructural characterization and phase transformation of ternary alloys near at Al3Ti compound

    International Nuclear Information System (INIS)

    Angeles Ch, C.

    1999-01-01

    This research work is related with the structural characteristic and compositional values of the crystalline phases, which are found in ternary alloys of Ti-Al-Fe and TI-Al-Cu. These types of alloys were obtained using a rapid solidification technique (10 3 -10 4 K/s) and pure elements such as Al, Ti, Fe and Cu (99.99%). These cooling velocities allow the formation of stable phases and small grain sizes (approximately in range of a few micras). The obtained results indicate the presence of Al 3 Ti and others phases of L1 2 type. These phases are commonly found in a matrix rich in A1. The microalloyed elements (Cu and Fe) substitute the aluminum in both kinds of phases. Alloys with low content of Cu show transition states from the tetragonal structure DO 22 to the cubic phases L1 2 . The structural characteristics of the alloys are related with some microhardness measurement. The results show that the presence of the L1 2 phase tends to increase to hardness depending of the content of this phase

  12. Thermodynamic and kinetic aspects on the selective surface oxidation of binary, ternary and quarternary model alloys

    Energy Technology Data Exchange (ETDEWEB)

    Swaminathan, Srinivasan [High Temperature Reactions Group, Department of Interface Chemistry and Surface Engineering, Max-Planck-Institut fuer Eisenforschung GmbH, Max-Planck-Str. 1, D-40237 Duesseldorf (Germany)]. E-mail: s.swaminathan@mpie.de; Spiegel, Michael [High Temperature Reactions Group, Department of Interface Chemistry and Surface Engineering, Max-Planck-Institut fuer Eisenforschung GmbH, Max-Planck-Str. 1, D-40237 Duesseldorf (Germany)

    2007-03-15

    Segregation and selective oxidation phenomena of minor alloying elements during annealing of steel sheets lead to the formation of bare spots after hot dip galvanizing. In order to understand the influence of common alloying elements on the surface chemistry after annealing, model alloys of binary (Fe-2Si, Fe-2Mn and Fe-0.8Cr), ternary (Fe-2Mn-2Si, Fe-2Mn-0.8Cr and Fe-2Si-0.8Cr) and quarternary (Fe-2Mn-2Si-0.8Cr) systems were investigated. The specimens were annealed for 60 s at 820 deg. C in N{sub 2}-5% H{sub 2} gas atmospheres with different dew points -80 and -40 deg. C, respectively. Surface chemistry of the annealed specimens was obtained by using X-ray photoelectron spectroscopy (XPS). The field emission scanning electron microscopy (FE-SEM) was used to view surface morphology. At low dew point -80 deg. C, apart from the thermodynamical calculations such as solubility product of oxides and their critical solute concentrations, kinetics play a decisive role on the selective oxidation, i.e. oxygen competition. As expected, the amount of external selective oxidation of alloying elements are well pronounced at higher dew point -40 deg. C. An attempt has been made to explain the dominant process of Si and Mn on Cr-oxidation and segregation. It is observed that annealing of quarternary system at higher dew point shifts the Cr-oxidation from external to internal.

  13. Investigations of binary and ternary phase change alloys for future memory applications

    Energy Technology Data Exchange (ETDEWEB)

    Rausch, Pascal

    2012-09-13

    The understanding of phase change materials is of great importance because it enables us to predict properties and tailor alloys which might be even better suitable to tackle challenges of future memory applications. Within this thesis two topics have been approached: on the one hand the understanding of the alloy In{sub 3}Sb{sub 1}Te{sub 2} and on the other hand the so called resistivity drift of amorphous Ge-Sn-Te phase change materials. The main topic covers an in depth discussion of the ternary alloy In{sub 3}Sb{sub 1}Te{sub 2}. At first glance, this alloy does not fit into the established concepts of phase alloys: e.g. the existence of resonant bonding in the crystalline phase is not obvious and the number of p-electrons is very low compared to other phase change alloys. Furthermore amorphous phase change alloys with high indium content are usually not discussed in literature, an exception being the recent work by Spreafico et al. on InGeTe{sub 2}. For the first time a complete description of In{sub 3}Sb{sub 1}Te{sub 2} alloy is given in this work for the crystalline phase, amorphous phase and crystallization process. In addition comparisons are drawn to typical phase change materials like Ge{sub 2}Sb{sub 2}Te{sub 5}/GeTe or prototype systems like AgInTe{sub 2} and InTe. The second topic of this thesis deals with the issue of resistivity drift, i.e. the increase of resistivity of amorphous phase change alloys with aging. This drift effect greatly hampers the introduction of multilevel phase change memory devices into the market. Recently a systematic decrease of drift coefficient with stoichiometry has been observed in our group going from GeTe over Ge{sub 3}Sn{sub 1}Te{sub 4} to Ge{sub 2}Sn{sub 2}Te{sub 4}. These alloys are investigated with respect to constraint theory.

  14. Formation, Characteristics and Electrocatalytic Properties of Nanoporous Metals Formed by Dealloying of Ternary-Noble Alloys

    Science.gov (United States)

    Vega Zuniga, Adrian A.

    Nanoporous metals formed by electrochemical dealloying of silver from Ag-Au-Pt alloys, with 77 at.% silver and platinum contents of 1, 2 and 3 at.%, have been studied. The presence of platinum, which is immobile relative to gold, refine the ligament size and stabilized the nanostructure against coarsening, even under experimental conditions that would be expected to promote coarsening (e.g., exposure to high temperature, longer dealloying times). By adding only 1 at.% Pt to the alloy precursor, the ligament/pore size was reduced by 50% with respect to that in nanoporous gold (NPG), which was formed on a Ag-Au alloy with the same silver content as ternary alloys. A further decrease in the ligament size was observed by increasing the platinum content of the precursor; however, most of the improvement occurred with 1 at.% Pt. The adsorbate-induced surface segregation of platinum was also investigated for these nanoporous metals. By exposing freshly-dealloyed nanostructures to moderate temperatures in the presence of air, platinum segregated to the ligament surface; in contrast, in an inert atmosphere (Ar-H 2), platinum mostly reverted to the bulk of the ligaments. This thermally activated process was thermodynamically driven by the interaction between platinum and oxygen; however, at the desorption temperature of oxygen, platinum de-segregated from the surface. Moreover, the co-segregation of platinum and oxygen hindered the thermal coarsening of the ligaments. Finally, the electrocatalytic abilities of these nanostructures were studied towards methanol and ethanol electro-oxidation, in alkaline and acidic media, showing significantly improved response in comparison to that observed in NPG. The synergistic effect between gold and platinum atoms and the smaller feature size of the nanostructures were directly associated with this behaviour. In alkaline electrolyte, the nanostructure formed on the alloy with 1 at.% Pt showed higher catalytic response than the other two

  15. Composition Optimization of Lithium-Based Ternary Alloy Blankets for Fusion Reactors

    Science.gov (United States)

    Jolodosky, Alejandra

    The goal of this dissertation is to examine the neutronic properties of a novel type of fusion reactor blanket material in the form of lithium-based ternary alloys. Pure liquid lithium, first proposed as a blanket for fusion reactors, is utilized as both a tritium breeder and a coolant. It has many attractive features such as high heat transfer and low corrosion properties, but most importantly, it has a very high tritium solubility and results in very low levels of tritium permeation throughout the facility infrastructure. However, lithium metal vigorously reacts with air and water and presents plant safety concerns including degradation of the concrete containment structure. The work of this thesis began as a collaboration with Lawrence Livermore National Laboratory in an effort to develop a lithium-based ternary alloy that can maintain the beneficial properties of lithium while reducing the reactivity concerns. The first studies down-selected alloys based on the analysis and performance of both neutronic and activation characteristics. First, 3-D Monte Carlo calculations were performed to evaluate two main neutronics performance parameters for the blanket: tritium breeding ratio (TBR), and energy multiplication factor (EMF). Alloys with adequate results based on TBR and EMF calculations were considered for activation analysis. Activation simulations were executed with 50 years of irradiation and 300 years of cooling. It was discovered that bismuth is a poor choice due to achieving the highest decay heat, contact dose rates, and accident doses. In addition, it does not meet the waste disposal ratings (WDR). The straightforward approach to obtain Monte Carlo TBR and EMF results required 231 simulations per alloy and became computationally expensive, time consuming, and inefficient. Consequently, alternate methods were pursued. A collision history-based methodology recently developed for the Monte Carlo code Serpent, calculates perturbation effects on practically

  16. The dynamics of nucleation and growth of a particle in the ternary alloy melt with anisotropic surface tension.

    Science.gov (United States)

    Chen, Ming-Wen; Li, Lin-Yan; Guo, Hui-Min

    2017-08-28

    The dynamics of nucleation and growth of a particle affected by anisotropic surface tension in the ternary alloy melt is studied. The uniformly valid asymptotic solution for temperature field, concentration field, and interface evolution of nucleation and particle growth is obtained by means of the multiple variable expansion method. The asymptotic solution reveals the critical radius of nucleation in the ternary alloy melt and an inward melting mechanism of the particle induced by the anisotropic effect of surface tension. The critical radius of nucleation is dependent on isotropic surface tension, temperature undercooling, and constitutional undercooling in the ternary alloy melt, and the solute diffusion melt decreases the critical radius of nucleation. Immediately after a nucleus forms in the initial stage of solidification, the anisotropic effect of surface tension makes some parts of its interface grow inward while some parts grow outward. Until the inward melting attains a certain distance (which is defined as "the melting depth"), these parts of interface start to grow outward with other parts. The interface of the particle evolves into an ear-like deformation, whose inner diameter may be less than two times the critical radius of nucleation within a short time in the initial stage of solidification. The solute diffusion in the ternary alloy melt decreases the effect of anisotropic surface tension on the interface deformation.

  17. L1{sub 0} phase formation in ternary FePdNi alloys

    Energy Technology Data Exchange (ETDEWEB)

    Montes-Arango, A.M. [Department of Mechanical and Industrial Engineering, Northeastern University, Boston, MA 02115 (United States); Bordeaux, N.C. [Department of Chemical Engineering, Northeastern University, Boston, MA 02115 (United States); Liu, J.; Barmak, K. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027 (United States); Lewis, L.H., E-mail: lhlewis@neu.edu [Department of Mechanical and Industrial Engineering, Northeastern University, Boston, MA 02115 (United States); Department of Chemical Engineering, Northeastern University, Boston, MA 02115 (United States)

    2015-11-05

    Metallurgical routes to highly metastable phases are required to access new materials with new functionalities. To this end, the stability of the tetragonal chemically ordered L1{sub 0} phase in the ternary Fe–Pd–Ni system is quantified to provide enabling information concerning synthesis of L1{sub 0}-type FeNi, a highly attractive yet highly elusive advanced permanent magnet candidate. Fe{sub 50}Pd{sub 50−x}Ni{sub x} (x = 0–7 at%) samples were arc-melted and annealed at 773 K (500 °C) for 100 h to induce formation of the chemically ordered L1{sub 0} phase. Coupled calorimetry, structural and magnetic investigations allow determination of an isothermal section of the ternary Fe–Pd–Ni phase diagram featuring a single phase L1{sub 0} region near the FePd boundary for x < 6 at%. It is demonstrated that increased Ni content in Fe{sub 50}Pd{sub 50−x}Ni{sub x} alloys systematically decreases the order-disorder transition temperature, resulting in a lower thermodynamic driving force for the ordering phase transformation. The Fe{sub 50}Pd{sub 50−x}Ni{sub x} L1{sub 0} → fcc disordering transformation is determined to occur via a two-step process, with compositionally-dependent enthalpies and transition temperatures. These results highlight the need to investigate ternary alloys with higher Ni content to determine the stability range of the L1{sub 0} phase near the FeNi boundary, thereby facilitating kinetic access to the important L1{sub 0} FeNi ferromagnetic phase. - Highlights: • Chemical ordering in FePdNi enhances intrinsic and extrinsic magnetic properties. • 773 K annealed FePdNi alloys studied show a stable L1{sub 0} phase for Ni ≤ 5.2 at%. • Chemical disordering in FePdNi occurs by a previously unreported two-step process. • Ni additions to FePd dramatically decrease the chemical order-disorder temperature. • The chemical-ordering transformation kinetics are greatly affected by Ni content.

  18. Sn-Sb-Se based binary and ternary alloys for phase change memory applications

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Kyung-Min

    2008-10-28

    In this work, the effect of replacing Ge by Sn and Te by Se was studied for a systematic understanding and prediction of new potential candidates for phase change random access memories applications. The temperature dependence of the electrical/structural properties and crystallization kinetics of the Sn-Se based binary and Sn-Sb-Se based ternary alloys were determined and compared with those of the GeTe and Ge-Sb-Te system. The temperature dependence of electrical and structural properties were investigated by van der Pauw measurements, X-ray diffraction, X-ray reflectometry. By varying the heating rate, the Kissinger analysis has been used to determine the combined activation barrier for crystallization. To screen the kinetics of crystallization, a static laser tester was employed. In case of binary alloys of the type Sn{sub x}Se{sub 1-x}, the most interesting candidate is SnSe{sub 2} since it crystallizes into a single crystalline phase and has high electrical contrast and reasonably high activation energy for crystallization. In addition, the SnSe{sub 2}-Sb{sub 2}Se{sub 3} pseudobinary alloy system also might be sufficient for data retention due to their higher transition temperature and activation energy for crystallization in comparison to GeTe-Sb{sub 2}Te{sub 3} system. Furthermore, SnSe{sub 2}-Sb{sub 2}Se{sub 3} pseudobinary alloys have a higher crystalline resistivity. The desired rapid crystallization speed can be obtained for Sn{sub 1}Sb{sub 2}Se{sub 5} and Sn{sub 2}Sb{sub 2}Se{sub 7} alloys. (orig.)

  19. Glass forming ability: Miedema approach to (Zr, Ti, Hf)-(Cu, Ni) binary and ternary alloys

    Energy Technology Data Exchange (ETDEWEB)

    Basu, Joysurya [Department of Chemical, Materials and Biomolecular Engineering, 191 Auditorium Road, University of Connecticut, Storrs 06269, CT (United States)], E-mail: jbasu@engr.uconn.edu; Murty, B.S. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Ranganathan, S. [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India)

    2008-10-06

    Miedema's approach has been useful in determining the glass forming composition range for a particular alloy system. The concept of mixing enthalpy and mismatch entropy can be used in order to quantify Inoue's criteria of bulk metallic glass formation. In the present study, glass forming composition range has been determined for different binary and ternary (Zr, Ti, Hf)-(Cu, Ni) alloys based on the mixing enthalpy and mismatch entropy calculations. Though copper and nickel appear next to each other in the periodic table, the glass forming ability of the copper and nickel bearing alloys is different. Thermodynamic analysis reveals that the glass forming behaviour of Zr and Hf is similar, whereas it is different from that of Ti. The smaller atomic size of Ti and the difference in the heat of mixing of Ti, Zr, Hf with Cu and Ni leads to the observed changes in the glass forming behaviour. Enthalpy contour plots can be used to distinguish the glass forming compositions on the basis of the increasing negative enthalpy of the composition. This method reveals the high glass forming ability of binary Zr-Cu, Hf-Cu, Hf-Ni systems over a narrow composition range.

  20. Mechanical properties of some binary, ternary and quaternary III-V compound semiconductor alloys

    International Nuclear Information System (INIS)

    Navamathavan, R.; Arivuoli, D.; Attolini, G.; Pelosi, C.; Choi, Chi Kyu

    2007-01-01

    Vicker's microindentation tests have been carried out on InP/InP, GaAs/InP, InGaAs/InP and InGaAsP/InP III-V compound semiconductor alloys. The detailed mechanical properties of these binary, ternary and quaternary epilayers were determined from the indentation experiments. Microindentation studies of (1 1 1) GaAs/InP both A and B faces show that the hardness value increases with load and attains a constant for further increase in load and the microhardness values were found to lie between 3.5 and 4.0 GPa. The microhardness values of InGaAs/InP epilayers with different thickness were found to lie between 3.93 and 4.312 GPa. The microhardness values of InGaAsP/InP with different elemental composition were found to lie between 5.08 and 5.73 GPa. The results show that the hardness of the quaternary alloy drastically increases, the reason may be that the increase in As concentration hardens the lattice when phosphorous concentration is less and hardness decreases when phosphorous is increased. It was interestingly observed that the hardness value increases as we proceed from binary to quaternary III-V compound semiconductor alloys

  1. Effects of magnesium contents in ZnMgO ternary alloys grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Sheng-Yao, E-mail: shenghu2729@yahoo.com [Department of Digital Technology Design, Tungfang Design Institute, Hunei, Kaohsiung 82941, Taiwan (China); Chou, Wu-Ching [Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Weng, Yu-Hsiang [Department of Electrical Engineering, National Taiwan Ocean University, Keelung 20224, Taiwan (China)

    2015-07-05

    Highlights: • ZnMgO alloys with different Mg contents have been produced by MBE. • Optical and structural properties have been measured and investigated. • Stress is tensile and is increased as the increasing of Mg contents. • The asymmetric behavior of the Raman mode was influenced due to the Mg contents. - Abstract: Ternary alloys of ZnMgO samples with different magnesium contents have been grown by molecular beam epitaxy on the sapphire substrates. Room temperature photoluminescence energy of ZnMgO shifted as high as 3.677 eV by increasing Mg contents corresponding to the higher Urbach average localization energy which indicates more randomness in the alloys with higher Mg contents. XRD results are also verified that the c-axis length decreases as the increasing Mg contents linking to the increased tensile stress produced by the Mg atoms. Raman spectra analyzed by the spatial correlation model to describe that the linewidth Γ is decreased but the correlation length L is increased as the increasing of Mg contents.

  2. Effects of magnesium contents in ZnMgO ternary alloys grown by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Hu, Sheng-Yao; Chou, Wu-Ching; Weng, Yu-Hsiang

    2015-01-01

    Highlights: • ZnMgO alloys with different Mg contents have been produced by MBE. • Optical and structural properties have been measured and investigated. • Stress is tensile and is increased as the increasing of Mg contents. • The asymmetric behavior of the Raman mode was influenced due to the Mg contents. - Abstract: Ternary alloys of ZnMgO samples with different magnesium contents have been grown by molecular beam epitaxy on the sapphire substrates. Room temperature photoluminescence energy of ZnMgO shifted as high as 3.677 eV by increasing Mg contents corresponding to the higher Urbach average localization energy which indicates more randomness in the alloys with higher Mg contents. XRD results are also verified that the c-axis length decreases as the increasing Mg contents linking to the increased tensile stress produced by the Mg atoms. Raman spectra analyzed by the spatial correlation model to describe that the linewidth Γ is decreased but the correlation length L is increased as the increasing of Mg contents

  3. Cooling thermal parameters and microstructure features of directionally solidified ternary Sn–Bi–(Cu,Ag) solder alloys

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Bismarck L., E-mail: bismarck_luiz@yahoo.com.br [Department of Materials Engineering, Federal University of São Carlos, UFSCar, 13565-905 São Carlos, SP (Brazil); Garcia, Amauri [Department of Manufacturing and Materials Engineering, University of Campinas, UNICAMP, 13083-860 Campinas, SP (Brazil); Spinelli, José E. [Department of Materials Engineering, Federal University of São Carlos, UFSCar, 13565-905 São Carlos, SP (Brazil)

    2016-04-15

    Low temperature soldering technology encompasses Sn–Bi based alloys as reference materials for joints since such alloys may be molten at temperatures less than 180 °C. Despite the relatively high strength of these alloys, segregation problems and low ductility are recognized as potential disadvantages. Thus, for low-temperature applications, Bi–Sn eutectic or near-eutectic compositions with or without additions of alloying elements are considered interesting possibilities. In this context, additions of third elements such as Cu and Ag may be an alternative in order to reach sounder solder joints. The length scale of the phases and their proportions are known to be the most important factors affecting the final wear, mechanical and corrosions properties of ternary Sn–Bi–(Cu,Ag) alloys. In spite of this promising outlook, studies emphasizing interrelations of microstructure features and solidification thermal parameters regarding these multicomponent alloys are rare in the literature. In the present investigation Sn–Bi–(Cu,Ag) alloys were directionally solidified (DS) under transient heat flow conditions. A complete characterization is performed including experimental cooling thermal parameters, segregation (XRF), optical and scanning electron microscopies, X-ray diffraction (XRD) and length scale of the microstructural phases. Experimental growth laws relating dendritic spacings to solidification thermal parameters have been proposed with emphasis on the effects of Ag and Cu. The theoretical predictions of the Rappaz-Boettinger model are shown to be slightly above the experimental scatter of secondary dendritic arm spacings for both ternary Sn–Bi–Cu and Sn–Bi–Ag alloys examined. - Highlights: • Dendritic growth prevailed for the ternary Sn–Bi–Cu and Sn–Bi–Ag solder alloys. • Bi precipitates within Sn-rich dendrites were shown to be unevenly distributed. • Morphology and preferential region for the Ag{sub 3}Sn growth depend on Ag

  4. Crystallization processes in Ni-Ti-B glassy alloys of near-ternary-eutectic composition

    International Nuclear Information System (INIS)

    Merk, N.; Morris, D.G.; Stadelmann, P.

    1987-01-01

    The crystallization kinetics and mechanisms of three Ni-Ti-B glasses have been examined with a view to elucidating the roles of chemical composition and quenched structure on behaviour. Alloys of composition near a ternary-eutectic point have been chosen because they represent a real and complex situation where several crystalline phases may form simultaneously. Crystallization processes are analysed in terms of nucleation and growth stages. Different nucleation mechanisms seem to be best explained in terms of the short range ordered structure of the quenched glass. Analysis of crystal glass interface energies indicates that it is not this energy term which controls the nucleation of crystals on annealing. Crystal growth may involve a eutectic mechanism or a single-phase mechanism controlled by interface or matrix-diffusion kinetics. Crystallization is fastest when eutectic nucleation and growth occurs. Formation of the eutectic colony requires the initial formation of the phase of complex structure followed by the phase of simpler structure

  5. A comparative study of critical phenomena and magnetocaloric properties of ferromagnetic ternary alloys

    Science.gov (United States)

    Yüksel, Yusuf; Akinci, Ümit

    2018-01-01

    Magnetic and magnetocaloric properties, as well as the phase diagrams of a ferromagnetic ternary alloy system have been studied. A detailed comparison of two different methods, namely the effective field theory (EFT), and Monte Carlo (MC) simulations has been provided. Our numerical data show that the general qualitative picture presented by two methods are in a good agreement with each other. In terms of the magnetocaloric properties, our results yield that it is possible to design magnetic materials with a variety of working temperatures and magnetocaloric properties (such as large ΔSM and q values) by manipulating the magnetic phase transition via tuning the compositional factor (i.e. the mixing ratio of sublattice ions). The observed magnetocaloric effect has been found to be a direct one with ΔSM < 0 associated with a second order phase transition.

  6. Molecular dynamics study of the ternary Cu50Ti25Zr25 bulk glass forming alloy

    Directory of Open Access Journals (Sweden)

    Celtek M.

    2011-05-01

    Full Text Available The structure and thermodynamic properties of a ternary Cu50Ti25Zr25 metallic glass forming alloy in solid-liquid to glass phases were studied using molecular dynamics (MD method based on tight-binding (TB potentials. An atomic description of the melting, glass formation and crystallization process has been analyzed using different heating and cooling rates. The computed Glass Forming Ability (GFA parameters are in good agreement with experimental data. The structure analysis of the Cu50Ti25Zr25 based on molecular dynamics simulation will be also presented and compared with available MD results. We have also discussed the crystallization transition with two different interatomic potentials used in this work

  7. The ternary alloy with a structure of Prussian blue analogs in a transverse field

    International Nuclear Information System (INIS)

    Dely, J.; Bobak, A.

    2007-01-01

    The effects of applied transverse field on transition and compensation temperatures of the AB p C 1-p ternary alloy consisting of spins S A =3/2 , S B =2, and S C =5/2 are investigated by the use of a mean-field theory. The structure and the spin values of the model correspond to the Prussian blue analog of the type (Fe p II Mn 1-p II ) 1.5 [Cr III (CN) 6 ].nH 2 O. We find that two or even three compensation points may be induced by a transverse field for the system with appropriate values of the parameters in the model Hamiltonian. In particular, the influence of a transverse field on the compensation point in the ground state is examined

  8. The single-ion anisotropy effects in the mixed-spin ternary-alloy

    Science.gov (United States)

    Albayrak, Erhan

    2018-04-01

    The effect of single-ion anisotropy on the thermal properties of the ternary-alloy in the form of ABpC1-p is investigated on the Bethe lattice (BL) in terms of exact recursion relations. The simulation on the BL consists of placing A atoms (spin-1/2) on the odd shells and randomly placing B (spin-3/2) or C (spin-5/2) atoms with concentrations p and 1 - p, respectively, on the even shells. The phase diagrams are calculated in possible planes spanned by the system parameters: temperature, single-ion anisotropy, concentration and ratio of the bilinear interaction parameters for z = 3 corresponding to the honeycomb lattice. It is found that the crystal field drives the system to the lowest possible state therefore reducing the temperatures of the critical lines in agreement with the literature.

  9. Formation of metal-alloy nanoclusters in silica by ion implantation and annealing in selected atmosphere

    International Nuclear Information System (INIS)

    Battaglin, G.; Cattaruzza, E.; Gonella, F.; Mattei, G.; Mazzoldi, P.; Sada, C.; Zhang, X.

    2000-01-01

    The formation of binary alloy clusters in sequentially ion-implanted Au-Cu or Au-Ag silica glass has been studied as a function of the annealing atmosphere. Alloy formation has been evidenced in the as-implanted samples. The selective influence on Au precipitation of either oxygen or hydrogen annealing atmosphere governs the alloy cluster formation and the thermal stability

  10. Equiaxed and columnar dendrite growth simulation in Al-7Si- Mg ternary alloys using cellular automaton method

    International Nuclear Information System (INIS)

    Chen, Rui; Xu, Qingyan; Liu, Baicheng

    2015-01-01

    In this paper, a modified cellular automaton (MCA) model allowing for the prediction of dendrite growth of Al-Si-Mg ternary alloys in two and three dimensions is presented. The growth kinetic of S/L interface is calculated based on the solute equilibrium approach. In order to describe the dendrite growth with arbitrarily crystallographic orientations, this model introduces a modified decentered octahedron algorithm for neighborhood tracking to eliminate the effect of mesh dependency on dendrite growth. The thermody namic and kinetic data needed for dendrite growth is obtained through coupling with Pandat software package in combination with thermodynamic/kinetic/equilibrium phase diagram calculation databases. The effect of interactions between various alloying elements on solute diffusion coefficient is considered in the model. This model has first been used to simulate Al-7Si (weight percent) binary dendrite growth followed by a validation using theoretical predictions. For ternary alloy, Al-7Si-0.5Mg dendrite simulation has been carried out and the effects of solute interactions on diffusion matrix as well as the differences of Si and Mg in solute distribution have been analyzed. For actual application, this model has been applied to simulate the equiaxed dendrite growth with various crystallographic orientations of Al-7Si-0.36Mg ternary alloy, and the predicted secondary dendrite arm spacing (SDAS) shows a reasonable agreement with the experimental ones. Furthermore, the columnar dendrite growth in directional solidification has also been simulated and the predicted primary dendrite arm spacing (PDAS) is in good agreement with experiments. The simulated results effectively demonstrate the abilities of the model in prediction of dendritic microstructure of Al-Si-Mg ternary alloy. (paper)

  11. Equiaxed and columnar dendrite growth simulation in Al-7Si- Mg ternary alloys using cellular automaton method

    Science.gov (United States)

    Chen, Rui; Xu, Qingyan; Liu, Baicheng

    2015-06-01

    In this paper, a modified cellular automaton (MCA) model allowing for the prediction of dendrite growth of Al-Si-Mg ternary alloys in two and three dimensions is presented. The growth kinetic of S/L interface is calculated based on the solute equilibrium approach. In order to describe the dendrite growth with arbitrarily crystallographic orientations, this model introduces a modified decentered octahedron algorithm for neighborhood tracking to eliminate the effect of mesh dependency on dendrite growth. The thermody namic and kinetic data needed for dendrite growth is obtained through coupling with Pandat software package in combination with thermodynamic/kinetic/equilibrium phase diagram calculation databases. The effect of interactions between various alloying elements on solute diffusion coefficient is considered in the model. This model has first been used to simulate Al-7Si (weight percent) binary dendrite growth followed by a validation using theoretical predictions. For ternary alloy, Al-7Si-0.5Mg dendrite simulation has been carried out and the effects of solute interactions on diffusion matrix as well as the differences of Si and Mg in solute distribution have been analyzed. For actual application, this model has been applied to simulate the equiaxed dendrite growth with various crystallographic orientations of Al-7Si-0.36Mg ternary alloy, and the predicted secondary dendrite arm spacing (SDAS) shows a reasonable agreement with the experimental ones. Furthermore, the columnar dendrite growth in directional solidification has also been simulated and the predicted primary dendrite arm spacing (PDAS) is in good agreement with experiments. The simulated results effectively demonstrate the abilities of the model in prediction of dendritic microstructure of Al-Si-Mg ternary alloy.

  12. Multifunctional properties related to magnetostructural transitions in ternary and quaternary Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Dubenko, Igor, E-mail: igor_doubenko@yahoo.com [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States); Quetz, Abdiel; Pandey, Sudip; Aryal, Anil; Eubank, Michael [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States); Rodionov, Igor; Prudnikov, Valerii; Granovsky, Alexander [Faculty of Physics, Moscow State University, Vorob' evy Gory, 11999I Moscow (Russian Federation); Lahderanta, Erkki [Lappeenranta University of Technology, 53851 (Finland); Samanta, Tapas; Saleheen, Ahmad; Stadler, Shane [Department of Physics & Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Ali, Naushad [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States)

    2015-06-01

    In this report, the results of a study on the effects of compositional variations induced by the small changes in concentrations of the parent components and/or by the substitution of Ni, Mn, or In by an extra element Z, on the phase transitions, and phenomena related to the magnetostructural transitions in off-stoichiometric Ni–Mn–In based Heusler alloys are summarized. The crystal structures, phase transitions temperatures, and magnetic and magnetocaloric properties were analyzed for representative samples of the following systems (all near 15 at% indium concentration): Ni–Mn–In, Ni–Mn–In–Si, Ni–Mn–In–B, Ni–Mn–In–Cu, Ni–Mn–In–Cu–B, Ni–Mn–In–Fe, Ni–Mn–In–Ag, and Ni–Mn–In–Al. - Highlights: • The experimental results on phase transitions temperatures, adiabatic temperature changes, magnetoresistance and heat flow for the ternary and quaternary Heusler alloys based on Ni{sub 50}Mn{sub 35}In{sub 15} demonstrate high sensitivity of magnetic properties to the small changes in concentrations of the parent components and/or by the substitution of Ni, Mn, or In by an additional element Z. • The phenomena related to the magnetostructural transitions strongly depend on the weighted average radius of constituent ions.

  13. Determination of thermodynamic properties of aluminum based binary and ternary alloys

    Energy Technology Data Exchange (ETDEWEB)

    Altıntas, Yemliha [Abdullah Gül University, Faculty of Engineering, Department of Materials Science and Nanotechnology, 38039, Kayseri (Turkey); Aksöz, Sezen [Nevşehir Hacı Bektaş Veli University, Faculty of Arts and Science, Department of Physics, 50300, Nevşehir (Turkey); Keşlioğlu, Kâzım, E-mail: kesli@erciyes.edu.tr [Erciyes University, Faculty of Science, Department of Physics, 38039, Kayseri (Turkey); Maraşlı, Necmettin [Yıldız Technical University, Faculty of Chemical and Metallurgical Engineering, Department of Metallurgical and Materials Engineering, 34210, Davutpaşa, İstanbul (Turkey)

    2015-11-15

    In the present work, the Gibbs–Thomson coefficient, solid–liquid and solid–solid interfacial energies and grain boundary energy of a solid Al solution in the Al–Cu–Si eutectic system were determined from the observed grain boundary groove shapes by measuring the thermal conductivity of the solid and liquid phases and temperature gradient. Some thermodynamic properties such as the enthalpy of fusion, entropy of fusion, the change of specific heat from liquid to solid and the electrical conductivity of solid phases at their melting temperature were also evaluated by using the measured values of relevant data for Al–Cu, Al–Si, Al–Mg, Al–Ni, Al–Ti, Al–Cu–Ag, Al–Cu–Si binary and ternary alloys. - Highlights: • The microstructure of the Al–Cu–Si eutectic alloy was observed through SEM. • The three eutectic phases (α-Al, Si, CuAl{sub 2}) have been determined by EDX analysis. • Solid–liquid and solid–solid interfacial energies of α-Al solution were determined. • ΔS{sub f},ΔH{sub M}, ΔC{sub P}, electrical conductivity of solid phases for solid Al solutions were determined. • G–T coefficient and grain boundary energy of solid Al solution were determined.

  14. The constitution of alloys in the Al-rich corner of the Al-Si-Sm ternary system

    International Nuclear Information System (INIS)

    Markoli, B.; Spaic, S.; Zupanic, F.

    2001-01-01

    The constitution of alloys and the liquidus surface in the Al-rich corner of the Al-Si-Sm ternary system were determined by the examination of controlled heated and cooled specimens, as well as heat-treated specimens by means of optical and scanning electron microscopy, energy-dispersive X-ray spectroscopy, differential thermal analysis and X-ray diffraction. The Al-rich corner of the Al-Si-Sm ternary system comprises five regions of primary crystallisation (α Al , β Si , Al 3 Sm, Al 2 Si 2 Sm and AlSiSm) with following characteristic invariant reaction sequences: ternary eutectic reaction L → α Al + β Si + Al 2 Si 2 Sm, and two liquidus transition reactions, i. e., L + Al 3 Sm → α Al + AlSiSm, and L + AlSiSm → α Al + Al 2 Si 2 Sm. Along with the position of ternary eutectic and both interstitial points in the Al-rich corner of the Al-Si-Sm ternary system, the temperatures for each reaction were determined. (orig.)

  15. The constitution of alloys in the Al-rich corner of the Al-Si-Sm ternary system

    Energy Technology Data Exchange (ETDEWEB)

    Markoli, B.; Spaic, S. [Ljubljana Univ. (Slovenia). Faculty of Natural Science and Engineering; Zupanic, F. [Maribor Univ. (Slovenia). Faculty of Mechanical Engineering

    2001-09-01

    The constitution of alloys and the liquidus surface in the Al-rich corner of the Al-Si-Sm ternary system were determined by the examination of controlled heated and cooled specimens, as well as heat-treated specimens by means of optical and scanning electron microscopy, energy-dispersive X-ray spectroscopy, differential thermal analysis and X-ray diffraction. The Al-rich corner of the Al-Si-Sm ternary system comprises five regions of primary crystallisation ({alpha}{sub Al}, {beta}{sub Si}, Al{sub 3}Sm, Al{sub 2}Si{sub 2}Sm and AlSiSm) with following characteristic invariant reaction sequences: ternary eutectic reaction L {yields} {alpha}{sub Al} + {beta}{sub Si} + Al{sub 2}Si{sub 2}Sm, and two liquidus transition reactions, i. e., L + Al{sub 3}Sm {yields} {alpha}{sub Al} + AlSiSm, and L + AlSiSm {yields} {alpha}{sub Al} + Al{sub 2}Si{sub 2}Sm. Along with the position of ternary eutectic and both interstitial points in the Al-rich corner of the Al-Si-Sm ternary system, the temperatures for each reaction were determined. (orig.)

  16. Hydrogen storage properties for Mg–Zn–Y quasicrystal and ternary alloys

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Xuanli, E-mail: Xuanli.Luo@nottingham.ac.uk; Grant, David M., E-mail: David.Grant@nottingham.ac.uk; Walker, Gavin S., E-mail: Gavin.Walker@nottingham.ac.uk

    2015-10-05

    Highlights: • Quasicrystal (QC) and H-phase alloys were detected in the Zn–Mg–Y samples. • Hydrogen storage properties of Zn–Mg–Y samples were investigated. • Zn{sub 50}Mg{sub 42}Y{sub 8} showed a capacity of 0.9 wt.% and decomposition temperature of 445 °C. - Abstract: Three Zn–Mg–Y alloys with nominal compositions of Zn{sub 50}Mg{sub 42}Y{sub 8} and Zn{sub 60}Mg{sub 30}Y{sub 10} were prepared by induction melting or gas atomisation. XRD and SEM analysis shows samples ZMY-1 and ZMY-2 consisted of multiple phases including icosahedral quasicrystal (QC) i-phase, hexagonal H-phase and Mg{sub 7}Zn{sub 3}, whilst ZMY-3 contained QC only. The hydrogen storage properties of the Zn–Mg–Y quasicrystal and ternary alloys were investigated for the first time. The quasicrystal sample ZMY-3 hydrogenated at 300 °C had 0.3 wt.% capacity and the DSC decomposition peak temperature was 503 °C. Amongst the three samples, the highest hydrogen storage capacity (0.9 wt.%) and the lowest decomposition peak temperature (445 °C) was achieved by sample ZMY-1. The pressure–composition–isotherm (PCI) curve of ZMY-1 sample showed a flat plateau gave a plateau pressure of 3.5 bar at 300 °C, which indicates a lower dehydrogenation enthalpy than MgH{sub 2}.

  17. Phase transformation and microstructure study of the as-cast Cu-rich Cu-Al-Mn ternary alloys

    Directory of Open Access Journals (Sweden)

    Holjevac-Grgurić T.

    2017-01-01

    Full Text Available Four Cu-rich alloys from the ternary Cu-Al-Mn system were prepared in the electric-arc furnace and casted in cylindrical moulds with dimensions: f=8 mm and length 12 mm. Microstructural investigations of the prepared samples were performed by using optical microscopy (OM and scanning electron microscopy, equipped by energy dispersive spectroscopy (SEM-EDS. Assignation of crystalline phases was confirmed by XRD analysis. Phase transition temperatures were determined using simultaneous thermal analyzer STA DSC/TG. Phase equilibria calculation of the ternary Cu-Al-Mn system was performed using optimized thermodynamic parameters from literature. Microstructure and phase transitions of the prepared as-cast alloys were investigated and experimental results were compared with the results of thermodynamic calculations.

  18. Beta decomposition of (Hf/sub x/Zr/sub 1-x/)80Nb20 ternary alloys

    International Nuclear Information System (INIS)

    Jones, W.B.; Taggart, R.; Polonis, D.H.

    1978-01-01

    The processes of beta decomposition have been examined in ternary alloys of the form (Hf/sub x/Zr/sub 1-x/) 80 Nb 20 to determine the influence of Hf additions to a basic Zr 80 Nb 20 composition. In the chill cast condition, Hf additions have been found to decrease the temperature coefficient of electrical resistivity from a value of -0.0015%/K for the binary Zr 80 Nb 20 alloy to a value of -0.011%/K for a (Hf 50 Zr 50 ) 80 Nb 20 ternary alloy. This change is explained in terms of the bcc lattice instability typical of Ti, Zr, and Hf alloys. The Hf additions enhance the kinetics of omega-phase precipitation during aging at 648 K. The aging of a (Hf 05 Zr 95 ) 80 Nb 20 alloy for 12 h results in the precipitation of a high volume fraction of cuboidal shaped omega-phase particles. A phase separation which results in the formation of solute lean discs (β/sub l/) occurs together with the precipitation of the omega-phase. These discs formed both randomly within the matrix and heterogeneously along dislocations and at grain boundaries

  19. A comparison of acoustic levitation with microgravity processing for containerless solidification of ternary Al-Cu-Sn alloy

    Science.gov (United States)

    Yan, N.; Hong, Z. Y.; Geng, D. L.; Wei, B.

    2015-07-01

    The containerless rapid solidification of liquid ternary Al-5 %Cu-65 %Sn immiscible alloy was accomplished at both ultrasonic levitation and free fall conditions. A maximum undercooling of 185 K (0.22 T L) was obtained for the ultrasonically levitated alloy melt at a cooling rate of about 122 K s-1. Meanwhile, the cooling rate of alloy droplets in drop tube varied from 102 to 104 K s-1. The macrosegregation was effectively suppressed through the complex melt flow under ultrasonic levitation condition. In contrast, macrosegregation became conspicuous and core-shell structures with different layers were formed during free fall. The microstructure formation mechanisms during rapid solidification at containerless states were investigated in comparison with the conventional static solidification process. It was found that the liquid phase separation and structural growth kinetics may be modulated by controlling both alloy undercooling and cooling rate.

  20. Strong composition-dependence on glass-forming ability in Ni-(Ti,Zr)-Si pseudo-ternary alloys

    International Nuclear Information System (INIS)

    Yang, H.; Wang, J.Q.; Li, Y.

    2006-01-01

    The glass formation in Ni-(Ti,Zr)-Si pseudo-ternary alloys was studied. For suction casting, by carefully adjusting the alloy composition and studying the microstructure changes, the best glass-forming alloy with a 2 mm diameter is pinpointed in a narrow composition region of 57.5-58.5 at.% Ni, 36.5-38.5 at.% (Ti + Zr) and 5-5.5 at.% Si. The main competing crystalline phases, identified by XRD and SEM, were Ni 10 (Zr,Ti) 7 , Ni(Ti,Zr) and an unidentified Si-containing phase. Our results indicate a clear need for monitoring the microstructure change in the cross section of the ingots to locate the best glass-forming alloys

  1. Structure of the liquid-vapor interface of a dilute ternary alloy: Pb and In in Ga

    International Nuclear Information System (INIS)

    Yang Bin; Li Dongxu; Rice, Stuart A.

    2003-01-01

    We report the results of experimental studies of how the competition between two solutes to segregate in the liquid-vapor interface of a dilute ternary alloy influences the composition and structure of that interface. The system studied has small amounts of Pb and In dissolved in Ga; it differs from a previous study of dilute alloys containing small amounts of Pb and Sn dissolved in Ga by the addition of a new variable, namely, the valence difference between the solute atoms Pb and In. This valence difference influences the electron density distribution in the alloy liquid-vapor interface in proportion to the excess concentrations of the solute species in the interface, and thereby should affect the structure of the interface. We find that for a ternary PbInGa alloy that contains 0.039 at. % Pb and 6.31 at. % In, the Pb that segregates in the liquid-vapor interface forms a two-dimensional hexagonal crystal phase that undergoes a first-order transition to a disordered phase at T=29.0±0.1 deg. C. The two-dimensional crystalline Pb forms about 0.6 of a full monolayer; the remainder of the outer stratum of the liquid-vapor interface is filled with two-dimensional liquid In. For a ternary PbInGa alloy that contains the same amount of Pb and 12.2 at. % In, the Pb that segregates in the liquid-vapor interface forms a two-dimensional liquid down to 26.0 deg. C, the lowest temperature at which data were taken. For temperatures in excess of 29.0 deg. C two-dimensional liquid Pb and two-dimensional liquid In coexist in the interface, with the fractional occupation of the monolayer by In exceeding the fractional occupation by Pb

  2. Geometric Effects of La1+xMg2-xNi9 (x=0.0~1.0) Ternary Alloys on Their Hydrogen Storage Capacities

    Institute of Scientific and Technical Information of China (English)

    Zhiqing YUAN; Guanglie LU; Bin LIAO; Yongquan LEI

    2005-01-01

    Structural analysis was made using X-ray diffraction (XRD) Rietveld refinement on a series of La1+xMg2-xNi9(x=0.0~1.0) ternary alloys. Results showed that each of La1+xMg2-xNi9 alloys was a PuNi3-type structure stacked by LaNi5 and (La, Mg) Ni2 blocks. Electrochemical tests revealed that discharge abilities of these La-Mg-Ni ternary alloys mainly depended on their atomic distances between (La, Mg) and Ni, which could be modified by varying the atomic ratios of La/Mg.

  3. Contribution to the Study of the Relation between Microstructure and Electrochemical Behavior of Iron-Based FeCoC Ternary Alloys

    Directory of Open Access Journals (Sweden)

    Farida Benhalla-Haddad

    2012-01-01

    Full Text Available This work deals with the relation between microstructure and electrochemical behavior of four iron-based FeCoC ternary alloys. First, the arc-melted studied alloys were characterized using differential thermal analyses and scanning electron microscopy. The established solidification sequences of these alloys show the presence of two primary crystallization phases (δ(Fe and graphite as well as two univariante lines : peritectic L+(Fe↔(Fe and eutectic L↔(Fe+Cgraphite. The ternary alloys were thereafter studied in nondeaerated solution of 10−3 M NaHCO3 + 10−3 M Na2SO4, at 25°C, by means of the potentiodynamic technique. The results indicate that the corrosion resistance of the FeCoC alloys depends on the carbon amount and the morphology of the phases present in the studied alloys.

  4. Metallic oxide nano-clusters synthesis by ion implantation in high purity Fe10Cr alloy

    International Nuclear Information System (INIS)

    Zheng, Ce

    2015-01-01

    ODS (Oxide Dispersed Strengthened) steels, which are reinforced with metal dispersions of nano-oxides (based on Y, Ti and O elements), are promising materials for future nuclear reactors. The detailed understanding of the mechanisms involved in the precipitation of these nano-oxides would improve manufacturing and mechanical properties of these ODS steels, with a strong economic impact for their industrialization. To experimentally study these mechanisms, an analytical approach by ion implantation is used, to control various parameters of synthesis of these precipitates as the temperature and concentration. This study demonstrated the feasibility of this method and concerned the behaviour of alloys models (based on aluminium oxide) under thermal annealing. High purity Fe-10Cr alloys were implanted with Al and O ions at room temperature. Transmission electron microscopy observations showed that the nano-oxides appear in the Fe-10Cr matrix upon ion implantation at room temperature without subsequent annealing. The mobility of implanted elements is caused by the defects created during ion implantation, allowing the nucleation of these nanoparticles, of a few nm in diameter. These nanoparticles are composed of aluminium and oxygen, and also chromium. The high-resolution experiments show that their crystallographic structure is that of a non-equilibrium compound of aluminium oxide (cubic γ-Al 2 O 3 type). The heat treatment performed after implantation induces the growth of the nano-sized oxides, and a phase change that tends to balance to the equilibrium structure (hexagonal α-Al 2 O 3 type). These results on model alloys are fully applicable to industrial materials: indeed ion implantation reproduces the conditions of milling and heat treatments are at equivalent temperatures to those of thermo-mechanical treatments. A mechanism involving the precipitation of nano-oxide dispersed in ODS alloys is proposed in this manuscript based on the obtained experimental results

  5. Glass-forming ability and stability of ternary Ni-early transition metal (Ti/Zr/Hf) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Basu, Joysurya [Department of Metallurgy, Indian Institute of Science, Bangalore 560 012 (India); Ranganathan, S. [Department of Metallurgy, Indian Institute of Science, Bangalore 560 012 (India)]. E-mail: rangu@met.iisc.ernet.in

    2006-08-15

    Four Ni-bearing Ti, Zr and Hf ternary alloys of nominal composition Zr{sub 41.5}Ti{sub 41.5}Ni{sub 17}, Zr{sub 25}Ti{sub 25}Ni{sub 50}, Zr{sub 41.5}Hf{sub 41.5}Ni{sub 17} and Ti{sub 41.5}Hf{sub 41.5}Ni{sub 17} were rapidly solidified in order to produce ribbons. The Zr-Ti-Ni and Ti-Hf-Ni alloys become amorphous, whereas the Zr-Hf-Ni alloy shows precipitation of a cubic phase. The devitrification of all three alloys was followed and the relative tendency to form nanoquasicrystals and cF96 phases analysed. The relative glass-forming ability of the alloys can be explained by taking into account their atomic size difference. Addition of Ni often leads to quasicrystallisation or quasicrystal-related phases. This can be explained by the atomic radius and heat of mixing of the constituent elements. The phases precipitated at the initial stages of crystallisation indicate the possible presence of Frank-Kasper polyhedral structure in the amorphous alloys. Structural analysis reveals that the Laves and the anti-Laves phases have the same polyhedral structural unit, which is similar to the structural characteristics of glass.

  6. Tunable fluorescence emission of ternary nonstoichiometric Ag-In-S alloyed nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Feng Jian, E-mail: dhjfeng@ciac.jl.cn; Yang Xiurong, E-mail: xryang@ciac.jl.cn [Chinese Academy of Sciences, State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry (China)

    2012-08-15

    Low toxic, nonstoichiometric colloidal Ag-In-S ternary quantum dots with different Ag content were synthesized by a one-pot hot-injection method based on the reaction of metal acetylacetonates with sulfur dissolved in octadecene. X-ray diffraction (XRD), transmission electron microscopy, and high-resolution transmission electron microscopy (HRTEM) were used to characterize the size, structure, and morphology of these samples. ICP-MS was employed to analyze the compositions of Ag-In-S nanocrystals. The optical properties were characterized by UV-Vis absorption, photoluminescence (PL) spectroscopy, and time-resolved photoluminescence. Varying the fraction of cationic and capping agents, the compositions of Ag-In-S nanocrystals were precisely controlled. XRD and HRTEM results indicate the compositional homogeneity of Ag-In-S. The emission spectra across the different compositions exhibiting a single bandgap feature further confirm the formation of Ag-In-S alloy NCs, rather than phase separated Ag{sub 2}S and In{sub 2}S{sub 3}. Composition-dependent tunable PL emissions have been observed. The relative PL quantum yield is up to 16 %, which exhibited substantially enhanced comparing with the stoichiometric AgInS{sub 2} semiconductor core QDs reported in previous literature. The PL decay curve of Ag-In-S has a biexponential characteristic, which indicates that the recombination of an electron and a hole is dominated by the surface defect and the recombination process associated with internal traps is reduced significantly. The large Stokes shift between the absorption peaks and their emissions should inhibit the reabsorption and Foerster energy transfer between Ag-In-S nanocrystals, which provides the alternative in the further applications where high-concentrations of nanocrystals are needed.

  7. Compositional trends and magnetic excitations in binary and ternary Fe–Pd–X magnetic shape memory alloys

    International Nuclear Information System (INIS)

    Gruner, Markus Ernst; Hamann, Sven; Brunken, Hayo; Ludwig, Alfred; Entel, Peter

    2013-01-01

    Highlights: ► We discuss compositional trends in Fe–Pd–Cu and Fe–Pd–Mn magnetic shape memory alloys. ► We combine density functional theory and combinatorial thin film experiments. ► Magnetic excitations contribute decisively to the structural transformation behavior. -- Abstract: High throughput thin film experiments and first-principles calculations are combined in order to get insight into the relation between finite temperature transformation behavior and structural ground state properties of ternary Fe–Pd–X alloys. In particular, we consider the binding surface, i.e., the energy of the disordered alloy calculated along the Bain path between bcc and fcc which we model by a 108 atom supercell. We compare stoichiometric Fe 75 Pd 25 with ternary systems, where 4.6% of the Fe atoms were substituted by Cu and Mn, respectively. The computational trends are related to combinatorial experiments on thin film libraries for the systems Fe–Pd–Mn and Fe–Pd–Cu which reveal a systematic evolution of the martensitic start temperature with composition within the relevant concentration range for magnetic shape memory (MSM) applications. Our calculations include atomic relaxations, which were shown to be relevant for a correct description of the structural properties. Furthermore, we find that magnetic excitations can substantially alter the binding surface. The comparison of experimental and theoretical trends indicates that, both, compositional changes and magnetic excitations contribute significantly to the structural stability which may thus be tailored by specifically adding antiferromagnetic components

  8. One-step synthesis of PtPdAu ternary alloy nanoparticles on graphene with superior methanol electrooxidation activity

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yuzhen; Gu Yonge; Lin Shaoxiong; Wei Jinping; Wang Zaihua [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Wang Chunming, E-mail: wangcm@lzu.edu.cn [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Du Yongling; Ye Weichun [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China)

    2011-10-01

    Highlights: > PtPdAu nanoparticles were synthesized on graphene sheets via chemical reduction method. > The prepared PtPdAu nanoparticles were ternary alloy with fcc structure. > The catalyst exhibited superior catalytic activity and stability for MOR in alkaline. - Abstract: Well-dispersed PtPdAu ternary alloy nanoparticles were synthesized on graphene sheets via a simple one-step chemical reduction method in ethylene glycol (EG) and water system, in which EG served as both reductive and dispersing agent. The electrocatalytic activity of PtPdAu/G was tested by methanol oxidation reaction (MOR). The catalyst was further characterized by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), which indicated that the as-synthesized PtPdAu nanoparticles with alloy structures were successfully dispersed on the graphene sheets. Electrocatalytic properties of the catalyst for MOR in alkaline have been investigated by cyclic voltammetry (CV), chronoamperometry and Tafel curves. The electrocatalytic activity and stability of PtPdAu/G were superior to PtPd/G, PtAu/G and Pt/G. In addition, the anodic peak current on PtPdAu/G catalyst was proportional to the concentration of methanol in the range of 0.05-1.00 M. This study implies that the prepared catalyst have great potential applications in fuel cells.

  9. Tuning the energy band gap of ternary alloyed Cd1-xPbxS quantum dots for photovoltaic applications

    Science.gov (United States)

    Badawi, Ali

    2016-02-01

    Tuning the energy band gap of ternary alloyed Cd1-xPbxS (x: 0, 0.33, 0.5, 0.67 and 1) quantum dots (QDs) for photovoltaic applications is studied. Alloyed Cd1-xPbxS QDs were adsorbed onto TiO2 nanoparticles (NPs) using ssuccessive ionic layer adsorption and reaction (SILAR) methode. EDX measurements ensure the success adsorption of alloyed Cd1-xPbxS QDs onto the TiO2 electrode. At 100 mW/cm2 (AM 1.5) sun illumination, the photovoltaic performance of alloyed Cd1-xPbxS QDs sensitized solar cells (QDSSCs) was measured. The maximum values of Jsc (1.92 mA/cm2) and η (0.36%) for the alloyed Cd1-xPbxS QDSSCs were obtained when the molar ratio of Cd/Pb is 0.33/0.67. the open circuit voltage (Voc) is equal 0.61 ± 0.01 V for all alloyed Cd1-xPbxS QDSSCs. The electron back recombination rates decrease considerably for alloyed Cd1-xPbxS QDSSCs as x value increases, peaking at 0.67. The electron lifetime (τ) for Cd0.33Pb0.67S QDSSCs is one order of magnitude larger than that of the other alloyed Cd1-xPbxS QDSSCs with different x value. Under ON-OFF cycles to solar illumination, the open circuit voltage decay measurements show the high sensitivity and reproducibility of alloyed Cd1-xPbxS QDSSCs.

  10. Neutronics Evaluation of Lithium-Based Ternary Alloys in IFE Blankets

    Energy Technology Data Exchange (ETDEWEB)

    Jolodosky, A. [Univ. of California, Berkeley, CA (United States); Fratoni, M. [Univ. of California, Berkeley, CA (United States)

    2015-09-22

    , low electrical conductivity and therefore low MHD pressure drop, low chemical reactivity, and extremely low tritium inventory; the addition of sodium (FLiNaBe) has been considered because it retains the properties of FliBe but also lowers the melting point. Although many of these blanket concepts are promising, challenges still remain. The limited amount of beryllium available poses a problem for ceramic breeders such as the HCPB. FLiBe and FLiNaBe are highly viscous and have a low thermal conductivity. Lithium lead possesses a poor thermal conductivity which can cause problems in both DCLL and LiPb blankets. Additionally, the tritium permeation from these two blankets into plant components can be a problem and must be reduced. Consequently, Lawrence Livermore National Laboratory (LLNL) is attempting to develop a lithium-based alloy—most likely a ternary alloy—which maintains the beneficial properties of lithium (e.g. high tritium breeding and solubility) while reducing overall flammability concerns for use in the blanket of an inertial fusion energy (IFE) power plant. The LLNL concept employs inertial confinement fusion (ICF) through the use of lasers aimed at an indirect-driven target composed of deuterium-tritium fuel. The fusion driver/target design implements the same physics currently experimented at the National Ignition Facility (NIF). The plant uses lithium in both the primary coolant and blanket; therefore, lithium-related hazards are of primary concern. Although reducing chemical reactivity is the primary motivation for the development of new lithium alloys, the successful candidates will have to guarantee acceptable performance in all their functions. The scope of this study is to evaluate the neutronics performance of a large number of lithium-based alloys in the blanket of the IFE engine and assess their properties upon activation. This manuscript is organized as follows: Section 12 presents the models and methodologies used for the analysis; Section

  11. Quantum chemical analysis of binary and ternary ferromagnetic alloys; Quantenchemische Untersuchungen binaerer und ternaerer ferromagnetischer Legierungen

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Yasemin Erika Charlotte

    2007-02-23

    In this work the electronic structures, densities of states, chemical bonding, magnetic exchange Parameters and Curie temperatures of binary and ternary ferromagnetic alloys are analyzed. The electronic structure of ferromagnetic MnAl has been calculated using density-functional techniques (TB-LMTO-ASA, FPLAPW) and quantum chemically analyzed by means of the crystal orbital Hamilton population analysis. The crystal structure of the ferromagnetic tetragonal MnAl may be understood to originate from the structure of nonmagnetic cubic MnAl with a CsCl motif through a two-step process. While the nonmagnetic cubic structure is stable against a structural deformation, antibonding Mn-Mn interactions at the Fermi level lead to spin polarization and the onset of magnetism, i.e., a symmetry reduction taking place solely in the electronic degrees of freedom, by that emptying antibonding Mn-Mn states. Residual antibonding Al--Al states can only be removed by a subsequent, energetically smaller structural deformation towards the tetragonal system. As a final result, homonuclear bonding is strengthened and heteronuclear bonding is weakened. Corresponding DFT calculations of the electronic structure as well as the calculation of the chemical bonding and the magnetic exchange interactions have been performed on the basis of LDA and GGA for a series of ferromagnetic full Heusler alloys of general formula Co2MnZ (Z=Ga,Si,Ge,Sn), Rh2MnZ (Z=Ge,Sn,Pb), Ni2MnZ (Z=Ga,In,Sn), Pd2MnZ (Z=Sn,Sb) and Cu2MnZ (Z=Al,In,Sn). The connection between the electronic spectra and the magnetic interactions have been studied. Correlations between the chemical bondings in Heusler alloys derived from COHP analysis and magnetic phenomena are obvious, and different mechanisms leading to spin polarization and ferromagnetism are derived. The band dependence of the exchange parameters, their dependence on volume and valence electron concentration have been thoroughly analyzed within the Green function technique

  12. Ternary systems

    International Nuclear Information System (INIS)

    Kagan, D.N.; Hubberstey, P.; Barker, M.G.

    1985-01-01

    The paper reviews the experimental and theoretical studies carried out on multicomponent alkali metal systems. Solid-liquid phase equilibria studies are mainly concerned with the systems Na-K-Rb and Na-K-Cs, and data on the liquidus temperatures in these systems are presented. The thermodynamic properties of the ternary Na-K-Cs eutectic system have been determined experimentally, and the enthalpy, heat capacity and excess functions of the alloy are given. An analysis of calculational methods used in determining thermodynamic functions of ternary liquid metals systems is described. Finally, data are tabulated for the density, compressibility, saturated vapour pressure, viscosity and thermal conductivity of the ternary Na-K-Cs eutectic system. (UK)

  13. Energy gaps, effective masses and ionicity of AlxGa1-xSb ternary semiconductor alloys

    Science.gov (United States)

    Bouarissa, N.; Boucenna, M.; Saib, S.; Siddiqui, S. A.

    2017-12-01

    A pseudopotential calculation of the electronic structure of AlxGa1-xSb ternary alloys in the zinc-blende structure has been performed. The compositional dependence of energy gaps, electron and heavy hole effective masses and ionicity of the material system of interest have been examined and discussed. Special attention has been given to the effect of the alloy disorder on the direct (Γ-Γ) bandgap energy. It is found that all features of interest vary monotonically with increasing the Al concentration x. Besides, bandgap bowing parameters and extent of the direct-to-indirect bandgap transition have been determined. Our findings agree generally well with the data reported in the literature. Trends in ionicity are found to be consistent with the Phillips ionicity scale.

  14. Phase-field modeling of the microstructure evolution and heterogeneous nucleation in solidifying ternary Al–Cu–Ni alloys

    International Nuclear Information System (INIS)

    Kundin, Julia; Pogorelov, Evgeny; Emmerich, Heike

    2015-01-01

    We have investigated the microstructure evolution during the isothermal and non-isothermal solidification of ternary Al–Cu–Ni alloys by means of a general multi-phase-field model for an arbitrary number of phases. The stability requirements for the model functions on every dual interface guarantee the absence of “ghost” phases. The aim was to generate a realistic microstructure by coupling the thermodynamic parameters of the phases and the thermodynamically consistent phase-field evolution equations. It is shown that the specially constructed thermal noise terms disturb the stability on the dual interfaces and can produce heterogeneous nucleation of product phases at energetically favorable points. Similar behavior can be observed in triple junctions where the heterogeneous nucleation of a fourth phase is more favorable. Finally, the model predicts the growth of a combined eutectic-like and peritectic-like structure that is comparable to the observed experimental microstructure in various alloys

  15. Theoretical investigation of the structural stabilities, optoelectronic properties and thermodynamic characteristics of GaPxSb1-x ternary alloys

    Science.gov (United States)

    Oumelaz, F.; Nemiri, O.; Boumaza, A.; Ghemid, S.; Meradji, H.; Bin Omran, S.; El Haj Hassan, F.; Rai, D. P.; Khenata, R.

    2018-06-01

    In this theoretical study, we have investigated the structural, phase transition, electronic, thermodynamic and optical properties of GaPxSb1-x ternary alloys. Our calculations are performed with the WIEN2k code based on density functional theory using the full-potential linearized augmented plane wave method. For the electron exchange-correlation potential, a generalized gradient approximation within Wu-Cohen scheme is considered. The recently developed Tran-Blaha modified Becke-Johnson potential has also been used to improve the underestimated band gap. The structural properties, including the lattice constants, the bulk moduli and their pressure derivatives are in very good agreement with the available experimental data and theoretical results. Several structural phase transitions were studied here to establish the stable structure and to predict the phase transition under hydrostatic pressure. The computed transition pressure (Pt) of the material of our interest from the zinc blende (B3) to the rock salt (B1) phase has been determined and found to agree well with the experimental and theoretical data. The calculated band structure shows that GaSb binary compound and the ternary alloys are direct band gap semiconductors. Optical parameters such as the dielectric constants and the refractive indices are calculated and analyzed. The thermodynamic results are also interpreted and analyzed.

  16. Thermodynamic mixing effects of liquid ternary Au–Fe–Pd alloys by computer-aided Knudsen cell mass spectrometry

    International Nuclear Information System (INIS)

    Tomiska, Josef

    2012-01-01

    Highlights: ► Thermodynamic mixing behavior of liquid Au–Fe–Pd alloys over the whole range of composition. ► Experimental investigations by means of the computer-aided Knudsen cell mass spectrometry. ► Algebraic representation of the molar excess properties by TAP series concept. ► The corresponding TAP parameters are presented. ► The values of all molar excess functions, and thermodynamic activities at 1850 K are given. - Abstract: Thermodynamic investigations on liquid ternary Au–Fe–Pd alloys have been performed by means of the computer-aided Knudsen cell mass spectrometry. The “Digital Intensity-Ratio” (DIR) – method has been applied for the determination of the thermodynamic mixing behaviour. The ternary thermodynamically adapted power (TAP) series concept is used for the algebraic representation of the molar excess properties. The corresponding TAP parameters, and the values of the molar excess quantities Z E (Z = Gibbs energy G, heat of mixing H, and entropy S) as well as the thermodynamic activities of all three constituents at 1850 K are presented.

  17. Growth and properties of Al-rich InxAl1-xN ternary alloy grown on GaN template by metalorganic chemical vapour deposition

    International Nuclear Information System (INIS)

    Oh, Tae Su; Suh, Eun-Kyung; Kim, Jong Ock; Jeong, Hyun; Lee, Yong Seok; Nagarajan, S; Lim, Kee Young; Hong, Chang-Hee

    2008-01-01

    An Al-rich In x Al 1-x N ternary alloy was grown on a GaN template by metal-organic chemical vapour deposition (MOCVD). The GaN template was fabricated on a c-plane sapphire with a low temperature GaN nucleation layer. The growth of the 300 nm thick In x Al 1-x N layer was carried out under various growth temperatures and pressures. The surface morphology and the InN molar fraction of the In x Al 1-x N layer were assessed by using atomic force microscopy (AFM) and high resolution x-ray diffraction, respectively. The AFM surface images of the In x Al 1-x N ternary alloy exhibited quantum dot-like grains caused by the 3D island growth mode. The grains, however, disappeared rapidly by increasing diffusion length and mobility of the Al adatoms with increasing growth temperature and the full width at half maximum value of ternary peaks in HR-XRD decreased with decreasing growth pressure. The MOCVD growth condition with the increased growth temperature and decreased growth pressure would be effective to grow the In x Al 1-x N ternary alloy with a smooth surface and improved quality. The optical band edge of In x Al 1-x N ternary alloys was estimated by optical absorbance and, based on the results of HR-XRD and optical absorbance measurements, we obtained the bowing parameter of the In x Al 1-x N ternary alloy at b = 5.3 eV, which was slightly larger than that of previous reports

  18. Martensitic transformation behavior in Ti–Ni–X (Ag, In, Sn, Sb, Te, Tl, Pb, Bi) ternary alloys

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jai-young; Chun, Su-jin; Kim, Nam-suk; Cho, Jeung-won; Kim, Jae-hyun [School of Materials Science and Engineering, Gyeongsang National University, 900 Gazwadong, Jinju, Gyeongnam 660-701 (Korea, Republic of); Yeom, Jong-taek [Light Metal Division, Korea Institute of Materials Science (KIMS), Changwon 642-831 (Korea, Republic of); Kim, Jae-il [Materials Science and Engineering, University of Dong-A, Hadan-dong, Saha-gu, Busan 604-714 (Korea, Republic of); Nam, Tae-hyun, E-mail: tahynam@gnu.ac.kr [School of Materials Science and Engineering, Gyeongsang National University, 900 Gazwadong, Jinju, Gyeongnam 660-701 (Korea, Republic of)

    2013-12-15

    Graphical abstract: - Highlights: • Ag, In and Sn were soluble in TiNi matrix, while Sb, Te, Tl, Pb and Bi were not. • The B2-R-B19′transformation occurred in Ti-Ni-(Ag, In, Sn) alloys. • Solid solution hardening was essential for inducing the B2-R transformation. - Abstract: The microstructures and transformation behaviors of Ti–Ni–X (Ag, In, Sn, Sb, Te, Tl, Pb, Bi) ternary alloys were investigated using electron probe micro-analysis (EPMA), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and Micro Vickers hardness tests. All specimens consisted of Ti–Ni matrices and second phase particles. Ag, In and Sn were soluble in Ti–Ni matrices with a limited solubility (≤1.0 at%), while Sb, Te, Tl, Pb and Bi were not soluble. Two-stage B2-R-B19′ transformation occurred in Ti–48.8Ni–1.2Ag, Ti–49.0Ni–1.0In and Ti–49.0Ni–1.0Sn alloys, while one-stage B2-B19′ transformation occurred in Ti–49.0Ni–1.0Ag, Ti–49.0Ni–1.0Sb, Ti–49.0Ni–1.0Te, Ti–49.0Ni–1.0Pb and Ti–49.0Ni–1.0Bi alloys. Micro Vickers hardness of the alloys displaying the B2-R-B19′ transformation (Hv 250–368) was much larger than that (alloys displaying the B2-B19′ transformation. Solid solution hardening was an important factor for inducing the B2-R transformation in Ti–Ni–X (X = non-transition elements) alloys.

  19. Martensitic transformation behavior in Ti–Ni–X (Ag, In, Sn, Sb, Te, Tl, Pb, Bi) ternary alloys

    International Nuclear Information System (INIS)

    Jang, Jai-young; Chun, Su-jin; Kim, Nam-suk; Cho, Jeung-won; Kim, Jae-hyun; Yeom, Jong-taek; Kim, Jae-il; Nam, Tae-hyun

    2013-01-01

    Graphical abstract: - Highlights: • Ag, In and Sn were soluble in TiNi matrix, while Sb, Te, Tl, Pb and Bi were not. • The B2-R-B19′transformation occurred in Ti-Ni-(Ag, In, Sn) alloys. • Solid solution hardening was essential for inducing the B2-R transformation. - Abstract: The microstructures and transformation behaviors of Ti–Ni–X (Ag, In, Sn, Sb, Te, Tl, Pb, Bi) ternary alloys were investigated using electron probe micro-analysis (EPMA), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and Micro Vickers hardness tests. All specimens consisted of Ti–Ni matrices and second phase particles. Ag, In and Sn were soluble in Ti–Ni matrices with a limited solubility (≤1.0 at%), while Sb, Te, Tl, Pb and Bi were not soluble. Two-stage B2-R-B19′ transformation occurred in Ti–48.8Ni–1.2Ag, Ti–49.0Ni–1.0In and Ti–49.0Ni–1.0Sn alloys, while one-stage B2-B19′ transformation occurred in Ti–49.0Ni–1.0Ag, Ti–49.0Ni–1.0Sb, Ti–49.0Ni–1.0Te, Ti–49.0Ni–1.0Pb and Ti–49.0Ni–1.0Bi alloys. Micro Vickers hardness of the alloys displaying the B2-R-B19′ transformation (Hv 250–368) was much larger than that (< Hv 200) of the alloys displaying the B2-B19′ transformation. Solid solution hardening was an important factor for inducing the B2-R transformation in Ti–Ni–X (X = non-transition elements) alloys

  20. First-principles study on half-metallic ferromagnetic properties of Zn1- x V x Se ternary alloys

    Science.gov (United States)

    Khatta, Swati; Tripathi, S. K.; Prakash, Satya

    2017-09-01

    The spin-polarised density functional theory along with self-consistent plane-wave pseudopotential is used to investigate the half-metallic ferromagnetic properties of ternary alloys Zn1- x V x Se. The generalized gradient approximation is used for exchange-correlation potential. The equilibrium lattice constants, bulk modulus, and its derivatives are calculated. The calculated spin-polarised energy-band structures reveal that these alloys are half-metallic for x = 0.375 and 0.50 and nearly half-metallic for other values of x. The estimated direct and indirect bandgaps may be useful for the magneto-optical absorption experiments. It is found that there is strong Zn 4s, Se 4p, and V 3d orbital hybridization in the conduction bands of both the spins, while Se 4p and V 3d orbital hybridization predominates in the valence bands of both the spins. The s, p-d, and p-d orbital hybridization reduces the local magnetic moment of V atoms and small local magnetic moments are produced on Zn and Se atoms which get coupled with V atoms in ferromagnetic and antiferromagnetic phases, respectively. The conduction and valence-band-edge splittings and exchange constants predict the ferromagnetism in these alloys. The conduction band-impurity (s and p-d) exchange interaction is more significant for ferromagnetism in these alloys than the valence band-impurity (p-d) exchange interaction.

  1. First-principles investigations on structural, elastic and mechanical properties of BNxAs1‑x ternary alloys

    Science.gov (United States)

    Zhang, Junqin; Ma, Huihui; Zhao, Bin; Wei, Qun; Yang, Yintang

    2018-05-01

    A systematic investigation of the structural optimization, elastic and mechanical properties of the BNxAs1‑x ternary alloys are reported in the present work using the density-functional theory with the generalized gradient approximation (GGA) of the exchange-correlation functional. Some of the constants which are used to analyze the properties including elastic constants and modulus, and some parameters describing the elastic anisotropy and Debye temperature are also calculated. Our calculations were performed to evaluate the equilibrium lattice constant and band structure compared with the available theoretical works. On the one hand, our results might be expected to provide a theoretical basis for future study of BNxAs1‑x alloys towards elastic or mechanical properties. On the other hand, we draw a conclusion that BNxAs1‑x alloys show direct bandgap when x equals 0.25, 0.5 or 0.75. We obtained the elastic modulus, Poisson’s ratio and universal anisotropic index which are used to demonstrate the elastic anisotropy of these alloys which is proved according to our calculations. Also, we calculated the Debye temperature to illustrate covalent interactions and obtained the lower limit of the thermal conductivity for further research.

  2. Calculation of glass forming ranges in Al-Ni-RE (Ce, La, Y) ternary alloys and their sub-binaries based on Miedema's model

    International Nuclear Information System (INIS)

    Sun, S.P.; Yi, D.Q.; Liu, H.Q.; Zang, B.; Jiang, Y.

    2010-01-01

    Research highlights: → A method based on semi-empirical Miedema's and Toop's model for predicting glass forming range of ternary alloy system has been systematically described. → The method is superior to conventional models by considering the effect of the thermodynamic asymmetric component when dealing with a ternary alloy system. → The glass forming ranges of Al-Ni-RE (Al-Ni-Ce, Al-Ni-Y and Al-Ni-La) systems and their sub-binaries have been successfully calculated. → The present calculations using the method are in well agreement with experiments. → This model is especially useful for predicting the glass forming range of ternary alloy system because the calculations do not require experimental data. - Abstract: A method based on the semi-empirical Miedema's and Toop's model for calculating the glass forming range of a ternary alloy system was systematically described. The method is superior to conventional models by considering the effect of the thermodynamic asymmetric component when dealing with a ternary alloy system. Using this method, the glass forming ranges of Al-Ni-RE (Ce, La, Y) systems and their sub-binaries were successfully predicted. The mixing enthalpy and mismatch entropy were calculated, and their effects on the glass forming abilities of Al-Ni-RE (Ce, La, Y) systems were also discussed. The glass forming abilities of Al-Ni-Ce, Al-Ni-La and Al-Ni-Y are found to be close. The calculated glass forming ranges agree with experiments well. Meanwhile, the enthalpy change from amorphous phase to solid solution in the glass forming ranges was calculated, and the results suggest that those alloys close to the Ni-RE sub-binary system have higher glass forming abilities.

  3. Study on the Mg-Li-Zn ternary alloy system with improved mechanical properties, good degradation performance and different responses to cells

    NARCIS (Netherlands)

    Liu, Yang; Wu, Yuanhao; Bian, Dong; Gao, Shuang; Leeflang, M.A.; Guo, Hui; Zheng, Yufeng; Zhou, J.

    2017-01-01

    Novel Mg-(3.5, 6.5wt%)Li-(0.5, 2, 4wt%)Zn ternary alloys were developed as new kinds of biodegradable metallic materials with potential for stent application. Their mechanical properties, degradation behavior, cytocompatibility and hemocompatibility were studied. These potential biomaterials

  4. Fabrication of Ternary AgPdAu Alloy Nanoparticles on c-Plane Sapphire by the Systematical Control of Film Thickness and Deposition Sequence

    Science.gov (United States)

    Kunwar, Sundar; Pandey, Puran; Sui, Mao; Bastola, Sushil; Lee, Jihoon

    2018-06-01

    In this work, a systematic study on the fabrication of ternary AgPdAu alloy nanoparticles (NPs) on c-plane sapphire (0001) is presented and the corresponding structural and optical characteristics are demonstrated. The metallic trilayers of various thicknesses and deposition orders are annealed in a controlled manner (400 °C to 900 °C) to induce the solid-state dewetting that yields the various structural configurations of AgPdAu alloy NPs. The dewetting of relatively thicker trilayers (15 nm) is gradually progressed with void nucleation, growth, and coalescence, isolated NP formation, and shape transformation, along with the temperature control. For 6 nm thickness, owing to the sufficient dewetting of trilayers along with enhanced diffusion, dense and small spherical alloy NPs are fabricated. Depending on the specific growth condition, the surface diffusion and interdiffusion of metal atoms, surface and interface energy minimization, Rayleigh instability, and equilibrium configuration are correlated to describe the fabrication of ternary alloy NPs. Ternary alloy NPs exhibit morphology-dependent ultraviolet-visible-near infrared (UV-VIS-NIR) reflectance properties such as the inverse relationship of average reflectance with the surface coverage, absorption enhancement in specific regions, and reflectance maxima in UV and NIR regions. In addition, Raman spectra depict the six active phonon modes of sapphires and their intensity and position modulation by the alloy NPs.

  5. Fe-Cr-V ternary alloy-based ferritic steels for high- and low-temperature applications

    International Nuclear Information System (INIS)

    Rieth, M.; Materna-Morris, E.; Dudarev, S.L.; Boutard, J.-L.; Keppler, H.; Mayor, J.

    2009-01-01

    The phase stability of alloys and steels developed for application in nuclear fission and fusion technology is one of the decisive factors determining the potential range of operating temperatures and radiation conditions that the core elements of a power plant can tolerate. In the case of ferritic and ferritic-martensitic steels, the choice of the chemical composition is dictated by the phase diagram for binary FeCr alloys where in the 0-9% range of Cr composition the alloy remains in the solid solution phase at and below the room temperature. For Cr concentrations exceeding 9% the steels operating at relatively low temperatures are therefore expected to exhibit the formation of α' Cr-rich precipitates. These precipitates form obstacles for the propagation of dislocations, impeding plastic deformation and embrittling the material. This sets the low temperature limit for the use of of high (14% to 20%) Cr steels, which for the 20% Cr steels is at approximately 600 deg. C. On the other hand, steels containing 12% or less Cr cannot be used at temperatures exceeding ∼600 deg. C due to the occurrence of the α-γ transition (912 deg. C in pure iron and 830 deg. C in 7% Cr alloy), which weakens the steel in the high temperature limit. In this study, we investigate the physical properties of a concentrated ternary alloy system that attracted relatively little attention so far. The phase diagram of ternary Fe-Cr-V alloy shows no phase boundaries within a certain broad range of Cr and V concentrations. This makes the alloy sufficiently resistant to corrosion and suggests that steels and dispersion strengthened materials based on this alloy composition may have better strength and stability at high temperatures. Experimental heats were produced on a laboratory scale by arc melting the material components to pellets, then by melting the pellets in an induction furnace and casting the melt into copper moulds. The compositions in weight percent (iron base) are 10Cr5V, 10Cr

  6. Solidification and solid state phenomena during TLP bonding of IN718 superalloy using Ni–Si–B ternary filler alloy

    Energy Technology Data Exchange (ETDEWEB)

    Pouranvari, M., E-mail: mpouranvari@yahoo.com [Department of Materials Science and Engineering, Sharif University of Technology, Tehran 11365-11155 (Iran, Islamic Republic of); Ekrami, A.; Kokabi, A.H. [Department of Materials Science and Engineering, Sharif University of Technology, Tehran 11365-11155 (Iran, Islamic Republic of)

    2013-06-25

    Highlights: ► Microstructure evolution during TLP bonding of IN718 using Ni–Si–B filler. ► Athermal solidification path is influenced by severe segregation of B and Si in residual liquid. ► High hardness of ASZ microconstituents necessitates designing a PBHT to avert brittleness. ► Diffusion induced Cr–Mo–Nb based boride precipitation was observed in DAZ. ► Boride precipitates in DAZ influence the corrosion resistance and aging behavior. -- Abstract: This paper addresses solidification and solid state precipitation phenomena during transient liquid phase (TLP) bonding of wrought IN718 nickel base superalloy using Ni–4.5Si–3.2B (wt.%) ternary filler alloy. The solidification sequence of the residual liquid in the joint centerline was found to be (1) formation of proeutectic γ, followed by (2) γ/Ni{sub 3}B eutectic reaction, followed by (3) ternary eutectic of γ/Ni{sub 3}B/Ni{sub 6}Si{sub 2}B. Extensive fine Ni{sub 3}Si formed within the eutectic-γ via solid state precipitation during cooling. Extensive Cr–Mo–Nb rich boride precipitates were formed in the substrate region due to boron diffusion into the base metal during bonding process. The implications of the phase transformations on the mechanical properties, corrosion resistance and aging behavior of the joint, which are pertinent to the development of an optimum post bond heat treatment, are highlighted.

  7. Solidification and solid state phenomena during TLP bonding of IN718 superalloy using Ni–Si–B ternary filler alloy

    International Nuclear Information System (INIS)

    Pouranvari, M.; Ekrami, A.; Kokabi, A.H.

    2013-01-01

    Highlights: ► Microstructure evolution during TLP bonding of IN718 using Ni–Si–B filler. ► Athermal solidification path is influenced by severe segregation of B and Si in residual liquid. ► High hardness of ASZ microconstituents necessitates designing a PBHT to avert brittleness. ► Diffusion induced Cr–Mo–Nb based boride precipitation was observed in DAZ. ► Boride precipitates in DAZ influence the corrosion resistance and aging behavior. -- Abstract: This paper addresses solidification and solid state precipitation phenomena during transient liquid phase (TLP) bonding of wrought IN718 nickel base superalloy using Ni–4.5Si–3.2B (wt.%) ternary filler alloy. The solidification sequence of the residual liquid in the joint centerline was found to be (1) formation of proeutectic γ, followed by (2) γ/Ni 3 B eutectic reaction, followed by (3) ternary eutectic of γ/Ni 3 B/Ni 6 Si 2 B. Extensive fine Ni 3 Si formed within the eutectic-γ via solid state precipitation during cooling. Extensive Cr–Mo–Nb rich boride precipitates were formed in the substrate region due to boron diffusion into the base metal during bonding process. The implications of the phase transformations on the mechanical properties, corrosion resistance and aging behavior of the joint, which are pertinent to the development of an optimum post bond heat treatment, are highlighted

  8. Hydrogen induced dis-proportionation studies on Zr-Co-M (M=Ni, Fe, Ti) ternary alloys

    International Nuclear Information System (INIS)

    Jat, Ram Avtar; Pati, Subhasis; Parida, S.C.; Agarwal, Renu; Mukerjee, S.K.; Sastry, P.U.; Jayakrishnan, V.B.

    2016-01-01

    The intermetallic compound ZrCo is considered as a suitable material for storage, supply and recovery of hydrogen isotopes in International Thermonuclear Experimental Reactor (ITER). However, upon repeated hydriding-dehydriding cycles, the hydrogen storage capacity of ZrCo decreases, which is attributed to the disproportionate reaction ZrCo + H 2 ↔ ZrH 2 + ZrCo 2 . The reduction of hydrogen storage capacity of ZrCo is not desirable for its use in tritium facilities. In our previous studies, attempts were made to improve the durability of ZrCo against dis-proportionation by including a third element. The present study is aimed to investigate the hydrogen induced dis-proportionation of Zr-Co-M (M=Ni, Fe and Ti) ternary alloys under hydrogen delivery conditions

  9. A tunable amorphous p-type ternary oxide system: The highly mismatched alloy of copper tin oxide

    Energy Technology Data Exchange (ETDEWEB)

    Isherwood, Patrick J. M., E-mail: P.J.M.Isherwood@lboro.ac.uk; Walls, John M. [CREST, School of Electronic, Electrical and Systems Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom); Butler, Keith T.; Walsh, Aron [Centre for Sustainable Technologies and Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)

    2015-09-14

    The approach of combining two mismatched materials to form an amorphous alloy was used to synthesise ternary oxides of CuO and SnO{sub 2}. These materials were analysed across a range of compositions, and the electronic structure was modelled using density functional theory. In contrast to the gradual reduction in optical band gap, the films show a sharp reduction in both transparency and electrical resistivity with copper contents greater than 50%. Simulations indicate that this change is caused by a transition from a dominant Sn 5s to Cu 3d contribution to the upper valence band. A corresponding decrease in energetic disorder results in increased charge percolation pathways: a “compositional mobility edge.” Contributions from Cu(II) sub band-gap states are responsible for the reduction in optical transparency.

  10. Effect of Ternary Addition of Iron on Shape Memory Characteristics of Cu-Al Alloys

    Science.gov (United States)

    Raju, T. N.; Sampath, V.

    2011-07-01

    The effect of alloying Cu-Al alloys with Fe on their transformation temperatures and shape memory properties was investigated by differential scanning calorimetry and bend test. It was found that the minor additions of iron resulted in change of transformation temperatures and led to excellent shape memory properties of the alloys. Since the transformation temperatures are high, they are an ideal choice for high-temperature applications.

  11. Designing and Validating Ternary Pd Alloys for Optimum Sulfur/Carbon Resistance in Hydrogen Separation and Carbon Capture Membrane Systems Using High-Throughput Combinatorial Methods

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Amanda [Pall Corporation, Port Washington, NY (United States); Zhao, Hongbin [Pall Corporation, Port Washington, NY (United States); Hopkins, Scott [Pall Corporation, Port Washington, NY (United States)

    2014-12-01

    This report summarizes the work completed under the U.S. Department of Energy Project Award No.: DE-FE0001181 titled “Designing and Validating Ternary Pd Alloys for Optimum Sulfur/Carbon Resistance in Hydrogen Separation and Carbon Capture Membrane Systems Using High-Throughput Combinatorial Methods.” The project started in October 1, 2009 and was finished September 30, 2014. Pall Corporation worked with Cornell University to sputter and test palladium-based ternary alloys onto silicon wafers to examine many alloys at once. With the specialized equipment at Georgia Institute of Technology that analyzed the wafers for adsorbed carbon and sulfur species six compositions were identified to have resistance to carbon and sulfur species. These compositions were deposited on Pall AccuSep® supports by Colorado School of Mines and then tested in simulated synthetic coal gas at the Pall Corporation. Two of the six alloys were chosen for further investigations based on their performance. Alloy reproducibility and long-term testing of PdAuAg and PdZrAu provided insight to the ability to manufacture these compositions for testing. PdAuAg is the most promising alloy found in this work based on the fabrication reproducibility and resistance to carbon and sulfur. Although PdZrAu had great initial resistance to carbon and sulfur species, the alloy composition has a very narrow range that hindered testing reproducibility.

  12. Influence of layer compositions and annealing conditions on complete formation of ternary PdAgCu alloys prepared by sequential electroless and electroplating methods

    Energy Technology Data Exchange (ETDEWEB)

    Sumrunronnasak, Sarocha [Graduate Program of Petrochemistry and Polymer Science, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Tantayanon, Supawan, E-mail: supawan.t@chula.ac.th [Green Chemistry Research Laboratory, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Kiatgamolchai, Somchai [Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand)

    2017-01-01

    PdAgCu ternary alloy membranes were synthesized by the sequential electroless plating of Pd following by electroplating of Ag and Cu onto stainless steel substrate. The composition of the composite was varied by changing the deposition times. The fabricated layers were annealed at the temperatures between 500 and 600 °C for 20–60 h. The Energy Dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) were employed to investigate the element distribution in the membrane which provided the insight on membrane alloying process. Complete formation of the alloy could be obtained when the Pd composition was greater than a critical value of 60 wt%, and Ag and Cu contents were in the range of 18–30 wt% and 2–13 wt%, respectively. Deposition times of Ag and Cu were found to affect the completion of alloy formation. Excess amount of the deposited Cu particularly tended to segregate on the surface of the membrane. - Highlights: • Ternary PdAgCu alloy membranes were successfully prepared by the sequential electroless and electroplating methods. • The average Pd composition required to form alloy was found to be approximately at least 60%wt. • The alloy region was achieved for f Pd 60–73 wt%, Cu 18–30 wt% and Ag 2–13 wt%. • Suitable annealing temperature in the range of 500–600 °C for an adequate period of treating time (20–60 h).

  13. Microstructure and magnetic behavior of Cu–Co–Si ternary alloy synthesized by mechanical alloying and isothermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Chabri, Sumit, E-mail: sumitchabri2006@gmail.com [Department of Metallurgy & Materials Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103 (India); Bera, S. [Department of Metallurgical & Materials Engineering, National Institute of Technology, Durgapur 713209 (India); Mondal, B.N. [Department of Central Scientific Services, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India); Basumallick, A.; Chattopadhyay, P.P. [Department of Metallurgy & Materials Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103 (India)

    2017-03-15

    Microstructure and magnetic behavior of nanocrystalline 50Cu–40Co–10Si (at%) alloy prepared by mechanical alloying and subsequent isothermal annealing in the temperature range of 450–650 °C have been studied. Phase evolution during mechanical alloying and isothermal annealing is characterized by X-ray diffraction (XRD), differential thermal analyzer (DTA), high resolution transmission electron microscopy (HRTEM) and magnetic measurement. Addition of Si has been found to facilitate the metastable alloying of Co in Cu resulting into the formation of single phase solid solution having average grain size of 9 nm after ball milling for 50 h duration. Annealing of the ball milled alloy improves the magnetic properties significantly and best combination of magnetic properties has been obtained after annealing at 550 °C for 1 h duration.

  14. Isothermal oxidation behavior of ternary Zr-Nb-Y alloys at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Prajitno, Djoko Hadi, E-mail: djokohp@batan.go.id [Research Center for Nuclear Materials and Radiometry, Jl. Tamansari 71, Bandung 40132 (Indonesia); Soepriyanto, Syoni; Basuki, Eddy Agus [Metallurgy Engineering, Institute Technology Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia); Wiryolukito, Slameto [Materials Engineering, Institute Technology Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2014-03-24

    The effect of yttrium content on isothermal oxidation behavior of Zr-2,5%Nb-0,5%Y, Zr-2,5%Nb-1%Y Zr-2,5%Nb-1,5%Y alloy at high temperature has been studied. High temperature oxidation carried out at tube furnace in air at 600,700 and 800°C for 1 hour. Optical microscope is used for microstructure characterization of the alloy. Oxidized and un oxidized specimen was characterized by x-ray diffraction. In this study, kinetic oxidation of Zr-2,5%Nb with different Y content at high temperature has also been studied. Characterization by optical microscope showed that microstructure of Zr-Nb-Y alloys relatively unchanged and showed equiaxed microstructure. X-ray diffraction of the alloys depicted that the oxide scale formed during oxidation of zirconium alloys is monoclinic ZrO2 while unoxidised alloy showed two phase α and β phase. SEM-EDS examination shows that depletion of Zr composition took place under the oxide layer. Kinetic rate of oxidation of zirconium alloy showed that increasing oxidation temperature will increase oxidation rate but increasing yttrium content in the alloys will decrease oxidation rate.

  15. Site preference and elastic properties of ternary alloying additions in B2 YAg alloys by first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Wu Yurong, E-mail: winwyr@126.com [College of Electromechanical Engineering, Hunan University of Science and Technology, Xiantang 411201 (China); Hu Wangyu [Department of Applied Physics, Hunan University, Changsha 410082 (China); Xu Longshan [Department of Materials Science and Engineering, Xiamen University of Technology, Xiamen 361024 (China)

    2012-09-15

    First-principles calculations were preformed to study the site preference behavior and elastic properties of 3d (Ti-Cu) transition-metal elements in B2 ductility YAg alloy. In YAg, Ti is found to occupy the Y sublattice whereas V, Cr, Co, Fe, Ni and Cu tend to substitute for Ag sublattice. Due to the addition of 3d transition metals, the lattice parameters of YAg is decreased in the order: Valloy, and Fe is the most effective element to improve the ductility of YAg, while Ti, Ni and V alloying elements can reduce the ductility of YAg alloy, especially, V transforms ductile into brittle for YAg alloy. In addition, both V and Ni alloying elements can increase the hardness of YAg alloy, and Y{sub 8}Ag{sub 7}V is harder than Y{sub 8}Ag{sub 7}Ni.

  16. The A1 to L10 transformation in FePt films with ternary alloying additions of Mg, V, Mn, and B

    International Nuclear Information System (INIS)

    Wang, B.; Barmak, K.; Klemmer, T. J.

    2011-01-01

    The impact of ternary additions of Mg, V, Mn, and B on the A1 [face centered cubic (fcc)] to L1 0 phase transformation has been studied. The films were cosputter deposited from elemental targets at room temperature and annealed after deposition. The films had Mg additions in the range ∼0-2.6 at.%, V additions in the range 0.7-12.2 at.%, Mn additions in the range 2.2-16.3 at.%, and B additions in the range 1.2-12.9 at.%. For all four ternary alloy systems, annealing resulted in the formation of no other phases than the L1 0 phase. Ternary additions of C than the binary FePt films with the same Pt content.

  17. Structural and magnetic study of mechanically deformed Fe rich FeAlSi ternary alloys

    International Nuclear Information System (INIS)

    Legarra, E.; Apiñaniz, E.; Plazaola, F.

    2012-01-01

    Highlights: ► Addition of Si to binary Fe–Al alloys makes the disordering more difficult. ► Si addition opposes the large volume increase found in FeAl alloys with deformation. ► Disordering induces a redistribution of non-ferrous atoms around Fe atoms in Fe 75 Al 25−x Si x and Fe 70 Al 30−x Si x . ► Addition of Si to binary Fe 75 Al 25 and Fe 70 Al 30 alloys opposes the magnetic behavior induced by Al in the magnetism of Fe. ► Si inhibits the para-ferro transition found in Fe 60 Al 40 alloy with disordering. - Abstract: In this work we study systematically the influence of different Al/Si ratios on the magnetic and structural properties of mechanically disordered powder Fe 75 Al 25−x Si x , Fe 70 Al 30−x Si x and Fe 60 Al 40−x Si x alloys by means of Mössbauer spectroscopy, X-ray diffraction and magnetic measurements. In order to obtain different stages of disorder the alloys were deformed by different methods: crushing induction melted alloys and ball milling annealed (ordered) alloys using different number of balls and speed. X-ray and Mössbauer data show that mechanical deformation induces the disordered A2 structure in these alloys. The results indicate that addition of Si to binary Fe–Al alloys makes the disordering more difficult. In addition, X-ray diffraction patterns show that the normalized lattice parameter variation of the disordered alloys of each composition decreases monotonically with Si content, indicating clearly that Si addition opposes the large volume increase found in FeAl alloys with deformation. The study of the hyperfine fields indicates that there is a redistribution of non-ferrous atoms around Fe atoms with the disordering; indeed, there is an inversion of the behavior of the hyperfine field of the Fe atoms. On the other hand, the magnetic measurements indicate that addition of Si to binary Fe 75 Al 25 and Fe 70 Al 30 alloys opposes the magnetic behavior induced by Al in the magnetism of Fe.

  18. Solid-state reactions during mechanical alloying of ternary Fe–Al–X (X=Ni, Mn, Cu, Ti, Cr, B, Si) systems: A review

    Energy Technology Data Exchange (ETDEWEB)

    Hadef, Fatma, E-mail: hadef77@yahoo.fr [Laboratoire de Recherche sur la Physico-Chimie des Surfaces et Interfaces, LRPCSI, Université 20 Août 1955, BP 26, Route d’El-Haddaiek, Skikda 21000 (Algeria); Département de Physique, Faculté des Sciences, Université 20 Août 1955, BP 26, Route d’El-Haddaiek, Skikda 21000 (Algeria)

    2016-12-01

    The last decade has witnessed an intensive research in the field of nanocrystalline materials due to their enhanced properties. A lot of processing techniques were developed in order to synthesis these novel materials, among them mechanical alloying or high-energy ball milling. In fact, mechanical alloying is one of the most common operations in the processing of solids. It can be used to quickly and easily synthesize a variety of technologically useful materials which are very difficult to manufacture by other techniques. One advantage of MA over many other techniques is that is a solid state technique and consequently problems associated with melting and solidification are bypassed. Special attention is being paid to the synthesis of alloys through reactions mainly occurring in solid state in many metallic ternary Fe–Al–X systems, in order to improve mainly Fe–Al structural and mechanical properties. The results show that nanocrystallization is the common result occurring in all systems during MA process. The aim of this work is to illustrate the uniqueness of MA process to induce phase transformation in metallic Fe–Al–X (X=Ni, Mn, Cu, Ti, Cr, B, Si) systems. - Highlights: • A review of state of the art on binary Fe–Al alloys was presented. • Structural and microstructural properties of MA ternary Fe–Al–X alloys were summerized. • MA process is a powerful tool for producing metallic alloys at the nanometer scale.

  19. Metastable nanocrystalline carbides in chemically synthesized W-Co-C ternary alloys

    International Nuclear Information System (INIS)

    McCandlish, L.E.; Kear, B.H.; Kim, B.K.; Wu, L.W.

    1989-01-01

    Nanophase materials can be prepared either by physical methods or chemical methods. Physical methods include thermal evaporation, sputtering and melt quenching, whereas chemical methods include glow-discharge decomposition, chemical vapor deposition, sol-gel dehydration and gas-solid reaction. Recently, the authors have used controlled activity gas-solid reactions to prepare nanophase WC-Co cermet powders at different WC loadings. In the process they have discovered some new metastable phases in the W-Co-C ternary system at temperatures below 1000 degrees C

  20. Study on the Mg-Li-Zn ternary alloy system with improved mechanical properties, good degradation performance and different responses to cells.

    Science.gov (United States)

    Liu, Yang; Wu, Yuanhao; Bian, Dong; Gao, Shuang; Leeflang, Sander; Guo, Hui; Zheng, Yufeng; Zhou, Jie

    2017-10-15

    Novel Mg-(3.5, 6.5wt%)Li-(0.5, 2, 4wt%)Zn ternary alloys were developed as new kinds of biodegradable metallic materials with potential for stent application. Their mechanical properties, degradation behavior, cytocompatibility and hemocompatibility were studied. These potential biomaterials showed higher ultimate tensile strength than previously reported binary Mg-Li alloys and ternary Mg-Li-X (X=Al, Y, Ce, Sc, Mn and Ag) alloys. Among the alloys studied, the Mg-3.5Li-2Zn and Mg-6.5Li-2Zn alloys exhibited comparable corrosion resistance in Hank's solution to pure magnesium and better corrosion resistance in a cell culture medium than pure magnesium. Corrosion products observed on the corroded surface were composed of Mg(OH) 2 , MgCO 3 and Ca-free Mg/P inorganics and Ca/P inorganics. In vitro cytotoxicity assay revealed different behaviors of Human Umbilical Vein Endothelial Cells (HUVECs) and Human Aorta Vascular Smooth Muscle Cells (VSMCs) to material extracts. HUVECs showed increasing nitric oxide (NO) release and tolerable toxicity, whereas VSMCs exhibited limited decreasing viability with time. Platelet adhesion, hemolysis and coagulation tests of these Mg-Li-Zn alloys showed different degrees of activation behavior, in which the hemolysis of the Mg-3.5Li-2Zn alloy was lower than 5%. These results indicated the potential of the Mg-Li-Zn alloys as good candidate materials for cardiovascular stent applications. Mg-Li alloys are promising as absorbable metallic biomaterials, which however have not received significant attention since the low strength, controversial corrosion performance and the doubts in Li toxicity. The Mg-Li-Zn alloy in the present study revealed much improved mechanical properties higher than most reported binary Mg-Li and ternary Mg-Li-X alloys, with superior corrosion resistance in cell culture media. Surprisingly, the addition of Li and Zn showed increased nitric oxide release. The present study indicates good potential of Mg-Li-Zn alloy as

  1. Effects of Ni content on nanocrystalline Fe–Co–Ni ternary alloys synthesized by a chemical reduction method

    Energy Technology Data Exchange (ETDEWEB)

    Chokprasombat, Komkrich, E-mail: komkrich28@gmail.com [Department of Physics, Faculty of Science, Thaksin University, Phatthalung 93210 Thailand (Thailand); Pinitsoontorn, Supree [Integrated Nanotechnology Research Center, Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 Thailand (Thailand); Maensiri, Santi [School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000 Thailand (Thailand)

    2016-05-01

    Magnetic properties of Fe–Co–Ni ternary alloys could be altered by changing of the particle size, elemental compositions, and crystalline structures. In this work, Fe{sub 50}Co{sub 50−x}Ni{sub x} nanoparticles (x=10, 20, 40, and 50) were prepared by the novel chemical reduction process. Hydrazine monohydrate was used as a reducing agent under the concentrated basic condition with the presence of poly(vinylpyrrolidone). We found that the nanoparticles were composed of Fe, Co and Ni with compositions according to the molar ratio of the metal sources. Interestingly, the particles were well-crystalline at the as-prepared state without post-annealing at high temperature. Increasing Ni content resulted in phase transformation from body centered cubic (bcc) to face centered cubic (fcc). For the fcc phase, the average particle size decreased when increased the Ni content; the Fe{sub 50}Ni{sub 50} nanoparticles had the smallest average size with the narrowest size distribution. In additions, the particles exhibited ferromagnetic properties at room temperature with the coercivities higher than 300 Oe, and the saturation magnetiation decreased with increasing Ni content. These results suggest that the structural and magnetic properties of Fe–Co–Ni alloys could be adjusted by varying the Ni content. - Highlights: • We prepared nanocrystalline Fe–Co–Ni alloys by a novel chemical reduction process. • Elemental compositions could be well controlled by the molar ratio of metal sources. • Particle size and magnetic properties clearly depended on the Ni contents. • Fe{sub 50}Co{sub 10}Ni{sub 40} exhibited high saturation magnetization of 126.3 emu/g.

  2. Radiation-sustained nanocluster metastability in oxide dispersion strengthened materials

    Science.gov (United States)

    Ribis, J.; Bordas, E.; Trocellier, P.; Serruys, Y.; de Carlan, Y.; Legris, A.

    2015-12-01

    ODS materials constitute a new promising class of structural materials for advanced fission and fusion energy application. These Fe-Cr based ferritic steels contain ultra-high density of dispersion-strengthening nanoclusters conferring excellent mechanical properties to the alloy. Hence, guarantee the nanocluster stability under irradiation remain a critical issue. Nanoclusters are non-equilibrium multicomponent compounds (YTiCrO) forming through a complex nucleation pathway during the elaboration process. In this paper, it is proposed to observe the response of these nanoclusters when the system is placed far from equilibrium by means of ion beam. The results indicate that the Y, Ti, O and Cr atoms self-organized so that nanoclusters coarsened but maintain their non-equilibrium chemical composition. It is discussed that the radiation-sustained nanocluster metastability emerges from cooperative effects: radiation-induced Ostwald ripening, permanent creation of vacancies in the clusters, and fast Cr diffusion mediated by interstitials.

  3. Radiation-sustained nanocluster metastability in oxide dispersion strengthened materials

    International Nuclear Information System (INIS)

    Ribis, J.; Bordas, E.; Trocellier, P.; Serruys, Y.; Carlan, Y. de; Legris, A.

    2015-01-01

    ODS materials constitute a new promising class of structural materials for advanced fission and fusion energy application. These Fe–Cr based ferritic steels contain ultra-high density of dispersion-strengthening nanoclusters conferring excellent mechanical properties to the alloy. Hence, guarantee the nanocluster stability under irradiation remain a critical issue. Nanoclusters are non-equilibrium multicomponent compounds (YTiCrO) forming through a complex nucleation pathway during the elaboration process. In this paper, it is proposed to observe the response of these nanoclusters when the system is placed far from equilibrium by means of ion beam. The results indicate that the Y, Ti, O and Cr atoms self-organized so that nanoclusters coarsened but maintain their non-equilibrium chemical composition. It is discussed that the radiation-sustained nanocluster metastability emerges from cooperative effects: radiation-induced Ostwald ripening, permanent creation of vacancies in the clusters, and fast Cr diffusion mediated by interstitials.

  4. Microstructures of neutron-irradiated Fe-12Cr-XMn (X=15-30) ternary alloys

    International Nuclear Information System (INIS)

    Miyahara, K.; Hosoi, Y.; Garner, F.A.

    1992-01-01

    The objective of this effort is to determine the factors which control the stability of irradiated alloys proposed for reduced activation applications. The Fe-Cr-Mn alloy system is being studied as an alternative to the Fe-Cr-Ni system because of the need to reduce long-term radioactivation in fusion-power devices. In this study, four Fe-12Cr-XMn (X =15, 20, 25, 30 wt%) alloys were irradiated in the Fast Flux Test Facility to 20 dpa at 643K and 40 dpa at 679, 793, and 873K to investigate the influence of manganese content on void swelling and phase stability. The results confirm and expand the results of earlier studies that indicate that the Fe-Cr-Mn system is relatively unstable compared to that of the Fe-Cr-Ni system, with alpha and sigma phases forming as a consequence of thermal aging or high temperature irradiation

  5. Determination of the enthalpy of fusion and thermal diffusivity for ternary Cu_6_0_−_xSn_xSb_4_0 alloys

    International Nuclear Information System (INIS)

    Zhai, W.; Zhou, K.; Hu, L.; Wei, B.

    2016-01-01

    Highlights: • The increasing Sn content reduces the liquidus temperature. • High Sn content results in lower enthalpy of fusion by polynomial functions. • The thermal diffusivity drops from the solid toward the semi-solid state. • Undercoolability of alloys with primary Cu_2Sb phase is stronger than others. - Abstract: The liquidus and solidus temperatures, enthalpy of fusion, and the temperature dependence of thermal diffusivity for ternary Cu_6_0_−_xSn_xSb_4_0 alloys were systematically measured by DSC and laser flash methods. It is found that both the liquidus temperature and the enthalpy of fusion decrease with the rise of Sn content, and their relationships with alloy composition were established by polynomial functions. The thermal diffusivity usually drops from the solid toward the semi-solid state. The undercoolability of those liquid Cu_6_0_−_xSn_xSb_4_0 alloys with primary Cu_2Sb solid phase is stronger than the others with primary β(SnSb) intermetallic compound, and the increase of cooling rate facilitates further undercooling. Microstructural observation indicates that both of the primary Cu_2Sb and β(SnSb) intermetallic compounds in ternary Cu_6_0_−_xSn_xSb_4_0 alloys grow in faceted mode, and develop into coarse flakes and polygonal blocks.

  6. A study of the effective atomic number of SixPb0.7-x(Fe2O30.3 ternary alloys for photons

    Directory of Open Access Journals (Sweden)

    Buyukyildiz Mehmet

    2016-01-01

    Full Text Available The effective atomic number (Zeff of SixPb0.7-x(Fe2O30.3 ternary alloys was obtained for photons. Rayleigh to Compton scattering ratio (R/C has been determined to obtain the Zeff of SixPb0.7-x(Fe2O30.3 ternary alloys of varying Si and Pb (10 %-60 % content for scattering of 59.54 keV g-rays at an angle of 130°. The theoretical R/C ratios of elements were plotted as a function of the atomic number and fitted to a polynomial equation. Experimental R/C values of alloys were then used to obtain Zeff using this fit equation. Also, Zeff values of these alloys were determined for the first time by interpolating the R/C of the material using the R/C data of adjacent elements in between the R/C of the alloy lies. The agreement between the interpolation method and the fit equation was quite satisfactory. The obtained Zeff for photon scattering were then compared to the Zeff for total photon attenuation obtained using the Auto-Zeff program. Significant variations were observed between the Zeff for scattering and the total attenuation of gamma rays.

  7. Strong enhancement of the electrochemiluminescence of luminol by AuAg and PtAg alloy nanoclusters, and its sensitization by phenolic artificial oestrogens

    International Nuclear Information System (INIS)

    Wang, Ke; Tu, Yifeng; Wei, Xiuhua

    2014-01-01

    This paper reports on the synthesis of AuAg and PtAg alloy nanoclusters (NCs) and their enhancement effect on the electrochemiluminescence (ECL) of luminol. The conditions of synthesis were optimized, and the structure and properties of the NCs were characterized by X-ray diffraction, transmission electron microscopy, electrochemistry, and optical spectroscopy. The NCs are found to intensify (by up to 20 times) the ECL of luminol in solution of pH 8.5. This finding can largely extend the useful pH range of the ECL of luminol. The enhanced ECL is strongly affected by oxygen and hydrogen peroxide, and the mechanism of enhancement is attributed to the accelerated production of reactive oxygen species. The enhanced ECL is also affected by phenolic artificial estrogens, and this was used for their determination with detection limits as low as 700 pg L −1 (with AuAg) and 1.6 ng L −1 (with PtAg). The method was applied to the determination of such estrogens in egg samples using diethylstilbestrol as a reference substance. (author)

  8. Magnetic transition induced by mechanical deformation in Fe{sub 60}Al{sub 40−x}Si{sub x} ternary alloys

    Energy Technology Data Exchange (ETDEWEB)

    Legarra, E., E-mail: estibaliz.legarra@ehu.es [Dpto. Electricidad y Electronica, Universidad del Pais Vasco (UPV/EHU), CP. 644, 48080 Bilbao (Spain); Apiñaniz, E. [Dpto. Fisica Aplicada I, Universidad del Pais Vasco, Alameda de Urquijo s/n, 48013 Bilbao (Spain); Plazaola, F. [Dpto. Electricidad y Electronica, Universidad del Pais Vasco (UPV/EHU), CP. 644, 48080 Bilbao (Spain); Jimenez, J.A. [Centro Nacional de Investigaciones Metalurgicas (CENIM), Avda. Gregorio del amo 8, 28040 Madrid (Spain)

    2014-02-15

    Highlights: • Fe{sub 60}Al{sub 40−x}Si{sub x} alloys were disordered by means of planetary ball milling technique. • Paramagnetic to ferromagnetic transition is observed with disordering. • Si addition hinders the disordering process and the increase of the lattice parameter. • Si addition promotes the paramagnetic to ferromagnetic transition. -- Abstract: We have used Mössbauer spectroscopy and X-ray diffraction to study the influence of different Al/Si ratios on the structural and magnetic properties of the mechanically deformed Fe{sub 60}Al{sub 40−x}Si{sub x} alloys. The results indicate that ternary alloys also present the magnetic transition with disordering observed in binary Fe{sub 60}Al{sub 40} alloys. Besides, Si introduction has two opposite contributions. From a structural point of view, hinders the disordering process, but, from a magnetic point of view promotes the magnetic transition.

  9. Fullerene alloy formation and the benefits for efficient printing of ternary blend organic solar cells

    DEFF Research Database (Denmark)

    Angmo, Dechan; Bjerring, Morten; Nielsen, Niels Chr.

    2015-01-01

    behaving as pseudo-binary mixtures due to alloying of the fullerene components. This finding has vast implications for the understanding of polymer–fullerene mixtures and quite certainly also their application in organic solar cells where performance hinges critically on the blend behaviour which is also...

  10. Point defect properties of ternary fcc Fe-Cr-Ni alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wróbel, J.S., E-mail: jan.wrobel@inmat.pw.edu.pl [Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland); Nguyen-Manh, D.; Dudarev, S.L. [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Kurzydłowski, K.J. [Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland)

    2017-02-15

    Highlights: • Properties of point defects depend on the local atomic environment. • As the degree of chemical order increases, the formation energies increase, too. • Relaxation volumes are larger for the more ordered structures. - Abstract: The properties of point defects in Fe-Cr-Ni alloys are investigated, using density functional theory (DFT), for two alloy compositions, Fe{sub 50}Cr{sub 25}Ni{sub 25} and Fe{sub 55}Cr{sub 15}Ni{sub 30}, assuming various degrees of short-range order. DFT-based Monte Carlo simulations are applied to explore short-range order parameters and generate representative structures of alloys. Chemical potentials for the relevant structures are estimated from the minimum of the substitutional energy at representative atoms sites. Vacancies and 〈1 0 0〉 dumbbells are introduced in the Fe{sub 2}CrNi intermetallic phase as well as in two Fe{sub 55}Cr{sub 15}Ni{sub 30} alloy structures: the disordered and short range-ordered structures, generated using Monte Carlo simulations at 2000 K and 300 K, respectively. Formation energies and relaxation volumes of defects as well as changes of magnetic moments caused by the presence of defects are investigated as functions of the local environment of a defect.

  11. Ni–Mo–Co ternary alloy as a replacement for hard chrome

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Meenu, E-mail: meenu_srivas@yahoo.co.uk; Anandan, C.; Grips, V.K. William

    2013-11-15

    Hard chrome is the most extensively used electroplated coating in the aerospace and automotive industries due to its attractive properties such as high hardness and excellent wear resistance. However, due to the health risks associated with the use of hexavalent chromium baths during electroplating, there is a need to identify an alternative to this coating. In this study a nickel–molybdenum alloy with cobalt as the alloying element has been developed. The coating was characterized for its micro hardness, wear resistance, coefficient of friction and corrosion resistance. The coating was also subjected to heat treatment at temperatures in the range of 200°–600 °C. It was observed that the micro hardness of Ni–Mo–Co (730 KHN) alloy coating under optimized conditions is apparently quiet similar to that of the most probable substitute Co–P (745 VHN) and hard chrome (800 VHN) coatings. The tribological properties like the wear rate and coefficient of friction of the 400 °C heat treated Ni–Mo–Co coating were noticed to be better compared to hard chrome coating. The electrochemical impedance and polarization studies showed that the corrosion resistance of heat treated Ni–Mo–Co alloy was better than as-deposited Ni–Mo–Co and Ni–Mo coating.

  12. Ni–Mo–Co ternary alloy as a replacement for hard chrome

    International Nuclear Information System (INIS)

    Srivastava, Meenu; Anandan, C.; Grips, V.K. William

    2013-01-01

    Hard chrome is the most extensively used electroplated coating in the aerospace and automotive industries due to its attractive properties such as high hardness and excellent wear resistance. However, due to the health risks associated with the use of hexavalent chromium baths during electroplating, there is a need to identify an alternative to this coating. In this study a nickel–molybdenum alloy with cobalt as the alloying element has been developed. The coating was characterized for its micro hardness, wear resistance, coefficient of friction and corrosion resistance. The coating was also subjected to heat treatment at temperatures in the range of 200°–600 °C. It was observed that the micro hardness of Ni–Mo–Co (730 KHN) alloy coating under optimized conditions is apparently quiet similar to that of the most probable substitute Co–P (745 VHN) and hard chrome (800 VHN) coatings. The tribological properties like the wear rate and coefficient of friction of the 400 °C heat treated Ni–Mo–Co coating were noticed to be better compared to hard chrome coating. The electrochemical impedance and polarization studies showed that the corrosion resistance of heat treated Ni–Mo–Co alloy was better than as-deposited Ni–Mo–Co and Ni–Mo coating.

  13. Structure and microstructure evolution of a ternary Fe–Cr–Ni alloy akin to super martensitic stainless steel

    International Nuclear Information System (INIS)

    Ravi Kumar, B.; Sharma, Sailaja; Munda, Parikshit; Minz, R.K.

    2013-01-01

    Highlights: • Reaustenisation by recrystallisation rather by a diffusion controlled process. • Ultrafine grained austenite formation in martensite matrix by recrystallisation. • In situ high temperature austenite transformation studies by X-ray diffraction. • Microstructure tailoring to achieve tensile strength (∼1 GPa) with good ductility. - Abstract: A ternary Fe–Cr–Ni alloy, akin to super martensitic stainless steels was prepared in vacuum induction furnace. The as cast ingot was solution treated at 1200 °C for 25 h and then hot forged and rolled to reduce into plate form. The hot rolled plate of martensitic microstructure was then cold rolled to 80% of thickness reduction. The phase transformation studies by X-ray diffraction analysis of hot and cold rolled specimens showed presence of retained austenite in air cooled as well as in water quenched state after annealing/austenising temperature of 1060 °C. The reaustenisation behaviour of the cold rolled alloy in water quenched state was studied by high temperature X-ray diffraction analysis. It showed very stable martensitic phase and the completion of reaustenisation process were observed to occur at about 950 °C. The recrystallisation behaviour of cold rolled material under isothermal and repeated annealing treatment was studied in detail by electron microscope. The tensile properties of the material were evaluated after various annealing treatments. The study revealed that by a suitable sequence of repetitive annealing process microstructure could be tailored to achieve tensile strength above 1 GPa with good ductility in a super martensitic stainless steel

  14. Precipitation kinetics in binary Fe–Cu and ternary Fe–Cu–Ni alloys via kMC method

    Directory of Open Access Journals (Sweden)

    Yi Wang

    2017-08-01

    Full Text Available The precipitation kinetics of coherent Cu rich precipitates (CRPs in binary Fe–Cu and ternary Fe–Cu–Ni alloys during thermal aging was modelled by the kinetic Monte Carlo method (kMC. A good agreement of the precipitation kinetics of Fe–Cu was found between the simulation and experimental results, as observed by means of advancement factor and cluster number density. This agreement was obtained owing to the correct description of the fast cluster mobility. The simulation results indicate that the effects of Ni are two-fold: Ni promotes the nucleation of Cu clusters; while the precipitation kinetics appears to be delayed by Ni addition during the coarsening stage. The apparent delayed precipitation kinetics is revealed to be related with the cluster mobility, which are reduced by Ni addition. The reduction effect of the cluster mobility weakens when the CRPs sizes increase. The results provide a view angle on the effects of solute elements upon Cu precipitation kinetics through the consideration of the non-conventional cluster growth mechanism, and kMC is verified to be a powerful approach on that.

  15. Ternary and quaternary solid solutions in rare earth alloy phases with the CaCu5-type structure

    International Nuclear Information System (INIS)

    Malani, G.K.; Raman, A.; Mohanty, R.C.

    1992-01-01

    Crystal structural data were analyzed in seleced CaCu 5 -type ternary and quaternary solid solutions to assess the crystal chemical characteristics and stability features of the CaCu 5 -type structure in rare earth containing alloy phases. LaNi 5 was found to dissolve 100 mol% LaCu 5 , 100 mol% ErNi 5 , about 50 mol% LaIr 5 , 40 mol% 'LaMn 5 ', 20 mol% 'LaFe 5 ', and 25 mol% ErRh 5 . In contrast, LaCo 5 did not dissolve any Mn or any of the other elements other than Al - it dissolved about 20 mol% 'LaAl 5 '. LaCu 5 behaves similar to LaNi 5 in solid solutions. From the lack of solubility of any other element in LaFe 5 , LaCo 5 , LaRh 5 , and LaIr 5 and their great instability, these are inferred to be borderline cases in the realm of the CaCu 5 -type structure. In the CaCu 5 and related crystal structures, Ir is compatible with Ni, but not with Co or Rh, and Rh is not compatible with either Ni or Ir. (orig.) [de

  16. The stochastic model for ternary and quaternary alloys: Application of the Bernoulli relation to the phonon spectra of mixed crystals

    Energy Technology Data Exchange (ETDEWEB)

    Marchewka, M., E-mail: marmi@ur.edu.pl; Woźny, M.; Polit, J.; Sheregii, E. M. [Faculty of Mathematics and Natural Sciences, Centre for Microelectronics and Nanotechnology, University of Rzeszów, Pigonia 1, 35-959 Rzeszów (Poland); Kisiel, A. [Institute of Physics, Jagiellonian University, Reymonta 4, Kraków 30-059 (Poland); Robouch, B. V.; Marcelli, A. [INFN-Laboratori Nazionali di Frascati, Via E. Fermi 40, I-00044 Frascati (Italy)

    2014-03-21

    To understand and interpret the experimental data on the phonon spectra of the solid solutions, it is necessary to describe mathematically the non-regular distribution of atoms in their lattices. It appears that such description is possible in case of the strongly stochastically homogenous distribution which requires a great number of atoms and very carefully mixed alloys. These conditions are generally fulfilled in case of high quality homogenous semiconductor solid solutions of the III–V and II–VI semiconductor compounds. In this case, we can use the Bernoulli relation describing probability of the occurrence of one n equivalent event which can be applied, to the probability of finding one from n configurations in the solid solution lattice. The results described in this paper for ternary HgCdTe and GaAsP as well as quaternary ZnCdHgTe can provide an affirmative answer to the question: whether stochastic geometry, e.g., the Bernoulli relation, is enough to describe the observed phonon spectra.

  17. The stochastic model for ternary and quaternary alloys: Application of the Bernoulli relation to the phonon spectra of mixed crystals

    International Nuclear Information System (INIS)

    Marchewka, M.; Woźny, M.; Polit, J.; Sheregii, E. M.; Kisiel, A.; Robouch, B. V.; Marcelli, A.

    2014-01-01

    To understand and interpret the experimental data on the phonon spectra of the solid solutions, it is necessary to describe mathematically the non-regular distribution of atoms in their lattices. It appears that such description is possible in case of the strongly stochastically homogenous distribution which requires a great number of atoms and very carefully mixed alloys. These conditions are generally fulfilled in case of high quality homogenous semiconductor solid solutions of the III–V and II–VI semiconductor compounds. In this case, we can use the Bernoulli relation describing probability of the occurrence of one n equivalent event which can be applied, to the probability of finding one from n configurations in the solid solution lattice. The results described in this paper for ternary HgCdTe and GaAsP as well as quaternary ZnCdHgTe can provide an affirmative answer to the question: whether stochastic geometry, e.g., the Bernoulli relation, is enough to describe the observed phonon spectra

  18. The stochastic model for ternary and quaternary alloys: Application of the Bernoulli relation to the phonon spectra of mixed crystals

    Science.gov (United States)

    Marchewka, M.; Woźny, M.; Polit, J.; Kisiel, A.; Robouch, B. V.; Marcelli, A.; Sheregii, E. M.

    2014-03-01

    To understand and interpret the experimental data on the phonon spectra of the solid solutions, it is necessary to describe mathematically the non-regular distribution of atoms in their lattices. It appears that such description is possible in case of the strongly stochastically homogenous distribution which requires a great number of atoms and very carefully mixed alloys. These conditions are generally fulfilled in case of high quality homogenous semiconductor solid solutions of the III-V and II-VI semiconductor compounds. In this case, we can use the Bernoulli relation describing probability of the occurrence of one n equivalent event which can be applied, to the probability of finding one from n configurations in the solid solution lattice. The results described in this paper for ternary HgCdTe and GaAsP as well as quaternary ZnCdHgTe can provide an affirmative answer to the question: whether stochastic geometry, e.g., the Bernoulli relation, is enough to describe the observed phonon spectra.

  19. Structural, mechanical, electronic and optical properties of BBi, BP and their ternary alloys BBi1−xPx

    International Nuclear Information System (INIS)

    Bagci, Sadik; Yalcin, Battal G

    2015-01-01

    The ground state properties of BBi, BP and their ternary alloys BBi 1−x P x are reported using first-principles calculations based on density functional theory (DFT). The modified Becke–Johnson (mBJ) potential together with the generalized gradient approximation (GGA) for the correlation potential has been used here as it is a superior method for estimating band inversion strength and band order. The zincblende phase is found to be more stable than the other phases for all studied materials. The calculated lattice constants exhibit a small deviation from the linear Vegard’s law with a downward bowing value of 0.11 Å. The calculated ground state parameters for the studied binary compounds agree with available theoretical and experimental results. The bandgap value of the studied materials calculated with the mBJ potential is considerably enhanced with respect to values from the GGA functional. Optical properties have been calculated and analysed with photon incident energy up to 21.0 eV. The spin–orbit interaction (SOI) has also been considered for structural and electronic calculations and the results are compared with those of non-SOI calculations. The real and imaginary parts of the dielectric function have also been calculated and discussed. (paper)

  20. Investigation of solidification behavior of the Sn-rich ternary Sn–Bi–Zn alloys

    Directory of Open Access Journals (Sweden)

    S Mladenović

    2017-03-01

    Full Text Available Solidification properties and microstructure of six as-cast Sn–Bi–Zn alloys with 80 at.% of Sn and variable contents of Bi and Zn were experimentally investigated using the scanning electron microscopy (SEM with energy-dispersive X-ray spectroscopy (EDS and differential scanning calorimetry (DSC. The experimentally obtained results were compared with predicted phase equilibria according to the calculation of phase diagram (CALPHAD method and by the Scheil solidification simulation.

  1. Modeling diffusion-governed solidification of ternary alloys - Part 2: Macroscopic transport phenomena and macrosegregation.

    Science.gov (United States)

    Wu, M; Li, J; Ludwig, A; Kharicha, A

    2014-09-01

    Part 1 of this two-part investigation presented a multiphase solidification model incorporating the finite diffusion kinetics and ternary phase diagram with the macroscopic transport phenomena (Wu et al., 2013). In Part 2, the importance of proper treatment of the finite diffusion kinetics in the calculation of macrosegregation is addressed. Calculations for a two-dimensional (2D) square casting (50 × 50 mm 2 ) of Fe-0.45 wt.%C-1.06 wt.%Mn considering thermo-solutal convection and crystal sedimentation are performed. The modeling result indicates that the infinite liquid mixing kinetics as assumed by classical models (e.g., the Gulliver-Scheil or lever rule), which cannot properly consider the solute enrichment of the interdendritic or inter-granular melt at the early stage of solidification, might lead to an erroneous estimation of the macrosegregation. To confirm this statement, further theoretical and experimental evaluations are desired. The pattern and intensity of the flow and crystal sedimentation are dependent on the crystal morphologies (columnar or equiaxed); hence, the potential error of the calculated macrosegregation caused by the assumed growth kinetics depends on the crystal morphology. Finally, an illustrative simulation of an engineering 2.45-ton steel ingot is performed, and the results are compared with experimental results. This example demonstrates the model applicability for engineering castings regarding both the calculation efficiency and functionality.

  2. Simulation of the precipitation process of ordered intermetallic compounds in binary and ternary Ni-Al-based alloys by the phase-field model

    International Nuclear Information System (INIS)

    Hou Hua; Zhao Yuhong; Zhao Yuhui

    2009-01-01

    With the microscopic phase-field model, atomic-scale computer simulation programs for the precipitation mechanism of the ordered intermetallic compound γ' in binary Ni-15.5 at.%Al alloy, θ and γ' in ternary Ni 75 Al x V 25-x alloys were worked out based on the microscopic diffusion equation and non-equilibrium free energy. The simulation can be applied to the whole precipitation process and composition range. A prior assumptions on the new phase structure or transformation path was unnecessary, the possible non-equilibrium phases, atomic clustering and ordering could be described automatically, and atomic images, order parameters and volume fractions of precipitates were obtained. Computer simulation was performed systematically on the precipitation mechanism, precipitation sequence of θ and γ' in complicated system with ordering and clustering simultaneously. Through the simulated atomic images and chemical order parameters of precipitates, we can explain the complex precipitation mechanisms of θ (Ni 3 V) and γ' (Ni 3 Al) ordered phases. For the binary alloy, the precipitation mechanism of γ' phase has the characteristic of both non-classical nucleation and growth (NCNG) and congruent ordering and spinodal decomposition (COSD). For the ternary alloys, the precipitation characteristic of γ' phase transforms from NCNG to COSD gradually, otherwise, the precipitation characteristic of θ phase transforms from COSD to NCNG mechanism gradually

  3. Band gap characterization of ternary BBi1−xNx (0≤x≤1) alloys using modified Becke–Johnson (mBJ) potential

    International Nuclear Information System (INIS)

    Yalcin, Battal G.

    2015-01-01

    The semi-local Becke–Johnson (BJ) exchange-correlation potential and its modified form proposed by Tran and Blaha have attracted a lot of interest recently because of the surprisingly accurate band gaps they can deliver for many semiconductors and insulators (e.g., sp semiconductors, noble-gas solids, and transition-metal oxides). The structural and electronic properties of ternary alloys BBi 1−x N x (0≤x≤1) in zinc-blende phase have been reported in this study. The results of the studied binary compounds (BN and BBi) and ternary alloys BBi 1−x N x structures are presented by means of density functional theory. The exchange and correlation effects are taken into account by using the generalized gradient approximation (GGA) functional of Wu and Cohen (WC) which is an improved form of the most popular Perdew–Burke–Ernzerhof (PBE). For electronic properties the modified Becke–Johnson (mBJ) potential, which is more accurate than standard semi-local LDA and PBE calculations, has been chosen. Geometric optimization has been implemented before the volume optimization calculations for all the studied alloys structure. The obtained equilibrium lattice constants of the studied binary compounds are in coincidence with experimental works. And, the variation of the lattice parameter of ternary alloys BBi 1−x N x almost perfectly matches with Vegard's law. The spin–orbit interaction (SOI) has been also considered for structural and electronic calculations and the results are compared to those of non-SOI calculations

  4. Development of Bi-Sb-Te ternary alloy with compositionally graded structure

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, A; Ohta, T

    1997-07-01

    Compositionally graded p-type Bi-Sb-Te thermoelectric material was synthesized by PIES (Pulverized and Intermixed Elements Sintering) method. The materials consisted of three segmented regions of different alloy composition, i.e., y = 0.8/0.825/0.9 in (Bi{sub 2}Te{sub 3}){sub 1{minus}y} (Sb{sub 2}Te{sub 3}){sub y} system. It was found that the electrical power output of the compositionally graded material was larger than that of the best single composition material when the temperature difference was the designed value.

  5. Ab initio Investigation of Helium in Vanadium Oxide Nanoclusters

    Science.gov (United States)

    Danielson, Thomas; Tea, Eric; Hin, Celine

    Nanostructured ferritic alloys (NFAs) are strong candidate materials for the next generation of fission reactors and future fusion reactors. They are characterized by a large number density of oxide nanoclusters dispersed throughout a BCC iron matrix, where current oxide nanoclusters are primarily comprised of Y-Ti-O compounds. The oxide nanoclusters provide the alloy with high resistance to neutron irradiation, high yield strength and high creep strength at the elevated temperatures of a reactor environment. In addition, the oxide nanoclusters serve as trapping sites for transmutation product helium providing substantially increased resistance to catastrophic cracking and embrittlement. Although the mechanical properties and radiation resistance of the existing NFAs is promising, the problem of forming large scale reactor components continues to present a formidable challenge due to the high hardness and unpredictable fracture behavior of the alloys. An alternative alloy has been previously proposed and fabricated where vanadium is added in order to form vanadium oxide nanoclusters that serve as deflection sites for crack propagation. Although experiments have shown evidence that the fracture behavior of the alloys is improved, it is unknown whether or not the vanadium oxide nanoclusters are effective trapping sites for helium. We present results obtained using density functional theory investigating the thermodynamic stability of helium with the vanadium oxide matrix to make a comparison of trapping effectiveness to traditional Y-Ti-O compounds.

  6. InN/GaN short-period superlattices as ordered InGaN ternary alloys

    International Nuclear Information System (INIS)

    Kusakabe, Kazuhide; Imai, Daichi; Wang, Ke; Yoshikawa, Akihiko

    2016-01-01

    Coherent (InN) 1 /(GaN) n short-period superlattices (SPSs) were successfully grown through dynamic atomic layer epitaxy (D-ALEp) mode by RF-plasma molecular beam epitaxy (MBE), where GaN layer thicknesses n were thinned down to 4 monolayer (ML). After this achievement, we demonstrated quasi-ternary InGaN behavior in their photoluminescence (PL) spectra for the first time. It was found interestingly that GaN layer thickness of n = 4 ML was the criterion both for structural control and continuum-band formation. Although highly lattice-mismatched InN/GaN interfaces easily introduce relaxation in (InN) 1 /(GaN) 4 SPSs during growth depending on the dynamic surface stoichiometry condition, this problem was overcome by precise control/removal of fluid-like residual In/Ga metals on the growth front with in-situ monitoring method. The (InN) 1 /(GaN) n SPSs with n ≥ 7 ML showed a constant PL peak energy around 3.2 eV at 12 K, reflecting discrete electron/hole wavefunctions. On the other hand, the (InN) 1 /(GaN) 4 SPSs indicated the red-shifted PL peak at 2.93 eV at 12 K, which was attributed to the continuum-band state with increasing in the overlap of electrons/hole wavefunctions. This result is concluded that the (InN) 1 /(GaN) 4 SPSs can be considered as ordered InGaN alloys. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Study on Mg/Al Weld Seam Based on Zn–Mg–Al Ternary Alloy

    Directory of Open Access Journals (Sweden)

    Liming Liu

    2014-02-01

    Full Text Available Based on the idea of alloying welding seams, a series of Zn–xAl filler metals was calculated and designed for joining Mg/Al dissimilar metals by gas tungsten arc (GTA welding. An infrared thermography system was used to measure the temperature of the welding pool during the welding process to investigate the solidification process. It was found that the mechanical properties of the welded joints were improved with the increasing of the Al content in the Zn–xAl filler metals, and when Zn–30Al was used as the filler metal, the ultimate tensile strength could reach a maximum of 120 MPa. The reason for the average tensile strength of the joint increasing was that the weak zone of the joint using Zn–30Al filler metal was generated primarily by α-Al instead of MgZn2. When Zn–40Al was used as the filler metal, a new transition zone, about 20 μm-wide, appeared in the edge of the fusion zone near the Mg base metal. Due to the transition zones consisting of MgZn2- and Al-based solid solution, the mechanical property of the joints was deteriorated.

  8. Composition Dependence of Surface Phonon Polariton Mode in Wurtzite InxGa1−xN (0 ≤ x ≤ 1) Ternary Alloy

    International Nuclear Information System (INIS)

    Ng, S. S.; Hassan, Z.; Hassan, H. Abu

    2008-01-01

    We present a theoretical study on the composition dependence of the surface phonon polariton (SPP) mode in wurtzite structure α-In x Ga 1-x N ternary alloy over the whole composition range. The SPP modes are obtained by the theoretical simulations by means of an anisotropy model. The results reveal that the SPP mode of α-In x Ga 1-x N semiconductors exhibits one-mode behaviour. From these data, composition dependence of the SPP mode with bowing parameter of −28.9 cm −1 is theoretically obtained

  9. Ab-initio study of structural, elastic, electronic and thermodynamic properties of BaxSr1−xS ternary alloys

    Directory of Open Access Journals (Sweden)

    Chelli S.

    2015-12-01

    Full Text Available The structural, elastic, electronic and thermodynamic properties of BaxSr1−xS ternary alloys have been investigated using the full-potential (linearized augmented plane wave method. The ground state properties, such as lattice constant, bulk modulus and elastic constants, are in good agreement with numerous experimental and theoretical data. The dependence of the lattice parameters, bulk modulus and band gap on the composition x was analyzed. Deviation of the lattice constant from Vegard’s law and the bulk modulus from linear concentration dependence (LCD was observed. The microscopic origins of the gap bowing were explained by using the approach of Zunger et al. The thermodynamic stability of BaxSr1−xS alloy was investigated by calculating the excess enthalpy of mixing, ΔHm and the calculated phase diagram showed a broad miscibility gap with a critical temperature.

  10. Growing Platinum-Ruthenium-Tin ternary alloy nanoparticles on reduced graphene oxide for strong ligand effect toward enhanced ethanol oxidation reaction.

    Science.gov (United States)

    Xia, Qing Qing; Zhang, Lian Ying; Zhao, Zhi Liang; Li, Chang Ming

    2017-11-15

    Uniform Pt 1 Ru 0.5 Sn 0.5 ternary alloy nanoparticles are in situ deposited on reduced graphene oxide (Pt 1 Ru 0.5 Sn 0.5 -RGO) through its functional groups and defects as nucleation sites to greatly electrocatalyze ethanol oxidation reaction for much higher mass current densities, larger apparent specific current densities and better stability than commercial Pt-C catalyst (Pt-C(commer)). Mechanistic studies indicate that the excellent electrocatalytic activity and anti-poisoning are resulted from a strong ligand effect of the ternary alloy components, in which the charge transfer is boosted while decreasing the density of states close to the Fermi level of Pt to reduce bond energy between Pt and CO-like adsorbates for greatly improved anti-poisoning ability. This work holds a great promise to fabricate a high performance anode catalyst with a low Pt loading for direct ethanol fuel cells. Copyright © 2017. Published by Elsevier Inc.

  11. First-principle study of the electronic band structure and the effective mass of the ternary alloy GaxIn1-xP

    Science.gov (United States)

    Yang, H. Q.; Song, T. L.; Liang, X. X.; Zhao, G. J.

    2015-01-01

    In this work, the electronic band structure and the effective mass of the ternary alloy GaxIn1-xP are studied by the first principle calculations. The software QUANTUM ESPRESSO and the generalized gradient approximation (GGA) for the exchange correlations have been used in the calculations. We calculate the lattice parameter, band gap and effective mass of the ternary alloy GaxIn1-xP for the Ga composition x varying from 0.0 to 1.0 by the step of 0.125. The effect of the Ga composition on the lattice parameter and the electronic density of states are discussed. The results show that the lattice parameter varies with the composition almost linearly following the Vegard's law. A direct-to-indirect band-gap crossover is found to occur close to x = 0.7. The effective masses are also calculated at Γ(000) high symmetry point along the [100] direction. The results show that the band gap and the electron effective mass vary nonlinearly with composition x.

  12. A Platinum Monolayer Core-Shell Catalyst with a Ternary Alloy Nanoparticle Core and Enhanced Stability for the Oxygen Reduction Reaction

    Directory of Open Access Journals (Sweden)

    Haoxiong Nan

    2015-01-01

    Full Text Available We synthesize a platinum monolayer core-shell catalyst with a ternary alloy nanoparticle core of Pd, Ir, and Ni. A Pt monolayer is deposited on carbon-supported PdIrNi nanoparticles using an underpotential deposition method, in which a copper monolayer is applied to the ternary nanoparticles; this is followed by the galvanic displacement of Cu with Pt to generate a Pt monolayer on the surface of the core. The core-shell Pd1Ir1Ni2@Pt/C catalyst exhibits excellent oxygen reduction reaction activity, yielding a mass activity significantly higher than that of Pt monolayer catalysts containing PdIr or PdNi nanoparticles as cores and four times higher than that of a commercial Pt/C electrocatalyst. In 0.1 M HClO4, the half-wave potential reaches 0.91 V, about 30 mV higher than that of Pt/C. We verify the structure and composition of the carbon-supported PdIrNi nanoparticles using X-ray powder diffraction, X-ray photoelectron spectroscopy, thermogravimetry, transmission electron microscopy, and energy dispersive X-ray spectrometry, and we perform a stability test that confirms the excellent stability of our core-shell catalyst. We suggest that the porous structure resulting from the dissolution of Ni in the alloy nanoparticles may be the main reason for the catalyst’s enhanced performance.

  13. First-principles study on half-metallic ferromagnetic properties of Zn{sub 1-x}V{sub x}Se ternary alloys

    Energy Technology Data Exchange (ETDEWEB)

    Khatta, Swati; Tripathi, S.K.; Prakash, Satya [Panjab University, Central of Advanced Study in Physics, Department of Physics, Chandigarh (India)

    2017-09-15

    The spin-polarised density functional theory along with self-consistent plane-wave pseudopotential is used to investigate the half-metallic ferromagnetic properties of ternary alloys Zn{sub 1-x}V{sub x}Se. The generalized gradient approximation is used for exchange-correlation potential. The equilibrium lattice constants, bulk modulus, and its derivatives are calculated. The calculated spin-polarised energy-band structures reveal that these alloys are half-metallic for x = 0.375 and 0.50 and nearly half-metallic for other values of x. The estimated direct and indirect bandgaps may be useful for the magneto-optical absorption experiments. It is found that there is strong Zn 4s, Se 4p, and V 3d orbital hybridization in the conduction bands of both the spins, while Se 4p and V 3d orbital hybridization predominates in the valence bands of both the spins. The s, p-d, and p-d orbital hybridization reduces the local magnetic moment of V atoms and small local magnetic moments are produced on Zn and Se atoms which get coupled with V atoms in ferromagnetic and antiferromagnetic phases, respectively. The conduction and valence-band-edge splittings and exchange constants predict the ferromagnetism in these alloys. The conduction band-impurity (s and p-d) exchange interaction is more significant for ferromagnetism in these alloys than the valence band-impurity (p-d) exchange interaction. (orig.)

  14. Synthesis and Mechanical Characterization of Binary and Ternary Intermetallic Alloys Based on Fe-Ti-Al by Resonant Ultrasound Vibrational Methods.

    Science.gov (United States)

    Chanbi, Daoud; Ogam, Erick; Amara, Sif Eddine; Fellah, Z E A

    2018-05-07

    Precise but simple experimental and inverse methods allowing the recovery of mechanical material parameters are necessary for the exploration of materials with novel crystallographic structures and elastic properties, particularly for new materials and those existing only in theory. The alloys studied herein are of new atomic compositions. This paper reports an experimental study involving the synthesis and development of methods for the determination of the elastic properties of binary (Fe-Al, Fe-Ti and Ti-Al) and ternary (Fe-Ti-Al) intermetallic alloys with different concentrations of their individual constituents. The alloys studied were synthesized from high purity metals using an arc furnace with argon flow to ensure their uniformity and homogeneity. Precise but simple methods for the recovery of the elastic constants of the isotropic metals from resonant ultrasound vibration data were developed. These methods allowed the fine analysis of the relationships between the atomic concentration of a given constituent and the Young’s modulus or alloy density.

  15. Investigation of strain effects on phase diagrams in the ternary nitride alloys (InAlN, AlGaN, InGaN)

    Energy Technology Data Exchange (ETDEWEB)

    Mohamad, Ranim; Chen, Jun; Ruterana, Pierre [CIMAP, UMR 6252, CNRS-ENSICAEN-CEA-UNICAEN, Caen (France); Bere, Antoine [Laboratoire de Physique et de Chimie de l' Environnement, Universite Ouaga I Pr Joseph KI-ZERBO, Ouagadougou (Burkina Faso)

    2017-09-15

    In this work, we used a modified Stillinger-Weber potential and a methodology of free energy calculation based on numerical computation of the configuration partition function of an alloy, to make a comprehensive study of the properties of group-III nitride ternary compounds (In{sub x}Ga{sub 1-x}N; In{sub x}Al{sub 1-x}N; Al{sub x}Ga{sub 1-x}N). The wurtzite structure was used; and the critical temperatures for the random ternary alloys are determined as 2717 K for In{sub x}Al{sub 1-x}N, 1718 K for In{sub x}Ga{sub 1-x}N, and 177 K for Al{sub x}Ga{sub 1-x}N, respectively. Therefore, Al{sub x}Ga{sub 1-x}N has no unstable mixing region at typical growth temperatures around 1100 C. In contrast, In{sub x}Al{sub 1-x}N and In{sub x}Ga{sub 1-x}N exhibit a wide unstable region, which means that being thick layers, their stability as homogeneous alloys is probably limited. In agreement with other reports, it is also pointed out that the critical temperature T{sub c} may be decreased when the layers are grown under strain. Although the compression and extension have the same effect below 1.5% strain, it is shown, for the first time, that when the compressive strain goes beyond, T{sub c} abruptly increases in contrast to the case of tensile strain where it continues to decrease. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. A comparative study of ternary Al-Sn-Cu immiscible alloys prepared by conventional casting and casting under high-intensity ultrasonic irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kotadia, H.R., E-mail: hiren.kotadia@kcl.ac.uk [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Das, A. [Materials Research Centre, College of Engineering, Swansea University, Singleton Park, Swansea, SA2 8PP (United Kingdom); Doernberg, E.; Schmid-Fetzer, R. [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Systematic investigation on the solidification microstructure of ternary Al-Sn-Cu immiscible system aided by computational thermodynamics calculations. Black-Right-Pointing-Pointer Comparative study of conventional casting and casting under high-intensity ultrasonic irradiation. Black-Right-Pointing-Pointer Demonstrated the high effectiveness of ultrasound exposure during solidification. Black-Right-Pointing-Pointer Effect of cavitation on nucleation and the relative effects of cavitation and acoustic streaming on the dispersion of Sn-rich liquid phases have been explained from the experimental observation. Cavitation was found to promote fragmentation and dispersion of Sn-rich liquid leading to homogeneous dispersion of refined Sn phase. Microstructural modification was found to be contributed by cavitation and associated shockwave generation while bulk fluid flow under acoustic streaming was found to be less effective on the microstructure evolution. Black-Right-Pointing-Pointer Globular and highly refined {alpha}-Al formed near the radiator through enhanced heterogeneous nucleation in contrast to dendritic {alpha}-Al observed in conventional solidification. - Abstract: A comparative study on the microstructure of four ternary Al-Sn-Cu immiscible alloys, guided by the recent thermodynamic assessment of the system, was carried out with specific focus on the soft Sn particulate distribution in hard Al-rich matrix in the presence and absence of ultrasonic irradiation during solidification. The results clearly demonstrate high effectiveness of ultrasonication in promoting significantly refined and homogeneously dispersed microstructure, probably aided by enhanced nucleation and droplet fragmentation under cavitation. While conventional solidification produced highly segregated Sn phase at the centre and bottom of Sn-rich alloy ingots, ultrasonic treatment produced effective dispersion irrespective of the alloy constitution in

  17. Relaxation path of metastable nanoclusters in oxide dispersion strengthened materials

    Energy Technology Data Exchange (ETDEWEB)

    Ribis, J., E-mail: joel.ribis@cea.fr [DEN-Service de Recherches Métallurgiques Appliquées, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Thual, M.A. [LLB, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191, Gif-sur-Yvette (France); Guilbert, T.; Carlan, Y. de [DEN-Service de Recherches Métallurgiques Appliquées, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Legris, A. [UMET, CNRS/UMR 8207, Bât. C6, Univ. Lille 1, 59655 Villeneuve d’Ascq (France)

    2017-02-15

    ODS steels are a promising class of structural materials for sodium cooled fast reactor application. The ultra-high density of the strengthening nanoclusters dispersed within the ferritic matrix is responsible of the excellent creep properties of the alloy. Fine characterization of the nanoclusters has been conducted on a Fe-14Cr-0.3Ti-0.3Y{sub 2}O{sub 3} ODS material using High Resolution and Energy Filtered Transmission Electron Microscopy. The nanoclusters exhibit a cubic symmetry possibly identified as f.c.c and display a non-equilibrium YTiCrO chemical composition thought to be stabilized by a vacancy supersaturation. These nanoclusters undergo relaxation towards the Y{sub 2}Ti{sub 2}O{sub 7}-like state as they grow. A Cr shell is observed around the relaxed nano-oxides, this size-dependent shell may form after the release of Cr by the particles. The relaxation energy barrier appears to be higher for the smaller particles probably owing to a volume/surface ratio effect in reason to the full coherency of the nanoclusters. - Highlights: • The nanoclusters display a f.c.c. cubic symmetry and a non-equilibrium YTiCrO chemical composition. • During thermal annealing the coherent nanocluster transform into semi-coherent pyrochlore particles. • A Cr ring is observed around the relaxed pyrochlore type particles.

  18. Solid-state reactions during mechanical alloying of ternary Fe-Al-X (X=Ni, Mn, Cu, Ti, Cr, B, Si) systems: A review

    Science.gov (United States)

    Hadef, Fatma

    2016-12-01

    The last decade has witnessed an intensive research in the field of nanocrystalline materials due to their enhanced properties. A lot of processing techniques were developed in order to synthesis these novel materials, among them mechanical alloying or high-energy ball milling. In fact, mechanical alloying is one of the most common operations in the processing of solids. It can be used to quickly and easily synthesize a variety of technologically useful materials which are very difficult to manufacture by other techniques. One advantage of MA over many other techniques is that is a solid state technique and consequently problems associated with melting and solidification are bypassed. Special attention is being paid to the synthesis of alloys through reactions mainly occurring in solid state in many metallic ternary Fe-Al-X systems, in order to improve mainly Fe-Al structural and mechanical properties. The results show that nanocrystallization is the common result occurring in all systems during MA process. The aim of this work is to illustrate the uniqueness of MA process to induce phase transformation in metallic Fe-Al-X (X=Ni, Mn, Cu, Ti, Cr, B, Si) systems.

  19. Ternary superconductors

    International Nuclear Information System (INIS)

    Giorgi, A.L.

    1987-01-01

    Ternary superconductors constitute a class of superconducting compounds with exceptional properties such as high transition temperatures (≅ 15.2 K), extremely high critical fields (H c2 >60 Tesla), and the coexistence of superconductivity and long-range magnetic order. This has generated great interest in the scientific community and resulted in a large number of experimental and theoretical investigations in which many new ternary compounds have been discovered. A review of some of the properties of these ternary compounds is presented with particular emphasis on the ternary molybdenum chalcogenides and the ternary rare earth transition metal tetraborides. The effect of partial substitution of a second metal atom to form pseudoternary compounds is examined as well as some of the proposed correlations between the superconducting transition temperature and the structural and electronic properties of the ternary superconductors

  20. Study of fatigue and fracture behavior of NbCr{sub 2}-based alloys: Phase stability in Nb-Cr-Ni ternary system

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, J.H.; Liaw, P.K. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Liu, C.T. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1997-12-01

    Phase stability in a ternary Nb-Cr-Ni Laves phase system was studied in this paper. Their previous study in NbCr{sub 2}-based transition-metal Laves phases has shown that the average electron concentration factor, e/a, is the dominating factor in controlling the phase stability of NbCr{sub 2}-based Laves phases when the atomic size ratios are kept identical. Since Ni has ten out-shell electrons, the substitution of Ni for Cr in NbCr{sub 2} will increase the average electron concentration of the alloy, thus leading to the change of the crystal structures from C15 to C14. In this paper, a number of pseudo-binary Nb(Cr,Ni){sub 2} alloys were prepared, and the crystal structures of the alloys after a long heat-treatment at 1000 C as a function of the Ni content were determined by the X-ray diffraction technique. The boundaries of the C15/C14 transition were determined and compared to their previous predictions. It was found that the electron concentration and phase stability correlation is obeyed in the Nb-Cr-Ni system. However, the e/a ratio corresponding to the C15/C14 phase transition was found to move to a higher value than the predicted one. The changes in the lattice constant, Vickers hardness and fracture toughness were also determined as a function of the Ni content, which were discussed in light of the phase stability difference of the alloys.

  1. Ternary fission

    Indian Academy of Sciences (India)

    the energy minimization of all possible ternary breakups of a heavy radioactive nucleus. Further, within the TCM we have analysed the competition between different geometries as well as different positioning of the fragments. Also, an attempt was made to calculate the mass distribution of ternary fission process within the ...

  2. Trace element control in binary Ni-25Cr and ternary Ni-30Co-30Cr master alloy castings

    Energy Technology Data Exchange (ETDEWEB)

    Detrois, Martin [National Energy Technology Lab. (NETL), Albany, OR (United States); Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States); Jablonski, Paul D. [National Energy Technology Lab. (NETL), Albany, OR (United States);

    2017-10-23

    Electro-slag remelting (ESR) is used for control of unwanted elements in commercial alloys. This study focuses on master alloys of Ni-25Cr and Ni-30Co-30Cr, processed through a combination of vacuum induction melting (VIM) and electro-slag remelting (ESR). Minor additions were made to control tramp element levels and modify the melting characteristics. Nitrogen and sulfur levels below 10 ppm and oxygen levels below 100 ppm were obtained in the final products. The role of the alloy additions in lowering the tramp element content, the resulting residual inclusions and the melting characteristics were determined computationally and confirmed experimentally. Additions of titanium were beneficial to the control of oxygen levels during VIM and nitrogen levels during ESR. Aluminum additions helped to control oxygen levels during remelting, however, aluminum pickup occurred when excess titanium was present during ESR. The usefulness of these master alloys for use as experimental remelt stock will also be discussed.

  3. Glass-forming ability and crystallization behavior of some binary and ternary Ni-based glassy alloys

    International Nuclear Information System (INIS)

    Louzguine-Luzgin, Dmitri V.; Louzguina-Luzgina, Larissa V.; Xie Guoqiang; Li Song; Zhang Wei; Inoue, Akihisa

    2008-01-01

    The purpose of the current paper is to study the influence of Ti, V, Nb, Al, Sn and Pd additions on the glass-forming ability, formation of a supercooled liquid region and a devitrification process of some Ni-Zr glassy alloys as well as to compare the results with those obtained for similar Cu-based alloys studied earlier. The Ni-based glassy alloys were investigated by using X-ray diffraction, differential scanning and isothermal calorimetries. Although the studied Ni-based alloys showed high values of the reduced glass-transition temperature of about 0.6, their glass-forming ability is quite low. This fact may be explained by low stability of the supercooled liquid against crystallization and formation of the equilibrium intermetallic compounds with a high growth rate compared to those observed in similar Cu-based alloys studied earlier. Relatively low thermal conductivity of Ni-based alloys is also found to be another factor limiting their glass-forming ability

  4. Phase Equilibria of the Ternary Sn-Pb-Co System at 250°C and Interfacial Reactions of Co with Sn-Pb Alloys

    Science.gov (United States)

    Wang, Chao-hong; Kuo, Chun-yi; Yang, Nian-cih

    2015-11-01

    The isothermal section of the ternary Sn-Pb-Co system at 250°C was experimentally determined through a series of the equilibrated Sn-Pb-Co alloys of various compositions. The equilibrium phases were identified on the basis of compositional analysis. For the Sn-Co intermetallic compounds (IMCs), CoSn3, CoSn2, CoSn and Co3Sn2, the Pb solubility was very limited. There exist five tie-triangle regions. The Co-Pb system involves one monotectic reaction, so the phase separation of liquid alloys near the Co-Pb side occurred prior to solidification. The immiscibility field was also determined. Additionally, interfacial reactions between Co and Sn-Pb alloys were conducted. The reaction phase for the Sn-48 at.%Pb and Sn-58 at.%Pb at 250°C was CoSn3 and CoSn2, respectively. Both of them were simultaneously formed in the Sn-53 at.%Pb/Co. The formed IMCs were closely associated to the phase equilibria relationship of the liquid-CoSn3-CoSn2 tie-triangle. Furthermore, with increasing temperatures, the phase formed in equilibrium with Sn-37 wt.%Pb was found to transit from CoSn3 to CoSn2 at 275°C. We propose a simple method of examining the phase transition temperature in the interfacial reactions to determine the boundaries of the liquid-CoSn3-CoSn2 tie-triangles at different temperatures.

  5. Study of the ternary alloy systems Al-Ni-Fe and Al-Cu-Ru with special regard to quasicrystalline phases

    International Nuclear Information System (INIS)

    Lemmerz, U.

    1996-07-01

    Two ternary alloy-systems, the Al-Ni-Fe system and the Al-Cu-Ru system were studied with special regard to quasicrystalline phases. Isothermal sections were established in both systems in the stoichiometric area of the quasicrystalline phase. In the Al-Ni-Fe system a new stable decagonal phase was found. Its stoichiometric range is very small around Al 71.6 Ni 23.0 Fe 5.4 . The temperature range in which it is stable lies between 847 and 930 C. The decagonal phase undergoes a eutectoid reaction to the three crystalline phases Al 3 Ni 2 , Al 3 Ni and Al 13 Fe 4 at 847 C. It melts peritectically at 930 C forming Al 13 Fe 4 , Al 3 Ni 2 and a liquid. The investigations in the Al-Cu-Ru system concentrated on the phase equilibria between the icosahedral phase and its neighbouring phases in a temperature range between 600 and 1000 C. The icosahedral phase was observed in the whole temperature range. The investigated stoichiometric area extends down to Al contents of 45%, which allows the fields of existence to be determined for the ternary phases α-AlCuRu, the icosahedral phase and Al 7 Cu 2 Ru. Binary phases were determined down to the upper (high Al content) border of AlRu. No hitherto unknown phase was observed in the investigated area. Rietveld analyses were carried out on α-AlCuRu and Al 7 Cu 2 Ru showing some discrepancies from the α-AlMnSi structure taken as a base for α-AlCuRu and confirming the Al 7 Cu 2 Fe structure for Al 7 Cu 2 Ru. (orig.)

  6. VANADIUM ALLOYS

    Science.gov (United States)

    Smith, K.F.; Van Thyne, R.J.

    1959-05-12

    This patent deals with vanadium based ternary alloys useful as fuel element jackets. According to the invention the ternary vanadium alloys, prepared in an arc furnace, contain from 2.5 to 15% by weight titanium and from 0.5 to 10% by weight niobium. Characteristics of these alloys are good thermal conductivity, low neutron capture cross section, good corrosion resistance, good welding and fabricating properties, low expansion coefficient, and high strength.

  7. Distinct metal-exchange pathways of doped Ag25 nanoclusters

    KAUST Repository

    Bootharaju, Megalamane Siddaramappa; Sinatra, Lutfan; Bakr, Osman

    2016-01-01

    Atomically precise metal nanoclusters (NCs) containing more than one type of metal atom (i.e., doped or alloyed), due to synergistic effects, open new avenues for engineering the catalytic and optical properties of NCs in a manner that homometal NCs

  8. Establishment of technological basis for fabrication of U-Pu-Zr ternary alloy fuel pins for irradiation tests in Japan

    International Nuclear Information System (INIS)

    Kikuchi, Hironobu; Iwai, Takashi; Nakajima, Kunihisa; Arai, Yasuo; Nakamura, Kinya; Ogata, Takanari

    2011-01-01

    A high-purity Ar gas atmosphere glove box accommodating injection casting and sodium-bonding apparatuses was newly installed in the Plutonium Fuel Research Facility of Oarai Research and Development Center, Japan Atomic Energy Agency, in which several nitride and carbide fuel pins were fabricated for irradiation tests. The experiences led to the establishment of the technological basis of the fabrication of U-Pu-Zr alloy fuel pins for the first time in Japan. After the injection casting of the U-Pu-Zr alloy, the metallic fuel pins were fabricated by welding upper and lower end plugs with cladding tubes of ferritic-martensitic steel. Subsequent to the sodium bonding for filling the annular gap region between the U-Pu-Zr alloy and the cladding tube with the melted sodium, the fuel pins for irradiation tests are inspected. This paper shows the apparatuses and the technological basis for the fabrication of U-Pu-Zr alloy fuel pins for the irradiation test planned at the experimental fast test reactor Joyo. (author)

  9. Applying a new criterion to predict glass forming alloys in the Zr–Ni–Cu ternary system

    Energy Technology Data Exchange (ETDEWEB)

    Déo, L.P., E-mail: leonardopratavieira@gmail.com [Universidade de São Paulo, EESC, SMM - Av. Trabalhador São Carlense, 400 – São Carlos, SP 13566-590 (Brazil); Mendes, M.A.B., E-mail: marcio.andreato@gmail.com [Universidade Federal de São Carlos, DEMa - Rod. Washington Luiz, Km 235 – São Carlos, SP 13565-905 (Brazil); Costa, A.M.S., E-mail: alexmatos1980@gmail.com [Universidade de São Paulo, DEMAR, EEL – Polo Urbo-Industrial Gleba AI-6, s/n – Lorena, SP 12600-970 (Brazil); Campos Neto, N.D., E-mail: nelsonddcn@gmail.com [Universidade de São Paulo, EESC, SMM - Av. Trabalhador São Carlense, 400 – São Carlos, SP 13566-590 (Brazil); Oliveira, M.F. de, E-mail: falcao@sc.usp.br [Universidade de São Paulo, EESC, SMM - Av. Trabalhador São Carlense, 400 – São Carlos, SP 13566-590 (Brazil)

    2013-03-15

    Highlights: ► Calculation to predict and select the glass forming ability (GFA) of metallic alloys in Zr–Ni–Cu system. ► Good correlation between theoretical and experimental GFA samples. ► Combination of X-ray diffraction (XRD) and differential scanning calorimetry (DSC) techniques mainly to characterize the samples. ► Oxygen impurity dramatically reduced the GFA. ► The selection criterion used opens the possibility to obtain new amorphous alloys, reducing the experimental procedures of trial and error. -- Abstract: A new criterion has been recently proposed to predict and select the glass forming ability (GFA) of metallic alloys. It was found that the critical cooling rate for glass formation (R{sub c}) correlates well with a proper combination of two factors, the minimum topological instability (λ{sub min}) and the thermodynamic parameter (Δh). The (λ{sub min}) criterion is based on the concept of topological instability of stable crystalline structures and (Δh) depends on the average work function difference (Δϕ) and the average electron density difference Δn{sub ws}{sup 1/3} among the constituent elements of the alloy. In the present work, the selection criterion was applied in the Zr–Ni–Cu system and its predictability was analyzed experimentally. Ribbon-shaped and splat-shaped samples were produced by melt-spinning and splat-cooling techniques respectively. The crystallization content and behavior were analyzed by X-ray diffraction (XRD) and differential scanning calorimetry (DSC), respectively. The results showed a good correlation between the theoretical GFA values and the amorphous phase percentages found in different alloy compositions.

  10. Chemical- or radiation-assisted selective dealloying in bimetallic nanoclusters

    International Nuclear Information System (INIS)

    Mattei, G.; De Marchi, G.; Maurizio, C.; Mazzoldi, P.; Sada, C.; Bello, V.; Battaglin, G.

    2003-01-01

    A selective dealloying in bimetallic nanoclusters prepared by ion implantation has been found upon thermal annealing in oxidizing atmosphere or irradiation with light ions. In the first process, the incoming oxygen interacts preferentially with copper promoting Cu 2 O formation, therefore extracting copper from the alloy. In the second process the irradiation with Ne ions promotes a preferential extraction of Au from the alloy, resulting in the formation of Au-enriched 'satellite' nanoparticles around the original Au x Cu 1-x cluster

  11. Ternary fission

    International Nuclear Information System (INIS)

    Wagemans, C.

    1991-01-01

    Since its discovery in 1946, light (charged) particle accompanied fission (ternary fission) has been extensively studied, for spontaneous as well as for induced fission reactions. The reason for this interest was twofold: the ternary particles being emitted in space and time close to the scission point were expected to supply information on the scission point configuration and the ternary fission process was an important source of helium, tritium, and hydrogen production in nuclear reactors, for which data were requested by the nuclear industry. Significant experimental progress has been realized with the advent of high-resolution detectors, powerful multiparameter data acquisition systems, and intense neutron and photon beams. As far as theory is concerned, the trajectory calculations (in which scission point parameters are deduced from the experimental observations) have been very much improved. An attempt was made to explain ternary particle emission in terms of a Plateau-Rayleigh hydrodynamical instability of a relatively long cylindrical neck or cylindrical nucleus. New results have also been obtained on the so-called open-quotes trueclose quotes ternary fission (fission in three about-equal fragments). The spontaneous emission of charged particles has also clearly been demonstrated in recent years. This chapter discusses the main characteristics of ternary fission, theoretical models, light particle emission probabilities, the dependence of the emission probabilities on experimental variables, light particle energy distributions, light particle angular distributions, correlations between light particle accompanied fission observables, open-quotes trueclose quotes ternary fission, and spontaneous emission of heavy ions. 143 refs., 18 figs., 8 tabs

  12. Synthesis and Doping of Ligand-Protected Atomically-Precise Metal Nanoclusters

    KAUST Repository

    Aljuhani, Maha A.

    2016-05-01

    Rapidly expanding research in nanotechnology has led to exciting progress in a versatile array of applications from medical diagnostics to catalysis. This success resulted from the manipulation of the desired properties of nanomaterials by controlling their size, shape, and composition. Among the most thriving areas of research about nanoparticle is the synthesis and doping of the ligand-protected atomically-precise metal nanoclusters. In this thesis, we developed three different novel metal nanoclusters, such as doped Ag29 with five gold (Au) atoms leading to enhance its quantum yield with remarkable stability. We also developed half-doped (alloyed) cluster of Ni6 nanocluster with molybdenum (Mo). This enabled enhanced stability and better catalytic activity. The third metal nanocluster that we synthesized was Au28 nanocluster by using di-thiolate as the ligand stabilizer instead of mono-thiolate. The new metal clusters obtained have been characterized by spectroscopic, electrochemical and crystallographic methods.

  13. Extractive spectrophotometric determination of molybdenum in steels and nickel base high-temperature alloys as a ternary complex with hydroxylamine hydrochloride and 4-(2-pyridylazo) resorcinol

    International Nuclear Information System (INIS)

    Reddy, M.R.P.; Kumar, P.V.S.; Shyamsundar, J.P.; Anjaneyulu, Y.

    1990-01-01

    The red coloured, ternary complex formed by molybdenum(VI) with hydroxylamine hydrchloride and 4-(2-pyridylazo) resorcinol (PAR), on heating for 20 minutes in a hot water bath at pH 6-8, can be extracted with a mixture of n-butanol and benzene (4:1). This complex exhibits absorption maximum at 530nm with a molar absorptivity of 2.8x10 4 lit. mol -1 cm -1 and obeys Beer's law upto 4.5μg/ml of Mo(VI). The composition of the complex is found to be 1:1:1, for Mo(VI): hydroxylamine hydrochloride: PAR. Large amounts of tartaric acid and 2, 2-diamino-cyclohexane tetra acetic acid (CyDTA) can be tolerated in this method. The extraction becomes highly selective in presence of CyDTA (3ml of 5x10 -2 M) and interference of ions like Fe(III)(5mg), Pb(II)(4mg), Zn(II)(2mg), Cu(II)(4mg), Mn(II)(3mg), Ni(II)(4mg), Sn(II)(3mg), Cr(VI)(2mg) and Bi(III)(0.5mg) can be effectively supressed in the determination of 10-45μg of molybdenum. The method can be successfully applied for the determination of molybdenum in steels and nickel base high temperature alloys. (author). 2 tabs., 8 refs

  14. First-principle study of the structural, electronic, and optical properties of cubic InN{sub x}P{sub 1-x} ternary alloys under hydrostatic pressure

    Energy Technology Data Exchange (ETDEWEB)

    Hattabi, I. [Ibn Khaldoun Univ. de Tiaret (Algeria). Lab. Synthese et Catalyse; Abdiche, A.; Riane, R. [Sidi-bel-Abbes Univ. (Algeria). Applied Materials Lab.; Moussa, R. [Sidi-bel-Abbes Univ. (Algeria). Physic Dept.; Hadji, K. [Ibn Khaldoun Univ. de Tiaret (Algeria). Science and Technology Dept.; Soyalp, F. [Yuezuencue Yil Univ., Van (Turkey). Dept. of Physics; Varshney, Dinesh [Devi Ahilya Univ., Indore (India). Materials Science Lab.; Syrotyuk, S.V. [National Univ. ' Lviv Polytechnic' , Lviv (Ukraine). Semiconductor Electronics Dept.; Khenata, R. [Mascara Univ. (Algeria). Lab. de Physique Quantique et de Modelisation Mathematique (LPQ3M)

    2016-07-01

    In this article, we present results of the first-principle study of the structural, electronic, and optical properties of the InN, InP binary compounds and their related ternary alloy InN{sub x}P{sub 1-x} in the zinc-blend (ZB) phase within a nonrelativistic full potential linearised augmented plan wave (FP-LAPW) method using Wien2k code based on the density functional theory (DFT). Different approximations of exchange-correlation energy were used for the calculation of the lattice constant, bulk modulus, and first-order pressure derivative of the bulk modulus. Whereas the lattice constant decreases with increasing nitride composition x. Our results present a good agreement with theoretical and experimental data. The electronic band structures calculated using Tran-Blaha-modified Becke-Johnson (TB-mBJ) approach present a direct band gap semiconductor character for InN{sub x}P{sub 1-x} compounds at different x values. The electronic properties were also calculated under hydrostatic pressure for (P=0.00, 5.00, 10.0, 15.0, 20.0, 25.0 GPa) where it is found that the InP compound change from direct to indirect band gap at the pressure P≥7.80 GPa. Furthermore, the pressure effect on the dielectric function and the refractive index was carried out. Results obtained in our calculations present a good agreement with available theoretical reports and experimental data.

  15. Characterization of Ternary NiTiPd High-Temperature Shape-Memory Alloys under Load-Biased Thermal Cycling

    Science.gov (United States)

    Bigelow, Glen S.; Padula, Santo A.; Noebe, Ronald D.; Garg, Anita; Gaydosh, Darrell

    2010-01-01

    While NiTiPd alloys have been extensively studied for proposed use in high-temperature shape-memory applications, little is known about the shape-memory response of these materials under stress. Consequently, the isobaric thermal cyclic responses of five (Ni,Pd)49.5Ti50.5 alloys with constant stoichiometry and Pd contents ranging from 15 to 46 at. pct were investigated. From these tests, transformation temperatures, transformation strain (which is proportional to work output), and unrecovered strain per cycle (a measure of dimensional instability) were determined as a function of stress for each alloy. It was found that increasing the Pd content over this range resulted in a linear increase in transformation temperature, as expected. At a given stress level, work output decreased while the amount of unrecovered strain produced during each load-biased thermal cycle increased with increasing Pd content, during the initial thermal cycles. However, continued thermal cycling at constant stress resulted in a saturation of the work output and nearly eliminated further unrecovered strain under certain conditions, resulting in stable behavior amenable to many actuator applications.

  16. High-field superconductivity in the Nb-Ti-Zr ternary system

    International Nuclear Information System (INIS)

    Ralls, K.M.; Rose, R.M.; Wulff, J.

    1980-01-01

    Resistive critical current densities, critical fields, and normal-state electrical resistivities were obtained at 4.2 0 K for 55 alloys in the Nb-Ti-Zr ternary alloy system, excepting Ti-Zr binary compositions. The resistive critical field as a function of ternary composition has a saddle point between the Nb-Ti and Nb-Zr binaries, so that ternary alloying in this system is not expected to result in higher critical fields than the binary alloys

  17. High-field superconductivity in the Nb-Ti-Zr ternary system

    Science.gov (United States)

    Ralls, K. M.; Rose, R. M.; Wulff, J.

    1980-06-01

    Resistive critical current densities, critical fields, and normal-state electrical resistivities were obtained at 4.2 °K for 55 alloys in the Nb-Ti-Zr ternary alloy system, excepting Ti-Zr binary compositions. The resistive critical field as a function of ternary composition has a saddle point between the Nb-Ti and Nb-Zr binaries, so that ternary alloying in this system is not expected to result in higher critical fields than the binary alloys.

  18. Silver- and Zirconium-added ternary and quaternary TiAu based high temperature shape memory alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wadood, A., E-mail: abdul.wadood@ist.edu.pk [High Temperature Materials Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Department of Materials Science and Engineering, Institute of Space Technology (IST), Near Rawat Toll Plaza, Islamabad (Pakistan); Yamabe-Mitarai, Y. [High Temperature Materials Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

    2015-10-15

    Low strength in B2 phase, incomplete shape memory effect and high cost of Au are obstacles for the use of Ti–50Au as a high temperature shape memory alloy. We investigated the effects of partial substitution of Ti with Zr and Au with Ag in Ti–Au on phase constitution, phase transformation, and high temperature thermo-mechanical and shape memory properties. Partial substitution of Ti with Zr in Ti–50Au and Ti–40Au–10Ag was found to improve the thermo-mechanical and shape memory effect. However, partial substitution of Au with Ag in Ti–50Au and Ti–50Au–10Zr was found to have negligible effects. Reasons for such different behavior of Zr- and Ag-added Ti–Au alloys are considered. - Highlights: • Au, Ag and Ti, Zr belong to same group. Effects of partial substitution of Au with Ag and Ti with Zr in Ti–Au are investigated. • Zr was found more effective than Ag in improving shape memory and mechanical properties. • Same atomic size of Au and Ag and large size misfit b/w Ti and Zr atoms. • Ag resulted large amount of precipitation in Ti–Au.

  19. First-principles study of the nucleation and stability of ordered precipitates in ternary Al-Sc-Li alloys

    International Nuclear Information System (INIS)

    Mao, Z.; Chen, W.; Seidman, D.N.; Wolverton, C.

    2011-01-01

    First-principles density functional calculations are used to study the nucleation and stability of L1 2 -ordered precipitates in Al-Sc-Li alloys. For dilute Al alloys, there are three possible ordered L1 2 precipitates: Al 3 Sc, Al 3 Li and an Al 3 Sc/Al 3 Li core/shell structure. To calculate the nucleation behavior, information about bulk thermodynamics (both static total energies and vibrational free energies), interfacial energetics and coherency strain is required. The study finds the following: (1) the coherency strain energies for forming coherent interfaces between Al/Al 3 Sc, Al/Al 3 Li and Al 3 Sc/Al 3 Li are relatively small, owing to the small atomic size mismatches in these systems; (2) the sublattice site preferences of Sc and Li are calculated, and it is demonstrated that Sc and Li share the same sublattice sites in both Al 3 Sc(L1 2 ) and Al 3 Li(L1 2 ), in agreement with recent experimental results; (3) the calculated solubilities of Sc and Li in α-Al alloys are in good agreement with experimental values and, for Sc, agree well with prior first-principles results; (4) the interfacial energies for Al/Al 3 Sc, Al/Al 3 Li and Al 3 Sc/Al 3 Li for (1 0 0), (1 1 0) and (1 1 1) interfaces are calculated: the values of the Al/Al 3 Sc interfacial energies are significantly larger than those of the Al/Al 3 Li and Al 3 Sc/Al 3 Li interfaces; (5) combining the bulk and interfacial energies yields the nucleation barriers and critical radii for Al 3 Sc and Al 3 Li precipitates; and (6) the energetic stability of the Al 3 Sc/Al 3 Li core/shell structure is compared with individual Al 3 Sc and Al 3 Li nuclei, and the range of precipitate sizes for which the core/shell structure is energetically favored is determined quantitatively.

  20. Nanoclusters in bcc-Fe containing vacancies, copper and nickel: Structure and energetics

    International Nuclear Information System (INIS)

    Al-Motasem, A.T.; Posselt, M.; Bergner, F.

    2011-01-01

    Highlights: → Fe-Cu-Ni model alloys for RPV steels. → Atomistic simulation, mainly MMC and MD simulations. → Finding the most stable configurations of defect clusters. → Energetics of clusters, formation and binding energies. → Size dependence of monomer binding energy formula as input for OKMC methods. - Abstract: The most stable atomic configuration of coherent nanoclusters in bcc-Fe formed by vacancies, Cu and Ni as well as the corresponding energetics are determined by on-lattice simulated annealing and subsequent off-lattice relaxation. An interatomic potential recently designed for investigations of radiation-induced effects in the ternary Fe-Cu-Ni system is used in the atomistic simulations. Ternary v l Cu m Ni n clusters show a core-shell structure with vacancies in the core coated by a shell of Cu atoms, followed by a shell of Ni atoms. In binary Cu m Ni n clusters the Cu core is covered by a shell of Ni atoms. On the contrary, binary v l Ni n clusters consist of a pure vacancy cluster surrounded by an agglomeration of Ni atoms. The latter is similar to a pure Ni cluster (Ni n ) and consists of Ni atoms at the second nearest neighbor distance. Because of this special arrangement of atoms v l Ni n and Ni n are also called quasi-clusters. In all clusters investigated Ni atoms may be nearest neighbors of Cu atoms but never nearest neighbors of vacancies or other Ni atoms. The atomic configurations found can be understood by the peculiarities of the binding between vacancies, Cu, Ni and Fe atoms. The structure obtained for Cu m Ni n clusters is in agreement with previous theoretical results and with indications from measurements while for the other clusters reference data are not available. It is shown that the presence of Ni atoms promotes the nucleation of clusters containing vacancies and Cu. This is in agreement with experimental observations and with recent results of atomic kinetic Monte Carlo simulations. Based on the specific atomic structure

  1. Investigations into the corrosion resistance of copper aluminium alloys. Effect of phosphorus as corrosion resistant third alloying element in the ternary system CuAl20P1

    International Nuclear Information System (INIS)

    Allwardt, A.

    1997-01-01

    The effect of phosphorus on the corrosion resistance of Al-bronzes is studied in detail in this work. A literature review showed that there are a lot of things known about the microstructure and the mechanical properties of Al-bronzes. In spite of their corrosion resistance the corrosion properties and the structure of the protective oxide films of Al-bronzes were seldom a matter of interest. Systematic studies of the influence of different alloying elements on the oxide film and the corrosion properties are rare. Therefore, it is not possible to predict the corrosion resistance of Al-bronzes, made by alloying particular elements. The high corrosion resistance of the new alloy CuAl 20 P 1 was the reason to investigate the influence of phosphorus on the corrosion properties of Al-bronzes in more detail. A systematic study of the microstructure and the corrosion properties of Cu, CuP x , CuAl 20 and CuAl 20 P x offers an insight into the effect of aluminium and phosphorus on the formation of the oxide film on Al-bronzes. It was found that there exists a critical amount of 1 at.-% of phosphorus. Above and below this amount the corrosion resistance becomes worse. This behaviour could be explained by XPS-and electrochemical measurements. Although there are still some questions about the influence of phosphorus on the corrosion resistance of Al-bronzes, this work has produced some important results, which in the future may be helpful to develop new high corrosion resistant Al-bronzes more efficiently: - on clean surface Al-bronze, the oxidation of Al and Cu takes place simultaneously, - Al promotes the formation of Cu 2 O but impedes the formation of Cu(II)-oxide/-hydride in neutral solutions, - P impedes the formation of Cu 2 O and as a consequence promotes the formation of aluminium oxide. This results in a higher amount of Al in the oxide film on the surface of the alloy, which leads to a better corrosion resistance. (author) figs., tabs., 106 refs

  2. Influence of aging at 180C on the corrosion behaviour of a ternary Al-Li-Zr alloy

    DEFF Research Database (Denmark)

    Ambat, Rajan; Prasad, R.K.; Dwarakadasa, E.S.

    1994-01-01

    decreased for samples aged up to 6 h at 180 °C whereas Icorr increased for samples aged for longer times. Values of OCP and pitting potential initially shifted in the noble direction and then towards more active values. This change in OCP was observed on samples that had been aged for 20 h while in the case...... of pitting potential an aging time of only 6 h was required. The overall change in passive current density was small, although at longer aging times (> 40h) it showed an increase. As the amount of lithium depletion increased, OCP and pitting potential shifted in the active direction while passive current......The influence of aging at 180 °C on the corrosion behaviour of an Al-1.5%Li-0.1%Zr alloy has been studied using weight loss, open circuit potential (OCP) measurements and potentiodynamic polarization measurements in 3.5% NaCl solution. Corrosion rates obtained from weight loss and Icorr values...

  3. 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

  4. 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.

  5. In situ martensitic transformation in a ternary MgO-Y/sub 2/O/sub 3/-ZrO/sub 2/ alloy: II, transformation in tetragonal ZrO/sub 2/ precipitates

    International Nuclear Information System (INIS)

    Lee, R.R.; Heuer, A.H.

    1988-01-01

    The stress-induced martensitic transformation of t-ZrO/sub 2/ precipitates in a ternary MgO-Y/sub 2/O/sub 3/-ZrO/sub 2/ alloy has been studied in situ in the transmission electron microscope. The transformation occurs autocatalytically and takes place by piecewise growth of two twin-related m-ZrO/sub 2/ variants. Unloading causes retransformation of partially transformed precipitates, but this reverse (m → t) transformation of fully transformed precipitates only occurs on heating. The martensitic transformation in this system is clearly thermoeleastic

  6. Synthesis and characterization of colloidal fluorescent silver nanoclusters.

    Science.gov (United States)

    Huang, Sherry; Pfeiffer, Christian; Hollmann, Jana; Friede, Sebastian; Chen, Justin Jin-Ching; Beyer, Andreas; Haas, Benedikt; Volz, Kerstin; Heimbrodt, Wolfram; Montenegro Martos, Jose Maria; Chang, Walter; Parak, Wolfgang J

    2012-06-19

    Ultrasmall water-soluble silver nanoclusters are synthesized, and their properties are investigated. The silver nanoclusters have high colloidal stability and show fluorescence in the red. This demonstrates that like gold nanoclusters also silver nanoclusters can be fluorescent.

  7. Alleviation of Fermi level pinning at metal/n-Ge interface with lattice-matched Si x Ge1‑ x ‑ y Sn y ternary alloy interlayer on Ge

    Science.gov (United States)

    Suzuki, Akihiro; Nakatsuka, Osamu; Sakashita, Mitsuo; Zaima, Shigeaki

    2018-06-01

    The impact of a silicon germanium tin (Si x Ge1‑ x ‑ y Sn y ) ternary alloy interlayer on the Schottky barrier height (SBH) of metal/Ge contacts with various metal work functions has been investigated. Lattice matching at the Si x Ge1‑ x ‑ y Sn y /Ge heterointerface is a key factor for controlling Fermi level pinning (FLP) at the metal/Ge interface. The Si x Ge1‑ x ‑ y Sn y ternary alloy interlayer having a small lattice mismatch with the Ge substrate can alleviate FLP at the metal/Ge interface significantly. A Si0.11Ge0.86Sn0.03 interlayer increases the slope parameter for the work function dependence of the SBH to 0.4. An ohmic behavior with an SBH below 0.15 eV can be obtained with Zr and Al/Si0.11Ge0.86Sn0.03/n-Ge contacts at room temperature.

  8. Ge nanoclusters in PECVD-deposited glass after heat treating and electron irradiation

    DEFF Research Database (Denmark)

    Ou, Haiyan; Rørdam, Troels Peter; Rottwitt, Karsten

    2007-01-01

    This paper reports the formation of Ge nanoclusters in silica glass thin films deposited by plasma-enhanced chemical vapor deposition (PECVD). We studied the samples by transmission electron microscopy (TEM) and Raman spectroscopy after annealing. TEM investigation shows that the Ge nanoclusters...... at two areaswere formed by different mechanisms. The Ge nanoclusters formed in a single row along the interface of a silicon substrate and the silica glass film by annealing during high-temperature heat treatment. Ge nanoclusters did not initially form in the bulk of the film but could be subsequently...... formed by the electron-beam irradiation. The interface between the silicon substrate and the silica glass film was investigated by Raman spectroscopy. The shift of the Raman peaks around 286.8 cm−1 and 495 cm−1 suggests that the interface is a Si1−xGex alloy film and that the composition x varies along...

  9. Microstructural characterization and phase transformation of ternary alloys near at Al{sub 3}Ti compound; Caracterizacion microestructural y transformaciones de fase de aleaciones ternareas cercanas al compuesto Al{sub 3}Ti

    Energy Technology Data Exchange (ETDEWEB)

    Angeles Ch, C [Instituto Nacional de Investigaciones Nucleares. Depto.de Sintesis y Caracterizacion de Materiales. Carretera Mexico-Toluca Km. 36.5 C.P. 52045, Ocoyoacac, Edo. de Mexico (Mexico)

    1999-07-01

    This research work is related with the structural characteristic and compositional values of the crystalline phases, which are found in ternary alloys of Ti-Al-Fe and TI-Al-Cu. These types of alloys were obtained using a rapid solidification technique (10{sup 3}-10{sup 4} K/s) and pure elements such as Al, Ti, Fe and Cu (99.99%). These cooling velocities allow the formation of stable phases and small grain sizes (approximately in range of a few micras). The obtained results indicate the presence of Al{sub 3}Ti and others phases of L1{sub 2} type. These phases are commonly found in a matrix rich in A1. The microalloyed elements (Cu and Fe) substitute the aluminum in both kinds of phases. Alloys with low content of Cu show transition states from the tetragonal structure DO{sub 22} to the cubic phases L1{sub 2}. The structural characteristics of the alloys are related with some microhardness measurement. The results show that the presence of the L1{sub 2} phase tends to increase to hardness depending of the content of this phase.

  10. Calculation of ternary interdiffusion coefficients using a single diffusion couple

    Czech Academy of Sciences Publication Activity Database

    Čermák, Jiří; Rothová, Věra

    2016-01-01

    Roč. 54, č. 5 (2016), s. 305-314 ISSN 0023-432X R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : diffusion * interdiffusion * ternary alloys * ternary diffusion coefficients Subject RIV: BJ - Thermodynamics Impact factor: 0.366, year: 2016

  11. Amorphous phase formation in the Cu_3_6Zr_5_9A_l_5 and Cu_4_8Zr_4_3A_l_9 ternary alloys studied by molecular dynamics

    International Nuclear Information System (INIS)

    Aliaga, L.C.R.; Schimidt, C.S.; Lima, L.V.; Domingues, G.M.B.; Bastos, I.N.

    2016-01-01

    Amorphous alloys presents better mechanical and physical properties than its crystalline counterparts. However, there is a scarce understanding on structure - properties relationship in this class of materials. This paper presents the results of the molecular dynamics application to obtain an atomistic description of melting, solidification and the glass forming ability in the ternary Cu_3_6Zr_5_9A_l_5 and Cu_4_8Zr_4_3A_l_9 alloys. In the study we used the EAM potential and different cooling rates, β = 0.1, 1 and 100 K/ps to form the amorphous phase in a system consisting of 32,000 atoms by using the free code LAMMPS. The solidus and liquidus temperatures, on a heating rate of the 5 K/ps, were obtained. Also, on the cooling down step, it was observed that the glass transition temperature (T_g) decreases as cooling rate increases. The structural evolution was analyzed through the radial distribution functions and Voronoi polyhedra. Furthermore, it was determined the evolution of viscosity upper T_g, as well as the fragility (m) parameter for each amorphous alloy. The thermal parameters of the simulation obtained are compared with those of the experiments. (author)

  12. Ternary alloy systems. Phase diagrams, crystallographic and thermodynamic data critically evaluated by MSIT registered. Subvol. C. Non-ferrous metal systems. Pt. 4: Selected nuclear materials and engineering systems

    International Nuclear Information System (INIS)

    Effenberg, Guenter; Ilyenko, Svitlana; Aldinger, Fritz; Bochvar, Nataliya; Cacciamani, Gabriele

    2007-01-01

    The present volume in the New Series of Landolt-Boernstein provides critically evaluated data on phase diagrams, crystallographic and thermodynamic data of ternary alloy systems. Reliable phase diagrams provide materials scientists and engineers with basic information important for fundamental research, development and optimization of materials. The often conflicting literature data have been critically evaluated by Materials Science International Team, MSIT registered , a team working together since many years, and with expertise in a broad range of methods, materials and applications. All evaluation reports published here have undergone a thorough review process in which the reviewers had access to all the original data. The data for each ternary system are provided in a standard format which includes text, tables and diagrams. The topics presented are literature data, binary systems, solid phases, pseudobinary systems, invariant equilibria, liquidus, solidus, and solvus surfaces, isothermal sections, temperature-composition sections, thermodynamics, materials properties and applications, and miscellanea. Finally, a detailed bibliography of all cited references is provided. In the present volume IV/11C selected non-ferrous-metal systems are considered, especially selected nuclear materials and engineering systems in this Part 4. (orig.)

  13. The ternary system nickel-boron-silicon

    International Nuclear Information System (INIS)

    Lugscheider, E.; Reimann, H.; Knotek, O.

    1975-01-01

    The ternary system Nickel-Boron-Silicon was established at 850 0 C by means of X-ray diffraction, metallographic and micro-hardness examinations. The well known binary nickel borides and silicides resp. were confirmed. In the boron-silicon system two binary phases, SiBsub(4-x) with x approximately 0.7 and SiB 6 were found the latter in equilibrium with the β-rhombohedral boron. Confirming the two ternary silicon borides a greater homogeneity range was found for Ni 6 Si 2 B, the phase Nisub(4,6)Si 2 B published by Uraz and Rundqvist can better be described by the formula Nisub(4.29)Si 2 Bsub(1.43). In relation to further investigations we measured melting temperatures in ternary Ni-10 B-Si alloys by differential thermoanalysis. (author)

  14. Phenomenological model of nanocluster in polymer matrix

    International Nuclear Information System (INIS)

    Oksengendler, B.L.; Turaeva, N.N.; Azimov, J.; Rashidova, S.Sh.

    2010-01-01

    The phenomenological model of matrix nanoclusters is presented based on the Wood-Saxon potential used in nuclear physics. In frame of this model the following problems have been considered: calculation of width of diffusive layer between nanocluster and matrix, definition of Tamm surface electronic state taking into account the diffusive layer width, receiving the expression for specific magnetic moment of nanoclusters taking into account the interface width. (authors)

  15. Nanocluster production for solar cell applications

    International Nuclear Information System (INIS)

    Al Dosari, Haila M.; Ayesh, Ahmad I.

    2013-01-01

    This research focuses on the fabrication and characterization of silver (Ag) and silicon (Si) nanoclusters that might be used for solar cell applications. Silver and silicon nanoclusters have been synthesized by means of dc magnetron sputtering and inert gas condensation inside an ultra-high vacuum compatible system. We have found that nanocluster size distributions can be tuned by various source parameters, such as the sputtering discharge power, flow rate of argon inert gas, and aggregation length. Quadrupole mass filter and transmission electron microscopy were used to evaluate the size distribution of Ag and Si nanoclusters. Ag nanoclusters with average size in the range of 3.6–8.3 nm were synthesized (herein size refers to the nanocluster diameter), whereas Si nanoclusters' average size was controlled to range between 2.9 and 7.4 nm by controlling the source parameters. This work illustrates the ability of controlling the Si and Ag nanoclusters' sizes by proper optimization of the operation conditions. By controlling nanoclusters' sizes, one can alter their surface properties to suit the need to enhance solar cell efficiency. Herein, Ag nanoclusters were deposited on commercial polycrystalline solar cells. Short circuit current (I SC ), open circuit voltage (V OC ), fill factor, and efficiency (η) were obtained under light source with an intensity of 30 mW/cm 2 . A 22.7% enhancement in solar cell efficiency could be measured after deposition of Ag nanoclusters, which demonstrates that Ag nanoclusters generated in this work are useful to enhance solar cell efficiency

  16. Binary and ternary systems

    International Nuclear Information System (INIS)

    Petrov, D.A.

    1986-01-01

    Conditions for thermodynamical equilibrium in binary and ternary systems are considered. Main types of binary and ternary system phase diagrams are sequently constructed on the basis of general regularities on the character of transition from one equilibria to others. New statements on equilibrium line direction in the diagram triple points and their isothermal cross sections are developed. New represenations on equilibria in case of monovariant curve minimum and maximum on three-phase equilibrium formation in ternary system are introduced

  17. Possibility of superradiance by magnetic nanoclusters

    International Nuclear Information System (INIS)

    Yukalov, V I; Yukalova, E P

    2011-01-01

    The possibility of realizing spin superradiance by an assembly of magnetic nanoclusters is analyzed. The known obstacles for realizing such a coherent radiation by magnetic nanoclusters are their large magnetic anisotropy, strong dephasing dipole interactions, and an essential nonuniformity of their sizes. In order to give a persuasive conclusion, a microscopic theory is developed, providing an accurate description of nanocluster spin dynamics. It is shown that, despite the obstacles, it is feasible to organize such a setup that magnetic nanoclusters would produce strong superradiant emission

  18. Synthesis and electrochemical properties of binary MgTi and ternary MgTiX (X=Ni, Si) hydrogen storage alloys

    NARCIS (Netherlands)

    Gobichettipalayam Manivasagam, T.; Iliksu, M.; Danilov, D.L.; Notten, P.H.L.

    2017-01-01

    Mg-based hydrogen storage alloys are promising candidate for many hydrogen storage applications because of the high gravimetric hydrogen storage capacity and favourable (de)hydrogenation kinetics. In the present study we have investigated the synthesis and electrochemical hydrogen storage properties

  19. Spiral patterns of gold nanoclusters in silicon (100) produced by metal vapour vacuum arc implantation of gold ions

    International Nuclear Information System (INIS)

    Venkatachalam, Dinesh Kumar; Sood, Dinesh Kumar; Bhargava, Suresh Kumar

    2008-01-01

    Self-assembled gold nanoclusters are attractive building blocks for future nanoscale sensors and optical devices due to their exciting catalytic properties. In this work, we report direct bottom-up synthesis of spiral patterns of gold nanoclusters in silicon (100) substrates by Au ion implantation followed by thermal annealing. This unique phenomenon is observed only above a critical threshold implantation dose and annealing temperature. Systematic study by electron microscopy, analytical x-ray diffraction and atomic force microscopy shows the temperature- and time-dependent nucleation, growth of Au nanoclusters and evolution of the spiral patterns. The observed patterns of gold nanoclusters bear a resemblance to the spiral growth prevalent in some directionally solidified eutectic alloys. Based on this systematic study of the growth and morphology of nanoclusters, a tentative model has been proposed for the formation mechanism of this unusual self-assembled pattern in an amorphous Si/Au system. This model shows that melting of the implanted layer is essential and without which no spiral patterns are observed. A better understanding of this self-assembly process will open up new ways to fabricate ordered arrays of gold nanoclusters in silicon substrates for seeding selective growth of one-dimensional nanostructures

  20. Valence-electron configuration of Fe, Cr, and Ni in binary and ternary alloys from Kβ -to- Kα x-ray intensity ratios

    Science.gov (United States)

    Han, I.; Demir, L.

    2009-11-01

    Kβ -to- Kα x-ray intensity ratios of Fe, Cr, and Ni have been measured in pure metals and in alloys of FexNi1-x ( x=0.8 , 0.7, 0.6, 0.5, 0.4, 0.3, and 0.2), NixCr1-x ( x=0.8 , 0.6, 0.5, 0.4, and 0.2), FexCr1-x ( x=0.9 , 0.7, and 0.5), and FexCryNi1-(x+y) ( x=0.7-y=0.1 , x=0.5-y=0.2 , x=0.4-y=0.3 , x=0.3-y=0.3 , x=0.2-y=0.2 , and x=0.1-y=0.2 ) following excitation by 22.69 keV x rays from a 10 mCi C109d radioactive point source. The valence-electron configurations of these metals were determined by corporation of measured Kβ -to- Kα x-ray intensity ratios with the results of multiconfiguration Dirac-Fock calculation for various valence-electron configurations. Valence-electron configurations of 3d transition metals in alloys indicate significant differences with respect to the pure metals. Our analysis indicates that these differences arise from delocalization and/or charge transfer phenomena in alloys. Namely, the observed change of the valence-electron configurations of metals in alloys can be explained with the transfer of 3d electrons from one element to the other element and/or the rearrangement of electrons between 3d and 4s,4p states of individual metal atoms.

  1. The role of bismuth on the microstructure and corrosion behavior of ternary Mg–1.2Ca–xBi alloys for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Tok, H.Y.; Hamzah, E., E-mail: Esah@fkm.utm.my; Bakhsheshi-Rad, H.R.

    2015-08-15

    Highlights: • Secondary phases have a significant effect on corrosion properties of the alloys. • Microstructure of Mg–Ca–xBi was refined significantly after Bi addition. • Addition of 0.5 wt.% Bi to Mg–Ca alloy leads to increase corrosion resistance. • Microstructure analysis showed needle-shaped precipitates at the grain boundaries. - Abstract: In this study the influence of various Bi additions on the microstructure and corrosion behavior of the Mg–1.2Ca–xBi alloys (x = 0.5, 1.5, 3, 5, 12 wt.%) were evaluated by using optical and scanning electron microscopy, immersion and electrochemical tests. Microstructural observations showed that the refinement efficiency became more pronounced with increased Bi amount. Microstructural results of Mg–1.2Ca–xBi (x = 0.5, 1.5, and 3) indicated that the formation of three distinct phases—namely α-Mg, Mg{sub 2}Ca and Mg{sub 3}Bi{sub 2}. However, further addition of Bi to 5 and 12 wt.% leads to evolution of α-Mg, Mg{sub 3}Bi{sub 2}, and Mg{sub 2}Bi{sub 2}Ca phases. The addition of Bi up to 0.5 wt.% enhanced corrosion resistance while further addition from 1.5 to 12 wt.% accelerated the degradation rate because of the emergence of more galvanic coupling between the α-Mg phases and secondary phases. The analyses showed that the Mg–1.2Ca–0.5Bi alloy gives the best corrosion resistance behavior, which makes it ideal for biodegradable medical applications.

  2. Thermodynamic modeling of the Ti-Al-Cr ternary system

    International Nuclear Information System (INIS)

    Chen Leyi; Qiu Aitao; Liu Lanjie; Jiang Ming; Lu Xionggang; Li Chonghe

    2011-01-01

    Research highlights: → The full experimental results of the Ti-Al-Cr ternary system and its sub-binary systems are reviewed and analysed in detail. → Based on the latest thermodynamic assessments of the Ti-Al, Ti-Cr and Al-Cr systems and the ternary experimental data in literature, the thermodynamic parameters of the Ti-Al-Cr ternary system are fully assessed by the Calphad method. → The transformation of disorder to order (bcc a 2 to B2) and the new ternary compound L 12T i 25 Cr 8 Al 67 are considered in this work. - Abstract: The Ti-Al-Cr ternary system is one of the most important systems to studying the titanium alloys. Some experimental data of this ternary system are available and a few partial thermodynamic assessments are reported. However, no full thermodynamic descriptions were published. In this study, the previous work on the Ti-Al-Cr system and its related binary systems are reviewed. Based on the thermodynamic descriptions of the Ti-Al, Ti-Cr and Al-Cr systems and the ternary experimental data in literature, the Ti-Al-Cr ternary system is assessed by means of the Calphad method. Several isothermal sections from 1073 K to 1573 K and some invariant reactions are calculated, which are in good agreement with the most of the experimental results.

  3. Zr-Fe-Sn Ternary System Phase Diagrams- New Experimental Results

    International Nuclear Information System (INIS)

    Nieva, N; Gomez, A; Arias, D

    2004-01-01

    New experimental results for the Zr-Fe-Sn ternary system are presented in this paper. The phases present and equilibrium relations for the 900 o C isothermal on the central zone of the Gibbs triangle are analysed. A set of ternary alloys was designed and obtained, and they were analysed by semi quantitative SEM- EDS, XRD, and metallographic samples. The resulting ternary phase diagrams are presented here (JCH)

  4. Experimental investigation of phase equilibria in the Co-W-V ternary system

    International Nuclear Information System (INIS)

    Liu Xingjun; Zhu Yihong; Yu Yan; Wang Cuiping

    2011-01-01

    Highlights: → Three isothermal sections of the Co-W-V ternary system at 1100 deg. C, 1200 deg. C and 1300 deg. C were determined. → No ternary compound was found in the Co-W-V ternary system. → A stable liquid miscibility gap is newly discovered in the Co-W-V ternary system. → This work is of great essence to establish the thermodynamic database for the Co-based alloys. - Abstract: The phase equilibria in the Co-W-V ternary system were experimentally investigated by optical microscopy (OM), electron probe microanalysis (EPMA) and X-ray diffraction (XRD) on the equilibrated alloys. Three isothermal sections of the Co-W-V ternary system at 1100 deg. C, 1200 deg. C and 1300 deg. C were determined, and no ternary compound was found in this system. In addition, a novel phenomena induced by the liquid phase separation in the Co-W-V alloys was firstly discovered, suggesting that a stable liquid miscibility gap exists in the Co-W-V ternary system. The newly determined phase equilibria and firstly discovered phase separation phenomena in the Co-W-V system will provide important information for the development of Co-W based alloys.

  5. Ternary chalcopyrite semiconductors

    CERN Document Server

    Shay, J L; Pamplin, B R

    2013-01-01

    Ternary Chalcopyrite Semiconductors: Growth, Electronic Properties, and Applications covers the developments of work in the I-III-VI2 and II-IV-V2 ternary chalcopyrite compounds. This book is composed of eight chapters that focus on the crystal growth, characterization, and applications of these compounds to optical communications systems. After briefly dealing with the status of ternary chalcopyrite compounds, this book goes on describing the crystal growth of II-IV-V2 and I-III-VI2 single crystals. Chapters 3 and 4 examine the energy band structure of these semiconductor compounds, illustrat

  6. Ternary Pt9RhFex Nanoscale Alloys as Highly Efficient Catalysts with Enhanced Activity and Excellent CO-Poisoning Tolerance for Ethanol Oxidation.

    Science.gov (United States)

    Wang, Peng; Yin, Shibin; Wen, Ying; Tian, Zhiqun; Wang, Ningzhang; Key, Julian; Wang, Shuangbao; Shen, Pei Kang

    2017-03-22

    To address the problems of high cost and poor stability of anode catalysts in direct ethanol fuel cells (DEFCs), ternary nanoparticles Pt 9 RhFe x (x = 1, 3, 5, 7, and 9) supported on carbon powders (XC-72R) have been synthesized via a facile method involving reduction by sodium borohydride followed by thermal annealing in N 2 at ambient pressure. The catalysts are physically characterized by X-ray diffraction, scanning transmission electron microscopy, and X-ray photoelectron spectroscopy, and their catalytic performance for the ethanol oxidation reaction (EOR) is evaluated by cyclic and linear scan voltammetry, CO-stripping voltammograms, and chronopotentiometry. All the Pt 9 RhFe x /C catalysts of different atomic ratios produce high EOR catalytic activity. The catalyst of atomic ratio composition 9:1:3 (Pt/Rh/Fe) has the highest activity and excellent CO-poisoning tolerance. Moreover, the enhanced EOR catalytic activity on Pt 9 RhFe 3 /C when compared to Pt 9 Rh/C, Pt 3 Fe/C, and Pt/C clearly demonstrates the presence of Fe improves catalytic performance. Notably, the onset potential for CO oxidation on Pt 9 RhFe 3 /C (0.271 V) is ∼55, 75, and 191 mV more negative than on Pt 9 Rh/C (0.326 V), Pt 3 Fe/C (0.346 V), and Pt/C (0.462 V), respectively, which implies the presence of Fe atoms dramatically improves CO-poisoning tolerance. Meanwhile, compared to the commercial PtRu/C catalyst, the peak potential on Pt 9 RhFe 3 /C for CO oxidation was just slightly changed after several thousand cycles, which shows high stability against the potential cycling. The possible mechanism by which Fe and Rh atoms facilitate the observed enhanced performance is also considered herein, and we conclude Pt 9 RhFe 3 /C offers a promising anode catalyst for direct ethanol fuel cells.

  7. Nanoclusters a bridge across disciplines

    CERN Document Server

    Jena, Purusottam

    2010-01-01

    This comprehensive book on Nanoclusters comprises sixteen authoritative chapters written by leading researchers in the field. It provides insight into topics that are currently at the cutting edge of cluster science, with the main focus on metal and metal compound systems that are of particular interest in materials science, and also on aspects related to biology and medicine. While there are numerous books on clusters, the focus on clusters as a bridge across disciplines sets this book apart from others. Delivers cutting edge coverage of cluster science Covers a broad range of topics in

  8. Kinetic study of lithium-cadmium ternary amalgam decomposition

    International Nuclear Information System (INIS)

    Cordova, M.H.; Andrade, C.E.

    1992-01-01

    The effect of metals, which form stable lithium phase in binary alloys, on the formation of intermetallic species in ternary amalgams and their effect on thermal decomposition in contact with water is analyzed. Cd is selected as ternary metal, based on general experimental selection criteria. Cd (Hg) binary amalgams are prepared by direct contact Cd-Hg, whereas Li is formed by electrolysis of Li OH aq using a liquid Cd (Hg) cathodic well. The decomposition kinetic of Li C(Hg) in contact with 0.6 M Li OH is studied in function of ageing and temperature, and these results are compared with the binary amalgam Li (Hg) decomposition. The decomposition rate is constant during one hour for binary and ternary systems. Ageing does not affect the binary systems but increases the decomposition activation energy of ternary systems. A reaction mechanism that considers an intermetallic specie participating in the activated complex is proposed and a kinetic law is suggested. (author)

  9. 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.

  10. Carbon/ternary alloy/carbon optical stack on mylar as an optical data storage medium to potentially replace magnetic tape.

    Science.gov (United States)

    Wang, Hao; Lunt, Barry M; Gates, Richard J; Asplund, Matthew C; Shutthanandan, V; Davis, Robert C; Linford, Matthew R

    2013-09-11

    A novel write-once-read-many (WORM) optical stack on Mylar tape is proposed as a replacement for magnetic tape for archival data storage. This optical tape contains a cosputtered bismuth-tellurium-selenium (BTS) alloy as the write layer sandwiched between thin, protective films of reactively sputtered carbon. The composition and thickness of the BTS layer were confirmed by Rutherford Backscattering (RBS) and atomic force microscopy (AFM), respectively. The C/BTS/C stack on Mylar was written to/marked by 532 nm laser pulses. Under the same conditions, control Mylar films without the optical stack were unaffected. Marks, which showed craters/movement of the write material, were characterized by optical microscopy and AFM. The threshold laser powers for making marks on C/BTS/C stacks with different thicknesses were explored. Higher quality marks were made with a 60× objective compared to a 40× objective in our marking apparatus. The laser writing process was simulated with COMSOL.

  11. Surface monitoring for pitting evolution into uniform corrosion on Cu-Ni-Zn ternary alloy in alkaline chloride solution: ex-situ LCM and in-situ SECM

    Science.gov (United States)

    Kong, Decheng; Dong, Chaofang; Zheng, Zhaoran; Mao, Feixiong; Xu, Aoni; Ni, Xiaoqing; Man, Cheng; Yao, Jizheng; Xiao, Kui; Li, Xiaogang

    2018-05-01

    The evolution of the corrosion process on Cu-Ni-Zn alloy in alkaline chloride solution was investigated by in-situ scanning electrochemical microscopy, X-ray photoelectron spectroscopy, and ex-situ laser confocal microscopy, and the effects of ambient temperature and polarization time were also discussed. The results demonstrated a higher pitting nucleation rate and lower pit growth rate at low temperature. The ratio of pit depth to mouth diameter decreased with increasing pit volume and temperature, indicating that pits preferentially propagate in the horizontal direction rather than the vertical direction owing to the presence of corrosion products and deposited copper. The surface current was uniform and stabilized at approximately 2.2 nA during the passive stage, whereas the current increased after the pits were formed with the maximum approaching 3 nA. Increasing the temperature led to an increase in porous corrosion products (CuO, Zn(OH)2, and Ni(OH)2) and significantly increased the rate of transition from pitting to uniform corrosion. Dezincification corrosion was detected by energy dispersive spectrometry, and a mechanism for pitting transition into uniform corrosion induced by dezincification at the grain boundaries is proposed.

  12. First principles investigation of the electronic and structural properties of Mg{sub 3x}Be{sub 3-3x}N{sub 2} ternary alloy

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtari, A; Akbarzadeh, H [Department of Physics, Isfahan University of Technology, Isfahan 8415683111 (Iran, Islamic Republic of)

    2004-09-01

    The first ab initio calculations were carried out for the electronic and structural properties of the wide band gap semiconductor alloy Mg{sub 3x}Be{sub 3-3x}N{sub 2} employing the full potential linearized augmented plane wave (FP-LAPW) method within density functional theory (DFT). We used the Perdew et al generalized gradient approximation (GGA96), which is based on exchange-correlation energy optimization, to optimize the internal parameters by relaxing the atomic positions in the force directions and to calculate the total energy. For band structure calculations, we utilized both the Engel-Vosko's generalized gradient approximation (EVGGA), which optimizes the exchange-correlation potential, and also GGA96. We investigated the effect of composition on a variety of different structural and electronic parameters such as lattice constant, bond length, internal parameter, bulk modulus and band gap. We found out that the linear concentration dependence (LCD) is inadequate to explain the results, hence we fitted our data with a quadratic expression and were able to obtain the bowing parameter for each case. Our results for the band gap, lattice parameter, cohesive energy and bulk modulus indicate that each of them can be explained by a constant bowing parameter.

  13. Carbon/Ternary Alloy/Carbon Optical Stack on Mylar as an Optical Data Storage Medium to Potentially Replace Magnetic Tape

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hao; Lunt, Barry M.; Gates, Richard J.; Asplund, Matthew C.; Shutthanandan, V.; Davis, Robert C.; Linford, Matthew R.

    2013-09-11

    A novel write-once-read-many (WORM) optical stack on Mylar tape is proposed as a replacement for magnetic tape for archival data storage. This optical tape contains a cosputtered bismuth–tellurium–selenium (BTS) alloy as the write layer sandwiched between thin, protective films of reactively sputtered carbon. The composition and thickness of the BTS layer were confirmed by Rutherford Backscattering (RBS) and atomic force microscopy (AFM), respectively. The C/BTS/C stack on Mylar was written to/marked by 532 nm laser pulses. Under the same conditions, control Mylar films without the optical stack were unaffected. Marks, which showed craters/movement of the write material, were characterized by optical microscopy and AFM. The threshold laser powers for making marks on C/BTS/C stacks with different thicknesses were explored. Higher quality marks were made with a 60× objective compared to a 40× objective in our marking apparatus. Finally, the laser writing process was simulated with COMSOL.

  14. Formation of nanoclusters of gadolinium atoms in silicon

    International Nuclear Information System (INIS)

    Iliev, Kh.M.; Saparniyazova, Z.M.; Ismajlov, K.A.; Madzhitov, M.Kh.

    2011-01-01

    A technology of stage wise low temperature diffusion of gadolinium into silicon that makes it possible to form nanoclusters of impurity atoms with a significant magnetic moment distributed throughout the volume of the material has been developed. It is shown that, unlike the samples obtained by high temperature diffusion doping, the samples prepared by the new technology do not have surface erosion, and alloys and silicides are not formed in the near surface region. Nanoclusters of impurity atoms of gadolinium in the volume of the crystal lattice of the silicon are studied using an MIK-5 infrared microscope. It is found that, in the stage wise low temperature diffusion, the temperature and time of the diffusion have an effect not only on the depth of penetration of the impurities but also on the sizes of the resulting clusters; these factors can also prevent the formation of clusters. The study of the effect of low temperature treatments on the size and distribution of clusters shows that, upon annealing in the temperature range of 500-700 degrees Celsius, the ordering of the clusters of gadolinium impurity atoms is observed. A further increase in the annealing temperature leads to the destruction of gadolinium clusters in the silicon bulk. (authors)

  15. The ternary system nickel-nobium-carbon

    International Nuclear Information System (INIS)

    Stadelmaier, H.H.; Fiedler, M.L.

    1975-01-01

    The ternary system nickel-niobium-carbon was studied by metallographic and X-ray diffraction methods to produce a liquidus projection and an isothermal section at 1,100 0 C. The liquidus projection is dominated by a wide field of primary NbC that extends far into the nickel corner of the composition triangle. Only one ternary compound is observed in this system, an eta-carbide formed in a peritectoid reaction. It has a narrow homogeneity range at Ni 2 Nb 4 C, and its lattice constant in alloys quenched from 1,100 0 C varies between 11.659 and 11.667 A. No eta-carbide Ni 3 Nb 3 C or Ni 6 Nb 6 could be detected. (orig.) [de

  16. Ferritic oxide dispersion strengthened alloys by spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Allahar, Kerry N., E-mail: KerryAllahar@boisestate.edu [Materials and Science Engineering Department, Boise State University, 1910 University Blvd., Boise, ID 83725 (United States); Center for Advanced Energy Studies, 995 University Blvd., Idaho Falls, ID 83401 (United States); Burns, Jatuporn [Materials and Science Engineering Department, Boise State University, 1910 University Blvd., Boise, ID 83725 (United States); Center for Advanced Energy Studies, 995 University Blvd., Idaho Falls, ID 83401 (United States); Jaques, Brian [Materials and Science Engineering Department, Boise State University, 1910 University Blvd., Boise, ID 83725 (United States); Wu, Y.Q. [Materials and Science Engineering Department, Boise State University, 1910 University Blvd., Boise, ID 83725 (United States); Center for Advanced Energy Studies, 995 University Blvd., Idaho Falls, ID 83401 (United States); Charit, Indrajit [Department of Chemical and Materials Engineering, University of Idaho, McClure Hall Room 405D, Moscow, ID 83844 (United States); Cole, James [Idaho National Laboratory, Idaho Falls, ID 83401 (United States); Butt, Darryl P. [Materials and Science Engineering Department, Boise State University, 1910 University Blvd., Boise, ID 83725 (United States); Center for Advanced Energy Studies, 995 University Blvd., Idaho Falls, ID 83401 (United States)

    2013-11-15

    Spark plasma sintering (SPS) was used to consolidate a Fe–16Cr–3Al (wt.%) powder that was mechanically alloyed with Y{sub 2}O{sub 3} and Ti powders to produce 0.5 Y{sub 2}O{sub 3} and 0.5 Y{sub 2}O{sub 3}–1Ti powders. The effects of mechanical alloying and sintering conditions on the microstructure, relative density and hardness of the sintered oxide dispersion strengthened (ODS) alloys are presented. Scanning electron microscopy indicated a mixed fine-grain and coarse-grain microstructure that was attributed to recrystallization and grain growth during sintering. Analysis of the transmission electron microscopy (TEM) and atom probe tomography (APT) data identified Y–O and Y–O–Ti nanoclusters. Elemental ratios of these nanoclusters were consistent with that observed in hot-extruded ODS alloys. The influence of Ti was to refine the grains as well as the nanoclusters with there being greater number density and smaller sizes of the Y–O–Ti nanoclusters as compared to the Y–O nanoclusters. This resulted in the Ti-containing samples being harder than the Ti-free alloys. The hardness of the alloys with the Y–O–Ti nanoclusters was insensitive to sintering time while smaller hardness values were associated with longer sintering times for the alloys with the Y–O nanoclusters. Pressures greater than 80 MPa are recommended for improved densification as higher sintering temperatures and longer sintering times at 80 MPa did not improve the relative density beyond 97.5%.

  17. Positron confinement in embedded lithium nanoclusters

    Science.gov (United States)

    van Huis, M. A.; van Veen, A.; Schut, H.; Falub, C. V.; Eijt, S. W.; Mijnarends, P. E.; Kuriplach, J.

    2002-02-01

    Quantum confinement of positrons in nanoclusters offers the opportunity to obtain detailed information on the electronic structure of nanoclusters by application of positron annihilation spectroscopy techniques. In this work, positron confinement is investigated in lithium nanoclusters embedded in monocrystalline MgO. These nanoclusters were created by means of ion implantation and subsequent annealing. It was found from the results of Doppler broadening positron beam analysis that approximately 92% of the implanted positrons annihilate in lithium nanoclusters rather than in the embedding MgO, while the local fraction of lithium at the implantation depth is only 1.3 at. %. The results of two-dimensional angular correlation of annihilation radiation confirm the presence of crystalline bulk lithium. The confinement of positrons is ascribed to the difference in positron affinity between lithium and MgO. The nanocluster acts as a potential well for positrons, where the depth of the potential well is equal to the difference in the positron affinities of lithium and MgO. These affinities were calculated using the linear muffin-tin orbital atomic sphere approximation method. This yields a positronic potential step at the MgO||Li interface of 1.8 eV using the generalized gradient approximation and 2.8 eV using the insulator model.

  18. Atomically Precise Metal Nanoclusters for Catalytic Application

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Rongchao [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2016-11-18

    The central goal of this project is to explore the catalytic application of atomically precise gold nanoclusters. By solving the total structures of ligand-protected nanoclusters, we aim to correlate the catalytic properties of metal nanoclusters with their atomic/electronic structures. Such correlation unravel some fundamental aspects of nanocatalysis, such as the nature of particle size effect, origin of catalytic selectivity, particle-support interactions, the identification of catalytically active centers, etc. The well-defined nanocluster catalysts mediate the knowledge gap between single crystal model catalysts and real-world conventional nanocatalysts. These nanoclusters also hold great promise in catalyzing certain types of reactions with extraordinarily high selectivity. These aims are in line with the overall goals of the catalytic science and technology of DOE and advance the BES mission “to support fundamental research to understand, predict, and ultimately control matter and energy at the level of electrons, atoms, and molecules”. Our group has successfully prepared different sized, robust gold nanoclusters protected by thiolates, such as Au25(SR)18, Au28(SR)20, Au38(SR)24, Au99(SR)42, Au144(SR)60, etc. Some of these nanoclusters have been crystallographically characterized through X-ray crystallography. These ultrasmall nanoclusters (< 2 nm diameter) exhibit discrete electronic structures due to quantum size effect, as opposed to quasicontinuous band structure of conventional metal nanoparticles or bulk metals. The available atomic structures (metal core plus surface ligands) of nanoclusters serve as the basis for structure-property correlations. We have investigated the unique catalytic properties of nanoclusters (i.e. not observed in conventional nanogold catalysts) and revealed the structure-selectivity relationships. Highlights of our

  19. Phase formation in multicomponent monotectic aluminium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Mirkovic, Djordje; Groebner, Joachim; Schmid-Fetzer, Rainer [Institute of Metallurgy, Clausthal University of Technology (Germany)

    2008-07-01

    Alloys with a miscibility gap in the liquid state are potential materials for advanced bearings in automotive and other applications. While binary alloys, such as Al-Pb or Al-Bi, are well known, the information available for ternary monotectic Al-alloys is scarce. However, the phase formation in multicomponent alloys is not only more challenging from a scientific aspect, it is also a prerequisite for a focused development of advanced alloys. This motivated our detailed study of monotectic Al-Bi-Cu-Sn alloys including both experimental and computational thermodynamic methods. Based on the initially established systematic classification of monotectic ternary Al-alloys, the first promising monotectic reaction was observed in the ternary Al-Bi-Zn system. Further ternary systems Al-Cu-Sn, Al-Bi-Sn, Al-Bi-Cu and Bi-Cu-Sn were investigated as basis for quaternary Al-Bi-Cu-Sn alloys. Experimental investigations of phase equilibria, enthalpies and solidification microstructures were combined with thermodynamic modeling. The results demonstrate that the developed precise thermodynamic description is vital to reveal the distinct multicomponent monotectic features of pertinent phase diagrams. The solidification paths of ternary monotectic alloy systems, Al-Bi-Zn, Al-Sn-Cu and Al-Bi-Cu, were also studied using thermodynamic calculations, revealing specific details of phase formation during solidification of selected alloys.

  20. Ternary alloy nanocatalysts for hydrogen evolution reaction

    Indian Academy of Sciences (India)

    Generation of hydrogen through water splitting is an impor- tant area of research. ... Splitting of water using electricity makes this reaction feasible, but requires a catalyst to overcome .... The obtained product was dried in air and heated at 700.

  1. Constitutional studies of the molybdenum-ruthenium-palladium ternary system

    International Nuclear Information System (INIS)

    Cornish, L.A.; Pratt, J.N.

    1997-01-01

    An experimental and computational study has been made of phase equilibria in the Mo-Ru-Pd ternary system. The constitution of annealed binary and ternary alloys was investigated using optical and electron microscopy, X-ray diffraction and SEM phase analysis techniques. Limited thermodynamic measurements were made using the ZrO 2 solid electrolyte e.m.f. method. The data obtained from the various techniques were used to construct a ternary isothermal section at 1473 K. The experimentally determined section is compared with a calculated section for the same temperature, computed using thermodynamic coefficients derived solely from binary system information. Lattice parameters are reported for the b.c.c., f.c.c. and c.p.h. solid solutions and for the σ phase. (orig.)

  2. New ternary hydride formation in U-Ti-H system

    International Nuclear Information System (INIS)

    Yamamoto, Takuya; Kayano, Hideo; Yamawaki, Michio.

    1991-01-01

    Hydrogen absorption properties of two titanium-rich uranium alloys, UTi 2 and UTi 4 , were studied in order to prepare and identify the recently found ternary hydride. They slowly reacted with hydrogen of the initial pressure of 10 5 Pa at 873K to form the ternary hydride. The hydrogenated specimen mainly consisted of the pursued ternary hydride but contained also U(or UO 2 ), TiH x , and some transient phases. X-ray powder diffraction and Electron Probe Micro Analysis proved that it was the UTi 2 H x with the expected MgCu 2 structure, though all the X-ray peaks were broad probably because of inhomogeneity. This compound had extremely high resistance to powdering on its formation, which showed high potential utilities for a non-powdering tritium storage system or for other purposes. (author)

  3. Plasmon tsunamis on metallic nanoclusters.

    Science.gov (United States)

    Lucas, A A; Sunjic, M

    2012-03-14

    A model is constructed to describe inelastic scattering events accompanying electron capture by a highly charged ion flying by a metallic nanosphere. The electronic energy liberated by an electron leaving the Fermi level of the metal and dropping into a deep Rydberg state of the ion is used to increase the ion kinetic energy and, simultaneously, to excite multiple surface plasmons around the positively charged hole left behind on the metal sphere. This tsunami-like phenomenon manifests itself as periodic oscillations in the kinetic energy gain spectrum of the ion. The theory developed here extends our previous treatment (Lucas et al 2011 New J. Phys. 13 013034) of the Ar(q+)/C(60) charge exchange system. We provide an analysis of how the individual multipolar surface plasmons of the metallic sphere contribute to the formation of the oscillatory gain spectrum. Gain spectra showing characteristic, tsunami-like oscillations are simulated for Ar(15+) ions capturing one electron in distant collisions with Al and Na nanoclusters.

  4. Surface mediated assembly of small, metastable gold nanoclusters

    Science.gov (United States)

    Pettibone, John M.; Osborn, William A.; Rykaczewski, Konrad; Talin, A. Alec; Bonevich, John E.; Hudgens, Jeffrey W.; Allendorf, Mark D.

    2013-06-01

    The unique properties of metallic nanoclusters are attractive for numerous commercial and industrial applications but are generally less stable than nanocrystals. Thus, developing methodologies for stabilizing nanoclusters and retaining their enhanced functionality is of great interest. We report the assembly of PPh3-protected Au9 clusters from a heterogeneous mixture into films consisting of sub 3 nm nanocluster assemblies. The depositing nanoclusters are metastable in solution, but the resulting nanocluster assemblies are stabilized indefinitely in air or fresh solvent. The films exhibit distinct structure from Au nanoparticles observed by X-ray diffraction, and film dissolution data support the preservation of small nanoclusters. UV-Vis spectroscopy, electrospray ionization mass spectrometry, X-ray photoelectron spectroscopy and electron microscopy are used to elucidate information regarding the nanocluster formation and assembly mechanism. Preferential deposition of nanocluster assemblies can be achieved on multiple substrates, including polymer, Cr, Si, SiO2, SiNx, and metal-organic frameworks (MOFs). Unlike other vapor phase coating processes, nanocluster assembly on the MIL-68(In) MOF crystal is capable of preferentially coating the external surface and stabilizing the crystal structure in hydrothermal conditions, which should enhance their storage, separation and delivery capabilities.The unique properties of metallic nanoclusters are attractive for numerous commercial and industrial applications but are generally less stable than nanocrystals. Thus, developing methodologies for stabilizing nanoclusters and retaining their enhanced functionality is of great interest. We report the assembly of PPh3-protected Au9 clusters from a heterogeneous mixture into films consisting of sub 3 nm nanocluster assemblies. The depositing nanoclusters are metastable in solution, but the resulting nanocluster assemblies are stabilized indefinitely in air or fresh solvent. The

  5. Short range order in FeCo-X alloys

    International Nuclear Information System (INIS)

    Fultz, B.

    1988-01-01

    Moessbauer spectrometry was used to study the kinetics of chemical ordering in FeCo and in FeCo alloyed with ternary solutes. With respect to the binary FeCo alloy, the kinetics of B2 ordering were slowed when 2% of 4d- or 5d-series ternary solute atoms were present, but 3p- and 3d-series ternary solutes had little effect on ordering kinetics. The relaxation of order around the ternary solute atoms could be discerned in Moessbauer spectra, and it seems that the development of B2 short range order is influenced by structural relaxations around the ternary solute atoms. Different thermal treatments were shown to cause different relaxations of and correlations, suggesting that Moessbauer spectrometry can be used to identify different kinetic paths of ordering in ternary alloys. (orig.)

  6. Calculation of Fe–B–V ternary phase diagram

    International Nuclear Information System (INIS)

    Homolová, Viera; Kroupa, Aleš; Výrostková, Anna

    2012-01-01

    Highlights: ► Phase diagram of Fe–B–V system was modelled by CALPHAD method. ► Database for thermodynamic calculations for Fe–B–V system was created. ► The new ternary phase was found in 67Fe–18B–15V [in at.%] alloy. - Abstract: The phase equilibria of the Fe–B–V ternary system are studied experimentally and theoretically in this paper. Phase diagram of the system was modelled by CALPHAD method. Boron was modelled as an interstitial element in the FCC and BCC solid solutions. The calculations of isothermal sections of phase diagram are compared with our experimental results at 903 and 1353 K and with available literature experimental data. New ternary phase (with chemical composition 28Fe32V40B in at.%) was found in 67Fe–18B–15V alloy [in at.%]. Further experimental studies for the determination of exact nature of the ternary phase including crystallographic information are necessary.

  7. Magnetic interaction reversal in watermelon nanostructured Cr-doped Fe nanoclusters

    International Nuclear Information System (INIS)

    Kaur, Maninder; Qiang, You; Dai, Qilin; Tang, Jinke; Bowden, Mark; Engelhard, Mark; Wu, Yaqiao

    2013-01-01

    Cr-doped core-shell Fe/Fe-oxide nanoclusters (NCs) were synthesized at varied atomic percentages of Cr from 0 at. % to 8 at. %. The low concentrations of Cr ( 2 O 3 and the Fe core to FeCr alloy. The magnetic interaction in Fe/Fe-oxide NCs (∼25 nm) can be controlled by antiferromagnetic Cr-dopant. We report the origin of σ-FeCr phase at very low Cr concentration (2 at. %) unlike in previous studies, and the interaction reversal from dipolar to exchange interaction in watermelon-like Cr-doped core-shell NCs

  8. Radiation Stability of Nanoclusters in Nano-structured Oxide Dispersion Strengthened (ODS) Steels

    International Nuclear Information System (INIS)

    Certain, Alicia G.; Kuchibhatla, Satyanarayana; Shutthanandan, V.; Allen, T. R.

    2013-01-01

    Nanostructured oxide dispersion strengthened (ODS) steels are considered candidates for nuclear fission and fusion applications at high temperature and dose. The complex oxide nanoclusters in these alloys provide high-temperature strength and are expected to afford better radiation resistance. Proton, heavy ion, and neutron irradiations have been performed to evaluate cluster stability in 14YWT and 9CrODS steel under a range of irradiation conditions. Energy-filtered transmission electron microscopy and atom probe tomography were used in this work to analyze the evolution of the oxide population.

  9. Theoretical Studies of Nanoclusters (Briefing Charts)

    Science.gov (United States)

    2015-07-23

    nanoclusters. However, scanning transmission electron microscopy ( STEM ) measures show cluster inversion occurred to produce MgyCux(!) a) copper atoms b...methane (née CLL -1) as a potential explosive ingredient: a theoretical study”, Propellants, Explosives, Pyrotechnics 38, 9-13 (2013). Jesus Paulo L

  10. Peptide-stabilized, fluorescent silver nanoclusters

    DEFF Research Database (Denmark)

    Gregersen, Simon; Vosch, Tom André Jos; Jensen, Knud Jørgen

    2016-01-01

    Few-atom silver nanoclusters (AgNCs) can exhibit strong fluorescence; however, they require ligands to prevent aggregation into larger nanoparticles. Fluorescent AgNCs in biopolymer scaffolds have so far mainly been synthesized in solution, and peptides have only found limited use compared to DNA...

  11. Phase Equilibria of Sn-Co-Cu Ternary System

    Science.gov (United States)

    Chen, Yu-Kai; Hsu, Chia-Ming; Chen, Sinn-Wen; Chen, Chih-Ming; Huang, Yu-Chih

    2012-10-01

    Sn-Co-Cu ternary alloys are promising lead-free solders, and isothermal sections of Sn-Co-Cu phase equilibria are fundamentally important for the alloys' development and applications. Sn-Co-Cu ternary alloys were prepared and equilibrated at 523 K, 1073 K, and 1273 K (250 °C, 800 °C, and 1000 °C), and the equilibrium phases were experimentally determined. In addition to the terminal solid solutions and binary intermetallic compounds, a new ternary compound, Sn3Co2Cu8, was found. The solubilities of Cu in the α-CoSn3 and CoSn2 phases at 523 K (250 °C) are 4.2 and 1.6 at. pct, respectively, while the Cu solubility in the α-Co3Sn2 phase is as high as 20.0 at. pct. The Cu solubility increases with temperature and is around 30.0 at. pct in the β-Co3Sn2 at 1073 K (800 °C). The Co solubility in the η-Cu6Sn5 phase is also significant and is 15.5 at. pct at 523 K (250 °C).

  12. Fluorescent Pressure Response of Protein-Nanocluster Polymer Composites

    Science.gov (United States)

    2016-05-01

    composites as pressure sensitive indicators of brain damage. The PNC composites are made up of protein coated gold nanoclusters and a styrene-ethylene...enhancement of the BSA- protected gold nanoclusters and the corresponding conformational changes of protein, J Phys Chem C. 2013;117:639–647...public release; distribution is unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT This research focuses on the uses of polymer gold nanocluster (PNC

  13. Experimental measurements of U60 nanocluster stability in aqueous solution

    Science.gov (United States)

    Flynn, Shannon L.; Szymanowski, Jennifer E. S.; Gao, Yunyi; Liu, Tianbo; Burns, Peter C.; Fein, Jeremy B.

    2015-05-01

    In this study, the aqueous behavior of isolated U60 nanoclusters (K16Li25[UO2(O2)OH]60)-19 was studied under several pH conditions and nanocluster concentrations to determine if the nanoclusters exhibit solid phase buffering behavior or if they exhibit behavior more like aqueous complexes. U60 is a cage cluster consisting of 60 (UO2)(O2)2(OH)2 uranyl polyhedral which share OH and O2 groups with their neighboring uranyl polyhedral, resulting in negatively charged cage clusters whose charge is at least partially offset by K+ and Li+ in the aqueous phase. Batch experiments to monitor nanocluster stability were conducted for 16 days at pH 7.5, 8.0 and 8.5 at nanocluster suspension concentrations of 1.4, 2.8 and 6.0 g/L. The aqueous concentrations of U, Li, and K, determined after 10 kDa molecular weight filtration, achieved steady-state with the nanoclusters within 24 h. The steady-state aqueous U, Li, and K concentrations were independent of solution pH, however they increased with increasing nanocluster concentration, indicating that the nanoclusters do not buffer the aqueous activities as a bulk solid phase would, but exhibit behavior that is more characteristic of dissolved aqueous complexes. The ion activity product (I.A.P.) value was calculated using two approaches: (1) treating the nanoclusters as a solid phase with an activity of one, and (2) treating the nanoclusters as aqueous complexes with a non-unit activity equal to their concentration in solution. The I.A.P. values that were calculated with non-unit activity for the nanoclusters exhibited significantly less variation as a function of nanocluster concentration compared to the I.A.P. values calculated with a nanocluster activity of one. The results yield a calculated log dissociation constant for the U60 nanoclusters of 9.2 + 0.2/-0.3 (1σ). Our findings provide a better understanding of the thermodynamic stability and behavior of U60 nanoclusters in aqueous systems, and can be used to estimate the

  14. Disorder effect on heat capacity, self-diffusion coefficient, and choosing best potential model for melting temperature, in gold–copper bimetallic nanocluster with 55 atoms

    International Nuclear Information System (INIS)

    Taherkhani, Farid; Akbarzadeh, Hamed; Feyzi, Mostafa; Rafiee, Hamid Reza

    2015-01-01

    Molecular dynamics simulation has been implemented for doping effect on melting temperature, heat capacity, self-diffusion coefficient of gold–copper bimetallic nanostructure with 55 total gold and copper atom numbers and its bulk alloy. Trend of melting temperature for gold–copper bimetallic nanocluster is not same as melting temperature copper–gold bulk alloy. Molecular dynamics simulation of our result regarding bulk melting temperature is consistence with available experimental data. Molecular dynamics simulation shows that melting temperature of gold–copper bimetallic nanocluster increases with copper atom fraction. Semi-empirical potential model and quantum Sutton–Chen potential models do not change melting temperature trend with copper doping of gold–copper bimetallic nanocluster. Self-diffusion coefficient of copper atom is greater than gold atom in gold–copper bimetallic nanocluster. Semi-empirical potential within the tight-binding second moment approximation as new application potential model for melting temperature of gold–copper bulk structure shows better result in comparison with EAM, Sutton–Chen potential, and quantum Sutton–Chen potential models

  15. Disorder effect on heat capacity, self-diffusion coefficient, and choosing best potential model for melting temperature, in gold–copper bimetallic nanocluster with 55 atoms

    Energy Technology Data Exchange (ETDEWEB)

    Taherkhani, Farid, E-mail: faridtaherkhani@gmail.com, E-mail: f.taherkhani@razi.ac.ir [Razi University, Department of Physical Chemistry (Iran, Islamic Republic of); Akbarzadeh, Hamed [Hakim Sabzevari University, Department of Chemistry (Iran, Islamic Republic of); Feyzi, Mostafa; Rafiee, Hamid Reza [Razi University, Department of Physical Chemistry (Iran, Islamic Republic of)

    2015-01-15

    Molecular dynamics simulation has been implemented for doping effect on melting temperature, heat capacity, self-diffusion coefficient of gold–copper bimetallic nanostructure with 55 total gold and copper atom numbers and its bulk alloy. Trend of melting temperature for gold–copper bimetallic nanocluster is not same as melting temperature copper–gold bulk alloy. Molecular dynamics simulation of our result regarding bulk melting temperature is consistence with available experimental data. Molecular dynamics simulation shows that melting temperature of gold–copper bimetallic nanocluster increases with copper atom fraction. Semi-empirical potential model and quantum Sutton–Chen potential models do not change melting temperature trend with copper doping of gold–copper bimetallic nanocluster. Self-diffusion coefficient of copper atom is greater than gold atom in gold–copper bimetallic nanocluster. Semi-empirical potential within the tight-binding second moment approximation as new application potential model for melting temperature of gold–copper bulk structure shows better result in comparison with EAM, Sutton–Chen potential, and quantum Sutton–Chen potential models.

  16. Using Ternary Alloy Additions to Engineer Nitinol Shape Memory Alloys

    Data.gov (United States)

    National Aeronautics and Space Administration — Improving travel capabilities is essential in order to further investigative space exploration. For aerospace applications, weight savings is essential. Shape memory...

  17. New ternary superconducting germanides

    Science.gov (United States)

    Moschalkov, V. V.; Muttik, I. G.; Samarin, N. A.; Seropegin, Yu. D.; Rudometkina, M. V.

    1991-12-01

    We have studied the structure, electrical and magnetic properties of new ternary compounds with germanium and transition metals of IV and V groups (Ti 0.7V 0.3Ge 3, Hf 2V 3Ge, Zr 32-36V 32-36Ge 30-32, Hf 2Nb 3Ge 4, HfVGe, Zr 15-17V 39-40Ge 44-45, Hf 10.8-21.7V 36.0-42.8). The homogeneity fields for all new phases are determined. Resistivity (T) and magnetic susceptibility χ(T) are investigated at T=4.2…300 K. Two new superconductors have been found - Zr 32-36V 32-36Ge 30-32 and HfVGe with T c=4.7 K and 5.7 K, respectively.

  18. Electroactive mesoporous yttria stabilized zirconia containing platinum or nickel oxide nanoclusters: a new class of solid oxide fuel cell electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Mamak, M.; Coombs, N.; Ozin, G.A. [Toronto Univ., ON (Canada). Dept. of Chemistry

    2001-02-01

    The electroactivity of surfactant-templated mesoporous yttria stabilized zirconia, containing nanoclusters of platinum or nickel oxide, is explored by alternating current (AC) complex impedance spectroscopy. The observed oxygen ion and mixed oxygen ion-electron charge-transport behavior for these materials, compared to the sintered-densified non-porous crystalline versions, is ascribed to the unique integration of mesoporosity and nanocrystallinity within the binary and ternary solid solution microstructure. These attributes inspire interest in this new class of materials as candidates for the development of improved performance solid oxide fuel cell electrodes. (orig.)

  19. Platinum-gold nanoclusters as catalyst for direct methanol fuel cells.

    Science.gov (United States)

    Giorgi, L; Giorgi, R; Gagliardi, S; Serra, E; Alvisi, M; Signore, M A; Piscopiello, E

    2011-10-01

    Nanosized platinum-gold alloys clusters have been deposited on gas diffusion electrode by sputter deposition. The deposits were characterized by FE-SEM, TEM and XPS in order to verify the formation of alloy nanoparticles and to study the influence of deposition technique on the nanomorphology. The deposition by sputtering process allowed a uniform distribution of metal particles on porous surface of carbon supports. Typical island growth mode was observed with the formation of a dispersed metal nanoclusters (mean size about 5 nm). Cyclic voltammetry was used to determine the electrochemical active surface and the electrocatalytic performance of the PtAu electrocatalysts for methanol oxidation reaction. The data were re-calculated in the form of mass specific activity (MSA). The sputter-catalyzed electrodes showed higher performance and stability compared to commercial catalysts.

  20. Interfacial electron transfer dynamics of photosensitized zinc oxide nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Murakoshi, Kei; Yanagida, Shozo [Osaka Univ. (Japan). Graduate School of Engineering; Capel, M. [Brookhaven National Lab., Upton, NY (United States)] [and others

    1997-06-01

    The authors have prepared and characterized photosensitized zinc oxide (ZnO) nanoclusters, dispersed in methanol, using carboxylated coumarin dyes for surface adsorption. Femtosecond time-resolved emission spectroscopy allows the authors to measure the photo-induced charge carrier injection rate constant from the adsorbed photosensitizer to the n-type semiconductor nanocluster. These results are compared with other photosensitized semiconductors.

  1. Synthesis and characterization of mixed ligand chiral nanoclusters

    KAUST Repository

    Guven, Zekiye P.

    2016-06-22

    Chiral mixed ligand silver nanoclusters were synthesized in the presence of a chiral and an achiral ligand. While the chiral ligand led mostly to the formation of nanoparticles, the presence of the achiral ligand drastically increased the yield of nanoclusters with enhanced chiral properties. © 2016 The Royal Society of Chemistry.

  2. Synthesis and characterization of mixed ligand chiral nanoclusters

    KAUST Repository

    Guven, Zekiye P.; Ustbas, Burcin; Harkness, Kellen M.; Coskun, Hikmet; Joshi, Chakra Prasad; Besong, Tabot M.D.; Stellacci, Francesco; Bakr, Osman; Akbulut, Ozge

    2016-01-01

    Chiral mixed ligand silver nanoclusters were synthesized in the presence of a chiral and an achiral ligand. While the chiral ligand led mostly to the formation of nanoparticles, the presence of the achiral ligand drastically increased the yield of nanoclusters with enhanced chiral properties. © 2016 The Royal Society of Chemistry.

  3. Molecular interactions in particular Van der Waals nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Jungclas, Hartmut; Schmidt, Lothar [Marburg Univ. (Germany). Chemistry Dept.; Komarov, Viacheslav V.; Popova, Anna M. [Marburg Univ. (Germany). Chemistry Dept.; Lomonosov Moscow State Univ. (Russian Federation). Skobeltzin Inst. of Nuclear Physics

    2017-04-01

    A method is presented to analyse the interaction energies in a nanocluster, which is consisting of three neutral molecules bound by non-covalent long range Van der Waals forces. One of the molecules (M{sub 0}) in the nanocluster has a permanent dipole moment, whereas the two other molecules (M{sub 1} and M{sub 2}) are non-polar. Analytical expressions are obtained for the numerical calculation of the dispersion and induction energies of the molecules in the considered nanocluster. The repulsive forces at short intermolecular distances are taken into account by introduction of damping functions. Dispersion and induction energies are calculated for a nanocluster with a definite geometry, in which the polar molecule M{sub 0} is a linear hydrocarbon molecule C{sub 5}H{sub 10} and M{sub 1} and M{sub 2} are pyrene molecules. The calculations are done for fixed distances between the two pyrene molecules. The results show that the induction energies in the considered three-molecular nanocluster are comparable with the dispersion energies. Furthermore, the sum of induction energies in the substructure (M{sub 0}, M{sub 1}) of the considered nanocluster is much higher than the sum of induction energies in a two-molecular nanocluster with similar molecules (M{sub 0}, M{sub 1}) because of the absence of an electrostatic field in the latter case. This effect can be explained by the essential intermolecular induction in the three-molecular nanocluster.

  4. Experimental investigation of phase equilibria in the Zr-Cu-Ni ternary system

    International Nuclear Information System (INIS)

    Yang, Mujin; Wang, Cuiping; Yang, Shuiyuan; Shi, Zhan; Han, Jiajia; Liu, Xingjun

    2017-01-01

    The phase equilibria in the Zr-Cu-Ni ternary system are investigated combined with X-ray diffraction, electron probe micro-analysis and differential scanning calorimetry. Two isothermal sections of the Zr-Cu-Ni ternary system at 1 000 C and 1 100 C are experimentally established. Most of the binary intermetallic compounds, e.g. Zr 7 Ni 10 , ZrNi, ZrNi 5 , Zr 14 Cu 51 , and Zr 2 Cu 9 , show a remarkable ternary solubility. A new ternary compound named τ 3 (Zr 31.1-30.7 . Cu 28.5-40.3 Ni 40.4-29.0 ) is detected at 1 000 C and dissolved at 1 020 C because the nearby large liquid phase field further expands. The newly determined phase equilibria will provide important information for both thermodynamic assessment and alloy design of Zr-based metallic glass.

  5. Iron binary and ternary coatings with molybdenum and tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Yar-Mukhamedova, Gulmira, E-mail: gulmira-alma-ata@mail.ru [Institute Experimental and Theoretical Physics Al-Farabi Kazakh National University, 050038, Al-Farabi av., 71, Almaty (Kazakhstan); Ved, Maryna; Sakhnenko, Nikolay; Karakurkchi, Anna; Yermolenko, Iryna [National Technical University “Kharkov Polytechnic Institute”, Kharkov (Ukraine)

    2016-10-15

    Highlights: • High quality coatings of double Fe-Mo and ternary Fe-Mo-W electrolytic alloys can be produced both in a dc and a pulsed mode. • Application of unipolar pulsed current allows receiving an increased content of the alloying components and their more uniform distribution over the surface. • It is established that Fe-Mo and Fe-Mo-W coatings have an amorphous structure and exhibit improved corrosion resistance and microhardness as compared with the steel substrate due to the inclusion molybdenum and tungsten. - Abstract: Electrodeposition of Fe-Mo-W and Fe-Mo layers from a citrate solution containing iron(III) on steel and iron substrates is compared. The utilization of iron(III) compounds significantly improved the electrolyte stability eliminating side anodic redox reactions. The influence of concentration ratios and electrodeposition mode on quality, chemical composition, and functional properties of the alloys is determined. It has been found that alloys deposited in pulse mode have more uniform surface morphology and chemical composition and contain less impurities. Improvement in physical and mechanical properties as well as corrosion resistance of Fe-Mo and Fe-Mo-W deposits when compared with main alloy forming metals is driven by alloying components chemical passivity as well as by alloys amorphous structure. Indicated deposits can be considered promising materials in surface hardening technologies and repair of worn out items.

  6. Experimental investigation of the Ag–Bi–I ternary system and thermodynamic properties of the ternary phases

    International Nuclear Information System (INIS)

    Mashadieva, Leyla F.; Aliev, Ziya S.; Shevelkov, Andrei V.; Babanly, Mahammad B.

    2013-01-01

    Highlights: ► The self-consistent phase diagram of the Ag–Bi–I system is constructed. ► Ag 2 BiI 5 and AgBi 2 I 7 are the only ternary phases of the system. ► Standard thermodynamic functions of formation and the standard entropies of Ag 2 BiI 5 and AgBi 2 I 7 are calculated. - Abstract: The phase equilibriums in the Ag–Bi–I ternary system and thermodynamic properties of the ternary phases were experimentally determined by using DTA and XRD techniques and EMF measurements with the Ag 4 RbI 5 solid electrolyte. According to the obtained experimental results, the polythermal sections of the ternary phase diagram, its isothermal section at 300 K as well as the projection of the liquids surface have been revised. The fields of the primary crystallization and types and coordinates of nonvariant and monovariant equilibriums were determined. The partial molar functions of silver iodide and silver in the alloys as well as the standard thermodynamic functions of formation and the standard entropies of Ag 2 BiI 5 and AgBi 2 I 7 were calculated based on EMF measurements.

  7. Nano-scale clusters formed in the early stage of phase decomposition of Al-Mg-Si alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hirosawa, S.; Sato, T. [Dept. of Metallurgy and Ceramics Science, Tokyo Inst. of Tech. (Japan)

    2005-07-01

    The formation of nano-scale clusters (nanoclusters) prior to the precipitation of the strengthening {beta}'' phase significantly influences two-step aging behavior of Al-Mg-Si alloys. In this work, the existence of two kinds of nanoclusters has been verified in the early stage of phase decomposition by differential scanning calorimetry (DSC) and three-dimensional atom probe (3DAP). Pre-aging treatment at 373 K before natural aging was also found to form preferentially one of the two nanoclusters, resulting in the remarkable restoration of age-hardenability at paint-bake temperatures. Such microstructural control by means of optimized heat-treatments; i.e. nanocluster assist processing (NCAP), possesses great potential for enabling Al-Mg-Si alloys to be used more widely as a body-sheet material of automobiles. (orig.)

  8. Nanostructured Platinum Alloys for Use as Catalyst Materials

    Science.gov (United States)

    Narayan, Sri R. (Inventor); Hays, Charles C. (Inventor)

    2015-01-01

    A series of binary and ternary Pt-alloys, that promote the important reactions for catalysis at an alloy surface; oxygen reduction, hydrogen oxidation, and hydrogen and oxygen evolution. The first two of these reactions are essential when applying the alloy for use in a PEMFC.

  9. Grain refinement of 7075Al alloy microstructures by inoculation with Al-Ti-B master alloy

    Science.gov (United States)

    Hotea, V.; Juhasz, J.; Cadar, F.

    2017-05-01

    This paper aims to bring some clarification on grain refinement and modification of high strength alloys used in aerospace technique. In this work it was taken into account 7075 Al alloy, and the melt treatment was carried out by placing in the form of master alloy wire ternary AlTiB the casting trough at 730°C. The morphology of the resulting microstructures was characterized by optical microscopy. Micrographs unfinished and finished with pre-alloy containing ternary Al5Ti1B evidence fine crystals, crystal containing no columnar structure and highlights the size of the dendrites, and intermetallic phases occurring at grain boundaries in Al-Zn-Mg-Cu alloy. It has been found that these intermetallic compounds are MgZn2 type. AlTiB master alloys finishing ensures a fine eutectic structure, which determines the properties of hardware and improving the mechanical properties of aluminum alloys used in aeronautical engineering.

  10. Nanoclusters and Microparticles in Gases and Vapors

    CERN Document Server

    Smirnov, Boris M

    2012-01-01

    Research of processes involving Nanoclusters and Microparticleshas been developing fastin many fields of rescent research, in particular in materials science. To stay at the cutting edge of this development, a sound understanding of the processes is needed. In this work, several processes involving small particles are described, such as transport processes in gases, charging of small particles in gases, chemical processes, atom attachment and quenching of excited atomic particles on surfaces, nucleation, coagulation, coalescence and growth processes for particles and aggregates. This work pres

  11. Ternary Weighted Function and Beurling Ternary Banach Algebra l1ω(S

    Directory of Open Access Journals (Sweden)

    Mehdi Dehghanian

    2011-01-01

    Full Text Available Let S be a ternary semigroup. In this paper, we introduce our notation and prove some elementary properties of a ternary weight function ω on S. Also, we make ternary weighted algebra l1ω(S and show that l1ω(S is a ternary Banach algebra.

  12. Contribution to the aluminum-tin-zinc ternary system

    Science.gov (United States)

    Drápala, J.; Kostiuková, G.; Losertová, M.

    2017-11-01

    The Sn-Zn-Al alloys are one of significant candidates in the proposal of alternative lead-free solders for higher temperature soldering. This paper deals with the study of the aluminum-tin-zinc system. Twenty Sn-Zn-Al alloys together with six binary Sn-Zn alloys were prepared and studied experimentally. Alloys were prepared from pure Sn, Zn and Al (melting and cooling in a vacuum resistance furnace). The specimens were studied metallographically including the micro-hardness measurements, complete chemical analysis (ICP-AES, OES), X-ray micro-analysis of alloys by SEM and EDX in order to determine the composition and identification of individual phases. Significant temperatures and enthalpies of phase transformations were determined by DTA. After long-term annealing of selected alloys in vacuum followed by quenching the structural and chemical microanalyses of the present phases and their limit concentrations were carried out. The achieved results were compared with the thermodynamic modelling of the ternary Sn-Zn-Al system (computer programs THERMOCALC, MTDATA, PANDAT and databases CALPHAD, COST). Electrical resistivity, density, magnetic susceptibility and wettability of Sn-Zn-Al solders were measured as well.

  13. 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.

  14. 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.

  15. Discovery of a metalloenzyme-like cooperative catalytic system of metal nanoclusters and catechol derivatives for the aerobic oxidation of amines.

    Science.gov (United States)

    Yuan, Hao; Yoo, Woo-Jin; Miyamura, Hiroyuki; Kobayashi, Shū

    2012-08-29

    We have discovered a new class of cooperative catalytic system, consisting of heterogeneous polymer-immobilized bimetallic Pt/Ir alloyed nanoclusters (NCs) and 4-tert-butylcatechol, for the aerobic oxidation of amines to imines under ambient conditions. After optimization, the desired imines were obtained in good to excellent yields with broad substrate scope. The reaction rate was determined to be first-order with respect to the substrate and catechol and zero-order for the alloyed Pt/Ir NC catalyst. Control studies revealed that both the heterogeneous NC catalyst and 4-tert-butylcatechol are essential and act cooperatively to facilitate the aerobic oxidation under mild conditions.

  16. Building machine learning force fields for nanoclusters

    Science.gov (United States)

    Zeni, Claudio; Rossi, Kevin; Glielmo, Aldo; Fekete, Ádám; Gaston, Nicola; Baletto, Francesca; De Vita, Alessandro

    2018-06-01

    We assess Gaussian process (GP) regression as a technique to model interatomic forces in metal nanoclusters by analyzing the performance of 2-body, 3-body, and many-body kernel functions on a set of 19-atom Ni cluster structures. We find that 2-body GP kernels fail to provide faithful force estimates, despite succeeding in bulk Ni systems. However, both 3- and many-body kernels predict forces within an ˜0.1 eV/Å average error even for small training datasets and achieve high accuracy even on out-of-sample, high temperature structures. While training and testing on the same structure always provide satisfactory accuracy, cross-testing on dissimilar structures leads to higher prediction errors, posing an extrapolation problem. This can be cured using heterogeneous training on databases that contain more than one structure, which results in a good trade-off between versatility and overall accuracy. Starting from a 3-body kernel trained this way, we build an efficient non-parametric 3-body force field that allows accurate prediction of structural properties at finite temperatures, following a newly developed scheme [A. Glielmo et al., Phys. Rev. B 95, 214302 (2017)]. We use this to assess the thermal stability of Ni19 nanoclusters at a fractional cost of full ab initio calculations.

  17. First principle study of cubic ScGaN ternaries

    International Nuclear Information System (INIS)

    Adli, W.; Mecheref, R.; Sekkal, N.; Tair, F.; Amrani, B.

    2008-08-01

    The electronic properties of the Sc x Ga1- x N ternary alloy are investigated. The transition from rocksalt (B1) to zinc blende (B3) structure is found to occur rapidly after incorporating just a small fraction (less than 1%) of Ga. In the present paper, the first principles method the full potential linear muffin-tin orbitals method (FPLMTO) in its atomic sphere approximation (ASA) coupled to the technique of the empty spheres is employed. Our results concerning the electronic properties are different from those reported in literature. (author)

  18. Phase diagram of the ternary Zr-Ti-Sn system

    International Nuclear Information System (INIS)

    Arias, D.; Gonzalez Camus, M.

    1987-01-01

    It is well known that Ti stabilizes the high temperature cubic phase of Zr and that Sn stabilizes the low temperature hexagonal phase of Zr. The effect of Sn on the Zr-Ti diagram has been studied in the present paper. Using high purity metals, nine different alloys have been prepared, with 4-32 at % Ti, 0.7-2.2 at % Sn and Zr till 100%. Resistivity and optical and SEM metallography techniques have been employed. Effect of some impurities have been analyzed. The results are discussed and different isothermic sections of the ternary Zr-Ti-Sn diagram are presented. (Author) [es

  19. Passivation of cobalt nanocluster assembled thin films with hydrogen

    DEFF Research Database (Denmark)

    Romero, C.P.; Volodin, A.; Di Vece, M.

    2012-01-01

    The effect of hydrogen passivation on bare and Pd capped cobalt nanocluster assembled thin films was studied with Rutherford backscattering spectrometry (RBS) and magnetic force microscopy (MFM) after exposure to ambient conditions. The nanoclusters are produced in a laser vaporization cluster...... source in which the helium carrier gas was mixed with hydrogen. RBS revealed that oxidation of the Co nanoclusters is considerably reduced by the presence of hydrogen during cluster formation. The capping did not modify the influence of the passivation. The hydrogen passivation method is especially...... effective in cases when capping of the films is not desirable, for example for magnetic studies. Clear differences in the magnetic domain structures between hydrogen passivated and non-passivated Co nanocluster films were demonstrated by MFM and are attributed to a difference in inter-cluster magnetic...

  20. Adsorption of small gas molecules on B36 nanocluster

    Indian Academy of Sciences (India)

    Supplementary Information. Journal of Chemical Sciences. Adsorption of small gas molecules on B36 nanocluster. YOUNES VALADBEIGI. *. , HOSSEIN FARROKHPOUR and MAHMOUD TABRIZCHI. Department of chemistry, Isfahan University of Technology, Isfahan, 84156-83111, Iran. *. Corresponding Author: Younes ...

  1. Tunneling-Electron-Induced Light Emission from Single Gold Nanoclusters.

    Science.gov (United States)

    Yu, Arthur; Li, Shaowei; Czap, Gregory; Ho, W

    2016-09-14

    The coupling of tunneling electrons with the tip-nanocluster-substrate junction plasmon was investigated by monitoring light emission in a scanning tunneling microscope (STM). Gold atoms were evaporated onto the ∼5 Å thick Al2O3 thin film grown on the NiAl (110) surface where they formed nanoclusters 3-7 nm wide. Scanning tunneling spectroscopy (STS) of these nanoclusters revealed quantum-confined electronic states. Spatially resolved photon imaging showed localized emission hot spots. Size dependent study and light emission from nanocluster dimers further support the viewpoint that coupling of tunneling electrons to the junction plasmon is the main radiative mechanism. These results showed the potential of the STM to reveal the electronic and optical properties of nanoscale metallic systems in the confined geometry of the tunnel junction.

  2. Switching a Nanocluster Core from Hollow to Non-hollow

    KAUST Repository

    Bootharaju, Megalamane Siddaramappa; Joshi, Chakra Prasad; Alhilaly, Mohammad J.; Bakr, Osman

    2016-01-01

    Modulating the structure-property relationship in atomically precise nanoclusters (NCs) is vital for developing novel NC materials and advancing their applications. While promising biphasic ligand-exchange (LE) strategies have been developed

  3. Ternary systems Sr-{Ni,Cu}-Si: Phase equilibria and crystal structure of ternary phases

    International Nuclear Information System (INIS)

    Nasir, Navida; Melnychenko-Koblyuk, Nataliya; Grytsiv, Andriy; Rogl, Peter; Giester, Gerald; Wosik, Jaroslaw; Nauer, Gerhard E.

    2010-01-01

    Phase relations were established in the Sr-poor part of the ternary systems Sr-Ni-Si (900 deg. C) and Sr-Cu-Si (800 deg. C) by light optical microscopy, electron probe microanalysis and X-ray diffraction on as cast and annealed alloys. Two new ternary compounds SrNiSi 3 (BaNiSn 3 -type) and SrNi 9-x Si 4+x (own-type) were found in the Sr-Ni-Si system along with previously reported Sr(Ni x Si 1-x ) 2 (AlB 2 -type). The crystal structure of SrNi 9-x Si 4+x (own-type, x=2.7, a=0.78998(3), c=1.1337(2) nm; space group P4/nbm) was determined from X-ray single crystal counter to be a low symmetry derivative of the cubic, parent NaZn 13 -type. At higher Si-content X-ray Rietveld refinements reveal the formation of a vacant site (□) corresponding to a formula SrNi 5.5 Si 6.5 □ 1.0 . Phase equilibria in the Sr-Cu-Si system are characterized by the compounds SrCu 2-x Si 2+x (ThCr 2 Si 2 -type), Sr(Cu x Si 1-x ) 2 (AlB 2 -type), SrCu 9-x Si 4+x (0≤x≤1.0; CeNi 8.5 Si 4.5 -type) and SrCu 13-x Si x (4≤x≤1.8; NaZn 13 -type). The latter two structure types appear within a continuous solid solution. Neither a type-I nor a type-IX clathrate compound was encountered in the Sr-{Cu,Ni}-Si systems. Structural details are furthermore given for about 14 new ternary compounds from related alloy systems with Ba. - Graphical abstract: The crystal structure of SrNi 9-x Si 4+x (own-type, x=2.7, a=0.78998(3), c=1.1337(2) nm; space group P4/nbm) was determined from X-ray single crystal counter to be a low symmetry derivative of the cubic, parent NaZn 13 -type and is related to CeNi 8.5 Si 4.5 -type.

  4. Experimental determination of the phase equilibria in the Co-Fe-Zr ternary system

    International Nuclear Information System (INIS)

    Wang, C.P.; Yu, Y.; Zhang, H.H.; Hu, H.F.; Liu, X.J.

    2011-01-01

    Research highlights: → We determined four isothermal sections of the Co-Fe-Zr system from 1000 o C to 1300 o C. → No ternary compound was found in the Co-Fe-Zr ternary system. → The solubility of Fe in the liquid phase at 1300 o C is extremely large. → The (Co, Fe) 2 Zr phase form the continuous solution from Co-Zr side to Fe-Zr side. → The solubility of Zr in the fcc (Co, Fe) phase is extremely small. - Abstract: The phase equilibria in the Co-Fe-Zr ternary system were investigated by means of optical microscopy (OM), electron probe microanalysis (EPMA), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) on equilibrated ternary alloys. Four isothermal sections of the Co-Fe-Zr ternary system at 1300 o C, 1200 o C, 1100 o C and 1000 o C were experimentally established. The experimental results indicate that (1) no ternary compound was found in this system; (2) the solubility of Fe in the liquid phase of the Co-rich corner at 1300 o C is extremely large; (3) the liquid phase in the Zr-rich corner and the (Co,Fe) 2 Zr phase form the continuous solid solutions from the Co-Zr side to the Fe-Zr side; (4) the solubility of Zr in the fcc (Co, Fe) phase is extremely small.

  5. ZIRCONIUM-TITANIUM-BERYLLIUM BRAZING ALLOY

    Science.gov (United States)

    Gilliland, R.G.; Patriarca, P.; Slaughter, G.M.; Williams, L.C.

    1962-06-12

    A new and improved ternary alloy is described which is of particular utility in braze-bonding parts made of a refractory metal selected from Group IV, V, and VI of the periodic table and alloys containing said metal as a predominating alloying ingredient. The brazing alloy contains, by weight, 40 to 50 per cent zirconium, 40 to 50 per cent titanium, and the balance beryllium in amounts ranging from 1 to 20 per cent, said alloy having a melting point in the range 950 to 1400 deg C. (AEC)

  6. Distinct metal-exchange pathways of doped Ag25 nanoclusters

    KAUST Repository

    Bootharaju, Megalamane Siddaramappa

    2016-09-09

    Atomically precise metal nanoclusters (NCs) containing more than one type of metal atom (i.e., doped or alloyed), due to synergistic effects, open new avenues for engineering the catalytic and optical properties of NCs in a manner that homometal NCs cannot. Unfortunately, it is still a major challenge to controllably introduce multimetallic dopants in NCs, understanding the dopants\\' positions, mechanism, and synergistic effects. To overcome these challenges, we designed a metal-exchange approach involving NCs as molecular templates and metal ions as the source of the incoming dopant. In particular, two structurally similar monodoped silver-rich NCs, [MAg24(SR)(18)](2-) (M = Pd/Pt and SR: thiolate), were synthesized as templates to study their mechanistic transformation in response to the introduction of gold atoms. The controllable incorporation of Au atoms into the MAg24 framework facilitated the elucidation of distinct doping pathways through high-resolution mass spectrometry, optical spectroscopy and elemental analysis. Interestingly, gold replaced the central Pd atom of [PdAg24(SR)(18)](2-) clusters to produce predominantly bimetallic [AuAg24(SR)(18)](-) clusters along with a minor product of an [Au2Ag23(SR)(18)](-) cluster. In contrast, the central Pt atom remained intact in [PtAg24(SR)(18)](2-) clusters, and gold replaced the noncentral Ag atoms to form trimetallic [AuxPtAg24-x(SR)(18)](2-) NCs, where x = 1-2, with a portion of the starting [PtAg24(SR)(18)](2-) NCs remaining. This study reveals some of the unusual metal-exchange pathways of doped NCs and the important role played by the initial metal dopant in directing the position of a second dopant in the final product.

  7. True ternary fission in 310126X

    International Nuclear Information System (INIS)

    Banupriya, B.; Vijayaraghavan, K.R.; Balasubramaniam, M.

    2015-01-01

    All possible combinations are minimized by the two dimensional minimization process and minimized with respect to neutron numbers and proton numbers of the fragments. Potential energy is low and Q - value is high at true ternary fission region. It shows that true ternary mode is the dominant mode in the ternary fission of superheavy nuclei. Also, the results show that the fragments with neutron magic numbers are the dominant one in the ternary fission of superheavy nuclei whereas the fragments with proton magic numbers are the dominant one in the ternary fission of heavy nuclei

  8. Tailoring the magnetic properties of cobalt-ferrite nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Vega, A. Estrada de la; Garza-Navarro, M. A., E-mail: marco.garzanr@uanl.edu.mx; Durán-Guerrero, J. G.; Moreno Cortez, I. E.; Lucio-Porto, R.; González-González, V. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica (Mexico)

    2016-01-15

    In this contribution, we report on the tuning of magnetic properties of cobalt-ferrite nanoclusters. The cobalt-ferrite nanoclusters were synthesized from a two-step approach that consists of the synthesis of cobalt-ferrite nanoparticles in organic media, followed by their dispersion into aqueous dissolution to form an oil-in-water emulsion. These emulsions were prepared at three different concentrations of the cationic surfactant cetyltrimethylammonium bromide (CTAB), in order to control the size and clustering density of the nanoparticles in the nanoclusters. The synthesized samples were characterized by transmission electron microscopy and their related techniques, such as bright-field and Z-contrast imaging, electron diffraction and energy-dispersive X-ray spectrometry; as well as static magnetic measures. The experimental evidence indicates that the size, morphology, and nanoparticles clustering density in the nanoclusters is highly dependent of the cobalt-ferrite:CTAB molar ratio that is used in their synthesis. In addition, due to the clustering of the nanoparticles into the nanoclusters, their magnetic moments are blocked to relax cooperatively. Hence, the magnetic response of the nanoclusters can be tailored by controlling the size and nanoparticles clustering density.

  9. Data and analyses of phase relations in the Ce-Fe-Sb ternary system.

    Science.gov (United States)

    Zhu, Daiman; Xu, Chengliang; Li, Changrong; Guo, Cuiping; Zheng, Raowen; Du, Zhenmin; Li, Junqin

    2018-02-01

    These data and analyses support the research article "Experimental study on phase relations in the Ce-Fe-Sb ternary system" Zhu et al. (2017) [1]. The data and analyses presented here include the experimental results of XRD, SEM and EPMA for the determination of the whole liquidus projection and the isothermal section at 823 K in the Ce-Fe-Sb system. All the results enable the understanding of the constituent phases and the solidification processes of the as-cast alloys as well as the phase relations and the equilibrium regions at 823 K in the Ce-Fe-Sb ternary system over the entire composition.

  10. Amorphous phase formation in the Cu{sub 36}Zr{sub 59}A{sub l5} and Cu{sub 48}Zr{sub 43}A{sub l9} ternary alloys studied by molecular dynamics; Estudo da formacao de fase amorfa nas ligas ternarias Cu{sub 36}Zr{sub 59}A{sub l5} e Cu{sub 48}Zr{sub 43}A{sub l9} por dinamica molecular

    Energy Technology Data Exchange (ETDEWEB)

    Aliaga, L.C.R.; Schimidt, C.S.; Lima, L.V.; Domingues, G.M.B.; Bastos, I.N., E-mail: aliaga@iprj.uer.br [Universidade do Estado do Rio de Janeiro (UERJ), Nova friburgo, RJ (Brazil). Departamento de Materiais

    2016-07-01

    Amorphous alloys presents better mechanical and physical properties than its crystalline counterparts. However, there is a scarce understanding on structure - properties relationship in this class of materials. This paper presents the results of the molecular dynamics application to obtain an atomistic description of melting, solidification and the glass forming ability in the ternary Cu{sub 36}Zr{sub 59}A{sub l5} and Cu{sub 48}Zr{sub 43}A{sub l9} alloys. In the study we used the EAM potential and different cooling rates, β = 0.1, 1 and 100 K/ps to form the amorphous phase in a system consisting of 32,000 atoms by using the free code LAMMPS. The solidus and liquidus temperatures, on a heating rate of the 5 K/ps, were obtained. Also, on the cooling down step, it was observed that the glass transition temperature (T{sub g}) decreases as cooling rate increases. The structural evolution was analyzed through the radial distribution functions and Voronoi polyhedra. Furthermore, it was determined the evolution of viscosity upper T{sub g}, as well as the fragility (m) parameter for each amorphous alloy. The thermal parameters of the simulation obtained are compared with those of the experiments. (author)

  11. Phase equilibria of the Mo-Al-Ho ternary system

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yitai; Chen, Xiaoxian; Liu, Hao [Guangxi Univ., Nanning (China). College of Materials Science and Engineering; Guangxi Univ., Nanning (China). Guangxi Key Laboratory of Processing for Non-ferrous Metal and Featured Materials; Zhan, Yongzhong [Guangxi Univ., Nanning (China). College of Materials Science and Engineering; Guangxi Univ., Nanning (China). Guangxi Key Laboratory of Processing for Non-ferrous Metal and Featured Materials; Guangxi Univ., Nanning (China). Center of Ecological Collaborative Innovation for Aluminum Industry

    2017-08-15

    Investigation into the reactions and phase equilibria of transition metal elements (i.e. Mo, Zr, Cr, V and Ti), Al and rare earths is academically and industrially important for the development of both refractory alloys and lightweight high-temperature materials. In this work, the equilibria of the Mo-Al-Ho ternary system at 773 K have been determined by using X-ray powder diffraction and scanning electron microscopy equipped with energy dispersive X-ray analysis. A new ternary phase Al{sub 4}Mo{sub 2}Ho has been found and the other ternary phase Al{sub 43}Mo{sub 4}Ho{sub 6} is observed. Ten binary phases in the Al-Mo and Al-Ho systems, including Al{sub 17}Mo{sub 4} rather than Al{sub 4}Mo, have been determined to exist at 773 K. The homogeneity ranges of AlMo{sub 3} and Al{sub 8}Mo{sub 3} phase are 7.5 at.% and 1 at.%, respectively. According to the phase-disappearing method, the maximum solubility of Al in Mo is about 16 at.%.

  12. Magnetic interaction reversal in watermelon nanostructured Cr-doped Fe nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Maninder; Qiang, You, E-mail: youqiang@uidaho.edu [Department of Physics, University of Idaho, Moscow, Idaho 83844 (United States); Dai, Qilin; Tang, Jinke [Department of Physics and Astronomy, University of Wyoming, Laramie, Wyoming 82071 (United States); Bowden, Mark; Engelhard, Mark [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States); Wu, Yaqiao [Department of Materials Science and Engineering, Boise State University, Boise, Idaho 83725 (United States); Center for Advanced Energy Studies, Idaho Falls, Idaho 83401 (United States)

    2013-11-11

    Cr-doped core-shell Fe/Fe-oxide nanoclusters (NCs) were synthesized at varied atomic percentages of Cr from 0 at. % to 8 at. %. The low concentrations of Cr (<10 at. %) were selected in order to inhibit the complete conversion of the Fe-oxide shell to Cr{sub 2}O{sub 3} and the Fe core to FeCr alloy. The magnetic interaction in Fe/Fe-oxide NCs (∼25 nm) can be controlled by antiferromagnetic Cr-dopant. We report the origin of σ-FeCr phase at very low Cr concentration (2 at. %) unlike in previous studies, and the interaction reversal from dipolar to exchange interaction in watermelon-like Cr-doped core-shell NCs.

  13. Modelling radiation-induced phase changes in binary FeCu and ternary FeCuNi alloys using an artificial intelligence-based atomistic kinetic Monte Carlo approach

    International Nuclear Information System (INIS)

    Castin, N.; Malerba, L.; Bonny, G.; Pascuet, M.I.; Hou, M.

    2009-01-01

    We apply a novel atomistic kinetic Monte Carlo model, which includes local chemistry and relaxation effects when assessing the migration energy barriers of point defects, to the study of the microchemical evolution driven by vacancy diffusion in FeCu and FeCuNi alloys. These alloys are of importance for nuclear applications because Cu precipitation, enhanced by the presence of Ni, is one of the main causes of hardening and embrittlement in reactor pressure vessel steels used in existing nuclear power plants. Local chemistry and relaxation effects are introduced using artificial intelligence techniques, namely a conveniently trained artificial neural network, to calculate the migration energy barriers of vacancies as functions of the local atomic configuration. We prove, through a number of results, that the use of the neural network is fully equivalent to calculating the migration energy barriers on-the-fly, using computationally expensive methods such as nudged elastic bands with an interatomic potential. The use of the neural network makes the computational cost affordable, so that simulations of the same type as those hitherto carried out using heuristic formulas for the assessment of the energy barriers can now be performed, at the same computational cost, using more rigorously calculated barriers. This method opens the way to properly treating more complex problems, such as the case of self-interstitial cluster formation, in an atomistic kinetic Monte Carlo framework.

  14. Modelling radiation-induced phase changes in binary FeCu and ternary FeCuNi alloys using an artificial intelligence-based atomistic kinetic Monte Carlo approach

    Science.gov (United States)

    Castin, N.; Malerba, L.; Bonny, G.; Pascuet, M. I.; Hou, M.

    2009-09-01

    We apply a novel atomistic kinetic Monte Carlo model, which includes local chemistry and relaxation effects when assessing the migration energy barriers of point defects, to the study of the microchemical evolution driven by vacancy diffusion in FeCu and FeCuNi alloys. These alloys are of importance for nuclear applications because Cu precipitation, enhanced by the presence of Ni, is one of the main causes of hardening and embrittlement in reactor pressure vessel steels used in existing nuclear power plants. Local chemistry and relaxation effects are introduced using artificial intelligence techniques, namely a conveniently trained artificial neural network, to calculate the migration energy barriers of vacancies as functions of the local atomic configuration. We prove, through a number of results, that the use of the neural network is fully equivalent to calculating the migration energy barriers on-the-fly, using computationally expensive methods such as nudged elastic bands with an interatomic potential. The use of the neural network makes the computational cost affordable, so that simulations of the same type as those hitherto carried out using heuristic formulas for the assessment of the energy barriers can now be performed, at the same computational cost, using more rigorously calculated barriers. This method opens the way to properly treating more complex problems, such as the case of self-interstitial cluster formation, in an atomistic kinetic Monte Carlo framework.

  15. Modelling radiation-induced phase changes in binary FeCu and ternary FeCuNi alloys using an artificial intelligence-based atomistic kinetic Monte Carlo approach

    Energy Technology Data Exchange (ETDEWEB)

    Castin, N. [Structural Materials Group, Nuclear Materials Science Institute, Kernenergie Centre d' Etude de l' Energie Nucleaire (SCK CEN), Studiecentrum voor, Boeretang 200, 2400 Mol (Belgium); Physique des Solides Irradies et des Nanostructures (PSIN), Universite Libre de Bruxelles (ULB), Boulevard du Triomphe CP234, 1050 Brussels (Belgium); Malerba, L. [Structural Materials Group, Nuclear Materials Science Institute, Kernenergie Centre d' Etude de l' Energie Nucleaire (SCK CEN), Studiecentrum voor, Boeretang 200, 2400 Mol (Belgium)], E-mail: lmalerba@sckcen.be; Bonny, G. [Structural Materials Group, Nuclear Materials Science Institute, Kernenergie Centre d' Etude de l' Energie Nucleaire (SCK CEN), Studiecentrum voor, Boeretang 200, 2400 Mol (Belgium); Laboratory of Theoretical Physics, Universiteit Gent, Proeftuinstraat 86, B-9000 Gent (Belgium); Pascuet, M.I. [Structural Materials Group, Nuclear Materials Science Institute, Kernenergie Centre d' Etude de l' Energie Nucleaire (SCK CEN), Studiecentrum voor, Boeretang 200, 2400 Mol (Belgium); CAC-CNEA, Departamento de Materiales, Avda. Gral. Paz 1499, 1650 San Martin, Pcia. Buenos Aires (Argentina); CONICET, Avda. Rivadavia 1917, 1033 Buenos Aires (Argentina); Hou, M. [Physique des Solides Irradies et des Nanostructures (PSIN), Universite Libre de Bruxelles (ULB), Boulevard du Triomphe CP234, 1050 Brussels (Belgium)

    2009-09-15

    We apply a novel atomistic kinetic Monte Carlo model, which includes local chemistry and relaxation effects when assessing the migration energy barriers of point defects, to the study of the microchemical evolution driven by vacancy diffusion in FeCu and FeCuNi alloys. These alloys are of importance for nuclear applications because Cu precipitation, enhanced by the presence of Ni, is one of the main causes of hardening and embrittlement in reactor pressure vessel steels used in existing nuclear power plants. Local chemistry and relaxation effects are introduced using artificial intelligence techniques, namely a conveniently trained artificial neural network, to calculate the migration energy barriers of vacancies as functions of the local atomic configuration. We prove, through a number of results, that the use of the neural network is fully equivalent to calculating the migration energy barriers on-the-fly, using computationally expensive methods such as nudged elastic bands with an interatomic potential. The use of the neural network makes the computational cost affordable, so that simulations of the same type as those hitherto carried out using heuristic formulas for the assessment of the energy barriers can now be performed, at the same computational cost, using more rigorously calculated barriers. This method opens the way to properly treating more complex problems, such as the case of self-interstitial cluster formation, in an atomistic kinetic Monte Carlo framework.

  16. Bond charges and electronic charge transfer in ternary semiconductors

    International Nuclear Information System (INIS)

    Pietsch, U.

    1986-01-01

    By means of a simple molecule-theoretic model of 'linear superposition of two-electron molecules' the bond charges between nearest neighbours and the effective charges of ions are calculated for ternary zinc-blende structure alloys as well as chalcopyrite semiconductors. Taking into account both, the charge transfer among the ions caused by the differences of electronegativities of atoms used and between the bonds created by the internal stress of the lattice a nearly unvaried averaged bond charge amount of the alloy is found, but rather dramatically changed local bond charge parameters in comparison with the respective values of binary compounds used. This fact should influence the noncentral force interaction in such semiconductors. (author)

  17. Atomistic approach to predict the glass-forming ability in Zr–Cu–Al ternary metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Yu, C.Y. [Center for Advanced Structural Materials, Department of Mechanical and Biomedical Engineering, College of Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong (China); Liu, X.J. [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Zheng, G.P. [Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong (China); Niu, X.R. [Center for Advanced Structural Materials, Department of Mechanical and Biomedical Engineering, College of Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong (China); Liu, C.T., E-mail: chainliu@cityu.edu.hk [Center for Advanced Structural Materials, Department of Mechanical and Biomedical Engineering, College of Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong (China)

    2015-04-05

    Highlights: • An atomistic approach has been developed to predict the glass forming ability (GFA) in Zr–Cu–Al ternary alloy system. • Both of the thermodynamic and structure-dependent kinetic effects to glass formation have been taken into account. • The first-principles calculation and molecular dynamics simulation have been performed. • The approach predicts the best glass former in the model Zr–Cu–Al alloy system. • The predicted GFA is consistent with various experimental results. - Abstract: Prediction of composition-dependent glass-forming ability (GFA) remains to be a key scientific challenge in the metallic-glass community, especially in multi-component alloy systems. In the present study, we apply an atomistic approach to predict the trend of GFA effectively in the Zr–Cu–Al ternary alloy system from alloy compositions alone. This approach is derived from the first-principles calculations based on the density-functional theory and molecular dynamic (MD) simulations. By considering of both the thermodynamic and atomic-structure induced kinetic effects, the predicted GFA trend from this approach shows an excellent agreement with experimental data available in this alloy system, manifesting its capability of seeking metallic glasses with superior GFA in ternary alloy systems.

  18. Synthesis of crystalline Ge nanoclusters in PE-CVD-deposited SiO2 films

    DEFF Research Database (Denmark)

    Leervad Pedersen, T.P.; Skov Jensen, J.; Chevallier, J.

    2005-01-01

    The synthesis of evenly distributed Ge nanoclusters in plasma-enhanced chemical-vapour-deposited (PE-CVD) SiO2 thin films containing 8 at. % Ge is reported. This is of importance for the application of nanoclusters in semiconductor technology. The average diameter of the Ge nanoclusters can...

  19. Silver Nanocluster Reparative Effect in Hernioplasty

    Directory of Open Access Journals (Sweden)

    Nikolay M. Anichkov

    2014-06-01

    Full Text Available Background: The acceleration of re-epithelialization and fibroblast differentiation were noted during the experiments with silver nanoclusters (SNs by interrupting the negative development of inflammation at the level of cytokines and promoting a positive course of reparative processes. The aim of this work was to elaborate the experimental model of prosthesis hernioplasty in subcutaneous and intraperitoneal locations of hernioprostheses with SNs, which allowed us to study the course of reparative reactions in all layers of the anterior abdominal wall. Material and Methods: We used a modified hernioprosthesis made from polyester fibers coated with a metal-polymer composition, including the stabilized SN in a concentration of 6.8 and 11.3 mg per 1 g of the hernioprosthesis mesh. During this research we used guinea pigs to study the in vivo tissue reactions. The clinical part of the study included the group of 212 patients who underwent removal of an inguinal hernia. We have identified various factors associated with infectious and toxic effects on the body by determining the level of the serum glutamate-pyruvate-transaminase (SGPT. Results: In implantation of the hernioprostheses, including the high concentration of SN in the laparotomy wound, the exudative component of the inflammation was weakly expressed. It was mostly the proliferative changes that took place. We did not find either CD8-positive type T lymphocytes or PAX5-positive type B activated cells in the exudate. Conclusion: Our research has shown that the use of hernioprostheses that include silver nanoclusters leads to the reduction of inflammation in the exudative phase and to a more favorable course of reparative processes.

  20. Some new ternary linear codes

    Directory of Open Access Journals (Sweden)

    Rumen Daskalov

    2017-07-01

    Full Text Available Let an $[n,k,d]_q$ code be a linear code of length $n$, dimension $k$ and minimum Hamming distance $d$ over $GF(q$. One of the most important problems in coding theory is to construct codes with optimal minimum distances. In this paper 22 new ternary linear codes are presented. Two of them are optimal. All new codes improve the respective lower bounds in [11].

  1. NanoClusters Enhance Drug Delivery in Mechanical Ventilation

    Science.gov (United States)

    Pornputtapitak, Warangkana

    The overall goal of this thesis was to develop a dry powder delivery system for patients on mechanical ventilation. The studies were divided into two parts: the formulation development and the device design. The pulmonary system is an attractive route for drug delivery since the lungs have a large accessible surface area for treatment or drug absorption. For ventilated patients, inhaled drugs have to successfully navigate ventilator tubing and an endotracheal tube. Agglomerates of drug nanoparticles (also known as 'NanoClusters') are fine dry powder aerosols that were hypothesized to enable drug delivery through ventilator circuits. This Thesis systematically investigated formulations of NanoClusters and their aerosol performance in a conventional inhaler and a device designed for use during mechanical ventilation. These engineered powders of budesonide (NC-Bud) were delivered via a MonodoseRTM inhaler or a novel device through commercial endotracheal tubes, and analyzed by cascade impaction. NC-Bud had a higher efficiency of aerosol delivery compared to micronized stock budesonide. The delivery efficiency was independent of ventilator parameters such as inspiration patterns, inspiration volumes, and inspiration flow rates. A novel device designed to fit directly to the ventilator and endotracheal tubing connections and the MonodoseRTM inhaler showed the same efficiency of drug delivery. The new device combined with NanoCluster formulation technology, therefore, allowed convenient and efficient drug delivery through endotracheal tubes. Furthermore, itraconazole (ITZ), a triazole antifungal agent, was formulated as a NanoCluster powder via milling (top-down process) or precipitation (bottom-up process) without using any excipients. ITZ NanoClusters prepared by wet milling showed better aerosol performance compared to micronized stock ITZ and ITZ NanoClusters prepared by precipitation. ITZ NanoClusters prepared by precipitation methods also showed an amorphous state

  2. Study of nanocluster-assembled ZnO thin films by nanocluster-beam deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Zhiwei; Lei, Wei; Zhang, Xiaobing [School of Electronic Science and Engieering, Southeast University, Nanjing (China); Tay, Beng Kang [School of Electronical and Electronic Engineering, Nanyang Technological University, Nanyang (Singapore)

    2012-01-15

    Nanocluster-assembled ZnO thin films were obtained by nanocluster-beam deposition, in which nanoclusters were produced by a magnetron sputtering gas aggregation source. Two kinds of ZnO thin films were obtained using this method with the one grown under the on-line heating temperature of 700 C, and the other grown without on-line heating. Film microstructure and optical properties are investigated by various diagnostic techniques. It was found that both of film microstructure of ZnO thin films keep wurtzite structure as that of ZnO bulk materials. The averaged particle size for the film grown without on-line heating is around 6 nm, which is a little lower than that grown with the on-line heating. It was also found that as increasing the wavelength, both of the absorbance spectra for the films decrease sharply near ultra-visible to extend slowly to the visible and infrared wavelength range. For the film grown without on-line heating, the bandgap energy was estimated to 3.77 eV, while for the film grown with on-line heating, the bandgap energy was redshift to 3.71 eV. Similar behavior was also found for PL spectra analysis, where PL spectrum exhibited a peak centered at 3.31 eV without on-line heating, while it redshift to 3.20 eV with on-line heating. The mechanisms behind these behaviors were presented in this article. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Cluster perturbation theory for calculation of electronic properties of ensembles of metal nanoclusters

    Science.gov (United States)

    Zhumagulov, Yaroslav V.; Krasavin, Andrey V.; Kashurnikov, Vladimir A.

    2018-05-01

    The method is developed for calculation of electronic properties of an ensemble of metal nanoclusters with the use of cluster perturbation theory. This method is applied to the system of gold nanoclusters. The Greens function of single nanocluster is obtained by ab initio calculations within the framework of the density functional theory, and then is used in Dyson equation to group nanoclusters together and to compute the Greens function as well as the electron density of states of the whole ensemble. The transition from insulator state of a single nanocluster to metallic state of bulk gold is observed.

  4. Ultrafast, 2 min synthesis of monolayer-protected gold nanoclusters (d < 2 nm)

    Science.gov (United States)

    Martin, Matthew N.; Li, Dawei; Dass, Amala; Eah, Sang-Kee

    2012-06-01

    An ultrafast synthesis method is presented for hexanethiolate-coated gold nanoclusters (d gold nanoclusters are separated from the reaction byproducts fast and easily without any need for post-synthesis cleaning.An ultrafast synthesis method is presented for hexanethiolate-coated gold nanoclusters (d gold nanoclusters are separated from the reaction byproducts fast and easily without any need for post-synthesis cleaning. Electronic supplementary information (ESI) available: Experimental details of gold nanocluster synthesis and mass-spectrometry. See DOI: 10.1039/c2nr30890h

  5. Atomically Precise Nanocluster Assemblies Encapsulating Plasmonic Gold Nanorods.

    Science.gov (United States)

    Chakraborty, Amrita; Fernandez, Ann Candice; Som, Anirban; Mondal, Biswajit; Natarajan, Ganapati; Paramasivam, Ganesan; Lahtinen, Tanja; Häkkinen, Hannu; Nonappa, Nonappa; Pradeep, Thalappil

    2018-04-01

    We present the self-assembled structures of atomically precise, ligand-protected noble metal nanoclusters leading to encapsulation of plasmonic gold nanorods (GNRs). Unlike highly sophisticated DNA nanotechnology, our approach demonstrates a strategically simple hydrogen bonding-directed self-assembly of nanoclusters leading to octahedral nanocrystals encapsulating GNRs. Specifically, we use the p-mercaptobenzoic acid (pMBA) protected atomically precise nanocluster, Na4[Ag44(pMBA)30] and pMBA functionalized GNRs. High resolution transmission and scanning transmission electron tomographic reconstructions suggest that the geometry of the GNR surface is responsible for directing the assembly of silver nanoclusters via H-bonding leading to octahedral symmetry. Further, use of water dispersible gold nanoclusters, Au~250(pMBA)n and Au102(pMBA)44 also formed layered shells encapsulating GNRs. Such cluster assemblies on colloidal particles present a new category of precision hybrids with diverse possibilities. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Ternary scandium and transition metals germanides

    International Nuclear Information System (INIS)

    Kotur, B.Ya.

    1992-01-01

    Brief review of data on phase diagram of ternary Sc-Me-Ge systems (Me-d - , f-transition element) is given. Isothermal sections at 870 and 1070 K of 17 ternary systems are plotted. Compositions and their structural characteristics are presented. Variability of crystal structure is typical for ternary scandium germanides: 70 compounds with the studied structure belong to 23 structural types. Ternary germanides isostructural to types of Sm 4 Ge 4 , ZrCrSi 2 , ZrNiAl, ScCeSi, TiNiSi U 4 Re 7 Si 6 145 compounds from 70 under investigation are mostly formed in studied systems

  7. Homologous series of layered structures in binary and ternary Bi-Sb-Te-Se systems : Ab initio study

    NARCIS (Netherlands)

    Govaerts, K.; Sluiter, M.H.F.; Partoens, B.; Lamoen, D.

    2014-01-01

    In order to account explicitly for the existence of long-periodic layered structures and the strong structural relaxations in the most common binary and ternary alloys of the Bi-Sb-Te-Se system, we have developed a one-dimensional cluster expansion (CE) based on first-principles electronic structure

  8. A simple method for determining the lattice parameter and chemical composition in ternary bcc-Fe rich nanocrystals

    International Nuclear Information System (INIS)

    Moya, Javier A.; Gamarra Caramella, Soledad; Marta, Leonardo J.; Berejnoi, Carlos

    2015-01-01

    Highlights: • A method for determining composition in ternary nanocrystals is presented. • X-ray diffraction and Mössbauer spectroscopy data were employed. • We perform theoretical charts for lattice parameter of Fe-rich ternary alloys. • A linear relationship in lattice parameter for binary alloys is evaluated. • A parabolic relationship is proposed for the Fe–Co–Si alloy. - Abstract: Charts containing lattice parameters of Fe 1−x (M,N) x ternary systems with M and N = Si, Al, Ge or Co, and 0 ⩽ x ⩽ ∼0.3, were developed by implementing a linear relationship between the respective binary alloys with the same solute content of the ternary one. Charts were validated with experimental data obtained from literature. For the Fe–Co–Si system, the linear relationship does not fit the experimental data. For the other systems (except the Fe–Co–Ge one where no experimental data was found), the lineal relationship constitute a very good approximation. Using these charts and the lattice parameter data obtained from X-ray diffraction technique combining with the solute content data obtained from Mössbauer spectroscopy technique it is possible to determine the chemical composition of nanograins in soft magnetic nanocomposite materials and some examples are provided

  9. A simple method for determining the lattice parameter and chemical composition in ternary bcc-Fe rich nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Moya, Javier A., E-mail: jmoya.fi.uba@gmail.com [Grupo Interdisciplinario en Materiales-IESIING, Universidad Católica de Salta, INTECIN UBA-CONICET, Salta (Argentina); Gamarra Caramella, Soledad; Marta, Leonardo J. [Grupo Interdisciplinario en Materiales-IESIING, Universidad Católica de Salta, INTECIN UBA-CONICET, Salta (Argentina); Berejnoi, Carlos [Universidad Nacional de Salta, Facultad de Ingeniería, Salta (Argentina)

    2015-05-15

    Highlights: • A method for determining composition in ternary nanocrystals is presented. • X-ray diffraction and Mössbauer spectroscopy data were employed. • We perform theoretical charts for lattice parameter of Fe-rich ternary alloys. • A linear relationship in lattice parameter for binary alloys is evaluated. • A parabolic relationship is proposed for the Fe–Co–Si alloy. - Abstract: Charts containing lattice parameters of Fe{sub 1−x}(M,N){sub x} ternary systems with M and N = Si, Al, Ge or Co, and 0 ⩽ x ⩽ ∼0.3, were developed by implementing a linear relationship between the respective binary alloys with the same solute content of the ternary one. Charts were validated with experimental data obtained from literature. For the Fe–Co–Si system, the linear relationship does not fit the experimental data. For the other systems (except the Fe–Co–Ge one where no experimental data was found), the lineal relationship constitute a very good approximation. Using these charts and the lattice parameter data obtained from X-ray diffraction technique combining with the solute content data obtained from Mössbauer spectroscopy technique it is possible to determine the chemical composition of nanograins in soft magnetic nanocomposite materials and some examples are provided.

  10. Density functional theory based screening of ternary alkali-transition metal borohydrides: A computational material design project

    DEFF Research Database (Denmark)

    Hummelshøj, Jens Strabo; Landis, David; Voss, Johannes

    2009-01-01

    We present a computational screening study of ternary metal borohydrides for reversible hydrogen storage based on density functional theory. We investigate the stability and decomposition of alloys containing 1 alkali metal atom, Li, Na, or K (M1); and 1 alkali, alkaline earth or 3d/4d transition...

  11. Surface tension modelling of liquid Cd-Sn-Zn alloys

    Science.gov (United States)

    Fima, Przemyslaw; Novakovic, Rada

    2018-06-01

    The thermodynamic model in conjunction with Butler equation and the geometric models were used for the surface tension calculation of Cd-Sn-Zn liquid alloys. Good agreement was found between the experimental data for limiting binaries and model calculations performed with Butler model. In the case of ternary alloys, the surface tension variation with Cd content is better reproduced in the case of alloys lying on vertical sections defined by high Sn to Zn molar fraction ratio. The calculated surface tension is in relatively good agreement with the available experimental data. In addition, the surface segregation of liquid ternary Cd-Sn-Zn and constituent binaries has also been calculated.

  12. Straightforward and robust synthesis of monodisperse surface-functionalized gold nanoclusters

    Directory of Open Access Journals (Sweden)

    Silvia Varela-Aramburu

    2016-09-01

    Full Text Available Gold nanoclusters are small (1–3 nm nanoparticles with a high surface area that are useful for biomedical studies and drug delivery. The synthesis of small, surface-functionalized gold nanoclusters is greatly dependent on the reaction conditions. Here, we describe a straightforward, efficient and robust room temperature one-pot synthesis of 2 nm gold nanoclusters using thioglucose as a reducing and stabilizing agent, which was discovered by serendipity. The resultant monodisperse gold nanoclusters are more stable than those generated using some other common methods. The carboxylic acid contained in the stabilizing agent on the cluster surface serves as anchor for nanocluster functionalization. Alternatively, the addition of thiols serves to functionalize the nanoclusters. The resulting non-cytotoxic nanoclusters are taken up by cells and constitute a tuneable platform for biomedical applications including drug delivery.

  13. Ordering and site occupancy of ternary elements in Fe{sub 3}Al

    Energy Technology Data Exchange (ETDEWEB)

    Rademacher, Thomas; Al-Kassab, Talaat; Kirchheim, Reiner [Institut fuer Materialphysik, Universitaet Goettingen (Germany)

    2009-07-01

    Ordered iron aluminides exhibit a number of advantageous properties, such as high-temperature strength, corrosion resistance and low cost. Therefore, iron aluminum based alloys are considered to replace in some cases high alloyed ferritic stainless steels, especially DO{sub 3} - ordered Fe{sub 3}Al. The mechanical properties and high-temperature stability can be optimized when ternary elements are added. In this study the site occupancy of ternary elements (4at.%V, 5at.%Cr, 5at.%Mn) has been investigated by means of Atom Probe Tomography (APT). A special analysis algorithm allows resolving the atom layers for different measurement directions which enables determining site preferences. Additionally, comparing the succession of layers with simulations the binding energies of the participating elements can be estimated.

  14. On the ternary Ag – Cu – Ga system: Electromotive force measurement and thermodynamic modeling

    International Nuclear Information System (INIS)

    Gierlotka, Wojciech; Jendrzejczyk-Handzlik, Dominika; Fitzner, Krzysztof; Handzlik, Piotr

    2015-01-01

    The ternary silver–copper–gallium system found application as a solder material in jewel crafting and electronics, thus a phase diagram of this system seems to be important tool, which is necessary for a proper application of different alloys. The activity of gallium in liquid phase was determined by electromotive measurement technique and after that the equilibrium diagram of Ag – Cu – Ga was modeled based on available experimental data using Calphad approach. A set of Gibbs energies was found and used for calculation a phase diagram and thermodynamic properties of liquid phase. The experimental data was reproduced well by calculation. - Highlights: • For the first time activity of Ga in liquid Ag – Cu – Ga alloys was measured. • For the first time the ternary Ag – Cu – Ga system was thermodynamically modeled. • Modeled Ag – Cu – Ga system reproduces experimental data well

  15. Ternary cobalt-molybdenum-zirconium coatings for alternative energies

    Science.gov (United States)

    Yar-Mukhamedova, Gulmira; Ved', Maryna; Sakhnenko, Nikolay; Koziar, Maryna

    2017-11-01

    Consistent patterns for electrodeposition of Co-Mo-Zr coatings from polyligand citrate-pyrophosphate bath were investigated. The effect of both current density amplitude and pulse on/off time on the quality, composition and surface morphology of the galvanic alloys were determined. It was established the coating Co-Mo-Zr enrichment by molybdenum with current density increasing up to 8 A dm-2 as well as the rising of pulse time and pause duration promotes the content of molybdenum because of subsequent chemical reduction of its intermediate oxides by hydrogen ad-atoms. It was found that the content of the alloying metals in the coating Co-Mo-Zr depends on the current density and on/off times extremely and maximum Mo and Zr content corresponds to the current density interval 4-6 A dm-2, on-/off-time 2-10 ms. Chemical resistance of binary and ternary coatings based on cobalt is caused by the increased tendency to passivity and high resistance to pitting corrosion in the presence of molybdenum and zirconium, as well as the acid nature of their oxides. Binary coating with molybdenum content not less than 20 at.% and ternary ones with zirconium content in terms of corrosion deep index are in a group ;very proof;. It was shown that Co-Mo-Zr alloys exhibits the greatest level of catalytic properties as cathode material for hydrogen electrolytic production from acidic media which is not inferior a platinum electrode. The deposits Co-Mo-Zr with zirconium content 2-4 at.% demonstrate high catalytic properties in the carbon(II) oxide conversion. This confirms the efficiency of materials as catalysts for the gaseous wastes purification and gives the reason to recommend them as catalysts for red-ox processes activating by oxygen as well as electrode materials for red-ox batteries.

  16. Solidification paths of multicomponent monotectic aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Mirkovic, Djordje; Groebner, Joachim [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Street 42, D-38678 Clausthal-Zellerfeld (Germany); Schmid-Fetzer, Rainer [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Street 42, D-38678 Clausthal-Zellerfeld (Germany)], E-mail: schmid-fetzer@tu-clausthal.de

    2008-10-15

    Solidification paths of three ternary monotectic alloy systems, Al-Bi-Zn, Al-Sn-Cu and Al-Bi-Cu, are studied using thermodynamic calculations, both for the pertinent phase diagrams and also for specific details concerning the solidification of selected alloy compositions. The coupled composition variation in two different liquids is quantitatively given. Various ternary monotectic four-phase reactions are encountered during solidification, as opposed to the simple binary monotectic, L' {yields} L'' + solid. These intricacies are reflected in the solidification microstructures, as demonstrated for these three aluminum alloy systems, selected in view of their distinctive features. This examination of solidification paths and microstructure formation may be relevant for advanced solidification processing of multicomponent monotectic alloys.

  17. Enhanced pulsed magneto-motive ultrasound imaging using superparamagnetic nanoclusters

    International Nuclear Information System (INIS)

    Mehrmohammadi, M; Qu, M; Emelianov, S Y; Yoon, K Y; Johnston, K P

    2011-01-01

    Recently, pulsed magneto-motive ultrasound (pMMUS) imaging augmented with ultra-small magnetic nanoparticles has been introduced as a tool capable of imaging events at molecular and cellular levels. The sensitivity of a pMMUS system depends on several parameters, including the size, geometry and magnetic properties of the nanoparticles. Under the same magnetic field, larger magnetic nanostructures experience a stronger magnetic force and produce larger displacement, thus improving the sensitivity and signal-to-noise ratio (SNR) of pMMUS imaging. Unfortunately, large magnetic iron-oxide nanoparticles are typically ferromagnetic and thus are very difficult to stabilize against colloidal aggregation. In the current study we demonstrate improvement of pMMUS image quality by using large size superparamagnetic nanoclusters characterized by strong magnetization per particle. Water-soluble magnetic nanoclusters of two sizes (15 and 55 nm average size) were synthesized from 3 nm iron precursors in the presence of citrate capping ligand. The size distribution of synthesized nanoclusters and individual nanoparticles was characterized using dynamic light scattering (DLS) analysis and transmission electron microscopy (TEM). Tissue mimicking phantoms containing single nanoparticles and two sizes of nanoclusters were imaged using a custom-built pMMUS imaging system. While the magnetic properties of citrate-coated nanoclusters are identical to those of superparamagnetic nanoparticles, the magneto-motive signal detected from nanoclusters is larger, i.e. the same magnetic field produced larger magnetically induced displacement. Therefore, our study demonstrates that clusters of superparamagnetic nanoparticles result in pMMUS images with higher contrast and SNR.

  18. Luminescent Metal Nanoclusters for Potential Chemosensor Applications

    Directory of Open Access Journals (Sweden)

    Muthaiah Shellaiah

    2017-12-01

    Full Text Available Studies of metal nanocluster (M-NCs-based sensors for specific analyte detection have achieved significant progress in recent decades. Ultra-small-size (<2 nm M-NCs consist of several to a few hundred metal atoms and exhibit extraordinary physical and chemical properties. Similar to organic molecules, M-NCs display absorption and emission properties via electronic transitions between energy levels upon interaction with light. As such, researchers tend to apply M-NCs in diverse fields, such as in chemosensors, biological imaging, catalysis, and environmental and electronic devices. Chemo- and bio-sensory uses have been extensively explored with luminescent NCs of Au, Ag, Cu, and Pt as potential sensory materials. Luminescent bi-metallic NCs, such as Au-Ag, Au-Cu, Au-Pd, and Au-Pt have also been used as probes in chemosensory investigations. Both metallic and bi-metallic NCs have been utilized to detect various analytes, such as metal ions, anions, biomolecules, proteins, acidity or alkalinity of a solution (pH, and nucleic acids, at diverse detection ranges and limits. In this review, we have summarized the chemosensory applications of luminescent M-NCs and bi-metallic NCs.

  19. Catalytic photooxidation of pentachlorophenol using semiconductor nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    WILCOXON,JESS P.

    2000-04-17

    Pentachlorophenol (PCP) is a toxic chlorinated aromatic molecule widely used as fungicide, a bactericide and a wood preservation, and thus ubiquitous in the environment. The authors report photo-oxidation of PCP using a variety of nanosize semiconductor metal oxides and sulfides in both aqueous and polar organic solvents and compare the photo-oxidation kinetics of these nanoclusters to widely studied bulk powders like Degussa P-25 TiO{sub 2} and CdS. They study both the light intensity dependence of PCP photooxidation for nanosize SnO{sub 2} and the size dependence of PCP photooxidation for both nanosize SnO{sub 2} and MoS{sub 2}. They find an extremely strong size dependence for the latter which they attribute to its size-dependent band gap and the associated change in redox potentials due to quantum confinement of the hole-electron pair. The authors show that nanosize MoS{sub 2} with a diameter of d=3.0 nm and an absorbance edge of {approximately}450 nm is a very effective photooxidation catalyst for complete PCP mineralization, even when using only visible light irradiation.

  20. Effect of composition on the superplasticity of aluminium scandium alloys

    International Nuclear Information System (INIS)

    Bradley, E.L. III; Morris, J.W. Jr.

    1992-01-01

    Several aluminum alloys have been shown to exhibit superplasticty in the as-rolled condition. Previous work has shown that aluminum-scandium alloys also exhibit this behavior, but only with the addition of ternary alloying elements such as lithium and magnesium. These additions raised the strain-rate sensitivity of these alloys to 0.4-0.5 for selected strain rates at temperatures above 400 degrees C. A systematic study was undertaken of five Al-Sc alloys with varying lithium and magnesium concentrations in order to fully characterize the high temperature deformation mechanism. Specimens were deformed at a constant strain rate to predetermined true strains for textural and microstructural characterization. In this paper work is presented that will elucidate the effect of these different ternary additives on the superplastic deformation mechanism in these alloys

  1. Magnetic interaction reversal in watermelon nanostructured Cr-doped Fe nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Maninder; Dai, Qilin; Bowden, Mark; Engelhard, Mark; Wu, Yaqiao; Tang, Jinke; Qiang, You

    2013-01-01

    Cr-doped core-shell Fe/Fe-oxide nanoclusters (NCs) were synthesized at varied atomic percentages of Cr from 0 at. % to 8 at. %. The low concentrations of Cr (<10 at. %) were selected in order to inhibit the complete conversion of the Fe-oxide shell to Cr2O3 and the Fe core to FeCr alloy. The magnetic interaction in Fe/Fe-oxide NCs (rv25 nm) can be controlled by antiferromagnetic Cr-dopant. We report the origin of r-FeCr phase at very low Cr concentration (2 at. %) unlike in previous studies, and the interaction reversal from dipolar to exchange interaction in watermelon-like Cr-doped core-shell NCs. The giant magnetoresistance (GMR) effect,1,2 where an antiferromagnetic (AFM) exchange coupling exists between two ferromagnetic (FM) layers separated by a certain type of magnetic or non-magnetic spacer,3 has significant potential for application in the magnetic recording industry. Soon after the discovery of the GMR, the magnetic properties of multilayer systems (FeCr) became a subject of intensive study. The application of bulk iron-chromium (Fe-Cr) alloys has been of great interest, as these alloys exhibit favorable prop- erties including corrosion resistance, high strength, hardness, low oxidation rate, and strength retention at elevated temper- ature. However, the structural and magnetic properties of Cr-doped Fe nanoclusters (NCs) have not been investigated in-depth. Of all NCs, Fe-based clusters have unique magnetic properties as well as favorable catalytic characteristics in reactivity, selectivity, and durability.4 The incorporation of dopant of varied type and concentration in Fe can modify its chemical ordering, thereby optimizing its electrical, optical, and magnetic properties and opening up many new applications. The substitution of an Fe atom (1.24 A°) by a Cr atom (1.25 A° ) can easily modify the magnetic properties, since (i) the curie temperature (Tc ) of Fe is 1043 K, while Cr is an itinerant AFM with a bulk Neel temperature TN =311 K, and (ii) Fe

  2. High-Efficient Circuits for Ternary Addition

    Directory of Open Access Journals (Sweden)

    Reza Faghih Mirzaee

    2014-01-01

    Full Text Available New ternary adders, which are fundamental components of ternary addition, are presented in this paper. They are on the basis of a logic style which mostly generates binary signals. Therefore, static power dissipation reaches its minimum extent. Extensive different analyses are carried out to examine how efficient the new designs are. For instance, the ternary ripple adder constructed by the proposed ternary half and full adders consumes 2.33 μW less power than the one implemented by the previous adder cells. It is almost twice faster as well. Due to their unique superior characteristics for ternary circuitry, carbon nanotube field-effect transistors are used to form the novel circuits, which are entirely suitable for practical applications.

  3. Laser alloyed Al-Ni-Fe coatings

    CSIR Research Space (South Africa)

    Pityana, SL

    2008-10-01

    Full Text Available The aim of this work was to produce crack-free thin surface layers consisting of binary (Al-Ni, Al-Fe) and ternary (Al-Ni-Fe) intermetallic phases by means of a high power laser beam. The laser surface alloying was carried out by melting Fe and Ni...

  4. First-principles interatomic potentials for transition-metal aluminides. III. Extension to ternary phase diagrams

    International Nuclear Information System (INIS)

    Widom, Mike; Al-Lehyani, Ibrahim; Moriarty, John A.

    2000-01-01

    Modeling structural and mechanical properties of intermetallic compounds and alloys requires detailed knowledge of their interatomic interactions. The first two papers of this series [Phys. Rev. B 56, 7905 (1997); 58, 8967 (1998)] derived first-principles interatomic potentials for transition-metal (TM) aluminides using generalized pseudopotential theory (GPT). Those papers focused on binary alloys of aluminum with first-row transition metals and assessed the ability of GPT potentials to reproduce and elucidate the alloy phase diagrams of Al-Co and Al-Ni. This paper addresses the phase diagrams of the binary alloy Al-Cu and the ternary systems Al-Co-Cu and Al-Co-Ni, using GPT pair potentials calculated in the limit of vanishing transition-metal concentration. Despite this highly simplifying approximation, we find rough agreement with the known low-temperature phase diagrams, up to 50% total TM concentration provided the Co fraction is below 25%. Full composition-dependent potentials and many-body interactions would be required to correct deficiencies at higher Co concentration. Outside this troublesome region, the experimentally determined stable and metastable phases all lie on or near the convex hull of a scatter plot of energy versus composition. We verify, qualitatively, reported solubility ranges extending binary alloys into the ternary diagram in both Al-Co-Cu and Al-Co-Ni. Finally, we reproduce previously conjectured transition-metal positions in the decagonal quasicrystal phase. (c) 2000 The American Physical Society

  5. First-principles interatomic potentials for transition-metal aluminides. III. Extension to ternary phase diagrams

    Science.gov (United States)

    Widom, Mike; Al-Lehyani, Ibrahim; Moriarty, John A.

    2000-08-01

    Modeling structural and mechanical properties of intermetallic compounds and alloys requires detailed knowledge of their interatomic interactions. The first two papers of this series [Phys. Rev. B 56, 7905 (1997); 58, 8967 (1998)] derived first-principles interatomic potentials for transition-metal (TM) aluminides using generalized pseudopotential theory (GPT). Those papers focused on binary alloys of aluminum with first-row transition metals and assessed the ability of GPT potentials to reproduce and elucidate the alloy phase diagrams of Al-Co and Al-Ni. This paper addresses the phase diagrams of the binary alloy Al-Cu and the ternary systems Al-Co-Cu and Al-Co-Ni, using GPT pair potentials calculated in the limit of vanishing transition-metal concentration. Despite this highly simplifying approximation, we find rough agreement with the known low-temperature phase diagrams, up to 50% total TM concentration provided the Co fraction is below 25%. Full composition-dependent potentials and many-body interactions would be required to correct deficiencies at higher Co concentration. Outside this troublesome region, the experimentally determined stable and metastable phases all lie on or near the convex hull of a scatter plot of energy versus composition. We verify, qualitatively, reported solubility ranges extending binary alloys into the ternary diagram in both Al-Co-Cu and Al-Co-Ni. Finally, we reproduce previously conjectured transition-metal positions in the decagonal quasicrystal phase.

  6. Deposition and characterization of Pt nanocluster films by means of gas aggregation cluster source

    Energy Technology Data Exchange (ETDEWEB)

    Kylián, Ondřej, E-mail: ondrej.kylian@gmail.com; Prokeš, Jan; Polonskyi, Oleksandr; Čechvala, Juraj; Kousal, Jaroslav; Pešička, Josef; Hanuš, Jan; Biederman, Hynek

    2014-11-28

    In this study we report on the deposition of Pt nanocluster films prepared by gas aggregation source that was operated with argon as working gas. The aim of this study was optimization of deposition process as well as determination of properties of deposited nanocluster films and their temporal stability. It was found that the production of Pt nanoclusters reached maximum value for pressure of 100 Pa and increases monotonously with magnetron current. The deposition rate at optimized deposition conditions was 0.7 nm of the Pt nanocluster film per second. Deposited films were porous and composed of 4 nm Pt nanoclusters. The nanoclusters were metallic and no sights of their oxidation were observed after 1 year on open air as witnessed by X-ray photoelectron spectroscopy. Regarding the electrical properties, a dramatic decrease of the resistivity was observed with increasing amount of deposited nanoclusters. This decrease saturated for the films approximately 50 nm thick. Such behavior indicates transition between different mechanisms of electrical conductivity: charge hopping for thin discontinuous films and current conduction through conducting path formed when higher amount of nanoclusters is deposited. Different mechanisms of electrical conduction for thin and thick layers of Pt were confirmed by subsequent investigation of temperature dependence of resistivity. In addition, no changes in resistivity were observed after one year on open air that confirms stability of produced Pt nanocluster films. - Highlights: • Pt nanocluster films were deposited by gas aggregation nanocluster source. • Conditions leading to effective deposition of Pt nanocluster films were found. • Deposited nanocluster films have good temporal stability. • Electrical properties of Pt films were found to depend on their thickness.

  7. Hydrogen solubility in austenite of Fe-Ni-Cr alloys

    International Nuclear Information System (INIS)

    Zhirnova, V.V.; Mogutnov, B.M.; Tomilin, I.A.

    1981-01-01

    Hydrogen solubility in Fe-Ni-Cr alloys at 600-1000 deg C is determined. Hydrogen solubility in ternary alloys can not be predicted on the basis of the data on its solubility in binary Fe-Ni, Fe-Cr alloys. Chromium and nickel effect on hydrogen solubility in iron is insignificant in comparison with the effect of these elements on carbon or nitrogen solubility [ru

  8. The ternary system Zr-Cr-O. Equilibrium diagrams in the zirconium rich zone at different temperatures

    International Nuclear Information System (INIS)

    Gonzalez, Ruben O.; Gribaudo, Luis M.

    2003-01-01

    Equilibria among hcp α, bcc β solid solutions and cubic C 15 type intermetallic ZrCr 2 are represented graphically over Gibbs triangles in the Zr-rich zone of the ternary Zr-Cr-O system. Experimental results are obtained from zirconium-based alloys containing different oxygen compositions (0,24 and 0,62 % at.). Phase boundaries of the ternary system are extrapolated to the Zr-O and Zr-Cr binaries. The obtained values are compared to recently published evaluated diagrams of these two systems. Chromium compositions of the studied alloys were 0,3 - 1 - 2 - 4 and 15 at. %. Thermal treatment temperatures in order to allow equilibria in alloys were 840, 860, 900 and 960 C degrees. (author)

  9. "light-on" sensing of antioxidants using gold nanoclusters

    KAUST Repository

    Hu, Lianzhe; Deng, Lin; Alsaiari, Shahad K.; Zhang, Dingyuan; Khashab, Niveen M.

    2014-01-01

    preservatives, and cosmetics has proved to be very vital. Gold nanoclusters (Au-NCs) have a core size below 2 nm and contain several metal atoms. They have interesting photophysical properties, are readily functionalized, and are safe to use in various

  10. In-vitro Synthesis of Gold Nanoclusters in Neurons

    Science.gov (United States)

    2016-04-01

    ARL-TN-0753 ● APR 2016 US Army Research Laboratory In-vitro Synthesis of Gold Nanoclusters in Neurons by Maggie Gillan and...longer needed. Do not return it to the originator. ARL-TN-0753 ● APR 2016 US Army Research Laboratory In-vitro Synthesis of...

  11. Organization of copper nanoclusters in Langmuir–Blodgett films

    Indian Academy of Sciences (India)

    Stable nanoclusters of Cu were synthesized using Langmuir–Blodgett films of octadecylsuccinic acid (ODSA) as template. The Langmuir–Blodgett films of ODSA formed from subphase containing copper ions were first subjected to sulphidation (S) using sodium sulphide and then hydrogenated (H) using hydrogen gas.

  12. Enhanced electrochemical water oxidation: the impact of nanoclusters and nanocavities

    NARCIS (Netherlands)

    Zhang, X.; Cao, C.; Bieberle, A.

    2017-01-01

    The structures of transition metal surfaces and metal oxides are commonly believed to have a significant effect on the catalytic reactions. Density functional theory calculations are therefore used in this study to investigate the oxygen evolution reaction (OER) over nanostructured, i.e. nanocluster

  13. Nanoclustering as a dominant feature of plasma membrane organization

    NARCIS (Netherlands)

    Garcia-Parajo, M.F.; Cambi, A.; Torreno-Pina, J.A.; Thompson, N.; Jacobson, K.

    2014-01-01

    Early studies have revealed that some mammalian plasma membrane proteins exist in small nanoclusters. The advent of super-resolution microscopy has corroborated and extended this picture, and led to the suggestion that many, if not most, membrane proteins are clustered at the plasma membrane at

  14. Phase Equilibria of the Sn-Ni-Si Ternary System and Interfacial Reactions in Sn-(Cu)/Ni-Si Couples

    Science.gov (United States)

    Fang, Gu; Chen, Chih-chi

    2015-07-01

    Interfacial reactions in Sn/Ni-4.5 wt.%Si and Sn-Cu/Ni-4.5 wt.%Si couples at 250°C, and Sn-Ni-Si ternary phase equilibria at 250°C were investigated in this study. Ni-Si alloys, which are nonmagnetic, can be regarded as a diffusion barrier layer material in flip chip packaging. Solder/Ni-4.5 wt.%Si interfacial reactions are crucial to the reliability of soldered joints. Phase equilibria information is essential for development of solder/Ni-Si materials. No ternary compound is present in the Sn-Ni-Si ternary system at 250°C. Extended solubility of Si in the phases Ni3Sn2 and Ni3Sn is 3.8 and 6.1 at.%, respectively. As more Si dissolves in these phases their lattice constants decrease. No noticeable ternary solubility is observed for the other intermetallics. Interfacial reactions in solder/Ni-4.5 wt.%Si are similar to those for solder/Ni. Si does not alter the reaction phases. No Si solubility in the reaction phases was detected, although rates of growth of the reaction phases were reduced. Because the alloy Ni-4.5 wt.%Si reacts more slowly with solders than pure Ni, the Ni-4.5 wt.%Si alloy could be a potential new diffusion barrier layer material for flip chip packaging.

  15. Evolution of embedded lithium nanoclusters in lithium implanted alumina

    International Nuclear Information System (INIS)

    Gaikwad, P.V.; Sharma, S.K.; Mukherjee, S.; Sudarshan, K.; Kshirsagar, A.; Pujari, P.K.

    2016-01-01

    High dose of ion implantation followed by annealing is considered a feasible way to generate thermally stable nanoclusters inside a transparent host matrix. Low energy (50 keV) Li ions have been implanted into single crystals of alumina with different fluence (1 × 10"1"5–1 × 10"1"7 ions/cm"2). The samples have been annealed at temperatures ranging from 500 to 1100 °C in air in step of 100 °C. Depth dependent Doppler broadening measurements have been carried out using high purity germanium detector coupled to a variable energy slow positron beam. Fractional area in the central and wing regions of Doppler broadened annihilation radiation spectrum, namely, S- and W- parameters, were evaluated from each spectrum. Any variation in positron annihilation probability with valence and core electrons which occurs on trapping of positrons at a defect site is reflected in these parameters. The effect of ion fluence and annealing temperature on evolution of defects and formation of embedded Li nanoclusters have been studied by indexing the variation in line shape S- (W-) parameter as a function of positron implantation depth. These studies supplemented by theoretical calculations confirm that with annealing up to 700 °C, vacancy clusters are created due to the aggregation of vacancies wherein Li nanoclusters are formed. On annealing at higher temperature, there is evidence for the breakdown of these Li clusters leaving behind vacancy clusters in the samples. - Highlights: • Embedded Li nanoclusters are efficiently created by annealing Li implanted Al_2O_3 crystal. • Depth dependent DBAR is a suitable method to characterize embedded nanoclusters. • The formation of Li nanoclusters is assisted by vacancy migration to form clusters. • At very high annealing temperature (>1000 °C), Li nanoclusters undergo breakdown. • e"+ annihilation at V_A_l site shows a unique observation i.e. a reduction in S-parameter.

  16. Experimental and thermodynamic study of the Er-H-Zr ternary system

    International Nuclear Information System (INIS)

    Mascaro, A.

    2012-01-01

    This work at CEA is being achieved in the framework of the development of an innovating concept including the neutronic solid burnable poison, such as erbium, inside the cladding of pressurized water reactors. These new claddings are constituted by a liner of a zirconium base alloy slightly enriched in erbium between two liners of industrial zirconium alloys. Into the reactor core, the water dissociates at the surface of the cladding. So it is interesting to evaluate the interactions between the hydrogen released and the Zr-Er alloy. To do so, the Er-H-Zr ternary system has to be determined such similarly to its associated binaries. This can be done by experimental determination and by thermodynamic modelling. Both techniques were used in this work. Er-Zr and H-Zr have already been studied experimentally and modelled, but the Er-H binary system is almost unknown. So, we studied it experimentally. Then, it has been modelled using the Calphad method. We obtain a new evaluation of the Er-H binary system with phases limits rather different than what has been proposed in the literature. In order to determine the phase limits and, the potential existence of a ternary compound in the Er-H-Zr ternary system, an experimental study has been carried out. An original technique has been used to obtain the chemical compositions: ERDA combined with RBS. In this study, we propose a new isothermal section at 350 C of the Er-H-Zr ternary system. About the modelling, the compatibility of the three modelled binaries has been checked in order to optimize the ternary system by the projection of the three binaries. The calculation obtained is in good agreement with the experimental isothermal section at 350 C determined in our work. Finally, uniaxial tensile test campaigns have been conducted to evaluate the impact of erbium and/or hydrogen on the mechanical properties of an industrial zirconium pure alloy. We evidenced a hardening effect of erbium and hydrogen but these effects are not

  17. Thermodynamic Database for Zirconium Alloys

    International Nuclear Information System (INIS)

    Jerlerud Perez, Rosa

    2003-05-01

    For many decades zirconium alloys have been commonly used in the nuclear power industry as fuel cladding material. Besides their good corrosion resistance and acceptable mechanical properties the main reason of using these alloys is the low neutron absorption. Zirconium alloys are exposed to a very severe environment during the nuclear fission process and there is a demand for better design of this material. To meet this requirement a thermodynamic database is developed to support material designers. In this thesis some aspects about the development of a thermodynamic database for zirconium alloys are presented. A thermodynamic database represents an important facility in applying thermodynamic equilibrium calculations for a given material providing: 1) relevant information about the thermodynamic properties of the alloys e.g. enthalpies, activities, heat capacity, and 2) significant information for the manufacturing process e.g. heat treatment temperature. The basic information in the database is first the unary data, i.e. pure elements; those are taken from the compilation of the Scientific Group Thermodata Europe (SGTE) and then the binary and ternary systems. All phases present in those binary and ternary systems are described by means of the Gibbs energy dependence on composition and temperature. Many of those binary systems have been taken from published or unpublished works and others have been assessed in the present work. All the calculations have been made using Thermo C alc software and the representation of the Gibbs energy obtained by applying Calphad technique

  18. A high-throughput search for new ternary superalloys

    Science.gov (United States)

    Nyshadham, Chandramouli; Hansen, Jacob; Oses, Corey; Curtarolo, Stefano; Hart, Gus

    In 2006 an unexpected new superalloy, Co3[Al,W], was discovered. This new alloy is cobalt-based, in contrast to conventional superalloys, which are nickel-based. Inspired by this new discovery, we performed first-principles calculations, searching through 2224 ternary metallic systems of the form A3[B0.5C0.5], where A = Ni/Co/Fe and [B, C] = all binary combinations of 40 different elements chosen from the periodic table. We found 175 new systems that are better than the Co3[Al, W] superalloy. 75 of these systems are brand new--they have never been reported in experimental literature. These 75 new potential superalloys are good candidates for further experiments. Our calculations are consistent with current experimental literature where data exists. Work supported under: ONR (MURI N00014-13-1-0635).

  19. Description of the ternary system Cu-Ge-Te

    International Nuclear Information System (INIS)

    Dogguy, M.; Carcaly, C.; Rivet, J.; Flahaut, J.

    1977-01-01

    The Cu-Ge-Te ternary system has been studied by DTA and by crystallographic and metallographic analysis. The existence of a ternary compound Cu 2 GeTe 3 is demonstrated; this compound has a ternary incongruent melting point at 500 0 C. This ternary compound has a superstructure of a zinc blende type. The study shows the existence of five ternary eutectics. Two liquid-liquid miscibility gaps exist: the first is situated entirely in the ternary system; the second gives a monotectic region within the ternary system. (Auth.)

  20. Effect of aluminum content on the passivation behavior of Fe-Al alloys in sulfuric acid solution

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Luu, W.C.; Wu, J.K.

    2006-01-01

    -Al alloys, which the Al content of alloy exceeds 19 at %, have wide passivation regions with low passivation current. However, when the Al content of Fe-Al alloys exceeds this range, the increment of Al content has slight influence on passivation behavior compared with ternary Cr addition....

  1. All-optical symmetric ternary logic gate

    Science.gov (United States)

    Chattopadhyay, Tanay

    2010-09-01

    Symmetric ternary number (radix=3) has three logical states (1¯, 0, 1). It is very much useful in carry free arithmetical operation. Beside this, the logical operation using this type of number system is also effective in high speed computation and communication in multi-valued logic. In this literature all-optical circuits for three basic symmetrical ternary logical operations (inversion, MIN and MAX) are proposed and described. Numerical simulation verifies the theoretical model. In this present scheme the different ternary logical states are represented by different polarized state of light. Terahertz optical asymmetric demultiplexer (TOAD) based interferometric switch has been used categorically in this manuscript.

  2. Performance Estimation for Lowpass Ternary Filters

    Directory of Open Access Journals (Sweden)

    Brenton Steele

    2003-11-01

    Full Text Available Ternary filters have tap values limited to −1, 0, or +1. This restriction in tap values greatly simplifies the multipliers required by the filter, making ternary filters very well suited to hardware implementations. Because they incorporate coarse quantisation, their performance is typically limited by tap quantisation error. This paper derives formulae for estimating the achievable performance of lowpass ternary filters, thereby allowing the number of computationally intensive design iterations to be reduced. Motivated by practical communications systems requirements, the performance measure which is used is the worst-case stopband attenuation.

  3. Development of Cu-Hf-Al ternary systems and tungsten wire/particle reinforced Cu48Hf43Al9 bulk metallic glass composites for strengthening

    International Nuclear Information System (INIS)

    Park, Joyoung; An, Jihye; Choi-Yim, Haein

    2010-01-01

    Stable bulk glass forming alloys can be developed over a wide range of compositions in Cu-Hf-Al ternary systems starting from the Cu 49 Hf 42 Al 9 bulk metallic glass. Ternary Cu-Hf-Al alloys can be cast directly from the melt into copper molds to form fully amorphous strips with thicknesses of 1 to 6 mm. The maximum critical diameter of the new Cu-Hf-Al ternary alloy was 6 mm. X-ray diffraction patterns were used to confirm the amorphous nature of the ternary Cu-Hf-Al alloys. To increase the toughness of these metallic glasses, we reinforced the Cu 48 Hf 43 Al 9 bulk metallic glass-forming liquid with a 50% volume fraction of tungsten particles and an 80% volume fraction of tungsten wires with diameters of 242.4 μm. Composites with a critical diameter of 7 mm and length 70 mm were synthesized. The structure of the composites was confirmed by using X-ray diffraction (XRD), and the scanning electron microscopy (SEM). The mechanical properties of the composites were studied in compression tests. The thermal stability and the crystallization processes of the Cu-Hf-Al alloys and composites were investigated by using differential scanning calorimetry (DSC). Values of the glass transition temperature (T g ), the crystallization temperature (T x ), and the supercooled liquid region (ΔT = T x - T g ) are given in this paper.

  4. Mechanical Properties of Magnesium-Rare Earth Alloy Systems: A Review

    Directory of Open Access Journals (Sweden)

    Sravya Tekumalla

    2014-12-01

    Full Text Available Magnesium-rare earth based alloys are increasingly being investigated due to the formation of highly stable strengthening phases, activation of additional deformation modes and improvement in mechanical properties. Several investigations have been done to study the effect of rare earths when they are alloyed to pure magnesium and other Mg alloys. In this review, the mechanical properties of the previously investigated different magnesium-rare earth based binary alloys, ternary alloys and other higher alloys with more than three alloying elements are presented.

  5. Hydrophilic magnetic nanoclusters with thermo-responsive properties and their drug controlled release

    International Nuclear Information System (INIS)

    Meerod, Siraprapa; Rutnakornpituk, Boonjira; Wichai, Uthai; Rutnakornpituk, Metha

    2015-01-01

    Synthesis and drug controlled release properties of thermo-responsive magnetic nanoclusters grafted with poly(N-isopropylacrylamide) (poly(NIPAAm)) and poly(NIPAAm-co-poly(ethylene glycol) methyl ether methacrylate) (PEGMA) copolymers were described. These magnetic nanoclusters were synthesized via an in situ radical polymerization in the presence of acrylamide-grafted magnetic nanoparticles (MNPs). Poly(NIPAAm) provided thermo-responsive properties, while PEGMA played a role in good water dispersibility to the nanoclusters. The ratios of PEGMA to NIPAAm in the (co)polymerization in the presence of the MNPs were fine-tuned such that the nanoclusters with good water dispersibility, good magnetic sensitivity and thermo responsiveness were obtained. The size of the nanoclusters was in the range of 50–100 nm in diameter with about 100–200 particles/cluster. The nanoclusters were well dispersible in water at room temperature and can be suddenly agglomerated when temperature was increased beyond the lower critical solution temperature (LCST) (32 °C). The release behavior of an indomethacin model drug from the nanoclusters was also investigated. These novel magnetic nanoclusters with good dispersibility in water and reversible thermo-responsive properties might be good candidates for the targeting drug controlled release applications. - Highlights: • Nanoclusters with good water dispersibility and magnetic response were prepared. • They were grafted with thermo-responsive poly(NIPAAm) and/or poly(PEGMA). • Poly(NIPAAm) provided thermo-responsive properties to the nanoclusters. • Poly(PEGMA) provided good water dispersibilityto the nanoclusters. • Accelerated and controllable releases of a drug from the nanoclusters were shown

  6. Photoluminescent Gold Nanoclusters in Cancer Cells: Cellular Uptake, Toxicity, and Generation of Reactive Oxygen Species

    OpenAIRE

    Marija Matulionyte; Dominyka Dapkute; Laima Budenaite; Greta Jarockyte; Ricardas Rotomskis

    2017-01-01

    In recent years, photoluminescent gold nanoclusters have attracted considerable interest in both fundamental biomedical research and practical applications. Due to their ultrasmall size, unique molecule-like optical properties, and facile synthesis gold nanoclusters have been considered very promising photoluminescent agents for biosensing, bioimaging, and targeted therapy. Yet, interaction of such ultra-small nanoclusters with cells and other biological objects remains poorly understood. The...

  7. Mass spectrometric identification of Au68(SR)34 molecular gold nanoclusters with 34-electron shell closing.

    Science.gov (United States)

    Dass, Amala

    2009-08-26

    The molecular formula Au(68)(SCH(2)CH(2)Ph)(34) has been assigned to the 14 kDa nanocluster using MALDI-TOF mass spectrometry. The 34-electron shell closing in a macroscopically obtained thiolated gold nanocluster is demonstrated. The Au(68) nanocluster is predicted to have a 49 atom Marks decahedral core with 19 inner core atoms and 30 outer atoms chelating with the staple motifs. The nanoclusters' predicted formulation is [Au](19+30) [Au(SR)(2)](11) [Au(2)(SR)(3)](4).

  8. Electrostatic Interactions Positively Regulate K-Ras Nanocluster Formation and Function▿

    Science.gov (United States)

    Plowman, Sarah J.; Ariotti, Nicholas; Goodall, Andrew; Parton, Robert G.; Hancock, John F.

    2008-01-01

    The organization of Ras proteins into plasma membrane nanoclusters is essential for high-fidelity signal transmission, but whether the nanoscale enviroments of different Ras nanoclusters regulate effector interactions is unknown. We show using high-resolution spatial mapping that Raf-1 is recruited to and retained in K-Ras-GTP nanoclusters. In contrast, Raf-1 recruited to the plasma membrane by H-Ras is not retained in H-Ras-GTP nanoclusters. Similarly, upon epidermal growth factor receptor activation, Raf-1 is preferentially recruited to K-Ras-GTP and not H-Ras-GTP nanoclusters. The formation of K-Ras-GTP nanoclusters is inhibited by phosphorylation of S181 in the C-terminal polybasic domain or enhanced by blocking S181 phosphorylation, with a concomitant reduction or increase in Raf-1 plasma membrane recruitment, respectively. Phosphorylation of S181 does not, however, regulate in vivo interactions with the nanocluster scaffold galectin-3 (Gal3), indicating separate roles for the polybasic domain and Gal3 in driving K-Ras nanocluster formation. Together, these data illustrate that Ras nanocluster composition regulates effector recruitment and highlight the importance of lipid/protein nanoscale environments to the activation of signaling cascades. PMID:18458061

  9. Coercivity enhancement in HDDR near-stoichiometric ternary Nd–Fe–B powders

    International Nuclear Information System (INIS)

    Wan, Fangming; Han, Jingzhi; Zhang, Yinfeng; Wang, Changsheng; Liu, Shunquan; Yang, Jinbo; Yang, Yingchang; Sun, Aizhi; Yang, Fuqiang; Song, Renbo

    2014-01-01

    Anisotropic HDDR near-stoichiometric ternary Nd–Fe–B powders have been prepared. The coercivity of the powders was improved from 208.6 to 980.1 kA/m by the subsequent diffusion treatment using the Pr–Cu alloy. For comparison, Nd 11.5 Fe 80.7 B 6.1 Pr 1.2 Cu 0.5 alloy, in which Pr and Cu elements were directly added into the original Nd–Fe–B alloy, was also treated by the same HDDR process and the coercivity was only 557.3 kA/m. Microstructural investigations showed that a large area of (Nd, Pr)-rich phases concentrated at triangle regions in the HDDR Nd 11.5 Fe 80.7 B 6.1 Pr 1.2 Cu 0.5 powders, while the (Nd, Pr)-rich phases distributed uniformly in the diffusion treated powders. The uniform grain boundary layer can pin the motion of domain wall more effectively, resulting in a higher coercivity in diffusion treated HDDR Nd–Fe–B powders. - Highlights: • Anisotropic HDDR near-stoichiometric ternary Nd–Fe–B powders have been prepared. • The coercivity of the powders was improved from 2.62 to 12.31 kOe by the diffusion of Pr–Cu alloy. • The uniform grain boundary layer leads to a higher coercivity in diffusion treated powders

  10. Experimental investigation of phase equilibria in the Zr-Cu-Ni ternary system

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Mujin; Wang, Cuiping; Yang, Shuiyuan; Shi, Zhan; Han, Jiajia; Liu, Xingjun [Xiamen Univ. (China). College of Materials and Fujian Provincial Key Lab. of Materials Genome

    2017-08-15

    The phase equilibria in the Zr-Cu-Ni ternary system are investigated combined with X-ray diffraction, electron probe micro-analysis and differential scanning calorimetry. Two isothermal sections of the Zr-Cu-Ni ternary system at 1 000 C and 1 100 C are experimentally established. Most of the binary intermetallic compounds, e.g. Zr{sub 7}Ni{sub 10}, ZrNi, ZrNi{sub 5}, Zr{sub 14}Cu{sub 51}, and Zr{sub 2}Cu{sub 9}, show a remarkable ternary solubility. A new ternary compound named τ{sub 3} (Zr{sub 31.1-30.7} . Cu{sub 28.5-40.3}Ni{sub 40.4-29.0}) is detected at 1 000 C and dissolved at 1 020 C because the nearby large liquid phase field further expands. The newly determined phase equilibria will provide important information for both thermodynamic assessment and alloy design of Zr-based metallic glass.

  11. Volume dependence of T/sub c/ of Ternary A-15 Phases

    International Nuclear Information System (INIS)

    Shamrai, V.

    1984-01-01

    Results are presented of measurements of the superconducting transition temperature T/sub c/, lattice constant a, magnetic susceptibility /sub chi/, and critical field H/sub c/ 2 for many Nb 3 Al and V 3 Si-based ternary phases and Nb 3 SnH/sub x/. For V 3 Si-based ternary systems and Nb 3 SnH/sub x/ the density of states at the Fermi level N(epsilon/sub F/) sharply decreases with the concentration of the alloying element. The variation of N(epsilon/sub F/) in these ternary systems cannot be explained by the variation of a. In ternary phases Nb 3 (Al/sub 1-x/dY/sub x/), where Y can be Ge, Ga, Sb, or Se, a quite clear correlation is revealed between T/sub c/ and a. The dependence of T/sub c/ on V in these systems is due to the variation of the matrix element of the electron-phonon interaction 2 >

  12. Synthesis, structural and magnetic characterization of soft magnetic nanocrystalline ternary FeNiCo particles

    Energy Technology Data Exchange (ETDEWEB)

    Toparli, Cigdem [Department of Metallurgical & Materials Eng., Istanbul Technical University, 34469 Istanbul (Turkey); Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf (Germany); Ebin, Burçak [Department of Metallurgical & Materials Eng., Istanbul Technical University, 34469 Istanbul (Turkey); Nuclear Chemistry and Industrial Material Recycling, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, S-412 96 Gothenburg (Sweden); Gürmen, Sebahattin, E-mail: gurmen@itu.edu.tr [Department of Metallurgical & Materials Eng., Istanbul Technical University, 34469 Istanbul (Turkey)

    2017-02-01

    The present study focuses on the synthesis, microstructural and magnetic properties of ternary FeNiCo nanoparticles. Nanocrystalline ternary FeNiCo particles were synthesized via hydrogen reduction assisted ultrasonic spray pyrolysis method in single step. The effect of precursor concentration on the morphology and the size of particles was investigated. The syntheses were performed at 800 °C. Structure, morphology and magnetic properties of the as-prepared products were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) studies. Scherer calculation revealed that crystallite size of the ternary particles ranged between 36 and 60 nm. SEM and TEM investigations showed that the particle size was strongly influenced by the precursor concentration and Fe, Ni, Co elemental composition of individual particles was homogeneous. Finally, the soft magnetic properties of the particles were observed to be a function of their size. - Highlights: • Ternary FeNiCo alloy nanocrystalline particles were synthesized in a single step. • Cubic crystalline structure and spherical morphology was observed by XRD, SEM and TEM investigations. • The analysis of magnetic properties indicates the soft magnetic features of particles.

  13. Experimental investigation of phase equilibria in the Cu–Ni–Si ternary system

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xingjun; Xiang, Shulin; Yang, Shuiyuan; Shi, Rongpei; Wang, Cuiping, E-mail: wangcp@xmu.edu.cn

    2013-11-25

    Highlights: •Three isothermal sections of the Cu–Ni–Si system have been investigated. •The ternary compound τ{sub 1} and the liquid phase are confirmed at 1073 K. •The γ (Cu{sub 5}Si) and θ (Ni{sub 2}Si) phases can be stabilized at higher or lower temperatures. -- Abstract: The phase equilibria in the Cu–Ni–Si ternary system have been investigated experimentally by means of electron probe microanalysis (EPMA), X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis on equilibrated ternary alloys. Three isothermal sections at 1073, 1173 and 1273 K are determined in the whole composition range. The existence of liquid phase and the ternary compound τ{sub 1} is confirmed at 1073 K. The binary γ (Cu{sub 5}Si), γ (Ni{sub 31}Si{sub 12}), δ (Ni{sub 2}Si) and θ (Ni{sub 2}Si) phases exhibit a considerable solubility of a third element. In addition, the γ (Cu{sub 5}Si) and θ (Ni{sub 2}Si) phases can be stabilized by the addition of Ni and Cu, respectively.

  14. Ternary networks reliability and Monte Carlo

    CERN Document Server

    Gertsbakh, Ilya; Vaisman, Radislav

    2014-01-01

    Ternary means “based on three”. This book deals with reliability investigations of  networks whose components subject to failures can be in three states –up, down and middle (mid), contrary to traditionally considered networks  having only binary (up/down) components. Extending binary case to ternary allows to consider more realistic and flexible models for communication, flow and supply networks.

  15. Regularity in the formation of compounds in ternary R-Me-Sn systems, R - REM, Me - Fe, Co, Ni, Cu

    International Nuclear Information System (INIS)

    Skolozdra, R.V.; Komarovskaya, L.P.; Koretskaya, O.Eh.

    1992-01-01

    For the ternary alloy systems of (La, Y, Gd, Lu)-Fe-Sn, (Ce, Y, Gd)-Co-Sn, (Ce, Y, Gd, Lu)-Ni-Sn and (Pr, Gd, Lu)-Cu-Sn isothermal sections of phase diagrams were plotted within the range of 670 to 870 K. It was revealed that substitution of transition metal in the kFe-Co-Ni-Cu series led to changes both in a number of ternary stannides and their structural types. A tendency was observed in change of stannide numbers depending on quantity ratio of R and Me components. Crystallochemical analysis of compounds obtained showed that they could be treated as interstitial structures or lsuperstructures with respect to them. The results of magnetic properties measurements were used for explanation of structural features of ternary compounds considered

  16. Theoretical prediction and experimental confirmation of unusual ternary ordered semiconductor compounds in Sr-Pb-S system.

    Science.gov (United States)

    Hao, Shiqiang; Zhao, Li-Dong; Chen, Chang-Qiang; Dravid, Vinayak P; Kanatzidis, Mercouri G; Wolverton, Christopher M

    2014-01-29

    We examine the thermodynamics of phase separation and ordering in the ternary Ca(x)Pb(1-x)S and Sr(x)Pb(1-x)S systems by density-functional theory combined with a cluster expansion and Monte Carlo simulations. Similar to most other ternary III-V or IV-VI semiconductor alloys, we find that bulk phase separation is thermodynamically preferred for PbS-CaS. However, we predict the surprising existence of stable, ordered ternary compounds in the PbS-SrS system. These phases are previously unreported ordered rocksalt-based compounds: SrPb3S4, SrPbS2, and Sr3PbS4. The stability of these predicted ordered phases is confirmed by transmission electron microscopy observations and band gap measurements. We believe this work paves the way for a combined theory-experiment approach to decipher complex phase relations in multicomponent chalcogenide systems.

  17. Ternary alloys based on II-VI semiconductor compounds

    CERN Document Server

    Tomashyk, Vasyl; Shcherbak, Larysa

    2013-01-01

    Phase Equilibria in the Systems Based on ZnSSystems Based on ZnSeSystems Based on ZnTeSystems Based on CdSSystem Based on CdSeSystem Based on CdTeSystems Based on HgSSystems Based on HgSeSystems Based on HgTeIndexReferences appear at the end of each chapter.

  18. Ternary alloy material prediction using genetic algorithm and cluster expansion

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chong [Iowa State Univ., Ames, IA (United States)

    2015-12-01

    This thesis summarizes our study on the crystal structures prediction of Fe-V-Si system using genetic algorithm and cluster expansion. Our goal is to explore and look for new stable compounds. We started from the current ten known experimental phases, and calculated formation energies of those compounds using density functional theory (DFT) package, namely, VASP. The convex hull was generated based on the DFT calculations of the experimental known phases. Then we did random search on some metal rich (Fe and V) compositions and found that the lowest energy structures were body centered cube (bcc) underlying lattice, under which we did our computational systematic searches using genetic algorithm and cluster expansion. Among hundreds of the searched compositions, thirteen were selected and DFT formation energies were obtained by VASP. The stability checking of those thirteen compounds was done in reference to the experimental convex hull. We found that the composition, 24-8-16, i.e., Fe3VSi2 is a new stable phase and it can be very inspiring to the future experiments.

  19. Size-dependent structure of CdSe nanoclusters formed after ion implantation in MgO

    NARCIS (Netherlands)

    van Huis, MA; van Veen, A; Schut, H; Eijt, SWH; Kooi, BJ; De Hosson, JTM

    The band gap as well as the optical and structural properties of semiconductor CdSe nanoclusters change as a function of the nanocluster size. Embedded CdSe nanoclusters in MgO were created by means of sequential Cd and Se ion implantation followed by thermal annealing. Changes during annealing were

  20. Size effect on the adsorption and dissociation of CO{sub 2} on Co nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Haiyan; Cao, Dapeng; Fisher, Adrian [International Research Center for Soft Matter, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Johnston, Roy L. [School of Chemistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT (United Kingdom); Cheng, Daojian, E-mail: chengdj@mail.buct.edu.cn [International Research Center for Soft Matter, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China)

    2017-02-28

    Highlights: • Co{sub 13}, Co{sub 38} and Co{sub 55} nanoclusters were predicted as the high-symmetry structures. • CO{sub 2} dissociation on the size-selected Co{sub 13}, Co{sub 38} and Co{sub 55} nanoclusters was studied. • Co{sub 55} nanocluster possesses the highest activity relevant to CO{sub 2} dissociation. • A non-monotonous behavior of the dissociation barrier of CO{sub 2} with the size was found. - Abstract: Spin-polarized density functional theory calculations were carried out to study the adsorption and dissociation properties of CO{sub 2} on size-selected Co{sub 13}, Co{sub 38} and Co{sub 55} nanoclusters. Based on genetic algorithm method, Co{sub 13}, Co{sub 38} and Co{sub 55} nanoclusters were predicted as the most stable high-symmetry structures among these Co{sub n} (n = 2–58) nanoclusters from the Gupta potential. For the adsorption of CO{sub 2}, CO and O on size-selected Co{sub 13}, Co{sub 38} and Co{sub 55} nanoclusters, the lowest adsorption strength is found for all the different adsorbates on Co{sub 55} nanocluster. For the dissociation of CO{sub 2} on these size-selected Co nanoclusters, the largest Co{sub 55} nanocluster possesses the greatest catalytic activity for the dissociation of CO{sub 2}, with the smallest reaction barrier of 0.38 eV. Our results reveal a non-monotonous behavior of the catalytic activities of Co nanoclusters on size, which is of fundamental interest for the design of new Co catalysts for the conversion of CO{sub 2}.

  1. Experimental investigation of the ternary system Ni–Pd–Sn with special focus on the B8-type phase

    International Nuclear Information System (INIS)

    Jandl, Isabella; Ipser, Herbert; Richter, Klaus W.

    2015-01-01

    The ternary alloy system Ni–Pd–Sn was investigated experimentally from 700 °C upwards, with special focus on the general NiAs-type compounds. The phase diagram and crystallographic parameters were studied by means of powder X-ray diffraction (XRD), differential thermal analysis (DTA), light optical microscopy (LOM) and scanning electron microscopy (SEM) in combination with energy dispersive X-ray spectroscopy (EDX). An isothermal section at 700 °C was constructed wherein a continuous phase field between the binary NiAs-type compounds γ (PdSn) and Ni 3 Sn 2 (high temperature modification) was detected. A series of samples throughout this phase field was used to investigate lattice parameter variations, occupation of the atomic sites and the melting behaviour. A partial ordering of the transition metals was observed. Moreover, three vertical sections at 30 at.%, 40 at.% and 50 at.% Sn were determined. Altogether, seven ternary invariant phase reactions were discovered: two ternary eutectic reactions, one ternary eutectoid reaction, three ternary transition reactions and one maximum. A complete reaction scheme for the investigated temperature range is given. Furthermore, a partial liquidus surface projection, except for the low-temperature Sn-rich region, was developed. - Highlights: • Detailed study of the ternary alloy system Ni–Pd–Sn. • 1 Isotherm, 3 vertical sections, a partial liquidus projection and a reaction scheme. • A continuous phase field, between γ and Ni 3 Sn 2 , was discovered. • Lattice parameters and structural features in this phase field were analysed. • A partial order of Ni and Pd in this phase field was observed

  2. A nanocluster-based fluorescent sensor for sensitive hemoglobin detection.

    Science.gov (United States)

    Yang, Dongqin; Meng, Huijie; Tu, Yifeng; Yan, Jilin

    2017-08-01

    In this report, a fluorescence sensor for sensitive detection of hemoglobin was developed. Gold nanoclusters were first synthesized with bovine serum albumin. It was found that both hydrogen peroxide and hemoglobin could weakly quench the fluorescence from the gold nanoclusters, but when these two were applied onto the nanolcusters simultaneously, a much improved quenching was resulted. This enhancing effect was proved to come from the catalytic generation of hydroxyl radical by hemoglobin. Under an optimized condition, the quenching linearly related to the concentration of hemoglobin in the range of 1-250nM, and a limit of detection as low as 0.36nM could be obtained. This provided a sensitive means for the quantification of Hb. The sensor was then successfully applied for blood analyses with simple sample pretreatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. The expanding universe of thiolated gold nanoclusters and beyond.

    Science.gov (United States)

    Jiang, De-en

    2013-08-21

    Thiolated gold nanoclusters form a universe of their own. Researchers in this field are constantly pushing the boundary of this universe by identifying new compositions and in a few "lucky" cases, solving their structures. Such solved structures, even if there are only few, provide important hints for predicting the many identified compositions that are yet to be crystallized or structure determined. Structure prediction is the most pressing issue for a computational chemist in this field. The success of the density functional theory method in gauging the energetic ordering of isomers for thiolated gold clusters has been truly remarkable, but to predict the most stable structure for a given composition remains a great challenge. In this feature article from a computational chemist's point of view, the author shows how one understands and predicts structures for thiolated gold nanoclusters based on his old and new results. To further entertain the reader, the author also offers several "imaginative" structures, claims, and challenges for this field.

  4. Effect of adding Si on shape memory effect in Co-Ni alloy system

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Weimin [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030 (China); Liu Yan [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Jiang Bohong [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030 (China)]. E-mail: bhjiang@sjtu.edu.cn; Zhou Pingnan [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030 (China)

    2006-11-25

    In this paper, the effect of adding Si to Co-31.5 mass% Ni alloys on fcc-hcp martensitic transformation is investigated. The Co-Ni-Si ternary alloys with different amount of Si from 1 to 5 mass% were prepared. The stacking fault probability of Co-Ni-Si polycrystalline alloys were determined by X-ray diffraction profile analysis and compared with the binary Co-Ni alloy. The results show that the stacking fault probability of the fcc phase of alloys increases with increasing Si content. The effect of Si on phase transformation and shape memory behavior is evaluated. The experimental results show that both the critical strength and the shape memory effect of the ternary alloys will increase by the addition of Si. The improvement mechanism of the shape memory effect by adding Si to binary Co-Ni alloys is discussed.

  5. Theory of Nanocluster Size Distributions from Ion Beam Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, C.W.; Yi, D.O.; Sharp, I.D.; Shin, S.J.; Liao, C.Y.; Guzman, J.; Ager III, J.W.; Haller, E.E.; Chrzan, D.C.

    2008-06-13

    Ion beam synthesis of nanoclusters is studied via both kinetic Monte Carlo simulations and the self-consistent mean-field solution to a set of coupled rate equations. Both approaches predict the existence of a steady state shape for the cluster size distribution that depends only on a characteristic length determined by the ratio of the effective diffusion coefficient to the ion flux. The average cluster size in the steady state regime is determined by the implanted species/matrix interface energy.

  6. Improvement of magnetocaloric properties of Gd-Ge-Si alloys by alloying with iron

    Directory of Open Access Journals (Sweden)

    Erenc-Sędziak T.

    2013-01-01

    Full Text Available The influence of annealing of Gd5Ge2Si2Fex alloys at 1200°C and of alloying with various amount of iron on structure as well as thermal and magnetocaloric properties is investigated. It was found that annealing for 1 to 10 hours improves the entropy change, but reduces the temperature of maximum magnetocaloric effect by up to 50 K. Prolonged annealing of the Gd5Ge2Si2 alloy results in the decrease of entropy change due to the reduction of Gd5Ge2Si2 phase content. Addition of iron to the ternary alloy enhances the magnetocaloric effect, if x = 0.4 – 0.6, especially if alloying is combined with annealing at 1200°C: the peak value of the isothermal entropy change from 0 to 2 T increases from 3.5 to 11 J/kgK. Simultaneously, the temperature of maximum magnetocaloric effect drops to 250 K. The changes in magnetocaloric properties are related to the change in phase transformation from the second order for arc molten ternary alloy to first order in the case of annealed and/or alloyed with iron. The results of this study indicate that the minor addition of iron and heat treatment to Gd-Ge-Si alloys may be useful in improving the materials’ magnetocaloric properties..

  7. Prediction of phase equilibria and thermal analysis in the Bi-Cu-Pb ternary system

    Energy Technology Data Exchange (ETDEWEB)

    Manasijevic, Dragan [University of Belgrade, Technical Faculty, VJ 12, 19210 Bor (Serbia); Mitovski, Aleksandra, E-mail: amitovski@tf.bor.ac.rs [University of Belgrade, Technical Faculty, VJ 12, 19210 Bor (Serbia); Minic, Dusko [University of Pristina, Faculty of Technical Sciences, 38220 Kosovska Mitrovica (Serbia); Zivkovic, Dragana; Marjanovic, Sasa [University of Belgrade, Technical Faculty, VJ 12, 19210 Bor (Serbia); Todorovic, Radisa [Institute of Mining and Metallurgy, Zeleni Bulevar 35, 19210 Bor (Serbia); Balanovic, Ljubisa [University of Belgrade, Technical Faculty, VJ 12, 19210 Bor (Serbia)

    2010-05-20

    The knowledge about phase diagram of the Bi-Cu-Pb ternary system is of importance in development of copper-lead based bearing materials, soldering and in refining of copper and lead. In this work, the phase diagram of the Bi-Cu-Pb ternary system was calculated by the CALPHAD method using binary thermodynamic parameters included in the COST 531 database. The results include liquidus projection, invariant equilibria and three vertical sections with molar ratio Cu:Pb = 1, Cu:Pb = 1:3 and Bi:Cu = 1. Alloys, with compositions along three predicted vertical sections, were measured using differential scanning calorimetry (DSC). The experimentally determined phase transition temperatures were compared with calculated results and good mutual agreement was noticed.

  8. Prediction of phase equilibria and thermal analysis in the Bi-Cu-Pb ternary system

    International Nuclear Information System (INIS)

    Manasijevic, Dragan; Mitovski, Aleksandra; Minic, Dusko; Zivkovic, Dragana; Marjanovic, Sasa; Todorovic, Radisa; Balanovic, Ljubisa

    2010-01-01

    The knowledge about phase diagram of the Bi-Cu-Pb ternary system is of importance in development of copper-lead based bearing materials, soldering and in refining of copper and lead. In this work, the phase diagram of the Bi-Cu-Pb ternary system was calculated by the CALPHAD method using binary thermodynamic parameters included in the COST 531 database. The results include liquidus projection, invariant equilibria and three vertical sections with molar ratio Cu:Pb = 1, Cu:Pb = 1:3 and Bi:Cu = 1. Alloys, with compositions along three predicted vertical sections, were measured using differential scanning calorimetry (DSC). The experimentally determined phase transition temperatures were compared with calculated results and good mutual agreement was noticed.

  9. Chiral Gold Nanoclusters: Atomic Level Origins of Chirality.

    Science.gov (United States)

    Zeng, Chenjie; Jin, Rongchao

    2017-08-04

    Chiral nanomaterials have received wide interest in many areas, but the exact origin of chirality at the atomic level remains elusive in many cases. With recent significant progress in atomically precise gold nanoclusters (e.g., thiolate-protected Au n (SR) m ), several origins of chirality have been unveiled based upon atomic structures determined by using single-crystal X-ray crystallography. The reported chiral Au n (SR) m structures explicitly reveal a predominant origin of chirality that arises from the Au-S chiral patterns at the metal-ligand interface, as opposed to the chiral arrangement of metal atoms in the inner core (i.e. kernel). In addition, chirality can also be introduced by a chiral ligand, manifested in the circular dichroism response from metal-based electronic transitions other than the ligand's own transition(s). Lastly, the chiral arrangement of carbon tails of the ligands has also been discovered in a very recent work on chiral Au 133 (SR) 52 and Au 246 (SR) 80 nanoclusters. Overall, the origins of chirality discovered in Au n (SR) m nanoclusters may provide models for the understanding of chirality origins in other types of nanomaterials and also constitute the basis for the development of various applications of chiral nanoparticles. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. UV luminescence of dendrimer-encapsulated gold nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Hyeong Seop; Kim, Jun Myung; Sohn, So Hyeong; Han, Noh Soo; Park, Seung Min [Dept. of Chemistry, Kyung Hee University, Seoul (Korea, Republic of)

    2016-10-15

    Size-dependent luminescence color is one of the interesting properties of metal nanocrystals, whose sizes are in the dimension of the Fermi wavelength of an electron. Despite the short Fermi wavelength of electrons in gold (-0.7 nm), luminescence of gold nanoclusters has been reported to range from the near-infrared to near-ultraviolet, depending on the number of atoms in the nanoclusters. The photoluminescence of G4-OH (Au) obtained by the excitation of 266 nm showed UV emission in addition to the well-known blue emission. The higher intensity and red-shifted emission of the gold nanoclusters was distinguished from the emission of dendrimers. The UV emission at 352 nm matched the emission energy of Au{sub 4} in the spherical jellium model, rather than the planar Au{sub 8}, which supported the emission of Au{sub 4} formed in G4-OH. Despite the change of [HAuCl{sub 4} ]/[G4-OH], the relative population between Au{sub 4} and Au{sub 8} was similar in G4-OH(Au), which indicated that the closed electronic and geometric structures stabilized the magic number of Au{sub 4}.

  11. Growth and characterization of III-N ternary thin films by plasma assisted atomic layer epitaxy at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Nepal, Neeraj; Anderson, Virginia R.; Hite, Jennifer K.; Eddy, Charles R.

    2015-08-31

    We report the growth and characterization of III-nitride ternary thin films (Al{sub x}Ga{sub 1−x}N, In{sub x}Al{sub 1−x}N and In{sub x}Ga{sub 1−x}N) at ≤ 500 °C by plasma assisted atomic layer epitaxy (PA-ALE) over a wide stoichiometric range including the range where phase separation has been an issue for films grown by molecular beam epitaxy and metal organic chemical vapor deposition. The composition of these ternaries was intentionally varied through alterations in the cycle ratios of the III-nitride binary layers (AlN, GaN, and InN). By this digital alloy growth method, we are able to grow III-nitride ternaries by PA-ALE over nearly the entire stoichiometry range including in the spinodal decomposition region (x = 15–85%). These early efforts suggest great promise of PA-ALE at low temperatures for addressing miscibility gap challenges encountered with conventional growth methods and realizing high performance optoelectronic and electronic devices involving ternary/binary heterojunctions, which are not currently possible. - Highlights: • III-N ternaries grown at ≤ 500 °C by plasma assisted atomic layer epitaxy • Growth of InGaN and AlInN in the spinodal decomposition region (15–85%) • Epitaxial, smooth and uniform III-N film growth at low temperatures.

  12. Growth and characterization of III-N ternary thin films by plasma assisted atomic layer epitaxy at low temperatures

    International Nuclear Information System (INIS)

    Nepal, Neeraj; Anderson, Virginia R.; Hite, Jennifer K.; Eddy, Charles R.

    2015-01-01

    We report the growth and characterization of III-nitride ternary thin films (Al x Ga 1−x N, In x Al 1−x N and In x Ga 1−x N) at ≤ 500 °C by plasma assisted atomic layer epitaxy (PA-ALE) over a wide stoichiometric range including the range where phase separation has been an issue for films grown by molecular beam epitaxy and metal organic chemical vapor deposition. The composition of these ternaries was intentionally varied through alterations in the cycle ratios of the III-nitride binary layers (AlN, GaN, and InN). By this digital alloy growth method, we are able to grow III-nitride ternaries by PA-ALE over nearly the entire stoichiometry range including in the spinodal decomposition region (x = 15–85%). These early efforts suggest great promise of PA-ALE at low temperatures for addressing miscibility gap challenges encountered with conventional growth methods and realizing high performance optoelectronic and electronic devices involving ternary/binary heterojunctions, which are not currently possible. - Highlights: • III-N ternaries grown at ≤ 500 °C by plasma assisted atomic layer epitaxy • Growth of InGaN and AlInN in the spinodal decomposition region (15–85%) • Epitaxial, smooth and uniform III-N film growth at low temperatures

  13. Structure and properties of alloys of A15 type compounds with carbon

    International Nuclear Information System (INIS)

    Savitskij, E.M.; Efimov, Yu.V.; Myasnikova, E.A.

    1983-01-01

    Microstructure and some properties of the alloys on the base of the phases of A15 type in the V-Si-C, Nb-Si-C, Nb-Sn-C, Nb-Al-C, Nb-Ga-C, V-Ga-C ternary systems are investigated. It is established that in the niobium-rich corners of the A-B-C ternary systems the new ternary conpounds do not form, as a rule, bUt the wide ranges of threephase equilibrium A-A 3 B-C exist. New ternary phases with A15 type structure stabilized with carbon are established only in the Nb-Si-C and V-Al-C systems. Alloying with carbon results in sharp refining of structural components of stable and metastable alloys, promotes transition of the alloys into amorphous state at super fast cooling of the melts as well as increases stability of metastable state of the alloys against tempering. After super fast quenching and tempering Tsub(c) of the ternary alloys close to the A15 phases exceed Tsub(c) of equilibrium samples

  14. Powder metallurgy preparation of Al-Cu-Fe quasicrystals using mechanical alloying and Spark Plasma Sintering

    Czech Academy of Sciences Publication Activity Database

    Novák, P.; Kubatík, Tomáš František; Vystrčil, J.; Hendrych, R.; Kříž, J.; Mlynár, J.; Vojtěch, D.

    2014-01-01

    Roč. 52, September (2014), s. 131-137 ISSN 0966-9795 Institutional support: RVO:61389021 Keywords : Nanostructure intermetallics * Ternary alloys systems * Mechanical alloying and milling * Sintering * Diffraction Subject RIV: JG - Metallurgy Impact factor: 2.131, year: 2014 http://www.sciencedirect.com/science/article/pii/S0966979514001198#

  15. A Comparative XAFS Study of Gold-thiolate Nanoparticles and Nanoclusters

    International Nuclear Information System (INIS)

    Chevrier, D M; Chatt, A; Zhang, P; Sham, T K

    2013-01-01

    Tiopronin-capped gold nanoparticles and gold nanoclusters of sizes 3.0 and 1.5 nm, respectively, were investigated with XAFS at the gold L 3 -edge. The specific EXAFS fitting procedure is discussed for obtaining reliable fit parameters for each system. The difficulties and challenges faced when analysing EXAFS data for gold nanoparticles and nanoclusters are also mentioned. Fitting results for gold nanoparticles reveal a small amount of surface Au-thiolate interactions with a large Au-Au metal core. For gold nanoclusters, only a one-shell fit was obtainable. Instead of Au-Au metal core, long-range interactions are expected for gold nanoclusters. Tiopronin-capped gold nanoclusters are proposed to be polymeric in nature, which helps explain the observed red luminescence.

  16. pH-Induced transformation of ligated Au25 to brighter Au23 nanoclusters.

    Science.gov (United States)

    Waszkielewicz, Magdalena; Olesiak-Banska, Joanna; Comby-Zerbino, Clothilde; Bertorelle, Franck; Dagany, Xavier; Bansal, Ashu K; Sajjad, Muhammad T; Samuel, Ifor D W; Sanader, Zeljka; Rozycka, Miroslawa; Wojtas, Magdalena; Matczyszyn, Katarzyna; Bonacic-Koutecky, Vlasta; Antoine, Rodolphe; Ozyhar, Andrzej; Samoc, Marek

    2018-05-01

    Thiolate-protected gold nanoclusters have recently attracted considerable attention due to their size-dependent luminescence characterized by a long lifetime and large Stokes shift. However, the optimization of nanocluster properties such as the luminescence quantum yield is still a challenge. We report here the transformation of Au25Capt18 (Capt labels captopril) nanoclusters occurring at low pH and yielding a product with a much increased luminescence quantum yield which we have identified as Au23Capt17. We applied a simple method of treatment with HCl to accomplish this transformation and we characterized the absorption and emission of the newly created ligated nanoclusters as well as their morphology. Based on DFT calculations we show which Au nanocluster size transformations can lead to highly luminescent species such as Au23Capt17.

  17. The formation of Cr2O3 nanoclusters over graphene sheet and carbon nanotubes

    Science.gov (United States)

    Dabaghmanesh, Samira; Neek-Amal, Mehdi; Partoens, Bart; Neyts, Erik C.

    2017-11-01

    Carbon supported metal oxide nanoparticles hold promise for various future applications in diverse areas including spintronics, catalysis and biomedicine. These applications, however, typically depend on the structure and morphology of the nanoparticles. In this contribution, we employ classical molecular dynamic simulations based on a recently developed force field to study the structural properties of Cr2O3 nanoclusters over graphene and carbon nanotubes. We observe that Cr2O3 nanoclusters tend to aggregate over both freestanding graphene and carbon nanotubes and form larger nanoclusters. These large nanoclusters are characterized by their worm-like shape with a lattice constant similar to that of bulk Cr2O3. We also investigate the structural deformation induced in graphene due to the presence of Cr2O3 nanoclusters.

  18. Generalized rate-equation analysis of excitation exchange between silicon nanoclusters and erbium ions

    International Nuclear Information System (INIS)

    Kenyon, A. J.; Wojdak, M.; Ahmad, I.; Loh, W. H.; Oton, C. J.

    2008-01-01

    We discuss the use of rate equations to analyze the sensitization of erbium luminescence by silicon nanoclusters. In applying the general form of second-order coupled rate-equations to the Si nanocluster-erbium system, we find that the photoluminescence dynamics cannot be described using a simple rate equation model. Both rise and fall times exhibit a stretched exponential behavior, which we propose arises from a combination of a strongly distance-dependent nanocluster-erbium interaction, along with the finite size distribution and indirect band gap of the silicon nanoclusters. Furthermore, the low fraction of erbium ions that can be excited nonresonantly is a result of the small number of ions coupled to nanoclusters

  19. Magnesium and related low alloys

    International Nuclear Information System (INIS)

    Bernard, J.; Caillat, R.; Darras, R.

    1959-01-01

    In the first part the authors examine the comparative corrosion of commercial magnesium, of a magnesium-zirconium alloy (0,4 per cent ≤ Zr ≤ 0,7 per cent) of a ternary magnesium-zinc-zirconium alloy (0,8 per cent ≤ Zn ≤ 1,2 per cent) and of english 'Magnox type' alloys, in dry carbon dioxide-free air, in damp carbon dioxide-free air, and in dry and damp carbon dioxide, at temperatures from 300 to 600 deg. C. In the second part the structural stability of these materials is studied after annealings, of 10 to 1000 hours at 300 to 450 deg. C. Variations in grain after these heat treatments and mechanical stretching properties at room temperature are presented. Finally various creep rate and life time diagrams are given for these materials, for temperatures ranging from 300 to 450 deg. C. (author) [fr

  20. Corrosion resistance improvement of titanium base alloys

    Directory of Open Access Journals (Sweden)

    Mihai V. Popa

    2010-01-01

    Full Text Available The corrosion resistance of the new Ti-6Al-4V-1Zr alloy in comparison with ternary Ti-6Al-4V alloy in Ringer-Brown solution and artificial Carter-Brugirard saliva of different pH values was studied. In Ringer-Brown solution, the new alloy presented an improvement of all electrochemical parameters due to the alloying with Zr; also, impedance spectra revealed better protective properties of its passive layer. In Carter-Brugirard artificial saliva, an increase of the passive film thickness was proved. Fluoride ions had a slight negative influence on the corrosion and ion release rates, without to affect the very good stability of the new Ti-6Al-4V-1Zr alloy.

  1. Analysis of phase formation in Ni-rich alloys of the Ni-Ta-W system by calorimetry, DTA, SEM, and TEM

    Energy Technology Data Exchange (ETDEWEB)

    Witusiewicz, V.T.; Hecht, U.; Warnken, N.; Fries, S.G. [Access e.V., Aachen (Germany); Hu Weiping [Inst. fuer Metallkunde und Metallphysik der RWTH Aachen (Germany)

    2006-04-15

    The partial enthalpies of dissolution of pure Ni, W and Ta in liquid ternary Ni-Ta-W alloys have been determined at (1773 {+-} 5) K using a high temperature isoperibolic calorimeter. Measurements were performed in Ni-rich alloys (from 80 to 100 at.% Ni) along sections with constant Ta:W atomic ratios 1:0, 2:1, 1:2, and 0:1. The partial enthalpies and thereby the integral enthalpy of mixing of these ternary alloys are calculated from the partial enthalpies of dissolution using SGTE Gibbs energies for pure elements as reference. The obtained thermochemical data confirm that in the investigated Ni-rich alloys the binary interactions between Ta and W as well as the ternary Ni-Ta-W interactions are negligibly small. Due to this the variation of the integral enthalpy of mixing of the ternary alloys is well described as linear combination of the constituent Ni-Ta and Ni-W binaries. Such behaviour of the ternary liquid alloys is related to a very low probability of new ternary stable phases to occur in solid state. This prediction is confirmed by differential thermal analysis, scanning electron microscopy, and transmission electron microscopy of the as-solidified and annealed samples obtained as last alloy compositions in the series of calorimetric dissolution. (orig.)

  2. Crystallization features of ternary reversible reciprocal systems

    International Nuclear Information System (INIS)

    Tomashik, V.N.; Shcherbak, L.P.; Fejchuk, P.I.; Grytsiv, V.I.

    2006-01-01

    Some features of the primary crystallization of phases in ternary reversible reciprocal system are considered and discussed. The diagonal join CdTe-GeSe of the CdTe + GeSe = CdSe + GeTe ternary reciprocal system is studied to show that the features in primary and secondary heating and cooling curves in such systems under fully equilibrium conditions are not reproduced upon consecutive heating and cooling sessions, because of the existence of different amounts of the reagents and the reaction products in the mixture; the temperatures of each transformation lie in a range. Those who experimentally investigate other ternary and more complex reversible reciprocal systems should take this fact into account [ru

  3. Ternary fission induced by polarized neutrons

    Directory of Open Access Journals (Sweden)

    Gönnenwein Friedrich

    2013-12-01

    Full Text Available Ternary fission of (e,e U- and Pu- isotopes induced by cold polarized neutrons discloses some new facets of the process. In the so-called ROT effect shifts in the angular distributions of ternary particles relative to the fission fragments show up. In the so-called TRI effect an asymmetry in the emission of ternary particles relative to a plane formed by the fragment momentum and the spin of the neutron appear. The two effects are shown to be linked to the components of angular momentum perpendicular and parallel to the fission axis at the saddle point of fission. Based on theoretical models the spectroscopic properties of the collective transitional states at the saddle point are inferred from experiment.

  4. Calorimetric measurements of the Ca-Li liquid alloys

    Directory of Open Access Journals (Sweden)

    Dębski A.

    2017-01-01

    Full Text Available The ternary Cu-Al-Sn phase diagram is the base for several important types of alloys, with relevant industrial interest and applications. The knowledge of the melting/solidification alloys characteristics are determinant for their preparation and properties control. However, there is a lack of experimental information on the ternary phase diagram, at high temperature. In this work, several alloys, with high copper content and additions of Al, up to 10%, and Sn, up to 14% (in wt%, were studied by thermal analysis and by isothermal phase equilibria determination. The alloys liquidus and solidus lines and the binary α + β phase field, at 800 °C, are presented for the studied range of compositions.

  5. Nonequilibrium synthesis of Nb-Al alloys by laser processing

    International Nuclear Information System (INIS)

    Tewari, S.K.; Mazumder, J.

    1993-01-01

    The technique of laser surface modification provides a unique means of synthesizing novel nonequilibrium materials in near net shape. Claddings of several NbAl 3 alloys with Ti, B and Hf as a ternary alloy addition were prepared using a CW CO 2 laser. Isothermal oxidation behavior of the clads were examined in air. Oxidation tests at 800, 1,200 and 1,400 C. Alternating layers of alumina and NbAlO 4 were not observed in any of the samples as reported in literature for conventionally processed NbAl 3 oxidized under similar conditions. The parabolic rate constants for all the alloys, except 0 B, were comparable to that for isothermal oxidation of β-NiAl, at 1,200 and 1,400 C in 0.1 atm oxygen, which is a known alumina former. Ternary alloying additions for improved oxidation resistance at 1,400 C accompanied with improved ductility were identified

  6. The excess enthalpies of liquid Ge-Pb-Te alloys

    International Nuclear Information System (INIS)

    Blachnik, R.; Binder, J.; Schlieper, A.

    1997-01-01

    The excess enthalpies of liquid alloys in the ternary system Ge-Pb-Te were determined at 1210 K in a heat flow calorimeter for five sections Ge y Pb 1-y -Te with y = 0.2, 0.4, 0.5, 0.6 and 0.8 and at 1153 K for Ge 0.5 Pb 0.5 -Te. The enthalpy surface in the ternary system is determined by a valley of exothermic minima, stretching from an exothermic minimum at the composition GeTe to one at the composition PbTe in the respective binaries. The excess enthalpies in the limiting metallic binary were adapted with the Redlich-Kister formalism. For the description of the thermodynamic functions in the ternary system the equation of Bonnier was taken using ternary coefficients. The calculated curves are in good agreement with the experimental data. (orig.)

  7. Development of metallic fuel fabrication - A study on the interdiffusion behavior between ternary metallic fuel and cladding materials

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Soo; Seol, Kyung Won; Shon, In Jin [Chonbuk National University, Chonju (Korea)

    1999-04-01

    To study a new ternary metallic fuel for liquid metal reactor, various U-Zr-X alloys have been made by induction melting. The specimens were prepared for thermal stability tests at 630 deg. C upto 5000 hours in order to estimate the decomposition of the lamellar structure. Interdiffusion studies were carried out at 700 deg. C for 200 hours for the diffusion couples assembled with U-Zr-X ternary fuel versus austenitic stainless steel D9 and martensitic stainless steel HT9, respectively, to investigate the fuel-cladding compatibility. The ternary alloy, especially U-Zr-Mo and U-Zr-Nb alloys showed relatively good thermal stability as long as 5000hrs at 630 deg. C. From the composition profiles of the interdiffusion study, Fe penetrated deeper to the fuel side than other cladding elements such as Ni and Cr, whereas U did to the cladding side of fuel elements in the fuel/D9 couples. On the contrary, the reaction layers of Fuel/HT9 couple were thinner than that of Fuel/D9 couples and were less affected by cladding element, which was believed to be due to Zr rich layer between the fuel-cladding interface. HT9 is considered to be superior to D9 and a favorable choice as a cladding material in terms of fuel-cladding compatibility. 21 refs., 24 figs., 7 tabs. (Author)

  8. True ternary fission of 252Cf

    International Nuclear Information System (INIS)

    Vijayaraghavan, K.R.; Balasubramaniam, M.; Oertzen, W. von

    2014-01-01

    Splitting of heavy radioactive nucleus into three fragments is known as ternary fission. If the size of the fragments are almost equal it is referred to as true ternary fission. Recently, Yu. V. Pyatkov et al observed/reported the experimental observation of true ternary fission in 252 Cf. In this work, the possibilities of different true ternary fission modes of 252 Cf through potential energy surface (PES) calculations based on three cluster model (TCM) are discussed. In TCM a condition on the mass numbers of the fission fragments is implied as A 1 ≥ A 2 ≥ A 3 in order to avoid repetition of combinations. Due to this condition, the values of Z 3 vary from 0 to 36 and Z 2 vary from 16 to 51. Of the different pairs having similar (Z 2 , Z 3 ) with different potential energy, a pair possessing minimum potential energy is chosen. Thus identified favourable combinations are plotted. For the PES calculations the arrangement of the fragments is considered in the order of A 1 +A 2 +A 3 . i.e. the heavy and the lightest fragments are kept at the ends. It is seen that the deepest minimum in the PES occurs for Z 3 =2 labelled as (Z 2 ; 2) indicating He accompanied breakup as the most favourable one. Of which, the breakup with Z 2 around 46 to 48 is the least (shown by dashed (Z 1 = 50) and dotted (Z 1 = 52) lines indicating a constant Z 1 value). The other notable minima in the PES are labelled and they correspond to the (Z 2 , Z 3 ) pairs viz., (20, 20), (28, 20), (28, 28) and (32, 32). Of these four minima, the first three are associated with the magic numbers 20 and 28. For Z 3 =20, there are two minimums at (20,20) and (28,20) among them (28,20) is the lowest minimum through which the minimum-path passes, and it is the ternary decay observed by Yu. V. Pyatkov et al. The fourth minima is the most interesting due to the fact that it corresponds to true ternary fission mode with Z 2 =32, Z 3 =32 and Z 1 =34. The minimum potential energy path also goes through this true

  9. A Josephson ternary associative memory cell

    International Nuclear Information System (INIS)

    Morisue, M.; Suzuki, K.

    1989-01-01

    This paper describes a three-valued content addressable memory cell using a Josephson complementary ternary logic circuit named as JCTL. The memory cell proposed here can perform three operations of searching, writing and reading in ternary logic system. The principle of the memory circuit is illustrated in detail by using the threshold-characteristics of the JCTL. In order to investigate how a high performance operation can be achieved, computer simulations have been made. Simulation results show that the cycle time of memory operation is 120psec, power consumption is about 0.5 μW/cell and tolerances of writing and reading operation are +-15% and +-24%, respectively

  10. A study of phase transformations in complex matallic alloys Al73Mn23Pd4 and Al73Mn21Pd6

    Czech Academy of Sciences Publication Activity Database

    Priputen, P.; Černičková, I.; Kusý, M.; Illeková, E.; Švec, P.; Buršík, Jiří; Svoboda, Milan; Dolinšek, J.; Janovec, J.

    2011-01-01

    Roč. 465, - (2011), s. 302-305 ISSN 1013-9826 Institutional research plan: CEZ:AV0Z20410507 Keywords : ternary alloy system * phase transformation * DTA/SEM Subject RIV: BM - Solid Matter Physics ; Magnetism

  11. Calculated site substitution in ternary gamma'-Ni3Al: Temperature and composition effects

    DEFF Research Database (Denmark)

    Ruban, Andrei; Skriver, Hans Lomholt

    1997-01-01

    -tin orbitals method in conjunction with the local-density and multisublattice coherent-potential approximations and include all 3d, 4d, 5d, and noble metals. The calculations show the existence of simple trends in the alloying behavior of the gamma' phase which may be explained in a Friedel-like model based...... on the interaction between Ni and the added species. It is shown that the commonly accepted interpretation of the site substitution behavior of Cu and Pd may be incorrect because of site substitution reversal at high temperatures. It is further shown that the direction of the solubility lobe in the ternary phase...

  12. Investigation of new type Cu-Hf-Al bulk glassy alloys

    International Nuclear Information System (INIS)

    Nagy, E; Ronto, V; Solyom, J; Roosz, A

    2009-01-01

    In the last years new type Cu-Hf-Al ternary alloys were developed with high glass forming ability and ductility. The addition of Al to Cu-Hf alloys results in improvements in glass formation, thermal stability and mechanical properties of these alloys. We have investigated new Cu-based bulk amorphous alloys in Cu-Hf-Al ternary system. The alloys with Cu 49 Hf 42 Al 9 , Cu 46 Hf 45 Al 9 , Cu 50 Hf 42.5 Al 7.5 and Cu 50 Hf 45 Al 5 compositions were prepared by arc melting. The samples were made by centrifugal casting and were investigated by X-ray diffraction method. Thermodynamic properties were examined by differential scanning calorimetry and the structure of the crystallising phases by scanning electron microscopy. The determination of liquidus temperatures of alloys were measured by differential thermal analysis.

  13. Development of Mo base alloys for conductive metal-alumina cermet applications

    International Nuclear Information System (INIS)

    Stephens, J.J.; Damkroger, B.K.; Monroe, S.L.

    1996-01-01

    A study of thermal expansion for binary Mo-V and ternary Mo-V-Fe/Mo-V-Co alloys has been conducted, with the aim of finding a composition which matches the CTE of 94% alumina ceramic. The overall goal was to identify an alloy which can be used in conductive 27 vol.% metal/73 vol.% alumina cermets. Besides thermal expansion properties, two additional requirements exist for this alloy: (1) compatibility with a hydrogen sinter fire atmosphere and (2) a single phase BCC microstructure. They have identified a ternary alloy with a nominal composition of Mo-22wt.% V-3Fe for use in cermet fabrication efforts. This paper summarizes thermal expansion properties of the various alloys studied, and compares the results with previous CTE data for Mo-V binary alloys

  14. Ternary-fragmentation-driving potential energies of 252Cf

    Science.gov (United States)

    Karthikraj, C.; Ren, Zhongzhou

    2017-12-01

    Within the framework of a simple macroscopic model, the ternary-fragmentation-driving potential energies of 252Cf are studied. In this work, all possible ternary-fragment combinations of 252Cf are generated by the use of atomic mass evaluation-2016 (AME2016) data and these combinations are minimized by using a two-dimensional minimization approach. This minimization process can be done in two ways: (i) with respect to proton numbers (Z1, Z2, Z3) and (ii) with respect to neutron numbers (N1, N2, N3) of the ternary fragments. In this paper, the driving potential energies for the ternary breakup of 252Cf are presented for both the spherical and deformed as well as the proton-minimized and neutron-minimized ternary fragments. From the proton-minimized spherical ternary fragments, we have obtained different possible ternary configurations with a minimum driving potential, in particular, the experimental expectation of Sn + Ni + Ca ternary fragmentation. However, the neutron-minimized ternary fragments exhibit a driving potential minimum in the true-ternary-fission (TTF) region as well. Further, the Q -value energy systematics of the neutron-minimized ternary fragments show larger values for the TTF fragments. From this, we have concluded that the TTF region fragments with the least driving potential and high Q values have a strong possibility in the ternary fragmentation of 252Cf. Further, the role of ground-state deformations (β2, β3, β4, and β6) in the ternary breakup of 252Cf is also studied. The deformed ternary fragmentation, which involves Z3=12 -19 fragments, possesses the driving potential minimum due to the larger oblate deformations. We also found that the ground-state deformations, particularly β2, strongly influence the driving potential energies and play a major role in determining the most probable fragment combinations in the ternary breakup of 252Cf.

  15. Microwave-heating synthesis and sensing applications of bright gold nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    He, Ding-Fei; Xiang, Yang; Wang, Xu [Department of Physics, Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Yu, Xue-Feng, E-mail: yxf@whu.edu.cn [Department of Physics, Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072 (China)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer We establish a microwave-heating method to synthesize protein-stabilized Au nanoclusters. Black-Right-Pointing-Pointer The obtained Au nanoclusters show bright red fluorescence. Black-Right-Pointing-Pointer The Au nanoclusters can be used as efficient fluorescence probe for Cu{sup 2+} ion sensing. -- Abstract: A rapid microwave-heating method has been developed for the synthesis of bright Au nanoclusters by using bull serum albumin as the template in an aqueous environment. The reaction time needed is only 7.0 min, and the weight of the products at one batch can reach 15 g. The Au nanoclusters exhibit bright fluorescence at {approx}613 nm with quantum yield of {approx}6.0%. By adjusting the pH value, the products can be controlled to precipitate or re-disperse in aqueous solution. Furthermore, the Au nanoclusters have exhibited high sensitivity and selectivity in the determination of Cu{sup 2+} ions in water. These results suggest an efficient method for obtaining metal nanoclusters for the detection and sensing applications.

  16. A DFT study for the structural and electronic properties of Zn m Se n nanoclusters

    Science.gov (United States)

    Yadav, Phool Singh; Pandey, Dheeraj Kumar

    2012-09-01

    An ab initio study has been performed for the stability, structural and electronic properties of 19 small zinc selenide Zn m Se n ( m + n = 2-4) nanoclusters. Out of these nanoclusters, one nanocluster is found to be unstable due to its imaginary vibrational frequency. A B3LYP-DFT/6-311G(3df) method is used in the optimization of the geometries of the nanoclusters. We have calculated the zero point energy (ZPE), which is ignored by the other workers. The binding energies (BE), HOMO-LUMO gaps and bond lengths have been obtained for all the optimized nanoclusters. For the same value of ` m' and ` n', we designate the most stable structure the one, which has maximum final binding energy (FBE) per atom. The adiabatic and vertical ionization potentials (IP) and electron affinities (EA), dipole moments and charge on atoms have been investigated for the most stable nanoclusters. For the same value of ` m' and ` n', the nanocluster containing maximum number of Se atoms is found to be most stable.

  17. Undercooling and demixing of copper-based alloys

    DEFF Research Database (Denmark)

    Kolbe, M.; Brillo, J.; Egry, I.

    2006-01-01

    Since the beginning of materials science research under microgravity conditions immiscible alloys have been an interesting subject. New possibilities to investigate such systems are offered by containerless processing techniques. Of particular interest is the ternary system Cu-Fe-Co, and its...

  18. Indacenodithienothiophene-Based Ternary Organic Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Gasparini, Nicola, E-mail: nicola.gasparini@fau.de [Institute of Materials for Electronics and Energy Technology (I-MEET), Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen (Germany); García-Rodríguez, Amaranda [Macromolecular Chemistry Group (buwmakro), Institute for Polymer Technology, BergischeUniversität Wuppertal, Wuppertal (Germany); Prosa, Mario [Istituto per lo Studio dei Materiali Nanostrutturati (ISMN), Consiglio Nazionale delle Ricerche (CNR), Bologna (Italy); Bayseç, Şebnem; Palma-Cando, Alex [Macromolecular Chemistry Group (buwmakro), Institute for Polymer Technology, BergischeUniversität Wuppertal, Wuppertal (Germany); Katsouras, Athanasios; Avgeropoulos, Apostolos [Department of Materials Science Engineering, University of Ioannina, Ioannina (Greece); Pagona, Georgia; Gregoriou, Vasilis G. [Advent Technologies SA, Patras Science Park, Patra (Greece); National Hellenic Research Foundation (NHRF), Athens (Greece); Chochos, Christos L. [Department of Materials Science Engineering, University of Ioannina, Ioannina (Greece); Advent Technologies SA, Patras Science Park, Patra (Greece); Allard, Sybille; Scherf, Ulrich [Macromolecular Chemistry Group (buwmakro), Institute for Polymer Technology, BergischeUniversität Wuppertal, Wuppertal (Germany); Brabec, Christoph J. [Institute of Materials for Electronics and Energy Technology (I-MEET), Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen (Germany); Bavarian Center for Applied Energy Research (ZAE Bayern), Erlangen (Germany); Ameri, Tayebeh, E-mail: nicola.gasparini@fau.de [Institute of Materials for Electronics and Energy Technology (I-MEET), Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen (Germany)

    2017-01-13

    One of the key aspects to achieve high efficiency in ternary bulk-hetorojunction solar cells is the physical and chemical compatibility between the donor materials. Here, we report the synthesis of a novel conjugated polymer (P1) containing alternating pyridyl[2,1,3]thiadiazole between two different donor fragments, dithienosilole and indacenodithienothiophene (IDTT), used as a sensitizer in a host system of indacenodithieno[3,2-b]thiophene,2,3-bis(3-(octyloxy)phenyl)quinoxaline (PIDTTQ) and [6,6]-phenyl C{sub 70} butyric acid methyl ester (PC{sub 71}BM). We found that the use of the same IDTT unit in the host and guest materials does not lead to significant changes in the morphology of the ternary blend compared to the host binary. With the complementary use of optoelectronic characterizations, we found that the ternary cells suffer from a lower mobility-lifetime (μτ) product, adversely impacting the fill factor. However, the significant light harvesting in the near infrared region improvement, compensating the transport losses, results in an overall power conversion efficiency enhancement of ~7% for ternary blends as compared to the PIDTTQ:PC{sub 71}BM devices.

  19. Self-triggered coordination with ternary controllers

    NARCIS (Netherlands)

    De Persis, Claudio; Frasca, Paolo

    2012-01-01

    This paper regards coordination of networked systems with ternary controllers. We develop a hybrid coordination system which implements a self-triggered communication policy, based on polling the neighbors upon need. We prove that the proposed scheme ensures finite-time convergence to a neighborhood

  20. Ternary gradient metal-organic frameworks.

    Science.gov (United States)

    Liu, Chong; Rosi, Nathaniel L

    2017-09-08

    Gradient MOFs contain directional gradients of either structure or functionality. We have successfully prepared two ternary gradient MOFs based on bMOF-100 analogues, namely bMOF-100/102/106 and bMOF-110/100/102, via cascade ligand exchange reactions. The cubic unit cell parameter discrepancy within an individual ternary gradient MOF crystal is as large as ∼1 nm, demonstrating the impressive compatibility and flexibility of the component MOF materials. Because of the presence of a continuum of unit cells, the pore diameters within individual crystals also change in a gradient fashion from ∼2.5 nm to ∼3.0 nm for bMOF-100/102/106, and from ∼2.2 nm to ∼2.7 nm for bMOF-110/100/102, indicating significant porosity gradients. Like previously reported binary gradient MOFs, the composition of the ternary gradient MOFs can be easily controlled by adjusting the reaction conditions. Finally, X-ray diffraction and microspectrophotometry were used to analyse fractured gradient MOF crystals by comparing unit cell parameters and absorbance spectra at different locations, thus revealing the profile of heterogeneity (i.e. gradient distribution of properties) and further confirming the formation of ternary gradient MOFs.

  1. Does Science Also Prefer a Ternary Pattern?

    Science.gov (United States)

    Pogliani, L.; Klein, D. J.; Balaban, A. T.

    2006-01-01

    Through the importance of the number three in our culture and the strange preference for a ternary pattern of our nature one can perceive how and why number theory degraded to numerology. The strong preference of our minds for simple patterns can be read as the key to understanding not only the development of numerology, but also why scientists…

  2. Angular distribution in ternary cold fission

    International Nuclear Information System (INIS)

    Delion, D.S.; J.W. Goethe Univ., Frankfurt; Sandulescu, A.; J.W. Goethe Univ., Frankfurt; Greiner, W.

    2003-01-01

    We describe the spontaneous ternary cold fission of 252 Cf, accompanied by 4 He, 10 Be and 14 C. The light cluster decays from the first resonant eigenstate in the Coulomb potential plus a harmonic oscillator potential. We have shown that the angular distribution of the emitted light particle is strongly connected with its deformation and the equatorial distance. (author)

  3. Superconducting state parameters of ternary metallic glasses

    Indian Academy of Sciences (India)

    Administrator

    to binary metallic glasses. They are of interest since third element can modify the physical properties of binary metallic glasses and can also be used as a probe to study the host. ..... conducting nature in the present case. When we. Figure 6. Variation of transition temperature (TC) with valance (Z) of ternary metallic glasses.

  4. Templated Atom-Precise Galvanic Synthesis and Structure Elucidation of a [Ag 24 Au(SR) 18 ] − Nanocluster

    KAUST Repository

    Bootharaju, Megalamane Siddaramappa

    2015-11-27

    Synthesis of atom-precise alloy nanoclusters with uniform composition is challenging when the alloying atoms are similar in size (for example, Ag and Au). A galvanic exchange strategy has been devised to produce a compositionally uniform [Ag24Au(SR)18]- cluster (SR: thiolate) using a pure [Ag25(SR)18]- cluster as a template. Conversely, the direct synthesis of Ag24Au cluster leads to a mixture of [Ag25-xAux(SR)18]-, x=1-8. Mass spectrometry and crystallography of [Ag24Au(SR)18]- reveal the presence of the Au heteroatom at the Ag25 center, forming Ag24Au. The successful exchange of the central Ag of Ag25 with Au causes perturbations in the Ag25 crystal structure, which are reflected in the absorption, luminescence, and ambient stability of the particle. These properties are compared with those of Ag25 and Ag24Pd clusters with same ligand and structural framework, providing new insights into the modulation of cluster properties with dopants at the single-atom level.

  5. 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.

  6. Ion implantation induced conducting nano-cluster formation in PPO

    International Nuclear Information System (INIS)

    Das, A.; Patnaik, A.; Ghosh, G.; Dhara, S.

    1997-01-01

    Conversion of polymers and non-polymeric organic molecules from insulating to semiconducting materials as an effect of energetic ion implantation is an established fact. Formation of nano-clusters enriched with carbonaceous materials are made responsible for the insulator-semiconductor transition. Conduction in these implanted materials is observed to follow variable range hopping (VRH) mechanism. Poly(2,6-dimethyl phenylene oxide) [PPO] compatible in various proportion with polystyrene is used as a high thermal resistant insulating polymer. PPO has been used for the first time in the ion implantation study

  7. Enantioselective silver nanoclusters: Preparation, characterization and photoluminescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Farrag, Mostafa, E-mail: mostafafarrag@aun.edu.eg

    2016-09-01

    Herein, we report a new wet-synthesis method to separate some water-soluble chiral silver nanoclusters with high yield. The cluster material was obtained by the reduction of silver nitrate with NaBH{sub 4} in the presence of three ligands L-penicillamine (L-pen), D-penicillamine (D-pen) and racemic mixture of penicillamine (rac-pen), functioning as capping ligand. For characterizing all silver cluster samples, the particle size was assessed by transmission electron microscopy (TEM) and powder X-ray diffraction (XRD) and their average chemical formula was determined from thermogravimetric analysis (TGA) and elemental analysis (EA). The particles sizes of all three clusters are 2.1 ± 0.2 nm. The optical properties of the samples were studied by four different methods: UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), photoluminescence spectroscopy (PL) and circular dichroism (CD) spectroscopy. The spectra are dominated by the typical and intense plasmon peak at 486 nm accompanied by a small shoulder at 540 nm. Infrared spectroscopy was measured for the free ligand and protected silver nanoclusters, where the disappearance of the S-H vibrational band (2535–2570 cm{sup −1}) in the silver nanoclusters confirmed anchoring of ligand to the cluster surface through the sulfur atom. PL studies yielded the fluorescent properties of the samples. The main focus of this work, however, lies in the chirality of the particles. For all silver clusters CD spectra were recorded. While for clusters capped with one of the two enantiomers (D- or L-form) typical CD spectra were observed, no significant signals were detected for a racemic ligand mixture. Furthermore, silver clusters show quite large asymmetry factors (up to 3 × 10{sup −4}) in comparison to most other ligand protected clusters. These large factors and bands in the visible range of the spectrum suggest a strong chiral induction from the ligand to the metal core. Textural features of the

  8. Ultrafast coherence transfer in DNA-templated silver nanoclusters

    DEFF Research Database (Denmark)

    Thyrhaug, Erling; Bogh, Sidsel Ammitzbøll; Carro, Miguel

    2017-01-01

    DNA-templated silver nanoclusters of a few tens of atoms or less have come into prominence over the last several years due to very strong absorption and efficient emission. Applications in microscopy and sensing have already been realized, however little is known about the excited-state structure...... and dynamics in these clusters. Here we report on a multidimensional spectroscopy investigation of the energy-level structure and the early-time relaxation cascade, which eventually results in the population of an emitting state. We find that the ultrafast intramolecular relaxation is strongly coupled...

  9. Effect of quencher, denaturants, temperature and pH on the fluorescent properties of BSA protected gold nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Chib, Rahul, E-mail: Rahul.chib@live.unthsc.edu [Department of Cell Biology and Immunology, Center for Fluorescence Technologies and Nanomedicine, University of North Texas Health Science Center, Fort Worth, TX 76107 (United States); Butler, Susan [Department of Cell Biology and Immunology, Center for Fluorescence Technologies and Nanomedicine, University of North Texas Health Science Center, Fort Worth, TX 76107 (United States); Raut, Sangram [Department of Cell Biology and Immunology, Center for Fluorescence Technologies and Nanomedicine, University of North Texas Health Science Center, Fort Worth, TX 76107 (United States); Department of Physics and Astronomy, Texas Christian University, Fort Worth, TX 76129 (United States); Shah, Sunil; Borejdo, Julian [Department of Cell Biology and Immunology, Center for Fluorescence Technologies and Nanomedicine, University of North Texas Health Science Center, Fort Worth, TX 76107 (United States); Gryczynski, Zygmunt [Department of Cell Biology and Immunology, Center for Fluorescence Technologies and Nanomedicine, University of North Texas Health Science Center, Fort Worth, TX 76107 (United States); Department of Physics and Astronomy, Texas Christian University, Fort Worth, TX 76129 (United States); Gryczynski, Ignacy, E-mail: ignacy.gryczynski@unthsc.edu [Department of Cell Biology and Immunology, Center for Fluorescence Technologies and Nanomedicine, University of North Texas Health Science Center, Fort Worth, TX 76107 (United States)

    2015-12-15

    In this paper, we have synthesized BSA protected gold nanoclusters (BSA Au nanocluster) and studied the effect of quencher, protein denaturant, pH and temperature on the fluorescence properties of the tryptophan molecule of the BSA Au nanocluster and native BSA. We have also studied their effect on the peak emission of BSA Au nanoclusters (650 nm). The photophysical characterization of a newly developed fluorophore in different environments is absolutely necessary to futher develop their biomedical and analytical applications. It was observed from our experiments that the tryptophan in BSA Au nanoclusters is better shielded from the polar environment. Tryptophan in native BSA showed a red shift in its peak emission wavelength position. Tryptophan is a highly polarity sensitive dye and a minimal change in its microenvironment can be easily observed in its photophysical properties. - Highlights: • Tryptophan is easily accessible in native BSA compared to BSA Au nanoclusters. • Guanidine HCL denatures native BSA more compared to BSA Au nanoclusters. • High temperature decreases the quantum yield of tryptophan and BSA Au nanocluster. • Emission wavelength of BSA Au nanoclusters remains constant with increasing pH. • BSA Au nanoclusters are robust to the changes in their environments.

  10. Effect of quencher, denaturants, temperature and pH on the fluorescent properties of BSA protected gold nanoclusters

    International Nuclear Information System (INIS)

    Chib, Rahul; Butler, Susan; Raut, Sangram; Shah, Sunil; Borejdo, Julian; Gryczynski, Zygmunt; Gryczynski, Ignacy

    2015-01-01

    In this paper, we have synthesized BSA protected gold nanoclusters (BSA Au nanocluster) and studied the effect of quencher, protein denaturant, pH and temperature on the fluorescence properties of the tryptophan molecule of the BSA Au nanocluster and native BSA. We have also studied their effect on the peak emission of BSA Au nanoclusters (650 nm). The photophysical characterization of a newly developed fluorophore in different environments is absolutely necessary to futher develop their biomedical and analytical applications. It was observed from our experiments that the tryptophan in BSA Au nanoclusters is better shielded from the polar environment. Tryptophan in native BSA showed a red shift in its peak emission wavelength position. Tryptophan is a highly polarity sensitive dye and a minimal change in its microenvironment can be easily observed in its photophysical properties. - Highlights: • Tryptophan is easily accessible in native BSA compared to BSA Au nanoclusters. • Guanidine HCL denatures native BSA more compared to BSA Au nanoclusters. • High temperature decreases the quantum yield of tryptophan and BSA Au nanocluster. • Emission wavelength of BSA Au nanoclusters remains constant with increasing pH. • BSA Au nanoclusters are robust to the changes in their environments.

  11. Design of a novel quantum reversible ternary up-counter

    Science.gov (United States)

    Houshmand, Pouran; Haghparast, Majid

    2015-08-01

    Reversible logic has been recently considered as an interesting and important issue in designing combinational and sequential circuits. The combination of reversible logic and multi-valued logic can improve power dissipation, time and space utilization rate of designed circuits. Only few works have been reported about sequential reversible circuits and almost there are no paper exhibited about quantum ternary reversible counter. In this paper, first we designed 2-qutrit and 3-qutrit quantum reversible ternary up-counters using quantum ternary reversible T-flip-flop and quantum reversible ternary gates. Then we proposed generalized quantum reversible ternary n-qutrit up-counter. We also introduced a new approach for designing any type of n-qutrit ternary and reversible counter. According to the results, we can conclude that applying second approach quantum reversible ternary up-counter is better than the others.

  12. Protein mediated synthesis of fluorescent Au-nanoclusters for metal sensory coatings

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, Manja; Raff, Johannes [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biogeochemistry

    2017-06-01

    Fluorescent Au-nanocluster were successfully synthesized and used for the selective detection of Cu{sup 2} {sup +}. The synthesized Au-BSA-nanoclusters remain functional also after immobilization and show high thermal stability. Additionally, the transfer of the protein mediated Au-nanocluster synthesis route to S-layer proteins was achieved. (The presented work is part of the project BIONEWS dealing with long-term stable cells for the set-up and regeneration of sensor and actor materials for strategic relevant metals, in particular rare earth elements).

  13. Size-Dependent Specific Surface Area of Nanoporous Film Assembled by Core-Shell Iron Nanoclusters

    Directory of Open Access Journals (Sweden)

    Jiji Antony

    2006-01-01

    Full Text Available Nanoporous films of core-shell iron nanoclusters have improved possibilities for remediation, chemical reactivity rate, and environmentally favorable reaction pathways. Conventional methods often have difficulties to yield stable monodispersed core-shell nanoparticles. We produced core-shell nanoclusters by a cluster source that utilizes combination of Fe target sputtering along with gas aggregations in an inert atmosphere at 7∘C. Sizes of core-shell iron-iron oxide nanoclusters are observed with transmission electron microscopy (TEM. The specific surface areas of the porous films obtained from Brunauer-Emmett-Teller (BET process are size-dependent and compared with the calculated data.

  14. Ge nanoclusters in PECVD-deposited glass caused only by heat treatment

    DEFF Research Database (Denmark)

    Ou, Haiyan; Rørdam, Troels Peter; Rottwitt, Karsten

    2008-01-01

    This paper reports the formation of Ge nanoclusters in a multi-layer structure consisting of alternating thin films of Ge-doped silica glass and SiGe, deposited by plasma-enhanced chemical vapor deposition (PECVD) and post annealed at 1100 °C in N2 atmosphere. We studied the annealed samples...... embedded with Ge nanoclusters after annealing. These nanoclusters are crystalline and varied in size. There were no clusters in the Ge-doped glass layer. Raman spectra verified the existence of crystalline Ge clusters. The positional shift of the Ge vibrational peak with the change of the focus depth...

  15. Experimental investigation of phase equilibria in the Co-Ni-Zr ternary system

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xingjun; Yang, Shuiyuan; Yu, Wenjie; Wang, Cuiping [Xiamen Univ. (China). Fujian Key Laboratory of Materials Genome; Xiong, Huaping; Cheng, Yaoyong; Wu, Xin [Beijing Institute of Aeronautical Materials (China). Div. of Welding and Forging

    2016-10-15

    The phase equilibria of the Co-Ni-Zr ternary system at 1 000 C, 1 100 C and 1 200 C were experimentally investigated by means of back-scattered electron imaging, electron probe microanalysis and X-ray diffraction on the equilibrated ternary alloys. In this study, no ternary compound is found. The (αCo, Ni) phase region extends from the Ni-rich corner to the Co-rich corner with small solubility of Zr at three sections. At 1 000 C and 1 100 C, Ni{sub 5}Zr, Co{sub 2}Zr and Ni{sub 10}Zr{sub 7} phases have large solid solution ranges, but Ni{sub 10}Zr{sub 7} phase disappears at 1 200 C. The Ni{sub 7}Zr{sub 2}, NiZr, Co{sub 11}Zr{sub 2}, Co{sub 23}Zr{sub 6} and CoZr phases exhibit nearly linear compounds in the studied sections, and have large composition ranges. Additionally, some differences in phase relationship exist among the above three isothermal sections.

  16. The isothermal section at 500 deg. C of the Gd-Tb-Ga ternary system

    International Nuclear Information System (INIS)

    Li, J.Q.; Jian, Y.X.; Ao, W.Q.; Zhuang, Y.H.; He, W.

    2006-01-01

    Phase equilibria in the Gd-Tb-Ga ternary system at 500 deg. C were investigated by X-ray powder diffraction and differential scanning calorimetry. The binary compounds, Gd 5 Ga 3 , Gd 3 Ga 2 , GdGa, GdGa 2 , Tb 5 Ga 3 , TbGa, TbGa 2 and TbGa 3 have been confirmed at 500 deg. C. No ternary compound was found in this system. The isothermal section of this system at 500 deg. C was constructed. It is composed of 7 single-phase regions, 8 two-phase regions and 2 three-phase regions. Four ternary continuous solid solutions (Gd, Tb), (Gd, Tb) 5 Ga 3 , (Gd, Tb)Ga, (Gd, Tb)Ga 2 were formed in this isothermal section. The maximum solid solubilities of Ga in (Gd, Tb) at 500 deg. C is 5.0 at.%. The homogeneity range of (Gd, Tb)Ga 2 is from 20 to 33.3 at.% Ga in Gd-Ga side but limited in Tb-Ga side. The solid solubilities of Ga in the other phases cannot be detected. The Curie temperatures of the Gd 0.6 Tb 0.4-x Ga x alloys increase from 270 to 298 K as x increases from 0 to 0.03

  17. Calculation of the thermodynamic properties of liquid Ag–In–Sb alloys

    Directory of Open Access Journals (Sweden)

    DRAGANA ZIVKOVIC

    2006-03-01

    Full Text Available The results of calculations of the thermodynamic properties of liquid Ag–In–Sb alloys are presented in this paper. The Redlich–Kister–Muggianu model was used for the calculations. Based on known thermodynamic data for constitutive binary systems and available experimental data for the investigated ternary system, the ternary interaction parameter for the liquid phase in the temperature range 1000–1200 K was determined. Comparison between experimental and calculated results showed their good mutual agreement.

  18. Experimental measurements of U24Py nanocluster behavior in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, Shannon L.; Szymanowski, Jennifer E.S.; Fein, Jeremy B. [Univ. of Notre Dame, IN (United States). Department of Civil and Environmental Engineering and Earth Sciences; Dembowski, Mateusz [Univ. of Notre Dame, IN (United States). Department of Chemistry and Biochemistry; Burns, Peter C. [Univ. of Notre Dame, IN (United States). Department of Civil and Environmental Engineering and Earth Sciences; Univ. of Notre Dame, IN (United States). Department of Chemistry and Biochemistry

    2016-07-01

    Uranyl peroxide nanoclusters may impact the mobility and partitioning of uranium at contaminated sites and could be used in the isolation of uranium during the reprocessing of nuclear waste. Their behavior in aqueous systems must be better understood to predict the environmental fate of uranyl peroxide nanoclusters and for their use in engineered systems. The aqueous stability of only one uranyl peroxide nanocluster, U60 (K{sub 16}Li{sub 44}[UO{sub 2}(O{sub 2})OH]{sub 60}), has been studied to date [Flynn, S. L., Szymanowski, J. E. S., Gao, Y., Liu, T., Burns, P. C., Fein, J. B.: Experimental measurements of U60 nanocluster stability in aqueous solution. Geochemica et Cosmochimica Acta 156, 94-105 (2015)]. In this study, we measured the aqueous stability of a second uranyl peroxide nanocluster, U24Py (Na{sub 30}[(UO{sub 2}){sub 24}(O{sub 2}){sub 24}(HP{sub 2}O{sub 7}){sub 6}(H{sub 2}P{sub 2}O{sub 7}){sub 6}]), in batch systems as a function of time, pH, and nanocluster concentration, and then compared the aqueous behavior of U24Py to U60 to determine whether the size and morphology differences result in differences in their aqueous behaviors. Systems containing U24Py nanoclusters took over 30 days to achieve steady-state concentrations of monomeric U, Na, and P, illustrating slower reaction kinetics than parallel U60 systems. Furthermore, U24Py exhibited lower stability in solution than U60, with an average of 72% of the total mass in each nanocluster suspension being associated with the U24Py nanocluster, whereas 97% was associated with the U60 nanocluster in parallel experiments [Flynn, S. L., Szymanowski, J. E. S., Gao, Y., Liu, T., Burns, P. C., Fein, J. B.: Experimental measurements of U60 nanocluster stability in aqueous solution. Geochemica et Cosmochimica Acta 156, 94-105 (2015)]. The measurements from the batch experiments were used to calculate ion activity product (IAP) values for the reaction between the U24Py nanocluster and its constituent monomeric

  19. The analysis of fuel constituent redistribution for ternary metallic fuel slug

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byoung Oon; Lee, Dong Uk; Kim, Young Kyun; Chang, Jin Wook; Lee, Ki Bok; Kim, Young Il

    2004-02-01

    U-TRU-Zr metallic alloy is being considered as the fuel slug for the proliferation resistance core of KALIMER. The radial fuel constituent migration is a general phenomenon in the metallic alloys. This phenomenon may affect the in-reactor performance of metallic fuel rods, influencing such factors as melting temperature, thermal conductivity, power generation rate, phase boundaries and eutectic melting of the fuel slug. Thus, constituent redistribution modeling is essential when developing a metallic fuel performance code. The constituent migration model adopted in this report was based on the Ishida's model and Hofman's theory. A subroutine program has been made and installed into the MACSIS code to simulate constituent redistribution. The radial profile of Zr redistribution was calculated for the ternary metallic fuel, and compared with the measured data.

  20. Computational investigation of CO adsorbed on Aux, Agx and (AuAg)x nanoclusters (x = 1 - 5, 147) and monometallic Au and Ag low-energy surfaces*

    Science.gov (United States)

    Gould, Anna L.; Catlow, C. Richard A.; Logsdail, Andrew J.

    2018-02-01

    Density functional theory calculations have been performed to investigate the use of CO as a probe molecule for the determination of the structure and composition of Au, Ag and AuAg nanoparticles. For very small nanoclusters (x = 1 - 5), the CO vibrational frequencies can be directly correlated to CO adsorption strength, whereas larger 147-atom nanoparticles show a strong energetic preference for CO adsorption at a vertex position but the highest wavenumbers are for the bridge positions. We also studied CO adsorption on Au and Ag (100) and (111) surfaces, for a 1 monolayer coverage, which proves to be energetically favourable on atop only and bridge positions for Au (100) and atop for Ag (100); vibrational frequencies of the CO molecules red-shift to lower wavenumbers as a result of increased metal coordination. We conclude that CO vibrational frequencies cannot be solely relied upon in order to obtain accurate compositional analysis, but we do propose that elemental rearrangement in the core@shell nanoclusters, from Ag@Au (or Au@Ag) to an alloy, would result in a shift in the CO vibrational frequencies that indicate changes in the surface composition. Contribution to the Topical Issue "Shaping Nanocatalysts", edited by Francesca Baletto, Roy L. Johnston, Jochen Blumberger and Alex Shluger.Supplementary material in the form of one pdf file available from the Journal web page at http://https://doi.org/10.1140/epjb/e2017-80280-7

  1. Design of lead-free candidate alloys for high-temperature soldering based on the Au–Sn system

    DEFF Research Database (Denmark)

    Chidambaram, Vivek; Hattel, Jesper Henri; Hald, John

    2010-01-01

    of the Au–Sn binary system were explored in this work. Furthermore, the effects of thermal aging on the microstructure and microhardness of these promising Au–Sn based ternary alloys were investigated. For this purpose, the candidate alloys were aged at a lower temperature, 150°C for up to 1week...

  2. Analysis of iron-base alloys by low-wattage glow discharge emission spectrometry

    International Nuclear Information System (INIS)

    Wagatsuma, K.; Hirokawa, K.

    1984-01-01

    Several iron-base alloys were investigated by low-wattage glow discharge emission spectrometry. The emission intensity principally depended on the sputtering parameters of constituent elements in the alloy. However, in the case of chromium, stable and firm oxides formed on the surface influencing the yield of ejected atoms. This paper discusses the relation between the sputtering parameters in Fe-Ni, Fe-Cr, and Fe-Co alloys and their relative emission intensities. Additionally, quantitative analysis was performed for some ternary iron-base alloys and commercial stainless steels with the calibration factors of binary alloy systems

  3. Corrosion resistance of nickel alloys with chromium and silicon to the red fuming nitric acid

    International Nuclear Information System (INIS)

    Gurvich, L.Ya.; Zhirnov, A.D.

    1994-01-01

    Corrosion and electrochemical behaviour of binary Ni-Cr, Ni-Si nickel and ternary Ni-Cr-Si alloys in the red fuming nitric acid (RFNA) (8-% of HNO 3 +20% of N 2 O 4 ) is studied. It is shown that nickel alloying with chromium improves its corrosion resistance to the red fuming nitric acid. Nickel alloying with silicon in quantities of up to 5 % reduces, and up to 10%-increases abruptly the corrosion resistance with subsequent decrease of the latter after the further increase of concentration. Ni-15% of Cr alloy alloying with silicon increases monotonously the corrosion resistance. 10 refs., 7 figs., 3 tabs

  4. Internal oxidation of laminated ternary Ru–Ta–Zr coatings

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yung-I, E-mail: yichen@mail.ntou.edu.tw; Lu, Tso-Shen

    2015-10-30

    Highlights: • Internal oxidation was observed in annealed and laminated Ru–Ta–Zr coatings. • The oxidized Ru–Ta–Zr coatings comprised three alternately stacked sublayers. • Correlated variations of O{sup 2-} and Zr{sup 4+} binding energies were verified in XPS spectra. - Abstract: Researchers have observed the internal oxidation phenomenon in binary alloy coatings when developing refractory alloy coatings for protective purposes by conducting annealing at high temperatures and in oxygen-containing atmospheres. The coatings were assembled using cyclical gradient concentration deposition during cosputtering by employing a substrate holder rotating at a slow speed. The internally oxidized zone demonstrated a laminated structure, comprising alternating oxygen-rich and oxygen-deficient layers stacked in a general orientation. In the current study, Ru–Ta–Zr coatings were prepared with various stacking sequences during cosputtering. The Ru–Ta–Zr coatings were annealed at 600 °C in an atmosphere continuously purged with 1% O{sub 2}–99% Ar mixed gas for 30 min. A transmission electron microscope was used to examine the periods of the laminated layers and crystallinity of the annealed coatings. Depth profiles produced using an Auger electron spectroscope and X-ray photoelectron spectroscope were used to certify the periodic variation of the related constituents and chemical states of the elements, respectively. The results indicate that the internally oxidized ternary coatings are stacked of Ru-, Ta{sub 2}O{sub 5}-, and ZrO{sub 2}-dominant sublayers and that the stacking sequences of the sublayers affect the crystalline structure of the coatings. Zr is oxidized preferentially in the Ru–Ta–Zr coatings, increasing the surface hardness of the oxidized coatings.

  5. Coherent radiation by quantum dots and magnetic nanoclusters

    International Nuclear Information System (INIS)

    Yukalov, V. I.; Yukalova, E. P.

    2014-01-01

    The assemblies of either quantum dots or magnetic nanoclusters are studied. It is shown that such assemblies can produce coherent radiation. A method is developed for solving the systems of nonlinear equations describing the dynamics of such assemblies. The method is shown to be general and applicable to systems of different physical nature. Despite mathematical similarities of dynamical equations, the physics of the processes for quantum dots and magnetic nanoclusters is rather different. In a quantum dot assembly, coherence develops due to the Dicke effect of dot interactions through the common radiation field. For a system of magnetic clusters, coherence in the spin motion appears due to the Purcell effect caused by the feedback action of a resonator. Self-organized coherent spin radiation cannot arise without a resonator. This principal difference is connected with the different physical nature of dipole forces between the objects. Effective dipole interactions between the radiating quantum dots, appearing due to photon exchange, collectivize the dot radiation. While the dipolar spin interactions exist from the beginning, yet before radiation, and on the contrary, they dephase spin motion, thus destroying the coherence of moving spins. In addition, quantum dot radiation exhibits turbulent photon filamentation that is absent for radiating spins

  6. Fluorescence enhancement of DNA-silver nanoclusters from guanine proximity

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, Hsin-chih [Los Alamos National Laboratory; Sharma, Jaswinder [Los Alamos National Laboratory; Yoo, Hyojong [Los Alamos National Laboratory; Martinez, Jennifer S [Los Alamos National Laboratory

    2010-01-01

    Oligonucleotide-templated, silver nanoclusters (DNA/Ag NCs) are a versatile set of fluorophores and have already been used for live cell imaging, detection of specific metal ions, and single-nucleotide variation identification. Compared to commonly used organic dyes, these fluorescent nanoclusters have much better photostability and are often a few times brighter. Owing to their small size, simple preparation, and biocompatibility (i.e. made of nontoxic metals), DNA/Ag NCs should find more applications in biological imaging and chemical detection in the years to come. While clearly promising as new fluorophores, DNA/Ag NCs possess a unique and poorly understood dynamic process not shared by organic dyes or photoluminescent nanocrystals - the conversion among different NC species due to silver oxidation/reduction or NC regrouping. While this environmental sensitivity can be viewed as a drawback, in the appropriate context, it can be used as a sensor or reporter. Often reversible, conversions among different NC species have been found to depend upon a number of factors, including time, temperature, oxygen and salt content. In this communication, we report significant fluorescence enhancement of DNA/Ag NCs via interactions with guanine-rich DNA sequences. Moreover, we demonstrated this property can be used for sensitive detection of specific target DNA from a human oncogene (i.e. Braf gene).

  7. GRAIN-REFINEMENT AND THE RELATED PHENOMENA IN QUATERNARY Cu-Al-Ni-Ti SHAPE MEMORY ALLOYS

    OpenAIRE

    Sugimoto , K.; Kamei , K.; Matsumoto , H.; Komatsu , S.; Akamatsu , K.; Sugimoto , T.

    1982-01-01

    It was reported that the addition of a small amount of titanium (0.5 - 3.99%) to a Cu-13.93%Al-3.36%Ni ternary alloy resulted in a remarkable grain-refining. The original grain-size of about 750 microns under hot-rolled and quenched conditions of the ternary alloy was reduced to that of the order of about 100 microns by addition of tiatanium. It was suggested that several technical improvements of the mechanical properties of Cu-Al-Ni shape memory alloys, such as better formability, less crac...

  8. Glass formation, magnetic properties and magnetocaloric effect of ternary Ho–Al–Co bulk metallic glass

    International Nuclear Information System (INIS)

    Zhang, Huiyan; Li, Ran; Ji, Yunfei; Liu, Fanmao; Luo, Qiang; Zhang, Tao

    2012-01-01

    A ternary Ho–Al–Co system with high glass-forming ability (GFA) was developed and fully glassy rods with diameters up to 1 cm can be produced for the best glass former of Ho 55 Al 27.5 Co 17.5 alloy. The thermal stability and low-temperature magnetic properties of the Ho 55 Al 27.5 Co 17.5 bulk metallic glass (BMG) were studied. The magnetic transition temperature of this alloy is ∼14 K as determined by the thermomagnetic measurement. Two indicators, i.e. isothermal magnetic entropy change (ΔS M ) and the relative cooling power (RCP), were adopted to evaluate the magnetocaloric effect (MCE) of the alloy under a low magnetic field up to 2 T, which can be generated by permanent magnets. The values of |ΔS M | and RCP are 7.98 J kg −1 K −1 and 191.5 J kg −1 , respectively. The Ho 55 Al 27.5 Co 17.5 BMG with good MCE and high GFA provides an attractive candidate for magnetic refrigeration applications, like hydrogen liquefaction and storage. - Highlights: ► A ternary Ho–Al–Co BMG system with high glass-forming ability was developed. ► Fully glassy rods of Ho 55 Al 27.5 Co 17.5 alloy were produced up to 1 cm in diameter. ► The thermal stability and magnetic properties of the BMG were evaluated. ► The BMG exhibits good magnetocaloric effect under a low magnetic field up to 2 T.

  9. Insight of magnesium alloys and composites for orthopedic implant applications – a review

    Directory of Open Access Journals (Sweden)

    R Radha

    2017-09-01

    Full Text Available Magnesium (Mg and its alloys have been widely researched for orthopedic applications recently. Mg alloys have stupendous advantages over the commercially available stainless steel, Co-Cr-Ni alloy and titanium implants. Till date, extensive mechanical, in-vitro and in-vivo studies have been done to improve the biomedical performance of Mg alloys through alloying, processing conditions, surface modification etc. This review comprehensively describes the strategies for improving the mechanical and degradation performance of Mg alloys through properly tailoring the composition of alloying elements, reinforcements and processing techniques. It also highlights the status and progress of research in to (i the selection of nutrient elements for alloying, reinforcement and its effects (ii type of Mg alloy system (binary, ternary and quaternary and composites (iii grain refinement for strengthening through severe plastic deformation techniques. Furthermore it also emphasizes on the importance of Mg composites with regard to hard tissue applications.

  10. Hydrothermal Synthesis of Nanoclusters of ZnS Comprised on Nanowires

    Directory of Open Access Journals (Sweden)

    Magnus Willander

    2013-09-01

    Full Text Available Cetyltrimethyl ammonium bromide cationic (CTAB surfactant was used as template for the synthesis of nanoclusters of ZnS composed of nanowires, by hydrothermal method. The structural and morphological studies were performed by using X-ray diffraction (XRD, scanning electron microscopy (SEM and high resolution transmission electron microscopy (HRTEM techniques. The synthesized ZnS nanoclusters are composed of nanowires and high yield on the substrate was observed. The ZnS nanocrystalline consists of hexagonal phase and polycrystalline in nature. The chemical composition of ZnS nanoclusters composed of nanowires was studied by X-ray photo electron microscopy (XPS. This investigation has shown that the ZnS nanoclusters are composed of Zn and S atoms.

  11. Hydrothermal Synthesis of Nanoclusters of ZnS Comprised on Nanowires.

    Science.gov (United States)

    Ibupoto, Zafar Hussain; Khun, Kimleang; Liu, Xianjie; Willander, Magnus

    2013-09-09

    Cetyltrimethyl ammonium bromide cationic (CTAB) surfactant was used as template for the synthesis of nanoclusters of ZnS composed of nanowires, by hydrothermal method. The structural and morphological studies were performed by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) techniques. The synthesized ZnS nanoclusters are composed of nanowires and high yield on the substrate was observed. The ZnS nanocrystalline consists of hexagonal phase and polycrystalline in nature. The chemical composition of ZnS nanoclusters composed of nanowires was studied by X-ray photo electron microscopy (XPS). This investigation has shown that the ZnS nanoclusters are composed of Zn and S atoms.

  12. Multilayered nanoclusters of platinum and gold: insights on electrodeposition pathways, electrocatalysis, surface and bulk compositional properties

    CSIR Research Space (South Africa)

    Mkwizu, TS

    2013-06-01

    Full Text Available Electrochemical, surface and bulk compositional properties of multilayered nanoclusters of Pt and Au, electrochemically deposited on glassy carbon under conditions involving sequential surface–limited redox–replacement reactions (performed at open...

  13. Mechanical stability of titanium and plasma polymer nanoclusters in nanocomposite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Palesch, E. [Institute of Materials Chemistry, Brno University of Technology, Brno (Czech Republic); Marek, A. [HVM Plasma, spol. s r.o., Prague (Czech Republic); Solar, P.; Kylian, O. [Faculty of Mathematics and Physics, Charles University, Prague (Czech Republic); Vyskocil, J. [HVM Plasma, spol. s r.o., Prague (Czech Republic); Biederman, H. [Faculty of Mathematics and Physics, Charles University, Prague (Czech Republic); Cech, V., E-mail: cech@fch.vutbr.cz [Institute of Materials Chemistry, Brno University of Technology, Brno (Czech Republic)

    2013-10-01

    The mechanical stability of nanoclusters embedded in nanocomposite coatings was investigated by scratch and wear tests supported by atomic force microscopy using surface topography mode. Titanium and plasma polymer nanoclusters were deposited on planar substrates (glass, titanium) using a magnetron-based gas aggregation cluster source. The deposited clusters were overcoated with a thin titanium film of different thicknesses to stabilize the position of the clusters in the nanocomposite coating. Nanotribological measurements were carried out to optimize the thickness of the overcoating film for sufficient interfacial adhesion of the cluster/film system. - Highlights: ► Titanium and plasma polymer nanoclusters were overcoated with thin titanium film. ► The mechanical stability of nanoclusters was characterized by nanotribological tests. ► The film thickness was optimized to stabilize the position of the clusters in coating.

  14. A colloidal assembly approach to synthesize magnetic porous composite nanoclusters for efficient protein adsorption

    Science.gov (United States)

    Yang, Qi; Lan, Fang; Yi, Qiangying; Wu, Yao; Gu, Zhongwei

    2015-10-01

    A combination strategy of the inverse emulsion crosslinking approach and the colloidal assembly technique is first proposed to synthesize Fe3O4/histidine composite nanoclusters as new-type magnetic porous nanomaterials. The nanoclusters possess uniform morphology, high magnetic content and excellent protein adsorption capacity, exhibiting their great potential for bio-separation.A combination strategy of the inverse emulsion crosslinking approach and the colloidal assembly technique is first proposed to synthesize Fe3O4/histidine composite nanoclusters as new-type magnetic porous nanomaterials. The nanoclusters possess uniform morphology, high magnetic content and excellent protein adsorption capacity, exhibiting their great potential for bio-separation. Electronic supplementary information (ESI) available: Experimental details. See DOI: 10.1039/c5nr05800g

  15. Pure white-light emitting ultrasmall organic-inorganic hybrid perovskite nanoclusters.

    Science.gov (United States)

    Teunis, Meghan B; Lawrence, Katie N; Dutta, Poulami; Siegel, Amanda P; Sardar, Rajesh

    2016-10-14

    Organic-inorganic hybrid perovskites, direct band-gap semiconductors, have shown tremendous promise for optoelectronic device fabrication. We report the first colloidal synthetic approach to prepare ultrasmall (∼1.5 nm diameter), white-light emitting, organic-inorganic hybrid perovskite nanoclusters. The nearly pure white-light emitting ultrasmall nanoclusters were obtained by selectively manipulating the surface chemistry (passivating ligands and surface trap-states) and controlled substitution of halide ions. The nanoclusters displayed a combination of band-edge and broadband photoluminescence properties, covering a major part of the visible region of the solar spectrum with unprecedentedly large quantum yields of ∼12% and photoluminescence lifetime of ∼20 ns. The intrinsic white-light emission of perovskite nanoclusters makes them ideal and low cost hybrid nanomaterials for solid-state lighting applications.

  16. Encapsulation of nanoclusters in dried gel materials via an inverse micelle/sol gel synthesis

    Science.gov (United States)

    Martino, Anthony; Yamanaka, Stacey A.; Kawola, Jeffrey S.; Showalter, Steven K.; Loy, Douglas A.

    1998-01-01

    A dried gel material sterically entrapping nanoclusters of a catalytically active material and a process to make the material via an inverse micelle/sol-gel synthesis. A surfactant is mixed with an apolar solvent to form an inverse micelle solution. A salt of a catalytically active material, such as gold chloride, is added along with a silica gel precursor to the solution to form a mixture. To the mixture are then added a reducing agent for the purpose of reducing the gold in the gold chloride to atomic gold to form the nanoclusters and a condensing agent to form the gel which sterically entraps the nanoclusters. The nanoclusters are normally in the average size range of from 5-10 nm in diameter with a monodisperse size distribution.

  17. Synthesis and Optical Properties of a Dithiolate/Phosphine-Protected Au28 Nanocluster

    KAUST Repository

    Aljuhani, Maha A.; Bootharaju, Megalamane Siddaramappa; Sinatra, Lutfan; Basset, Jean-Marie; Mohammed, Omar F.; Bakr, Osman

    2016-01-01

    While monothiols and simple phosphines are commonly exploited for size-controlled synthesis of atomically precise gold nanoclusters (NCs), dithiols or dithiol-phosphine combinations are seldom applied. Herein, we used a dithiol (benzene-1,3-dithiol

  18. Synthesis of Co–Al layered double hydroxide nanoclusters as reduction nanocatalyst in aqueous media

    Directory of Open Access Journals (Sweden)

    Daisuke Kino

    2017-12-01

    Full Text Available Layered double hydroxides (LDHs have attracted attention as green materials due to their catalytic ability in benign aqueous solvents. We here demonstrate the synthesis of colloidal Co–Al LDH nanoclusters with an average size of <10 nm via a facile liquid-phase reaction for the enhancement of the catalytic activity. To the best of our knowledge, the present LDH is the smallest Co–Al LDH with an extremely large surface area and stability in an aqueous solvent, forming a stable and concentrated colloidal solution as high as 40 g/L. We investigated the formation mechanism, and the catalytic activity of Co–Al LDH nanoclusters. The Co–Al LDH nanoclusters showed 47 times higher rate of the reduction of dye molecules in the aqueous media than standard Co–Al LDH particles with a micrometer size. LDH nanoclusters demonstrated here are promising green nanocatalysts for the aqueous reaction processes.

  19. Magnetic properties of MnAs nanoclusters embedded in a GaAs semiconductor matrix

    International Nuclear Information System (INIS)

    Hai, Pham Nam; Takahashi, Keisuke; Yokoyama, Masafumi; Ohya, Shinobu; Tanaka, Masaaki

    2007-01-01

    We have clarified fundamental magnetic properties of MnAs nanoclusters (10 nm in diameter) embedded in a thin GaAs matrix (referred to as GaAs:MnAs) through tunneling magnetoresistance (TMR) characteristics of magnetic tunnel junctions (MTJs) consisting of a GaAs:MnAs thin film and a MnAs metal thin film as ferromagnetic electrodes. Although MnAs nanoclusters have coercive forces as small as 150 Oe at 7 K, they show unusually high blocking temperature, which is as large as 300 K. The remanent magnetization of the MnAs nanocluster system linearly decreases with increasing temperature. Those magnetic behaviors cannot be explained by the non-interacting particle model, revealing the important existence of dipolar interactions in MnAs nanocluster system

  20. Synthesis and Doping of Ligand-Protected Atomically-Precise Metal Nanoclusters

    KAUST Repository

    Aljuhani, Maha A.

    2016-01-01

    by controlling their size, shape, and composition. Among the most thriving areas of research about nanoparticle is the synthesis and doping of the ligand-protected atomically-precise metal nanoclusters. In this thesis, we developed three different novel metal

  1. Composition design and mechanical properties of ternary Cu–Zr–Ti bulk metallic glasses

    International Nuclear Information System (INIS)

    Pan, Ye; Zeng, Yuqiao; Jing, Lijun; Zhang, Lu; Pi, Jinhong

    2014-01-01

    Highlights: • Newly designed monolithic bulk metallic glasses are of good glass-forming ability. • Cu 50 Zr 44 Ti 6 exhibits excellent plastic deformation up to ∼7.4%. • Copious and intersected shear bans are observed in the fractography of Cu 50 Zr 44 Ti 6 . • Cu 50 Zr 44 Ti 6 has the best plasticity in the ternary Cu–Zr–Ti bulk metallic glasses. - Abstract: The new compositions of ternary Cu–Zr–Ti bulk metallic glasses are predicted by integrating calculation of vacancy formation energy, mixing enthalpy and configuration entropy of the alloys based on thermodynamics of glass formers. The monolithic amorphous rods of 3 mm diameter have been successfully fabricated, and characterized by X-ray diffractometry, differential scanning calorimetry, scanning electronic microscopy, transmission electronic microscopy and compression tests. The results show that the designed alloys possess good glass forming ability and excellent mechanical properties. The mechanical properties of the samples can be effectively improved by regulating their composition. The monolithic amorphous rod of Cu 50 Zr 44 Ti 6 exhibits a high fracture strength of 1855 MPa and excellent plastic deformation up to ∼7.4%. The formation and propagation of shear bands in samples are also investigated. The enhancement of plastic deformation is mainly contributed to multiplication and intersection of shear bands

  2. Nb-Based Nb-Al-Fe Alloys: Solidification Behavior and High-Temperature Phase Equilibria

    Science.gov (United States)

    Stein, Frank; Philips, Noah

    2018-03-01

    High-melting Nb-based alloys hold significant promise for the development of novel high-temperature materials for structural applications. In order to understand the effect of alloying elements Al and Fe, the Nb-rich part of the ternary Nb-Al-Fe system was investigated. A series of Nb-rich ternary alloys were synthesized from high-purity Nb, Al, and Fe metals by arc melting. Solidification paths were identified and the liquidus surface of the Nb corner of the ternary system was established by analysis of the as-melted microstructures and thermal analysis. Complementary analysis of heat-treated samples yielded isothermal sections at 1723 K and 1873 K (1450 °C and 1600 °C).

  3. Investigation of as-cast alloys in the Pt-Al-Cr system

    International Nuclear Information System (INIS)

    Suess, R.; Cornish, L.A.; Witcomb, M.J.

    2010-01-01

    Platinum-based alloys are being developed which have microstructures that are analogous to the γ/γ' microstructure of the nickel-based superalloys. These Pt-based alloys have the potential to be used for high-temperature applications. The ternary Pt-Al-Cr system was investigated as part of the continued development of a thermodynamic database for the Pt-Al-Cr-Ru system. Scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) analyses were used to obtain phase equilibria data. The alloys were studied in the as-cast condition. A solidification projection was constructed and a liquidus surface derived. It was concluded that all phase regions were identified correctly since the results were self-consistent. Three ternary phases and 21 ternary invariant reactions were identified.

  4. Stable silver nanoclusters electrochemically deposited on nitrogen-doped graphene as efficient electrocatalyst for oxygen reduction reaction

    Science.gov (United States)

    Jin, Shi; Chen, Man; Dong, Haifeng; He, Bingyu; Lu, Huiting; Su, Lei; Dai, Wenhao; Zhang, Qiaochu; Zhang, Xueji

    2015-01-01

    Metal nanoclusters exhibit unusually high catalytic activity toward oxygen reduction reaction (ORR) due to their small size and unique electronic structures. However, controllable synthesis of stable metal nanoclusters is a challenge, and the durability of metal clusters suffers from the deficiency of dissolution, aggregation, and sintering during catalysis reactions. Herein, silver nanoclusters (AgNCs) (diameter , which is vital in high performance fuel cells, batteries and nanodevices.

  5. Stabilizing Protein Effects on the Pressure Sensitivity of Fluorescent Gold Nanoclusters

    Science.gov (United States)

    2016-01-13

    affected by the environment of the stabilizing protein, allowing these hybrid systems to act as sensors in many applications.2,9,14–19 This has led...Biosens Bioelectron. 2012;32:297–299. 8. Joseph D, Geckeler KE. Synthesis of highly fluorescent gold nanoclusters using egg white proteins. Colloids Surf...Chang HW, Chien YC, Hsiao JK, Cheng JT, Chou PT. Insulin -directed synthesis of fluorescent gold nanoclusters: preservation of insulin bioactivity and

  6. Kernel Tuning and Nonuniform Influence on Optical and Electrochemical Gaps of Bimetal Nanoclusters.

    Science.gov (United States)

    He, Lizhong; Yuan, Jinyun; Xia, Nan; Liao, Lingwen; Liu, Xu; Gan, Zibao; Wang, Chengming; Yang, Jinlong; Wu, Zhikun

    2018-03-14

    Fine tuning nanoparticles with atomic precision is exciting and challenging and is critical for tuning the properties, understanding the structure-property correlation and determining the practical applications of nanoparticles. Some ultrasmall thiolated metal nanoparticles (metal nanoclusters) have been shown to be precisely doped, and even the protecting staple metal atom could be precisely reduced. However, the precise addition or reduction of the kernel atom while the other metal atoms in the nanocluster remain the same has not been successful until now, to the best of our knowledge. Here, by carefully selecting the protecting ligand with adequate steric hindrance, we synthesized a novel nanocluster in which the kernel can be regarded as that formed by the addition of two silver atoms to both ends of the Pt@Ag 12 icosohedral kernel of the Ag 24 Pt(SR) 18 (SR: thiolate) nanocluster, as revealed by single crystal X-ray crystallography. Interestingly, compared with the previously reported Ag 24 Pt(SR) 18 nanocluster, the as-obtained novel bimetal nanocluster exhibits a similar absorption but a different electrochemical gap. One possible explanation for this result is that the kernel tuning does not essentially change the electronic structure, but obviously influences the charge on the Pt@Ag 12 kernel, as demonstrated by natural population analysis, thus possibly resulting in the large electrochemical gap difference between the two nanoclusters. This work not only provides a novel strategy to tune metal nanoclusters but also reveals that the kernel change does not necessarily alter the optical and electrochemical gaps in a uniform manner, which has important implications for the structure-property correlation of nanoparticles.

  7. Effect of alloying on elastic properties of ZrN based transition metal nitride alloys

    KAUST Repository

    Kanoun, Mohammed; Goumri-Said, Souraya

    2014-01-01

    We report the effect of composition and metal sublattice substitutional element on the structural, elastic and electronic properties of ternary transition metal nitrides Zr1-xMxN with M=Al, Ti, Hf, V, Nb, W and Mo. The analysis of the elastic constants, bulk modulus, shear modulus, Young's modulus, and Poisson's ratio provides insights regarding the mechanical behavior of Zr1-xMxN. We predict that ternary alloys are more ductile compared to their parent binary compounds. The revealed trend in the mechanical behavior might help for experimentalists on the ability of tuning the mechanical properties during the alloying process by varying the concentration of the transition metal. © 2014 Elsevier B.V.

  8. Effect of alloying on elastic properties of ZrN based transition metal nitride alloys

    KAUST Repository

    Kanoun, Mohammed

    2014-09-01

    We report the effect of composition and metal sublattice substitutional element on the structural, elastic and electronic properties of ternary transition metal nitrides Zr1-xMxN with M=Al, Ti, Hf, V, Nb, W and Mo. The analysis of the elastic constants, bulk modulus, shear modulus, Young\\'s modulus, and Poisson\\'s ratio provides insights regarding the mechanical behavior of Zr1-xMxN. We predict that ternary alloys are more ductile compared to their parent binary compounds. The revealed trend in the mechanical behavior might help for experimentalists on the ability of tuning the mechanical properties during the alloying process by varying the concentration of the transition metal. © 2014 Elsevier B.V.

  9. Alloy materials

    Energy Technology Data Exchange (ETDEWEB)

    Hans Thieme, Cornelis Leo (Westborough, MA); Thompson, Elliott D. (Coventry, RI); Fritzemeier, Leslie G. (Acton, MA); Cameron, Robert D. (Franklin, MA); Siegal, Edward J. (Malden, MA)

    2002-01-01

    An alloy that contains at least two metals and can be used as a substrate for a superconductor is disclosed. The alloy can contain an oxide former. The alloy can have a biaxial or cube texture. The substrate can be used in a multilayer superconductor, which can further include one or more buffer layers disposed between the substrate and the superconductor material. The alloys can be made a by process that involves first rolling the alloy then annealing the alloy. A relatively large volume percentage of the alloy can be formed of grains having a biaxial or cube texture.

  10. Heat storage in alloy transformations

    Science.gov (United States)

    Birchenall, C. E.

    1980-01-01

    Heats of transformation of eutectic alloys were measured for many binary and ternary systems by differential scanning calorimetry and thermal analysis. Only the relatively cheap and plentiful elements Mg, Al, Si, P, Ca, Cu, Zn were considered. A method for measuring volume change during transformation was developed using x-ray absorption in a confined sample. Thermal expansion coefficients of both solid and liquid states of aluminum and of its eutectics with copper and with silicon also were determined. Preliminary evaluation of containment materials lead to the selection of silicon carbide as the initial material for study. Possible applications of alloy PCMs for heat storage in conventional and solar central power stations, small solar receivers and industrial furnace operations are under consideration.

  11. Grain refinement of zinc-aluminium alloys

    International Nuclear Information System (INIS)

    Zaid, A.I.O.

    2006-01-01

    It is now well-established that the structure of the zinc-aluminum die casting alloys can be modified by the binary Al-Ti or the ternary Al-Ti-B master alloys. in this paper, grain refinement of zinc-aluminum alloys by rare earth materials is reviewed and discussed. The importance of grain refining of these alloys and parameters affecting it are presented and discussed. These include parameters related to the Zn-Al alloys cast, parameters related to the grain refining elements or alloys and parameters related to the process. The effect of addition of other alloying elements e.g. Zr either alone or in the presence of the main grain refiners Ti or Ti + B on the grain refining efficiency is also reviewed and discussed. Furthermore, based on the grain refinement and the parameters affecting it, a criterion for selection of the optimum grain refiner is suggested. Finally, the recent research work on the effect of grain refiners on the mechanical behaviour, impact strength, wear resistance, and fatigue life of these alloys are presented and discussed. (author)

  12. Prospects for designing structural cast eutectic alloys on Al-Ce-Ni system base

    International Nuclear Information System (INIS)

    Belov, N.A.; Naumova, E.S.

    1996-01-01

    The phase diagram of Al-Ce-Ni system is built for an aluminium corner at component concentration up to 16 mass %Ce and 8 mass%Ni. A ternary eutectic reaction is established at 12%Ce, 5%Ni and 626 deg C. The ternary eutectic alloy is similar in structure to rapidly cooled Al base alloys with transition metals. The possibility to design new cast alloys based on three-phase (Al)+NiAl 3 +CeAl 4 eutectics is under consideration. Al-Zn-Mg-Cu, Al-Sc and Al-Zr base alloys can be used as (Al) constituent of the eutectics. The new alloys may be considered as heat resistant ones due to the fact that no structural changes are observed in castings on heating up to 350 deg C. 18 refs.; 4 figs.; 2 tabs

  13. Iron/iron oxide core-shell nanoclusters for biomedical applications

    International Nuclear Information System (INIS)

    Qiang You; Antony, Jiji; Sharma, Amit; Nutting, Joseph; Sikes, Daniel; Meyer, Daniel

    2006-01-01

    Biocompatible magnetic nanoparticles have been found promising in several biomedical applications for tagging, imaging, sensing and separation in recent years. Most magnetic particles or beads currently used in biomedical applications are based on ferromagnetic iron oxides with very low specific magnetic moments of about 20-30 emu/g. Here we report a new approach to synthesize monodispersed core-shell nanostructured clusters with high specific magnetic moments above 200 emu/g. Iron nanoclusters with monodispersive size of diameters from 2 nm to 100 nm are produced by our newly developed nanocluster source and go to a deposition chamber, where a chemical reaction starts, and the nanoclusters are coated with iron oxides. HRTEM Images show the coatings are very uniform and stable. The core-shell nanoclusters are superparamagnetic at room temperature for sizes less than 15 nm, and then become ferromagnetic when the cluster size increases. The specific magnetic moment of core-shell nanoclusters is size dependent, and increases rapidly from about 80 emu/g at the cluster size of around 3 nm to over 200 emu/g up to the size of 100 nm. The use of high magnetic moment nanoclusters for biomedical applications could dramatically enhance the contrast for MRI, reduce the concentration of magnetic particle needs for cell separation, or make drug delivery possible with much lower magnetic field gradients

  14. Optical properties of multicomponent antimony-silver nanoclusters formed in silica by sequential ion implantation

    International Nuclear Information System (INIS)

    Zuhr, R.A.

    1995-11-01

    The linear and nonlinear optical properties of nanometer dimension metal colloids embedded in a dielectric depend explicitly on the electronic structure of the metal nanoclusters. The ability to control the electronic structure of the nanoclusters may make it possible to tailor the optical properties for enhanced performance. By sequential implantation of different metal ion species multi-component nanoclusters can be formed with significantly different optical properties than single element metal nanoclusters. The authors report the formation of multi-component Sb/Ag nanoclusters in silica by sequential implantation of Sb and Ag. Samples were implanted with relative ratios of Sb to Ag of 1:1 and 3:1. A second set of samples was made by single element implantations of Ag and Sb at the same energies and doses used to make the sequentially implanted samples. All samples were characterized using RBS and both linear and nonlinear optical measurements. The presence of both ions significantly modifies the optical properties of the composites compared to the single element nanocluster glass composites. In the sequentially implanted samples the optical density is lower, and the strong surface plasmon resonance absorption observed in the Ag implanted samples is not present. At the same time the nonlinear response of the these samples is larger than for the samples implanted with Sb alone, suggesting that the addition of Ag can increase the nonlinear response of the Sb particles formed. The results are consistent with the formation of multi-component Sb/Ag colloids

  15. Photoluminescent Gold Nanoclusters in Cancer Cells: Cellular Uptake, Toxicity, and Generation of Reactive Oxygen Species.

    Science.gov (United States)

    Matulionyte, Marija; Dapkute, Dominyka; Budenaite, Laima; Jarockyte, Greta; Rotomskis, Ricardas

    2017-02-10

    In recent years, photoluminescent gold nanoclusters have attracted considerable interest in both fundamental biomedical research and practical applications. Due to their ultrasmall size, unique molecule-like optical properties, and facile synthesis gold nanoclusters have been considered very promising photoluminescent agents for biosensing, bioimaging, and targeted therapy. Yet, interaction of such ultra-small nanoclusters with cells and other biological objects remains poorly understood. Therefore, the assessment of the biocompatibility and potential toxicity of gold nanoclusters is of major importance before their clinical application. In this study, the cellular uptake, cytotoxicity, and intracellular generation of reactive oxygen species (ROS) of bovine serum albumin-encapsulated (BSA-Au NCs) and 2-(N-morpholino) ethanesulfonic acid (MES)capped photoluminescent gold nanoclusters (Au-MES NCs) were investigated. The results showed that BSA-Au NCs accumulate in cells in a similar manner as BSA alone, indicating an endocytotic uptake mechanism while ultrasmall Au-MES NCs were distributed homogeneously throughout the whole cell volume including cell nucleus. The cytotoxicity of BSA-Au NCs was negligible, demonstrating good biocompatibility of such BSA-protected Au NCs. In contrast, possibly due to ultrasmall size and thin coating layer, Au-MES NCs exhibited exposure time-dependent high cytotoxicity and higher reactivity which led to highly increased generation of reactive oxygen species. The results demonstrate the importance of the coating layer to biocompatibility and toxicity of ultrasmall photoluminescent gold nanoclusters.

  16. Photoluminescent Gold Nanoclusters in Cancer Cells: Cellular Uptake, Toxicity, and Generation of Reactive Oxygen Species

    Directory of Open Access Journals (Sweden)

    Marija Matulionyte

    2017-02-01

    Full Text Available In recent years, photoluminescent gold nanoclusters have attracted considerable interest in both fundamental biomedical research and practical applications. Due to their ultrasmall size, unique molecule-like optical properties, and facile synthesis gold nanoclusters have been considered very promising photoluminescent agents for biosensing, bioimaging, and targeted therapy. Yet, interaction of such ultra-small nanoclusters with cells and other biological objects remains poorly understood. Therefore, the assessment of the biocompatibility and potential toxicity of gold nanoclusters is of major importance before their clinical application. In this study, the cellular uptake, cytotoxicity, and intracellular generation of reactive oxygen species (ROS of bovine serum albumin-encapsulated (BSA-Au NCs and 2-(N-morpholino ethanesulfonic acid (MEScapped photoluminescent gold nanoclusters (Au-MES NCs were investigated. The results showed that BSA-Au NCs accumulate in cells in a similar manner as BSA alone, indicating an endocytotic uptake mechanism while ultrasmall Au-MES NCs were distributed homogeneously throughout the whole cell volume including cell nucleus. The cytotoxicity of BSA-Au NCs was negligible, demonstrating good biocompatibility of such BSA-protected Au NCs. In contrast, possibly due to ultrasmall size and thin coating layer, Au-MES NCs exhibited exposure time-dependent high cytotoxicity and higher reactivity which led to highly increased generation of reactive oxygen species. The results demonstrate the importance of the coating layer to biocompatibility and toxicity of ultrasmall photoluminescent gold nanoclusters.

  17. Equilibrium study for ternary mixtures of biodiesel

    Science.gov (United States)

    Doungsri, S.; Sookkumnerd, T.; Wongkoblap, A.; Nuchitprasittichai, A.

    2017-11-01

    The liquid-liquid equilibrium (LLE) data for the ternary mixtures of methanol + fatty acid methyl ester (FAME) + palm oil and FAME + palm oil + glycerol at various temperatures from 35 to 55°C, the tie lines and binodial curves were also investigated and plotted in the equilibrium curve. The experimental results showed that the binodial curves of methanol + FAME + palm oil depended significantly with temperature while the binodial curves of FAME + palm oil + glycerol illustrated insignificant change with temperatures. The interaction parameters between liquid pair obtained for NRTL (Nonrandom Two-Liquid) and UNIQUAC (Universal Quasi-Chemical Theory) models from the experimental data were also investigated. It was found that the correlated parameters of UNIQUAC model for system of FAME + palm oil + glycerol, denoted as a13 and a31, were 580.42K and -123.69K, respectively, while those for system of methanol + FAME + palm oil, denoted as a42 and a24, were 71.48 K and 965.57K, respectively. The ternary LLE data reported here would be beneficial for engineers and scientists to use for prediction of yield and purity of biodiesel for the production. The UNIQUAC model agreed well with the experimental data of ternary mixtures of biodiesel.

  18. Design of ternary clocked adiabatic static random access memory

    International Nuclear Information System (INIS)

    Wang Pengjun; Mei Fengna

    2011-01-01

    Based on multi-valued logic, adiabatic circuits and the structure of ternary static random access memory (SRAM), a design scheme of a novel ternary clocked adiabatic SRAM is presented. The scheme adopts bootstrapped NMOS transistors, and an address decoder, a storage cell and a sense amplifier are charged and discharged in the adiabatic way, so the charges stored in the large switch capacitance of word lines, bit lines and the address decoder can be effectively restored to achieve energy recovery during reading and writing of ternary signals. The PSPICE simulation results indicate that the ternary clocked adiabatic SRAM has a correct logic function and low power consumption. Compared with ternary conventional SRAM, the average power consumption of the ternary adiabatic SRAM saves up to 68% in the same conditions. (semiconductor integrated circuits)

  19. Design of ternary clocked adiabatic static random access memory

    Science.gov (United States)

    Pengjun, Wang; Fengna, Mei

    2011-10-01

    Based on multi-valued logic, adiabatic circuits and the structure of ternary static random access memory (SRAM), a design scheme of a novel ternary clocked adiabatic SRAM is presented. The scheme adopts bootstrapped NMOS transistors, and an address decoder, a storage cell and a sense amplifier are charged and discharged in the adiabatic way, so the charges stored in the large switch capacitance of word lines, bit lines and the address decoder can be effectively restored to achieve energy recovery during reading and writing of ternary signals. The PSPICE simulation results indicate that the ternary clocked adiabatic SRAM has a correct logic function and low power consumption. Compared with ternary conventional SRAM, the average power consumption of the ternary adiabatic SRAM saves up to 68% in the same conditions.

  20. Simulation of Concurrent Precipitation of Two Strengthening Phases in Magnesium Alloys

    Science.gov (United States)

    Sun, Weihua; Zhang, Chuan; Klarner, Andrew D.; Cao, Weisheng; Luo, Alan A.

    The precipitation kinetics and microtructure in Mg-Sn binary and Mg-Al-Sn ternary alloys are simulated using PanPrecipitation coupled with Mg thermodynamic database and a newly established mobility database of the Mg-Al-Sn ternary system. Both Mg2Sn and Mg17Al12 precipitates are considered in this work. The obtained kinetic parameters for these two precipitates can be used in the simulation of both individual and concurrent precipitations of Mg17Al12 and Mg2Sn in Mg-Al-Sn alloys. The simulated microstructure evolution, such as the particle size and number density, are in agreement with experimental data.

  1. Application of the Fundamental Parameter Method for X-ray fluorescence analysis of gold jewellery alloys

    International Nuclear Information System (INIS)

    Le Hong Khiem

    2004-01-01

    The Fundamental Parameter Method has been used for the correction of the matrix effects for determination of the fineness of gold in the ternary Au-Ag-Cu yellow jewellery alloys. A computer code GOLDANA based on this algorithm has been developed for both data taking and on-line determining the fineness of gold jewellery. Only one ternary Au-Ag-Cu standard sample is required. The analysis performance has been tested by measurements conducted on certified gold reference materials, with the use of the fundamental method, could be used for quickly determining the gold concentration in gold jewellery alloys with an acceptable accuracy for the gold jewellery producers. (author)

  2. Ternary q-Virasoro-Witt Hom-Nambu-Lie algebras

    International Nuclear Information System (INIS)

    Ammar, F; Makhlouf, A; Silvestrov, S

    2010-01-01

    In this paper we construct ternary q-Virasoro-Witt algebras which q-deform the ternary Virasoro-Witt algebras constructed by Curtright, Fairlie and Zachos using su(1, 1) enveloping algebra techniques. The ternary Virasoro-Witt algebras constructed by Curtright, Fairlie and Zachos depend on a parameter and are not Nambu-Lie algebras for all but finitely many values of this parameter. For the parameter values for which the ternary Virasoro-Witt algebras are Nambu-Lie, the corresponding ternary q-Virasoro-Witt algebras constructed in this paper are also Hom-Nambu-Lie because they are obtained from the ternary Nambu-Lie algebras using the composition method. For other parameter values this composition method does not yield a Hom-Nambu-Lie algebra structure for q-Virasoro-Witt algebras. We show however, using a different construction, that the ternary Virasoro-Witt algebras of Curtright, Fairlie and Zachos, as well as the general ternary q-Virasoro-Witt algebras we construct, carry a structure of the ternary Hom-Nambu-Lie algebra for all values of the involved parameters.

  3. Description of light charged particle emission in ternary fission

    International Nuclear Information System (INIS)

    Andreev, A. V.; Adamian, G. G.; Antonenko, N. V.; Kuklin, S. N.; Scheid, W.

    2010-01-01

    We consider the motion of three fragments starting from the scission point of ternary system. In the alpha-accompanied ternary fission the initial conditions are not the free parameters and determined by minimization of potential energy at scission point. In the trajectory calculations the angular distribution and mean value of the kinetic energy of the alpha-particles are well described in the spontaneous ternary fission of 252 Cf. In the Be- and C-accompanied ternary fission we found that the emission of the third particle occurs from one of the heavy fragments after their separation. (authors)

  4. Role of ternary fission in synthesis of bypassed nuclei

    International Nuclear Information System (INIS)

    Kramarovskij, Ya.M.; Chechev, V.P.

    1983-01-01

    A possible influence of ternary fission with escape of neutron-enriched light charged particles on the synthesis of bypassed nuclides is considered. It is shown that this concept cannot give explanation of bypassed isotope concentrations, but it can make some contribution, if the probability of ternary fission for superheavy nuclei grows sharply with Z 2 /A parameter. The account of β-delayed fission contributes to the shift of ternary fission fragments into the region of neutron-deficient isotopes. Consistent consideration of the ternary fission role in the nucleosynthesis is possible only with an important accumulation of experimental and theoretical data on this process, particularly for the nuclei with Z > 100

  5. Fusibility diagram of ternary system with incongruently melting double compound

    International Nuclear Information System (INIS)

    Lutsyk, V.I.; Vorob'eva, V.P.; Sumkina, O.G.

    1989-01-01

    Temperature calculation and properties of ternary eutectics and concentration coordinates of ternary peritectics accoriding to the linear model of initial crystallization surfaces as an element of the expert system for simulating fusibility diagrams of ternary systems is considered. It is shown that the calculated and experimental data on coordinates of ternary nonvariant points in the systems NaCl-PbCl 2 -CdCl 2 , PbCl 2 -CaCl 2 -UCl 4 , CaF 2 -NaF-CsF and UCl 3 -CaCl 2 -ThCl 4 are in good agreement

  6. Imparting passivity to vapor deposited magnesium alloys

    Science.gov (United States)

    Wolfe, Ryan C.

    Magnesium has the lowest density of all structural metals. Utilization of low density materials is advantageous from a design standpoint, because lower weight translates into improved performance of engineered products (i.e., notebook computers are more portable, vehicles achieve better gas mileage, and aircraft can carry more payload). Despite their low density and high strength to weight ratio, however, the widespread implementation of magnesium alloys is currently hindered by their relatively poor corrosion resistance. The objective of this research dissertation is to develop a scientific basis for the creation of a corrosion resistant magnesium alloy. The corrosion resistance of magnesium alloys is affected by several interrelated factors. Among these are alloying, microstructure, impurities, galvanic corrosion effects, and service conditions, among others. Alloying and modification of the microstructure are primary approaches to controlling corrosion. Furthermore, nonequilibrium alloying of magnesium via physical vapor deposition allows for the formation of single-phase magnesium alloys with supersaturated concentrations of passivity-enhancing elements. The microstructure and surface morphology is also modifiable during physical vapor deposition through the variation of evaporation power, pressure, temperature, ion bombardment, and the source-to-substrate distance. Aluminum, titanium, yttrium, and zirconium were initially chosen as candidates likely to impart passivity on vapor deposited magnesium alloys. Prior to this research, alloys of this type have never before been produced, much less studied. All of these metals were observed to afford some degree of corrosion resistance to magnesium. Due to the especially promising results from nonequilibrium alloying of magnesium with yttrium and titanium, the ternary magnesium-yttrium-titanium system was investigated in depth. While all of the alloys are lustrous, surface morphology is observed under the scanning

  7. Eco-friendly (green) synthesis of magnetically active gold nanoclusters

    Science.gov (United States)

    Kadasala, Naveen Reddy; Lin, Lu; Gilpin, Christopher; Wei, Alexander

    2017-12-01

    Au-FexOy composite nanoparticles (NPs) are of great technological interest due to their combined optical and magnetic properties. However, typical syntheses are neither simple nor ecologically friendly, creating a challenging situation for process scale-up. Here we describe conditions for preparing Au-FexOy NPs in aqueous solutions and at ambient temperatures, without resorting to solvents or amphiphilic surfactants with poor sustainability profiles. These magnetic gold nanoclusters (MGNCs) are prepared in practical yields with average sizes slightly below 100 nm, and surface plasmon resonances that extend to near-infrared wavelengths, and sufficient magnetic moment (up to 6 emu g-1) to permit collection within minutes by handheld magnets. The MGNCs also produce significant photoluminescence when excited at 488 nm. Energy dispersive X-ray (EDX) analysis indicates a relatively even distribution of Fe within the MGNCs, as opposed to a central magnetic core.

  8. Gold Nanocluster-Mediated Cellular Death under Electromagnetic Radiation.

    Science.gov (United States)

    Cifuentes-Rius, Anna; Ivask, Angela; Das, Shreya; Penya-Auladell, Nuria; Fabregas, Laura; Fletcher, Nicholas L; Houston, Zachary H; Thurecht, Kristofer J; Voelcker, Nicolas H

    2017-11-29

    Gold nanoclusters (Au NCs) have become a promising nanomaterial for cancer therapy because of their biocompatibility and fluorescent properties. In this study, the effect of ultrasmall protein-stabilized 2 nm Au NCs on six types of mammalian cells (fibroblasts, B-lymphocytes, glioblastoma, neuroblastoma, and two types of prostate cancer cells) under electromagnetic radiation is investigated. Cellular association of Au NCs in vitro is concentration-dependent, and Au NCs have low intrinsic toxicity. However, when Au NC-incubated cells are exposed to a 1 GHz electromagnetic field (microwave radiation), cell viability significantly decreases, thus demonstrating that Au NCs exhibit specific microwave-dependent cytotoxicity, likely resulting from localized heating. Upon i.v. injection in mice, Au NCs are still present at 24 h post administration. Considering the specific microwave-dependent cytotoxicity and low intrinsic toxicity, our work suggests the potential of Au NCs as effective and safe nanomedicines for cancer therapy.

  9. Exploring Low Internal Reorganization Energies for Silicene Nanoclusters

    Science.gov (United States)

    Pablo-Pedro, Ricardo; Lopez-Rios, Hector; Mendoza-Cortes, Jose-L.; Kong, Jing; Fomine, Serguei; Van Voorhis, Troy; Dresselhaus, Mildred S.

    2018-05-01

    This paper is a contribution to the Physical Review Applied collection in memory of Mildred S. Dresselhaus. High-performance materials rely on small reorganization energies to facilitate both charge separation and charge transport. Here, we perform density-functional-theory calculations to predict small reorganization energies of rectangular silicene nanoclusters with hydrogen-passivated edges denoted by H-SiNC. We observe that across all geometries, H-SiNCs feature large electron affinities and highly stabilized anionic states, indicating their potential as n -type materials. Our findings suggest that fine-tuning the size of H-SiNCs along the "zigzag" and "armchair" directions may permit the design of novel n -type electronic materials and spintronics devices that incorporate both high electron affinities and very low internal reorganization energies.

  10. A comparison of interatomic potentials for modeling tungsten nanocluster structures

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Jiannan; Shu, Xiaolin, E-mail: shuxlin@buaa.edu.cn; Jin, Shuo; Zhang, Xuesong; Zhang, Ying; Lu, Guang-Hong

    2017-02-15

    Molecular dynamic simulation is utilized to study the nanocluster and the fuzz structure on the PFM surface of tungsten. The polyhedral and linear cluster structures based on the icosahedron, cuboctahedron and rhombic dodecahedron are built up. Three interatomic potentials are used in calculating the relationship between the cluster energy and the number of atoms. The results are compared with first-principles calculation to show each potential’s best application scale. Furthermore, the transition between the icosahedral and the cuboctahedral clusters is observed in molecular dynamic simulation at different temperatures, which follows a critical curve for different numbers of atoms. The linear structures are proved to be stable at experimental temperatures by thermodynamics. The work presents a selection of interatomic potentials in simulating tungsten cluster systems and helps researchers understand the growth and evolution laws of clusters and the fuzz-like structure formation process in fusion devices.

  11. Electrically driven light emission from an array of Si nanoclusters

    International Nuclear Information System (INIS)

    Mazzitello, K I; Martin, H O; Aldao, C M; Roman, H E

    2004-01-01

    Charge transport and light emission properties of an array of silicon nanoclusters (NCs), sandwiched between a p-type and an n-type doped silicon crystal, are studied theoretically by assuming that electrons and holes enter from the opposite sides of the array in response to an applied electric field. The size of the NCs considered ranges from 16 nm down to 3.6 nm and their spatial distribution is optimized so that light emission, resulting from radiative recombinations, is peaked in the visible red around 1.8 eV. The light emission efficiency is limited by the carrier hopping times and is found to be in the range 2-0.5%, for fields ranging from 100 kV cm -1 to 500 kV cm -1 , respectively

  12. Melting of Cu nanoclusters by molecular dynamics simulation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Li; Zhang, Yanning; Bian, Xiufang; Chen, Ying

    2003-04-14

    We present a detailed molecular dynamics study of the melting of copper nanoclusters with up to 8628 atoms within the framework of the embedded-atom method. The finding indicates that there exists an intermediate nanocrystal regime above 456 atoms. The linear relation between the cluster size and its thermodynamics properties is obeyed in this regime. Melting first occurs at the surface of the clusters, leading to T{sub m,N}=T{sub m,Bulk}-{alpha}N{sup -1/3}, dropping from T{sub m,Bulk}=1360 K to T{sub m,456}=990 K. In addition, the size, surface energy as well as the root mean square displacement (RMSD) of the clusters in the intermediate regime have been investigated.

  13. Exploring Low Internal Reorganization Energies for Silicene Nanoclusters

    KAUST Repository

    Pablo-Pedro, Ricardo

    2017-08-17

    High-performance materials rely on small reorganization energies to facilitate both charge separation and charge transport. Here, we performed DFT calculations to predict small reorganization energies of rectangular silicene nanoclusters with hydrogen-passivated edges denoted by H-SiNC. We observe that across all geometries, H-SiNCs feature large electron affinities and highly stabilized anionic states, indicating their potential as n-type materials. Our findings suggest that fine-tuning the size of H-SiNCs along the zigzag and armchair directions may permit the design of novel n-type electronic materials and spinctronics devices that incorporate both high electron affinities and very low internal reorganization energies.

  14. A comparison of interatomic potentials for modeling tungsten nanocluster structures

    International Nuclear Information System (INIS)

    Hao, Jiannan; Shu, Xiaolin; Jin, Shuo; Zhang, Xuesong; Zhang, Ying; Lu, Guang-Hong

    2017-01-01

    Molecular dynamic simulation is utilized to study the nanocluster and the fuzz structure on the PFM surface of tungsten. The polyhedral and linear cluster structures based on the icosahedron, cuboctahedron and rhombic dodecahedron are built up. Three interatomic potentials are used in calculating the relationship between the cluster energy and the number of atoms. The results are compared with first-principles calculation to show each potential’s best application scale. Furthermore, the transition between the icosahedral and the cuboctahedral clusters is observed in molecular dynamic simulation at different temperatures, which follows a critical curve for different numbers of atoms. The linear structures are proved to be stable at experimental temperatures by thermodynamics. The work presents a selection of interatomic potentials in simulating tungsten cluster systems and helps researchers understand the growth and evolution laws of clusters and the fuzz-like structure formation process in fusion devices.

  15. Connections Between Theory and Experiment for Gold and Silver Nanoclusters

    Science.gov (United States)

    Weerawardene, K. L. Dimuthu M.; Häkkinen, Hannu; Aikens, Christine M.

    2018-04-01

    Ligand-stabilized gold and silver nanoparticles are of tremendous current interest in sensing, catalysis, and energy applications. Experimental and theoretical studies have closely interacted to elucidate properties such as the geometric and electronic structures of these fascinating systems. In this review, the interplay between theory and experiment is described; areas such as optical absorption and doping, where the theory-experiment connections are well established, are discussed in detail; and the current status of these connections in newer fields of study, such as luminescence, transient absorption, and the effects of solvent and the surrounding environment, are highlighted. Close communication between theory and experiment has been extremely valuable for developing an understanding of these nanocluster systems in the past decade and will undoubtedly continue to play a major role in future years.

  16. Critical sizes and critical characteristics of nanoclusters, nanostructures and nanomaterials

    International Nuclear Information System (INIS)

    Suzdalev, I.P.

    2005-01-01

    Full text: Critical sizes and characteristics of nanoclusters and nanostructures are introduced as the parameters of nanosystems and nanomaterials. The next critical characteristics are considered: atomic and electronic 'magic number', critical size of cluster nucleation, critical size of melting-freezing of cluster, critical size of quantum (laser) radiation, critical sizes for the single electron conductivity, critical energy and magnetic field for the magnetic tunneling, critical cluster sizes for the giant magnetic resistance, critical size of the first order magnetic phase transition. The critical characteristics are estimated by thermodynamic approaches, by Moessbauer spectroscopy, AFM, heat capacity, SQUID magnetometry and other technique, The influence of cluster-cluster interactions, cluster-matrix interactions and cluster defects on cluster atomic dynamics, cluster melting, cluster critical sizes, Curie or Neel points and the character of magnetic phase transitions were investigated. The applications of critical size and critical characteristic parameters for the nanomaterial characterization are considered

  17. Modeling the photosensitizing properties of thiolate-protected gold nanoclusters.

    Science.gov (United States)

    Azarias, Cloé; Adamo, Carlo; Perrier, Aurélie

    2016-03-21

    An accurate computational strategy for studying the structural, redox and optical properties of thiolated gold nanoclusters (GNCs) using (Time-Dependent) Density Functional Theory is proposed. The influence of the pseudopotential/basis set, solvent description and the choice of the functional has been investigated to model the structural and electronic properties of the Au25(SR)18(-) system, with R being an organic ligand. This study aims to describe with a comparable precision both the GNC and the organic ligands and rationalize the effect of coating on different GNC properties. Two differently coated GNCs have been considered: the system with R = CH2CH2Ph and the GNC coated with 17 alkyl chains (C6H13) and functionalized by one fluorophore pyrene derivative (CH2CH2(NH)(CO)Py). The computational protocol we propose should then be used to design more efficient metal cluster-sensitized solar cells.

  18. Grain refinement of aluminum and its alloys

    International Nuclear Information System (INIS)

    Zaid, A.I.O.

    2001-01-01

    Grain refinement of aluminum and its alloys by the binary Al-Ti and Ternary Al-Ti-B master alloys is reviewed and discussed. The importance of grain refining to the cast industry and the parameters affecting it are presented and discussed. These include parameters related to the cast, parameters related to the grain refining alloy and parameters related to the process. The different mechanisms, suggested in the literature for the process of grain refining are presented and discussed, from which it is found that although the mechanism of refining by the binary Al-Ti is well established the mechanism of grain refining by the ternary Al-Ti-B is still a controversial matter and some research work is still needed in this area. The effect of the addition of other alloying elements in the presence of the grain refiner on the grain refining efficiency is also reviewed and discussed. It is found that some elements e.g. V, Mo, C improves the grain refining efficiency, whereas other elements e.g. Cr, Zr, Ta poisons the grain refinement. Based on the parameters affecting the grain refinement and its mechanism, a criterion for selection of the optimum grain refiner is forwarded and discussed. (author)

  19. Electrical transport properties in Co nanocluster-assembled granular film

    Science.gov (United States)

    Zhang, Qin-Fu; Wang, Lai-Sen; Wang, Xiong-Zhi; Zheng, Hong-Fei; Liu, Xiang; Xie, Jia; Qiu, Yu-Long; Chen, Yuanzhi; Peng, Dong-Liang

    2017-03-01

    A Co nanocluster-assembled granular film with three-dimensional cross-connection paralleled conductive paths was fabricated by using the plasma-gas-condensation method in a vacuum environment. The temperature-dependent longitudinal resistivity and anomalous Hall effect of this new type granular film were systematically studied. The longitudinal resistivity of the Co nanocluster-assembled granular film first decreased and then increased with increasing measuring temperature, revealing a minimum value at certain temperature, T min . In a low temperature region ( T governed the electrical transport process, and the temperature coefficient of resistance (TCR) showed an insulator-type behavior. The thermal fluctuation-induced tunneling conduction progressively increased with increasing temperature, which led to a decrease in the longitudinal resistivity. In a high temperature region, the TCR showed a metallic-type behavior, which was primarily attributed to the temperature-dependent scattering. Different from the longitudinal resistivity behavior, the saturated anomalous Hall resistivity increased monotonically with increasing measuring temperature. The value of the anomalous Hall coefficient ( R S ) reached 2.3 × 10-9 (Ω cm)/G at 300 K, which was about three orders of magnitude larger than previously reported in blocky single-crystal Co [E. N. Kondorskii, Sov. Phys. JETP 38, 977 (1974)]. Interestingly, the scaling relation ( ρx y A ∝ ρx x γ ) between saturated anomalous Hall resistivity ( ρx y A ) and longitudinal resistivity ( ρ x x ) was divided into two regions by T min . However, after excluding the contribution of tunneling, the scaling relation followed the same rule. The corresponding physical mechanism was also proposed to explain these phenomena.

  20. Alloy Design Data Generated for B2-Ordered Compounds

    Science.gov (United States)

    Noebe, Ronald D.; Bozzolo, Guillermo; Abel, Phillip B.

    2003-01-01

    Developing alloys based on ordered compounds is significantly more complicated than developing designs based on disordered materials. In ordered compounds, the major constituent elements reside on particular sublattices. Therefore, the addition of a ternary element to a binary-ordered compound is complicated by the manner in which the ternary addition is made (at the expense of which binary component). When ternary additions are substituted for the wrong constituent, the physical and mechanical properties usually degrade. In some cases the resulting degradation in properties can be quite severe. For example, adding alloying additions to NiAl in the wrong combination (i.e., alloying additions that prefer the Al sublattice but are added at the expense of Ni) will severely embrittle the alloy to the point that it can literally fall apart during processing on cooling from the molten state. Consequently, alloying additions that strongly prefer one sublattice over another should always be added at the expense of that component during alloy development. Elements that have a very weak preference for a sublattice can usually be safely added at the expense of either element and will accommodate any deviation from stoichiometry by filling in for the deficient component. Unfortunately, this type of information is not known beforehand for most ordered systems. Therefore, a computational survey study, using a recently developed quantum approximate method, was undertaken at the NASA Glenn Research Center to determine the preferred site occupancy of ternary alloying additions to 12 different B2-ordered compounds including NiAl, FeAl, CoAl, CoFe, CoHf, CoTi, FeTi, RuAl, RuSi, RuHf, RuTi, and RuZr. Some of these compounds are potential high temperature structural alloys; others are used in thin-film magnetic and other electronic applications. The results are summarized. The italicized elements represent the previous sum total alloying information known and verify the computational

  1. Miedema model based methodology to predict amorphous-forming-composition range in binary and ternary systems

    Energy Technology Data Exchange (ETDEWEB)

    Das, N., E-mail: nirupamd@barc.gov.in [Materials Science Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Mittra, J. [Materials Science Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Murty, B.S. [Department of Metallurgical and Materials Engineering, IIT Madras, Chennai 600 036 (India); Pabi, S.K. [Department of Metallurgical and Materials Engineering, IIT Kharagpur, Kharagpur 721 302 (India); Kulkarni, U.D.; Dey, G.K. [Materials Science Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2013-02-15

    Highlights: Black-Right-Pointing-Pointer A methodology was proposed to predict amorphous forming compositions (AFCs). Black-Right-Pointing-Pointer Chemical contribution to enthalpy of mixing {proportional_to} enthalpy of amorphous for AFCs. Black-Right-Pointing-Pointer Accuracy in the prediction of AFC-range was noticed in Al-Ni-Ti system. Black-Right-Pointing-Pointer Mechanical alloying (MA) results of Al-Ni-Ti followed the predicted AFC-range. Black-Right-Pointing-Pointer Earlier MA results of Al-Ni-Ti also conformed to the predicted AFC-range. - Abstract: From the earlier works on the prediction of amorphous forming composition range (AFCR) using Miedema based model and also, on mechanical alloying experiments it has been observed that all amorphous forming compositions of a given alloy system falls within a linear band when the chemical contribution to enthalpy of the solid solution ({Delta}H{sup ss}) is plotted against the enthalpy of mixing in the amorphous phase ({Delta}H{sup amor}). On the basis of this observation, a methodology has been proposed in this article to identify the AFCR of a ternary system that is likely to be more precise than what can be obtained using {Delta}H{sup amor} - {Delta}H{sup ss} < 0 criterion. MA experiments on various compositions of Al-Ni-Ti system, producing amorphous, crystalline, and mixture of amorphous plus crystalline phases have been carried out and the phases have been characterized using X-ray diffraction and transmission electron microscopy techniques. Data from the present MA experiments and, also, from the literature have been used to validate the proposed approach. Also, the proximity of compositions, producing a mixture of amorphous and crystalline phases to the boundary of AFCR in the Al-Ni-Ti ternary has been found useful to validate the effectiveness of the prediction.

  2. Ternary Magnesium-Lithium Base Constitution Diagrams and Magnesium Alloys of Low Alloy Additions

    Science.gov (United States)

    1951-03-01

    Future Operation. 69 x DummmCTIO M1D3 Y4AJESB)LL! HRM BASEZ TI ALY e&PO eeee0! e eeeee ee 64# ee A& e00S 71ee6 9 ee . 00@e L.%y Diffraction at Elevated...used for filing soft metals (for example, an automobile body bumping file). The extremely sharp teeth and the wide spacing simulate a miorotome effect

  3. Electrical transport properties in Fe-Cr nanocluster-assembled granular films

    Science.gov (United States)

    Wang, Xiong-Zhi; Wang, Lai-Sen; Zhang, Qin-Fu; Liu, Xiang; Xie, Jia; Su, A.-Mei; Zheng, Hong-Fei; Peng, Dong-Liang

    2017-09-01

    The Fe100-xCrx nanocluster-assembled granular films with Cr atomic fraction (x) ranging from 0 to 100 were fabricated by using a plasma-gas-condensation cluster deposition system. The TEM characterization revealed that the uniform Fe clusters were coated with a Cr layer to form a Fe-Cr core-shell structure. Then, the as-prepared Fe100-xCrx nanoclusters were randomly assembled into a granular film in vacuum environments with increasing the deposition time. Because of the competition between interfacial resistance and shunting effect of Cr layer, the room temperature resistivity of the Fe100-xCrx nanocluster-assembled granular films first increased and then decreased with increasing the Cr atomic fraction (x), and revealed a maximum of 2 × 104 μΩ cm at x = 26 at.%. The temperature-dependent longitudinal resistivity (ρxx), magnetoresistance (MR) effect and anomalous Hall effect (AHE) of these Fe100-xCrx nanocluster-assembled granular films were also studied systematically. As the x increased from 0 to 100, the ρxx of all samples firstly decreased and then increased with increasing the measuring temperature. The dependence of ρxx on temperature could be well addressed by a mechanism incorporated for the fluctuation-induced-tunneling (FIT) conduction process and temperature-dependent scattering effect. It was found that the anomalous Hall effect (AHE) had no legible scaling relation in Fe100-xCrx nanocluster-assembled granular films. However, after deducting the contribution of tunneling effect, the scaling relation was unambiguous. Additionally, the Fe100-xCrx nanocluster-assembled granular films revealed a small negative magnetoresistance (MR), which decreased with the increase of x. The detailed physical mechanism of the electrical transport properties in these Fe100-xCrx nanocluster-assembled granular films was also studied.

  4. A scalable synthesis of highly stable and water dispersible Ag 44(SR)30 nanoclusters

    KAUST Repository

    AbdulHalim, Lina G.; Ashraf, Sumaira; Katsiev, Khabiboulakh; Kirmani, Ahmad R.; Kothalawala, Nuwan; Anjum, Dalaver H.; Abbas, Sikandar Zameer; Amassian, Aram; Stellacci, Francesco; Dass, Amala; Hussain, Irshad; Bakr, Osman

    2013-01-01

    We report the synthesis of atomically monodisperse thiol-protected silver nanoclusters [Ag44(SR)30] m, (SR = 5-mercapto-2-nitrobenzoic acid) in which the product nanocluster is highly stable in contrast to previous preparation methods. The method is one-pot, scalable, and produces nanoclusters that are stable in aqueous solution for at least 9 months at room temperature under ambient conditions, with very little degradation to their unique UV-Vis optical absorption spectrum. The composition, size, and monodispersity were determined by electrospray ionization mass spectrometry and analytical ultracentrifugation. The produced nanoclusters are likely to be in a superatom charge-state of m = 4-, due to the fact that their optical absorption spectrum shares most of the unique features of the intense and broadly absorbing nanoparticles identified as [Ag44(SR) 30]4- by Harkness et al. (Nanoscale, 2012, 4, 4269). A protocol to transfer the nanoclusters to organic solvents is also described. Using the disperse nanoclusters in organic media, we fabricated solid-state films of [Ag44(SR)30]m that retained all the distinct features of the optical absorption spectrum of the nanoclusters in solution. The films were studied by X-ray diffraction and photoelectron spectroscopy in order to investigate their crystallinity, atomic composition and valence band structure. The stability, scalability, and the film fabrication method demonstrated in this work pave the way towards the crystallization of [Ag44(SR)30]m and its full structural determination by single crystal X-ray diffraction. Moreover, due to their unique and attractive optical properties with multiple optical transitions, we anticipate these clusters to find practical applications in light-harvesting, such as photovoltaics and photocatalysis, which have been hindered so far by the instability of previous generations of the cluster. © 2013 The Royal Society of Chemistry.

  5. Phase formation in Mg-Sn-Si and Mg-Sn-Si-Ca alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kozlov, A.; Groebner, J. [Institute of Metallurgy, Clausthal University of Technology, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany); Schmid-Fetzer, R., E-mail: schmid-fetzer@tu-clausthal.de [Institute of Metallurgy, Clausthal University of Technology, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany)

    2011-02-17

    Research highlights: > The solidification paths of ternary and quaternary alloys are analyzed in detail, using the tool of thermodynamic calculations. > The precipitation sequence of phases and their amounts compare well with the microstructure of alloys. > The most efficient comparison to the experimental thermal analysis data is done by calculation of the enthalpy variation with temperature. > The viability of a procedure for the selection of multicomponent key samples is demonstrated for the development of the Mg-Ca-Si-Sn phase diagram. - Abstract: Experimental work is done and combined with the Calphad method to generate a consistent thermodynamic description of the Mg-Ca-Si-Sn quaternary system, validated for Mg-rich alloys. The viability of a procedure for the selection of multicomponent key samples is demonstrated for this multicomponent system. Dedicated thermal analysis with DTA/DSC on sealed samples is performed and the microstructure of slowly solidified alloys is analyzed using SEM/EDX. The thermodynamic description and phase diagram of the ternary Mg-Si-Sn system, developed in detail also in this work, deviates significantly from a previous literature proposal. The phase formation in ternary and quaternary alloys is analyzed using the tool of thermodynamic equilibrium and Scheil calculations for the solidification paths and compared with present experimental data. The significant ternary/quaternary solid solubilities of pertinent intermetallic phases are quantitatively introduced in the quaternary Mg-Ca-Si-Sn phase diagram and validated by experimental data.

  6. Neutron Damage and MAX Phase Ternary Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Barsoum, Michael [Drexel Univ., Philadelphia, PA (United States); Hoffman, Elizabeth [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Sindelar, Robert [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Garcua-Duaz, Brenda [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Kohse, Gordon [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2014-06-17

    The Demands of Gen IV nuclear power plants for long service life under neutron radiation at high temperature are severe. Advanced materials that would withstand high temperatures (up to 1000+ C) to high doses in a neutron field would be ideal for reactor internal structures and would add to the long service life and reliability of the reactors. The objective of this work is to investigate the response of a new class of machinable, conductive, layered, ternary transition metal carbides and nitrides - the so-called MAX phases - to low and moderate neutron dose levels.

  7. Neutron Damage and MAX Phase Ternary Compounds

    International Nuclear Information System (INIS)

    Barsoum, Michael; Hoffman, Elizabeth; Sindelar, Robert; Garcua-Diaz, Brenda; Kohse, Gordon

    2014-01-01

    The Demands of Gen IV nuclear power plants for long service life under neutron radiation at high temperature are severe. Advanced materials that would withstand high temperatures (up to 1000+ C) to high doses in a neutron field would be ideal for reactor internal structures and would add to the long service life and reliability of the reactors. The objective of this work is to investigate the response of a new class of machinable, conductive, layered, ternary transition metal carbides and nitrides - the so-called MAX phases - to low and moderate neutron dose levels.

  8. Synthesis of biocompatible AuAgS/Ag2S nanoclusters and their applications in photocatalysis and mercury detection

    International Nuclear Information System (INIS)

    Zhao, Qian; Chen, Shenna; Zhang, Lingyang; Huang, Haowen; Liu, Fengping; Liu, Xuanyong

    2014-01-01

    In this paper, a facile approach for preparation of AuAgS/Ag 2 S nanoclusters was developed. The unique AuAgS/Ag 2 S nanoclusters capped with biomolecules exhibit interesting excellent optical and catalytic properties. The fluorescent AuAgS/Ag 2 S nanoclusters show tunable luminescence depending on the nanocluster size. The apoptosis assay demonstrated that the AuAgS/Ag 2 S nanoclusters showed low cytotoxicity and good biocompatibility. Therefore, the nanoclusters can be used not only as a probe for labeling cells but also for their photocatalytic activity for photodegradation of organic dye. Moreover, a highly selective and sensitive assay for detection of mercury including Hg 2+ and undissociated mercury complexes was developed based on the quenching fluorescent AuAgS/Ag 2 S nanoclusters, which provides a promising approach for determining various forms of Hg in the mercury-based compounds in environment. These unique nanoclusters may have potential applications in biological labeling, sensing mercury, and photodegradation of various organic pollutants in waste water.Graphical Abstract

  9. Embedding complete ternary tree in hypercubes using AVL trees

    NARCIS (Netherlands)

    S.A. Choudum; I. Raman (Indhumathi)

    2008-01-01

    htmlabstractA complete ternary tree is a tree in which every non-leaf vertex has exactly three children. We prove that a complete ternary tree of height h, TTh, is embeddable in a hypercube of dimension . This result coincides with the result of [2]. However, in this paper, the embedding utilizes

  10. Density-Driven segregation in Binary and Ternary Granular Systems

    NARCIS (Netherlands)

    Windows-Yule, Kit; Parker, David

    2015-01-01

    We present a first experimental study of density-induced segregation within a three-dimensional, vibrofluidised, ternary granular system. Using Positron Emission Particle Tracking (PEPT), we study the steady-state particle distributions achieved by binary and ternary granular beds under a variety of

  11. A high-speed interconnect network using ternary logic

    DEFF Research Database (Denmark)

    Madsen, Jens Kargaard; Long, S. I.

    1995-01-01

    This paper describes the design and implementation of a high-speed interconnect network (ICN) for a multiprocessor system using ternary logic. By using ternary logic and a fast point-to-point communication technique called STARI (Self-Timed At Receiver's Input), the communication between...

  12. 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)

  13. Development Program for Natural Aging Aluminum Casting Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Geoffrey K. Sigworth

    2004-05-14

    A number of 7xx aluminum casting alloys are based on the ternary Al-Zn-Mg system. These alloys age naturally to high strength at room temperature. A high temperature solution and aging treatment is not required. Consequently, these alloys have the potential to deliver properties nearly equivalent to conventional A356-T6 (Al-Si-Mg) castings, with a significant cost saving. An energy savings is also possible. In spite of these advantages, the 7xx casting alloys are seldom used, primarily because of their reputation for poor castibility. This paper describes the results obtained in a DOE-funded research study of these alloys, which is part of the DOE-OIT ''Cast Metals Industries of the Future'' Program. Suggestions for possible commercial use are also given.

  14. The development of platinum-based alloys and their thermodynamic database

    OpenAIRE

    Cornish L.A.; Hohls J.; Hill P.J.; Prins S.; Süss R.; Compton D.N.

    2002-01-01

    A series of quaternary platinum-based alloys have been demonstrated to exhibit the same two-phase structure as Ni-based superalloys and showed good mechanical properties. The properties of ternary alloys were a good indication that the quaternary alloys, with their better microstructure, will be even better. The quaternary alloy composition has been optimised at Pt84:Al11:Ru2:Cr3 for the best microstructure and hardness. Work has begun on establishing a thermodynamic database for Pt-Al-Ru-Cr ...

  15. The effect of tungsten on mechanical properties of the Ti-9% Al-3% Zr alloy

    International Nuclear Information System (INIS)

    Nartova, T.T.; Grigor'ev, I.P.; Stepanov, Yu.N.; Tarasova, O.B.

    1979-01-01

    The effect of tungsten (from 0 to 10 %) on mechanical properties of the ternary Ti-9 %, Al-3 % Zr alloy, has been studied. The microstructure, tensile properties at 20 and 600 deg C and Vickers hardness in as-forged and as-annealed states have been studied. The experiments have shown that the ultimate strength increases with tungsten content. Titanium alloys with 9 % Al and 3 % Zr in the case of varying tungsten content at 20 deg C fracture by brittle mechanism. The dUctility of the annealed alloy does not rise at 20 deg C, but at the test temperature of 600 deg C the alloy becomes ductile

  16. Creep and creep rupture properties of unalloyed vanadium and solid-solution-strengthened vanadium-base alloys

    International Nuclear Information System (INIS)

    Kainuma, T.; Iwao, N.; Suzuki, T.; Watanabe, R.

    1982-01-01

    The creep and creep rupture properties of vanadium and vanadium-base alloys were studied at 700 and 1000 0 C. The alloys were vanadium-base binary alloys containing about 5 - 21 at.% Al, Ti, Nb, Ta, Cr, Mo or Fe, three V-20wt.%Nb-base ternary alloys containing 5 or 10 wt.% Al, Cr or Mo, V-10wt.%Ta-10wt.%Al and V-25wt.%Cr-0.8wt.%Zr. The creep rupture stress of the binary alloys, except the V-Al and V-Ti alloys, increased linearly with increasing concentration of the alloying elements. The V-Nb alloy had the best properties with respect to the rupture stress and creep rate at 700 0 C and the rupture stress at 1000 0 C, but the V-Mo alloy appeared likely to have better creep properties at longer times and higher temperatures. Of the five ternary alloys, V-20wt.%Nb-5wt.%Cr and V-20wt.%Nb-10wt.%Mo showed the best creep properties. The creep properties of these two alloys were compared with those of other vanadium alloys and of type 316 stainless steel. (Auth.)

  17. Synthesis of indium nanoclusters and formation of thin film contacts on plastic substrates for organic and flexible electronics applications

    International Nuclear Information System (INIS)

    Shi, Frank F; Bulkowski, Michal; Hsieh, K C

    2007-01-01

    In this work, we described the processes of synthesizing free-standing indium nanoclusters using inverse micelles and microemulsions as well as synthesizing organic-encapsulated indium nanoclusters using alkanethiols as the organic encapsulants. The synthesized organic-encapsulated indium nanoclusters have demonstrated the feasibilities to be used as plastic compatible soft metal contacts for emerging organic devices. The homogeneously distributed indium nanoclusters with sizes of 10-30 nm have been fabricated on a few different plastic substrates. By changing the alkanethiol carbon chain length and the sizes of the indium nanoclusters, the annealing temperature required to form low-resistance indium thin film conductors has been reduced to 80-100 deg. C, which is acceptable for a variety of organic thin films

  18. Real-time transmission electron microscope observation of gold nanoclusters diffusing into silicon at room temperature

    International Nuclear Information System (INIS)

    Ishida, Tadashi; Nakajima, Yuuki; Fujita, Hiroyuki; Endo, Junji; Collard, Dominique

    2009-01-01

    Gold diffusion into silicon at room temperature was observed in real time with atomic resolution. Gold nanoclusters were formed on a silicon surface by an electrical discharge between a silicon tip and a gold coated tip inside an ultrahigh-vacuum transmission electron microscope (TEM) specimen chamber. At the moment of the gold nanocluster deposition, the gold nanoclusters had a crystalline structure. The crystalline structure gradually disappeared due to the interdiffusion between silicon and gold as observed after the deposition of gold nanoclusters. The shape of the nanocluster gradually changed due to the gold diffusion into the damaged silicon. The diffusion front between silicon and gold moved toward the silicon side. From the observations of the diffusion front, the gold diffusivity at room temperature was extracted. The extracted activation energy, 0.21 eV, matched the activation energy in bulk diffusion between damaged silicon and gold. This information is useful for optimizing the hybridization between solid-state and biological nanodevices in which gold is used as an adhesive layer between the two devices.

  19. Self-trapping nature of Tl nanoclusters on the Si(111)-7x7 surface

    International Nuclear Information System (INIS)

    Hwang, C G; Kim, N D; Lee, G; Shin, S Y; Kim, J S; Chung, J W

    2008-01-01

    We have studied properties of thallium (Tl) nanoclusters formed on the Si(111)-7x7 surface at room temperature (RT) by utilizing photoemission spectroscopy (PES) and high-resolution electron-energy-loss spectroscopy (HREELS) combined with first principles calculations. Our PES data reveal that the surface states stemming from the Si substrate remain quite inert with Tl adsorption producing no Tl-induced state until saturation at Tl coverage θ=0.21 monolayers. Such a behavior, in sharp contrast with the extremely reactive surface states upon the formation of Na or Li nanoclusters, together with the presence of a unique Tl-induced loss peak in HREELS spectra suggests no strong Si-Tl bonding, and is well understood in terms of gradual filling of Si dangling bonds with increasing θ. Our calculation further indicates the presence of several metastable atomic structures of Tl nanoclusters at RT rapidly transforming from one to another faster than 10 10 flippings per second. We thus conclude that the highly mobile Tl atoms form self-trapped nanoclusters within the attractive basins of the Si substrate at RT with several metastable phases. The mobile and multi-phased nature of Tl nanoclusters not only accounts for all the existing experimental observations available at present, but also provides an example of self-trapping of atoms in a nanometre-scale region

  20. Enthalpy of mixing of liquid Ag–Bi–Cu alloys at 1073 K

    International Nuclear Information System (INIS)

    Fima, Przemysław; Flandorfer, Hans

    2014-01-01

    Highlights: • Partial and integral mixing enthalpies of liquid Ag–Bi–Cu alloys were determined. • Integral mixing enthalpies are small and endothermic, similar to limiting binaries. • The ternary data were fitted on the basis of Redlich–Kister–Muggianu model. - Abstract: The Ag–Bi–Cu system is among those ternary systems which have not been fully studied yet, in particular the thermodynamic description of the liquid phase is missing. Partial and integral enthalpies of mixing of liquid ternary Ag–Bi–Cu alloys were determined over a broad composition range along six sections: x(Ag)/x(Bi) = 0.25, 1, 4; x(Ag)/x(Cu) = 1.5; x(Bi)/x(Cu) = 1.86, 4. Measurements were carried out at 1073 K using two Calvet type microcalorimeters and drop calorimetric technique. It was found that integral enthalpies of mixing are small and endothermic, similarly to limiting binary alloys. The ternary data were fitted on the basis of an extended Redlich–Kister–Muggianu model for substitutional solutions. There are no significant additional ternary interactions